Image Number 4 for United States Patent #4626248.
The replaceable cassette is integrally formed with a small primary container for fast response time when aspirating, and an integrally formed, larger secondary container into which the contents of the primary container are periodically flushed. During aspiration, the secondary container is sealed from the primary container and, therefore, has no adverse effect on aspiration response time. The primary container is located above the secondary container and the two containers are connected by a standpipe through which substances are flushed by the force of gravity in emptying the contents of the primary container into the secondary container. Although the cassette will operate with microsurgical consoles having two separate vacuum sources, only one vacuum source is required.