Light treatment device and method of operation of a light treatment device

Abstract

The light treatment device 1 is provided with a laser light source 8 that irradiates laser light to a target site T, a limit switch 10 that detects that the laser light source 8 is brought to a prescribed distance with respect to the target site T and outputs a proximity signal, and an optical sensor 7 that detects a distance to the target site T and outputs a distance signal S corresponding to the distance, and is configured to set a reference value L0 based on the distance signal S detected after the proximity signal is detected, and to allow irradiation by the laser light of the laser light source 8 in accordance with the amount of variation of the distance signal S with respect to the reference value L0.

Description

Technical Field

[0001] This invention relates to a phototherapy device and a method for operating the phototherapy device. Background Technology

[0002] Phototherapy devices are used to irradiate biological tissues with lasers for therapeutic and adjunctive purposes, such as promoting blood circulation and metabolism. Under the laser safety standard JIS C 6802, compliance with Level 1C is mandatory when using high-output phototherapy devices of Level 3 or higher for home medical treatment. Level 1C requires limiting exposure to areas outside the intended target tissue. Therefore, phototherapy devices need an interlocking mechanism to stop laser irradiation when the probe containing the laser light source is separated from the skin at the designated target tissue by a specified distance (e.g., 12 mm, equivalent to the width of one finger).

[0003] However, there is a known phototherapy device that is configured to use optical sensors or the like to detect the distance between the probe or laser light source and the skin, and to control the laser irradiation based on the detected value, that is, based on whether the detected value is within a predetermined allowable range (Patent Document 1 and Patent Document 2).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2016-512783

[0007] Patent Document 2: Japanese Patent Publication No. 2013-509222. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] According to the detection methods of the phototherapy apparatus described in Patent Documents 1 and 2, the detection values ​​will differ depending on the location and condition of the target skin, such as skin color, moisture content, and degree of wrinkles. This is even more pronounced when the subjects are different, and can occur even with the same subject. Therefore, it is necessary to adjust the settings for laser irradiation individually based on the detection values. Furthermore, in the phototherapy apparatus described in Patent Document 1, the distance between the laser source and the target tissue may be misdetected when the sensor is tilted relative to the skin. In addition, a highly sophisticated optical system is required to implement an optical displacement sensor that measures defocusing, increasing manufacturing costs. Therefore, it is preferable to be able to perform laser irradiation appropriately using a simple method that is independent of the subject and the location and condition of the skin.

[0010] An optical sensor has a light-emitting part that emits light to a target area and a light-receiving part that receives the light reflected from the target area. In phototherapy devices, if an optical sensor is used, it may sometimes misdetect the light reflected from the target area by the laser source, failing to obtain the correct distance signal corresponding to the distance to the target area. As a result, the distance to the target area cannot be measured correctly, and laser irradiation cannot be performed appropriately.

[0011] The purpose of this invention is to provide a phototherapy device capable of appropriately performing laser irradiation. Preferably, this invention provides a phototherapy device capable of accurately measuring the distance to the target area and appropriately performing laser irradiation.

[0012] Solution for solving the problem

[0013] According to one aspect of the present invention, a phototherapy device is provided, comprising: a laser light source that irradiates a target area with laser light; a proximity detection unit that detects that the laser light source has approached the target area to a predetermined distance and outputs a proximity signal; and a distance detection unit that detects the distance to the target area and outputs a distance signal corresponding to the distance, configured to set a reference value based on the distance signal detected after the proximity signal is detected, and to allow laser irradiation by the laser light source according to the amount of change of the distance signal relative to the reference value.

[0014] According to another aspect of the present invention, a method for operating a phototherapy device is provided, comprising: a step of detecting that a laser source approaches a target area to a predetermined distance and outputting a proximity signal; a step of detecting the distance to the target area and outputting a distance signal corresponding to the distance; a step of setting a reference value based on the distance signal detected after the proximity signal is detected; and a step of allowing laser irradiation by the laser source according to the amount of change of the distance signal relative to the reference value.

