Miniaturized 3‐Lead Electrocardiogram System Based on Einthoven Triangle for Wireless Cardiac Care Monitoring

Monitoring heart health typically requires a 12‐lead electrocardiogram (ECG) system with a sampling frequency of ≥400 Hz with high power requirements. This allows the detection of clinically relevant cardiovascular events using P, Q, R, S, and T signature peaks in ECG. These requirements limit the scope of ECG use, especially in proactive monitoring, cardiac event prevention, and wireless wearable devices. Herein, a skin‐mountable 3‐lead wireless sensor patch based on the Einthoven triangle is experimentally demonstrated. It allows us to gather vital cardiac information in place of a conventional 12‐lead ECG system. The patch uses the industry's lowest‐power Bluetooth low‐energy system on chip which requires 50 Hz sampling frequency to detect all critical events. A firmware for the chip is developed to transmit data wirelessly at extremely low power (−19 dB), resulting in uninterrupted operation for ≈4 days using a simple CR1632 battery. An Android app records and plots ECG data on a smartphone for real‐time visual monitoring and transmits the data to the cloud‐connected interface for remote monitoring. The demonstration with low‐power operation and integration to the cloud‐connected interface is a significant step for nonassisted home‐based caring to enable preventive health management without being widely constrained by battery and tethered operation.