Apple Inc.
Hydration measurement with a watch

Abstract:

Hydration measurement capabilities can be provided by a wearable electronic device, such as a watch, to allow a user to easily track hydration. A watch can be positioned to receive and measure one or more electrical properties of perspiration produced by the user wearing the watch. The watch provides electrodes for measuring the electrical properties of the perspiration. The electrical properties, such as electrical conductance, can represent a concentration of electrolytes in the perspiration, which in turn represents a hydration level of the user. The hydration tracking can be performed non-invasively, repeatedly, accurately, automatically, and with minimal user intervention. The measurements can be used to provide useful feedback and health tracking information to a user, thereby allowing the user to better manage hydration and overall health.