Automatic calibration of the sensitivity of a subject to a drug

• US 8,512,273 B2
• Filed: 02/28/2007
• Issued: 08/20/2013
• Est. Priority Date: 03/06/2006
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Rantala, Tor Borje, Paloheimo, Morkku
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): CARPENTER, WILLIAM R
• Application Number:
  US11/680,328
• Publication Number:
  US 20070208322A1
• Time in Patent Office: 2,365 Days
• Field of Search: 604/23, 604/24, 604/26, 604/65, 604/500, 604/512, 604/514, 600/300, 600/544, 600/545, 128/910
• US Class Current: 604/23
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4821 Determining level or depth of anaesthesia A61B5/1106 takes precedence
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2202/0241 Anaesthetics; Analgesics
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

A method, a system, and a computer program for calibration of sensitivity of a subject to a drug. The subject is delivered with the drug at a delivery rate and a signal responsive to the drug is measured from the subject. When determining the sensitivity of the subject to the drug in question, a change in the delivery rate of the drug is initiated. The change in the delivery rate causes a small change in the signal responsive to the drug. The change in the measured signal caused by the drug delivery rate change is detected, and the sensitivity of the patient is determined.

Claims

1. A method for calculating a current sensitivity of a subject to administration of an anesthetic drug during surgery, said method comprising the steps of:

changing an infusion rate of the drug by a calibration amount during surgery for calibration, in addition to a therapeutic infusion of the drug;

detecting a change in an entropy signal in response to the infusion rate change; and

determining a current sensitivity of the subject to the drug based on the change in the entropy signal wherein the current sensitivity has a value defined by a ratio comprising the change in the entropy signal and the change in the infusion rate.

2. The method according to claim 1, further comprising the step of:

adjusting a delivery rate of the drug based on the current sensitivity of the subject.

3. The method according to claim 1, wherein said entropy signal is derived from an electroencephalogram (EEG) signal.

4. The method according to claim 1, wherein said entropy signal is derived from an electroencephalogram (EEG) signal and a frontalis electromyographic (FEMG).

5. The method according to claim 1, further comprising calculating the infusion rate change corresponding to a desired anesthesia level.

6. The method according to claim 1, further comprising calculating the calibration amount corresponding to a desired anesthesia level.

7. The method according to claim 1, wherein the method further comprises:

automatically initiating the calibration of the subject'"'"'s sensitivity to the drug.

8. The method according to claim 1, wherein the method further comprises:

calibrating the subject'"'"'s sensitivity to the drug at given intervals.

9. A method according to claim 1, wherein the method further comprises the step of:

setting at least one safety limit so that the subject is never given the drug over the safety limit.