JPH05285140A - Ultrasonic device - Google Patents

Abstract

PURPOSE:To safely insert the device even into a minute part, while photographing the front of a catheter in a blood vessel by installing an ultrasonic transmitter/receiver in which the direction for transmitting or receiving an ultrasonic wave is varied by a signal frequency, and a guide wire hole, and providing them in the catheter. CONSTITUTION:Plural vibrator arrays 1, 1 are arranged symmetrically against the center shaft of a catheter 2, and they are held in a truncated chevron shape by an acoustic damping material 6. Also, the tip part of the catheter 2 is covered with a transparent protective material 10, and also, the part between each vibrator array 1, 1 is formed by an acoustic coupling material 8. On the other hand, an ultrasonic beam in the prescribed direction is absorbed by plural acoustic absorbers 3, 3. Also, each vibrator array 1, 1 is coupled to a signal processor of the outside of the catheter 2 by a signal line 9. Moreover, in the center shaft position of the catheter 2, a guide rail 5 consisting of a tube which a guide wire 4 passes through is provided. In this case, each scanning face 7, 7 of the ultrasonic beam is driven by the same or different center frequency, and scanned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic device, and more particularly to a device effective for diagnosis and treatment of blood vessels and the like.

[0002]

2. Description of the Related Art An ultrasonic wave transmitter in which the directions of transmission and reception of ultrasonic waves change depending on the signal frequency is described in "High Speed 2" published in the Proceedings of the Japan Society of Ultrasonics in Medicine (November 1974).
3D imager ". The operating principle of such an ultrasonic wave transmitter / receiver will be described with reference to FIG.
As shown in FIG. 5, the ultrasonic wave transmitter / receiver includes an oscillator array 1 that is inverted polarized (directions of polarization are alternately indicated by arrows having different directions) and ground electrodes 8 provided on both surfaces thereof.
And hot electrode 9. When a burst wave is applied between the electrodes, a different direction θ (θ represents the direction of the ultrasonic wave emission or incident surface, that is, the normal direction of the transducer array surface and the ultrasonic wave emission or incident direction) depending on the signal frequency. angle)
It is capable of radiating and injecting an ultrasonic beam into. Figure 5
The arc line shows the wavefront, and the phase is 18 with the solid line and the broken line.
0 degrees different. Since the phases of adjacent wave fronts at the same time are inverted, they are canceled in the normal direction, and the incident radiation of the ultrasonic beam is two directions symmetrical with respect to the normal direction of the emission surface of the ultrasonic wave (shown in FIG. 5). The direction of the solid line and the dotted line). This incident / radiation angle θ is given by Equation 1 as a vibrator pitch d, a driving frequency f, and its wavelength λ. θ = sin ⁻¹ (λ / (2d)) (Equation 1) Further, the far field directivity characteristic R (θ) at this time is given by Equation 2. R (θ) = sin (0.5n (φ−γ)) / sin (0.5 (φ−γ)) φ = π, γ = 2πd sin (θ) / λ (Equation 2) Utilizing these relationships Then, the ultrasonic beam is scanned, and the ultrasonic beam can be sector-scanned by frequency sweeping with one signal line. In addition, JP-A-2-2646
An ultrasonic probe consisting of a single member is formed on the electrode 48 by continuously changing the pitch and width of the electrodes, and the probe is arranged so that the transducer surface is inclined with respect to the insertion direction into the blood vessel. A method of tilting with respect to the central axis of the catheter, holding it at the distal end of the catheter, and performing ultrasonic beam sweeping is described.
Further, as a catheter which has a guide wire hole for guiding when the catheter is introduced into a blood vessel and is advanced and which can perform ultrasonic imaging of the blood vessel wall, an imaging catheter (Imaging) manufactured by CVIS is available.
Catheter, Boston S
Cientific's Sonicas CV catheter (Son
icath CV Catheter) etc. All of these images the side of the catheter that is substantially orthogonal to the traveling direction.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to incorporate an ultrasonic wave transmitter / receiver into a catheter so that the ultrasonic wave transmitter / receiver can be guided to a fine blood vessel for imaging the front and side of the advancing direction of the catheter. It is an object of the present invention to provide an ultrasonic device capable of imaging a thrombus that cannot be imaged by a lateral vision system because a clearance due to a stenosis is smaller than a diameter and insertion is impossible.

