ELECTRODE DEVICE, ELECTROPHYSIOLOGICAL RECORDING SYSTEM AND COMPUTER PROGRAM

Abstract

An electrode device for recording electrophysiological neurosignals in nervous tissue of a living being includes a bundle of insulated electrical cables, where each cable has an electrical wire made of electrically conductive material and an insulation layer which covers and insulates the electrical wire. An electrical connector connects the electrical wires to a recording device. A free end of the bundle of insulated electrical cables distant from the electrical connector includes an implantation section for implantation in the nervous tissue of the living being. An electrophysiological recording system will have at least one such electrode device and a computer program arranged for execution on a computer.

Claims

1. An electrode device for recording electrophysiological neurosignals in nervous tissue of a living being, comprising: a bundle of insulated electrical cables, wherein each cable of the bundle of insulated electrical cables comprises an electrical wire made of electrically conductive material and an insulation layer which covers and insulates the electrical wire; an electrical connector for connecting the electrical wire of each cable of the bundle of insulated electrical cables to a recording device; and an implantation section at or close to a free end of the bundle of insulated electrical cables spaced away from the electrical connector configured for implantation in the nervous tissue of the living being, wherein several or all of the insulated electrical cables in the bundle of insulated electrical cables have at least one side opening in the insulation layer distant from the free end of the bundle of insulated electrical cables which provides direct galvanic contact of the electrical wire to the nervous tissue.

2. The electrode device according to claim 1, wherein several or all of the insulated electrical cables in the bundle have a plurality of side openings in the insulation layer.

3. The electrode device according to claim 2, wherein each of the plurality of side openings in the insulation layer are distant from each other in a longitudinal direction of the insulated electrical cable.

4. The electrode device according to claim 1 wherein several or all of the insulated electrical cables have insulation material of the insulation layer at a free end located at the free end of the bundle of electrical cables, wherein the insulation material of the insulation layer at the free end covers and isolates the free end of the electrical wire of each of the insulated electrical cables.

5. The electrode device according to claim 2 wherein at least some of the plurality of side openings on different electrical cables in the bundle of insulated electrical cables are at different longitudinal positions relative to each other.

6. The electrode device according to claim 1 wherein the bundle of insulated electrical cables comprises at least one pair of electrical cables wherein both of the at least one pair of electrical cables include the at least one side opening at a same longitudinal position on each of the at least one pair of electrical cables.

7. The electrode device according to claim 1 wherein the bundle of insulated electrical cables are in a wound, twisted, and/or woven structure.

8. The electrode device according to claim 2 wherein the plurality of side openings of the electrical cables of the bundle of insulated electrical cables are present in a geometrical pattern which allows recording electrophysiological neurosignals at different positions in the nervous tissue, wherein the geometrical pattern allows for distinguishing electrophysiological neurosignals from each other by applying a demultiplexing algorithm to the electrical signals measured at the electrical connector of the electrode device.

9. An electrophysiological recording system, comprising: at least one electrode device according to claim 1; and a recording device connected to the electrical connector of the at least one electrode device, wherein the recording device comprises a computer which operates a demultiplexing algorithm for demultiplexing electrical signals (measured at the electrical connector of the at least one electrode device, wherein the computer is configured to output demultiplexed signals which represent electrophysiological neurosignals of a living being at different positions in nervous tissue.

10. The electrophysiological recording system according to claim 9, wherein the demultiplexing algorithm is arranged for calculating a location origin of the electrophysiological neurosignals in the nervous tissue from the electrical signals measured at the electrical connector of the at least one electrode device.

11. A non-transient memory encoded with a computer program executable by a computer of an electrophysiological recording system according to claim 9 comprising the demultiplexing algorithm.

Description

DESCRIPTION OF THE DRAWINGS

[0034] The invention is further described by exemplary embodiments which are depicted in the drawings. The drawings shown in

[0035] FIG. 1 an electrophysiological recording system and

[0036] FIG. 2 the process of signal demultiplexing in the system of FIG. 1.

DETAILED DESCRIPTION

[0037] The exemplary embodiment of FIG. 1 depicts an electrode device 1 which is connected by a cable 9 to a recording device 10. The electrode device 1 and the recording device 10 form an electrophysiological recording system for recording electrophysiological neurosignals in nervous tissue 13 of a living being.

