The Total Artificial Heart
Cardiovascular disease is one of the most common diseases worldwide. The gold standard for the treatment of end-stage heart failure is heart transplantation. In 2012, only one third of patients in Europe and two thirds of patients in the US on the waiting lists received a heart transplant (Eurotransplant/ OPTN). As the shortage of donor organs continues to grow, waiting lists become longer and many patients die due to the lack of available donor organs. For these patients, there are no real alternative treatments, as the total artificial hearts available today are only designated for bridge to transplant and not for destination therapy.
A fully implantable total artificial heart that functions without any connection through the skin would be a breakthrough therapy for many of those end-stage heart failure patients.
- Compliance System
- Transcutaneous Energy System
- Internal Controller & Buffer Battery
- External Controller
- External power supply
At the Institute of Applied Medical Engineering, initial research for the development of an artificial heart was started in the 1990s. Since 2009, a fully implantable heart with new and innovate features, called ReinHeart, has been under development. An interdisciplinary team of engineers, technicians and surgeons is working closely together to make this vision of a maintenance-free TAH that is small enough to be implanted in the majority of patients become reality.
The central element of the artificial heart system is the pumping unit which completely replaces the human heart. It includes an innovative, maintenance-free linear drive, which mimics the native heart function. The pumping chambers and the artificial valves imitate the function of the heart chambers. The drive unit is controlled by a separate implantable controller unit which contains an internal battery. A coil system attached to the controller unit allows energy transmission through the closed skin to charge the battery. The coil system consists of a receiver coil, which is implanted under the skin, and a transmitter coil, which is positioned on the skin outside of the body. The energy to power the system is provided by batteries that are worn externally.
There are strict durability requirements for an artificial system that operates continuously without the option for repairs after implantation. The durability of the crucial components of the ReinHeart has been proven in extensive laboratory tests. These results can be contributed to the unique drive design. Additionally, the size and fit of the system has been optimized in anatomical studies.
The ReinHeart provides two major advantages for the patient. First, the use of the coil system to charge the internal battery eliminates the risk of infection due to skin incisions. In addition, the internal battery and the light weight external components provide the patient with a high degree of mobility, which contributes significantly to the quality of life. The functionality of the system has been tested in acute and first chronic in-vivo experiments.
The current priority is to validate these results through prolonged chronic in-vivo experiments as well as extensive full system durability tests. Based on the in-vivo results, a flow control system and the design of the external components will be completed.
The TAH is beeing developed as a cooperation project together with the ReinHeart TAH GmbH and has been funded by the state of North-Rhine-Westfalia.
Figure 3: Animation of the function and implantation procedure of the Aachen TAH.
Link to full screen video: