[ ASUS VivoWatch] What’s the meaning of PTT Index in ASUS VivoWatch BP?
The PTT Index, which represents Pulse Transit Time, is mainly used to measure the speed of blood flow in the human body as blood flow fluctuations are associated with human emotional responses. With human blood flow rate as a benchmark, blood flow rate will slow down when feeling calm; whereas blood flow rate increases with tension and anger.
It also tracks heart rate variability (how fast the heart rate is and the interval of the heart rate) as an indicator of mood and stress.
The reason why there are two values for the Pulse Transmission Index is mainly because it provides an index interval through the high and low values, then users can observe the related changes of emotional pressure.