Ultraviolet therapy device and ultraviolet irradiation method for ultraviolet therapy device

Abstract

In an ultraviolet treatment device using an LED as a light source, stable treatment effects are obtained regardless of the temperature of the LED element. The ultraviolet treatment device includes an LED light source that emits light containing ultraviolet rays, a control section that controls the lighting of the LED light source, and a detection section that detects the temperature change of the LED light source with respect to a reference temperature. The control section includes a calculation section that calculates a correction value that corrects the amount of light irradiation based on the variation in the degree of influence on the human body caused by the variation in the spectral distribution of the light accompanying the temperature change detected by the detection section, and a lighting control section that causes the LED light source to light based on the correction value calculated by the calculation section.

Description

Technical Field

[0001] This invention relates to an ultraviolet therapy device using LEDs as a light source and an ultraviolet irradiation method for the ultraviolet therapy device. Background Technology

[0002] Previously, phototherapy utilized ultraviolet light, specifically UVA (wavelength 320nm–400nm) and UVB (wavelength 280–320nm) wavelengths. Ultraviolet therapy aimed to suppress the immune system and achieve therapeutic effects through ultraviolet irradiation.

[0003] For example, Patent Document 1 (Japanese Patent Application Publication No. 2017-131522) discloses an ultraviolet therapy device that uses ultraviolet light to treat skin diseases. This ultraviolet therapy device includes a lamp source and an LED as the ultraviolet light source.

[0004] When using LEDs as the light source, a simpler circuit structure than that of a lamp power supply can be achieved, enabling miniaturization and weight reduction of the device. Therefore, in recent years, ultraviolet therapy devices using ultraviolet light-emitting elements (UVLEDs) as the ultraviolet light source have been proposed.

[0005] In addition, in the following description, light containing ultraviolet rays and ultraviolet light will sometimes be referred to simply as "light".

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-131522 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Unlike lamps, the wavelength and irradiance of the emitted light from LEDs vary depending on the element temperature. Furthermore, when ultraviolet light is applied to the skin, the likelihood of developing side effects, such as erythema, varies depending on the wavelength. In other words, even with the same device and the same irradiation time in an LED-based ultraviolet therapy device, differences in the temperature of the LED element can lead to variations in the likelihood of developing side effects.

[0011] Therefore, the objective of this invention is to achieve stable therapeutic effects in an ultraviolet therapy device using LEDs as the light source, independent of the temperature of the LED element.

[0012] Methods for solving problems

[0013] To address the aforementioned issues, one aspect of the ultraviolet therapy device of the present invention includes an LED light source emitting light containing ultraviolet rays and a control unit controlling the illumination of the LED light source. The ultraviolet therapy device includes a detection unit that detects temperature changes of the LED light source relative to a reference temperature. The control unit includes: a calculation unit that calculates a correction value for adjusting the amount of light irradiation based on changes in the degree of influence on the human body caused by variations in the spectroscopic spectrum of the light accompanying the temperature change detected by the detection unit; and an illumination control unit that illuminates the LED light source based on the correction value calculated by the calculation unit.

[0014] In this way, by monitoring the temperature changes of the LED light source and considering the changes in the spectral distribution associated with these temperature changes, which affect the human body (e.g., the ease with which erythema develops), the amount of light irradiation can be adjusted. Therefore, stable therapeutic effects can be achieved in the same therapeutic device regardless of the temperature of the LED light source.

[0015] Alternatively, the ultraviolet therapy device described above may include a recording unit that records first information related to the apparent irradiance obtained by taking into account the erythema effect at each wavelength of the irradiance at the irradiated surface, and the calculation unit uses the first information recorded by the recording unit to calculate the correction value.

[0016] In this case, appropriate corrections can be made using the apparent irradiance that takes into account the erythema effect at each wavelength.

[0017] Furthermore, in the aforementioned ultraviolet therapy device, the following can also be used: the first information is information representing the relationship between parameters related to the temperature of the LED light source and the apparent irradiance; the calculation unit, based on the temperature change detected by the detection unit and the first information recorded in the recording unit, derives a first correction coefficient by dividing the apparent irradiance at the reference temperature by the apparent irradiance corresponding to the temperature of the LED light source; and calculates the correction value by multiplying the parameter that determines the amount of light irradiation at the reference temperature by the first correction coefficient.

[0018] In this case, the change in apparent irradiance relative to the reference temperature can be appropriately estimated by measuring the temperature change of the LED light source relative to the reference temperature. The reciprocal of the proportion of apparent irradiance at the detection temperature to that at the reference temperature can then be used as a first correction factor. By multiplying this first correction factor by the parameter determining the amount of light irradiance at the reference temperature, the aforementioned correction value can be easily and appropriately calculated.

[0019] Alternatively, in the aforementioned ultraviolet therapy device, the following may also be used: the first information is the information required to calculate the apparent irradiance, including the spectroscopic spectrum of the light and the erythema spectrum; the calculation unit calculates the apparent irradiance of the LED light source at the temperature based on the temperature change detected by the detection unit and the first information recorded in the recording unit, and calculates the correction value based on the calculated apparent irradiance.

[0020] In this case, the apparent irradiance of the LED light source at the detection temperature can be directly estimated, and the above correction value can be calculated appropriately.

[0021] Alternatively, the ultraviolet therapy device described above may include a recording unit that records second information related to the apparent irradiance derived from the change in apparent irradiance at the irradiated surface when the LED light source is lit, taking into account the erythema effect at each wavelength. The calculation unit uses the second information recorded by the recording unit to calculate the correction value.

[0022] In this case, appropriate corrections can be made considering that the apparent irradiance decreases as the temperature of the LED light source increases when it is lit.

