JPH0525495B2 - - Google Patents

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a device for crushing stones formed in the body using laser light, and in particular for determining the type of stone,
The present invention relates to a stone crushing device that can set optimal laser irradiation conditions accordingly.

"Prior Art" It is known that components of secretions and excreta accumulate and precipitate in the kidneys, bladder, ureters, etc., forming stones and causing pain to the human body. Especially in recent years, as the food intake has become more Westernized, the occurrence of stones has increased.
It has become a frequent disease in the urological field. Moreover, since it causes great pain to patients, an appropriate treatment method is desired.

Treatment methods include dissolving the stone with drugs, removing it through surgery, and applying shock waves to break it up into small pieces that are naturally excreted in the urine.A new treatment method is to irradiate the stone with pulsed laser light and use this energy to break up the stone. Natural excretion has been proposed, and some doctors are experimenting with it.

The conventional method of crushing stones using this laser
This will be explained based on the schematic diagram shown in FIG. An endoscope 9 having optical fiber channels 6, 7, and 8 is opposed to a stone 2 formed in a ureter 1. Light from a white light source 3 (usually a xenon lamp is used) illuminates the stone 2 through a fiber channel 6, and an image of the stone 2 obtained by reflected light and scattered light is transmitted to the observer through a fiber channel 8. 5 and observed with the naked eye. A laser beam source 4 is passed through the fiber channel 7 (this is a quartz optical fiber inserted into the forceps hole of the endoscope 9) to the stone 2 that has been targeted by this observation.
Laser light pulses emitted from are sent. The laser beam irradiates the surface of the stone 2, and its energy breaks it into small pieces. The laser is a YAG laser (wavelength
1.06 μm) or visible light dye pulse laser (wavelength
504nm) is used.

``Problem to be solved by the invention'' When using the YAG laser described above, stones are destroyed by the thermal energy of the laser, but since this YAG laser uses infrared light with a wavelength of 1.06 μm, where can the laser be used? It is difficult to determine whether the light is being emitted. If nearby living tissue is irradiated, there is a great risk of tissue damage or perforation.

The stone crushing process using dye pulsed laser light is said to be as follows. When the laser beam is irradiated, the surface of the stone is heated and the tiny stone particles are evaporated and released. These microparticles absorb the laser light, heat up further, and emit electrons, creating plasma. This plasma absorbs the laser light and begins to expand rapidly, generating strong pressure waves that destroy the stone.

Laser light at 504 nm was selected because the optical absorption of hemoglobin in red blood cells in blood reaches a minimum around a wavelength of 504 nm. In other words, it is said that by using this laser, it is possible to crush stones without damaging living tissue.

This 504nm laser light pulse crushes the stone.
It is more effective (much safer) than those using YAG laser, but the effectiveness varies depending on the type of stone. For example, calcium oxalate (Ca
oxalate, CaC ₂ O ₄ ) stones are easy to fracture with a 504 nm laser, but calcium phosphate (CaC 2 O 4 ) stones
CaPO ₄ ) is less susceptible to fragmentation than calcium oxalate. In addition, magnesium phosphate,
There are materials such as ammonium phosphate and cystine, but the degree of crushing varies. Especially cystine
It is not easily fractured by 504nm laser light.

The present invention aims to sufficiently improve the crushing effect in stone crushing using pulsed laser light by changing the laser irradiation conditions depending on the type of stone.

"Means for Solving the Problems" The present invention provides an apparatus for monitoring a stone with white light and crushing it using a laser beam, including a white light source that emits pulsed white light for stone illumination necessary for monitoring the stone; A pulsed laser generator that emits pulsed laser light necessary for crushing a stone; and an endoscope that transmits the pulsed white light, the pulsed laser light, and the detection light obtained when the stone is irradiated with these lights. , a light splitter that splits the detection light transmitted from this endoscope into two, a spectrometer that spectrally spectrally spectra one of the split lights, and a spectrometer that doubles the spectral image obtained by this spectrometer. an image multiplier, an image pickup tube for capturing an image obtained by the image multiplier, and a TV for capturing a stone image obtained by the other light divided by the splitter.
a camera, a processor that processes signals from the image pickup tube and the TV camera and sends a video signal to a TV monitor, and a TV monitor that displays a stone image and a spectral image based on the video signal sent from the processor. and a laser irradiation condition setting device for changing the output, repetition rate, and wavelength of the pulsed laser light obtained from the pulsed laser generator by analyzing the spectral image displayed on the TV monitor. It is.

