Flexible wireless passive pressure sensors for biomedical applicatons

Abstract

Passive resonant sensors have been studied by many groups as an approach to sensing of physical properties in inaccessible locations without the need for incorporating any on-board power sources. In this work, we report two types of wireless flexible micromachined passive pressure sensors. Since the devices are flexible, they can be rolled or folded into compact shapes suitable for catheter-based delivery into the body. One design is semi-hermetic, intended for acute use. A second design is hermetic, intended for chronic use. Standard flexible and ceramic electronics packaging techniques are used to fabricate the devices. Devices were tested acutely in vivo for > 30 days in canine models simulating abdominal aortic aneurysms (AAA) which incorporated a wired reference pressure transducer. The sensor real-time dynamic pressure waveforms were measured and compared to acute devices, with indications for potential extensions to chronic use.