Electrode assembly for EEG headset

• US 5,357,957 A
• Filed: 04/28/1993
• Issued: 10/25/1994
• Est. Priority Date: 08/01/1991
• Status: Expired due to Fees

• Current Assignee: HZI Research Center Incorporated
• Original Assignee: Emin Eralp, Turan M. Itil
• Inventors: Eralp, Emin, Itil, Turan M.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US08/053,432
• Time in Patent Office: 545 Days
• Field of Search: 128/639, 128/644, 128/731, 607/139, 607/153
• US Class Current: 600/383
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/0217 Electrolyte containing
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]

Abstract

An electrode assembly for an EEG headset has a cylinder and piston, at least one disk-shaped mounting element with an inner portion for mounting the cylinder therethrough and an outer portion overlapping onto the liner of the headset, an electrode body made of insulative material mounted to the piston and holding an electrode tip, and an electrode tip made of conductive material with a wire lead for transmitting electrical signals from the tip to an external signal processing unit separately from the rest of the electrode assembly. Preferably, the mounting element is a pair of rubber washers supporting the cylinder from each side of the liner. The electrode body has a threaded end for threading in the piston, and a central passage for supplying electrolyte gel to the electrode tip. The electrode tip has a disk shape with a relatively large surface area for maintaining good contact with the subject'"'"'s scalp. The electrode body may also have a ball joint between its piston-mounting portion and tip-holding portion. Other types of electrode tips may be mounted on the assemblies. The headset and electrode structures provide a shorter signal transmission system, which greatly reduces extraneous noise, and allow for direct connection to an external recording or EEG device. The headset may include signal conditioning hardware in the form of a VLSI digital amplifier/signal conditioning unit that can output analog, digital, or telephonic modulated EEG signals, or an FM telemetry system mounted on the headset for wireless transmission.

Claims

1. An EEG headset system, comprising:

a headset having at least one bellows component movably mounting a plurality of electrode assemblies thereto facing inwardly in a depthwise direction toward the head of a wearer of said headset, wherein said at least one bellows component includes;

a pair of semirigid, elongated strips mounted to said headset spaced apart a given space in parallel transverse to the depthwise direction;

an inflatable, elongated tube mounted in the space between the pair of elongated strips, for expanding and contracting in response to fluid pressure therein,

wherein an innermost one in the depthwise direction of said pair of elongated strips has a plurality of slits formed at positions corresponding to positions at which said plurality of electrode assemblies are to be mounted, said slits having portions of said tube protrudable therethrough under pressure so as to form respective movable pistons for said electrode assemblies; and

said electrode assemblies each being formed with an electrode mounting element made of an electrically insulative material having one portion mounted to an end of a piston and another portion holding an electrode tip made of a conductive material and having a conductive lead encapsulated in an insulative shielding connected thereto for transmitting electrical signals obtained by the electrode tip to an external signal processing unit.

2. An EEG headset system according to claim 1 wherein said electrode mounting element consists of a swing arm attached to a respective piston of said bellows component.

3. An EEG headset system according to claim 1, further comprising means for feeding electrolyte gel through a delivery line to each of the electrode tips of said electrode assemblies.