Multiplexed catheter-integrated pressure sensing system for endoluminal interventions

Advances in flexible catheters pave the way for minimally invasive diagnosis and treatment of luminal organs and tubular structures through endoluminal interventions. A key challenge is in establishing non-constraining pressure monitoring at the interfaces between medical catheters and intraluminal anatomy, where catheter-tissue interactions may be influenced by lumen curvature, structural variability, and physiological motion. In this work, we present a scalable and multi-purpose pressure sensing system for multidirectional monitoring of tissue interactions, establishing a robust solution for deploying diagnostic and therapeutic instruments in various types of endoluminal interventions. This approach provides an integrated pressure sensing platform that combines a thin-film piezoelectric sensor array with a bespoke multi-lumen catheter and a custom signal acquisition circuit. The sensor array is fabricated from an ultrathin poly (vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) film using a multilayer sandwich architecture with patterned gold electrodes, resulting in a flexible device with a total thickness of approximately 20 µm and sensing units as small as 2.25 mm². The multi-lumen catheter is fabricated with a cost-effective and highly scalable fiber drawing technology, establishing a means of fast prototyping catheters with bespoke microstructures for sensor integration and medical instrument deployment. Supported by a custom high-impedance acquisition circuit, the system achieves a sensitivity of 16 mV per kPa, which is approximately 25 times higher than state-of-the-art catheter-integrated sensors, while maintaining a sensing range from 0 to 80 kPa. Through in-vitro phantom studies, the system performs precise multi-directional sensing within various clinical endoluminal scenarios, showing its potential in digitalizing tissue interactions during endoluminal interventions.