Decoupled Robotic Knee Testing Device for Ligament Evaluation
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Solution Overview
Problem
Current methods for evaluating knee joint instability, particularly due to ligament damage, rely on subjective manual tests that are inconsistent and lack objective, reproducible measurements, leading to inaccurate diagnoses and potential delays in treatment.
Innovation Solution
A robotic knee testing device with three drives configured to manipulate the tibia relative to the femur about mutually perpendicular axes, allowing for controlled application of torque in different directions to evaluate internal-external rotation, anterior-posterior movement, and varus-valgus conditions, providing objective and reproducible data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual tests are used to evaluate knee joint stability, then the testing process is simple and accessible, but the measurement precision and reliability are poor due to subjective clinician evaluation
Solution Approach 1:
The patent replaces manual mechanical testing with an automated robotic system that applies controlled torques and measures joint responses objectively. The robotic device uses computer-controlled actuators to apply precise rotational forces and sensors to measure joint play, eliminating subjective clinician evaluation and significantly improving measurement precision and reliability.
2Adaptability or versatility
If a robotic system with multiple coupled drives is used to evaluate knee joint motion, then the ability to apply complex multi-directional torques is improved, but the difficulty of controlling and coordinating the drives increases
Solution Approach 1:
The patent divides the robotic system into three separate, mutually decoupled drive assemblies, each responsible for applying torque about one of three orthogonal axes (X, Y, and Z). This segmentation allows each drive to be controlled independently, simplifying the control architecture while maintaining the ability to apply complex multi-directional torques by coordinating the independent drives. The decoupling eliminates the need for complex coordination between drives, reducing control difficulty.
Data Source
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AI summary
Various limb manipulation and evaluation devices are provided. The devices generally include three drives, namely a first drive configured to manipulate a first bone relative to a second bone in a first direction, a second drive configured to manipulate the first bone relative to the second bone in a second direction, a third drive configured to manipulate the first bone relative to the second bone in a second direction. The three directions are different relative to each other and in some embodiments represent three distinct axes. The devices are further configured such that at least one of the drives is mutually decoupled relative to at least one other drive, such that operation of the one drive does not affect the position or movement of the another drive. One or multiple of the drives may be decoupled. A corresponding method of operating such decoupled drives is also provided.