Abstract: This specification describes a new analyzer for the determination of total hemoglobin; percent oxyhemoglobin, deoxyhemoglobin, methmoglobin, sulfhemoglobin; and oxygen capacity in a micro sample (5 to 10 .mu.l) of hole human blood. The essential components of the analyzer are (1) a cuvette in which simultaneous measurements of PO.sub.2 (by an oxygen electrode) and absorbance (by a dual wavelength optical system) are made, (2) an automatic pump system for filling and emptying the cuvette, (3) an equilibrating tonometer to equilibrate the reagent with air or another gas phase, (4) electronic circuits for the measurement of light intensity and oxygen pressure, (5) an analogue computer, and (6) a printer. Other essential parts of the invention are (a) original procedures and (b) ad hoc developed physico-chemical equations.

Abstract: A circuit for use with an oximeter system which provides constant current pulses to light-emitting diodes in a sequential and cyclical manner. The circuit maintains magnitudes of pulses in the pulse train equal to certain other pulses in the pulse train over extremes of temperature variation, voltage variation, and time duration. Each diode is energized by a series of pulses having the same magnitude, although pulse magnitudes will vary from diode to diode. Therefore, light output from one light-emitting diode remains proportional to light output from the others.

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 Oximeter Cuvette having a complimentary cover with a stirrer that extends into the cuvette cavity and which is rotated relative to the cuvette by the oximeter unit is particularly advantageous to permit a plurality of samples to be evaluated rapidly.