Anomaly detection based on signal variations

• US 6,993,383 B2
• Filed: 05/23/2002
• Issued: 01/31/2006
• Est. Priority Date: 05/24/2001
• Status: Expired due to Fees

• Current Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Original Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Inventors: Assenheimer, Michel
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Assistant Examiner(s): Kremer, Matthew
• Application Number:
  US10/155,888
• Publication Number:
  US 20030004432A1
• Time in Patent Office: 1,349 Days
• Field of Search: 600/547, 600/372, 600/382, 600/384, 600/386, 600/461, 600/476, 600/477, 600/478, 600552-555
• US Class Current: 600/547
• CPC Class Codes: A61B 5/0536 Impedance imaging, e.g. by tomography
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence

Abstract

A method of analyzing the type of tissue of a body portion of a subject. The method includes applying an excitation signal to the subject, sensing electrical signals from the subject responsive to the excitation signal, determining a stationary impedance map of the body portion responsive to the sensed signals, determining a change waveform of at least a part of the stationary impedance map, and providing an indication on a tissue type of at least part of the body portion, responsive to the change waveform.

Claims

1. A method of analyzing the type of tissue of a body portion of a subject, comprising:

applying an excitation signal to the subject;

sensing electrical signals from the subject responsive to the excitation signal;

determining a stationary impedance map of the body portion responsive to the sensed signals;

determining, for at least one pixel of the map, a waveform of a change over time in a parameter of the sensed electrical signals corresponding to the at least one pixel, which change waveform corresponds to a related event in the subject that is at least partially due to application of an external stimuli to the subject; and

providing an indication on a tissue type of at least part of the body portion, responsive to the change waveform.

2. A method according to claim 1, comprising generating a change map which is a map of a parameter of the change waveform for the at least part of the stationary map.

3. A method according to claim 2, wherein generating the change map of a parameter of the change waveform comprises generating a change map of the amplitude of the change waveform.

4. A method according to claim 2, comprising displaying the change map.

5. A method according to claim 2, comprising correlating the change map and the stationary map.

6. A method according to claim 5, comprising displaying the change map overlaid on the stationary map.

7. A method according to claim 2, comprising determining areas of increased perfusion of blood in the body portion, responsive to the change map.

8. A method according to claim 1, wherein sensing the signals comprises sensing from a plurality of points on the surface of the body portion and determining the change waveform for each of the plurality of points.

9. A method according to claim 1, wherein sensing the signals comprises sensing electrical currents.

10. A method according to claim 1, wherein sensing the signals comprises sensing electrical voltages.

11. A method according to claim 1, wherein applying signals to the subject comprises applying electrification signals from at least two electrodes which are electrified with signals of different phases.

12. A method according to claim 1, wherein the application of the external stimuli to the subject comprises injecting a stimuli to the blood stream of the subject.

13. A method according to claim 1, wherein the application of the external stimuli to the subject comprises applying pressure to the body portion of the subject.

14. A method according to claim 1, wherein providing the indication comprises filtering at least one frequency from the change waveform and providing the indication responsive to the filtering waveform. analyzing the type of tissue of a body portion of a subject, comprising:

applying an excitation signal to the subject;

sensing signals from the subject responsive to the excitation signal;

injecting a stimulus to the blood stream of the subject;

extracting from the sensed signals a time dependent change waveform responsive to the injected stimulus; and

providing an indication of whether the body portion includes cancerous tissue, responsive to the change waveform.

15. A method according to claim 1, wherein determining the time dependent change waveform comprises determining based on at least 25 samples taken at different times.

16. A method of analyzing the type of tissue of a body portion of a subject, comprising:

applying an excitation signal to the subject;

sensing signals from the subject responsive to the excitation signal;

injecting a stimulus to the blood stream of the subject;

extracting from the sensed signals a time dependent change waveform of a change in a parameter of the sensed signals, responsive to the injected stimulus; and

providing an indication of an identification of a tissue type of at least part of the body portion, responsive to the change waveform,

wherein sensing the signals comprises sensing signals at a plurality of points on the surface of the body portion and determining the change waveform for each of the plurality of points.

17. A method according to claim 16, comprising determining the amplitude of the chage waveform.

18. A method according to claim 16, wherein sensing signals from the subject comprises sensing electrical signals.

19. A method according to claim 16, wherein providing the indication comprises filtering at least one frequency from the change waveform and providing the indication responsive to the filtered waveform.

20. A method according to claim 16, wherein determining the time dependent change waveform comprises determining based on at least 3 samples taken at different times.

21. A method according to claim 16, wherein determining the time dependent change waveform comprises determining based on at least 25 samples taken at different times.

22. A method according to claim 16, wherein determining the time dependent change waveform comprises determining based on samples acquired in a plurality of cardiac cycles of the patient, a plurality of samples being acquired in each cardiac cycle.

23. A method of analyzing the type of tissue of a body portion of a subject, comprising:

applying an excitation signal to the subject;

sensing signals from the subject responsive to the excitation signal;

injecting a stimulus to the blood stream of the subject;

extracting from the sensed signals a time dependent change waveform of a change in a parameter of the sensed signals, responsive to the change waveform,

wherein sensing the signals comprises sensing signals at a plurality of points on the surface of the body portion and determining the change waveform for each of the plurality of points.

24. A method according to claim 23, wherein providing the indication on tissue type of at least part of the body portion comprises providing indication on whether an anomaly is malignant.

25. A method according to claim 23, wherein providing the indication comprises filtering at least one freqeuncy from the change waveform and provdiding the indication responsive to the filtered waveform.

26. A method according to claim 23, wherein determining the time dependent change waveform comprises determining based on at least 25 samples taken at different times.

27. A method of analyzing the type of tissue of a body portion of a subject, comprising:

applying an excitation signal to the subject;

sensing signals from the subject responsive to the excitation signal;

injecting a stimulus to the blood stream of the subject;

extracting from the sensed signals a response to the injected stimulus; and

generating a map, including for each pixel a parameter value characterizing the response to the injected stimulus at a corresponding location of the body portion.

28. A method according to claim 27, wherein sensing signals from the subject comprises sensing electrical signals.

29. A method according to claim 27, wherein generating the map comprises generating a map in which each pixel has a value of a pulsatile amplitude.

30. A method according to claim 27, comprising determining whether the subject has cancer responsive to the map.

31. A method according to claim 27, comprising determining whether the subject has cancer responsive to the map.

32. A method according to claim 27, wherein extracting the response from the sensed signals comprises extracting at least one frequency from the sensed signals.

33. A method according to claim 27, wherein extracting the response from the sensed signals comprises extracting a response based on at least 3 samples taken at different times.

34. A method according to claim 27, wherein extracting the response from the sensed signals comprises extracting a response based on at least 25 samples taken at different times.

35. A method according to claim 27, wherein extracting the response from the sensed signals comprises extracting a response based on a plurality of samples acquired in each of a plurality of cardiac cycles of the patient.