Abstract:
Method and apparatus for storing and dispensing articles, one at a time, from the bottom of a stack of like articles. The articles are yieldably supported in at least one upright stack above an outlet, e.g., a resilient choke, sized to pass the articles if forced therethrough. Articles are dispensed by pressing downwardly on the stack with sufficient force and for sufficient duration to overcome the yieldable supporting force and move the lowest article through the outlet. Sensors may be provided for sensing when an article is dispensed, when the tube is empty, and the type of article in the holder. The method and apparatus are especially useful in a vial-based automated system for processing multiple specimens of biological fluid, wherein a filter assembly must be dispensed into a filtration chamber associated with each specimen vial.
Abstract:
A method and apparatus for collecting a cell sample of desired concentration on a filter collection site from a biological liquid specimen in a container. Specimen liquid is moved through a filter while the volume rate of liquid flow through the filter is monitored. The monitored liquid flow rate is compared to a reference value, and liquid flow through the filter is terminated when the ratio value. The predetermined ratio value preferably is a function of the protocol for processing the specimen. An alternative method and apparatus relies on the rate of change of the measured weight of the container. This rate is compared to a reference value, and liquid flow through the filter is terminated when the rate of change diminishes to or below a predetermined value.