A medical monitoring instrument such as a pulse oximeter uses vertical cavity surface emitting laser diodes (VCSELs) to produce at least two high intensity, essentially monochromatic light beams. The VCSELs are located either in: (1) the probe itself, (2) the connector to the probe, or (3) the monitor...http://www.google.se/patents/US6253097?utm_source=gb-gplus-sharePatent US6253097 - Noninvasive medical monitoring instrument using surface emitting laser devices
