Multi-functional valve with unitary valving member and improved safety

A method of controlling an aspirating suction level communicating to a patient from an aspirator during a surgical procedure, said method comprising the steps of:

• providing a yieldable pressure-responsive valve member comprising an elongate cylindrical section of elastomeric material having an outer surface and an inner surface, said cylindrical section of elastomeric material defining a first area on said outer surface thereof communicating with ambient and an opposite second area on said inner surface thereof communicating with said aspirating suction;
• causing said yieldable pressure-responsive valve member to communicate ambient air to said aspirator at a certain level of aspiration suction;
• providing a check valve isolating both said patient and said second pressure-responsive area from reverse flow positive pressure and defining a third pressure-responsive area effective to yield said valve member at a determined level of reverse flow positive pressure to communicate said reverse flow positive pressure to ambient;
• and
• communicating an inlet positive pressure to said second pressure-responsive area to assist said pressure-responsive valve member in sealingly engaging said housing to prevent venting of said inlet positive pressure.

A multi-function control valve comprising:

• a housing defining an inlet, an outlet, and a flow path extending between said inlet and said outlet to communicate a flow of fluid therebetween;
• a multi-function valve member sealingly disposed in said flow path and including a check valve feature preventing fluid flow from said outlet to said inlet;
• said housing defining a vent port opening outwardly from said flow path downstream of the check valve feature;
• said multi-function valve member including a pressure-responsive yieldable member sealingly cooperating with the housing to prevent fluid flow through said vent passage, said yieldable member comprising a cylindrical section of elastomeric material extending along said flow path, said cylindrical section comprising an inner surface and an outer surface, said yieldable member further comprising a first pressure-responsive area on said outer surface of said cylindrical section communicating with ambient, and a second pressure-responsive area on said inner surface of said cylindrical section communicating with said inlet port and isolated from said outlet port by said check valve feature, said yieldable member yielding in response to a determined pressure level on said check valve feature to open said vent port;
• said pressure-responsive yieldable member on the one hand yielding in response to a certain level of negative pressure in said flow path to admit ambient air thereto via said vent port, and on the other hand said yieldable member yielding in response to said determined level of pressurized fluid communicating to said outlet port to vent pressurized fluid from said vent port;
• pressurized fluid communicating with said inlet port and being communicated with the outlet port via the check valve feature also acting on said second pressure-responsive area to maintain said yieldable member in sealing relation with said housing, whereby pressurized fluid communicating to said inlet port is not vented;
• and
• wherein said housing defines a radially inwardly extending circumferential rib which sealingly cooperates with said cylindrical section of elastomeric material.