[0023] Furthermore, in the aforementioned ultraviolet therapy device, the following may also be used: the second information is information indicating the relationship between the set irradiation amount to be irradiated to the patient and the proportion of the apparent irradiation amount to the set irradiation amount; the ultraviolet therapy device also includes an input unit for inputting the set irradiation amount; the calculation unit, based on the set irradiation amount input through the input unit and the second information recorded in the recording unit, derives the reciprocal of the proportion, i.e., the second correction coefficient, and calculates the correction value by multiplying the parameter that determines the irradiation amount of light by the second correction coefficient.

[0024] In this case, it is possible to appropriately estimate how the apparent irradiance changes relative to the set irradiance, and to derive the reciprocal of the proportion of the apparent irradiance to the set irradiance as a second correction factor. By multiplying this second correction factor by the parameter that determines the irradiance of light, the aforementioned correction value can be easily and appropriately calculated.

[0025] Alternatively, in the aforementioned ultraviolet therapy device, the detection unit can detect any one of the following: the temperature of the LED substrate on which the LED light source is mounted, the forward voltage of the LED light source, and the characteristics of the light from the LED light source. As the characteristics of the light from the LED light source, spectroscopic spectrum, irradiance, radiant flux, etc., can be used. In this case, changes in the optical characteristics of the LED light source can be appropriately detected.

[0026] Furthermore, in the aforementioned ultraviolet therapy device, the calculation unit can calculate any one of the following as the correction value: the irradiation time of the light, the input current to the LED light source, and the temperature adjustment amount of the LED light source. In this case, the parameters for correcting the amount of light irradiation can be appropriately calculated.

[0027] Alternatively, in the aforementioned ultraviolet therapy device, the detection unit may detect the temperature change of the LED light source before the lighting control unit lights it up, the calculation unit may calculate the irradiation time of the light as the correction value before the lighting control unit lights it up, and the control unit may include a display control unit that displays the irradiation time of the light calculated by the calculation unit on the display unit before the lighting control unit lights it up.

[0028] In this case, the duration of light exposure (treatment time) can be shown to the user (doctor, patient, etc.) before the LED is turned on.

[0029] Furthermore, one aspect of the ultraviolet irradiation method of the ultraviolet therapy device of the present invention is an ultraviolet irradiation method of an ultraviolet therapy device having an LED light source emitting light containing ultraviolet rays, wherein the method includes: a first step of detecting the temperature change of the LED light source relative to a reference temperature; a second step of calculating a correction value for correcting the irradiation amount of the light based on the change in the degree of influence on the human body caused by the change in the spectroscopic spectrum of the light accompanying the temperature change; and a third step of illuminating the LED light source based on the correction value.

[0030] In this way, by monitoring the temperature changes of the LED light source and considering the changes in the ease of erythema formation caused by the accompanying variations in the spectroscopic distribution of the LED light source, the amount of light irradiation can be adjusted. Therefore, stable therapeutic effects can be obtained in the same therapeutic device regardless of the temperature of the LED light source.

[0031] Invention Effects

[0032] According to the present invention, in an ultraviolet therapy device that uses an LED (UVLED) that emits ultraviolet light as a light source, a stable therapeutic effect can be obtained without depending on the temperature of the LED element.

[0033] Those skilled in the art should be able to understand the objectives, methods, and effects of the invention described above, as well as the objectives, methods, and effects of the invention not described above, from the following detailed description of the invention by referring to the accompanying drawings and claims. Attached Figure Description

[0034] Figure 1 This is a chart showing the erythema spectrum of CIE.

[0035] Figure 2 It is a graph showing the changes in LED substrate temperature and peak wavelength over time.

[0036] Figure 3 It is a graph showing the changes in LED substrate temperature and relative illuminance over time.

[0037] Figure 4 It is a graph showing the change of apparent illuminance relative to the duration of irradiation.

[0038] Figure 5A This is a diagram illustrating the apparent radiation dose.

[0039] Figure 5B This is a diagram used to illustrate the concept of correction method 1.

[0040] Figure 6A This is a graph showing the relationship between the rate of change of substrate temperature and apparent illuminance when the substrate is lit.

[0041] Figure 6B This is a graph representing the correction factor α.

[0042] Figure 7 This is a diagram used to illustrate the concept of correction method 2.

[0043] Figure 8A It is a graph showing the relationship between the set exposure dose and the apparent exposure dose / set exposure dose.

[0044] Figure 8B This is a graph representing the correction factor β.

[0045] Figure 9A This indicates that the set irradiation dose is 200 mJ / cm. 2 The graph shows the effects of various correction methods under different conditions.

[0046] Figure 9B This indicates that the set radiation dose is 1500 mJ / cm². 2 The graph shows the effects of various correction methods under different conditions.

[0047] Figure 10 This is a diagram illustrating the processing flow of an ultraviolet therapy device.

[0048] Figure 11 This is a block diagram illustrating an example of the structure of an ultraviolet therapy device. Detailed Implementation

[0049] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0050] In this embodiment, an ultraviolet therapy device equipped with a treatment apparatus that emits ultraviolet light, for example, light containing ultraviolet light in the region of UVB (wavelength 280nm to 320nm). Here, an ultraviolet therapy device equipped with an LED light source, for example, emitting light with a peak at a wavelength of 308nm, will be described.

[0051] When UVB radiation is applied to human skin, erythema (redness) occurs as a side effect. Erythema refers to a reddening of the skin surface due to factors such as capillary dilation. The lowest amount of ultraviolet radiation that produces erythema is called the minimum erythema dose (MED). Furthermore, the unit for MED is mJ / cm³. 2 Just as the ease with which a tan develops varies from person to person, the ease with which erythema (mastitis exacerbated by tanning) develops, or melasma, also varies from person to person.

[0052] Furthermore, the ease with which ultraviolet (UV) radiation causes erythema, i.e., the degree of UV impact on the human body, varies depending on the wavelength of the UV radiation. The relative impact on the human body at each wavelength has been defined by the International Commission on Illumination (CIE) as the erythema spectrum.