``Work'' When a stone is irradiated with laser light, the stone evaporates from the irradiated surface, creating a kind of plasma state. At this time, an emission spectrum is observed from the elements that make up the stone (this is known as the "laser microprobe method"). Therefore, by examining this emission spectrum, the constituent components of the stone can be known, and a laser wavelength suitable for these constituent components can be set. Since actual stones contain various elements, it is necessary to research in advance which wavelength is most suitable for the composition ratio of those elements (which has the effect of crushing the stone). In order to prevent damage to living tissue by laser light,
Since the laser wavelength is desirably in the range of about 450 to 510 nm, where tissue absorption is low, the actual laser irradiation wavelength is selected within this range.

"Example" Hereinafter, an example of the present invention will be described based on the drawings.
In FIG. 1, which shows an overall view of the device according to the present invention, an endoscope 9 is inserted into a ureter 1, and the tip of the endoscope 9 is opposed to a stone 2 formed inside. This endoscope 9 includes a pulsed white light source 3 (this is Xe
Pulsed light 1 from (using a flash lamp)
2, an optical fiber channel 7 that passes the laser beam 11 from the pulsed laser generator 4, and a large number of fibers that pass the detection light 13 obtained from the stone 2 during laser beam irradiation. The configuration includes an optical fiber channel 8. The number of the optical fiber channels 6 may be one, but it may also be configured with two as shown in FIG. 2. In the case of a two-light configuration, the amount of pulsed white light that irradiates the stone 2 increases and a brighter image can be obtained. The optical fiber channel 7 is used by being inserted into the forceps hole 10 of the endoscope 9 so that it can be replaced when it is damaged by the laser beam. Reference numeral 14 denotes a beam splitter, and this beam splitter 14 is for splitting and sending the detection light 13 obtained from the calculus 2 through the optical fiber channel 8 to the color TV camera 23 and the spectrometer 16. One of the detection lights 13 split into two by the beam splitter 14 is sent to the spectroscope 1 by the condenser lens 15.
The light is focused onto the incident slit 16a of No.6. The detection light passing through the entrance slit 16a is reflected by the reflecting mirror 17 and enters the concave diffraction grating 18, where the diffracted light is split into two parts. ) 19 is imaged on the photocathode. That is, the slit-shaped spectral array of the spectroscope 16 is distributed on the photocathode of the II tube 19. This II tube 19 emphasizes the image of the spectral train and forms the image on the phosphor screen on the emission side.
This image is captured by an image pickup tube 20, and its output signal is processed by a processor 21 and then sent to a TV monitor 2.
4 and a stone spectrum 26 is displayed. On the other hand, the other detection light split by the beam spiriter 14 is sent to the TV camera 23. At this time, the lens 22 is used to form a stone image 25 sent by the optical fiber channel 8 onto the photocathode of the TV camera 23. The output signal from the TV camera is processed by a processor 21 and then sent to a TV monitor 24 where a stone image 25 is displayed.
In this way, the processor 21 displays two images (videos), namely the stone image 25 and the stone spectrum 26, on the TV monitor 24.