[0004]

In order to achieve the above object, an ultrasonic device is provided with an ultrasonic transmitter / receiver and a guide wire hole in which the direction of transmitting or receiving ultrasonic waves changes depending on the signal frequency. It is composed of a transducer array in which wave filters are alternately inverted and polarized. In addition, the ultrasonic device has an ultrasonic wave transmitter / receiver whose guide direction is changed depending on the signal frequency, and a guide wire hole in the catheter. The ultrasonic wave transmitter / receiver is alternately inverted and polarized. It consists of. More specifically, a guide wire hole is arranged at the position of substantially the central axis of the catheter, and a plurality of transducer arrays are symmetrically arranged in the catheter to scan a plurality of ultrasonic beams. In addition, a guide wire hole is arranged at a position that does not cross the central axis of the catheter and does not intersect the ultrasonic beam, and the transducer array is arranged asymmetrically in the catheter to scan a single ultrasonic beam. Further, a guide wire hole is arranged at a position substantially at the center axis of the catheter, and a plurality of transducer arrays are arranged asymmetrically in the catheter to scan a plurality of ultrasonic beams. Further, a guide wire hole is arranged at a position which deviates from the central axis of the catheter and intersects with the ultrasonic beam, and the transducer array is arranged asymmetrically in the catheter to scan a single ultrasonic beam.

[0005]

When the oscillator array 1 which is alternately inverted and polarized (the arrow indicates the polarization direction) is driven by frequency sweeping as shown in FIG. 5, the direction corresponding to the signal frequency (the normal direction of the oscillator array surface and The ultrasonic beam can be emitted in two directions indicated by a solid line and a dotted line forming an angle θ. Ultrasonic beams in a direction that is symmetrical to the intended direction of radiating the ultrasonic beam and the direction normal to the transducer array are absorbed and removed by the acoustic absorber, and the ultrasonic beam is emitted in the desired direction. can do. The frequency is swept before and after the signal frequency, and the scanning plane of the ultrasonic beam is obtained from each of the two transducer arrays.
The scanning planes of the ultrasonic beams can be driven and scanned at the same or different center frequencies, so that different target objects can be imaged alternately and simultaneously so that the ultrasonic beams do not overlap. You can also
An acoustic absorber is not used for a transducer array driven at a high frequency, but a window for propagating an ultrasonic beam is provided on the side of the tip of the catheter, and one transducer array is operated at a high frequency. By driving, the blood vessel wall on the side of the distal end of the catheter can be imaged and observed with high resolution. Further, the center frequencies are made different by changing the thicknesses of the two transducer arrays A and B, and for example, the transducer array A has a higher frequency characteristic than that of the transducer array B. When imaging and observing the structure of the blood vessel wall, the transducer array A is used for imaging, and when imaging and observing the front of the distal end of the catheter, the transducer array B is used for high resolution of the blood vessel wall. Thus, a sufficient imaging distance can be secured in front of the tip of the catheter. In this case, no acoustic absorber is used for the transducer array A, and a window for propagating the ultrasonic beam is provided on the side of the distal end portion of the catheter. In this way, a sufficient imaging distance can be secured in front of the tip of the catheter, so that a guide wire can be used to safely guide the patient to a fine blood vessel. Can be imaged and observed with high resolution.