[0053] Figure 1 This is a chart representing the spectrum of erythema effects.

[0054] In Figure 1 In the diagram, the horizontal axis represents wavelength (nm), and the vertical axis represents relative influence. Erythema effect spectrum S er It is defined in the range of wavelength λ from 250 nm to 400 nm, as shown in the definition in equation (1) below, and is expressed as the relative influence of each wavelength when the effect of light with wavelengths from 250 nm to 298 nm on the skin is set to 1.

[0055] [Equation 1]

[0056]

[0057] Depend on Figure 1 As can be roughly seen from the shape of the graph, the shorter the wavelength, the greater the impact on the human body and the more likely erythema will occur. Specifically, light with wavelengths longer than UVB, strictly speaking, light with wavelengths longer than 328 nm compared to UVB, if the above formula (1) is applied, will hardly have any effect on the skin. On the other hand, if the wavelength is below 328 nm, it begins to have an effect on the skin, and the shorter the wavelength, the greater the effect.

[0058] Furthermore, as defined in equation (2) below, the overall impact of ultraviolet radiation on the human body is determined by the spectroscopic irradiance E of the irradiated ultraviolet radiation in the range of 250 nm to 400 nm. λ Spectrum of interaction with erythema S er The effect is obtained by integrating the product with wavelength. The influence obtained in this way is called the erythema ultraviolet radiation intensity I. CIE Erythema UVD I CIE The higher the value, the more likely the light will produce erythema.

[0059] [Equation 2]

[0060]

[0061] Depend on Figure 1 It is also known that, especially in the wavelength range of 298nm and above to 310nm, even a difference of only 1nm in wavelength can significantly change the impact on the human body.

[0062] It is generally known that in LED light sources, optical characteristics vary due to component temperature.

[0063] Figure 2 This is a graph showing the time-varying changes in substrate temperature and peak wavelength at the irradiated surface after the LED is lit. Figure 3 This is a graph showing the time-dependent changes in substrate temperature and relative irradiance at the illuminated surface after the LED is lit. Furthermore, since the temperature of the LED element itself cannot be measured, the LED substrate temperature, which is correlated with the LED element temperature, is used here.

[0064] Such as Figure 2 , Figure 3 As shown, after the LED is lit, if the component temperature (substrate temperature) rises due to the power supply, the wavelength of the emitted light will become longer, and the irradiance at the irradiated surface will decrease. This result means that the light emitted from the same LED light source becomes less likely to produce a red spot over time.

[0065] In other words, even when using the same ultraviolet therapy device for the same irradiation time, the treatment effect and the manner in which side effects occur can vary due to differences in the temperature of the LED components.

[0066] In this embodiment, the changes in the optical characteristics of such an LED light source are monitored, and the ultraviolet irradiation amount is adjusted to ensure that the therapeutic effect of the ultraviolet therapy device remains unchanged (by irradiating the desired amount of ultraviolet light). Here, the case in which the LED substrate temperature is measured as a means of monitoring the optical characteristics of the LED, and the ultraviolet irradiation amount is adjusted by correcting the irradiation time, a parameter that determines the amount of ultraviolet irradiation, will be described.

[0067] The following section provides a detailed explanation of the impact of variations in the spectral distribution of LED light sources on treatment.

[0068] As described above, the emitted light from the LED light source becomes longer in wavelength as the temperature of the LED element rises. Therefore, in LED-type ultraviolet therapy devices, the emitted light becomes less likely to cause erythema over time, which appears to be a decrease in irradiance at the irradiated surface. Therefore, as an indicator that takes into account the ease with which erythema occurs at each wavelength, the irradiance at the irradiated surface is defined as "apparent irradiance" in the following formula. Hereinafter, "apparent irradiance" will be referred to simply as "apparent illuminance" and will be used in the explanation.

[0069] [Equation 3]

[0070]

[0071] In equation (3) above, E′(T) is the apparent illuminance at LED substrate temperature T. Additionally, E(T) is the actual irradiance at the irradiated surface at LED substrate temperature T. T is the LED substrate temperature, and T0 is the reference temperature of the LED substrate (e.g., 25°C). Furthermore, I CIE (T) is the amount of red spot ultraviolet radiation in the emitted light relative to the LED substrate temperature T. CIE (T0) is the amount of red spot ultraviolet radiation in the emitted light relative to the LED substrate temperature T0. Additionally, E... λ (T, λ) represents the spectral irradiance at LED substrate temperature T, and S er (λ) is the erythema effect spectrum, and P(T,λ) is the area-normalized spectrophotometer.

[0072] Thus, by taking into account both the variation in erythema caused by the variation in the spectroscopic spectrum accompanying the variation in LED substrate temperature and the variation in actual irradiance caused by the variation in LED substrate temperature, the apparent irradiance E′(T) at any temperature T can be obtained. Furthermore, the variation in actual irradiance caused by the variation in LED substrate temperature (equivalent to E(T) / E(T0)) can also be calculated from parameters related to irradiance (e.g., the wavelength integral value of the spectroscopic spectrum).

[0073] When the emitted light from the LED light source contains light with wavelengths between 298 nm and 400 nm, the apparent illuminance decreases monotonically as the LED substrate temperature increases. Therefore, if the relationship between the LED substrate temperature and apparent illuminance is not considered, setting the irradiation time using only the initial irradiance in an ultraviolet therapy device will not yield an adequate irradiation dose.

[0074] The actual treatment process is taken into consideration. In ultraviolet therapy devices, the irradiation time is automatically calculated based on the set irradiation dose input by the user. In conventional ultraviolet therapy devices, the irradiation time was calculated by dividing the set irradiation dose input by the user by the value of the radiation irradiance (initial radiation irradiance) preset for the therapy device.

