An Electrocardiogram (ECG) records the activity in the heart through the acquisition of electrical signals. The key challenges of realizing an ECG application on a wearable device with small form-factor electrodes include (i) high contact impedance from small, dry electrodes and (ii) need for a quick signal acquisition. The TI signal chain for wearable ECG has several attributes to mitigate these challenges including (i) high-input impedance, (ii) right-leg drive (RLD) which enables high common-mode rejection ratio (CMRR), and (iii) DC cancellation with fast recovery.

Cuffless blood pressure (BP) monitoring on a wearable device is based on the concept of Pulse Wave Velocity (PWV) which refers to the velocity of the pulse wave across the arteries due to cardiac activity, and can be estimated by measuring the relative delay between the ECG and photoplethysmogram (PPG) waveforms. TI analog front ends (AFE) have the capability to do synchronized acquisition of ECG and PPG waveforms, enabling cuffless BP estimation.