SENSOR UNIT AND PROCEDURE FOR MONITORING INTRACRANIAL PHYSIOLOGICAL PROPERTIES

• US 20090143696A1
• Filed: 12/01/2008
• Published: 06/04/2009
• Est. Priority Date: 11/29/2007
• Status: Abandoned Application

• Current Assignee: Integrated Sensing Systems Incorporated
• Original Assignee: Integrated Sensing Systems Incorporated
• Inventors: Hook-Morgan, Catherine, Najafi, Nader, Massoud-Ansari, Sonbol, Goetzinger, David Joseph
• Application Number:
  US12/325,502
• Publication Number:
  US 20090143696A1
• Time in Patent Office: Days
• US Class Current: 600/561
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/031 Intracranial pressure
• 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 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/6864 Burr holes

Abstract

An anchor for an implantable sensing device, a sensor unit formed by the anchor and sensing device, and a surgical procedure for implanting the sensor unit for monitoring a physiological parameter within a cavity of a living body, such as an intracranial physiological property. The anchor includes a shank portion and a head portion. The shank portion defines a distal end of the anchor and has a bore defining an opening at the distal end. The head portion defines a proximal end of the anchor and has a larger cross-sectional dimension than the shank portion. The sensor unit comprises the anchor and the sensing device placed and secured within the bore of the anchor so that a sensing element of the sensing device is exposed for sensing the physiological parameter within the cavity.

Claims

1. An sensor unit configured to position a sensing element for monitoring a physiological parameter within a cavity of a living body, the sensor unit having an anchor comprising:

a shank portion defining a distal end of the anchor and having a bore defining an opening at the distal end; and

a head portion defining a proximal end of the anchor and having a larger cross-sectional dimension than the shank portion.

2. The sensor unit according to claim 1, wherein the shank portion comprises means for securing the anchor within a hole.

3. The sensor unit according to claim 2, wherein the securing means is at least one biocompatible attachment device chosen from the group consisting of inserts, threads, nails, screws, springs, and adhesives.

4. The sensor unit according to claim 2, wherein the anchor consists of the shank portion, the head portion, the bore, and the securing means.

5. The sensor unit according to claim 1, further comprising a sensing device within the bore of the anchor, the sensing device comprising a sensing element exposed and adapted to sense the physiological parameter within the cavity.

6. The sensor unit according to claim 5, wherein the sensing device is operable to telemetrically communicate a reading of the physiological parameter to a readout device that is not adapted to be implanted in the living body.

7. The sensor unit according to claim 5, wherein the sensing device has a distal end and the sensing element is disposed at the distal end of the sensing device.

8. The sensor unit according to claim 7, wherein the distal end of the sensing device protrudes from the bore of the anchor such that the sensing device defines a distal end of the sensor unit.

9. The sensor unit according to claim 7, wherein the sensing device has an oppositely-disposed proximal end concealed within the anchor.

10. The sensor unit according to claim 5, wherein the physiological parameter is pressure.

11. The sensor unit according to claim 10, wherein the sensing element comprises a diaphragm responsive to pressure.

12. The sensor unit according to claim 11, wherein the diaphragm is at a distal surface of the sensing device.

13. The sensor unit according to claim 5, wherein the sensing element comprises a micromachined structure.

14. The sensor unit according to claim 5, further comprising a telemetry antenna adapted for telemetrically communicating a reading of the physiological parameter sensed by the sensing element and optionally electromagnetically receiving power for the sensing device.

15. The sensor unit according to claim 14, wherein the telemetry antenna is within the sensing device.

16. The sensor unit according to claim 14, wherein the sensor unit is wirelessly coupled with the telemetry antenna to a readout device that is not adapted to be implanted in the living body.

17. The sensor unit according to claim 16, wherein the sensor unit is wirelessly coupled to the readout device for telemetric communication therewith using a resonant scheme in which the sensing device telemetrically receives power from the readout device.

18. The sensor unit according to claim 16, wherein the sensor unit is wirelessly coupled to the readout device for telemetric communication therewith using a passive scheme in which the sensing device telemetrically receives electromagnetic power from the readout device.

