Robotic Surgical Tool Calibration Using Linkage Force Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robotic surgical systems face challenges in accurately determining the initial position of end effectors, leading to reduced intuitiveness, dexterity, and sensitivity in minimally invasive surgeries due to mechanical hysteresis and lack of precise articulation control.
Innovation Solution
A method and system for calibrating robotic surgical tools by constraining the end effector, applying forces to linkage members to determine resistance thresholds, and averaging articulation angles to establish a home position, using a homing mechanism to adjust the end effector's zero position, and storing force values associated with articulation angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional minimally invasive surgical instruments are used, then small incisions and reduced recovery time are achieved, but surgical dexterity and intuitive control are reduced
Solution Approach 1:
A robotic system acts as an intermediary between the surgeon and the surgical site, translating surgeon inputs into precise end effector movements. The master control devices capture surgeon intent and the robotic slave tools execute with enhanced dexterity, bridging the gap between limited incision access and complex surgical maneuvers.
Solution Approach 2:
The patent replaces traditional direct mechanical manipulation by the surgeon with an automated robotic mechanical system. The robotic arms and end effectors are controlled through electronic feedback loops and control algorithms, substituting the surgeon's direct hand manipulation with an automated mechanical system that provides enhanced precision and intuitiveness.
2Length of moving object
If endoscopic instruments with added length are used, then access to deep surgical sites is improved, but force feedback sensitivity is reduced
Solution Approach 1:
The robotic system replaces long endoscopic instruments with robotic arms that can achieve deep access while maintaining force feedback sensitivity. The robotic system's direct drive mechanisms and force feedback sensors provide real-time tactile information to the surgeon, eliminating the force attenuation problem inherent in long flexible endoscopic shafts.
3Measurement precision
If robotic surgical systems are implemented, then surgical precision and control are improved, but system complexity increases
Solution Approach 1:
The robotic surgical system is designed as a universal platform that can accommodate multiple different end effectors and perform various surgical tasks. The standardized interface and programmable control allow a single complex system to provide multiple functions, justifying the complexity through enhanced precision and versatility.
Solution Approach 2:
The system employs extensive feedback mechanisms including position sensors, force sensors, and vision systems that continuously monitor end effector location and tissue interaction forces. This feedback is processed by control algorithms that automatically adjust motor commands to maintain precise positioning and provide force feedback, managing system complexity through closed-loop control.
4Speed
If articulation calibration is not performed, then rapid tool deployment is achieved, but surgical control accuracy deteriorates
Solution Approach 1:
The system performs articulation calibration as a preliminary action during the tool initialization process. The calibration determines the home position and articulation characteristics of each end effector before surgical use, storing these parameters for subsequent operations. This preliminary characterization enables accurate control without requiring continuous calibration during surgery.
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 precise control of end effector movement, allowing for more efficient and safe surgical procedures by accurately positioning the end effector, reducing the risk of unintended tissue damage, and enabling rapid calibration upon tool coupling.
Implementation Method 1
at least one linkage member extending along the shaft and operably coupled to the end effector such that force selectively applied to the linkage member causes at least one of a pitch and a yaw motion of the end effector
Implementation Method 2
applying a first force to at least one linkage member operably coupled to the end effector to attempt articulation of the end effector in a first direction until a resistance against further articulation exceeds a first threshold
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Systems and methods for articulation calibration of a surgical tool configured to be coupled to a robotic surgical system are provided. The tool including a tool shaft with an end effector has at least one linkage member extending along the shaft and operably coupled to the end effector such that force selectively applied to the linkage member is able to cause articulation of the end effector. The tool can also include a homing mechanism. To perform articulation calibration of the end effector, it can be constrained, force can be applied to the linkage member to attempt articulation of the end effector until a resistance against further articulation exceeds a threshold, and a home position of the end effector can be determined based on a force at which the resistance has exceeded the threshold.