Heart-hugging robotic sleeve helps pump blood
A new device could significantly cut the risk of infection and stroke for heart patients. Amy Middleton reports.
We've heard about wearing your heart on your sleeve, but what about wearing a sleeve on your heart?
Patients with a failing heart could soon get help from such a device: a soft robot that gently squeezes the organ to restore normal blood flow, according to new research.
The new technology could revolutionise cardiac ventricular assist devices (VAD), significantly reducing the often-serious complications that arise from current implants used to treat heart conditions.
While existing devices have a high success rate, they are in constant contact with blood, bringing the risk of infection or stroke. Patients also need lifelong blood-thinning medication to prevent coagulation.
Now, a team led by Ellen Roche, a biomedical engineer at Harvard University, is developing a new VAD candidate: a soft, silicone-based robotic sleeve, which sits snugly around the heart like a glove.
It compresses and twists, mimicking cardiac function, but does not breach the heart walls, eliminating both the possibility of infection and the need for thinners.
In laboratory testing, the device successfully recovered blood flow in six pigs following a drug-induced cardiac arrest.
Described in Science Translational Medicine, the implant is inspired by our own organs: once in place, it mimics the flexibility and movements of the two outer muscle layers of the mammalian heart, using a mainline-compressed air supply.
When the five-centimetre-thick device isn’t activated, it sits passively and allows unrestricted heart function. Because failure is often intermittent and affects only part of the heart, a patient fitted with the sleeve could theoretically control when they received assistance, and where it is applied.
“Although external cardiac assist devices have been previously explored, many have imposed nonphysiological motions that have failed to mimic the natural motion of the heart,” the researchers explain.
But they add that more long-term animal testing is needed before human implantation can be considered.