METHOD FOR FORMING AND STERILIZING CATHETERS
First Claim
1. A method of forming into a predetermined shape an elongated strip of thermoplastic material having a temperature above which it is free forming and below which it tends to retain its shape, the method including the steps of:
- 1. preparing a forming board having a groove of shape to support a catheter in a predetermined desired configuration;
2. supporting the catheter in said groove to constitute a forming board-catheter unit;
3. heating thIs unit at least to the free form temperature of the catheter material; and
4. reducing the temperature of the unit to substantially below the free form temperature.
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Accused Products
Abstract
A catheter for insertion into the human body and made of a thermoplastic tubing, is preformed to a desired shape by heating it above its free form temperature and allowing it to cool while held in that shape. To hold the catheter in position for such forming, a forming board having a catheter receiving groove of the desired shape is used. The cross-sectional shape of this groove is wider at the bottom and narrower at the open top where it becomes a part of the board so as to hold the catheter in place during the forming and storage and to allow the catheter to be easily removed thereafter. This forming board is made by vacuum forming a sheet of thermosetting plastic over a solid, non-heat responsive, master representation of the exact longitudinal shape of the final preformed catheter. The crosssectional shape of the master is the negative of the desired cross-section of the final forming board groove. When the catheter has been so preformed, it and its forming board are packaged in a sealed plastic bag which is, like the catheter and the forming board, permeable to sterilizing gas. The resulting package is gas claved and stored in this sealed condition until ready for use. The catheter is removed from the sealed package and the forming board immediately before insertion into the body. When it has served its purpose, it is removed from the body, cleaned, positioned back into the forming board, preformed with heat when necessary, placed in another sealed film container, and resterilized for storage until it is again needed.
58 Citations
7 Claims
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1. A method of forming into a predetermined shape an elongated strip of thermoplastic material having a temperature above which it is free forming and below which it tends to retain its shape, the method including the steps of:
- 1. preparing a forming board having a groove of shape to support a catheter in a predetermined desired configuration;
2. supporting the catheter in said groove to constitute a forming board-catheter unit;
3. heating thIs unit at least to the free form temperature of the catheter material; and
4. reducing the temperature of the unit to substantially below the free form temperature.
- 1. preparing a forming board having a groove of shape to support a catheter in a predetermined desired configuration;
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2. A method of making and preserving in readiness for use a catheter for use within the human body, including the steps enumerated in claim 1, followed by the following steps:
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3. heating thIs unit at least to the free form temperature of the catheter material;
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4. The method of claim 1 wherein the forming board has been prepared to have a groove of shape to support a catheter by preparing a master having such predetermined desired configuration, setting this master on an air permeable base, heating a sheet of thermosetting plastic, and drawing it down on the master and the base by vacuum forming methods, allowing it to cool and removing it from the base and the master from it.
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5. encompassing the forming board-elongated strip unit in a hermetically sealed envelope;
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6. sterilizing the interior of the envelope and the contents thereof;
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7. retaining the catheter in the forming board and in the envelope until it is ready to be used.
Specification