Powered Circular Stapling Device Transfer Switch Mechanism

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Solution Overview

Problem

There is a need for a simple and reliable switch mechanism in surgical stapling devices to selectively control the transmission of power between the approximation and firing mechanisms, which is not adequately addressed in existing technologies.

Innovation Solution

A powered circular stapling device with a transfer switch assembly that includes a worm gear assembly and biasing mechanisms, allowing the device to switch between clamping and firing modes by engaging the fire gear or clamp gear, enabling the motor to drive either the anvil assembly or the staple pusher for staple ejection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a manual switch mechanism is used to control power transmission between clamping and firing mechanisms, then the device complexity is reduced, but the reliability and precision of mode switching deteriorates

Engineering Contradiction:
Improveswitch mechanism complexityVSAvoidmode switching reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces manual mechanical switching with an automated transfer switch assembly that uses a motor-driven worm gear mechanism. This automated system provides reliable, precise control of power transmission between clamping and firing mechanisms without requiring manual intervention, thereby improving reliability while maintaining acceptable complexity through integration with the existing motor system.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The transfer switch assembly automatically engages or disengages power transmission to different mechanisms based on operational requirements. The system self-regulates the switching between clamping and firing modes through the worm gear's inherent self-locking特性, eliminating the need for external manual control and improving operational reliability.

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If a simple switch mechanism is used, then the ease of manufacture is improved, but the precision of power transmission control deteriorates

Engineering Contradiction:
Improveswitch assembly manufacturingVSAvoidpower transmission control precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs a motor-driven worm gear mechanism within the transfer switch assembly to achieve precise control of power transmission. This mechanical substitution provides accurate, repeatable engagement and disengagement of power to different mechanisms, ensuring precise control while maintaining manufacturability through standard mechanical components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The transfer switch assembly incorporates a dynamically adjustable mechanism that can smoothly transition between different power transmission states. The worm gear mechanism allows for controlled engagement and disengagement, providing precise dynamic control over which mechanism receives power from the motor, thereby achieving accurate power transmission control.

Inventive Principle:
Principle #15Dynamics

3Productivity

If a motor-driven transmission assembly is used, then the productivity is improved, but the device complexity increases

Engineering Contradiction:
Improvestapling procedure efficiencyVSAvoidtransmission assembly complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The motor-driven transmission assembly serves multiple functions: it drives both the clamping mechanism and the firing mechanism through the transfer switch assembly. This multi-functionality improves productivity by automating both critical operations with a single motor system, while the complexity is managed through the integrated design that shares common components like the motor and transmission housing.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the clamping and firing drive mechanisms into a single motor-driven transmission system. The transfer switch assembly combines the control functions for both mechanisms into one integrated unit, reducing overall system complexity while maintaining the productivity benefits of motor-driven operation for both functions.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If a transfer switch assembly with worm gear is used, then the reliability of power direction control is improved, but the device complexity increases

Engineering Contradiction:
Improvepower direction controlVSAvoidtransfer switch assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a worm gear mechanism within the transfer switch assembly to provide reliable, self-locking control over power direction. This mechanical substitution ensures that power is transmitted only to the intended mechanism (clamping or firing) without drift or unintended activation, improving reliability while containing complexity through the use of a well-established mechanical component.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The transfer switch assembly acts as an intermediary between the motor and the two driven mechanisms. The worm gear within this assembly mediates the power transmission, providing reliable directional control by mechanically isolating power flow to only the active mechanism. This intermediary role improves control reliability while managing complexity through functional separation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This solution provides a reliable and efficient method to control the stapling device, allowing for precise operation between clamping and firing modes, minimizing trauma to the patient and reducing procedural time by enabling non-invasive stapling.

Implementation Method 1

The transfer switch assembly includes a worm gear assembly including a worm gear that is engaged with the fire gear when the transfer switch is in the first position and engaged with the clamp gear when the transfer switch is in the second position.

Methodology Applied
Scientific EffectWorm gear mechanism: Worm Drive

Data Source

PatentEP3840669B1Powered circular stapling device
Publication Date: 2024.04.17 COVIDIEN LP
  • EP3840669B1 patent drawingFigure 1
  • EP3840669B1 patent drawingFigure 2~3
  • EP3840669B1 patent drawingFigure 4

AI summary

A powered circular stapling device (10) includes a transfer switch assembly (90) for a transmission assembly (40) to selectively direct power between clamping and firing mechanisms of the stapling device (10). The transfer switch assembly (90) includes a carriage (92), a worm gear assembly (94), and first and second biasing mechanisms (96). The worm gear assembly (94) is supported on the carriage (92) and movable in relation to the carriage (92) to allow the worm gear assembly (94) to engage with a first or second gear (44, 46) of the transmission assembly (40). The biasing mechanisms (96) allow the worm gear assembly (94) to move in relation to the carriage (92) when the gear teeth of the worm gear (94) are misaligned with the gear teeth of one of the first and second gears (44, 46) of the transmission assembly (40), to allow the gear teeth of the worm gear (94) to move into alignment with the gear teeth of the other one of the first and second gears (44, 46) of the transmission assembly (40).