Shape-Memory IUD Expansion to Limit Uterine Migration
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Solution Overview
Problem
Current intrauterine devices (IUDs) face issues such as significant side effects, discomfort during insertion, and higher failure rates due to larger copper or hormone exposure areas, as well as challenges in delivering devices through the cervix without causing pain.
Innovation Solution
The development of IUDs made from shape memory materials like Nitinol, which expand within the uterus to apply pressure against the uterine wall, deliver copper or other substances focally near fallopian tubes and the cervical os, and limit migration using tissue contact surfaces, reducing the total exposed surface area to less than 200 mm².
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the surface area of copper or hormone exposed in the uterus is increased, then the contraceptive action is improved, but the risk of abnormal bleeding or side effects increases
Solution Approach 1:
The patent applies local quality by transitioning from uniform copper/hormone distribution to focal delivery. The IUD delivers copper or hormone specifically at targeted locations (fallopian tube openings and cervical os) rather than uniformly across the entire uterine surface. This localized delivery achieves effective contraceptive action at the critical sites where sperm penetration is most likely to occur, while significantly reducing the total exposed surface area and associated side effects.
Solution Approach 2:
The patent segments the continuous copper or hormone release system into discrete focal delivery points. Instead of a single large exposed surface, the IUD incorporates multiple separate delivery locations positioned at specific anatomical landmarks. This segmentation allows the contraceptive substance to be delivered at multiple strategic points simultaneously, maintaining effective coverage while reducing the surface area at any single location and overall system complexity.
2Reliability
If the size of the IUD is increased to provide adequate contraceptive surface area, then the contraceptive effectiveness is improved, but the discomfort and pain during insertion increases
Solution Approach 1:
The patent employs the nesting principle by designing the IUD to be delivered in a compressed or collapsed configuration within a delivery sheath, then allowing it to expand to its full functional size once inside the uterus. The nested delivery configuration enables passage through the cervical canal with minimal discomfort, while the expanded post-delivery configuration provides adequate surface area for effective contraception. This temporal separation of sizes resolves the contradiction between insertion comfort and contraceptive effectiveness.
Solution Approach 2:
The patent applies dynamics by making the IUD size changeable rather than fixed. The device transitions from a small compressed state during delivery to a larger expanded state within the uterus. This dynamic size adjustment allows the IUD to adapt to different anatomical constraints during insertion while providing sufficient surface area for effectiveness once positioned, thereby resolving the contradiction between insertion ease and contraceptive reliability.
3Device complexity
If the IUD is delivered through the cervix using a delivery sheath, then the delivery process is simplified, but the pain and discomfort upon insertion increases
Solution Approach 1:
The patent applies preliminary action by compressing or collapsing the IUD before delivery through the cervix, and by pre-positioning the IUD within the delivery sheath. This preparation allows the IUD to pass through the cervical canal in a minimized configuration, reducing trauma to cervical tissues and associated pain. Once inside the uterus, the IUD is allowed to expand to its full functional size. The preliminary compression and positioning actions resolve the contradiction between delivery simplicity and insertion comfort.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These IUDs provide effective contraception with minimal side effects and improved delivery comfort by using shape memory materials to expand and maintain position within the uterus, preventing migration and reducing exposure to minimize discomfort and side effects.
Implementation Method 1
The IUDs described herein are generally made at least in part of shape memory material, such as but not limited to Nitinol
Implementation Method 2
an IUD may deliver copper and/or another spermicide in a targeted fashion to one or more targeted areas within the uterus
Data Source
AI summary
A method for promoting contraception by placing a contraceptive device within a uterus without blocking fallopian tubes may involve advancing a distal end of a delivery device through a cervix, advancing the contraceptive device comprising an elongate shape memory member out of the distal end of the delivery device and into the uterus, and limiting inferior migration of the contraceptive device within the uterus. Inferior migration may be limited by allowing the contraceptive device to assume a shape, when subjected to pressure that tends to cause a downward migration of the device within the uterus, in which an expandable middle portion of the device is expanded to contact the inner wall of the uterus and thus limit the downward migration of the device.