Patent ID: 7413567

Claim:
A skin sensor comprising, a housing having an aperture shaped to be placed against a surface being sensed; a radiation source inside said housing and positioned to emit radiation in three or more distinct wavelength bands through said aperture and onto said surface being sensed so that radiation is remitted by the surface being sensed; a detector inside said housing positioned to receive the radiation remitted by said surface being sensed; a control circuit to power said radiation source so that radiation from each of the three or more distinct wavelength bands is emitted at distinct times; said control circuit further measuring the remitted radiation for each said three or more distinct wavelength bands to obtain a spectral remittance of said surface being sensed; said control circuit further comparing the spectral remittance of the surface being sensed to a reference spectral remittance previously determined for skin; said control circuit providing an indication when the spectral remittance of the surface being sensed is substantially the same as the reference spectral remittance.