Segmented Force Sensing Module for Knee Balancing
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Solution Overview
Problem
Conventional force sensing systems in orthopedic surgery are inadequate for accurately measuring medial and lateral forces at the tibiofemoral interface, failing to provide sufficient isolation between these forces and not allowing for real-time tracking of force location and magnitude as a function of joint angles, which hinders precise knee balancing during joint replacement surgeries.
Innovation Solution
A computer-implemented method and system that includes a force sensing module with resistive or capacitive transducers, inertial measurement units, and a processing system to track kinematic and kinetic parameters of an orthopedic joint, providing real-time data on force location, magnitude, and joint angles, enabling precise adjustments during surgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional force sensing systems are used, then the system structure is simple, but the measurement precision of medial and lateral forces is insufficient
Solution Approach 1:
The force sensing module is divided into multiple independent force sensing elements arranged in an array pattern. Each element independently measures force in specific directions, allowing separate measurement of medial and lateral forces. This segmentation enables precise force measurement while maintaining manageable system complexity through modular design.
Solution Approach 2:
Different regions of the articular surface are equipped with specific force sensing elements tailored to measure local force characteristics. The medial and lateral portions have dedicated sensing elements optimized for their respective force measurement needs, providing localized high-precision measurement without requiring the entire system to be overly complex.
2Loss of information
If conventional force sensing systems are used, then the device complexity is low, but the real-time tracking capability of force location and magnitude is insufficient
Solution Approach 1:
The processing system continuously receives force data from the force sensing module and provides real-time feedback on force location and magnitude. This feedback mechanism enables dynamic tracking of force parameters during joint movement, with the system automatically updating measurements as the joint articulates through different ranges of motion.
Solution Approach 2:
Conventional mechanical force measurement methods are replaced with electrical force sensing elements and digital signal processing. This substitution enables more precise and automated tracking of force parameters, reducing manual intervention while improving the accuracy and real-time capability of force location and magnitude measurement.
3Reliability
If conventional transducers are used, then the manufacturing is simple, but the isolation between medial and lateral force measurements is insufficient
Solution Approach 1:
The transducer system is segmented into multiple independent force sensing elements, each responsible for measuring forces in specific regions. This segmentation provides natural isolation between medial and lateral force measurements, improving measurement reliability while the modular structure facilitates standardized manufacturing processes.
Solution Approach 2:
Individual force sensing elements act as intermediaries between the applied forces and the measurement system. Each element is specifically positioned and oriented to measure forces in its designated region, providing isolated and reliable measurements of medial and lateral forces without cross-contamination from other force components.
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
Enables accurate and real-time monitoring of joint performance parameters, allowing for improved knee balancing and reduced uncertainty in surgical outcomes, leading to better patient recovery and reduced need for corrective surgeries.
Implementation Method 1
A force sensing module with resistive or capacitive transducers
Implementation Method 2
A force sensing module with resistive or capacitive transducers
Implementation Method 3
inertial measurement units
Data Source
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AI summary
A knee balancing system for measuring performance parameters associated with an orthopedic articular joint comprises a force sensing module (130) and one or more inertial measurement units. The force sensing module comprises a housing that includes an articular surface (430a) having a medial portion (330a) and a lateral portion (330b), each of which is substantially mechanically isolated from the other. The force sensing module also includes first (640a) and second (640b) sets of sensors disposed within the housing. The first set of sensors is mechanically coupled to the medial portion of the articular surface and configured to detect information indicative of a first force incident upon the medial portion of the articular surface. The second set of sensors is mechanically coupled to the lateral portion of the articular surface and configured to detect information indicative of a second force incident upon a lateral portion of the articular surface. The inertial measurement unit is configured to detect information indicative of an orientation of at least one of a first bone and a second bone of a knee joint.