WO1985000278A1

WO1985000278A1 - Sphygmomanometer

Info

Publication number: WO1985000278A1
Application number: PCT/AT1984/000024
Authority: WO
Inventors: Falko Skrabal
Original assignee: Falko Skrabal
Priority date: 1983-07-01
Filing date: 1984-06-27
Publication date: 1985-01-31
Also published as: AU3068984A; EP0148221A1

Abstract

Sphygmomanometer comprising at least one device (8) filled with a liquid and arranged against a body artery (3), device enabling to continuously record by means of an inertia-free manometer (13) the arterial blood pressure communicated to the liquid, thereby enabling to continuously vary the pressure by means of a pressure regulating apparatus (14) and wherein at least one recording apparatus, such as an acoustic sensing apparatus (10) or an ultrasonic transceiver (11), is arranged in such a way that the signals from the artery reach, through the liquid, the recorder and wherein a volume detector (31) is further provided and is capable of recording the volume variations within said device, which variations are continuously fed to the device from the artery and which is capable of an inertia-free response with respect to those variations through a mechanism.

Description

Sphygmomanometer

The invention relates to a device for measuring blood pressure, consisting of at least one pressure transducer filled with fluid lying above an artery, with a pressure line to a pressure measuring device with a connected computer and display or registration.

For many years, an inflatable cuff, mostly on the upper arm, has mainly been used for blood pressure measurement, and just below this is usually the Korotkoff noise with a stetoscope, or more rarely with an ultrasound probe with sound transmitter and sound receiver, which was caused by the Doppler effect Frequency or phase shift measured between the transmitted and reflected sound. These devices have the disadvantages that the pressure in the cuff must be increased again and again above the value of the systolic blood pressure, and thus the blood supply to the extremity is interrupted, furthermore that it is impossible to continuously record the individual pressure values of each individual pulse beat, and that the pressure values are influenced by the position of the extremity relative to the heart. These drawbacks will be Although partially improved by other inventions (e.g. AT-PS 350170, US-PS 4030484, US-PS 4206764, DE-OS 3037684-35, US-PS 4202348), there is currently no device that is reliable, both systolic and diastolic blood pressure can be continuously measured precisely with every pulse and at which the blood flow to the extremity is maintained. So devices have been described (US-PS 3903873, US-PS 4030484, US-PS 4320767, EP-AI 41696), in which a mechanical pressure transducer lies over an artery, or devices in which the pressure waves are transmitted to the pressure transducer via liquid are (US-PS 4206764, DE-OS 2910302, EP-AI 41222, US-PS 41542-31) or devices in which the pressure waves are transmitted to the pressure transducer via air (US-PS 4127114, US-PS 4307728), however None of these devices succeed in adequately calibrating the recording of the pressure fluctuations in the absolute height. An attempt has also been made to achieve this calibration by increasing the pressure until the pressure waves caused by the pulse disappear in the pressure measuring device (DT-OS 3037686, US-PS 4271843, EP-AI 41696, EP-AI 41222), however experience has shown that it is unreliable to rely solely on pressure waves, since such pressure waves can also arise from movement artifacts.

Devices have therefore also been described (US Pat. No. 4,127,114) in which an air-filled pressure chamber with a deformable outer membrane is applied by hand to an artery, the internal pressure in the pressure chamber first being increased by increasing the manual contact pressure on the body, and then the air can slowly escape through an opening, with an ultrasound transmitter and receiver mounted in the lum-filled pressure chamber, registering the change in Doppler signals and registering systolic and diastolic pressure once. You then have to wait until the air-filled chamber slowly returns to its original shape, by one to be able to carry out the next measurement. This device is therefore not suitable for continuous pressure recording of each individual pulse, it works in principle like a conventional blood pressure monitor, in which the pressure is increased above the systolic value and then slowly released, and then when the pressure is released, the Doppler signal of an individual Display heartbeat as a systolic value and a single heartbeat as a diastolic pressure. In addition, the air is suitable, and only with this does the device work, only as a poor medium for the transmission of the Doppler signal. In practice, the device cannot work either because the deformable membrane, after being applied to the body, also absorbs part of the arterial pressure and, due to the possible deformation, cannot pass it on to the pressure transducer, so that the pressure transducer only part of the pressure and therefore not the real values registered. A cardiac diagnosis system has also been described (US Pat. No. 4,154,231) which is intended to receive a series of signals such as EKG, sound, Doppler signals and pulse waves from the heart and to process them via a computer by attaching the device between the ribs on the chest , wherein liquid is used as the transmission medium for the energy signals. It is quite obvious that this device is not intended or suitable for measuring blood pressure, because although pulse waves can be registered by the contraction of the heart, the device cannot be calibrated because the pressure in this device cannot be changed. Rather, this device is only suitable for diagnosing cardiac diseases by observing cardiac electrics, cardiac muscle mechanics and heart valve movements.

