System and method for determining a minimal erythema dose of phototherapy

Abstract

This document discloses a phototherapy device and related systems and methods having features for determining a user's dosage regimen. In some embodiments, the phototherapy device may include a colorimetric testing component positioned to acquire measurement data of a treatment area on a user's skin. The phototherapy device may use this measurement data to calculate the average Individual Type Angle (ITA) of the user's skin across the entire treatment area and use the average ITA to determine a dosage regimen tailored to the user's skin characteristics. The phototherapy device then irradiates the treatment area with a specific dose of ultraviolet radiation according to the dosage regimen.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 531,290, filed August 7, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This technology generally relates to phototherapy equipment, systems, and methods. Specifically, various embodiments of this technology relate to systems and methods, and related equipment for determining phototherapy dosing protocols. Background Technology

[0003] Vitamin D refers to a type of fat-soluble open-ring steroid that the human body can synthesize through sufficient sunlight exposure. Specifically, vitamin D3 is produced in the skin when 7-dehydrocholesterol reacts with UVB rays. Vitamin D can also be obtained from various dietary sources, including oily fish (such as salmon and tuna), vitamin D-fortified foods (such as dairy products and fruit juices), and vitamin D supplements. Once absorbed, vitamin D travels through the bloodstream to the liver, where it is converted into the pro-hormone calcidiol. Subsequently, calcidiol is converted into calcitriol (the hormonally active form of vitamin D) by monocytes / macrophages in the kidneys or immune system. When synthesized by monocytes / macrophages, calcitriol acts as a cytokine, defending against microbial invasion. Calcitriol synthesized by the kidneys circulates throughout the body to regulate the concentration of calcium and phosphate in the blood, thereby promoting adequate bone mineralization, growth, and rebuilding. Therefore, insufficient vitamin D levels (typically manifested as a blood calcidiol concentration below 20-40 ng / mL) can lead to various osteomalacia diseases, such as rickets in children and osteomalacia in adults. Vitamin D deficiency is also associated with many other diseases and conditions, such as depression, heart disease, gout, autoimmune diseases, and various types of cancer.

[0004] In recent years, vitamin D deficiency has become increasingly prominent, partly due to the rapid increase in urban population and the resulting prevalence of indoor lifestyles, which hinder the body's daily synthesis of vitamin D through sunlight. The growing emphasis on skin cancer prevention and sun protection measures (sunscreen blocks UVB rays) may also exacerbate the spread of vitamin D deficiency. Furthermore, various environmental factors such as geographical latitude, seasonal changes, and smog further hinder the synthesis of sufficient vitamin D.

[0005] Doctors have recommended vitamin D supplements as a preventative measure to increase vitamin D levels. For example, the Institute of Medicine in the United States recommends a daily dietary vitamin D intake of 600 IU for people aged 1-70 and 800 IU for people aged 71 and older. Other organizations recommend varying daily vitamin D intakes. These daily dose restrictions aim to prevent toxic effects from excessive vitamin D intake. In contrast, the human body is physiologically adapted to obtaining significantly higher daily vitamin D doses from sunlight (e.g., 4000-20000 IU / day or more). UVB radiation is considered a more ideal source of vitamin D because it readily promotes vitamin D synthesis through sunlight exposure, and the body has a natural ability to inhibit excessive vitamin D intake through the skin. Attached Figure Description

[0006] Figure 1A This is an isometric front view of a phototherapy device configured according to certain embodiments of the present technology.

[0007] Figure 1B According to certain embodiments of this technology, Figure 1A An isometric view of the phototherapy equipment in a compact configuration.

[0008] Figure 2 This is a flowchart illustrating the process of determining a user dosage scheme for a phototherapy device according to certain embodiments of the present technology.

[0009] Figure 3A This is a partial schematic side view of a phototherapy system for determining a dosage regimen for a user, according to certain embodiments of the present technology.

[0010] Figure 3B According to certain embodiments of this technology, Figure 3A The phototherapy system shown is partially schematically viewed from the side when irradiated with UV radiation.

[0011] Figure 4 This is an isometric view of a test component used to determine a dosage regimen in a phototherapy system configured according to certain embodiments of the present technology.

[0012] Figure 5 This is a flowchart illustrating the process of determining a dosage regimen using test components according to certain embodiments of the present technology.

[0013] Figure 6A and Figure 6B This illustrates certain embodiments of the present technology, performed for different users. Figure 5 The result of the process shown.

[0014] Figure 7 This is an isometric view of a test component portion of a phototherapy system configured according to certain embodiments of the present technology.

[0015] The accompanying drawings are not strictly to scale. Similarly, to illustrate certain embodiments of the present technology, some components and / or operations may be separated into different modules or combined into a single module. Furthermore, although the present technology can be modified in various ways and adopted in alternative forms, specific embodiments are shown in the accompanying drawings by way of example and will be described in detail below. However, this specification is not intended to limit the present technology to the specific embodiments described. Detailed Implementation

[0016] This technology relates to systems and methods for determining phototherapy dosage regimens, and related equipment. The following will refer to... Figures 1A to 7 Specific details of several embodiments of the present technology are described herein. However, the present technology can still be practiced even without some of these specific details. In some cases, to avoid obscuring the main points of the present technology, well-known structures and conventional techniques related to fields such as phototherapy have not been shown in detail. The terminology used in the following description should be interpreted in the broadest and most reasonable way, even when used in conjunction with the detailed description of certain specific embodiments of this disclosure. Certain terms may be particularly emphasized below; however, any term intended to be interpreted in a limiting manner will be clearly and specifically defined in this Detailed Description section.

[0017] The accompanying drawings illustrate embodiments of the present technology but should not be construed as limiting its scope. The dimensions of various components in the drawings are not necessarily drawn to scale, and these components may be enlarged arbitrarily to improve readability. The drawings may abstract component details when details such as component positions and specific precision connections are not necessary for understanding how the present technology is manufactured and used. The numerous details, dimensions, angles, and other features shown in the drawings are merely illustrative of specific embodiments of this disclosure. Therefore, other embodiments may employ different details, dimensions, angles, and features without departing from the spirit or scope of the present technology.

