Importance

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Abstract

An improvement in the implantable shunt device of the type disclosed in U.S. Pat. No. 4,181,132 wherein each valving slit within the elastomeric body of the shunt is formed by a flattened sleeve of woven vascular prosthesis material presenting opposed interior surfaces interengaged when the valving slit is in a closed condition and spaced apart when the valving slit is in an open condition. The opposed surfaces of the sleeve are formed by a material having a coefficient of friction with respect to the material of the cannula insertable therethrough less than that of the elastomeric material of the body. A separate yieldable bias operable in addition to the bias provided by the elastomeric material of the body is provided for yieldably biasing the opposed surfaces of the flattened sleeve into sealed relation when in the closed interengaged condition and into sealed relation to the exterior periphery of the portion of the cannula extending therethrough when in the open spaced apart condition. The additional bias is provided by filling under pressure opposed cavities in the elastomeric body with a yieldable material so located with respect to the flattened sleeve as to transmit the pressure thereof as the additional bias of the opposed surfaces into sealed relation when in the closed interengaged condition and into sealed relation with the exterior periphery of the cannula when in the open spaced apart condition.

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First Claim