JP2003275206A - Ultrasonic examination apparatus having position detection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus using an optical fiber as an ultrasonic transmission passage, having an ultrasonic transmitter-receiver arranged to the outside thereof, constituted so as not only to rotationally drive an ultrasonic reflecting mirror at a sheath leading end part but also to detect the rotation of the ultrasonic reflecting mirror, equipped with a function for preventing the deterioration of an image due to rotation irregularity and having a compact structure. <P>SOLUTION: The ultrasonic diagnostic apparatus uses the optical fiber as the ultrasonic transmission passage and has the ultrasonic transmitter-receiver arranged outside in order to obtain extremely compact constitution. The ultrasonic reflecting mirror is directly rotated and driven at the sheath leading end part by a small-sized actuator. Further, the rotation of the ultrasonic reflecting mirror is detected by a position mark reading means in order to prevent the deterioration of an ultrasonic image due to rotation irregularity to be fed to the outside through the optical fiber. The optical fiber used as the ultrasonic transmission passage and the optical fiber for feeding a position mark detection signal are made common at least on the way of feed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ultrasonic diagnostic / ultrasonic flaw detector used in the fields of medical treatment and nondestructive inspection.

[0002]

2. Description of the Related Art There is an ultrasonic diagnostic apparatus as a non-invasive inspection method that does not destroy an observation inspection object, and is widely applied in the fields of medicine and the like. The ultrasonic diagnosis is not limited to the ultrasonic transmission / reception form from the outer surface of the body, and an ultrasonic diagnosis device of the ultrasonic transmission / reception form from inside the body by inserting a catheter is often used.
An ultrasonic diagnostic image is generally a two-dimensional tomographic image, but an ultrasonic diagnostic image of the ultrasonic wave transmission / reception form from inside the body is a radial ultrasonic wave when the ultrasonic wave transmission source is placed at a predetermined position in the body and rotated at that position. In general, a so-called radar system that radiates light and receives a reflected signal from the boundary surface to form an image. At this time, in order to obtain a clear image, it is necessary to accurately grasp the ultrasonic wave transmission / reception angle at each time point, that is, the rotational position, and perform imaging by the received signal.

Conventionally, this type of device uses an electromagnetic motor as a rotary drive source, but it is difficult to miniaturize the motor so that it can be mounted on a catheter. Eventually, the motor is installed outside the body and a flexible rod is used. The torque of the motor is transmitted to the ultrasonic transmitter / receiver. For this reason, not only the device becomes large, but also it is difficult to realize smooth rotation because it is driven by a remote motor, and it is difficult to obtain a clear image because the rotation unevenness becomes noise in the signal processing premised on constant speed rotation. Had a problem. In order to solve this problem, it is conceivable that a sensor for detecting the rotation state is separately provided and image processing is performed in correspondence with accurate rotation position information, but such a system is used because the catheter tip has a very small space. Is difficult to achieve.

As an apparatus for performing image processing while detecting the position of an ultrasonic transmitter / receiver in an ultrasonic diagnostic apparatus, Japanese Patent Application Laid-Open No. 2001-2001
-327504, there is a method disclosed in Japanese Patent Publication No. 327504 to grasp the forward / backward position in the axial direction in the method of obtaining a three-dimensional image by rotating and scanning the ultrasonic transmitter / receiver in the axial direction of the sheath. However, it is not intended to obtain a clear image by coping with the uneven rotation that is now a problem.

Further, recently, in the ultrasonic diagnostic apparatus for transmitting and receiving ultrasonic waves from the inside of the body by inserting the catheter, an optical fiber is used as an ultrasonic transmission path and the ultrasonic transmitter and receiver are installed outside the body, thereby reducing the size of the apparatus. The ones that have been adapted are also presented. In this case, an ultrasonic reflection mirror that is rotationally driven to rotate the emission direction of ultrasonic waves is required. The present applicant has previously proposed that the rod-shaped vibrating body in a rod-type ultrasonic motor having a vibrating body composed of a piezoelectric vibrator and an elastic body is provided with a radial projecting portion to support the vibrating body and the rotor. The pressurization mechanism between the body and the rotor and the conductive structure between the piezoelectric vibrator electrodes are simplified, and the motor is downsized. Then, a mechanism for rotating the mirror of the endoscope in the extremely small space at the tip of the catheter by using this small ultrasonic motor was presented, and a patent application (Japanese Patent Application No. 2001-345243) was made.

