Automatic Balance Regulation in a Pediatric Total Artificial Heart

Unbalanced pressures and volumes between the right and left atrium will cause systemic and/or pulmonary congestion. The continuous-flow (CF) total artificial hearts (TAHs) developed at the Cleveland Clinic mitigate pressure imbalance by titrating right pump output via pressure-related changes in rotor axial position. Hall effect sensors were placed and calibrated at both ends of the pediatric CF TAH (P-CFTAH) stator bore to track the rotor's permanent magnet location. The P-CFTAH was placed on a mock loop in water/glycerin, where several hemodynamic conditions, both pulsatile flow (PF) and CF, were tested while recording both left and right atrial pressures (LAP and RAP), outlet pressures (aortic pressure [AoP] and pulmonary artery pressure [PAP]), flows, and Hall effect sensor output. There was a positive correlation of ≥0.80 (p < 0.0001) between rotor position and flow, and a negative correlation of ≥-0.80 (p < 0.0001) between rotor position and atrial balance, systemic vascular resistance (SVR), and LAP. The rotor's maximum movement per cycle during pulsatile testing was 1.32 mm, and the minimum was 0.51 mm, indicating a significant positive correlation (≥0.80; p < 0.0001) with pulse pressure and flow pulse. The passive balancing features of P-CFTAH are effective across a range of steady-state conditions.