[0038] For example, the electrode device 1 can be implanted with its implantation section 7 within a part 12 of the living being, for example the brain. The implantation section 7 is located at some place within the nervous tissue 13.

[0039] The electrode device 1 comprises a plurality of electrically insulated cables 2 which extend in a longitudinal direction from an electrical connector 8 to a free end 5. The cables 2 form a bundle of insulated electrical cables which ends at the free end 5. The electrical connector 8 can be a usual electrical plug-in connector. It can comprise standard termination techniques and plug assemblies.

[0040] Each electrical cable 2 has an electrical wire 3 made of electrically conductive material. Further, each cable 2 has an insulation layer 4 which covers the electrical wire 3 of the respective cable 2. In this way, the electric wire 3 of a cable 2 is insulated against the ambience.

[0041] The electrical wires 3 of the cables 2 are also covered by the insulating material of the insulating layer 4 at the free end 5. In order to provide direct galvanic contact of the electrical wire 3 to the nervous tissue 13, there are one or more side openings 6 in each cable 2 within the implantation section 7. For example, the leftmost cable 2 has only one side opening 6 which is, compared to the other cables 2, at the closest position to the free end 5. The next cable 2, right of the leftmost cable 2, has two side openings 6. One of these side openings 6 is at the same longitudinal position as the side opening 6 of the leftmost cable 2, and the other side opening 6 is more distant from the free end 5.

[0042] The next cable 2 to the right has also two side openings 6. One of the side openings 6 is at the same longitudinal position as the upper side opening of the second cable 2. The second side opening 6 of the third cable 2 is more distant from the free end 5. The fourth cable 2, which means the rightmost cable 2, has only one side opening 6 at the same longitudinal position as the upper side opening of the neighboring cable 2.

[0043] While the cables 2 are shown for simplicity in a parallel manner, in an actual practical realization the cables 2 would be twisted, wound and/or woven into a bundle.

[0044] The connection cable 9 is connected via a plug-in connector to the electrical connector 8 of the electrode device 1. Via the connection cable 9 the electrical signals which are coupled through the side openings 6 into the electrical wires 3 are fed into the recording device 10. The recording device 10 comprises signal receiving and evaluation circuitry. In particular, the recording device 10 comprises a computer 11 which executes a computer program. The computer program can comprise signal evaluation algorithms, like a demultiplexing algorithm for demultiplexing the electrical signals measured at the electrical connector 8.

[0045] FIG. 2 shows an example of the measuring of the electrophysiological signals in the nervous tissue 13 and their transfer to the recording device 10 and the demultiplexing within the recording device 10. Diagram A shows the electrophysiological signals N1, N2, N3 appearing at different locations within the nervous tissue 13. The signals N1, N2, N3 can be voltage signals over time. These signals N1, N2, N3 are sensed by the electrical wires 3 at their side openings 6. It should be clear that in a practical application not only one signal per side opening 6 is measured, but a series of such signals over time (e.g. N1a, N1b, N1c, . . . , N2a, N2b, N2c, . . . , N3a, N3b, N3c, . . . ).

[0046] Diagram B shows the electrical signals S1, S2, S3, S4 appearing on the electrical connector 8 of the electrode device 1. Signal S1 is the same as signal N1, because the leftmost cable 2 (CH1) has only one side opening 6. Signal S2 is a superposition of the signals N1 and N2, due to the two side openings 6 in the second cable 2 (CH2). Signal S3 is a superposition of the signals N2 and N3, due to the two side openings 6 in the third cable 2 (CH3). Signal S4 is the same as signal N3, because the rightmost cable 2 (CH4) has only one side opening 6.

[0047] These signals S1, S2, S3, S4 are transferred to the recording device 10 and processed by the demultiplexing algorithm 14. The result of the demultiplexing algorithm 14 is shown in diagram C. Diagram C comprises signals O1, O2, O3, which are the same as signals N1, N2, N3. In particular, signal O1 is the reproduction of signal N1, signal 02 is the reproduction of signal N2 and signal O3 is the reproduction of signal N3.