JP7302789B2 - Phototherapy device and method of operating phototherapy device - Google Patents

Description

The present invention relates to a phototherapy device and a method of operating a phototherapy device.

2. Description of the Related Art A phototherapy device is used to irradiate living tissue with a laser beam for the purpose of treatment or treatment assistance, such as promoting blood circulation and metabolism. Among them, in the laser class of the laser safety standard JIS C 6802, if a high-output phototherapy device of class 3 or higher is used for home medical care, conformance to class 1C is an essential requirement. Class 1C requires limiting exposure beyond the intended target tissue. Therefore, the laser irradiation is stopped when the probe equipped with the laser light source of the phototherapy device and the skin at the predetermined site, which is the target tissue, are separated by a predetermined distance, for example, a distance of 12 mm corresponding to one finger. Second, the phototherapy device must have an interlock mechanism.

By the way, the distance between the probe or the laser light source and the skin is detected by an optical sensor or the like, and the laser irradiation is controlled according to the detected value, that is, whether the detected value is within a predetermined allowable range. A phototherapy device is known (US Pat.

Japanese Patent Publication No. 2016-512783 Japanese translation of PCT publication No. 2013-509222

The optical sensor has a light-emitting portion that emits light to a target site and a light-receiving portion that receives light reflected from the target site. When an optical sensor is used in a phototherapy device, the optical sensor may erroneously detect the light reflected from the target site by the laser light source, and an accurate distance signal corresponding to the distance to the target site may not be obtained. be. As a result, the distance to the target site cannot be measured accurately, and laser irradiation cannot be performed appropriately.

An object of the present invention is to provide a phototherapy device capable of accurately measuring the distance to a target site and appropriately performing laser irradiation.

According to one aspect of the present invention, a laser light source that irradiates a target site with a laser, and a distance detection unit that detects a distance to the target site and outputs a distance signal corresponding to the distance, In the irradiation of the laser by the laser light source, a laser irradiation period and a laser stop period are alternately repeated, and the distance detection unit comprises a light emitting unit that emits light to the target site and a light receiving unit that receives light reflected from the target site. wherein the light emission and the light reception are performed during the laser stop period, and laser irradiation by the laser light source is permitted according to the variation amount of the distance signal An apparatus is provided.

According to another aspect of the present invention, in laser irradiation from a laser light source in which a laser irradiation period and a laser stop period are alternately repeated, light is emitted to a target site and reflected from the target site during the laser stop period. a step of detecting a distance to a target site by receiving the light emitted from the target site and outputting a distance signal corresponding to the distance; A method of operating a phototherapy device is provided, comprising:

At least part of the laser wavelength of the laser light source may be included in the light receiving wavelength range of the light receiving section of the distance detection section. The light-receiving part of the distance detection part may be further configured to detect light reflected from the target site by the laser emitted from the laser light source. A reference value may be set based on the distance signal, and laser irradiation by the laser light source may be permitted when the distance signal is within a predetermined range with respect to the reference value. Laser irradiation from the laser light source may be prohibited when the distance signal is out of a predetermined range with respect to the reference value. The reference value may be reset when the distance signal is out of a predetermined range with respect to the reference value. The distance detection unit has a plurality of detection units, and the reference value is set based on the plurality of distance signals when the plurality of distance signals detected by the plurality of detection units fall within a predetermined deviation. good too. The distance detection unit may have a plurality of detection units, and detection of the distance to the target site by the plurality of detection units may be performed sequentially. The distance detection unit detects a detection value obtained by receiving the light reflected from the target site when the light emitting unit emits light and the light reflected from the target site when the light emitting unit does not emit light. The distance signal may be output based on the difference from the detected value of the light received by the light receiving section.

ADVANTAGE OF THE INVENTION According to the aspect of this invention, there exists a common effect of providing the phototherapy apparatus which can measure the distance to a target site|part correctly and can perform laser irradiation appropriately.

