JP7453695B2 - System and method for motion compensation in ultrasound respiratory monitoring - Google Patents

Description

The present disclosure relates to methods, devices, and systems for motion compensation in ultrasound respiratory monitoring of a patient, including correcting measurement errors due to movement of the abdominal region during breathing.

Measuring and monitoring respiration is important for the treatment of a wide range of medical conditions in patients. The diaphragm is a major respiratory muscle, and its dysfunction can be a sign of many respiratory disorders and conditions.

Various ultrasound transducer device probes have been utilized to monitor respiration. For example, an ultrasound transducer device may be located within the housing of the probe and embedded therein by an ultrasound sonolucent material, such as a silicone rubber material or another material that allows the passage of ultrasound waves. The ultrasound transducer probe may be placed on the skin surface of the patient's body using double-sided adhesive tape, with a reinforcing web between its two adhesive layers.

Although such probes can be useful in monitoring patient respiratory properties, it is important to consider correction of the error signal caused by movement of the probe over the patient's anterior surface during breathing. . For example, the abdominal region of the body moves as the patient breathes, which causes the probe to move. In some cases, the magnitude of such error signals can be significant to measurement reliability.

The present disclosure relates to systems and methods for correcting measurement errors during ultrasound respiratory monitoring, where the measurement errors are due to abdominal movement of a patient's body during breathing. Embodiments of the invention detect movement of various tissues and structures within the body, including, for example, the spleen, liver, or kidneys. However, for the purpose of illustrating the principles of embodiments of the present invention, the following discussion will primarily focus on liver motion detection. For example, when comparing measurements made with an abdominal probe that is attached to the front of the body and moves with the abdominal wall, the liver deflection is approximately 30 It is thought that it is less than ~40%.

These measurement errors are caused by the respiratory motion imposed on the probe, which counteracts echo distance variations along the direction of the ultrasound beam. Such errors may present a risk to the reliability of the assessment of patient breathing modes and parameters, particularly for patients with breathing problems of medical concern. Accordingly, aspects of the present disclosure relate to effectively compensating for such highly unnecessary errors and providing higher accuracy in respiratory monitoring.

In certain embodiments, as defined in claim 1, the respiratory detection system includes a first probe and a second probe. The first probe is configured to be placed on the front side of the patient's body, and the second probe is configured to be placed on the dorsal side of the patient's body. The first probe includes an ultrasound transducer, a first accelerometer unit, and a first magnetic field unit, wherein the ultrasound transducer, the first accelerometer unit, and the first magnetic field unit are connected to the first Position stationary within the probe. The ultrasound transducer is stationary within the first probe and has a transmitting and receiving surface oriented at an acute angle to the front surface of the first probe. The ultrasound transducer is configured to generate an ultrasound beam at a transmitting and receiving surface for transmission into internal structures inside a patient's body. The second probe includes a second accelerometer unit and a second magnetic field unit, the second accelerometer unit and the second magnetic field unit being stationary within the second probe. The ultrasound transducer, first and second accelerometer units, and first and second magnetic field units are coupled to the signal processor. The combination of the first and second accelerometer units and the first and second magnetic units are configured to generate a corrected output signal that is a function of the spatial position movement and orientation of the ultrasound transducer in response to patient breathing. configured. The signal thus obtained is used to correct the ultrasound measurement of the distance between the first sensor and the moving tissue inside the human body, in order to provide a more accurate output signal. .

In another embodiment of the breath detection system, as defined in claim 26, the breath detection system is located stationary within the first probe and oriented at an acute angle with respect to the front surface of the first probe. an ultrasound transducer having a transmitting and receiving surface configured to generate an ultrasound beam at the transmitting and receiving surface for transmission into an internal structure inside a patient's body; an acoustic transducer, a first accelerometer unit, and a first magnetic field unit, the ultrasonic transducer, the first accelerometer unit, and the first magnetic field unit being stationary within the first probe; a first probe, a second accelerometer unit, and a second magnetic field unit, the second accelerometer unit and the second magnetic field unit comprising a second magnetic field unit; a second magnetic field unit stationary within the probe, the second probe comprising an ultrasound transducer, first and second accelerometer units, and first and second magnetic field units; is coupled to the signal processor, the first probe is configured to be placed on the front side of the patient's body, and the second probe is configured to be placed on the dorsal side of the patient's body; The processor determines an expected direction of motion of internal structures inside the patient's body based on inputs from the first and second accelerometer units and from the first magnetic field unit interacting with the second magnetic field unit. the patient's abdominal wall relative to a respiratory parameter associated with the patient's respiratory muscles.

In another embodiment, as defined in claim 38, a method for motion compensation in ultrasound-based detection of respiratory parameters of a patient is disclosed. The method includes the steps of attaching a first probe to an anterior body surface of a human, the first probe having an ultrasound transducer, a first accelerometer unit, and a first magnetic field unit. attaching a second probe to a dorsal body surface of the human, the second probe having a second accelerometer unit and a second magnetic field unit; an ultrasound transducer; providing a signal processor coupled to the first and second accelerometer units and the first and second magnetic field units. The method further includes transmitting an ultrasound beam from an ultrasound transducer in the first probe into an internal structure inside a patient's body; receiving an ultrasonic echo signal; generating a magnetic field transmitted by the second magnetic field unit to and detected by the first magnetic field unit; and using the signal processor, the first accelerometer. Calculate the orientation of the first accelerometer unit with respect to a fixed coordinate frame using derived parameters from the unit, and derive the derived parameters as a unit vector representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit. and further calculating. In addition, the method uses a signal processor to calculate the orientation of the second accelerometer unit with respect to a fixed coordinate frame using further derived parameters, such as a body back support tilt angle ( α) and further derived parameters, including a unit vector representing the spatial direction from the second magnetic field unit to the first magnetic field unit, the orientation of the second magnetic field unit, and the expected direction of movement of the internal structures during exhalation. calculating, using a signal processor, an arbitrary varying distance between the first magnetic field unit and the second magnetic field unit based on the detection of the magnetic field; Processing the results from the calculated orientations of the first and second accelerometer units, the derived parameters from the first and second accelerometer units, and the variable distance to generate correction parameters and movement of the ultrasound transducer. and compensating for measurement errors in the received ultrasound echo signals caused by.

