Researchers from Northwestern University and University of Illinois at Urbana-Champaign have combined a number of tools for performing cardiac electrophysiological mappings and ablations onto one catheter that would otherwise have to be deployed sequentially. The balloon catheter includes temperature, pressure, and EKG sensors, and an LED that can ablate cardiac tissue.
The electronics Huang and Rogers use in this study are based on a “pop-out” design of interconnects, similar to their early design for stretchable electronics but with much larger — approximately 130 percent — stretchability. The type of arrhythmia the team focuses on is tachycardia, when the heart beats too fast; the tissue that induces this condition is the target of their ablation therapy.
This ability of the electronics to stretch is important because the researchers print all the necessary medical devices on a section of a standard endocardial balloon catheter (a thin, flexible tube) where the wall is thinner than the rest. (This section is slightly recessed from the rest of the catheter’s surface.) There the sensitive devices and actuators are protected during the catheter’s trip through the body to the heart. Once the catheter reaches the heart, the catheter is inflated, and the thin section expands significantly; the electronics are now exposed and in contact with the heart.
Once the catheter is in place, the individual devices can perform their specific tasks when needed. The pressure sensor determines the pressure on the heart; the EKG sensor monitors the heart’s condition during the procedure; the LED sheds light for imaging and also provides the energy for ablation therapy to eliminate (ablate) the tachycardia-inducing tissue; and the temperature sensor controls the temperature so as not to damage other, good tissue.
The entire system is designed to operate reliably without any changes in properties as the balloon inflates and deflates.
These devices can deliver critical high-quality information, such as temperature, mechanical force, blood flow and electrogram, to the surgeon in real time. While the multifunctional catheter has not been used with humans, the researchers have demonstrated the utility of the device with anesthetized animals.
Full story from Northwestern: Cardiac Catheter That Can Do It All…
Abstract in Nature Materials: Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy
