Apple's iWatch may include optical sensors designed to measure physical functions like heart rate and oxygen levels, according to electronics analyst Sun Chang Xu of Chinese site Electrical Engineering Times [Google Translation], who cites supply chain sources with knowledge of the matter. Xu also indicated that while Apple had planned on glucose monitoring, non-invasive methods have proven to be highly inaccurate and thus may not be included in the final product. Measuring oxygen levels and heart rate are two features the iWatch has been previously rumored to include and optical sensors, which are used in many medical and health-related products, are a logical choice for the smart watch.
