Originally Posted by wolfgang
The info talks about HRV (heart rate variance) that is the difference between each heart beat. This difference between beats changes a certain amount - so math people? isn't that just the first derivative?
If they are talking about the change in heart rate, then, yes, it would be basically the first derivative. And it wouldn't be difficult to build a decent software for displaying it. As you say, all it needs is to get the signal into your PC.