Further features and advantages, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. Note that the specific embodiments described herein are not intended to be limiting. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to those skilled in the art based on the teachings contained herein.
The present invention provides, for example, the following items.
(Item 1)
A respiration detection system, comprising:
A first probe (102),
an ultrasound transducer (112), the ultrasound transducer (112) being stationary within the first probe and at an acute angle (114) with respect to the front surface (114) of the first probe (102); Ω), said ultrasound transducer (112) transmitting an ultrasound beam at said transmitting and receiving surface (113) for transmission into internal structures inside a patient's body. an ultrasonic transducer (112) configured to generate (143);
a first accelerometer unit (121);
A first magnetic field unit (122), the ultrasonic transducer (112), the first accelerometer unit (121), and the first magnetic field unit (122) are connected to the first probe (102). ) a first magnetic field unit (122) stationary within the
a first probe (102) comprising;
a second probe (104),
a second accelerometer unit (128);
a second magnetic field unit (129), the second accelerometer unit (128) and the second magnetic field unit (129) being stationary within the second probe (104); A second magnetic field unit (129) and
a second probe (104) comprising:
Equipped with
the ultrasound transducer (112), the first and second accelerometer units (121; 128), and the first and second magnetic field units (122; 129) are coupled to a signal processor (134);
The first probe (102) is configured to be installed on the front side (103) of the patient's body (101),
The second probe (104) is configured to be installed on the dorsal side (105) of the body (101),
A signal from said first accelerometer unit (121) is transmitted to a first space of said first probe (102) having said ultrasound transducer (112) and said first magnetic field unit (122) therein. indicates the orientation,
a signal from said second accelerometer unit (128) is indicative of a second spatial orientation of said second probe (104) having said second magnetic field unit (129) therein;
the first and second spatial orientations are with respect to a fixed coordinate frame;
provided by a signal from said first magnetic field unit (122) interacting with said second magnetic field unit (129) and a signal from said first and second accelerometer unit (121; 128); The orientation of said magnetic field unit (122; 129) is an input to said signal processor (134) for calculating a variable spatial distance between said first probe (102) and said second probe (104). , thereby calculating the spatial movement and orientation of the ultrasound transducer (112) induced by the patient's breathing;
Breathing detection system.
(Item 2)
Respiration detection system according to item 1, wherein said first and second accelerometer units (121; 128) each comprise at least two accelerometers.
(Item 3)
A respiration detection system according to item 1, wherein said first accelerometer unit (121) comprises a three-axis accelerometer device.
(Item 4)
2. The respiratory detection system of item 1, wherein the spatial movement and the orientation are related to at least one of heave, roll, pitch, and yaw movement.
(Item 5)
Said ultrasonic transducer (112) uses said first body of material (115) comprising an ultrasonic non-sonolucent material extending towards the front surface (114) of said first probe (102) to located within the first probe (102);
said body (115) of first material surrounds a recess (116) extending from said transmitting and receiving surface (113) towards said front surface (114);
A first body portion (117) of a second material comprising an ultrasound sonolucent material extends towards the front surface (114) of the transmitting/receiving surface (113) of the ultrasound transducer (112) and of the recess in front thereof. located within
A second body portion (117) of said second material is applied onto and integrally engaged with the front surface of said body of first material, said first and second body portions , is integral,
Breath detection system according to item 1.
(Item 6)
The ultrasound transducer (112) is engaged within a socket-like member (120) positioned within the recess (116), the socket-like member (120) being formed from an ultrasound non-sonolucent material. , the respiration detection system according to item 5.
(Item 7)
The front surface of the body (117) of said second material has inherent adhesive properties, an attachment surface (117') for an adhesive member (124) or double-sided adhesive tape, or an adhesive layer of the body (117) of a third material. 6. The respiratory detection system of item 5, comprising an engagement surface for.
(Item 8)
Item wherein said adhesive member (124) or said double-sided adhesive tape is ultrasonic sonolucent at least within a region defined by an ultrasound beam path in front of a transmitting and receiving surface (113) of said ultrasound transducer (112). 7. The respiratory detection system according to 7.
(Item 9)
8. The respiratory detection system of item 7, wherein the adhesive layer of the third material body is ultrasonic sonorucent.
(Item 10)
According to item 7, said first accelerometer unit (121) and said first magnetic field unit (122) are located stationary within said first probe (102) by use of said first material. breathing detection system.
(Item 11)
Said second accelerometer unit (128) and said second magnetic field unit (129) are located stationary within said second probe (104) using a body of fourth material, item 7 The respiration detection system described.
(Item 12)
The front surface (132') of said body (132) of said fourth material has an adhesive property, an attachment surface for an adhesive member or double-sided adhesive tape, or an attachment surface for an adhesive layer of said body of fifth material. The respiration detection system according to item 11, comprising a mating surface.
(Item 13)
13. The respiratory detection system of item 12, wherein at least one of the first, second, third, fourth, and fifth materials is of silicone type.
(Item 14)
A first of the first magnetic field unit (122) and the second magnetic field unit (129) includes a magnetic field sensor device, and the first magnetic field unit (122) and the second magnetic field unit The other of (129) comprises an electromagnetic device configured to generate a magnetic field to be detected by said magnetic field sensor device, said magnetic field being connected to said first and second probes (102; 104). ).) The respiration detection system according to item 1.
(Item 15)
15. The respiratory detection system of item 14, wherein the signal processor (134) controls the strength, frequency, and duration of the generated magnetic field.
(Item 16)
The first probe (102) is positioned vertically above the second probe (104), which is positioned on the dorsal side (105) of the patient's body when the patient's body is in a supine position. The respiratory detection system according to item 1, configured to be placed on the front side (103) of the patient's body.
(Item 17)
The first probe (102) is configured to be placed on the front side (103) of the patient's body in a position aligned with the second probe (104) on the dorsal side (105) of the patient's body. The respiration detection system according to item 1.
(Item 18)
A respiratory detection system according to item 1, wherein the second accelerometer unit (128) provides a measurement of the tilt angle of a surface supporting the dorsal side (105) of the patient's body.
(Item 19)
15. The respiration detection system of item 14, wherein the magnetic field sensor device is a magnetic pickup coil.
(Item 20)
The surface (132'; 133) of the second probe (134) configured to contact the dorsal skin area of the patient's body comprises a biocompatible material; The respiration detection system according to item 1 , wherein the skin contact area of the surface is within the range of 5 to 100 cm ² .
(Item 21)
Said signal processor (134) receives signals from said first and second accelerometer units (121; 128) and from said first magnetic field unit (122) interacting with said second magnetic field unit (129). movement of the ultrasound transducer (112) within the first probe (102) with respect to the expected direction of movement of the internal structure (144) inside the patient's body relative to the patient's longitudinal axis based on input; 2. The respiratory sensing system of item 1, wherein the movement and orientation of the ultrasound transducer (112) are related to respiratory parameters associated with respiratory muscles of the patient.
(Item 22)
22. The respiratory detection system of item 21, wherein the internal structure is one of the patient's liver (144), spleen, or kidney.
(Item 23)
22. A respiratory detection system according to item 21, wherein the expected direction of movement of the internal structure (144) is a function of diaphragm movement (145) within the patient's body.
(Item 24)
the ultrasound transducer (112) in the first probe (102) is configured to receive ultrasound echo signals from the internal structure;
said second magnetic field unit (129) is configured to generate a magnetic field that is transmitted to and detected by said first magnetic field unit (121);
The signal processor (134) includes:
an orientation of the first accelerometer unit (121) with respect to the fixed coordinate frame using derived parameters from the first accelerometer unit (121);
the derived parameter as a unit vector representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
orienting the second accelerometer unit (128) relative to the fixed coordinate frame using further derived parameters from the second accelerometer unit (128);
said further derived parameters comprising a unit vector representing the body back (105) support tilt angle (α) and the spatial direction from said second magnetic field unit to said first magnetic field unit (122);
Orientation of the second magnetic field unit (129);
the expected direction of movement of the internal structure (144) relative to the longitudinal axis of the patient's torso during exhalation of the patient;
Any variable distance between the first and second magnetic field units (122; 129) based on the detection of the magnetic field;
is configured to calculate
the orientation of the ultrasound beam, the orientation of the first magnetic field unit (122) and the orientation of the second magnetic field unit (129) are with respect to the fixed coordinate frame;
Said signal processor (134) further comprises: from the calculated orientations of said first and second accelerometer units (121; 128), derived parameters from said first and second accelerometer units, and said variation distance. and generate correction parameters to compensate for measurement errors in the received ultrasound echo signals caused by spatial movement and orientation of the ultrasound transducer (112) induced by the patient's breathing. composed of,
Breath detection system according to item 1.
(Item 25)
In order to generate the correction parameters, the signal processor further:
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
differentiating the resolved vector representing the distance in time to yield an incremental motion value;
adding said incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from said internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
summing the above corrected and summed motion values to obtain internal structure position variations that describe the corrected respiratory parameters;
25. The respiration detection system of item 24, configured to perform.
(Item 26)
The first probe (102) is placed on the patient's body and configured to direct an ultrasound beam toward internal structures inside the patient's body and receive ultrasound echo signals from the internal structures. consists of
The first probe (102) further includes a housing (110) with a cavity (111),
The ultrasonic transducer (112) is located within the cavity (111), and the transmitting/receiving surface (113) of the ultrasonic transducer (112) is located at the cavity opening of the cavity (111) of the housing (110). or adjacent thereto at an acute angle (Ω) to the front surface (114) of the housing;
The ultrasonic transducer (112) is fixedly located within the cavity (111) of the housing (110),
an open-ended socket-like member (120) of ultrasonic non-sonolucent material defines a recess extending from said transmitting and receiving surface (113) toward said front surface (114);
a first body portion (117) of ultrasound sonolucent material is located within the transmitting and receiving surface (113) of the ultrasound transducer (112) towards the front surface (114) and in the recess in front thereof;
the first accelerometer unit (121) and the first magnetic field detection unit (122) are connected to a printed circuit board (119) within the cavity (111) of the housing (110);
The front surface of said first probe (102) exhibits at least one of inherent adhesive properties, an attachment surface for an adhesive member or double-sided adhesive tape, or an engagement surface for an adhesive body layer. ,
the ultrasound transducer (112) is configured to connect to a transceiver section of the signal processor (134);
Breath detection system according to item 1.
(Item 27)
27. Breath detection system according to item 26, wherein the ultrasonic transducer (112) is mounted in the bottom region of the open-ended socket-like member (120), the material of which exhibits acoustic damping properties.
(Item 28)
27. A respiratory detection system according to item 26, wherein the ultrasound transducer (112) and the open-ended socket-like member (120) extend from the printed circuit board (119).
(Item 29)
The front surface (114) of the body of the first probe (102) has adhesive surface properties and is provided with a protective cover (123), which protects the first probe on the skin of the patient's body. 27. The respiratory detection system of item 26, which is removable prior to application of the probe (102).
(Item 30)
The adhesive member or the double-sided adhesive tape is attached to the front surface, and the adhesive member or the double-sided adhesive tape is attached to the front surface, and the adhesive member or the double-sided adhesive tape is attached to the front surface of the ultrasound transducer. 27. The respiratory detection system of item 26, which is Lucent.
(Item 31)
27. The respiration detection system of item 26, wherein the material type of the first body portion of the ultrasonic sonolucent material is a silicone type material.
(Item 32)
The respiration detection system according to item 26, wherein the acute angle (Ω) is within a range of 0 to 60 degrees.
(Item 33)
A method for motion compensation in ultrasound-based detection of human respiratory parameters, the method comprising:
attaching a first probe (102) to the anterior body surface (103) of said human, said first probe (102) comprising an ultrasound transducer (112) and a first accelerometer unit (121); ) and a first magnetic field unit (122);
attaching a second probe (104) to the dorsal body surface (105) of said human, said second probe (104) having a second accelerometer unit (122) and a second magnetic field; having a unit (129);
providing a signal processor (134) coupled to said ultrasound transducer (112), said first and second accelerometer units (121; 128), and said first and second magnetic field units (122; 129); to do and
transmitting an ultrasound beam from the ultrasound transducer (112) in the first probe (102) into an internal structure (144) inside the human body;
receiving an ultrasound echo signal from the internal structure at the ultrasound transducer (112) in the first probe (102);
generating a magnetic field transmitted by said second magnetic field unit (129) to and detected by said first magnetic field unit (122);
using the signal processor (134) to calculate an orientation of the first accelerometer unit (121) with respect to a fixed coordinate frame using derived parameters from the first accelerometer unit (121); further calculating the derived parameters as unit vectors representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
The signal processor (134) is used to calculate the orientation of the second accelerometer unit (128) relative to a fixed coordinate frame using further derived parameters, including the body back support tilt angle (α) and the said further derived parameters comprising a unit vector representing the spatial direction from said second magnetic field unit (129) to said first magnetic field unit (122), the orientation of said second magnetic field unit (129), and the calculating the expected direction of movement of the internal structure relative to the longitudinal axis of the human torso;
using the signal processor (134) to calculate any varying distance between the first and second magnetic field units (122; 129) based on the detection of the magnetic field;
Using said signal processor (134), the calculated orientation of said first and second accelerometer units (121; 128) and the calculated orientation of said first and second accelerometer units (121; 128) further derived parameters and processing the results from said varying distances measured by said first and second magnetic field units (122; 129) to generate correction parameters caused by the movement of said ultrasound transducer (112); compensation for measurement errors in the received ultrasonic echo signals.
including methods.
(Item 34)
Generating the correction parameters is
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
differentiating the resolved vector representing the distance in time to yield an incremental motion value;
adding said incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from said internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
summing the above corrected and summed motion values to obtain internal structure position variations that describe the corrected respiratory parameters;
The method according to item 33, comprising:
(Item 35)
34. The method of item 33, wherein said internal structure is one of said human liver, spleen, or kidney.
(Item 36)
Said signal processor (134) receives signals from said first and second accelerometer units (121; 128) and from said first magnetic field unit (122) interacting with said second magnetic field unit (129). based on the input, calculating movement and orientation of the ultrasound transducer (112) within the first probe (102) with respect to the expected direction of movement of the internal structure (144) relative to the longitudinal axis of the human; 34. The method of item 33, wherein the movement and orientation of the ultrasound transducer (112) is related to respiratory activity.
(Item 37)
34. The method of item 33, wherein the movement of the internal structure is a function of diaphragm movement within the human body.
(Item 38)
34. The method of item 33, wherein sustained variations in beam orientation, bed angle, and abdominal surface motion are utilized in the compensation.
(Item 39)
35. The method of item 34, wherein sustained variations in beam orientation, bed angle, and abdominal surface motion are utilized in the compensation.
(Item 40)
39. The method of item 38, wherein the compensation assumes that the abdominal surface of the person moves in a direction perpendicular (v _mm ) to the surface on which the person lies.
(Item 41)
40. The method of item 39, wherein the compensation assumes that the abdominal surface of the person moves in a direction perpendicular (v _mm ) to the surface on which the person lies.
(Item 42)
measuring tilt based on the direction of gravity using said first and second accelerometer units (121; 128); ) comprises a 3-axis accelerometer unit;
measuring the vertical movement of the first probe (102) using the first magnetic field unit (122) with the aid of a magnetic field emitted by the second magnetic field unit (129); and the measured tilt and the measured vertical motion are used to compensate for the measurement error.
The method according to item 33, further comprising:
(Item 43)
41. A method according to item 40, wherein said first and second accelerometer units (121; 128) comprise triaxial accelerometer units.
(Item 44)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 34. The method of item 33, further comprising measuring the tilt angle (α) of the surface.
(Item 45)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 43. The method of item 42, further comprising measuring the tilt angle (α) of the surface.
(Item 46)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 44. The method of item 43, further comprising measuring the tilt angle (α) of the surface.
(Item 47)
34. The method of item 33, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 48)
35. The method of item 34, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 49)
43. The method of item 42, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 50)
44. The method of item 43, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 51)
48. The method of item 47, wherein said internal structure is one of said human liver, spleen, or kidney.
(Item 52)
49. The method of item 48, wherein said internal structure is one of said human liver, spleen, or kidney.

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, further explain the principles of the invention and enable those skilled in the art to make the invention. and play a role in enabling its use.

1A-1C illustrate exemplary diagrams of a human torso showing ultrasound transducer device installation according to embodiments of the present disclosure.

2A and 2B illustrate example diagrams of probe locations on a human body for liver, spleen, or kidney motion detection, according to embodiments of the present disclosure.

FIG. 3 illustrates a rear perspective view of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 4 illustrates a rear view of the probe of FIG. 3, according to an embodiment of the present disclosure.

FIG. 5 illustrates a cross-sectional view of a first embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 6 illustrates a cross-sectional view of a second embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 7 illustrates a cross-sectional view of a third embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 8 illustrates a cross-sectional view of a fourth embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 9 illustrates a cross-sectional view of a fifth embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 10 illustrates a cross-sectional view of a sixth embodiment of an anterior ultrasound transducer device probe, according to embodiments of the present disclosure.

FIG. 11 illustrates a cross-sectional view of a seventh embodiment of an anterior ultrasound transducer device probe, according to embodiments of the present disclosure.

FIG. 12 illustrates a cross-sectional view of an eighth embodiment of an anterior ultrasound transducer device probe, according to an embodiment of the present disclosure.

FIG. 13 illustrates a perspective front overall view of the probe of FIGS. 9 and 10 prior to placement of first and second materials within the probe, according to an embodiment of the present disclosure.

FIG. 14 illustrates another perspective front overall view of the probe of FIG. 13 from a different angle, according to an embodiment of the present disclosure.

FIG. 15 illustrates a perspective front cross-sectional view of the probe of FIGS. 13 and 14, according to an embodiment of the present disclosure.

