Optical perspiration sensor using frustrated total internal reflection

A method comprising:

• receiving an electrical measurement signal from a first photodetector coupled to a first waveguide;
• determining a total intensity level of reflected light in the first waveguide based on the electrical measurement signal;
• and
• determining a perspiration level of skin in contact with the first waveguide based on the total intensity level of the reflected light.

At least one computer readable storage medium comprising a set of instructions which, when executed by a computing system, cause the computing system to:

• receive an electrical measurement signal from a first photodetector coupled to a first waveguide;
• determine a total intensity level of reflected light in the first waveguide based on the electrical measurement signal;
• and
• determine a perspiration level of skin in contact with the first waveguide based on the total intensity level of the reflected light.

An apparatus comprising:

• a measurement stage to receive an electrical measurement signal from a first photodetector coupled to a first waveguide;
• an intensity quantifier coupled to the measurement stage, the intensity quantifier to determine a total intensity level of reflected light in the first waveguide based on the electrical measurement signal;
• and
• a perspiration quantifier coupled to the intensity quantifier, the perspiration quantifier to determine a perspiration level of skin in contact with the first waveguide based on the total intensity level of the reflected light.