Ultrasonic End Effector Articulation With Opposing Thread Drive
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Solution Overview
Problem
Existing ultrasonic surgical instruments lack efficient mechanisms for articulating the end effector to enhance precision and versatility in cutting and coagulating tissue.
Innovation Solution
An ultrasonic surgical instrument with an opposing thread drive mechanism that allows for articulation of the end effector, enabling precise control over the end effector's position and angle through a shaft assembly with an articulation section and a drive system that includes a cable and lead screw mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a traditional single-thread drive mechanism is used for end effector articulation, then the device complexity is reduced, but the manufacturing precision and control precision of the end effector position deteriorate
Solution Approach 1:
The drive mechanism is segmented into two independent thread drives (first thread drive and second thread drive) that separately control the articulation of the end effector. Each thread drive operates independently to control different aspects of end effector positioning, thereby improving manufacturing precision and control precision while managing device complexity through modular segmentation
Solution Approach 2:
The opposing thread drive mechanism adds a dimensional aspect to the control system by using two threads positioned opposite each other, allowing for more precise control of the end effector's articulation through differential movement of the two threads, thereby enhancing positioning precision without excessive complexity
2Adaptability or versatility
If the end effector articulation mechanism is simplified, then the device complexity is reduced, but the adaptability and versatility of the surgical instrument deteriorate
Solution Approach 1:
The end effector is designed with dynamic articulation capability through the opposing thread drive mechanism, allowing it to change its angular position and orientation dynamically during surgical procedures. This enables the end effector to adapt to different surgical scenarios and access various tissue angles, enhancing versatility while maintaining a relatively compact shaft assembly
Solution Approach 2:
The opposing thread drive mechanism provides multi-functional control of the end effector, enabling both articulation and positioning functions through a single integrated system. This universal mechanism allows the surgical instrument to perform multiple tasks including cutting, coagulating, and articulating with precision, thereby enhancing adaptability without proportionally increasing device complexity
3Measurement precision
If a cable and lead screw mechanism is used for articulation control, then the manufacturing precision of end effector positioning is improved, but the device complexity increases
Solution Approach 1:
The cable and lead screw mechanism acts as an intermediary transmission system that converts rotational motion into precise linear and angular positioning of the end effector. The lead screw translates rotational input from the control mechanism into controlled articulation movement, while the cable transmits force efficiently, thereby achieving high measurement precision and control accuracy while managing the complexity through functional intermediaries
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 opposing thread drive mechanism enhances the precision and versatility of tissue cutting and coagulation by allowing for controlled articulation of the end effector, improving surgical outcomes.
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
a drive system that includes a cable and lead screw mechanism
Data Source
AI summary
An apparatus comprises a body assembly, a shaft assembly, an end effector, an articulation section, and an articulation control assembly. The end effector is located at a distal end of the shaft assembly and comprises an ultrasonic blade. The articulation section is coupled with the shaft assembly and is operable to articulate to thereby deflect the end effector from the longitudinal axis. The articulation control assembly comprises first and second threaded members and an articulation control. The first and second threaded members have respective first and second pitch orientations. The articulation control is rotatable to thereby drive articulation of the articulation section by causing translation of the first and second threaded members along a path that is parallel to the longitudinal axis of the shaft assembly. The axis of rotation of the articulation control is non-parallel with the longitudinal axis of the shaft assembly.