19. The sensor unit according to claim 16, wherein the sensing device further comprises processing circuitry for processing electrical communications between the sensing element and the telemetry antenna.

20. The sensor unit according to claim 19, wherein the processing circuitry causes the telemetry antenna to transmit an amplitude modulation transmission.

21. The sensor unit according to claim 5, wherein the sensor unit consists of the sensing device, the anchor, and means for telemetrically communicating a reading of the physiological parameter to a readout device.

22. A surgical procedure comprising:

assembling a sensor unit by placing a sensing device within a bore of an anchor so that a sensing element of the sensing device is exposed at a distal end of the anchor, the sensing element being adapted to sense a physiological parameter;

making an incision in the scalp of a patient to expose a portion of the skull;

making a hole through the skull;

placing the sensor unit in the hole such that the distal end of the sensor unit is flush with or protrudes into the cranial cavity within the skull and an oppositely-disposed proximal end of the sensor unit is outside the skull;

securing the anchor to the skull such that the sensing device is secured to the skull by the anchor and the hole is occluded by the sensor unit; and

then

telemetrically communicating with the sensing device to obtain a reading of the physiological parameter using a readout device located outside the patient.

23. The surgical procedure according to claim 22, wherein the sensing device has a distal end, the sensing element is disposed at the distal end of the sensing device, and the distal end of the sensing device protrudes from the anchor such that the sensing device defines the distal end of the sensor unit.

24. The surgical procedure according to claim 22, wherein the anchor comprises a shank portion at the distal end of the sensor unit and a head portion that defines the proximal end of the sensor unit, the shank portion is inserted into the hole during the placing step and occludes the hole as a result of the placing step, and the head portion is not inserted into the hole during the placing step but instead is external to the skull following the placing step.

25. The surgical procedure according to claim 24, wherein the securing step comprises securing the shank portion of the anchor to the skull.

26. The surgical procedure according to claim 25, wherein the shank portion of the anchor is secured within the hole in the skull by an interference fit therebetween.

27. The surgical procedure according to claim 25, wherein the shank portion of the anchor is secured within the hole in the skull by an element chosen from the group consisting of inserts, threads, nails, screws, springs, and adhesives.

28. The surgical procedure according to claim 24, wherein an interference fit does not exist between the shank portion of the anchor and the hole in the skull.

29. The surgical procedure according to claim 24, wherein the securing step comprises securing the head portion of the anchor to the skull.

30. The surgical procedure according to claim 29, wherein the head portion of the anchor is secured to the skull by an element chosen from the group consisting of nails, screws, springs, and adhesives.

31. The surgical procedure according to claim 24, wherein the bore of the anchor is located within the shank portion of the anchor.

32. The surgical procedure according to claim 22, wherein the physiological parameter is pressure.

33. The surgical procedure according to claim 22, wherein the telemetric communicating step between the sensing device and the readout device is established using a resonant scheme in which the sensing device telemetrically receives power from the readout device.

34. The surgical procedure according to claim 22, wherein the telemetric communicating step between the sensing device and the readout device is established using a passive scheme in which the sensing device telemetrically receives electromagnetic power from the readout device.

35. The surgical procedure according to claim 22, further comprising processing electrical communications between the sensing element and a telemetry antenna of the sensor unit.

36. The surgical procedure according to claim 35, wherein the telemetry antenna of the sensor unit transmits an amplitude modulation transmission to the readout device.

37. The surgical procedure according to claim 22, wherein the surgical procedure is part of at least one of the following medical procedures:

diagnosis, treatment intervention, tailoring of medications, disease management, identification of complications, and chronic disease management.

38. The surgical procedure according to claim 22, wherein the readout device is used to perform at least one of the following:

remote monitoring of the patient, closed-loop drug delivery of medications to treat the patient, warning of changes in the physiological parameter, portable or ambulatory monitoring or diagnosis, monitoring of battery operation, data storage, reporting global positioning coordinates for emergency applications, and communication with other medical devices.

39. The surgical procedure according to claim 22, wherein the sensor unit consists of the sensing device, the anchor, and means for telemetrically communicating the reading of the physiological parameter to the readout device.