Alexander Lang writes:
The gentlemen for whom I’m developing this hardware for has requested some additional functionality. The additional functionality requested is a Pulse Oximetry measurement. Pulse Oximetry is the measurement of a person’s pulse along with how much oxygen is present within their blood. It is a common measurement made by medical practitioners to ensure their patients are in good health. I suspect for the medical device, this information will be correlated with a person’s breathing to assess how well a person’s lungs are working and how much oxygen from the air is getting into their blood.
See the full post on his blog here.