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`US 005567 120A
`
`United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,567,120
`
`Hungerford et al.
`
`[45] Date of Patent:
`
`Oct. 22, 1996
`
`[54] ELECTRONIC INFUSION DEVICE AND
`NOVEL ROLLER CLAMP HOLDEN
`THEREFOR
`
`[75]
`
`Inventors, Roger L_ Hnngenfnnd Medina.
`Christopher D_ Cimeman,
`Cheektowagal P3111 J- Hufnagels
`Clarence; Robert J- Pit‘-l‘0l1i, L6WiS'E0I1,
`311 Of N-Y-
`
`Assignee: Sigma International, Medina, N.Y.
`
`APPL N05 3221432
`Filed:
`Oct. 13, 1994
`
`Int. CL6 ............................. F04B 49/00; F0413 43/09
`U.S. Cl.
`............................. 417/63; 417/474; 604/250
`Field of Search ........................... .. 417/474, 63, 360;
`604/34, 153, 250
`
`References Cited
`
`4,155,362
`4,460,358
`4,586,691
`4,539,043
`418111190
`4,857,050
`4,878,896
`5,017,192
`5,039,279
`
`U'S‘ PATENT DOCUNLENTS
`5/1979 Jess ................................... .. 128/214 F
`7/1984 Somerville et al
`..... .. 604/250
`5/1986 Kozlow ... .. ... .. . .
`... . .. .. 251/7
`3/1937 B15113 ----- --
`504/250
`4/1989 Pelmulder
`417/350
`........ ..
`8/1989 I./entz et al.
`.. 604/67
`11/1989 Garrison et al.
`...... 604/65
`.....
`5/1991 Dodge et al.
`........
`604/250
`8/1991 Natwick et al.
`........................ 417/474
`
`5,116,203
`5,219,327
`5,300,044
`5,437,625
`
`5/1992 Natwick et al.
`6/1993
`....
`4/1994 Classey et al.
`8/1995 Fields et a1.
`. .. ....
`
`...................... .. 417/474
`.... .. 604/250
`. ... .. 604/250
`. ... .. 604/250
`
`8/1995 Thilletal. ................... 604/250
`5,437,642
`1/1996 Williamson etal.
`................... 417/474
`5,482,446
`Primary Examiner—Timothy S. Thorpe
`Assistant Examiner——Peter G. Korytnyk
`Attorney, Agent,
`or
`Firm—Shlesinger
`Shlesinger
`
`Fitzsimrnons
`
`I57]
`
`ABSTRACT
`
`A holder for an IV tube roller clamp is removably secured
`1n the housing of an electronic 1I1fllS10I1 device, and has in
`opposite ends thereof a pair of photo—electric devices’, one of
`which detects when the roller of the clamp is in its tube
`opening position, and the other detects when the roller is in
`tube closing position. A lever is pivotal on the housing
`between a closed position in which it operatively connects
`the IV tube to a pump unit in the housing, and an open
`position in which it permits removal of the IV tube from the
`unit. The spring-loaded armature of a solenoid prevents the
`lever from being opened until the solenoid coil is energized,
`and the photoelectric devices prevent the solenoid coil from
`being energized until the roller is in its tube closing position.
`When closed, the lever overlies part of the tube channel in
`which the IV tube is seated and also shifts a pressure plate
`in the pump unit to a position in which a lip thereon overlies
`-
`-
`amther pom” °f Said Channel‘
`
`20 Claims, 4 Drawing Sheets
`
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`0°on=U‘Ni‘I--I L.‘IIllllllll
`
`ACTA EX. 1012-001
`
`ACTA Ex. 1012-001
`
`

`
`U.S. Patent
`
`Oct. 22, 1996
`
`Sheet 1 of 4
`
`5,567,120
`
`
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`
`ACTA EX. 1012-002
`
`ACTA Ex. 1012-002
`
`

`
`U.S. Patent
`
`Oct. 22, 1996
`
`Sheet 2 of 4
`
`83
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`ACTA Ex. 1012-003
`
`

`
`U.S. Patent
`
`Oct. 22, 1996
`
`-
`
`Sheet 3 of4
`
`5,567,120
`
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`ACTA EX. 1012-004
`
`ACTA Ex. 1012-004
`
`

`
`U.S. Patent
`
`Oct. 22, £996
`
`Sheet 4 of 4
`
`5,567,120
`
`ACTA EX. 1012-005
`
`ACTA Ex. 1012-005
`
`

`
`1
`ELECTRONIC INFUSION DEVICE AND
`NOVEL ROLLER CLAMP HOLDEN
`THEREFOR
`
`BACKGROUND OF THE INVENTION
`
`This invention relates to an improved electronic infusion
`device which causes the roller clamp of an intravenous
`administration set to interact with the device in such a way
`that dangerous, accidents gravity free flow will not occur.
