> Additionally, the comparison with 253 measurements from three volunteers against an automated sphygmomanometer indicated an accuracy within ±25%

I am having a hard time understanding the colour to put on this. The tone of the article implies this is a major success point. 25% variance around a recognised standard looks like a massive hill remains to be climbed.

What did I mis-understand? Is this just "at least as good as all the other not very good attempts" or is this somehow actually improvement on alternatives? Is this even useful diagnostically?

Also sample size of 3. C'mon.

(not a medico)