JPH02149263A - Calculus crushing device of shock wave external type - Google Patents

Abstract

PURPOSE:To make it possible to crush a small calculus which is growing prior to occurrence of symptoms for precaution by providing an ultrasonic wave transmitting/ receiving means having a vibrator element array for transmitting/receiving waves of an ultrasonic return transmission orthography forming means, and a shock wave transmitting vibrator element array for transmitting shock wave pulses. CONSTITUTION:An ultrasonic wave probe 1 is composed of an imaging array 2 for searching the position of a calculus and focusing, and a piezoelectric element 3 for generating shock waves disposed around it. This element 3 is disposed to make transmitted ultrasonic waves focused at a focus point, and connected with a power driver of a transmitter. A range gate 12 lets data pass for a time zone corresponding to their distance from the time of transmission when they are reflected at an echo generating part 24 and pass a target range 22, and the position of the range gate 12 can be changed, so a part to be observed can be changed for searching a calculus. Focus is set at the target zone 22 by transmitted/received waves from the imaging array 2, and pulse waves of a long cyclic period having a large current peak value are focused from the shock wave generating piezoelectric element 3 to be applied to a calculus which is growing to crush it.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an extracorporeal shock wave lithotripter that uses ultrasonic shock waves to crush stones from outside the body. The present invention relates to an extracorporeal shock wave lithotripter used in combination with an ultrasonic return transmission orthography device.

(Prior art) Regarding stones that occur in organs, stones do not form overnight; substances gradually deposit on the walls of lumens such as the bladder, gallbladder, or blood vessels, and these stones grow and grow. It is discovered only when the formed stone falls off the wall, flows with the fluid flowing in various parts, gets stuck in narrow parts such as the urethra, bile duct, or blood vessels, and causes severe pain as it obstructs the passage of fluids such as urine and blood. This is a phenomenon that occurs. It goes without saying that it is preferable to remove stones before they become lodged in small and narrow areas, since removing these stones poses biosafety issues and requires a large amount of money. Therefore, it is best to discover and treat stones when they are small, before they develop.

On the other hand, in medical terms, ultrasound systems irradiate ultrasound waves into the subject's body and observe and diagnose tissues and lesions using the echo signals that are reflected back from various tissues and lesions within the subject's body. However, recently, applications have been developed that utilize the high energy of elastic waves called ultrasonic waves, with the hope of causing irreversible and specific changes in tissue, such as destruction. One of these is the extracorporeal shock wave lithotripter (Extern).
al ShockWave Ljthotripte
r; hereinafter referred to as ESWL). This uses relatively low-frequency ultrasound and uses various ultrasound focusing techniques to sharply focus the ultrasound, and in this focal region, a large sound intensity of several hundred times or more than the emitted ultrasound intensity is generated. This is a device that crushes stones that have formed inside organs.

It has been found that when focused irradiation is performed in this way, localized destruction foci occur only at the position corresponding to the focal point, and the tissue intervening between the surface layer of the subject and the focal point is not affected at all. .

(Problems to be Solved by the Invention) In order to correctly determine the focal point position in this way, it is necessary to perform aiming imaging to determine the position of the stone in relation to organs and the like. As imaging means for this aiming, there are two methods used in the past, such as the X-ray stereoscopic inkstone and the new ultrasound B-mode ecography imager, which divide the medical world into two. In short, it was simply a combination of four, with the imager and the shock wave irradiation side placed side by side to facilitate aiming. By organically combining these two, one can find E in the state of a small stone before it develops as a stone.
SWL is desired.

The present invention has been made in view of the above points, and its object is to organically combine an imaging means for aiming that can easily detect even small stones, and a powerful pulse shock wave generation means. The aim is to realize ESWL.

(Means for Solving the Problems) The present invention, which solves the above-mentioned problems, includes an ultrasonic return transmission method orthography creation means used to aim at a target area, and a shock wave with a long repetition period to fragment stones. a shock wave transmission pulse generating means for transmitting a wave; a wave transmitting and receiving transducer element array of the ultrasonic return transmission method orthography generating means; The present invention is characterized by comprising an ultrasonic wave transmitting/receiving means including an array of transducer elements for transmitting shock waves. Furthermore, efficiency can be further improved by using the reflected wave of the single shock wave pulse as a transmission signal for position confirmation.

