摘要 |
The mixing apparatus and method of this invention combines centrifugation and vacuum mixing to provide a device for the centrifugation of cement under a partial vacuum for the reduction of porosity within bone cement. The results of centrifugation under a vacuum are an improvement over the results achieved in standard centrifugation or standard vacuum mixing techniques. The device includes a receptacle which is spun rapidly about an axis under a partial vacuum. Creating a partial vacuum within the receptacle causes the air bubbles trapped within the cement to grow in size. The centrifugation causes the larger air bubbles to migrate through the cement toward the axis of rotation. Centrifugation works especially well under a partial vacuum due to the increased size of the air bubbles, in that larger bubbles migrate easier and quicker than smaller bubbles. Under centrifugation, the smaller air bubbles are compressed to such a degree that they become insignificant within the cement.
|