The invention aims to avoid the difficulties described by creating a new pressure transducer for the registration of several signals for the exact determination of the blood pressure. The blood pressure monitor according to the invention is characterized in that at least one, but advantageously several liquid-filled devices with pressure-resistant outer wall and easily deformable inner wall are attached to the body over an artery in such a way that the pressure-resistant outer wall lies in a stable position with respect to the body in such a way that said easily deformable inner wall comes to lie over an artery, at least one pressure-resistant, liquid-filled line leading from said device to an inertia-free pressure measuring device and to a pressure control device, which are best placed in the opposite side of the heart, with an additional rigid connection with the pressure-resistant outer wall of said device at least one recording device, such as a transmitter and receiver of energy sources, such as an ultrasound transmitter and ultrasound receiver or to a transmitter and receiver of laser beams or a device for recording sound waves, such as a microphone, so a What is required is that the signal coming from the artery can be recorded, the liquid in said device serving as a conductive medium for conveying the signal, and for the registration of liquid shifts in said device, as caused by the changes in the blood filling in said artery are, in addition, a volume sensor, such as a deformable membrane or a piston, is available, which not only absorb the volume shifts in the liquid caused by the artery in the device described, but can counteract this without inertia by changing the position of said volume sensor as far as possible This change in position of the volume sensor is reversed without inertia by a mechanism such as a hydraulic, pneumatic, electrical, magnetic or mechanical countermeasure, so that the result is that the pressure in said device is always exactly the pressure in the corresponds to the underlying artery and thus the artery wall can remain completely relaxed even during the constant changes in blood pressure, with processing and registration of all incoming signals for the control of the recording Pumping and for the calculation of blood pressure an electronic calculator is available.

