JPH03228753A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To perform scanning in front of a catheter with a simple structure, form an image in the front area, and improve the diagnostic effect by providing a ultrasonic transmission/reception section on the inside of the tip section of the catheter, and providing a sonic velocity variable layer on its front side. CONSTITUTION:A ultrasonic pulse generated by a ultrasonic transmission/reception section 2 is fed to a sonic velocity variable layer 3 and propagated in the layer 3, when it reaches a sonic wave radiating face 4 which is the boundary between the sonic velocity variable layer 3 and an ambient medium 5, the ultrasonic pulse is refracted at the refraction angle determined by its incident angle into the radiating face 4 and the ratio between the sonic velocity on the variable layer 3 and the sonic velocity on the ambient medium 5 and transmitted into the ambient medium 5 in front of a catheter 1 and propagated in the medium 5. The ultrasonic pulse reflected by a Section under test 6 in front of the catheter 1 is returned on the same path as the outgoing path and received when it reaches the ultrasonic transmission/reception section 2. The applied voltage on the sonic velocity variable layer 3 is changed, the sonic velocity is changed, the refraction angle on the radiating face 4 is changed, and the ultrasonic pulse is transmitted and received in the same way as mentioned above. The front section of the catheter 1 is scanned by repeating the above action.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ultrasonic probe used in a catheter.

BACKGROUND OF THE INVENTION Recently, ultrasonic probes at the tip of catheters have been attracting attention in the medical field of the circulatory system. As the ultrasound probe at the tip of this catheter, for example, PR, 0CEE
DING OF THE IEEE VOL76, NO
9, 1988 is known. The conventional ultrasound probe at the tip of a catheter will be described below with reference to the drawings.

FIG. 6 is a sectional view showing a conventional ultrasound probe at the tip of a catheter. In Figure 6, ■ old is catheter, 1
02 is an acoustic window formed on the side of the distal end of the catheter 101, and lO3 is an acoustic window 10 formed inside the catheter 101.
An ultrasonic transducer 104 is disposed on the front side of the catheter 10 so that its ultrasonic transmitting surface is perpendicular to the acoustic window 102; This is an acoustic reflection plate that reflects the ultrasonic waves transmitted from the ultrasonic transducer 103 to the outside of the acoustic window 102.

The operation of the above configuration will be described below.

The ultrasound transmitted from the ultrasound transducer 103 is reflected by the acoustic reflection plate 4 in the lateral direction, that is, in the radial direction, of the catheter 101, passes through the acoustic window 112, and travels toward the test site of the subject. The ultrasonic waves reflected from the test site follow the same path as the transmission and are received by the ultrasonic transducer 103. The distal end portion of the catheter IO1 is configured to be rotatable in whole or in part, and scanning in the radial direction is performed by this rotation.

Problems to be Solved by the Invention However, in the configuration of the conventional example as described above, since the ultrasonic waves are transmitted in the radial direction of the catheter 101, it is difficult to scan the front of the catheter 101. The problem was that it was difficult to obtain information by visualizing the front of the 101.

The present invention aims to solve the problems of the prior art as described above, and it is possible to scan the front of the catheter, obtain information by imaging the front of the catheter, etc.
Therefore, the effectiveness of diagnosis can be improved, the structure is simple without requiring mechanical mechanisms or complicated electronic circuits, and it is advantageous for sealing and insulating the tip of the catheter, and furthermore, the cost can be reduced. It is an object of the present invention to provide an ultrasonic probe that can achieve the following.

Means for Solving the Problems The technical solution of the present invention for achieving the above object is as follows:
a catheter; an ultrasonic transceiver unit provided inside the distal end of the catheter for transmitting and receiving ultrasonic waves; and a voltage applied to the ultrasonic transceiver unit provided inside the distal end of the catheter in front of the ultrasonic transceiver unit. The catheter is equipped with a variable sound speed layer for controlling the refraction angle of the ultrasound transmitted from the ultrasound transmitting/receiving section so as to change the speed of sound due to a change in the speed of sound, and for scanning the front of the catheter.

