Suicide Risk Device Using Electrodermal and Photoplethysmographic Analysis

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Solution Overview

Problem

Current methods for evaluating suicide risk in depressed individuals are subjective and unreliable, often influenced by external factors and lack precision, making it difficult to accurately identify those at risk.

Innovation Solution

The device combines electrodermal activity measurement with photoplethysmographic analysis and noise interference detection to provide a more reliable assessment of suicidal propensity by incorporating blood volume variations and sound stimulus feedback, ensuring controlled testing conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional psychiatric interviews and patient responses to standard forms are used to evaluate suicide risk, then the evaluation can be conducted with simple equipment and procedures, but the reliability and precision of identifying suicidal patients is low due to subjective factors and patient deception

Engineering Contradiction:

Improvereliability of suicide risk evaluationVSAvoidcomplexity of evaluation system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/subjective system of psychiatric interviews and patient self-reporting with an automated physiological measurement system. The device uses electrodermal activity sensors, sound signal generators, and computer algorithms to objectively measure hyporeactivity, eliminating interviewer bias and patient deception while maintaining operational simplicity through automated analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If electrodermal activity measurement with sound signals is used to detect hyporeactivity, then the precision of identifying suicidal patients is improved, but external noise interference and other disturbing factors can affect the measuring result

Engineering Contradiction:

Improveprecision of electrodermal response measurementVSAvoidnoise interference and external disturbances

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates a microphone to detect ambient noise and feeds this information back to the computer system. The computer analyzes the relationship between sound signals, electrodermal responses, and detected noise levels to distinguish genuine hyporeactivity from responses caused by external disturbances, thereby maintaining measurement precision in noisy environments.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces noise detection as an intermediary measurement that mediates between the sound stimulus and the electrodermal response. By measuring ambient noise levels and incorporating them into the analysis, the system can differentiate between electrodermal changes caused by external disturbances and those caused by the test stimuli, preserving measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If multiple measurement parameters including blood volume variations are incorporated, then the comprehensive analysis capability is improved, but the device complexity and signal analysis requirements increase

Engineering Contradiction:

Improvecomprehensive analysis capabilityVSAvoidcomplexity of signal analysis

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple measurement functions (electrodermal activity, blood volume variations via photoplethysmography, and noise detection) into a single integrated device. The computer system receives and analyzes all signals simultaneously, using the combined information to improve diagnostic accuracy while managing complexity through unified signal processing.

Inventive Principle:

Principle #5Merging (Combining)

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

This approach enhances the precision and reliability of suicide risk evaluation by reducing external interference and providing a comprehensive analysis of electrodermal and blood volume responses, improving the accuracy of identifying hyporeactive individuals.

Implementation Method 1

The measuring unit measures the electrodermal activity in the fingers of the person in order to detect depressed persons who are at risk for suicide

Methodology Applied

Scientific EffectElectrodermal activity: Conduction (electrical)

Implementation Method 2

Methodology Applied

Scientific EffectPhotoplethysmography: Absorption (EM radiation)

Data Source

PatentEP3048974B1A device for use in the evaluation of suicide risk

Publication Date: 2022.12.14 EMOTRA

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AI summary

The invention relates to a device for use in the evaluation of suicide risk of a person. The device comprises a measuring unit (1) for measuring electrodermal activity in the fingers of the person in order to detect depressed persons who are at risk for suicide. The measuring unit is arranged to transmit a certain experimentally well defined sound signal or tone to the person and to provide a signal for the analysis of the electrodermal response from the person in question. To facilitate the analysis or increase the precision of the result of the analysis the device also comprises means for measuring orientation reactions in the form of blood volume variations of the person, preferably by means of a phtophletysmographic method peripherally in the fingers (21) and/or centrally in the frontal lobe of the brain through the forehead (22), and changes in the pulse rate of the test person.