OPTICAL APPARATUS FOR MEASURING A PHYSIOLOGICAL PROPERTY OF A BODY PART AND METHOD THEREFORE

摘要

An optical measurement apparatus comprises an optical system (100). The optical system (100) includes a source (102) and a detector (112). The source, when in use, emits a probe beam (116) and the optical system is arranged to direct the probe beam (116) to a location to be measured (114). The detector (112) is arranged to receive a reflected beam (120) from the location to be measured (114).The optical system (100) has a receiving numerical aperture associated therewith and is also arranged so that the probe beam (116) has a probe cone angle corresponding to a probe numerical aperture. The receiving numerical aperture is greater than the probe numerical aperture. Alternatively or additionally, the optical system (100) is arranged to apply a magnification ratio between the detector (112) and the location to be measured (114) so as to minimise deviation of the reflected beam from a receiving axis (119) of the optical system (100).