Ventricular shunt system and method

• US 8,870,787 B2
• Filed: 07/24/2009
• Issued: 10/28/2014
• Est. Priority Date: 09/16/2003
• Status: Expired due to Fees

• Current Assignee: St. Jude Medical Luxembourg Holdings Ii S.A.R.L.
• Original Assignee: CardioMEMS Incorporated
• Inventors: Yadav, Jay, Cros, Florent
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): TOTH, KAREN E
• Application Number:
  US12/509,053
• Publication Number:
  US 20100022896A1
• Time in Patent Office: 1,922 Days
• Field of Search: 600/486, 600/561
• US Class Current: 600/561
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/031 Intracranial pressure
• 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 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61M 27/006 Cerebrospinal drainage; Accessories therefor, e.g. valves
• CPC Class Codes: G01F 15/066 involving magnetic transmission devices
• CPC Class Codes: G01R 23/12 by converting frequency into phase shift
• CPC Class Codes: G01R 23/145 by heterodyning or by beat-frequency comparison with the harmonic of an oscillator
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A ventricular shunt systems and methods of preventing hydrocephalus are described herein. In one aspect, the ventricular shunt system has at least one pressure sensor that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and is variable in response to the pressure in a patient'"'"'s ventricle.

Claims

1. A ventricular shunt system comprising:

a catheter assembly comprising;

a valve having an inlet port and an outlet port, the valve configured to control a rate of fluid flow between the inlet port and the outlet port;

a ventricular catheter having a distal end and a proximal end, the proximal end of the ventricular catheter being coupled to the inlet port of the valve;

a drainage catheter having a distal end and a proximal end, the proximal end of the drainage catheter being coupled to the outlet port of the valve;

at least one pressure sensor mountable on a portion of the catheter assembly comprising a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of radio frequency (RF) energy;

wherein the passive electrical resonant circuit is variable in response to the pressure in a patient'"'"'s ventricle, wherein each passive electrical resonant circuit, in response to the electromagnetic coupling, is configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of pressure in the patient'"'"'s ventricle, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises an inductance-capacitance (LC) resonant circuit that comprises an inductor operably coupled to a capacitor; and

a sealed reservoir having a distal end positionable proximate the distal end of the ventricular catheter, the sealed reservoir configured to contain a non-compressible fluid, wherein a portion of the distal end of the reservoir is pliable,

wherein the at least one pressure sensor is mountable to detect the pressure of the non-compressible fluid within the sealed reservoir, and wherein the at least one pressure sensor is mounted in a wall of the reservoir.

2. The ventricular shunt system of claim 1, wherein the inductor is a coil inductor.

3. The ventricular shunt system of claim 1, wherein the capacitance of the capacitor is variable in response to the pressure therein the patient'"'"'s ventricle.

4. The ventricular shunt system of claim 1, wherein the capacitor comprises a first and second spaced capacitor elements, wherein at least one of the spaced capacitor elements are mounted in or on a flexible material, and wherein the respective first and second capacitor elements are movable relative to each other in response to pressure changes applied to the flexible material.

5. The ventricular shunt system of claim 1, wherein the inductor is configured to allow inductance in the passive electrical resonant circuit when the pressure sensor is subjected to a time variable electromagnetic field.

6. The ventricular shunt system of claim 1, wherein the inductance of the LC resonant circuit is between about 5 to about 15 micro-Henry.

7. The ventricular shunt system of claim 1, wherein the resonant frequency of the LC resonant circuit is between about 25 to about 45 MHz.

8. The ventricular shunt system of claim 1, wherein the capacitance of the LC resonant circuit is between about 1 to about 20 pF.

9. The ventricular shunt system of claim 1, wherein at least a portion of each pressure sensor is resiliently flexible.

10. The ventricular shunt system of claim 1, wherein the capacitor of each at least one pressure sensor is electrically coupled to a single inductor.

11. The ventricular shunt system of claim 1, wherein the at least one pressure sensor comprises a plurality of individually addressable pressure sensors, the plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.

12. The ventricular shunt system of claim 11, wherein at least one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the drainage catheter.

13. The ventricular shunt system of claim 1, wherein the at least one pressure sensor comprises a plurality of individually addressable pressure sensors, wherein one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the ventricular catheter adjacent the distal end of the ventricular catheter.

14. The ventricular shunt system of claim 13, wherein a plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.

15. The ventricular shunt system of claim 13, wherein at least one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the drainage catheter.

16. The ventricular shunt system of claim 1, wherein the valve is an adjustable valve configured to allow selective flow rates therebetween the respective inlet and outlet ports of the valve.

17. The ventricular shunt system of claim 1, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises a non-linear element and responds in a non-linear manner to an energizing signal.

18. A ventricular shunt system comprising:

a catheter assembly comprising;

a valve having an inlet port and an outlet port, the valve configured to control a rate of fluid flow between the inlet port and the outlet port;

a ventricular catheter having a distal end and a proximal end, the proximal end of the ventricular catheter being coupled to the inlet port of the valve;

a drainage catheter having a distal end and a proximal end, the proximal end of the drainage catheter being coupled to the outlet port of the valve; and

at least one pressure sensor mountable on a portion of the catheter assembly comprising a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of radio frequency (RF) energy;

wherein the passive electrical resonant circuit is variable in response to the pressure in a patient'"'"'s ventricle, and wherein each passive electrical resonant circuit, in response to the electromagnetic coupling, is configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of pressure in the patient'"'"'s ventricle; and

a sealed reservoir having a distal end positionable proximate the distal end of the ventricular catheter, the sealed reservoir configured to contain a non-compressible fluid, wherein a portion of the distal end of the reservoir is pliable,

wherein the at least one pressure sensor is mountable to detect the pressure of the non-compressible fluid within the sealed reservoir, and wherein the at least one pressure sensor is mounted in a wall of the reservoir.