`More specifically, the invention requires loading of the roller
`clamp into the infusion device and prevents removal of the
`IV set from the infusion device until the roller clamp is
`closed. This prevents fluid flow when the IV set is removed
`from the infusion device. It also enables a standard gravity
`IV set to become a “protected” set without the addition of
`any special components to the set.
`By way of Definition
`ELECTRONIC INFUSION DEVICES (EID), which are
`also known as infusion pumps or infusion controllers, are
`used accurately to regulate the flow rate of intravenous fluids
`and to electronically monitor and alarm should a variety of
`unsafe occurrences be detected relating to the infusion.
`INTRAVENOUS (IV) SETS, also called IV sets or grav-
`ity sets, are single use, disposable, sterile, tubing sets that
`connect the IV fluid container (a bag or bottle) with the
`patients’s catheter. IV sets are used either with EID’s or 11
`their own when the relatively inaccurate flow rates they are
`capable of providing are clinically acceptable.
`ROLLER CLAMPS are components found on IV sets.
`They consist of an operator adjusted roller wheel mounted in
`a small plastic housing. The roller wheel pinches the IV
`tubing to varying degrees ranging from fully closed to
`partially open (which results in controlled gravity flow), to
`fully open When an IV set is loaded n an EID the roller is
`left fully open to allow the EID to control flow rate.
`FREE FLOW occurs whenever an IV set is not in an EID
`
`and its roller clamp (and all other IV set clamps) are fully
`open. While there are a few clinical conditions where free
`flow is desirable, in most cases free flow refers to an
`accidental and dangerous condition that can lead to patient
`injury or death. These accidental free flow conditions most
`commonly occur when IV sets are removed from EID’s
`without the operator remembering to close the sets roller
`clamp first.
`PROTECTED IV SETS, as defined by ECR1 are either;
`dedicated infusion pump sets that include a special IV set
`component which interacts with the EID when the set is
`unloaded to prevent gravity free flow, or they are standard
`gravity IV sets whose roller clamps must be closed before
`the EID allows set removal.
`‘ECR1, Emergency Care Research Institute, is a non-profit organization that
`evaluates and reports on medical instrumentation to the health care industry.
`Some prior art EIDs (such as the trademark VAC 500 and
`which used standard gravity IV sets employed doors to keep
`the tubing closed, preventing free flow while the tubing was
`held in the device. However, if the device’ s door was opened
`before the sets’ roller clamp was closed, free-flow occurred.
`Other prior art EIDs (such as the SIGMA 5000) were
`equipped with both a door and a “flow stop”. If the door was
`opened with an open roller clamp the spring activated flow
`stop would close the IV tubing to prevent free flow. This two
`step process to initiate gravity flow was considered the
`industry standard for preventing Free flow and still is the
`AAMI (American Association of Medical Instrumentation)
`standard.
`
`5,567,120
`
`2
`
`However, due to the rising importance of preventing
`accidental free flow, ECRI (Emergency Care Research Insi-
`tute) has created a “quasi” standard. It states that in order to
`assure free-flow protection, either anti—free flow infusion
`sets (“protected sets”) should be used with EIDs (an
`' example being med’ s trademark Gemini V pump referenced
`in U.S. Pat. 2,689,043) or the EID design should force the
`operator to close the IV set’s roller clamp prior to removing
`the set from the device. _
`The primary object of this invention is to provide an EID
`design that interacts with the roller clamp of a standard IV
`set in such a way that the clamp is always closed prior to
`removal of the set from the EID, thus preventing accidental
`free flow.
