A circular capacitive sensor with crescent slots and PDMS dielectric showed high sensitivity (10.68 fF/mmHg) and a linear response for blood pressure monitoring.
Authors
Md Shams Tabraiz Alam, Department of Electrical Engineering, Jamia Millia Islamia, New Delhi 110025, India
Shabana Urooj, Department of Electrical Engineering, College of Engineering, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
Abdul Quaiyum Ansari, Department of Electrical Engineering, Jamia Millia Islamia, New Delhi 110025, India
Areiba Arif, Assistant Professor, Jindal Global Business School, O.P. Jindal Global University, Sonipat 131001, India
Summary
Highlights: The study focuses on the design and comparison of capacitive pressure sensors using distinct biocompatible materials for in-stent blood pressure. The circular electrode design with crescent-shaped slots and a PDMS dielectric material demonstrated the highest sensitivity. What are the main findings?
The circular sensor design with two crescent-shaped slots, a 20 µm thick PDMS dielectric, achieved a sensitivity of 10.68 fF/mmHg. The resonant frequency shift showed an exceptionally linear relationship with blood pressure (Pearson’s correlation coefficient of −0.99986 and R-squared value of 0.99972). What is the implication of the main finding? The high sensitivity and linear response of the sensor make it an ideal contender for precise, real-time pressure-monitoring applications. The optimized sensor design can be used in passive wireless pressure-sensing techniques for continuous health monitoring, particularly in detecting in-stent restenosis. This research outlines the design of capacitive pressure sensors fabricated from three biocompatible materials, featuring both circular and square geometries. The sensors were structured with a dielectric layer positioned between gold-plated electrodes at the top and bottom. Their performance was assessed through simulations conducted with ANSYS Workbench.
Of the various sensor configurations tested, the circular design that included two crescent-shaped slots and a 20 µm thick PDMS dielectric material demonstrated the highest sensitivity of 10.68 fF/mmHg. This study further investigated the relationship between resonant frequency shifts and arterial blood pressure, revealing an exceptionally linear response, as evidenced by a Pearson’s correlation coefficient of −0.99986 and an R-squared value of 0.99972. This confirmed the sensor’s applicability for obtaining precise blood pressure measurements. Additionally, a 3 × 30 mm cobalt–chromium (Co-Cr) stent was obtained, and its inductance was measured using an impedance analyzer.
Published in: Sensors
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