Electrical Energy Converters for Practical Human Total Artificial Hearts‐An Opinion in Support of Electropneumatic Systems

Summary: Until recently, most artificial hearts have served as research tools to acquire further knowledge necessary ultimately to design practical systems for human use. Transcutaneous systems or percutaneous systems utilizing permanently implanted energy converters, batteries, and electronics packages have a number of substantial problems that would not exist if most system elements were kept outside the body. These problems include physiologic control, fit and fixation, foreign body infection, hermetic sealing, cable insulation and fatigue, inherent system complexity, stringent requirements for maintenance‐free operation with long‐term high reliability, and high cost. Percutaneous systems, particularly those in which only the blood pump is implanted, are an attractive choice for practical systems in the near future. A wearable, battery‐powered electropneumatic total heart system should be developed. A practical artificial heart is one that patients can live with. Tether‐free, electrically powered devices certainly have the potential to provide an acceptable quality of life. Energy converter design must be part of an integrated systems approach that someday makes the crucial decision to utilize either the transcutaneous or percutaneous approach. There are many difficult technical problems with transcutaneous systems that can be avoided with percutaneous leads. Furthermore, the percutaneous approach leaves external components accessible for maintenance and replacement without surgery. In my opinion, percutaneous portable electropneumatic systems have the best potential for practical application to large numbers of human patients within the foreseeable future. They are particularly suited to orthotopic total artificial hearts using free diaphragm or tethered‐sac designs. Their development should be emphasized at this time.