A radio-frequency (RF) interrogation method for sensor-integrated "smart" stent implants is reported. This device, formed with a 2-cm-long inductive antenna stent and a micro capacitive pressure sensor, both based on a medical-grade stainless steel, serves as a wireless resonant pressure sensor designed to detect changes in local blood pressure for early detection of post-stenting complications. Wireless telemetry of the devices deployed in vascular model and graft is demonstrated by reading the decay of resonance in the stent excited with pulsed RF fields using two-and single-antenna setups at source powers of 4-20 dBm, showing the read ranges of up to 2.75 cm that are 2 ×-3 × larger than those measured with the conventional impedance-phase method. The devices immersed in saline are also successfully interrogated. The obtained results suggest that the proposed technique is a promising alternative path to wireless monitoring of the carotid artery through implanted smart stents.
- Wireless telemetry
- microelectromechanical systems
- transient resonance
ASJC Scopus subject areas
- Electrical and Electronic Engineering