The progress achieved with the blood pressure measuring device according to the invention can be seen in the fact that, on the one hand, by measuring the pressure fluctuations in said device, the pressure fluctuations of each individual pulse beat, which are constantly communicated by the underlying artery, can be registered without the artery being increased by an excessive increase in the Pressure in said device must be depressed, on the other hand, by intermittent pressure increase or decrease above the level of the systolic or below the diastolic pressure, the changing signal, such as a change in the amplitude of the pressure waves, or a change in the signals, such as the sound waves or the The ultrasound reflected from the artery, which is recorded by the at least one recording device attached to the pressure-resistant outer wall, can be used to determine the exact absolute level of the systolic and diastolic blood pressure l The pulse waves of the artery are continuously recorded by the volume sensor in said device and a force directed against these pulse waves is generated by a mechanism controlled by the volume sensor, so that a complete relaxation of the artery wall is continuously achieved during the pressure measurement by the synchronous counter pressure In this respect, a remarkable combination effect is achieved, which goes far beyond the sum of the individual effects and therefore does not constitute an aggregation, as the same simple device, not only because of its design, enables ideal pressure absorption, since on the one hand the device rests on the body with its edge and pressure waves can only communicate to the pressure transducer only via the slack membrane and the fluid without loss (one of the differences from US 4127114), the pressure transducer being additionally located in the area of the heart, so that absolutely correct pressure values are always registered regardless of the position of the device described, and since, on the other hand, increasing the pressure in said device in the vicinity of the intra-arterial pressure results in relaxation of the arterial wall. This is an essential prerequisite for a pressure measurement than in Persistence of the arterial wall tension absorbs some of the arterial pressure (e.g., in contrast to U.S. Patent No. 4,154,321 or U.S. Patent No. 4,127,114). Compared to the known devices, the greatest benefit and combi nation effect is that the simultaneous formation of the described device 1) for measuring the pressure 2) for arbitrarily changing the pressure as well as 3) for absorbing energy sources from the artery (sound waves and / or reflected ultrasound waves) at the same point and because of the same liquid medium an ideal signal transmission is possible in the first place. So the liquid medium is not only much better for transmission than air (e.g. US-PS 4202348 or US-PS 4127114), by generating the back pressure to the arterial pressure, the membrane also adapts ideally to the body surface, so that a liquid-filled cushion between pressure transducers and body surface (in contrast to EP-AI 41696) or between sound transducer and / or ultrasound transducer and body surface (eg in contrast to US-PS 4202348 and US-PS 4127114) always represents an ideal connection to the body surface, which simultaneously ensures optimal absorption of pressure waves, Sound waves and Utral sound waves allows. Another combination effect that goes beyond the sum of the individual effects results from the fact that exactly at the point at which the flow in the artery is measured by sound transmission or ultrasound Doppler effect, the same flow can be changed by increasing the pressure in the device, whereby by the increase in the pressure in the device does not worsen the transmission of the sound and ultrasound signals, but is additionally improved since the contact between the device and the body surface is intensified; this not only eliminates the need for additional transmission media, such as those in From von Schall transmitting pastes in US-PS 4154231 are recommended, the change in flow rate by changing the pressure in said device also takes place exactly at the point at which the change in flow rate is measured; This is a significant advantage over the devices in which pressure fluctuations but no sound or ultrasound signals are registered (for example DE-OS 241302, EP-AI 41696, EP-AI 41222) or over devices in which sound or ultrasound signals are registered (eg US-PS 4202348, US-PS 4154231) but at this point it is not possible to change the pressure in said device in order to change the sound or ultrasound signal there. In practice it is almost worthless to register any relative pressure fluctuations (such as according to US Pat. No. 4,154,231) if there is no possibility of absolutely calibrating them in any way. In the device described here there are, for example, at least three possibilities for an absolute calibration of the device: 1) A targeted pressure increase in said device via the level of the arterial pressure, this time being indicated, for example, by the fact that the artery suddenly collapses under said device, which manifested by a constant supply of liquid in said device in a kink in the continuous pressure curve because suddenly a larger volume of liquid would have to be pumped into said device in order to further increase the pressure, the larger amount of the pumped volume at the time of the collapse the artery can be used as a calibration feature. Such a calibration option is not available, for example, in US Pat. No. 4,142,031, nor US Pat. No. 4,127,114, DE-OS 2910,302, EP 41696, US Pat. No. 4307728 nor in US Pat. No. 4,232,348. 2) A change in the flow characteristic in said artery, which is simple and continuous by the ultrasonic signals are determined, strictly dependent on the controlled change in pressure in said device, which goes beyond arterial systolic blood pressure up to the disappearance of the blood flow when the pressure in said device increases, so that there is a further, very reliable possibility of calibrating the absolute pressures Calibration is, for example, neither in US-PS 4307728, EP 41222, EP 41696, DE-OS 2910302, US-PS 4154231, nor US-PS 4202348, US-PS 4271843, US-PS 4030484, US-PS4206764, US-PS 9009709 , DE-OS 3037685 or US-PS 4074711 given. 3) A change in the sound waves emanating from said artery when external pressure is exerted on the artery. Such a calibration possibility is, for example, neither in US-PS 4154231, DE-OS 2910302, EP 41696, EP 41222, US-PS 4127114 or US-PS 4307728, US-PS 4271843, US-PS 4030484, US-PS 4206764, US -PS 4009709, DE-PS 3037686 and US-PS 4074111 given.

The blood pressure measuring device according to the invention is preferably attached above an artery which is not solely responsible for the blood supply to the extremity, so that the blood supply in the underlying artery, but not in the extremity, is interrupted by intermittent pressure increase via the level of the systolic blood pressure. A further advantage is brought about by the preferred attachment of the inertia-free pressure measuring device in the area of the heart, whereby pressure values that are always measured absolutely correctly are guaranteed, regardless of the position of the extremity.

