US2618269A - Sphygmomanometer cuff - Google Patents

Description

W. A. BAUM ET AL SPHYGMOMANOMETER CUFF Fild April 24, 1948 Nov. 18, 1952 INVENTORS Patented Nov. 18,Y 1952 UNITED STATES PAUTENFI OFFICE SBHYGMOMANOMEEER CUFF William` A. Baum, Forest Hilfs, and? Bernard M; Hanafm, Kew Gardens, N. Y., assignors to WL A. Baum.Co^.,.Inc.,New York, N.' Y., a;corporation of. N ew Yiorki A 6 Claimsr This invention relates to an inflatable` cuff vpariticul'a'rly adapted foruse inA sphygmomanometerapparatus The invention provides for the rst timeI aL relatively short-lengtl'i;v Wholly flexible cuff of" the simple Wrap-aroundv type,l Without reinforcing means therein; Without positive lock-ing or' fastening' devices thereon, andv wherein the retention of theV improved cu-i inproper position and relationon" the subjects limbduring blood pressure measurements is attained substantially entirelybyfan-l inherent self-locking action developedbyf` the 4specially preparedisurfaee of the cuffmateria'l in adj acentlayer frictionalcontact rela-n tion, and which self-locking action isfprogres-J sively4 enhanced#y andv ultimatelyfullyv attained? by the.1infl'aton of the. iniiatable -bag` assoeiatedlWith-y thecu'.

In; accordance-With al preferred embodiment off ourfv inventionthe cuff is-Lformed'l of: a stripy of.'

iiexibl fmateralwithoutl reinforcing. or stiifening means-therein,- with a: pocket. at one` end` forn the supportlof; an iniiatalole;` bag.- Thevinflatable bag provides ameasure ofi theE arterial pressure .when inlatedi to constrict the` now.- oi blood in; the.

artery;- a-ndLatithe Sametime.v xesftlie stripiupon.

thelimb. Therstrip isl of.' a: length: suiiicient to'. permit tn bei. wrapped.. around. human limbs; oncewith an overlap ofi not-morea than. onefturn.V

Inl.pla;ce: of theV tuckin-gon the free-end of the` strip under: one-side of thelassembled;andappliedl cuff as is customary with;thenveran-around.cuffs.A ofl then' prior art; which; are i Wrapped many.v times aroundl thelinib;L theicnl of; our; invention.- relies, upon. as selflocking; actionV between ther overl-f Iappedndszotheshort. strip which; is; developed;

uponination onthariniiatablebagn Inwiew of. the. curved. sectioni ofA the;y limb about; which. the; cui isi' appliedLthei force.v of friction. loetvszeen` the.

overlapping" areas.` at. the. outerV margin thereof.; i. e. at the free end of the strip, is eiective4 to;V

cuffs. Wrapped: repeatedlyi about the. limband! nallyi tucked in. or: tied in place. with: tapes, .nor' thei hooks.. snaps or: other. fasteners. of.. certain. shorteri length. cuffs: of laterfperiods... The com.- pl'etpliability andex-ibility. ofv the cuff' of our invention, Withoutf stiieners of metal. or other.A

materialjenables: measurements Vto be made under conditions similar.v tov those. under which the.

clinicali averages; of.'l bloodr pressure: now Widelyf isv 2 style spliygmcnnanonieterV cul* consisting. of an' inflatable bag supported' by a, long' strip: or flexible' material'.

Our inventionwill now'b'e" more fully described in'connection with theraccomp anying;drawingsin which:

Fig. 1 is` aL longitudinal sectional' perspective. View of a; cui' accordi-ng. to our invention in exe tended or unwrappedcondition;

Fig. 2'is ani enlarged: sectional view ofthe. cuff. of Fig.- 1 asY applied about therupper" armio'fa patient;

Fig; 3fisa perspe'ctiveviewofiam'odied forin-Y of` cuff inwhich means'areprovidedf'to apply'to' the overlapped ends ofA the cuff`- an auxiliary" compressive stress independently of" theA ination ofthe bag and independently 0f theorientation of theu cuff upon the patientslim'b'-,vr

Fig. 4' is aperspective'viewsimilarrtothatof" Fig. 3 showing a further modi'cati'on' of" our invention; and

