Skin inspection device for identifying abnormalities

Abstract

To provide a skin inspection device for identifying abnormalities.SOLUTION: The skin inspection device comprises: a transparent panel having an inspection area; an array of thermochromic liquid crystal (TLC) formations provided on the transparent panel which are operable to change color in response to a change of temperature; and one or more image capture devices having a wide angle lens for capturing an image of the TLC formations and an area of skin of a target located in the inspection area. At least some of the TLC formations have a warped shape while other TLC formations have a non-warped shape. The warped shaped TLC formations and the non-warped TLC formations define a pattern such that when viewed through the wide-angle lens, both the warped shaped TLC formations and the non-warped TLC formations appear non-warped.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] This disclosure relates to skin testing devices for identifying abnormalities, particularly, but not exclusively, to thermal sensing of the soles of a person's feet to predict the formation of ulcers. [Background technology]

[0002] Diabetic patients commonly suffer from a condition known as diabetic foot ulcer (DFU) throughout their lives. Diabetic patients are encouraged to inspect their feet daily to detect any abnormal damage to the skin that may be an indicator of the development of DFU. However, limiting factors such as poor vision, reduced mobility, lack of sensation due to peripheral neuropathy, and lack of education can prevent diabetic patients from adhering to daily foot inspections as recommended. Early identification of DFUs may improve outcomes and reduce medical procedure costs. The benefits would be even greater if DFUs could be detected before they form. The best available approach is to visually inspect the feet and report to a podiatrist on a regular basis.

[0003] Temperature monitoring is a known method of predicting DFU formation. It has been demonstrated that a temperature difference of 2.2°C between similar points on both feet indicates inflammation that may be a precursor to ulcer formation. Point temperature probes are known in the art that allow a patient to measure the temperature of the bottom of both feet so that spot-by-spot temperature comparisons can be made. Such point probes can be used to measure skin temperature at individual target spots. If a spot on one foot shows a difference in temperature compared to the same spot on the other foot and continues to exceed that difference (a sustained increase of 4°F (2.2°C) or more for more than two days), it indicates that a problem may be developing and the patient is alerted to consult a physician. The difficulty with this approach is that the same spot on the patient's foot needs to be measured over multiple days. It is difficult for the patient to identify the same spot in order to make an accurate measurement. Furthermore, it is the patient's responsibility to keep a record of the temperature readings to make comparisons, which can introduce human error. Daily visual inspection of the feet is recommended for all diabetic patients. As mentioned above, this can be difficult due to poor eyesight and mobility. Current temperature monitoring devices do not facilitate the recommended daily visual inspection.

[0004] The applicant's previously published PCT patent application WO2017202534 utilizes thermochromic liquid crystals (TLCs) that change color with respect to temperature. A light source, lens, and image sensor are used to measure the temperature and record the area of ​​the TLC. The captured image is then analyzed to measure the color of the TLC in a Region of Interest (ROI). The temperature can then be determined by using a calibration equation and the measured color to calculate the temperature. The array of TLC sensors is designed such that there is a light path between the sensors, thereby allowing a target behind the sensor to be visualized while an image of the TLC sensor is recorded. Such a design is useful for detecting anomalies that may present either or both thermal and visual signals. The TLC pattern 100 shown in FIG. 1 defines a uniform pattern in which the TLCs are substantially the same shape and size. One drawback of a uniform pattern of TLC is that when the image capture device has a wide angle lens, the captured image will be distorted, resulting in changes in the geometry of the TLC within the image. As an example, a rectilinear checkerboard such as that shown in Figure 2A will be distorted when viewed through a wide angle lens, as shown in Figure 2B, with increasing levels of distortion and reduction in size of each square as you move away from the center of the image.

[0005] What is needed is a skin testing device that addresses at least some of the shortcomings of the prior art. Summary of the Invention

[0006] These and other problems are addressed by providing a skin testing device for identifying abnormalities, the device comprising: a transparent panel having an inspection area; an array of thermochromic liquid crystal (TLC) formers disposed on a transparent panel and operable to change color in response to a change in temperature; one or more image capture devices having a wide angle lens for capturing images of the target TLC formations and the area of ​​skin located in the examination area, at least some of the TLC formations having a distorted shape and other TLC formations having a non-distorted shape; The distorted and undistorted TLC formations define a pattern such that when viewed through a wide angle lens, both the distorted and undistorted TLC formations appear undistorted.

[0007] In one embodiment, the amount of distortion in a distorted shaped TLC formation increases towards the periphery of the pattern.

[0008] In another embodiment, the features of the TLC features vary in size with position relative to the center of the pattern, with the TLC features towards the periphery of the pattern being larger than the TLC features adjacent to the center of the pattern.

[0009] In a further embodiment, the twist angle of the distorted TLC formations varies toward the periphery of the pattern such that the TLC formations have a larger twist angle than the TLC formations adjacent the center of the pattern.

