# A Review of Innovative Electromagnetic Technologies for a Totally Artificial Heart
## 7 Conclusions  
In the paper, different electromagnetic technologies considered for application in a ventricle-assisted device or a totally artificial heart (TAH) are presented. The review examined the innovative solutions utilized in the most promising projects focused on the development of the total system, as well as those proposed and checked in the literature as single components. Among all the devices, the transcutaneous energy transmission (TET) system and the electromagnetic actuator are distinguished in terms of performance and durability. In view of the possible application of new high-performance materials (e.g., high-energy PMs, low core loss, high permeable magnetic materials, and Litz wire windings), very high achievable efficiency and power density are achievable, enabling compact configurations with limited losses and positively affecting both battery life and heat generation.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**TAH Type** & **Actuator** & **Maturity** & **Compactness** & **Manufacturing** & **Control** & **Overall** \\  & & & & **Simplicity** & **Simplicity** & **Efficiency** \\ \hline FD & brushless motor & High & Low & Medium & High & Medium \\ EM & brushless motor & High & Low & Medium & High & Medium \\ CF & brushless motor & Medium & Medium & Medium & Low & High \\ EM & VR-LOA & Low & Low & High & High & Low \\ EM & MC-LOA & Medium & High & Medium & Medium & High \\ EM & MM-LOA & Medium & High & High & High & High \\ EM & PM VR-LOA & Low & Low & Low & Medium & Medium \\ EM & CPT & Low & High & Medium & Low & High \\ EM & MC-LiRA & Medium & High & Low & Medium & High \\ EM & Conventional LiRA & Low & Medium & Low & Low & High \\ \hline \hline \end{tabular}
\end{table}
Table 2: Overall comparison of the main actuators for TAH applications.  
As for the TET, despite the inherent significant air-gap due to the biological tissue thickness, the high-frequency operation enables efficiency up to 90%. For the actuator, two solutions seem very convenient and effective. The first one, adopted in the BiVACOR project, relies on an axial flux PM motor that interacts with an axial magnetic bearing, integrating both the pumping and the pulsatile effects in a rotating motor. The other one is based on a linear oscillating actuator (LOA), acting on both artificial ventricles realized in biocompatible materials. Among the various families of PM-LOAs that can effectively mimic the heart operation, the seemingly most advanced one is applied in the ReinHeart project, but other configurations exhibit favorable features (dual-mover, linear-rotating motion, and bearingless arrangement) and are potential candidates for a future commercial TAH.  
Formal analysis, M.A.; investigation, E.F. and A.T.; data curation, E.F.; writing--original draft preparation, E.F.; writing--review and editing, M.A. and A.T.; supervision, M.A. and A.T.; funding acquisition, A.T. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Department of Industrial Engineering-University of Padova, under the project entitled \"Reliable and minimally invasive electrodynamic actuator for longer lasting artificial heart\" ID TORT_BIRD2121_01.  
The authors declare no conflict of interest.