In this application example, as shown in FIG. 5, the ultrasonic motor 10 of the present invention is arranged in the distal end portion of the endoscope, and the mirror 8 is attached to the drive shaft 31. An optical fiber 9 is passed through the tube section of the endoscope, and the fiber 9 has a function of guiding light from a light source to illuminate the affected area and guiding an image of the affected area, which is imaged through the mirror 8, to the outside of the body. It has. The mirror 8 is rotationally driven by driving the small ultrasonic motor 10 of the invention, and the inner surface of the blood vessel and the inner surface of the intestine or organ can be observed 360 degrees.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic diagnostic apparatus in which an optical fiber is used as an ultrasonic wave transmission path and an ultrasonic wave transmitter / receiver is externally installed. An object of the present invention is to provide an ultrasonic diagnostic apparatus having a compact structure that is driven and detects the rotation of the ultrasonic reflection mirror, and has a function of preventing image deterioration due to uneven rotation.

[0008]

The ultrasonic diagnostic apparatus of the present invention has an extremely compact structure. Therefore, an optical fiber is used as an ultrasonic transmission path, and an ultrasonic transceiver is installed outside. The ultrasonic reflection mirror was directly driven to rotate at the tip of the sheath by a small ultrasonic motor. Further, in order to prevent the deterioration of the ultrasonic image due to the uneven rotation, the rotation of the ultrasonic reflection mirror is detected by the position mark reading means, and the function of conveying it to the outside through the optical fiber is provided.

Further, the optical fiber used as the ultrasonic wave conveying path and the optical fiber for conveying the position mark detection signal to the outside are made common at least during the conveyance, thereby achieving further downsizing.

Further, according to the present invention, in order to obtain accurate position information, an annular scale line around the ultrasonic axis is used as a position mark around the ultrasonic mirror to prevent interference between image information and position information. In order to avoid it, position marks should be provided on the back side of the ultrasonic mirror pedestal, or the ultrasonic mirror is a sub-mirror that is a material that transmits light and internally reflects light in a direction different from the ultrasonic radiation direction. I used the one with built-in.

[0011]

FIG. 1 shows the basic configuration of an ultrasonic diagnostic apparatus of the present invention. Reference numeral 1 is an elongated flexible sheath to be inserted into the body to be inspected, and a small ultrasonic motor 2 is provided at the tip thereof.
Is arranged, and the ultrasonic wave reflecting mirror 3 is rotationally driven together with the pedestal 4 by the ultrasonic wave motor 2. It should be noted that instead of the ultrasonic motor, another actuator, for example, an electromagnetic motor may be used. An optical fiber 5 for propagating ultrasonic transmission / reception signals in the elongated sheath 1.
, Extends from an ultrasonic transmitter / receiver arranged outside to a position facing the surface of the ultrasonic reflection mirror 3. According to the present invention, the ultrasonic transmitter / receiver is externally arranged as described above, and then the optical fiber 5 for propagating the ultrasonic transmitter / receiver signal is arranged in the sheath 1, and the ultrasonic reflection mirror 3 is arranged in the sheath 1. By adopting a configuration in which a small ultrasonic motor 2 is arranged and driven at the tip portion, the device is made compact.

In operation, an ultrasonic wave signal transmitted from an ultrasonic wave transmitter / receiver arranged outside is propagated through the optical fiber 5 and is emitted from the tip end portion to propagate in an appropriate liquid medium such as oil. It reaches the reflection surface of the ultrasonic reflection mirror 3. After being reflected by the reflecting surface, it further propagates in the liquid medium, passes through the sheath 1, and is emitted to the object to be inspected. The ultrasonic waves emitted to the subject are reflected back by the discontinuous medium portion in the subject. The reflected signal is received by the receiving portion of the ultrasonic transmitter / receiver disposed outside through the ultrasonic reflecting mirror 3 and the optical fiber 5, and the position of the discontinuous medium portion from the reflecting surface of the ultrasonic reflecting mirror 3 is received. Information indexed as image information.