`*
`Still another objective is to be able to remove the EID’s
`modular roller clamp holder so that it can be replaced with
`new roller clamp holders able to accommodate roller clamps
`of varying dimension. In this manner, the EID is compatible
`with the IV sets and roller clamps of multiple manufacturers.
`Other objectives of this invention will be apparent here-
`inafter from the specification and from recital of the
`appended claims, particularly when read with the accompa-
`nying drawings.
`
`SUMMARY
`
`The invention includes a roller clamp holder mounted to
`open on the front facerof the EID. Into this holder is loaded
`the IV set’ s roller clamp. The roller clamp holder includes an
`electronic power supply switch which causes the EID to turn
`on as soon as the roller clamp is loaded. The roller clamp
`holder also includes electronic detectors which are able to
`determine the roller wheel position, whether fully closed,
`partially open, or fully open. The roller clamp holder will
`accept most standard IV set roller clamps, and its modular
`removable design allows one holder to be replaced by
`another one to accommodate roller clamps of varying
`dimension.
`
`Immediately below the roller clamp holder is the EID’s
`peristaltic (tube squeezing) pumping mechanism. Extending
`through this mechanism is the pump section of a vertical
`tube channel into which the IV set tubing is loaded. On one
`side of the pump section of the channel are the peristaltic
`pump’s fingers, which are push rods driven by the pump’s
`camshaft: On the other side of this section is a pressure plate
`which is retracted to enable the loading of the IV set tubing.
`After the IV set tubing has been loaded into the tube channel,
`the pressure plate is advanced so that the registering tubing
`is squeezed between the pump fingers and the pressure plate.
`Once loaded, the tubing in the pump section is covered by
`an overlapping lip on the pressure plate which overlies the
`pump section of the tube channel. Thus loaded, the tubing
`cannot be unloaded until the pressure plate lip is pulled back
`out of the way, which in turn opens the tube channel. A lever
`located just below the peristaltic pump, is connected to the
`pressure plate. By means of this manually operated lever, the
`pressure plate is moved out of the way to facilitate IV tube
`loading and unloading.
`The lever is controlled by a solenoid actuated locking
`mechanism. This mechanism is in turn controlled by the
`EID’s electronics, specifically its micro controller. The lever
`remains locked at all times except when two consecutive
`events take place. These events are roller clamp holder
`detecting the roller wheel is closed and the load/unload key
`of the EID’s key board being pushed. The combination of
`these two things causes the lever locking solenoid to actuate,
`which then results in the lever unlocking. The lever can then
`
`ACTA EX. 1012-006
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`ACTA Ex. 1012-006
`
`

`
`3
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`4
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`5,567,120
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`be opened and the pressure plate is pulled back so that its lip
`no longer overlaps the tubing. The tube channel is then open
`and the IV set can be removed safely with its closed roller
`clamp. When the lever is re-closed it remains locked until
`the next time both a closed roller is sensed and the load!
`unload key is pushed. When the IV set is locked in the
`peristaltic finger pumps one of the pump fingers is always in
`a fully outward position. This causes the IV tubing to be
`closed which prevents any flow when the pump is stopped
`and not running. As a consequence, the invention prevents
`both loading and unloading the IV set with the IV set’s roller
`clamp in other than a fully closed, no flow position.