[0018] Phototherapy systems provide users with UVB (ultraviolet-medium wave) radiation to stimulate vitamin D production in the skin. Typically, a suitable phototherapy system includes one or more UV radiation sources (e.g., one or more UV lamps, one or more light-emitting diodes (LEDs), microplasma films, etc.) and one or more optical components for filtering and shaping UV radiation (e.g., emitting only UVB radiation). Furthermore, the phototherapy system may include a dose controller to help regulate the amount of UV radiation provided by the system. The dose controller can set the intensity and / or duration of the dose delivered to the user, track the dose, confirm whether erythema has occurred since the last irradiation, and / or automatically adjust the dose over time as the user develops and / or their tolerance to UV radiation decreases (e.g., after experiencing an erythema event, prolonged periods without irradiation, etc.).

[0019] The Fitzpatrick Skin Type Scale has been used to determine the initial dose for phototherapy. The Fitzpatrick Skin Type Scale is a numerical classification scheme based on human skin color as a way to assess how a user responds to UV radiation and / or how much UV radiation they can tolerate. For example, a user can be categorized into one of six skin types (Type I through VI) based on their responses to questions about skin tone, hair color, eye color, and sunburn tendency. The user's minimum erythema dose (MED) can then be estimated based on that skin type. A user's MED is the UV dose that would produce a perceptible erythema on the user's skin 24 hours after exposure to UV radiation.

[0020] Because skin type is determined based on user assessments of subjective questions (e.g., how does your skin react to one hour of sun exposure), the question-based Fitzpatrick assessment can be inaccurate. Furthermore, the Fitzpatrick Skin Type Scale fails to account for differences within skin types that can affect skin's response to UV radiation. For example, a user who is generally relatively sensitive to UV radiation but has tanned due to repeated phototherapy and / or sun exposure will have relatively higher skin tolerance, resulting in a higher UV radiation dose required to reach their MED. Conversely, a user with prior sunburn will have a lower (or even no) radiation dose required to reach their MED.

[0021] Due to limitations in the Fitzpatrick Skin Type Scale (FST) assessment, previous vitamin D phototherapy systems often estimated the user's Menstrual Effect Level (MED) based on skin type, setting an initial dose significantly lower than the user's MED. The radiation dose was then slowly increased in each treatment session until the estimated MED was reached, with fixed intervals between treatments (e.g., one week). While this method safely and gradually increases UV exposure to reduce or eliminate the risk of sunburn, the slow increase means users may need 6-8 weeks to fully reap the benefits of phototherapy. Furthermore, if treatment is interrupted (e.g., stopped for a month), the user's tolerance to UV radiation typically decreases, necessitating a reduction in the UV dose followed by a gradual increase.

[0022] The phototherapy devices, related systems, and methods disclosed herein aim to provide accurate skin tone assessments that can be completed within a short timeframe (e.g., seconds, minutes, hours, 24 hours, and / or any time period within this timeframe). This allows the phototherapy system to set the phototherapy dose to appropriate parameters, lower than or equal to the user's MED dose, before each phototherapy session, ensuring sufficient exposure to achieve the beneficial effects of phototherapy (e.g., vitamin D synthesis) in each session, without requiring lengthy calibration cycles.

[0023] In some embodiments, the phototherapy device may include a color testing component (e.g., a colorimeter) for acquiring images (or other measurement data) of the user's skin. The phototherapy device (or other devices communicatively coupled to it, such as a remote server) can convert the images into L*a*b* format (sometimes also called the CIELAB color format), which accurately measures all perceptible colors within the treatment area of ​​the user's skin. The characters L*, a*, and b* represent three values ​​in the CIELAB color space used to measure objective colors and calculate color differences. L* represents luminance, ranging from 0 (black) to 100 (white); a* and b* represent chromaticity values ​​without a specific range. Negative a* values ​​typically correspond to green, and positive a* values ​​typically correspond to red; negative b* values ​​typically correspond to blue, and positive b* values ​​typically correspond to yellow.

[0024] The L*a*b* format is particularly useful because its values ​​are correlated with the user's Individual Type Angle (ITA). ITA is an indicator of skin pigmentation, reflecting the degree to which melanin in a user's skin absorbs light. ITA can classify a user's skin into six broad categories, corresponding to different levels of UV radiation tolerance. However, within these categories, ITA provides a continuous numerical spectrum, expressed in angles, which can then be used to calculate the user's MED (Mean Effect Level).

[0025] Because ITA values ​​are obtained through objective color measurements of the user's skin, they provide a more accurate method for calculating MED. Therefore, phototherapy devices that use ITA to estimate a user's MED and / or determine the dosage regimen dosing ...

[0026] In some embodiments, the phototherapy system disclosed herein may employ a strip testing component (also known as a "zap test") in addition to or as an alternative to the color testing component. The strip testing component irradiates discrete areas of a user's skin with multiple escalating doses of UV radiation. This escalating irradiation helps determine the user's skin type and / or the appropriate irradiation dose for that skin type by directly exposing them to UV radiation of varying intensities. After a predetermined time period (e.g., 24 hours) following the strip test, the user, others (e.g., medical professionals), and / or the imaging component can assess the discrete locations to determine the number of erythema events experienced by the user and / or the maximum dose that did not induce erythema events. The phototherapy system can then use this information to set a dosage regimen for the user. While this strip testing method may result in some UV-induced pigmentation on the user's skin to determine the appropriate UV radiation dose, the discrete locations tested are relatively small compared to the treatment area (e.g., 1 cm, 2.6 cm, less than 2.6 cm, less than 1 cm), thus avoiding UV-induced pigmentation over the entire treatment area. Furthermore, the strip test method can determine the appropriate dose of UV radiation within 24 hours of the test, without the need for weeks of gradual adjustments. Therefore, users can begin to experience the full benefits of phototherapy within 24 hours of their initial test.

[0027] For ease of explanation, the phototherapy device, its components, and testing equipment are sometimes described herein with reference to the spatial orientation of the embodiments shown in the accompanying drawings, using terms such as up / down, high / low, upward / downward, and / or horizontal plane, xy plane, vertical direction, or z-direction. However, it should be understood that the phototherapy device, its components, and testing equipment can be moved to different spatial orientations for use without altering the structure and / or function of the embodiments disclosed herein.

[0028] Furthermore, although this document primarily discusses determining a user's MED and / or dosage regimen for a phototherapy system, those skilled in the art will understand that the scope of this technology is not limited thereto. For example, the systems and methods disclosed herein can also be used to determine a user's ITA, MED, and / or UV dose tolerance in other medical treatments. Therefore, the scope of protection of this technology is not limited to any specific subset of embodiments disclosed herein.

