`
`[19]
`
`Fields et al.
`
`[54]
`
`[75]
`
`TUBE FLOW LIIVIITER, SAFETY FLOW
`CLIP, AND TUBE PINCHER MECHANISM
`Inventors:
`
`Antony Fields, San Francisco, Calif.;
`Terry Branson, Round Rock, Tex.;
`David J. Harrison, Carrollton, Tex.;
`Dana J. Owens, Irving, Tex.; Aaron
`T. Raines, Dallas, Tex.; Edward G.
`Rasmussen, Carrollton, Tex.
`
`Assignee:
`
`McGaw, Inc., Carrollton, Tex.
`
`Appl. N0.:
`Filed:
`
`167,413
`
`Dec. 14, 1993
`
`Related U.S. Application Data
`
`Continuation-in-part of Ser. No. 880,642, May 6, 1992,
`abandoned.
`
`Int. CL5 ........................................... .. A61M 31/00
`U.S. Cl. .................................... .. 604/65; 604/153;
`604/250; 128/DIG. 12
`Field of Search ........................................ 604/4-6,
`604/34, 65-67, 151, 153, 245, 246,250;
`128/DIG. 12, DIG. 13; 251/7, 9
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`2,889,848
`4,142,524
`4,155,362
`4,199,307
`4,236,880
`4,322,201
`4,382,753
`4,397,642
`4,586,691
`4,657,490
`4,689,043
`4,758,220
`
`6/1959
`3/1979
`5/1979
`4/1980
`12/1980
`3/1982
`5/1983
`8/1983
`5/1986
`4/1987
`8/1987
`7/1988
`
`Redmer .
`........... .. 128/214 F
`Jassawalla ct al.
`Jess .............................. 128/214 F
`Jassawalla
`........... 417/474
`
`Archibald
`
`Lamadrid ..
`
`Abbott ......
`
`....... 417/279
`..... .. 417/479
`....... 604/245
`........... 251/7
`....... 417/478
`....... 604/250
`Sundblom et al. .................... 604/65
`
`US005437635A
`
`[11]
`
`[45]
`
`Patent Number:
`
`5,437,635
`
`Date of Patent:
`
`Aug. 1, 1995
`
`Garrison et al. ...................... 604/65
`Groshong et al. ..
`...... 604/67
`Pastrone et al.
`
`4,878,896 11/1989
`4,898,579 2/1990
`4,927,411
`5/1990
`4,944,485 7/1990
`5,219,327 6/1993
`5,302,093 4/1994 Owens et al.
`
`....................... 604/153
`
`FOREIGN PATENT DOCUMENTS
`
`0450736 10/1991 European Pat. Off.
`
`............ 604/153
`
`Primary Examz'ner—C. Fred Rosenbaum
`Assistant Examiner——Frank Wilkens, III
`Attorney, Agent, or Firm—John W. Montgomery; Ross,
`Clapp, Korn & Montgomery
`
`ABSTRACI‘
`[57]
`A flow limiter mechanism for use with an infusion
`
`pump of the type operating upon a disposable cassette
`held by the infusion pump and having a flow tube con-
`nected to the cassette. The flow limiter includes a re-
`
`ceiving chaimel located on the infusion pump adjacent
`to the disposable cassette held by the infusion pump. A
`tube pincher is operatively associated with the receiv-
`ing channel to pinch the flow tube in a clamped position
`and mechanically retractable to an unclamped position
`to allow the flow tube to open. Electrical controls are
`connected for selectably operating the tube pincher
`from the clamped closed position to the unclamped
`opened position while the disposable cassette is held by
`the infusion pump. A flow clip is attached to the flow
`tube and is manually operable between opened and
`closed clipping positions prior to inserting the dispos-
`able cassette into the infusion pump. The flow tube and
`attached flow clip are prevented from being removed
`from the flow limiter mechanism unless the flow clip is
`in the closed clipping position.
`
`14 Claims, 5 Drawing Sheets
`
`ACTA EX. 1010-001
`
`ACTA Ex. 1010-001
`
`
`
`U.S. Patent
`
`M...A
`
`5«N1L.
`
`Sheet 1 of 5
`
`ACTA Ex 1010 oo2
`
`ACTA Ex. 1010-002
`
`
`
`U.S. Patent
`
`Aug. 1, 1995
`
`Sheet 2 of 5
`
`5,437,635
`
`G?)
