Diagnostic device and method for sensing hydration state of a mammalian subject

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 in the mouth 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 salivary stimulating agent arranged for placement into the mouth of the mammalian subject prior to or substantially concurrently with placement of the at least a portion of the liquid collection element in fluid communication with oral mucosa of the mammalian subject;
• at least one first electrode or sensing element arranged to sense a condition indicative of exposure of a portion of the liquid collection element to oral mucosa in the mouth of a mammalian subject;
• at least one second electrode or sensing element arranged to sense a condition indicative of movement by saliva through at least a portion of the liquid collection element;
• a timing element arranged to be initiated responsive to receipt of a signal from or detection of change of state of the at least one first electrode or sensing element, and to generate a time value indicative of elapsed time since said initiation upon receipt of a signal from or detection of a change of state of the at least one second electrode or sensing element;
• 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 time value.

A method of sensing a state of euhydration, state of dehydration, or salivary secretion rate of a mammalian subject, the method comprising:

• inserting a salivary stimulating agent into the mouth of the mammalian subject to stimulate saliva flow;
• placing at least a portion of a liquid collection element of predefined liquid holding volumetric capacity in contact with oral mucosa of the mammalian subject;
• detecting a condition indicative of presence of saliva on or adjacent to the liquid collection element upon exposure of the at least a portion of the liquid collection element to oral mucosa of the mammalian subject, and responsively starting a timer;
• detecting a condition indicative of movement of saliva through at least a portion of the liquid collection element while the at least a portion of the liquid collection element is exposed to oral mucosa of the mammalian subject, and responsively storing a time value indicative of elapsed time since the timer was started;
• and
• utilizing the time value to generate an output signal indicative of state of euhydration, state of dehydration, or salivary secretion rate of the mammalian subject.

A method for sensing a state of euhydration or dehydration of a mammalian subject, the method comprising:

• placing at least a portion of a liquid collection element of predefined liquid holding volumetric capacity in contact with oral mucosa of the mammalian subject;
• detecting presence of saliva at first, second, and third positions along or adjacent to the liquid collection element with respect to time while the at least a portion of the liquid collection element is in contact with oral mucosa of the mammalian subject, to determine a first time value indicative of migration of saliva from the first position to the second position, and to determine a second time value indicative of migration of saliva between the second position and the third position;
• and
• utilizing the first time value and the second time value to generate an output signal indicative of state of euhydration, state of dehydration, or salivary secretion rate of the mammalian subject.