Powered Circular Stapler Stroke Compensation for Actuation Accuracy
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Solution Overview
Problem
Conventional circular clamping, cutting, and stapling instruments experience inaccurate actuation due to incomplete transmission of actuation forces through the adapter assembly, leading to improper stapling and cutting operations.
Innovation Solution
A powered circular stapler with an adapter assembly that undergoes an end-of-line final functional test to map stroke loss characteristics, using a second-order equation and specific coefficients to compensate for mechanical losses in the transmission assembly, and a controller that monitors strain gauge feedback to adjust motor output in real time for precise stapling and cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the transmission assembly is used to transmit actuation forces from the powered handle to the staple cartridge, then the surgical device can be operated remotely, but the actuation forces are not fully transmitted resulting in inaccurate actuation
Solution Approach 1:
The patent implements a feedback mechanism using strain gauges mounted on the adapter assembly to measure actual actuation forces transmitted through the transmission assembly. This feedback is sent to a controller that calculates compensation values based on the measured forces and applies corrections to the motor actuation commands, ensuring accurate staple cartridge actuation despite transmission losses
Solution Approach 2:
The system dynamically adjusts actuation parameters by applying compensation values to motor commands based on real-time strain gauge measurements. The controller modifies the relationship between motor position and actual cartridge position by adding compensation strokes calculated from the second-order equation, transforming the inaccurate mechanical transmission into precise actuation through parameter correction
2Adaptability or versatility
If the adapter assembly with transmission assembly is used to connect the powered handle to the staple cartridge, then the device can be reused across multiple procedures, but mechanical losses occur in the transmission assembly leading to stroke inaccuracies
Solution Approach 1:
Strain gauges on the adapter assembly provide real-time feedback on transmission assembly performance across multiple procedures. The controller continuously monitors actuation forces and applies dynamic compensation to maintain stroke accuracy regardless of wear or variations in the reusable adapter assembly
Solution Approach 2:
The system performs preliminary characterization of the transmission assembly by mapping stroke loss characteristics during end-of-line functional testing. This preliminary data is stored and used to establish baseline compensation parameters that are refined during actual use through continuous strain gauge feedback
3Extent of automation
If the controller uses encoder feedback from the motor to determine position, then the system can track motor movement, but the feedback does not account for dynamic losses of the transmission assembly
Solution Approach 1:
The system combines encoder feedback from the motor with strain gauge feedback from the adapter assembly. The strain gauge measurements provide information about actual forces transmitted through the transmission assembly, allowing the controller to calculate compensation values that correct the position information derived from encoder feedback alone
Solution Approach 2:
The strain gauge acts as an intermediary measurement device that bridges the gap between motor position (encoder) and actual cartridge position. By measuring the forces in the transmission assembly, the strain gauge provides data that mediates the relationship between motor actuation and cartridge movement, enabling accurate position determination despite transmission losses
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
Ensures accurate and consistent stapling and cutting performance across various tissue types and thicknesses, providing reliable surgical outcomes by compensating for mechanical losses in the transmission assembly.
Implementation Method 1
a controller of the power handle monitors the force from a strain gauge disposed in the adapter assembly
Implementation Method 2
a powered handle, an adapter assembly, and an end effector... a motor coupled to the power source
Data Source
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AI summary
A surgical device includes a handle assembly having a power source, a motor coupled to the power source, and a controller configured to control the motor. The device also includes an adapter assembly configured to selectively couple to the handle assembly, the adapter assembly including a stapling transmission assembly movable by the motor. The device also includes a reload configured to selectively couple to a distal portion of the adapter assembly, the reload including a plurality of staples ejectable from the reload by the stapling transmission assembly. The device also includes an anvil assembly selectively couplable to the distal portion of the adapter assembly, the anvil assembly being movable relative to the reload, where the controller may be further configured to control the motor to move the stapling transmission assembly to eject the staples while compensating for mechanical losses of the stapling transmission assembly.