EVALUATION OF TEMPERATURE GRADIENT CHANGES OF TISSUE USING VISUALIZATION

Abstract

This invention relates to apparatus and method for detection of human skin lesion malignancy. The method relies on two independent wavelengths regions: (a) visible and Near IR circa (0.4-1.3 um); (b) Far Infrared (6-12 um). The visible and NIR wavelengths will analyze sub-skin scattering and absorbance to detect structural and diffusion abnormalities, and the FIR wavelengths will monitor the thermal blood perfusion, as reflected by monitoring temperature variation of suspected region. An apparatus according to the present invention would comprise a cooling/heating component which encloses the suspected area, MIR camera or thermal sensors, visible and NIR camera. Evaluation of the rate of the skin temperature changes and propagation in the suspected area will enable to detect increased blood perfusion and metabolic heat, identifying alarming signals related to skin diseases. Parallelly, the sub-skin density and coagulation will be analyzed by peripheral illumination. Evaluation procedure will include image analysis and artificial intelligence to enhance the detection capabilities. Using two independent technologies minimizes the false-negative detection and increases sensitivity and specificity. This invention relates to different body parts without limitations.

Claims

1. A medical screening device for skin screening by obtaining blood flow perfusion and diffusion properties of a tissue comprising: a thermoelectric ring having an orifice on its center placed upon a skin lesion to heat or cool the surrounding of a suspected tissue area; a temperature detecting device to observe the temperature and temperature gradient as a function of time; a ring of lights to be applied around a suspect tissue area surface; an opaque tubular profile to be applied on skin surface concentric to said ring of lights allow light to penetrate only through the tissue; said ring of lights comprising of multiple sources of light in wavelengths 0.3-1.3 um, each one controllable independently; one or more cameras sensitive to said light emitting sources; and a computer vision device to analyze and compare information from said cameras and temperature detecting device.

2. The device of claim 1 wherein the temperature detecting device is a thermal camera.

3. The device of claim 1 further compromising a camera capable of shifting its focus for different depths within the tissue.

4. The device of claim 1 wherein said tissue includes: skin, nail, breast, testicle, and the measured properties are related to density, absorbance and scattering, blood content and heat generation of the tissue.

5. A method and apparatus for measuring the diffusion properties and blood perfusion of a skin tissue comprising: activating a thermoelectric ring having an orifice placed upon a skin lesion to heat or cool the surrounding of a suspected tissue area; recording images or data from a temperature detecting device to observe the temperature and temperature gradient including as a function of time; activating a ring of light sources with wavelengths range between 300-1300 nm, around a lesion, each light source controlled independently; recording images created by each said light source as it propagates by diffusion under the skin; and analyzing the light propagation wavefront for detecting irregularities.

6. The method and apparatus of claim 5 wherein the temperature detecting device is a thermal camera.

7. The method and apparatus of claim 5 wherein the pictures are taken from different depths within the tissue.

8. The method and apparatus of claim 5 wherein said tissue includes: skin, nail, breast, testicle, and the measured properties are related to density, absorbance and scattering, blood content and heat generation of the tissue.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0029] One embodiment of the invention with reference to the appended drawing is now described. Other embodiments of the invention have not been shown in detail as not to obscure the understanding of this description.

[0030] FIG. 1 is the skin tissue with malignant lesion and its blood vessels structure

[0031] FIG. 2 is a schematic diagram of the preferred embodiment featuring a thermoelectric device (TEC) with central hole, a copper plate below the TEC, a plurality of light sources, and a dual camera for thermal, visible and NIR wavelengths.

[0032] FIG. 2A is a transection section of preferred embodiment

[0033] FIG. 2B is a longitudinal section of preferred embodiment.

[0034] FIG. 3 shows the temperature gradient within the tissue.

[0035] FIG. 3A is the temperature gradient in healthy skin tissue.

[0036] FIG. 3B is the temperature gradient in cancerous skin tissue.

[0037] FIG. 4 shows light wave-front propagation and absorbance within healthy and malignant tissues which is affected by tissue density.

DETAILED DESCRIPTION OF EMBODIMENTS

[0038] The embodiment of the invention here is a system and process that are based on two different wavelengths regions in order to identify several different alarming signs of skin cancer. The first wavelengths region is visible and MR (350-1300 nm)penetration of light wavelength into the tissue through diffusion. The light sources in the peripheral circle of the device aim to reveal sub-skin abnormalities and evolvement of the mole/ lesion. The light sources are turned-on simultaneously, then in sequential mode, and the captured images of light propagation, absorption and scattering within the tissue from different directions will be saved. For the second wavelength region (FIR 7-12 m), a thermoelectric cooler will be applied and a copper plate with few millimeters length cylinder at its center will be attached to the thermoelectric cooler. The copper cylinder will form a cooling ring that will be applied on skin surface, and the changes of the temperature propagation and rate will be measured using thermal camera or array of sensors. The plate with the LEDs at wavelengths between 350-1300 nm will be attached to the copper plate to allow the light to penetrate to the skin. The device will contain dual wavelengths camera or two cameras to detect the different wavelengths range.

