Abstract: A system and method to help maintain quality control and reduce cannibalization of accessories and attached probes in a highly sensitive patient monitor, such as a pulse oximetry system. One or more attached components may have information elements designed to designate what quality control mechanisms a patient monitor should look to find on that or another component or designate other components with which the one component may properly work. In a further embodiment, such information elements may also include data indicating the appropriate life of the component.

Abstract: A patient monitor has multiple sensors adapted to attach to tissue sites of a living subject. The sensors generate sensor signals that are responsive to at least two wavelengths of optical radiation after attenuation by pulsatile blood within the tissue sites. A patient monitor uses the plurality of signals to reduce the effects of noise.