Abstract: An improved pulse oximeter apparatus and method for the measurement of oxygen saturation in the blood, which is faster and more accurate than conventional pulse oximeters. Improved speed and accuracy is attained by elimination of normalization and feedback circuitry and the use of analog to digital converting devices having a wide dynamic range along with a sophisticated computer analysis. The instant invention eliminates inaccuricies resulting from channel matching errors, and detects and eliminates aberrant input data.

Abstract: A magnetic stimulator of neuro-muscular tissue has a discharge capacitor, at least one discharge control switch for allowing discharge of the discharge capacitor into a stimulating coil and a circuit for recovering energy from the stimulating coil when current flow from the discharge capacitor to the stimulating coil is interrupted, the energy being recovered either by the discharge capacitor or a capacitor additional to the discharge capacitor. The additional capacitor may be a reservoir capacitor connected for charging by a power supply and there may be a circuit for pumping charge from the reservoir capacitor to a transfer capacitor and for pumping charge from the transfer capacitor to the discharge capacitor.