IMPLANTABLE ELECTRONIC DEVICES FOR DETECTING HYPOGLYCAEMIA USING EEG SIGNALS

• US 20100317955A1
• Filed: 01/02/2009
• Published: 12/16/2010
• Est. Priority Date: 01/14/2008
• Status: Active Grant

• Current Assignee: Hypo-Safe A/S
• Original Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Inventors: Madsen, Rasmus Elsborg, Beck-Nielsen, Henning
• Granted Patent: US 8,849,368 B2
• Time in Patent Office: Days
• US Class Current: 600/377
• CPC Class Codes: A61B 17/3439 with means for changing the inner diameter of the cannula, e.g. expandable A61B17/3423, A61B17/3431 take precedence; catheters A61M25/0662
• 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 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61M 25/0668 splittable, tear apart

Abstract

Apparatus for capturing EEG signals comprising an implantable signal capture unit (34) connected to a proximal end of at least one implantable electrode (32) is implanted by passing a tubular guide sheath (24,26) along a subcutaneous path from an implantation site, passing the distal end of a said electrode through said guide sheath to bring said signal capture unit to said implantation site, and withdrawing said guide sheath from the electrode whilst progressively axially splitting the guide sheath to enable its removal. The signal capture unit may have a housing having at least two electrode contacts on its for capturing EEG signals in operative connection with circuitry within said housing for receiving said EEG signals and for wireless transmission thereof for reception at a location exterior to the body of the patient.

Claims

1. A method for implanting apparatus for capturing EEG signals comprising an implantable signal capture unit having connected thereto a proximal end of at least one implantable electrode having a free distal end, said method comprising passing a tubular guide sheath along a subcutaneous path from an implantation site, passing the distal end of a said electrode through said guide sheath to bring said signal capture unit attached to the proximal end of said electrode into said implantation site, and withdrawing said guide sheath from the electrode whilst progressively axially splitting the guide sheath to enable its removal.

2. A method as claimed in claim 1, wherein the proximal end of said electrode is sealed into the signal capture unit.

3. A method as claimed in claim 1, wherein the tubular guide sheath comprises at least one axial line of weakening enabling it to be pulled apart as it is withdrawn.

4. A method as claimed in claim 1, wherein a bundle of at least two electrodes is passed through said guide sheath.

5. A method as claimed in claim 1, wherein at least one further tubular guide sheath is passed from the implantation site along a second subcutaneous path and the distal end of at least a second said electrode is passed through said further tubular guide sheath as the signal capture unit is brought to the implantation site, and said further guide sheath is withdrawn from said second electrode whilst being progressively axially split to enable its removal from the electrode.

6. A method as claimed in claim 5, wherein said second electrode is a member of a bundle of at least two electrodes that are passed through said further tubular guide sheath.

7. A method as claimed in claim 1, wherein each electrode has an elongate insulated body and an uninsulated tip for gathering EEG signals.

8. A method as claimed in claim 1, wherein the length of the or each said electrode is no more than 6 cm.

9. A method as claimed in claim 1, wherein the implantation site is behind the ear of a human patient.

10. A method as claimed in claim 1, wherein after the implantation an electrode extends from the implantation site to gather EEG signals at a location which is preferably within a circular zone of about 5 cm diameter centred approximately at the mid point of a line joining standard electrode positions C3 and T5.

11. A method as claimed in claim 1, wherein a second electrode extends from the implantation site to gather EEG signals at a location at a location which is preferably within a circular zone of about 5 cm diameter centred approximately 1.5 cm below the mid point of a line joining standard electrode positions C3 and T5.

12. A method as claimed in claim 1, wherein the implanted apparatus cooperates in use with an EEG signal analysis unit for determining when EEG signals received from the said electrode indicate a specific physiological condition.

13. An implantable apparatus for capturing and transmitting EEG signals comprising a housing suitable for subcutaneous implantation beneath the scalp of a patient and having at least two electrode contacts on the exterior thereof for capturing EEG signals in use, said electrode contacts being in operative connection with circuitry within said housing for receiving said EEG signals and for wireless transmission thereof for reception at a location exterior to the body of the patient.

14. Apparatus as claimed in claim 13, wherein two said electrodes are separated by at least 1.5 cm.

15. Apparatus as claimed in claim 13, wherein the longest external dimension of said apparatus is from 1.5 to 3 cm.

16. Apparatus as claimed in claim 13, wherein the smallest external dimension of said apparatus does not exceed 0.5 cm.

17. Apparatus for use in preventing hypoglycaemia comprising an EEG based detector for the onset of hypoglycaemia operatively connected to an actuatable release device for the administration to a patient of a hypoglycaemia preventing substance.

18. Apparatus as claimed in claim 17, wherein the EEG based detector comprises an implantable signal capture unit operatively connected to at least two EEG sensor electrodes adapted for subcutaneous implantation.

19. Apparatus as claimed in claim 17, wherein said actuatable release device is a pump.

20. Apparatus as claimed in claim 19, wherein said pump is operatively connected to a reservoir containing glucose or glucagon.

21. Apparatus as claimed in claim 17, further comprising a generator of an alarm signal perceivable by a user of said apparatus.

22. Apparatus as claimed in claim 20, configured to initiate administration of said substance by said pump following a predetermined time lapse from the generation of a said alarm signal, and comprising an input for a cancellation signal by said user such that input of said cancellation signal by the user prevents or halts actuation of said pump.

23. A subcutaneously implantable EEG apparatus comprising at least one elongate, flexible electrode having a proximal end in permanent electrical connection with a signal capture unit contained in a housing, and a guide sheath extending over the electrode and running the length of the electrode, the guide sheath having an internal bore containing the electrode that is too small to pass over said housing, wherein said guide sheath has an axial line of weakness to allow manual splitting of the guide sheath and stripping of the guide sheath progressively from the electrode.