Patent attributes
A valve assembly is disclosed which partitions a conventional syringe into proximal and distal chambers to provide a multi-chamber, sequentially dispensing syringe apparatus. Incorporated in the valve assembly is a valved stopper having a valve (e.g. a slit valve) and a separator which filters out gas from liquid being dispensed through the valve assembly. A syringe plunger communicates through fluid in the proximal chamber to force displacement of the valve assembly. The valve is actuated by differential pressure of a force greater than the valve assembly displacement force. The valve assembly may be made from two parts: (1) a valved stopper (may be molded from basic syringe plunger material); (2) a separator (may be injection molded from syringe barrel material). Key features of such a multi-chamber syringe apparatus are (1) fluids in the chambers are kept disparate; (2) the valve assembly may be used in conventional syringes; (3) gas in a closed chamber is filtered from delivered liquid; (4) bi-stable operation of a valve assembly valve permits reflux free operation; (5) a clinch in the separator holds the valve securely closed until the valve is opened by a predetermined action, such action being tactilely sensible. A tubing set is disclosed which may be added to provide a third disparate chamber.
