This device can tune your heart, then undo it

The first medical implant of this breakthrough was a thin sheet that electrically shakes the injured tissue initiate nerve regeneration, which the team tested on rats. Rogers then met with cardiologists, including Arora, who saw the possibility of abandoning the traditional temporary pacemakers used to treat slow heart rhythms. Rogers compares this soluble device to an internal wound healer, an “electronic medicine” in which all components are soluble.

At first glance, a device half an inch wide and half an inch long looks like a weak plastic band. But the truth is, it’s a dynamic stack of carefully selected surfaces. Electrical contacts are a mixture of tungsten and magnesium. These wireless energy is introduced into these contacts by a flat winding antenna made of the same material. Energy comes from a nearby communication area or from an NFC-enabled antenna that can be placed on a hospital bed or in a patch that can be worn. (Sorry, the NFC’s touch-paying phone isn’t effective enough to break hearts.)

Having stable electrical contact is essential for any heart device, as it depends on each contraction that pumps blood. the heart cells emit rapid impulses. But a device must also be dynamic. When the wet heart fills and empties, its curved surface causes stress and tension. Both are challenged to do something that is stable and flexible “has been an open question for this area for a while,” Rogers says. “Bioelectronics is great, but then how do you maintain strong interfaces over time?”

The team overcame this problem with an adhesive hydrogel that only sticks mechanically to the heart. chemically. The hydrogel creates covalent bonds with the surface of the tissue. Loose molecular threads are chemically woven into the hydrogel and heart. Nitrogen atoms in one fuse with carbon atoms in the other and vice versa to form strong protein-like bonds. “It provides intimate and smooth mechanical electrical coupling,” says Rogers.

Each layer can begin to dissolve as soon as it is exposed, and it is important not to degrade it before the device is set. So the pacemaker is placed inside a polymer-soluble solvent that acts as a buffer against time — the hardware has two weeks to work while the shell dissolves. The rest then begins to break, but by then, the patient should not need a pacemaker. In cases where a long-lasting device is needed, the team can build a version with a thicker capsule.

The team tested the device with small-hearted animals (rats and mice), medium-sized animals (rabbits), and animals with almost human-sized hearts (dogs). In all cases, their device can control the rhythm of the animal’s heartbeat. (They also tested tissues isolated from human donors and found the same success.)

The Rogers and Arora teams also tested how pacemakers disappeared in rats. They showed that the devices had been intact for a week, most of which had been dismantled in three weeks and stopped working for four weeks. By 12 weeks, they were completely gone.

“Complying with that functionality, but also eliminating all things without being a by-product that can be dangerous or toxic. That’s a big challenge,” he says. Ellen Roche, An MIT biomedical engineer who develops cardiac devices, was not involved in the work. “Independently, any of them is doable,” Roche continues. “But doing both together, I think, is a great achievement.”

“It’s very easy to see simple materials; we already know their toxicity load, “says Chris Bettinger, a biomedical engineer at Carnegie Mellon.” I think simplicity is often underestimated. “

But an invasive device like a pacemaker will need much more testing to prove the safety and effectiveness of humans. Another challenge could be the superficial landscape of the heart, which would be much more damaged among heart patients than among laboratory animals. Raman, a cardiologist who is not a member of the Arora group, noted that some people who may need this type of device already have tissue scars caused by heart disease and blockages, which would make it difficult to form electrical connections. “But based on the design, it would be likely to work,” Raman says.