The present invention provides non-invasive devices, methods, and systems for determining a pressure of blood within a cardiovascular
system of a user, the cardiovascular
system including a heart and the user having a
wrist covered by
skin. More particularly, the present invention discloses a variety of
wrist-worn devices having a variety of sensors configured to non-invasively engage the
skin on the
wrist of the user for sensing a variety of user signals from the cardiovascular
system of the user. Generally, approaches disclosed herein may passively track
blood pressure values without any interaction required on the part of the user or may allow for
on demand or point measurements of
blood pressure values by having a user actively interact with the sensors of the wrist-worn device. Approaches disclosed herein further allow for absolute
blood pressure values to be determined directly without the requirement for any periodic calibrations or for relative blood pressure values to be tracked so as to provide relative blood pressure indices.