JPH0284950A - Ultrasonic calculus crushing device - Google Patents

Abstract

PURPOSE:To confirm the position of a calculus in an object and to crush the calculus by providing an ultrasonic transducer, which has a recessed shape and forms the convergent point of an ultrasonic wave in a geometrical central point, and a pulser to selectively generate either a powerful ultrasonic wave or a weak ultrasonic wave. CONSTITUTION:An acoustic coupler 22 supported by a fixing frame 20 of an applicator 3 is loaded on a body surface 33M (on the back, for example) of the object and an ultrasonic transducer 2 is driven. Then, the tomographic image of the object is displayed on the screen of a display means 10. At a stage that a renal calculus picture 35 is drawn in the tomographic image, the fine adjustment of the applicator 3 is further executed and the applicator is set so that the renal calculus picture 35 can be positioned in a convergent point marker 38. Then, the applicator 3 is fixed in such a condition. Next, an operator depressed the push button of a pulse generating switch 13 and a control signal is sent through a CPU 6 and a controller 7 to a pulser 24. Thus, an ultrasonic pulse is transmitted from the pulser 24 toward a renal calculus 35M in the position of the convergent point marker 38.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an ultrasonic stone crushing device that crushes a stone within a subject using focused ultrasonic energy.

(Prior Art) In recent years, devices that use shock wave energy to crush stones within a subject have been put into practical use.

In this device, a subject with a stone is placed in a container of a predetermined size and filled with water at an appropriate temperature, and the position of the stone is aligned with the focal position of one of the spheroids. At the other focal point, a shock wave is generated by the explosion or discharge phenomenon of gunpowder, and a spheroidal acoustic mirror placed around the shock wave is focused on the calculus, so that the shock wave energy crushes the calculus. This is what I did.

In this case, confirmation of the location of the stone in the subject is performed while displaying the stone portion using an X-ray fluoroscope placed outside the container.

(Problem to be Solved by the Invention) However, when the above-mentioned device repeats the crushing action tens to hundreds of times, the gunpowder and electrodes must be replaced each time a shock wave is generated, which requires a lot of time. There are problems in that it requires a lot of time and costs a lot.

In addition, in the case of this apparatus, it is troublesome to place the subject in a container filled with water, and furthermore, since observation using X-ray fluoroscopy is essential, the amount of radiation exposure to which the subject and the operator are exposed cannot be ignored.

Furthermore, there is a problem that the device becomes large-scale and extremely expensive.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an ultrasonic stone crushing device that can accurately destroy stones in a subject without any risk of exposure to X-rays, and that is inexpensive. This is the purpose.

[Structure of the Invention] (Means for Solving the Problems) The outline of the present invention for achieving the above object is to provide a stone crushing device that irradiates shock waves from outside the body to stones, etc. inside a subject to crush the stones. An ultrasonic transducer that has a concave shape and forms a focal point of ultrasonic waves at its geometric center point, and a pulser that is connected to this ultrasonic transducer and selectively generates either strong ultrasonic waves or weak ultrasonic waves. The apparatus is characterized in that the pulser generates weak ultrasonic waves, and the resulting echo signals are received to confirm the position of the stone within the subject.

(Function) According to the above configuration, after confirming the location of the stone using weak ultrasound waves, the stone can be accurately crushed using powerful ultrasound waves.

