JPS62292149A - Ultrasonic remedy apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention focuses ultrasonic shock waves from outside the body on the stone to be treated, and is used for ultrasonic treatment such as a stone destruction device that destroys the stone. Regarding equipment.

[Conventional technology]

Generally, in a stone destruction device, a probe consisting of piezoelectric elements arranged in a mosaic pattern on a quadratic curved surface is brought into contact with the human body from behind through a water bag filled with water, etc. It concentrates sonic shock waves to destroy the stones.

A shock wave is generated by applying a pulsed voltage to a piezoelectric element. Note that an ultrasonic observation device, an X-ray observation device, etc. are used to discover the stone and confirm its position.

Based on the observed image by the observation device, the position of the probe, the shape of the water bag, etc. are adjusted so that the focal position of the quadratic curved surface coincides with the position of the stone. This means that if the distance from each piezoelectric element to the stone is the same, and a pulsed voltage is applied to all piezoelectric elements at the same time, the phase of the shock waves generated from each piezoelectric element will match at the position of the stone, effectively destroying the stone. This is because it can be done.

[Problems to be solved by the invention] However, since the surface of the human body does not perfectly match the quadratic curved surface on which the piezoelectric elements are arranged in a mosaic pattern, the distance from each piezoelectric element to the stone is equal. However, the ratio of the distance within the water bag to the distance within the human body on the path from each piezoelectric element to the stone is not equal. For this reason, the phase of the shock wave is in the same phase on the surface of the piezoelectric element, but as it propagates from each piezoelectric element to the stone, there is a delay depending on the ratio of the distance inside the water bag to the distance inside the human body. It does not match. Therefore, the vectors of the shock waves are different, and when they are combined at the location of the stone, part of the energy of the shock waves is lost, reducing the efficiency of stone destruction.

This invention was made to deal with the above-mentioned circumstances,
The purpose is to provide an ultrasonic treatment device that can match the phases of shock waves generated from each piezoelectric element at the position of the object to be treated, and can efficiently treat the object.

[Means for solving problems]

The ultrasonic treatment device according to the present invention includes a plurality of piezoelectric elements 6a to 6g arranged in an array, a distance Ων in the water bag on the path from each of the piezoelectric elements 6a to 6II to the stone 3, and a distance Ων in the human body. It includes a central processing unit (CPU) 3B that calculates the distance Nt, and timing circuits 14a to 14.17 that drive the piezoelectric elements 6a to 6R at timings based on the detected distance ρWSρt.

[Effect]

According to the ultrasonic treatment device according to the present invention, the piezoelectric element 6a
By determining the distance ρν in the water bag and the distance Ωt in the human body on the path from each of the piezoelectric elements 6a to θρ to the stone 3, the position of the shock wave from each piezoelectric element 6a to θρ can be determined.
By changing the timing at which the piezoelectric elements 6a to 6g are driven so that the phase difference at the position can be detected and this phase difference becomes zero, each piezoelectric element Ba to 6j! The shock waves generated by the shock waves can be synthesized in the same phase at the position of the calculus 3, and the efficiency of destroying the calculus 3 can be improved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ultrasonic treatment apparatus according to the present invention will be described below with reference to the drawings. The figure is a block diagram of a stone destruction device as an example. There is a stone 3 to be treated in the kidney 2 of a living body 1 as a subject. A probe configured by arranging piezoelectric elements Ba to 6g in a mosaic pattern on a quadratic curved surface is brought into contact with the living body 1 via a water bag 4 filled with water.

Piezoelectric elements 6a-6.1! There are actually many more, but
For convenience of explanation, illustration is omitted. Shock wave generation circuits 10a to 10g are connected to the piezoelectric elements 6a to 6g, respectively, and piezoelectric cords 6a to 6g are generated by applying a pulsed voltage from the shock wave generation circuits 10a to 10g to the piezoelectric elements 6a to BN.
A shock wave is generated. Shock wave generation circuit lea~10
1 are connected to timing circuits 14a to 14ρ, respectively, which control the timing of the generation of this shock wave.

The center position of piezoelectric element θa-6g, that is, piezoelectric element 8r
, 8g, a mechanical scanning type ultrasonic probe 18 for observation is arranged. The ultrasonic probe 18 is connected to an ultrasonic observation device 20, and the output of the ultrasonic observation device 20 is CR.
The signal is supplied to a T monitor 22 and an analog/digital (A/D) converter 24. The output of the A/D converter 24 is written to the frame memory 2B.

