U.S. patent application number 09/916824 was filed with the patent office on 2002-03-07 for portable eeg electrode locator headgear.
Invention is credited to Berka, Christine, Konstantinovic, Zoran R., Levendowski, Daniel J..
Application Number | 20020029005 09/916824 |
Document ID | / |
Family ID | 22928059 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020029005 |
Kind Code |
A1 |
Levendowski, Daniel J. ; et
al. |
March 7, 2002 |
Portable EEG electrode locator headgear
Abstract
The EEG electrode locator headgear allows the user to locate and
apply disposable EEG electrodes accurately according to the
International 10/20 System without technical assistance, to allow
the acquisition of high quality EEG signals. The headgear includes
a front forehead pad, a base strap assembly connected to the front
forehead pad, a plurality of EEG electrode locators for receiving
EEG electrodes, and a plurality of locator straps connected to the
front pad of material, the base strap assembly, and to the
plurality of EEG electrode locators for accurately positioning the
plurality of EEG electrode locators positioned relative to the
scalp of a user. A visor can be attached to the front pad of
material, and the base strap assembly may include an occipital
locator device. A plunger assembly with spreadable fingers for
optionally parting the hair of the user's scalp is also provided
that is inserted in the electrode locators to optionally prepare
the user's scalp and to seat the electrodes. In one embodiment, a
spreader portion of the plunger assembly is formed of electrically
conductive material, such as electrically conductive silicone. An
elastic, stretchable cap portion may also be connected to the EEG
electrode locators, for biasing the plurality of electrode locators
toward the user's scalp.
Inventors: |
Levendowski, Daniel J.;
(Carlsbad, CA) ; Berka, Christine; (Carlsbad,
CA) ; Konstantinovic, Zoran R.; (Vista, CA) |
Correspondence
Address: |
FULWIDER PATTON LEE & UTECHT, LLP
HOWARD HUGHES CENTER
6060 CENTER DRIVE
TENTH FLOOR
LOS ANGELES
CA
90045
US
|
Family ID: |
22928059 |
Appl. No.: |
09/916824 |
Filed: |
July 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09916824 |
Jul 26, 2001 |
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09492380 |
Jan 27, 2000 |
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09492380 |
Jan 27, 2000 |
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09245784 |
Feb 5, 1999 |
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6161030 |
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Current U.S.
Class: |
600/545 ;
600/383 |
Current CPC
Class: |
A61B 5/291 20210101;
A61B 5/6803 20130101; A61B 5/6804 20130101 |
Class at
Publication: |
600/545 ;
600/383 |
International
Class: |
A61B 005/0482 |
Goverment Interests
[0002] The United States Government has rights in this invention
pursuant to research supported in the whole or in part by NIH
Contracts R43-NS-62344, N43-NS-72367 and N44-NS-72367 and grants
R43-NS-35387, R44-NS-35387and R44-NS-38036 awarded by the National
Institute of Neurological Disorders and Stroke.
Claims
What is claimed is:
1. An electroencephalograph (EEG) electrode locator headgear,
comprising: a base strap assembly adapted to be secured comfortably
around the circumference of a user's head; an elastic, stretchable
cap portion connected to said plurality of EEG electrode locators;
a plurality of EEG electrode locators mounted to said elastic,
stretchable cap portion for accurately positioning said plurality
of EEG electrode locators relative to the user's scalp, and for
biasing said plurality of electrode locators toward the user's
scalp; and a plurality of EEG electrodes adapted to be received in
and cooperate with said plurality of EEG electrode locators,
respectively, each of said EEG electrodes including a plunger
assembly adapted to prepare the user's scalp and to seat the
electrode in one of said EEG electrode locators, said plunger
assembly including a plunger member having upper and lower ends,
and said plunger assembly including an electrically conductive
spreader member mounted to said lower end of said plunger member,
said spreader member having a plurality of flexible, resilient
fingers having distal ends biased to meet at a common distal
central location, and said flexible, resilient fingers being
adapted to spread apart by exertion of downward pressure of said
plunger assembly against the user's scalp and to thereby part the
hair of the user's scalp.
2. The EEG electrode locator headgear of claim 1, wherein said
plunger is adapted to be inserted in the electrode locator to
spread the distal flexible, resilient fingers.
3. The EEG electrode locator headgear of claim 1, wherein said
plunger assembly comprises a cap connected to the upper portion of
the plunger member.
4. The EEG electrode locator headgear of claim 1, wherein said
spreader member comprises a cushion portion located between said
flexible, resilient fingers adapted to rest against the user's
scalp after the electrode has been pressed downward to seat the
electrode on the user's scalp and spread the flexible, resilient
fingers, to cushion the pressure of the electrode on the user's
scalp for additional comfort.
5. The EEG electrode locator headgear of claim 4, further
comprising a conductive gel adapted to contact the user's scalp,
said conductive gel disposed adjacent to the cushion portion of the
spreader member and between the flexible, resilient fingers.
6. The EEG electrode locator headgear of claim 1, wherein said
plunger assembly comprises an electrical conductor mounted to said
plunger member adapted and electrically connected between said
electrically conductive spreader member and said EEG electrode
locator for conducting EEG signals from said electrodes to an EEG
monitor.
7. The EEG electrode locator headgear of claim 1, wherein said
spreader member is formed of electrically conductive silicone.
8. The EEG electrode locator headgear of claim 1, wherein said
elastic, stretchable cap portion comprises at least one elastic
locator strap connected to said plurality of EEG electrode
locators.
9. The EEG electrode locator headgear of claim 8, wherein said at
least one elastic locator strap comprises a plurality of elastic
locator straps.
10. The EEG electrode locator headgear of claim 9, wherein said
plurality of locator straps are made of elastic material.
11. The EEG electrode locator headgear of claim 9, wherein said
plurality of locator straps are formed of elasticized fabric.
12. The EEG electrode locator headgear of claim 1, wherein said
elastic, stretchable cap portion comprises a stretch mesh cap of
elastic, fabric material.
13. The EEG electrode locator headgear of claim 1, further
comprising an outer cap shell disposed over said elastic,
stretchable cap portion.
14. The EEG electrode locator headgear of claim 1, wherein said
base strap assembly comprises a front pad of material having first
and second ends, said front pad of material being adapted to extend
across a user's forehead, said base strap assembly having a first
end connected to said first end of said front pad of material, and
a second end connected to said second end of said front pad of
material, said front pad of material and said base strap assembly
being adapted to be secured comfortably around the circumference of
a user's head.
15. The EEG electrode locator headgear of claim 14, further
comprising a visor attached to said front pad of material.
16. The EEG electrode locator headgear of claim 1, wherein said
base strap assembly is adjustable.