[0006]

Embodiments of the present invention will be described below with reference to FIGS. The ultrasonic transducer, in which the direction of transmitting and receiving ultrasonic waves changes depending on the signal frequency, is a transducer array,
It is composed of an acoustic damping material, a protective material, an acoustic absorber, an acoustic coupling material, etc., and is fixed to the distal end portion of the catheter. An embodiment will be described by taking an oscillator array (inverted polarization array) that is alternately inverted and polarized as the oscillator array. Figure 1
1 shows a first embodiment of an ultrasonic device having an ultrasonic wave transmitter / receiver for arranging a guide wire hole 5 for passing a guide wire 4 almost in the center of a catheter and scanning a plurality of ultrasonic beams. FIG. 1A is a vertical cross section passing through the center of the catheter 2 in the longitudinal direction, and FIG. 1B is a diagram showing the positional relationship between the guide wire hole and the transducer array as seen through from the distal end portion of the catheter 2. is there. In this embodiment, the transducer array 1 and the transducer array 1 ′ are arranged symmetrically with respect to the central axis of the catheter 2. As shown in FIG. 1 (a), the transducer arrays 1 and 1'are held in a V shape by an acoustic damping material 6 (including a transducer holding function, but not shown), and the acoustic damping material 6 is a catheter. It is fixed to the inner wall of the tip of No. 2. The tip of the catheter 2 in the traveling direction is covered with an acoustically transparent protective material 10, and an acoustic coupling material 8 is provided between the protective material 10 and the transducer arrays 1 and 1 '. The protective material 10 may also serve as an acoustic lens. Transducer array 1 and oscillator array 1 '
May be arranged symmetrically or asymmetrically with respect to the central axis of the catheter 2. The ultrasonic beam in a direction symmetrical to the intended direction of radiating the ultrasonic beam and the direction normal to the oscillator array is absorbed and removed by the acoustic absorbers 3 and 3 '. Each oscillating array is coupled by signal lines 9 to a signal processor of the ultrasound system external to the catheter 2. An impedance converter may be provided at the end of the transducer that is fixed to the tip of the catheter 2.

As shown in FIG. 1B, in this embodiment,
A guide rail 5 made of an annular tube through which a guide wire 4 passes is provided at a position substantially on the central axis of the catheter 2. The scanning planes 7 and 7 ′ of the ultrasonic beams can be driven and scanned at the same or different center frequencies, respectively, and may be imaged alternately, or at the same time, images should be taken so that the ultrasonic beams do not overlap. You can also It is possible to drive the transducer array 1 at a high frequency, and use the transducer array 1 to perform imaging and observation of a blood vessel wall with high resolution. in this case,
For the transducer array 1, the acoustic absorber 3 is provided on the guide rail side, and a window for propagating an ultrasonic beam is provided on the side of the distal end portion of the catheter 2. In addition, the transducer array 1,
The center frequency is changed by changing the thickness of 1 ', for example,
The transducer array 1 has a higher frequency characteristic than that of the transducer array 1 ', and when imaging and observing the structure of the blood vessel wall, the transducer array 1 is used to image the front of the distal end portion of the catheter 2, When the observation is performed using the transducer array 1 ′, the blood vessel wall can be imaged with high resolution and even in front of the distal end portion of the catheter 2.

As described above, since the front of the tip of the catheter can be imaged, the stenosis can be imaged even if the stenosis is higher than the outer diameter of the catheter. In addition, a guide wire can be used to safely guide a fine blood vessel, and the blood vessel wall lateral to the distal end of the catheter can be imaged and observed with high resolution.
In this embodiment, the transducer arrays 1 and 1'are arranged so as to sandwich the guide wire hole provided at the substantially center of the catheter 2, but the transducer array 1 and the transducer array 1'are further arranged.
It is also possible to arrange the transducer array so as to sandwich the guide wire hole in a direction substantially orthogonal to the direction connecting the two. In Figure 2,
2 shows a second embodiment of an ultrasonic device having an ultrasonic transducer in which a guide wire hole is arranged off the center of the catheter and a single ultrasonic beam is scanned. Figure 2 (a)
Is a longitudinal section passing through the center of the catheter 2 in the longitudinal direction,
FIG. 2B is a diagram showing the positional relationship between the guide wire holes and the transducer array as seen through the distal end portion of the catheter 2.
In this embodiment, the transducer array 1 is arranged asymmetrically with respect to the central axis of the catheter 2. The transducer array 1 is supported at the tip of the catheter 2 while being inclined with respect to the central axis of the catheter 2, and a guide wire hole is arranged at a position next to the transducer array 1 that does not intersect the scanning plane 7 of the ultrasonic beam. ..

