MEMS-based implantable heart monitoring system with integrated pacing function

Miniaturized accelerometer-based implantable heart monitoring systems may increase safety during cardiac surgery. Such systems can provide sustained monitoring compared to imaging techniques. During ischemia, changes in acceleration occur instantly and before changes can be observed by electrocardiography. This may allow earlier detection of adverse events like graft occlusion. Recent designs have been made to meet requirements for postoperative use by easy and safe removal. However, the implantation procedure has been too complicated. The system presented in this paper is a reworked package in which a 3-axis accelerometer is placed inside a stainless steel capsule fabricated by additive manufacturing (3D printing). A needle attached to the package allows for easy implantation. In addition, the metallic capsule makes it possible to use the device as a pacing lead. The system demonstrates easy implantation. Furthermore, in conjunction with a second electrode, pacing and electrical potential sensing functionality is demonstrated.