`_ _'E
`
`i"
`
`0
`
`I
`
`_.—-—
`
`‘
`
`-9- L
`
`I
`
`"
`
`II?-=.—'7"P.—‘.'-'
`
`-————-F01
`
`ACTA EX. 1010-003
`
`ACTA Ex. 1010-003
`
`
`
`U.S. Patent
`
`Aug. 1,1995
`
`
`
`Sheet 3 of 5
`
`5,437,635
`
`ACTA EX. 1010-004
`
`ACTA Ex. 1010-004
`
`
`
`U.S. Patent
`
`%
`
`Aug. 1,1995
`
`Sheet 4 of 5
`
`5,437,635
`
`FIG.
`
`'7
`
`ACTA EX. 1010-005
`
`ACTA Ex. 1010-005
`
`
`
`U.S. Patent
`
`Aug. 1, 1995
`
`Sheet 5 of 5
`
`5,437,635
`
`94
`
`132
`
`66
`
`DOOR
`SENSOR
`TUBE
`
`SENSOR
`
`PINCHER
`POSI'l‘ION
`SENSOR
`
`144
`
`JMR
`
`SENSOR
`
`0
`
`14
`
`(
`
`142
`
`CENTRAL
`R
`P OCESSOR
`CONTROL
`PROGRAM
`
`148
`
`90
`
`74
`
`1o
`
`SOLENOH
`RELEASE
`sommom
`
`CONTROL
`
`INFUSION
`PUMPING
`MECHANISM
`
`ACTA EX. 1010-006
`
`ACTA Ex. 1010-006
`
`
`
`1
`
`5,437,635
`
`TUBE FLOW LIIVIITER, SAFETY FLOW CLIP, AND
`TUBE PINCHIER MECHANISM
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This is a continuation-in-part filed under 37 C.F.R.
`§1.53 of prior U.S. patent application Ser. No.
`07/880,642, filed May 6, 1992 now abandoned in the
`United States Patent and Trademark Office.
`
`10
`
`TECHNICAL FIELD OF THE INVENTION
`This invention relates to a flow limiter mechanism for
`an infusion pump and disposable cassette system, and in
`particular to a flow limiter mechanism which includes a
`clip for preventing fluid flow before the cassette is
`loaded into the pump and after the cassette is unloaded
`from the infusion pump and also includes a tube pincher
`associated with the infusion pump for selectively per-
`mitting or preventing fluid flow to a patient when the
`cassette is held in the infusion pump.
`BACKGROUND OF THE INVENTION
`
`15
`
`Infusion of fluids, such as drugs and plasma, into a
`patient is commonplace in the medical field. Two com-
`mon infusion methods are intravenous delivery of fluids
`by gravity and either intravenous or interarterial deliv-
`ery by mechanically pressurizing the fluids for delivery
`to the patient. Infusion pumps with disposable cassettes
`have been employed with the significant advantage of 30
`providing a simple disposable element in combination
`with a relatively straightforward pumping action.
`One infusion pump, which incorporates a cassette
`formed by bonding of two substantially flat sheets, has
`been disclosed in U.S. Pat. No. 4,657,490. With the use
`of such disposable cassettes the fluid to be infused into
`the patient comes into contact only with the cassette.
`The pumping mechanism itself does not contact the
`fluid. Thus, the cassettes and associated input and out-
`put tubing can be maintained in a sterile condition. The
`cassette and the tubing are disposed of and replaced
`between patients or between changes in the fluid to be
`infused. The new cassettes are loaded into an infusion
`pump having a cassette receiving section in which the
`cassette is operated upon by valve members and pump-
`ing members of the infusion pump. A pressure sensor
`monitors the pressure exerted on the cassette and an
`outlet restriction valve is controlled to maintain accu-
`racy of delivery. The pumping stroke is timed to obtain
`the desired flow rate. Pressure limits can be set beyond
`which pumping action will not be performed.
`Prior to the present invention, disposable cassette
`pumping systems have relied upon relatively inconve-
`nient tubing clamps to prevent unwanted flow through
`the cassette to the patient before the cassette was
`loaded, while the cassette was being loaded and after it
`was removed from the cassette receiving section of the
`pumping mechanism. Care and attention to the external
`tubing clamps had to be exercised to insure that the flow
`was completely terminated to avoid rapid or unmetered
`flow to the patient. When the cassette was loaded, the
`external clamps were released and the valves for re-
`stricting the flow through the cassette were primarily
`relied upon to accomplish a selected no-flow period of
`operation while the cassette remained in the pumping 65
`device.