`
`DRAWINGS
`
`FIG. 1 is a front elevational view of an improved elec-
`tronic infusion device having mounted therein a, modular
`roller clamp holder of the type made according to one
`embodiment of this invention, part of the front wall of the
`device being cut away for purposes of illustration,
`FIG. 2 is an enlarged fragmentary sectional view taken
`generally along the line 2-2 in FIG. 1 looking in the
`direction of the arrows, but with portions of the illustrated
`roller clamp being shown in full;
`FIG. 3 is a fragmentary sectional view taken generally
`along the line 3-3 in FIG. 2 looking in the direction of the
`arrows;
`
`FIG. 4 is a fragmentary sectional view taken generally
`along the line 4-4 in FIG. 1 looking in the direction of the
`arrows;
`
`FIG. 5 is a wiring diagram showing one manner in which
`the electrical control means of the device may be wired to
`prevent accidental free flow of IV fluids to a patient; and
`FIG. 6 is an enlarged fragmentary sectional view taken
`generally along the line 6-6 in FIG. 1 looking in the
`direction of the arrows.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIIVIENTS
`
`Referring now to the drawings by numerals of reference,
`and first to FIGS. 1 to 3, 10 denotes generally the housing
`of an electronic infusion device containing a linear peristal-
`tic pump unit part of the upper wall 11 of which is illustrated
`in FIG. 1, and having a hand grip section or portion 12 for
`use in carrying the housing 10. The front wall 13 of housing
`10 has therein an elongate, vertically extending I.V. tubing
`channel 14, which extends continuously between the upper
`and lower ends, respectively, of housing 10 for accommo-
`dating the tube T of a conventional IV. tubing set. Fluid
`flows from a supply thereof (not illustrated) through the tube
`T, and for example downwardly in FIG. 1, when the tube is
`mounted in housing 10 as described in greater detail here-
`inafter.
`
`When the tube T is properly mounted in the housing 10,
`the tubing channel 14 in the front wall 13 is parfially closed
`or covered by a lever 16, which is secured adjacent one end
`thereof (the left end in FIGS. 1 and 4) to a shaft 18 adjacent
`the lower end thereof. Shaft 18 is rotatably mounted at its
`lower end in the bottom of housing 10, and at its upper end
`in the pump wall 11 with its axis extending vertically and
`parallel to the axis of the tube- accommodating channel 14.
`Lever 16 is pivotal manually about shaft 18 between the
`closed position s shown by solid lines in FIGS. 1 and 4, and
`an open position as illustrated by broken lines in FIG. 4.
`When the lever 16 is in its closed position a projection 19 on
`
`the inside surface thereof registers with the tube T, which is
`seated in the tube channel 14. Also when lever 16 is moved
`to its closed position, the spring-loaded armature 21 of a
`solenoid 22, which is mounted in housing 10 above the lever
`16, slides up a camrning surface 23 on the lever and drops
`into a registering, annular boss 24 that is formed on the lever
`16 adjacent shaft 18. In this manner lever 16 is locked or
`secured in its closed position until such time that the coil of
`solenoid 22 is energized in order to withdraw its armature 21
`upwardly and out of the boss 24 in lever 16. Also when lever
`16 is closed, a portion of the lever 16 overlies a portion of
`tube channel 14 and the tube T, thereby preventing, together
`with additional means noted hereinafter, removal of the tube
`from housing 10.
`Above the lever 16 the Front wall 13 has therein a large
`opening 31, which forms the forward, open end of a simi-
`larly shaped housing denoted generally by the numeral 32 in
`FIGS. 2 and 3. Housing 32 comprises spaced, parallel upper
`and lower walls 33 and 34 (FIG. 2), and spaced side walls
`35 and 36 (FIG. 3) extending transversely of walls We and
`34. Walls 33-36 are integral with and project rearwardly
`from the inside surface of the front wall 13 of housing 10,
`and are connected at their inner ends or edges by an integral,
`transverse end wall 37. Housing walls 33 and 34 have
`projecting inwardly from their forward edges elongate,
`registering slots 33' and 34' respectively, which register with
`the tubing channel 14 in the housing 10 to allow a section of
`the IV tube T to be inserted into the opening 31 in housing
`10 as noted in greater detail hereinafter. End wall B7 has
`therethrough a small hole 38 through which extends a cable
`C for a purpose noted hereinafter.
