Sensor Developed to Detect Endothelialization on an Active Coronary Stent

One of the main complications with drug-eluting coronary stents is late stage thrombosis, which is cause by exposed struts of the stent that are not covered by endothelial cells in the healing process. Researchers K. Musick, A. Coffey, and P. Irazoqui have presented work towards developing a sensor that can detect the progress of the healing process in the artery, and placing these sensors on several struts in the stent would allow an observer to see the heterogeneity of healing across the stent. Essentially, the device detects the presence of endothelial cells on its surface while remaining biocompatible and functional in ionic liquids, a condition required for implantation.

The sensor works by utilizing a piezoelectric microcantilever insulated with parylene. When endothelial cells attach to the surface of the device, the increase in mass results in a decrease in the resonant frequencies of the cantilever, and this frequency shift is detected electrically through an LCR meter. As the device is self-sensing and self-actuating, no external optical detection system is required for the cantilever to work, making it ideal as an implantable device. Current limitations of the device include an inability to differentiate between types of cells or other potential objects that may end up on the surface of the stent. The device would ideally also have to be smaller than the struts of the stent as to minimize additional risk for thrombosis, which would require design of a smaller cantilever than the researchers currently possessed.

This article was of interest to me because it improves the effectiveness of coronary stents, which remain one of the leading treatments for those with coronary artery disease, despite having a high rate of complications. In addition, our proposed solution to our Physiology Device Design project relies heavily on mimicking stent design and functionality, while attempting to alleviate or find remedy for the more common mechanical and physiological problems associated with stent implantation. A sensor such as this one could theoretically provide crucial detail about the physiological processes occurring in the coronary arteries after stent placement in real time, allowing for faster detection of late stage thrombosis and as a result, the faster treatment of patients.

Link: http://www.biomedical-engineering-online.com/content/9/1/67

John Gruetzner

VTPP 434 - 501