The Impact of Pulsatile Flow on Suspension Force for Hydrodynamically Levitated Blood Pump

Abstract

Hydrodynamically levitated rotary blood pumps (RBPs) with noncontact bearing are effective to enhance the blood compatibility. The spiral groove bearing (SGB) is one of the key components which offer the suspension force to the RBP. Current studies focus on the suspension performance of the SGB under continuous flow condition. However, the RBP shows pulsatile characteristics in the actual clinical application, which may affect the suspension performance of the SGB. In this paper, the impact of pulsatile flow upon the suspension force from the SGB is studied. A model of the SGB with a groove formed of wedge-shaped spirals is built. Then, the CFD calculation of the hydrodynamic force offered by designed SGB under simulated pulsatile flow is introduced to obtain the pulsatile performance of the suspension force. The proposed method was validated by experiments measuring the hydrodynamic force with different bearing gaps. The results show that the suspension force of the SGB under pulsate flow is the same as under steady flow with equivalent effective pressure. This paper provides a method for suspension performance test of the SGB.

Hydrodynamic Bearing Structural Design of Blood Pump Based on Axial Passive Suspension Stability Analysis of Magnetic–Hydrodynamic Hybrid Suspension System

“…Hydraulic bearings can be categorized into hydrostatic bearings and hydrodynamic bearings. The hydraulic suspension structure design and suspension stability analysis has been extensive studied [13,14]. For example, Wang et al [15] designed a hydraulic bearing for the radial suspension support of an axial flow blood pump; established a theoretical model for the hydraulic bearing force; studied the influence law of the rotating speed and radial eccentricity on the bearing force through numerical simulation, and measured the magnetic-hydrodynamic, double-levitated impeller stability under different external circulation experiments via the Hall sensor and laser vibration meter.…”

Total Artificial Heart Computational Fluid Dynamics: Modeling of Stator Bore Design Effects on Journal-Bearing Performance

“…Such hydrodynamically suspended rotary blood pumps with noncontact bearings are particularly effective at enhancing blood compatibility. 7,8…”

“…Such hydrodynamically suspended rotary blood pumps with noncontact bearings are particularly effective at enhancing blood compatibility. 7,8 Cleveland Clinic's CF total artificial heart (CFTAH) is a double-ended centrifugal blood pump and is composed of a single rotating assembly. The right impeller sends the blood coming from the body through the right atrium to the lungs.…”

“…6 The modern, CF MCS-based therapy is realized as an implantation of a blood pump with a rotor bearing necessary to ensure its reliability during extended operation. 7 Due to their simple structure and low power consumption, blood pumps with hydrodynamic bearings are making their way into clinical applications. Such hydrodynamically suspended rotary blood pumps with noncontact bearings are particularly effective at enhancing blood compatibility.…”