The Role of Time in Health IoT

As the biological processes in the body change constantly, comparable measurements should be taken simultaneously in time and place. In practice, this is hard to achieve. Synchronicity is required to certify medical accuracy for a new device by reference to a certified one. In a typical health IoT, synchronicity cannot be enforced procedurally and timing needs to be part of the network architecture. Popular examples are in blood pressure measurement. Putting the blood flow in a known pinch-off situation performs synchronization. But this principle cannot be extended to other non-invasive measurements. Hence the chapter proposes to synchronize on basis of the heart rate extracted from the blood flow at arbitrary positions on the body. This models the blood flow in the body and relates all to the rhythm of the heart. It brings existing phenomena into a single, multi-level model that allows wireless networked wearables into a single health-monitoring scheme.