EMG Seizure Detection via T-Squared Spectral Analysis

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Solution Overview

Problem

Current seizure detection methods, particularly EEG-based systems, are cumbersome, invasive, and not suitable for long-term home use, often failing to detect seizures without violent motor movements, which can be absent in some cases, posing a risk for Sudden Unexplained Death in Epilepsy (SUDEP) due to lack of timely intervention.

Innovation Solution

A non-invasive EMG-based system that detects muscle activity using EMG electrodes and digital filtering to isolate spectral data within specific frequency bands (2 Hz to 1000 Hz), calculates T-squared or PCA values, and compares these to reference values to trigger an alarm, allowing for seizure detection even without violent motion and in home settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If EEG-based seizure detection systems are used, then seizure detection capability is improved, but device complexity and ease of operation deteriorate due to multiple electrodes and technical expertise requirements

Engineering Contradiction:
Improveseizure detection capabilityVSAvoidnumber of electrodes and monitoring equipment
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the seizure detection function from the complex EEG system by using EMG electrodes placed on muscles to detect electrical activity. Instead of monitoring brain waves directly with multiple scalp electrodes, the system extracts muscle electrical signals that correlate with seizure activity, simplifying the device while maintaining detection capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/electrical EEG electrode system with an EMG-based system that detects muscle electrical activity. This substitution uses a different physiological mechanism (muscle electrical signals rather than brain waves) to achieve the same diagnostic goal, reducing device complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If EEG-based seizure detection systems are used, then seizure detection capability is improved, but ease of operation deteriorates due to requirement for technical expertise and staffed clinical environment

Engineering Contradiction:
Improveseizure detection capabilityVSAvoidtechnical expertise and clinical environment requirement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent enables the system to function autonomously in home settings without requiring staffed clinical environments. The EMG-based device can be operated by patients or caregivers with minimal training, as it automatically detects and records seizure-related muscle activity without needing technical expertise for electrode placement or system operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of requiring complex clinical infrastructure to achieve reliable detection, the patent inverts the approach by using simple EMG electrodes that can be placed on muscles and connected to portable recording devices, enabling reliable seizure detection in home environments without clinical staff

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If accelerometer-based seizure detection is used, then detection of violent motor movements is improved, but reliability deteriorates because seizures without violent movement are not detected

Engineering Contradiction:
Improvedetection of violent motor movementsVSAvoidseizure detection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent uses EMG signals as an intermediary between brain activity and observable movement. By detecting electrical activity in muscles before and during contraction, the system identifies seizure-related muscle activation even when no violent movement occurs, serving as an early warning indicator that bridges the gap between neural activity and motor output

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent detects muscle electrical activity that precedes actual muscle contraction and movement. By monitoring EMG signals, the system identifies seizure onset in muscles before violent movements occur, providing advance warning and enabling detection of seizures that would be invisible to accelerometer-based systems

Inventive Principle:
Principle #10Preliminary action

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 system provides accurate and minimally intrusive seizure detection, alerting caregivers and being adaptable for individual demographics, thus reducing the risk of SUDEP by enabling timely intervention during seizures with motor manifestations.

Implementation Method 1

electromyography (EMG) is a little-used technique in which an electrode may be placed on or near the skin, over a muscle, to detect an electrical current or change in electric potential in response to redistribution of ions within muscle fibers

Methodology Applied
Scientific EffectElectromyography (EMG):

Implementation Method 2

Changes in states of ion channels initiate a change in the permeability of a cell membrane, and subsequent redistribution of charged ions

Methodology Applied
Scientific EffectIon channel redistribution:

Implementation Method 3

using digital filtering to isolate from the EMG signals spectral data for a plurality of frequencies bands selected from the range of about 2 Hz to about 1000 Hz

Methodology Applied
Scientific EffectDigital filtering: Filter (electronic)

Implementation Method 4

calculating a first T-squared value, the first T-squared value being determined from spectral data for the plurality of frequency ranges

Methodology Applied
Scientific EffectT-squared statistics:

Implementation Method 5

calculating a first PCA value, the first PCA value being determined from spectral data for the plurality of frequency ranges

Methodology Applied
Scientific EffectPrincipal Component Analysis (PCA):

Data Source

PatentUS9439596B2Method and apparatus for detecting seizures
Publication Date: 2016.09.13 NOVELA NEUROTECHNOLOGY
  • US9439596B2 patent drawing
  • US9439596B2 patent drawing
  • US9439596B2 patent drawing

AI summary

A method and apparatus for detecting seizures with motor manifestations including detecting EMG signals, isolating from the EMG signals spectral data for a plurality of frequency bands, and calculating a T-squared value there from. The T-squared values may be detected in real time, such as in a patient's home environment, and the T-squared data may be compared to a threshold T-squared value to determine whether an alarm is sent.