[0015] When the distance signal is within a specified range relative to the reference value, laser irradiation by the laser source is permitted. When the distance signal falls outside the specified range relative to the reference value, laser irradiation by the laser source is prohibited. When the distance signal falls outside the specified range relative to the reference value, the reference value can be reset. The distance detection unit may have multiple detection units, which can sequentially detect the distance to the target location. The distance detection unit may have multiple detection units, and the reference value can be set based on the multiple distance signals obtained by the multiple detection units when they converge to a specified deviation. During laser irradiation by the laser source, the laser irradiation period and the laser stop period can be alternately repeated. The distance detection unit has an optical sensor, which has a light-emitting unit that emits light towards the target location and a light-receiving unit that receives light reflected from the target location. The light emission and the light reception occur during the laser stop period. The distance detection unit can output the distance signal, which is the difference between the detection value of light received by the light receiving unit when the light-emitting unit is emitting light and the detection value of light received by the light receiving unit when the light-emitting unit is not emitting light. The proximity detection unit can have a contact sensor. It can also include a probe, which has: the laser light source, the proximity detection unit, the distance detection unit, a main body, and a movable part. The movable part can move along the axis of the main body by pressing on the target part. The proximity detection unit is configured to detect that the laser light source has approached the target part to a predetermined distance by the relative movement between the main body and the movable part. The distance detection unit is disposed in the movable part.

[0016] Furthermore, according to another aspect of the present invention, a phototherapy device is provided, comprising: a laser light source that irradiates a target area with laser light; and a distance detection unit that detects the distance to the target area and outputs a distance signal corresponding to the distance. During laser irradiation by the laser light source, the laser irradiation period and the laser stop period are alternately repeated. The distance detection unit has an optical sensor, which has a light-emitting part that emits light to the target area and a light-receiving part that receives light reflected from the target area. The light emission and the light reception occur during the laser stop period and are configured to allow laser irradiation by the laser light source based on the amount of variation in the distance signal.

[0017] According to another aspect of the present invention, a method of operating a phototherapy device is provided, comprising: alternating laser irradiation by a laser source during laser irradiation and laser cessation, wherein during the laser cessation, light is emitted toward a target site, and light is received from light reflected from the target site, thereby detecting a distance to the target site and outputting a distance signal corresponding to the distance; and a step of allowing laser irradiation by the laser source based on a variation in the distance signal.

[0018] At least a portion of the laser wavelength of the laser source may be included within the light-receiving wavelength range of the light-receiving unit of the distance detection unit. The light-receiving unit of the distance detection unit may also be configured to detect light reflected from the target location by the laser from the laser source. A reference value may be set based on the distance signal; when the distance signal is within a specified range relative to the reference value, laser irradiation by the laser source is permitted. When the distance signal falls outside the specified range relative to the reference value, laser irradiation by the laser source may be prohibited. When the distance signal falls outside the specified range relative to the reference value, the reference value may be reset. The distance detection unit may have multiple detection units, and the reference value is set based on the multiple distance signals obtained by the multiple detection units when they converge to a specified deviation. The distance detection unit may have multiple detection units, and the distance to the target location is detected sequentially by the multiple detection units. The distance detection unit can output the distance signal, which is the difference between the detection value of the light receiving unit receiving light reflected from the target part when the light emitting unit is emitting light and the detection value of the light receiving unit receiving light reflected from the target part when the light emitting unit is not emitting light.

[0019] Invention Effects

[0020] According to the present invention, the combined effect of providing a phototherapy device capable of appropriate laser irradiation is achieved. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a phototherapy device according to an embodiment of the present invention;

[0022] Figure 2 This is a diagram illustrating the operation of the probe;

[0023] Figure 3 This is a graph showing the relationship between changes in the distance signal and laser irradiation;

[0024] Figure 4 This is a flowchart illustrating the operation of the phototherapy device;

[0025] Figure 5 This is a flowchart illustrating another operation of the phototherapy device;

[0026] Figure 6 This is a graph showing the relationship between laser irradiation and distance signal detection;

[0027] Figure 7 This diagram illustrates the working relationship between the light-emitting part and the light-receiving part. Detailed Implementation

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In all the drawings, corresponding constituent elements are labeled with common reference numerals.

[0029] Figure 1 This is a schematic diagram of a phototherapy device 1 according to an embodiment of the present invention. Figure 2 This is a diagram showing the operation of probe 3.

