EXTERNAL CONTINUOUS FIELD TOMOGRAPHY

• US 20070135721A1
• Filed: 11/22/2006
• Published: 06/14/2007
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Proteus Digital Health, Inc. (Otsuka Holdings Company Limited)
• Original Assignee: Proteus Digital Health, Inc. (Otsuka Holdings Company Limited)
• Inventors: ZDEBLICK, MARK
• Granted Patent: US 8,204,586 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration

Abstract

Methods for evaluating tissue motion of a tissue location, e.g., a cardiac location, via external continuous field tomography are provided. Aspects of the methods include generating at least one substantially linear continuous field gradient across the tissue location of interest, and using a resultant signal from a sensing element stably associated with the tissue location to evaluate motion of the tissue location. Also provided are systems, devices and related compositions for practicing the subject methods. The subject methods and devices find use in a variety of different applications, including cardiac resynchronization therapy.

Claims

1. A method for evaluating an internal tissue location in a subject, said method comprising:

(a) generating a substantially linear field gradient in said subject across said tissue location;

(b) obtaining a linear field gradient dependent reading from a sensing element stably associated with said tissue location; and

(c) evaluating said internal tissue location using said reading.

2. The method according to claim 1, wherein said substantially linear field gradient is a substantially linear electric field gradient.

3. The method according to claim 2, wherein said substantially linear field gradient is generated from a set of external electrode pairs.

4. The method according to claim 3, wherein each electrode member of said set broadcasts at two or more frequencies.

5. The method according to claim 3, wherein each pair of said set comprises its own electrodes.

6. The method according to claim 3, wherein at least two pair members of said set share a common electrode.

7. The method according to claim 3, wherein said set comprises three or more electrode pairs.

8. The method according to claim 3, wherein said set comprises electrode pairs arranged circumferentially around a portion of said subject.

9. The method according to claim 3, wherein said generating comprises locating each electrode of said set in three-dimensional space and actuating electrode members of said set based on said locating in a manner sufficient to produce said substantially linear field gradient.

10. The method according to claim 2, wherein said linear field gradient dependent reading is a voltage.

11. The method according to claim 10, wherein said voltage is an AC voltage.

12. The method according to claim 2, wherein said linear field gradient dependent reading is a gradient reading.

13. The method according to claim 12, wherein said gradient reading is employed to evaluate said internal tissue location.

14. The method according to claim 2, wherein said method comprises generating two or more distinguishable substantially linear electric field gradients.

15. The method according to claim 14, wherein said two or more distinguishable substantially linear electric field gradients differ from each other by frequency.

16. The method according to claim 1, wherein said evaluating comprises using said reading to determine location of said sensing element.

17. The method according to claim 1, wherein said evaluating comprises using said reading to determine velocity of said sensing element.

18. The method according to claim 1, wherein said evaluating comprises using said reading to determine acceleration of said sensing element.

19. The method according to claim 1, wherein said tissue location is a cardiac location.

20. The method according to claim 19, wherein said cardiac location is a heart wall location.

21. The method according to claim 1, wherein said sensing element is an electrode.

22. The method according to claim 21, wherein said electrode is present on a lead.

23. The method according to claim 1, wherein said method comprises obtaining a reading at least twice over a duration of time to evaluate movement of said tissue location.

24. The method according to claim 1, wherein said method is a method of determining timing of cardiac wall motion.

25. The method according to claim 24, wherein said method is a method of determining cardiac wall motion of a first cardiac wall relative to a second cardiac wall.

26. The method according to claim 25, wherein said method is a method of determining timing of cardiac wall motion of a first cardiac wall relative to a second cardiac wall.

27. The method according to claim 26, wherein said method is a method of detecting ventricular mechanical dyssynchrony.

28. The method according to claim 27, wherein said method further comprises performing cardiac resynchronization therapy based on said detected dyssynchrony.

30. A computer readable storage medium having a processing program stored thereon, wherein said processing program operates a processor which operates a system according to claim 29 to perform a method according to claim 1.

31. A processor comprising a computer readable medium according to claim 30.

32. A kit comprising;

a computer readable storage medium according to claim 30.

33. The kit according to claim 32, wherein said computer readable storage medium is present in a processor according to claim 31.

29. A system comprising:

(a) an external substantially linear field gradient generator;

(b) a sensing element for obtaining a linear field gradient dependent reading;

(c) a locator for three dimensionally locating sources of said substantially linear field gradient; and

(d) a signal processing element configured to employ a reading obtained from said sensing element to evaluate an internal tissue location.