METHODS AND DEVICES FOR MEASURING IMPEDANCE IN A GASTRIC RESTRICTION SYSTEM

• US 20090192404A1
• Filed: 01/28/2008
• Published: 07/30/2009
• Est. Priority Date: 01/28/2008
• Status: Active Grant

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Ortiz, Mark S., Dlugos, Daniel F. JR., Plescia, David N., Marcotte, Amy L., Yates, David C.
• Granted Patent: US 8,192,350 B2
• Time in Patent Office: Days
• US Class Current: 600/547
• CPC Class Codes: A61B 2562/164 the sensor is mounted in or on a conformable substrate or carrier
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/107 Measuring physical dimensions, e.g. size of the entire body or parts thereof
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/4238 stomach
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61F 2005/0016 comprising measuring means
• CPC Class Codes: A61F 5/005 Gastric bands

Abstract

Methods and devices are provided for gathering impedance data related to implantable restriction devices. In general, the methods and devices can enable patients, health care providers, and others to use gathered data as a feedback mechanism to non-invasively monitor efficacy of an implantable restriction device in a patient and to identify, modify, and/or prescribe a treatment plan for the patient considering the gathered data. Impedance data can be gathered and analyzed for tissue proximate to the restriction device, e.g., a fat pad between a gastric band and the patient'"'"'s stomach. Electrodes in contact with the tissue can measure an impedance of the tissue, with the impedance between the electrodes changing as the tissue reduces in size (e.g., as fat cells shrink) and/or changes configuration.

Claims

1. A restriction system for forming a restriction in a patient, comprising:

an implantable restriction device configured to form a restriction in a patient;

at least two sensor electrodes disposed on a tissue-contacting surface of the implantable restriction device; and

an impedance measuring device configured to be in electronic communication with the sensor electrodes and to measure an impedance between the sensor electrodes.

2. The system of claim 1, wherein the implantable restriction device comprises an adjustable gastric band.

3. The system of claim 1, further comprising a processor configured to compare an impedance measured between the sensor electrodes with a range of impedance values.

4. The system of claim 1, wherein the sensor electrodes are configured to be in contact with tissue proximate to the restriction formed by the implantable restriction device, and wherein the impedance measuring device is configured to measure the impedance of the tissue.

5. The system of claim 1, further comprising a processor configured to signal for a corrective action if the impedance measuring device measures an impedance between the sensor electrodes that differs from a threshold impedance value.

6. The system of claim 5, wherein the threshold impedance value reflects a baseline amount of tissue proximate to the restriction formed by the implantable restriction device.

7. The system of claim 5, wherein a measured impedance value between the sensor electrodes that differs from a threshold impedance value indicates either patient weight loss or patient weight gain.

8. The system of claim 5, wherein the processor is configured to determine if measured impedance values gathered over a period of time are each at a substantially constant value indicative of a weight loss plateau, and, if so, to signal an alarm.

9. The system of claim 5, wherein the corrective action includes suggesting a change in pressure within the implantable restriction device.

10. The system of claim 5, wherein the corrective action includes suggesting a modification of the patient'"'"'s treatment plan.

11. A restriction system for forming a restriction in a patient, comprising:

an implantable measuring device configured to be in communication with an implantable restriction device configured to form a restriction in a patient, and to gather data related to a weight of the patient; and

a controller configured to signal for an adjustment of the patient'"'"'s treatment concerning the implantable restriction device if the gathered data indicates an inflection regarding the weight of the patient.

12. The system of claim 11, wherein the measuring device includes at least two sensor electrodes disposed on a tissue-contacting surface on the implantable restriction device, and an impedance measuring device configured to be in electronic communication with the sensor electrodes and to measure an impedance between the sensor electrodes.

13. The system of claim 12, wherein the sensor electrodes are configured to be in contact with tissue proximate to the restriction formed by the implantable restriction device, and wherein the impedance measuring device is configured to measure the impedance of the tissue.

14. The system of claim 13, wherein the controller is configured to signal for a change of fluid volume within the implantable restriction device if the measured impedance falls within a range of impedance values.

15. The system of claim 11, wherein the controller is configured to analyze the gathered data for an inflection in a plot line indicating a minimization of a fat pad of the patient.

16. The system of claim 11, further comprising a pressure sensor configured to sense a pressure of fluid within the implantable restriction device and to communicate pressure data to the controller, wherein the controller is configured to use the pressure data to corroborate an inflection regarding the weight of the patient and to signal for an adjustment of the patient'"'"'s treatment if so corroborated.

17. The system of claim 11, wherein the signal for an adjustment of the patient'"'"'s treatment includes a signal to adjust an amount of fluid within the implantable restriction device.

18. The system of claim 11, wherein the signal for an adjustment of the patient'"'"'s treatment includes a signal to modify the patient'"'"'s treatment plan.

19. A method of controlling weight loss in a patient, comprising:

providing a restriction device configured to be implantable in a patient and having at least two electrodes on a tissue-contacting surface thereof, and

measuring with an impedance sensor an impedance of tissue surrounded by the restriction device.

20. The method of claim 19, further comprising coupling the impedance sensor to a tissue-contacting surface of the restriction device.

21. The method of claim 19, further comprising triggering an alarm signal if the measured impedance differs from a threshold impedance value or falls outside a range of impedance values.

22. The method of claim 21, wherein triggering an alarm signal includes transmitting a signal to an external display device configured to display a notice indicating that the measured impedance differs from the threshold impedance value or falls outside a range of impedance values.

23. The method of claim 21, further comprising, if an alarm signal is triggered, adjusting an amount of fluid within the restriction device.

24. The method of claim 19, further comprising triggering an alarm signal if measured impedance values gathered over a period of time are each at a substantially constant value indicative of a weight loss plateau.

25. The method of claim 19, wherein a difference between the measured impedance of the tissue and an immediately prior measured impedance of the tissue indicates at least one of a bolus of food and a fold in the tissue between the two electrodes.