[0030] The phototherapy device 1 includes a control unit 2, a probe 3, and a cable 4 electrically connecting the control unit 2 and the probe 3. The control unit 2 includes one or more processors, a storage unit, and peripheral circuitry. Based on a computer program pre-stored in the storage unit, the control unit 2 comprehensively controls the overall operation of the probe 3, as shown in the flowchart below. During this process, the control unit 2 receives signals from various sensors, such as optical sensors (described below), and sends control signals related to the irradiation and cessation of the laser light source. The control unit 2 may have input / output units, such as a display unit like a monitor, operation buttons, or a touch panel.

[0031] The probe 3 has a cylindrical main body 5, a cylindrical movable part 6 arranged inside the main body 5 so as to be movable along the axis of the main body 5, four optical sensors 7 provided on the front end face of the movable part 6, a laser light source 8 disposed inside the main body 5, an optical window 9 provided on the front surface of the main body 5, and a limit switch 10 disposed inside the main body 5. The movable part 6 applies force forward against the main body 5 through an elastic member (not shown).

[0032] The optical sensor 7 and the limit switch 10 are disposed inside the probe 3 and are configured not to directly contact the skin. Therefore, the risk of sebum and other contaminants adhering to the optical sensor 7 and the limit switch 10 is minimized, maintaining stable performance. Furthermore, the optical sensor 7 and the limit switch 10 are configured not to obstruct the movement of the movable part 6 or the irradiation by the laser from the laser source 8.

[0033] In the laser safety standard JIS C 6802, when a phototherapy device 1 equipped with a high-output laser source 8 of level 3 or higher is used for home medical treatment, the phototherapy device 1 needs to meet level 1C, but is not limited to this. Laser sources 8 that meet other standards for home medical treatment can also be used.

[0034] Figure 2 (A) shows the state before the probe 3 is pressed against the target tissue of the organism, i.e., the target site T. Figure 2 (B) shows the state with probe 3 pressed against the target area T. From Figure 2 In the state shown in (A), when probe 3 is pressed against the target part T, movable part 6 retracts, and limit switch 10 is activated. Figure 2 (B) That is, the limit switch 10 constitutes a proximity detection unit, which detects that the laser source 8 has approached to a predetermined distance relative to the target part T and outputs a proximity signal. The output proximity signal is detected by the control device 2. On the other hand, when the probe 3 releases its pressure on the target part T, the movable part 6 retracts due to the force applied by the elastic member, and the limit switch 10 is disconnected. Figure 2 (A)).

[0035] Four optical sensors 7 are arranged at equal intervals along the circumferential direction on the front end face of the movable part 6. Furthermore, the phototherapy device 1 may have one, two, or three optical sensors 7, or even five or more optical sensors 7. When the phototherapy device 1 has multiple optical sensors 7, the multiple optical sensors 7 are preferably arranged at equal intervals along the circumferential direction. Each of the one or more optical sensors 7 is a detection unit, which, as a whole, constitutes a distance detection unit that detects the distance to the target part 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 towards the target part T, and a light-receiving part (not shown) that receives light reflected from the target part T. The optical sensor 7 evaluates the distance to the target part T based on the displacement of the intensity of the reflected light received by the light-receiving part. The distance from, for example, the laser source 8 to the target part T can be calculated based on the distance signal.

[0036] Reference Figure 3 and Figure 4 To explain the operation of the phototherapy device 1. Figure 3 This is a graph showing the relationship between the change in the distance signal S and the laser illumination. In Figure 3 The upper figure shows the time-varying value of the distance signal S from the optical sensor 7, while the lower figure shows the laser irradiation status. Figure 4 This is a flowchart illustrating the operation of the light therapy device 1.

[0037] exist Figure 4In the process, firstly, in step 101, the user presses probe 3 towards the target area T, and the proximity signal output due to the activation of limit switch 10 is detected. Next, in step 102, using the proximity signal as a trigger, the detection of a distance signal S (at time t1) corresponding to the distance to the target area T is initiated. Then, in step 103, a reference value L0 is set based on the distance signal S detected after the proximity signal is detected following the activation of limit switch 10. Next, in step 104, it is determined whether the distance signal S is within a specified range relative to the reference value L0, i.e., whether it is within the range between the lower limit L1 and the upper limit L2. If the distance signal S is within the specified range relative to the reference value L0, the process proceeds to step 105, allowing laser light from laser source 8 to irradiate the target area T.

