Noninvasive Technology
The TruTouch technology is a 100% noninvasive, touch-based alcohol measurement that offers significant improvements in safety and ease-of-use relative to existing measurement approaches. The noninvasive technology employs near-infrared (NIR) absorption spectroscopy to measure the concentration of alcohol by introducing NIR light into the skin and collecting the light that returns to the tissue surface (often referred to as diffuse reflectance).

Alcohol Sensitivity and Selectivity
An advantage of NIR spectroscopy is that the structure of a molecule dictates the specific manner in which it absorbs NIR light. Thus, the absorbance spectrum of each molecular species is unique, which allows the spectrum of alcohol to be discriminated from those of other molecules, such as water, that are commonly present in the body. In addition, Beer’s Law states that the magnitude of the absorbance signal for a given substance (e.g. alcohol) is proportional to its concentration. Consequently, NIR spectroscopy provides noninvasive tissue measurements that are both sensitive and selective for alcohol.

Biometric Identity Verification
The skin is primarily comprised of the epidermis, dermis, and subcutaneous layers. Each layer has different characteristics that influence its relative contribution to the TruTouch spectroscopic measurement. For example, the subcutaneous layer is largely comprised of lipids (fats) while the dermal layer is composed primarily of water and collagen. The TruTouch measurement inherently contains contributions from each layer, which provides insight into both the chemical composition and structure of the tissue. Because all people have different tissue properties (dermal hydration, collagen density, and layer thicknesses), the TruTouch measurement captures these inter-personal differences and uses them as the basis for its unique biometric identity verification feature.