`Various slide clamps which constrict or obstruct “V”
`lines are known, including a safety slide clamp as dis-
`
`2
`closed in Kozlo, U.S. Pat. No. 4,586,691, which com-
`prises a blade formed with a teardrop shaped aperture
`through which the tubing is positioned having an en-
`larged portion and a narrow portion. The enlarged
`portion allows flow through the tubing and tapers to the
`narrow portion which is engageable with the tubing to
`prevent flow therethrough. There is a retainer for sup-
`porting the blade and retaining the tubing so that the
`blade can be moved with respect to the tubing to and
`from the open and closed positions. The clamping blade
`can be removed from the retainer base only upon first
`placing the tube into the clamped position and may be
`received in the base only when the blade is in the
`clamped position.
`Another tube clamp is disclosed in U.S. Pat. No.
`4,689,043 for use in a peristaltic infusion pump. It in-
`cludes a slide clamp which constricts or obstructs the
`I.V. line similar to that as in Kozlo, however, the clamp
`is in that the clamp cannot be mounted into the infusion
`medical device unless the clamp is in the closed posi-
`tion. The device disclosed further cooperates with a
`handle which urges the clamp from a closed position to
`an open position when the tube is engaged in the peri-
`staltic pumping mechanism. The handle also automati-
`cally operates to urge the clamp from the open position
`to the closed position prior to and in preparation of the
`removal of the tube from the peristaltic pumping mech-
`anism.
`Other devices are formed, such as stop cock valves,
`directly in the fluid path within a cast structure inter-
`posed in the fluid path. The blade clamps are improve-
`ments over such in fluid path valve structures, however
`currently, such flow clip blade structures either operate
`automatically so that the flow is automatically opened
`upon installation of the I.V.
`tube into the pumping
`mechanism, or must be in a closed position before instal-
`lation of the clamp and flow tube into engagement with
`an infusion pump.
`Thus, none of the foregoing art possesses in combina-
`tion the advantages of the present invention in provid-
`ing a reliable mechanism with the capability of com-
`pletely and conveniently stopping the flow of fluid
`through a disposable cassette, either in or out of the
`pumping mechanism, such that the cassette cannot be
`installed unless the flow limiter is in place, such that the
`flow is automatically closed if the cassette is not held in
`an operable pumping position, such that the closing or
`opening of flow through the flow limiter is selectably
`controlled by the instrument programming when in-
`stalled, such that the cassette cannot be removed until
`the flow is closed, such that a clip on the removed
`cassette can be manually moved from closed to open
`flow and such that a cassette is installable into the pump
`whether it is manually clipped closed or opened.
`
`SUMMARY OF THE INVENTION
`In accordance with one embodiment of the invention,
`a reliable flow limiter mechanism is provided for com-
`pletely stopping flow through a disposable cassette and
`is sealed to inlet and outlet tubing. The flow limiter
`mechanism is operatively associated with an infusion
`pump and includes a tube pincher which automatically
`pinches the outlet tubing closed if a door holding the
`cassette in place is opened at any time. The tube pincher
`can be electrically opened and closed under software
`control of the fluid pumping mechanism. The flow
`limiter mechanism also includes a flow clip which is
`
`_
`
`ACTA EX. 1010-007
`
`ACTA Ex. 1010-007
`
`
`
`3
`
`5,437,635
`
`held on the outlet tubing with a carrier and is operable
`for manually closing the flow through the cassette
`while it is outside of the pumping mechanism of the
`infusion pump. The flow clip and carrier are designed
`for convenient installation onto the cassette. The flow
`clip and carrier are also conveniently insertable into
`cooperation with other portions of the flow limiter
`mechanism both when the flow clip is in a closed clip
`position and when it is in an open clip position. The
`flow clip and carrier cooperate as part of the flow lim-
`iter mechanism to prevent removal of the disposable
`cassette unless the flow clip is manually actuated into a
`closed clip position, thus preventing flow through the
`cassette.
`
`In accordance with another aspect of the present
`invention, an infusion pump is provided for pumping
`fluid to a patient for infusion. The pump includes a
`pumping mechanism, and a disposable cassette which is
`sealingly connected to inlet tubing and outlet tubing.
`The cassette is held in place adjacent the appropriate
`pumping mechanism by means of a closable door which
`latches in place. A flow limiter mechanism is mounted
`to the pump adjacent the pumping mechanism into
`which the cassette is received. The flow limiter mecha-
`nism includes a tube pincher comprising a channel into
`which the outlet tubing is held by the closable door.
