Development of a Left Heart Assist Blood Pump

摘要

This report completes the development activity associated with the Model 12C parathoracic ventricular assist device (PVAD), a blood pump designed specifically for human use to be powered by an intracorporeal actuator. In the last year of the program, the device was brought to its final form, and fabrication methods were implemented to bring it to a state of ready manufacturability. The preferred configuration for the pump employs a blood interface consisting of diffusion bonded titanium microspheres on the rigid, investment cast pump housing, and integrally textured polyurethane for the pump diaphragm. The entire textured surface blood interface of the device is thus fabricated without adhesives. In vivo testing of complete blood pump and electric motor systems were carried out to 4-month mean duration (n = 2), and the calcification that had been seen in the early pump studies was shown to be related to excessive mechanical strain which resulted from overdriving the diaphragm. Finally, textured membrane compliance chamber systems were used in vivo with good results thus far to 6-month duration (n = 3), suggesting that this approach can provide a variable volume compensation method for pulsatile blood pump systems. The goals of the Model 12C development effort have thus been substantially met.