Disposable Magnetically Levitated Centrifugal Blood Pump: Design and In Vitro Performance

Abstract

A magnetically levitated (MagLev) centrifugal blood pump (CBP) with a disposable pump head has been designed to realize a safe, easy-to-handle, reliable, and low-cost extracorporeal blood pump system. It consisted of a radial magnetic-coupled driver with a magnetic bearing having a two-degree freedom control and a disposable pump head unit with a priming volume of 24 mL. The easy on-off disposable pump head unit was made into a three-piece system consisting of the top and bottom housings, and the impeller-rotor assembly. The size and weight of the disposable pump unit were 75 mm x 45 mm and 100 g, respectively. Because the structure of the pump head unit is easily attachable and removable, the gap between the electromagnets of the stator and the target material in the rotor increased to 1.8 mm in comparison to the original integrated bearing system of 1.0 mm. The pump performance, power requirements, and controllability of the magnetic bearing revealed that from 1400 to 2400 rpm, the pump performance remained fairly unchanged. The amplitudes of the X- and Y-axis rotor oscillation increased to +/- 24 microm. The axial displacement of the rotor, 0.4 mm, toward the top housing was also observed at the pump rpm between 1400 and 2400. The axial and rotational stiffness of the bearing were 15.9 N/mm and 4.4 Nm/rad, respectively. The MagLev power was within 0.7 Watts. This study demonstrated the feasibility of a disposable, magnetically suspended CBP as the safe, reliable, easy-to-handle, low-cost extracorporeal circulation support device.

Development of a Disposable Maglev Centrifugal Blood Pump Intended for One‐Month Support in Bridge‐to‐Bridge Applications: In Vitro and Initial In Vivo Evaluation

“…The MedTech Dispo system and its theory of operation have been detailed in previous papers (12)(13)(14)(15)(16)(17)(18). The system consists of (i) a disposable pump head unit; (ii) a reusable maglev and motor drive unit; and (iii) a maglev control/drive console (Fig.…”

“…We have developed a preprototype maglev DCRBP named MedTech Dispo intended for 1-month support, and have reported its sufficient hydrodynamic performance and low hemolytic characteristics (12)(13)(14)(15)(16)(17). On the basis of these results, a prototype MedTech Dispo with improved hydrodynamic performance has been designed for the conduct of initial 2-week animal testing prior to 1-month in vivo studies.…”

Third‐generation Blood Pumps With Mechanical Noncontact Magnetic Bearings

“…The nominal design flow of 5 L/min at 100 mm Hg pressure rise was successfully achieved at the design speed of 3000 rpm. Power consumptions of the maglev system and motor were < 0.5 and 6 W. The hemolysis rate was NIH < 0.01 g/100 L. TMDU/TIT external motor system with radial levitation (54)(55)(56)(57)(58) In this maglev system, the impeller is suspended with two pairs of electromagnets in two DOF controlling in x -and y -directions. Strong magnetic bias flux was also produced between the rotor and the magnetized steel in the outer pump housing to passively control the movement of the impeller in the zaxis and rotational axes.…”

Gyro-effect Stabilizes Unstable Permanent Maglev Centrifugal Pump

“…The first applicable maglev centrifugal pump was developed by Akamatzu et al, using a hybrid or combined bearing system of electro-magnetic bearing (EMB) and permanent magnetic bearing (PMB) [2]. This principle has been applied in many other maglev pumps by now [3][4][5][6].…”