[0010] In an exemplary embodiment, the captured images of the TLC formations have uniform dimensions regardless of their position within the pattern. Advantageously, the captured images of the TLC formations have uniform shapes regardless of their position within the pattern. Preferably, the captured images of the TLC formations have uniform angles regardless of their position within the pattern. In an exemplary embodiment, the captured images of the TLC formations have uniform dimensions regardless of their position within the pattern.

[0011] In one embodiment, the geometry of the TLC formation is tailored to the parameters of a particular wide-angle lens, which may advantageously include at least one of the focal length and the field of view.

[0012] In an exemplary embodiment, the geometry of the TLC formations is tailored to the parameters of a particular image sensor, advantageously including at least one of the following: resolution and aspect ratio.

[0013] In another embodiment, the TLC formations extend radially from a central point in the pattern, and the level of distortion of the TLC formations increases the further the TLC formations are located from the central point. Advantageously, the twist angle of the distorted TLC formations increases the further the TLC formations are located from the central point. Preferably, the size of the distorted TLC formations increases the further the TLC formations are located from the central point.

[0014] The present disclosure also relates to a method for identifying skin abnormalities, the method comprising: providing a transparent panel having an inspection area; providing an array of thermochromic liquid crystal (TLC) formers on a transparent panel, the TLC formers operable to change color in response to a change in temperature; providing one or more image capture devices having a wide angle lens for capturing images of the target TLC formations and the area of ​​skin located in the examination area, at least some of the TLC formations having a distorted shape and other TLC formations having a non-distorted shape; The distorted and undistorted TLC formations define a pattern such that when viewed through a wide angle lens, both the distorted and undistorted TLC formations appear undistorted.

[0015] These and other configurations may be better understood with reference to the accompanying drawings, which are provided to aid in understanding the teachings of the present invention. [Brief description of the drawings]

[0016] The teachings of the present invention will now be described with reference to the accompanying drawings, in which: [Figure 1]FIG. 1 illustrates a prior art skin testing device. [Figure 2A] FIG. 2 illustrates the distortion resulting from a wide-angle lens. [Figure 2B] FIG. 2 illustrates the distortion resulting from a wide-angle lens. [Diagram 3] FIG. 1 illustrates details of an exemplary skin testing device. [Figure 4] 4A and 4B each show a skin testing device in accordance with the teachings of the present invention. [Figure 4C] FIG. 1 illustrates a skin testing device in accordance with the teachings of the present invention. [Diagram 5] 5A and 5B each illustrate a skin testing device in accordance with the teachings of the present invention. [Figure 6] 1 is a flowchart detailing example steps of a method for identifying skin anomalies. [Figure 7A] 1 is a flowchart detailing an exemplary approach for creating a physical geometry of a TLC sensor that appears as a desired geometry when viewed through a wide-angle lens. [Figure 7B] 4 is a flow chart detailing exemplary calibration steps. [Figure 8] FIG. 1 illustrates exemplary components of a skin testing device in accordance with the teachings of the present invention. [Figure 9] 4 is a flow chart detailing exemplary steps performed by a skin testing device in accordance with the teachings of the present invention. [Figure 10] 4 is a flow chart detailing exemplary steps performed by a skin testing device in accordance with the teachings of the present invention. [Figure 11] 4 is a flow chart detailing exemplary steps performed by a skin testing device in accordance with the teachings of the present invention.

[0017] Detailed Description of the Drawings The present disclosure will now be described with reference to some exemplary skin testing devices. It will be understood that the exemplary skin testing devices are provided to aid in the understanding of the teachings and should not be construed as limiting in any way. Furthermore, elements or components described with reference to any one of the figures may be interchanged with those of other figures or other equivalent elements without departing from the spirit of the teachings of the present invention. It will be understood that, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or similar elements for simplicity and clarity of description.

[0018] Referring now to the figures and initially to FIG. 1, which discloses a prior art skin testing device 100 from WO2017202534. The device 100 comprises a transparent panel 102 defining a testing area that cooperates with an area of ​​the body under test. For example, the area under test may be the foot, hand, arm, leg, etc. In an exemplary arrangement, the area under test is the sole of a foot 109 as shown in FIG. 2. The transparent panel 102 provides a foot plate on which the foot 109 rests during testing. An array of thermochromic liquid crystal (TLC) formations 105 are provided on the transparent panel 102, the TLC formations 105 being operable to change color in response to detection of a temperature change.

[0019] The transparent panel 102 is supported on a housing 106 that contains the components of the device 100. The housing 106 includes a base 111 having a sidewall 112 extending upwardly therefrom that together define a hollow interior region 113. One or more image capture devices 107 are provided within the hollow interior region 113 for capturing color images of the TLC formations and the area of ​​skin located on the foot 109. One or more light sources in the form of LEDs 122 may also be disposed within the hollow interior region 113. Other types of light sources besides LEDs may be used, such as cold cathode lamps, electroluminescent coating materials, e.g., tapes, panels, wires, xenon or halogen bulbs, etc. A central processing unit 115 is also provided within the hollow interior region 113 and is configured to control the operation of the device 100, as described in more detail below.

