Question

question 17 (multiple choice worth 5 points) (02.02 lc) which of the following devices directly measures the heart rate through electrical signals? chest - strap monitor smartphone app sn rt ring wrist - based device

Explanation:

A chest - strap monitor has electrodes that detect the electrical signals (electrocardiogram or ECG - like signals) generated by the heart as it contracts. Smartphone apps typically use the camera (photoplethysmography - PPG) to measure heart rate by detecting changes in blood volume. Smart rings and wrist - based devices also often use PPG (by shining light onto the skin and measuring the reflected light to detect blood volume changes related to heartbeats) rather than directly measuring electrical signals.

Answer:

Chest - strap monitor