(Function) The transmitted ultrasonic pulse or the reflected pulse transmitted through the object is displayed as an image by the return transmission method orthography generating means, and the aim is determined by the shock wave transmitting pulse generating means. The generated pulses are transmitted by a shock wave transmission transducer element array to crush the stone. When there are two or more stones, from the second time onwards, aiming can be carried out efficiently by using the reflected wave from the shock wave as an echo signal in the return transmission method.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a main part of an ultrasonic probe used in an apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of an aiming imager using ultrasonic return transmission method orthography according to an embodiment of the present invention. It is a block diagram. In Fig. 1, reference numeral 1 denotes an ultrasonic probe used in this device to transmit and receive ultrasonic waves, an imaging array 2 for locating and aiming at the stone, and a shock wave array placed around it. It is configured as a generation piezoelectric element 3. The shock wave generating piezoelectric elements 3 are arranged so as to focus the transmitted ultrasonic waves at a focal position, and are respectively connected to power drivers (not shown) of the transmitter. 4 covers these ultrasound probes,
It is a sound-permeable membrane that contains a liquid to form a liquid chamber 5 in order to acoustically couple the transducer element and the living body. A protector 6 surrounds the imaging array 2 and prevents it from being damaged by high energy shock waves from the shock wave generating piezoelectric element 3. An imaging probe 7 consisting of an imaging array 2 and a protector 6 is connected to an aiming imager through the center of a shock wave generation probe 8 to which a shock wave generation piezoelectric element 3 is attached. .

FIG. 2 is a block diagram showing only the receiving section of the imager for transmitting and receiving ultrasonic waves using the imaging probe 7 and aiming shock waves at the stone to be irradiated. The transmitting section simultaneously transmits waves from all elements of the imaging array 2, and is no different from a normal device, so FIG. 2 only shows the receiving section for one channel. In the figure, parts equivalent to those in FIG. 1 are given the same reference numerals.

11 is an amplifier for amplifying the signal received by the imaging array 2; 12 is a range gate for extracting only the data of the target area; the output data is coherently detected by the detector 13, and is combined with the i signal of the in-phase signal. Outputs the q signal of the orthogonal signal.

14 is a RAM 15.1 that stores a complex hologram. Digital signal processor (hereinafter referred to as D) that performs Fourier transform calculations
(referred to as SP) 1.6. DSP 16 (7) is an image reconstruction calculation device consisting of a FROM 17 that stores software such as instructions related to calculation processing, and a RAM 18 that stores data of calculation results.

19 is a digital scan converter (hereinafter referred to as DsC) that converts the human input signal into a television format, and displays the converted data on the TV 20.

Prior to explaining the operation of the device configured as described above, the principle and features of this aiming imager will be explained.

As explained earlier, the ESWL of this example detects stones that are developing before they develop, so ultrasound is irradiated into the subject's body as usual and the reflected waves are observed. With the conventional method, it is extremely difficult to detect small stones because there are too many targets that reflect ultrasonic waves, but with the transmission method, it is easy to find stones with low transmittance compared to the surrounding tissue. Therefore, the transmission method is used.

In the transmission method, it is necessary to transmit the wave from the other side of the target object,
Since the equipment is large-scale, we adopt the return path transmission method as shown below. The principle diagram of the return passage method is shown in Figure 3.

In the figure, 21 is approximately the desired angle of view (solid angle) when transmitting waves.
A two-dimensional array transducer that transmits long pulses all at once without focusing at an illumination angle that covers the entire area, and when receiving the waves, focuses on the target area 2 and scans and receives the waves. The space 23 is provided as long as possible to obtain the desired results. 24
1" is an echo generating part for reflecting the transmitted ultrasonic waves from the two-dimensional array transducer 21 behind the 2-dimensional array transducer 22, and the reflected waves from the echo generating part 24 do not produce a clear image. It is desirable to have something that looks like this.

Next, a method of creating an orthogonal projection image obtained by ultrasonic waves transmitted and received in the arrangement as described above will be explained. For example, a long pulse of about 30 to 50 μs at 2 MHz is transmitted toward the target area 22 so as to cover the entire angle of view from the two-dimensional array transducer 21 . The transmitted ultrasonic wave passes through the target area 22, is reflected by the echo generator 4, passes through the target area 22 again, and reaches the two-dimensional array transducer 21. Since there is a limit to the angle of view for creating an orthogonal projection image, the space 23 is set as long as possible. A hologram is obtained in the two-dimensional array transducer 21 at the time when the reflected wave returns from the echo generator 24. Since the pulse width is long, it can be considered as a CW mode, and the received data becomes one piece of complex data for each element of the two-dimensional array transducer 21. Specifically, the echoes from the echo generator 24 pass through the target area 22 and return to the two-dimensional array transducer 21 in a time period that matches the interval width and sending timing of the transmitted long pulse. , Coherent detection of data is performed for each element, the data separated into in-phase components and quadrature components are separately integrated to obtain complex reception data of the element, and data of all elements are collected to form a complex hologram. Store this data in your computer's memory.

Based on this two-dimensional hologram, using the Fresnel approximation method or Kirchhoff's exact solution method, the propagation length to the target region 22 is determined while specifying the relevant aperture internal partial region each time if necessary, and the propagation term is solved. Complex data of the target area 22 is obtained by a wavefront backpropagation algorithm. This part of the calculation is basically an inverse Fresnel transform, and can be implemented by adding a phase correction term to the inverse Fourier transform, as is known.

