Heat-curling polymeric needle for safe disposal
Inventors
Mather, Patrick T. • Yang, Pine
Assignees
Publication Number
US-11400236-B2
Publication Date
2022-08-02
Expiration Date
2034-04-08
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Abstract
A needle having shaft that forms a tip and a portion proximate to the tip that is formed from a shape memory polymer. The shaft of the needle may be programmed to curl from a straight configuration to a curved configuration upon triggering by heat, thereby moving the sharp tip and providing a non-stick needle for safe and easy disposal.
Core Innovation
The invention is a needle having a shaft with a tip, where a portion proximate to the tip is formed from a shape memory polymer (SMP). This portion of the needle shaft is programmed to transition from a straight configuration to a curved configuration upon triggering by heat, thus moving the sharp tip and providing a non-stick needle for safe and easy disposal. The SMP may be high molecular weight poly(methyl methacrylate) (PMMA), which has favorable shape memory properties.
The invention addresses the healthcare problem of improper and unsafe needle-syringe disposal, which leads to infections and hazards, particularly for recycling workers. Conventional steel needles are difficult to dispose of and remain sharp even after disabling. Existing auto-disable needle-syringe designs are complicated and do not solve the needle disposal and recycling issue.
By utilizing a shape memory polymer for the needle tip, the present invention provides a simple and effective means for disabling needles after use. Upon heating to a specific temperature, the SMP portion of the shaft curls, rendering the sharp tip non-stick and facilitating easy and safe disposal and recycling. The design eliminates the need for complex mechanical parts, offering a straightforward disabling process.
Claims Coverage
There are three independent claims in the patent, each covering a main inventive feature.
Needle with heat-triggered curling tip made from shape memory polymer
A needle comprising a hollow shaft including a tip and a portion proximate to the tip that is formed from a shape memory polymer having a glass transition temperature above 100 degrees Celsius. This portion transitions from a temporary straight configuration to a permanent curved configuration when heated to at least the glass transition temperature. The portion comprises a film formed from a plurality of fibers, and the curve formed in the permanent configuration is sufficient to bend the hollow shaft about 180 degrees when heated to 150 degrees Celsius.
Method of using a heat-curling shape memory polymer needle
A method involving providing a needle as described, using it to inject a subject, and then heating the needle to 150 degrees Celsius until the portion transitions from a straight to a curved permanent configuration, which renders the needle safe for disposal.
Method of manufacturing a heat-curling needle
A method that includes extruding a needle with a hollow shaft and shape memory polymer portion as described, setting the permanent configuration by heating above a temporary temperature, programming the temporary configuration by heating under load to a lower temperature, and forming a sharp tip by freeze fracturing the shaft.
The independent claims define inventive features focused on a needle with a heat-triggerable shape memory polymer tip, methods for its use in safe disposal, and methods for manufacturing such a needle.
Stated Advantages
Provides a disabling process for needles that is easy, fast, and safe.
Enables safe and easy disposal and recycling by curling the needle tip into a non-stick shape.
Eliminates the need for complicated designs and multiple actuating parts found in traditional auto-disable syringes.
Offers a simple way for fabricating a polymeric non-stick needle.
Documented Applications
Use in hypodermic needles for safe disposal after injection.
Application in needle recycling processes.
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