The timing of the pulsed laser generator 4 and the pulsed white light source 3 is determined by a timing circuit 28.
controlled by. That is, the laser light 11 and the white light 12 are not emitted at the same time, but are emitted alternately in time. This is controlled by a trigger signal issued from timing circuit 28. If two lights are emitted at the same time, the stone 2 will pass through the fiber channel 8.
The reflected white light from the stone and the detection light emitted from the stone 2 by laser irradiation reach the II tube 19 at the same time. Since the amount of reflected white light is greater than the detection light, the detection light is buried in this white light, making it difficult to detect the spectrum of stone 2.
II tube 19 is damaged by the strong reflected white light. To avoid this problem, the two lights are emitted alternately. The gate circuit 29 receives reflected white light.
When it enters the tube 19, it outputs a gate signal that prevents the II tube 19 from operating. When reflected light enters the II tube 19 due to this gate signal,
The voltage applied to the photocathode is cut off, and the multiplication function of the II tube 19 is stopped. In Fig. 4, a shows the time relationship between the laser beam 11, b the emission spectrum obtained by irradiating the laser beam 11, and the white light 12, and shows the case where the pulse repetition frequency is 10 Hz. . Also, the laser light pulse width is approximately
The pulse width of the white light is approximately 20 msec. 27
is a laser irradiation condition setting device that measures and judges stone components from the stone spectrum 26, and accordingly,
This is for setting the laser wavelength, laser energy, pulse repetition frequency, etc. suitable for crushing the stone 2.

FIG. 3 shows a specific example of the configuration of the pulse laser generator 4 used in the apparatus of the present invention.
The inner surface of the laser head 40 is finished to be highly reflective, and a flash lamp 41 and a cell 42 are housed inside. Of these, cell 42
has a dye solution inlet 43 and a dye solution outlet 44, through which the dye solution that generates laser light flows in and out. On the axis of the cell 42 (which coincides with the laser optical axis), a total reflection mirror 45 and a partial reflection transmission mirror 46 are arranged at the rear and front, respectively, and the flash lamp 41 is powered by electricity supplied from a power source 48. When discharged and emitted light with energy, the dye within the cell 42 is excited to emit fluorescence. The fluorescence from this dye undergoes multiple reflections between the total reflection mirror 45 and the transmission mirror 46, and the light intensity increases and becomes the laser beam 11, which passes through the transmission mirror 46 and forms the optical fiber channel shown in FIG. 7 will be introduced. Although not shown, the flash lamp 41 needs to be water-cooled in order to operate stably over a long period of time. The wavelength variable device 47 is for varying the laser wavelength, and can vary the wavelength by a signal from the laser irradiation condition setting device 27 (the details of the wavelength variable device 47 will be explained later).

The pulsed laser generator 4 is configured to be able to use three types of dyes. That is, 49, 50, 51, 52, 53, 5 of the dye solution supply system.
4, 55, 56, 57 are electromagnetic valves, and corresponding switches 58, 59, 60, 61,
The opening/closing operations of 62, 63, 64, 65, and 66 result in energization or power outage, and control the opening/closing of the electromagnetic valves. Between the electromagnetic valves 49 and 50, 51,
Liquid reservoir 6 between 52, 53 and 54, and 55 and 56
7, 68, 69, and 70 each contain a cleaning solution (methyl alcohol), a first dye solution, a second dye solution,
A third dye solution is contained (the first dye, second dye, and third dye use methyl alcohol as a solvent). Among these, liquid reservoirs 68, 69,
At 70, the dye solution is cooled for stable laser oscillation. In addition, supply tanks 71, 72, 7
3 and 74 are cleaning liquid (methyl alcohol), respectively.
It is prepared to replenish the solutions of the first, second and third dyes, and is supplied from here when the dyes deteriorate and need to be replaced with new ones. Although not shown, the supply tank 7
1, 72, 73, 74 and liquid reservoirs 67, 68, 6
9 and 70 are connected by electromagnetic valves,
Open the valve to supply new fluid as needed.

