| abstract |
A concave optical sensor comprising at least one light source having at least one wavelength, wherein the light source is configured to emit light beams, and at least one light receiver responsive to the light beams emitted from the light source. Both the at least one light source and the at least one light receiver are positioned on a concave segment. The concave segment cane be an elastic segment or can further be provided with a resilient element configured to press the sensor against a body part to obtain optimal coupling and to prevent motion artifacts. |