(Example) Examples of the present invention will be described in detail below. The embodiment shown in FIG. 1 includes an applicator 3 including first and second ultrasonic transducers 1 and 2 for transmitting and receiving ultrasonic waves forming different sound field regions, which will be described in detail later. and,
a first signal processing system 4 that transmits two types of strong and weak pulse signals to the first ultrasonic transducer 1 and receives and processes an ultrasonic echo signal from the first ultrasonic transducer 1; A second signal that sends a pulse signal to the second ultrasonic transducer 2 to generate ultrasonic waves, scans in a fan shape, receives an ultrasonic echo signal from the second ultrasonic transducer 2, and processes the signal. A processing system 5, a CPU (central processing unit) 6 that controls each part of this device based on predetermined parameters, and the first. second signal processing system 4,
a control system 8 consisting of a controller 7 that controls the transmission/reception timing, amplitude, frequency, etc. of the pulse signal in the second signal processing system 5; and a signal conversion system (controlled by the CPU 6) that performs signal conversion processing on the output signal of the second signal processing system 5. For example, a digital scan converter) 9, a fan-shaped sound field area 31 by the second ultrasonic transducer 2 based on the output signal of this signal conversion system 9, a body surface image 33 of the subject. Kidney image 34.
Kidney stone image 35 etc. and position 36 of first ultrasound transducer 1. Sound field area 37. a display means 10 such as a TV monitor that displays a focal point marker 38, etc.; and a stone position confirmation means 11 such as a speaker that confirms the position of a kidney stone within the subject based on the output signal of the first signal processing system 5. , a subject signal detection element 12 that is formed so as to be able to come into contact with a part of the subject, such as a limb, and sends a subject signal indicative of the subject's heartbeat etc. to the CPU 6; and the first signal processing system 4. The generation timing of the pulse signal sent to the first ultrasonic transducer 1 must be set (pulse generation switch 13 consisting of first and second pushbuttons connected to the CPU 6 and signal conversion time in the signal conversion system 9). (Sound velocity setting means 1 connected to CPU 6)
4. Next, the specific configuration of the applicator 3 will be explained. As shown in FIG. 2, the first ultrasonic transducer 1 includes a concave vibrator 15 having a curvature of, for example, a diameter of 10 cm at a resonance frequency IMH2, and a hole of a predetermined shape provided in the center of the concave vibrator 15. It consists of a backing material 16 uniformly adhered to the back surface, and a first cable 17 is connected to an electrode (not shown) of the concave vibrator 15.

The second ultrasonic transducer 2 is a sector probe that is fixed in the hole and has a transducer array 2a formed by arranging thin transducers facing the curved surface of the concave transducer 15. to second cable 1
I'm pulling out an 8.

The outer periphery of the first ultrasonic transducer 1 is supported by a fixed frame 20 having a shaft 19, and this fixed frame 20 is coupled to an arm 21 to move the fixed frame 20 to move the first ultrasonic transducer 1. second ultrasonic transducer 1,
2 can be moved to a desired position and fixed at that position.

Said 1st. The second ultrasonic transducer 1°2 is acoustically coupled to the subject's body surface 33M by an acoustic coupler 22. As shown in FIG. 2, this acoustic coupler 22 is composed of a bag 23 formed of a thin film having almost the same acoustic impedance as water, and water 23a filled in this bag 23. Said 1st. By arranging the second ultrasonic transducers 1 and 2 on the side of the sound field region, the first ultrasonic transducer 1 and 2 are placed on the sound field side. Second ultrasonic transducer1.
Ultrasonic waves are transmitted and received efficiently between the test object 2 and the subject.

Next, the first signal processing system 4 will be explained. The first signal processing system 4 is controlled by the controller 7 of the control system 8, and transmits a large amplitude signal to the first ultrasonic transducer 1 via the first cable 17.

A pulser 24 sends two types of small-amplitude pulse signals and excites the first ultrasonic transducer 1 so that two types of strong and weak ultrasonic waves are generated, and the first ultrasonic transducer 1 transmits the waves to the subject. A receiving circuit 25 receives an echo signal based on the weak ultrasonic waves transmitted via the first cable 17, and the output signal of this receiving circuit 5 is inputted and converted into an audio signal of an audible frequency to confirm the location of the stone. Means 11
and a first signal processing circuit 26 that sends signals to the first signal.

Next, the second signal processing system 5 will be explained. The second signal processing system 5 is controlled by the controller 7 of the control system 8, and sends a pulse signal to the second ultrasonic transducer 2 at a predetermined timing so that the second ultrasonic transducer 2 performs sector scanning. A transmitting/receiving circuit 27 receives an echo signal from the second ultrasonic transducer 2 based on this sector scan, and inputs the output signal of this transmitting/receiving circuit 27, performs amplitude detection on it, and converts it into a video signal. The second signal processing circuit 28 sends signals to the signal conversion system 9.

Next, the basic operation of the apparatus having the above-mentioned structure will be explained by taking as an example a case where a kidney stone 35M in a kidney 34M in a subject is crushed.

First, the acoustic coupler 22 supported by the fixed frame 20 of the applicator 3 is placed on the body surface (for example, the back) 33M of the subject, and in this state, the second signal processing system 5 and the signal conversion system 9
and drives the second ultrasonic transducer 2 to display a tomographic image of the subject on the screen of the display means 10.

When the kidney image 34 is depicted in this tomographic image, the kidney stone image 35 therein is searched for.