[0029] Selected Examples of Phototherapy Devices and Related Systems and Methods Using ITA Figure 1A This is an isometric view of a phototherapy device 100 configured according to certain embodiments of the present technology. For example... Figure 1AAs shown, the phototherapy device 100 (hereinafter referred to as "device 100") includes a housing 110, the housing having a head 112, a first panel 114, and a second panel 116 coupled to the first panel 114 via a hinge 118. The head 112 can support various control electronics 120 (e.g., controllers and / or other compatible electronics), while the first panel 114 and the second panel 116 can support a UV emitter array 130 and / or a color testing assembly 140.

[0030] Control electronics 120 may include non-volatile memory, a processor, communication components, etc. The memory and processor can perform any of the processes described herein to control components of device 100 (e.g., UV emitter array 130, color testing component 140, communication components, etc.), and communicate with other devices (e.g., user-associated personal electronic devices, remote servers, etc.). In some embodiments, control electronics 120 includes one or more input devices (e.g., touchscreen, keyboard, etc.) allowing the user to interact directly with device 100 (e.g., without using other electronic devices such as smartphones) to perform operations such as turning on device 100, setting dosage schemes, receiving UV radiation doses, and turning off device 100. Additionally or alternatively, the input devices may include various audio, video, and / or biometric sensors to help verify user identity and quickly retrieve information such as dosage schemes, treatment records, and medical data.

[0031] UV emitter array 130 is configured to emit UV radiation to a user of device 100 at a uniform (or substantially uniform) density. For example, the UV emitter array 130 may include an array of light-emitting diodes (LEDs) emitting UV radiation and one or more optical components to extend, collimate, and / or filter the UV radiation from the LEDs. In various embodiments, the LEDs may emit UV radiation with wavelengths between about 285 nm and about 315 nm, between about 293 nm and 305 nm, or about 297 nm. The optical components then extend and collimate the beam emitted by the LEDs, resulting in a uniform (or substantially uniform) radiation density of UV radiation emitted by device 100. This uniform (or substantially uniform) radiation density helps improve the consistency of UV radiation received by the user from device 100. This consistency helps reduce the number of exposure points receiving excessive UV radiation (e.g., leading to localized erythema). Additionally or alternatively, the optical components may filter the UV radiation, removing radiation that is outside a predetermined range, above a predetermined threshold, and / or below a predetermined threshold. Studies have shown that UV radiation at specific wavelengths (such as about 297 nm) can maximize vitamin D synthesis. Therefore, by reducing UV radiation outside the target range (e.g., from about 285 nm to about 305 nm), this filtration can reduce the user's overall exposure to UV radiation without diminishing the vitamin D-related efficacy. For further details on examples of suitable components for the UV emitter array 130, see U.S. Patent Application No. 18 / 021,922, filed February 17, 2023, by Gary Lauder et al., the entire contents of which are incorporated herein by reference.

[0032] When a user stands in front of the first and second panels 114 and 116, the color testing component 140 is positioned to measure various parameters of the user's skin (e.g., the melanin content in the skin). For example, the color testing component 140 may include a colorimeter, a light-emitting device with an RGB sensor, or other imaging sensors, and / or any other suitable components for performing one or more measurements on the user's skin (referred to herein as "images" of the user's skin). These images may contain L*a*b* data, chromaticity data, hue data, and / or RGB data related to the absorption (and reflection) of different wavelengths of light by the user's skin. As described in more detail below, the color testing component 140 and / or control electronics 120 may use these images to calculate the Individual Type Angle (ITA) for the user, calculate the Minimum Erythema Dose (MED) and / or dosing scheme based on the ITA, and detect erythema, melanin, etc., in the user's skin.

[0033] like Figure 1AAs further shown, device 100 may also include an external power supply 102 (e.g., a power cord). The external power supply 102 simplifies and stabilizes the operation of device 100 by providing a stable power source (e.g., preventing a decrease in actual UV radiation output when the battery is low). However, in some embodiments, device 100 is powered by an internal power supply component (e.g., an onboard battery) that can be charged and / or replaced on demand. The internal power supply component improves portability by reducing device 100's dependence on an external power source during use.

[0034] Figure 1B This is an isometric view of the device 100 in a compact state (also referred to as a folded state, a stowed state, a stored state, etc.) according to certain embodiments of the present technology. Figure 1B As shown, the second panel 116 can be folded down via hinge 118 to contact the first panel 114. This covers the UV emitter array 130 on the first and second panels 114 and 116, helping to reduce the possibility of accidental exposure of the device 100.

[0035] Figure 2 This is a flowchart of a process 200 for determining a user's dosage regimen for a phototherapy device according to certain embodiments of the present technology. This process 200 can be performed by… Figure 1A The control electronics 120 shown and / or any other suitable controller (e.g., a remote server coupled to the control electronics 120) are implemented.

[0036] Process 200 begins at box 202 by acquiring (e.g., capturing, receiving, etc.) one or more images of the user's treatment area. In some embodiments, acquiring the image at box 202 includes: operating a colorimeter to emit light with a known wavelength composition (e.g., a white LED) and measuring reflected light from the treatment area using an imaging sensor (e.g., an RGB sensor and / or other suitable sensor). In some embodiments, acquiring the image at box 202 includes sequentially and / or simultaneously imaging the treatment area and a calibration component. The calibration component may have a known color (e.g., a known yellow hue), allowing the imaging sensor (or any suitable processor) to account for the effects of ambient light. For example, process 200 may determine a correction filter at box 202 based on an image of the calibration component that takes into account the known color, and then apply the correction filter to one or more pre-filtered images of the treatment area. In some embodiments, the process of acquiring the image at box 202 also includes receiving an image from a separate component (e.g., from the user's smartphone).

[0037] At box 204, process 200 includes determining the ITA of the treatment area based on the image. Determining the ITA may include converting the image to L*a*b* format (sometimes also called CIELAB color format), where L* represents perceived brightness, ranging from 0 (black) to 100 (white); a* represents the green-magenta color axis, ranging on a negative / positive scale (typically -128 to +127); and b* represents the blue-yellow color axis, ranging on a negative / positive scale (typically -128 to +127). The ITA can be calculated from the L*a*b* data using the following formula: (1) In some embodiments, the L*a*b* data across the entire treatment area is averaged before calculating a single ITA. In other embodiments, multiple ITAs are calculated (e.g., for each pixel in the treatment area image), and then the average is taken to determine the final ITA. This average may take into account factors such as pigmentation variations across the entire treatment area, localized areas of high UV sensitivity (e.g., small areas of sunburn), and overall UV sensitivity (e.g., considering the degree of tanning). Therefore, compared to sampling from a single point in the treatment area, this average allows process 200 to determine an ITA that more accurately reflects the entire treatment area.