[0020] Thermochromism, as is well known in the art, is the property of a substance to change color with a change in temperature. The TLC dots 105 are designed to change color at a precise temperature and are used as a method of determining the temperature of the foot. The TLC dots 105 change color over a predetermined range, for example from red to blue over the course of a temperature range change of 20° C. (e.g., red is 20° C. and blue is 40° C.). The temperature range required for application in diabetic foot ulcers is 15-38° C. The TLC dots 105 change color in response to heat. Digital photographic images of the TLC dots 105 are taken by the image capture device 107. A CPU 115 is configured to analyze the images of the TLC dots 105. The CPU 115 is operable to analyze the color change and convert the color information into a temperature value. Thus, the color of the TLC dots 105 indicates the temperature at various points on the foot that are aligned with the TLC dots. The CPU 115 may be configured to indicate a difference in temperature at a point on one foot compared to the same point on the other foot, and if that temperature difference is sustained (a sustained increase of 4 degrees Fahrenheit or more for more than two days), indicate that a DFU problem may be developing and the patient is alerted to consult a physician.

[0021] 4A, there is shown a skin testing device 200 according to the present invention. The skin testing device 200 is substantially similar to the skin testing device 100, and like elements are indicated by like reference numerals. The main difference between the skin testing device 200 and the skin testing device 100 is that in the device 200, a pattern of TLC formations 205 on a transparent panel is arranged to eliminate image distortion when the image capture device has a wide angle lens. The skin testing device 200 comprises a transparent panel 105 having a test area. An array of thermochromic liquid crystal (TLC) formations 205 is provided on the transparent panel, which formations 205 are operable to change color in response to a change in temperature. One or more image capture devices 107 having a wide angle lens are provided to capture images of the TLC formations 205 and the area of ​​the target skin located in the test area. The pattern of TLC formations 205 is arranged such that at least some of the TLC formations have distorted shapes 207 while other TLC formations have undistorted shapes 209. The distorted and undistorted shapes 207 and 209 define a pattern such that when viewed through a wide angle lens 211, both the distorted and undistorted TLC formations appear undistorted, as best shown in FIG. 4B. FIG. 4C shows a perspective view of an apparatus 200 having a pattern of TLC formations 205 as shown in FIG. 4A disposed on a transparent panel 102. Those skilled in the art will appreciate that although FIG. 4A shows a single image capture device 107, additional image capture devices may be provided as desired.

[0022] FIG. 4A illustrates an exemplary array of diamond-shaped TLC formations 205 that are designed such that the size, shape, and angle of the TLCs when viewed through a wide-angle lens 211 results in a consistent square shape, as illustrated in FIG. 4B. In the pattern of FIG. 4A, the size, shape, and / or angle vary based on location relative to the center of the image. An image of the pattern of FIG. 4A viewed through a wide-angle lens 211 is shown in FIG. 4B, which shows that the TLC formations 205 have consistent size, shape, and angle regardless of their location relative to the center of the image 215. FIG. 5A illustrates an exemplary array of oval-shaped TLC formations 205 that are designed such that the size, shape, and angle of the TLCs when viewed through a wide-angle lens 211 results in a consistent circular shape, as illustrated in FIG. 4B. In the pattern of FIG. 5A, the size, shape, and / or angle vary based on location relative to the center of the image. An image of the pattern of Figure 4A viewed through a wide angle lens 211 is shown in Figure 5B, which shows that the TLC formations 205 have a consistent size, shape, and angle regardless of their position relative to the center of the image 215. Figure 5C shows a perspective view of an apparatus 200 having a pattern of TLC formations 205 as shown in Figure 5A disposed on a transparent panel 102. Those skilled in the art will appreciate that although Figure 5A shows a single image capture device 107, additional image capture devices may be provided as desired.

[0023] Those skilled in the art will understand that the term "distorted shape" has an irregular geometric shape, while the term "undistorted shape" has a regular geometric shape. The irregularity in the geometry of the TLC formation has an angular component that is determined by the position of the TLC formation relative to the center of the image, and thus the majority of the distortion of the formation is radial.

[0024] In the exemplary configuration above, the amount of distortion of the distorted shaped TLC formers increases towards the periphery of the pattern. The shapes of the TLC formers vary in size with position relative to the center of the pattern, with the TLC formers being larger towards the periphery of the pattern than the TLC formers adjacent to the center of the pattern. The twist angle of the distorted TLC formers varies such that the TLC formers have larger twist angles towards the periphery of the pattern than the TLC formers adjacent to the center of the pattern. The captured images of the TLC formers have uniform dimensions regardless of their position within the pattern. The captured images of the TLC formers have uniform shapes regardless of their position within the pattern. The captured images of the TLC formers have uniform angles regardless of their position within the pattern. The captured images of the TLC formers have uniform dimensions regardless of their position within the pattern.

