Spring-Loaded Bag Brim for Intact Tissue Retrieval
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Minimally-invasive surgical procedures face challenges in retrieving large tissue specimens due to restricted access and the risk of cancer cell seeding, as existing devices made from expensive shape memory alloys like Nitinol are costly and require breaking down specimens into smaller pieces.
Innovation Solution
A tissue specimen retrieval device with a telescopically movable shaft and an end effector assembly featuring a spring-loaded bag brim made from high yield stainless steel or other materials, which automatically expands to facilitate specimen collection and retraction, allowing for intact specimen retrieval without breaking it down.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If shape memory alloy (Nitinol) is used for the bag brim, then the bag brim can be deployed and collapsed effectively, but the device cost increases significantly
Solution Approach 1:
The patent changes the material parameter from shape memory alloy to spring-loaded mechanism, maintaining the deployment/collapse functionality while reducing cost. The spring assembly (155a, 155b) provides the mechanical force needed for bag brim expansion and contraction without requiring expensive Nitinol material properties
Solution Approach 2:
The patent employs a disposable spring assembly that is inexpensive compared to shape memory alloys. The spring-loaded mechanism is designed as a single-use component that can be discarded after one procedure, eliminating the need for expensive, reusable shape memory alloy components
2Length of moving object
If the tissue specimen is broken down into smaller pieces, then it can be retrieved through minimally-invasive openings, but the risk of cancer cell seeding increases
Solution Approach 1:
The patent segments the retrieval process into two distinct phases: (1) the bag brim collapses within the shaft during insertion, and (2) the bag brim expands distal to the shaft to capture and retrieve the intact specimen. This segmentation allows the specimen to remain intact during retrieval while still passing through the minimally-invasive opening
Solution Approach 2:
The bag brim acts as an intermediary structure that captures the tissue specimen within an enclosed environment. The specimen bag (160) supported on the bag brim provides an enclosed space for specimen retrieval, preventing cancer cell seeding while facilitating passage through small openings
3Volume of moving object
If the bag brim is made from flat material, then it can be collapsed for insertion, but it requires additional mechanism to ensure reliable expansion
Solution Approach 1:
The spring assembly (155a, 155b) is configured to automatically expand the bag brim upon deployment from the shaft without requiring additional actuators or complex control mechanisms. The stored elastic energy in the springs self-propels the expansion process
Solution Approach 2:
The patent combines the spring assembly with the bag brim structure itself, integrating the expansion mechanism into the bag brim design. The springs are attached directly to the bag brim arms, merging the structural component with the actuation mechanism
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
Enables efficient and intact retrieval of tissue specimens, reducing the risk of cancer cell seeding and lowering costs by using cost-effective materials while maintaining the integrity of the specimen during minimally-invasive procedures.
Implementation Method 1
The spring assembly includes a torsion spring having opposing legs extending therefrom, each leg configured to operably engage one of the first and second ends of the bag brim
Implementation Method 2
The spring assembly includes two torsion springs each having opposing legs extending therefrom, each leg of each torsion spring configured to operably engage one of the first and second ends of the bag brim
Data Source
AI summary
A tissue specimen retrieval device includes first and second shafts telescopically movable relative to one another. The second shaft supports an end effector that is movable relative to the first shaft between a retracted position, wherein the end effector is disposed within the first shaft, and a deployed position, wherein the end effector extends distally from the first shaft in an expanded configuration. The end effector includes a bag brim having first and second ends that operably engage the distal end of the second shaft. The bag brim is transitionable from a first collapsed configuration for disposition within the first shaft to an expanded, configuration upon deployment from the first shaft. The bag brim includes a spring assembly disposed between the first and second ends thereof that is configured to facilitate automatic expansion of the bag brim to the expanded configuration upon deployment thereof from within the first shaft.