How ECG Sensor Design Impacts Signal Quality: Reducing Noise and Enhancing Patient Care

Written By Akmal Khwaja

Electrocardiogram (ECG) sensors are fundamental in monitoring heart activity, yet not all sensors are created equal. The design of an ECG sensor significantly influences signal quality, noise levels, and patient outcomes. In this article, we explore how innovative sensor design, particularly offset fitting design, improve ECG signal accuracy and reduce false alarms.

The Problem with Signal Noise in ECG Monitoring

False alarms caused by signal noise, motion artefacts, and poor electrical contact are a widespread issue in patient monitoring systems. Research has shown that false alarms make up over 80% of alerts in intensive care units (ICUs), leading to increased stress for healthcare professionals, and disrupted patient care (Dammeyer & Hansen, 2021).

Key sources of signal noise include:

  • External pressure: Applying force during sensor use can cause gel spreading and disrupt electrical contact.

  • Lead wire pulling: Movement or tension on lead wires can create artefacts and baseline drift, compromising data quality.

The Role of ECG Sensor Design

Two sensor designs have been tested for their ability to mitigate external forces:

  1. Centre Fitting Design:

    • Components, including gel and electrodes, are stacked at the centre.

    • Prone to signal disturbances due to pressure or movement directly affecting the sensor area.

  2. Offset Fitting Design:

    • Components are strategically positioned to dissipate forces away from the sensor area.

    • Allows for connection and disconnection of lead wires without applying pressure to the patient.

    • Demonstrates improved resistance to noise and artifacts during external force application.

Clinical Benefits of Offset Fitting ECG Sensors

Studies show that offset fitting sensors outperform centre fitting designs in maintaining signal integrity. When tested under conditions mimicking clinical use—such as tapping and lead wire pulling—the offset design consistently delivered cleaner, more stable ECG data (Dammeyer & Hansen, 2021).

Key advantages include:

  • Reduced false alarms: Enhances accuracy in critical care monitoring.

  • Improved patient comfort: Prevents adhesive failure and unnecessary pressure on the skin.

  • Enhanced usability: Simplifies lead wire connection and removal.

Why This Matters for Healthcare

Reliable ECG monitoring is crucial in critical care settings, where timely and accurate data can save lives. By adopting advanced sensor designs like offset fittings, hospitals can improve diagnostic accuracy, reduce alarm fatigue, and enhance the overall quality of care.

Conclusion

The design of ECG sensors plays a pivotal role in signal quality. Offset fitting sensors have proven to be superior in mitigating noise caused by external forces, offering better performance and usability compared to traditional centre fitting designs. These innovations pave the way for more reliable patient monitoring and improved outcomes in clinical settings.

Reference
Dammeyer, M. R. & Hansen, D., 2021. The Impact of ECG Sensor Design on Signal Noise. Ambu A/S.

Akmal Khwaja