Depending on the embodiment, up to three different signals are available in the device according to the invention in order to determine the absolute level of the blood pressure: 1) A change in the amplitude of the pressure fluctuations in said device with a change in the absolute pressure in said liquid-filled device. 2) A change in the quality of the sound waves with increasing the pressure above the systolic blood pressure and lowering the pressure in the device under the diastolic blood pressure and 3) a phase or frequency shift of the ultrasound reflected from the artery upon increasing and decreasing the pressure in said device. It makes sense to link the up to three different signals for determining the absolute value of the blood pressure in the computer in such a way that when the absolute values determined approximately match, the mean value of the blood pressure values calculated from the up to three different signals is displayed and registered, or in the case of a large one Deviation of one signal from the other, for example, due to movement artifacts that can be used to display and register the remaining signals.

In addition, it may be necessary to register at the same time; of an EKG to determine whether the registered signals from said blood pressure meter coincide with the EKG in such a way that they are signals which are generated by the pulse wave and not by artifacts, otherwise the signals are suppressed and are not used to determine the blood pressure.

Another embodiment of the device described would consist in that two devices close to the body (closer to the heart) and distant from the body (further to the heart) with pressure-resistant outer and easily deformable inner wall come to lie over the same artery, in which case two pressure lines lead to two inertias Pressure gauges and lead to two pressure control devices, the additional registration devices, such as ultrasound transmitters and ultrasound receivers or microphones, being mounted in the device remote from the body, so that in the device close to the body, the pressure can be changed as desired above the level of the systolic or below the level of the diastolic pressure, in order to register the signals thereby changed in the device away from the body. The combination of two devices which lie one behind the other on the same artery is in no way a duplication of the device, it only makes a specific new one Effect possible: in the device close to the body, a targeted change in the flow velocity of the blood is achieved by changing the pressure, which can then be precisely evaluated in the device located directly behind it by the change in pressure waves, sound waves or ultrasound signals; So both the body-near and the body-far device must be equipped with an inertia-free pressure measuring and pressure control device in order to achieve independent and possibly opposing pressure changes in said device; however, the analyzers of sound waves and ultrasonic waves must be housed in the device away from the body in order to achieve a specific combination effect which goes beyond the sum of the individual effects.

A further embodiment could consist in that three described devices with an outer pressure-resistant wall and an inner, easily deformable wall come to lie one behind the other in a row over an artery, in which case three pressure lines would lead to inertia-free pressure measuring devices and inertia-free pressure control devices, in which case said registration devices, such as ultrasound transmitter and ultrasound receiver or microphone would come to rest in the middle of the three devices, in order to be able to change in the near-body and in the distant device, regardless of pressure above the systolic and below the diastolic pressure, in order to be able to change the to register changed signals. This can be advantageous if the artery receives arterial blood from another body through another artery. As model tests have shown, it may therefore additionally be necessary to install a further additional device with inertia-free pressure measuring and control device, even away from the device in which ultrasound and sound analyzers are accommodated, in order to prevent inadvertent occurrence from the body distant signals of the device which is equipped with sound and / or ultrasound analyzers, thereby announcing that in the distant body the said artery from another Artery receives blood. In this respect, this third device does not represent a duplication, but brings an additional specific effect. To differentiate it from other devices in which several pressure transducers are used (e.g. US-PS 4307728), it must be emphasized that in these the multiple pressure transducers are only suitable for receiving signals that do not come from the artery, but from surrounding tissues The devices described are also unsuitable for generating targeted pressure themselves.

For the function of this embodiment, it is not essential whether the outer pressure-resistant wall consists of a common or several separate pieces, as long as only the liquid-filled devices are separated from one another by intermediate walls, so that different pressures can be generated in the individual devices. Only the pressure-resistant outer and easily deformable inner wall of all devices appears to be essential, so that if the device is not as flexible as possible, the pressure can be changed significantly in the shortest possible time, which is absolutely necessary, and not only to avoid the individual volume fluctuations of the artery with every pulse beat to compensate, but also to increase the pressure in the device synchronously over the arterial pressure even during a single pulse beat and possibly only for the same duration, so that the change in the signals from the recording devices can be processed in the computer in the shortest possible time. In a simplifying manner, in the embodiment with the three devices described, the body-near and the body-far device could have a common pressure-resistant line to a common pressure measuring device and pressure control device separate from the middle device. It is obvious that the measuring device described is suitable in different complex versions for different purposes, for example in a small portable version for the permanent monitoring of living beings throughout the day or in more complex versions for stationary monitoring, or with the display of each one Blood pressure fluctuation of every single pulse beat for complex circulatory examinations.

