Implantable sensor method and system

• US 20040064133A1
• Filed: 12/31/2002
• Published: 04/01/2004
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic-Minimed
• Inventors: Shah, Rajiv, Miller, Michael E.
• Granted Patent: US 7,736,309 B2
• Time in Patent Office: Days
• US Class Current: 604/890.1
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/6847 mounted on an invasive device
• CPC Class Codes: A61B 5/6882 Anchoring means
• CPC Class Codes: A61M 1/1698 Blood oxygenators with or without heat-exchangers intracorporal A61M1/1678; manufacturing of membranes therefor B01D67/00; semi-permeable membranes for separation processes characterised by their properties B01D69/00; semi-permeable membranes characterised by their material B01D71/00
• CPC Class Codes: A61M 2230/20 Blood composition characteristics
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

Systems and methods for non-vascular sensor implantation and for measuring physiological parameters in areas of a body where the physiological parameters are heterogeneous. An implant unit is implanted in an area of a body and a foreign body capsule is allowed to form around the implant unit area. A sensor may be directed into a body cavity such as, for example, the peritoneal space, subcutaneous tissues, the foreign body capsule, or other area. A subcutaneous area of the body may be tunneled for sensor placement. Spatially separated sensing elements may be used for detecting individual amounts of the physiological parameter. An overall amount of the physiological parameter may be determined by calculating a statistical measurement of the individual sensed amounts in the area. Another embodiment of the invention, a multi-analyte measuring device, may include a substrate having an electrode array on one side and an integrated circuit on another side.

Claims

1. A method for non-vascular implant of a sensor comprising

implanting an implant unit in an area of a body;

allowing a foreign body capsule to form around the area of the implant unit; and

directing the sensor into the foreign body capsule.

2. The method of claim 1, wherein implanting an implant unit comprises incising an area of the body large enough for the implant unit.

3. The method of claim 1, further comprising placing a material around the implant unit for promoting growth characteristics.

4. The method of claim 1, wherein the implant unit comprises electronics.

5. The method of claim 1, wherein the implant unit comprises a pump.

6. The method of claim 1, wherein allowing a foreign body capsule to form comprises inserting materials around the implant unit to promote growth characteristics.

7. The method of claim 1, further comprising attaching the sensor to the implant unit.

8. The method of claim 7, wherein the sensor is attached to the implant unit prior to formation of the foreign body capsule.

9. The method of claim 7, wherein the sensor is attached to the implant unit subsequent to formation of the foreign body capsule.

10. The method of claim 1, further comprising incising an area of the body large enough for the sensor.

11. The method of claim 10, wherein the incised area of the body large enough for the sensor is smaller than an incised area of the body large enough for the implant unit.

12. A method for non-vascular implant of a sensor comprising:

incising an area of a body large enough for inserting an implant unit;

incising an area remote from a sensor location for inserting a sensor;

directing the sensor into a body cavity;

connecting the sensor to the implant unit; and

inserting the implant unit into the body.

13. The method of claim 12, wherein inserting the implant unit into the body comprises inserting the implant unit into a pocket formed when incising an area of the body large enough for inserting the implant unit.

14. The method of claim 12, further comprising fixing the sensor in place using suture.

15. A non-vascular implant system comprising

an implant unit;

a sensor for detecting a physiological parameter, the sensor being separate from and connectable to the implant unit,

wherein the sensor is placed in a non-vascular area of the human body.

16. The system of claim 15, wherein the implant unit comprises a pump.

17. The system of claim 15, wherein the implant unit comprises electronics.

18. The system of claim 15, wherein the implant unit delivers drug to a human body.

19. The system of claim 18, wherein the drug is insulin.

20. The system of claim 15, wherein the sensor comprises a biomolecule.

21. The system of claim 15, wherein the sensor comprises a lead.

22. The system of claim 15, wherein the sensor comprises a sensing element.

23. The system of claim 22, wherein the sensing element is a biomolecule.

24. The system of claim 23, wherein the biomolecule is a glucose oxidase enzyme.

25. The system of claim 15, wherein the physiological parameter is oxygen.

26. The system of claim 15, wherein the physiological parameter is glucose.

27. The system of claim 15, wherein the non-vascular area of the human body is the peritoneum.

28. The system of claim 15, wherein the non-vascular area of the human body is subcutaneous tissue.

29. A method for non-vascular implant of a sensor comprising:

incising an area of a body large enough for inserting an implant unit;

creating a tunnel in subcutaneous tissue;

directing the sensor through the tunnel;

connecting the sensor to the implant unit; and

inserting the implant unit into the body.

