Physiological State Detection Using Change-Point Voting

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Solution Overview

Problem

Conventional systems fail to account for individual differences among human subjects and require extensive data for training, making it challenging to reliably identify abrupt physiological changes such as emotions, stress, and drowsiness using deep learning algorithms.

Innovation Solution

An unsupervised machine-learning approach that uses change point detection, voting processes, and clustering to identify critical change points in physiological signals, allowing for accurate segmentation and probabilistic analysis to detect anomalies without requiring years of data, and includes a feedback mechanism to adjust algorithm thresholds based on ground-truth data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deep learning algorithms are used for anomaly detection, then measurement precision improves, but loss of time increases due to extensive data training requirements

Engineering Contradiction:
Improveanomaly detection accuracyVSAvoidtraining data requirement
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the anomaly detection process into multiple independent change point detection algorithms that operate in parallel on different physiological signal features. Each algorithm detects change points independently, and their results are combined through voting. This segmentation eliminates the need for extensive training data while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a voting mechanism as an intermediary that aggregates results from multiple simple change point detection algorithms. This voting process mediates between individual algorithm outputs to produce the final anomaly detection result, achieving high precision without requiring deep learning training data.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If conventional anomaly detection systems are used, then device complexity is reduced, but reliability worsens due to inability to account for individual differences

Engineering Contradiction:
Improveindividual difference adaptationVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adaptation by continuously updating baseline physiological profiles for each individual subject over time. The system learns each subject's unique baseline state and variations, allowing reliable anomaly detection that accounts for individual differences without requiring complex pre-training on population data.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a universal anomaly detection framework that works across different individuals and physiological conditions using the same multi-algorithm voting approach. The system is universally applicable to various subjects while adapting to their individual characteristics through continuous baseline learning.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250366751A1Systems and methods for identifying physiological states of human subjects
Publication Date: 2025.12.04 TOYOTA MOTOR ENG & MFG NORTH AMERICA INC
  • US20250366751A1 patent drawing
  • US20250366751A1 patent drawing
  • US20250366751A1 patent drawing

AI summary

Systems and methods for identifying physiological states of human subjects are disclosed herein. In one embodiment, a system receives, from one or more sensors, physiological signals of a human subject. The system processes the physiological signals to extract feature signals as time series. The system identifies change points in the feature signals. The system identifies critical change points in the feature signals by applying a voting process to the change points in the feature signals. The system partitions the feature signals into segments based on the critical change points. The system detects a predetermined physiological state (an anomalous physiological state) of the human subject by applying clustering and probabilistic analysis to the segments. In response to detecting the predetermined physiological state, the system automatically takes an action to assist the human subject.