[0025] The geometry of the TLC formations 205 may be tailored to the parameters of a particular wide angle lens 211, e.g., the parameters may include at least one of focal length and field of view. The geometry of the TLC formations 205 may be tailored to the parameters of a particular image sensor (image capture device 122), e.g., the parameters of the image sensor may include at least one of resolution and aspect ratio. In one example, the TLC formations 205 extend radially from a center point 213 in the pattern, and the further the TLC formations 200 are located from the center point 213, the greater the level of distortion of the TLC formations. The twist angle of the distorted TLC formations 205 increases the further the TLC formations 205 are located from the center point 213. The size of the distorted TLC formations 205 increases the further the TLC formations 205 are located from the center point 213. Those skilled in the art will appreciate that a "distorted shape" is a transformation of a "reference shape" located at a central point 213 in the pattern. For example, the "reference shape" in FIG. 4A is a square that is transformed (distorted) into a diamond at locations extending radially from the central point. In another example, the "reference shape" in FIG. 5A is a circle that is transformed (distorted) into an ellipse. The "reference shape" may be bent or twisted from its original form, and its dimensions may be altered to produce the "distorted shape." In other words, the "distorted shape" may be a distorted version of the "reference shape."

[0026] The use of wide-angle lenses has many advantages. It is advantageous to minimize the height of such a device 200, as this makes the use of the device 200 as simple as possible while at the same time ensuring that a field of view wide enough to image the entire width of the sole and the array of temperature sensors is maintained. This can be achieved by the use of wide-angle lenses. Furthermore, wide-angle lenses allow for a wider field of view by compressing areas at the edges of the field of view, resulting in light from these areas impinging on the image sensor that would not impinge on the image sensor with a lens with a narrower field of view. The level of optical compression applied by the lens increases with increasing distance from the center of the lens.

[0027] One drawback of wide-angle lenses is the distortion of the resulting image and the resulting change in the geometry of the objects in the image. As an example, a rectilinear checkerboard such as that shown in Figure 2A, when viewed through a wide-angle lens, will be distorted as shown in Figure 2B, with increasing levels of distortion and reduction in size of each square as you move away from the center of the image.

[0028] Image sensors are typically used to create digital images by recording the level of light transmitted towards the image sensor relative to visible light within 400-700 nanometers (nm), the portion of the electromagnetic spectrum perceived by the human eye. Some image sensors may also record wavelengths above and below the visible light spectrum. Image sensors come in a variety of different sizes, such as ¼ inch, ⅓ inch, and ½ inch. Image sensors are typically offered with a range of different resolutions given in megapixels (MP), for example 1MP, 5MP, 108MP, etc. Resolution is calculated by multiplying the width and height of the sensor in pixels. Thus, a 2592×1944 image sensor would have a total of 5,038,848 pixels and would be called a 5MP image sensor.

[0029] Since image sensors record light, the scene being imaged is required to have sufficient illumination to allow light to be transmitted to the image sensor in order to record information. A variety of different light sources may be used, such as sunlight, incandescent bulbs, and light-emitting diodes (LEDs). The light is focused onto the image sensor using a lens. A fisheye lens is a form of ultra-wide-angle lens that allows a wider field of view by compressing the areas at the edges of the field of view, so that light from these areas that would not fall on the image sensor with a narrower field of view lens falls on the image sensor. Wide-angle lenses typically have a field of view (FOV) ranging from 60° to 180°, and in some cases well over 200°. The focal length of a wide-angle lens can vary greatly, from less than 4 mm to more than 30 mm. In addition, some lenses have an adjustable aperture, but the aperture can vary and is usually specified as an F-stop, which is the ratio of focal length to effective aperture, with a typical range of F / 2.8 to F / 22. The level of optical compression applied by a lens increases with increasing distance from the center of the lens. One of the drawbacks of wide-angle lenses is the distortion of the resulting image and of the object within the image. The distortion is related to the various lens parameters mentioned above and also due to the position of the object relative to the optical center of the image, and typically the level of distortion increases with increasing distance from the center.

[0030] The effect of a wide-angle fisheye lens on a region of interest (ROI) observed by a thermochromic liquid crystal will be understood by those skilled in the art. To measure temperature, color information is measured from the region of the image where the TLC appears. The location of the ROI may be defined by the coordinates of a pixel in the captured image. The pixel coordinates of the center of the ROI are defined along with the geometric shape of the bounding region centered on that pixel. For example, a square boundary may be defined by the height and width of the square in pixels (e.g., 1×1, 3×3, 5×5, etc.). The greater the number of pixels in the bounding region, the stronger the color signal will be. For example, a 5×5 square ROI contains 25 pixels, and a 1×1 contains only 1 pixel. Therefore, it is advantageous that the TLC region in the captured image is of a size that ensures that the minimum ROI can fit on the TLC.

[0031] FIG. 2 shows how an object is compressed when viewed through a wide-angle lens, and how that compression increases with increasing distance from the center. This means that TLC sensors of consistent physical size will have different sizes in the captured image. It would therefore be advantageous to provide a means to ensure that all TLC sensors have the same size in the image. Given that the nature of wide-angle lenses means that the level of compression varies with distance from the center of the image, this means that the physical size of the TLC sensor required to meet the minimum ROI will vary based on location. However, it is also advantageous to minimize the size of the TLC sensor to maximize the visibility of the feet behind it. It is therefore possible to design a sensor array that meets the minimum TLC size threshold while simultaneously minimizing the size of the TLC sensor.