The device according to the invention is described in more detail below with reference to FIGS. 1 to 5.

Fig. 1 shows a preferred embodiment of said blood pressure measuring device, consisting of a device with a pressure-resistant outer wall -1-, the cavity -8-. is attached above an artery -3-, the edge -2- of the exemplary embodiment being fixed by a double-adhesive film -4-, an additional, stretchable or non-stretchable band -5- around the extremity -7- is placed to hold the device in place when the pressure in the cavity -8-, which is delimited by the deformable membrane -9- from the extremity -7-, is held in place. In addition, at least one further device for generating a pressure, such as a bag filled with liquid or gas -6-, can be attached exactly visavis from said device -1- to said extremity, the sole purpose of which is to lift off said device - 1- to prevent from the body surface when the pressure in it is increased by synchromically generating a pressure in this device -6- which increases the tension of the band -5- when the pressure in the device -8- increases and reduces the tension of the belt -5- when the pressure in device -8- falls. This device -6- can be arranged so that an increase in pressure in devices 1 and 6 does not affect the blood flow through the veins -18-. This achieves a constant system pressure of the device -1- regardless of the internal pressure and the wearing comfort of the blood pressure monitor is greatly improved if the interval is not being measured. The device -6- could also have a pressure-resistant outer wall in order to accommodate the capacity of the device -6 To keep the pressure increase as small as possible. To register the contact pressure of the edge -2- of the pressure-resistant wall -1- on the body -7-, for example, 2 pressure transducers -21a- are attached to the edge -2- of the pressure-resistant wall -1-, via which the contact pressure of the device -1- can be regulated on the body -7-, for example by changing the pressure in device -6-. An additional pressure control unit -22

- to be available. In the exemplary embodiment of the sphygmomanometer, both a microphone -10- and an ultrasonic transmitter and receiver -11 are attached to the pressure-resistant wall - 1 so that the liquid contained in the cavity -8- as a conductive medium between the microphone -10- uride ultrasonic transmitter and receiver -11 on the one hand and artery -3- on the other. In the exemplary embodiment, a pressure-resistant line -12- leads from the cavity -8- to an inertia-free pressure measuring device -13- on the one hand and to an inertia-free pressure control device -14- on the other. This inertia-free pressure control device can be, for example, either in a controlled pump device with a controlled drain valve or in a container with compressed gas, a reducing valve with a subsequent control device and a controlled drain valve for the exact setting of the pressure, so that any pressure in the cavity -8- is inertia-free. Advantageously, in the exemplary embodiment, additional signals from the microphone -10- and ultrasound transmitter and receiver -11- can be transmitted via corresponding analyzers of Korotkoff's noise -16- or analyzers of the ultrasound advance -17- to the computer -15- who can process them in any desired form, so that the true systolic and diastolic blood pressure and its current fluctuations can be brought to the attention of the display and recorder -19 and are available for further processing by storage -20-. In addition, there is the possibility of the simultaneous registration of an EKG -22- that the artifact recognition of signals from the pressure measuring device -13- Korotkoff analyzer -16 and ultrasound analyzer -17- is made considerably easier. In the exemplary embodiment described, even when the pressure in the cavity is increased, the height of the systolic is -8-. Pressure of the blood flow in the extremities is not interrupted, since a further artery -21- is not compressed by increasing the pressure in the cavity -8-. Fig. 2 shows a further exemplary embodiment of said blood pressure measuring device in longitudinal section, wherein in the said device with pressure-resistant outer wall -1- a central cavity -8- contains the sound pickup -10 and ultrasound transmitter and receiver -11-, but additionally a further cavity -23 - Body-close to cavity -8- and in addition a further cavity -24- distant from cavity -8- is attached above the same artery -3, all of which are separated from the extremity -7- by a deformable membrane -9a-c. Both cavity -23- has a separate pressure line -25- to a pressure control device -26- and to a pressure measuring device -27-, and cavity -24- has a separate pressure line -28- to a pressure measuring device -29- and a pressure control device - 30- leads so that separate prints can be generated in all three cavities -8-, -23- and -24-, all signals arriving from the pressure chambers -8-, -23- and -24- being processed in the computer -15- This embodiment has the advantage that, by increasing the pressure in the liquid-filled cavity -24-, specific changes in the signals from the liquid-filled central cavity -8- are brought about, namely changes in the pressure fluctuations in the cavity -8- communicated by the artery -3- , which are registered in the pressure measuring device -13, or changes in the signals arriving at the microphone -10- and at the ultrasound receiver -11-. It is obvious that when using controllable valves which can interrupt the liquid flow in one of the pressure-resistant lines -12-, -24-, -29 -, - 32- and open in one of the other lines, the number of pressure control devices is saved could be reduced.

