Motor Design And Vibration Analysis Of A Percutaneous Catheter Pump Using FPCB Winding

Percutaneous catheter pumps are interventional ventricular assist devices that can replace the hearts to pump blood and have been used in various high-risk PCI surgical treatments.The catheter pump motor is a key component for driving a catheter pump.This article uses flexible printed circuit board(FPCB)technology to design a permanent magnet slotless brushless DC motor for a percutaneous catheter pump.Based on theoretical calculations and finite element analysis,the optimization design of the motor’s winding structure and the permanent magnet eccentricity structure is achieved.A prototype is also made to conduct experimental research on electromagnetic performance and vibration noise to verify the feasibility of the FPCB catheter pump motor and the effectiveness of the optimization scheme.The main research contents are as follows.Firstly,based on the requirements of implantability,driving ability,and smoothness of the percutaneous catheter pump,this paper designs a FPCB percutaneous catheter pump motor with a diameter of 12 mm.The parameters of each part of the motor are determined through theoretical calculation,and the preliminary motor design is completed.Electromagnetic performance of the designed motor model are analyzed and compared with finite element simulation to determine the effectiveness of the 3D simulation model and theoretical calculation of the FPCB catheter pump motor.At the same time,based on the requirements of smoothness,combined with theoretical calculations,spatiotemporal analysis of the electromagnetic force of the motor is carried out to determine the main factors affecting the vibration and noise of the motor,which are used for subsequent optimization design.Secondly,the winding structure of the FPCB catheter pump motor is optimized.This article proposes a new arc-shaped winding structure,which analyzes the output performance of the motor by defining a performance evaluation parameter,and then determines the design parameters of the arc-shaped winding.Through theoretical calculation and finite element simulation analysis,the motors’ electromagnetic performance and vibration noise before and after optimization are compared.The results show that the electromagnetic performance of the motor using the arcshaped winding structure is significantly improved,the vibration noise is weakened to a certain extent,the smoothness of the motor operation is enhanced,and the overall performance of the motor is improved.Next,the permanent magnet structure of the FPCB catheter pump motor is also optimized.Due to the inability of single objective optimization based on eccentric magnetic poles to simultaneously weaken motor vibration noise and maintain motor output torque performance,this paper establishes a multi-objective optimization design scheme with permanent magnet size,magnetic pole eccentricity distance,and air gap length as optimization variables.By taking electromagnetic torque,torque ripple,and copper loss of the motor as the objectives to be optimized,sensitivity analysis and response surface method are combined to determine the optimal results.The optimized catheter pump motor effectively avoids torque performance loss,weakens motor vibration noise to a certain extent,and improves motor output performance.Finally,prototypes of the diamond-shaped winding structure motor and the optimized arcshaped winding structure motor are made to carry out,experimental research on the electromagnetic performance testing platform,the modal experimental platform,and the vibration noise testing platform developed by the author.The experimental results show that the counterelectromotive force waveform of the two prototypes has good sine degree,and the natural mode,vibration acceleration and sound pressure waveform are almost consistent with the simulation results,and the vibration acceleration and sound pressure values of the arc-shaped winding structure motor are weakened to a certain extent compared to the diamond-shaped winding structure motor,which verifies the rationality of the two prototype designs and the feasibility of the optimization scheme.