Robotic Soft Tissue Evaluation for Joint Balance Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional manual evaluation of soft tissue in joint replacement surgeries, such as partial or total knee replacements, often results in imbalanced joints, leading to patient discomfort, limited motion, and potential complications, necessitating revision surgeries.
Innovation Solution
A robotic ligament evaluator system with force-torque sensing capabilities and encoders, coupled with a computer-assisted surgery system, is used to assess and balance soft tissues by precisely controlling joint positions and applying forces, compensating for patient weight, and providing continuous tracking and registration of anatomical positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual evaluation of soft tissue is performed by surgeons, then the surgical process is simple and quick to set up, but the joint balance precision and measurement accuracy are insufficient leading to imbalanced joints
Solution Approach 1:
The patent replaces manual mechanical evaluation by surgeons with an automated robotic system that uses force-torque sensors and encoders to objectively measure joint balance. The robotic arm applies controlled forces and torques to the joint while sensors capture precise measurements, eliminating subjectivity and improving measurement accuracy despite increased system complexity.
Solution Approach 2:
The patent introduces a robotic arm as an intermediary between the surgeon and the joint evaluation process. The robotic arm serves as a mediator that applies standardized forces and positions the joint precisely, allowing for consistent and repeatable measurements that improve joint balance precision while reducing reliance on manual techniques.
2Measurement precision
If robotic evaluation system is used to precisely control joint positions and apply forces, then measurement precision and joint balance are improved, but device complexity and ease of operation are reduced
Solution Approach 1:
The robotic evaluation system performs self-calibration and self-positioning using encoders and force-torque sensors to automatically determine joint neutral positions and measurement parameters. The system autonomously adjusts its own operation without requiring constant manual intervention, maintaining high measurement precision while reducing operational complexity through automated feedback loops.
Solution Approach 2:
The patent implements real-time feedback through force-torque sensors that continuously monitor joint reactions during evaluation. This feedback is processed by control algorithms that automatically adjust robotic arm positioning and applied forces to maintain optimal measurement conditions, improving measurement accuracy while the system self-regulates to simplify operation.
3Reliability
If trial implants are manually tested in flexion and extension, then the surgical workflow is straightforward, but the evaluation reliability and consistency are insufficient
Solution Approach 1:
The patent replaces inconsistent manual testing of trial implants with a standardized robotic evaluation system. The robotic arm systematically moves the joint through predefined flexion and extension ranges while force-torque sensors capture consistent, repeatable data. This automated mechanical system eliminates variability between different surgeons' manual testing techniques, significantly improving evaluation reliability.
Solution Approach 2:
The robotic system performs preliminary evaluation of trial implants before final implantation by systematically testing joint balance across the full range of motion. This pre-evaluation identifies necessary adjustments to ligaments or implant positioning, ensuring reliable assessment is completed beforehand to guide the final surgical outcome without requiring complex intraoperative adjustments.
4Manufacturing precision
If continuous tracking and registration of anatomical positions is implemented, then surgical precision and joint balance are enhanced, but device complexity and setup time increase
Solution Approach 1:
The patent introduces a tracking system with markers and sensors as an intermediary between the surgical field and the robotic control system. This intermediary continuously captures anatomical position data and transmits it to the robotic controller, enabling real-time precision adjustments while the tracking subsystem handles the complexity of continuous monitoring, keeping the main robotic system relatively simple.
Solution Approach 2:
The patent replaces periodic manual measurement checks with continuous automated tracking using optical or electromagnetic sensors. The tracking system continuously records anatomical positions and feeds this data to the robotic control system, maintaining constant surgical precision without requiring complex manual measurement instruments or frequent surgical interruptions for reassessment.
Data Source
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.