17. The EEG electrode locator headgear of claim 1, wherein said
base strap assembly comprises a pair of adjustable elastic straps
connected at one end to said front pad of material and adjustably
connected together at the other end.
18. The EEG electrode locator headgear of claim 1, wherein said
base strap assembly further comprises an occipital locator device
adapted to be seated on a region of the user's scalp over the
user's occipital bone, said base strap assembly comprising first
and second elastic edge straps connected at one end to said front
pad of material, and adjustably connected at the other end to said
occipital locator device.
19. The EEG electrode locator headgear of claim 1, wherein said
plurality of EEG electrode locators each comprise a plurality of
slots for receiving at least one locator strap.
20. The EEG electrode locator headgear of claim 1, wherein each of
said electrode locators comprises an electrode locator electrical
conductor adapted to be electrically connected to one of said EEG
electrodes inserted in said electrode locator.
21. The EEG electrode locator headgear of claim 20, wherein said
electrode locator electrical conductor comprises a plurality of
electrically conductive spring connectors.
22. The EEG electrode locator headgear of claim 21, wherein each of
said electrode locators comprises a circuit board base member
mounted to said electrode locator electrical conductor, and wherein
said plurality of electrically conductive spring connectors are
mounted to said circuit board base member.
23. The EEG electrode locator headgear of claim 1, wherein each of
said electrode locators comprises a plurality of spring loaded
detent pins for engagement with said electrode.
24. The EEG electrode locator headgear of claim 20, further
comprising an operational pre-amplifier electrically connected to
said electrode locator electrical conductor to receive EEG signals
from said electrode.
25. The EEG electrode locator headgear of claim 21, wherein said
plunger assembly is adapted to form an electrical connection with
said electrically conductive spring connectors.
26. The EEG electrode locator headgear of claim 24, wherein the EEG
signals from the electrode locators are conducted from said
pre-amplifier to an analog to digital converter mounted on the EEG
electrode locator headgear.
27. The EEG electrode locator headgear of claim 26, further
comprising an RF transmitter connected to receive output from the
analog to digital converter, said RF transmitter being mounted on
the EEG electrode locator headgear for communicating digital EEG
signals to apparatus for analyzing the digital EEG signals from the
user.
28. The EEG electrode locator headgear of claim 26, wherein said
apparatus for analyzing the digital EEG signals from the user
comprises a data processing unit for analyzing EEG signals from the
user, and for providing feedback to the user.
29. The EEG electrode locator headgear of claim 28, wherein said
data processing unit is battery powered.
30. The EEG electrode locator headgear of claim 28, wherein said
data processing unit includes a speaker for transmitting audio
alert messages to the user.
31. The EEG electrode locator headgear of claim 27, wherein said RF
transmitter of the EEG electrode locator headgear is a
bi-directional RF transmitter-receiver for receiving feedback
signals from said apparatus for analyzing the digital EEG signals
from the user.
32. The EEG electrode locator headgear of claim 31, further
comprising a speaker mounted in the EEG electrode locator headgear
for communicating audio messages from the apparatus for analyzing
the digital EEG signals to the user.
33. The EEG electrode locator headgear of claim 31, further
comprising storage means mounted in the EEG electrode locator
headgear for storing audio messages in analog format.
34. The EEG electrode locator headgear of claim 1, further
comprising a Faraday shield to shield the pre-amplifiers from
external noise and artifacts which may result from the use of the
RF transmitter.
35. The EEG electrode locator headgear of claim 22, wherein said
plunger assembly is adapted to be received in said circuit board
base member of the electrode locator.
36. The EEG electrode locator headgear of claim 23, wherein said
cylindrical plunger member preferably has a plurality of grooves
for engagement with the corresponding spring loaded detent pins in
the circuit board member for seating the plunger assembly in the
electrode locators.
Description
RELATED APPLICATIONS
[0001] This is a continuation in part of Ser. No. 09/245,784 filed
Feb. 5, 1999.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates generally to devices for the
acquisition of electroencephalographic (EEG) signals, and more
particularly concerns an electrode locator device that can be
applied by a user without assistance for acquiring high quality EEG
signals, and is comfortable and cosmetically acceptable for use
during daily activities.
[0005] 2. Description of Related Art
[0006] Advances in detection and characterization of
electroencephalographic (EEG) signals from the brain have allowed
EEG monitoring to be useful in analysis of neurological disorders,
and laboratory studies of awareness and sleep. Recent advances
have, for example, provided much information about the correlation
between EEG signals and an individual's level of arousal, in a
continuum from vigilance to drowsiness, and sleep onset. Devices
for monitoring EEG signals are typically used in a laboratory
environment or in a home for sleep studies, but are typically set
up and operated by trained technicians. Shifts in EEG signals have
been directly correlated with changes in performance, particularly
during tasks which require sustained attention over prolonged
periods of time. However, application of EEG monitoring to
environments for study and monitoring of brain performance, such as
for monitoring brain activity in the home, office, aircraft
cockpit, and train or truck operations cabins, for example, has
been severely hampered by cumbersome detection and recording
equipment, and the need for the assistance of a technician
typically required to obtain high quality data.
[0007] In fitting EEG electrodes to the scalp of a subject being
monitored, an EEG technician will typically first measure the
distances between the nasium and the occipital bone, and between
the mastoid processes, to identify the top center (Cz) of the head,
and will then position all other electrodes relative to these
landmarks to comply with the International 10/20 System that is
well known in the art as the standard for positioning of EEG
electrodes. The technician will then part the hair of the scalp of
the subject at the intended electrode sites, clean the electrode
sites to remove dirt, hair oil, and the like, and prepare the scalp
to remove the top layer of dead skin, to ensure that low
scalp-electrode impedance values are obtained.
[0008] Conventionally, after preparation of the intended electrode
sites on the scalp, electrodes are glued to the scalp with
collodion, typically a viscous solution of pyroxilin, a
commercially available nitrocellulose, in ether and alcohol, that
is a particularly noxious preparation that can bond with the scalp
and hair, to provide a stable scalp-electrode interface, until
dissolved by a solvent such as acetone, or a non-acetone, oil based
collodion remover.
[0009] A variety of hats, caps, helmets and headgear are known that
have been developed to position EEG electrodes according to the
International 10/20 System and provide a scalp-electrode interface
without the use of an adhesive such as collodion.
[0010] In another presently preferred aspect of the invention, the
plurality of locator straps are made of elastic material, such that
the locator straps bias the plurality of EEG electrode locators,
and thereby the electrodes inserted into the electrode locators,
with a biasing pressure toward the user's scalp, to provide a
stable electrode-scalp interface capable of producing a high signal
quality. A plurality of electrodes are also provided that are
adapted to be seated in the plurality of electrode locators,
respectively. As noted above, at least three electrodes are
provided, although the electrode headgear can be adapted to accept
more or fewer than three EEG electrodes, as desired. The electrodes
are preferably disposable.
