Method of making balloon retention catheter

The method of forming a thin-walled expanded portion of a tube length which comprises the steps of providing a tube length of thermoformable plastic, having a determined minimum wall thickness and a maximum outer diameter, providing a mold having a channel therein with a first portion having a larger inner diameter than an outer diameter of a portion of the tube to be expanded, inserting the tube in the mold channel with the portion to be expanded positioned interior of the increased inner diameter first portion of the channel, closing the mold and encasing at least portions of the tube length interior of the mold channel, substantially filling the tube length with a substantially incompressible liquid at a first pressure, heating the tube length to a thermoforming temperature range of the tube, substantially instantaneously sharply increasing the pressure of the liquid interior of the tube to a second pressure to apply a high pressure spike by abruptly forcing a fixed predetermined additional quantity of said liquid into said tube and thereby expanding by liquid pressure at least the portion of the tube interior of the increased inner diameter portion of the channel, maintaining pressure interior of the tube at a third pressure while cooling the tube to a temperature below the thermoforming temperature of the tube.

A method of manufacture of a balloon catheter comprising the steps of providing a hollow tube length formed of thermoplastic material having a wall thickness, providing a mold having a channel therein dimensioned for receipt of the tube length and having an increased diameter section of substantially greater inner diameter than the outer diameter of a portion of the tube length to be received therein, inserting the tube in the channel with a first portion of the tube received interior of the increased diameter portion of the channel, filling the tube interior with a substantially incompressible fluid, elevating the temperature of the tube to a thermoforming temperature range of the tube material, substantially instantaneously increasing pressure of the fluid interior of the tube to apply a high pressure spike by abruptly forcing a fixed predetermined additional quantity of said liquid into said tube and thereby expanding the tube portion interior of the increased diameter portion of the channel by stretching and thinning the wall thickness of the tube portion, thereafter reducing the pressure of the fluid while maintaining the fluid at a greater than atmospheric pressure, cooling the tube to a temperature below the thermoforming temperature range, and thereafter withdrawing the tube length from the mold.

The method of making an expanded diameter section tube comprising the steps of:

• (A) providing a mold having a molding channel bore therein with first and second spaced apart axial ends and an intermediate area positioned between the ends, the intermediate area having an inner diameter greater than other sections of the bore, (B) providing a hollow tube length formed of thermoplastics material, (C) inserting the tube length in the bore with a portion thereof in the intermediate area, (D) substantially filling the interior of the tube with a substantially incompressible liquid, (E) increasing the temperature of the tube until at least the portion of the tube in the intermediate area reaches a thermoplastic temperature range, (F) substantially instantaneously sharply increasing the pressure of the fluid interior of the tube to apply a high pressure spike by abruptly forcing a fixed predetermined additional quantity of said liquid into said tube and thereby expanding the portion of the tube in the intermediate area while stretching and thinning the wall thickness of the expanded portion, and (G) thereafter cooling the tube in the mold.