JPS6037635B2 - Gas laser emission device - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention stably obtains optical power in a wide range from low output to high output by switching between two sinks, and is particularly useful when applied to medical equipment. The present invention relates to a gas laser emitting device that improves safety by eliminating the danger associated with laser switching.

(Prior art) Conventionally, carbon dioxide lasers have been used as medical devices in laser scalpels and vascular anastomosis devices, but in this case, laser scalpels usually require a light output of about 1 to 1 μm, while vascular anastomosis devices require a light output of 5. - A weak output of about 100 skin w,
.

As described above, since the required output levels of the two systems are greatly different, conventionally each has been configured as a dedicated machine. By the way, in a series of surgeries where both incision and anastomosis are performed alternately, it goes without saying that it is extremely desirable to be able to switch the power range of a single device so that it can be used for both purposes. As mentioned above, there are various technical obstacles to incorporating one power range with greatly different outputs into a single device, and therefore it has not been realized in the end.The problems will be described below. , which shows a conventional carbon dioxide laser emission device, in which 1 is a gas laser discharge tube, 2 is a high-voltage power supply, and 3 is a discharge current adjustment circuit, which constitute a laser oscillation section.

4 is a beam splitter consisting of a partially transmitting mirror, which converts the laser beam Po emitted from the laser oscillation unit into a working beam P.4. and monitor light P2.

The working light P is focused by an optical system (not shown) and irradiated onto an affected area, etc., and is used for incision of living tissue and blood vessel anastomosis. On the other hand, the monitor light P2 is detected by the photodetector 5, and its detection output is negatively fed back to the discharge current adjustment circuit 3 via the control circuit 6 to control the laser output. The working light P, which is split by the beam splitter 4, and the monitor light P2 have a value of, for example, P2/P, = 1/1 Chikuka degree, and the working light P, is as large as several tens of watts, as in the case of a laser scalpel. When a stable optical output is obtained with relatively little output loss,
However, if this device is used for applications that use weak working light P, ranging from several mW to several tens of W, as in the case of vascular anastomosis, the following problems arise. be.

That is, if a beam splitter with the above-mentioned splitting ratio is used, the monitor light P2 will have an extremely small value of 0.1 to 10 ww, and controllability will inevitably deteriorate.
In other words, if one beam splitter is used as both a laser scalpel and a blood vessel anastomosis device, the monitor light P2 will change by more than three orders of magnitude, from 0.1 w to several w. Therefore, the photodetector 5 usually uses a highly sensitive thermopile element, but an element that can accurately detect light energy of 0.1 w becomes a permanent element when loaded with light energy of the order of w. Conversely, high-output detection elements have low sensitivity to weak energy and cannot be used for control. This cannot be avoided in principle as long as light energy is detected using a thermoelectric stack element. In addition, in carbon dioxide laser oscillation, in order to cover a three-digit range from low output to high output and obtain stable output, it was necessary to obtain extremely sophisticated and complicated control means. In order to stably obtain high output and low output with the same device, it is necessary to overcome the above problems.

One solution is to prepare two splitters with different transmittances, so that the working light P. The key is to select and use a splitter according to the required output. In this way, the oscillation output range of the laser oscillation section can be narrowed, and
It also solves the photodetector problem. However, at the same time, it is necessary to switch the control system in accordance with the switching of the beam splitter, and if this is manually switched each time, the operation will be very complicated and there will still be a risk of switching errors.
(Purpose of the invention) Therefore, the present invention switches between two ranges, high output and low output, by switching the beam splitter, and at the same time detects the switching of the beam splitter and uses the detected output to set the reference setting value of the control system. The present invention provides an extremely safe gas laser emitting device that can be used as both a laser scalpel and a blood vessel anastomosis device.

Hereinafter, embodiments will be described in detail with reference to the drawings. (Embodiment) Fig. 2 shows an embodiment of the present invention, in which the same reference numerals as in Fig. 1 indicate the same elements, and 11
Beam splitters a and 11b have different transmittances, for example, P2/P, and the splitting ratio is 1.1a is 1/10, and 11b is 10/1.

