Wearable Device for Non-Invasive Beat-to-Beat Blood Pressure Monitoring using Pulse Transit Time

The commercial Blood Pressure (BP) monitoring devices do not provide continuous monitoring of arterial blood pressure. The project aims to develop a wearable device suitable for continuously and non-invasively measuring the blood pressure (see figure below). Further, the device will be portable, easy to use and will be customised for a large scale deployment in low resource settings. The proposed system uses the concept of Pulse Transit Time (PTT) for the calculation of BP. The Fig. 1 shows the conceptual diagram of the proposed blood pressure monitoring device. Experiments were performed to show the existence of a correlation between PTT and BP.

Fig. 1: Proposed wearable device for continuous blood pressure monitoring

Prototypes were developed as a small portable device to realise the proposed BP measuring system. The prototype consists of an in-house developed board having ARM based microcontroller which integrates various modules for information display, wireless communication, PPG sensor interface and power management. Several prototypes of the wrist device were developed with improved form factor at CSIR-CEERI Chennai Centre. Preliminary measurements taken for various subjects show that the blood pressure of a person can be tracked with good accuracy.