JPH04285550A - Laser irradiating system - Google Patents

Abstract

PURPOSE:To provide a laser irradiating system capable of conducting laser irradiating treatment without cauterizing parts other than a cautery required part by detecting the form of the cautery required part generated in a celom, and setting the optimum laser irradiating direction for cauterizing the cautery required part on the basis of the detected form. CONSTITUTION:In a laser irradiating system for cauterizing a cautery required part generated in a celom, the form of the cautery required part is detected by an ultrasonic probe 2 having an ultrasonic element 3, and the irradiating part of a laser probe 4 is displaced by an arithmetic circuit 12, a shape memory alloy spring selecting circuit 14 and a shape memory alloy spring 5, whereby the optimum laser irradiating direction for cauterizing the cautery required part is set.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser irradiation system, and more particularly to a laser irradiation system having an ultrasonic element.

0002

[Prior Art] Conventionally, when an endoscope and a laser device are used to perform therapeutic procedures within a body cavity, for example, to stop bleeding or to cauterize malignant tissue such as cancer, animal experiments or desk experiments have been carried out in advance. Laser output, laser irradiation time, etc. were determined according to the treatment details and distance to the subject, and clinical practice was conducted based on these experimental results.

In the case of treatment inside a body cavity, the laser irradiation time is relatively short and the distance from the laser irradiation end to the subject is difficult to ascertain under an endoscope. I don't know how deep the light was irradiated. For this reason, the reality is that treatment by laser irradiation is mostly performed based on the intuition and experience of the surgeon.

[0004] For this reason, there is a risk that the cauterization may be performed too deeply, causing bleeding or perforation, or that unnecessary portions may be burned. On the other hand, there is a risk that the area that should be cauterized may be left unburned, resulting in incomplete treatment.

As a means to solve these problems, a laser device using an ultrasonic diagnostic means using an ultrasonic element has been proposed, as shown in Japanese Patent Publication No. 63-20547.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 2-5936, a laser device that uses a combination of ultrasonic diagnostic means using the above-mentioned ultrasonic elements is applied to remove atheroma formed in blood vessels. is proposed.

[0007] However, the thickness of a thrombus that occurs within a blood vessel, which is an object to be irradiated, is not necessarily uniform, and the narrowed portion is often uneven. However, the above-mentioned special public service
With the laser devices shown in Japanese Patent No. 47 and the above-mentioned Japanese Patent Application Laid-Open No. 2-5936, for example, when irradiating a blood clot in a blood vessel with a laser, the laser cannot be irradiated in the desired direction. There was a problem in that there was a risk of damaging the inner wall of the blood vessel.

[0008]

[Problems to be Solved by the Invention] As described above, in the conventional laser device described above, when performing laser irradiation treatment on a region requiring ablation occurring inside a body cavity, it is difficult to displace the laser irradiation part in a desired direction. Therefore, there was a problem in that there was a risk of cauterizing parts other than the area that needed to be cauterized.

The present invention has been made in view of such problems, and includes a method for detecting the shape of a region requiring ablation occurring inside the body cavity and cauterizing the region requiring ablation based on the detected shape. The purpose of the present invention is to provide a laser irradiation system that can perform laser irradiation treatment without cauterizing areas other than the area requiring ablation by setting an optimal laser irradiation direction.

0010

[Means for Solving the Problems] In order to achieve the above object, a laser irradiation system according to the present invention includes a laser oscillator, a laser beam obtained from the laser oscillator, and an irradiation section provided at the tip of the laser irradiation system. A laser light transmission means whose direction can be freely varied, an ultrasound irradiation detection means that irradiates the inside of a body cavity with ultrasound and detects the reflected waves, and a signal of the reflected waves detected by the ultrasound irradiation detection means is processed. detection signal processing means for obtaining a tomographic image inside the body cavity;
, means for controlling the direction of the irradiation section of the laser beam transmission means based on the tomographic image obtained by the detection signal processing means; and means for controlling the direction of the irradiation section of the laser beam transmission means, and a driving means for displacing the laser beam transmission means so as to direct the laser beam in a predetermined direction.

