THIS NEW ROBOT WILL HELP KEEP HEARTS PUMPING
YOU DON’T WANT to be among the first human cyborgs. Because doctors won’t be replacing all your limbs with super-strong robotic ones, and they won’t be giving you cameras for eyes. More than likely, they’ll be saving your life by wrapping your heart in a robot.
Today in the journal Science Robotics, researchers introduced a new kind of device to keep a heart pumping: It cradles the organ and uses a probe to anchor to the wall that separates the heart’s lower chambers. The robot can precisely manipulate a particular chamber, and that could lead to devices that let doctors assist a heart in its normal function instead of relying on a transplant. (Another sort of robotic heart announced earlier this year envelops the organ like a sleeve, but this new robot can work on a single diseased chamber.)
These days, doctors keep a heart pumping blood with something called a ventricular assist device. This is a pump external to the body that helps ferry blood around when the heart just can’t manage on its own. Problem is, because blood is flowing through machinery, the patient has to take blood thinners to make sure the works don’t get gummed up. And doctors don’t like putting people on blood thinners if they can avoid it.
This new robot is incorporated right into the heart, and acts to encourage the organ’s normal function. The bit that rests on the heart is a soft robot made of polymers, meaning it’s, well, soft, so it better conforms to the organ and doesn’t irritate the flesh. But it’s also soft in its operation: Instead of using traditional motors that are complicated and bulky, it’s pneumatically activated, which is a gentler way to manipulate the heart.
The second bit of the robot is a rod that actually enters the heart and anchors to the wall that separates one ventricle from the other, known as a septum. A needle pierces the septum and a delivery shaft opens up an anchor on the other side of the wall like an umbrella. Then an operator places a disk on the other side to complete the anchor.
So in addition to the soft robot on the outside pumping the free wall of the ventricle, the shaft pulls the septum toward the wall, squeezing the ventricle to get blood flowing. Without pulling on the septum, the device wouldn’t really be replicating the beating of a heart. “The septum is very actively engaged in the ventricular contraction,” says study coauthor Nikolay Vasilyev, a scientist in the Department of Cardiac Surgery at Boston Children's Hospital. “When the heart contracts, it's not only the free walls that move. The septum thickens during the contraction and moves inward into the respective ventricle.”
By manipulating both the outside of the organ with a soft robot and tugging on the septum with a rod, this device helps the heart pump blood much more precisely than other devices: The system reads either the electrical signals from the heart or pressure changes within the ventricle to time its movements in concert with the normal operation of the organ.
The researchers have already shown the robot working in a live pig. The next step could be to actually implant the thing in an animal and stitch it up, then watch the robot work over the course of months.
“In terms of technological development, I believe we are almost at the stage where a large company or a pool of investors take this technology to the next level and make a product out of it,” says University of Leeds roboticist Pietro Valdastri, who was not involved in the study. “I frankly hope this is going to happen, as this technology looks pretty ready to me for this type of jump.”
Robots have already stolen our hearts. Now they're keeping them beating, too.