[0032] Two exemplary array designs are given based on two of the most common shapes used to define regions in image processing: a square as shown in FIG. 4A and a circle as shown in FIG. 4B. However, it will be understood that this design methodology may be applied to any other shapes deemed appropriate, and thus the present disclosure is not intended to be limited to the exemplary shapes described. The physical shape of the sensor is designed / tuned to fit the particular lens specifications (e.g., focal length, angle of view).

[0033] The use of a wide-angle lens minimizes the height of the device giving improved usage characteristics. The use of TLC sensors allows for a clear light path between the sensors and therefore allows for simultaneous visual inspection. Minimizing the size of the TLC sensors is therefore advantageous for maximizing the visibility of the foot. In addition, it reduces the amount of TLC material used and therefore reduces costs. The noise in the TLC sensor measurements increases as the size of the TLC ROI in the image decreases. It is therefore advantageous to ensure that all TLC ROIs are above a certain threshold size, as this would ensure that the sensor noise would rise to an unacceptable level. It is advantageous to maintain a consistent size of the TLC ROI in the captured image, so that the level of noise is consistent across all sensors. A consistent ROI geometry in the captured image is advantageous for the application of image processing software to make measurements from the ROI. As all ROIs are of the same geometry, there is no need to modify the software sampling parameters for different areas. This is advantageous for reducing the complexity of the software and manufacturing process.

[0034] Referring to FIG. 6, a flow chart 300 is shown detailing exemplary steps for identifying skin anomalies. In step 302, a transparent panel having an inspection area is provided. In step 304, an array of thermochromic liquid crystal (TLC) formations operable to change color in response to a change in temperature is provided on the transparent panel. In step 306, one or more image capture devices are provided having a wide-angle lens for capturing images of the target TLC formations and the area of ​​skin located in the inspection area, where at least some of the TLC formations have distorted shapes and other TLC formations have undistorted shapes. In step 308, the distorted and undistorted shapes of the TLC formations define a pattern such that both the distorted and undistorted shapes of the TLC formations appear undistorted when viewed through the wide-angle lens.

[0035] Referring to FIG. 7A, a flow chart 400 is shown detailing an exemplary approach for generating a physical geometry of a TLC sensor that appears as a desired geometry when viewed through a wide-angle lens. In step 402, a wide-angle lens calibration process is performed to generate a calibration algorithm that can eliminate distortion of an image captured by a wide-angle lens. In step 404, a reference image is captured through the lens (distorted image). In step 406, a desired geometry of a region of interest (ROI) is applied to the captured distorted image. In step 408, the developed calibration algorithm is used to correct the image distortion. In step 410, the geometry of the ROI is modified by the calibration algorithm to provide a geometry that produces the desired geometry when viewed through the wide-angle lens.

[0036] Those skilled in the art will understand wide-angle lens calibration as a means of generating a mapping function that transforms a distorted image captured by a wide-angle lens into an undistorted spherical aberration corrected image. The method described by Scaramuzza et al. (see A Toolbox for Easily Calibrating Omnidirectional Cameras 2006) is widely known. Step 402 is extended by exemplary steps as shown in FIG. 7B. It includes a process step 412 of capturing a number of images in which the checkerboard is present, and then a process step 414 of running software that analyzes the images and generates a calibration equation / model. In step 416, the equation / model is stored and can be applied in a distortion correction step 408. The calibration takes into account lens parameters such as focal length, field of view, etc. In step 418, the distorted image is read. In step 420, the calibration equation / model is applied to the distorted image. The calibrated corrected image is stored in step 422.

[0037] Thus, by using the methods described in this disclosure, it is understood that this approach can be taken to determine the physical shape of the subject required to achieve the desired observed shape, and will work for any combination of image sensor, lens, light source, and desired TLC formation shape.

[0038] It will be understood that the device 200 includes one or more software modules programmed to implement certain functions. The device 200 includes various hardware and software components that function to execute the methods according to the present disclosure. The device 200 includes a user interface 150, a CPU 115 in communication with a memory 160, and a communication interface 165. The CPU 115 functions to execute software instructions that can be loaded and stored in the memory 160. The CPU 115 may include several processors, a multi-processor core, or some other type of processor, depending on the particular implementation aspect. The memory 160 may be accessible by the CPU 115, thereby enabling the CPU 115 to receive and execute instructions stored in the memory 160. The memory 160 may be, for example, a random access memory (RAM), or any other suitable volatile or non-volatile computer-readable storage medium. Additionally, memory 160 may be fixed or removable and may include one or more components or devices, such as a hard drive, flash memory, a rewritable optical disk, a rewritable magnetic tape, or any combination of the above.

