Ring-shaped MEMS-based piezoresistive force sensor for cardiac ablation catheters
Catheter ablation, a minimally invasive surgical procedure that uses radiofrequency (RF), has simplified the treatment process of cardiac arrhythmias. The success of cardiac ablation procedures greatly depends on effective lesion formation, which relies on the contact force between tissue and the tip. Thus, a real-time estimate of catheter tip contact force is essential during cardiac ablation procedures.
In a new study, researchers led by Hardik J. Pandya, Assistant Professor in the Department of Electronic Systems Engineering, present the design, fabrication, and characterisation of a piezoresistive Micro-Electro-Mechanical System (MEMS)-based force sensor for measuring catheter tip contact force in real-time. The sensor has four bridges with boron-doped piezoresistive elements for detecting the contact force. The sensor dimensions and the piezoresistor doping concentrations were optimised using finite element analysis. The sensor is designed to measure a catheter tip contact force between 0 – 0.8 N. An in-house indentation setup is developed and integrated with a commercial load cell to characterise the fabricated sensor. The sensor results showed linearity of 99.5%, maximum hysteresis of 5%, and sensitivity of 108 ± 11 Ω/N. A customised catheter tip integrated with the fabricated force sensor was tested on excised porcine heart tissues to measure the catheter tip contact force.
V. S. N. Sitaramgupta V, B. S. Arjun, B. Behera, D. Padmanabhan, and H. J. Pandya, “A Ring-Shaped MEMS-based Piezoresistive Force Sensor for Cardiac Ablation Catheters,” IEEE Sensors Journal, early access, 2021. doi: 10.1109/JSEN.2021.3118298.
LAB WEBSITE: https://labs.dese.iisc.ac.in/beeslab/