Fig.' 5'is a view i'n section along7 theline of Figi E Referring te` Figl; thev` spliygmomanometerVv cui of our invention vincl-idesan iniiata'ble bag? |10* supportedl byv4 means` ofE a-l limb-encirclingfbandion strip -generallyfindicatedat AI 5l Theband l-Smay' be made upof'oneor more pieces-of'flexiblemate-frial which function to supporti thebag-and`to-pro'' vide the frietional contact by which the entire minis-'retained in position on=the1patientesllimb; In the cui of Fig. 1. thereA is provided ars-trip Ill` of flexible material?, which-mayfbey af woven'fabric'f or a, plastic substitute?therefor,` off a.: lengtli== suil cient t@ encircle` the largest-limbsencountered practice and tol overlap itself' by one eonipl'etefY turn around the limb, or less. Fon cufls'intendedr` to-be appliedlto humanlarms-itheeffective diam/w eter. of the limb is. about ve': and three*quartersL inches, soithatf the totallleng-thty ofi tliesstripvneed be only. Ofi'the order ofi sonrie'lftvvo` feet'.-r

A pocket'I IIB; suitable to.- containfthe i-natable bag l @,ui's. provided!on.oneesurfacefV Hi ofthe strip; adjacent oneen'dil thereof Thesurfa'cevlil willi be: referredLtn.- as the innen surfacef inasmuch: as'- the; cuit. is,`- applied tof. the patient.l with A this'. sur face adjacent the limb. The pocket I8 maybeformedfby sewing: orsotherwise aixing-l api'eceiof iiexiblematerial'. 221 to the strip I li;n mthsuitableopenings. along the edgesforinsertionandi-Eresmoval; of; the. bag,`v and.v fori flexible tubes? which connect the; bag: with; an; inlatin'gi bulbi` andlafk measuring instrument' sueltas. anmanoinetezr.` (noti shawn):l ThefpocketfformingmatchzzwillLhave laccepted were determinediwithpthei oldsbandagesl 551 the: width; oi; the:v strip IB; andtshouldipreferab'lyf be highly flexible and pliable so as to permit the bag I to adapt itself to the contour of the limb without unnecessary stresses which might distort the bag and falsify the relation between bag pressure and arterial pressure. The cuil is applied by wrapping about the limb beginning with the end I'I and with the pocket-forming patch 22 next the skin of the patient.

On the outer surface I2 of the strip I6 opposite the pocket I8 there is provided at the bagsupporting end I1 an area 24 of frictional material chosen to have, in conjunction with a related area 26 on the inner surface II at the free end I9 of the strip, a high coefficient of friction when the two areas are placed in overlapping relation. The areas 24 and 26 may consist simply of rubber-impregnated areas on the strip I6, or areas coated with a pressure-sensitive tacky adhesive material, or patches of a finely corrugated rubber sheeting may be used, or a Woven fabric having a rough surface. The entire strip I6 may be made of rubber-impregnated material so that the areas 24 and 26 are coextensive, respectively, with the outer and inner surfaces of the strip, except in the latter case for the area covered by the pocket-forming patch 22.

The cuff is applied by wrapping about the limb, beginning with the bag-supporting end I'I until the outside end I9 has been brought down over the bag end I'I with the areas 24 and 26 in overlapping relation, both overlying the inatable bag I0. In applying the cuff to the upper arm of a patient, the bag-supporting end is applied to the side of the arm next the body so that the brachial artery will come approximately at the midpoint of the circumferential length of the bag I0. This is shown in Fig. 2, which is a View in section through the upper arm of a patient with the cuff of Fig. 1 applied thereabout, looking toward the extremity of the arm. The bag IIl is shown partially inflated and the brachial artery 2 is partly compressed. With the cui so applied the free end I9 of the strip overlies the top of the arm and is retained in contact with the underlying layer of the cu by means of its own weight. The frictional areas, 24 on the outer surface of the strip-at the bag-supporting end I'I and 26 on the inner surface of the strip at the free end I9, are shown in overlapping relation.

'Iv-he force of friction available between the contacting layers of fabric at the end I9 by virtue of the normal stress provided by the weight of the strip material, when called into action to withstand the tangential force tending to separate the overlapping portions of the strip which is generated when inflation of the bag commences, provides at circumferential locations back of the end I9 a progressively increasing holding stress because of the curved section of the arm. This holding stress holds the outer layer down over the inner layer so that the expansive force of the bag, as inflation is continued, stresses the overlapped layers of the cuff ever more tightly together. Inflation of the bag may proceed until the ilow of bloodin the artery 2l is entirely shut oil, so that the-usual measurements of systolic pressure may be made.

