Mechanism of Self‐Regulation and In Vivo Performance of the Cleveland Clinic Continuous‐Flow Total Artificial Heart

• DOI: 10.1111/aor.12780
• Publication Date: 2016-07-12T10:36:38Z
• Authors: David Horvath; Nicole Byram; Jamshid H. Karimov; Barry Kuban; Gengo Sunagawa; Leonard A.R. Golding; Nader Moazami; Kiyotaka Fukamachi
• Keywords: Prosthesis Implantation; 03 medical and health sciences; 0302 clinical medicine; Pulsatile Flow; 0206 medical engineering; Hemodynamics; Animals; Blood Pressure; Cattle; Vascular Resistance; 02 engineering and technology; Heart, Artificial; Prosthesis Design

AbstractCleveland Clinic's continuous‐flow total artificial heart (CFTAH) provides systemic and pulmonary circulations using one assembly (one motor, two impellers). The right pump hydraulic output to the pulmonary circulation is self‐regulated by the rotating assembly's passive axial movement in response to atrial differential pressure to balance itself to the left pump output. This combination of features integrates a biocompatible, pressure‐balancing regulator with a double‐ended pump. The CFTAH requires no flow or pressure sensors. The only control parameter is pump speed, modulated at programmable rates (60–120 beats/min) and amplitudes (0 to ±25%) to provide flow pulses. In bench studies, passive self‐regulation (range: −5 mm Hg ≤ [left atrial pressure – right atrial pressure] ≤ 10 mm Hg) was demonstrated over a systemic/vascular resistance ratio range of 2.0–20 and a flow range of 3–9 L/min. Performance of the most recent pump configuration was demonstrated in chronic studies, including three consecutive long‐term experiments (30, 90, and 90 days). These experiments were performed at a constant postoperative mean speed with a ±15% speed modulation, demonstrating a totally self‐regulating mode of operation, from 3 days after implant to explant, despite a weight gain of up to 40%. The mechanism of self‐regulation functioned properly, continuously throughout the chronic in vivo experiments, demonstrating the performance goals.