[hedora]

The independent claims in that patent seem to exactly describe technologies from the 1970’s, except that the detector is flat and uses 4 LEDs. The Massimo page you cite claims they invented their signal processing technique in 1989, and Wikipedia says they shipped it in 1995.

The patent you cite was filed in 2009, and is set to expire in 2028. Patents only are supposed to last 17 years in the US, not 39 years.

Anyway, the clip on one’s probably don’t use the algorithms from 1989 or and whatever is in the patent, since the innovation was using a flat detector instead of a clip. Clips were working fine for 20 years before SET.

[Godel_unicode]

Clips work by observing transmission of light through the finger being absorbed by oxygen-carrying blood as opposed to the single chip wearable which depends on measuring reflected light. Different techniques, different patents.

[solardev]

Thanks for explaining this! I was wondering why "clip on" vs "wrist worn" would matter, and your comment cleared it up.

[AlbertCory]

"17 years from issuance" is ancient. It's been "20 years from filing date" for > 25 years now.