Pulse oximeter sensor

A pulse oximetry sensor assembly for attachment to the lower half of the palm or the ulnar edge of the palm, the sensor assembly comprising:

• a) an elongate body supporting a light emitting source and a detector for detecting scattered light originating from the light emitting source, wherein the light emitting source and the detector are configured to detect scattered light from a surface of the lower half of the palm or the ulnar edge of the palm;
• and
• b) a means for transmitting signals acquired by the detector to a signal processing unit, wherein the signals correspond to the scattered light.