The ultrasonic reflection mirror 3 is an ultrasonic motor 2
Since the ultrasonic wave emitted to the subject changes its direction sequentially, image information covering 360 degrees can be obtained, and a two-dimensional tomographic image can be obtained. Here, the optical axis emitted from the tip of the optical fiber 5 and directed to the ultrasonic reflection mirror 3 preferably coincides with the rotation axis of the ultrasonic reflection mirror 3. At this time, if the rotation of the ultrasonic reflection mirror 3 is uneven, an error occurs in the orientation of the ultrasonic reflection signals that are sequentially obtained, and the image becomes unclear. Therefore, the present invention constantly detects the rotational position of the ultrasonic reflection mirror 3 so that no error occurs in the orientation of the ultrasonic reflection signals sequentially obtained. In the present invention, the term “ultrasound diagnostic apparatus” does not necessarily mean that the subject is a living body such as a human body, but broadly means an ultrasound examination apparatus applicable to general nondestructive testing.

A first embodiment of the present invention is shown in 1) of FIG. In this example, the reflecting surface of the ultrasonic reflecting mirror 3 is formed in a concave shape so that the emitted ultrasonic waves do not diverge.
On the surface of the pedestal 4 of the ultrasonic wave reflection mirror 3, a pattern 6 for position detection is provided in a ring shape around the rotation axis. In this example, a radial scale line is written in the position detection pattern, but a similar pattern may be formed with slits. Then, an optical fiber 7 for detecting a rotational position having a tip portion is arranged at a position facing the position portion of the annular position detecting pattern 6.

Optical fiber 5 for transmitting ultrasonic transmission / reception signals
The arrangement is the same as the basic configuration of FIG. 1 described above, and the optical axis emitted from the tip end toward the ultrasonic reflection mirror 3 coincides with the rotation axis of the ultrasonic reflection mirror 3. The optical axis of the tip of the optical fiber 7 for detecting the rotational position is arranged to be parallel to this rotational axis. By adopting such a configuration, the rotational position of the ultrasonic reflection mirror 3, that is, the propagation azimuth of the ultrasonic waves emitted to the object to be inspected, is detected by the optical fiber for rotational position detection, which serves as an optical reading means. It can be detected by reading at the tip of 7. For example, if the scale line which is the position detection pattern is a black line written on the reflecting surface, the intensity of the reflected light from the pattern corresponds to the scale line. By correlating the successive positional information with the ultrasonic wave reception signal reflected and returned in the subject, the rotational position angle can be accurately captured and a clear image can be obtained.

FIG. 2B) shows a second embodiment of the present invention. In this example, a pattern 6 for position detection is annularly formed on the back surface of the pedestal 4 of the ultrasonic reflection mirror 3 around the rotation axis, and an optical fiber 7 for rotational position detection which is an optical reading means of the pattern for position detection. This is different from the previous embodiment in that the tip portion of (1) extends to the proximity position of the pattern for position detection on the back surface of the pedestal 4 of the ultrasonic reflection mirror 3. In the above example, the position of the tip end of the optical fiber 7 for detecting the rotational position is arranged so as to be apart from the pattern 6 for detecting the position so that the existence of the optical fiber 7 for detecting the rotational position does not hinder the transmission and reception of ultrasonic waves for diagnosis. In this example, it is necessary to extend the optical fiber 7 for detecting the rotational position to the back surface side of the pedestal 4, which means that the optical fiber 7 will pass the ultrasonic radiation region. On the other hand, there is a merit that the tip of the optical fiber 7 for detecting the rotational position can be brought to the proximity position of the pattern for position detection, and the accuracy of position detection can be improved.