[0038] At box 206, process 200 calculates the user's estimated MED based on the ITA determined at box 204. The estimated MED can be calculated using the following formula: (2) In some embodiments, process 200 determines multiple ITAs (e.g., the ITA for each pixel in an image of the treatment area) at box 204, and then calculates multiple MEDs at box 206. Process 200 can calculate a final MED by averaging the MEDs calculated based on the multiple ITAs.

[0039] At box 208, process 200 includes receiving and / or obtaining answers to one or more secondary questions (e.g., safety questions). Secondary questions may include: whether the user is taking medication that may increase or decrease their actual MED (even though their ITA is normal); whether the user has recently been exposed to sunlight (or other UV radiation), which may have contributed to bringing them closer to their MED; and whether the user has a particular sensitivity to UV radiation, which helps identify outliers (e.g., users who have a history of being more prone to sunburn than average based on their ITA). These answers can be obtained through user input on the phototherapy device (e.g., via...). Figure 1A Input is obtained from the touchscreen of device 100 and / or from a device communicating with the phototherapy device (e.g., input on the user's smartphone). In some embodiments, process 200 may skip box 208. For example, when a user receives treatment daily, process 200 may skip box 208 to avoid repeatedly prompting the user to answer.

[0040] At box 210, process 200 includes determining a dosing scheme based on the calculated MED and / or the answers to safety questions. This dosing scheme may include determining parameters such as the power level of the UV emitter, the duration of exposure, etc., to adjust the total amount and / or UV radiation density delivered to the user. In some embodiments, the dosing scheme is set to deliver a dose lower than the user's MED. For example, the dosing scheme may be set to deliver between about 0.5 MED and about 0.95 MED, between about 0.6 MED and about 0.9 MED, or about 0.8 MED. In these examples, the dosing scheme helps reduce the likelihood of the user experiencing UV-induced pigmentation (such as tanning or sunburn) from the phototherapy device (e.g., when the user's MED calculated based on their ITA is an outlier, or when they receive UV radiation from sunlight in addition to using the phototherapy device). Furthermore, the dosing scheme may be set lower than the calculated MED when the answers to safety questions indicate that the user is taking medication to reduce UV radiation tolerance, has recently received a significant dose of UV radiation (such as prolonged sun exposure), and / or the user has a high tendency to sunburn. In some embodiments, the dosing regimen is derived directly from MED conversions, irradiating UV radiation at a specified intensity and duration such that the total UV exposure is equivalent to the maximum UV radiation dose a user can tolerate without experiencing erythema events (e.g., no sunburn, no significant skin discoloration). In other embodiments, the dosing regimen is derived directly from MED conversions, irradiating UV radiation at a specified intensity and duration such that the total UV exposure is equivalent to a level of UV radiation below the maximum tolerable dose that will not induce an erythema reaction, while still providing a significant vitamin D stimulation.

[0041] Since Process 200 is primarily based on acquiring images of the treatment area and performing image-based calculations, its steps can be executed instantly (or nearly instantly). Therefore, the main bottleneck of Process 200 lies in the speed of acquiring images of the treatment area and / or the responsiveness of the user in answering safety questions. Consequently, users can have a smooth experience when using a phototherapy system that implements Process 200 to determine their dosage regimen. Furthermore, because Process 200 can be executed completely in a relatively short time (e.g., on the order of a few minutes), it can be implemented every time a user receives phototherapy to quickly and accurately determine the appropriate dosage regimen for applying their MED (or a dose close to their MED). In other words, Process 200 can calculate the user's MED, determine the appropriate dosage regimen, and allow the phototherapy device to provide treatment to the user on the same day, rather than requiring weeks of gradual increases from a known safe dose to their MED, and / or irradiation tests requiring at least 24 hours to obtain results. This simplified process can improve treatment outcomes by providing treatment to new users more quickly; rapidly adapting to changes in a user's MED (e.g., when a user tans / fades, develops tolerance to treatment, etc.); and quickly adjusting users who have experienced prolonged treatment interruptions (leading to decreased tolerance).

[0042] Figure 3A This is a partially schematic side view of a phototherapy system 300 used to determine a dosage regimen for a user according to certain embodiments of the present technology. More specifically, Figure 3A The phototherapy system 300 (hereinafter referred to as "System 300") is shown according to Figure 2 The process of acquiring an image of the treatment area for user P using the middle frame 202. (Example) Figure 3A As shown, the system 300 includes a phototherapy device 310 (hereinafter referred to as "device 310"), which is connected to... Figure 1A and Figure 1B The phototherapy device 100 described herein is substantially similar (or completely identical). Furthermore, as... Figure 3A As shown, the phototherapy device 310 includes an effective surface 312 and a color testing component 314 positioned to image forward from the effective surface 312. To determine its dosage regimen, the user P can stand in front of the effective surface, at which point the color testing component 314 will capture one or more images of the test area 10 (e.g., a portion of the treatment area). In the illustrated embodiment, the test area 10 is located on the back torso of the user P. However, it should be understood that the test area 10 can be any other part of the user P's body suitable for receiving ultraviolet radiation (e.g., the user's chest torso).

[0043] In various embodiments, the color testing component 314 can image an area with a width (or diameter) between about 1 inch and about 15 inches, or about 5 inches and about 10 inches, or about 8 inches. As described above, the larger area imaged by the color testing component 314 allows the system 300 (or other components communicatively coupled thereto, such as a remote server) to determine the average ITA and / or average MED over the entire test area 10. In turn, the average ITA and / or average MED helps to calculate a more accurate dosing regimen for user P covering the entire treatment area. For example, sampling a relatively small area (e.g., less than 1 inch) of the test area 10 may inadvertently select an area with a darker, more tanned skin than most of the test area 10, and thus a higher tolerance to UV radiation. In this example, the calculated MED would be higher than the result obtained by averaging the ITA and / or MED over a relatively large area (e.g., more than 1 square inch, such as an area spanning 8 square inches). Therefore, user P will be exposed to a UV radiation dose that is more likely to cause some degree of erythema compared to using a larger sample.