[0075] As an example, consider 2000 mJ / cm 2 The light irradiance is 100 mW / cm². 2 Under ideal lighting conditions where the irradiance does not change over time, the illumination time is 20 seconds. However, as mentioned earlier, the apparent irradiance decreases after the LED is lit, therefore even if the apparent irradiance at the start of LED lighting is the initial irradiance of 100 mW / cm², the illumination time will still be affected. 2 If the irradiation time is estimated based on the initial irradiance, the irradiation amount will be insufficient and an appropriate amount of irradiation cannot be achieved.

[0076] Next, consider setting the irradiation dose to 2000 mJ / cm. 2 For the case of five consecutive irradiations, the irradiation time is set to 20 seconds per irradiation, and the interval between irradiations is set to 1 second, based on the previous calculations. Figure 4 The results of the apparent illuminance measurement under these conditions are shown in the figure.

[0077] exist Figure 4 In the diagram, the dashed box A represents the irradiance under ideal light source conditions (set irradiance), and the solid boxes B1 to B5 represent the apparent irradiance for the first to fifth exposures. Figure 4 It is known that in LEDs, the apparent illuminance decreases over time during a single irradiation, and the apparent illuminance at the initial illumination of the LED decreases with each subsequent irradiation. Furthermore, the difference between the set irradiation dose and the apparent irradiation dose (irradiation dose error) increases with each subsequent irradiation, making it impossible to provide adequate irradiation towards the end of multiple irradiations. This means that in LED-type ultraviolet therapy devices, even with the same irradiation time, the apparent irradiation dose varies with each irradiation, failing to provide a uniform therapeutic effect.

[0078] (Revision Method 1)

[0079] Because the apparent illuminance varies depending on the LED substrate temperature, a method was considered to acquire the LED substrate temperature each time irradiation begins (when the irradiation switch is pressed), estimate the apparent illuminance based on the acquired LED substrate temperature, and correct the irradiation time. This correction method is referred to as "Correction Method 1".

[0080] like Figure 5AAs shown, if multiple irradiations (in this case, two) are performed consecutively within the same irradiation time, the temperature of the LED substrate increases during the second irradiation, resulting in a lower apparent illuminance at the start of irradiation. Therefore, the apparent irradiance B2 of the second irradiation is smaller than the apparent irradiance B1 of the first irradiation.

[0081] Therefore, the irradiation time is adjusted to take into account this reduction in apparent illuminance. Specifically, the LED substrate temperature is measured each time irradiation begins, the apparent illuminance at the start of irradiation is estimated, and the irradiation time is adjusted accordingly. Figure 5B The irradiation time is increased as shown. As a result, the apparent irradiation dose for the second time is increased by an additional amount C through the correction of the irradiation time. It is foreseeable that the error between the first and second irradiation doses will be reduced, that is, the deviation of the apparent irradiation dose at each irradiation will be reduced.

[0082] Figure 6A This is a graph showing the relationship between LED substrate temperature and apparent illuminance. In Figure 6A In the figure, the vertical axis represents the rate of change of apparent illuminance, which has been normalized to a substrate temperature of 25°C. This rate of change of apparent illuminance is the proportion of the apparent illuminance at LED substrate temperature T to the apparent illuminance at a reference temperature of 25°C.

[0083] In this embodiment, Figure 6A The reciprocal of the rate of change of apparent illuminance shown (the value obtained by dividing the apparent illuminance at the reference temperature of 25°C on the LED substrate by the apparent illuminance at the LED substrate temperature T) is set as the correction factor α. The irradiation time is corrected by multiplying the correction factor α by the irradiation time. Figure 6B This is a graph showing the relationship between the LED substrate temperature and the correction factor α. Figure 6B The correction coefficient α shown is pre-recorded as a function or matrix (table) in the ultraviolet therapy device.

[0084] For example, the correction factor α is 1.00 when the LED substrate temperature is 25℃, and the correction factor α is 1.20 when the LED substrate temperature is 50℃.

[0085] Therefore, at a radiation irradiance of, for example, 100 mW / cm² 2 In a therapeutic device with a substrate temperature of 25°C, the irradiation dose is set to 200 mJ / cm². 2 In the case of an LED substrate temperature of 25℃, the irradiation time is 200 / 100×1.00=2.00sec, and the irradiation time is 200 / 100×1.20=2.40sec when the LED substrate temperature is 50℃.

[0086] In this way, the changes in optical characteristics (changes in apparent illuminance) are estimated based on the LED substrate temperature at the start of irradiation, and the irradiation time is adjusted for each irradiation.

[0087] (Revised Method 2)

[0088] In LED light sources, as the temperature of the LED substrate rises after lighting, the apparent illuminance decreases monotonically. Therefore, it is assumed that if the set illuminance increases (or the illuminance time increases), the illuminance error will increase. Thus, a method for correcting the illuminance time based on the set illuminance was considered. This correction method is referred to as "Correction Method 2".

[0089] As an example, with an initial illuminance of 100 mW / cm² 2 In the treatment device, the irradiation dose is considered to be set at 200 mJ / cm. 2 The situation and 1500mJ / cm 2 The situation. Figure 7 The concept diagram is shown in the image.

[0090] exist Figure 7 In the diagram, the dashed box A1 indicates a set irradiation dose of 200 mJ / cm². 2 The dashed box A2 indicates a set irradiation dose of 1500 mJ / cm². 2 As this Figure 7 As shown, the apparent illuminance decreases over time. Furthermore, if the set illuminance is increased, the illuminance time becomes longer. Therefore, the higher the set illuminance, the greater the illuminance error.

[0091] Figure 8A This is a graph showing the relationship between the set exposure and the apparent exposure / set exposure. Here, apparent exposure is... Figure 7 The integral value is obtained from the "irradiation time - apparent illuminance" curve shown. Figure 8A As shown, the larger the set irradiance, the smaller the proportion of apparent irradiance to set irradiance.

