FEEDBACK CONTROLLED GASTRO-INTESTINAL STIMULATION

• US 20100222841A1
• Filed: 10/03/2008
• Published: 09/02/2010
• Est. Priority Date: 10/05/2007
• Status: Active Grant

• Current Assignee: UTI Limited Partnership
• Original Assignee: UTI Limited Partnership
• Inventors: Mintchev, Martin P.
• Granted Patent: US 9,707,392 B2
• Time in Patent Office: Days
• US Class Current: 607/40
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/4238 stomach
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control

Abstract

Neural Gastric Electrical Stimulation (NGES) is a new method for invoking gastric contractions under microprocessor control. However, optimization of this technique using feedback mechanisms to minimize power consumption and maximize effectiveness has been lacking. An apparatus and method are provided for inducing controlled gastro paresis. The apparatus comprises a contraction sensor, a stomach contraction generator, and a controller. The contraction sensor is responsive to circumferential contractions of the stomach, and outputs a signal indicative of a circumferential contraction. The stomach contraction generator induces a circumferential contraction upon receipt of an electrical signal from the controller. The controller sends the electrical signal to the generator upon receipt of the output signal from the sensor. The method comprises the steps of sensing a circumferential contraction of the stomach, and invoking a circumferential contraction of the stomach in response to sensing the circumferential contraction.

Claims

1. An apparatus comprising:

a contraction sensor located on a portion of a gastrointestinal tract and responsive to a circumferential contraction of the portion of a gastrointestinal tract, the contraction sensor having as output a signal indicative of circumferential contraction of the portion of a gastrointestinal tract;

a contraction generator located in relation to the portion of a gastrointestinal tract, spaced distally from the contraction sensor, the contraction generator being located to induce a circumferential contraction upon receipt of an electrical signal at the contraction generator; and

a controller having as at least one input the output from the contraction sensor, and configured to output an electrical signal to the contraction generator upon receipt of output from the contraction sensor indicative of a contraction.

2. The apparatus of claim 1 in which the portion of the gastrointestinal tract is the stomach, and the contraction generator is located closer to the pylorus than the contraction sensor.

3. The apparatus of claim 2 in which the contraction sensor comprises a first set of electrodes implanted in the stomach, wherein the stomach has a gastric axis, and in which the first set of electrodes is implanted circumferentially around a first circumference defined by a radius about the gastric axis.

4. The apparatus of claim 3 in which the controller is configured to measure impedance between electrodes of the first set of electrodes.

5. The apparatus of claim 4 in which the contraction generator comprises;

a second set of electrodes implanted in the stomach, wherein the second set of electrodes is implanted circumferentially around a second circumference defined by a radius about the gastric axis.

6. The apparatus of claim 5 in which the stomach further comprises an antrum, and wherein the first set of electrodes and the second set of electrodes are implanted in the antrum.

7. The method of claim 6 in which the second set of electrodes is positioned 2-3 cm from the pylorus.

8. The method of claim 7 in which the second set of electrodes is positioned 3-4 cm from the first set of electrodes.

9. The apparatus of claim 5 in which the controller is configured to apply to the second set of electrodes an electrical current that overrides natural contractions of the stomach.

10. The apparatus of claim 3 in which the contraction generator comprises;

a second set of electrodes implanted in the stomach, wherein the second set of electrodes is implanted circumferentially around a second circumference defined by a radius about the gastric axis.

11. The apparatus of claim 2 in which the contraction sensor comprises at least one force transducer.

12. A method of inducing controlled gastroparesis, comprising:

sensing a circumferential contraction of a portion of a gastrointestinal tract at a first location on the gastrointestinal tract; and

in response to sensing the circumferential contraction, invoking a circumferential contraction of the portion of a gastrointestinal tract at a second location on the portion of a gastrointestinal tract, the second location being located distally in relation to the first location.

13. The method of claim 12 in which the portion of a gastrointestinal tract is the stomach, the second location is closer to the pylorus than the first location.

14. The method of claim 13 in which sensing a circumferential contraction comprises sensing impedance between electrodes implanted in the stomach.

15. The method of claim 14 in which the contraction is invoked in the antrum of the stomach.

16. The method of claim 15 in which invoking a contraction comprises applying an electrical current to the stomach at the second location.

17. The method of claim 16 in which invoking a contraction further comprises overriding a natural contraction of the stomach.

18. The method of claim 17 in which invoking a contraction further comprises applying an electrical current to the stomach at a third location, the third location being further from the pylorus than the second location.

19. The method of claim 14 in which sensing the impedance comprises the steps of:

a) measuring the impedance along a circumference of the stomach wall defined by the gastric axis;

b) repeating step a) when the measured impedance is above a threshold value; and

c) sending a signal to invoke a contraction when the measured impedance is below the threshold value.

20. The method of claim 19 further comprising subtracting a moving average from the measured impedance prior to comparing the measured impedance to a threshold value.

21. The method of claim 20 in which the moving average of impedance measurements is calculated from the last twenty seconds.

22. The method of claim 14 in which the step of sensing the circumferential contraction comprises sensing the force of deformation of the stomach wall.

23. The method of claim 22 in which sensing the force of deformation further comprises the steps of:

a) measuring the force of deformation of the stomach wall;

b) repeating step a) when the measured force is below the threshold value; and

c) sending a signal to invoke a contraction when the measured force is above the threshold value.

24. The method of claim 23 further comprising subtracting a moving average from the measured force prior to comparing the measured force to a threshold value.

25. The method of claim 13 further comprising the steps of:

observing a refractory period after invoking a contraction; and

repeating the steps.

26. The method of claim 25 wherein the refractory period is longer than twenty seconds.

27. A method for sensing a contraction in a gastrointestinal tract, the gastrointestinal tract comprising a gastric axis, the method comprising:

a) measuring the impedance along a first circumference of the gastrointestinal tract defined by a radius of the gastric axis;

b) repeating step (a) when the measured impedance is above a threshold value; and

c) sending a signal indicating that a circumferential contraction has been sensed when the measured impedance is below the threshold value.

28. The method of claim 27 further comprising subtracting a moving average from the measured impedance prior to comparing the measured impedance to a threshold value.

29. The method of claim 28 in which the moving average is calculated from the last twenty seconds.

30. The method of claim 27 in which the impedance is measured by a set of electrodes.

31. The method of claim 30 further comprising the step of:

invoking a circumferential contraction along a second circumference of the gastrointestinal tract defined by a radius of the gastric axis in response to sensing the circumferential contraction, the second circumference being closer to the rectum than the first circumference.

32. The method of claim 31 wherein invoking a contraction further comprises applying an electrical current to the gastrointestinal tract along the second circumference.

33. The method of claim 32 wherein invoking a contraction further comprises applying an electrical current to the gastrointestinal tract along the first circumference.

34. The method of claim 32 wherein invoking a contraction further comprises applying an electrical current to the gastrointestinal tract along a third circumference of the gastrointestinal tract, the third circumference defined by a radius of the gastric axis.

35. The method of claim 31 further comprising the steps of:

observing a refractory period after invoking a contraction; and

repeating the steps.

36. The method of claim 35 wherein the refractory period is longer than twenty seconds.

37. The method of claim 31 in which the invoked contraction overrides the sensed circumferential contraction.