30. The method of claim 29, wherein the tunnel is created using a blunt instrument.

31. The method of claim 29, wherein the blunt instrument causes minimal trauma to the subcutaneous tissue.

32. The method of claim 29, wherein the blunt instrument is a trocar.

33. A method for spatially sensing a physiological parameter, comprising:

implanting in an area of a body a plurality of spatially separated sensing elements for detecting a physiological parameter such that each of the sensing elements senses individual amounts of the physiological parameter within the area;

generating a signal from each of the plurality of spatially separated sensing elements, the generated signals each representing an individual sensed amount of the physiological parameter; and

determining an overall amount of the physiological parameter in the area by calculating a statistical measurement of the individual sensed amounts from the signals generated from a plurality of sensing elements.

34. The method of claim 33, wherein the statistical measurement is at least one of a maximum amount for the individual sensed amounts, an average amount of the individual sensed amounts, a median of the individual sensed amounts, an arithmetic mean of the individual sensed amounts, and a weighted arithmetic mean of the individual sensed amounts.

35. The method of claim 33, wherein the statistical measurement is calculated using at least one algorithm that employs values associated with signals generated from a plurality of sensing elements.

36. The method of claim 33, wherein each of the sensing elements substantially simultaneously senses individual amounts of the physiological parameter within the area.

37. The method of claim 33, wherein providing a plurality of spatially separated sensing elements includes providing a one-dimensional array of sensing elements.

38. The method of claim 33, wherein providing a plurality of spatially separated sensing elements includes providing a two-dimensional array of sensing elements.

39. The method of claim 33, wherein providing a plurality of spatially separated sensing elements includes providing a three-dimensional array of sensing elements.

40. The method of claim 33, wherein providing a plurality of spatially separated sensing elements includes providing a sensor lead including the plurality of spatially separated sensing elements along at least a portion of the length of the lead.

41. The method of claim 33, wherein the plurality of spatially separated sensing elements are connected in a daisy chain.

42. The method of claim 33, wherein the physiological parameter is oxygen.

43. The method of claim 33, wherein the physiological parameter is glucose.

44. The method of claim 33, wherein the sensing elements are implanted in a peritoneum.

45. The method of claim 33, wherein the sensing elements are implanted in a vascular area of the body.

46. A method for processing a signal representing a physiological parameter, comprising:

implanting in a body a plurality of spatially separated sensing elements, each of the sensing elements for sensing individual amounts of the physiological parameter in the body;

detecting a first signal representing a first individual sensed amount of the physiological parameter from one of the plurality of sensing elements, the first signal including a first amount of noise;

detecting a second signal representing a second individual sensed amount of the physiological parameter from another of the plurality of sensing elements, the second signal including a second amount of noise; and

determining a third signal representing an overall amount of the physiological parameter by calculating a statistical measurement of the first and second individual sensed amounts, the third signal having a third amount of noise less than both the first and second amounts of noise.

47. The method of claim 46, wherein the statistical measurement is at least one of a maximum amount for the individual sensed amounts, an average amount of the individual sensed amounts, a median of the individual sensed amounts, an arithmetic mean of the individual sensed amounts, and a weighted arithmetic mean of the individual sensed amounts.

48. The method of claim 46, wherein the statistical measurement is calculated using at least one algorithm that employs values associated with signals generated from a plurality of sensing elements.

49. The method of claim 46, wherein the first and second signals are detected substantially simultaneously.

50. The method of claim 46, wherein implanting in a body a plurality of spatially separated sensing elements includes implanting a sensor lead including the plurality of spatially separated sensing elements along at least a portion of the length of the lead.