[0092] Therefore, in this embodiment, Figure 8A The reciprocal of the apparent irradiance / set irradiance is set as the correction factor β. The irradiance time is corrected by multiplying this correction factor β by the irradiance time. Figure 8B This is a graph showing the relationship between the set exposure dose and the correction factor β. Figure 8B The correction coefficient β shown is pre-recorded as a function or matrix (table) in the ultraviolet therapy device.

[0093] For example, setting the irradiation dose to 200 mJ / cm 2 The correction factor β is 1.09, and the set exposure dose is 1500 mJ / cm². 2 The correction factor β is 1.13.

[0094] Therefore, at a radiation irradiance of, for example, 100 mW / cm² 2In a therapeutic device with a substrate temperature of 25°C, the irradiation dose is set to 200 mJ / cm². 2 The irradiation time is 200 / 100 × 1.09 = 2.18 seconds, and the irradiation dose is set at 1500 mJ / cm². 2 The irradiation time is 1500 / 100×1.13=17.0sec.

[0095] In this way, the irradiation time is adjusted according to each set irradiation dose.

[0096] The effects of the corrections were confirmed when only correction method 1 was implemented, when only correction method 2 was implemented, and when correction method 2 was implemented based on correction method 1. Figure 9A and Figure 9B The results are shown in the figure.

[0097] Figure 9A This indicates that the set irradiation dose is 200 mJ / cm. 2 In this situation, Figure 9B This indicates that the set irradiation dose is 1500 mJ / cm². 2 The irradiation time was adjusted for various irradiation levels at LED substrate temperatures of 25°C and 50°C, and the results were compared. Furthermore, Figure 9A and Figure 9B The value in parentheses is the apparent irradiance / set irradiance.

[0098] When only correction method 1 is implemented, no correction is made to the irradiation time when the LED substrate temperature is the reference temperature of 25°C. On the other hand, when the LED substrate temperature is 50°C, the irradiation time is corrected (added) to compensate for the decrease in apparent illuminance. As a result, the deviation in apparent illuminance caused by temperature is reduced under the same set illuminance. In other words, a constant therapeutic effect is obtained independently of temperature when the set illuminance is the same.

[0099] However, when the irradiation dose is set to 200 mJ / cm 2 Under the condition of 1500mJ / cm 2 Under different conditions, the exposure dose error will vary. Specifically, when the exposure dose is set to 1500 mJ / cm², the error will be different. 2 Under the condition that the set irradiation dose is 200mJ / cm 2 Compared to the previous case, the exposure error becomes larger. Therefore, implementing correction method 1 alone cannot solve the problem of different exposure errors under each set exposure dose.

[0100] On the other hand, when only correction method 2 is implemented, the irradiation time is corrected according to the set irradiation amount. As a result, under the same temperature conditions, the irradiation amount error remains approximately constant regardless of the magnitude of the set irradiation amount. However, if only correction method 2 is implemented, it is impossible to correct the difference in irradiation amount error caused by the different LED substrate temperatures at the start of irradiation.

[0101] In contrast, by combining correction method 1 and correction method 2, an irradiation dose closer to the set irradiation dose can be administered under any circumstances, regardless of the LED substrate temperature at the start of irradiation or the set irradiation dose. Thus, by implementing correction method 1 and correction method 2 together, the appropriate irradiation dose to be administered to the patient can be achieved.

[0102] Reference Figure 10 The processing procedure for using the LED-type ultraviolet therapy device in this embodiment will be described.

[0103] Furthermore, in ultraviolet therapy devices, for example, the irradiance E [mW / cm²] at the irradiated surface was recorded at a reference temperature (25°C) pre-measured before leaving the factory. 2 ] and information used to derive the correction coefficients α and β ( Figure 6B , Figure 8B Ultraviolet therapy devices that use LEDs as light sources typically have multiple LED light sources (e.g., a 5×5 LED array). The aforementioned irradiance is the irradiance of the composite light emitted from multiple LED light sources.

[0104] In step S1, the ultraviolet therapy device acquires the set irradiation dose H [mJ / cm²] determined and input by the physician based on the patient's condition. 2 Then proceed to step S2.

[0105] In step S2, the ultraviolet therapy device uses the set irradiation dose H obtained in step S1 as a basis, and refers to... Figure 8B The corresponding table is used to derive the correction coefficient β.

[0106] In step S3, the ultraviolet therapy device obtains the LED substrate temperature T.

[0107] In step S4, the ultraviolet therapy device uses the LED substrate temperature T obtained in step S3 as a basis, and refers to... Figure 6B The correction factor α is derived from the corresponding table.

[0108] In step S5, the ultraviolet therapy device calculates the irradiation time t as a correction value for adjusting the light irradiation amount. Specifically, the ultraviolet therapy device calculates the irradiation time t [sec] by dividing the set irradiation amount H by the radiation illuminance E recorded by the ultraviolet therapy device and multiplying it by correction factors α and β, respectively.

[0109] t=H / E×α×β………(4)

[0110] In step S6, the ultraviolet therapy device performs display control to make the display unit of the ultraviolet therapy device display the irradiation time t calculated in step S5.

[0111] In step S7, the LED is lit up based on the situation where a physician, or in some cases a nurse or other medical personnel press the switch on the ultraviolet therapy device.

[0112] In step S8, the count of the time since the start of ultraviolet therapy is performed.

[0113] In step S9, the ultraviolet therapy device determines whether the remaining irradiation time has become 0. If the device determines that the remaining irradiation time is not 0, the LED remains lit. If the device determines that the remaining irradiation time has become 0, it proceeds to step S10 and turns off the LED. In this way, a treatment with an irradiation time of t seconds is performed.

[0114] In this way, the set radiation dose H [mJ / cm] input by the physician can be used. 2 Based on the LED substrate temperature T [°C] at the start of irradiation, the appropriate irradiation time t, taking into account the variation in the optical characteristics of the LED light source, is calculated.

