? The overall objective of the proposed SBIR effort is to design, manufacture, and evaluate a small non-thrombogenic rotary LVAD employing a novel biocompatible and non-wetting coating, MiTi's hybrid active.passive magnetic levitation system and a redundant hydrodynamic thrust bearing. All blood-contacting surfaces will be manufactured from Ti-6AI-4V alloy coated with an innovative fully hydrogenated diamond like carbon (DLC) coating. A top layer of heparinized organic film will be applied to the rotating DLC coated titanium alloy surfaces. The combination of hydrophobic DLC and hydrophilic organic coating provides an innovative means to reduce the shear stresses on bearing surfaces, thus reducing the potential for hemolysis and thrombosis.
The Specific Aims of the Phase I feasibility study are to (1) develop an interfacial film (TiC and/or TiN) on titanium alloy test coupons to enhance adhesion of DLC coating and evaluate coating adhesion using conventional indentation testing, (2) confirm hemocompatibility of DLC coated titanium alloy test coupons through assessment of platelet morphology and fibrin formation, and (3) complete the preliminary redesign the MiTiHeart LVAD for 40% volume reduction and incorporate the concept of hydrophobic bearing surfaces while maintaining the pump output. Upon successful completion of Phase I objectives, a new blood pump will be manufactured in phase II. The performance of the new pump will be evaluated in vitro and in vivo using a bovine calf model. The animal testing will be conducted at the Pennsylvania State University, Hershey Medical Center. Key technical innovations of the proposed integrated hybrid magnetic bearing centrifugal blood pump design that is mechanically simpler and smaller than existing pulsatile configurations include (1) a novel hydrophobic, hydrogenated DLC coating and a hydrophillic heparinized film, (2) permanent magnet radial bearings; (3) a hydrodynamic thrust bearing system for impact shock loads and emergency backup; (4) a single actively controlled magnetic thrust bearing; (5) a radial out-flow impeller; and 6) an efficient bushless dc micro-motor. The MiTiHeart LVAD will be designed for use as destination therapy for adult heart failure patients of small to medium frame that are not being served by present pulsatile devices. The final LVAD design information will be licensed to MiTiHeart Corporation, a subsidiary of MiTi, for further animal testing and initiation of the FDA approval process. ? ?
| Jahanmir, Said; Hunsberger, Andrew Z; Ren, Zhaohui et al. (2009) Design of a small centrifugal blood pump with magnetic bearings. Artif Organs 33:714-26 |
| Ren, Zhaohui; Jahanmir, Said; Heshmat, Hooshang et al. (2009) Design analysis and performance assessment of hybrid magnetic bearings for a rotary centrifugal blood pump. ASAIO J 55:340-7 |
