Canfield Scientific Inc.

Sachin V Patwardhan

Daniel Eric DiGregorio

Athula Mandanayake

Methods and apparatuses are disclosed for modifying images of skin so as to reduce or enhance the appearance of component pigments, such as melanin and hemoglobin. A diffuse reflectance image of skin, such as a cross-polarized contact dermoscopy image, which conveys information regarding subsurface features of the skin, is processed so as to extract pigment distribution information, which is then used to correct the diffuse reflectance image, such as by reducing the appearance of melanin to allow better visualization of hemoglobin-related structures, such as vasculature. Alternatively, the diffuse reflectance image can be corrected so as to reduce the appearance of hemoglobin to allow better visualization of melanin-related structures.

Enhancing pigmentation in dermoscopy images

Methods and apparatuses are disclosed for capturing and analyzing images of tissue, such as human skin, using variable polarization. Exemplary devices are described having a detection polarizer via which an area of tissue is imaged and one or more light sources whose emitted light is polarized with one or more source polarizers. In a first such device, one or more of the detection polarizer and a source polarizer is rotatable so as to allow the angle between their polarizations to be varied. An area of tissue can be imaged as the angle is varied. Another device has multiple fixed source polarizers of different polarization orientations, each source polarizer polarizing the light emitted by a corresponding group of light sources which can be selectively activated, thereby enabling the device to illuminate an area of tissue with polarized light of different orientations relative to the orientation of the detection polarizer. Images of an area of tissue captured with different polarizations provide information from different depths, allowing visualization of superficial as well as subsurface features.

Variable polarization and skin depth analysis methods and apparatuses

Apparatuses and methods are disclosed for assessing the texture of skin using images thereof. In exemplary embodiments, a texture map of an area of skin is generated from a combination of a parallel-polarized image and a cross-polarized image of the area of skin. The texture map is then flattened to remove the underlying curvature of the skin. A texture roughness metric is then generated based on the flattened texture map. An image of the texture map and the metric can be displayed to provide visual and alphanumeric representations of the texture of skin, thereby facilitating the comparison of baseline and follow-up images of the skin, such as those taken before and after treatment.

Skin assessment using image fusion

Apparatuses and methods are disclosed for generating a quantitative indication of the degree of oiliness of skin. In exemplary embodiments, a difference image generated from parallel- and a cross-polarized images of an area of skin is subjected to an intensity thresholding operation. An oiliness metric is generated based on the average intensity of those pixels whose intensities do not exceed the threshold, and/or on the average intensity of those pixels whose intensities exceed the threshold. An indication based on the metric is generated and output.

Skin reflectance and oiliness measurement

Methods and apparatuses are disclosed for assessing pigmentation of skin based on images thereof. In disclosed implementations, a cross-polarized blue image of skin is obtained and processed to extract pigment distribution information. Useful applications include assessing depigmentation, as in the skin condition vitiligo, as well as assessing re-pigmentation such as due to treatment. In addition to the spatial extent of depigmentation, implementations of the present disclosure can also provide the degree of depigmentation. The degree and area of depigmentation can be measured with better accuracy and sensitivity than known techniques.

Imaging-based methods and apparatuses for assessing skin pigmentation

Apparatuses and methods are disclosed for assessing the texture of skin using images thereof. In exemplary embodiments, a texture map of an area of skin is generated from a combination of a standard white light image, a parallel-polarized image, and a cross-polarized image of the area of skin. The texture map is then flattened to remove the underlying curvature of the skin. A texture roughness metric is then generated based on the flattened texture map. An image of the texture map and the metric can be displayed to provide visual and alphanumeric representations of the texture of skin, thereby facilitating the comparison of baseline and follow-up images of the skin, such as those taken before and after treatment.

A dermatoscope has a generally circular viewing opening, a plurality of light sources including first and second groups of light sources arranged about the viewing opening, a first polarizer for polarizing light passing through the viewing opening, and a second polarizer for polarizing light emitted from the first group of light sources, wherein the first and second groups of light sources are arranged at different distances from a center of the viewing opening so that light from the second group of light sources is not polarized by the second polarizer. A further dermatoscope has a head portion including a generally circular viewing opening, and at least one light source arranged proximate to the viewing opening; and a body portion including an image capture device, wherein the head portion is pivotally attached to the body portion selectively allowing alignment of the center of the viewing opening with the center of the field of view of the image capture device. Yet a further dermatoscope has a generally circular viewing opening, a selectively extendable element that can be selectively extended coaxially with the viewing opening, and a contact element for contacting a surface to be viewed, the contact element being removably attachable to a distal end of the selectively extendable element.

Dermatoscope devices

Methods and apparatus are described that provide the ability to estimate the diffuse reflection component of an image of tissue such as skin captured without cross-polarization. It is thereby possible to estimate skin pigmentation information from an image of skin captured conventionally, such as, for example, a total reflection image, obtained in a conventional manner by shining white light on the skin and capturing the reflected light. The image may also be a partially diffuse reflection image, such as a low quality cross-polarized image. The diffuse reflection component of a captured image can then be further processed to obtain Red and Brown pigmentation images, useful for indicating the distribution of hemoglobin and melanin, the primary chromophores of skin. Additionally, a standard captured image of skin can be analyzed to obtain an estimate of the surface reflection component of the reflected light. The surface reflection component can then be used to generate a surface reflection image, useful for showing the distribution of light on the skin and to highlight superficial features such as wrinkles, fine lines, folds, pores, texture, and visible spots.

Reflectance imaging and analysis for evaluating tissue pigmentation

In an arrangement for detecting acne, particularly in its earliest stages before any humanly visible or palpable manifestations thereof have emerged, a green fluorescence image of skin illuminated with blue light is captured and processed to detect the presence of microcomedones. After correcting the green fluorescence image for the non-uniform distribution of excitation light on the skin, fluorescent spots are detected therein. The subset of fluorescent spots having an intensity lower than an intensity threshold and an area smaller than an area threshold are selected as representing candidate microcomedones. The subset can be further refined by eliminating fluorescent spots having irregular shapes, are associated with inflammation, or exhibit comedone features. Additional filtering can be applied by selecting those spots whose locations correspond to pore locations. A dermatoscope with a blue illumination source and a green-filtered viewer allows live imaging of skin spots indicative of acne, including microcomedones not otherwise visible.

Acne imaging methods and apparatus

Apparatus and methods are disclosed for multi-spectral imaging of tissue to obtain information about the distribution of fluorophores and chromophores in the tissue. Using specific spectral bands for illumination and specific spectral bands for detection, the signal-to-noise ratio and information related to the distribution of specific fluorophores is enhanced as compared to UV photography, which uses a single RGB image. Furthermore, the chromophore distribution information derived from the multi-spectral absorption images can be used to correct the fluorescence measurements. The combined fluorescence, absorption, and broadband reflectance data can be analyzed for disease diagnosis and skin feature detection.

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Mount Tabor, NJ, United States of America

Sachin V Patwardhan