JPH02228974A - Medical laser apparatus - Google Patents

Abstract

PURPOSE:To avoid the continuation of the irradiation of a region other than a necessary range with laser beam without being aware of this irradiation state by mounting a control means discriminating the over-radiation of a living boyd part having an electrode arranged thereto with laser beam on the basis of the signal generated by a detection means to stop the oscillation operation of a laser oscillator. CONSTITUTION:When a measured current (i) is lower than a predetermined value, the electrode 11 in the body is regarded to be not sufficiently brought into contact with a living body and a current measuring device 8 sends the signal corresponding to this state to a laser oscillator 1 to perform control so that laser beam is not oscillated from the laser oscillator 1. When the current (i) is equal to or more than said value, the electrode 11 in the body is regarded to be sufficiently brought into contact with the living body to bring the laser oscillator 1 to such a state that oscillation operation is possible. The current measuring device 8 always compares the stored current value (i) with the current value i' during irradiation and, when the change quantity i'-i exceeds a predetermined value, for example, 0.1mA, a stop signal 12 is transmitted to the laser oscillator 1 to automatically stop the oscillation of laser beam. By this method, the continuous irradiation of the normal tissue of a living body other than a lesion part 6 can be prevented and safety is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a medical laser device that performs treatment by irradiating a lesion such as cancer in a living body with laser light.

[Prior Art] Conventionally, a device using this type of laser device is known from Japanese Patent Laid-Open No. 61-203952. This laser device is used in combination with an endoscope when treating a lesion in a body cavity by irradiating the lesion with laser light. That is, in this case, the laser fiber probe is inserted into the body cavity through the forceps channel of the endoscope, and the lesion is irradiated with laser light through the laser fiber probe while observing through the observation window of the endoscope. There is.

[Problems to be Solved by the Invention] However, during irradiation with laser light, it is common for the irradiated area to become difficult to see due to the flash of light, and for this reason, the laser beam irradiates areas other than the lesion that should be irradiated. There was a risk that it would be difficult to notice even if it was present, and that it could cauterize and cause necrosis of normal tissue. Therefore, in order to ensure safety, it was sometimes necessary to temporarily stop the laser beam irradiation and check.

The present invention has been made with attention to the above-mentioned problems, and its purpose is to provide safety that prevents the laser beam from continuing to be irradiated without noticing even if a part other than the required area is irradiated with a laser beam. The purpose of the present invention is to provide a medical laser device.

[Means and effects for solving the problems] In order to solve the above problems, the present invention uses an irradiation detection electrode installed around the irradiation target site to measure the electrical characteristics of the surrounding tissues by D.
The system is designed to stop the laser beam irradiation if it is detected that the electrical characteristics of the surrounding tissues have changed during the laser beam irradiation. This makes it possible to avoid continuing irradiation even if a portion other than the required range is irradiated with laser light.

[Embodiment] FIGS. 1 to 4 show a first embodiment of the present invention. Reference numeral 1 in FIG. 1 indicates a laser oscillator, and a laser probe 2 is detachably attached to the laser oscillator 1.

This laser probe 2 can be introduced through a forceps channel 4 of an endoscope 3 into a living body 5 into which the endoscope 3 has been inserted. Under operation and observation using the endoscope 3, the emitting tip of the laser probe 2 is made to face a lesion 6 within the body cavity of the living body 5.

The alternating current type g7 of the laser oscillator 1 generates weak alternating current that does not adversely affect the living body 5 or other equipment, and the generated voltage and frequency may be variable, but in this first embodiment, It is constant while the oscillation operation is performed. One end of the AC power source 7 is connected to a current measuring device 8 as a detection means. Further, a plate-shaped extracorporeal electrode 9' having a relatively large area and placed in close contact with the body surface of the living body 5 is connected to the current Δ-1 regulator 8. The current n1 regulator 8 has a built-in storage section that stores the measured current value i.