[0044] Figure 3B yes Figure 3A The illustrated system 300 is a partial schematic side view during operation of a dosing regimen according to certain embodiments of the present technology. (See attached image.) Figure 3B As shown, device 310 includes one or more UV emitters 316 (e.g., an array of LED components and other optical components) positioned to emit UV radiation 322 forward from effective surface 312. Therefore, when user P stands in front of device 310, the UV emitters 316 irradiate UV radiation 322 onto treatment area 12 (or any other suitable location) on user P's back torso. Figure 3A As further shown, system 300 includes a controller 330, which is operatively coupled to the color testing component 314 and the UV emitter 316 to control system operation. By way of example only, controller 330 can be implemented with... Figure 2 The process 200 is substantially similar to (or exactly the same as) the process of determining the dosage scheme for user P, and then causing system 300 to irradiate UV radiation according to the dosage scheme.

[0045] In some embodiments, such as Figure 3A and Figure 3B As shown, user P can stand at a first distance D1 from device 310 when determining their dosage regimen (e.g., during the testing phase). Figure 3AThe user P stands at a position relative to the device 310. Then, while receiving the UV radiation dose, the user stands at a position at a second distance D2 from the device 310. In some embodiments, the first distance D1 is smaller than the second distance D2. In such embodiments, for example, the user P stands relatively close to the device 310 during the testing phase to help improve measurement accuracy by reducing the influence of ambient light. They then move away from the device 310 during the dosing phase to help improve the safety of the device 310 (e.g., standing too close could lead to overexposure). However, in some embodiments, the first distance D1 is equal to (or approximately equal to) the second distance D2, allowing the user to stand in a position while the phototherapy system 300 determines an appropriate dosing scheme and irradiates the user with the UV radiation dose according to that scheme.

[0046] Selected Examples of Systems and Methods for Dosage Testing of User Skin Figure 4 This is an isometric view of a test assembly 400 configured according to certain embodiments of the present technology for determining a dosage scheme for a phototherapy system. In some embodiments, the test assembly 400 is communicatively coupled to a phototherapy device (e.g., referred to above). Figure 1A The device 100 described. In other embodiments, the testing component 400 is independent, allowing a user (or medical professional) to test a user's MED and then independently provide the results to the phototherapy device.

[0047] In the illustrated embodiment, the test assembly 400 includes a housing 410 and active electronics 420 disposed therein. The housing includes a test surface 412 (e.g., an effective surface, a lower surface, etc.) that includes a plurality of openings 414. The active electronics 420 includes an input / output (I / O) assembly 422, a plurality of UV emitters 424 (e.g., LEDs) aligned with the plurality of openings 414, and one or more status indicator lights 426. Figure 4 Two are shown in the diagram), and a power port 428 for connecting a power cord (e.g., to charge and / or power the test assembly 400). The I / O assembly 422 may include a touchscreen, one or more input buttons, one or more rotary components (e.g., knobs, rotary switches, etc.), a switch, a display, and / or other adapter components. Input allows users (or medical professionals) to perform the following operations: turn on the test assembly 400, set test dose parameters (e.g., minimum dose, maximum dose, step values ​​between doses, etc.), start / stop dose irradiation, select the estimated skin type, select the estimated MED, etc. For example, a user can turn on the test assembly and enter their estimated ITA, skin type, and / or MED. The I / O assembly 422 will determine the test range (e.g., -25% to +25% of the MED value) based on the input data and set up test protocols for multiple UV emitters 424.

[0048] As detailed below, this testing scheme involves irradiating each of a plurality of UV emitters 424 with a different dose of UV radiation, which can then be used to precisely determine a suitable dosing scheme. For example, the plurality of UV emitters 424 may irradiate a percentage of the user's estimated MED in 5% increments. In this example, from left to right, the plurality of UV emitters 424 may irradiate 75%, 80%, 85%, 90%, 95%, 105%, 110%, 115%, and 120% of the user's estimated MED, respectively. In many other examples, the increment may be set to 1%, 2%, 3%, 4%, 10%, and / or any other suitable value. Additionally or alternatively, the maximum dose may be adjusted such that one, two, three, and / or any other suitable number of emitters of the plurality of UV emitters 424 provide a dose exceeding the user's estimated MED.

[0049] like Figure 4 As further shown, the test assembly 400 may include a calibration port 430. This calibration port 430 allows external devices (such as computers, smart devices, etc.) to access the active electronics 420 for testing / calibrating the active electronics 420, installing one or more updates, etc. Additionally or alternatively, the calibration port 430 may provide sampling of environmental conditions (such as humidity, light intensity, etc.) so that the test assembly 400 can adjust the test dose according to the environmental conditions.

[0050] In some embodiments, the test assembly 400 includes a color measurement device (e.g., a colorimeter) coupled to an active electronics device 420. For example, this color measurement device may be aligned with one of a plurality of openings 414 to image the user's skin. The image can be used to obtain estimates of the user's ITA, skin type, and / or MED. As previously described, these estimates can then be used to set the range (and increments) of the dose irradiated by the test assembly 400. In some embodiments, because the color measurement device can provide relatively accurate estimates of the user's ITA, skin type, and / or MED, the dose range irradiated by the test assembly 400 can be smaller. This improves the accuracy of the results from the test assembly 400, allowing for a more precise determination of the appropriate dose for the user.

[0051] Figure 5 This is a flowchart of a process 500 for determining a dosage regimen using a testing component according to certain embodiments of the present technology. This process 500 can be performed by a user, a medical professional, and / or a phototherapy system connected to the testing device, in conjunction with the foregoing reference. Figure 4 The test component 400 of the aforementioned type is used for implementation.

[0052] Process 500 begins at frame 502, positioning the test equipment adjacent to the test area on the user. For example, housing 410 ( Figure 4 The effective surface 412 of the device comes into contact with the user's skin in the selected test area. This test area may be a site that needs to be treated (such as the back trunk) and / or an easily accessible site (such as the wrist).