[0011] A plunger assembly is also preferably provided that is
adapted to cooperate with the plurality of electrode locators
either prior to or in conjunction with insertion of the EEG
electrodes. The plunger assembly includes a hollow tubular base
having an upper portion and a lower portion, and a plunger adapted
to be received in the hollow tubular base. The plunger assembly is
adapted to be inserted in the electrode locators to prepare the
scalp of the user and to seat the electrodes.
[0012] The lower portion of the hollow tubular base advantageously
includes a plurality of flexible, resilient fingers having distal
ends that are biased to meet at a common distal central location,
and that can be spread in order to part the hair of the scalp of
the user at a desired site on the scalp of the user in preparation
of the site for receiving an EEG electrode. The flexible, resilient
fingers on the hollow tubular base of the plunger assembly are
presently preferably plastic. The distal flexible, resilient
fingers of the plunger hollow tubular base can be spread by
insertion of an electrode through the plunger hollow tubular base,
so that the plunger assembly can be used to simultaneously part the
hair by spreading of the distal fingers of the plunger hollow
tubular base, and seat the disposable electrode, and optionally
also may be used to abrade the scalp of the user at the intended
location of the electrode, such as by manually twisting the hollow
tubular base to rub the distal ends of the distal fingers against
the scalp of the user. The plunger is adapted to be inserted in the
hollow tubular base of the plunger assembly to spread the distal
flexible, resilient fingers.
[0013] In one presently preferred alternate embodiment, the plunger
has an external helical rib, and the hollow tubular base has a
corresponding interior groove for receiving and guiding the
external helical rib of the plunger as the plunger is inserted in
the hollow tubular base of the plunger assembly, to provide a
predetermined turning and torque to the plunger as it is inserted.
In another presently preferred aspect, the hollow tubular base of
the plunger assembly includes an electrical conductor adapted to be
electrically connected between an electrode inserted in the hollow
tubular base and one of the electrode locators for conducting EEG
signals from the electrodes to an EEG monitor.
[0014] In a second preferred embodiment, the invention provides for
an electroencephalograph (EEG) electrode locator headgear
comprising a base strap assembly adapted to be secured comfortably
around the circumference of a user's head, an elastic, stretchable
cap portion connected to the plurality of EEG electrode locators,
and a plurality of EEG electrode locators mounted to the elastic,
stretchable cap portion for accurately positioning the plurality of
EEG electrode locators relative to the user's scalp, and for
biasing the plurality of electrode locators toward the user's
scalp. A plurality of EEG electrodes are also provided that are
adapted to be received in and cooperate with the plurality of EEG
electrode locators, respectively. Each of the EEG electrodes
includes a plunger assembly adapted to optionally prepare the
user's scalp and to seat the electrode in one of the EEG electrode
locators. The plunger assembly includes a plunger member having an
electrically conductive spreader member mounted to the lower end of
the plunger member, and the spreader member advantageously includes
a plurality of flexible, resilient fingers having distal ends
biased to meet at a common distal central location. The plunger
assembly preferably comprises an electrical conductor mounted to
the plunger member adapted and electrically connected between the
electrically conductive spreader member and the EEG electrode
locator for conducting EEG signals from the electrodes to an EEG
monitor. The flexible, resilient fingers are adapted to spread
apart by exertion of downward pressure of the plunger assembly
against the user's scalp, so as to part the hair of the user's
scalp, for preparation of the scalp for effective contact by the
electrodes. The plunger is preferably adapted to be inserted in the
electrode locator to spread the distal flexible, resilient fingers,
and the plunger assembly can be used to abrade the user's scalp at
the intended location of the electrode by manually twisting the
plunger assembly to rub the distal ends of the distal fingers
against the user's scalp. In one presently preferred aspect, the
plunger assembly comprises a cap connected to the upper portion of
the plunger member. In order to improve the comfort of the user in
applying the electrodes to the user's scalp, the spreader member
preferably comprises an electrically conductive cushion portion
located between the flexible, resilient fingers adapted to rest
against the user's scalp after the electrode has been pressed
downward to seat the electrode on the user's scalp and spread the
flexible, resilient fingers, to cushion the pressure of the
electrode on the user's scalp for additional comfort, and a
conductive gel may also be disposed adjacent to the cushion portion
of the spreader member and between the flexible, resilient
fingers.
[0015] In a presently preferred aspect, the elastic, stretchable
cap portion comprises one or more elastic locator straps connected
to the plurality of EEG electrode locators, and preferably
comprises a plurality of elastic locator straps, which can be made
of elastic material, such as an elasticized fabric. The plurality
of EEG electrode locators each comprise a plurality of slots for
receiving the locator straps. In another presently preferred
aspect, the elastic, stretchable cap portion comprises a stretch
mesh cap of elastic, fabric material. An outer cap shell can
optionally be further disposed over the elastic, stretchable cap
portion, and may include shielding.
[0016] In another currently preferred aspect of the invention, the
base strap assembly comprises a front pad of material adapted to
extend across a user's forehead, and a visor or front bill of the
headgear may also attached to the front pad of material. The base
strap assembly is currently preferably adjustable, and in one
presently preferred embodiment comprises a pair of adjustable
elastic straps connected at one end to the front pad of material
and adjustably connected together at the other end. The base strap
assembly may also further comprise an occipital locator device
adapted to be seated on a region of the user's scalp over the
user's occipital bone.
[0017] In the second embodiment, each of the electrode locators
preferably includes an electrical conductor adapted to be
electrically connected to one of the EEG electrodes inserted in the
electrode locator, and in a presently preferred aspect, the
electrode locator electrical conductor comprises a plurality of
electrically conductive spring connectors. In a preferred
embodiment, a circuit board base member is mounted to the electrode
locator electrical conductor, and the plurality of electrically
conductive spring connectors are mounted to the circuit board base
member. In another preferred aspect, the electrode locators include
spring loaded detent pins for engagement with the electrode, and
the plunger member preferably has a plurality of grooves or ratchet
strips for engagement with the corresponding spring loaded detent
pins for seating the plunger assembly in the electrode
locators.
