抄録
The integrity of the shaft seal is a critical factor in the success of an implantable rotary blood pump. A precision mechanical seal has been developed to address this requirement. The seal incorporates a recirculating cooling water system to provide lubrication and prevent deposition of blood elements. The objective of this study is to evaluate the sealing properties of this mechanical seal by a chronic animal experiment. The leakage rate of plasma into the cooling water through the mechanical seal was measured by monitoring the infiltration of sodium ions from bovine blood. The leakage rate of the cooling water into the blood through the mechanical seal was measured by monitoring the volume of the cooling water in the reservoir. The cooling water temperatures were monitored at 2 points to evaluate heat dissipation. Over a period of 153 days, the leakage rate of plasma was 0.022ml/day and the leakage rate of the cooling water was 0.497 ml/day. The heat dissipation by the cooling water was 10-14 W in the range of flow rate at 50-100 ml/min. In conclusion, the mechanical seal performed acceptably well to support its use in a rotary blood pump for chronic application.