[0039] One or more software modules 170 may be encoded in the memory 160. The software modules 170 may include one or more software programs or applications having computer program codes or instruction sets configured to be executed by the processor 115. Such computer program codes or instructions for performing operations of aspects of the systems and methods disclosed herein may be written in any combination of one or more programming languages. During execution of the software modules 170, the CPU 115 configures the device 200 to perform various operations related to identifying skin anomaly formations according to embodiments of the present disclosure. The CPU 115 may be configured to process images captured by the image capture device 107 to determine target temperatures at multiple distinct locations. The CPU 115 may be operable to process the images and convert the colors of the identified TLC formers to corresponding temperature values. The CPU 115 may be programmed to convert the colors of the identified TLC formers to corresponding temperature values ​​based on the hue / saturation / brightness of the dots and a color temperature conversion table. Those skilled in the art will appreciate that other color spaces may be used, such as, for example, hue / saturation / value (HSV) or red, green, blue (RGB). Additionally, the CPU 115 may be configured to generate a temperature map based on the temperature values. In one exemplary configuration, the CPU 115 is operable to overlay a temperature map on the captured image of the target. In another configuration, the CPU 115 is configured to perform image analysis on the temperature map and the captured image. The CPU may be programmed to compare temperatures at similar points of the captured image. The CPU 115 may be operable to generate an indication of the appearance of an ulcer and / or other skin abnormality based on the image analysis of the captured image. The CPU 115 may be operable to generate an indication of the appearance of an ulcer and / or other skin abnormality at a particular location on the captured image. The indication may be in the form of, for example, an output image.In another example, the CPU 115 is configured to detect areas on the captured image that include at least one of excess calluses, blisters, moisture, and discoloration.

[0040] Other information and / or data relevant to the operation of the system and methods may also be stored in memory 160, such as, for example, a database 185. Database 185 may contain and / or maintain various data items and elements utilized throughout various operations. It should be noted that while database 185 is shown configured locally to device 100, in certain embodiments database 185 and / or various other data elements stored therein may be located remotely. Such elements may be located on a remote device or server not shown and may be connected to device 100 via a network in a manner known to those skilled in the art for loading and execution on the processor.

[0041] Furthermore, the program code in the software modules 170 and one or more computer readable storage devices (such as memory 160) form a computer program product that can be manufactured and / or distributed in accordance with the present disclosure, as known to those of skill in the art.

[0042] The communication interface 165 may also be any interface operatively connected to the CPU 115 and enabling communication between the device 100 and external devices, machines, and / or elements. The communication interface 165 is configured to transmit and / or receive data. For example, the communication interface 165 may include, but is not limited to, a Bluetooth, WiFi, or cellular transceiver, a wireless module, a satellite transmitter / receiver, an optical port, and / or any other such interface for connecting the device 110 to an external device.

[0043] A user interface 150 is also operatively connected to the CPU 115. The user interface may comprise one or more input device(s), such as, for example, switch(es), button(s), key(s), or a touch screen. The user interface 150 functions to allow for the input of data. The user interface 150 functions to facilitate the capture of commands from a user, such as, for example, on and off commands or settings related to the operation of the methods described above.

[0044] A display 190 may also be operatively connected to the CPU 115. The display 190 may include a screen or any other such display device that allows a user to view various options, parameters, and results. The display 190 may be a digital display, such as, for example, an LED display. The device 110 may be powered via a power source 192. An alert mechanism 195 is provided for generating an alert. The alert mechanism 195 is operable to communicate the alert to a remote entity via a telecommunications network.

[0045] An exemplary operation of the device 200 is described with reference to flowcharts 500, 300A, 300B, and 300C. In block 502, a user places a foot on the transparent panel 102. In block 504, a strain gauge 169 operably coupled to the CPU 115 senses a weight load on the transparent panel 102. The strain gauge 169 is configured to determine when the user is in a stable position in block 506. In block 2508, the CPU 115 activates the LED 122. In this exemplary embodiment, in block 510, the two image capture devices 107 are activated to capture an image of the individual's sole 109 and a pattern of TLC dots 105 that change color to indicate the temperature of the corresponding point on the sole 109. In block 212, the temperature sensor 118 records the temperature of the transparent panel 102. In block 214, in this example, the skin testing device 110 can also function as a weight scale to capture the individual's weight. In step 216, the image data, weight data, baseline temperature data, and time stamp are sent to the CPU 115 for processing.

[0046] The processing of the data is described with reference to the flow chart 600 of FIG. 10. In block 602, the CPU 115 receives image data, weight data, reference temperature data, and a time stamp. In block 604, since two image capture devices were used to capture the image data, the captured images are stitched together. In block 306, the CPU 115 analyzes the captured image against the color calibration target. In block 608, the CPU 115 interprets the color calibration target and applies a color offset to the captured image. Furthermore, in block 610, the location of the TLC dots 105 is identified by the CPU 115. In block 612, the color of the TLC dots 105 is converted to a temperature value by the CPU 115. In block 614, the reference temperature and offset algorithm is applied to the temperature value by the CPU 115. In block 616, the corrected temperature value is stored in the patient database. The image data, weight data, reference temperature, and time stamp are also stored in the database 618. If, at block 620, it is determined that the temperature values ​​are indicative of the formation of a DFU, an appropriate indicia is displayed on the display 190 to alert the individual of the potential ulcer formation.

