Abstract: A system for measuring capillary refill time includes a wearable device and a control unit. The wearable device includes a force sensor to obtain a force signal and an optical sensor to obtain an optical signal. The system ensures that an applied force is acceptable in both magnitude and duration, and that a duration over which the applied force is released or removed is acceptable. These factors can establish that a capillary refill time determined or calculated therein is accurate. The system can also determine the capillary refill time based on the force and optical signals obtained by the force and optical sensors, respectively.

Abstract: An example system for estimating a hydration level of an individual can include: a mechanism configured to apply mechanical pressure to a digit of the individual; an light detector configured to sense the light from the digit; and a controller programmed to perform functions including: send a first signal to the mechanism to apply the mechanical pressure to the digit; send a second signal to the mechanism to release the mechanical pressure on the digit; determine a capillary refill time based upon a third signal from the light detector indicating an amount of time for capillaries of the individual to refill with blood; and estimate the hydration level of the individual based upon the capillary refill time and one or more additional parameters.

Abstract: An example system for estimating a hydration level of an individual can include: a mechanism configured to apply mechanical pressure to a digit of the individual; an light detector configured to sense the light from the digit; and a controller programmed to perform functions including: send a first signal to the mechanism to apply the mechanical pressure to the digit; send a second signal to the mechanism to release the mechanical pressure on the digit; determine a capillary refill time based upon a third signal from the light detector indicating an amount of time for capillaries of the individual to refill with blood; and estimate the hydration level of the individual based upon the capillary refill time and one or more additional parameters.

Abstract: A system for measuring capillary refill time includes a wearable device and a control unit. The wearable device includes a force sensor to obtain a force signal and an optical sensor to obtain an optical signal. The system ensures that an applied force is acceptable in both magnitude and duration, and that a duration over which the applied force is released or removed is acceptable. These factors can establish that a capillary refill time determined or calculated therein is accurate. The system can also determine the capillary refill time based on the force and optical signals obtained by the force and optical sensors, respectively.

Abstract: An example system for estimating a hydration level of an individual can include: a mechanism configured to apply mechanical pressure to a digit of the individual; an light detector configured to sense the light from the digit; and a controller programmed to perform functions including: send a first signal to the mechanism to apply the mechanical pressure to the digit; send a second signal to the mechanism to release the mechanical pressure on the digit; determine a capillary refill time based upon a third signal from the light detector indicating an amount of time for capillaries of the individual to refill with blood; and estimate the hydration level of the individual based upon the capillary refill time and one or more additional parameters.