This Small Business Innovation Research (SBIR) Phase I project aims to develop a new instrument for detecting and measuring the melanin or pigmentation in human skin. The intellectual merit stems from developing a deeper and more quantitative understanding of the trade-offs inherent in creating a market disruptive, low-cost melanin-measuring device. The technology is based on using intensity-modulated light to detect melanin noninvasively. The technical challenge for this project is to identify the optimal components and design parameters of the prototype, using a flexible breadboard configuration and to develop a roadmap for miniaturization. The R&D effort will include the identification of components that result in an instrument that will yield a repeatable and reliable melanin measurement that is designed for ease-of use by the general public.
The broader impact/commercial potential of this project is the extension of the melanin measuring technology to the detection of incipient skin cancer (abnormal melanin levels within localized areas of the skin is a key indicator of this disease). Because of the estimated low cost of the instrument it has the potential of being used by local pharmacies or by individuals at home. This could have a major medical benefit by enabling regular personalized monitoring to guard against this insidious condition that becomes more prevalent in an aging population. It is well documented in the medical literature that early cancer detection can result in more cost-effective treatments, helping to stem the tide of rising health-care costs.
After successfully completing the first round of NSF Innovation Corps (I-Corps) Grant in 2011, we founded MySkin Technologies, a start-up company, to develop the device described below. The I-Corps "out-of-the-building" activities identified a market need in the hyperpigmentation sector of the skincare industry for a low-cost, easy-to-use instrument that could selectively measure melanin concentration in skin. Our concept was to develop a safe, low-cost instrument that quantitatively measured the efficacy of expensive skin-care products for treating discolorations and uneven skin tone in an effort to boost sales and get consumers to buy successive bottles of the product. Discussions with skin-care/cosmetics companies revealed several critical factors that, if not realized, would make our proposed product unacceptable. These factors included melanin sensitivity, selectivity, measurement accuracy and repeatability, all at low cost. Prior research had revealed that, when excited with high-power lasers, melanin (from squid melanin and human hair samples) emitted a novel fluorescence signature unique to melanin. These experiments were performed at Northeastern University on a $700,000 instrument (the Keck 3-D Fusion Microscope). We postulated that we would get similar results using inexpensive laser diodes in a pump-probe configuration to discriminate melanin from the surrounding tissue components at low operational power levels. This concept yielded preliminary results that were promising with the possibility of constructing a small, low-cost melanin meter for a commercially viable product. Under the SBIR Phase I, this low-cost diode laser system with low-irradiance exhibited a great deal of instability and drift. We performed extensive modeling and experimentation to understand the discrepancy in the two methods. We now believe the low-power, pump-probe mechanism to be predominantly governed by a thermal effect rather than the photonic effect we observed on the Keck as fluorescence. In an effort to stabilize the melanin reading, we experimented with parameters such as voltage, current, modulation frequency and laser wavelength to improve device performance. We also varied the optical components by reducing the number of mirrors, deleting prisms, changing splitter type, and incorporating a tight bandpass filter at the probe wavelength. Although we did achieve improvement in S/N ratio by at least 20 db, we were unable to correct for the drift in the measurement. During our empirical study, we developed a unique process to make uniform melanin samples that replaced the need for human subjects. We are investigating the market for the melanin samples that precludes the need for Internal Review Board approval. Because the observed signal is explained better by a model based on thermo-mechanical fluctuations and resulting variations in scattering instead of a multi-photon absorption phenomenon, we were forced from product development back into the fundamental research mode. After extensive modeling and experimentation, we determined that using the low-irradiance laser diodes resulted in a thermal absorption mechanisms that was not as selective to melanin, and therefore did not offer a unique advantage over existing instruments. Key findings of the research conducted under the SBIR include: The technical difficulties encountered proved insurmountable within this time frame. We will not apply for a Phase II SBIR. The breadboard modifications yielded a 20 db improvement in S/N ratio; however, measurement fidelity and selectivity to melanin are major obstacles to delivering an instrument to satisfy the skincare market. The multi-photon pump-probe instrument design provisional patent was abandoned due to experimental finding that invalidated the claim. Since the breadboard exhibited a great deal of instability, we were forced to develop uniform melanin samples for optimizing the breadboard’s performance. We are investigating the market viability of supplying the industry with uniform, thin-film melanin samples. The market need identified during the I-Corps was proven to be compelling and several new low-cost, easy-to-use imaging devices have been introduced into the market, possibly preempting our entry.
