Bearingless flux reversal motor for neonatal and pediatric extracorporeal life support applications

The clinical need for cardiac and cardiopulmonary support devices in the neonatal and pediatric populations is
well documented. Clinically available circulatory support devices include both pulsatile ventricular assist
devices (e.g., Berlin Heart Excor) and rotary blood pumps (e.g., Geringe Rotoflow). Bearingless (magnetically
levitated) rotary blood pump configurations have been developed to extend device life by eliminating
problematic wear and heat generation associated with blood seals and rotating mechanical bearings. The
consequences of blood seal and bearing wear contribute to hemolysis and thrombosis as well as to other
failure modes. The sole clinically available bearingless pediatric blood pump is the Abbott PediMag. As with
many neonatal and pediatric medical products, the PediMag is a scaled-down version of an adult blood pump
that was originally designed for post-cardiotomy support (Abbott CentriMag). While PediMag has been used
clinically for several years, broader application is encumbered by several factors including lack of ancillary
componentry designed specifically for the pump system (e.g., pediatric blood oxygenator), complex control
algorithms, complex manufacturing, and high disposable cost (approximately $8000 per disposable PediMag
pump head).
To address these shortcomings, Ension has developed a multifunctional, advanced compact ECLS (ACE)
system incorporating an innovative bearingless (magnetically levitation) flux reversal motor (FRM). This
bearingless motor topology has not been previously described in the literature and is patent pending. The
FRM motor is the foundation of Ension’s bearingless pediatric cardiopulmonary assist system (pCAS). pCAS
is comprised of a single-use pump (depending on the desired therapy, an oxygenator or integrated pump-
oxygenator may be added) and a system controller. The system controller is a microprocessor-controller
device designed to operate on either AC or on internal rechargeable batteries and includes a touchscreen-
based control console and a reusable motor stator. The disposable bearingless pump or pump-oxygenator
attaches to the reusable stator which supplies power and control signals. After appropriately sized cannula are
placed in the patient’s vessels, the pCAS system pumps and, depending on the therapy, also adds oxygen
and/or removes carbon oxide from the blood before returning it to the patient. pCAS operates continuously
after the user enters parameters via the control console’s touchscreen-based interface such as pump speed,
appropriate alarm settings, and data storage parameters.
This Direct to Phase II SBIR application represents the final phase of development of the bearingless pCAS
system. The goal of this work is to extend the operating range of the bearingless FRM motor to accommodate
the high pressure and low flow requirements in neonates and infants weighing between 5kg and 15 kg.

Grant Number: 1R44HL178134-01
NIH Institute/Center: NIH
Principal Investigator: Patrick Cahalan