Anomaly detection based on signal variations

• US 20030004432A1
• Filed: 05/23/2002
• Published: 01/02/2003
• Est. Priority Date: 05/24/2001
• Status: Active Grant

• Current Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Original Assignee: Mirabel Medical Systems Ltd. (Ronny Ginor, MD)
• Inventors: Assenheimer, Michel
• Granted Patent: US 6,993,383 B2
• Time in Patent Office: Days
• 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 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.

2. A method according to claim 1, comprising generating a change 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 determining the change waveform comprises determining a waveform portion which corresponds to a related event in the patient.

13. A method according to claim 12, wherein determining a waveform portion which corresponds to a related event in the patient comprises determining a waveform which is at least partially due to application of an external stimuli to the subject.

14. A method according to claim 13, wherein the application of the external stimuli to the subject comprises injecting a stimuli to the blood stream of the subject.

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

16. A method according to claim 12, wherein determining the change waveform comprises determining a waveform which is mostly due to a cyclic variation in the subject.

17. A method according to claim 16, comprising measuring the frequency of the cyclic variation of the subject and wherein determining the change waveform comprises extracting a signal with the measured frequency.

18. A method according to claim 17, wherein measuring the frequency of the cyclic variation comprises measuring from the sensed signals.

19. 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;

extracting from the sensed signals a time dependent change waveform;

filtering the change waveform so at to remove at least one frequency from the change waveform; and

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

20. 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;

determining at least one parameter of an internal event in the subject;

extracting from the sensed signals a time dependent change waveform responsive to the at least one parameter of the internal event; and

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