Amazon.com, Inc.
System to optically determine blood pressure

Abstract:

A camera sensitive to near infrared light is placed proximate to the skin of a user and the area illuminated by one or more infrared light sources. A set of images of one or more blood vessels is obtained at successive times. The images are processed to determine a change in size of the vessel(s) from one time to another, corresponding to expansion and contraction of the vessels responsive to contraction of the user's heart. This change may be used to determine pulse rate, elasticity of the vessel, blood pressure, or other data about the user's physiological status. The data may be used to assess health status at a particular time, determine health trends for the user, and so forth.