CA1305900C

CA1305900C - Contamination protection system for endoscope control handles

Info

Publication number: CA1305900C
Application number: CA000599154A
Authority: CA
Inventors: Eric A. Opie; Fred E. Silverstein
Original assignee: OPIELAB Inc
Current assignee: OPIELAB Inc
Priority date: 1988-05-13
Filing date: 1989-05-09
Publication date: 1992-08-04
Anticipated expiration: 2009-08-04
Also published as: US4825850A; EP0341719A1; JP2746651B2; JPH0219128A

Abstract

CONTAMINATION PROTECTION SYSTEM FOR
ENDOSCOPE CONTROL HANDLES

Abstract of the Disclosure A contamination system for endoscopes having a handle, an insertion tube projecting from the handle, and control knobs detachably mounted on control shafts projecting from the handle to control the angular orientation of distal end of the insertion tube. The handle is placed in a liquid-impermeable bag, with the control shafts projecting through an aperture in the bag. The control knobs are then attached to the shafts prior to performing an endoscopic procedure. After the procedure has been com-pleted, the control knobs are removed from the shafts and decontaminated, the handle is removed from the bag, and the bag is discarded.

Description

~escr.~tion CONTAMINATION PROTECT10N SYS'l`~M EOR ENDOSCO~E
CONTROL ~ANDLES

Field of the Inve_tion This i.nven~ion re~.ates to ~he field of endoscopy, and more particularly, to a system for isolating an endoscope Erom v.iruses and bacteri.a during use.

~ackgr_und Art The use of endoscopes or diagnostic and thera-peutic indications is rapidly expanding. ~o improve performance, endoscopes have been optimized ta best accom-plish their purpose. Therefore, there are upper endoscopes for examinat.ion of the esophagus, stomach and duodenum;
colonoscopes for examining the colon; angioscopes Eor examining blood véssels; bronchoscopes for examining the bronchi; laparoscopes for exami.ning ~he peritoneal cavi.ty;
and arthroscopes for examining joi.nt spaces. 1'he discus-sion which PolJ.ows wall apply to al.l of these types o~
endoscopes.
Instruments to examine the rec~um and sigmoid colon, known as flex.ible s;gmo.idoscopes, are good examples of the usefulness of endoscop.ic technology. These devices are expensive, and they are used in a con~ami.nated envi.ron-~ment lor a procedure which is bri.ef (5-10 m.inu~es) and where problems o cJeaning time~ and contaminat.ion are important factors. There has been a large increase in the use of the "fJ.exi.ble sigmoidoscope" for use in screening symptomatic and asymptomatic patients ~or colon and rec-al cancer. Ideally, f].exi.ble sigmoidoscopes must be used rapidly and inexpensively ;n order to maintai.n the cost o such screening at acceptable ].evels. 'l'ypically, a clinic would like to perorm five sigmoidoscope examinations each hour. ~ significant probl.em with making such examinations ) 13059~ ) quick and inexpensive is the tjme necessary for adequately c:leaning the device.
~ lthough endoscopes can be super~icially cleaned in two to four minutes, this relati.vely cursory cleaning may not be adequa~e .Eor complete disin~ection or sterilization. )?.ven a more comp.lete cleaning requi.ring on the order of eight to ten minutes may not allow adequate cleaning, particularly in view of the increasing prob~ems with contagious viruses. Even with the use of chemicals such as gluteraldehyde, dependi.ng on cleaning methods, adequate cleanliness may not be possible.
The cleaning problem not only includes the outside of the endoscope, but also ~he multip:le smal).
channe].s .inside the endoscope. 'l`his i.ncludes channcls ~or:
air i.nsufflation; water to wash the tip; and biopsy and suct;.on. Fach channel also has a control valve. The channe~s extend along the length of the endoscope and come into contact with body tissues and fluids. lt is extremely di~ficult to adequately cLean these channels even when skilJ.ed health practit.i.oners spend a great. dea.l o tim~ on the cleaning procedure.
Even if endo~copes can be adequately cleaned in eight to ten minutes, the c].eaning still prevents endoscopy examinations from being relat.ively inexpensive. Wh.ile a physician may spend five to ten minutes perorming some types of endoscopy, he or she will generally waste a great deal of time waiting for the endoscope to be cleaned before he or she can conduct another endoscopy. A parti.al solu-tion to the "idle time" problem is to ~urchase multiple instruments so one can be uscd as the others are being cleaned. ~lowever, the expense of having duplicate endo-scopes of each of the many types described above makes th:is so].ution impractical especially for physicians' offices and smaller clinics.
Not only must the idJe t.ime o~ the physician be added to the cost of endoscopic examinations, but the time spent by a nurse or other hospital personnel it) the clean-13Q~i9()0 ing as wel.l as the cos~ o~ disinfec~i.ng chemica.ls and other costs of the c:leaning process must a:lso be added to ~he cost of the examination. ~I.though automatic washi.ng machines are avai~able to clean endoscopes, these machines are expensive, take up signifi.cant amounts o~ space, ar~
noisy and are not faster than washing by hand. ~iur~her, regardless of whether the cleaning is done manually or by machi.ne, the cleaning chemicals can be harmrul ~o the endoscope and thus significantly shorten its life. The cleaning chemical.s, being toxic, are also potentiall.y injurious to the sta~f who use them, and o the environmen~
into which they are discharged. 'rO use some o~ these chemicals safely, such as gluteraldehyde, requires a dedicated ventilated hood, which uses up space and is expensive to install and operate. q'he chemic31s are also potentialLy toxic to the pat.ient in that, if residue rema.ins atcr cleaning and rinsing the instrument, the patient could have a reaction to the chemicals.
~s a result o~ these many problems, convent;.onal endoscope c.leaning techniques increase the cos~ of endoscop.ic procedures. E'urthermore, while the r.isk oE
contamination ùsing endoscopes is often ar less than Lhe risk o~ alternative procedures, such as surgery, there is nevertheless a risk that endoscope~ are not adequatel.y cleaned to pr~vent the risk Oe transmi.ssion oE in~ectious d.iseases ~rom one patient lo the next.
In the health care ~ield, ~he problems of contami-nated instruments transmitting disease from one pa~ient to the next have generally been solved by making such instru-ments d.isposable. However, this approach has not beenthought possible in the field of endoscopy because endo-scopes are very expensive i.ns~ruments. Moreover, it has not been Lhought possible to isolate the endoscope rrom the patient or the external environment because the endoscope itsel~ has channels inside .it that are used as a condu.it for body flu.;ds and tissues, such as, for example, in takjng biopsies. 'l'he only method curren~ly avail.ab].e to 13~59~

