Abstract: A measurement apparatus comprises a probe system (100) operably coupled, when in use, to a processing resource (134). The probe system (100) and the processing resource (134) are arranged, when in use, to measure an apparent thickness change of a volume of the medium (108) to be measured and to determine a physiological parameter using the measurement of the apparent thickness change.

Abstract: An optical measurement apparatus comprises an optical system (100) having a receiving axis (115). The optical system (100) comprises a source (102) that generates a probe beam that is directed to a location to be measured (114). A detector (112) of the optical system receives a reflected beam from the location to be measured (114). The apparatus also comprises a processing resource that receives an output signal from the detector (112) and makes an assessment of a characteristic of the output signal in order to determine a degree of alignment of the location to be measured (114) with the receiving axis (115) of the optical system (100).

Abstract: An optical measurement apparatus comprises an optical system. The optical system comprises a source and an image capture device. The source is arranged to generate, when in use, a beam of electromagnetic radiation. Further, the optical system is arranged to direct the beam of electromagnetic radiation to a location to be measured. The optical measurement apparatus also comprises a feedback arrangement arranged to receive a reflected beam from the location to be measured and to provide feedback information in response to receipt of the reflected beam, the feedback information being indicative of degree of alignment of the location to be measured with the optical system.