The frame memory 26 has a storage area corresponding to the screen of the CRT monitor 22. Data read from the frame memory 26 is supplied to the comparator 30 via the read buffer circuit 28. Also connected to the frame memory 26 is a multiplexer 34 for switching the outputs of the write address generator 32 and the read address generator 36.

The outputs of the comparator 30 and the read address generator 3B are input to the CPU 311 via the data bus 42.

Address bus 40 and data bus 42 for CPO 38
are connected, and an address bus 40 and a data bus 42 are connected to timing circuits 14a to 14R. Note that peripheral circuits of the CPU 38, such as a memory and a clock circuit, are not shown. Further, the power supplies for the shock wave generating circuits 10a to 10g are also omitted from illustration.

Next, the operation of this embodiment will be explained. As previously mentioned,
With the probe consisting of the piezoelectric elements 6a to 6g in contact with the living body 1 via the water bag 4, the mechanical scan type ultrasound probe 18 performs sector scanning of ultrasonic waves to detect the living body 1, the kidney 2, and the stone 3. Obtain the echo signal.

The echo signal is processed by the ultrasound observation device 20 to obtain a signal representing a tomographic image of the subject, and the tomographic image is displayed on a CRT monitor 22.
is displayed. Piezoelectric elements 6a to 8g are arranged 2
The position of the probe and the shape of the water bag 4 are adjusted based on the displayed tomographic image so that the focal position of the second curved surface coincides with the position of the stone 3. In this way, each piezoelectric element 6
The distances from a to 6g to stone 3 are made equal.

The tomographic image signal output from the ultrasound observation device 20 is an A/D
It is also supplied to the converter 24, where it is A/D converted.
It is written into the frame memory 2G as tomographic image data for each pixel. When writing to frame memory 2B, multiplexer 34 selects the output of write address generator 32 and supplies 01 to frame memory 26.

When one screen worth of tomographic image data is written into the frame memory 26, the multiplexer 34 outputs the read address generator 5.
1 is selected and supplied to the frame memory 26. The data read in this way is stored in the read buffer circuit 2.
8 to a comparator 47. When the tomographic image data of each pixel within one screen is greater than or equal to a certain threshold, the comparator 47 identifies that pixel as the surface of the living body I. The address of the pixel on the surface of the living body 1 is transferred to C via the data bus 42.
It is supplied to PU18. The CPU 38 controls each piezoelectric element 6a to
The distance ρW inside the water bag and the distance gt inside the human body on the path from 6g to the calculus 3 are determined, and shock waves are generated from the piezoelectric elements 6a to 6g at timings corresponding to the ratio of these distances. Here, the timing can be controlled by delaying the drive timing of the other piezoelectric elements 6b to 6g based on the drive timing of a certain piezoelectric element (for example, piezoelectric element Ba).

- As an example, the operation of determining the delay time of the drive timing of the piezoelectric element 6f with respect to the drive timing of the piezoelectric element 6a will be explained. The coordinates of the surface of the living body 1 on the path from the piezoelectric element B a s 6 f to the stone 3 are (xi,
yl), (x6.y6). X11y1, X6, y
As described above, 6 is the coordinate of a pixel whose tomographic image data on the path from the piezoelectric element Ba5Bf to the stone 3 is detected by the comparator 30 to be equal to or higher than a certain threshold value. Since the coordinates of the piezoelectric elements Ba and 8f are also known, the CPU 8B calculates the distance ρw1.9w6 inside the water bag and the distance tl and 11t8 inside the human body on the route from the piezoelectric element 6as6f' to the calculus 3.

When pν1, lj v6, Ωt1, ρt6 are calculated,
The phase of the shock wave from the piezoelectric element 8 a s B f at the location of the calculus 3 is calculated. If the sound speed of the shock wave in water is Cv, and the sound speed in living tissue is Ct, then the piezoelectric cord 6
The time required for the shock wave generated from a to pass through water and living tissue is ρν1/Cν, 1)tl/
It becomes Ct. Therefore, the piezoelectric element 6 at the location of the calculus 8
The phase θ1 of the shock wave from a is 2 yr f/ (j!
wl/Cw+Ωtl/Ct) There is. Similarly, the phase θ2 of the shock wave from the piezoelectric element 6f is 2 yr f / (Ω
VB/Cv+Ωt13/Ct).

