Sweat derived from eccrine glands in human skin contains valuable information about physiological performance and dysfunction. Importantly, sweat data can be captured discreetly and non-invasively. Captured data can be transmitted securely in real-time to remote systems where the relationship among measured sweat molecules can be automatically integrated with other bio-parameters and interpreted as to its physiological relevance. Results can then be translated into alerts, actions, and reports.
KEY Attributes of Sweat
Sweat is actively secreted onto the surface of the skin through the action of eccrine glands, making sweat an ideal source for the non-invasive capture of real-time bio-molecular data. Tears, saliva, and breath are alternative non-invasive sources, but each face special challenges due to anatomical location and other undesirable characteristics.
Sweat naturally contains an array of important analytes, including electrolytes, metabolites, amino acids, proteins, and nucleic acids. Sweat can also contain metals and synthetic molecules that are the byproducts of environmental pollution or resulting from the administration of pharmaceutical agents and other substances.
low infection risk
Sweat can be captured without breaching the skin surface. Other capture technologies, like micro-needles, breach the immune barrier and may increase infection risk due to transmission of infectious agents. They also represent a potential biohazard given that children or others may accidentally "stick" contaminated micro-needles into their skin when handling discarded micro-needle patches or other disposable devices.
Sweat sensor patches can be worn discreetly under clothing and without interference with daily activities or while sleeping. In comparison, devices for analyzing tears, saliva, or breath are far less discreet and can interfere with common daily functions such as eating, drinking, communicating, or viewing.
Sweat is less prone to variability compared to other non-invasive sources. For example, the content of saliva is affected by food and drink, as well as gum inflammation. Concentrations of breath molecules will vary based on depth of breathing and volatile food or drinks. Tears are produced irregularly and old and new tear fluid mixes uncontrollably.
Eccrine sweat glands are located in most areas of human skin. The anatomical abundance of sweat glands enables placement of one or more wearable sensor systems without causing discomfort or interference with daily activities or sleep.