Medtronic, Inc.

Morris H Deitermann

Don H Tran

Glen L Lieber

Sharon Schwab

Jeffrey S Trinidad

David B Cowgill

Donald R Waller

A spiral balloon perfusion catheter assembly having a retaining wire and method of making the balloon. Also, a retaining wire for such a catheter and method of forming the retaining wire. A typical spiral catheter balloon has a spiral configuration of lobes and channels mounted on a catheter extending beyond the balloon ends. A retaining wire formed from a shape memory alloy is configured to have a central region having a spaced spiral configuration conforming to the spiral balloon channel and end regions configured to have a contiguous spiral configuration conforming to the catheter diameter. When placed over a spiral balloon, the central spiral region prevents expansion of the channel when the balloon is inflated, while the end regions secure the retaining wire to the catheter. Preferred shape memory alloys comprise nickel and titanium. The retaining wire is made by heating the wire above the crystal phase change temperature of the alloy, shaping the spirals then cooling the product below the crystal phase change temperature. The spiral end regions may be unwound and placed over the catheter adjacent to the balloon with the wire in the central spiral region conforming to the balloon channel.

Spiral sheath retainer for autoperfusion dilatation catheter balloon

A method and apparatus for forming perfusion balloons from thermoplastic materials. A helical member having a cross section corresponding to a desired perfusion channel cross section is placed in a tubular mold in contact with the mold wall. A thermoplastic tube is inserted into the helical member in the mold. The assembly is heated to the glass transition temperature of the tube and the tube is pressurized to expand into contact with the helical member and mold wall. After cooling, the formed balloon is removed from the mold. The helical member has a 'T' shaped, or rectangular, or square, or triangular cross section. Limited pre-pressure and pre-stretch are preferably applied prior to the tube expansion and post forming tube conditioning may be used. Axial stretching of the tube in a mold, with our without the helical member, by microprocessor controlled air actuators provides highest quality balloons having selected wall thicknesses.

Method for making catheter balloons

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San Diego, CA, United States of America

Morris H Deitermann