Researchers Printed Artificial Heart on 3D Printer

Henrietta Brewer
July 15, 2017

Blood pumps are now used as a substitute or as a stopgap while a patient waits for a donor heart or to recover from the heart problem.

Tests show the heart can last around 3,000 beats or 30 to 45 minutes of operation, after which the material starts to collapse under the strain. According to the Swiss group, the silicone structure is "the first entirely soft artificial heart". Sometimes, however, the mechanical parts of the pump can cause unwanted complications that can ruin the operation, threatening the life of the patient.

Each year, about 26 million people worldwide suffer a heart failure and donors barely cover a fraction of the demand. The silicone heart has been developed by Nicholas Cohrs, a doctoral student in the group led by Wendelin Stark, Professor of Functional Materials Engineering at ETH Zurich.

One problem with artificial hearts is that metal and plastic mechanisms can be hard to integrate with tissue, or damage the blood due to their unnatural movement style. Just like the real thing, it has a right and left ventricle, which is separated by a chamber that serves as the organ's muscle. Instead, an additional chamber is used, which is inflated and deflated by pressurized air. However, it still has one problem: it now lasts for about only 3,000 beats, which corresponds to a lifetime of half to three quarters of an hour. "It is a silicone monoblock with complex inner structure", explains Cohrs.

The researchers were able to evaluate the performance of the heart in a testing environment that simulates human cardiovascular systems. "Our goal was not to present a heart ready for implantation, but to think about a new direction for the development of artificial hearts", said Cohrs.

In tests the heart worked quite well, pushing a blood-like fluid along against body-like pressures. Using a fluid with the same viscosity of blood, the researches pumped the liquid through the artificial heart's blood chambers. Moving forward, the team will work to increase tensile strengths of the material, and improve its overall performance.

The researchers' work is published this week in the journal Artificial Organs (naturally).

"As a mechanical engineer, I would never have thought that I would ever hold a soft heart in my hands", said Anastasios Petrou, a doctoral student on the project.

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