[0011]

[Function] In the present invention, the inside of the body cavity is irradiated with ultrasonic waves, and the direction of the laser beam transmission means is set based on the tomographic image of the inside of the body cavity obtained by the reflected waves, and the laser beam is directed in the set direction. irradiate.

0012

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] In the following embodiments, a thrombus generated in a blood vessel will be described as an example of a portion requiring ablation occurring inside a body cavity which is a subject to be irradiated with a laser according to the present invention.

FIGS. 1 to 5 relate to a first embodiment of the present invention, and FIG. 1 is a sectional view showing the configuration of the distal end of a catheter in a laser irradiation system that is one embodiment of the present invention;
FIG. 2 is an explanatory diagram showing the system configuration of the present invention, FIG. 3 is a perspective view showing a case where a catheter is inserted into a blood vessel, and FIG. FIG. 5 is an explanatory diagram of the arithmetic processing for selecting directions.
FIG. 4 is an explanatory diagram showing the magnitude of the reflected echo in C) on a time axis.

FIG. 1(a) is a sectional view showing the configuration of the distal end portion of a catheter in a laser irradiation system which is an embodiment of the present invention, and shows a state when a thrombus is observed.

As shown in FIG. 1(a), inside the catheter 1, there is an ultrasonic probe 2 (hereinafter referred to as US probe 2) having an ultrasonic element 3 (hereinafter referred to as US element 3), and an irradiation part with a free end. A laser probe 4, which is a laser beam transmission means for irradiating an object to be irradiated such as a blood clot, and a guide wire 6 for guiding the catheter 1 are provided, and the laser probe 4 and the inner peripheral wall of the catheter 1 are connected to each other. In between, there is provided one or more shape memory alloy springs 5 (hereinafter referred to as SMA springs 5), which are driving parts that displace the direction of the irradiation part of the laser probe 4 and are capable of passing an electric current.

For example, when observing a thrombus, the US probe 2 is protruded from the tip opening of the catheter 1, and the US probe 2 is scanned all around the inner wall of the blood vessel to check the state of the thrombus. The laser irradiation direction is set by observing the object and using the method described later. .

FIG. 1(b) is also a cross-sectional view showing the configuration of the distal end of the catheter in the laser irradiation system which is an embodiment of the present invention, and shows the state in which laser irradiation is actually performed. There is.

When performing this laser irradiation, the US probe 2 and the guide wire 6, which were protruded for observation of thrombi in FIG. The forward irradiation direction of the laser probe 4 is controlled by applying a current to the SMA spring 5 provided between the catheter 1 and the inner peripheral wall of the catheter 1 using a control method described later and adjusting the length of the SMA spring 5. It is designed to emit a laser.

FIG. 2 is an explanatory diagram showing a system configuration diagram of the present invention.

In FIG. 2, a pulse generator 9 is a device that supplies transmission pulses to the US element 3 when observing a thrombus, and is connected to the US element 3. Ultrasonic waves are transmitted to the inner wall of the blood vessel using pulses supplied from the pulse generator 9, while echoes reflected from the transmitted ultrasound waves are received and converted into electrical signals. Further, this US element 3 is connected to an amplifier 10 via a circulator (not shown),
This amplifier 10 is configured to amplify and detect the reflected echo signal received by the US element 3, and its output end is connected to a coordinate converter 11 and an arithmetic circuit 12. This coordinate converter 11 is a converter that converts the coordinates of the output signal of the amplifier 10, and is connected to a monitor 13. This monitor 13 is a device that displays a signal whose coordinates have been converted by the coordinate converter 11, that is, a tomographic image inside a blood vessel as an image. On the other hand, the arithmetic circuit 12 is configured to perform arithmetic processing on the output signal of the amplifier 10 by a method described later, and is connected to the shape memory alloy spring selection circuit 14, and is connected to the shape memory alloy spring selection circuit 14 and uses the arithmetic processing result to select the shape memory alloy spring. This is a circuit that supplies the circuit 14.