19. The ventricular shunt system of claim 18, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises an inductance-capacitance (LC) resonant circuit that comprises an inductor operably coupled to a capacitor.

20. The ventricular shunt system of claim 19, wherein the capacitance of the capacitor is variable in response to the pressure therein the patient'"'"'s ventricle.

21. The ventricular shunt system of claim 19, wherein the capacitor comprises a first and second spaced capacitor elements, wherein at least one of the spaced capacitor elements are mounted in or on a flexible material, and wherein the respective first and second capacitor elements are movable relative to each other in response to pressure changes applied to the flexible material.

22. The ventricular shunt system of claim 19, wherein the inductor is configured to allow inductance in the passive electrical resonant circuit when the pressure sensor is subjected to a time variable electromagnetic field.

23. The ventricular shunt system of claim 18, wherein the at least one pressure sensor comprises a plurality of individually addressable pressure sensors, wherein at least one pressure sensor of the plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.

24. The ventricular shunt system of claim 23, wherein at least one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the drainage catheter.

25. The ventricular shunt system of claim 18, wherein the valve is an adjustable valve configured to allow selective flow rates therebetween the respective inlet and outlet ports of the valve.

26. The ventricular shunt system of claim 19, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises a non-linear element and responds in a non-linear manner to an energizing signal.

27. A ventricular shunt system comprising:

a catheter assembly comprising;

a valve having an inlet port and an outlet port, the valve configured to control a rate of fluid flow between the inlet port and the outlet port;

a ventricular catheter having a distal end and a proximal end, the proximal end of the ventricular catheter being coupled to the inlet port of the valve;

a drainage catheter having a distal end and a proximal end, the proximal end of the drainage catheter being coupled to the outlet port of the valve; and

a plurality of individually addressable pressure sensors mountable on a portion of the catheter assembly, each pressure sensor comprising a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of radio frequency (RF) energy;

wherein the passive electrical resonant circuit is variable in response to the pressure in a patient'"'"'s ventricle, wherein each passive electrical resonant circuit, in response to the electromagnetic coupling, is configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of pressure in the patient'"'"'s ventricle, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises an inductance-capacitance (LC) resonant circuit that comprises an inductor operably coupled to a capacitor,

wherein one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the ventricular catheter adjacent the distal end of the ventricular catheter, and wherein at least one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the drainage catheter.

28. The ventricular shunt system of claim 27, wherein the capacitance of the capacitor is variable in response to the pressure therein the patient'"'"'s ventricle.

29. The ventricular shunt system of claim 27, wherein the capacitor comprises a first and second spaced capacitor elements, wherein at least one of the spaced capacitor elements are mounted in or on a flexible material, and wherein the respective first and second capacitor elements are movable relative to each other in response to pressure changes applied to the flexible material.

30. The ventricular shunt system of claim 27, wherein the inductor is configured to allow inductance in the passive electrical resonant circuit when the pressure sensor is subjected to a time variable electromagnetic field.

31. The ventricular shunt system of claim 27, wherein the valve is an adjustable valve configured to allow selective flow rates therebetween the respective inlet and outlet ports of the valve.

32. The ventricular shunt system of claim 27, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises a non-linear element and responds in a non-linear manner to an energizing signal.

33. The ventricular shunt system of claim 27, wherein the plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.

34. A ventricular shunt system comprising:

a catheter assembly comprising;

a valve having an inlet port and an outlet port, the valve configured to control a rate of fluid flow between the inlet port and the outlet port;

a ventricular catheter having a distal end and a proximal end, the proximal end of the ventricular catheter being coupled to the inlet port of the valve;

a drainage catheter having a distal end and a proximal end, the proximal end of the drainage catheter being coupled to the outlet port of the valve; and

at least one pressure sensor mountable on a portion of the catheter assembly comprising a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of radio frequency (RF) energy;

wherein the passive electrical resonant circuit is variable in response to the pressure in a patient'"'"'s ventricle, and wherein each passive electrical resonant circuit, in response to the electromagnetic coupling, is configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of pressure in the patient'"'"'s ventricle,

wherein one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the ventricular catheter adjacent the distal end of the ventricular catheter, and wherein at least one pressure sensor of the plurality of individually addressable pressure sensors is mounted within the drainage catheter.

35. The ventricular shunt system of claim 34, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises an inductance-capacitance (LC) resonant circuit that comprises an inductor operably coupled to a capacitor.

36. The ventricular shunt system of claim 35, wherein the capacitance of the capacitor is variable in response to the pressure therein the patient'"'"'s ventricle.

37. The ventricular shunt system of claim 35, wherein the capacitor comprises a first and second spaced capacitor elements, wherein at least one of the spaced capacitor elements are mounted in or on a flexible material, and wherein the respective first and second capacitor elements are movable relative to each other in response to pressure changes applied to the flexible material.

38. The ventricular shunt system of claim 35, wherein the inductor is configured to allow inductance in the passive electrical resonant circuit when the pressure sensor is subjected to a time variable electromagnetic field.

39. The ventricular shunt system of claim 34, wherein the at least one pressure sensor comprises a plurality of individually addressable pressure sensors, wherein at least one pressure sensor of the plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.

40. The ventricular shunt system of claim 35, wherein the passive electrical resonant circuit of the at least one pressure sensor comprises a non-linear element and responds in a non-linear manner to an energizing signal.

41. The ventricular shunt system of claim 34, wherein the plurality of individually addressable pressure sensors are mounted within the ventricular catheter in spaced relationship.