actuall.y sterilize an endoscope i.s to use gas sterilization with ethylene oxide gas. Ilow~ver, here are several disadvantages in using this procedure. 'l'he procedure is very slow (up to 24 hours) during which the endoscope cannot be used. Also, the gas affects the plast.ic of the endoscope and may limit its life span. Finally, th~ gas is toxic, and, therefore, great care must be taken ~o ensure that no residue remains ~hat might cause patient or sta~f, irritation or allergic reacti.on during contact with the endoscope.
As a result of the above-described ].imitations ;n using and cleaning endoscopes by conventional ~echniques, there has not heretofore been an acceptable solution to the problem of making endoscopy procedures both inexpensive and entirely saEe.
A new approach to the problem of endoscope contami.nation .is dcscribed ;n U.S. Patent No. ~,646,722.
1'hi.s new approach involves the use of an endoscope sheath l-aving a flex.ib].e tube surrounding the elongated core of an endoscope. The flexi.ble tube has a transparent window near its dis~al end posltioned in front of the viewing window of the endoscope. Channels that come into contact with the patient or the patient's body fl-lids, e.g. channels for taking biopsies, injecting air or inj~cting water to wash tlle window of the sheath, extend along the endoscope, either inside or outside the sheath. Where the channels are positioned inside the sheath, they may be inserted in a longiLudi.nal groove formed in ~he endoscope core. ~`he protective sheath may be used with either end-viewing endoscopes or side-vi.ewing endoscopes. The protective sheath may be instal~.ed by ro].ling the elastomeric tube into an annular conf.iguration and then unro].ling the tube ov~r the core of the endoscope. Alternatively, the tube may be .inflated in its unrolled configurat.ion to expand the tube and allow it to be easily slipped onto the endoscope core. ~ variety of spec.ialized endoscopes may be created by using protective sheaths having a variety of special oo purpose medical instruments moun~ed at the end of a biopsy channel and operated through the chann~l.
The endoscope us~d in ~h~ implementa-ion o~ ~he abovc described concept in one conFigura-ion must have a groove ~ormed along i~s lengt,h. A tu~e is inserted into this groove to provide channels for air, water and suction.
Once the groove is inserted, it is covered with the sheath.
After use, the sheath and channel insert are removed and disposed of, leaving the endoscope free of contamination resulting from the endoscopic procedure.
~ 'he sheath concept covers the insertion tube o the endoscope and a]lows for the disposal of this sheath and the channels which are incorporated into the sheath insert: air channel; water channeL; and suction/biopsy channeL. However, there is still a problem with ~he control handLe o~ the endoscope. ~'he way endoscopes are used cli,nically is that the control body of the instrumenL
i,s he,ld in the endoscopist's left hand. l'he right hand is usually p,l,aced on the endoscope's shaft o advance th,e instrument into the pa~ient 3nd ~o pull ~he ins~tument out of ~he patient. This results in contamination of the right hand with patient ~ecretions including blood, mucus, stool, and tissue. 'l'his contaminatior) occurs during every endo-sco~ic proc.edure. The endoscopist wears gloves to protect his or her hand. Ilowever, during the procedure, the endoscopist frequen~ly must reach up with his or her right hand and move the endoscope control wheels. Irhese two wheels control up/down and right/left movement of the contro]lable tip bending section o~ the endoscope.
Al.though it is possible o control these wheels somewhat with the le~t hand, it is olten essential to reach up with the r;ght hand to assist with a complex control movement.
1'his results i,n the immediate contamination of the endo-scope control wheels. The body o~ the endoscope control unit also becomes contaminated because oE the right hand going ~rom the contaminated insertion tuhe to the control section. Often the body of the section is contaminated as .- ) 13Q59Qo ) .. 6 well as the wheel.s. lt is ~his contamination o~ the con~rol whee.ls and ~he con~rol Ull.it body which is addressed by this invention.