Also, is it an exchange type? The other end of R7 is connected to an internal electrode 11, which will be described later, via a lead wire 10. This internal electrode 11
is constructed as shown in FIG. 2(a) or (b). As shown in FIGS. 2(a) and 2(b), a plurality of electrode wires 11a having appropriate elasticity at the tip of the lead wire 10
,llb.

It is structured by branching into lie. Each electrode wire 11a,
llb and llc branch out and protrude forward as they spread out.

Further, the laser probe 2 and the lead wire 10 may be completely separate bodies, or may be integrally formed. In the case of separate bodies, both may be passed through the same forceps channel 4 of the endoscope 3 as shown in FIG. 1, or may be passed through another forceps channel (not shown). On the other hand, when both are integrated, a lead wire 10 is attached to the side surface of the laser probe 2 along its longitudinal axis, as shown in FIG. 2(a).
Alternatively, a lead wire 10 may be spirally attached to the side surface of the laser probe 2 as shown in FIG. 2(b).

Each electrode wire 11a, llb of the internal electrode 11.

Since each of the 11C has appropriate elasticity, its tip closes within the forceps channel 4 of the endoscope 3 as shown in FIG. 3(a), allowing smooth movement within the forceps channel 4. Further, when the lead wire 10 is pushed out alone or together with the laser probe 2, and its tip is pushed out from the tip opening of the forceps channel 4, as shown in FIG. 3(b), the electrode wire 11a, ll
b.

The tip of 11c opens radially.

Next, the operation of this embodiment device will be explained. The laser probe 2 is inserted into the body cavity through the forceps channel 4 in the inner NvL 3 inserted into the body, and the lead wire 10 is protruded from the tip opening of the forceps channel 4. As a result, the tip of the internal electrode 11 opens. Then, as shown in FIG. 4, each electrode wire 1 of the opened intracorporeal electrode 11 is
The tips of 1a, 11b, and llc are brought into contact with the surrounding areas surrounding the lesion 6, respectively. In other words, it is brought into contact with a normal tissue site that is close to the diseased area 6 and does not require treatment. , the tips of the electrode wires 11a, 11b, 11c that straddle each other may be punctured into living tissue instead of simply being brought into contact with each other. On the other hand, an extracorporeal electrode 9 is brought into close contact with the outer surface of the living body 5. If arranged in such a state, a current i will flow through the thread path. This current l is then measured by the current measuring device 8.

In general, the electrical impedance of the living body 5 varies depending on the part of the living body and the frequency of the AC Fi, 7, but in the case of human gastric mucosa, it is about IKΩ at 14 KHz.

At this time, if the voltage of the AC power supply 7 is 2V, the flowing current will be about 2mA.

Therefore, if the measured current i is less than this value, it is assumed that the internal electrode 11 is not in sufficient contact with the living body 5, and the current Δ11 regulator 8 sends a corresponding signal to the laser oscillator 1. , controls the laser oscillator 1 so that it does not emit laser light.

On the other hand, if the current l is above this value, it is assumed that the in-body electrode 11 is in sufficient contact with the living body 5, and the laser oscillator 1 is enabled to oscillate, and a soft switch (not shown) is pressed, etc. By doing this, it is possible to oscillate laser light.

By the way, each electrode wire 11a of the internal electrode 11.

Assume that there are three 11b and 1ic, and the flowing current i is equal to or higher than the predetermined value mentioned above. Furthermore, each electrode I
Assume that the equivalent impedances between lla, llb, llc and the extracorporeal electrodes are R1, R2°R3, respectively.

Further, a storage section built into the current measuring device 8 stores the measured current value i.

Therefore, after confirming the position using the private greeting vL3, a laser beam is emitted through the laser probe 2 and irradiated onto the lesion 6. Treatment is performed in this way, but if for some reason the laser beam is not accurately irradiated only to the lesion 6 and the irradiation is deviated, the in-body electrode 1
For example, at least one of the normal living tissue parts near the electrode wire 11C is irradiated by mistake. Then, due to the cauterization, the equivalent impedance between the electrode wire 11C and the extracorporeal electrode 9 changes from R3 to R3-, and therefore the flowing current changes from i to 1'.