[0018] In another presently preferred aspect of the second
embodiment, the EEG electrode locator headgear further comprises an
operational pre-amplifier electrically connected to the electrode
locator electrical conductor to receive EEG signals from the
electrode, and the EEG signals from the electrode locators are
conducted from the pre-amplifier to an analog to digital converter
mounted on the EEG electrode locator headgear. An RF transmitter is
preferably connected to receive output from the analog to digital
converter, for communicating digital EEG signals to an apparatus
for analyzing the digital EEG signals from the user, which
preferably comprises a data processing unit for also providing
feedback to the user. In a presently preferred aspect, the data
processing unit is battery powered, and includes a speaker for
transmitting audio alert messages to the user. In another presently
preferred aspect, the RF transmitter of the EEG electrode locator
headgear is a bi-directional RF transmitter-receiver for receiving
feedback signals from the apparatus for analyzing the digital EEG
signals from the user, and a speaker is mounted in the EEG
electrode locator headgear for communicating audio messages from
the data processing unit. Storage means may also be mounted in the
EEG electrode locator headgear for storing audio messages in analog
format. In another preferred aspect, the outer cap shell of the EEG
electrode locator headgear includes a Faraday shield to shield the
pre-amplifiers from external noise and artifacts which may result
from the use of the RF transmitter.
[0019] These and other aspects and advantages of the invention will
become apparent from the following detailed description and the
accompanying drawings, which illustrate by way of example the
features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a top perspective view of a preferred embodiment
of the EEG electrode locator headgear of the present invention;
[0021] FIG. 2 is a bottom perspective view of the EEG electrode
locator headgear of FIG. 1;
[0022] FIG. 3 is a side elevational view of an EEG electrode
locator of the EEG electrode locator headgear of FIG. 1,
illustrating an EEG electrode, plunger assembly being inserted in
the EEG electrode locator;
[0023] FIG. 4 is a cross-sectional view of the EEG electrode fully
inserted in the plunger assembly and electrode locator of FIG:
3;
[0024] FIG. 5A is a side elevational view of an EEG electrode
locator of the EEG electrode locator headgear of FIG. 1,
illustrating an alternate plunger assembly being inserted in the
EEG electrode locator;
[0025] FIG. 5B is a top plan view of the plunger assembly of FIG.
5A;
[0026] FIG. 6 is a cross-sectional view of an EEG electrode fully
inserted in the plunger assembly and electrode locator of FIG.
5;
[0027] FIG. 7 is a bottom perspective view of an alternate
embodiment of the EEG electrode locator headgear of the invention
showing a front locator strap;
[0028] FIG. 8 is a perspective view of an occipital locator of the
base strap of the EEG electrode locator headgear of FIG. 1;
[0029] FIG. 9 is an exploded perspective view of a second preferred
embodiment of the EEG electrode locator headgear of the present
invention;
[0030] FIG. 10 is a top perspective view of the EEG electrode
locator headgear of FIG. 9 without the cap shell to show the
positions of the electrode locators;
[0031] FIG. 11 is a bottom perspective view of the outer cap shell
of the EEG electrode locator headgear of FIG. 9;
[0032] FIG. 12 is an exploded view of an EEG electrode plunger
assembly of the embodiment of FIG. 9;
[0033] FIG. 13 is a side elevational view of the EEG electrode
plunger of FIG. 12;
[0034] FIG. 14 is a front view of the EEG electrode plunger of FIG.
12;
[0035] FIG. 15 is a partial sectional view of the EEG electrode
plunger assembly of FIG. 12;
[0036] FIG. 16 is a sectional view of the EEG electrode plunger
assembly of FIG. 12 inserted in an electrode locator prior to
downward deployment of the EEG electrode plunger assembly onto the
scalp of a user;
[0037] FIG. 17 is a sectional view of the EEG electrode plunger
assembly of FIG. 12 inserted in an electrode locator following
downward deployment of the EEG electrode plunger assembly onto the
scalp of a user;
[0038] FIG. 18 is an exploded view of an alternate embodiment of an
EEG electrode plunger assembly according to the present
invention;
[0039] FIG. 19 is an exploded perspective view of one presently
preferred embodiment of an electrically conductive spreader member
of the EEG electrode plunger assembly of FIG. 18;
[0040] FIG. 20 is an exploded side elevational view of the
electrically conductive spreader member of the EEG electrode
plunger assembly of FIG. 19;
[0041] FIG. 21 is a sectional view of the electrically conductive
spreader member of FIG. 20 taken along line 21-21;
[0042] FIG. 22 is a top plan view of the electrically conductive
spreader member of the EEG electrode plunger assembly of FIG.
19;
[0043] FIG. 23 is a bottom plan view of the electrically conductive
spreader member of the EEG electrode plunger assembly of FIG.
19;
[0044] FIG. 24 is an exploded perspective view of another presently
preferred embodiment of an electrically conductive spreader member
of the EEG electrode plunger assembly of FIG. 18;
[0045] FIG. 25 is an exploded side elevational view of the
electrically conductive spreader member of the EEG electrode
plunger assembly of FIG. 24;
[0046] FIG. 26 is a sectional view of the electrically conductive
spreader member of FIG. 25 taken along line 26-26;
[0047] FIG. 27 is a top plan view of the electrically conductive
spreader member of the EEG electrode plunger assembly of FIG.
24;
[0048] FIG. 28 is a bottom plan view of the electrically conductive
spreader member of the EEG electrode plunger assembly of FIG.
24;
[0049] FIG. 29 is a schematic diagram of a self-contained
processing mode of utilizing the EEG electrode locator headgear of
the invention in an EEG monitoring system;
[0050] FIG. 30 is a schematic diagram of a computer interfaced
processing mode of utilizing the EEG electrode locator headgear of
the invention in an EEG monitoring system; and
[0051] FIGS. 31A and 31B illustrate a schematic diagram of a
modular real-time processing mode of utilizing the EEG electrode
locator headgear of the invention in an EEG monitoring system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] The application of EEG monitoring to common daily
environments for study and monitoring of brain performance during
the normal course of daily activities has been severely hampered by
cumbersome detection and recording equipment, and the need for the
assistance of a technician to set up and monitor the acquisition of
data in order to obtain high quality data. Simply parting the hair
of the scalp and preparation of the desired portions of the scalp
of a subject for proper placement of electrodes has commonly
required the assistance of a technician. Particularly when
disposable electrodes are to be applied by a user that are not
bonded to the scalp of the user to provide an electrode-scalp
interface, the proper preparation and placement of an electrode
over hair can be critical for obtaining high quality signal
data.