Disclosure of the Invention It is an object of the invention to prov.ide an endoscope having easily removable conteo:l wheels so that the wheels can be either ster.ilized or discarded after use It is ano~her object o.~ the inventi~n ~o provide a disposable bag ~or the control handle of an endoscope in order to prevent contam.ination of the control hand.l.e.
It is stil~ aoothcr object oE the invention to provide a.contami.nation protection system for an endoscope that can be used on e.ithcr convent;onal endoscopes or on lS endoscopes that are specially colligured for use with a disposable endoscope sheath.
It is a urthcr object of the invention to provide a contaminati.on protecti.on system for an endoscope that does not adverse.l.y ef~ect the operahil.ity of the endoscope.
These and othe~ objects of the .invention are provided by a disposabl.e, ~luid-impeeMeable bag surround.ing the handle of an endoscope. The bag has formed therein an aperture to allow removablc control. knobs to be positioned externally of the bag. The endos~,ope may also include a protective sheath surrounding the insert.ion tube, and the bag and sheath may be interconnected so that their interiors arc sealed from ~he externa). environment. l`he bag pre~erably has an insertion opening formed at an end thereo~ that is opposite the shcath. ~ flexib.le, nonresiliellt mcmbee may surround at least a portion.of the insertion opcning to maintain the insertion open.illg open when the handl.e is inseeted in the bag. The i.nsertion opening may be sealed by a layer o~ pressure sensitive adhesive surrounding at Jeast a portion o~ the insertion opening to ma;ntain ~he insertion open.ing closed duri.ng use.
The conteo].s are preferably mounted on respective shafts - ? ~59~ ) projecting through the open.ing in the bag, and ~hey are preferably r~tatab1y nterconnected so ~ha~ ~hey are removed from the hand.Le of ~he endoscope as a unit.
In use, the 1uid-impermeab].e bag is firs~ placed around the handle of the endoscope. The control knobs are then re]easab].y mounted on the hand.l.e externally oI the bag through the aperture formed in ~he bag. A~ter the endo-scope has been used to per~orm an en~oscopic procedure, ~he control knobs are detached from the handle and ~he endo-scope is r~moved from the bag. Finally, the control knobsare decontami.nated or steri].ized be~ore they are once aga.in at~tached to the endoscope to perform an endoscopic procedure. If a protective sheath is used, it is placed around the insertion tube before performing the endoscopic procedure and .it is removed after the procedure has been completed.

B ief Descr~pt _n of the Draw ngs Figure l is an isometric view of an endoscope handle u~ilizing the inventive contamination protec~i.on system.
Figure 2 is an isometric view of the endoscope handle o~ Figure l showi.ng il:s control wheels and braking mechanism eemoved.
25Figure 3 .i.s a side elevational view showing the portion o~ the endoscope hand].e of ~igure l on which its contro]. wheels and braki.ng mechanism are mounted.
Fiyure ~ is a s.ide elevational view showing the down/up braki.ng mechanism mounted on the endoscope handle oE Figure ]..
Figure 5 is an exploded elevationa1 view of ~he contro1 whecl and brak.ing mec:han.ism uscd in tlle inventive contamination protection system of Figure l.
Figure 6 is a cross-sectional view of the remov-ab.l.e control wheel and ~rak;ng mechanism used in theinventive contami.nation protection system of ligure ]. shown in its assemb~ed condit;.on.

13(~59~0 ) Figure 7 is an exploded cross-s~ctional. view of the right/1eft hrake assembly used in the control wheel an~
braking mechanism of Fi~urcs 5 and 6.
Figure 8 is a cross-sectional view of an alterna-tive embodiment of the portion of an endoscope handle onwhich an altern~tive embodiment of a removab].e con~rol wheel. and brakin~ mechani.sm is mounted.
Figure 9 is a cross-sectional vi.ew of an alterna-tive embodiment o~ a remov~ble control wheel and braki.ng mechani.sm for use with the endoscope handle of E'igure 8.
Figut-e lO is a partial exp~oded cross--sectional vi.ew o~ the a).terna~ive embodiment o~ the removab3.e control wheel and braking mechanism of Figure 9 and the ~ndoscope handle o~ l;'i.gure 8.
].5 Figure ll ;s a side elevational. vi~w of an endoscope using the inventive contamination protection system in ~Ihich a splatter guard is placed between Che CGntrO]. knobs of the endoscope.
Figure 12 is a ct-oss-sectional view taken a].ong the li.ne 1.2-12 of E'igure 11.

Best Mode Eor Carry;ng Out the Invention 'rhe inventive endoscope lO, illustrate~ in ~igure 1, has the ~ame appearance as a conventi.onal endoscope.
25 The ~ndoscope includes a handle 12 having an eyepiece 1~
and an elongateA, .1exible insertion tube 16. As is well-known in ~he art, the inser~ion l.ube 16 is inserted into a body cavity, and light emi~ting from the distal elld o.~ Lhe insertion tube ].6 illuminates tissu-s in he body cav.ity.
7~he image viewed through the distal end o~ ~he insertion tube 16 js conveyed to the endoscope han<lle 12, either through an i.nternal f.iberoptic bundle or electronj.cally rrom a miniature television camera mounted at the dis~al end Oe the insertion tube 16. ]n the embodiment illustra-! 35 ted in E'.igure 1, the image is conveyed through the inser-ti.on tube 16 through a fiberoptic bundlé and ;s visib].e Lhrough the eyepiece l4.

...... ..

v~

~ he insertion tube 16 a].so norma~.ly includes i.nternal channels (not shown) opening at the distal end of the insertion tube .16. These tubes are used for suction.ing fluids from the body cavity, for inserting air into the body cavi.ty and for spraying water onto a lens (not shown) at the di.stal end of the inser~ion tube 16, in order ~o clean the lens. The suction through the suction channel of the insertion tube 16 is controlled by a suct.ion valve 30 while the flow of air and water through ~he air and water channels, respectively, is controlled by a combi.nation air/water valve 32.
When conducting an endoscopic procedu~e, it is necessary to mani.pulate the ~ngular orientation of the dista]. end of he insertion tube ]6. The insertion tube .is manipulated in the up and down d.irection by rotating an up/down ("U/D") control wheel 40 in opposite directions and in the r;ght and le~t directions by manipulating a right/le~t ("R/L") control. wheel 44. As explained in greater deta.i.l below, the control wheels 40, 44 drive respective pulleys, each of which retract and pay out a pair of complementary control cab.les extending through the insertion tube 16 to its distal end. The control wheels 4~, 44 can be fr.ictionally locked through respective, internal braking mechani.sms, as also described in greater detail below.
The inventive endoscope 10 is most advanl:ageously used with the protective er-doscope sheath described in and claimed in U.S. ~atent No. 4,646,722. 1'he use of a protective endoscope sheath surrounding the inseetion tube 16 and incorporat;ng suction ~IJp, air/water and biopsy channels, completely prevents con~amination of the inser-tion tube 16. However, as expJa.ined above, .it is possibl.e for the endoscopist to contaminate handle 12 of the endo-scope by grasping the contaminated outer sur~ace of the sheath and then graspi.ng the handle 12, such as wh~n manipulating the control wheels 40, 44. Ilowever, in the inventive contam.inat.ion protecti.on system the handle 12, ~3~i9~0 exc~pt for the eyepiece 14, is surrounded by a protective bag 50 that preven~s contamination of the handle 12. The bag 50 preferably mates with a protective sheath 52 to prevent contamination of the endoscope 10 at the junction between the bag 50 and sheath 52.
The bag 50 and sheath 52 are installed on the endoscope by inserting the insertion tube 16 into the sheath 52 through an opening 54 in the bag 50. As best illustrated in Figure 2, the control wheels 40, 44 and internal braking mechanism (not shown) are specially adapted to be removed from the handle 12 so that the control wheels 40, 44 may be mounted outside the bag 50.
After the handle 12 has been inserted in the bag 50, the opening 54 is closed by suitable means such as by removing a backing strip 56 from a strip of adhesive app]ied to the bag so that opposite edges of the bag opening 54 adhere to each other. The control wheels 40, 44 are then mounted on the handle 12, as illustrated in Figure 1, thereby making the endoscope 10 ready for use.