[0053] At box 504, process 500 provides incremental doses of UV radiation to multiple discrete locations within the test area. For example, multiple UV emitters 424 ( Figure 4 Each of the UV emitters can be irradiated with a different dose of UV radiation. For this purpose, for example, process 500 can adjust the power level of the UV emitter irradiating the UV auxiliary radiation and / or change the irradiation duration. In some embodiments, the range of incremental doses allows process 500 to determine the appropriate dose without user information (e.g., covering a dose range from the most UV-sensitive user to the least UV-sensitive user). In such embodiments, process 500 determines the appropriate dose without user input. In some embodiments, process 500 estimates and / or measures the user's ITA, skin type, and / or MED before starting to determine the starting point and / or range of the dose. For example, process 500 may include acquiring an image (and / or other measurement data) of the user's skin, calculating the ITA of the test area, calculating an estimated MED from the ITA, and determining the dose starting point by multiplying the estimated MED by a coefficient. In such embodiments, process 500 can determine the appropriate dose at a higher level of accuracy and / or avoid providing doses far exceeding the user's appropriate dose level.

[0054] At box 506, process 500 includes removing the testing equipment and waiting for a predetermined color development period. The color development period refers to the time required for the user's skin to develop a color reaction (if any) under the UV dose. Typically, it takes approximately 24 hours for all erythema (or tanning) induced by the UV dose to fully develop. However, in various embodiments, the predetermined color development period can be set between 12 and 48 hours, allowing process 500 to be flexibly implemented to suit the user's schedule.

[0055] At box 508, process 500 includes evaluating a test area to determine the number of erythema events experienced by the user and / or the last dose that did not induce erythema. The evaluation includes observing the presence of perceptible erythema at discrete locations within the test area. In some embodiments, the evaluation is performed by the user and / or another person (such as a medical professional). In some embodiments, the evaluation is performed by imaging the test area and processing the images to detect discrete erythema events.

[0056] At block 510, process 500 includes determining a UV dosing scheme based on the results of block 508. For example, the dosing scheme may be configured to irradiate with a dose equal to (or approximately equal to) the dose of the last time no erythema event occurred. In some embodiments, the dosing scheme may be determined based on the number of erythema events that occurred. For example, when a dose range is not set using user information, process 500 may extrapolate an estimated MED for the user based on the number of erythema events that occurred, and then set the dosing scheme to irradiate that estimated MED (or a percentage of the estimated MED).

[0057] Figure 6A and 6B This illustrates certain embodiments of the present technology, tailored to different users. Figure 5 The results 600 and 610 generated by process box 506. In the illustrated embodiment, each discrete location within the test area receives the same dose of UV radiation. Figure 6A The result 600 shown includes one unaffected location 602 and nine affected locations 604. This result 600 indicates that the corresponding user is relatively sensitive to UV radiation; therefore, process 500 can be configured to administer a lower dose of UV radiation during phototherapy. Conversely, Figure 6B The results 610 shown include seven unaffected locations 612 and three affected locations 614. Results 610 indicate that the corresponding users have above-average tolerance to UV radiation. Therefore, process 500 can be configured to administer medium to high doses of UV radiation during phototherapy.

[0058] Figure 7 This is an isometric view of the skin-interfacing component 711 of a phototherapy system configured according to certain embodiments of the present technology. The skin-interfacing component 711 may constitute... Figure 4 The test assembly 400 shown is located on a portion of its effective surface and / or on that effective surface. In the illustrated embodiment, the skin interface assembly 711 includes a skin contact surface 712 (also referred to as the outermost surface, first surface, lower surface, etc.) and a plurality of openings 714 extending through the skin contact surface 712. The plurality of openings 714 provide a channel through the skin interface assembly 711 for the UV emitter and / or color testing component in the test assembly to contact the user's skin. In the illustrated embodiment, the skin interface assembly 711 includes five openings 714 aligned with corresponding UV emitters and / or color testing components. In some embodiments, the skin interface assembly 711 may have fewer than five or more openings 714 aligned with a corresponding number of UV emitters and / or color testing components.

[0059] like Figure 7As further shown, the skin contact surface 712 may have a curved profile (e.g., forming an arcuate surface) so that the surface 712 of the skin interface assembly 711 can fit flush or substantially flush with the user's skin in the test area (e.g., wrist, side of torso, etc.). Therefore, the curved profile helps to block ambient light during testing and / or helps to limit UV radiation to multiple discrete locations accessible via the multiple openings 714 (e.g., thereby preventing accidental exposure due to UV leakage).

[0060] For example, the present technology is described below in accordance with the various aspects described. For convenience, multiple examples of the various aspects of the present technology are presented in numbered form (e.g., 1, 2, 3, etc.). These are provided as examples only and do not constitute a limitation on the present technology. It should be noted that any dependent examples may be combined in an appropriate manner and incorporated into the corresponding independent examples. Other examples may also be presented in a similar manner.

[0061] 1. A method for determining a dosage scheme for skin irradiation of a user, the method comprising: Obtain one or more images of the treated areas of the user's skin from the color testing component; The average individual type angle (ITA) of the user's skin over the entire treatment area is determined based on the one or more images using the controller of the phototherapy device. The controller determines the estimated minimum erythema dose (MED) for the treatment area based on the average ITA across the entire treatment area; and The controller creates the dosage scheme based on the estimated MED of the treatment area, wherein the dosage scheme includes control settings for one or more ultraviolet (UV) emitters in the phototherapy device to irradiate the user's skin with a dose of UV radiation lower than its actual MED during a single treatment session.

[0062] 2. The method as described in Example 1, wherein acquiring one or more images of the treatment area includes: Emitting light with a predetermined wavelength composition; and An imaging sensor is used to measure the light reflected back from the treatment area.

[0063] 3. The method as described in any one of Examples 1-2, wherein acquiring one or more images of the treatment area comprises: Capture one or more pre-filtered images of the treatment area; Capture one or more images with a calibration component having a known color composition; Based on the required corrections to one or more images of the calibration component and the known color composition, a correction filter is determined for one or more pre-filtered images of the treatment area; and The correction filter is applied to each of one or more pre-filtered images of the treatment area.

[0064] 4. The method as described in any one of Examples 1-3, wherein acquiring one or more images of the treatment area from the color testing component comprises: receiving one or more images from the imaging sensor of the phototherapy device.

[0065] 5. The method as described in any one of Examples 1-4, wherein determining the average ITA of the user's skin within the treatment area comprises: Convert one or more images of the treatment area to L*a*b* format; and For each individual image, calculate the individual ITA of that individual image according to the L*a*b* format.

[0066] 6. The method as described in Example 5, wherein the formula for calculating the individual ITA is: .

[0067] 7. The method as described in Example 5 or 6, wherein determining the average ITA of the user's skin over the entire treatment area further comprises: for each individual image, averaging the L*, a*, b* data in that individual image before calculating the individual ITA for that individual image.

