Abstract: A sensor assembly and sensing method is provided for proximity detection for assessing an attachment state of a sensing probe with respect to a subject. A probe is coupled to an electronic probe controller. The probe includes a proximity sensor having a passive energy storing circuit element, and a biological sensor receptacle configured to receive a biological sensor for sensing a biological characteristic of an object. The electronic probe controller excites a circuit network incorporating the proximity sensor with an excitation signal and determines a characteristic of the circuit network that is excited by the excitation signal. The electronic probe controller further generates a proximity indication indicating whether the probe is attached to the object based on the characteristic of the circuit network.

Abstract: The present disclosure provides systems and methods for multi-distance, multi-wavelength diffuse correlation spectroscopy (MD-MW DCS). The systems and methods can include two, three, or more different wavelengths and two, three, or more different source-detector distances. The dynamics of a target medium can be determined using detected signals at the different wavelengths and different source-detector distances.

Abstract: An optical probe comprising a light source providing a light that is directed along a first axis; a diffusive element positioned proximate to the light source to receive the light and to diffuse the light as it exits the diffusive element; and a directional optical element directing the light exiting the diffusive element along at least one of the first axis and a second axis generally perpendicular to the first axis to project the light out of the optical probe and onto a subject.

Abstract: The quantitative determination of various materials in highly scattering media such as living tissue may be determined in an external, photometric manner by the use of a plurality of light sources positioned at differing distances from a sensor. The light from said sources is amplitude modulated, and, in accordance with conventional frequency domain fluorometry or phosphorimetry techniques, the gain of the sensor is modulated at a frequency different from the frequency of the light modulation. Data may be acquired from each of the light sources at differing distances at a frequency which is the difference between the two frequencies described above. From these sets of data from each individual light source, curves may be constructed, and the slopes used to quantitatively determine the amount of certain materials present, for example oxyhemoglobin and deoxyhemoglobin in living tissue.

Abstract: The relative concentration of a material such as glucose in a turbid medium such as living tissue may determining the scattering coefficient of the light that has passed through the turbid medium; and comparing the scattering coefficient with a previous scattering coefficient determined with respect to the turbid medium.