Visualisation of the blood flow in the artificial heart. Credit: CMIV
Researchers designing a prototype artificial heart have visualised the real-time blood flow dynamics happening inside it to minimise the risk of common complications such as blood clots and red blood cell damage.
The number of patients with end stage heart failure who require a heart transplant to live has been increasing globally, but only about 10,000 surgeries are performed worldwide each year.
Total artificial hearts (TAHs) are devices designed to completely replace the function of a failing heart.
But according to Twan Bakker, a PhD student at the Center for Medical Image Science and Visualization at Linköping University (LiU), Sweden, finding a biologically compatible heart for a transplant can take a long time.
“In those cases, an artificial heart can enable the patient to wait at home. They may not be running around like Usain Bolt, but patients can be with their loved ones during the waiting period.”
Bakker is co-lead author of a new study which has used 4D flow magnetic resonance imaging (MRI) to visualise blood flow inside a prototype TAH.
Study co-authors Tino Ebbers and Twan Bakker with the full-scale model of the human circulatory system they built to observe blood flow in the artificial heart in real time in the MRI. Credit: Emma Busk Winquist
High speed and turbulence can lead to the destruction of red blood cells, while low speeds increase the risk of blood clots forming and causing stroke.
The Researchers at LiU, in collaboration with the company Scandinavian Real Heart, connected the Realheart artificial heart to a mock circulatory loop which mimicked heart rates of 80, 105 and 120 beats per minute.
“Using this approach, both recirculation regions and turbulent flow patterns were discovered and could be measured, improving the understanding of the flow dynamics in the mechanical heart, and providing invaluable information for the iterative design process,” the authors write in the paper published in Scientific Reports.
“Stasis and viscous energy loss in the artificial heart were found to be similar to healthy native hearts. Elevated turbulent kinetic energy was found in several areas, but values were well below those found in patients with valvular disease.”
Pre-clinical and clinical studies are needed before the device can be greenlit for clinical use. Ultimately, Bakker says the dream is to develop an artificial heart as a permanent solution.
“We’re not there yet, as we’re required to first show that it functions as a bridge to transplantation so as to prevent the patient from dying while waiting for a heart. But our ultimate goal is fantastic, and when we reach it, there will be no need for donor hearts.”