[0068] 8. The method of any one of Examples 5-7, wherein determining the average ITA of the user's skin over the entire treatment area further comprises: determining the average ITA based on the average value of individual ITAs for each individual image via the controller.

[0069] 9. The method as described in any one of Examples 1-8, wherein the estimated MED is calculated using the following formula: .

[0070] 10. The method of any one of Examples 1-9 further includes receiving user input via a user input device related to the answer to one or more secondary questions, wherein the one or more secondary questions relate to factors affecting the actual MED of the user's skin throughout the treatment area.

[0071] 11. The method as described in Example 10, wherein the one or more secondary issues include one or more of the following: Is the user currently taking medications that affect MED? Whether the user has recently been exposed to sunlight and / or other UV radiation; and / or The user is known to be sensitive to UV radiation.

[0072] 12. The method as described in any one of Examples 10-11, wherein determining the dosage regimen comprises: The power level of one or more UV emitters in the phototherapy device and the duration of irradiation during treatment are determined to adjust the intensity and total amount of UV radiation irradiated onto the treatment area of ​​the user's skin.

[0073] 13. The method as described in any one of Examples 10-12, wherein determining the dosage regimen comprises: Treatment parameters were determined to irradiate the user with a total amount of UV radiation approximately 0.8 times the estimated MED.

[0074] 14. A phototherapy system, comprising: A phototherapy device having an effective surface on which a plurality of light-emitting diodes (LEDs) are disposed, the plurality of LEDs being positioned to emit ultraviolet (UV) radiation forward from the effective surface during operation of the phototherapy system; A color testing component, positioned to acquire one or more images of the treatment area of ​​a user's skin when the user stands in front of the effective surface; and A controller operatively coupled to the plurality of LEDs and the color testing assembly, wherein the controller includes a processor and a memory storing instructions that, when executed by the processor, cause the controller to: When the user stands at a predetermined distance from the effective surface, one or more images of the treatment area of ​​the user's skin are received from the color testing component; Based on the one or more images, determine the average individual type angle (ITA) of the user's skin across the entire treatment area. The estimated minimum erythema dose (MED) for the treatment area is determined based on the average ITA over the entire treatment area. A dosage scheme provided to the phototherapy device based on the estimated MED of the treatment area, wherein the dosage scheme includes control settings for the plurality of LEDs to irradiate the user's skin with a UV radiation dose lower than the estimated MED during a single treatment session; and The phototherapy device operates the plurality of LEDs according to the dosage scheme.

[0075] 15. The phototherapy system as described in Example 14, wherein the predetermined distance is between approximately 5 inches and approximately 10 inches from the effective surface.

[0076] 16. The phototherapy system of any one of Examples 14-15, wherein the average ITA corresponds to the average ITA of the portion of the treatment area with an area greater than 1 square inch.

[0077] 17. The phototherapy system as described in any one of Examples 14-16, wherein: The phototherapy device includes: The upper panel has a first portion of the effective surface; and The lower panel, which is hinged to the upper panel, and has a second portion having the effective surface; and The phototherapy device can move between a folded position and an unfolded position, wherein in the folded position the second portion of the effective surface faces the first portion of the effective surface; and in the unfolded position the first portion and the second portion of the effective surface face forward.

[0078] 18. A method for determining a dosage regimen for a user's skin, the method comprising: The estimated initial dose to the user's skin is calculated by the controller of the phototherapy system; An incremental dose of ultraviolet (UV) radiation is delivered to discrete locations within a test area of ​​the user's skin via a test device positioned in contact with the user's skin, wherein the lowest dose of the incremental UV radiation is equal to the estimated initial dose; and The controller determines a UV dosing scheme based on the number of erythema events occurring in the test area after the color development period in response to the incremental dose of UV radiation; wherein the dosing scheme includes control settings for the light-emitting diodes (LEDs) in the phototherapy device to irradiate the user's skin with a UV radiation dose lower than the actual MED of the user's skin during treatment.

[0079] 19. The method as described in Example 18, wherein calculating the estimated starting dose comprises: The test area of ​​the user's skin is imaged to determine the Individual Type Angle (ITA) of the test area. Based on the ITA of the test area, calculate the estimated minimum erythema dose (MED) for that test area; and Multiply the estimated MED by a predetermined coefficient.

[0080] 20. The method as described in Example 18 or 19, wherein, between each increment of UV radiation dose, the increment of the UV radiation dose is less than about 5% of the estimated minimum erythema dose of the user's skin.

[0081] in conclusion In summary, the specific technical embodiments described herein are intended for illustrative purposes. However, to avoid unnecessarily obscuring the description of the technical embodiments, well-known structures and functions have not been shown or described in detail. If any material cited conflicts with this disclosure, this disclosure shall prevail. Where the context permits, singular or plural terms may respectively have plural or singular meanings. Furthermore, unless the word "or" is explicitly limited to referring to only one of two or more items when listing two or more items (excluding other items), the use of "or" in such a listing should be interpreted as including: (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. Additionally, "and / or" (such as "A and / or B") in this specification simultaneously covers A alone, B alone, and combinations of A and B. Furthermore, the terms "comprising," "including," "having," and "with" all indicate that at least the stated features are included, and do not exclude the addition of a greater number of the same features and / or other types of features. It should also be noted that the terms "about" and "approximately" herein mean within 10% of a given value or range. For example, an approximate ratio refers to within 10% of a given ratio.

[0082] Several embodiments of the disclosed technology have been described above with reference to the accompanying drawings. A computing device capable of implementing this technology may include one or more central processing units, memory, input devices (such as keyboards and pointing devices), output devices (such as display devices), storage devices (such as disk drives), and network devices (such as network interfaces). The memory and storage devices, as computer-readable storage media, may store instructions implementing at least a portion of the technology. Furthermore, data structures and message structures may be stored or transmitted via data transmission media (such as signals on a communication link). Various communication links may be used, such as the Internet, local area networks, wide area networks, or point-to-point dial-up connections. Therefore, a computer-readable medium may include computer-readable storage media (e.g., "non-transitory" media) and computer-readable transmission media.

[0083] As can be seen from the above, it should also be understood that various modifications can be made without departing from the scope of this technical disclosure. For example, those skilled in the art will understand that the components of this technology can be further subdivided into sub-components, or different components and functions in this technology can be combined or integrated. Furthermore, certain aspects of this technology described in the context of a specific embodiment may be combined or omitted in other embodiments.

