Linearly Actuated Lock Collar for Reusable Surgical Stapler
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Solution Overview
Problem
Conventional circular surgical stapling instruments are typically disposable after a single use due to a fixedly attached cartridge or shell assembly, lacking a simple and cost-effective method for reuse.
Innovation Solution
A loading unit with a shell assembly, lock collar, and release collar that securely attaches and detaches from a surgical instrument, utilizing cam surfaces and flanges to transition between locked and unlocked configurations, allowing for easy attachment and detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixedly attached cartridge or shell assembly is used in conventional circular stapling instruments, then the instrument structure is simple and reliable, but the instrument must be disposed of after a single use, increasing waste and cost
Solution Approach 1:
The instrument is divided into separable components: a reusable surgical instrument body and a replaceable loading unit with shell assembly. This segmentation allows the instrument to be reused while the loading unit is discarded, resolving the contradiction between reusability and waste reduction.
Solution Approach 2:
The attachment mechanism transitions from a fixed, static connection to a dynamic, reversible connection. The lock collar can be actuated between locked and unlocked states, enabling the loading unit to be securely attached during use and easily removed afterward, facilitating instrument reuse.
2Adaptability or versatility
If a replaceable cartridge or shell assembly is implemented, then instrument reuse becomes possible, but a complex locking mechanism is typically required, increasing device complexity
Solution Approach 1:
The lock collar is disposed about the coupling ring, with the lock extending through the shell assembly. This nested arrangement allows the locking mechanism to be compact and integrated within the existing structure, reducing overall complexity while enabling secure attachment and release.
Solution Approach 2:
The resilient locking flange automatically engages with the cam surface of the release collar to lock the loading unit in place. The system uses its own components (resilient flange, cam surface) to achieve automatic locking without requiring additional actuators or complex mechanisms.
3Ease of operation
If a simple release mechanism is used to facilitate loading unit removal, then ease of operation is improved, but reliability of the locked configuration may be compromised
Solution Approach 1:
The cam surface of the release collar and the cam surface of the locking flange use curved, angled surfaces to convert linear motion of the release collar into rotational or lifting motion of the lock. This curved surface interaction provides smooth, reliable engagement and disengagement while maintaining security during the locked state.
Solution Approach 2:
The cam surface acts as an intermediary between the release collar and the locking flange. When the release collar is actuated, its cam surface interacts with the cam surface of the locking flange to reliably transition the lock from engaged to disengaged state, ensuring both security when locked and ease of release when actuated.
4Reliability
If a resilient locking flange with cam surface is used to secure the loading unit, then reliability of locking is improved, but the structure becomes more complex
Solution Approach 1:
The locking flange combines multiple functions in a single component: it provides resilient engagement with the coupling ring, incorporates a cam surface for interaction with the release collar, and includes a lock for securing the loading unit. This merging reduces the number of separate parts while maintaining reliability.
Solution Approach 2:
The locking flange serves multiple purposes: it acts as a retaining element, a camming element, and a locking element. This multi-functionality reduces overall mechanism complexity while ensuring reliable locking, as one component performs several critical functions that would otherwise require separate elements.
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 the reuse of circular stapling instruments by providing a secure and efficient mechanism for attaching and detaching the loading unit, reducing waste and costs associated with single-use instruments.
Implementation Method 1
The lock collar may include a lock ring and a first resilient locking flange that extends proximally from the lock ring. The second locking flange may have a cam surface that is angled distally inward
Implementation Method 2
The first locking flange may include a cam surface that is angled distally inward and the release collar may have a first camming surface that is angled proximally outward
Data Source
AI summary
A loading unit includes a shell assembly, a lock collar, and a release collar. The shell assembly has a coupling ring that defines a lock slot and a proximal opening configured to receive a distal end portion of a surgical instrument. The lock collar is disposed about the coupling ring and has a radially extending lock that is configured to be received within the lock slot. The lock collar is transitionable between a locked configuration in which the lock is positioned within the lock slot and an unlocked configuration in which the lock is lifted from within the lock slot. The release collar is disposed about the coupling ring proximal of the lock collar and is transitionable between an unactuated position and an actuated position. The release collar transitioning the lock collar to the unlocked configuration as the release collar is translated from the unactutated position towards the actuated position.