51. The method of claim 46, wherein the sensing elements are connected in a daisy chain.

52. The method of claim 46, wherein the physiological parameter is oxygen.

53. The method of claim 46, wherein the physiological parameter is glucose.

54. The method of claim 46, wherein the sensing elements are implanted in a peritoneum.

55. The method of claim 46, wherein the sensing elements are implanted in a vascular area of the body.

56. The method of claim 46, further including filtering at least one of the first signal, the second signal and the third signal to further reduce noise within the at least one of the first signal, the second signal and the third signal.

57. The method of claim 56, wherein the filtering is performed using a single-pole IIR filter.

58. The method of claim 46, further including processing at least one of the first signal, the second signal and the third signal in a digital signal processor to further reduce noise within the at least one of the first signal, the second signal and the third signal.

59. A system for sensing physiological parameters in an area of a body, comprising:

a plurality of spatially separated sensing elements implanted in the area of the body, each of the sensing elements for sensing an individual amount of a physiological parameter and generating a signal representing the individual sensed amount; and

a computing element for determining an overall amount of the physiological parameter in the area of the body by calculating a statistical measurement of the individual sensed amounts from the signals generated from a plurality of sensing elements.

60. The system of claim 59, wherein the statistical measurement is at least one of a maximum amount for the individual sensed amounts, an average amount of the individual sensed amounts, a median of the individual sensed amounts, an arithmetic mean of the individual sensed amounts, and a weighted arithmetic mean of the individual sensed amounts.

61. The system of claim 59, wherein the statistical measurement is calculated using at least one algorithm that employs values associated with signals generated from a plurality of sensing elements.

62. The system of claim 59, further including a sensor lead, the plurality of spatially separated sensing elements being located along at least a portion of the length of the lead.

63. The system of claim 62, wherein the sensor lead includes a first sensing element located at a proximal end of the sensor lead and a second sensing element located at a distal end of the sensor lead.

64. The system of claim 59, further including an implant unit for delivering a drug to the body.

65. The system of claim 64, wherein the sensing elements are connected to the implant unit in a daisy chain.

66. The system of claim 64, wherein the computing element is located in the implant unit.

67. The system of claim 59, wherein the area of the body is a peritoneum.

68. The system of claim 59, wherein the sensing elements are implanted in a vascular area of the body.

69. A structure for defining an in vivo implant site comprising:

a cylinder having a hollow area in an interior portion thereof,

wherein a portion of the cylinder is covered with a coating.

70. The structure of claim 69, wherein the coating is silicone rubber.

71. The structure of claim 69, wherein the cylinder is a right circular cylinder.

72. The structure of claim 69, wherein the hollow area is sufficiently large to accept a sensor.

73. The structure of claim 69, wherein the cylinder has at least one hole in an outer surface thereof.

74. A multi-analyte measuring device comprising:

a substrate;

an electrode array on a first side of the substrate; and

an integrated circuit on a second side of the substrate.

75. The multi-analyte measuring device of claim 74, wherein the electrode array and the integrated circuit are electrically connected.

76. The multi-analyte measuring device of claim 74, wherein the integrated circuit processes signals.

77. The multi-analyte measuring device of claim 74, wherein the integrated circuit monitors signals.

78. The multi-analyte measuring device of claim 74, wherein the electrode array includes an agent.

79. The multi-analyte measuring device of claim 78, wherein the agent is an enzyme.

80. The multi-analyte measuring device of claim 74, wherein the substrate comprises channels.

81. The multi-analyte measuring device of claim 74, further comprising a connector for providing access to the integrated circuit.

82. The multi-analyte measuring device of claim 81, wherein the connector connects to a display device.

83. The multi-analyte measuring device of claim 81, wherein the connector connects to a monitoring device.

84. The multi-analyte measuring device of claim 74, further comprising a power supply.

85. The multi-analyte measuring device of claim 84, wherein the power supply is a battery.

86. The multi-analyte measuring device of claim 84, wherein the power supply is a capacitor.