[0053] As is illustrated in the drawings, the invention is embodied
in an electroencephalograph (EEG) electrode locator headgear that
is portable and comfortable, and allows a user to locate and apply
disposable EEG electrodes accurately according to the International
10/20 System without technical assistance, to allow the acquisition
of high quality EEG signals. Referring to FIG. 1, the EEG electrode
locator headgear 10 includes a plurality of EEG electrode locators
12 for receiving EEG electrodes for accurate positioning on the
scalp of a user. The electrode locators each include a hollow
tubular base 14 adapted to receive an EEG electrode plunger 16 and
EEG electrode 17, as illustrated in FIGS. 4 and 6, and has an
annular flange 18 extending from an upper edge 20 of the hollow
tubular base. A plurality of electrodes are preferably provided,
and are adapted to be seated in the corresponding plurality of
electrode locators, respectively, by an interference or snap fit
with the electrode locators, or by an interference or snap fit with
a plunger assembly to be inserted in the electrode locators, as is
further explained below. The annular flange typically includes a
plurality of slots 22 for receiving a plurality of locator straps
24 that are currently preferably formed of elasticized fabric, in
order to assist in biasing the electrode locators toward the scalp
of the user, but non-elastic straps, such as fabric or nylon, for
example, may also be suitable.
[0054] In a presently preferred embodiment, the hollow tubular base
of the electrode locator includes an electrical conductor such as a
conductor strip 26, shown in FIG. 4, adapted to be electrically
connected to an EEG electrode, inserted in the hollow tubular base
via a plunger assembly, or directly, as will be further explained
below. Alternatively, the electrode locator can be made of an
electrically conductive metal. The electrical conductor of the
hollow tubular base is preferably adapted to be connected, such as
by a cable 27 connectable to an electrically conductive connector
29 electrically connected to the electrode locators, to an EEG
monitor 28 which is preferably a portable EEG monitor for
ambulatory use, such as the portable EEG monitor disclosed in
provisional application No. 60/114,528, filed Dec. 31, 1998, and
non-provisional application No. 09/345,046 filed Jun. 30, 1999,
which are incorporated herein by reference in their entirety. In a
presently preferred embodiment, three EEG electrode locators are
provided that are adapted to be positioned at the top central (Cz),
parietal (Pz), and occipital (Oz) positions relative to the scalp
of a user, although alternatively additional or fewer electrode
locators may also be provided in the headgear for locating EEG
electrodes according to the International 10/20 system.
[0055] In a presently preferred embodiment, as is best seen in
FIGS. 1 and 2, the EEG electrode locator headgear advantageously
includes a front pad of material 30, having a first end 31 and a
second end 32. The front pad of material is adapted to extend
across a user's forehead to provide a secure footing for the EEG
electrode locator headgear. The front pad of material is preferably
made of a non-elastic electrically conductive fabric material, such
as fabric containing silver or other metallic, electrically
conductive threads, for example. A front visor or bill 34 is
preferably attached to the front pad of material. A base strap
assembly 36 is also provided, having a first anterior end 38
connected to the first end of the front pad of material, and a
second anterior end being connected at the first anterior end 38,
and the second elastic edge strap 42b being connected at the second
anterior end 39 of the front pad of material, and adjustably
connected together at the posterior end 40. The plurality of
locator straps preferably form a network of locator straps
connected to the front pad of material, the base strap assembly,
and to the plurality of EEG electrode locators for accurately
positioning the plurality of EEG electrode locators positioned
relative to the scalp of a user. The plurality of locator straps
are preferably made of elastic material, such that the locator
straps bias the plurality of electrode locators with a biasing
pressure toward the user's scalp, and thereby bias the electrodes
inserted into the electrode locators toward the user's scalp, to
provide a stable electrode-scalp interface capable of producing a
high signal quality.
[0056] In another presently preferred embodiment illustrated in
FIG. 8, the base strap assembly includes an occipital locator
device 44 adapted to be seated on a region of the user's scalp over
the user's occipital bone. The base strap assembly first and second
elastic edge straps are thus preferably connected at one end to the
front pad of material, and adjustably connected at the other end to
the occipital locator device, which is currently preferably a ring,
such as a D ring, for example, having a plurality of feet 46
adapted to be positioned over the user's occipital bone.
[0057] In another preferred aspect of the EEG electrode locator
headgear, an anterior locator strap 50 is connected to the front
pad of material, with a free end 52 adapted to be positioned over
the user's nasium to confirm accurate placement of the electrode
locators.
[0058] The EEG electrodes are preferably of the type that are
disposable, and as is illustrated in FIGS. 3, 4 and 6, are adapted
to be seated in the plurality of electrode locators, respectively.
In a presently preferred embodiment, a plunger assembly 54 is also
provided that is adapted be used for preparation of the scalp of
the user for placement of the disposable electrodes, and is adapted
to cooperate with the plurality of electrode locators. In one
presently preferred embodiment, the plunger assembly includes a
hollow tubular base 56 having an upper portion 58 and a lower
portion 60, and a plunger 62 adapted to be received in the hollow
tubular base. The upper portion of the plunger assembly tubular
base preferably can be seated in the electrode locators by
interference or snap fit, although a slot and groove interlocking
assembly may alternatively be provided for seating the plunger
assembly tubular base in the electrode locators. The lower portion
of the hollow tubular base advantageously includes a plurality of
flexible, resilient fingers 64 having distal ends 66 biased to come
together at a common distal central location 68, and that can be
spread by the plunger 62 in order to part the hair of the scalp of
the user. As can be seen in FIG. 4, the plunger and electrode may
also be used for spreading the flexible, resilient fingers of the
tubular base of the plunger assembly. In a presently preferred
aspect, the spreadable fingers are formed of a plastic, such as a
thermoplastic that can be readily molded, for example. The plunger
assembly hollow tubular base preferably includes an electrical
conductor such as the electrical conductor strip 26 adapted to be
electrically connected between an electrode inserted in the hollow
tubular base and a corresponding electrical conductor of one of the
electrode locators for conducting EEG signals from the electrodes
to the EEG monitor 28. The distal flexible, resilient fingers of
the plunger hollow tubular base can be spread by insertion of an
electrode through the plunger hollow tubular base, so that the
plunger assembly can be used to simultaneously part the hair by
spreading of the distal fingers of the plunger hollow tubular base,
seat the disposable electrode, and optionally also abrade the scalp
of the user at the intended location of the electrode, such as by
manually twisting the hollow tubular base to rub the distal ends of
the distal fingers against the scalp of the user.
[0059] In another presently preferred alternate embodiment
illustrated in FIGS. 5 and 6, the plunger can be provided with an
external helical rib 72, and the hollow tubular base can be
provided with a corresponding internal groove 74 for receiving and
guiding the external helical rib of the plunger as the plunger and
electrode are inserted in the hollow tubular base of the plunger
assembly, to provide a predetermined turning and torque to the
plunger as it is inserted.
