Abbott Laboratories Corporation

Mike W Lawless

John D Gjata

Thomas A Kramer

Stephen J Kreinick

Scott M Defenbaugh

Robert Brose

Alex P Soberon

David Johnston

A disposable cassette for use with a medical infusion pump. An elastomeric membrane is captured between a facing member and a base of the cassette and is displaced into a pumping chamber. The elastomeric membrane includes a generally T-shaped lip, and corresponding grooves are provided on the facing member and base. As the cassette is assembled, an interference fit between the lip and the grooves causes the membrane to stretch taut and to be securely anchored, eliminating a break-in period when the cassette is initially used. &ldquo;Lobes&rdquo; of increased thickness provided on the undersurface of a portion of the elastomeric membrane overlying the pumping chamber reduce the residual volume of the pumping chamber, thereby reducing the volume of air retained within the chamber and increasing the accuracy of the cassette. The lobes also sweep air bubbles from the sides of the pumping chamber during operation, further reducing air bubbles retained in the pumping chamber. A distal tube support retains a distal fluid line between air or pressure sensors included on a pump drive mechanism, thus reducing the likelihood of sensing errors. Inlet and outlet valve flaps and corresponding seating surfaces included in the base are configured to provide quieter operation, further reduce the residual volume of the pumping chamber, increase fluid velocity through the outlet valve to sweep air bubbles from the pumping chamber, and protect against a &ldquo;blown&rdquo; inlet valve.

Disposable infusion cassette with low air bubble retention and improved valves

An improved rotor for use with a segmented peristaltic cartridge comprising a housing and a cover for assembly, said assembled housing and cover defining a pumping chamber which holds the improved rotor, a rotor sleeve and a section of flexible tubing wrapped around the rotor and connected to respective inlet and outlet ports of the cartridge. The flexible rotor includes an eccentric structure wherein flexible beam members provided on an outer surface of the rotor form a compliant member which improves the flexibility of the rotor assembly to avoid excessive compression loads or high torque and/or dynamic leak back or low torque for the tubing in the cartridge.

Compliant rotor for an improved cartridge for drug infusion pump

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Poway, CA, United States of America

Mike W Lawless