Using an inexpensive 3D printer, biomedical engineers have developed a custom-fitted, implantable device with embedded sensors that could predict cardiac disorders and change how they are treated.
The 3D elastic membrane is made of a soft, flexible, silicon material that is precisely shaped to match the heart’s epicardium, or the outer layer of the wall of the heart. Current technology is two-dimensional and cannot cover the full surface of the epicardium or maintain reliable contact for continual use without sutures or adhesives.
The team can then print tiny sensors onto the membrane that can precisely measure temperature, mechanical strain, and pH, among other markers, or deliver a pulse of electricity in cases of arrhythmia.
Those sensors could assist physicians with determining the health of the heart, deliver treatment, or predict an impending heart attack before a patient exhibits any physical signs.
The findings are published online in Nature Communications.
“Each heart is a different shape, and current devices are one-size-fits-all and don’t at all conform to the geometry of a patient’s heart,” says Igor Efimov, a professor of biomedical engineering and radiology, cell biology, and physiology at Washington University in St. Louis.
“With this application, we image the patient’s heart through MRI or CT scan, then computationally extract the image to build a 3D model that we can print on a 3D printer. We then mold the shape of the membrane that will constitute the base of the device deployed on the surface of the heart.”
Ultimately, the membrane could be used to treat diseases of the ventricles in the lower chambers of the heart or could be inserted inside the heart to treat a variety of disorders, including atrial fibrillation, which affects 3 million to 5 million people in the United States.
“Currently, medical devices to treat heart rhythm diseases are essentially based on two electrodes inserted through the veins and deployed inside the chambers,” Efimov says. “Contact with the tissue is only at one or two points, and it is at a very low resolution.
“What we want to create is an approach that will allow you to have numerous points of contact and to correct the problem with high-definition diagnostics and high-definition therapy.
‘Just the beginning’
“Because this is implantable, it will allow physicians to monitor vital functions in different organs and intervene when necessary to provide therapy. In the case of heart rhythm disorders, it could be used to stimulate cardiac muscle or the brain, or in renal disorders, it would monitor ionic concentrations of calcium, potassium, and sodium.”
The membrane could even hold a sensor to measure troponin, a protein expressed in heart cells and a hallmark of a heart attack. Analysis for troponin is standard of care for patients with suspected heart attacks. Ultimately, such devices will be combined with ventricular assist devices, Efimov says.
“This is just the beginning. Previous devices have shown huge promise and have saved millions of lives. Now we can take the next step and tackle some arrhythmia issues that we don’t know how to treat.”
Researchers from the University of Illinois at Urbana-Champaign contributed to the study.