Wearable Sensor Measurement Confidence via Signal Quality Metrics

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Solution Overview

Problem

Wearable devices face challenges in accurately determining measurement confidence for biometric data due to hardware and software limitations, leading to inappropriate data processing and reduced confidence in feedback accuracy, especially in real-time non-parametric data and when determining if the device is being worn by a user.

Innovation Solution

Implementing a wearable device with sensors that collect and process biometric data, using frequency transformation to create non-parametric data sets for probabilistic modeling, estimating signal quality, and determining measurement confidence through signal quality metrics, which helps validate the accuracy of biometric data and confirm if the device is being worn.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wearable devices use multiple biometric sensors to collect and process data, then the quantity and speed of feedback is improved, but the accuracy and confidence in measurement data deteriorates due to hardware and software limitations

Engineering Contradiction:
Improvefeedback speedVSAvoidmeasurement confidence
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by collecting reference biometric data during a calibration period when the device is known to be worn correctly. This reference data is stored and used later to compare against new measurements, enabling the system to validate measurement confidence in real-time without sacrificing feedback speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously comparing new biometric measurements against the reference data to calculate measurement confidence scores. This feedback mechanism allows the device to identify and filter low-quality measurements while maintaining high feedback speed through efficient computational algorithms.

Inventive Principle:
Principle #23Feedback

2Productivity

If the device processes all collected data as biometric measurement data, then the productivity is improved, but the reliability deteriorates due to inappropriate data being processed

Engineering Contradiction:
Improvedata processing throughputVSAvoiddata accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system extracts and separates appropriate biometric measurement data from inappropriate data using measurement confidence analysis. By calculating confidence scores based on reference data comparison, the system identifies and extracts only the reliable measurements for further processing, while filtering out noise and artifacts.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes parameters by introducing measurement confidence scores as an additional parameter to evaluate data quality. This allows the system to dynamically adjust which data points are processed based on their confidence levels, maintaining high throughput while ensuring reliability through parameter-based filtering.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the device determines measurement confidence using reference data and signal quality metrics, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvebiometric data accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the complexity by dividing the measurement validation process into distinct modules: reference data collection, signal quality metric calculation, confidence score computation, and data filtering. This segmentation allows each component to be optimized independently and processed efficiently in a pipeline architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies partial action by calculating measurement confidence selectively based on signal quality thresholds. Instead of performing complex confidence analysis on every single data point, the system first filters data using signal quality metrics and only performs detailed confidence analysis on data that passes initial quality checks, reducing overall computational complexity.

Inventive Principle:
Principle #16Partial or excessive action

4Reliability

If the device uses voltage threshold checks and signal quality metrics to determine wear status, then the reliability of wear detection is improved, but the measurement time increases

Engineering Contradiction:
Improvewear detection accuracyVSAvoidmeasurement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system uses periodic action by implementing a multi-stage verification process with voltage threshold checks performed at regular intervals during the calibration period. This periodic sampling approach allows the system to accumulate sufficient evidence for wear status determination without requiring continuous analysis, balancing reliability with time efficiency.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS9729693B1Determining measurement confidence for data collected from sensors of a wearable device
Publication Date: 2017.08.08 ZEPP INC
  • US9729693B1 patent drawing
  • US9729693B1 patent drawing
  • US9729693B1 patent drawing

AI summary

Systems and methods determining measurement confidence for data collected from sensors of a wearable device are herein disclosed. In an implementation, a confidence measurement that a wearable device is worn by a user can be determined by determining that the wearable device is not in motion, comparing sample voltages collected using a light emitter to thresholds indicative of a surface on which the light is being reflected, calculating a signal quality metric using data collected using a pulse oximeter, and comparing the signal quality metric to thresholds indicative of typical biometric data measurements. Other implementations for confidence measurement can include frequency transforming signal data stored in a buffer, performing probabilistic modelling on the frequency transformed data, and determining a confidence measurement using a signal quality estimation based on the modelled data.