`Interposed in the channel is a tube pincher arm which
`blocks insertion of the tubing while the tube pincher is
`in a closed position. The tube pincher arm is manually
`movable out of the channel by the operator for insertion
`of the cassette and outlet tube portion thereinto. Upon
`insertion of the cassette, the tube pincher arm is manu-
`ally released to close upon the outlet tube with suffi-
`cient compression force to stop the flow of fluid com-
`pletely. Upon closing the door into a latched position,
`the tube pincher arm is operable by electrical actuation
`selectively between an open and a closed position ac-
`cording to control circuitry associated with the pump-
`ing mechanism. The flow limiter mechanism further
`includes a flow clip which is attached and positioned on
`the outlet tubing of the cassette to be manually actuated
`by the operator outside of the pumping instrument se-
`lectively between an open and a closed position. The
`flow limiter mechanism further includes a receptacle for
`the flow clip, which, receptacle will receive the flow
`clip thereinto, whether it is in an open or a closed posi-
`tion, but which receptacle is designed in operative asso-
`ciation with the flow clip to prevent removal of the tube
`carrier and attached cassette unless the flow clip is in a
`closed position. Manually moving the flow clip to a
`closed position actuates the receptacle to allow re-
`moval.
`
`In accordance with yet another aspect of the present
`invention, the flow limiter mechanism includes a tube
`pincher mechanism which is mechanically biased as
`with a spring into a closed position. A portion of the
`tube pincher blocks insertion of the cassette when in a
`closed position. The bias can be overcome either
`through a manually pivotable lever arm or through a
`second pivotable lever arm actuated by an electrical
`solenoid. The electrical solenoid lever arm becomes
`mechanically latched in its open position after actua-
`tion; however, upon opening of the door, the latching
`mechanism is released so that the lever arm returns to its
`biased closed position. A directionally shaped carrier 65
`plate holds a flow clip oriented on a portion of tubing
`sealed to a cassette. A corresponding directionally
`shaped indentation is formed as a portion of a flow clip
`
`4
`receptacle in the flow limiter for receiving the carrier
`adjacent
`to the pumping mechanism of an infusion
`pump. The carrier plate securely holds the tubing and
`slidably holds the flow clip for manual movement with
`respect to the tubing perpendicular to the direction of
`the tubing. The flow clip defines an orifice there-
`through sized for non-restrictive passage of the tubing.
`The flow clip further defines a narrow slit extending
`from the orifice and having opposed inwardly facing
`surfaces sufficiently closely spaced such that the tubing
`can be forced therebetween, to thereby close off the
`tubing. Thus, when the clip is slid into a first position,
`the tubing is aligned with the orifice so that the tubing
`is open, and when the clip is slid to a second position,
`the tubing becomes lodged between the inwardly facing
`surfaces of the slit so that the tubing is closed. An auto-
`matic gripping means is operatively associated with the
`carrier, the flow clip, and the flow clip receptacle so
`that it releases the carrier only when the flow clip is in
`the closed position with the tubing crimped therebe-
`tween. Thus, after the flow clip and carrier are received
`in the receptacle and directional indentation of the flow
`limiter mechanism, it can only be removed when the
`flow clip is manually closed.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`A more complete understanding of the invention may
`be had by reference to the following detailed descrip-
`tion and claims, when taken in conjunction with the
`accompanying drawings, in which like numerals repre-
`sent like elements, and wherein:
`FIG. 1 is a schematic representation of an infusion
`pump with the flow limiter mechanism mounted adja-
`cent to the pumping mechanism and cassette receiving
`portion of the infusion pump;
`FIG. 2 is a schematic plan view of a disposable cas-
`sette having a flow tube attached and upon which the
`flow limiter of the present invention acts;
`FIG. 3 is an assembled plan view of the flow limiter
`mechanism according to the present invention;
`FIG. 4 is a top plan view of the flow limiter and tube
`pincher mechanism according to the present invention;
`FIG. 5 is a top plan view of the flow limiter tube clip
`receptacle and gripping mechanism according to the
`present invention;
`FIG. 6 is a front plan view of the flow limiter tube
`clip receptacle and gripping mechanism according to
`the present invention;
`FIG. 7 is a perspective view of the flow tube clip and
`carrier plate mounted on the flow tubing;
`FIG. 8 is a cross-sectional view of the flow clip and
`carrier of FIG. 7 taken line 8-8;
`FIG. 9 is a cross-sectional view of the flow clip and
`carrier of FIG. 8 taken along line 9-9; and
`FIG. 10 is a schematic block diagram of a control
`circuit for the flow limiter according to the present
`invention.
