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Published April 15, 2014 | public
Journal Article

Stretchable electrochemical impedance sensors for intravascular detection of lipid-rich lesions in New Zealand White rabbits


Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed (1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and (2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5° at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5° at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions.

Additional Information

© 2013 Elsevier B. V. Received 22 August 2013; Received in revised form 12 November 2013; Accepted 20 November 2013; Available online 1 December 2013. The authors would like to express gratitude for technical advice from Dr. David Shavelle in the Division of Cardiovascular Medicine at USC, and technical support for animal studies from Sharon Hale and Dr. Robert Klonner in the Heart Institute at Good Samaritan Medical Center, Los Angeles. This project was supported by National Institutes of Health, HL083015 (T.K.H.) and HL111437 (T.K.H. and Y.C.T.).

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