FIG. 16 illustrates a perspective rear view of a posterior probe placed on the dorsal side of a human body and to interface with an anterior probe on the front side of the human body, according to an embodiment of the present disclosure.

FIG. 17 illustrates a perspective front overall view of the probe of FIG. 16 prior to placement of the fourth material and optional application of the adhesive body, according to an embodiment of the present disclosure.

FIG. 18 illustrates a perspective front cross-sectional view of the probe of FIG. 17, according to an embodiment of the present disclosure.

FIG. 19 illustrates a cross-sectional view of the rear probe prior to placement of the fourth material, according to an embodiment of the present disclosure.

FIG. 20 illustrates the cross-sectional view of FIG. 19 after placement of the fourth material, according to an embodiment of the present disclosure.

FIG. 21 illustrates the cross-sectional view of FIG. 20 after the addition of a fifth material adhesive body, adhesive member, or double-sided adhesive tape material, according to an embodiment of the present disclosure.

FIG. 22 illustrates a simplified block schematic diagram of an embodiment of an inventive system for performing range calculations and signal processing related to motion compensation, according to embodiments of the present disclosure.

FIG. 23 illustrates a cross-sectional view showing the basic principle for respiration detection using an ultrasound beam directed at a human liver, according to an embodiment of the present disclosure.

FIG. 24 illustrates a cross-sectional view showing the motion of the thoracic and abdominal regions of a human body during breathing, according to an embodiment of the present disclosure.

FIG. 25 illustrates a cross-sectional view showing the effects of abdominal shape changes during breathing, according to an embodiment of the present disclosure.

FIG. 26 illustrates a cross-sectional view showing a rear (auxiliary) sensor probe installation as also shown in FIGS. 1A, 1B, or 2, according to embodiments of the present disclosure.

FIG. 27 illustrates a schematic diagram showing the derivation of signals from accelerometers in the anterior and posterior probes according to embodiments of the present disclosure.

FIG. 28 illustrates a schematic diagram showing signal processing associated with range calculation and motion compensation, according to embodiments of the present disclosure.

FIG. 29 illustrates an example graph showing a first rotation (ρ) as viewed from the positive x-axis, according to an embodiment of the present disclosure.

FIG. 30 illustrates an example graph showing the orientation of the gravity vector prior to the second rotation as viewed from the positive y-axis, according to an embodiment of the present disclosure.

FIG. 31 illustrates an example graph showing probe coordinates and measured accelerations viewed from the positive y-axis, according to embodiments of the present disclosure.

FIG. 32 illustrates an example graph showing the situation after a first rotation as viewed from the global positive x-axis, according to an embodiment of the present disclosure.

FIG. 33 illustrates the direction of the measured acceleration vector after a second rotation, according to an embodiment of the present disclosure.

FIG. 34 illustrates calibration settings, according to an embodiment of the present disclosure.

Embodiments of the invention will be described with reference to the accompanying drawings.

The following detailed description, with reference to the accompanying drawings, illustrates exemplary embodiments consistent with this disclosure. References in the Detailed Description to “one exemplary embodiment,” “an exemplary embodiment,” “an example of an exemplary embodiment,” and the like refer to references to “one exemplary embodiment,” “an exemplary embodiment,” “an example of an exemplary embodiment,” and the like, which refer to the may include, but not all exemplary embodiments may necessarily include a particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same exemplary embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an example embodiment, whether or not explicitly described, such feature, structure, or characteristic is It is within the knowledge of those skilled in the art to influence the characteristics, structure, or properties of

The exemplary embodiments described herein are provided for purposes of illustration and not limitation. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments within the spirit and scope of this disclosure. Therefore, the detailed description is not intended to limit the invention. Rather, the scope of the invention is defined solely in accordance with the following claims and their equivalents.

Embodiments may be implemented in hardware (eg, circuitry), firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (eg, a computing device). For example, machine-readable media can include read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, electrical, optical, acoustic, or other forms of propagated signals ( (eg, carrier waves, infrared signals, digital signals, etc.), and others. Additionally, firmware, software, routines, and instructions may be described herein as performing certain actions. However, such descriptions are for convenience only and such actions may actually be caused by a computing device, processor, controller, or other device executing firmware, software, routines, instructions, etc. I hope you understand that. Additionally, any of the implementation variations may be performed by a general purpose computer, as described below.

For purposes of this discussion, any reference to the term "module" or the term "unit" refers to software, firmware, or hardware (one or more of circuits, microchips, and devices, or and any combination thereof. In addition, each module or unit may include one or more components within the actual device, and each component forming part of a described module may include any other component forming part of the module. It is to be understood that it may function either in conjunction with or independently of the components of. Conversely, modules or units described herein may represent a single component within an actual device. Additionally, components within a module or unit may be within a single device or distributed among multiple devices in a wired or wireless manner.

The following detailed description of illustrative embodiments is provided so that others may understand such illustrative embodiments by applying the knowledge of those skilled in the art, without undue experimentation, without departing from the spirit and scope of the present disclosure. The general nature of the invention will be fully apparent, such that the embodiments can be easily modified and/or adapted for various uses. Accordingly, such adaptations and modifications are intended to be within the meaning and equivalents of the example embodiments based on the teachings and guidelines presented herein. The language and terminology herein are for purposes of illustration and not limitation and are to be interpreted by those skilled in the art in light of the teachings herein. I want you to understand.

1A-1C illustrate exemplary diagrams of a human torso showing ultrasound transducer device installation according to embodiments of the present disclosure. In particular, FIG. 1A shows a right side view of a human torso 101 in which an anterior probe 102 and a different posterior probe 104 of an ultrasound transducer device are both attached to the anterior side 103 and dorsal side 105 of the human, respectively. FIG. 1B shows the tentative location of the posterior probe 104 and FIG. 1C shows the tentative location of the anterior probe 102. In some embodiments, the anterior and posterior probes may be referred to as first and second probes, respectively.

Probes 102, 104 are seen positioned near the right midclavicular line 106, but these probes are shown in FIGS. 1B and 1C to the side of and/or along the direction of line 106. It should be understood that the location may be different from the location. The right midclavicular line is represented as 106 and the left midclavicular line is represented as 108. When the ultrasound beam is directed toward the spleen within the body, the probe is preferably located adjacent line 108. When the ultrasound beam is directed towards a kidney, the probe is preferably positioned adjacent to either line 106 or line 108, depending on the selected kidney within the body.

It will be readily appreciated that measuring the movement of internal tissue regions or structures is not limited to the liver. Any parenchymal soft tissue that can be accessed by ultrasound from the body surface may be used. In addition to the liver, the spleen and kidneys are of particular interest for recording diaphragm movement, according to some embodiments.

The invention will be described with reference to the presently preferred mode of detection, which involves detecting liver movement. This description is used to facilitate explaining the structure, principle, and operation of various embodiments of the invention, and is intended to be illustrative rather than restrictive.

2A and 2B illustrate example diagrams of probe locations on a human body for liver, spleen, or kidney motion detection, according to embodiments of the present disclosure. Similar to FIG. 1, FIG. 2A shows probe locations on a human body 101 where probes 102, 104 are preferably linked or coupled to a processor (e.g., signal processor 134 shown in FIG. 22) and a display 109. Illustrated. FIG. 2B illustrates the anterior probe 102 location for liver, spleen, or kidney motion detection within a patient's body.

FIG. 3 illustrates a rear perspective view of the anterior ultrasound transducer device probe 102, according to an embodiment of the present disclosure. FIG. 4 illustrates a rear view of the probe 102 of FIG. 3, according to an embodiment of the present disclosure.

The front probe 102 of the ultrasound transducer device is further described with reference to FIGS. 5, 6, 9, and 10. The illustrated probe 102 is configured to be placed on a human's anterior body surface 103 to direct an ultrasound beam toward and receive ultrasound echo signals from internal structures. The internal structure is at least one of a human liver, spleen, or kidney. In some embodiments, a tissue region may be referred to as an internal structure inside a patient's body.

The probe illustrated in FIGS. 5, 6, 9, and 10 includes a housing 110, preferably made of a hard shell plastic material, in a non-limiting example, with a cavity 111 in which an ultrasound transducer 112 is located. has. A transmitting/receiving surface 113 of the transducer 112 is oriented at an acute angle Ω with respect to the front surface 114 of the housing at or adjacent to the cavity mouth of the housing cavity. In some embodiments, the acute angle is preferably within the range of 0 to 60 degrees.

Transducer 112 is fixedly positioned within cavity 111 of housing 110 with at least a body 115 of first material comprising an ultrasound non-sonolucent material extending toward front surface 114 . It may be observed that the body 115 of first material surrounds a recess 116 extending from the transmitting/receiving surface 113 towards the front surface 114 .

A first portion of a second body 117 of material comprising ultrasonic sonolucent material is located within the transmitting/receiving surface 113 of the transducer and the recess 116 in front thereof toward the front surface 114. A second portion of the second body of material 117 is additionally applied onto and integrally engaged with the front surface 115' of the first body of material. In some embodiments, the first and second portions of body 117 are unitary.

7, 8, 11, and 12 illustrate additional embodiments of anterior ultrasound transducer device probes. In particular, the embodiment of FIGS. 7, 8, 11, and 12, which differs from the embodiment of FIGS. 5, 6, 9, and 10, lacks the shell housing 110 and housing cavity 111. Alternatively, in the embodiments of FIGS. 7, 8, 11, and 12, the housing is simply constituted or formed by a body of first material 118, preferably the same type of material as that of body 115. be done.

Note that as shown in the embodiment of FIGS. 9-12, the transducer 112 is supported differently than in the embodiment of FIGS. 5-8. For example, in FIGS. 5-8, transducer 112 is supported by printed circuit board 119 and body 115. In FIG. In FIGS. 9-12, the recess is lined with an open-ended socket-like member 120 of ultrasonic non-sonolucent material, and the transducer 112 is mounted in the bottom region of the open-ended socket-like member 120. In FIGS. The material of member 120 exhibits acoustically attenuating properties, and the outer wall of member 120 is configured to engage the first body of material 115, 118. 9-12, transducer 112 and open-ended socket-like member 120 extend from printed circuit board 119. In FIGS. The member 120, in which the transducer 112 is located, and the printed circuit board are supported by and embedded in the first body of material 115, 118.

The probe 102 also contains an accelerometer unit 121 (shown schematically) and a magnetic field detection unit 122 embedded (eg, encapsulated) in the first material body 115, 118. Accelerometer unit 121, magnetic field detection unit 122, and transducer 112 are connected or coupled to printed circuit board 119 and signal processor 134 (as shown in FIG. 22). The signal processor is further described below with respect to FIG.

The housing 110 with the cavity 111 and the body 115 of the first material particularly bond well together, but preferably have compatible properties, e.g., also have similar thermal expansion properties. Made of material with For example, the material for the housing 110 may include a suitable plastic material or polymer, and/or the first material body 115 may include an ultrasonic non-sonolucent silicone rubber material or the like. A variety of potential additives are available to make silicone rubber materials ultrasonic non-sonoluccent (e.g., calcium carbonate, titanium dioxide, zinc oxide, quartz, glass, or other additives). ). An example of a silicone rubber with additives is ELASTOSIL® RT 602 A/B. The same or similar additives may be used to render plastic materials ultrasonic non-sonollucent. Accordingly, such additives may be used if the socket-like member 120 is formed from a plastic material. In some cases, the acoustic damping properties of such additives within silicone rubber or plastic materials may depend on particle size and particle mass density (e.g., preferably particle densities are both about 1,000 kg/ m ³ (very different from the density of silicone rubber or plastic).

According to the embodiment of FIGS. 5-8 (e.g., the housing shell 110 is not present), the body 118 of the first material forming the probe housing has a rear surface area such as that visible in FIGS. 3 and 4. (e.g., a surface area that does not face the skin of the human body). In some embodiments, the first material present preferably has non-stick surface properties.