[0060] Referring to FIGS. 9 to 17, in another presently preferred
embodiment, the invention provides for an EEG electrode locator
headgear 110 having a cap portion 111 with a plurality of EEG
electrode locators 112 for receiving EEG electrodes for accurate
positioning on the scalp of a user. An outer cap shell 114 that can
be made of cotton, wool or other fabric, for example, or the like,
may be fitted over and connectable to the cap portion by one or
more fasteners such as an electrically conductive connector 113, or
other similar fasteners such as snaps, hook and loop fasteners 109,
buttons, or the like, to protect and conceal the EEG electrode
locators. The outer cap shell may also include electromagnetic
shielding, as will be described farther below, which is to be
electrically connected through the electrically conductive
connector to the front pad of material that also serves as an
electrical ground. The electrode locators each have a tubular
opening 115 adapted to receive an EEG electrode 116, as is
illustrated in FIGS. 12, 16 and 17. As is shown in FIG. 12, the EEG
electrode locators each include a plurality of slots 122 for
receiving locator straps 124 that are currently preferably formed
of elasticized fabric, in order to assist in biasing the electrode
locators toward the scalp of the user, but non-elastic straps, such
as fabric or nylon, for example, may also be suitable. Although a
single locator strap is illustrated in FIG. 9 for locating each of
the EEG electrode locators, additional locator straps may also be
attached to the EEG electrode locators as is illustrated in FIG.
12.
[0061] In this embodiment, the EEG electrodes are preferably
adapted to be connected for electrical communication by radio
frequency (RF) transmission with an EEG monitor, which is
preferably a portable EEG monitor for ambulatory use, as will be
further explained below. Three EEG electrode locators are
preferably provided that are adapted to be positioned at the top
central (Cz), parietal (Pz), and occipital (Oz) positions relative
to the scalp of a user, although alternatively additional or fewer
electrode locators may also be provided in the headgear for
locating EEG electrodes according to the International 10/20
system.
[0062] Referring to FIGS. 9 to 12, the base strap assembly 130 of
the EEG electrode locator headgear includes a front pad of material
132, having first and second ends 133, 134, adapted to extend
across a user's forehead to provide a secure footing and electrical
ground for the EEG electrode locator headgear on the user's
forehead. The front pad of material is preferably made of a
non-elastic electrically conductive fabric material, as described
above. A front visor or bill 136 is preferably attached to the
front pad of material. The base strap assembly has a first anterior
end 138 connected to the first end of the front pad of material,
and a second anterior end 139 connected to the second end of the
front pad of material, and a posterior end 140. Together, the front
pad of material and the base strap assembly are adapted to be
secured comfortably around the circumference of the user's head,
and the base strap assembly is adjustable. The base strap
preferably comprises a pair of adjustable elastic edge straps, with
the first elastic edge strap 142a connected at the first anterior
end 138, and the second elastic edge strap 142b being connected at
the second anterior end 139 of the front pad of material, and
adjustably connected together at the posterior end 140. As is
illustrated in FIGS. 9 and 10, the base strap assembly includes an
occipital locator device 144 adapted to be seated on a region of
the user's scalp over the user's occipital bone. The base strap
assembly first and second elastic edge straps are thus preferably
connected at one end to the front pad of material, and adjustably
connected at the other end to the occipital locator device, which
in another currently preferred embodiment comprises an annular ring
having a plurality of feet 145 adapted to be positioned around and
over the user's occipital bone.
[0063] As is illustrated in FIGS. 9 to 11, a stretch mesh cap 146
of elastic, fabric material may also be provided in addition to, or
as an alternative to, the locator straps, connected to the front
pad of material, the base strap assembly, and to the plurality of
EEG electrode locators for accurately positioning the plurality of
EEG electrode locators relative to the scalp of a user. The stretch
mesh and locator straps are preferably made of elastic material, in
order to bias the electrode locators and electrodes with a downward
biasing pressure toward the user's scalp, to provide a stable
electrode-scalp interface capable of producing a high signal
quality.
[0064] Referring to FIGS. 12 to 17, the EEG electrodes are
preferably of the type that are disposable, and are adapted to be
seated in the electrode locators. In this embodiment, each of the
EEG electrodes include a plunger assembly 148 with a generally
cylindrical plunger member 150 having an upper portion 152 and a
lower portion 154. The plunger assembly may also include a cap 156
connected to the upper portion of the plunger member. As is
illustrated in FIG. 12, the plunger assembly is adapted to be
received in a circuit board base member 158 mounted on or in an
electrode locator and having a plurality of spring loaded detents
159 and electrically conductive spring connectors 160. The
cylindrical plunger member preferably has a plurality of grooves or
ratchet strips 161 for engagement with the corresponding spring
loaded detents in the circuit board member for seating the plunger
assembly tubular base in the electrode locators.
[0065] The lower portion of the plunger preferably includes an
electrically conductive spreader member 162 having a plurality of
flexible, resilient fingers 164 having distal ends 166 biased to
come together at a common distal central location 168, and that can
be spread by the application of downward force of the plunger
assembly against a user's scalp in order to part the hair of the
scalp of the user. The spreader member also includes an
electrically conductive thick cushion portion 169 that will rest
against the scalp of the user after the electrode has been pressed
downward to seat the electrode on the user's scalp and spread the
flexible, resilient fingers, to cushion the pressure of the
electrode on the user's scalp for additional comfort. As is
illustrated in FIG. 12, an electrical conductor strip 170 is
disposed over the lower portion and opposing sides of the
cylindrical plunger member, to provide electrical communication
between the electrical spring connectors of the electrode locator
circuit board and the electrically conductive spreader member for
communicating EEG signals from the electrodes to the EEG monitor.
The initial positioning of the flexible, resilient fingers prior to
spreading of the fingers can provide a seal and protection of a
conductive gel 172 that can also be placed adjacent to the cushion
portion of the spreader member and between the flexible, resilient
fingers for additional comfort of the user and improved acquisition
of EEG signals from the user's scalp.
[0066] The distal flexible, resilient fingers of the plunger hollow
tubular base can be spread by insertion of an electrode through an
electrode locator to press downwardly against the user's scalp 171,
so that the plunger assembly can be used to simultaneously part the
hair by spreading of the distal fingers of the plunger hollow
tubular base and seat the disposable electrode. The distal fingers
can also be used to abrade the scalp of the user at the intended
location of the electrode, such as by manually twisting the hollow
tubular base to rub the distal ends of the distal fingers against
the scalp of the user. The spreader member and the spreadable
fingers are currently preferably formed of an electrically
conductive silicone, such as silicone containing carbon, or
containing other similar electrically conductive material, for
example, for improved acquisition of EEG signals from the user's
scalp.