The current measuring device 8 constantly compares the stored current value i and the current value l- during irradiation, and if the change 1--i exceeds a predetermined value, for example, 0.1 mA, the laser oscillator 1 A stop signal 12 is transmitted to the device to automatically stop the oscillation of the laser beam. Therefore, it is possible to prevent continuous irradiation of laser light to normal biological tissues other than the lesioned area 6, and to ensure safety. In addition, there is little need to stop cautery from time to time and perform irradiation while frequently checking again, and work efficiency is significantly improved.

Note that the current +1?1 regulator 8 may be placed between the AC power source 7 and the internal electrode 11.

FIG. 5 shows a second embodiment of the invention. In this second embodiment, one end of the AC power source 7 is connected to an extracorporeal electrode, and the other end is connected to a plurality of, for example three, current measuring devices 8a, 8b, 8c. Each current measuring device 8a, 8b, 8c has a separate lead wire 10a.
, 10b.

10c is connected. Each lead wire 10a.

Electrodes 11a, llb, and llc of the intracorporeal electrode 11 are connected to the tips of 10b and 10c, respectively.

Further, stop l-signal lines 13a, 13b, 13c are led out from each current n1 regulator 8a, 8b, 8c, respectively, and the ends of these stop signal lines 13a, 13b, 13c are connected to the input side of the OR circuit 14. ing. The output side of the OR circuit 14 is connected to the laser oscillator 1.

In this embodiment, the electrode wires 11a and 11b of each internal electrode 11 are connected to each other before laser beam irradiation.

11C, and if any one of the current values is smaller than a predetermined value, the electrode wire 11a
, llb, llc connected to current measurement M8a, 8
Signals are manually input to the OR circuit 14 from b and 8c. The OR circuit 14 sends a stop signal 1 to the laser oscillator 1 if there is an input signal from one of the plurality of current measuring devices 8a, 8b, 8c.
2, and prevents the laser oscillator 1 from performing the laser oscillation operation.

In addition, when both of the current measuring devices i are below a predetermined value and therefore the ζ laser oscillator 1 sends out a laser beam and performs irradiation, the electrode wires 11 a, 11 b of the electrodes 11 inside the body. , 11 c If the impedance of the tissue in that area changes by irradiating and cauterizing the tissue in the vicinity, the electrode wire 11 a,
Since the current flowing through the terminals 11b and 11c changes, the corresponding current measuring devices 3a and 3b.

Since an input is generated from 8C to the OR circuit 14 and a stop signal 12 is sent to the laser oscillator 1, the laser beam oscillation operation in the laser oscillator 1 is automatically stopped.

In this example, which current 8g1 regulator ga, gb.

If 8c has issued a stop signal, the corresponding current measurement ri8a.

If a notification means such as lighting a light emitting element (not shown) such as an LED provided at the corresponding input section of 8b, 8c or the OR circuit 14 is used, which electrode wire 11a, ll
b. Did you cauterize the tissue near the llc, or which electrode! 11 a.

11b and llc have poor contact with the living body 5.

FIG. 6 shows a third embodiment of the invention. In this third embodiment, a lead 111 to which an internal electrode 11 is connected is used.
0 and the external electrode 9 are connected by an impedance measuring device 15.

This impedance n1 regulator 15 has a built-in AC'v&g, current measuring device, etc., and can determine the impedance size, phase, etc. at each frequency while changing the frequency of the AC power source. There is.

Then, in the same way as described above, before starting the laser beam irradiation, the frequency characteristics such as the impedance and phase of the biological tissue are measured and memorized, and during the irradiation, the tissue near the installation of the internal electrode 11 is cauterized. If this happens, the frequency characteristics will change, so this change is detected and a stop signal 12 is sent to the laser oscillator 1 to stop the laser beam oscillation operation.