12a and 12b are beam splitters 11a and 1, respectively.
1b is set at the normal position; 13 is a set value switch that outputs a reference signal e or e2 predetermined by the detection signal of the position sensor 2a or 12b; 14 is a set value switch that outputs reference signal e or e2
This is an error amplifier that compares the detection signal of the photodetector 5 with the detection signal of the photodetector 5, and outputs a control signal for the discharge current adjustment circuit 3.

Furthermore, when both the beam splitters 11a and 11b are not at the normal set position, that is, when the beam splitter is in an intermediate position during switching, etc., it detects that the beam splitter is in the intermediate position, and issues a signal to cut off the high voltage power supply 2 and start laser oscillation. This is an intermediate position detector that stops the In the above configuration, when used as a laser scalpel, the beam splitter 11a is selected and set.

At this time, if the working light P, is about several tens of W, the monitor light P2
is on the order of several w. The position sensor 12a detects this by setting the beam splitter 11a, and the reference signal e for the high output range is output based on the detected power signal. This reference signal e, is compared with the output of the photodetector 5 that detected the monitor light P2 in the error amplifier 14, and the discharge current adjustment circuit 3 is controlled by this output to maintain stable oscillation of the required output. Next, when it is used for blood vessel anastomosis, it is switched to the beam splitter 11b. At this time, if the working light P, is about several degrees W, the monitor light P2 is 1
It is on the order of 0 mw, and the high output photodetector 5 can be used as is. The position sensor 12b detects the setting of the beam splitter 11b, and the set value switch 13 outputs a reference signal e2 for the low output range. Thereby, as in the case of the high output range, it is possible to stably maintain oscillation of the required output in the laser discharge section. Furthermore, since the intermediate position detector 15 detects this during the beam splitter switching and stops the oscillation, there is no possibility that the laser beam will inadvertently damage living tissue. Note that the position sensors 2a and 12b that detect the positions of the beam splitters 11a and 11b may be of a mechanical contact type such as a microswitch, or may be a non-contact type detection element such as a magnetic sensor or an optical sensor.

(Effects of the Invention) As explained above, according to the present invention, predetermined reference setting values are automatically selected in response to switching between a high output range and a low output range. ,
It is possible to prevent malfunctions caused by switching, greatly improving operability and safety.

Furthermore, when the beam splitter is not set in the correct position and is offset, the high voltage circuit is cut off and oscillation is stopped, further increasing safety. In this way, laser light ranging from low output to high output can be stably and safely emitted by the scissors, so it can be used both as a laser scalpel and as a blood vessel anastomosis device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example, and FIG. 2 is a block diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Gas laser discharge tube, 2...High voltage power supply, 3...Discharge current adjustment circuit, 5...Photodetector, 11a, 11b...Beam splitter, 12a ,1
2b...Position sensor, 13...Setting value switch, 14...Error amplifier, 15...Intermediate position detector, P. ...Work light, P2...
・Monitor light. Figure lFigure 2

Claims (1)

[Claims] 1. A laser oscillation section consisting of a gas laser discharge tube, a high-voltage power supply, and a discharge current adjustment circuit, and a beam splitter section that splits the laser light emitted from the laser oscillation section into working light and monitor light. and a monitor light detection section that detects the monitor light, and the beam splitter section is composed of two beam splitters with different splitting ratios, and the beam splitter is selected and switched according to the required output range. a switching detection means for detecting a switching mechanism; a means for outputting a predetermined reference signal according to a signal from the switching detection means; 1. A gas laser emitting device comprising: a means for determining and outputting a control signal for the discharge current adjusting circuit by comparing the two. 2. Claim 1, wherein the switching detection means outputs a signal to cut off the high voltage power supply and stop laser oscillation when neither of the two beam splitters is in a normal set position. The gas laser emission device described in Section 1.