Catheter tubes

Claim 1

An improved catheter comprising: a. a tubular, silicone rubber body portion having an outer surface and a central passage therein extending axially in said body from a proximal to a distal end, said distal end being shaped to provide a smooth, gently pointed tip for ease of insertion into contact with tissues, and said central passage communicating with an opening at the distal end thereof, b. an axially extending inflation lumen disposed contiguous with a wall of said body portion defined between said outer surface thereof and said central passage therein, said inflation lumen communicating with a pilot tube disposed adjacent the proximal end of said body portion, c. an expansible cuff portion disposed medially of said distal end of said body portion and communicating with said inflation lumen, said expansible cuff portion being substantially cylindrical in its initial deflated condition and having proximal and distal margins circumferentially secured to said body portion, and conforming generally to the outer surface shape of said silicone rubber body portion in its initial deflated condition, said expansible cuff portion being composed of a low modulus silicone rubber having properties of a Shore A hardness of less than about 30, a tensile strength of below about 700 psi, an elongation of above about 1,000 percent, and a stress value upon sealing inflation of less than about 30 percent of the breaking stress of said cuff material, said properties of the silicone rubber cuff thereby resulting in pressures, at substantially complete seal, of less than vascular compressive pressures inducive of significant tissue pressure necrosis, whereby said cuff upon expansion conforms to irregularities in contacted tissue surfaces and provides lateral sealing while reducing lesions.