[0084] Furthermore, while the advantages of certain technical embodiments have been described in the corresponding embodiments, other embodiments may also exhibit such advantages, and not all embodiments must possess such advantages to fall within the scope of this technology. Therefore, this disclosure and related technologies may cover other embodiments not expressly shown or described in this specification.

Claims

1. A method for determining a dosage scheme for skin irradiation of a user, the method comprising: Obtain one or more images of the treated areas of the user's skin from the color testing component; The average individual type angle (ITA) of the user's skin over the entire treatment area is determined based on the one or more images using the controller of the phototherapy device. The controller determines the estimated minimum erythema dose (MED) for the treatment area based on the average ITA over the entire treatment area. as well as The controller creates the dosage scheme based on the estimated MED of the treatment area, wherein the dosage scheme includes control settings for one or more ultraviolet (UV) emitters in the phototherapy device to irradiate the user's skin with a dose of UV radiation lower than its actual MED during a single treatment session.

2. The method of claim 1, wherein, Acquiring one or more images of the treatment area includes: Emitting light with a predetermined wavelength composition; and An imaging sensor is used to measure the light reflected back from the treatment area.

3. The method as described in claim 1, wherein, Acquiring one or more images of the treatment area includes: Capture one or more pre-filtered images of the treatment area; Capture one or more images with a calibration component having a known color composition; Based on the required corrections to one or more images of the calibration component and the known color composition, a correction filter is determined for one or more pre-filtered images of the treatment area; and The correction filter is applied to each of one or more pre-filtered images of the treatment area.

4. The method of claim 1, wherein, Acquiring one or more images of the treatment area from the color testing component includes receiving one or more images from the imaging sensor of the phototherapy device.

5. The method of claim 1, wherein, Determining the average ITA of the user's skin within the treatment area includes: Convert one or more images of the treatment area to L*a*b* format; and For each individual image, calculate the individual ITA of that individual image according to the L*a*b* format.

6. The method of claim 5, wherein, The formula for calculating the individual ITA is as follows: .

7. The method of claim 5, wherein, Determining the average ITA of the user's skin over the entire treatment area further includes: for each individual image, averaging the L*, a*, b* data in that individual image before calculating the individual ITA of that individual image.

8. The method of claim 5, wherein, Determining the average ITA of the user's skin across the entire treatment area further includes: determining the average ITA based on the average of the individual ITAs for each individual image via the controller.

9. The method of claim 1, wherein, The estimated MED is calculated using the following formula: .

10. The method of claim 1, further comprising receiving user input related to the answers to one or more secondary questions via a user input device, wherein, This one or more secondary issue concerns factors that affect the actual MED on the user's skin throughout the treatment area.

11. The method of claim 10, wherein, The one or more sub-issues include one or more of the following: Is the user currently taking medications that affect MED? Whether the user has recently been exposed to sunlight and / or other UV radiation; and / or The user is known to be sensitive to UV radiation.

12. The method of claim 10, wherein, Determining the dosage regimen includes: The power level of one or more UV emitters in the phototherapy device and the duration of irradiation during treatment are determined to adjust the intensity and total amount of UV radiation irradiated onto the treatment area of ​​the user's skin.

13. The method of claim 10, wherein, Determining the dosage regimen includes: Treatment parameters were determined to irradiate the user with a total amount of UV radiation approximately 0.8 times the estimated MED.

14. A phototherapy system, comprising: A phototherapy device having an effective surface on which a plurality of light-emitting diodes (LEDs) are disposed, the plurality of LEDs being positioned to emit ultraviolet (UV) radiation forward from the effective surface during operation of the phototherapy system; A color testing component is positioned to acquire one or more images of the treatment area of ​​a user's skin when the user stands in front of the effective surface; as well as A controller operatively coupled to the plurality of LEDs and the color testing assembly, wherein the controller includes a processor and a memory storing instructions that, when executed by the processor, cause the controller to: When the user stands at a predetermined distance from the effective surface, one or more images of the treatment area of ​​the user's skin are received from the color testing component; Based on the one or more images, determine the average individual type angle (ITA) of the user's skin across the entire treatment area. The estimated minimum erythema dose (MED) for the treatment area is determined based on the average ITA over the entire treatment area. A dosage scheme provided to the phototherapy device based on the estimated MED of the treatment area, wherein the dosage scheme includes control settings for the plurality of LEDs to irradiate the user's skin with a UV radiation dose lower than the estimated MED during a single treatment session; and The phototherapy device operates the plurality of LEDs according to the dosage scheme.

15. The phototherapy system of claim 14, wherein, The predetermined distance is between approximately 5 inches and approximately 10 inches from the effective surface.

16. The phototherapy system of claim 14, wherein, The average ITA corresponds to the average ITA of the portion of the entire treatment area with an area greater than 1 square inch.

17. The phototherapy system of claim 14, wherein: The phototherapy device includes: The upper panel has a first portion of the effective surface; and The lower panel, which is hinged to the upper panel, and has a second portion having the effective surface; and The phototherapy device can move between a folded position and an unfolded position, wherein in the folded position the second portion of the effective surface faces the first portion of the effective surface; and in the unfolded position the first portion and the second portion of the effective surface face forward.

18. A method for determining a dosage regimen for a user's skin, the method comprising: The estimated initial dose to the user's skin is calculated by the controller of the phototherapy system; By positioning a test device in contact with the user's skin, incremental doses of ultraviolet (UV) radiation are delivered to discrete locations of the test area on the user's skin, wherein the lowest dose of the incremental UV radiation is equal to the estimated starting dose. as well as The controller determines a UV dosing scheme based on the number of erythema events occurring in the test area after the color development period in response to the incremental dose of UV radiation; wherein the dosing scheme includes control settings for the light-emitting diodes (LEDs) in the phototherapy device to irradiate the user's skin with a UV radiation dose lower than the actual MED of the user's skin during treatment.

19. The method of claim 18, wherein, Calculating the estimated starting dose includes: The test area of ​​the user's skin is imaged to determine the Individual Type Angle (ITA) of the test area. Based on the ITA of the test area, calculate the estimated minimum erythema dose (MED) for that test area; and Multiply the estimated MED by a predetermined coefficient.

20. The method of claim 18, wherein, Between each increment of UV radiation dose, the increment of the UV radiation dose is less than about 5% of the estimated minimum erythema dose of the user's skin.

Images