Surgical Tool Rotation Lock Mechanism for End Effector Orientation Control
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Solution Overview
Problem
Minimally invasive surgical instruments face limitations in control and range of motion, particularly in negotiating acute angles and maintaining precise orientation, leading to increased operative time and risk of tissue trauma.
Innovation Solution
The development of a shaft rotation mechanism with a first and second state, allowing for non-rotatable and rotatable positions, combined with an articulation mechanism using links and tension-bearing members, enables precise control and locking of the end effector's orientation relative to the handle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a rotation knob is rigidly fixed to the proximal end of the shaft to enable rotation control, then the end effector can be rotated about the shaft axis, but inadvertent rotation and larger torques can occur due to off-axis loading on the end effector
Solution Approach 1:
The rotation control mechanism is divided into separate functional components: a rotation knob for intentional rotation, a ratchet mechanism for one-way locking, and a friction mechanism for torque control. This segmentation allows each component to perform its specific function without interfering with others, preventing inadvertent rotation while maintaining ease of operation.
Solution Approach 2:
The ratchet and friction mechanisms act as intermediary elements between the rotation knob and the shaft. These intermediaries control the transmission of rotational motion and torque, allowing intentional rotation to pass through while blocking inadvertent rotation caused by off-axis loading on the end effector.
2Productivity
If conventional instruments are used in laparoscopic surgery, then the procedure can be performed with standard equipment, but it becomes physically taxing and control is limited as the procedure length increases
Solution Approach 1:
The instrument incorporates dynamic features including a rotatable shaft that can be intentionally rotated by the operator, and an end effector with controlled rotational capability. These dynamic features allow the surgeon to adjust the orientation and angle of the end effector during the procedure, maintaining optimal control and reducing physical fatigue even during lengthy procedures.
3Adaptability or versatility
If the shaft is rotatably attached to the handle with a rotation knob, then the end effector can be rotated, but the instrument has limited control and range of motion
Solution Approach 1:
The ratchet mechanism provides mechanical feedback by engaging at specific intervals during rotation, giving the operator tactile information about rotational position and preventing over-rotation. This feedback mechanism enhances control precision while maintaining the versatility of shaft rotation.
Data Source
AI summary
The invention provides surgical or diagnostic tools and associated methods that offer improved user control for operating remotely within regions of the body. These tools include a proximally-located actuator for the operation of a distal end effector, as well as proximally-located actuators for articulational and rotational movements of the end effector. Control mechanisms and methods refine operator control of end effector actuation and of these articulational and rotational movements. A rotation lock provides for enablement and disablement of rotatability of the end effector. The tool may also include other features. A multi-state ratchet for end effector actuation provides enablement-disablement options with tactile feedback. A force limiter mechanism protects the end effector and manipulated objects from the harm of potentially excessive force applied by the operator. An articulation lock allows the fixing and releasing of both neutral and articulated configurations of the tool and of consequent placement of the end effector.