`Removably secured in the opening 31 in housing 32 is a
`roller clamp holder, which is denoted generally by the
`numeral 41 in FIGS. 1 to 3. Holder 41 has spaced, parallel,
`upper and lower walls 42 and 43 (FIG. 2), which are seated
`against the inside surfaces of the housing walls 33 and 34,
`respectively, and spaced side walls 44 and 45 that are seated
`against the inside surfaces of housing walls 35 and 36,
`respectively. Walls 42 and 43 have formed in their outer or
`forward edges tube accommodating slots 42' and 43', respec-
`tively, which register with the slots 33' and 34' in housing 32.
`Integral with and extending transversely between the walls
`42-45 of the holder 41 is an end wall having a lower section
`46 which extends parallel to and is spaced from the rear wall
`37 of housing 32, and an inclined upper section 47 which
`extends, as shown in FIG. 2, diagonally upwardly and
`toward the rear housing wall 37 between section 46 and the
`upper wall 42 of the holder. Wall section 47 also forms a
`narrow notch section 48 immediately beneath the upper wall
`42 of the holder adjacent the inner end thereof. Holder 41 is
`removably secured in housing 32 by two screws 49, which
`extend through section 46 of the holder end wall, and thread
`into the confronting ends of a pair of cylindrical bosses 39
`that are integral with and project from rear wall 37 of
`housing 32.
`Removably mounted in a rectangular opening 50 in the
`holder 41 is a conventional roller clamp, which is denoted
`generally by the numeral 51 in FIGS. 1 to 3. Clamp 51 has
`a hollow, generally rectangularly shaped lower end the inner
`wall 52 of which is seated as shown in FIG. 2 against the
`inside surface of section 46 of the end wall of holder 41, and
`has an upper, enlarged, generally hollow head section which
`has adjacent its inner end an inclined outer surface 53 that
`is seated against the inclined wall section 47 of holder 41.
`Also, the inner end of the clamp head section has formed
`thereon a narrow lip section 54, which seats in the recess 48
`in the end wall of the holder 41.
`
`ACTA EX. 1012-007
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`ACTA Ex. 1012-007
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`

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`5,567,120
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`5
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`Mounted for movement in vertical slot 55 (FIG. 1) in the
`front wall the roller clamp 51 is a disc-shaped roller 56.
`Roller 56 has projecting coaxially from opposite sides
`thereof reduced-diameter pins 57 which slide in opposed,
`registering, longitudinally extending grooves 58 that are
`formed in the confronting walls of the clamp. Grooves 58
`are inclined slightly to the vertical, so that the lower ends
`thereof are positioned closer to the wall 52 of the clamp 51,
`while adjacent their upper ends the grooves 58 are inclined
`slightly as shown in FIG. 2 toward the front wall 13 of the
`housing 10. Consequently when the roller 56 is in its
`lowermost position as shown in full lines in FIGS. 1 to 3, its
`peripheral surface is forced by the grooves 58 inwardly
`against the adjacent tube T, thereby compressing the tube
`closed so that no fluid may flow from the supply thereof
`beyond the portion of the tube T which is crimped closed.
`Roller 56 has a Knurled outer peripheral surface which
`enables an operator to shift the roller manually in a known
`manner between its full line position as shown in FIGS. 2
`and 3, and its uppermost position, as shown by broken lines
`in FIGS. 1 and 2, where it engages and is stopped by a pair
`of lugs 59 (FIGS. 1 and 2) that project from the side walls
`of clamp 51. In its uppermost position the outer peripheral
`surface of roller 56 barely touches the tube T, so that the
`roller in no way impedes the flow of fluid through the tube.
`For releasably securing the roller clamp 51 in the holder
`41 an integral, flexible tab 40 projects downwardly (FIG. 2)
`from the upper wall 42 of holder 41 into the slot 55 in the
`roller clamp, and snugly and releasably into engagement
`with part of the top wall of clamp 51 adjacent the inner ends
`of the slots 33' and 42' that accommodate tube T. The tab 40
`
`is shown merely by way of example, and could be replaced,
`if desired, by a metal tab, or the like, secured to holder 41
`and projecting releasably into engagement with roller clamp
`51.
