When a patient is waiting for a donor's heart, surgeons usually implant a pump to keep the organ stable and functional. However, these ventricular assist devices are powered by hefty wires far stiffer than human skin.
Unfortunately, about half of the wearers are diagnosed with an infection caused by these thick cables. The rigid nature of these cables can result in open wounds that don't heal, leading to severe complications and compromising patients' overall well-being. Infections at the exit point of the electrical cable further exacerbate the issue.
Now, researchers from ETH Zurich have come up with a novel solution to prevent infection risks in heart pump users and improve patients' quality of life.
They have developed "a flexible cable solution with craters on the surface."
"The thick cable used in existing ventricular assist systems creates an open wound that doesn't heal and severely compromises patients' quality of life," said Andreas Kourouklis, ETH Zurich researcher and engineer.
As per the press release, this development is particularly advantageous because there are presently no wireless means for sending power to implanted heart devices.
The creation of a flexible, thin cable system
For this invention, the team used numerous thin and flexible wires with rough and uneven surfaces. "More flexible wires whose surface is full of microscopic craters help the skin heal," said Kourouklis.
The presence of craters on the wires allows for better adhesion to the skin's outermost layers. This inhibits inward growth, enabling new tissue to form more rapidly. As a result, the skin is more likely to remain intact and function as a strong barrier against bacterial infections.
The craters on the wires' surfaces were generated using a unique technology presently patented at ETH Zurich.
This method involves applying a thin silicone layer to the flexible cables and cooling them to minus 20 degrees Celsius (68 degrees Fahrenheit). This cooling renders the surface of the cables pliable.
They are then placed in a condensation chamber, where small water droplets are forced into the liquid silicone layer, resulting in miniscule craters.
"We can control the position of the craters on the cables by adjusting the humidity and temperature in the condensation chamber," Kourouklis added.
The novel cable system for heart pumps eliminates the risk of infections.
Testing of newly designed wire
As per the press release, the initial tests involved conducting experiments on skin cell cultures. After this, both the traditional thick cables and the new cable system were implanted in a sheep for further evaluation.
"The results make the ETH Zurich researcher optimistic," noted the press release.
The findings indicated that the recently crafted cables exhibited only minor inflammatory responses compared to their thicker ones. Additionally, none of the sheep experienced lasting injuries throughout the tests.
By tackling the long-standing issue of infections associated with standard ventricular assist devices, this discovery improves patient outcomes and paves the way for future advancements in implanted medical devices.
Originally published on Interesting Engineering : Original article