Surgical Instrument Motor Velocity Control via Open-Loop Timing
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Solution Overview
Problem
Motorized surgical stapling and cutting instruments lack user control over firing speed and articulation velocity, making it difficult for surgeons to adjust for varying tissue conditions during procedures.
Innovation Solution
A surgical instrument with a control circuit and display that allows users to manually select and set the motor velocity based on distance and time inputs, enabling adjustable firing speed and articulation velocity through open-loop and closed-loop configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the surgical instrument uses a fixed default firing speed and articulation velocity, then the device complexity is reduced and ease of operation is improved, but the adaptability to different tissue conditions deteriorates
Solution Approach 1:
The surgical instrument implements dynamic velocity control by allowing the displacement member to translate at different velocities based on user-selected velocity modes. The control circuit enables switching between multiple velocity modes (e.g., first velocity mode, second velocity mode) for the firing member and articulation, transforming the system from a static fixed-velocity design to a dynamic adjustable-velocity design that adapts to different tissue conditions and surgical requirements.
2Adaptability or versatility
If the surgical instrument provides multiple velocity modes and user control options, then the adaptability to different tissue conditions is improved, but the device complexity increases
Solution Approach 1:
The control circuit is designed with multi-functionality to manage various velocity modes and control operations. It can determine time periods for displacement member translation, present velocity mode selection menus on the display, receive user inputs, and execute different velocity modes for both firing and articulation. This universal control architecture consolidates multiple functions into a single integrated circuit, reducing overall system complexity despite the added adaptability features.
Solution Approach 2:
The control circuit automatically determines the time period required for the displacement member to translate a specified distance based on the selected velocity mode. This self-calculating feature eliminates the need for manual time setting or complex external timing devices, as the system self-adjusts operational parameters based on user input and pre-programmed velocity characteristics.
3Measurement precision
If the surgical instrument measures elapsed time and position to evaluate tissue conditions, then the measurement precision is improved, but the loss of time for measurements increases
Solution Approach 1:
The control circuit continuously monitors the position of the displacement member throughout its translation and automatically determines the time period required to traverse specific distances. This continuous measurement approach eliminates the need for separate, discrete measurement steps that would interrupt the surgical workflow. The system performs measurements in real-time during normal operation, maintaining measurement precision while avoiding additional time loss through integrated, uninterrupted data collection.
Data Source
AI summary
A surgical system is disclosed comprising a firing member movable from a proximal position toward a distal position during a firing stroke, a motor configured to drive the firing member toward the distal position, and a control system configured to operate in an open-loop configuration and a closed-loop configuration. In the open-loop configuration, the control system is configured to cause the motor to drive the firing member to a predetermined position between the proximal position and the distal position, determine a time required to drive the firing member to the predetermined position, compare the determined time to a predetermined time, and set a motor velocity of the motor based on the comparison. In the closed-loop configuration, the control system is configured to drive the firing member at the set motor velocity.