In this case, the position of the concave vibrator 15 is displayed on the display means 10 based on the signal sent from the CPU 6 to the signal conversion system 9.
The sound field area 37 and focal point marker 38 of the first ultrasound transducer 1 are displayed at fixed positions, and the tomographic image of the subject displayed in real time changes as the applicator moves 3 degrees. The displayed area changes.

Then, at the stage when the kidney stone image 35 is depicted in the tomographic image, the applicator 3 is further finely adjusted so that the kidney stone image 35 is located within the focal point marker 38, and in this state, the applicator 3 is to be fixed.

Next, the operator presses the first button of the pulse generation switch 13 and the CPU 6. A control signal is sent to the pulser 24 via the controller 7. As a result, pulsar 24
A large-amplitude pulse signal is sent to the first ultrasonic transducer 1, and the first ultrasonic transducer 1 sends an ultrasonic pulse with strong energy to the object at a position corresponding to the focus point marker 38. Send waves towards kidney stone 35M.

This ultrasonic pulse becomes a shock wave at the position of the kidney stone 35M, and crushes the kidney stone 35M.

By repeating the generation of such ultrasonic pulses as many times as necessary, the entire kidney stone 35M can be crushed.

Note that since the subject is moving slightly due to heartbeat, breathing, etc., the subject signal detection element 12 is placed in advance on the subject's hand 1.
The object signal obtained from the object signal detection element 12 and the pulse switch 1 are brought into contact with the foot, chest, nose, etc.
The pulser 24 is synchronized with the signal from 3 by the CPU 6.
It is more effective to control the timing at which the pulse signal is sent from.

The operation of the above embodiment apparatus is based on the position of the focal point of the ultrasonic pulse by the first ultrasonic transducer 1 and the display means 10.
This is based on the premise that the above focal point marker 38 corresponds without error, but in reality, these do not necessarily correspond completely. That is, the kidney stone image 35 is displayed on the display means 10.
Even if the focal point falls within the focal point marker 38, the true focal point of the first ultrasonic transducer 1 may not match the position of the kidney stone 35M within the subject.

This is because when displaying a tomographic image in real time from echo signals based on sector scanning by the second ultrasound transducer 2, the ultrasound propagation velocity within the subject is set to a constant value (for example, 1530 m/') in the signal conversion system 19. s), convert this propagation speed into a distance, convert the output signal from the second signal processing system 5, and display the result on the display means 10. That is, if the actual ultrasonic propagation velocity of the subject differs from the above-mentioned set value, the actual position of the kidney stone 35M will not be displayed correctly on the display means 10.

To explain with a specific example, a kidney stone 35 is detected from the body surface 33 of the subject.
If the speed of sound when the ultrasonic pulse reaches M is faster than the above-mentioned setting value of 1530 (m/S), the reflected echo will also return quickly, so that the position on the display means 10 will be closer than the actual position. The kidney stone image 35 is displayed with the positional relationship.

Furthermore, due to the effects of refraction of ultrasound pulses, kidney stone images3
The error in the display position of No. 5 becomes larger.

Therefore, the operation for crushing the kidney stone 35M while confirming the true position of the kidney stone 35M in the apparatus of this embodiment will be described below.

First, the operator adjusts the position of the applicator 3 so that the kidney stone image 35 falls within the focal point marker 38, as in the case described above.

Next, the operator presses the second button of the pulse generation switching 13 to send a signal to the CPU 6 to generate a weak pulse. This signal causes the controller 7 to
6, a control signal is sent to the pulser 24, and as a result, a small amplitude pulse signal is sent from the pulser 24 to the first ultrasonic transducer 1, and from the first ultrasonic transducer 1 toward the subject. Very weak ultrasonic pulses are transmitted.

This weak ultrasonic pulse hits various tissues of the subject and is reflected, becoming an ultrasonic echo, which is received by the first ultrasonic transducer 1 and exchanged into an echo signal. The receiving circuit 25 receives this echo signal and sends it to the first signal processing circuit 26. The first signal processing circuit 26 is controlled by the CPU 6, detects only the echo signal near the focal point from among the input echo signals, converts it into an audio signal of an audible frequency, and sends it out. The stone position confirmation means 11 generates an audible sound based on this acoustic signal.

The operator moves the applicator 3 so that the kidney stone image 35 is located within or around the focal point marker 38 while listening to the audible sound, and searches for the position where the audible sound is maximum.