This shape memory alloy spring selection circuit 14 (hereinafter referred to as SMA spring selection circuit 14) is a circuit that selects the SMA spring 5 to which current should flow based on the calculation result of the calculation circuit 12. 5 and the control circuit 16. This control circuit 16 is a circuit that controls the laser unit 15 upon receiving a signal from the SMA spring selection circuit 14 indicating the end of operation of the SMA spring 5, and is connected to the laser unit 15. This laser unit 15 is a device that is controlled by the control circuit 16 to generate a laser beam and output it to the laser probe 4, and is connected to the laser probe 4.

First, a transmission pulse is supplied to the US element 3 by the pulse generator 9, and the US probe 2 having this US element 3 rotates around the longitudinal direction of the catheter 1, so that the US probe 2 is rotated against the inner wall of the blood vessel. emits ultrasonic waves in the radial direction. The reflected echo is received again by the US element 3 and converted into an electrical signal. The reflected wave signal converted into an electric signal is amplified and detected by the amplifier 10 and output to the coordinate converter 11 and the arithmetic circuit 12. One of these output signals is converted into a tomographic image signal by the coordinate converter 11 and displayed on the monitor 13 as a tomographic image. The other output signal of the amplifier 10 is supplied to the arithmetic circuit 12 . By determining the position of the guide wire 6 and the time difference between the first echo and the second echo using a method described later in this calculation circuit 12, the thickest part of the thrombus can be recognized, and this calculation result is used as the SMA. It is supplied to the spring selection circuit 14.

Based on the arithmetic processing results obtained in the arithmetic circuit 12, the SMA spring selection circuit 14:
After selecting the SMA spring 5 to which current should flow, this S
A current is applied to the MA spring 5. Then, as a current flows, the length of the SMA spring 5 is varied, and the direction of the irradiation part of the laser probe 4 is displaced. Thereafter, the SMA spring selection circuit 14 transmits to the control circuit 16 that a current has been applied to the SMA spring 5. The control circuit 16 informed of this fact controls the laser unit 15 to enable laser irradiation.

Thereafter, the operator irradiates the laser with a switch such as a foot switch (not shown). After the laser irradiation is completed, the thrombus is observed again using the method described above, and the above operation is repeated until the thrombus disappears.

Next, how to set the laser irradiation direction in the first embodiment will be explained with reference to FIGS. 3 to 5.

In FIG. 3, the catheter 1 is multi-lumen, and includes a guide wire 6 that guides the catheter 1, a US probe 2 that observes the inner wall 17a of the blood vessel, and a blood vessel 1.
It is possible to pass a laser probe 4 (not shown in this figure) which cauterizes a thrombus 18 that has formed inside the tube. Here, the guide wire 6 is assumed to have reflection characteristics close to those of a total reflection material.

First, a tomographic image of the blood vessel 17 as shown in FIG. 4 is obtained using the US probe 2, and the presence of a thrombus 18 is confirmed. Next, by scanning the US probe 2 toward the blood vessel inner wall 17a, each scanning line (A, B in FIG.
, C (shown in three directions) are obtained. Here, in this FIG. 4, for example, the first echo of scanning line A is a1, the second echo is a2, and the same is true for scanning line B. Also, echo c on scanning line C
is a reflected echo of the guide wire 6.

The first echo is a reflected echo of the inner wall of the thrombus, and the second echo is a reflected echo of the inner wall 17a of the blood vessel. Therefore, the larger the time difference t between the first echo and the second echo, the thicker the thrombus 18 is, and the laser irradiation can be focused on that part (see FIG. 5). Figure 5
The emission pulses shown in are respectively emitted from the US element 3, t1 indicates the time difference between the first echo a1 and the second echo a2 of the scanning line A, and t2
are the first echo b1 and the second echo b2 of scanning line B.
It shows the time difference between

[0030] Here, the guide wire 6 is as described above.
Since the ultrasonic wave is almost totally reflected, it can be reliably detected and its position can be confirmed as shown in FIG. Therefore, the thrombus 18 can be cauterized by moving the irradiation section of the laser probe 4 in a desired direction using the above-described method of controlling the SMA spring based on the absolute position of the guide wire 6.

Next, as a modification of the first embodiment, an example in which the method of selecting the laser irradiation direction is different from the method used in FIG. 4 described above will be described with reference to FIG.