2~ When designing a bag for an endoscope handle, one must take into consideration ~he two basic different ~ypes of handles used in endoscopy today 'rhe basic diffeeence between the handles results from the type of imaging system used in the endoccope. One uses a fiber optic imaging ~ystem and the other utilizes a video imaging system.
The fiber optic system as depicted in Figure 1, shows an eyepiece 14 extending through insertion tube 16 allowing the endoscopist to view direct]y into the optical components. It is also possible to have the bag 50 cover the eyepiece 14 of the fiber optic system with a clear membrane to further isolate the endoscope handle 12 The primary reason for encouraging the design is to allow for quick and simple accessory attachment; such as cameras and teaching apparatus. It is also important to note that an endoscopist would not, under normal circumstances, touch the eyepiece 14 of his or her endoscope and hence a very low risk exists for cross contamination with this design.

~3V~;90~ ' T one wishes to ~limi.nat~ any possibility of cross contamination, an eyepiece cover must be used.
~ t is a~.so important to note ~hat in video endoscopy there is no eyepiece on ~he handle oE he endoscope. lns~ead, images are reconstruc~ed on a monitor.
It is therefor~ unnec~ssary to have an eyepiece 14 extend through the bag 50. In ~h;s case, the bag 50 for the video version would be closed entirely with no extending components.
At the conclusion o~ an endoscopic procedure, the control wheels ~0, 44 are removed from the llandle 12 and sterilized in an autoclave. ~l~he handle 12 is then removed from the bag 50 through the opening 54 after the edges of ~he opening 54 are pulled apart, and the insertion tube 16 .is removed ~rom the sheath 52. As a resu~t, the on].y portions of the endoscope l0 that become contaminated are the control wheels 40, 4~1. It will be understood that the control wheels 40, 44 could be placed inside the bag 50 so that the wheels 40, 44 are mani.pulat~d through the bag 50.
However, placing th~ contro:L whe~ls ~0, 4~ insi.de ~he bag 50 makes it very difficult ~o manipu~ate the controJ. wheels 40, 44, par~icularly when they must be rotated in opposite directi.ons.
The removable control wheels 40, ~4, braking mechanism~ and associated hardware arc il.lustrated in Fi~ures 3-7. With re~erence now to r'igure 3, a cylindrical housing 70 is mounted wi.thin the handle :l2 and encloses a ~i.rst pulley 72 on which right/l.eft control cab].es 74 are mounted and a second pulley 76 on which up/down control cables 78 are wound. As mentiolled above, the right/left control cables 74 are connected to d.i.ametrically opposite portions ot the insertion tube 16 at the distal ends to control the upward and downward movement o~ the distal end o the insertion tube ].6 responsive to the rotation oE the pu.ll.ey 72 i.n opposite direct.ions. Similarly, the up/down control cab].es 78 are connected to diametr.ically opposite porti.ons of the distal end of the i.nsertion tube 16 so that ,., ~

- .

.

? 130S90O

~he dista]. end o~ t.he i.n~erti~n tube 16 moves down and up responsi.ve Lo ro~a~ion o~ he puLley 76 in opposi te directions.
~ cylindrica]., threaded, hollow stud S0 projects outwardly from the housing 70. ~ first shaLt 86 extends ~hrough the stud 80 and is connected to the up/down pul.l.ey 76. Similar:ly, a second shaft 88 extends through the holl.ow axis of shaft 86 and is connected to the right/left pu.l.ley 72. Finally, a nonrotati.ng mounting pin 90 extends through the shar~s 86, 88 and is anchored ~o a stationary portion of ~he housing 12. A no-ch 92 Cormed in the mount-ing pin 90 allows the control mechanism to be ~ixedly secured to the housing 12 as exp].ained i.n greater d~tail bclow.
With re~er~llce to Figuee ~, a up/down brake includes a brake actuator member 100 having an i.nternally threaded cy~indrical portion 102 ~erm.inating in an outward-ly extending flange 10~. ~he cylindr.ical por~ion 102 is threaded onto the stud 80. An annular brake pad 1.06 of conventional material is moun~ed on the upper surface of the flange 104. Finally, a stainlcss steel plate 108 is retained on the up/down shaft ~6 by a convent.ional re~aini.ng ring 110 received within an annular groove in the sha.ft 86. As explained in greater detail. below, the shaf~
86 ha5 an octagonal shape, and the inner periphery of the - pla~e 1.08 is configured to match this octagonal. shape. As a result, the plate 108 and sha~t 86 rotate ~ogether.
p.lurality of circumferentia:lly spaced notches 11.2 are formed on the outer periphery Or the flange 104.
l~otation of the cy.lindrica:l porti.on 102 and f.lange 1.04 causes the fl.ange 10~ to move inwardly and ~ outwardly along the stud 80. Outward movelllent o~ the flange 104 forces the brake pads 106 aga.inst the brake plate to frict;onally restrain rotatlonal movement of the brake plate ]n8. Since the brake p.tate 108 is keyed to the shaft 86, rotation of the shaft 86 is restrailled by the fri~t.ion between the brake pads 1~6 and the brake plate 10~.