The apparatus of this embodiment uses the return path transmission method as described above. Returning to FIG. 2, the operation will be explained.

Reflected wave signals received based on the transmitted wave signals emitted all at once from the imaging array 2 are amplified by the amplifier 11 . The range gate 12 passes data in a time period corresponding to the distance from the time of transmission at the time when the wave is reflected by the echo generator 24 and transmitted through the target area 22 . The position of this range gate] 2 can be changed, and the observation area can be changed sequentially to search for stones. The data that has passed through the range gate 12 is subjected to coherent detection in a wave detector 13 and outputs a complex signal separated into an i signal and a q signal, which is input to an image reconstruction device 14 and first stored in a RAM 15. The data stored in RAM 1.5 is a complex hologram of all elements.

This two-dimensional hologram is subjected to the image reconstruction calculation described in the above method by the DSP 16 based on instructions from the FROM Mi 7, and the resulting data is stored in the RAM 18.

The pigs stored in the RAM 18 are read out sequentially and the DSC
In step 19, the image data is converted into TV image data and displayed on the TV 20.

A return transmission method orthography apparatus as described above provided with an algorithm for phase conjugation or refraction correction is used as the receiving section. The receiving section of this return transmission orthography apparatus is connected to the imaging array 2 of the ultrasound probe 1 shown in FIG. 1 together with the transmitting section. A target area 22 is set by transmitting and receiving waves from the imaging array 2, and a pulse wave having a high power peak value with a long repetition period is focused from the shock wave generating piezoelectric element 3 and applied to the developing stone. Crush. The shock wave generator is essentially the same as a normal device, except that it transmits ultrasonic pulses with a longer repetition period and a larger pulse wave peak value, so a description thereof will be omitted. The protector 6 protects the imaging array 2 from the impact of the waves of the high power pulses. The liquid chamber 5 optimizes the acoustic coupling between the subject and each transducer element of the ultrasonic probe, and forms the space 23 shown in FIG. 3.

As explained above, according to the first embodiment, by connecting the return path transmission method orthography device and the ESWL via the ultrasonic probe 1, it is possible to preventively remove stones before the onset of the disease. You will be able to do this.

Note that the present invention is not limited to the above embodiments. In the embodiment, the return transmission method orthography device transmitted waves by itself and received the echoes from the echo generator 24, but when there are two or more stones, the ESWL is used for the second and subsequent stone crushing. It is also possible to use an echo obtained by reflecting a shock wave from the echo generating section 24.

(Effects of the Invention) As described in detail above, according to the present invention, it becomes possible to preventively crush developing small stones before the onset of stone formation, which is useful in terms of biosafety and cost efficiency. The device can be realized and the practical effects are great. Further, the efficiency is further improved by using the shock wave for calculus fragmentation in place of the transmission signal of the return transmission method.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an ultrasonic probe according to an embodiment of the present invention, FIG. 2 is a block diagram of an embodiment of a receiving section of a return transmission method orthography apparatus used in the present invention, and FIG. FIG. 1 is an explanatory diagram of a method of return transmission orthography. 1... Ultrasonic probe 2... Imaging array 3... Piezoelectric element for shock wave generation 4... Sound transmitting membrane 5... Liquid chamber 6... Protector 7... Imaging probe Tentacle 8... Shock wave generation probe 12... Range gate 13... Detector 14...
Image reconstruction calculation device 15.18...RAM1.6...DSP17...
PROM 19...DSC21...Two-dimensional array transducer 22...Target area 23.
...Space 24...Echo generation part

Claims (3)

[Claims] (1) An ultrasonic return path transmission method orthography creation means used to aim at a target area, a shock wave transmission pulse generation means that sends a shock wave with a long repetition period to fragment a stone, and the ultrasonic return path An ultrasonic transmitter and receiver comprising a transducer element array for transmitting and receiving waves as a means for creating transmission method orthography, and a transducer element array for shock wave transmission provided around the transducer element array for transmitting shock wave pulses that focus the ultrasonic pulses on a target area. 1. An extracorporeal shock wave lithotripter, characterized in that it is equipped with a wave means. (2) Ultrasonic return transmission method Creating orthography using the echo signal of the shock wave transmitted by the shock wave transmission pulse generation means without transmitting the outward irradiation wave for the orthography creation means itself. The extracorporeal shock wave lithotripter according to claim 1, characterized in that: (3) The extracorporeal method according to claim 1 or 2, characterized in that the transmitting/receiving transducer element array of the ultrasonic return transmission method orthography creation means has a protection means for preventing it from being destroyed by directly receiving the shock wave pulse. Shock wave lithotripter.