[0038] On the other hand, in step 104, if the distance signal S falls outside the specified range relative to the reference value L0 due to changes in the position and posture of the probe 3 relative to the target area T (time t2), the process proceeds to step 106. Next, in step 106, laser irradiation by the laser source 8 is prohibited. Therefore, if laser irradiation is in progress after step 105, 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.

[0039] 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 a proximity signal is detected, the average value obtained from sampling by the four optical sensors 7 over a predetermined period of time can be used as the distance signal S and set as the reference value L0. Alternatively, the average value can be used as the distance signal S and set as the reference value L0 only if the distance signals S of the four optical sensors 7 converge to a predetermined deviation. If the distance signals do not converge to the predetermined deviation, even assuming a proximity signal is detected, the operation of the phototherapy device 1 can be terminated without setting the reference value L0.

[0040] The situation where the distance signals S of the four optical sensors 7 do not converge to the predetermined deviation is, for example, when the probe 3 is pressed in a tilted position relative to the target area T. In this case, a portion of the front end of the movable part 6 of the probe 3 abuts against the target area T, while the opposite portion separates from the target area T. Therefore, each of the distance signals S obtained by the multiple optical sensors 7 arranged at equal intervals along the circumferential direction is significantly different from the others. When laser irradiation is performed in this state, the laser will irradiate beyond the target area T, so laser irradiation must be prohibited. Therefore, it is effective to determine whether the multiple distance signals S converge to the predetermined deviation.

[0041] like Figure 3As shown, the specified range for the reference value L0 is the range between the lower limit L1 and the upper limit L2. The lower limit L1 and upper limit L2 are set, for example, as a ratio relative to the reference value, within ±5%. The upper limit L0 and lower limit L1 are determined considering the treatment effect and safety. For example, the lower limit L1 is determined by the possibility that the laser source 8 has left the target site T, resulting in irradiation of areas other than the target site. That is, the relationship between the reflected light from the optical sensor 7 and the distance to the object can be calculated in advance, and the range of the upper and lower limits can be set based on the amount of reflected light displacement corresponding to a gap of, for example, 12 mm (equivalent to the amount of one finger). A distance signal S outside the specified range relative to the reference value L0 means that the gap is more than the allowable range, and a finger may enter the gap. As a result, the high-output laser may directly irradiate biological tissue outside the target site T. Furthermore, the lower limit L1 and upper limit L2 can be set as absolute values, rather than as a ratio relative to the reference value. Alternatively, the upper limit L2 can be omitted, and only the lower limit L1 can be set, so that only the departure of the laser source 8 from the target site T is determined.

[0042] Furthermore, the reference value L0 can be set based on a pre-measured distance signal S, etc., instead of using a proximity signal as a trigger. That is, the limit switch 10 can also be omitted in the phototherapy device 1.

[0043] Figure 5 This is a flowchart illustrating another operation of the phototherapy device 1. Figure 5 In the process, firstly, in step 201, the user presses the probe 3 onto the target area T, detecting the proximity signal output due to the activation of the limit switch 10. Next, in step 202, using the proximity signal as a trigger, the user begins detecting the distance signal S (at time t1) corresponding to the distance to the target area T. Then, in step 203, a reference value L0 is set based on the distance signal S detected after the limit switch 10 is activated, i.e., after the proximity signal is detected. Then, in step 204, it is determined whether the distance signal S is within a specified range relative to the reference value L0, i.e., whether it is within the range between the lower limit L1 and the upper limit L2. If the distance signal S is within the specified range relative to the reference value L0, the process proceeds to step 205. Next, in step 205, it is determined whether a proximity signal indicating the activation of the limit switch 10 has been detected. If a proximity signal is detected, the process proceeds to step 206, allowing the laser source 8 to irradiate the target area T with laser light for laser irradiation.

[0044] On the other hand, in step 204, if the distance signal S falls outside the specified range relative to the reference value L0 due to changes in the position and posture of the probe 3 relative to the target area T (time t2), the process proceeds to step 207. Similarly, in step 205, if no proximity signal is detected, the process proceeds to step 207. Next, in step 207, laser irradiation by the laser source 8 is prohibited. Therefore, if laser irradiation is being performed after 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.