yIn order to provide at the outer or free end of our wrap-around cuff an initial compressive stress which will hold the overlapped layers thereof together independently of the orientation ofthe cuil upon the patients arm until inflation of the inflatable bag locks the overlapping portions together, we provide in a modified form of our invention an auxiliary stress perpendicular to the surfaces of the strip, by means acting independently of the inflation of the inflatable bag. This auxiliary stress may be provided by means attached to the outside edge of the free end of the strip. These means are immediately operable regardless of the girth of the limb about which the cuff is applied, i. e. regardless ofthe amount of overlap between the two ends of the strip. No fittings, spaced at discrete intervals or otherwise are required on the inner, underlying end of the strip to cooperate with these means. A cui of this modiiled type is shown in Fig. 3. The auxiliary stress at the outside margin of overlap, i. e. at the outermost edge of the free end of the strip, is provided in the cuff of Fig. 3 by means of an elastically distensible loop 40. The loop may be made of rubber. It is fastened at the free end 39 of the cuff of Fig. 3 and is of such length as to encircle the limb outside of the wrapped cuff, under tension, and to hook onto` a button or similar protuberance 42 ailixed to the outermost edge of the free end 39. The cuff of Fig. 3 is applied by wrapping about the limb, beginning with the bag-supporting end 3l until the free end 39 has been brought down over the bag end 3l with the fric-- tional areas thereof in overlapping relation. The elastic loop 40 is then stretched, in the same direction in wrapping, once around the limb overthe cuff, and secured to the button 42. The in-A flatable bag may then be inflated and the blood pressure measured in the usual way, the inflation of the bag increasing the pressure between the frictional areas which prevents separation of the*l ends of the cuff.

In place of the loop of rubber or elastic described in connection with Fig. 3 for provision of an auxiliary perpendicular stress independent of inflation of the bag, a pair of small flaps may be provided one at either side of the outer end of the v cuff. A cuff of this type is shown in Fig. 4 where tuck-in flaps 46 are disposed at the outer end 49 of a limb-encircling band 50. The flaps 46 are.

tucked under the inflatable bag contained in a pocket on the underside of the band. Thus in-l ilation of the bag stresses the two ends of thev Our invention is not intended toA be restrictedv to the details of construction illustrated and discussed herein nor to the specific materials' mentioned. Alternative materials having the proper.v ties set forth may of course be used. Changes and modifications may be made in the construction herein described without departing from the scope of our invention as set forth in the appended claims. We claim:

l. A pneumatically retained sphygmomanometer cuff comprising a strip of flexible material constructed to encircle a human limb with an area of overlap between the ends thereof, a` pocket formed on one end of the said strip, ian inflatable bag disposedv within the saidpocket,

and a pair of tuck-in flaps disposed one at either side of the end of said strip remote from the said bag, whereby upon the wrapping of the said strip about a patients limb beginning with the bagsupporting end thereof and upon tucking the said flaps under the overlapped inflatable bag.' inflation of the said bag stresses the overlapped lends of the said strip together.

2. An inflatable cuff adapted for use with sphygmomanometer apparatus comprising a strip of flexible material of a length sufcient to encircle a human limb not more than twice, an area of a tacky adhesive material applied to one side of said strip at one end thereof, an area of a tacky adhesive material applied to the other side of the said strip at the other end thereof, and an inatable bag supported adjacent one end of the strip on the side thereof opposite the adhesive area, whereby upon the wrapping of the said strip about a limb of a patient beginning V.with the bag-supporting end thereof and with the said bag adjacent the skin of the limb, the said adhesive areas are brought into overlapping frictional contact relation augmented upon ination of the inflatable bag.

3. A self-retaining inflatable cuff of the short wrap-around type consisting of flexible elements and comprising a strip of flexible material, an inflatable bag supported adjacent one end of the strip, the said strip having a length permitting it to be wrapped around human arms above the elbow with an overlap of less than one turn, and flexible means applied to the end of the strip remote from the bag providing adhesion between the overlapped ends of the strip when so wrapped.

4. A self-retaining inflatable cuff of the short wrap-around type consisting of flexible elements and comprising a strip of exible material at 30 least the overlapping end portions of which are adhesive to themselves and an inflatable bag disposed adjacent one end of said strip, said strip having a length permitting it to be wrapped 6 about a human limb with an overlap of less than one turn, whereby upon the wrapping of said strip about a limb of a patient said strip will be retained in place upon said limb by adhesion between the overlapped ends of said strip.

5. A self-retaining inflatable cuff as defined in claim 4 in which the strip of exible material is inherently non-adhesive and at least one of the surfaces of the end portions which contact on overlapping have adhesive material thereon.

6. A self-retaining inatable cuff as defined in claim 4 having an elastically distensible loop aiixed to the end of the strip remote from the inflatable bag and a loop-securing protuberance secured to the same end of the strip as the loop, whereby upon wrapping of said strip about a human limb beginning with the bag-supporting end and upon securing the loop around the limb over the strip and onto the protuberance the two ends of the strip are placed in overlapping position and retained in position by the loop.

WILLIAM A. BAUM. BERNARD M. HANAFIN.

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

UNITED STATES PATENTS Number Name Date 1,594,039 Baum July 27, 1926 1,885,007 Rosenblatt Oct. 25, 1932 2,029,912 Cossor Feb. 4, 1936 2,199,408 La Liberte May 7, 1940

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