FIG. 6 is a tomographic diagram of the blood vessel in which the thrombus shown in FIG. 3 has occurred, and is an explanatory diagram of the arithmetic processing for selecting the laser irradiation direction.

First, in the same way as the above method, the US probe 2
A tomographic image of the blood vessel 17 as shown in FIG. 6 was obtained, and the thrombus 18 was
Confirm that this is occurring. Next, three arbitrary points (a, b, c in FIG. 6) on the inner wall of the blood vessel are detected from this tomographic image, a circle including these three points is found, and its center point (d in FIG. 6) is determined. Also, any three points on the inner wall of the thrombus (a', b', c in Fig. 6)
') is detected, and a circle including these three points is found in the same manner as above, and its center point (d' in FIG. 6) is found. Then, the laser irradiation direction may be controlled so that the center point d' of the thrombus 18 is the same as the center point d of the blood vessel 17. Here, as described above, since the guide wire 6 substantially totally reflects the ultrasonic waves, it can be reliably detected as shown in FIG. 5, and its position can also be confirmed. Therefore, the thrombus 18 can be cauterized by moving the irradiation section of the laser probe 4 in a desired direction using the above-described method of controlling the SMA spring based on the absolute position of the guide wire 6.

In addition to the method of automatically setting the laser irradiation direction through arithmetic processing as shown in the first embodiment, it is also possible to manually set the direction of laser irradiation by referring to a tomographic image of a thrombus obtained by thrombus observation. There is also a method of setting the laser irradiation direction, which will be explained with reference to FIG.

This method of manually setting the laser irradiation direction is a system in which the arithmetic circuit 12 shown in FIG. 2 is omitted and the thrombus observation means and the laser irradiation direction setting means are separated. In this laser irradiation system, the operator uses the
The MA spring selection circuit 14 is operated to set the laser irradiation direction, and the system is the same as the first embodiment described above except for the operation performed by the operator.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8.

FIG. 7 is a sectional view showing the configuration of the distal end portion of a catheter in a laser irradiation system according to a second embodiment.

As shown in FIG. 7, a plurality of US elements 3 are
A balloon 19 is provided on the outer periphery of the distal end portion of the catheter 1 and has an annular shape or a plurality of expandable and retractable balloons 19 . Inside the catheter 1, a laser probe 4 and an SMA spring 5 having a structure similar to that of the first embodiment are provided.

First, a tomographic image inside a blood vessel is obtained in the same manner as in the first embodiment, and then the center point of the blood vessel is obtained in the same manner as in the second embodiment. Further, as in the first embodiment, the laser probe 4, whose laser irradiation part can be displaced by the SMA spring 5 through which a current can flow, is positioned at the center of the blood vessel determined by the above method. Laser irradiation is performed on the thrombus 18 under control in the same manner as in the first embodiment (see FIG. 8).

Here, as shown in FIG. 8, since the catheter 1 is fixed to the blood vessel wall by a balloon 19 provided on the outer periphery of the catheter 1, more reliable laser irradiation is possible.

[0041] The catheter 1 using this balloon 19
The fixing means may be used in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIGS. 9 and 10.

FIG. 9 is a perspective view showing the internal structure of the catheter in the third embodiment, and FIG. 10 is an explanatory diagram showing the state of the tip when the catheter is rotated in the third embodiment. be.

As shown in FIG. 9, the laser probe guide 21 is installed inside the catheter in the radial direction and is supported by a holder 20 provided at the distal end of the catheter. It has a circular shape with a hole, a laser probe 4 is disposed inside the hole, and the structure is such that the irradiation part of the laser probe 4 can be displaced in the radial direction of the catheter. Further, inside the laser probe guide 21, there is an SMA spring 5 provided between the inner wall of the laser probe guide 21 and the laser probe 4, which functions similarly to the first embodiment. There is.

By applying a current to this SMA spring 5, the irradiation part of the laser probe 4 is displaced on the radius of the catheter inside the laser probe guide 21 in the same manner as in the first embodiment.

