MODE COMPARISON STUDY FOR A COMPLETELY IMPLANTABLE TAH (CITAH) SYSTEM.

The long-range objective of the work reported has been the development of a control algorithm to meet the following requirements: 1) simple and reliable; 2) smallest physical package to meet anatomic constraints; and 3) adequate responses to all possible hemodynamic demands. If the alternate beating mode could maintain the recipient for extended periods and also have meaningful flow responses to demand, the overall volume and complexity of a CITAH would be reduced significantly. Some comparison studies with PP TAH systems have been published, a few aspects still remained to be investigated: 1) long-term effects of the alternate beating mode; 2) how to protect the lung circulation against any possible sudden hemodynamic changes, and 3) the possible requirements for built-in stroke volume differences between two ventricles. This study was designed and performed to answer these questions.