, .......................................... .

, - ) ~3~S~

The magnitude of this frictional restraint is controlled by the rotational posi~ion Or ~h~ cy~ in~rical porLion ~02 and flange 10~.
~eferring now to Figures 5 and 6, a cylindrical brake coupling ring 120 having an outwardly projecting brake handle 1.22 is secured to a brake coupling member 124 by a plurality of circumEerentially spaced screws 126 (~igure 6). The brake coupling member 12~ i.ncludes an outward.ly projec~i.ng ~lang~ 128 t,hat is cap~red by a retaining rir-g ~.30. The re-aining ring 130 is secured to a up/down control knob 134 by a plurality of ci.rcumferentially spaced screws 136. An annular spacer 138 spaces the retaining ring 130 a slight d;.stance ~rom the ~lange 128 of the brake coupling member :l2~. ~9 a resu.lt, the re-aining ring .130 secures the brake co~pling member 124 to the up/down control knob 134, bu~ allows the brake coupling member 124 to rotate wlth respect to ~he up/down contro:l knob 134. The brake coupli.ng member 12~ ;ncludes a p].urality of cogs 1~0 projecti.ng axially toward the handle 12. The cogs 1~0 are received by the respective notches 112 in th~ ~lange 104 of he brake actuator member 100 (Figure ~). As a result, wh~n the control wheel and hraking mechanism illustrated i.n l;igure 6 are inserted onto the up/~own beaking mechanism il.l.ustrated in l~.igure 4, rotation of the brake handle 122 rotaLes the brake actuator member 100 through the brake coupling member 124. At the same time, rotati.on of the up/down control. knob 134 rotates the up/down shaft 86 (Figure 4) since he interna~. bore of the up/down control knob 134 i5 keyed ~o thc hexagonal shape of the shaft 86.
The up/down control knob 13~ is rotatably secured to other components Or the control wheel and brake mechanism through a mounting member 150 having an outwardly projecting flange 152 surrounding a cylindrical portion 15~.
~he flange 152 is secured to the outer Eace Or the inner portion Or the up/down control knob 134 by suitable means, such as a conventional adhes.ive. ~ ba.ll bearing assembJ.y .

13~S9~U
.. .~

160 hav.i.ng inner and outer races 162, 16~, respect.ively, is moun~ed in the mounting ~ember 150 by s~curing h~ ou~cr surface oE the ou~er race 164 to the inner surface o~ the cyli.ndrical portion 154 of the mounting member 150.
The inner surface of th~ inn~r race 1.62 is secured around the outer surface oE a cylindrical portion 170 of a second mounting member 1,72 by suitable means, such as a conventional adhesive. ~rhe mounting member 172 includes an ou-wardly projecting ~lange J.74 that is secur~d to a righ,t/left control knob 176 by a plurality of circum-Eerentially spaced screws 178. 'l'he r.ight/left control knob 176 is thus rotatably secured to the up/down control knob through ~he mounting member 150, ball bearing assembly 160 and mounting member 172. The right/left con~ro~ knob 176 includes an integrally formed inward]y, depending cylindri.cal Elange 180 that surrounds the ball bearing assembl.y 3.60. A square aperture .~ormed at the cent~r o~
the right/le~t contro.L knob 176 is key to the square shape of the right/left control shart 88. A hexagonal aperture formed at the center o~ the up/down contro]. knob 134 is key ~o the hexagonal shape oE ~he up/down control sha~t 86 so ~,hat rotation oP the up/down control knob .13~ rota~es the up/down puJ,ley 76 through ~he up/down control shat 86.
A right/l~et brake assembly J90 is mounted on top Oe the right/le~t control knob 176. The right/,left brake assembly is best ill,ustrated in l?igures 6 and 7. 'l'he right/Jeft br,ake assembly includes a braking p].ate 200 having an inner surEace 20~, an outer surace 206, and a cylindei~ai boss 208. An annular brake pad 210 of fricti,onal braking material is secured to the inner surface 204 of the braking plate 200. 'J'he braking plate 200 a.Lso incJudes ou~er., axially extendi.ng flange 2.l.2 having a plurality o~ circumferentiall.y spaced notches l:ormed on its i.nner surface, the purpo~e oE which is explai.ned below.
'l'he braki.ng plate 200 is keyed to ~he square mounting pin 90 so ~hat the braking plate 200 cannot rotate.

... ..

13~59C0 ?