Note that in the embodiment of FIGS. 7 and 8, the body 118 of the first material creates a recess 116, and in FIGS. 11 and 12, the body 118 surrounds the socket member 120 in which the transducer is located. . The front surface 115', 118' of the first body 115, 118 of material has a second body 117 of material attached thereto. The front surface 117' of the body of the second material has inherent adhesive properties, an attachment surface for an adhesive member or double-sided adhesive tape, and an engagement surface for the adhesive layer of the body of the third material. may exhibit one of the following.

If the front surface 117' of the body 117 of the second material has adhesive surface properties, the probe may be provided with a removable protective cover 123, which covers the application of the probe on the skin of the body 101. It can be removed in advance. In this particular case, the probe is preferably of the self-adhesive type for single use, but the double-sided adhesive tape ensures that the surface 117' is not contaminated in such a way that the tape would not adhere. As a prerequisite, it may be attached to surface 117' after the first use of the probe.

If the front surface 117' is not used to adhere the probe 102 directly to the skin, an adhesive member or double-sided adhesive tape is attached to the body 117 of the second material, as indicated by the general element 124. It is attached to the front face 117'. The adhesive member or double-sided adhesive tape may be ultrasonic sonolucent at least in the area faced by the transducer transceiver surface 113. Additionally or alternatively, the general element 124 covering the front surface 117' of the second body of material 117 is an adhesive layer of the third body of material that is ultrasonic sonolucent.

The first and second materials are provided within the probe 102 as a unitary structure, and both materials exhibit similar or compatible thermal and mechanical properties. Further, the second material and the third material are at least one of the same, compatible in nature, and compatible in engagement. At least one body material type of the first, second, and third materials includes a silicone rubber material. If the first and second materials are similar, the ultrasonic non-sonolucent first material may have ingredients added to it to effectively obtain its desired properties. For example, additives such as calcium carbonate, titanium dioxide, zinc oxide, quartz, glass, or the like may be added to the silicone rubber material to render it non-sonoluccent. In an exemplary embodiment, the first material is silicone rubber with one or more additives, while the second and third materials are silicone rubber. Many suitable silicone rubber materials are commercially available. For example, the ultrasonic non-sonollucent silicone rubber material is ELASTOSIL® RT 602 A/B and the ultrasonic sonollucent material is ELASTOSIL® RT 601 A/B. In practice, it is important that the additive does not interfere with the silicone rubber setting procedure, is biocompatible, and exhibits good adhesion to the silicone rubber material.

FIG. 13 illustrates a perspective front overall view of the probe of FIGS. 9 and 10 prior to deployment of first and second materials encapsulated in the probe, according to an embodiment of the present disclosure. In particular, FIG. 13 shows the embedding (e.g., encapsulation) of the body 115 of the first material to fill the recess 116 up to the transducer transmitting/receiving surface 113 and further covering the front surface 115' up to the body 115 of the first material. Probe 102 is shown prior to deployment and application of second material body 117.

14 illustrates another perspective front overall view of the probe 102 as shown in FIG. 13 from different angles, while FIG. 15 illustrates a probe as shown in FIGS. 13 and 14 according to embodiments of the present disclosure. 102 illustrates a perspective front cross-sectional view of 102. FIG. The wiring from cable 125 onto printed circuit board 119 is not shown for clarity. In some embodiments, cable 125 provides an electrical connection between circuit board 119, processor, and display 109 (see FIG. 2A).

As discussed above, the first anterior probe 102 is configured to cooperate or interface with the second posterior probe 104. These probes (shown in FIGS. 1A, 1B, 1C, and 2) are contained within a respiratory detection system configured to be positioned on the human body surface.

In the anterior probe 102, the ultrasound transducer 112 is configured to generate an ultrasound beam directed outwardly from a plane 114 of the anterior surface toward an internal structure or tissue region inside the body, FIGS. 5-12. Position stationary as described with reference to. Furthermore, probe 102 incorporates a first accelerometer unit 121 and a first magnetic field unit 122.

The second rear probe 104 is shown in more detail in Figures 16-21. The probe 104 is in the form of a shell member of plastics material with an associated cavity in which a second accelerometer unit 128 and a second magnetic field unit 129 are stationarily located and preferably connected to a common printed circuit board 130. It has a housing 126 with 127. Wires from cable 131 connecting to the printed circuit board are not shown for clarity. In some embodiments, cable 131 provides an electrical connection between circuit board 130, processor, and display 109 (see FIG. 2A).

The transducer 112, the first and second accelerometer units 121, 128, and the first and second magnetic field units 122, 129 are connected to the signal processor 134, as will be further described with reference to FIG. Linked. A second accelerometer unit 128 provides a measurement of the tilt angle of the surface supporting the dorsal side of the human body. The magnetic field sensor device of the first magnetic field unit 122 is a magnetic pickup coil in the illustrated embodiment. In certain embodiments, first and second accelerometer units 121, 128 each represent at least two accelerometers. In some embodiments, first accelerometer unit 121 includes a three-axis accelerometer device.

By use of the first and second magnetic field units 122, 129, the output signals provided from the first and second accelerometer units 121, 128 to the signal processor 134 are connected to the front side of the patient during breathing. is a function of the spatial position movement and orientation of the first probe 102. The spatial position movement and orientation are related to at least one of heave, roll, pitch, and yaw movement due to breathing by the patient.

A second accelerometer unit 128 and a second magnetic field unit 129 are stationary located within the cavity 127 of the second housing 126 with a body 132 of fourth material.

The plane 132' of the front surface of the body 132 of the fourth material is of adhesive nature, an attachment surface for an adhesive member or double-sided adhesive tape, and an engagement surface for the adhesive layer of the body of the fifth material. Provide one of the following. In FIG. 21, at least one of the engagement surfaces for the adhesive member, the double-sided adhesive tape, and the adhesive layer of the body of the fifth material is generally represented by the reference numeral 133.

At least one of the first, second, third, fourth and fifth materials is preferably of silicone rubber type. In order to avoid possible skin ulcers on the dorsal side of the body, at least the surface area of the second probe that abuts or is to come into contact with the dorsal skin area of the body exhibits a biocompatible material; The contact surface area of the probe (eg, the area of the probe surface in contact with the skin) is preferably in the range of 5 to 100 cm ² . In the exemplary embodiments described above, the first material is a silicone rubber with additives included to render the silicone rubber ultrasonolucent, and the second and third materials are Sonic sonolucent silicone rubber. Continuing with the exemplary embodiment, the fourth and fifth materials are silicone rubber. In some embodiments, the fourth and fifth materials may not be present in the second probe 104, where the ultrasound transducer is located dorsally, so ultrasound aspects may not need to be considered. . In additional embodiments, the first, second, third, fourth, and fifth materials are commercially available.

In some embodiments, signal processor 134 (shown in FIG. 22) controls the strength, frequency, and duration of the magnetic field to be generated by the second magnetic field unit. The signal processor determines the expected movement of the internal structure based on inputs from the first and second accelerometer units 121 and 128 and from the first magnetic field unit 122 interacting with the second magnetic field unit 129. The apparatus is configured to calculate movement and orientation of the abdominal wall of the patient's body with respect to direction. Movement and orientation are related to respiratory parameters associated with the patient's abdominal muscles.

As explained above, the patient's internal structure or tissue region is at least one of the patient's liver, spleen, or kidney. It will be readily appreciated that the detected movement of the internal structure is a function of diaphragm movement within the patient's body.

As shown in FIG. 22, the processor 134 has a data storage device 135 associated therewith for storing patient respiratory data during the course of monitoring, and a visual representation of the current or stored respiratory data. It has a display 136 for displaying. Processor 134 also includes therein a transceiver section 134' that operates in conjunction with transducer 112. In some embodiments, processor 134 may cause respiratory alert unit 137 to generate one or more visual and/or audible alerts when one or more respiratory parameters of the patient depart from acceptable parameter ranges. Preferably, the front probe 102 has a first probe identification serial number device 138 and similarly the rear probe 104 has a second probe identification serial number device 139. These serial numbers 138, 139 are unique to the individual probe in use and may not be changed.

Additionally, a registration and operation comparator unit 140 is provided and linked or coupled to processor 134. In some embodiments, the patient's identification serial number (e.g., social security, tax personal code, or another identifier) is provided to the processor 134 prior to and/or during use of the respiratory detection system on the patient. It may be typed into unit 140 using a linked keyboard 141. Particularly for use on infected patients, it may be important that the anterior and posterior probes 102, 104, when removed, are not used on another patient. Unit 140 may therefore include an operating mode controller that prevents such secondary use. In other cases, secondary use may be acceptable if the probes 102, 104 are reused on the first patient rather than on a new patient.

In some embodiments, the reliability of the probes may deteriorate over time if the probes 102, 104 are reused too many times. Accordingly, the operating mode controller may electronically limit the number of reuses of the probe to a predetermined number of uses, e.g., 3 to 10 uses, after which the processor 134 and unit 140 may effectively block serial numbers from. In other cases, the probes 102, 104 typically have separate self-adhesive front surfaces 117', 132', such as may be used by an ICU (intensive care unit) for single use. Good too. For these single-use probes, probe identification may be blocked once the system is shut down and the probe is removed from the patient. In some embodiments, power supply 142 may deliver power to processor 134, data storage 135, display 136, and units 137, 140. In additional embodiments, the required power to the probes 102, 104 is delivered via the processor 134.

Exemplary methods for motion compensation of measurement errors during respiratory monitoring are described herein with reference to FIGS. 23-26. To more easily understand the functionality of the system, FIG. 27 schematically illustrates the derivation of signals from the accelerometers in the anterior and posterior probes and related to range calculation and motion compensation, according to embodiments of the present disclosure. Reference is also made to FIG. 28, which schematically illustrates the signal processing.

An exemplary method is used in ultrasound-based detection of patient respiratory parameters. Detection uses an ultrasound beam 143 directed from and to the ultrasound transducer device 112 in the anterior probe 102 (located on the front side of the body). Ultrasonic beam 143 is directed from the human's anterior body surface to an internal structure or tissue region inside the body and is reflected back to probe 102 as an ultrasound echo signal.

In certain embodiments, the method comprises:

(a) attaching a first probe 102 to the anterior body surface of the patient, the first probe 102 having an ultrasound transducer 112, a first accelerometer unit 121, a first magnetic field unit 122; having a step;

(b) attaching a second probe 104 to a dorsal body surface of the patient, the second probe 104 having a second accelerometer unit 128 and a second magnetic field unit 129; ,

(c) providing a signal processor 134 coupled to the transducer 112, the first and second accelerometer units 121, 128, and the first and second magnetic field units 122, 129;

(d) transmitting an ultrasound beam from an ultrasound transducer 112 in the first probe 102 into an internal structure (or tissue region) inside the patient's body;

(e) receiving an ultrasound echo signal from an internal structure at an ultrasound transducer 112 within the first probe 102;

(f) generating a magnetic field transmitted by the second magnetic field unit 129 to and detected by the first magnetic field unit 122;

(g) using the signal processor 134 to calculate the orientation of the first accelerometer unit 121 with respect to a fixed coordinate frame using the derived parameters from the first accelerometer unit 121 and using the ultrasound beam 143 ( further calculating derived parameters as unit vectors representing the orientation of the first magnetic field unit (see FIGS. 23-26) and the orientation of the first magnetic field unit;

(h) using the signal processor 134 to calculate the orientation of the second accelerometer unit 128 with respect to the fixed coordinate frame using the derived parameters from the unit 128, and calculating the body back support tilt angle (α) and Further derived parameters, including a unit vector representing the spatial direction from the second magnetic field unit 129 (e.g. an electromagnet) to the first magnetic field unit 122 (e.g. a sensor device located within the anterior probe 102), the second further calculating the orientation of the magnetic field unit 129 and the expected direction of movement of the internal structure or tissue region (e.g., liver, spleen, or kidney) during exhalation;

(i) calculating in the signal processor 134 any variation distance between the first and second magnetic field units 122, 129 based on the detection of the magnetic field;

(j) using signal processor 134 to process the results from the calculations in steps (g)-(i) and generate correction parameters to compensate for the received hypersensitivity caused by abdominal wall movement due to patient breathing; Compensating for measurement errors in the acoustic wave echo signal;
including.