`
`it is imperative that some means be
`As noted above,
`provided for preventing accidental, undesirable opening of
`the roller clamp 51 at the time when the IV supply is
`connected by the tube T to the patient. As a precaution,
`therefore, the holder 51 is provided with sensor means in the
`form of a conventional photo detector or transistor having a
`light source or emitter 61 (Figs. 1 and 2) mounted in a recess
`in holder 41 to direct its beam transversely across the space
`50 in which the roller clamp 51 is to be mounted, and a
`cooperating photo sensor element 62 mounted in a recess
`adjacent the opposite side of holder 41 to have its receptor
`lens positioned in registry with the beam emitted by emitter
`61. In this manner, whenever the roller 56 of the roller clamp
`51 is located in its uppermost or tube—open position, the
`beam emitted by the emitter 61 will be blocked by the roller
`56, whereby preventing its beam from being directed onto
`the sensor 62.
`
`Moreover, mounted in a similar recess adjacent the lower
`end of holder 41 is a photo cell device in the form of an
`emitter 64, for example an infra-red (IR) emitter, and an IR
`sensor 65, which are mounted in such a manner that the
`beam emitted by the emitter 64 strikes the surface of the
`roller 56, when the roller wheel 56 is in its lowermost
`position, thereby causing the beam to be reflected off of the
`surface of the roller 56 and onto the sensor 65. The advan-
`
`tage of this mechanism is that by using a reflected IR beam
`it prevents any accidental interruption of the beam from the
`emitter 64 to the sensor 65 as might occur if they were
`disposed coaxailly on opposite sides of the roller 56, in
`which case the insertion of any foreign object into the space
`between the emitter and sensor might accidentally interrupt
`the beam therebetween. By relying on the reflection of the
`
`6
`beam from the emitter 64 to the sensor 65, the beam will
`arrive at the sensor only when the roller 56 itself is in the
`lowermost or clamping position. As noted hereinafter, this
`reflective sensing technique ensures that the roller clamp
`(and IV set) can only be removed from the electronic
`infusion device when the roller is in its lowermost (closed)
`position, thus preventing any free or uncontrolled flow of IV
`fluids to the patient.
`An additional fail-safe device is represented by the sole-
`noid 22, the armature 21 of which normally prevents unde-
`sirable opening of the lever 16, which in turn prevents the
`insertion of a tube into the housing 10, or the removal
`therefrom, until such time that the lever 16 has been swung
`from its closed to its opened or broken line position as
`shown in FIG. 3. The only logical occurrance that allows the
`lever 16 to be opened and thus the IV set to be inserted or
`removed, is again when the lower reflective type sensor
`device (64, 65) senses that the roller wheel 56 of the roller
`clamp is present in the closed position.
`A printed circuit board B (FIGS. 2 and 3) is secured by a
`screw 67 to an internally threaded sleeve 68 that is secured
`coaxially in a boss 69 that projects from the rear surface of
`section 46 of the end wall of holder 41. Board B has thereon
`
`a connector (FIG. 2) which is connected by cable C to a
`power supply unit (not illustrated). Projecting from board B
`adjacent its lower end (FIG. 2) through a bore in another
`boss 73 that projects from wall section 46, and projecting
`through section 46 and into engagement with wall 52 of the
`roller clamp 51, is a normally open silicone rubber switch
`74, which functions to detect the presence of roller clamp 51
`in the holder 41. Switch 74 has a molded-in gasket to prevent
`fluid intrusion to board B, and has molded into the bottom
`thereof a conductive carbon pill which, when the switch is
`compressed, closes a circuit that energizes the photo detec-
`tors 61,62 and 64,65 as noted hereinafter.
`
`As an additional precaution against the occurrence of
`accidental free flow when IV tubing is mounted in the
`device, lever 16 also operates special pressure plate which is
`designed to cooperate with the tube engaging fingers of the
`peristaltic pump unit, which is mounted in housing 10
`beneath the roller clamp holder 41. Referring again to FIG.
`1, and also to FIG. 6, numerals 81 denote a series of
`reciprocable fingers which form part of the pump unit, and
`which are positioned at one side of the registering section of
`channel 14 and IV tube T for operation in a conventional
`manner such as disclosed for example in U.S. Pat. No.
