[neurotech1]

That and the Apple Watch is on the wrist, which could introduce artifact to the ECG.

There are single lead chest ECG patches used for specific diagnostic reasons. Zio patch is one common device used. [0]

[0] https://www.irhythmtech.com/patients/how-it-works

[Rssnkgp02]

Excellent points. Artifact is indeed a tricky problem for EKGs, and the ziopatch is a great device. Generally, multiple leads are needed (ideally 6 or 12 leads) to accurately measure repolarization of the heart.

[traceroute66]

> That and the Apple Watch is on the wrist, which could introduce artifact to the ECG.

If patent filings are a guide[1], Apple are aware and have been investigating options for user-friendly additional sensors elsewhere on the body.

Whether it comes to market is another matter, of course.

[1] http://patft1.uspto.gov/netacgi/nph-Parser?patentnumber=1108...

[Rssnkgp02]

Good points!