More specifically, processing step (j) includes:

(k) resolving a vector representing the distance between the first magnetic field unit 122 contained within the anterior probe 102 and the second magnetic field unit 129 located dorsally along the ultrasound beam direction 143; step and

(l) differentiating the resolved vector representing the distance in time to yield an incremental motion value;

(m) adding the incremental motion value in step (l) to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from the internal structure within at least the same time interval;

(n) correcting the summed motion value of step (m) with respect to the instantaneous cosine value of the angle between the ultrasound beam 143 and the direction of motion of the internal structure;

(o) summing the corrected and summed motion values to obtain internal structure position variations that account for the corrected respiratory parameters;
May include.

The need for anterior probe motion compensation will now be discussed in more detail below. Although the following discussion primarily relates to measuring liver motion detection, it is to be understood that embodiments of the present disclosure may also be applied to motion detection in other tissues such as the human spleen or kidney.

During pilot clinical trials for the evaluation of ultrasound transducer device probes, the reproducibility of measurements provided by such instruments was poor, and repositioning of the probe on the abdominal surface did not interfere with the measured liver (and diaphragm) was observed to result in undesirable changes or deviations in movement amplitude. By analyzing the possible causes in this regard, two factors were identified that may have been responsible for the deviation.

First, the probe on the patient's abdominal surface is moving up and down as the patient breathes. This motion has a vector component along the ultrasound beam direction 143, and the probe motion results in a variable underestimation of the true motion of the liver 144, as illustrated in FIGS. 23 and 24. When the liver 144 moves toward the probe 102 during inspiration, the probe simultaneously moves away from the liver and vice versa during exhalation. This occurrence was confirmed experimentally using a mechanically fixed probe that was not allowed to move, resulting in approximately 40% higher estimates of liver movement compared to a freely moving probe. brought about.

23 and 24 illustrate the basic principles for breath detection using ultrasound beams directed at the human liver and the motion of the thoracic and abdominal regions of the human body during breathing, according to embodiments of the present disclosure; Figure 3 illustrates a cross-sectional view. In particular, the cross-sectional views of FIGS. 23 and 24 illustrate liver 144 movement 145 and probe movement 146, and how the probe movement can be considered to have two components. One component 147 is along the ultrasound beam direction 143. This component will directly affect and interfere with the estimated movement of the liver 144.

Second, the abdominal surface is conical rather than cylindrical. This ventral shape will cause variable tilting of the transducer 112 and probe 102, thus affecting the direction of the ultrasound beam 143. Substantial concavity of the surface may exist in thin human subjects just below the costal margin where the anterior probe 102 is placed to have acoustic access to the liver 144. And in obese human subjects, the surface is convex as illustrated in FIG. 25. Therefore, the assumption of a fixed 45° angle between the acoustic beam 143 and the liver motion direction 145 may not be valid.

Thus, embodiments of the present invention alleviate the problems discussed above.

FIG. 26 illustrates a cross-sectional view showing the basic principle of distance measurement 148 through the use of dorsal (auxiliary) or posterior sensor probe 104 placement. In a non-limiting example, the human body is in a supine position (eg, lying face up) on the mattress of a bed.

The probe 102 is equipped with a 3-axis accelerometer module that uses the direction of the gravity vector to estimate the tilt and allows calculation of the actual spatial direction of the ultrasound beam relative to the movement of the liver.

In some embodiments, an additional second (auxiliary) sensor posterior probe 104 is added at a location on the dorsal side of the patient, vertically below the anterior probe 102 when the patient's body is in the supine position. When the patient is in an upright position, the anterior and posterior probes 102, 104 may be aligned substantially perpendicular to the human's spinal direction.

The rear second sensor probe 104 contains an additional accelerometer unit 128 to measure the tilt angle of the bed on which the patient lies, since most ICU patients have elevated beds. The tilt angle measurements may be utilized to have an estimate of the actual liver movement direction.

The rear sensor probe 104 also contains an electromagnet in unit 129 that generates a weak alternating magnetic field that is sensed by a magnetic pickup coil in unit 122 of the front probe 102. The use of electromagnets and magnetic pickup coils allows for continuous measurement of the vertical movement of the anterior probe 102 based on the known relationship between magnetic field strength and distance. By obtaining these calculations, the motion of the probe 102 can then be included in the estimate of liver motion.

It should therefore be appreciated that precise knowledge of probe orientation and vertical motion allows compensation for the effects of both anterior probe motion and abdominal surface topography.

In developing embodiments of the invention, several potential safety issues were addressed.

Magnetic field: An electromagnet on the patient's back generates a weak magnetic field, preferably at a frequency of 33 kHz, which decays with the inverse cube of distance. In all directions, the magnetic field strength is below 27 μT at distances greater than 15 mm from the centerline of the cylindrical magnet. For example, 27 μT is the recommended maximum magnetic field strength for sustained whole-body exposure for the general public at frequencies between 3 kHz and 10 MHz. This means that the few millimeters of skin and subcutaneous tissue close to the dorsal sensor will be exposed to magnetic field strengths above 27 μT, but always below 100 μT, which is the corresponding limit for sustained occupational whole body exposure. do.

New acceleration and magnetic sensor devices in the front probe 102 and the acceleration sensor device 128 in the rear probe: The accelerometers 121, 128 and magnetic pickup coils 122 added to the probes 102, 104 are passive without any energy emission. It is a device. They therefore do not have any potential to harm the patient.

Physical bedsores on the patient's back: The rear sensor probe 104 may have the potential to create bedsores. This has been taken into account during the design of the sensor. In one embodiment, the probe 104 is preferably encapsulated in a biocompatible soft silicone rubber, e.g., with no sharp edges and with a tapered shape toward its circumference, such as on the patient's skin or It has a circular 5 cm diameter flat contact surface for contacting surfaces within the range of 5 to 100 cm ² . A preferred attachment location is on the dorsal flank of the patient, where there is a soft tissue area between the thorax and pelvis, contributing to an even mechanical pressure distribution. In one embodiment, attachment to the skin is by using one of several attachment options used for anterior probes, such as double-sided silicone rubber tape. If the body of the fourth or fifth material is adhesive, the rear probe may be attached to the dorsal side of the body via one of these adhesive materials.

To prevent bedsores, the skin in or surrounding the sensor attachment area can be carefully inspected during daily reattachment of the posterior probe and during routine patient care visits. The occurrence of dermatitis may be recorded as an adverse event and patients in such circumstances may be excluded from further participation.

Electrical Safety: Both probes 102, 104 are preferably fully hermetically encapsulated in an electrically insulating material such as silicone rubber with 20 kV/mm electrical insulation. In certain embodiments, the shortest distance from the conductor inside the probe to the surface is at least 1 mm. The bodies of at least the first and fourth materials exhibit such electrically insulating properties.

In some embodiments, the device is preferably powered from a medical grade external power supply delivering 12VDC. The highest voltage found inside the device is preferably no more than 18-24 VDC.

Exemplary Embodiment: Motion Compensation

A simplified method of motion compensation based on accelerometer readings of the gravity vector in combination with magnetic range measurements will be discussed here. For simplified presentation, it is assumed that the sensor probe 102 movement is substantially along a direction perpendicular to the plane of the mattress on which the patient's body lies.
Rear (auxiliary) sensor probe 104 orientation

The calculation of the posterior sensor probe orientation (eg, the probe 104 located on the dorsal side of the patient) may be expressed as a rotation matrix with respect to a global coordinate frame and the calculation of the following derived parameters.
- sine and cosine of the mattress tilt angle (α) - unit vectors that describe:
- Direction from rear probe 104 to front probe 102. This is also the expected direction of movement of the anterior probe 102.
- Orientation of electromagnet 129 - Direction of expected liver movement 145, positive direction towards the patient's head - Forward sensor probe orientation

The calculation of the anterior probe 102 orientation using the derived parameters is based on the accelerometer 121 readings and mattress tilt input from the posterior (auxiliary) probe 104.

Based on the user instructions on how to orient the anterior and posterior probes, the output is:
-A unit vector that describes:
・Ultrasonic beam direction 143
・Magnet pickup orientation 149
Distance from rear probe to front probe

The distance is calculated from the magnetic pickup signal, the direction from electromagnet 129 to pickup 122, and the orientation of electromagnet 129 and pickup signal 122. The calculation also utilizes a single calibration value (k) determined during production of the system.
motion compensation

The distance 148 between the rear and front probes is resolved along the acoustic beam direction 143 and differentiated to provide incremental motion. This is added to the incremental motion detected by the Doppler system within the same time interval. The summed motion is then corrected for the instantaneous cosine of the angle between the acoustic beam and the liver motion direction. Displacement is then calculated by integration.
General aspects

All accelerometer readings are transformed to match the coordinate system in which the axial directions are:
X: towards the patient's head Y: towards the patient's left arm Z: downward

Assuming that the three-axis accelerometer IMU (Inertial Measurement Unit) is mounted in integer multiples of 90°, the coordinate system transformation is performed by a combination of permutation and sign reversal.

All coordinates and rotations in the formulas and illustrations are given in a global stationary coordinate system unless otherwise specified.

For the calculations below where only accelerometer readings are used to determine angular orientation, they do not need to be converted from raw binary format to metric as long as the numerical format is signed.
Rear probe 104 orientation:

The accelerometer readings are a _Ax , a _Ay and a _Az (signed, arbitrary units).

The electrical cord points straight outward to the patient's right side, and the cord, ferrite rod, and accelerometer y-axis are assumed to be parallel.

The orientation of probe 104 may be described by a sequence of two rotations.
1) Initial rotation (roll) of ρ around the global x-axis to account for the local lateral curvature of the patient's back
2) Rotation (pitch) of α around the global Y axis to account for bed tilting

The rotation is derived by considering the probe and its measured gravity vector as a rigid body and performing a rotation that aligns the gravity vector with the negative global z-axis. The first rotation aligns the gravity vector with the xz plane. For example, FIG. 29 illustrates an example graph showing the first rotation (ρ) viewed from the positive x-axis, which may be calculated as follows.

And the corresponding rotation matrix is:

FIG. 30 shows an example of the orientation of the gravity vector prior to the second rotation as seen from the positive y-axis. The second rotation is calculated as follows.

Note that sin(α) and cos(α) are typically utilized for calculation of anterior probe 102 orientation. The angle α itself may not need to be evaluated.

The corresponding rotation matrix is:

The total rotation is therefore:

The unit vector orientation of the electromagnets in the second field unit 129 of the rear probe 104 is:

The unit vector direction of liver motion expressed in the global coordinate system is:

The unit vector from the rear electromagnet 129 to the front sensor pickup 122 is:
Front probe 102 orientation:

The accelerometer readings are a _Px , a _Py , and a _Pz .

The bed tilt angle is α (expressed as sin(α) and cos(α) from the back sensor).

The sequence of rotations that positions the probe 102 in a manner that makes the measured acceleration vertical and upward and ensures that the probe 102 x-axis and body centerline are in the same plane is as follows.
1) rotation of φ around y to account for the local taper of the body surface 2) rotation of θ around x to account for the position of the probe 102 within the right flank 3) rotation of α around y (bed final rotation of tilting)

The calculation is derived by finding the sequence of rotations of the rigid body consisting of the probe 102 and its associated measured gravity vector that aligns the measured gravity vector with the global negative z-axis (upwards). Ru.

For rotation (1), the initial conditions are presented by equations 12-19 below and illustrated by FIG. For example, FIG. 31 illustrates probe coordinates and measured accelerations as viewed from the positive y-axis. The first rotation rotates y with an angle φ=β−γ, causing the measured acceleration vector to point such that the remaining distance to the global yz plane is g _P sin(α). around the axis.

The equation includes:

Note that the following conditions will be met for a valid calculation.

In some embodiments, user error in probe 102 installation (eg, improper orientation) may cause this condition. If this occurs, an error message may be given and the session may be restarted.

The rotation angle φ has the following properties.