In order to match the phases and match the shock wave vectors at the location of the calculus, the piezoelectric element 6f may be driven with a delay of αB from the drive timing of the piezoelectric element 6a as follows.

Ωvl/Cw+Ωtl/Ct = ρwe/Cw+1)tB/Ct +αB - (1)
By transforming equation (1), α6 can be expressed as follows.

α6=(ρwl/Cw +Ntl/Ct)−(
jJ v6/ Cv −N7 t6/ Ct )=,
11w1/Cw -Ω w8/Cv 10Ωtl/Ct
-ΩtB/Ct =1/Cw(ρwl-,lI)we)+1/Ct
(Q tl-OtB) ...(2) Here, since the distance from each piezoelectric cord 6a to 6Ω to the stone 3 is equal,
The following equation holds.

Rtl+j! wl=l) t8+j) v8-(3)
From equation (3), j? tl-1) tB --(, lJ wl-9w6
)...(4) is obtained, and by substituting equation (4) into equation (2), α6 becomes as follows.

a8-1/Cw (Rwl-1) v6)-1/C
t (Q wl-i) we)=(ffwl-ρwe
) x (1/Cw-1/Ct) −(5)ρν11ρ
Since Shiloh, Cw, and ct are known, α6 is calculated from equation (5).
is required.

Similarly, the piezoelectric elements 6b to 6g have delay times α2 to α1 based on the drive timing of the piezoelectric element 6a.
Find 2. The CPU 38 calculates these delay times α2 to α1.
2 is set in the timing circuits 14b to 14g. The delay time αl of the timing circuit 14a is set to zero.

Shock wave generation circuits 10a-10g are timing circuits 14a
- Piezoelectric element 6 at the timing according to the set time of 14R.
By driving a~6.17, each piezoelectric element 6a~
The phases of the shock waves generated from 6g can be matched at the position of the stone 3.

This invention is not limited to the embodiments described above, and can be modified in various ways. For example, it is not necessary that the stone 8 be located at the center of the device, ie, equidistant from each piezoelectric element 6a-6g. Since the distances ρv1 to ρv12 within the water bag and the distances gtl to Dt12 within the human body on the path from each piezoelectric element 6a to 6g to the stone 3 have been calculated,
Equation (2), that is, αt −(, 11vl/Cw +f
l tl/Ct ) −(j! wi/Cv+Ωti/
If the delay time α1 (1-2 to 12) of the drive timing of the piezoelectric element 61 is determined based on It can be matched at position 3. Furthermore, the target device is not limited to a stone destruction device, but can be applied to any device that focuses ultrasound waves on a target object for treatment.

〔Effect of the invention〕

As explained above, according to the present invention, the distance within the water bag and the distance within the human body on the path from each piezoelectric element to the treatment target are determined, and the phase difference between the shock waves from each piezoelectric element at the treatment target is calculated. Since the drive timing of each piezoelectric element can be determined such that the value becomes zero, it is possible to provide an ultrasonic treatment device that can efficiently treat the target object by aligning the phases of the shock waves from all the piezoelectric elements at the position of the target object. Ru.

[Brief explanation of the drawing]

The figure is a block diagram of a stone destruction device as an embodiment of the ultrasonic treatment device according to the present invention. 3... Stone 4... Water bag 6a-6g... Piezoelectric element 14a-1i... Timing circuit 18... Ultrasonic probe 26... Frame memory 30... Comparator 38...・Central Processing Unit Applicant Representative Patent Attorney Atsushi Tsuboi Procedural Amendment 1. Display of the case Japanese Patent Application No. 137453/1982 2 Name of the invention Ultrasonic treatment device 3 Person making the amendment Relationship to the case Patent applicant (037) Olympus Optical Industry Co., Ltd. 4 Agent 3 Kasumigaseki, Chiyoda-ku, Tokyo Chome 7-2 UBE Building 7,
“2” stated in page 4, line 16 to line 17 of the specification of contents of the amendment
Correct "on a spherical shell whose surface is a quadratic surface" to "on a spherical shell whose surface is a quadratic surface".

Claims (1)

[Claims] a plurality of piezoelectric elements arranged in an array; a means for detecting a phase of an ultrasonic wave generated from each of the plurality of piezoelectric elements at a target region; and a means for detecting a phase of each of the plurality of piezoelectric elements based on the detected phase. An ultrasonic treatment device comprising means for controlling drive timing of the device.