Dual-Ratio Articulation Drive for Surgical End-Effector Positioning
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Solution Overview
Problem
Existing ultrasonic surgical instruments lack a dual mode articulation control system that allows for both rapid and precise positioning of the end effector, limiting the surgeon's ability to perform complex surgical procedures efficiently.
Innovation Solution
A dual mode articulation control assembly is integrated into the surgical instrument, enabling two modes of operation: one for rapid articulation with less precision and another for fine adjustment with greater sensitivity, allowing for enhanced control over the positioning of the end effector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single mode articulation control is used, then the device complexity is reduced, but the adaptability for different surgical tasks deteriorates
Solution Approach 1:
The articulation control system dynamically switches between two operational modes (high ratio and low ratio) based on surgical needs. The system transitions from a static single-mode design to a dynamic multi-mode system that can adapt its mechanical advantage ratio during procedure, enabling both rapid positioning and fine adjustment capabilities without permanently increasing structural complexity.
Solution Approach 2:
The system changes the mechanical ratio parameter between two discrete values (high ratio for rapid articulation, low ratio for precise positioning). By varying this key parameter, the instrument adapts to different surgical tasks, transforming a fixed-parameter system into a variable-parameter system that enhances versatility while maintaining manageable complexity through discrete rather than continuous variation.
2Speed
If a high ratio drive is used for rapid articulation, then the speed of articulation is improved, but the positioning precision deteriorates
Solution Approach 1:
The system dynamically selects between high ratio and low ratio drive modes based on the required operation. During rapid positioning phases, the high ratio drive provides fast articulation response. During fine positioning phases, the system switches to low ratio drive for enhanced precision. This dynamic mode selection resolves the speed-precision tradeoff by allowing both extremes to be accessed as needed.
Solution Approach 2:
The articulation control operates in periodic cycles, alternating between rapid positioning mode (high ratio) and fine adjustment mode (low ratio). The surgeon periodically switches between these two operational states depending on the surgical phase, using high ratio for coarse rapid movements and low ratio for precise final positioning, thereby achieving both speed and precision through time-sequential operation.
3Measurement precision
If a low ratio drive is used for precise positioning, then the positioning precision is improved, but the articulation speed deteriorates
Solution Approach 1:
The system dynamically transitions between low ratio mode for precise positioning and high ratio mode for rapid articulation. The low ratio drive is engaged specifically when positioning precision is critical, while the high ratio drive handles speed-critical phases. This dynamic allocation of drive modes eliminates the need to compromise on speed when precision is required, as the system can switch to high ratio mode for non-critical rapid movements.
Solution Approach 2:
The control system operates periodically, using low ratio drive during phases requiring precise positioning and high ratio drive during phases requiring rapid movement. This periodic switching between precision-oriented and speed-oriented modes allows the instrument to achieve fine positioning when needed without permanently sacrificing articulation speed, as the high ratio capability remains available for rapid repositioning when required.
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
The dual mode articulation control system enhances the instrument's versatility, enabling surgeons to perform complex surgical tasks with improved accuracy and efficiency by allowing rapid or precise positioning of the end effector as needed.
Implementation Method 1
These instruments include piezoelectric elements that convert electrical power into ultrasonic vibrations, which are communicated along an acoustic waveguide to the blade element
Implementation Method 2
an end effector having a blade element that vibrates at ultrasonic frequencies to cut and/or seal tissue (e.g., by denaturing proteins in tissue cells)
Data Source
AI summary
A surgical instrument includes a shaft assembly and an articulation control assembly. The shaft assembly includes an articulation section. The distal end of the shaft assembly is configured to receive an end effector. The articulation section is configured to deflect the end effector from the longitudinal axis. The articulation control assembly includes a first articulation control member, a second articulation control member, and a transmission assembly. The transmission assembly includes a high ratio drive and a low ratio drive. The high ratio drive is configured to drive the articulation section to deflect the end effector at a high rate of articulation in response to actuation of the first articulation control member. The low ratio drive is configured to drive the articulation section to deflect the end effector at a low rate of articulation in response to actuation of the second articulation control member.