Handheld Orthopedic Robot With Force-Guided Tool Path Control
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Solution Overview
Problem
In orthopedic surgeries, existing technologies face challenges such as errors in positioning due to frequent jig changes, limited precision with computer-aided navigation, and reaction speed limitations with optical positioning systems, leading to potential safety issues and tool deviation from predetermined paths.
Innovation Solution
A handheld robot combining position/orientation information from a positioning unit with force/torque feedback from a force sensor to dynamically adjust the tool's motion, ensuring it stays within a predetermined operation plan, using a kinematic mechanism with six degrees of freedom and a specialized tool design to enhance sensitivity in detecting deviation forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical positioning system is used to track position and orientation, then positioning capability is provided, but reaction speed is limited and blockage occurs frequently
Solution Approach 1:
The patent combines optical positioning system with force sensor system to merge position/orientation information with force/torque information. This integration allows the system to overcome the limitations of optical positioning alone by using force feedback to detect bone contact and guide the tool, thereby improving reaction speed while maintaining positioning accuracy.
Solution Approach 2:
The force sensor acts as an intermediary between the tool and the bone, detecting contact forces and torques that indicate bone engagement. This intermediary measurement mechanism provides faster response than optical tracking alone, enabling real-time adjustment of tool position and orientation without waiting for optical system updates.
2Measurement precision
If optical positioning system is used for motion compensation, then positioning is assisted, but blockage prevents timely adjustment
Solution Approach 1:
The system implements feedback control by continuously monitoring force and torque measurements from the force sensor. When bone contact is detected or tool deviation is identified through force feedback, the system automatically adjusts the tool position and orientation. This closed-loop feedback mechanism ensures reliable operation even when optical positioning is blocked, as force sensors remain unaffected by line-of-sight issues.
3Device complexity
If conventional control method turns off motor when tool deviates, then simple control is achieved, but tool cannot be kept within operation range
Solution Approach 1:
The patent implements continuous feedback control using force sensor data to monitor tool position and orientation relative to the bone. Instead of simple on/off control, the system uses real-time force feedback to make continuous adjustments, keeping the tool within the predetermined operation range. This feedback mechanism maintains both simplicity and precision by automating the adjustment process based on objective force measurements.
4Ease of operation
If surgical jigs are used for positioning, then positioning assistance is provided, but frequent switching causes errors
Solution Approach 1:
The handheld robot with force feedback provides self-guidance capabilities, allowing the surgeon to feel resistance and alignment forces that indicate correct positioning. This tactile feedback replaces the need for multiple surgical jigs, as the system itself provides continuous positioning guidance through force feedback, eliminating the need for frequent tool switching while maintaining high positioning accuracy.
Data Source
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AI summary
The present invention provides a handheld robot for orthopedic surgery and a control method thereof. The handheld robot of the present invention includes a main body, a grip, a kinematic mechanism, a tool connector, a tool, a force sensor and a positioning unit. The handheld robot of the present invention combines the position/orientation information of the tool acquired by the positioning unit with the force/torque information acquired by the force sensor, and utilizes the combined information to adjust the position of the tool so as to keep the tool within the range/path of a predetermined operation plan. In this way, the precision of the orthopedic surgery can be enhanced, and the error occurred during the surgery can be minimized.