– The Firstbeat Body Guard has a White Paper for validation: https://assets.firstbeat.com/firstbeat/uploads/2015/10/white_paper_bodyguard2_final.pdf it has 67 citations since 2013 – The Bitalino Biomedical Toolkit also has a validation paper: https://mdpi-res.com/d_attachment/sensors/sensors-21-04485/article_deploy/sensors-21-04485-v2.pdf?version=1625205535 it has 1 citation since 2021 – The Biosignalsplux Solo 16 bit data acquisition system does not need a validation paper, since it has 16-bit resolution …