[0039] The device will include a processor to analyze the information that will be received from the dual wavelengths camera or the two cameras: image analysis of sub-skin illumination, light diffusion within the tissue from different directions, analysis of the rate of the temperature changes, and may include processing based on tomographic imaging algorithms.

[0040] The techniques described here may have a better capability to distinguish between healthy vs. cancerous tissue and generate a map of the temperature changes and propagation within the tissue to detect changes in blood perfusion, thereby improving cancerous tissue detection.

[0041] FIG. 1 shows the structure of healthy and malignant skin tissue with malignant lesion and blood vessels development. The upper layer is stratum corneum 101; squamous cells 102; basal cells 103; Melanocytes 104; blood vessels 105; melanoma cells 106; angiogenesisdevelopment of new blood vessels 107. Malignancy is characterized in angiogenesis, applying cold stimuli in the suspected area periphery will accelerate cooling of the malignant tissue by increased heat transfer through blood flow.

[0042] FIG. 2 is an example of an embodiment describing the computerized optical-thermal device that may assist in tissue screening for early detection of cancerous tissue, and it is composed of two different views denoted as 2A and 2B.

[0043] FIG. 2A shows the device consists of opaque cylindrical element 201; Light sources 202 are attached to an electric board 203; thermoelectric ring (TEC) 204 is connected on its cold side to copper plate with central hole 205; heat sink 206 are connected to the thermoelectric ring on its warm side along the opaque cylindrical element 201; a dual wavelengths camera 207 is mounted at the central axis of the cylindrical element; Said camera 207 is connected to focus ring 208 therefore it is free to move along its optical axis to allow focusing on various depths; Second set of light sources 209 are connected to the upper-inner side of the opaque cylindrical element 201. The device described in FIG. 2A is applied to the skin surface wherein 205 copper plate touches the tissue and cools the periphery of suspected area. Said light sources 202 illuminate the tissue through machined orifices in 205 members. Said TEC 204 is coupled to 205 on its cold side to actively cool the 205 member, and on its warm side it is equipped with cylindrical heat sink 206. Furthermore, another cylindrical member 201 is used like a spacer to allow mounting cameras designated as 207 and to prevent outside illumination. The dual camera works in two different wavelengths: the first is visible and NIR; second, thermal camera for FIR. The camera is mounted on said 201 cylinder and the light ring is mounted around the optical apertures and illuminated the suspected area from above. Cylinder 208 prevents lights to directly dazzle the camera and creates upper illumination on the suspected area.

[0044] FIG. 2B is a cross-section of the embodiment described in FIG. 2A.

[0045] FIG. 3 shows the thermal ring and the temperature gradient within the tissue.

[0046] FIG. 3A shows a thermal ring 301 which is applied on healthy tissue 302.

[0047] FIG. 3B shows a thermal ring 301 which is applied on a tissue 302 with a malignant lesion 303. The temperature gradient within the healthy tissue is moderate, while the temperature gradient within the cancerous tissue decrease faster and the malignant lesion is cooler than its surrounding tissue, because the blood perfusion to the lesion is significantly higher.

[0048] FIG. 4 shows light sources ring 401 with one illuminated light source 402; the wave-front of a beam within the tissue 403 is being distorted 404 by malignant lesion 405. Injecting directed beam of light at various wavelengths into the tissue to travel through by sub-skin diffusion to the suspected area allows to observe wave-front distortion and changes at the absorption and scattering of the light within the suspicious area. Applying this concept from different directions will create a full map of the suspected area. The image created by this phenomenon is recorded by upper camera as described in previous Figures.

[0049] Assessing and differentiating the absorption and scattering properties of a lesion compared to surrounding skin tissue is conducted by a special illumination procedure injected in the periphery area of suspected malignant tissue. Density variation in the biochemical composition of the tissue can be evaluated using specially designed illumination that emphasizes and differentiates between normal and abnormal densities and absorption differences below and above skin. By using a directed beam of light at various wavelengths to travel through the suspected area and observing distortion on its wave-front and auto-fluorescencea suspicious area could be detected. Moreover, by applying this concept from various directions created by ring of lights on the perimeter of suspected lesion, a comprehensive map could be reconstructed. These phenomena are easily detected using a camera observing the lesion from above.

[0050] The device will be applied on the suspected tissue area, to create positive attachment between LED source, the cooling ring and the skin tissue. The user will operate the device manually or via computer interface to turn on the thermoelectric ring, light sources simultaneously and in a sequential mode in the peripheral circle enclosing the suspected area. The rate of temperature changes, sub-skin images, and propagation of the light within the tissue and its wave front, light intensity and the angle of light scattering will provide information about different parameters of the preselected area. At the last stage, an analysis algorithm will cross all the information regarding the suspected area and analyze it, in order to find alarming signs for malignancy.