title: Mechanism of Self-Regulation and In Vivo Performance of the Cleveland Clinic Continuous-Flow Total Artificial Heart.
abstract: Cleveland 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.
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: David
authors.initials: D
authors.lastname: Horvath
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Nicole
authors.initials: N
authors.lastname: Byram
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Jamshid H
authors.initials: JH
authors.lastname: Karimov
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Barry
authors.initials: B
authors.lastname: Kuban
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Gengo
authors.initials: G
authors.lastname: Sunagawa
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Leonard A R
authors.initials: LAR
authors.lastname: Golding
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.|Department of Thoracic and Cardiovascular Surgery, Kaufman Center for Heart Failure, Cardiac Transplantation and Mechanical Circulatory Support, Miller Family Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Moazami
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
mesh_terms: D000818:Animals; D001794:Blood Pressure; D002417:Cattle; D006354:Heart, Artificial; D006439:Hemodynamics; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D011673:Pulsatile Flow; D014655:Vascular Resistance
keywords: Blood pump; Hemodynamics; Mock loop; Pressure regulation