An estimated 5.7 million Americans suffer from heart failure, or an inability to pump a sufficient amount of blood throughout the body. Many submit to drug therapy, with resulting side effects; a small percentage receive heart transplants, though there aren't nearly enough hearts to cover the demand for a healthier organ.

Now, researchers at Harvard, Cambridge, and other leading universities may have found an alternative solution: an implantable “soft” robot made of elastic material that can fit over the heart like a sleeve and assist it in pumping.   

According to a study published today in Science Translational Medicine [PDF], the robotic sleeve seeks to supplement—not replace—the heart’s natural motions. Silicone materials mimic cardiac tissue and conform to the heart’s surface anatomy; using compressed air delivered by a tethered line, the sleeve can twist itself, compress, or decompress to aid the organ in maintaining normal rhythms.

In the image below, you can see how the muscle fiber orientations of the outer layers of the heart (A) are mimicked by the device's design (B).

Roche et al. in Science Translational Medicine

In order to test the sleeve, the researchers implanted it in six sedated pigs who were put under general anesthesia and experienced drug-induced cardiac arrest. The result was an 88 percent restoration of cardiac output.

The device is also customizable to the individual, they write: "Our device could potentially be turned off when no longer required, and clinicians could tailor the device as a passive restraint device, partial support, or full support."

The study’s authors acknowledge that this is an early and limited trial, and more information is needed on how the sleeve will perform over long periods of time. But if they’re successful, the implantable sleeve could eliminate potential complications from drug therapies, serve as a bridge treatment for patients awaiting transplants, and help usher in a new era of “soft” robotics that could support other physical functions.