Magnetic Bearings for Mechanical Cardiac Assist Devices
5 Performance Considerations of Magnetic Bearings in VADs
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- Ris (Zotero)
- Reference Manager
In the US, device failure still accounts for approximately 8% of re-admittance of patients being treated for left-ventricular dysfunction using VADs. Though magnetic bearings offer a viable solution to extend design life of pumps and to reduce shear stress and heat generation associated with mechanical bearings, they do introduce an additional suite of complications. In many aspects, such as evaluating the theoretical reduction of thromboembolic potential when using wide-gap magnetic bearing configurations, the facts are obscured by challenges associated with assessing the true performance of devices in controlled environments, such as numerical simulations, bench-top experiments, or animal testing. Further, data from human trials in a large enough sample size requires years to obtain, and is seldom equivalent to a controlled environment. Nevertheless, pumps using magnetic suspension have to perform comparably to existing mechanical bearing devices in the short-term for them to be preferred by physicians and patients. The basic considerations necessary to achieve comparative performance, some of them unique to magnetic bearings, include size, battery life, ease and reliability of connectors, and the cable stiffness and diameter, some of which are discussed in this chapter.