[0115] By using this therapeutic device to treat patients with the calculated irradiation time t, it is possible to suppress the different ways in which the therapeutic effect and side effects occur during each irradiation, or to prevent the inability to obtain sufficient therapeutic effect without irradiating the set amount of irradiation.

[0116] Figure 11 This is a block diagram illustrating an example of the configuration of the ultraviolet therapy device 1 in this embodiment.

[0117] The ultraviolet therapy device 1 includes: a treatment device (light source) 2, which has an LED light source that emits light containing ultraviolet rays; and a main body 4, which controls the LED light source of the treatment device 2.

[0118] The treatment device 2 includes a detection unit 21 for detecting the temperature of an LED substrate. The detection unit 21 has a structure in which a temperature probe, such as a thermistor or thermocouple, is mounted on the LED substrate.

[0119] The main body 4 includes an input unit 41, a display unit 42, a recording unit 43, a power supply unit 44, a control unit (control unit) 45, and an LED driving unit 46. The treatment device 2 and the main body 4 are connected by a connecting cable 6, which includes a power line 6a (represented by a thick line) and a signal line 6b (represented by a thin line).

[0120] The input unit 41 acquires the set irradiation dose H input by the operator (e.g., a physician) and outputs the information to the control unit 45.

[0121] The display unit 42 can display the ultraviolet radiation intensity, irradiation time, and elapsed time during ultraviolet irradiation. Furthermore, the display unit 42 can also display information indicating an abnormality (error message, etc.) if certain abnormalities occur in the ultraviolet therapy device 1.

[0122] The recording unit 43 records the irradiance E at the irradiated surface of the ultraviolet therapy device 1 and information used to derive correction coefficients α and β.

[0123] The power supply unit 44 converts the power supplied from the external power supply 8 into the appropriate voltage for each subsequent unit and supplies it.

[0124] The control unit 45 acquires the LED substrate temperature T detected by the detection unit 21 and the set irradiation amount H input to the input unit 41, and derives correction coefficients α and β based on these. Furthermore, the control unit 45 uses the correction coefficients α and β to correct the irradiation time obtained by dividing the set irradiation amount H by the irradiance E recorded by the recording unit 43, and calculates the corrected irradiation time t. The control unit 45 also controls the LED driving unit 46 to control the irradiation amount (irradiation time t) of the LED light source in the treatment device 2. In other words, the control unit 45 has a calculation unit that calculates the correction value (in this case, the irradiation time) for correcting the irradiation amount and a lighting control unit that illuminates the LED light source based on the calculated correction value.

[0125] The LED driver unit 46 supplies power to the LED light source according to the control signal from the control unit 45.

[0126] The following describes the steps for an operator to irradiate the affected area with ultraviolet light using the ultraviolet therapy device 1 of this embodiment.

[0127] First, the operator operates the input unit 41 to input the amount of ultraviolet radiation to be irradiated onto the affected area (set irradiation amount H).

[0128] Next, the operator holds the treatment device 2 and brings the light-emitting surface of the LED light source close to or against the affected area. Then, the operator presses the switch (not shown) on the treatment device 2. The LED substrate temperature T is then detected in the ultraviolet therapy device 1, and the irradiation time t corresponding to the LED substrate temperature T and the set irradiation dose H is calculated. The calculated irradiation time t is displayed on the display unit 42, and then the LED light source is turned on, beginning the irradiation of the affected area with ultraviolet light.

[0129] Afterwards, if the irradiation time reaches the calculated irradiation time t, the LED light source will automatically turn off.

[0130] As explained above, the ultraviolet therapy device 1 in this embodiment includes: a treatment apparatus 2 having an LED light source that emits light containing ultraviolet rays; a control unit (control unit) 44 that controls the illumination of the LED light source; and a detection unit 21 that detects the temperature change of the LED light source relative to a reference temperature by detecting the temperature of the LED substrate. Furthermore, the control unit 45 calculates a correction value for adjusting the light irradiation amount based on the change in the spectral density of the light caused by the change in the light's spectroscopic distribution accompanying the temperature change of the LED light source (LED substrate temperature change), and illuminates the LED light source based on the calculated correction value. Here, the correction value can be set as the light irradiation time, which is a parameter determining the light irradiation amount.

[0131] Specifically, the ultraviolet therapy device 1 includes a recording unit 43 that records first information related to the apparent illuminance obtained by taking into account the erythema effect at each wavelength of the irradiance at the irradiated surface. This first information represents the relationship between parameters related to the temperature of the LED light source and the apparent illuminance, for example... Figure 6B As shown, it can be configured to establish a correspondence between the LED substrate temperature and a correction factor α (the first correction factor). Here, the correction factor α is... Figure 6A The reciprocal of the rate of change of apparent illuminance shown is the value obtained by dividing the apparent illuminance at the reference temperature (25°C) by the apparent illuminance at the detection temperature.

[0132] The control unit 45 derives a correction coefficient α from the LED substrate temperature based on the first information, and corrects the irradiation time by multiplying the parameter that determines the amount of light irradiation at the reference temperature (irradiation time H / E at the reference temperature) with the correction coefficient α (correction method 1).

[0133] In addition, the recording unit 43 can also record second information related to the apparent irradiance derived from the change in apparent irradiance when the LED light source is lit. This second information is information indicating the relationship between the set irradiance to be irradiated to the patient and the proportion of the apparent irradiance relative to the set irradiance, for example... Figure 8B As shown, it can be configured to establish a correspondence between the set exposure dose and the correction factor β (the second correction factor). Here, the correction factor β is... Figure 8A The apparent exposure is the reciprocal of the proportion of the set exposure.

[0134] The control unit 45 derives a correction coefficient β from the input set irradiation amount based on the second information, and corrects the irradiation time by multiplying the parameter that determines the irradiation amount of light (in this embodiment, the irradiation time H / E×α, which is corrected based on the LED substrate temperature) with the correction coefficient β (correction method 2).

