Abstract: A flexible, compressible reservoir draws a substantially constant vacuum to permit uniform removal of fluid from a surgical incision through a wound drain catheter. The reservoir includes a compression spring interposed between a pair of congruent articulated plates. The spring provides biasing force to expand the reservoir and create a vacuum therein. Each of the articulated plates has a central member hinged on opposite sides to wing members. As the reservoir expands, the wing members pivot relative to the central members to decrease the effective area to which the spring force is applied. Such decrease in the effective area permits the spring force per unit of area to remain more nearly constant, and thus, reduces changes in reservoir vacuum.

Abstract: The wound drain catheter of the present invention is comprised of a drain portion connected to an outflow tube portion. The drain portion comprises a central core with plural T-shaped members projecting therefrom to form plural lumens having respective longitudinal grooves for fluid communication with the wound. This drain has a uniform cross-sectional area and is preferably made from a silicone elastomer having a durometer shore between 40 and 70 shore A. Such uniform cross-sectional area provides added strength to prevent the drain from breaking during its removal from the patient's body, and the silicone elastomer provides sufficient elasticity to permit the cross-sectional area of the drain to decrease by at least 30 percent when a pulling force is applied thereto, thereby reducing the gripping force of tissue surrounding the wound.