Telemetric system for monitoring of endoleak in abdominal aorta aneurysm using multiple pressure sensors integrated on a stent graft

An abdominal aortic aneurysm (AAA) is the dilation of the abdominal aorta due to weakening of the arterial wall. Endovascular aneurysm repair (EVAR) using an implantable stent graft is the commonly used method for treatment of AAA. An endoleak, which is the leakage of blood around the stent graft, is the complication after EVAR creating trauma to the weakened arterial walls of the aneurysm leading to further enlargement and risk of rupture. This paper details the design, implementation and testing of a wirelessly powered implant device containing multiple pressure sensors to be mounted on a stent graft for detecting endoleak. The tested implant device can be powered for distance of 20 cm using an external RF power source of 2.65 W. A stent prototype with sixteen pressure sensors is fabricated and tested using an in-vitro chamber. The resolution and directionality of the pressure sensors in the stent prototype are measured. Different wire bonding glob top encapsulations are evaluated for mechanical stress induced during stent delivery.