FIG. 3 shows a further exemplary embodiment of the blood pressure monitor, in which a further cavity -32 extends from the cavity -8-, which communicates with the pressure line -12, through a deformable membrane -31- is delimited, whereby the volume shifts in the cavity-8- caused by the blood waves in said artery -3 can be registered in that one or more strain gauges -33- are attached to said membrane -31-, the signal of which controls a pressure control device -34- that there is always so great a pressure in the cavity -32- that the membrane -31 is brought back to its starting position as inertia as possible. This ensures that the pressure in the artery -3- is always counteracted by an equally large counterpressure in the cavity -32- and in the cavity -8- and thus the artery wall remains relaxed. Instead of the membrane, for example, an easily movable, sealing piston, the movement of which is registered, for example, by a barrier of energy waves, could be used. The cavity -32- can be filled with liquid or gas, whereby liquids offer advantages because of the lack of compressibility.

4 shows a further exemplary embodiment of the blood pressure measuring device, in which, in addition to sound transducer -10- and ultrasound transmitter and receiver -11-, also the volume transducer in the form of a deformable membrane -31- directly in the wall of the device with pressure-resistant outer wall -1- is installed in such a way that deformations of the membrane (drawn as -31a and -31 b-) immediately bring about a pressure adjustment in the cavity -32-, so that the membrane -31- returns to its original position.

Fig. 5 shows an example of a way to determine the absolute level of the systolic blood pressure with the help of the described blood pressure measuring device. When the pressure in the body-near device -23- increases above the systolic blood pressure, the blood flow in the artery -3- under the device -8- Bei steady release of pressure -39- in device -23-, below the level of systolic blood pressure initially the amplitude of blood flow -33- to -36- increases approximately linearly with the falling pressure in device -23- if by the linear part of the increase the blood flow If a linear function -37- is set in amplitude, the absolute level of the systolic blood pressure can be determined by the pressure prevailing in device -23- at the time at which the linear function crosses the zero line of the blood flow -38-. This calculation of the systolic blood pressure has the advantage that the rate of change of the pressure in device -23- can be significantly higher than if the level of systolic blood pressure only from the pressure in device -23- at the time the first blood flow appeared in the device -8- is determined. Instead of the linear function, an optimized mathematical function (for example a logarithmic-exponential - or power function) could also be put through the blood flow amplitudes -33- to -36- if the amplitude change does not correspond to a linear function. In the same way, the function -37 given by the changing amplitude summit -33- to -36- could also be obtained during a pressure increase in device -23-, or also by pressure changes in device -8-,

If the function obtained -37- does not represent a linear regression, another mathematical function could also be used with a mathematical optimization method, e.g. a logarithmic, exponential or power function can be used.

The evaluation method described has the advantage that the pressure change in device -8- or / and -23- could take place much more quickly than in conventional blood pressure measurements, than one does not look closely at the appearance or complete disappearance of blood flow from a single heartbeat is instructed how this is necessary in the blood pressure monitors described so far. In addition, the method described has the

Advantage that the pressure in the device -8- and / or -23- does not have to be changed above the systolic or below the diastolic blood pressure, so one

