Load-Detecting Orthosis Weighted Sum Threshold Warning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing load-sensing orthoses are either expensive, prone to false alarms, or require frequent battery changes, and lack efficient long-term operation without recharging, while also failing to provide accurate warnings and detailed load analysis.
Innovation Solution
A load-detecting orthosis with sensor elements in pressure zones and signal-evaluating electronics that weight characteristic values to generate information signals only when total load exceeds specified thresholds, using multiple weightings to differentiate between critical and non-critical loads, and providing adjustable warning thresholds and decay mechanisms for cumulative load evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple pressure sensors are used to improve measurement precision, then the device becomes more expensive and complex
Solution Approach 1:
The foot sole is divided into multiple pressure zones (heel, midfoot, forefoot, toes) with sensor elements distributed throughout. This segmentation allows the system to capture spatial load distribution patterns using a manageable number of sensors rather than requiring uniform high-density coverage, thereby reducing overall device complexity while maintaining measurement precision.
Solution Approach 2:
Different regions of the foot sole are assigned different sensor densities based on their functional importance for load detection. High-load areas like the heel and forefoot receive more sensor elements, while lower-load areas have fewer sensors. This non-uniform distribution optimizes measurement precision for critical zones without unnecessarily increasing complexity throughout the entire sensor array.
2Reliability
If continuous monitoring is implemented to detect all load events, then false alarms increase due to transient loads
Solution Approach 1:
The system performs preliminary evaluation of individual load events by analyzing their magnitude, duration, and pattern before generating warnings. Transient loads that exceed thresholds briefly are pre-filtered out through pattern recognition algorithms that compare current loads against historical data and expected gait patterns, preventing false alarms before they are generated.
Solution Approach 2:
The warning threshold is made dynamic rather than static, adapting to the user's gait cycle, activity level, and historical load patterns. The system adjusts threshold sensitivity in real-time based on whether the user is walking, running, or standing, and modifies threshold criteria based on the duration and repetition of load events, thereby reducing false alarms during normal activity variations.
3Reliability
If frequent threshold checks are performed to detect overload, then energy consumption increases
Solution Approach 1:
Instead of continuously monitoring at maximum sampling rates, the system employs periodic sampling at reduced rates during normal activity. The sampling frequency is dynamically adjusted based on detected gait phase and load characteristics, performing detailed threshold checks only at critical moments (e.g., heel strike, toe-off) rather than continuously, thereby reducing energy consumption while maintaining detection accuracy.
Solution Approach 2:
The system performs preliminary signal processing and feature extraction (such as calculating load magnitude, duration, and rate of change) before executing full threshold evaluation. This preliminary action filters out obviously non-critical events early in the processing chain, reducing the number of expensive full threshold checks required and thereby lowering overall energy consumption.
4Loss of information
If detailed load analysis is provided to improve feedback accuracy, then device complexity increases
Solution Approach 1:
The complex load signal is segmented into distinct gait phases (heel strike, midstance, forefoot, toe-off) and load characteristics (magnitude, duration, rate of change, impulse). This segmentation allows the system to provide detailed analytical feedback about specific phases and characteristics without processing the entire complex signal at once, reducing computational complexity while maintaining information completeness.
Solution Approach 2:
The system extracts and highlights only the most relevant load characteristics and gait phase information for feedback to the user, such as peak load magnitude, time to peak, and phase-specific load patterns. By taking out and presenting only the essential information rather than all raw data, the system provides detailed analysis without overwhelming the user or requiring complex processing of every data point.
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
The orthosis provides reliable warnings of harmful loading conditions while minimizing false alarms, enabling long-term operation without battery changes and offering detailed load analysis for improved patient feedback and rehabilitation outcomes.
Implementation Method 1
a sensor (2) generating sensor signals, comprising sensor elements (2a, 2b, 2c) in pressure zones (I, II)
Data Source
Figure 1~4
Figure 5a~5c
AI summary
The invention relates to a load-detecting orthesis comprising a sensor, which generates sensor signals and which has sensor elements in pressure zones, and comprising a sensor signal-analyzing electronic system for same, said system being designed to indicate critical loads. The sensor signal-analyzing electronic system is designed to ascertain characteristic values for pressure load events detected by means of the sensor elements at least in pressure zones, to form a sum value for which the characteristic values are taken into account in a weighted manner according to the magnitude such that at least three different weights are used, and to generate an indication signal if the sum value exceeds a specified magnitude.