Telecare Threshold Detection Using Statistical Metrics

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Solution Overview

Problem

Telecare systems face challenges in setting threshold values for detecting abnormal time intervals between events, leading to either excessive false alarms or delayed alerts, due to the lengthy 'learning' phase required to establish reliable threshold values, which hinders commercialization and widespread adoption.

Innovation Solution

A system that establishes reference threshold values based on statistical metrics from established nodes, allowing newly-installed nodes to quickly determine if a time period exceeds a threshold by comparing preliminary data with stored reference data, thereby reducing the learning period and enabling immediate or rapid detection of abnormal intervals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If threshold values are established through a lengthy learning phase using statistical metrics from sensed events, then the reliability of abnormal event detection is improved, but the time required for the system to become operational increases excessively

Engineering Contradiction:
Improvedetection reliabilityVSAvoidlearning period duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary data collection and statistical analysis during the normal operation phase, continuously gathering inter-event time interval data and calculating statistical metrics (mean, standard deviation) in the background. This preliminary action allows the threshold value to be established without requiring a separate, lengthy learning phase, thus resolving the contradiction between detection reliability and operational time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system automatically establishes its own threshold values by performing self-testing and self-calibration during normal operation. The monitoring system independently collects data, calculates statistical metrics, and determines appropriate threshold values without requiring extended external configuration or manual intervention, enabling rapid deployment while ensuring reliable detection.

Inventive Principle:
Principle #25Self-service

2Productivity

If a fixed threshold value is used for detecting abnormal time intervals, then the system can operate immediately without a learning phase, but the system generates excessive false alarms or delayed alerts

Engineering Contradiction:
Improvesystem operational speedVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The threshold value is made dynamic rather than fixed. The system continuously monitors inter-event time intervals and automatically adjusts the threshold based on real-time statistical metrics (mean and standard deviation of the data). This dynamic adaptation allows the system to operate immediately with a preliminary threshold while maintaining high detection accuracy by continuously optimizing the threshold based on actual operational data.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the threshold parameter based on statistical analysis of operational data. Instead of using a static threshold, the system calculates the mean and standard deviation of inter-event time intervals and dynamically adjusts the threshold to be mean plus n times standard deviation. This parameter change enables the system to achieve both rapid deployment and high detection accuracy.

Inventive Principle:
Principle #35Parameter changes

3Speed

If the threshold value is set too low to detect abnormal events quickly, then response time is reduced, but the number of false alarms increases excessively

Engineering Contradiction:
Improvedetection speedVSAvoidfalse alarm frequency
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The system incorporates feedback mechanisms where the detected events and their time intervals are continuously fed back into the statistical analysis. The threshold is adjusted based on feedback from the actual operational data, allowing the system to learn the normal variation patterns and distinguish true abnormalities from normal fluctuations. This feedback loop enables fast detection while minimizing false alarms.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary statistical analysis to establish baseline characteristics of normal operation before setting the final threshold. By pre-calculating the mean and standard deviation from initial data and using these to set an optimized threshold (mean + nĂ—standard deviation), the system achieves both rapid detection capability and low false alarm rate from the outset.

Inventive Principle:
Principle #10Preliminary action

4Object-generated harmful factors

If the threshold value is set too high to reduce false alarms, then false alarm frequency is reduced, but the system fails to detect abnormal events in a timely manner

Engineering Contradiction:
Improvefalse alarm frequencyVSAvoiddetection speed
Core Design Contradiction:
Object-generated harmful factorsVSSpeed

Solution Approach 1:

The system dynamically changes the threshold parameter based on statistical metrics calculated from operational data. By setting the threshold as mean plus n times standard deviation (where n is a configurable multiplier), the system adapts to the specific operational context and achieves optimal balance between false alarm reduction and timely detection. This parameter change allows the threshold to be neither too high nor too low, but optimally positioned.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system performs preliminary data collection and statistical analysis to establish the baseline characteristics of normal operation before finalizing the threshold setting. This preliminary action enables the system to understand the natural variation in inter-event intervals and set an appropriate threshold that reduces false alarms while maintaining detection sensitivity, avoiding both excessively high and low threshold settings.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS8471712B2Detecting abnormal time intervals
Publication Date: 2013.06.25 BRITISH TELECOM PLC
  • US8471712B2 patent drawing
  • US8471712B2 patent drawing
  • US8471712B2 patent drawing

AI summary

A system for determining if a time period after a sensing node has sensed an event exceeds a threshold value, including establishing means for establishing a plurality of reference threshold values, wherein each reference threshold value is associated with a set of reference inter-event time intervals or metrics statistically derived therefrom, calculating means for calculating a set of preliminary time intervals or metrics statistically derived therefrom, based on events sensed by the sensing node, comparing means for comparing the set of preliminary inter-event time intervals or metrics statistically derived therefrom, with each set of reference inter-event time intervals or metrics statistically derived therefrom, identifying means for identifying the reference threshold value associated with the set of reference inter-event time intervals or metrics statistically derived therefrom, being the closest match to the set of preliminary inter-event time intervals or metrics statistically derived therefrom, and determining means for determining if, upon the sensing node sensing a further event, the time period after the sensing node has sensed the event exceeds the identified reference threshold value before a yet further event is sensed by the sensing node or an associated sensing node.