Robotic Joint Soft Tissue Evaluation for Precise Ligament Balancing
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Solution Overview
Problem
Existing surgical methods for joint replacement, such as partial or total knee replacement, lack effective tools for pre-operative planning and intra-operative evaluation of soft tissue balance, leading to complications like discomfort, limited joint motion, and potential need for revision surgeries.
Innovation Solution
A robotic ligament evaluator system with force-torque sensing capabilities and encoders, integrated with a computer-assisted surgery system, allows for precise positioning and evaluation of joint soft tissues, providing real-time data and aiding in soft tissue balancing during and after surgical procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual evaluation methods are used for soft tissue assessment, then the surgical process is simple and quick to perform, but the measurement precision and reliability of soft tissue balance evaluation are insufficient
Solution Approach 1:
The patent replaces manual mechanical evaluation with a robotic system that uses force-torque sensors and encoders to objectively measure soft tissue characteristics. The robotic device applies controlled forces and torques to the joint while sensors detect the resulting movements, substituting subjective manual assessment with automated mechanical measurement.
Solution Approach 2:
The patent introduces a robotic device as an intermediary between the surgeon and the patient's joint. This intermediary device precisely controls the application of forces and torques while sensors act as intermediaries to detect joint responses, enabling accurate soft tissue evaluation without direct manual manipulation.
2Adaptability or versatility
If traditional manual manipulation devices are used, then the device structure is simple, but the ability to perform multi-directional bone manipulation and independent drive operation is limited
Solution Approach 1:
The patent divides the robotic manipulation system into three independent drives, each capable of manipulating bones along different axes. Each drive operates independently with its own motor and control system, allowing multi-directional manipulation without requiring complex mechanical linkages between drives.
Solution Approach 2:
The robotic device is designed with universal manipulation capabilities that can perform multiple functions: applying forces, applying torques, measuring soft tissue characteristics, and controlling joint movement. This multi-functional design eliminates the need for separate devices for each manipulation task.
3Reliability
If pre-operative planning and intra-operative evaluation tools are not adequately integrated, then the surgical workflow is simpler, but the reliability of achieving balanced joint replacement is reduced
Solution Approach 1:
The patent merges pre-operative planning software with intra-operative robotic evaluation capabilities into a single integrated system. The system combines imaging data, surgical planning algorithms, and real-time robotic measurement capabilities to provide comprehensive joint replacement guidance throughout the surgical workflow.
Solution Approach 2:
The robotic evaluation system provides real-time feedback on soft tissue characteristics and joint balance during surgery. This feedback is immediately available to the surgeon, allowing for intra-operative adjustments to achieve the desired balanced joint replacement outcome based on actual measured data rather than pre-operative estimates alone.
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 surgical outcomes by ensuring balanced joint replacement, reducing patient discomfort, and minimizing complications through accurate pre-operative planning and intra-operative adjustments.
Implementation Method 1
applying a load to the joint with the robotic device while moving the joint through a range of motion
Implementation Method 2
measuring the displacement of the joint in response to the applied load
Implementation Method 3
applying a torque to the joint with the robotic device while moving the joint through a range of motion
Implementation Method 4
measuring the rotation of the joint in response to the applied torque
Data Source
Figure 1
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Figure 3~4
AI summary
A method of robotically evaluating soft tissue characteristics of a joint includes measuring, by a robotic device, information about a joint during a controlled range of motion manipulation of the joint; determining a motion limit of the joint, using the information about the joint measured during the controlled range of motion manipulation of the joint, wherein the motion limit is at least one of a displacement limit or a force limit of the joint; and replicating, using a joint positioner controlled by the robotic device, the controlled range of motion manipulation of the joint while introducing perturbations to the joint, wherein the replicated range of motion manipulation is controlled, at least in part, based on the motion limit. The method further includes using data obtained by the computer-assisted surgery system during the range of motion manipulation with perturbations to characterize the constraints of a soft tissue envelope of the joint.