~ he boss 208 of the braking pla~e 200 is ex~er-nally threaded, and these threads mate wi~h internal threads lining ~he border of a coupli.ng member 222. The couplins member 222 is, in turn, enc~osed by a brake adjust-ing knob 230. A pair of radial recesses 236, 238 areformed in the coupling member 222 at axially spaced loca-~ions. The recesses 236, 238 reccive respective compres-sion springs 240, 2~2 which outwardl.y bias respec~ive ball bearings 24~, 246. BaLl 2~6 is biased agai.nst Lhe inner sur~ace of flange 212, which, i.t will be recalled, has ~ormed therein a plural.ity of circumferentially spaced notches adapted to receive ~he ball 246. Similar].y, the ball 236 is biased against the inner surface of a down-wardly exterldi.ng flange 250 forming part o.E the brake adjusti.ng knob 230. The inner surface of the f:lange 250 likewise has formed thcrein a pl.l~rali.ty of circum~er~n-ti.ally spaced grooves adapted to recei.ve the ball 2~. The spring constarit of the spring 2~2 is lower ~han the spring constant of the spring 240, ~he reason f:or which i.s explained below.
lhe brake adjust.ing knob 230 i.s rotatab:ly secured to the coupling member 222 by an annular nut 260 having external thr~ads 262 threaded .into the internal threads of the coupling member 222. The nut 260 is threaded i.nto the coupling member 222 unt.il a stepped shoulder 264 forcib:Ly contacts the upper end of the coupling member 260. ln this position, a second step shoulder 266 or the nut 260 is spaced slightly ~rom an inwardly stepped recess 268 o~ thc brake adjustment knob 230 so that t:he brake adjustmen~ knob 230 is free to rotate. The right/lcrt braked asscmbly i.s adjusted by rotating the brake adjus~ment knob 23~ he rotation of the brake adjustment knob 230 is then coupled to the coupling member 222 through the ball bearing 24~ and notches ~orme~ on the inte~ior surface of the flange 250 so that the coupling membcr 222 rotates with the brake adjust-ment knob 230. lnsofar as the spring 242 has a lighLer spring constant than the spring constant of the spring 2~0, ) ~3~

the bal.l bearing 246 mating with ~he notches formed i.n ~he rlange 212 o~ ~he sta~ionary braking plate 200 do~s no~
prevent rotation o~ the coupling member 222. Instead, the ball bearing 2~6 and notches maintain ~he position of the coupling mcrnber 222 until a rotational force grea~er ~han a predetermin~d value is applled ~o the brake adjustment knob 230. I~ota~ion o~ the coupli.ng member 222 appl.ies a down-ward axial rorce ~o the braking plate 2~0 through Lhe mating t~)reads of the coupling member 222 and braking plate 200, thereby forcing the brake pad 2:l0 against the upper surface of the up/down control knob 176 to increase ~he ~r;.ctional braking force. ~fter the braking ~orce has been adjust.ed up to a predetermincd value, ~he ball bearing 2~4 and no~ches formed in the flange 250 are no longer capable of coupling the rotationa]. force of the brake adjustment knob 220 to the coupling member 222, thereby allowing Lhe brake adjustment knob 230 to rota~e with respe-;t to the coupl.ing member 222. 'rhe spring 2~0 and ball bearing 2~
thus serve as a clutch to prevent excessive rigllt/.lert brake adjustments.
'l'he right/left brake assembly l90 :i 9 rotatab.ly securcd w.i~hin the r.ight/let con~rol knob ]76 by an annular ring 2R0 which is threaded into internal threads ~ormed in the right/le~t control knob 176. 'l'he lower end 282 of the ring contacts an outward).y extending peripheral ~.lange 284 ~ormed in the brake adjustment knob 230 to preven~ axial movement o~ the brake adjustment knob 230, coupling member 222 and braking plate 200.
It is apparent [rom an examination oE Figure 6 that virtually all o~ Lhe external componenLs o~ ~he control and brake mechanisms of the endoscope are removable as a unit. 'l'he only components oC the con~rol and braking mechanisms that remain on the halldle of Lhe el1doscope are ; the control sha~ts 88, 86, the threaded boss 80 and the mounting pin 90 (see 'igure 3). Ilowever, all of these components are shielded during use by the removable compo-nenLs .illustrated in Figure 6. ~s a result, the proLeclive 13~9~ ) bag 50, coupled with the removal. and sterilization oE the control and braki.ng mechanism after each use, prevents contami.nation of the endoscope 10.
With reference to l~'igures 3 and 7, the entire con~rol and brake mechanism .il:lustrated in F~igure 6 is secured to the handle of the endoscope by a clip member 290 (Figure 7) fitting onto a pair of studs 292 projecting from the brake adjustment knob 230. An internal elongated slot and recess ormed in the clip membcr 290 receives the end o the 'mount;.ng pin 90 as the clip member 290 slides onto the studs 292. ~'he clip member 290 thus rotates with t.he brake adjustment knob 230 and, in cooperation with ~he notch 92 formed in the mounting pin 90, releasably secures the clamp and brake mechani.sm to the handle o~ the endoscope.
An alternative embodiment of a removable control and braking mechanism i.s iJ..I.ustrated in Figure ~-10. With reEerence to Figure ~, the portions of the mechanisrn fixedly mounted in the handl.e 12 of thc endoscope 10 is basically the 5ame as in the embodiment of l~igures 3-7.
The major components o ~he embodiment of Figure 8 include concent ric rlght/.l.eft and up/down control sha~ts 300, 302, a braking plate 30~ retained in position on shaEt 302 by a retainlng eing 306 and an annular brake pad 308 of fri.ctional braking material mounted on a brake actuating plate 310 and connected o a brake actuating member 312 so that the actuating plate 310 and actuatiny member 3l2 rotate as a uni.t. As exp.lained in greater dctail below, the brake actuating member 312 i.s coupled to a removable portion of the control and braking mechanislll in order to rotate the actuating member 312. 'l'he brake act.uat;n~ plat,e 3l0 is mount.ed on a ~hreaded boss 314 so that rotatioll o~
the brake actuati.ng plate unscrews the actuating plate 310 from the bosq 3l4. As a resu.l.t, rotati.on o~ the brake actuating member 312 raises the brake actuating p.late 310, thereby forci.ng the frictiona.L brak.i.ng material 30~ against the plate 304. 'S'he plate 304 is ke~yed to the con~:rol shaft - 13~SgE~3 302 so that ~he frict.ion betw~en the material 30~ and the p~a~e 30~ restricts ro~ati.on of the s~laft 302. A s~a~ion-ary support sha~t 314 ~)rojects coaxially through the shats 300, 302. AS ~xplained in greater detail below, the remov-able portions of the contro1 and brak.ing mechanism aremounted on the shaft 314.
With reerence now to Figure 9, most of the removable components of the contro~ and braking mechani.sm in the embodiment o.E E'igures 8-10 are vi.rtually identical to the components in the embodiment Or Figures 3-7. In the i.nterest of brevi.ty, these virtually identical components will be given the same reference numera]s in both embodi-ments, and they will not b~ separateJy explained.
The embodiment of Fi.gures 8-l.0 differs ~rom the embodiment o Figure 3-7 pr.imari].y in the manner in which the removable control and braking mechanism is releasably secured to the handle ].2 of the endoscope 10. In the embodimcnt of Fi.gures 8-.l.0, an end plate 32~ is secured to the end o~ the brake actuating knob 220 by a pai.r o~ screws 322. A releAse button 330 is mounted in the end plale 320 at the ~nd Oe an elongat~d re~ease member 332. The release member 332 is sl.idably mounted ;.n a coupling shaEt 334 having a pair of apertures 336 receiving respective ball ' bearings 338. A recessed portion 340 of he release member 332 is positioned adjacent the bal1 bearings 338 when the r~lease button 330 i.s pressed. When the recess portion 340 is adjacent the baJl bearillgs 338, the ba.ll bear:ings can move inwardly. ~t all other ti.mes, ~he ball beari.ngs 33 are mainta.ined in their outer position by the Eull diameter o~ the release member 332.
With reference to F.i.gure lO, the coupl.i.ng shaEt 334 i.s inse~ted into the support sha[t 3l~ a~ter tlle release button 330 has been pressed to allow the locking balls 338 to move inwardly into the recess portion 340 oE
the release member 332. The rel.ease button 330 is biased upwardly by a compression spring 34~. ~s a result, when the locking balls 338 are positioned adjacent an annular ~ 3~5;9Q~3 groove 334 formed in the interior of the supp~rt shaEt 31~, the locking balls 338 are forced outwardly into the groove 334 by the upward movement of the release button 330. When the control and brake mechanism is to be removed, the rel~ase button 330 is pressed, thereby allowing the locking balls 338 to move inwardly into the recess portion 340.
The removable portion of the control and braking mechanism is then removed from the handle by sliding the coupling shaft 334 out of the support shaft 314.
Typically, an endoscopist uses his or her right hand to advance and retract the endoscope by manipulating the insertion tube 16 directly. The right hand then becomes contaminated from debris from the insertion tube 16.
The same hand would more than likely be used to control the right/left control knob 44 of the endoscope, thereby causing direct contamination from the insertion tube debris.
With reference to Figures 11 and 12, these contaminants can be prevented from traveling further onto the endoscope hand p;ece 12, by using a guard 390 in the form o a thin ~o circular plate between the up/down and the right/left control knob 44. The diameter of the guard 390 should be sub~tantially larger than the diameter of the right/left control knob 40 to prevent either the right/left control knob 40 from being manipulated by the right hand or the ~5 up/down control knob 44 from being manipulated by the left hand. The guard 390 prevents the leEt hand of the endoscopist from manipulating the right/left control knob 44 or inadvertently contacting the right/left control ~nob 44. Similarly, the guard 390 would prevent the endoscopist's right hand from inadvertently contacting the up/down control knob 40 or manipulating the up/down c,ontrol knob 40.