The rotation matrix is therefore:

For rotation (2), the situation is illustrated by FIG. 32 and related equations 20-22. For example, FIG. 32 shows the situation after rotation (1) as seen from the global positive x-axis. The next rotation (2) around the global x-axis may bring the acceleration vector into the global xz plane. The equation includes:

The rotation matrix is therefore:

Figure 33 shows the direction of the measured acceleration vector after rotation (2). The final rotation around the global y-axis will align the vector with the negative z-axis of the global coordinate system.

Regarding rotation (3), the rotation matrix is:

As noted, R _P3 may be the same as R _A2 from equation (7) and may not need to be recalculated.

The total rotation is then calculated as follows.

The ultrasound beam direction (45° downward) is as follows.

In some embodiments, these trigonometric functions are preferably precomputed.

The orientation of the magnetic pickup 122 (in one embodiment, angled at a 26° rotation about the probe x-axis) is as follows.

In some embodiments, these trigonometric functions are also preferably precomputed.
Magnet distance measurement 148:

The inputs to the distance calculation are:

_Ncal : Signal reading during calibration. The emitting magnets in the second magnetic field unit 129 and the receiving magnets in the first magnetic field unit 122 are parallel to each other in a plane and orthogonal to the distance between their center lines when the system is calibrated. It is assumed to be oriented as follows.

S _cal : distance between magnets 122, 129 during calibration.

N _meas : signal reading during measurement.

v _mm : unit vector from magnet 129 to pickup 122;

v _magnet : unit vector that provides the orientation of the electromagnet 129.

v _pickup : unit vector that provides the orientation of the magnetic pickup 122 within the front probe 102.

The equation for the external magnetic field from the dipole is calculated as follows.

S is the distance from the dipole along the direction given by v _mm and |μ| is the magnitude of the magnet dipole moment. Note that vector-vector multiplication is a scalar product. A circumflex (^) indicates a unit vector.

The received signal (N _meas ) from pickup coil 122 will be the component of the magnetic field that is parallel to pickup 122, according to the equation below.

where k is a constant that combines |μ|, coil physics, amplification, ADC properties, demodulation, and signal averaging. The constant k is determined by a calibration procedure.

Solving Equation 28 in terms of S yields the distance (S _mag ):

calibration:

K is determined during calibration. Assuming that the ferrite rods are located at a distance of S _cal from each other and oriented as shown by FIG. 34, then solving Equation 28 provides:

Inserting values for the vectors v _magnet , v _pickup , and v _mm , which describe the geometry of the calibration settings of FIG. 34, yields:

Note that the units of measurement for S _cal are the same as for S _mag . If the calibration is performed with the pickup rotated 26° (places the assembled probe on a flat surface), then k will instead be:
Practical implementation of calibrated distance measurement:

The constant k is determined during production of each system of probes and stored in non-volatile memory according to Equation 31. In the exemplary embodiment described herein, the practical value for S _cal is 0.25 m.
motion compensation

The motion compensation method described herein compensates for persistent variations in beam orientation, bed angle, and abdominal surface motion. This assumes that the abdominal surface moves in the direction perpendicular to the mattress (v _mm ).

The data from the different sensors of the probe are preconditioned to have the same sample rate and delay, and the sign of the ultrasound-based range measurement (S _ultr ) is positive for liver motion toward the patient's head. It's something like this. The letter delta (Δ) indicates the difference between consecutive samples.

The incremental movement of the liver between two consecutive sample points when corrected with respect to the angle between the magnet range measurement and the ultrasound beam and with respect to the angle between the ultrasound beam and the liver movement is .

v _beam and v _river are
Note that if close to perpendicular to each other, an error message or warning may be issued as the measurement value will then be highly angle dependent and inaccurate.

The instantaneous velocity of the liver 144 is found as:
where Δt is the time between samples.

The location of the liver is found by the summation of ΔS _liver .

Therefore, in order to compensate for movement detection errors associated with the internal structures of one of the human liver, spleen, and kidney, we utilize three-axis accelerometer units in the anterior and posterior probes to It is summarized that it is useful to measure the vertical movement of the probe using a magnetic field unit in the front probe, with the assistance of a second magnetic field unit that measures the tilting based on and emits a magnetic field. can be done. By adding a posterior probe to be located on the dorsal side of the human, that probe has a second accelerometer unit and also assuming that the liver moves along the same direction as the bed surface. It is also possible to measure the tilt angle of the bed on which the patient lies. It is then possible to calculate the angle between the liver motion and the ultrasound beam instead of assuming that the beam has a steady value of, for example, 45°. The present disclosure thereby provides the possibility of calculating the contribution of vertical motion to the provided ultrasound Doppler signal and thereby compensating for associated signal errors.

It is to be understood that the Detailed Description section, rather than the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may describe one or more, but not all, exemplary embodiments of the invention as contemplated by the inventors and, therefore, may describe the invention and the appended claims in any manner. It is not intended to limit the section.

Embodiments of the present invention have been described above using functional building blocks that illustrate the implementation of its specified functions and relationships. The boundaries of these functional building blocks are arbitrarily defined herein for convenience of explanation. Alternative boundaries can be defined so long as their defined functions and relationships are properly performed.

The foregoing description of specific embodiments will fully reveal the general nature of the present invention, such that others may easily modify and/or adapt such specific embodiments for various applications by applying knowledge within the art without departing from the general concept of the present invention and without undue experimentation. Such adaptations and modifications are therefore intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It should be understood that the phrases and terms used herein are for purposes of description and not limitation, and that the phrases and terms used herein are to be interpreted by those of skill in the art in light of the teachings and guidance.