As described above, although there are merits and demerits in this mode, it is necessary to secure the arrangement of various members within the limited space at the tip of the probe, and these are required when designing under given conditions. Will be an option. In addition, in the ultrasonic diagnostic apparatus of the present invention, a lead wire for driving the ultrasonic motor as shown in FIG. 5 is additionally required as a member that passes through the ultrasonic wave radiation region.

FIG. 3 shows a third embodiment of the present invention.
In this example, the structure is simplified by making the optical fiber 5 used as the ultrasonic wave conveying path and the optical fiber 7 for conveying the position mark detection signal to the outside at least during the conveyance. The one shown in 1) in the figure separates the optical fiber 5 serving as an ultrasonic wave carrier path from the outside, and the optical fiber 7 carrying the position mark detection signal,
The tip end facing the ultrasonic reflection mirror 3 has a common end.

The reflecting surface of the ultrasonic reflecting mirror 3 in this form must also be an optical mirror. The optical path is common with the ultrasonic wave path emitted from the fiber tip and reflected by the mirror surface, and if the sheath 1 is an opaque member, the position mark detection system optically detects the inner surface thereof. If the inner peripheral surface is provided with a position detection mark such as a scale, it is possible to detect the position detection mark to detect the rotational position of the ultrasonic reflection mirror 3. If the sheath 1 is a transparent member, the position mark detection system will optically detect the surface of the inspection object. In principle, if there is a pattern on the surface, it is possible to detect the rotation speed from the cycle and the rotation unevenness from the phase difference.

In the configuration shown in FIG. 2), the optical fiber 5 serving as an ultrasonic wave carrier path and the optical fiber 7 carrying a position mark detection signal are separated from each other on the outer side, and face the ultrasonic wave reflecting mirror 3. The tip portion is also branched to form a separate tip. The tip of the optical fiber 5 serving as the ultrasonic wave transport path is located at the center of rotation, and the orientation of the tip of the optical fiber 7 that carries the position mark detection signal is parallel to the rotation axis and the pedestal 4 on the extension thereof. An annular scale as the position detection mark 6 is drawn on the surface of the.

The reflecting surface of the ultrasonic reflecting mirror 3 in this form need not be an optical mirror. The optical fiber 5 used as the ultrasonic wave conveying path and the optical fiber 7 for conveying the position mark detection signal to the outside are made common during the conveyance, and the operation is similar to that of the example shown in 1) of FIG. It is the same. In this embodiment, as shown in 2) of FIG. 2, a pattern 6 for position detection is provided in an annular shape on the back surface of the pedestal 4 of the ultrasonic reflection mirror 3 around the rotation axis, and the pattern for position detection is optically read. A modification is possible in which the tip portion of the optical fiber 7 for detecting the rotational position, which is the means, extends to the proximity position of the pattern for position detection on the back surface of the base 4 of the ultrasonic reflection mirror 3.

FIG. 4 shows a fourth embodiment of the present invention.
This embodiment example is characterized in that the ultrasonic mirror used is made of a material that transmits light, and a sub-mirror that reflects light in a direction different from the ultrasonic radiation direction is incorporated therein. That is, the optical axis of the tip of the optical fiber for the ultrasonic carrier path and the carrier path for the position mark detection signal also coincides with the rotation axis, and the ultrasonic waves emitted from the tip end are reflected by the ultrasonic wave. Although it is reflected by the mirror surface of the mirror 3, this mirror surface is not a reflecting surface because it is optically transparent. Therefore, the ultrasonic path and the optical path are separated by this mirror surface.

In the embodiment shown by 2) in the drawing, the scale as the position detection mark 6 is drawn on the inner wall surface of the sheath 1 over 360 degrees. The scale 6 is reflected on the mirror surface of the sub-mirror, reflected upward in the figure, transmitted through the mirror surface of the ultrasonic reflection mirror 3, incident on the tip of the optical fiber, and read as position information by an optical member arranged outside. To be If the sheath 1 is a transparent member, the position mark detection system can optically detect the surface of the object to be inspected even in the configuration shown in 1) in which the position detection mark 6 is not provided on the inner wall surface of the sheath 1. If there is a pattern on the surface, the rotation position can be detected by detecting the rotation speed from the cycle and the rotation unevenness from the phase difference.

