US2549836A - Electrode-carrying headgear for electroencephalographic analysis - Google Patents

Description

Aprnl 24, 1951 A. R. MCINTYRE ET AL 2,549,835

ELECTRODE-CARRYING HEADGEAR FOR ELECTROENCEPHALOGRAPHIC ANALYSIS Filed June 14, 1946 2 Sheets-Sheet 1 IITTORNEY A. R. MCINTYRE ET AL 2,549,836 ELECTRODE-CARRYING HEADGEAR FOR ELECTROENCEPHALOGRAPHIC ANALYSIS April 24, 1951 2 Sheets-Sheet 2 Filed June 14 1946 INVEN'I'ORS ARCH/BAlD floss fi/c/mrms A/m ARTHUR ZOVELL Uu/v/v 11 TTORNE I Patented Apr. 24, 1951 ELECTRODE- CA'RREYING HEADGEKR; FOR ELECTROENCEPHALOGRAPHIG ANALYSIS Arohibald-lltaltiolntl/ and; Arthur L. Dunn, Omaha, Nehr z -G aims.

1 This invention relates to an .electrodeecarryi headgear for use in. electroencephalographic ex? aminations. More. particularly, it relates to; a

headgear equipped with a pluralitytofelectrodes each. adjustable to any-desiredposition in a given areaofzthe. scalp of-theipatientzonwhom theiheadgearisaused.

In making anexamination of; this. type, it: is necessary to: locate electrodes at diiferentpositions on, the scalp. and: tomake-v at record ofelectrical data .as it isrinfiuenced bythecharacteristics of. the. conducting paths between: the: particular electrodes used: for a: given. reading. It. has: been proposed to. usezgauze or'bands tohold-suohi eIec-- trodes. in place but: thattechnique: is slow; unwieldly; and; uncertain, It: has also been proposed to; fasten the electrodes in. place with col:- lodionor: similarcementing. materials; but that technique is likewise slow and best; results re- 7 quire a skillful operator-to apply andzremovethe electrodes.

The headgear herein described isdevoid oft the disadvantages inherent in: earlier methods of making electroencephalographic examinations. It facilities shifting pairs '01 groups of electrodes rapidly to any: partof-the-skull; enabling: an examination to be made inw-a minimum of timevand with maximum cooperation from the patient.

Ref erringto the drawings: Fig. 1 is a side elevation of. a headgear for making electroencephalographic examinations and The headgear is essentially a frame; consistin in partof an oval band lu made; of 4 /2;- x /g inch, fiber strip, and.. dimensioned. toallow aproximately 2; to. 3; inches; clearance all; around, between headv andghand; when. placed over a male. head ofaveragesize- (Figs; 14 and 2):.. The-frame consistsfilrther of; two members I. I:- and. t2 which arch above the head; andwhich; at their lower ends, are piyotallyconnected as at, l;3 to; the oval.

band at itsoppositesides These; connections are made .-wi th bolts; and wingnuts, I.4:which: facilitate ivotallv adjusting; the arched members and see. curing them in-their different aclciustedit si iolrs.=

The; arched. mem ers: H I and; I2.. like; the; avail 2 band. 10,,may-be made of l /zx' inchfiberstrip and preferably dimensioned to clear the head by about; 2 to 3* inches. "The oval band Ill and the arched-members Hi'and I2'are equipped with electrodes F5 to: whichfurther reference is made lateron.

During an: electroencephalographic. examination, it important that no portion ofzthe wei'ght of; the headgear be transmitted to the head of the patient; To'thisend, the headgear may be supported by a spring [.6 why a supportingdevice whi'chincludes a split. cylindrical clamp If! adapted to be tightenedirrplaceon a fixed horizontal bar supportlld. An angular shaped metal bracket 1 9., fastenedrati-ts' lower endfto onemembers'of the. split'clamp H, is connected' to the 'oval band Hi at..-the rear'by a hinge 2'0 which makes it possible quickly and easily to: swingthe head gear into or out of position relative to the patients head;

A head rest 2| at? the rear of the headgear serves to: support the patients head; It is VJ-shaped', padded at the front. for comfort and is held" in place by a U Sha'ped bracket 22 at the outer ends of whose legs it is secured; The legs are each made in two partswhich telescope together and" provide for a limited adjustment of theuheadfirest in a fore and'aft" direction. Thumb screws which pass through registering slots in thetelescoping legs enable the head rest to be secured in its different adjusted positions. The u sh'aped'bracltet'in turnis secured to the clamp 1.1 "which constitutes the primary support for the headgear;

During an examination, the patients' head'is clamped;betweenthe head rest 21' which engages the head: atrthe'rearand nose member 23 which engages the head at the front (Figs. 1; 2 and'6 The nose member is supported' in the oval band at' the front and is adjustable in a fore-and aft directionto accommodate headsof'difierent sizes.

The nose piece is adapted to engage the bridge ofthe-zpatients nose. To this-end; it is bent for wardly-"atithe' top to clear the forehead and forwardly' at the bottom where it is: concave toifit the nos e; The. upperfandl lower portions are, com nected together by.-a. reinforcing element 24 which swivels, at v the: inner; end of? the adjustable:

mounting.