The scope and scope of the invention should not be limited to any of the exemplary embodiments described above, but should be defined only in accordance with the following claims and their equivalents.
(Item 1)
A respiration detection system, comprising:
A first probe (102),
an ultrasound transducer (112), the ultrasound transducer (112) being stationary within the first probe and at an acute angle (114) with respect to the front surface (114) of the first probe (102); Ω), said ultrasound transducer (112) transmitting an ultrasound beam at said transmitting and receiving surface (113) for transmission into internal structures inside a patient's body. an ultrasonic transducer (112) configured to generate (143);
a first accelerometer unit (121);
A first magnetic field unit (122), the ultrasonic transducer (112), the first accelerometer unit (121), and the first magnetic field unit (122) are connected to the first probe (102). a first probe (102) comprising a first magnetic field unit (122) stationary within );
a second probe (104),
a second accelerometer unit (128);
a second magnetic field unit (129), the second accelerometer unit (128) and the second magnetic field unit (129) being stationary within the second probe (104); a second magnetic field unit (129); a second probe (104);
the ultrasound transducer (112), the first and second accelerometer units (121; 128), and the first and second magnetic field units (122; 129) are coupled to a signal processor (134);
The first probe (102) is configured to be installed on the front side (103) of the patient's body (101),
The second probe (104) is configured to be installed on the dorsal side (105) of the body (101),
The combination of said first and second accelerometer units (121; 128) and said first and second magnetic field units (122; 129) causes said ultrasonic transducer (112) to respond to breathing by said patient. configured to generate an output signal that is a function of spatial position movement and orientation;
Breathing detection system.
(Item 2)
Respiration detection system according to item 1, wherein said first and second accelerometer units (121; 128) each comprise at least two accelerometers.
(Item 3)
A respiration detection system according to item 1, wherein said first accelerometer unit (121) comprises a three-axis accelerometer device.
(Item 4)
2. The respiratory detection system of item 1, wherein the spatial position movement and the orientation are associated with at least one of heave, roll, pitch, and yaw movement.
(Item 5)
Said ultrasonic transducer (112) uses said first body of material (115) comprising an ultrasonic non-sonolucent material extending towards the front surface (114) of said first probe (102) to located within the first probe (102);
said body (115) of first material surrounds a recess (116) extending from said transmitting and receiving surface (113) towards said front surface (114);
A first body portion (117) of a second material comprising an ultrasound sonolucent material extends towards the front surface (114) of the transmitting/receiving surface (113) of the ultrasound transducer (112) and of the recess in front thereof. located within
A second body portion (117) of said second material is applied onto and integrally engaged with the front surface of said body of first material, said first and second body portions , is integral,
Breath detection system according to item 1.
(Item 6)
The ultrasound transducer (112) is engaged within a socket-like member (120) positioned within the recess (116), the socket-like member (120) being formed from an ultrasound non-sonolucent material. , the respiration detection system according to item 5.
(Item 7)
The front surface of the body (117) of said second material has inherent adhesive properties, an attachment surface (117') for an adhesive member (124) or double-sided adhesive tape, or an adhesive layer of the body (117) of a third material. 6. The respiratory detection system of item 5, comprising an engagement surface for.
(Item 8)
Item wherein said adhesive member (124) or said double-sided adhesive tape is ultrasonic sonolucent at least within a region defined by an ultrasound beam path in front of a transmitting and receiving surface (113) of said ultrasound transducer (112). 7. The respiratory detection system according to 7.
(Item 9)
8. The respiratory detection system of item 7, wherein the adhesive layer of the third material body is ultrasonic sonolucent.
(Item 10)
According to item 7, said first accelerometer unit (121) and said first magnetic field unit (122) are located stationary within said first probe (102) by use of said first material. breathing detection system.
(Item 11)
Said second accelerometer unit (128) and said second magnetic field unit (129) are located stationary within said second probe (104) using a body of fourth material, item 7 The respiration detection system described.
(Item 12)
The front surface (132') of said body (132) of said fourth material has an adhesive property, an attachment surface for an adhesive member or double-sided adhesive tape, or an attachment surface for an adhesive layer of said body of fifth material. The respiration detection system according to item 11, comprising a mating surface.
(Item 13)
13. The respiratory detection system of item 12, wherein at least one of the first, second, third, fourth, and fifth materials is of silicone type.
(Item 14)
A first of the first magnetic field unit (122) and the second magnetic field unit (129) includes a magnetic field sensor device, and the first magnetic field unit (122) and the second magnetic field unit The other of (129) comprises an electromagnetic device configured to generate a magnetic field to be detected by said magnetic field sensor device, said magnetic field being connected to said first and second probes (102; 104). ).) The respiration detection system according to item 1.
(Item 15)
15. The respiratory detection system of item 14, wherein the signal processor (134) controls the strength, frequency, and duration of the generated magnetic field.
(Item 16)
The first probe (102) is positioned vertically above the second probe (104), which is positioned on the dorsal side (105) of the patient's body when the patient's body is in a supine position. The respiratory detection system according to item 1, configured to be placed on the front side (103) of the patient's body.
(Item 17)
The first probe (102) is configured to be placed on the front side (103) of the patient's body in a position aligned with the second probe (104) on the dorsal side (105) of the patient's body. The respiration detection system according to item 1.
(Item 18)
A respiratory detection system according to item 1, wherein the second accelerometer unit (128) provides a measurement of the tilt angle of a surface supporting the dorsal side (105) of the patient's body.
(Item 19)
15. The respiration detection system of item 14, wherein the magnetic field sensor device is a magnetic pickup coil.
(Item 20)
The surface (132'; 133) of the second probe (134) configured to contact the dorsal skin area of the patient's body comprises a biocompatible material; The respiration detection system according to item 1, wherein the skin contact area of the surface is within the range of 5 to 100 cm ² .
(Item 21)
Said signal processor (134) receives signals from said first and second accelerometer units (121; 128) and from said first magnetic field unit (122) interacting with said second magnetic field unit (129). Based on the input, the movement and orientation of the patient's abdominal wall is configured to calculate the movement and orientation of the patient's abdominal wall with respect to the expected direction of movement of internal structures (144) inside the patient's body; The respiratory detection system of item 1, which is associated with respiratory parameters associated with the respiratory muscles of.
(Item 22)
22. The respiratory detection system of item 21, wherein the internal structure is one of the patient's liver (144), spleen, or kidney.
(Item 23)
22. A respiratory detection system according to item 21, wherein the expected movement of the internal structure (144) is a function of diaphragm movement (145) within the patient's body.
(Item 24)
the ultrasound transducer (112) in the first probe (102) is configured to receive ultrasound echo signals from the internal structure;
said second magnetic field unit (129) is configured to generate a magnetic field that is transmitted to and detected by said first magnetic field unit (121);
The signal processor (134) includes:
an orientation of the first accelerometer unit (121) with respect to a fixed coordinate frame using derived parameters from the first accelerometer unit (121);
the derived parameter as a unit vector representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
Orienting the second accelerometer unit (128) relative to a fixed coordinate frame using further derived parameters from the second accelerometer unit (128);
said further derived parameters comprising a unit vector representing the body back (105) support tilt angle (α) and the spatial direction from said second magnetic field unit to said first magnetic field unit (122);
Orientation of the second magnetic field unit (129);
the expected direction of movement of said internal structure (144) during exhalation;
an arbitrary variation distance between the first and second magnetic field units (122; 129) based on the detection of the magnetic field;
Said signal processor (134) further comprises: from the calculated orientations of said first and second accelerometer units (121; 128), derived parameters from said first and second accelerometer units, and said variation distance. configured to process the results of and generate correction parameters to compensate for measurement errors in the received ultrasound echo signal;
Breath detection system according to item 1.
(Item 25)
In order to generate the correction parameters, the signal processor further:
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
differentiating the resolved vector representing the distance in time to yield an incremental motion value;
adding said incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from said internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
25. The respiratory detection system of item 24, configured to: sum the corrected and summed motion values to obtain an internal structure position variation that describes a corrected respiratory parameter.
(Item 26)
A respiration detection system, comprising:
A first probe (102),
an ultrasound transducer (112) stationary within said first probe and having a transmitting and receiving surface (113) oriented at an acute angle (Ω) with respect to a front surface (114) of said first probe (102); the ultrasound transducer (112) is configured to generate an ultrasound beam (143) at the transmitting/receiving surface (113) for transmission into an internal structure (144) inside a patient's body. an ultrasonic transducer (112) comprising;
a first accelerometer unit (121);
A first magnetic field unit (122), the ultrasonic transducer (112), the first accelerometer unit (121), and the first magnetic field unit (122) are connected to the first probe (102). a first probe (102) comprising a first magnetic field unit (122) stationary within );
a second probe (104),
a second accelerometer unit (128);
a second magnetic field unit (129), the second accelerometer unit (128) and the second magnetic field unit (129) being stationary within the second probe (104); a second magnetic field unit (129); a second probe (104);
the ultrasound transducer (112), the first and second accelerometer units (121; 128), and the first and second magnetic field units (122; 129) are coupled to a signal processor (134);
The first probe (102) is configured to be installed on the front side (103) of the patient's body,
The second probe (104) is configured to be installed on the dorsal side (105) of the patient's body,
Said signal processor (134) receives signals from said first and second accelerometer units (121; 128) and from said first magnetic field unit (122) interacting with said second magnetic field unit (129). Based on the input, the movement and orientation of the patient's abdominal wall is configured to be calculated with respect to an expected direction of movement of internal structures inside the patient's body, and the movement and orientation of the abdominal wall is configured to related to respiratory parameters associated with
Breathing detection system.
(Item 27)
27. The respiratory detection system of item 26, wherein the internal structure is one of the patient's liver (144), spleen, or kidney.
(Item 28)
27. The respiratory sensing system of item 26, wherein the expected movement of the internal structure is a function of diaphragm movement within the patient's body.
(Item 29)
the ultrasound transducer (112) in the first probe (102) is configured to receive ultrasound echo signals from the internal structure;
said second magnetic field unit (129) is configured to generate a magnetic field that is transmitted to and detected by said first magnetic field unit (121);
The signal processor (134) includes:
an orientation of the first accelerometer unit (121) with respect to a fixed coordinate frame using derived parameters from the first accelerometer unit (121);
the derived parameter as a unit vector representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
Orienting the second accelerometer unit (128) relative to a fixed coordinate frame using further derived parameters from the second accelerometer unit (128);
said further derived parameters comprising a body back support tilt angle (α) and a unit vector representing the spatial direction from said second magnetic field unit (129) to said first magnetic field unit (122);
Orientation of the second magnetic field unit (129);
the expected direction of movement of said internal structure during exhalation;
an arbitrary variation distance between the first and second magnetic field units (122; 129) based on the detection of the magnetic field;
Said signal processor (134) further comprises: calculated orientations of said first and second accelerometer units (121; 128), derived parameters from said first and second accelerometer units (121; 128); and configured to process results from said varying distance and generate correction parameters to compensate for measurement errors in the received ultrasound echo signal.
The respiration detection system according to item 26.
(Item 30)
In order to generate the correction parameters, the signal processor further:
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
differentiating the resolved vector representing the distance in time to yield an incremental motion value;
adding said incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from said internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
30. The respiratory detection system of item 29, configured to: sum the corrected and summed motion values to obtain an internal structure position variation that describes a corrected respiratory parameter.
(Item 31)
The first probe (102) is placed on the patient's body and configured to direct an ultrasound beam toward internal structures inside the patient's body and receive ultrasound echo signals from the internal structures. consists of
The first probe (102) further includes a housing (110) with a cavity (111),
The ultrasonic transducer (112) is located within the cavity (111), and the transmitting/receiving surface (113) of the ultrasonic transducer (112) is located at the cavity opening of the cavity (111) of the housing (110). or adjacent thereto at an acute angle (Ω) to the front surface (114) of the housing;
The ultrasonic transducer (112) is fixedly located within the cavity (111) of the housing (110),
an open-ended socket-like member (120) of ultrasonic non-sonolucent material defines a recess extending from said transmitting and receiving surface (113) toward said front surface (114);
a first body portion (117) of ultrasound sonolucent material is located within the transmitting and receiving surface (113) of the ultrasound transducer (112) towards the front surface (114) and in the recess in front thereof;
the first accelerometer unit (121) and the first magnetic field detection unit (122) are connected to a printed circuit board (119) within the cavity (111) of the housing (110);
The front surface of said first probe (102) exhibits at least one of inherent adhesive properties, an attachment surface for an adhesive member or double-sided adhesive tape, or an engagement surface for an adhesive body layer. ,
the ultrasound transducer (112) is configured to connect to a transceiver section of the signal processor (134);
Breath detection system according to item 1.
(Item 32)
32. Breath detection system according to item 31, wherein the ultrasonic transducer (112) is mounted in the bottom region of the open-ended socket-like member (120), the material of which exhibits acoustic damping properties.
(Item 33)
32. A respiratory detection system according to item 31, wherein the ultrasound transducer (112) and the open-ended socket-like member (120) extend from the printed circuit board (119).
(Item 34)
The front surface (114) of the body of the first probe (102) has adhesive surface properties and is provided with a protective cover (123), which protects the first probe on the skin of the patient's body. 32. A respiratory detection system according to item 31, which is removable prior to application of the probe (102).
(Item 35)
The adhesive member or the double-sided adhesive tape is attached to the front surface, and the adhesive member or the double-sided adhesive tape is attached to the front surface, and the adhesive member or the double-sided adhesive tape is attached to the front surface of the ultrasound transducer. 32. The respiratory detection system of item 31, which is Lucent.
(Item 36)
32. The respiration detection system of item 31, wherein the material type of the first body portion of the ultrasonic sonolucent material is a silicone type material.
(Item 37)
The respiration detection system according to item 31, wherein the acute angle (Ω) is within a range of 0 to 60 degrees.
(Item 38)
A method for motion compensation in ultrasound-based detection of human respiratory parameters, the method comprising:
attaching a first probe (102) to the anterior body surface (103) of said human, said first probe (102) comprising an ultrasound transducer (112) and a first accelerometer unit (121); ) and a first magnetic field unit (122);
attaching a second probe (104) to the dorsal body surface (105) of said human, said second probe (104) having a second accelerometer unit (122) and a second magnetic field; having a unit (129);
providing a signal processor (134) coupled to said ultrasound transducer (112), said first and second accelerometer units (121; 128), and said first and second magnetic field units (122; 129); to do and
transmitting an ultrasound beam from the ultrasound transducer (112) in the first probe (102) into an internal structure inside the human body;
receiving an ultrasound echo signal from the internal structure at the ultrasound transducer (112) in the first probe (102);
generating a magnetic field transmitted by said second magnetic field unit (129) to and detected by said first magnetic field unit (122);
using the signal processor (134) to calculate an orientation of the first accelerometer unit (121) with respect to a fixed coordinate frame using derived parameters from the first accelerometer unit (121); further calculating the derived parameters as unit vectors representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
The signal processor (134) is used to calculate the orientation of the second accelerometer unit (128) relative to a fixed coordinate frame using further derived parameters, including the body back support tilt angle (α) and the said further derived parameters comprising a unit vector representing the spatial direction from said second magnetic field unit (129) to said first magnetic field unit (122), the orientation of said second magnetic field unit (129), and the calculating an expected direction of movement of said internal structure (144);
using the signal processor (134) to calculate any varying distance between the first and second magnetic field units (122; 129) based on the detection of the magnetic field;
Using said signal processor (134), the calculated orientation of said first and second accelerometer units (121; 128) and the calculated orientation of said first and second accelerometer units (121; 128) further derived parameters and processing the results from said varying distances measured by said first and second magnetic field units (122; 129) to generate correction parameters caused by the movement of said ultrasound transducer (112); and compensating for measurement errors in a received ultrasound echo signal.
(Item 39)
Generating the correction parameters is
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
differentiating the resolved vector representing the distance in time to yield an incremental motion value;
adding said incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from said internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
39. The method of item 38, comprising summing the corrected and summed motion values to obtain an internal structure position variation that describes the corrected respiratory parameter.
(Item 40)
39. The method of item 38, wherein said internal structure is one of said human liver, spleen, or kidney.
(Item 41)
Said signal processor (134) receives signals from said first and second accelerometer units (121; 128) and from said first magnetic field unit (122) interacting with said second magnetic field unit (129). and configured to calculate, based on the input, a movement and orientation of an abdominal wall of the human with respect to an expected direction of movement of the internal structures, the movement and orientation of the abdominal wall being related to respiratory parameters associated with abdominal muscles of the human. The method described in item 38.
(Item 42)
39. The method of item 38, wherein the movement of the internal structure is a function of diaphragm movement within the human body.
(Item 43)
39. The method of item 38, wherein sustained variations in beam orientation, bed angle, and abdominal surface motion are utilized in the compensation.
(Item 44)
40. The method of item 39, wherein sustained variations in beam orientation, bed angle, and abdominal surface motion are utilized in the compensation.
(Item 45)
44. The method of item 43, wherein the compensation assumes that the abdominal surface of the person moves in a direction perpendicular (v _mm ) to the surface on which the person lies.
(Item 46)
45. The method of item 44, wherein said compensation assumes that said person's abdominal surface moves in a direction perpendicular to the surface on which said person lies (v _mm ).
(Item 47)
measuring tilt based on the direction of gravity using said first and second accelerometer units (121; 128); ) comprises a 3-axis accelerometer unit;
measuring the vertical movement of the first probe (102) using the first magnetic field unit (122) with the aid of a magnetic field emitted by the second magnetic field unit (129); 39. The method of item 38, further comprising: the measured tilt and the measured vertical motion are used to compensate for the measurement error.
(Item 48)
46. A method according to item 45, wherein said first and second accelerometer units (121; 128) comprise triaxial accelerometer units.
(Item 49)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 39. The method of item 38, further comprising measuring the tilt angle (α) of the surface.
(Item 50)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 48. The method of item 47, further comprising measuring the tilt angle (α) of the surface.
(Item 51)
A second accelerometer unit (128) of the second probe (104) is used to detect the bed on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 49. The method of item 48, further comprising measuring the tilt angle (α) of the surface.
(Item 52)
39. The method of item 38, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 53)
40. The method of item 39, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 54)
48. The method of item 47, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 55)
49. The method of item 48, further comprising calculating the angle for each movement increment instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value.
(Item 56)
53. The method of item 52, wherein the internal structure is one of the human liver, spleen, or kidney.
(Item 57)
54. The method of item 53, wherein said internal structure is one of said human liver, spleen, or kidney.