Further, if the rotation speed is detected and the drive circuit is controlled by the control circuit, the rotation speed can be kept constant. Therefore, even if the number of markings is small and fine city detection cannot be performed, the image at a specific time The image for each position can be obtained from.

[0025]

The ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus in which an optical fiber is used as an ultrasonic carrier and an ultrasonic transmitter / receiver is installed outside, and an ultrasonic reflection mirror is provided at the tip of the sheath. Since the rotary actuator is directly driven to rotate and the rotation of the ultrasonic reflection mirror is detected by the position mark reading means, it is structurally extremely compact, the rotational drive is stable, and even if uneven rotation occurs, Since the position can be detected, a clear image can be obtained.

Further, if an ultrasonic motor is used as a drive motor, it is suitable for inspection of an object which is disliked by the electromagnetic field because it is compact and can produce a large output, and unlike an electromagnetic motor, it does not generate an electromagnetic field. In the present invention, the number of parts can be reduced and the structure can be further simplified by making the optical fiber used as the ultrasonic wave carrier path and the optical fiber that carries the position mark detection signal to the outside common at least during the carrying. .

In the present invention, a position detection mark such as a graduation line or a slit formed in an annular shape around the rotation axis around the ultrasonic mirror is used, or the position mark is provided on the back side of the ultrasonic mirror pedestal. By doing so, the position detection accuracy can be increased and a clear image can be obtained.

In the present invention, a material that transmits light is used as the ultrasonic mirror, and a sub-mirror that reflects light in a direction different from the ultrasonic radiation direction is incorporated therein. The structure can be simplified because there is no need to separate the operating fiber and the position detecting fiber. Further, since the present invention can adopt various embodiments, it is easy to design according to conditions in a limited narrow space at the distal end of the sheath, which is advantageous in terms of production cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an ultrasonic diagnostic apparatus according to the present invention.

2) FIG. 2) is a diagram showing a first embodiment of the present invention, and 2) is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating a prior art in which an ultrasonic motor is mounted to drive a rotating mirror at the tip of an endoscope.

[Explanation of symbols]

1 sheath 2 Ultrasonic motor 3 Ultrasonic reflection mirror 4 pedestals 5 Ultrasonic carrier fiber 6 Position detection mark 7 Position detection fiber 8 Deputy mirror

Continued front page    (72) Inventor, Watanabe Saint             1-8 Nakase, Nakase, Mihama-ku, Chiba City, Chiba Prefecture             Ceremony Company SII RDI Center             Within F-term (reference) 2G047 BA03 CA01 DB05 EA10 EA14                       GA19 GB26                 4C301 AA02 BB03 BB27 EE11 EE15                       GA06 GA12 GB31 GD01                 4C601 BB05 BB09 BB10 BB24 EE09                       EE12 GA01 GA06 GA11 GA12                       GA17 GA21 GB37

Claims (5)

[Claims] 1. An optical fiber is used as an ultrasonic carrier,
In an ultrasonic diagnostic apparatus in which an ultrasonic transmitter / receiver is installed outside, the ultrasonic reflecting mirror is directly driven to rotate by a small actuator at the sheath distal end, and the rotation of the ultrasonic reflecting mirror is detected by a position mark reading means, An ultrasonic diagnostic apparatus having a function of transferring the material to the outside via a fiber. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the optical fiber used as the ultrasonic wave conveying path and the optical fiber for conveying the position mark detection signal to the outside are common at least during the conveyance. 3. The ultrasonic diagnostic apparatus according to claim 1, wherein the position mark is a scale line formed around the ultrasonic mirror in an annular shape centering on the rotation axis. 4. The ultrasonic diagnostic apparatus according to claim 3, wherein the position mark is provided on the back surface side of the ultrasonic mirror pedestal. 5. The ultrasonic mirror is made of a material that transmits light,
The ultrasonic diagnostic apparatus according to claim 1 or 2, wherein a sub-mirror that reflects light in a direction different from an ultrasonic radiation direction is incorporated therein.