US Patent 7316666 Fluid warming cassette with rails and a stiffening member

A fluid warming cassette useful in a system for warming parenteral fluids is provided. The cassette comprises a thermally conductive, flexible fluid container with a fluid channel. Rails are disposed in the fluid container near its periphery, and a stiffener is disposed in the fluid container, between the rails, near an end of the cassette. Together, the rails and stiffener impart structural rigidity to the fluid container. The fluid container, rails and stiffener are joined into an integrated structure useful as a fluid warming cassette. One or more of the rails has a multilateral shape to key the cassette for insertion into a fluid warming unit.