FIG. 1 is a schematic diagram of a phototherapy device according to an embodiment of the invention. FIG. 2 is a diagram showing the operation of the probe. FIG. 3 is a diagram showing the relationship between changes in the distance signal and laser irradiation. FIG. 4 is a flow chart showing the operation of the phototherapy device. FIG. 5 is a flow chart showing another operation of the phototherapy device. FIG. 6 is a diagram showing the relationship between laser irradiation and distance signal detection. FIG. 7 is a diagram showing the relationship between the operations of the light-emitting section and the light-receiving section.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Corresponding elements are provided with common reference numerals throughout the drawings.

FIG. 1 is a schematic diagram of a phototherapy device 1 according to an embodiment of the invention, and FIG.

The phototherapy device 1 has a control device 2 , a probe 3 , and a cable 4 electrically connecting the control device 2 and the probe 3 . The control device 2 has one or more processors, a storage section, peripheral circuits thereof, and the like. The control device 2 centrally controls the overall operation of the probe 3, as shown in the flowcharts described later, based on a computer program stored in advance in the storage unit. During the processing, the control device 2 receives signals from various sensors such as an optical sensor, which will be described later, and transmits control signals regarding irradiation and stop of the laser light source. The control device 2 may have an input/output unit, for example, a display unit such as a display, and an input interface such as an operation button or a touch panel.

The probe 3 includes a cylindrical body portion 5, a cylindrical movable portion 6 disposed in the body portion 5 so as to be movable along the axial direction of the body portion 5, and a front end surface of the movable portion 6. It has four optical sensors 7, a laser light source 8 arranged inside the main body 5, an optical window 9 provided on the front surface of the main body 5, and a limit switch 10 arranged inside the main body 5. are doing. The movable portion 6 is biased forward with respect to the body portion 5 by an elastic member (not shown).

The optical sensor 7 and the limit switch 10 are arranged inside the probe 3 so as not to come into direct contact with the skin or the like. As a result, the risk of sebum stains or the like adhering to the optical sensor 7 and the limit switch 10 is reduced, and stable performance can be maintained. Also, the optical sensor 7 and the limit switch 10 are arranged so as not to interfere with the movement of the movable portion 6 and the laser irradiation from the laser light source 8 .

In the laser class of the laser safety standard JIS C 6802, when the phototherapy device 1 equipped with a high-output laser light source 8 of class 3 or higher is used for home medical care, the phototherapy device 1 must conform to class 1C. but not limited to this. A laser light source 8 suitable for home medical care according to other standards or the like can be applied.

FIG. 2(A) shows a state before the probe 3 is pressed against the target tissue of the living body, that is, the target site T, and FIG. 2(B) shows a state where the probe 3 is pressed against the target site T. ing. When the probe 3 is pressed against the target site T from the state shown in FIG. 2(A), the movable part 6 is retracted and the limit switch 10 is turned ON (FIG. 2(B)). That is, the limit switch 10 constitutes a proximity detector that detects that the laser light source 8 has approached the target site T to a predetermined distance and outputs a proximity signal. The output proximity signal is detected by the control device 2 . On the other hand, when the pressure of the probe 3 against the target site T is released, the movable part 6 is retracted by the biasing force of the elastic member, and the limit switch 10 is turned off (Fig. 2(A)).

The four optical sensors 7 are arranged at equal intervals along the circumferential direction on the front end face of the movable portion 6 . The phototherapy device 1 may have one, two or three optical sensors 7, or may have five or more optical sensors 7. FIG. When the phototherapy device 1 has a plurality of optical sensors 7, the plurality of optical sensors 7 are preferably arranged at regular intervals along the circumferential direction. Each of the one or more optical sensors 7 is a detection unit, and as a whole constitutes a distance detection unit that detects the distance to the target site T and outputs a distance signal corresponding to the distance. The output distance signal is detected by the control device 2 . The optical sensor 7 has a light emitting part (not shown) that emits light to the target site T and a light receiving part (not shown) that receives light reflected from the target site T. The optical sensor 7 evaluates the distance to the target site T from the change in the intensity of the reflected light received by the light receiving section. For example, the distance from the laser light source 8 to the target site T can be calculated from the distance signal.

The operation of the phototherapy device 1 will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a diagram showing the relationship between changes in the distance signal S and laser irradiation. In FIG. 3, the upper graph shows the change over time in the value of the distance signal S from the optical sensor 7, and the lower graph shows the status of laser irradiation. FIG. 4 is a flow chart showing the operation of the phototherapy device 1. As shown in FIG.