[0045] Figure 4 The operation of the phototherapy device 1 shown in the flowchart is as follows: Figure 5 The only difference in the operation of the phototherapy device 1 shown in the flowchart is that, after laser irradiation begins, it continues to determine whether a proximity signal is detected, i.e., whether the limit switch 10 is activated. Furthermore, in Figure 4 In the operation of the phototherapy device 1 shown in the flowchart, as a routine performed by interleaving at predetermined set times, it is also possible to determine whether the limit switch 10 is turned on and whether an approach signal is detected after the laser irradiation begins. By determining whether an approach signal is detected after the laser irradiation begins, it is possible to detect that the probe 3 has unintentionally moved away from the target area T. Thus, it is possible to prevent the laser from irradiating outside the target area T, and laser irradiation can be performed more appropriately.

[0046] According to the phototherapy device 1, a reference value L0 is set based on a distance signal S detected after a proximity signal is detected, and laser irradiation by the laser source 8 is performed based on the change in distance signal S relative to the reference value L0. Therefore, since the laser source 8 is sufficiently close to the target area T, laser irradiation can be reliably performed only on the target area T, and the laser will not irradiate areas outside the target area T. Furthermore, according to the phototherapy device 1, since the reference value L0 is set based on the target area T, the set reference value L0 will vary depending on the location and condition of the target skin, such as skin color, moisture content, and degree of wrinkles. Additionally, the defined range formed by the lower limit L1 and upper limit L2 of the reference value L0 will also differ. Therefore, it is not necessary to adjust the setting value for laser irradiation individually for each target area T. As a result, according to the phototherapy device 1, laser irradiation can be performed appropriately.

[0047] Furthermore, in the phototherapy device 1, laser irradiation stops when the distance signal S falls outside the specified range relative to the reference value L0. Since the reference value L0 is set based on the target area T, the phototherapy device 1 implements an interlocking mechanism that corresponds to the target area T for various skin locations and conditions. For example, a lower limit L1 and an upper limit L2 corresponding to the reference value L0 can be preset so that laser irradiation stops when the probe 3 moves away from the target area T by a specified distance (e.g., a distance equivalent to 12 mm, the width of one finger). This prevents the laser from stopping simply because the user changes or moves the probe 3, thus preventing a decrease in treatment compliance. In addition to proximity and distance signals, laser irradiation can also be stopped by detecting abnormalities such as temperature in the probe 3.

[0048] However, in the phototherapy device 1, if the optical sensor 7 is used as a distance detection unit, sometimes the optical sensor 7 may misdetect the light reflected from the target area T by the laser source 8, and thus fail to obtain the correct distance signal corresponding to the distance to the target area T. As a result, the distance to the target area T cannot be measured correctly, and laser irradiation cannot be performed appropriately. Regarding this point, refer to... Figure 6 Let me explain.

[0049] Figure 6 This is a graph showing the relationship between laser illumination and the detection of the distance signal S. Figure 6 The upper figure shows the timing of turning the laser light source 8 on or off, and the lower figure shows the timing of turning the optical sensor 7 on or off.

[0050] In the phototherapy device 1, the laser irradiation from the laser source 8 is not a continuous oscillation (CW), but a pulsed oscillation (PW). Therefore, during laser irradiation from the laser source 8, the laser irradiation period d1 and the laser stop period d2 are repeated alternately. This makes it easy to suppress the temperature rise of the target area caused by laser irradiation. The laser irradiation period d1 is, for example, 20 ms, and the laser stop period d2 is, for example, 180 ms.

[0051] Alternatively, a laser source with a continuous oscillation (CW) output waveform can be used, and control can be achieved by alternating the laser irradiation period and the laser stop period with a period that is sufficiently long compared to the case of pulsed oscillation (PW). Alternatively, continuous oscillation (CW) can be used without setting a laser irradiation period and a laser stop period. Figure 3 The laser-on period shown indicates the state in which laser irradiation is permitted, during which the oscillating laser can be either continuous oscillation (CW) or pulsed oscillation (PW).