Furthermore, as shown in FIG. 10, by rotating the catheter and displacing the irradiation part of the laser probe 4 by passing a current through the SMA spring as described above,
The irradiation part of this laser probe 4 can be displaced to all positions of the cross section of the tip of the catheter.

On the other hand, FIG. 11 shows the image guide 23 and
A laser device having a light guide 23, a laser probe 4 and a guide wire 6 is shown.

As shown in FIG. 11, this laser device has a structure in which the guide wire 6 has a channel near the laser probe 4, so that the catheter inserted into the blood vessel cannot be advanced by the thrombus. When this happens, the guide wire 6 may become an obstacle, making it impossible to irradiate laser light from the laser probe 4.

In contrast to the laser device shown in FIG. 11 above, in the laser irradiation device shown in FIGS. 12 and 13, the guide wire 6 and the laser probe 4 are arranged so as to sandwich the US probe 2. . The laser device shown in FIG. 12 has a US element 3 on the side of the US probe 2,
It has a configuration that allows scanning in the radial direction. In this laser device, since the guide wire 6 and the laser probe 4 are disposed at a separate position, laser irradiation is possible even when a thrombus becomes an obstacle as in the laser device shown in FIG. 11. Further, the laser device shown in FIG. 13 has a configuration in which a US element 3 is provided in front of the US probe 2 and is capable of scanning in the sector direction, and similar to the laser device shown in FIG. Laser irradiation is possible even in cases where thrombi pose an obstacle.

[0050]

As explained above, according to the present invention, the shape of the part requiring ablation occurring inside the body cavity is detected, and based on the detected shape, the optimal laser irradiation is performed to cauterize the part requiring ablation. Setting the direction has the effect that laser irradiation treatment can be performed without cauterizing areas other than the area requiring ablation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of the distal end portion of a catheter in a first embodiment.

FIG. 2 is an explanatory diagram showing the system configuration of the present invention in a first embodiment.

FIG. 3 is a perspective view showing a case where a catheter is inserted into a blood vessel in the first embodiment.

FIG. 4 is an explanatory diagram of calculation processing for selecting a laser irradiation direction in the first embodiment.

FIG. 5 is an explanatory diagram showing the magnitude of reflected echoes on the scanning line of the US probe on a time axis in the first embodiment.

FIG. 6 is an explanatory diagram of calculation processing for selecting a laser irradiation direction in a modification of the first embodiment.

FIG. 7 is a sectional view showing the configuration of the distal end portion of the catheter in the second embodiment.

FIG. 8 is a perspective view showing a case where a catheter is inserted into a blood vessel in a second embodiment.

FIG. 9 is a perspective view showing the internal configuration of a catheter in a third embodiment.

FIG. 10 is an explanatory diagram showing the state of the distal end of the catheter to be rotated in the third embodiment.

FIG. 11 is a perspective view of a conventional laser device.

FIG. 12 is a cross-sectional view of a catheter of a laser device capable of scanning in the radial direction.

FIG. 13 is a cross-sectional view of a catheter of a laser device capable of scanning in the sector direction.

[Explanation of symbols]

1...catheter 2...Ultrasonic probe 3...Ultrasonic element 4...Laser probe 5...Shape memory alloy spring 6...Guide wire 9...Pulse generator 10...Amplifier 11...Coordinate converter 12...Arithmetic circuit 13...Monitor 14...Shape memory alloy spring selection circuit 15...Laser unit 16...Control circuit

Claims (1)

[Claims] 1. A laser oscillator, a laser beam transmission means for transmitting the laser beam obtained from the laser oscillator, and capable of freely changing the direction of an irradiation part provided at the tip;
Ultrasonic irradiation detection means for irradiating ultrasound into the body cavity and detecting the reflected waves; and detection signal processing means for processing the signal of the reflected waves detected by the ultrasound irradiation detection means to obtain a tomographic image of the inside of the body cavity. and means for controlling the direction of the irradiation section of the laser beam transmission means based on the tomographic image obtained by the detection signal processing means; and means for controlling the direction of the irradiation section of the laser beam transmission means. 1. A laser irradiation system comprising: a drive means for displacing the laser beam transmission means so that the laser light transmission means is oriented in a predetermined direction.