In FIG. 4, first, in step 101, the user presses the probe 3 against the target site T, and the proximity signal output when the limit switch 10 is turned ON is detected. Next, in step 102, with the proximity signal as a trigger, the detection of the distance signal S output according to the distance to the target site T is started (time t1). Next, at step 103, a reference value L0 is set based on the distance signal S detected after the limit switch 10 is turned ON, that is, after the proximity signal is detected. Next, at step 104, it is determined whether or not the distance signal S is within a predetermined range with respect to the reference value L0, that is, within a range between the lower limit L1 and the upper limit L2. When the distance signal S is within the predetermined range with respect to the reference value L0, the process proceeds to step 105, laser irradiation from the laser light source 8 to the target portion T is permitted, and laser irradiation is performed.

On the other hand, in step 104, when the distance signal S is out of the predetermined range with respect to the reference value L0 due to changes in the position and posture of the probe 3 with respect to the target site T (time t2), the process proceeds to step 106. and proceed. Next, in step 106, laser irradiation by the laser light source 8 is prohibited. Therefore, if the laser irradiation has been performed through step 105, the laser irradiation is stopped. Next, in step 107, the reference value L0 set in step 103 is reset, and the operation of the phototherapy device 1 ends.

Here, the reference value L0 is set based on the distance signal S from the optical sensor 7, but the reference value L0 can be set by any method. For example, after the proximity signal is detected, the average value obtained by sampling the four optical sensors 7 for a predetermined period of time may be used as the distance signal S, and this may be set as the reference value L0. Alternatively, only when the distance signals S from the four optical sensors 7 fall within a predetermined deviation, the average value thereof may be used as the distance signal S and set as the reference value L0. If the deviation does not fall within the predetermined deviation, even if the proximity signal is detected, the operation of the phototherapy device 1 may be terminated without setting the reference value L0.

A case where the distance signals S of the four optical sensors 7 do not fall within a predetermined deviation is, for example, a case where the probe 3 is pressed against the target site T while being inclined. In this case, a portion of the distal end of the movable portion 6 of the probe 3 is in contact with the target site T, and the opposite portion is separated from the target site T. Therefore, the distance signals S from the plurality of optical sensors 7 arranged at equal intervals along the circumferential direction are greatly different from each other. If laser irradiation is performed in this state, the laser will irradiate areas other than the target site T, so laser irradiation must be prohibited. Therefore, it is effective to determine whether a plurality of distance signals S are within a predetermined deviation.

The predetermined range for the reference value L0 is the range between the lower limit L1 and the upper limit L2, as shown in FIG. The lower limit L1 and the upper limit L2 are, for example, ±5% with respect to the reference value, and are set as ratios to the reference value. The upper limit L0 and the lower limit L1 are determined in consideration of therapeutic efficacy, safety, and the like. For example, the lower limit L1 is determined by whether or not there is a possibility that the laser light source 8 is moved away from the target site T to irradiate a site other than the target site. That is, the relationship between the reflected light of the optical sensor 7 and the distance to the object may be determined in advance, and the upper and lower limits may be set from the reflected light displacement amount corresponding to a gap of 12 mm corresponding to one finger, for example. The fact that the distance signal S is outside the predetermined range with respect to the reference value L0 means that the gap is larger than the allowable range, and there is a possibility that the finger may get into the gap. As a result, a high-output laser is directly irradiated to living tissue other than the target site T. Note that the lower limit L1 and the upper limit L2 may be set as absolute values instead of ratios to the reference value. Further, only the lower limit L1 may be set without setting the upper limit L2 in order to determine only that the laser light source 8 is separated from the target site T. FIG.

Note that the reference value L0 may be set based on the distance signal S or the like measured in advance without using the proximity signal as a trigger. That is, in the phototherapy device 1, the limit switch 10 may be omitted.