[0052] The detection by the optical sensor 7 is performed by the light-emitting part emitting light towards the target location T when the optical sensor 7 is turned on, and the light-receiving part receiving the light reflected from the target location T. If the time for the optical sensor 7 to turn on, i.e., the detection time, is d3, and the time for the optical sensor 7 to turn off, i.e., the stopping time, is d4, then d3 and d4 are, for example, 1 ms. The detection by the optical sensor 7, i.e., the emission of light by the light-emitting part and the light reception by the light-receiving part, takes place during the laser stopping period d2. As a result, the optical sensor 7 does not detect the light reflected from the target location T by the laser from the laser source 8, and can obtain the correct distance signal corresponding to the distance to the target location T, thus enabling accurate measurement of the distance to the target location T. As a result, laser irradiation can be performed appropriately.

[0053] In the phototherapy device 1, the light receiver is configured such that all or at least a portion of the laser wavelength of the laser source 8 is included in the light receiving wavelength range of the light receiver of the optical sensor 7. Therefore, there are no limitations on the specifications of the light receiving element mounted in the optical sensor 7, allowing for the selection of inexpensive and high-quality light receiving elements.

[0054] Furthermore, regarding the detection of the distance to the target location T by the optical sensors 7 during the laser-stopped period d2, the four optical sensors 7 can also be used... Figure 6 The timing shown is simultaneous detection. However, detection of all four optical sensors 7 can also be performed sequentially. That is, the emission and reception of light by one optical sensor 7 can be performed at a timing that does not overlap with the emission and reception of light by other optical sensors 7. This prevents the reception of light reflected from the target area by the emission of light from other optical sensors 7. The detection of the optical sensors 7 can be performed either throughout the entire laser stop period d2 or within a portion of the laser stop period d2.

[0055] Next, refer to Figure 7 This is to illustrate the correct detection of optical sensor 7. Figure 7 This diagram illustrates the operational relationship between the light-emitting part and the light-receiving part. Figure 7 The upper figure shows the timing of turning the light-emitting part on or off, and the lower figure shows the timing of turning the light-receiving part on or off.

[0056] like Figure 7As shown, in the optical sensor 7, the light receiving unit receives light reflected from the target location T during a timing period P1 that coincides with the light emission of the light emitting unit, and during a timing period P2 between the light emission of the light emitting unit and the next light emission. Therefore, the optical sensor 7 outputs a distance signal S, which is the difference between the detection value of light receiving from the target location T when the light emitting unit is emitting light and the detection value of light receiving from the target location T when the light emitting unit is not emitting light.

[0057] Assuming that in the optical sensor 7, when the light receiving unit receives light reflected from the target location T only during a timing period P1 that coincides with the emission of light from the light emitting unit, the detection value appears to increase when stray or interfering light is incident between the optical sensor 7 and the target location T, making it impossible to measure the correct distance. On the other hand, in the optical sensor 7, the light receiving unit further receives light reflected from the target location T during a timing period P2 between the emission of light from the light emitting unit and the next emission, thereby enabling the apparent increase in the detection value to be known. Therefore, by obtaining the difference between the detection values ​​of the light receiving unit during periods P1 and P2, the variation caused by stray light, etc., can be removed, and an interference-resistant optical sensor 7 can be realized.

[0058] The light receiving unit of the optical sensor 7 can also be configured to detect light reflected from the target location T by the laser from the laser source 8. That is, by making the light receiving unit of the optical sensor 7 always, or at least when the laser from the laser source 8 is irradiating, it is also possible to detect light reflected from the target location T by the laser from the laser source 8. As a result, the irradiation time of the laser from the laser source 8 can be measured, and it is possible to confirm whether or not laser irradiation has occurred.

[0059] In the above embodiment, a limit switch 10 was used as a proximity detection unit. However, any other sensor can be used as long as it can detect when the laser source 8 approaches the target area T to a specified distance and output a proximity signal. Similarly, any other contact sensor can be used as long as it can detect the contact between the movable part 6 and the skin, or the retraction of the movable part 6. By using a contact sensor, the influence of the skin's location and condition can be eliminated.

[0060] Although an optical sensor 7 is used as the distance detection unit, any other sensor can be used as long as it can detect the distance to the target area T and output a distance signal S corresponding to the distance. However, considering cost and performance, as mentioned above, an optical sensor is preferred as the distance detection unit. Since optical sensors can perform measurements in a non-contact manner, the risk of adhesion of sebum and other contaminants is minimal, and stable performance can be maintained.