`4893,99l. As disclosed in that patent, when the pump unit is
`operating, the fingers 81 are designed repeatedly and pro-
`gressively to compress the confronting section of the IV tube
`T against a backup plate, or pres sure plate, which is mounted
`in the pump housing opposite the fingers, and which in the
`present embodiment is denoted by numeral 83.
`In the above—noted U.S. Pat. No. 4,893,991 the backup or
`pressure plate was mounted on a door hinged to the pump
`housing, so that when the door was closed the backup plate
`was swung into an operative position at one side of an IV
`tube. In the present embodiment however, pressure plate 83
`is resiliently mounted by compression springs 82 for limited
`movement on an elongate spring housing 84, which is
`mounted to reciprocate beneath wall 11 and between oppo-
`site sides of the pump unit toward and away from the tubing
`channel 14. Secured at opposite ends thereof to the rear or
`left hand surface of housing 84, as shown in FIG. 1, is a rigid
`strap or bracket 85 which overlies one side of an elongate
`arcuate groove 86 formed in the rear surface of housing 84.
`The groove 86 registers with a pair of vertically spaced earns
`87 that are secured to shaft 18 for rotation thereby.
`
`ACTA EX. 1012-008
`
`ACTA Ex. 1012-008
`
`

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`5,567,120
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`
`When lever 16 is in its closed, locked position as shown
`in FIGS. 1 and 4, the curved outer ends 88 of earns 87
`engage the back of housing 84 at the bottom of groove 86
`and hold housing 84 and its pressure plate 83 in an advanced
`or operative position as shown by solid lines in FIGS. 1 and
`6. In this position a narrow, longitudinally extending lip 89,
`which projects from the forward or right hand face of the
`pressure plate 83 as shown in the drawings, overlies and
`closes the outer end of that portion of tube charmel 14 that
`extends through the pump unit. The lip 89 also positions tube
`T in proper registry with fingers 81, and pinches and
`occludes part of any improperly loaded tube to prevent free
`flow therethrough. Also at such time, at least one of the
`numerous fingers 81 will have urged a section of tube T with
`such force against the face of the spring loaded pressure
`plate 83 that the tube will be completely occluded in at least
`one spot, as shown for example in FIG. 6.
`When lever 16 is swung to its open position (broken lines
`in FIG. 4), the earns 87 will be swung (clockwise in FIG. 6)
`approximately 90° by shaft 18 about the axis thereof, and in
`so doing the outer ends 88 of the cams will swing into
`engagement with the inside surface (right side in FIG. 1) of
`the strap 85, thus causing this strap and the attached housing
`84 and plate 83 to be drawn slightly away from channel 14,
`and into their retracted, broken line positions shown in
`FIGS. 1 and 6. This causes the lip 89 on plate 83 to be
`retracted to a position in which it uncovers the registering
`section of channel 14 to permit withdrawal of tube T from
`the pump and channel 14.
`Referring now to FIG. 5, L1 and L2 represent part of a
`control circuit across which an AC power supply, for
`example 115 volts, is adapted to be connected upon the
`closing of the switch 74, when clamp 51 is inserted in holder
`41. Connected in parallel to each other between the lines L1
`and L2 are the two emitters 61 and 64, which become
`energized upon the closing of switch 74. The receptor or
`light detector 62, which is disposed in coaxial registry with
`the emitter 61, is connected in series between lines L1 and
`L2 with a relay R1. The receptor 65, which receives light
`(for example IR light) from the emitter 64 only when the
`roller 56 is in its lowermost or tube-closing position,
`is
`connected in series with a second relay R2 between lines L1
`and L2. The solenoid 22, which operates the lever-locking
`armature 21, is connected in series between the lines L1 and
`L2 with the LOAD/UNLOAD switch S2, together with the
`norrnally-open switch contacts R2-1 that are controlled by
`relay R2, and with the norrnally-open switch contacts R1—1
`that are controlled by the relay R1. The motor M for
`operating the pumping section of the infusion device 10 is
`connected in series between lines L1 and L2 with normally-
`closed relay switch R1-2, and with a motor RUN-STOP
`switch S1, which as shown in FIG. 1 is one of a number of
`push-button switches located on the face of the housing of
`the device 10, along with number of other buttons which will
`not be described in greater detail herein, except for the
`button which is denoted in FIG. 1 as S2, the function of
`which is noted above. Connected in series between the lines
`
`L1 and L2 with a pair of normally closed switch contacts
`R2-2, also controlled by relay R2, is a warning lamp SC
`which, when energized,
`illuminates on the face of the
`housing of device 10 a warning message to “SHUT
`CLAMP”.
