Apparatus used to detect or stimulate activity of nerve tissue

1 . A method comprising:

disposing, in a cerebral blood vessel of an organism, an intravascular device including at least one electrode provided on a wire member; and

detecting activity of nerve tissue or stimulating of the nerve tissue with the electrode, the nerve tissue being positioned outside the blood vessel near the electrode,

wherein the wire member is formed from a single metal wire and an insulator covering the single metal wire, and

the electrode is provided in a ring shape around an entire circumference of the wire member, not covered by the insulator.

2 . The method according to claim 1 , wherein

the intravascular device is a single intravascular device or comprises a plurality of intravascular devices, and at least one of the intravascular devices has a plurality of the electrodes, and

the plurality of electrodes are provided on the same wire member and are spaced apart from each other by less than 1 cm.

3 . The method according to claim 1 , wherein the intravascular device comprises a plurality of intravascular devices, and the method further comprises:

using the plurality of intravascular devices, and

using electrodes included in the respective intravascular devices in such a manner that the electrodes are disposed in the blood vessel and are spaced apart from each other by 1 cm or more.

4 . The method according to claim 1 , wherein the wire member is expandable and contractable circumferentially, and includes a spiral portion, and the method further comprises:

retaining the spiral portion against a wall of the blood vessel in an expanded state.

5 . The method according to claim 1 , further comprising:

allowing the intravascular device to remain in the blood vessel for one day or longer.

6 . The method according to claim 1 , further comprising:

disposing the intravascular device in a cerebral venous sinus as the blood vessel.

7 . The method according to claim 1 , wherein the electrode is provided at a straight portion of the wire member.

8 . A method comprising:

disposing, in a cerebral blood vessel of an organism, an intravascular device including at least one electrode provided on a wire member; and

detecting activity of nerve tissue or stimulating of the nerve tissue with the electrode, the nerve tissue being positioned outside the blood vessel near the electrode,

wherein the wire member is formed from a single metal wire and an insulator covering the single metal wire.

9 . The method according to claim 8 , wherein the electrode is provided at a straight portion of the wire member.

10 . A method comprising:

disposing, in a cerebral blood vessel of an organism, an intravascular device including at least one electrode provided on a wire member; and

detecting activity of nerve tissue or stimulating of the nerve tissue with the electrode, the nerve tissue being positioned outside the blood vessel near the electrode,

wherein the wire member is formed from a single metal wire and an insulator covering the single metal wire, and

the electrode is provided both at a straight portion and a spiral portion of the wire member.