Next, the operation of this dye solution supply system will be explained.
When performing laser oscillation with the first dye, only the electromagnetic valves 51 and 52 are opened, and the other electromagnetic valves 49 and 52 are opened.
Close 50, 53-57. The first dye solution is circulated through a circuit connecting the cell 42 and the liquid reservoir 68 by a circulation pump 76, and discharges light from the flash lamp 41 to excite the first dye to obtain laser light 11.
Next, when changing from the first dye to the second dye,
First, for cleaning, only the electromagnetic valves 49 and 50 are opened and the other electromagnetic valves are closed. A cleaning liquid (methyl alcohol) flows into the cell 42 and is cleaned. The methyl alcohol after washing is discarded into the waste liquid reservoir 75 by opening the electromagnetic valve 57. After that, close the solenoid valves 49, 50, 57, and close the solenoid valve 5.
3 and 54 are opened, and the second dye is circulated through a circuit connected to the cell 42 and the liquid reservoir 69. The second dye laser beam 11 is obtained by discharge light emission from the flash lamp 41. Laser light 1 by third dye
In the same manner as described above, when obtaining No. 1, a laser beam is obtained using a solution of the third dye after washing with a washing liquid (methyl alcohol).

In the embodiment, the cell 42 has an inner diameter of 4
A quartz tube with a length of 20 mm and a quartz window plate attached to both ends was used, and the first, second, and third dyes were Coumarin 504, Coumarin 480, and Coumarin, respectively.
445 was used. In addition, each dye was dissolved in methyl alcohol and used at a concentration of about 0.05 to 0.4 mM.

The wavelength variable device 47 is for varying the wavelength of the laser beam. Specifically this is an acousto-optic filter, for example tellurium dioxide (TeO ₂ ).
A traveling wave of ultrasonic waves is created in a crystal, light is diffracted by this ultrasonic wave, and the property that the wavelength of this diffracted light is uniquely determined by the frequency of the ultrasonic wave is utilized.
Therefore, using the previously known relationship between ultrasound frequency and wavelength, the laser wavelength can be varied by changing the ultrasound frequency.

The wavelength of the laser is largely determined by the dye, but can be changed in detail by the wavelength variable device 47. For example, the pigments of Coumarin 504, Coumarin 480, and Coumarin 445 are 485-520, 455-495, respectively.
It has an oscillation band in the range of 420 to 460 nm,
The wavelength variable device 47 can also fix or vary the laser wavelength within these bands. The laser irradiation condition setter 27 sets the ultrasonic frequency for varying the laser wavelength, the input energy of the flash lamp 41 for varying the laser light energy, the laser light pulse repetition frequency, etc.

When a stone is irradiated with laser light, the stone 2 evaporates from the irradiated surface, creating a kind of plasma state. At this time, an emission spectrum from the elements constituting the stone 2 is observed. This is a technique known as "laser microprobe method." Therefore, we decided to investigate this emission spectrum.
Since the constituent components of the laser beam can be known, a laser wavelength suitable for this constituent component can be set.
Since the actual stone 2 contains various elements, it is difficult to determine which wavelength is most suitable for the composition ratio of those elements, that is, whether it has the effect of crushing the stone.
I'll look into it beforehand. In order to avoid damaging biological tissue with the laser beam 11, it is desirable that the laser wavelength be in the range of 450 to 510 nm, where tissue absorption is low, so the actual laser irradiation wavelength should be within this range and take into account the above matters. are selected taking into consideration.

When observing the calculus spectrum 26 on the TV monitor 24, a strong spectrum can be obtained by focusing the laser beam 11 on the surface of the calculus 21 and irradiating it. For this purpose, it is preferable that the tip of the optical fiber 7 has a convex lens shape so that the laser beam 11 can be focused. Further, the laser wavelength for observing the calculus spectrum 26 may be any of those obtained from the first dye, the second dye, and the third dye (the spectrum can be obtained from any of them).

"Effects of the Invention" Since the present invention is configured as described above, it has the following effects.

1. The type of stones inside the body can be investigated without removing them from the body.

2. When crushing stones, laser irradiation conditions can be set according to the type of stone in a way that is safe for the human body, so the stones can be crushed efficiently in a short time, reducing patient pain. can.

3. Capable of component analysis and crushing of urinary stones, gallstones, etc.

Although the example described above shows a case in which three dyes are provided, the number of dyes can be increased or decreased as appropriate depending on the situation without departing from the spirit of the present invention.

