Originally Posted by nightdiamond
Umm, Wolfgang, do you know where any instructions are for building one of these?
No I don't. Although I think if you had a way to get a signal into a PC and were a decent software programming one could take the signal and do the transform to get the basic feedback that is happening. But I don't know what the transform is. Come to think of it, the gizmo shows a graph that has more points then the heart beats, so I don't know where they get that data. 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?
Originally Posted by some web page
More recently control of the parasympathetic system has been demonstrated. “Effortless” diaphragmatic breathing at a frequency that corresponds to the resonant frequency of a particular individual’s heart rate will reduce sympathetic arousal and promote parasympathetic activity. This frequency is between 5 and 7 breaths per minute for most adults. Breathing evenly at this rate will increase the variations in heart rate frequency. Variation refers to the fact that the rate at which the heart beats (pulse) is constantly changing in a healthy individual. Your pulse rate, for example, may vary from 65 to 75 beats per minute and then go back to 65 beats per minute, making this change about 6 times per minute.