Claims (20)

A respiration detection system, comprising:
The respiration detection system includes a first probe (102) and a second probe (104),
The first probe (102) is
an ultrasound transducer (112), the ultrasound transducer (112) being stationary within the first probe and at an acute angle (114) with respect to the front surface (114) of the first probe (102); Ω), said ultrasound transducer (112) transmitting ultrasound waves at said transmitting and receiving surface (113) for transmission into internal structures inside the patient's body. an ultrasound transducer (112) configured to generate a beam (143);
a first accelerometer unit (121);
a first magnetic field unit (122) ;
Equipped with
the ultrasound transducer (112) and the first accelerometer unit (121) and the first magnetic field unit (122) are located stationary within the first probe (102);
The second probe (104) is
a second accelerometer unit (128);
A second magnetic field unit (129) and
Equipped with
the second accelerometer unit (128) and the second magnetic field unit (129) are stationary within the second probe (104);
The ultrasonic transducer (112) and the first accelerometer unit (121) and the second accelerometer unit (128) and the first magnetic field unit (122) and the second magnetic field unit (129) are , coupled to a signal processor (134);
The first probe (102) is configured to be installed on the front side (103) of the patient's body (101),
The second probe (104) is configured to be installed on the dorsal side (105) of the body (101),
A signal from said first accelerometer unit (121) is transmitted to a first space of said first probe (102) having said ultrasound transducer (112) and said first magnetic field unit (122) therein. indicates the orientation,
a signal from said second accelerometer unit (128) is indicative of a second spatial orientation of said second probe (104) having said second magnetic field unit (129) therein;
the first spatial orientation and the second spatial orientation are with respect to a fixed coordinate frame;
signals from said first magnetic field unit (122) interacting with said second magnetic field unit (129) and from said first accelerometer unit (121) and said second accelerometer unit (128); The orientation of the first magnetic field unit (122) and the second magnetic field unit (129) provided by the signals of a respiration detection system that is an input to the signal processor (134) for calculating a variable spatial distance, thereby calculating the spatial movement and orientation of the ultrasound transducer (112) induced by the patient's breathing; The ultrasonic transducer (112) uses a first body of material (115) comprising an ultrasonic non-sonolucent material extending towards the front surface (114) of the first probe (102) to located within the first probe (102);
the body (115) of the first material surrounds a recess (116) extending from the transmitting and receiving surface (113) towards the front surface (114);
A first body portion (117) of a second material comprising an ultrasonic sonolucent material connects the transmitting and receiving surface (113) of the ultrasonic transducer (112) towards the front surface (114) and the recess in front thereof. located within
A second body portion (117) of said second material is applied onto the front surface of said body of said first material and is integrally engaged therewith, said first body portion ( 117 ) 2. The respiratory detection system of claim 1 , wherein the two body portions are integral. The respiratory detection system of claim 1, wherein the ultrasonic transducer (112) is engaged within a socket-like member (120) forming a transducer recess (116) and is of an ultrasonic non-sonolucent material. . One of the first magnetic field unit (122) and the second magnetic field unit (129) comprises a magnetic field sensor device, and the first magnetic field unit (122) and the second magnetic field unit (129) The other one comprises an electromagnetic device configured to generate a magnetic field to be detected by the magnetic field sensor device, the magnetic field being connected to the first probe (102) and the second probe (104). ) The respiration detection system of claim 1 . The first probe (102) is placed on the front side (103) of the patient's body at a position aligned with the second probe (104) on the dorsal side (105) of the patient's body. The respiration detection system of claim 1, wherein the respiration detection system is configured . The respiratory detection system of claim 1, wherein the second accelerometer unit (128) provides a measurement of a tilt angle of a surface supporting the dorsal side (105) of the patient's body. The signal processor (134) receives inputs from the first accelerometer unit (121) and the second accelerometer unit (128) and the first magnetic field unit (129) that interacts with the second magnetic field unit (129). Based on input from a magnetic field unit (122), the ultrasonic wave in the first probe (102) is 10. The method of claim 1 , wherein the ultrasound transducer (112) is configured to calculate movement and orientation of an ultrasound transducer (112), the movement and orientation of the ultrasound transducer (112) being related to respiratory parameters associated with respiratory muscles of the patient. 1. The respiration detection system according to 1. the ultrasound transducer (112) in the first probe (102) is configured to receive ultrasound echo signals from the internal structure;
the second magnetic field unit (129) is configured to generate a magnetic field that is transmitted to and detected by the first magnetic field unit (121) ;
The signal processor (134) includes:
an orientation of the first accelerometer unit (121) with respect to the fixed coordinate frame using derived parameters from the first accelerometer unit (121);
the derived parameter as a unit vector representing the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122);
orienting the second accelerometer unit (128) with respect to the fixed coordinate frame using further derived parameters from the second accelerometer unit (128);
said further derived parameters comprising a unit vector representing the body back (105) support tilt angle (α) and the spatial direction from said second magnetic field unit to said first magnetic field unit (122);
an orientation of the second magnetic field unit (129);
an expected direction of movement of the internal structure (144) relative to a longitudinal axis of the patient's torso during exhalation of the patient;
an arbitrary varying distance between the first magnetic field unit (122) and the second magnetic field unit (129) based on the detection of the magnetic field ;
the orientation of the ultrasound beam and the orientation of the first magnetic field unit (122) and the orientation of the second magnetic field unit (129) are with respect to the fixed coordinate frame;
The signal processor (134 ) calculates the calculated orientation of the first accelerometer unit (121) and the second accelerometer unit (128) and the first accelerometer unit and the second accelerometer unit. generate correction parameters by processing the derived parameters from The respiratory detection system of claim 1 , further configured to compensate for measurement errors in the acoustic echo signal. In order to generate the correction parameters, the signal processor :
resolving a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
producing an incremental motion value by differentiating the resolved vector representing the distance in time;
adding the incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from the internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
9. The respiratory detection system of claim 8, further configured to: obtain internal structure position variations that describe a corrected respiratory parameter by summing the summed and corrected motion values. . The first probe (102) is arranged on the patient's body to direct an ultrasound beam towards internal structures inside the patient's body and to receive ultrasound echo signals from the internal structures. It is configured to be installed in
The first probe (102) further comprises a housing (110) with a cavity (111) ,
The ultrasonic transducer (112) is located within the cavity (111), and the transmitting and receiving surface (113) of the ultrasonic transducer (112) is located at the cavity opening of the cavity (111) of the housing (110). , or adjacent to the cavity mouth of the cavity (111) of the housing (110) and at an acute angle (Ω) with respect to the front face (114) of the housing;
Said ultrasonic transducer (112) is connected via an open-ended socket-like member (120) of ultrasonic non-sonolucent material providing a recess extending from said transmitting and receiving surface (113) towards said front surface (114). , fixedly located within the cavity (111) of the housing (110);
A first body portion (117) of ultrasonic sonolucent material is disposed within the transmitting and receiving surface (113) of the ultrasonic transducer (112) towards the front surface (114) and in the socket-like member (120) in front thereof. Position to,
the first accelerometer unit (121) and the first magnetic field detection unit (122) are connected to a printed circuit board (119) within the cavity (111) of the housing (110);
The front surface of the first probe (102) has at least one of the following: inherent adhesive properties, a mounting surface for an adhesive member or double-sided adhesive tape, or an engagement surface for an adhesive body layer. present,
The respiration detection system of claim 1, wherein the ultrasound transducer (112) is configured to connect to a transceiver section of the signal processor (134). A system for motion compensation in ultrasound-based detection of human respiratory parameters, the system comprising:
a first probe (102) configured to be attached to the anterior body surface (103) of the human, the first probe (102) comprising an ultrasound transducer (112) and a first a first probe (102) having an accelerometer unit (121) and a first magnetic field unit (122);
a second probe (104) configured to be attached to a dorsal body surface (105) of the human, the second probe (104) comprising a second accelerometer unit (122); , a second probe (104) having a second magnetic field unit (129);
the ultrasonic transducer (112) and the first accelerometer unit (121) and the second accelerometer unit (128) and the first magnetic field unit (122) and the second magnetic field unit (129); a signal processor (134) coupled ;
The ultrasound transducer (112) in the first probe (102) transmits an ultrasound beam into an internal structure (144) inside the human body and receives ultrasound echo signals from the internal structure. is configured to receive
the second magnetic field unit (129) is configured to generate a magnetic field that is transmitted to and detected by the first magnetic field unit (122) ;
The signal processor includes:
calculating the orientation of the first accelerometer unit (121) with respect to a fixed coordinate frame using derived parameters from the first accelerometer unit (121); further calculating said derived parameter as a unit vector representing the orientation of the magnetic field unit (122);
Calculating the orientation of said second accelerometer unit (128) with respect to a fixed coordinate frame using further derived parameters, the body back support tilt angle (α) and said second magnetic field unit (129) said further derived parameters comprising a unit vector representing the spatial direction up to one magnetic field unit (122) and the orientation of said second magnetic field unit (129) and of said internal structure with respect to the longitudinal axis of said human torso during exhalation. calculating the expected direction of motion;
calculating any variation distance between the first magnetic field unit (122) and the second magnetic field unit (129) based on the detection of the magnetic field;
a calculated orientation of the first accelerometer unit (121) and the second accelerometer unit (128) ; and the first accelerometer unit (121) and the second accelerometer unit (128). and the results from said varying distances measured by said first magnetic field unit (122) and said second magnetic field unit (129) to generate correction parameters and and compensating for measurement errors in received ultrasound echo signals caused by movement of the ultrasound transducer (112) in relation to activity . The signal processor includes:
decomposing a vector representing the distance between the first magnetic field unit (122) and the second magnetic field unit (129) along the direction of the ultrasound beam;
producing an incremental motion value by differentiating the resolved vector representing the distance in time;
adding the incremental motion value to an incremental Doppler effect motion value as detected by use of ultrasound echo signals from the internal structure within at least the same time interval;
correcting the summed motion value with respect to an instantaneous cosine value of the angle between the ultrasound beam and the direction of motion of the internal structure;
12. The method of claim 11, configured to generate a corrected parameter by summing the summed corrected motion values to obtain an internal structure position variation that describes a corrected respiratory parameter. system. The signal processor (134) receives inputs from the first accelerometer unit (121) and the second accelerometer unit (128) and the first magnetic field unit (129) that interacts with the second magnetic field unit (129). of the ultrasound transducer (112) in the first probe (102) with respect to the expected direction of movement of the internal structure (144) relative to the longitudinal axis of the human based on input from a magnetic field unit (122). 12. The system of claim 11, configured to calculate movement and orientation , wherein the orientation of the ultrasound transducer (112) is related to respiratory activity. 12. The system of claim 11, wherein the movement of the internal structure is a function of diaphragm movement within the human body. 13. The system of claim 11 or claim 12, wherein persistent variations in any one of beam orientation and bed angle and abdominal surface motion are utilized in the compensation. 16. The system of claim 15, wherein the compensation assumes that the abdominal surface of the person moves in a direction ( _vmm ) perpendicular to the surface on which the person lies. The first accelerometer unit (121) and the second accelerometer unit are configured to measure tilt based on the direction of gravity, and the first accelerometer unit (121) and the second accelerometer unit The accelerometer unit (128) includes a 3-axis accelerometer unit,
The first magnetic field unit is configured to measure the vertical movement of the first probe (102) with the aid of a magnetic field emitted by the second magnetic field unit (129); 12. The system of claim 11 , wherein measured tilt and measured vertical motion are used to compensate for the measurement error. The second accelerometer unit (128) of the second probe (104) is configured to move along the bed surface on which the person lies, assuming that the internal structure moves along the same direction as the bed surface. 18. A system according to claim 11 or claim 17, configured to measure a tilt angle (α). 4. The signal processor is configured to calculate the angle for each movement increment, instead of assuming that the angle between the ultrasound beam and the direction of movement of the internal structure has a steady-state value. 18. The system according to claim 11 or claim 17. 20. The system of claim 19, wherein the internal structure is one of the human's liver, spleen, or kidney.

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