One of the representative complications after the coronary artery stenting is restenosis (>420,000 deaths per year), therefore, continuous surveillance of the tissue ingrowth after the balloon angioplasty or stent placement is a key to assess the cure rates. While angioplasty or stenting procedures are currently widely used due to its minimally invasive nature, restenosis (i.e., re-narrowing of a coronary artery) usually happens within 3-12 months of the procedure. Therefore, the follow-up imaging is critical for detecting any restenosis development after the procedure. While a few imaging technologies can detect the restenosis, these would not be used in real-time surveillance with minimally invasive procedure. There are a few efforts to detect the restenosis using implantable pressure sensors, however, they are bulky and typically do not effectively work with the growth of artery tissue. To address these issues, we propose a newly designed electronic stent that incorporates a stretchable, nanostructured strain sensor and open-mesh coils, which enables a batteryless, wireless recording of strain change regarding restenosis monitoring. It is our hypothesis that this nanomembrane sensor package can be easily integrated with a commercially available stent without disturbing the stent's radial strength or mechanical flexibility. The thickening of the coronary artery due to the restenosis results in the strain alteration, which can be detected by the implanted strain sensor in a wireless way. The data detection mechanism based on inductive coupling without the use of a battery offers real-time monitoring of a strain change in the sensor via proximity contact of a portable, external device like a smart appliance. To achieve this goal, we will focus on three following tasks. First the sensor will be carefully designed base don the structural computational modeling and numerical calculation based on the strain changes in the coronary artery over time. Then, the device will be fabricated using a novel transfer printing technique. Various in vitro tests will be conducted to evaluate the functionality of the sensor with the stent. Through this study a new direction of the real-time monitoring will be introduced in the field of the assessment of the coronary artery stenting. The sensor developed through this project will be expanded to other endovascular devices if the strain changes critically influence the tissue remodeling process.
One of the major obstacles for balloon angioplasty or stenting in coronary artery is the restenosis, i.e., re-narrowing of a coronary artery after the procedure. While there are various imaging techniques available to detect restenosis, no techniques can provide a life-time continuous real-time surveillance of restenosis. This project investigates a novel electronic stent to wirelessly monitor restenosis incidence and progression by measuring arterial compliance changes with tissue growth.
