A Circuit for Heartbeat Detection

Applications

  • Wearable ECG device
  • Detection of other pulsatile biological signals

Problem Addressed

State-of-the-art heartbeat monitors are designed to detect several clinically relevant processes, including heartbeat rate and arrhythmia. Clinical ECG monitors, which capture fine signal features, imposes certain requirements on the ECG hardware responsible for the signal detection and recognition, leading to greater power consumption and size. On the other hand, detection of heartbeat rate requires less signal processing and therefore could be implemented with a simpler and more energy efficient circuit than the circuit currently used in the ECG monitors. In addition, such heartbeat information can be used to diagnose certain arrhythmia, such as atrial fibrillation.

Technology

The presented platform is a single-chip solution that replaces several distinct elements of a traditional ECG setup, allowing it to operate with tens of nanowatts of power. By removing an analog-to-digital converter, a traditional ECG instrumentation amplifier, and a signal processor responsible for digital signal processing, the inventors have been able to reduce the power consumption, the footprint, and the complexity of the device. The simplified circuit is capable of detecting the ECG signal and R-timing on various locations on the body in the presence of artifacts and degraded signal quality. Presented alterations have provided an opportunity to implement a more compact and lightweight long-term ECG monitor that is sufficiently low power for implantable and/or batteryless applications.

Advantages

• Tolerance to motion and ability to sense heartbeat on various locations on the body
• Long-term ECG monitoring, suitable for implantables
• The nanowatt power consumption of the circuit, which is approximately 100x lower than power consumption of the state of the art ECG circuits
• Reduced battery’s and device’s sizes