[0067] Referring to FIG. 12, in a currently preferred embodiment,
operational pre-amplifiers will be provided at each electrode site,
so that it will not be necessary to provide a second stage
differential amplification of the acquired EEG signals. In one
presently preferred implementation, each pre-amplifier 174 will be
mounted on the electrode locator, such as on the circuit board base
member 173 mounted on the upper surface of the electrode locator,
for example. Alternatively, the circuit board base member and
pre-amplifier may be contained within a housing provided by the
electrode locator, or the pre-amplifier may be provided in the
electrodes. Referring to FIGS. 9 and 10, the EEG signals from the
Cz, Pz, and Oz electrode locators will be routed by wires 175 from
the pre-amplifiers via electrical connector 177, which connects
with electrical connector 113, as the differential inputs of a
Sigma Delta analog to digital converter 176 currently preferably
mounted on a circuit board at the front of the headgear, and an
input is provided to the pre-amplifiers from the front ground pad
sewn into the portion of the headgear that contacts the forehead.
The output of the analog to digital converter will result in a
differential recording of EEG signals. The gain from the Cz
electrode locator is preferably set to a gain of one, while the
gains for the Pz and Oz electrode locators will be greater, and are
typically 10. All filtering of the EEG signals will typically be
performed digitally by programming of the analog to digital
converter. The analog to digital converter, microprocessor 178,
batteries 182, and an RF transmitter 184 are preferably mounted at
the front of the headgear. A Faraday shield 186 is also preferably
incorporated into the headgear, such as electromagnetic shielding
material sewn into the outer cap shell, for example, as shown in
FIG. 11, to create a Faraday shield to shield the pre-amplifiers
from external noise and artifacts which may result from the use of
the RF transmitter. Radio frequency transmission is currently
preferred for communication of the EEG signals to an RF receiver
188 connected to a computing device 190 used for acquiring and
analyzing the digital EEG signals from the user, so that no wires
are required to connect the user to a recording and/or data
analysis device. In one presently preferred configuration, the
computing device is a data processing unit (DPU) used to acquire
and analyze EEG signals from the user, and to provide feedback to
the user.
[0068] The DPU preferably includes a digital signal processing
(DSP) chip, power supply, digital to analog converter, a speaker
192, and batteries (not shown), so that the DPU is completely
portable. The DPU can thus acquire EEG signals from the EEG
electrode locator headgear, run the EEG data analysis algorithms,
and use the digital to analog converter and speaker to generate
audio feedback alert messages to the user. In order to provide the
audio messages to the user that may be required in noisy
environmental conditions, the RF transmitter 184 of the EEG
electrode locator headgear and the RF receiver 188 connected to the
DPU are preferably bi-directional RF transmitter-receivers, and an
amplifier 194 and speaker 196 are also mounted on the EEG electrode
locator headgear. Thus, when the DPU determines that an audio alert
message or verbal message should be transmitted to the user, a
signal is transmitted from the DPU to the EEG electrode locator
headgear to present a specific message. Audio messages can be
stored in analog format in flash memory in the EEG electrode
locator headgear where the analog to digital converter, power
supply and processor are mounted. The analog message can then be
presented to the user either through one or more speakers mounted
on the EEG electrode locator headgear, or through an earphone that
attaches to a connector incorporated into the EEG electrode locator
headgear.
[0069] Referring to FIG. 18, illustrating an assembly of an
alternate embodiment of an electrode locator and an electrode
according to the invention, it can be seen that the electrode
locator assembly 212 provides a tubular opening 215 for receiving
an EEG electrode 216. The EEG electrode locators each include a
plurality of slots 222 for receiving locator straps, as described
above. The EEG electrodes include a plunger assembly 248 with a
generally cylindrical plunger member 250 having an upper portion
252 and a lower portion 254. The plunger assembly may also include
a cap 256 connected to the upper portion of the plunger member. The
plunger assembly is adapted to be received in a circuit board base
member 258 mounted in the electrode locator with a spring detent
259 and one or more electrically conductive connectors 260. The
circuit board base member can be retained in the electrode locator
assembly by a retainer member 257 fitting in the bottom of the
electrode locator, for example. The cylindrical plunger member
preferably has a plurality of grooves in a side ratchet strip 261
for engagement with the corresponding spring detent in the circuit
board member for seating the plunger assembly tubular base in the
electrode locators.
[0070] Referring to FIGS. 18-23, the lower portion of the plunger
preferably includes an electrically conductive spreader member 262
having a spreadable base portion 263 comprising in this embodiment
a plurality of flexible, resilient fingers 264 having distal ends
266 biased to close together approximately at a common distal
central location 268, and that can be spread by the application of
downward force of the plunger assembly against a user's scalp in
order to part the hair of the scalp of the user. The spreader
member also includes an electrically conductive intermediate
portion with a thick electrically conductive cushion portion 269
that will rest against the scalp of the user after the electrode
has been pressed downward to seat the electrode on the user's scalp
and spread the flexible, resilient fingers, to cushion the pressure
of the electrode on the user's scalp for additional comfort.
Alternatively, an electrically conductive gel cap may also be
provided within the spreader member base portion to be pressed
against the scalp by the electrically conductive intermediate
cushion portion. An electrical conductor strip 270 is disposed over
the lower portion and opposing sides of the cylindrical plunger
member, to provide electrical communication between the one or more
electrical connectors of the electrode locator circuit board and
the electrically conductive spreader member for communicating EEG
signals from the electrodes to the EEG monitor. The initial
positioning of the flexible, resilient fingers prior to spreading
of the fingers can provide a seal and protection of the conductive
gel cap, when used.
[0071] The distal flexible, resilient fingers of the plunger hollow
tubular base can be spread by insertion of an electrode through an
electrode locator to press downwardly against the user's scalp, so
that the plunger assembly can be used to simultaneously part the
hair by spreading of the distal fingers of the plunger hollow
tubular base and seat the disposable electrode. As described above,
the distal fingers can also be used to abrade the scalp of the user
at the intended location of the electrode, such as by manually
twisting the hollow tubular base to rub the distal ends of the
distal fingers against the scalp of the user. The spreader member,
intermediate cushion portion, and spreadable fingers are currently
preferably formed of an electrically conductive silicone, such as
silicone containing carbon, or containing other similar
electrically conductive material, for example, for improved
acquisition of EEG signals from the user's scalp. Operational
pre-amplifiers will preferably be provided at each electrode site,
so that it will not be necessary to provide a second stage
differential amplification of the acquired EEG signals, as
described above.
[0072] Referring to FIGS. 24-31, in another presently preferred
embodiment, the electrode assembly has an electrically conductive
spreader member 262' having a spreadable base portion 263'
comprising a flexible and resilient, tapered base member 264'
having a generally annular but uneven lower end surface 265', with
slightly raised shoulder portions 266' and lower extending flange
portions 267'. The flexible, resilient tapered base member can be
spread by the application of downward force of the plunger assembly
against a user's scalp in order to part the hair of the scalp of
the user. The spreader member also includes an electrically
conductive intermediate portion with a thick cushion portion 269'
that will rest against the scalp of the user after the electrode
has been pressed downward to seat the electrode on the user's scalp
and spread the flexible, resilient fingers, to cushion the pressure
of the electrode on the user's scalp for additional comfort.
