Robotic Surgical End Effector Haptic Feedback via Strain Gauge
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Solution Overview
Problem
Robotic surgical systems lack haptic feedback, making it difficult for surgeons to accurately control the pressure between jaw members during tissue manipulation and sealing, leading to potential over-pressure applications.
Innovation Solution
Incorporating a strain gauge coupled to the jaw drive rod to measure strain and communicate it to a robotic controller, which adjusts the resistance of the lever on the handle, providing haptic feedback to the surgeon, and optionally using proximity devices to detect aperture size for further feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If robotic surgical systems are used to ease operation and reduce surgical fatigue, then ease of operation is improved, but haptic feedback is lost making it difficult to sense tissue thickness and closure pressure
Solution Approach 1:
The patent implements feedback by equipping the robotic surgical system with sensors (force sensors, torque sensors, strain gauges) that detect tissue thickness, closure pressure, and jaw member forces. This sensory information is fed back to the control system, which then adjusts the robotic arm's movements and the end effector's actuation to provide appropriate haptic feedback through the master console, resolving the information loss while maintaining ease of operation
Solution Approach 2:
The patent replaces direct mechanical haptic feedback transmission with an electronic sensing and feedback system. Instead of relying on mechanical coupling to transmit force feedback from the end effector to the surgeon's hands, the system uses sensors to detect mechanical parameters and electronically reconstructs haptic feedback signals, substituting the mechanical feedback path with an electronic control loop
2Measurement precision
If strain gauges and feedback mechanisms are added to provide haptic feedback, then measurement precision and control accuracy are improved, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by designing the robotic surgical system where a single integrated control system performs multiple functions: it controls the robotic arm movements, actuates the end effector, processes sensor data from multiple strain gauges and force sensors, and generates haptic feedback signals. This consolidation reduces overall system complexity compared to having separate dedicated systems for each function
Solution Approach 2:
The patent implements nesting by placing sensors, strain gauges, and control electronics within the compact structure of the end effector and robotic arm. The measurement and control systems are nested within the mechanical structure they monitor, minimizing additional space requirements and reducing the apparent complexity of the overall system
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
Enhances the surgeon's ability to feel tissue thickness and closure pressure remotely, reducing surgical fatigue and preventing unintended high pressures during procedures.
Implementation Method 1
A strain gauge is operably coupled to the jaw drive rod and is configured to measure an amount of strain thereon and communicate the amount of strain to a robotic controller
Implementation Method 2
A spring is operably coupled to the jaw drive rod and is configured to regulate the closure pressure between the jaw members
Data Source
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AI summary
A robotic system includes an electrosurgical instrument having an instrument housing with a shaft and first and second jaw members attached thereto movable to grasp tissue. An input is coupled to a jaw drive rod and is configured to move the jaw members. A strain gauge is coupled to the jaw drive rod and is configured to measure an amount of strain thereon and communicate the amount of strain to a robotic controller. A handle is remotely disposed relative to the instrument housing and is configured to communicate with the input for controlling the jaw members. The handle includes a housing having components therein and a lever operably associated therewith such that movement of the lever relative to the housing correlates to movement of the jaw members. The components are configured to operably regulate the resistance of the lever in response to the amount of strain from the strain gauge.