Which smart bracelet to choose with an ECG recording and with an open api for further refinement of the functionality, I don’t consider apple watch?

Question

Do it yourself

Which smart bracelet to choose with an ECG recording and with an open api for further refinement of the functionality, I don’t consider apple watch?
One lead is enough for me to implement my plan.
Many options for smart watches on Ali with the ECG function.
But does anyone have an open api?

Answer 1

The vast majority have an open ANT+ or Bluetooth HDP connection

Answer 2

... To measure the potential, at least two electrodes are required, with vectors directed across the heart ... - https://habr.com/ru/post/423489/
...we place a hand with a smart watch on a horizontal surface , and then press the screen with the index finger of the other hand for 30 seconds ... - www.procontent.ru/news/31363.html
Keyword "other hand" . You never know that the Chinese made electrodes on the clock, what's the use of them? It's like: on the fence there is a word of three letters ... there are electrodes, but there is no ECG. But there is no ECG - what's the difference what API is there.