[0047] An exemplary data processing technique is described with reference to flow chart 700 of FIG. 11. In block 302, CPU 115 receives image data, weight data, reference temperature data, and a timestamp. In block 704, the image data is processed by CPU 115. This processing may include CPU 115 applying an algorithm that scans the captured image and identifies the location of the temperature sensor 105. In block 706, the location of the temperature sensor 105 in the captured image is linked to the temperature data recorded by the sensor 105. In block 708, CPU 115 generates a temperature data set based on the recorded temperature values ​​of the sensor 105. The temperature data set is stored in database 185. In block 310, a reference temperature and offset algorithm is applied by CPU 115 to the temperature data set. In block 712, the corrected temperature data set is stored in the patient database. In block 714, the image data, weight data, reference temperature, and timestamp are also stored in the database. If, at block 716, it is determined that the temperature values ​​in the temperature dataset are indicative of DFU formation, an appropriate indicator is displayed on the display 190 to alert the individual of potential ulcer formation. It will be understood that it is not intended to limit the teachings of the present invention to the exemplary steps provided, or to the order and sequence of steps, which may be modified as necessary. For example, the inclusion of weight data may be optional in the data processing approach described above.

[0048] At block 318, the system may be configured to detect visual or thermal anomalies, or a combination of both. Detection of visual anomalies may begin by first identifying the foot in the image. The foot is then scanned for anomalous features. Thermal anomalies may be identified by using only thermal data or by combining visual images with thermal data. The location of the foot may be determined using the visual images. This is advantageous because the temperature of the foot may be similar to the ambient temperature and therefore it may be difficult to determine the location of the foot using only thermal data. As such, it may be difficult to perform a comparison between one foot point and another foot point, as it may be difficult to determine which points to compare.

[0049] By linking the image of the foot with the temperature data set, it is possible to determine the temperature at any location on the foot. Anomalies can be detected by comparing temperatures between similar points on both feet (contralateral comparison). Other methods of detecting anomalies can include comparing with average, maximum, minimum temperatures, or any other statistically generated values. Another method is to compare collected data with previously collected data. In some patients, there may be pre-existing temperature differences between contralateral sites, and for these patients, it would be advantageous to compare the temperature with previously recorded temperatures. In another embodiment, localized temperature comparisons can be made, such as the forefoot, heel, and big toe.

[0050] Considering two different sensing modality (thermal and visual) data sets is advantageous because it increases the level of information available to determine the presence of anomalies. Some anomalies may only be present in one of the data sets. This gives four potential outcomes, whereas with a single sensing modality there are only two potential outcomes, making the former advantageous.

[0051] [Table 1]

[0052] The system may be configured to vary the alert based on the type of abnormality detected, for example, an indication generated by an elevated contralateral temperature in the absence of visual abnormalities may be different than an indication generated if an active ulcer is detected.

[0053] Points in the image may be used to identify physical items such as the toes, heel, and arch. The image may be digitized to generate a geometric map of the foot. Different regions of the image may be classified based on characteristics. These classified regions may be used as a reference point(s) when comparing both feet. The geometric map may be used to identify physical formations at given coordinates. In this way, the geometric map allows for accurate comparison with the same region of the other foot. This allows for easy mapping of data at similar points from each foot.

[0054] The temperature of the foot is usually lower than body temperature. In many cases, the temperature of the foot may be similar to the ambient temperature. In such cases, it is not possible to determine where in the heat map the foot corresponds. Therefore, it may be difficult to perform a contralateral temperature comparison.

[0055] It should be understood that those skilled in the art can make various modifications to the above embodiments without departing from the scope of the present invention. Thus, it will be understood that the teachings should be limited only as deemed necessary in light of the appended claims. For ease of explanation, the TLC formers are referred to as dots throughout this disclosure. However, many different shapes may be used, examples include, but are not limited to, circles, triangles, squares, ellipses, pentagons, stars, chevrons, lines, curves, etc. It is envisioned that the TLC formers may be provided in any desired configuration. In the exemplary configuration, multiple image capture devices are illustrated, but it will be understood that only a single image capture device may be used.

[0056] The advantage of using an array of TLC dot formations is that it allows for the acquisition of temperature data at many separate locations while maintaining the ability to capture a visual image of the target location. For example, the table below shows the percentage of an image obscured by TLC dots of various diameters. In this example, the dots are arranged on a 1 cm pitch and 100 mm 2 It contains one dot per square. The area of ​​the circle is given by: π.r 2 where r is the radius of the circle

[0057] [Table 2] In this manner, due to the dispersed nature and size of the TLC dots, they do not obscure a significant portion of the plantar surface area from the view of the image capture device.

[0058] It should be understood that those skilled in the art can make various modifications to the above-described embodiments without departing from the scope of the present invention. Thus, it will be understood that the teachings should be limited only as deemed necessary in light of the appended claims. In an exemplary embodiment, the skin testing device 200 may be incorporated into a weight scale having a means for calculating an individual's weight.

[0059] Similarly, as used herein, the term comprises / comprising is used to specify the presence of stated formations, integers, steps, or components, but does not exclude the presence or addition of one or more additional formations, integers, steps, components, or groups thereof.