Function -37-. Other criteria, such as the speeds of the

Modulation of blood flow with changing pressure in device -8- and / or -23 could be used with a function, for example to determine the diastolic pressure. 6 shows a further exemplary embodiment of the blood pressure monitor in which the edge -2- of the pressure-resistant wall -1- consists at least partially of a deformable membrane - 40 - which bears against the body - 7 - and a further liquid or gas-filled cavity - 41 - in connection with the pressure-resistant wall - 1 -, which at least partially surrounds the liquid-filled cavity - 8, but is separated from the cavity - 8 - but by the pressure-resistant wall - 1. This embodiment, for example, has the advantage that the device with pressure-resistant wall - 1 - the body - 7 - regardless of its individually varying shape, always fits ideally if adequate filling of the cavity - 40 - is taken care of with liquid or gas. For example, a viscous liquid could also be suitable for filling the cavity. In addition, by fitting the cavity - 40- with a pressure transducer -22a- the application pressure of the device with a pressure-resistant wall - 1 - to the body - 7 - can be observed or regulated. In the exemplary embodiment, this is accomplished in that the device for increasing the contact pressure - 6 - is attached to the side of the pressure-resistant wall - 1 - facing away from the liquid-filled cavity - 8 - so that when the pressure in device - 6 is increased by mediation of the the body - 7 - placed tape -5 - the application pressure of the device with pressure-resistant wall - 1 - to the body - 7 - is increased. Instead of the tape - 5 - a rigid device could also be attached to the body - 7 - for example.

The example embodiment has the further advantage that the device for increasing the contact pressure - 6 - the sound pickup -10 - and the ultrasound pickup - 11 - are particularly well shielded against interference from the environment, and the pressure-resistant. Wall - 1 - could be made of sound-insulating, pressure-resistant but deformable material. It is obvious that, for example, for simplification, the pressure control device 22b for regulating the pressure in device 6 could also be controlled by the pressure measuring device 13. The area ratio of the membrane - 9 - to the pressure-exerting surface of the device - 6 - for determining the optimal contact pressure of the device - 1 - on the body could also be used. For the detection of the changes in the application pressure of the device - 1 - to the body - 7 - caused by body movements, however, a pressure transducer - 22a - provided for this purpose is particularly advantageous. It is also obvious that the recording of the ultrasound signals by the ultrasound transducer - 11 - could be improved, that more than one ultrasound transducer -11 - is available, so that even with small displacements of the device with pressure-resistant wall -1- on the body -7- through whose movements a constant ultrasound signal is nevertheless guaranteed.

Fig. 7 shows an example view of the device with pressure-resistant

Wall -1 - from the side of the cavity - 8 -, the membrane -9- delimiting the cavity -8 - being drawn in transparently, so that the position of the sound receiver - 10 - and the ultrasonic transmitter and receiver -11- can see back there, and wherein the deformable membrane - 40 - the membrane -9 - encloses, for example, on all sides. This makes it more uniform on all sides

System pressure of the device with pressure-resistant wall -1 - reached on the body.

The in Fig. 1 to 7 explained in more detail at game sweian embodiments of the blood pressure monitor are not only suitable for continuously recording the blood pressure, but the continuous recording and registration could also give the possibility of additionally measuring the blood pressure by non-pharmacological measures such as eg, through biofeedback or through pharmacological measures, such as by using computer -15- controlled infusion pumps with antihypertensive or antihypertensive medication to the desired level.

Claims

Claims:

1. blood pressure measuring device, consisting of at least one liquid-filled device (8) with pressure-resistant outer wall (1) and easily deformable inner wall (9), which can be attached to the body via an artery (3) in such a way that the pressure-resistant outer wall (1 ) is in a stable position relative to the artery (3), the artery pressure being measured by a pressure measuring device (13) acted upon by the liquid in the cavity (8), characterized in that at least one pressure-resistant line (12) from the liquid-filled device (8 ) to the inertia-free pressure measuring device (13) and to an inertia-free pressure control device (14) that at least one acoustic device, such as a sound recording device (10) or at least one transmitter and receiver of energy waves such as an ultrasound transmitter and receiver (11) or such as a laser transmitter and receiver. inside the device (8) in rigid connection with the pressure-resistant outer wall (1), and that a computing device (15) is connected to all devices for calculating the exact blood pressure values.

2. Sphygmomanometer according to claim -1-, characterized in that at the edge (2) of the pressure-resistant wall (1) at least one, but better several pressure sensors (22a) are attached, through which the contact pressure of the device (1) on the body (7 ) can be measured and regulated.

3. Blood pressure monitor according to claim - 1 -, characterized in that the device (1) is attached to the body in such a way that by at least one further device (6) in which the pressure can be changed, regardless of the pressure in the cavity (8) the contact pressure of the device (1) on the body can be regulated.