Through such operations, when the audible sound reaches its maximum since the acoustic impedance of the kidney stone is larger than that of other tissues, the true focal position of the ultrasound pulse by the first ultrasound transducer 1 and the position of the kidney stone 35M can be determined. This means that they match.

In this state, the operator operates the first pulse generation switch 13.
Press the Button button and press the Pulsa 2 button as described above.
4 sends a large-amplitude pulse signal to the first ultrasonic transducer 1 to crush the kidney stone 35M located at the focal point.

Through the above-described operations, the renal stone 35M within the renal body of the subject can be reliably crushed.

Next, the operation of crushing the kidney stone 35M by combining the stone position confirmation means 11 described above and the change in the scale factor of the tomographic image on the display means 10 in the apparatus of this embodiment will be described.

The tomographic image on the display means 10 can be enlarged or reduced by changing the sound velocity setting value, ie, the scale factor, in the signal conversion system 9.

To this end, the sound speed setting means 14 changes the sound speed setting value of the signal conversion system 9 via the CPU 6, and when the audible sound from the calculus position confirmation means 11 is at the maximum, The scale factor of the tomographic image is set so that the kidney stone image 35 is included.

Setting the scale factor in this manner is more convenient when applying ultrasonic pulses to crush the renal stone 35M of a certain subject many times.

Note that the above-mentioned automatic setting of the scale factor is also possible with the apparatus of this embodiment. The method will be explained below.

Let us consider a case in which tomographic images are obtained at 30 frames per second by the second ultrasonic transducer 2, and a weak ultrasonic pulse is transmitted from the first ultrasonic transducer 1 at each turn of each frame. In this way, the real-time tomographic image obtained by the second ultrasonic transducer 2 will not be affected in the same way (the first ultrasonic transducer 1 can transmit 30 ultrasonic pulses per second). .

Pulse a in FIG. 4(a). indicates a pulse transmitted from the first ultrasonic transducer 1,
Pulse waves 1 to a5 in FIG. 3A show detected waveforms of echo signals received by the first ultrasonic transducer 1 based on echoes reflected from the kidney stone 35M. Same figure (
As is clear from a), when the renal stone 35M is located closer to the body surface 33 than the focal point of the first ultrasonic transducer 1, the pulse a is generated. A wide pulse a1 with a small amplitude is obtained in a short time from the firing time of the pulse a1.

When the first ultrasonic transducer 1 of the applicator 3 is moved a little away from the body surface 33 and the kidney stone 35M is brought closer to the focal point, a pulse with a slower time and larger amplitude and narrower width than the above-mentioned pulse a1 is generated. a2 is obtained.

Furthermore, when the first ultrasonic transducer 1 is moved away from the body surface 33 and the position of the kidney stone 35M coincides with the position of the focal point, a pulse a3 having the maximum amplitude and the narrowest width is obtained.

When the first ultrasonic transducer 1 is further moved away from the body surface 33, the position of the kidney stone 35M becomes further away from the focal point position, and pulses such as pulses a4+a5 are obtained.

In this case, if the applicator 3 is moved continuously, pulses based on 30 reflected echoes are obtained every second, and the envelope line of each pulse is drawn as shown in FIG. 4(b). pulse a. The time T from the emission time to the peak point of this envelope line is the ultrasonic pulse emitted from this ultrasonic transducer 1 when the focal point of the first ultrasonic transducer 1 and the position of the kidney stone 35M coincide. Kidney stone 3'5
' This corresponds to the time it takes for the wave to hit M and be reflected and to be received by the first ultrasonic transducer 1.

That is, if the radius of curvature of the concave vibrator 15 is R, then the distance 2
The time required for the ultrasonic wave to propagate between R is T.

Here, since the radius of curvature R is predetermined by the geometrical shape of the concave transducer 15, if the time T is determined, the distance between the first ultrasonic transducer 1 and the acoustic coupler 22 at this time
The average speed of sound C until reaching the kidney stone 35M in the subject through
M can be represented by the following formula (1).

CM=2R/T (1) The procedure for determining the sound speed CM will be explained below.

