An adapter allows the interconnection of a sensor originating from one manufacturer
to be coupled with conventionally incompatible monitors originating from other
manufacturers to form a properly functioning pulse oximetry system. The adapter
matches a sensor driver in a monitor to the current requirements and light source
configuration of a sensor. The adapter also matches a sensor's light detector signal
level to the dynamic range requirements of a monitor preamplifier. Further, the
adapter provides compatible sensor calibration, sensor type and security information
to a monitor. The adapter may have a self-contained power source or it may derive
power from the monitor, allowing both passive and active adapter components. The
adapter is particular suited as an adapter cable, replacing a conventional patient
cable or sensor cable as the interconnection between a sensor to a monitor in a
pulse oximetry system.