Which is the most affordable heart rate monitor with the highest accuracy?

Last Updated on August 21, 2023 by pg@petergamma.org

OpenBCI boards with 8 channels and WIFI shield have become affordable on eBay and Aliexpress. These can be used for instance with open source tooboxes like HeartPy and Python. But as with the PPG watches, which cost about the same price, the question arrises: are these devices interesting for scientists? The specifications of a Cyton board are similar to an iWorx TA 220 channel recorder which has been used in many scientific papers. But the Cyton 3 channel ECG device has as far was we know only been tested in one paper to this date:

Researchers from the University of Calgary found that a 3-lead ECG device based on the OpenBCI Cyton board can be used for HRV measurements instead of an industry-standard 3 lead ECG device from Adinstruments and costs only about 4%

And no one has tested and used a 3 channel Cyton ECG with HeartPy to this date, and wrote a paper about it. But if we are interested in the most affordable device with the highest accuracy, we suppose that it is a Cyton 3 channel ECG device with HeartPy, and not the Apple watch Ultra or the Polar H10.