Smart Flexible Sensors for in-vivo Coronary Circulation Diagnostics (Coronary)

Themes: Flexible and Stretchable Electronics

Heart angioplasty surgery ("Dotteren" in Dutch) has developed into a quick and reliable procedure which has saved the lives of thousands of people all over the world. The procedure always starts with the insertion of a 300 um diameter guide wire into one of the patient's main arteries which is subsequently shifted - guided by X-ray imaging - to the blocking (stenosis) in the coronary artery. The guide wire then serves as a guide for the balloon, the stent and other instruments which are simply shifted over the guide wire to the location of the stenosis.

Until recently the surgeon solely had to rely on an X-ray image to decide on the type of therapy. However, with the miniaturization of sensors and electronic circuits it has become feasible to integrate advanced electronic functionality in the tip of these guide wires which are only three human hairs in diameter! Since the guide wire is always there, this means added diagnostic information without the need for additional manipulations in the Cath-Lab, making these procedures safer at little additional costs.

In this project we are developing a combined pressure and flow sensor which is so small that it can be positioned in the tip of the guide wire. An Application Specific IC (ASIC), the width of a human hair, processes the analog signals and translates them to the digital domain. The photograph shows a mechanical study whereby the sensor platform with ASIC solder bumped on top is shifted into a tube of 800 um diameter with a flexible foil containing the flow sensor wrapped around it. The next step is to further reduce the diameter to 300 um and add full sensor and electronic functionality.