[0061] The proximity detection unit and the distance detection unit can be selected from optical sensors, electrostatic capacitance sensors, temperature sensors, ultrasonic sensors, sound sensors, microwave sensors, and physical sensors, respectively. To improve the robustness of the phototherapy device 1, the proximity detection unit and the distance detection unit are preferably sensors of different types. Furthermore, the proximity detection unit can be composed of multiple sensors of the same or different types, and similarly, the distance detection unit can also be composed of multiple sensors of the same or different types.

[0062] In the aforementioned phototherapy device 1, the limit switch 10, i.e., the proximity detection unit, can be omitted. In this case, the phototherapy device may include a laser source for irradiating a target area with laser light, and a distance detection unit for detecting the distance to the target area and outputting a distance signal corresponding to the distance. During the laser irradiation period and the laser stop period, the distance detection unit has an optical sensor. This optical sensor has a light-emitting part for emitting light to the target area and a light-receiving part for receiving light reflected from the target area. During the stop period, it performs light emission and light reception, and is configured to perform laser irradiation by the laser source based on the change in the distance signal.

[0063] Explanation of reference numerals in the attached figures

[0064] 1: Phototherapy device

[0065] 2: Control device

[0066] 3: Probe

[0067] 4: Cables

[0068] 5: Main body

[0069] 6: Movable parts

[0070] 7: Optical Sensor

[0071] 8: Laser source

[0072] 9: Optical Window

[0073] 10: Limit switch

[0074] S: Distance signal

[0075] T: Target area

[0076] L0: Baseline value

[0077] L1: Lower limit

[0078] L2: upper limit

[0079] d1: During laser irradiation

[0080] d2: During laser shutdown.

Claims

1. A phototherapy device, wherein, have: Main body; A laser source, which is disposed inside the main body, irradiates the target area with laser light; A movable part that can move along the axial direction of the main body by pressing on a target area; The proximity detection unit includes a limit switch, which detects that the laser source has approached the target part to a predetermined distance based on the movable part being pressed against the target part, thereby activating the limit switch and outputting a proximity signal. as well as The distance detection unit, which has multiple detection units, uses the proximity signal as a trigger to detect the distance to the target location and outputs a distance signal corresponding to the distance. The phototherapy device is configured to set a reference value based on the distance signal detected after the proximity signal is detected, and to allow laser irradiation by the laser source according to the amount of change of the distance signal relative to the reference value.

2. The phototherapy device according to claim 1, wherein, When the distance signal is within a specified range relative to the reference value, laser irradiation by the laser source is permitted.

3. The phototherapy device according to claim 2, wherein, When the distance signal becomes outside the specified range relative to the reference value, laser irradiation by the laser source is prohibited.

4. The phototherapy device according to claim 3, wherein, When the distance signal becomes outside the specified range relative to the reference value, the reference value is reset.

5. The phototherapy device according to any one of claims 1 to 4, wherein, The distance to the target location is detected sequentially by the plurality of detection units.

6. The phototherapy device according to any one of claims 1 to 4, wherein, When the multiple distance signals obtained by the multiple detection units converge to a predetermined deviation, the reference value is set based on the multiple distance signals.

7. The phototherapy device according to any one of claims 1 to 4, wherein, During laser irradiation by the laser source, the distance detection unit has an optical sensor that alternately repeats the laser irradiation period and the laser stop period. The optical sensor has a light-emitting part that emits light to the target part and a light-receiving part that receives light reflected from the target part. The light emission and the light reception are performed during the laser stop period.

8. The phototherapy device according to claim 7, wherein, The distance detection unit outputs the distance signal, which is the difference between the detection value of the light receiving unit receiving light reflected from the target part when the light emitting unit is emitting light and the detection value of the light receiving unit receiving light reflected from the target part when the light emitting unit is not emitting light.

9. The phototherapy device according to any one of claims 1 to 4, wherein, The proximity detection unit has a contact-type sensor.

10. The phototherapy device according to any one of claims 1 to 4, wherein, It also has a probe. The probe includes: a laser light source, a proximity detection unit, a distance detection unit, a main body, and a movable part. The movable part can move along the axis of the main body by pressing on a target area. The proximity detection unit is configured to detect when the laser source approaches a predetermined distance relative to the target part by means of the relative movement between the main body and the movable part. The distance detection unit is disposed in the movable part.

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