Claims

1. A skin examination device for identifying abnormalities, A transparent panel having an inspection area, An array of thermochromic liquid crystal (TLC) bodies provided on the transparent panel and capable of changing color in response to temperature changes, The system comprises one or more image capture devices having wide-angle lenses for capturing images of the TLC formation bodies and areas of target skin located in the inspection area, wherein at least some of the TLC formation bodies have a distorted shape and other TLC formation bodies have a non-distorted shape. A skin inspection device that defines a pattern such that, when viewed through the wide-angle lens, both the distorted TLC forming body and the non-distorted TLC forming body appear undistorted.

2. The amount of distortion of the distorted TLC formed body increases towards the periphery of the pattern, according to claim 1, the skin inspection apparatus.

3. The skin inspection apparatus according to claim 1, wherein the shape of the TLC forming body varies in size depending on its position relative to the center of the pattern, and as it moves toward the periphery of the pattern, the TLC forming body becomes larger than the TLC forming body adjacent to the center of the pattern.

4. The skin inspection apparatus according to claim 1, wherein the twist angle of the distorted TLC formed body changes such that as it approaches the periphery of the pattern, the TLC formed body has a larger twist angle than the TLC formed body adjacent to the center of the pattern.

5. The skin inspection apparatus according to claim 1, wherein the captured images of the TLC formed bodies have uniform dimensions regardless of their positions in the pattern.

6. The skin inspection apparatus according to claim 1, wherein the captured image of the TLC formed body has a uniform shape regardless of their position in the pattern.

7. The skin inspection apparatus according to claim 1, wherein the captured images of the TLC formed bodies have a uniform angle regardless of their position in the pattern.

8. The skin inspection apparatus according to claim 1, wherein the geometric shape of the TLC-forming body is adjusted to the parameters of a specific wide-angle lens.

9. The skin inspection apparatus according to claim 8, wherein the parameters may include at least one of focal length and field of view.

10. The skin inspection apparatus according to claim 1, wherein the geometric shape of the TLC formed body is adjusted to the parameters of a specific image sensor.

11. The skin inspection apparatus according to claim 10, wherein the parameters of the image sensor include at least one of resolution and aspect ratio.

12. The skin inspection apparatus according to claim 1, wherein the TLC forming body extends radially from the center point in the pattern, and the level of strain of the TLC forming body increases as the TLC forming body is located further from the center point.

13. The skin inspection apparatus according to claim 12, wherein the twist angle of the distorted TLC forming body increases as the TLC forming body is located further from the center point.

14. The skin inspection apparatus according to claim 12, wherein the size of the distorted TLC forming body increases as the TLC forming body is located further from the center point.

15. A method for identifying skin abnormalities, The steps include providing a transparent panel having an inspection area, The steps include providing an array of thermochromic liquid crystal (TLC) bodies on the transparent panel that are capable of changing color in response to temperature changes, The step of providing one or more image capture devices having a wide-angle lens for capturing images of the TLC formed bodies and a region of target skin located in the inspection area, wherein at least some of the TLC formed bodies have a distorted shape and other TLC formed bodies have a non-distorted shape. A method for defining a pattern such that, when viewed through the wide-angle lens, both the distorted TLC forming body and the non-distorted TLC forming body appear undistorted.

16. The method according to claim 15, wherein the amount of distortion of the distorted TLC formed body increases towards the periphery of the pattern.

17. The method according to claim 15, wherein the shape of the TLC forming body varies in size depending on its position relative to the center of the pattern, and as it moves toward the periphery of the pattern, the TLC forming body becomes larger than the TLC forming body adjacent to the center of the pattern.

18. The method according to claim 15, wherein the twist angle of the distorted TLC formed body changes such that the TLC formed body has a larger twist angle towards the periphery of the pattern than the TLC formed body adjacent to the center of the pattern.

19. The method according to claim 15, wherein the captured images of the TLC formed bodies have uniform dimensions regardless of their positions in the pattern.

20. The method according to claim 15, wherein the captured image of the TLC formed body has a uniform shape regardless of their position in the pattern.

21. The method according to claim 15, wherein the captured images of the TLC formed bodies have a uniform angle regardless of their position in the pattern.

22. The method according to claim 15, wherein the geometric shape of the TLC formed body is adjusted to the parameters of a particular wide-angle lens.

23. The method according to claim 22, wherein the parameter may include at least one of focal length and field of view.

24. The method according to claim 15, wherein the geometric shape of the TLC-forming body is adjusted to match the parameters of a specific image sensor.

25. The method according to claim 24, wherein the parameters of the image sensor include at least one of resolution and aspect ratio.

26. The method according to claim 15, wherein the TLC forming body extends radially from the center point in the pattern, and the level of strain of the TLC forming body increases as the TLC forming body is located further from the center point.

27. The method according to claim 26, wherein the twist angle of the distorted TLC forming body increases as the TLC forming body is located further from the center point.

28. The method according to claim 26, wherein the size of the distorted TLC forming body increases as the TLC forming body is located further from the center point.

Images