Alternatively, an electrically conductive gel cap may also be
provided within the spreader member base portion to be pressed
against the scalp by the intermediate cushion portion, and the
tapered base member can provide a seal and protection of the
conductive gel cap, where used.
[0073] As described above, the distal spreader member of the
plunger hollow tubular base can be spread by insertion of an
electrode through an electrode locator to press downwardly against
the user's scalp, so that the plunger assembly can be used to
simultaneously part the hair by spreading of the tapered base
member of the spreader. The uneven bottom surface of the tapered
base member can also be used to abrade the scalp of the user at the
intended electrode site, such as by manually twisting the hollow
tubular base to rub the distal ends of the distal fingers against
the scalp of the user. The spreader member, intermediate cushion
portion, and spreadable fingers are currently preferably formed of
an electrically conductive silicone, such as silicone containing
carbon, or containing other similar electrically conductive
material.
[0074] It is contemplated that the EEG electrode locator headgear
of the invention can be utilized in three principal modes in a
portable EEG monitoring system for ambulatory use. All three modes
share the same basic features, including high input impedance low
noise pre-amplifiers mounted at the electrode site. The three modes
would also preferably utilized a Sigma-delta Analog/Digital (A/D)
converter which is programmed to provide sampling rates, and
filtering requirements specified by the EEG monitoring software
(i.e., 256 samples/sec, high and low pass filter cutoffs). Other
types of A/D converters can be used (e.g., successive
approximation), however, based on present technology circuitry must
be added with increase the weight, size and power consumption of
the system to provide the appropriate analog and/or digital
filtering. A micro-controller would also be provided that can be
programmed to operate the A/D, control the optional impedance
monitoring circuitry, select/transmit messages to be transmitted by
the voice unit to the speaker, and operate the radio transceiver,
when applicable. In addition, voice unit circuitry will generate
pre-recorded analog auditory alarms or verbal messages transmitted
to a speaker to notify the user based on the requirements of the
B-Alert software.
[0075] The impedance monitoring circuitry and A/D chip will
typically be mounted on an analog board, and the micro-controller,
power supply elements, battery, voice unit circuitry and radio
transceiver will typically be mounted on a second digital board to
minimize the noise contributed by the system to the analog inputs.
In one presently preferred implementation, all components can be
mounted on a single board, with an electro-mechanical layout that
isolates the radio transceiver and power supply to minimize system
noise.
[0076] The EEG monitoring system software can also provide for
monitoring noise attributed to excessive scalp-electrode impedance
without the use of impedance monitoring circuitry by calculating
the magnitude of 60 Hz interference. Alternatively, impedance
circuitry can be implemented which produces a low level driving
signal across the electrodes and then measures the induced voltage
or current depending on the circuit. This approach can be operated
in time sharing mode while acquiring the EEG signals, or continuous
monitoring is possible if the frequency of the impedance signal
generator is outside the frequency range used for the EEG
monitoring system software (i.e., 0.5 to 128 Hz).
[0077] A voice unit for playing audio messages can utilize analog
memory devices (such as ISD33120) or a D/A converter and standard
digital memory. To provide sufficient volume to the speaker, an
audio power amplifier may be required.
[0078] Referring to FIG. 29, when the processing unit in the
self-contained processing mode is a micro-controller, the system
can operate the portion of the EEG monitoring system software
designed to acquire high quality EEG recordings by monitoring and
providing feedback for excessive movement and muscle artifacts. If
the processing unit utilizes a Digital Signal Processing (DSP)
chip, this mode is capable of processing the EEG monitoring system
alertness monitoring software in real-time. Flash memory can be
used to store the EEG monitoring system software and the digital
data acquired while the system is in use. A serial computer
interface circuitry will allow software to be loaded in the flash
memory for use by the DSP and to download data stored in flash
memory to computer for off-line analysis and storage. The
self-contained processing mode with the DSP chip will be a
preferred embodiment for ambulatory use of the system at such time
as battery storage technologies improve the capacity of small
disposable batteries, or the power required to operate a DSP chip
and the EEG monitoring system software becomes less than that
required to operate the radio transceiver.
[0079] Referring to FIG. 30, the computer interfaced processing
mode is designed for use of the electrode locator headgear in
conjunction with a laptop or workstation computer (PC). A radio
transceiver is integrated with the PC through a computer interface.
The mode is capable of running the EEG monitoring system software
in the data acquisition mode, or if the CPU of the PC is
sufficiently fast, running the EEG monitoring system software for
real-time processing. The radio transceiver interfaced with the PC
(RTC) can transmit control messages initiated by the EEG monitoring
system software to the radio transceiver located on the electrode
locator headgear. The micro-controller on the electrode locator
headgear will interpret and implement the control messages,
including impedance monitoring and deliver of audio or verbal
messages to the user. Referring to FIGS. 31A and 31B, the modular
real-time processing mode provides all components necessary to
operate the EEG alertness monitoring software in real-time packaged
in a device the size of a pager. Digitized data transmitted from
the electrode locator headgear will be received by RTC, processed
using the EEG monitoring system software and DSP chip. Control
messages initiated by the EEG monitoring system software will be
transmitted by the RTC to the electrode locator headgear, which
will then be interpreted and implemented by the circuitry located
on the electrode locator headgear. Data will be stored on the flash
memory for use by the EEG monitoring system software and can be
downloaded to a PC using the serial computer interface.
[0080] It should be understood that the individual EEG electrodes
can alternatively be individually or collectively directly
connected such as by one or more cables to an EEG signal monitor,
and that other conventional modifications may also be suitable.
Although the EEG electrode locator headgear of the invention is
advantageously adapted to be usable without a chin strap by an
adult user, it should be appreciated that the EEG electrode locator
headgear of the invention could also be adapted to include a chin
strap for use by children or to meet the special requirements of an
individual user. In addition, although the present invention
contemplates the location of disposable EEG electrodes in
individual EEG electrode locators, it should be appreciated that
combined EEG electrode and locator assemblies, such as active,
amplified electrodes, for example, may be incorporated into the
headgear of the locations of the EEG electrode locators, in the
same or a similar manner. Alternatively, active electrodes or
pre-amplifiers could be incorporated into the plunger or connected
to the electrical conductor of the electrode locator. It will thus
be apparent from the foregoing that while particular forms of the
invention have been illustrated and described, various
modifications can be made without departing from the spirit and
scope of the invention. Accordingly, it is not intended that the
invention be limited, except as by the appended claims.
* * * * *