1. A piezoelectric material can be used for the sound velocity variable layer, and a planar ultrasonic vibrator may be used as the ultrasonic transmitter/receiver, or a cylindrical ultrasonic vibrator and this ultrasonic vibration may be used. A conical acoustic mirror can be used, which is placed inside the catheter and reflects ultrasound transmitted from the ultrasound transducer in the direction of the central axis of the catheter toward the front of the catheter. Further, the ultrasonic wave transmitted from the ultrasonic transmitting/receiving section may be configured to propagate through the variable sound velocity layer and scan the front part of the catheter in a fan-like manner.

Effect Therefore, according to the present invention, when the ultrasonic transmitter/receiver provided at the tip of the catheter transmits ultrasonic waves to the variable sound velocity layer, the ultrasonic waves incident on the variable sound velocity layer propagate inside the variable sound velocity layer. , refraction due to the sound speed difference between the variable sound velocity layer and the medium surrounding the catheter at the boundary with the medium surrounding the catheter,
Waves are transmitted to the front of the catheter. The ultrasound reflected from the test area in front of the catheter is refracted at the boundary between the surrounding medium and the variable sound velocity layer, enters the variable sound velocity layer, and propagates within the variable sound velocity layer, transmitting and receiving the ultrasound, just as during transmission. received by the department. By changing the voltage applied to the variable sound speed layer, the sound speed of the variable sound speed layer changes, and the refraction angle of the ultrasonic wave at the boundary between the variable sound speed layer and the surrounding medium changes.
By repeating this process, the front part of the catheter can be scanned.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

First, a first embodiment of the present invention will be described.

1 and 2 show an ultrasonic probe according to a first embodiment of the present invention, with FIG. 1 being a partially cutaway perspective view and FIG. 2 being a longitudinal sectional view.

In FIG. 1, ■ is a catheter, and 2 is an ultrasonic transmitting/receiving unit provided inside the tip of the catheter 1, which has an ultrasonic vibrator, a coupling medium, etc., and transmits ultrasonic waves.
and receive. Reference numeral 3 denotes a sound velocity variable layer provided inside the tip of the catheter l and in front of the ultrasound transmitting/receiving section 2.
The refraction angle of the ultrasonic waves transmitted from the ultrasonic wave is controlled to change. Reference numeral 4 designates a sound wave emitting surface on the front surface of the sound velocity variable layer 3, 5 a surrounding medium of the subject, and 6 a test part. The sound wave radiation surface 4;
At the boundary between the ultrasonic transmitter/receiver 2 and the variable sound velocity layer 3, there are angles θ1 and θ that are suitable for the variable sound velocity width of the variable sound velocity layer 3 and the scanning area.
2 is attached.

The operation of the above configuration will be described below.

The ultrasonic pulses generated in the ultrasonic transmitter/receiver 2 enter the variable sound speed layer 3 and propagate through the variable sound speed layer 3 . At this time, the sound speed of the sound speed variable layer 3 is determined by the voltage applied to the sound speed variable layer 3. When the ultrasonic pulse reaches the sound wave radiation surface 4 which is the boundary between the sound velocity variable layer 3 and the surrounding medium 5, this ultrasonic pulse is determined by the angle of incidence on the sound wave radiation surface 4, the sound velocity of the sound speed variable layer 3, and the surroundings. Speed of sound in medium 5♂
The wave is refracted at a refraction angle determined by the ratio of , is transmitted into the surrounding medium 5 in front of the catheter 1 , and propagates within the surrounding medium 5 . The ultrasonic pulse reflected by the test section 6 in front of the catheter l returns along the same path as the outgoing path, is refracted by the sound wave emitting surface 4, propagates through the variable sound velocity layer 3, and passes through the ultrasonic transmitter/receiver section 2.
reached and received. When the ultrasonic pulse transmission/reception operation is completed in this manner, the voltage applied to the sound velocity variable layer 3 is changed, the sound velocity is changed, and the refraction angle at the sound wave emission surface 4 is changed. In this state, ultrasonic pulses are transmitted and received in the same manner as above. Then, by repeating the above operations,
The anterior part of catheter I is scanned.