4. Blood pressure monitor according to claim -1-, characterized in that the liquid-filled device (8) is additionally equipped with a volume sensor (31) or communicates through a pressure-resistant line, the

Change in position sets a mechanism in motion that returns the volume sensor to its initial position as inertially as possible by counteracting the fluid movement exerted by the artery (3).

5. Blood pressure meter according to claim 1-, characterized in that the edge (2) of the pressure-resistant wall (1), which rests on the body (7), at least partially consists of a deformable membrane (40) which is at least one liquid or seals gas-filled cavity (41) which at least partially surrounds the liquid-filled cavity (8), but is separated from the cavity (8) by the pressure-resistant wall (1).

6. Blood pressure meter according to claim -5 -, characterized in that the liquid or gas-filled cavity (41) is equipped with at least one pressure sensor (22 a).

7. Blood pressure meter according to claim -3 -, characterized in that the device for changing the contact pressure (6) on the liquid-filled cavity (8) facing away from the device with pressure-resistant wall (1) is attached so that when pressure increases in the device (6) the contact pressure of the device with pressure-resistant wall (1) on the body (7) is increased.

8. blood pressure monitor according to claim - 3 -. characterized in that the device for changing the contact pressure (6) is controlled by the pressure measuring device (13).

9. Blood pressure monitor according to claim 3, characterized in that the device for changing the contact pressure is controlled by the pressure sensor (22a).

10. Blood pressure monitor according to claim -4-, characterized in that the

Volume sensor (31) is a deformable membrane on which one or more strain gauges (33) register the volume shift.

11. Blood pressure monitor according to claim -1-, characterized in that at least one further device with a pressure-resistant outer wall (1) and easily deformable inner wall (9b) forms a further liquid-filled cavity (23) which connects to the first device (8), wherein at least one further pressure-resistant line (25) leads to a further pressure measuring device (27) and to a pressure control device (26).

12. Blood pressure monitor according to claim -1-, characterized in that in the device (8) and / or (23) the pressure is changed with a certain time constant so that the amplitude peak of the blood flow in the artery (3) below the cavity (8) change, the changing amplitude peaks (33-36) of the flow velocities of the blood in the artery (3) registered in the device (8) by the ultrasound sensor (11) of at least 2 to a maximum of 30 heartbeats having a linear function ( 37), the absolute level of systolic blood pressure being given by the level of pressure in device (8) and / or (23) at the time when the linear function (37) set by the blood flow amplitude peaks is theoretical Zero line of blood flow cuts.

13. Blood pressure monitor according to claim -1-, characterized ,. that in the device (8) and / or (23) the pressure is changed with a certain time constant so that the amplitude peaks of the blood flow in the artery (3) under the cavity (8) change, with the peak in the device (8) an optimized mathematical function is placed by the ultrasound transducer (11) registered flow velocities of the blood in the artery (3) of at least 2 to a maximum of 30 heartbeats, the absolute level of the systolic blood pressure being determined by the level of the pressure in the device (8) and / or (23) is given at the point in time when the optimized function which is placed by the amplitude peaks intersects the theoretical zero line of the blood flow.

14. Blood pressure monitor according to claim -1-, characterized in that in the device (8) and / or (23) the pressure is changed with a time constant such that the speeds of the modulation of the blood flow in the artery (3) under the cavity (8) change, a linear or optimized mathematical function being placed by the speeds of the modulations of the blood flow in the artery (3) under the device (8) of the ultrasound transducer (11) of at least 2 to a maximum of 30 heartbeats, the absolute height of the diastolic blood pressure is given by the level of pressure in device (8) and / or (23) when the linear or optimized function, which is set by the speeds of the modulations of the blood flow, falls below a critical predetermined limit value of the speed modulation.

15. Blood pressure monitor according to claim -1-, characterized in that at the pre-calculated time of the amplitude peak of the blood flow, the pressure in the cavity (8) and / or (23) is changed in the short term only for the duration of the maximum blood flow of a single heartbeat to calculate the systolic blood pressure of the individual heartbeat from the change in blood flow during this time, or from the changes in the sound phenomena registered by the sound pickup (10).

16. Blood pressure monitor according to claim -1-, characterized in that at the pre-calculated time of the nadir of the blood flow, the pressure in the cavity (8) and / or (23) is changed briefly only for the duration of the nadir.