A team comprised of scientists, engineers, and physicians has successfully integrated stretchable electronics technology with standard endocardial balloon catheters. This integration may soon enable cardiologists to place sensitive electronics inside their patients’ hearts with minimal invasiveness, allowing improved diagnosis and treatment of arrhythmias. The study appeared in the March 6 online edition of Nature Materials.
Invasive cardiologists use catheters with electrodes at the end to detect and map arrhythmias and for ablation, or to selectively kill small patches of cells that beat off-rhythm. Currently, two separate, rigid catheter devices are used in arrhythmias procedures. One device maps the heart point-by-point as a cardiologist maneuvers the tube to find any irregularities, and the other ablates spots identified as aberrant, one at a time, with an electrode attached at the end.
Led by A. Rogers, the Lee J. Flory-Founder Chair in Engineering at Illinois, the team has developed a balloon that is capable of performing both functions over large areas of the heart simultaneously, utilizing integrated arrays of multifunctional sensors and ablation electrodes.
Rogers, a professor of materials science and engineering who also is affiliated with the Beckman Institute for Advanced Science and Technology at Illinois, says, “The idea here is instead of this single-point mapping and separate single-point zapping catheter, have a balloon that offers all that functionality, in a mode that can do spatial mapping in a single step. You just inflate it right into the cavity and softly push all of that electronics and functionality against the tissue.”
The team has made a meshwork of tiny sensor nodes that could mount directly onto a conventional catheter balloon. The device has sensors for measuring electrical activity of the cardiac muscle, blood flow, pressure, and temperature as the balloon presses against the tissue, along with electrodes for ablation.
“We put everything on the soft surface of a rubber balloon and blow it up without any of the devices failing,” adds Rogers.
The Illinois team worked with cardiologists at the University of Arizona and Massachusetts General Hospital (MGH) to determine the best features for patient care. For instance, the researchers added temperature sensors and mapped temperature distribution on actual tissue as areas were ablated. They used this data to develop a model for predicting temperature distribution to enable cardiologists to find out how deep into the tissue they are ablating.