FIG. 5 is a flow chart showing another operation of the phototherapy device 1. FIG. In FIG. 5, first, in step 201, the user presses the probe 3 against the target site T, and the proximity signal output when the limit switch 10 is turned ON is detected. Next, in step 202, with the proximity signal as a trigger, the detection of the distance signal S output according to the distance to the target site T is started (time t1). Next, at step 203, a reference value L0 is set based on the distance signal S detected after the limit switch 10 is turned ON, that is, after the proximity signal is detected. Next, at step 204, it is determined whether or not the distance signal S is within a predetermined range with respect to the reference value L0, that is, within a range between the lower limit L1 and the upper limit L2. If the distance signal S is within the predetermined range with respect to the reference value L0, the process proceeds to step 205; Next, at step 205, it is determined whether or not a proximity signal indicating that the limit switch 10 is ON is detected. If the proximity signal is detected, the process proceeds to step 206, the laser light source 8 is permitted to irradiate the target site T, and the laser is radiated.

On the other hand, in step 204, when the distance signal S is out of the predetermined range with respect to the reference value L0 (time t2) due to changes in the position and posture of the probe 3 with respect to the target site T, the process proceeds to step 207. and proceed. Similarly, if in step 205 no proximity signal is detected, step 207 is reached. Next, in step 207, laser irradiation by the laser light source 8 is prohibited. Therefore, if laser irradiation has been performed through step 206, laser irradiation is stopped. Next, in step 208, the reference value L0 set in step 203 is reset, and the operation of the phototherapy device 1 ends.

The operation of the phototherapy device 1 shown in the flow chart of FIG. 4 and the operation of the phototherapy device 1 shown in the flow chart of FIG. The only difference is that it continues to be determined whether the limit switch 10 is ON. In addition, in the operation of the phototherapy device 1 shown in the flowchart of FIG. 4, as a routine that is executed by an interruption every predetermined set time, after the start of laser irradiation, the limit switch 10 is turned on and the proximity signal is detected. Unintentional separation of the probe 3 from the target site T can be detected by determining whether or not the proximity signal is detected even after the start of laser irradiation. As a result, the laser can be prevented from irradiating a part other than the target site T, and the laser can be irradiated more appropriately.

According to the phototherapy device 1, the reference value L0 is set based on the distance signal S detected after the proximity signal is detected, and the laser irradiation by the laser light source 8 is performed according to the variation of the distance signal S with respect to the reference value L0. is done. Therefore, since the laser light source 8 is sufficiently close to the target site T, only the target site T can be reliably irradiated with the laser, and the laser is not irradiated to other than the target site T. In addition, according to the phototherapy device 1, since the reference value L0 is set according to the target site T, if the target site and condition of the skin, that is, the skin color, moisture content, degree of wrinkles, etc., are different, , the set reference value L0 is also different. Also, the predetermined range by the lower limit L1 and the upper limit L2 with respect to the reference value L0 is different. Therefore, it is not necessary to adjust the set value for laser irradiation according to the target site T one by one. As a result, according to the phototherapy device 1, laser irradiation can be appropriately performed.

Furthermore, in the phototherapy device 1, laser irradiation is stopped when the distance signal S is out of the predetermined range with respect to the reference value L0. Since the reference value L0 is set according to the target site T, the phototherapeutic device 1 realizes an interlock mechanism that can deal with target sites T of various skin sites and conditions. For example, the lower limit L1 and the upper limit L2 corresponding to the reference value L0 are set in advance so that the laser irradiation is stopped when the probe 3 is separated from the target site T by a predetermined distance, for example, by a distance of 12 mm corresponding to one finger. You may As a result, it is possible to prevent the laser from stopping due to the user simply switching or moving the probe 3, thereby preventing a decrease in treatment adherence. Inhibition of laser irradiation may be performed by detecting an abnormality such as a temperature in the probe 3 other than the proximity signal and the distance signal.

By the way, in the phototherapy device 1, if the optical sensor 7 is used as the distance detection unit, the optical sensor 7 will erroneously detect the light reflected from the target site T by the laser from the laser light source 8, and the distance to the target site T will be changed. Accurate distance signal may not be obtained. As a result, the distance to the target site T cannot be accurately measured, and laser irradiation cannot be performed appropriately. This will be described with reference to FIG.

FIG. 6 is a diagram showing the relationship between laser irradiation and distance signal S detection. In FIG. 6 , the upper graph shows the ON/OFF timing of laser irradiation by the laser light source 8 , and the lower graph shows the ON/OFF timing of detection by the optical sensor 7 .

In the phototherapy device 1, laser irradiation from the laser light source 8 is pulsed pulsed oscillation (PW) rather than continuous continuous oscillation (CW). Therefore, in laser irradiation by the laser light source 8, the laser irradiation period d1 and the laser stop period d2 are alternately repeated. As a result, it is possible to easily suppress the temperature rise of the target site due to laser irradiation. The laser irradiation period d1 is, for example, 20 ms, and the laser stop period d2 is, for example, 180 ms.

A laser light source having a continuous wave (CW) output waveform is used, and control is performed so that the laser irradiation period and the laser stop period are alternately repeated at a sufficiently longer period than in the case of pulsed oscillation (PW). good too. Note that continuous wave (CW) may be employed without providing the laser irradiation period and the laser stop period. The period in which the laser is ON shown in FIG. 3 indicates a state in which laser irradiation is permitted. PW).

Detection by the optical sensor 7 is performed by the light emitting unit emitting light to the target site T and the light receiving unit receiving light reflected from the target site T when the optical sensor 7 is ON. Assuming that the time during which the optical sensor 7 is ON, that is, the detection time is d3, and the time during which the optical sensor 7 is OFF, that is, the stop period is d4, d3 and d4 are, for example, 1 ms. Detection by the optical sensor 7, that is, light emission by the light emitting unit and light reception by the light receiving unit is performed during the laser stop period d2. As a result, the optical sensor 7 does not detect the light reflected from the target site T by the laser from the laser light source 8, and an accurate distance signal corresponding to the distance to the target site T is obtained. distance can be measured accurately. As a result, laser irradiation can be performed appropriately.

In the phototherapy device 1 , the light receiving section is configured such that all or at least part of the laser wavelength of the laser light source 8 is included in the light receiving wavelength range of the light receiving section of the optical sensor 7 . As a result, there is no restriction on the specifications of the light receiving element mounted on the optical sensor 7, and a low cost and high quality light receiving element can be selected.

Further, the detection of the distance to the target site T by the optical sensors 7 during the laser stop period d2 may be performed simultaneously by the four optical sensors 7 at the timings shown in FIG. However, detection by the four optical sensors 7 may be performed sequentially. That is, light emission and light reception by one optical sensor 7 may be performed at timings that do not overlap with light emission and light reception by another optical sensor 7 . As a result, it is possible to prevent the light reflected from the target site by the light emission of the other optical sensor 7 from being received. The detection by the optical sensor 7 may be performed during the entire laser stop period d2 or during a part of the laser stop period d2.

Next, accurate detection by the optical sensor 7 will be described with reference to FIG. FIG. 7 is a diagram showing the relationship between the operations of the light-emitting section and the light-receiving section. In FIG. 7, the upper graph shows the ON/OFF timing of light emission by the light emitting unit, and the lower graph shows the ON/OFF timing of light receiving by the light receiving unit.

As shown in FIG. 7, in the optical sensor 7, the light receiving section receives the light reflected from the target site T during the period P1 of the same timing as the light emission by the light emitting section, and the light emission by the light emitting section and the next light emission are detected. The light reflected from the target site T is also received during the period P2 between the timings of . Therefore, the optical sensor 7 detects the light reflected from the target site T when the light emitting section emits light and the light reflected from the target site T when the light emitting section does not emit light. is output as a distance signal S based on the difference from the detected value received by the light receiving unit.

If, in the optical sensor 7, the light receiving section receives the light reflected from the target site T only during the period P1 of the same timing as the light emission by the light emitting section, stray light or disturbance light is emitted between the optical sensor 7 and the target site T. is incident, the detected value apparently increases, making it impossible to accurately measure the distance. On the other hand, in the optical sensor 7, the light receiving section further receives the light reflected from the target site T during the timing period P2 between the light emission by the light emitting section and the next light emission. You can know the increment. Therefore, by obtaining the difference between the values detected by the light receiving units in the period P1 and the period P2, it is possible to remove the change caused by the stray light or the like, and the optical sensor 7 can be made resistant to disturbance.

