Thursday, March 26, 2015

SXSW™ 2015 Awards – Non-invasive skin cancer detection device

Copyright © Françoise Herrmann

The University of Texas Cockrell School of Engineering (Sharma, 2014) won the 2015 SXSW Interactive Innovations Award, in the “Sci-fi No Longer” category, with a non-invasive skin cancer detection device. This is a pen looking optical probe that uses light spectroscopy in three different modes to interrogate skin tissue. It is non-invasive as it requires no biopsy for testing and diagnosis of skin lesions.

The three spectroscopic technologies of this device, termed MMS -multimodal spectroscopy, are  Raman spectroscopy (RS), diffuse reflectance spectroscopy (DRS) and laser-induced fluorescence spectroscopy (LIFS). Together these technologies, and their different modes of emitting light, are designed to provide complementary sorts of micro-environmental and biochemical information about skin tissue, for a far improved and faster diagnosis, compared to traditional macro-visual biopsy-based detection.  For example, an interrogation of skin tissue using the multimodal spectroscopy (MMS) probe takes about 4.5 seconds (compared to several days for biopsy results).

US2012057145 (A1) titled Systems and methods for diagnosis of epithelial lesions is the patent application corresponding to this device and its algorithms.

In general, this invention addresses problems of skin cancer diagnosis and the current and most common methods of diagnosis involving tissue biopsy. Beyond the discomfort, cosmetics, expenses and turnaround time for biopsy results, this most common method of diagnosis invokes inherently qualitative methods of macro-visual clinical examination, that is, physician experience in visually identifying which lesions are biopsied.  In turn, critical reliance on physician experience enters the equation, because there are documented differences in the accuracy with which lesions are detected among general practitioners and dermatologists [US2012057145], compounded by issues of access to specialized dermatology care, whether due to costs, geographic location or scarcity, and the burden of unnecessary biopsy. Finally, the accuracy of this inventive diagnostic method is also intended to resolve issues of safety margins for the perimeter of excisions when surgery is required.

Skin lesion micro-environments and bio-chemical properties are interrogated via spectroscopy, that is: 1. emitting a light source into a skin tissue using an optic fiber, 2. collecting the light re-emitted from the skin tissue with a second optic fiber, and 3. generating spectra for the light re-emitted from the skin tissue in terms of diagnostically relevant parameters such as intrinsic fluorescence and absorption, reduced scattering coefficients and Raman scattering, using a spectrophotometer. Then, the spectral information is matched with known properties using a specifically generated look-up table algorithm. It is known for example that the fluorescence of certain endogenous fluorophores such as collagen changes in the presence disease, and that the scattering and absorption properties of light will be affected by morphological changes of the tissue. The analysis of the light emitted back from the skin tissue thus yields micro-information about the properties of the skin tissue, such as collagen structure, nuclear morphology, blood fraction, oxygen saturation and a tissue scattering coefficient. all which swiftly informs diagnosis.

The development of this invention device and its method - that is, of the hardware and software, as well as the associated research were funded by the Centers for Disease Control.

The abstract of this multimodal spectroscopy invention, recited in US2012057145 (A1) titled Systems and methods for diagnosis of epithelial lesions, is included below, as well as a an image of the front view of the probe surface in contact with skin, showing Raman spectroscopy delivery (red) and collection (blue) fibers, and the diffuse reflectance spectroscopy delivery (yellow)  and collection (green)  fibers (Sharma, 2014).  

"Systems comprising an optical fiber switch connected to a light source and an optical fiber probe, the optical fiber probe comprising a first optical fiber connected to the optical fiber switch and a second optical fiber connected to a spectrophotometer. Methods for determining one or more tissue parameters comprising: emitting light from a first optical fiber into a tissue; collecting the light reemitted from the tissue with a second optical fiber; generating a spectra of the light reemitted from the tissue with a spectrophotometer; and utilizing a look-up table based algorithm to determine one or more tissue parameters, wherein the lookup-table based algorithm comprises the steps of: generating a look-up table by measuring the functional form of a reflectance measured by the spectrophotometer using one or more calibration standards with known optical properties; and implementing an iterative fitting routine based on the lookup-table." Abstract US2012057145 (A1)

Work appears underway to attempt to correct the effects of skin pigmentation on spectroscopic methods of skin cancer detection (e.g.; Soyemi et. al., 2005; Bersha 2010), including the issue of the depth of skin tissue interrogation (Tseng et. al. (2008). If skin cancer is more prevalent in fair skin individuals, it is nonetheless more fatal in darker skin individuals due to late diagnosis and misinformation about epidemiological data (The Skin Cancer Foudnation, 2009). 

In any event, this award-winning, non-invasive diagnostic technology is indeed... no longer sci-fi... 

Bersha, K. S. (2010) Spectral imaging and analysis of human skin. file://psf/Home/Downloads/Spectral%20imaging%20and%20analysing%20human%20skin,%20Kusse%20Sukuta%20BERSHA%20(1).pdf
Meyers, C. (2014) 3 in 1 Optical skin Cancer Probe.
Sharma, S., Marple, E., Reichenberg, J. and James W. Tunnell (2014) Design and characterization of a novel multimodal fiber-optic probe and spectroscopy system for skin cancer applications.
Soyemi, O., Landry, MR., Yang, Y., Idwasi, P., and B. Soller (2005) Skin color correction for tissue spectroscopy: demonstration of a novel approach with tissue mimicking phantoms. Feb. Applied Spectroscopy, 59(2), pp. 237-44
SXSW™ 2015 Interactive Media Awards
Tseng, H.S., Grant, A. and A.J. Durkin (2008) In vivo determination of skin near0infrared optical properties using diffuse optical spectroscopy. Journal of Biomedical Optics, 13(1).
UT – University of Texas (2014) New device improves Skin Cancer Detection

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