A Novel Acoustic Reflection Principle for Developing Tactile Sensors Integrated with Catheters for Cardiac Ablation

Cardiac ablation is a commonly employed procedure for treating arrhythmias, but the absence of tactile feedback increases the risk of tissue trauma. To address this challenge, integrating tactile sensors with catheters allows for safer operations. However, cardiac catheterization necessitates a miniature tactile sensor with appropriate surgical properties. In this study, a novel acoustic reflection principle for developing a miniature tactile sensor is proposed to be integrated with sensorized catheters in cardiac ablation procedures. The principle involves utilizing a sinusoidal acoustic wave within an acoustic cavity comprising rigid and elastic components. When force is applied, the acoustic wave interacts with the elastic component, resulting in a measurable change in the reflected wave. Theoretical analyses were conducted to evaluate the acoustic wave's response to variations in the size of the sound tube. The analysis results aided in selecting an appropriate sound frequency for the tactile sensor's design. A prototype sensor was developed based on this principle, featuring a sensor tip with an acoustic cavity, a silicone tube, and an acoustic housing containing a speaker and a microphone. Experimental results demonstrated a direct relationship between the sensor output and the applied force. With a diameter of 3 mm, the developed sensor exhibits clinical applicability and can measure contact force within the range of 0–1 N, making it a promising tool to minimize faulty pathways and reduce heart tissue damage during cardiac ablation procedures.