Claims

1. A system for protecting an endoscope from external contamination, said endoscope having a handle, an elongated insertion tube extending from said handle to a distal end, a set of control cables for controlling the angular orientation of the distal end of said insertion tube, and control knobs applying control forces to said control cables, said system comprising:
a fluid-impermeable bag surrounding the handle of said endoscope, said bag having an aperture formed therein to allow said control knobs to be positioned externally of said bag; and fastening means for allowing said control knobs to be detached from said handle so that said control knobs can be decontaminated between uses of said endoscope.

2. The protection system of claim 1 wherein said endoscope further includes a protective sheath surrounding said insertion tube, and wherein said bag and sheath are intercon-nected and their interiors are sealed from the external environ-ment so that said bag and sheath isolate said endoscope from external contamination.

3. The protection system of claim 2 wherein said bag has an insertion opening formed at an end thereof that is opposite said sheath.

4. The protection system of claim 3 wherein said bag further includes a flexible, nonresilient member surrounding at least a portion of said insertion opening to maintain said insertion opening open when said handle is inserted in said bag.

5. The protection system of claim 3 wherein said bag further includes a layer of pressure-sensitive adhesive surrounding at least a portion of said insertion opening to maintain said insertion opening closed in use after said handle has been inserted in said bag.

6. The protection system of claim 1 wherein said controls are removably mounted on respective shafts and wherein said shafts project through said opening in said bag.

7. The protection system of claim 1 wherein said set of cables include a pair of up/down cables for controlling the vertical orientation of the distal end of said insertion tube, a pair of right/left cables for controlling the horizontal orientation of the distal end of said insertion tube, and concentric up/down and right/left control shafts driving said up/down and right/left cables, respectively, and wherein said control knobs include a up/down control knob removably engaging said up/down control shaft and a right/left control knob removably engaging said right/left control knob, and wherein said system further includes interconnecting means for restricting relative axial movement between said control knobs while permitting free relative rotational movement between said control knobs, whereby said control knobs can independently drive said up/down and right/left control cables but are removed from and installed on said handle as a unit.

8. The protection system of claim 7 wherein said endoscope further includes up/down braking means for restraining rotation of said up/down control shaft and right/left braking means for restraining rotation of said right/left control shaft, and wherein said interconnecting means restricts relative axial movement of said braking means with respect to each other and to said control knobs while permitting said braking means to operate independently of each other so that said braking means and said control knobs are removed from and installed on said handle as a unit.

