Fabrication of a MEMS accelerometer to detect heart bypass surgery complications

The purpose of this paper is to review the design and fabrication of a micro‐accelerometer to be used to measure the heart wall motion of patients who have just undergone coronary artery bypass graft (CABG) surgery. The sensor will provide a means of early warning for the medical staff of associated complications with this surgery occurring.

A feasibility paper is carried out with the use of commercially available MEMS three‐axis accelerometers. The sensors are used in animal studies during which the sensor is stitched directly to the surface of a pig's heart. A need for smaller sensors is required and these are designed in‐house and fabricated using a MEMS process. The final dimensions of the sensors are 2.5×3.5×1.4 mm in width, length and height, respectively.

The results of the feasibility studies demonstrate the viability of this type of sensor for heart wall motion measurement. It is possible to detect abnormalities, which can indicate complications associated with CABG. The sensors presented here are fabricated within the tight overall size specifications deemed necessary for this application.

This paper demonstrates an application of MEMS for implantable medical sensors.

In the UK, approximately 300,000 people have a heart attack each year. One of the most common surgeries that is used to treat this is CABG. This sensor is to be used by the medical staff in post‐surgery to provide “real‐time” monitoring of the heart and give early warning of regional cardiac ischemia which can save lives and reduce hospital waiting times and costs.

This paper demonstrates an original way of measuring heart wall motion. Results from the feasibility studies have proven that this can provide an invaluable way of providing early warning of complications after heart surgery.