Next Generation Development of Hybrid Continuous Flow Pediatric Total Artificial Heart Technology: Design–Build–Test

Abstract

To address the unmet clinical need for pediatric circulatory support, we are developing an operationally versatile, hybrid, continuous-flow, total artificial heart (“Dragon Heart”). This device integrates a magnetically levitated axial and centrifugal blood pump. Here, we utilized a validated axial flow pump, and we focused on the development of the centrifugal pump. A motor was integrated to drive the centrifugal pump, achieving 50% size reduction. The motor design was simulated by finite element analysis, and pump design improvement was attained by computational fluid dynamics. A prototype centrifugal pump was constructed from biocompatible 3D printed parts for the housing and machined metal parts for the drive system. Centrifugal prototype testing was conducted using water and then bovine blood. The fully combined device (i.e., axial pump nested inside of the centrifugal pump) was tested to ensure proper operation. We demonstrated the hydraulic performance of the two pumps operating in tandem, and we found that the centrifugal blood pump performance was not adversely impacted by the simultaneous operation of the axial blood pump. The current iteration of this design achieved a range of operation overlapping our target range. Future design iterations will further reduce size and incorporate complete and active magnetic levitation.

Practical Comparison of Two- and Three-Phase Bearingless Permanent Magnet Slice Motors for Blood Pumps

“…Across various industries, from chemical to biomedical, BPMSM pumps have gained prominence. In the biomedical sector, the BPMSM has found success in medical applications including mechanical circulatory support devices and rotary blood pumps [1][2][3][4][5][6][7].…”

“…These pumps generally operate in parallel with the beating diseased ventricle to provide adequate blood flow to the body. The design evolution of these medical devices has concentrated on the bearing support and motor drive systems [2][3][4][5][6][7]. First-generation blood pumps consist of pulsatile devices with pusher-plate or flexing diaphragms and valve configurations.…”

“…Second-generation devices comprise continuous-flow or rotary pumps that require mechanical bearings and seals that are in contact with the fluid; and the latest generation of blood pumps, third-generation blood pumps, include axial and radial rotary pumps with no mechanical bearings in contact with the fluid medium, usually integrating magnetic or non-contacting hydrodynamic bearings [13,16]. Figure 1 illustrates a unique blood pump technology that integrates both an axial and a centrifugal pump into one medical device [3]. Notably, the two blood pumps most frequently used clinically, CentrigMag (Abbott, Abbott Park, IL, USA) and HeartMate III (Abbott, Abbott Park, IL, USA), share a twophase configuration [17,18].…”