Abstract: The present invention provides a sensor (20) for radiance based diagnostics of body tissue including a performing component (21) and an adhering component (23). The performing component includes at least one radiance source (22) for radiating a tissue, and at least one detector (24) for detecting rays emitted from the radiance source. The adhering component is capable of fastening the performing component to a tissue such that the radiance source, and detector are facing and contiguous with the tissue. When operative, the adhering component fastens the performing component to the tissue to the extent that the detector receives only rays which are transmitted through or reflected from the tissue. The sensor may include a controlling device which senses external conditions and which is capable of controlling the sensor in response to the sensed conditions.

Abstract: A method and device for measurement of a level of at least one blood constituent. The device includes a light source and a light detector proximate the surface of an organ. The device also includes a pair of adjustable gain amplifiers and a processor/controller connected within a processing unit. The processing unit operates to separate an AC signal component from a DC signal component. The light source includes at least one light emitting unit. Preferably, the light source alternatingly emits light at two different wavelength ranges and normalizes the AC and DC output signals corresponding with the intensity of the light reflected from the organ and calculates a ratio of the normalized signals for each wavelength range. The device may determine the level of the blood constituent and may also use this level for monitoring and/or to activate an alarm when the level falls outside a predetermined range.