FIG. 3 shows a third embodiment of an ultrasonic device having an ultrasonic wave transmitter / receiver for arranging a guide wire hole substantially in the center of a catheter and scanning a plurality of ultrasonic waves. FIG. 3A is a vertical cross section that passes through the center of the catheter 2 in the longitudinal direction, and FIG. 3B is a diagram showing the positional relationship between the guide wire holes and the transducer array as seen from the distal end of the catheter 2. is there. In this embodiment, the transducer array 1 and the transducer array 1 ′ are arranged asymmetrically with respect to the central axis of the catheter 2. This embodiment is the same as the second embodiment shown in FIG.
A guide rail 5 formed of an annular tube through which a guide wire 4 passes is provided at a position substantially at the center axis of the catheter 2. Ultrasonic beams may be formed individually as in the first embodiment shown in FIG. 1, or when the diameter of the guide wire 4 is sufficiently smaller than the width in the direction orthogonal to the ultrasonic beam scanning direction, By adding a delay time to the operation of the transducer array 1 and the transducer array 1'and combining the ultrasonic beams, the actual aperture is the combined aperture of the transducer array 1 and the transducer array 1 ', and the ultrasonic beam Can also be formed.

FIG. 4 shows a fourth embodiment of an ultrasonic device having an ultrasonic transducer for arranging a guide wire hole off the center of the catheter and scanning a single ultrasonic beam. FIG. 4A is a vertical cross section passing through the center of the catheter 2 in the longitudinal direction, and FIG. 4B is a diagram showing the positional relationship between the guide wire hole and the transducer array as seen through from the distal end of the catheter 2. is there. In this embodiment, the transducer array 1 is arranged asymmetrically with respect to the central axis of the catheter 2.
This embodiment is different from the second embodiment shown in FIG. 2 in that the guide rail 5 is formed by an annular tube through which the guide wires 4 pass in the array direction of the vibrators of the vibrator array 1 (the direction intersecting the ultrasonic beam). It is provided. The second and third described above
Also in this embodiment, as described in the first embodiment,
The oscillator array 1 is driven at a high frequency, and the oscillator array 1
Can be used for high-resolution imaging and observation of the blood vessel wall. In this case, the acoustic absorber 3 is not used for the transducer array 1, but a window for propagating the ultrasonic beam is provided on the side of the distal end portion of the catheter 2. Further, in order to focus the ultrasonic beam in the above ultrasonic wave transmitter / receiver, an acoustic lens may be provided or the transducer array itself may be bent.

Further, the transducer array is divided into a plurality of portions in the direction orthogonal to the scanning plane of the ultrasonic beam, that is, in the minor axis direction, and a signal line is drawn out for each division to connect to a transmitting / receiving circuit outside the catheter, The configuration may be such that short-axis variable aperture scanning, short-axis variable focus scanning, and short-axis direction ultrasonic beam scanning are performed. The guide wire may be configured to pass through the catheter to the end opposite to the distal end where the transducer is provided, or to be outside the catheter before the distal end where the transducer is provided. You may comprise. Further, the guide wire may be configured to be detachable from the catheter, or may be configured to have a part thereof fixed to the catheter. As described above, in addition to incorporating the ultrasonic device of the present invention into a catheter, it can be combined with a laser treatment or applied to a balloon pumping catheter. Further, although the ultrasonic transducer using the array of transducers at equal intervals has been described, it can be applied to an ultrasonic transducer having an array of transducers at irregular intervals such as M series and Barker series. is there. Further, the ultrasonic wave transmitter / receiver in which the direction in which ultrasonic waves are transmitted or received changes depending on the signal frequency may be an ultrasonic wave transmitter / receiver in which a vibrator is formed by a series of different electrode periods and electrode widths.