Note that the refraction phenomenon on the sound wave emission surface 4 also occurs at the boundary between the ultrasound transmitting/receiving section 2 and the variable sound speed layer 3.

As described above, according to this embodiment, the ultrasonic transmitter/receiver 2 is provided inside the distal end of the catheter 1, and the speed of sound changes due to a change in the voltage applied at the front side of the ultrasonic transmitter/receiver 2 inside the distal end of the catheter 1. By providing the variable sound velocity layer 3, it is possible to scan the front part of the catheter I, obtain information on the scanning area, and image that part.

In this embodiment, the voltage applied to the sound velocity variable layer 3 is changed stepwise. However, if the ultrasonic transmission interval is significantly shorter than the scanning time, the applied voltage may be changed continuously. A similar effect can be obtained by changing it.

Next, a second embodiment of the present invention will be described.

In this embodiment, the sound velocity variable layer 3 in the first embodiment shown in FIGS. 1 and 2 is made of a piezoelectric material, and the other configurations are the same as in the first embodiment. be.

A piezoelectric material can change the speed of sound by changing its elastic modulus using voltage. Therefore, in the configuration of the first embodiment, the same effects as in the first embodiment can be obtained by configuring the variable sound speed layer 3 from a piezoelectric material as described above.

Next, a third embodiment of the present invention will be described.

FIG. 3 is a partially cutaway perspective view showing an ultrasound probe according to a third embodiment of the present invention.

In this embodiment, as shown in FIG. 3, the ultrasonic transmitter/receiver 2 is composed of a planar ultrasonic transducer 7 and a coupling medium 8 in front of the ultrasonic transducer 7, and the other components are as follows. This is the same as the first embodiment described above.

According to this embodiment, ultrasonic pulses are transmitted and received by the planar ultrasonic transducer 7 via the sycamore ring medium 8 and the variable sound velocity layer 3, and similarly to the first embodiment, the variable sound velocity layer By changing the sound velocity 3, the front part of the catheter 1 is scanned, information on the scanning area is obtained, and it becomes possible to visualize that part.

Although the planar ultrasonic transducer 7 is formed into a disk shape in this embodiment, the same effect can be obtained even if the ultrasonic transducer 7 is formed into a rectangular or rectangular shape.

Next, a fourth embodiment of the present invention will be described.

FIG. 4 is a longitudinal sectional view showing an ultrasonic probe in a fourth embodiment of the present invention.

In this embodiment, as shown in FIG. A conical acoustic mirror 10 that reflects the ultrasonic waves transmitted in the direction of the central axis of the catheter 1 from the ultrasonic transducer 9 toward the front of the catheter 1, and a coupling medium 11 in front of the acoustic mirror 10. The other configurations are the same as those of the first embodiment.

According to this embodiment, the ultrasonic pulses transmitted from the cylindrical ultrasonic transducer 9 in the direction of the central axis of the catheter 1 are reflected toward the front of the catheter 1 by the conical acoustic mirror 10, causing a force ybring. The sound propagates through the medium 11 and enters the sound velocity variable layer 3 . Thereafter, ultrasonic waves are transmitted and received in the same manner as in the first embodiment, and the sound velocity of the variable sound velocity layer 3 is changed to scan the front part of the catheter 1, and the information of the scanning area is is obtained, and it becomes possible to convert that part into an image f3.

In this embodiment, since the ultrasonic transducer 9 is formed into a cylindrical shape, its volume can be made relatively large.
It is possible to increase the sound output.

Next, a fifth embodiment of the present invention will be described.

FIG. 5 is a longitudinal sectional view showing an ultrasonic probe in a fifth embodiment of the present invention.

