Abstract: An optical non-invasive oximeter for measuring oxygen saturation in arterial blood utilizes a light source capable of giving off light having different wavelengths, such as light in the infrared and red region, and a pair of photoelectric devices, one responding to one wavelength and the other to the other wavelength, for detecting the amount of such light transmitted through living tissue. Each photoelectric device is connected to a computing circuit which generates a signal that represents the logarithm of the quotient of the signal received from the photoelectric device divided by its direct current component. The signals from each of the computing circuits are differentiated and then divided, one by the other, to provide an indication of oxygen saturation in the blood.

Abstract: An optical system in a single or double tube color television camera for minimizing color shading, moire patterns and color beats includes along the image optical axis a phase grating low pass filter, a color encoding filter and a lenticular lens member oriented relative to each other and the image scanning to minimize interference between the color encoding filter and striped patterns in the viewed object. The color encoding filter is striped, the low pass filter is either striped or has regularly longitudinally and transversely spaced phase retarding projections and the lenticular lens member includes transversely spaced longitudinal cylindrical lenses or regularly transversely and longitudinally spaced convex projections.