Further, in the embodiment, the laser wavelength variable device 47
Although an acousto-optic filter is used as the filter, other types of filters may be used. For example, a dispersive element such as a diffraction grating or a prism may be used. In this case, a mechanism (for example, a motor drive mechanism) is used to change the angle at which light enters the diffraction grating or prism in response to a signal from the laser irradiation conditions during wavelength tuning.

Although methyl alcohol was used as the dye washing liquid in the above embodiments, other liquids (ethyl alcohol, water, etc.) may be used.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a stone crushing device according to the present invention, FIG. 2 is a perspective view of an endoscope, FIG. 3 is a block diagram of a pulsed laser generator, and FIG.
The figure is a pulse waveform diagram, and FIG. 5 is an explanatory diagram of a conventional device. 1...Ureter, 2...Stone, 3...Pulsed white light source,
4...Pulse laser generator, 5...Observer, 6,
7, 8...Optical fiber channel, 9...Endoscope, 1
...forceps hole, 11...laser light, 12...white pulsed light, 13...detection light, 14...beam splitter, 1
5...Condensing lens, 16...Spectroscope, 16a...Incidence slit, 17...Reflector, 18...Concave diffraction grating, 1
9...Image intensifier (II) tube, 20...
Image pickup tube, 21... Processor, 22... Lens, 23
...TV camera, 24...TV monitor, 25...stone image,
26... Stone spectrum, 27... Laser irradiation condition setter, 28... Timing circuit, 29... Gate circuit, 40... Laser head, 41... Flash lamp, 42... Cell, 43... Dye solution inlet, 44...
Dye solution outlet, 45... Total reflection mirror, 46... Transmission mirror, 47... Wavelength variable device, 48... Power supply, 49-57
...Solenoid valve, 58-66...Switch, 67-7
0...liquid reservoir, 71-74...replenishment tank, 75...waste liquid reservoir, 76...circulation pump.

Claims (1)

[Scope of Claims] 1. A device for crushing a calculus using a laser beam while observing it under white light irradiation, comprising: a white light source that emits pulsed white light for illuminating the calculus necessary for monitoring the calculus; and a device for crushing the calculus. a pulsed laser generator that emits the pulsed laser light necessary for the purpose of A light splitter that splits the detection light transmitted from the endoscope into two, a spectrometer that spectrally spectrally spectra one of the split lights, and an image intensifier that doubles the spectral image obtained by this spectrometer. a magnifying device, an imaging tube for capturing an image obtained by the image multiplier, and an imaging tube for capturing a stone image obtained by the other light split by the light splitter;
A TV camera, a processor that processes signals from the image pickup tube and the TV camera and sends a video signal to a TV monitor, and a TV monitor that displays a stone image and a spectral image using the video signal sent from the processor. and a laser irradiation condition setting device for changing the output, repetition rate, and wavelength of the pulsed laser light obtained from the pulsed laser generator by analyzing the spectral image displayed on the TV monitor. A stone crushing device characterized by: 2 The pulse laser generator excites the dye solution contained in the cell with a flash lamp,
A dye laser light source capable of emitting laser light from the dye, and a dye solution circulation pump, a dye solution reservoir, and a dye solution reservoir between a dye solution inlet and a dye solution outlet attached to the cell. 2. The stone crushing device according to claim 1, further comprising fluid circuits connected to valves located at the front and back for opening and closing the flow of the dye solution and for stopping the flow of the dye solution. 3. The dye distribution system, which is a combination of a dye solution reservoir and valves connected before and after the dye solution reservoir, is provided for each different dye, and they are connected in parallel. The stone crushing device according to claim 2, characterized in that: 4. A combination of a dye solution reservoir and a valve connected before and after the dye solution reservoir, and a combination of a dye cleaning solution reservoir and a valve connected before and after the dye solution reservoir are connected in parallel to the dye distribution path. The stone crushing device according to claim 2. 5. The stone crushing device according to claim 2, 3 or 4, wherein the valves disposed before and after the dye solution reservoir and the dye cleaning solution reservoir are electromagnetic valves that are opened and closed by electrical signals. 6. The stone crushing device according to claim 1, wherein the pulsed white light and the pulsed laser light are emitted alternately in time.