Single-Battery Cooperative Sensors For Multi-Lead Long Term Ambulatory ECG Measurement

This work develops a multi-lead, single-battery, single-wire, dry-electrodes based system for long term ambulatory ECG monitoring. The designed system operates in a master-slave configuration, in which the master first simultaneously powers all the connected slaves and then measures the ECG signal w.r.t. the selected slave before repeating the powering cycle and measurement with the subsequent slave. The proof-of-concept system has 4 slave nodes, each housing a 180 nm CMOS slave ASIC while the master node, which houses the only battery, is designed with COTS components. The multi-lead system exploits the body as current-return path within the constraints of IEC60601-1 specification and is operational using a single unshielded wire for connection between the master and the 4 slave nodes. The peak-to-peak measured noise over 9 out of 10 periods of 10s within the 0.5Hz - 40Hz bandwidth required as per IEC 60601-2-47 for ambulatory ECG systems is 50.8µVppk and is comparable with the required specification of 50µVppk.