`
`In use, and assuming that switch 74 is closed and device
`10 has already been loaded with an IV set the clamp 51 of
`which is fully seated in the holder 41, the emitters 61 and 64
`will be energized, and the lever 16 will be secured in its
`closed position by the armature 21 of the solenoid 22. To
`
`8
`remove the IV set and its associated roller clamp, and
`assuming switch S1 has been operated to turn off the pump
`motor M, it is absolutely necessary that the roller 56 be
`shifted downwardly into its lowermost or tube closing
`position so that light from the emitter 64 will energize the
`receptor 65, thus completing a circuit through the normally
`non-conducting receptor 65, and thereby energizing relays
`R1 and R2. Until relay R2 is energized, the solenoid 22
`carmot be energized because the contacts R2—1 will be open.
`At the time that the roller 56 is in its lowermost position it
`does not interfere with the transmission of light from the
`emitter 61 to the receptor 62, so that at such a time relay R1
`is energized, and its relay contacts R1—1 are therefore
`closed, and contacts R1~2 are open to prevent operation of
`motor M. Therefore as soon as the receptor 65 conducts, the
`relay contacts R2-1 also close. This enables the solenoid 72
`to be energized upon the closing of the switch S2, which, if
`desired, can be a delayed-opening switch, which will give an
`operator ample time within which to swing the lever 16 from
`its closed to its opened position after operation of switch S2.
`As the lever 6 is opened, cams 87 retract pressure plate 83
`away from tube T, and at the same time the lip 89 on the plate
`uncovers the section of tube T formerly gripped between
`plate 83 and the fingers 81. The IV set can then be removed
`from device 10.
`
`In order to load the IV set into device 10 and assuming
`that lever 16 is closed the roller clamp 50 must be inserted
`into the holder 41 to its fully seated position, at which time
`it will close the switch 74, and will thus energize sensors 61,
`62 and 64, 65. At such time, if the roller 56 is not in its
`lowermost or closed position, then relay R2 will be dener-
`gized, and its contacts R2—2 will be in their normally-closed
`position, thereby energizing the warning lamp SC to instruct
`the operator to shift the roller 56 downwardly to its tube-
`closing position. After the roller 56 has reached its lower-
`most position the switch S2 may be operated, as noted above
`to energize the coil of solenoid 22, thereby permitting the
`opening of the lever 16 and the insertion of tube T into the
`now—open section of channel 14 that extends through the
`pump unit. As noted above, when it is thereafter desired to
`close the lever 16, the carnming surface 23 will enable the
`lever 16 to cam the spring-loaded armature 21 out of the way
`until the lever is fully closed, at which time the armature 21
`will drop into the locking recess 23, and the lip 89 on plate
`83 will have been shifted into its tube blocking position as
`shown in FIGS. 1 and 6. Also at such time at least one of the
`pump fingers 81 will have engaged and occluded the tube
`until such time that the pump is started.
`From the foregoing it will be apparent that the present
`invention provides an improved electronic infusion device,
`which precludes the loading and unloading of an IV set and
`its associated roller clamp into and out of the device until
`such time that the roller 56 has been shifted to its tube-
`
`closing position. In this way undesirable accidental free-
`flow of an IV liquid is precluded from being delivered
`accidentally to a patient. Moreover, by utilizing the remov-
`able, modular holder 41, it is possible to make slight changes
`in the design of the holder to