The adjustableimounting includesa' cylindrical supporting member 25 havinga largerouter portiOny presenting. a shoulder 2.6.; which. engages the ovalband In at: the front;- and; a smaller portion 217- passingthrough; ahole in sai-dnband. A nut '2 8z issthr adcdzup. tighten the; smaller portion. 21.

of the member to hold the latter securely in place. The adjustable mounting further includes a rod 29 formed with a head 30 at its outer end and which is threaded through a sleeve 3| slidably arranged in the supporting member which is axially drilled for the purpose. The sleeve is formed at its outer end with a flange 32 which is received in an enlarged hole drilled in the larger outer portion of the supporting member 25. This enlarged hole presents a shoulder at its base against which the flange 32 is resiliently held. by a spring 33 reacting between the flange and a bushing 34 threaded into the enlarged hole at its outer end. The rod 29 which is threaded through the sleeve 3! has an enlarged extension at its inner end to which the nosepiece 23 is swiveled. With this arrangement, the nosepiece 23 is moved inwardly into engagement with the patients nose as the screw head 3% is turned in one direction and, as the nosepiece engages the bridge of the patients nose, its further movement is against the reaction of the spring 33 which thus determines the clamping pressure exerted.

The headgear as shown supports four pairs of electrodes l5, although a greater number may be used if desired. Those for examining the frontal and parietal portions of the head are carried by the arched bands H and I 2, whereas those for examining the occipital portion of the head are carried by the oval band I!) near the rear. In addition, there are two mastoid electrodes adapted to engage the head just behind the ear.

Each electrode i5 is carried by an adjustable element comprising a threaded rod 3 1' formed at one end with an adjusting knob 3-5 and provided at the other end with an insulating rod 85 which is threaded or molded on the rod 34' (Figs. 3 and 4). The electrode itself is cylindrical in shape, overlies a substantial area of the head and is concave at the outer end where it makes contact with the head. It is hollowed out at its other end as at 31 to receive the insulating rod 36. The electrode 15 is drilled. through axially to accommodate a short rod 38 which, at its inner end, is threaded into the insulating rod 36, and at its outer end is upset to form an annular shoulder 39. A spring 46 which encircles the rod 38 and reacts between the end of the insulating rod and the base of the hollowed out portion 31 of the electrode, causes the concave surface of the electrode resiliently to engage the shoulder 39. Sufficient clearance is provided around the bar 33 to permit the electrode to pivot and assume whatever axial angularity is demanded to fit snugly against the head in a manner to encompass substantially the entire underlying area thereof. The spring 49 holds the electrode resiliently in p ce.

The rods 34 which carry the electrodes are each threaded through a ball 4i and those associated with the electrode carried by the arched members H and [2 are arranged for longitudinal adjustment along said members. For this purpose, the arched members are formed with longitudinal slots 42 large enough to accommodate the ball pivot. Each slot is equipped along its opposite edges with guides in which the ball is slidably received. The guides are formed by strips 43 of somewhat resilient metal which overlap the opposed edges or" the slots and which are secured by riveting on both sides of the members H and 12. According to this arrangement, the rods t l may be adjusted to move the electrodes it toward and away from the patients head, may be caused to assume any desired angular position with re- 4 spect to the members It, II and i2 which carry them, and may be moved along the members longitudinally to any desired position within the confines of the guides. The metal strips 43 forming the guides terminate short of the ends of the slots 42 so as to permit the insertion of more electrodes, should that appear desirable.

The mastoid electrodes are in-all respects the same as those just described except for the manner in which they are mounted .(Fig. 5). The mounting of a mastoid electrode includes a larger cylindrical portion 44 presenting an annular shoulder adapted to engage the inner face of a fiber element 15 depending from the oval band [B adjacent the ear, and a smaller threaded section 46 which extends through a slot in the depending element to, accommodate a nut c1 which may be screwed up tightly to hold the electrode mounting in different adjusted vertical positions. The element 54 has an enlarged socket which receives the ball 4| of an electrode unit which otherwise is the same as the electrode units previously discussed. The ball is held in position by a collar 48 threaded into the socket.

i Each electrode 55 is arranged to be connected with the'electroencephalograph (Figs. 1 and 3). To this end there is provided a terminal board 49 near the back of the frame which is supported by an upright bar fastened to the headgear at the rear. This board has connections to accommodate jacks 53 which, in turn, are connected. each by a flexible wire 52 to an appropriate electrode below its insulating element.

From what has been said, it is apparent that the improved headgear enables electrodes to be applied to the head and shifted from place to place thereon with the utmost speed and facility.

The invention has been described in connection with its preferred embodiment and many modifications thereof will suggest themselves within its spirit. The invention is to be limited, therefore, only by the scope of the appended claims.

What is claimed is:

1. An electrode for a headgear arrangement for use in electroencephalographic examinations and which inuse is adjustable into and out of engagement with the head, said electrode comprising a rod adapted, when mounted in the headgear, to be adjusted in a direction longitudinally of its axis, a head contacting element formed to overlie a substantial area of the head when in engagement therewith a pivotal connection scour ing said element at the end of the rod and per mitting angular adjustment between the element and the rod, and. a spring reacting between the head contacting element and the rod to cause the element normally to assume a given position with respect to the rod, said head contacting element being arranged to yield against the reaction of said spring and to adjust itself to encompass substantially the entire underlying head area as the electrode is'adjusted to bring its head contacting element into engagement with the head,

2. An electrode for a headgear arrangement for use in electroencephalographic examinations and which in use is adjustable into and out of engagement wth the head, said'ele'ctrode comprising an insulating rod, an electric conducting head con tacting element adapted to overlie a substantial area of the head when in engagement therewith, pivctally connected at one end of the rod to permit angular adjustment between the element and the rod, a spring reacting between the element and the rod to cause the element normally to as sumea-given position with respect to the rod,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Saighman Dec. 3, 1907 Cruse Nov. 29, 1921 Catlin Sept. 18, 1928 Ellis July 16, 1940 Garceau Oct. 8, 1946 Ulett et al Sept. 2, 1947

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