The light receiving portion of the optical sensor 7 may be further configured to detect light reflected from the target site T by the laser from the laser light source 8 . That is, by activating the light receiving part of the optical sensor 7 all the time or at least when the laser light source 8 irradiates the laser, the light reflected from the target site T by the laser light source 8 can also be detected. As a result, the laser irradiation time of the laser light source 8 can be actually measured, and the presence or absence of laser irradiation can be confirmed.

In the above-described embodiment, the limit switch 10 is used as the proximity detector. Other sensors or the like may be used. Other contact sensors may be used as long as they can detect the contact of the movable part 6 with the skin or the retraction of the movable part 6 . By using a contact-type sensor, it is possible to eliminate the influence of the site and condition of the skin.

Although the optical sensor 7 is used as the distance detector, other sensors may be used as long as they can detect the distance to the target site T and output the distance signal S corresponding to the distance. However, the distance detector is preferably an optical sensor, as described above, in consideration of cost and performance. Since the optical sensor can perform non-contact measurement, there is little risk of sebum stains or the like adhering to the sensor, and stable performance can be maintained.

The proximity detector and the distance detector may each be selected from optical sensors, capacitive sensors, temperature sensors, ultrasonic sensors, acoustic sensors, microwave sensors and physical sensors. In order to enhance robustness of the phototherapy device 1, the proximity detection unit and the distance detection unit are preferably sensors of different types. Further, the proximity detection section may be configured with a plurality of sensors of the same or different schemes, and similarly, the distance detection section may be configured with a plurality of sensors of the same or different schemes.

In the phototherapy device 1 described above, the limit switch 10, that is, the proximity detector may be omitted. In this case, the phototherapy device includes a laser light source that irradiates a laser to the target site, and a distance detection unit that detects the distance to the target site and outputs a distance signal corresponding to the distance, and the laser light source In the irradiation of the laser, the laser irradiation period and the laser stop period are alternately repeated, and the distance detection part has a light emitting part that emits light to the target site and a light receiving part that receives the light reflected from the target site Optical sensor , light emission and light reception are performed during the stop period, and laser irradiation from the laser light source is performed according to the amount of variation in the distance signal.

1 phototherapy device 2 control device 3 probe 4 cable 5 main body 6 movable part 7 optical sensor 8 laser light source 9 optical window 10 limit switch S distance signal T target site L0 reference value L1 lower limit L2 upper limit d1 laser irradiation period d2 laser stop period

Claims (6)

a laser light source that irradiates a laser to a target site;
a distance detection unit that detects the distance to the target site and outputs a distance signal corresponding to the distance,
In the laser irradiation by the laser light source, a laser irradiation period and a laser stop period are alternately repeated,
The distance detection unit has an optical sensor having a light emitting unit that emits light to a target site and a light receiving unit that receives light reflected from the target site by the light emitted by the light emitting unit ,
Light emission by the light emitting unit and light reception of the reflected light by the light receiving unit are performed only during the laser stop period,
laser irradiation by the laser light source is permitted according to the amount of variation in the distance signal,
At least part of the laser wavelength of the laser light source is included in the light receiving wavelength range of the light receiving section of the distance detection section . 2. The phototherapy apparatus according to claim 1 , wherein a reference value is set based on said distance signal, and laser irradiation by said laser light source is permitted when said distance signal is within a predetermined range with respect to said reference value. 3. The phototherapy apparatus according to claim 2 , wherein when the distance signal is out of a predetermined range with respect to the reference value, laser irradiation by the laser light source is prohibited. 4. The phototherapy device according to claim 3 , wherein the reference value is reset when the distance signal is out of a predetermined range with respect to the reference value. The phototherapy apparatus according to any one of claims 1 to 4 , wherein the distance detection unit has a plurality of detection units, and detection of the distance to the target site is sequentially performed by the plurality of detection units. The distance detection unit detects a detection value obtained by receiving the light reflected from the target site when the light emitting unit emits light and the light reflected from the target site when the light emitting unit does not emit light. The phototherapy apparatus according to any one of claims 1 to 5 , wherein the distance signal is output based on a difference from a detection value of light received by the light receiving unit.

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