A pulse oximeter sensor comprising a light emitter and a detector disposed on a substrate layer with a plurality of perforations or variations in thickness between the light emitter and the detector. The plurality of perforations or variations in thickness blocks or scatters light shunted via the substrate...http://www.google.de/patents/US7373188?utm_source=gb-gplus-sharePatent US7373188 - Shunt barrier in pulse oximeter sensor
