How do heart rate monitors work?

Answer 1

The two different types of heart rate monitors work in different ways.

Chest strap monitors

A chest strap monitor consists of a transmitter attached to a belt worn around the chest and a receiver worn on the wrist like a watch.

When your heart beats, a small electrical signal is sent through the heart muscles, causing it to contract.

The monitor detects this electrical signal through the skin and transmits it via Bluetooth to the wrist receiver, which displays the heart rate.

Wrist watch monitors


(From runblogger.com)

Wrist watch monitors use optical sensing technology called photoplethysmography (PPG) (Greek photos = "light" + plethysmos = "enlargement"+ graphein = "to write"), that is, using light to measure volume changes in the blood vessels.

Blood absorbs green light, so the back of the watch contains green LEDs that flash hundreds of times per second.

Each heart beat brings a spike in blood flow and changes in green light absorption.

Photodiodes measure the changes in light intensity and display the information as a heart rate on the front of the watch.

Sign up to view the whole answer

By signing up, you agree to our Terms of Service and Privacy Policy

Sign up with email
Answer 2

Heart rate monitors work by detecting and measuring the electrical signals produced by the heart as it contracts and pumps blood. This is usually done through sensors, such as electrodes, placed on the skin. The sensors detect the electrical impulses generated by the heart's activity and transmit this information to the monitor, which then calculates and displays the heart rate in beats per minute (bpm). Some monitors use optical sensors that measure blood flow through the skin to estimate heart rate.

Sign up to view the whole answer

By signing up, you agree to our Terms of Service and Privacy Policy

Sign up with email
Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

Not the question you need?

Drag image here or click to upload

Or press Ctrl + V to paste
Answer Background
HIX Tutor
Solve ANY homework problem with a smart AI
  • 98% accuracy study help
  • Covers math, physics, chemistry, biology, and more
  • Step-by-step, in-depth guides
  • Readily available 24/7