Method and apparatus for providing improved assessment of a physiological condition of a patient

• US 20060167368A1
• Filed: 01/27/2005
• Published: 07/27/2006
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Original Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Inventors: Sarkela, Mika
• Granted Patent: US 8,219,187 B2
• Time in Patent Office: Days
• US Class Current: 600/544
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/372 Analysis of electroencephalograms
• CPC Class Codes: A61B 5/397 Analysis of electromyograms

Abstract

In a method and apparatus for providing an indication suitable for assessing a physiological condition of a patient, at least two biosignals are obtained from the patient. The biosignals contain at least one common physiological data component, such as an EEG or EMG component. An analysis of each of the biosignals is carried out to obtain a complexity value for each of the biosignals. Or, the biosignals may be divided into their components and a complexity value is obtained for the biosignal components. Thereafter and on the basis of the complexity values, a complexity value indicative of at least one physiological data component present in the biosignals is selected and utilized to provide the physiological condition assessment indication of the patient.

Claims

1. A method for providing an indication suitable for assessing a physiological condition of a patient, said method comprising the steps of:

(a) obtaining at least two biosignals from the patient, the biosignals containing at least one common physiological data component related to the physiological condition of the patient;

(b) carrying out an analysis of each of the biosignals to obtain a complexity value for each of the biosignals;

(c) selecting, on the basis of the complexity values, at least one complexity value for use as an indication; and

(d) utilizing the selected complexity value to provide a physiological condition assessment indication of the patient.

2. The method of claim 1 wherein the obtained biosignals contain at least two common physiological data components, and wherein step (c) is further defined as selecting a complexity value indicative of each of the physiological data components and step (d) is further defined as utilizing the selected complexity values to provide a physiological condition assessment indication of the patient.

3. The method of claim 2 wherein a common physiological data component is an EEG component.

4. The method of claim 2 wherein a common physiological data component is an EMG component.

5. The method of claim 3 wherein a further common physiological data components are an EMG component.

6. The method of claim 1 wherein the obtained complexity values are the entropies of the biosignals.

7. The method of claim 6 wherein the obtained complexity values are the spectral entropies of the biosignals.

8. The method of claim 6 wherein the obtained complexity values are the approximate entropies of the biosignals.

9. The method of claim 1 or 2 wherein the obtained complexity values are the Lempel-Ziv complexities of the biosignals.

10. The method of claim 1 or 2 wherein the obtained complexity values are obtained from fractal spectrum analysis of the biosignals.

11. The method of claim 1 wherein steps (b), (c), and (d) are periodically repeated.

12. The method of claim 1 wherein the obtained biosignals contain at least two common physiological data components, said method further including the step of dividing the obtained biosignals into signal components;

wherein

step (b) is further defined as carrying out an analysis of each of the signal components to obtain a complexity value for each of the signal components, and wherein step (c) is further defined as selecting a complexity value indicative of each of the physiological data components and step (d) is further defined as utilizing the selected complexity values to provide a physiological condition assessment indication of the patient.

13. The method of claim 12 wherein the step of dividing the biosignals is carried out on a time domain basis.

14. The method of claim 12 wherein the step of dividing the biosignals is carried out on a frequency domain basis.

15. The method of claim 12 where a criterion used to divide the biosignals into components is changeable.

16. The method of claim 1, 3, 4, 5, 6, or 11 further defined as a method for assessing the state of sedation or anesthesia of a patient.

17. The method of claim 1, 3, 4, 5, 6, or 11 further defined as using the indication provided in step (d) to control the delivery of drugs to the patient.

29. The method of claim 2 wherein the obtained complexity values are the entropies of the biosignals.

18. Apparatus for providing an indication suitable for assessing a physiological condition of a patient, said method comprising:

means obtaining at least two biosignals from the patient, the biosignals containing at least one common physiological data component related to the physiological condition of the patient;

analysis means carrying out an analysis of each of the biosignals to obtain a complexity value for each of the biosignals;

means for selecting, on the basis of the complexity values, at least one complexity value for use as an indication; and

means for providing a physiological condition assessment indication of the patient from the selected complexity value or values.

19. The apparatus of claim 18 wherein the obtained biosignals contain at least two common physiological data components, and where said selecting means is further defined as selecting a complexity value indicative of each of the physiological data components and said providing means is further defined as providing a physiological condition assessment indication of the patient from the selected complexity values.

20. The apparatus of claim 19 wherein the physiological data components of the biosignals obtained by said obtaining means are EEG and EMG components.

21. The apparatus of claim 18 or 19 wherein said analysis means obtains a complexity value or values comprising the entropies of the biosignals.

22. The apparatus of claim 18 further including means for dividing the obtained biosignals into signal components;

and wherein said analysis means is further defined as carrying out an analysis of each of the signal components to obtain a complexity value for each of the signal components.

23. The apparatus of claim 22 wherein the selecting means is further defined as selecting a complexity value indicative of each of the physiological data components and said providing means is further defined as providing a physiological condition assessment indication of the patient from the selected complexity values.

24. The apparatus of claim 22 wherein said means for dividing the biosignals into signal components carries out the division on a time domain basis.

25. The apparatus of claim 22 wherein said means for dividing the biosignals into signal components carries out the division on a frequency domain basis.

26. The apparatus of claim 22 further including means to change a criterion used to divide the biosignals.

27. The apparatus of claim 18 or 22 further defined as one for assessing the state of sedation or anesthesia of a patient.

28. The apparatus of claim 18 or 22 further defined as including means for using the provided indication to control the delivery of drugs to a patient.