However, with the means of this third embodiment, since the frequency is not changed and n1 is constant, the change due to ablation appears larger, so it is necessary to detect the change and measure at a constant frequency. In this case, the oscillation operation of the laser beam can be stopped more reliably than in the case where the oscillation operation of the laser beam is stopped.

FIG. 7 shows a fourth embodiment of the present invention. In this fourth embodiment, the lead wire 10 and the internal electrode 11 are made into cables with a coaxial structure. Make it. Then, an alternating current is passed between the inner electrode 16 and the outer electrode 17, and frequency characteristics such as impedance and phase between the picture electrodes 16 and 17 are measured and detected. Therefore, the laser beam is irradiated to the electrode 16.
When the tissue around 17 is cauterized, this frequency characteristic changes, so this is detected and the laser beam oscillation is stopped. .

In this embodiment, since no extracorporeal electrodes are used, the configuration of the device can be prevented from becoming complicated.

FIGS. 8(a) and 8(c) show a fifth embodiment of the present invention. In the first embodiment, as shown in FIG. 2, the internal electrode 11 is compatible with the direct laser probe 2, but in the fifth embodiment, the in-body electrode 11 is shown in FIG. As shown, a side-to-side type laser probe 2 is employed, and its intracorporeal electrode 11 is oriented in the direction in which the laser beam is emitted. In this way, the internal electrode 1
Since the direction in which the laser probe 1 is derived is directed toward the emission direction of the laser beam, it can also be used with a side-to-side type laser probe 2.

Note that the present invention is not limited to the above-mentioned embodiments, and various other modifications are possible.

[Effects of the Invention] As explained above, according to the present invention, the electrical characteristics of the tissue around the irradiation target area are measured by the irradiation detection electrode placed around the irradiation target area, and the electrical characteristics of the tissue around the area are measured. When a change in the electrical characteristics of the surrounding tissue is detected, the laser beam irradiation is stopped. This makes it possible to avoid continuing irradiation even if a portion other than the required range is irradiated with laser light.

Even if a part other than the required range is irradiated with a laser beam, safety can be ensured since it is possible to prevent the irradiation from continuing without noticing this.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a block diagram of the entire system, and FIGS.
Figure (b) is a side view of the electrode part at the tip of the laser probe, Figures 3 (a) and 3 (b) are explanatory diagrams when the tip of the laser probe is inserted into and taken out of the forceps channel of the endoscope, and Figure 4. 5 is a diagram explaining the usage state, FIG. 5 is a configuration diagram of the entire system showing the second embodiment of the present invention, FIG. 6 is a configuration diagram of the entire system showing the third embodiment of the invention, and FIG. The figure is a configuration diagram of the entire system showing the fourth embodiment of the present invention.
FIG. 8(a) is a side view of a laser probe according to the fifth embodiment of the present invention, and FIG. 8(b) is a front view of the laser probe according to the fifth embodiment of the present invention. 1... Laser oscillator, 2... Laser probe, 3...
...Internal yL mirror, 5... Living body, 6... Lesion area, 8...
・Current measuring device, 11-・Body electrode, lla, llb,
11 c --- Electrode wire, 15 -- Impedance measuring device.

Claims (1)

[Claims] A laser oscillator that emits a laser beam, an electrode that is installed in a biological part around a target area to which the laser beam that is emitted by this laser oscillator is irradiated, a power source that supplies a current to the biological body through this electrode, and a power supply that supplies a current through the electrode. a detection means that detects a change in the electrical characteristics of the living body part through which the electrode has been applied and generates a signal; and a detection means that detects the over-irradiation of the living body part on which the electrode is installed based on the signal generated by the detection means; A medical laser device comprising: a control means for stopping oscillation operation of a laser oscillator.