[0135] Furthermore, the control unit 45 illuminates the LED light source with a corrected illumination time t.

[0136] In other words, the ultraviolet irradiation method of the ultraviolet therapy device 1 in this embodiment includes: a first step of detecting the temperature change of the LED light source relative to the reference temperature; a second step of calculating a correction value for correcting the amount of light irradiation based on the change in the degree of influence on the human body caused by the change in the spectroscopic spectrum of light accompanying the temperature change of the LED light source; and a third step of illuminating the LED light source based on the calculated correction value.

[0137] In this way, by monitoring the temperature changes of the LED light source and considering the changes in the ease of erythema formation caused by the changes in the spectroscopic distribution associated with the temperature changes of the LED light source, the amount of light irradiation is corrected. That is, not only are the actual irradiance changes associated with the temperature changes of the LED light source considered, but also the effects of wavelength shifts are taken into account for correction. As mentioned above, in ultraviolet therapy devices, a wavelength deviation of 1 nm in the emitted light can significantly affect the treatment effect. According to the ultraviolet therapy device 1 of this embodiment, a stable treatment effect can be obtained in the same device regardless of the temperature of the LED light source.

[0138] The ultraviolet therapy device 1 in this embodiment is a small therapy device that uses LEDs as a light source. Therefore, when treating a large area of ​​the affected area, the treatment light is not used up in a single irradiation, but rather the irradiation position is changed for multiple irradiations. In this case, if the treatment effect is not made the same in each irradiation, uneven treatment will occur.

[0139] As described above, by applying correction method 1 to take the LED element temperature into account, even if the LED element temperature changes due to multiple consecutive irradiations, irradiation can be performed with the same irradiation dose as long as the irradiation dose is set the same. Therefore, the same therapeutic effect can be obtained with each irradiation. In addition, in the case of multiple light irradiations, it is not necessary to wait for the LED element temperature to drop to the reference temperature before starting light irradiation each time in order to obtain the same therapeutic effect, which is a time-efficient method.

[0140] On the other hand, the severity of skin diseases varies from person to person, and the amount of light irradiation (set irradiation dose) in a single irradiation session differs from person to person. The temperature of the LED element gradually increases during a single irradiation session, while the apparent illuminance decreases. Therefore, the longer the irradiation time, the greater the error in the irradiation dose. Thus, if the correction method 1 described above is applied solely based on the LED element temperature at the start of irradiation, an appropriate therapeutic effect cannot be obtained.

[0141] As described above, by applying correction method 2 to correct the irradiation time according to each set irradiation dose, the irradiation dose error can be kept constant regardless of the magnitude of the set irradiation dose.

[0142] As described above, in this embodiment, by simultaneously performing irradiation time correction based on the LED element temperature at the start of irradiation and irradiation time correction based on the set irradiation amount, a consistently stable therapeutic effect can be provided in the same therapeutic device even when the temperature conditions and irradiation amount setting conditions are different.

[0143] (Modified Example)

[0144] In the above embodiment, the case of detecting the temperature change of the LED light source relative to the reference temperature by detecting the temperature of the LED substrate in the detection unit 21 is described.

[0145] However, to monitor changes in the optical characteristics of an LED light source, it is sufficient to detect parameters that are correlated with the LED element temperature. For example, the forward voltage Vf of the LED can be detected instead of the LED substrate temperature. The LED element temperature and the LED forward voltage Vf are correlated; if the LED element temperature rises, the LED forward voltage Vf decreases. Therefore, monitoring changes in optical characteristics can also be achieved by detecting the LED forward voltage Vf.

[0146] In addition, the characteristics of the light emitted from the LED light source can be measured instead of the LED substrate temperature. These characteristics include the spectroscopic spectrum, irradiance, and the radiant flux of the LED. In this case, variations in the irradiance and peak wavelength of the light emitted from the LED light source can be directly monitored.

[0147] Furthermore, in the above embodiments, the case of correcting the light irradiation time in order to suppress the variation in therapeutic effect caused by the variation in the optical characteristics of the LED light source was described.

[0148] However, the parameters used to correct the amount of light irradiation are not limited to the irradiation time; for example, the input current (forward current If) of the LED light source can also be corrected.

[0149] Furthermore, to suppress variations in therapeutic effects caused by changes in the optical characteristics of the LED light source, a temperature control unit for controlling the temperature of the LED substrate can be provided. For example, the temperature control unit can be configured to include a fan with variable rotation speed, a Peltier element, etc. In this case, a temperature adjustment amount is calculated as a correction value, and the temperature of the LED substrate is controlled by the temperature control unit based on the calculated temperature adjustment amount.

[0150] Furthermore, in the above embodiment, the data recorded in the recording unit 43 of the ultraviolet therapy device 1 is... Figure 6B , Figure 8B The information shown illustrates the case where the control unit 45 directly derives the correction coefficients α and β based on the LED substrate temperature T and the set irradiation amount H. However, the recording unit 43 only needs to record information related to the apparent illuminance used in correction method 1 (first information) and information related to the apparent irradiation amount used in correction method 2 (second information); the first information and the second information are not limited to these. Figure 6B , Figure 8B The information shown.

[0151] For example, it is also possible to record in the recording section 43. Figure 6A , Figure 8A The information shown. In this case, the control unit 45 uses the LED substrate temperature T as a basis, from Figure 6A The information shown derives the rate of change of apparent illuminance, and its reciprocal is calculated as a correction factor α. Additionally, the control unit 45, based on the set illuminance H, from... Figure 8A The information shown is used to derive the apparent exposure / set exposure, and its reciprocal is calculated as the correction factor β.

