Toward Real-Time Blood Pressure Monitoring via High-Fidelity Iontronic Tonometric Sensors with High Sensitivity and...

Area of Science:

• Materials Science
• Biomedical Engineering
• Sensors and Actuators

Background:

• Continuous, noninvasive blood pressure (CNIBP) monitoring is crucial for early cardiovascular disease detection.
• Wearable mechano-electric pressure sensors offer potential for CNIBP monitoring due to conformability and ease of use.
• Existing sensors struggle to achieve high-fidelity pulse waveforms, requiring high sensitivity and linearity over a wide pressure range.

Purpose of the Study:

• To develop a high-fidelity, iontronic-based tonometric sensor (ITS) for accurate CNIBP monitoring.
• To evaluate the sensor's sensitivity, linearity, dynamic range, and response time.
• To demonstrate the ITS's capability for real-time, beat-to-beat blood pressure measurement.

Main Methods:

• Fabrication of an iontronic-based tonometric sensor (ITS).
• Characterization of sensor performance, including sensitivity, linearity (R²), dynamic range, limit of detection, and response time.
• Testing the ITS for real-time monitoring of brachial and radial pulse waveforms.

Main Results:

• The ITS achieved high sensitivity (4.82 kPa⁻¹), excellent linearity (R² > 0.995), and a large dynamic range (up to 180% output change) from 0 to 38 kPa.
• The sensor exhibited a low limit of detection (40 Pa), fast response/release times (35 ms), and stability over 5000 cycles.
• Successful real-time, beat-to-beat blood pressure monitoring using the ITS was demonstrated by measuring pulse waveforms.

Conclusions:

• The developed ITS provides a rational design for wearable pressure sensors with superior sensitivity, linearity, and dynamic range.
• The ITS is a promising technology for high-fidelity, real-time CNIBP monitoring.
• Potential applications extend to human-interface interaction, electronic skins, and robotic haptics.