In this embodiment, as shown in FIG. 5, similarly to the first embodiment, an ultrasonic transmitting/receiving section 2 is provided inside the distal end of the catheter 1. A variable sound speed layer 3 is provided on the front side of the section 2, the speed of sound being changed by changing the applied voltage. Then, the ultrasonic pulses generated in the ultrasonic transmitter/receiver 2 are not refracted at the boundary between the ultrasonic transmitter/receiver 2 and the variable sound velocity layer 3, and propagate in a fixed direction through the variable sound velocity layer 3, and reach the variable sound velocity layer 3. By changing the applied voltage and changing the sound speed of the sound speed variable layer 3, the scanning of the sound wave emitting surface 54 by the ultrasonic pulses is set to be limited to a single plane in a fan shape. In Fig. 5, the central beam is shown as a representative).

According to this embodiment, the front part of the catheter 1 is scanned in a fan shape, two-dimensional information of that part is obtained, and the image 1
visualization becomes possible.

Effects of the Invention As described above, according to the present invention, an ultrasonic transmitter/receiver for transmitting and receiving ultrasonic waves is provided inside the distal end of the catheter, and a By providing a variable sound speed layer that changes the speed of sound by changing the applied voltage and can control the angle of refraction, it is possible to scan the front part of the catheter with ultrasound and obtain information about that part. Based on this information, the area in front of the catheter can be imaged. Therefore, it has a great effect on understanding the condition inside the tube into which the catheter is inserted. In addition, the front part of the catheter is scanned by ultrasound by changing the voltage applied to the variable sound velocity layer as described above, and there is no need for mechanical mechanisms or complicated electronic circuits, so the configuration is simple and This is advantageous for sealing and insulating the distal end of the catheter, and can also reduce costs.

In particular, when used in a medical setting, it is of great assistance in diagnosing diseases of the circulatory system.

[Brief explanation of drawings]

1 and 2 show ultrasonic probes according to the first and second embodiments of the present invention, in which FIG. 1 is a partially cutaway perspective view, FIG. 2 is a vertical sectional view, and FIG. A partially cutaway perspective view showing an ultrasound probe according to a third embodiment of the present invention, FIG. 4 is a longitudinal sectional view showing an ultrasound probe according to a fourth embodiment of the present invention,
FIG. 5 is a longitudinal sectional view showing an ultrasound probe according to a fifth embodiment of the present invention, and FIG. 6 is a longitudinal sectional view showing a conventional ultrasound probe. ■...Catheter, 2...Ultrasonic transmitter/receiver, 3...
・Sound velocity variable layer, 4...Sound wave emission surface, 5.Surrounding medium, 6
...Test part, 7.. Ultrasonic transducer, 8.. Coupling medium, 9.. Ultrasonic transducer, 10.. Conical acoustic mirror 11. Cambling medium.

Claims (5)

[Claims] (1) A catheter, an ultrasonic transceiver unit provided inside the distal end of the catheter for transmitting and receiving ultrasonic waves, and an ultrasonic transceiver disposed inside the distal end of the catheter in front of the ultrasonic transceiver unit for applying ultrasound waves. The ultrasonic probe is equipped with a sound velocity variable layer for controlling the refraction angle of the ultrasonic waves transmitted from the ultrasonic transmitter/receiver to change the speed of sound due to changes in the applied voltage, and for scanning the front of the catheter. Tentacles. (2) The ultrasonic probe according to claim 1, wherein the sound velocity variable layer is a piezoelectric material. (3) The ultrasonic probe according to claim 1 or 2, wherein the ultrasonic transmitting/receiving section is comprised of a planar ultrasonic transducer. (4) The ultrasonic transmitter/receiver includes a cylindrical ultrasonic transducer and is arranged inside the ultrasonic transducer, and transmits the ultrasonic waves transmitted from the ultrasonic transducer in the direction of the central axis of the catheter to the front of the catheter. 3. The ultrasonic probe according to claim 1, further comprising a conical acoustic mirror for reflecting the acoustic waves. (5) The ultrasonic probe according to claim 1, wherein the ultrasonic waves transmitted from the ultrasonic transmitting/receiving section propagate through the variable sound velocity layer and scan the front part of the catheter in a fan-like manner.