Closed-Loop Anesthesia Control with Dual-Frequency Injection

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Solution Overview

Problem

Current systems for controlling anesthesia or sedation in intravenous anesthesia or sedation modes lack effective and reliable methods for titrating anesthetic agents, as clinical signs are non-specific and may be absent, and existing closed-loop systems have not provided full satisfaction in maintaining stable anesthesia depth.

Innovation Solution

A system that acquires and analyzes electrocortical activity signals to derive a depth of anesthesia signal, using a closed-loop control mechanism to automatically regulate the injection of hypnotic and morphinomimetic agents, with distinct control frequencies and thresholds to maintain the anesthesia depth within a predetermined range, incorporating a PID controller for proportional, integral, and derivative actions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If clinical signs (movements, cardiovascular changes) are used to titrate anesthetic agents, then dosage adjustment can be performed, but the signs are non-specific or may be absent, reducing reliability

Engineering Contradiction:

Improvereliability of titrationVSAvoidcomplexity of monitoring system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical/physiological observation methods with electroencephalographic (EEG) monitoring to detect anesthesia depth. The EEG-based bispectral index (BIS) monitoring system substitutes clinical observation with electrical signal analysis, providing objective and reliable titration data without relying on non-specific clinical signs.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary processing system that analyzes EEG signals and converts them into a bispectral index (BIS) value. This intermediary layer translates complex neurological responses into a simplified, reliable metric that directly guides anesthetic titration, improving reliability while maintaining manageable system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If TCI tools are used to adjust anesthetic dosage faster, then response time improves, but the calculated concentrations have poor correlation with clinical state, reducing effectiveness

Engineering Contradiction:

Improvespeed of dosage adjustmentVSAvoidaccuracy of concentration calculation

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the BIS monitoring system continuously provides information about the actual clinical effect of anesthetic agents. This feedback loop allows real-time adjustment of TCI calculations, correcting discrepancies between calculated concentrations and actual clinical state, thereby improving both speed and reliability of dosage adjustment.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If EEG monitoring is used to measure depth of anesthesia, then measurement precision improves, but only trained electroencephalographers can detect changes, increasing operational complexity

Engineering Contradiction:

Improveprecision of anesthesia depth measurementVSAvoidease of EEG interpretation

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces an intermediary processing system that automatically analyzes EEG signals and converts them into a bispectral index (BIS) value. This intermediary layer translates complex neurological responses into a simplified, reliable metric that directly guides anesthetic titration, improving reliability while maintaining manageable system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Productivity

If closed-loop systems are implemented to automatically regulate anesthesia depth, then productivity improves, but the systems have not given full satisfaction, indicating reliability issues

Engineering Contradiction:

Improveautomation of anesthesia managementVSAvoideffectiveness of closed-loop control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP2391409B1System for controlling means for injection of anaesthetics or sedatives

Publication Date: 2017.02.15 MEDSTEER

AI summary

This system is characterized in that it comprises means (2) for obtaining a signal representative of the electrocortical activity of the patient (1), means (3) for analyzing this signal in order to derive from it a signal of depth of anaesthesia, means (4, 5, 6) for monitoring the value and development over time of this signal of depth of anaesthesia, these means being associated with means for calculation of control commands of the injection means, in order to regulate automatically in closed loop the signal of depth of anaesthesia in a predetermined range around a target value, and in that the means (7) for injection of anaesthetics comprise first means for injection of a hypnotic that receive control commands at a first frequency, and second means (8) for injection of a morphinomimetic that receive control commands at a second frequency higher than the first frequency.