[0012]

As described above, according to the present invention, the catheter is provided with the transducer and the guide wire hole capable of electrically scanning the ultrasonic beam with a small number of signal lines to obtain a tomographic image. It is possible to safely insert even a minute portion while imaging the front of the catheter in the blood vessel.

[Brief description of drawings]

FIG. 1 is a sectional view showing an ultrasonic device for scanning a plurality of ultrasonic beams, in which a guide wire hole is arranged at a position of substantially a central axis of a catheter of (a) a first embodiment according to the present invention;
(B) A diagram showing a positional relationship between the transducer array and the guide wire holes.

FIG. 2 (a) is a second embodiment of the present invention, in which a guide wire hole is arranged at a position deviated from the central axis of the catheter,
Sectional drawing which shows the ultrasonic device which scans a single ultrasonic beam, (b) The figure which shows the positional relationship of a transducer array and a guide wire hole.

FIG. 3 is a sectional view showing an ultrasonic device according to a third embodiment of the present invention (a) in which a guide wire hole is arranged at a position substantially at a central axis of a catheter and a plurality of ultrasonic beams are scanned.
(B) A diagram showing a positional relationship between the transducer array and the guide wire holes.

FIG. 4 (a) is a catheter according to a fourth embodiment of the present invention in which a guide wire hole is arranged at a position deviated from the central axis of the catheter;
Sectional drawing which shows the ultrasonic device which scans a single ultrasonic beam, (b) The figure which shows the positional relationship of a transducer array and a guide wire hole.

FIG. 5 is a diagram for explaining the operation principle of an ultrasonic wave transmitter / receiver including an array of transducers that are alternately inverted and polarized.

[Explanation of symbols]

1, 1 '... Transducer array, 2 ... Catheter, 3 and 3' ...
Acoustic absorber, 4 ... Guide wire, 5 ... Guide rail, 6
… Acoustic damping material (including transducer holding function), 7, 7 '...
Ultrasonic beam scanning surface, 8 ... Acoustic coupling material, 9 ... Signal line,
10 ... Protective material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Narendra Sangbi 1-280, Higashi Koigokubo, Kokubunji, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd.

Claims (9)

[Claims] 1. An ultrasonic device comprising: an ultrasonic wave transmitter / receiver that changes the direction of transmitting or receiving ultrasonic waves according to a signal frequency; and a guide wire hole. 2. The ultrasonic device according to claim 1, wherein the ultrasonic transmitter / receiver is composed of a transducer array which is alternately inverted and polarized. 3. An ultrasonic device, characterized in that a catheter is provided with an ultrasonic wave transmitter / receiver that changes the direction of transmitting or receiving ultrasonic waves according to the signal frequency and a guide wire hole. 4. The ultrasonic device according to claim 3, wherein the ultrasonic wave transmitter / receiver is composed of a transducer array which is alternately inverted and polarized. 5. The guide wire hole is arranged at a position of substantially the central axis of the catheter, and a plurality of the transducer arrays are symmetrically arranged in the catheter to scan a plurality of ultrasonic beams. The ultrasonic device according to claim 2. 6. The ultrasonic device according to claim 2, wherein the guide wire hole is arranged at a position deviating from the central axis of the catheter and not intersecting with the ultrasonic beam. 7. The guide wire hole is arranged at a position deviating from the central axis of the catheter and not intersecting with the ultrasonic beam, and the transducer array is arranged asymmetrically in the catheter to scan a single ultrasonic beam. The ultrasonic device according to claim 2, wherein: 8. The guide wire hole is arranged at a position of substantially the central axis of the catheter, a plurality of the transducer arrays are arranged asymmetrically in the catheter, and a plurality of ultrasonic beams are scanned. The ultrasonic device according to claim 2. 9. The guide wire hole is arranged at a position that is off the central axis of the catheter and intersects with the ultrasonic beam,
The ultrasonic device according to claim 2, wherein the transducer array is asymmetrically arranged in the catheter to scan a single ultrasonic beam.