SYSTEM FOR CONTROLLING MEANS FOR INJECTION OF ANESTHETICS OR SEDATIVES

• US 20110295196A1
• Filed: 12/04/2009
• Published: 12/01/2011
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Medsteer
• Original Assignee: Hopital Foch
• Inventors: Trillat, Bernard, Chazot, Thierry, Liu, Ngai
• Granted Patent: US 8,864,702 B2
• Time in Patent Office: Days
• US Class Current: 604/66
• CPC Class Codes: A61M 2202/048 Anaesthetics see also A61M19/00
• CPC Class Codes: A61M 2230/10 Electroencephalographic signals
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

A system comprising means for obtaining a signal representative of the electrocortical activity of the patient, means for analyzing this signal in order to derive from it a signal of depth of anaesthesia, means 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 for injection of anaesthetics comprise first means for injection of a hypnotic that receive control commands at a first frequency, and second means for injection of a morphinomimetic that receive control commands at a second frequency higher than the first frequency.

Claims

1. System for controlling means for injection of anesthetics or sedatives into a patient via an intravenous anesthesia or sedation mode that is concentration or mass flow target-controlled, for inducing and maintaining this anesthesia or this sedation comprising:

means for acquiring a signal representing the electro-cortical activity of the patient,

means for analyzing this signal to determine therefrom a signal of depth of anesthesia,

means for monitoring the value and development over time of this signal of depth of anesthesia, associated with means for calculating control commands of the injection means, for automatic closed-loop regulating of the signal of depth of anesthesia within a predetermined range around a target value,

and wherein;

the means for injecting anesthetic agents comprise first means for injecting a hypnotic agent receiving control commands at a first frequency, and second means for injecting a morphinomimetic agent receiving control commands at a second frequency higher than the first frequency.

2. The control system according to claim 1, further comprising means for input by an operator of the target value of the signal of depth of anesthesia, and means for determining a default target value.

3. The control system according to claim 1, comprising means for input by an operator of a type of anesthesia induction chosen among a group of induction types differing in the initial concentration of hypnotic agent.

4. The control system according to claim 3, wherein the means for inputting the type of induction comprise means for determining the initial concentration of hypnotic agent, with which an initial concentration of morphinomimetic agent predetermined according to the type of chosen induction is associated.

5. The control system according to claim 1, wherein the calculating means comprise means for determining intermediate target values for the signal of depth of anesthesia to define stages during the induction phase.

6. The system for controlling means for injection of anesthetic agents in an intravenous anesthesia mode according to claim 5, wherein the determining means are adapted to determine three intermediate values for stages of anesthesia.

7. The control system according to claim 1, wherein the calculating means comprise means for limiting and/or inhibiting control commands in reverse direction of the first and second injection means.

8. The control system according to claim 1, wherein the calculating means are adapted to increase the concentration of hypnotic agent after a determined number of modifications of the concentration of morphinomimetic agent, to return the signal of depth of anesthesia to within the predetermined range around the target value.

9. The control system according to claim 8, wherein the predetermined number of modifications is equal to three.

10. A method of returning a value of signal depth of anaesthesia to within a predetermined range comprising:

providing the control system according to claim 1, wherein the calculating means are adapted to calculate the difference between the current value of the signal of depth of anesthesia and the target value, and to compare this difference with predetermined threshold values, and optionally

if the current value of the signal of depth of anesthesia is above the target value;

increasing with priority the concentration of morphinomimetic agent when the difference is lower than a first threshold,

increasing the concentration of morphinomimetic agent and increasing the concentration of hypnotic agent to a small proportion when the difference is higher than the first threshold and lower than a second threshold, or

increasing the concentration of morphinomimetic agent and increasing the concentration of hypnotic agent to a larger proportion when the difference is higher than the second threshold,

wherein the value of the signal of depth of anesthesia is returned to within the predetermined range.

11. A method of returning a value of signal depth of anaesthesia to within a predetermined range comprising:

Providing the control system according to claim 1, wherein the calculating means are adapted to calculate the difference between the current value of the signal of depth of anesthesia and the target value, and to compare this difference with predetermined threshold values if the signal is lower than the target value, and optionally

if the current value of the signal of depth of anesthesia is below the target value;

reducing with priority the concentration of morphinomimetic agent when the difference is lower than a third threshold,

reducing the concentration of morphinomimetic agent and reducing the concentration of hypnotic agent to a small proportion when the difference is lower than the third threshold and higher than a fifth threshold, or

reducing the concentration of morphinomimetic agent and reducing the concentration of hypnotic agent to a larger proportion when the difference is lower than the fourth threshold,

wherein the value of the signal of depth of anesthesia is returned to within the predetermined range.

12. The control system according to claim 1 comprising means for determining upper and lower limit values for concentrations of the hypnotic and morphinomimetic agents.

13. The control system according to claim 12, comprising means for manual input by the operator of the upper and lower limit values for concentrations of the hypnotic and morphinomimetic agents.

14. The control system according to claim 1 comprising means for deactivating one and/or the other of the means for calculating control commands of the injection means, to enable the operator to take over the control of the agent injection means manually.

15. The control system according to claim 1 comprising means for maintaining the control commands at their last value before a loss of the signal of electro-cortical activity.

16. The control system according to claim 15, comprising sound and/or visual alert means to warn the operator in the event of loss of the signal of electro-cortical activity.

17. The control system according to claim 1, wherein the injection means comprise motorized means associated with controllers controlling the functioning thereof.

18. A system for controlling an injector of anesthetics or sedatives into a patient via an intravenous anesthesia or sedation mode that is concentration or mass flow target-controlled, for inducing and maintaining this anesthesia or this sedation comprising:

a detector configured to detect a signal representing the electro-cortical activity of the patient,

an analyzer configured to detect the signal to determine therefrom a signal of depth of anesthesia,

a monitor configured to monitor the value and development over time of this signal of depth of anesthesia, associated with a calculator for calculating control commands of the injector, for automatic closed-loop regulating of the signal of depth of anesthesia within a predetermined range around a target value,

and wherein the injector of anesthetic agents comprise a first injector for injecting a hypnotic agent receiving control commands at a first frequency, and second injector for injecting a morphinomimetic agent receiving control commands at a second frequency higher than the first frequency.