Traditional physiological monitors sample analog signals at fixed periodic intervals (e.g., 250 Hz or 1 kHz), generating continuous data regardless of whether the signal contains information or static baseline. This benchmark paper evaluates event-driven level-crossing sampling and AER routing against conventional synchronous ADCs across 1,000 hours of clinical ECG records.
Because the heart spends approximately 60% of each cycle in the quiescent isoelectric baseline, level-crossing sampling generated 78% fewer bytes, directly extending wearable patch battery life from 4 days to 18 days.
During the rapid ventricular depolarization (QRS complex), event sampling automatically increases effective temporal resolution to the equivalent of 4 kHz, capturing subtle pacemaker spikes without wasted idle bandwidth.