As mentioned above, the echo reflected from a kidney stone has a larger amplitude and a narrower width the closer it is to the focal point;
The waveform of each pulse a1 to a5 shown in a) is differentiated by the first signal processing circuit 26 controlled by the CPU 6, and the waveform of each pulse a1 to a5 shown in FIG.
If a differential waveform signal as shown in c) is used, the position of the focal point can be more clearly determined. Furthermore, Fig. 4(d)
represents the differential waveform signal envelope shown in FIG. 4(c). The reflected signal or its differential waveform signal is further subjected to A/D conversion processing, storage processing in a memory, and peak point detection processing using a digital circuit in the first signal processing circuit 26 to automatically detect the time T.

Then, the data of the detected time T is temporarily stored in the memory, and this data and the value of the radius of curvature R are taken in and the (
1) Calculation based on the formula is performed by a calculation means (not shown) to obtain the average sound speed CM, and this is sent to the signal conversion system 9 as a sound speed setting value via the CPU 6, thereby displaying the display means 1.
The kidney stone image 35 of the subject can be displayed on the screen 0 without any error, thereby making it possible to reliably crush the kidney stone 35M.

Of course, it is also possible to crush the kidney stone 35M by using such automatic setting of the scale factor and acoustic confirmation of the focal point position by the stone position confirmation means 11.

Note that, in actual diagnosis, there may be non-uniformity of the subject's tissue, attenuation of ultrasonic pulses, etc., so some correction may be added to the above equation (1).

Furthermore, since the focal point position may slightly deviate from the geometrical center of the concave transducer 15, the CPU 6 controls the signal conversion system 9 to adjust the sound field area 37 and the focal point by the first ultrasonic transducer 1. It is also possible to display the marker 38 slightly asymmetrically.

Further, the sound generated by the calculus position confirmation means 11 may be made proportional to the amplitude of the reflected echo, or may be an intermittent sound such that the larger the reflected echo, the narrower the interval.

Furthermore, considering the effect on the fine wave specimen using a speaker as the calculus position confirmation means 11, earphones may be used.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

For example, in the above-described embodiment, the case where the kidney stone position is confirmed acoustically is explained, but the present invention is not limited to this, and the display means 10 displays an echo signal as shown in FIG. 4 obtained by the first signal processing circuit 26. The generation timing of the pulse signal for crushing can be determined by checking the magnitude of the amplitude.

In addition, although the above-described embodiment apparatus has been described for crushing kidney stones, the present invention is not limited to this and can be applied to crushing gallstones, etc.

[Effects of the Invention] According to the invention described in detail above, it is possible to reliably and repeatedly crush the stone of a subject without being exposed to any radiation such as X-rays.

Further, it is possible to provide an ultrasonic stone crushing device that does not require a water tank or the like to house a subject, and the entire device can be made smaller and lower in price.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a device according to an embodiment of the present invention, FIG. 2 is a schematic explanatory diagram showing the configuration of an applicator in the same device and its sound field area, and FIG. 3 is a display state on a display means in the same device. FIG. 4(a) is an explanatory diagram showing the second
FIG. 4(b) is an explanatory diagram showing the envelope of the waveform shown in FIG. 4(a), and FIG. Waveform diagram showing the differential waveform of the received pulse shown in Figure (a), No. 4
FIG. 4D is an explanatory diagram showing the envelope of the waveform shown in FIG. 4C. 1... First ultrasonic transducer, 2... Second
an ultrasonic transducer, 3... an applicator,
4... First signal processing system, 5... Second signal processing system, 8... Control system, 9... Signal conversion system, 10...
-Display means, 11... Stone position confirmation means, 12... Subject signal detection element, 13... Pulse generation switch, 14... Sound velocity setting means, 33M... Body surface, 35.
...Kidney stone image, 35M...Kidney stone. hφ- Funeral map/

Claims (2)

[Claims] (1) In a stone crushing device that crushes a stone by irradiating a shock wave from outside the body to a stone, etc. inside the subject, an ultrasonic transducer that has a concave shape and forms a focal point of ultrasound at its geometric center point; , a pulser that is connected to the ultrasonic transducer and selectively generates either strong ultrasonic waves or weak ultrasonic waves, and a pulser that generates weak ultrasonic waves and receives echo signals from the ultrasonic waves to generate the ultrasonic waves within the subject. An ultrasonic stone crushing device characterized by confirming the location of stones. (2) The ultrasonic stone crushing device according to claim 1, wherein the ultrasonic stone crushing device generates strong ultrasonic waves only when it receives a stone echo signal caused by weak ultrasonic waves.