[0152] Additionally, the recording unit 43 can also record parameters required for calculating the apparent illuminance (spectral density at the reference temperature, erythema spectrum) as information related to apparent illuminance (first information). In this case, the control unit 45 calculates the apparent illuminance E′(T) at LED substrate temperature T based on the parameters recorded by the recording unit 43 and the spectroscopic density at LED substrate temperature T, according to equation (3) above. Furthermore, the control unit 45 calculates the irradiation time t by dividing the set irradiation amount H by the apparent illuminance E′(T). Thus, the same irradiation time (H / E×α) as when using the correction factor α can be obtained.

[0153] Furthermore, in the recording unit 43, information related to apparent exposure (secondary information) may also be recorded, for example, as a representation of... Figure 7 The information shown relates the irradiation time to the apparent illuminance. In this case, the control unit 45 calculates the apparent illuminance based on the input set illuminance and the information recorded in the recording unit 43, and calculates the correction factor β (set illuminance / apparent illuminance).

[0154] Furthermore, in the above embodiment, the case where the LED substrate temperature is detected only at the start of irradiation, and the irradiation amount is corrected using both correction method 1 and correction method 2, has been described. However, it is also possible to detect the LED substrate temperature during the irradiation process and correct the irradiation amount in real time using correction method 1. In this case, correction method 2 is no longer needed.

[0155] Alternatively, if the set exposure dose is small enough to allow for exposure dose error, correction method 2 can be omitted.

[0156] Furthermore, in the above embodiment, the case of using light with a wavelength of 308nm as the therapeutic light was described, but the wavelength of the therapeutic light can be arbitrarily set according to the disease.

[0157] The ultraviolet therapy device of the present invention is not limited to the above-described embodiments, and various modifications can be made.

[0158] 1…Ultraviolet Therapy Device

[0159] 2…therapeutic instruments

[0160] 21… Testing Department

[0161] 4…Main part

[0162] 41…Input Section

[0163] 42… Display Section

[0164] 43…Records Department

[0165] 44…Power Supply Unit

[0166] 45…Control Unit

[0167] 46…LED driver unit

Claims

1. An ultraviolet therapy device, comprising an LED light source emitting light containing ultraviolet rays and a control unit for controlling the illumination of the LED light source, characterized in that, The ultraviolet therapy device includes a detection unit that detects the temperature change of the LED light source relative to a reference temperature. The control unit includes: The calculation unit calculates a correction value for correcting the amount of light irradiation based on the change in the degree of influence on the human body caused by the change in the spectroscopic spectrum of light accompanying the temperature change detected by the detection unit. A lighting control unit illuminates the LED light source based on a correction value calculated by the calculation unit; and... The recording unit records first information related to the apparent irradiance of the light at the irradiated surface, taking into account the erythema effect at each wavelength. The calculation unit uses the first information recorded in the recording unit to calculate the correction value.

2. The ultraviolet therapy device according to claim 1, characterized in that, The first information represents the relationship between parameters related to the temperature of the LED light source and the apparent irradiance. The computing unit, Based on the temperature change detected by the detection unit and using the first information recorded in the recording unit, a first correction coefficient is derived. This first correction coefficient is a value obtained by dividing the apparent irradiance at the reference temperature by the apparent irradiance corresponding to the temperature of the LED light source. The correction value is calculated by multiplying the parameter that determines the amount of light irradiation at the reference temperature by the first correction factor.

3. The ultraviolet therapy device according to claim 1, characterized in that, The first information is the information required to calculate the apparent irradiance, including the spectroscopic spectrum of the light and the erythema spectrum. The computing unit, Based on the temperature change detected by the detection unit, and using the first information recorded in the recording unit, the apparent irradiance of the LED light source at the temperature is calculated. The correction value is calculated based on the calculated apparent irradiance.

4. The ultraviolet therapy device according to any one of claims 1 to 3, characterized in that, The ultraviolet therapy device includes a recording unit that records second information related to the apparent irradiance derived from the change in apparent irradiance at the irradiated surface, considering the erythema effect at each wavelength, based on the irradiance of the light at the irradiated surface when the LED light source is lit. The calculation unit uses the second information recorded in the recording unit to calculate the correction value.

5. The ultraviolet therapy device according to claim 4, characterized in that, The second information is information indicating the relationship between the set radiation dose to be irradiated to the patient and the proportion of the apparent radiation dose relative to that set radiation dose. The ultraviolet therapy device also has an input section for inputting the set irradiation amount. The computing unit, Based on the set irradiation dose input through the input unit and the second information recorded in the recording unit, the reciprocal of the ratio of the apparent irradiation dose to the set irradiation dose, i.e., the second correction coefficient, is derived. The correction value is calculated by multiplying the parameter that determines the amount of light irradiation by the second correction factor.

6. The ultraviolet therapy device according to any one of claims 1 to 3, characterized in that, The detection unit detects any one of the following: the temperature of the LED substrate on which the LED light source is mounted, the forward voltage of the LED light source, and the characteristics of the light from the LED light source, thereby detecting the temperature change.

7. The ultraviolet therapy device according to any one of claims 1 to 3, characterized in that, The calculation unit calculates the duration of light irradiation as the correction value.

8. The ultraviolet therapy device according to claim 1, characterized in that, The calculation unit calculates the input current to the LED light source as the correction value.

9. The ultraviolet therapy device according to claim 1, characterized in that, It also has: The second calculation unit calculates the temperature adjustment amount of the LED light source based on the change in the degree of influence on the human body caused by the change in the spectroscopic spectrum of light accompanying the temperature change detected by the detection unit. as well as The temperature control unit controls the temperature of the LED substrate on which the LED light source is mounted, based on the temperature adjustment amount of the LED light source calculated by the second calculation unit.

10. The ultraviolet therapy device according to any one of claims 1 to 3, characterized in that, The detection unit detects the temperature change of the LED light source before the lighting control unit lights it up. The calculation unit calculates the illumination time of the light as the correction value before using the lighting control unit to light up the LED light source. The control unit includes a display control unit that displays the illumination time of the light calculated by the calculation unit on the display unit before the LED light source is illuminated by the lighting control unit.

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