9. The system of claim 1 wherein said control knobs include a right/left control knob and an up/down control knob, said system further including a guard plate positioned between said right/left control knob and said up/down control knob, said guard plate having a minimum transverse dimension that is substantially larger than the diameter of the control knob having the largest diameter.

10. An endoscope having a handle and an elongated insertion tube extending from said handle to a distal end, said endoscope comprising:
a set of up/down cables for controlling the vertical orientation of the distal end of said insertion tube;
a set of right/left cables for controlling the hori-zontal orientation of the distal end of said insertion tube;
a first control shaft operating one set of said control cables;
a second control shaft operating the other set of said control cables, said second control shaft being concentri-cally positioned within said first control shaft;
an elongated support projecting from said handle, said support being concentrically positioned within said second control shaft;
a threaded stud surrounding said control shafts;
a first brake actuating member threaded onto said stud, said brake actuating member having an annular layer of frictional braking material mounted on an external surface of said brake actuating member and surrounding said stud;
an annular brake plate surrounding said threaded stud adjacent the frictional braking material on said brake actua-ting member, said brake plate being keyed to said first control shaft so that said brake plate and said shaft rotate with together, whereby rotation of said brake actuating member in one direction causes said actuating member to move toward said brake plate, thereby forcing said layer of frictional braking material against said brake plate with increasing force in order to restrain rotation of said first control shaft;

a first control knob releasably attached to said first control shaft so that rotation of said first control knob rotates said first control shaft;
a brake actuating lever rotatably mounted on said first control knob, said brake actuating lever being releasably coupled to said brake actuating member;
a second control knob releasably attached to said second control shaft so that rotation of said second control knob rotates said second control shaft, said second control knob being rotatably mounted on said first control knob, said second control shaft further including an annular braking surface concentrically surrounding said elongated support;
a second brake actuating member rotatably secured to said second control knob, said second brake actuating member having a second annular layer of frictional braking material positioned closely adjacent the braking surface of said second control knob, said brake actuating member further including adjusting means for causing said second brake actuating member to move in one direction toward said layer or frictional braking material, thereby forcing said layer or frictional braking material against the braking surface of said second control knob with increasing force in order to restrain rotation of said second control shaft; and fastening means for releasably and rotatably securing said second brake actuating member to said elongated support to secure said control knobs, said brake actuating lever and said second brake actuating member to the handle of said endoscope while allowing said control knobs, said brake actuating lever and said second brake actuating member to be removed from said endoscope handle as a unit.

11. The endoscope of claim 10 wherein said second brake actuating member includes a brake adjusting knob rotatably mounted on said second control knob, a brake disk nonrotatably mounted on said elongated support, said brake disk having said second annular layer of frictional braking material mounted thereon adjacent said second control knob, and a coupling member positioned between said brake adjusting knob and said said brake disk and connected to said brake adjusting knob, and wherein said adjusting means includes threads formed on said coupling member and mating with threads formed on said brake disk so that rotation of said coupling member in one direction moves said brake disk axially toward said second control knob, thereby causing said second layer of frictional braking material to engage said second control knob with increasing force.

12. The endoscope of claim 11 wherein said brake adjusting knob is connected to said coupling member through a first coupling mechanism that allows said adjusting knob to rotate with respect to said coupling member when the torque that said brake adjusting knob exerts on said coupling member exceeds a predetermined value, thereby limiting the maximum braking force to which said second brake actuating member can be adjusted.

13. The endoscope of claim 12 wherein said coupling member is connected to said brake plate through a second coupling mechanism that allows said coupling member to rotate with respect to said brake plate when the torque that said coupling member exerts on said brake plate exceeds a second predetermined value, thereby preventing the adjustmemt of said second brake actuating member unless a torque of at least said second predetermined value is applied to said brake adjusting knob, said first predetermined value being larger than said second predetermined value so that said second coupling mecha-nism releases to allow said coupling member to rotate with respect to said brake plate before said first coupling mecha-nism releases to allow said coupling member to remain station-ary as said brake adjusting knob is rotated.

14. The endoscope of claim 10 wherein said elongated support is formed by a hollow shaft projecting from said handle within said first and second control shafts, and wherein said fastening means includes a second shaft rotatably secured to said control knobs and extending along the axis thereof, said second shaft extending into the hollow shaft forming said elongated support, said endoscope further including fastening means releasably securing said second shaft within said hollow shaft.

15. The endoscope of claim 10, further including a guard plate positioned between said right/left and said up/down control knob, said guard plate having a minimum tansverse dimension that is substantially larger than the diameter of the largest diameter of said control knob.

16. A method of protecting an endoscope from external contamination, said endoscope having a handle, an elongated insertion tube extending from said handle to a distal end, a set of control cables for controlling the angular orientation of the distal end of said insertion tube, and control knobs applying control forces to said control cables, said method comprising:
placing a fluid-impermeable bag around the handle of said endoscope, said bag having an aperture formed therein to allow said control knobs to be positioned externally of said bag;
attaching control knobs to said handle externally of said bag;
using said endoscope to perform an endoscopic proce-dure;
detaching said control knobs from said handle;
removing said endoscope from said bag; and decontaminating or sterilizing said control knobs before they are once again attached to said endoscope to perform an endoscopic procedure.

17. The method of claim 16, further including the steps of placing a protective sheath around said insertion tube before performing said endoscopic procedure and removing said insertion tube from said sheath after said procedure has been completed.

18. The method of claim 17, further including the step of interconnecting said bag and sheath so that the interiors of said bag and sheath are sealed from the external environment, whereby said bag and sheath isolate said endoscope from external contamination.