Patent ID: 8326412

Claim:
An apparatus for sensing a state of euhydration, state of dehydration, or salivary secretion rate of a mammalian subject, the apparatus comprising: a liquid collection element arranged for placement in fluid communication with oral mucosa of a mammalian subject, the liquid collection element being liquid-permeable, being arranged to transport liquid by wicking, and having a predefined liquid holding capacity; a substrate arranged to support or engage the liquid collection element, with the substrate having arranged thereon a plurality of electrical contact pairs including a first electrical contact pair and a second electrical contact pair arranged downstream of the first electrical contact pair, wherein the first electrical contact pair is arranged to close a first electrical circuit upon exposure to saliva when the liquid collection element is placed in fluid communication with oral mucosa of the mammalian subject, and the second electrical contact pair is arranged to close a second electrical circuit upon exposure to saliva transported though at least a portion of the liquid collection element; a timing element arranged to receive a signal indicative of closure of the first electrical circuit, arranged to receive a signal indicative of closure of the second electrical circuit, and arranged to generate a first time value indicative of time elapsed between the closure of the second electrical circuit and the closure of the first electrical circuit; and a signaling element arranged to generate an output signal indicative of state of euhydration, state of dehydration, or salivary secretion rate of the mammalian subject based at least in part on the first time value.