`-
`
`DETAILED DESCRIPTION OF THE
`DRAWINGS
`
`In FIG. 1, infusion pump 10 is shown schematically in
`a perspective view. The infusion pump 10 has a pump-
`ing mechanism 11 in a cassette receiving section 12 and
`a means for holding the cassette in operable position,
`such as door 14. Door 14 has a latch 16, which may, for
`example, comprise a male latch portion 16a and a female
`portion latch portion 16b, or other suitable latching
`mechanism, to hold door 14 securely in place for opera-
`
`ACTA EX. 1010-008
`
`ACTA Ex. 1010-008
`
`
`
`5,437,635
`
`5
`tion of the infusion pump. An exposed portion of a flow
`limiter assembly 20 is shown in a position adjacent the
`cassette receiving section 12, in the outlet flow direc-
`tion. Flow limiter assembly 20 includes a tube pincher
`22 and a loading button '24 which cooperates with the
`internal mechanism of the fluid flow limiter assembly as
`will be more fully understood with reference to FIGS.
`3 and 4 below. There is an outlet tube receiving channel
`26 adjacent the pumping mechanism of the infusion
`P“mP-
`A disposable-cassette 30 is shown in a schematic plan
`view in FIG. 2. It includes a refill reservoir 32, a deliv-
`ery pumping chamber 34, and sealingly attached inlet
`tubing 36 and outlet tubing 38. A flow clip carrier 40
`carries a flow clip 42 which is slidingly received and
`held by the flow clip carrier 40. The flow clip carrier 40
`has a shape 44 for alignment with a corresponding re-
`ceptacle 28 which has a correspondingly shaped inden-
`tation 46 for alignment of the flow clip carrier therein.
`The flow clip carrier 40 is positioned along a flow tube,
`such as outlet tube 38 with a positioning attachment 48.
`Positioning attachment 48 may, for example, be con-
`structed for plastic welding or adhesion to the output
`tubing 38.
`With reference to FIG. 3 which is a front plan view
`and to FIG. 4 which is a top plan view of the fluid flow
`limiter assembly 20, the construction may be more fully
`understood. A tube pincher 22 includes a tube pincher
`lever 52 which is attached to a mechanical actuator 54.
`The mechanical actuator 54 interacts with and is con-
`tacted by loading button 24 (shown in FIG. 1). A spring
`bias 56 is attached to a pincher lever spring arm 58 for
`holding the tube pincher lever 52 downwardly into a
`slot 60 formed partially into channel 26. A support anvil
`63 is formed along channel 26 adjacent the slot 60 to
`support a flow tubing against pinching pressure exerted
`by lever 52. A portion 23 of the tube pincher lever 52 is
`interposed into the flow tube channel 26 and the tube
`pincher lever 52 is mounted about a pivot mount 62,
`such that the bias spring 56 pivots the pincher portion
`23 of tube lever 52 into a downward or closed position.
`Upon manual actuation of the loading button 24, the
`mechanical actuator 54, which cooperates with the
`loading button 24, is actuated, thereby pivoting tube
`pincher lever 52 and portion 23 thereof upward out of 45
`the outlet tube channel 26. This allows the cassette 30 to
`be inserted into the receiving section 12 and the carrier
`40 to be received within receptacle 28. Upon releasing
`button 24, lever arm 52 is pivoted through the bias
`action of spring 56 into a downward or pinched closed
`position. Spring 56 acts through pincher lever spring
`arm 58 with sufficient force to clamp the outlet tubing
`completely closed, and to eliminate flow therethrough,
`even with internal fluid pressures equivalent to 750
`mmHg, or greater. Preferably, the mechanical advan-
`tage of the lever 52, actuator 54, and button 24 over-
`comes the bias of spring 56 with a conveniently applied
`force, preferably about five pounds force, or less.
`Attached to lever arm 52 is a position tab 64, which
`interacts with a position detector 66 so that the position
`of the lever arm can be electrically monitored through
`electrical position sensor signal wires 68.
`Rigidly attached to pincher lever 52 is a lifting plate
`72 for purposes of actuating the lever arm 52 or the tube
`pincher 22 through electrical control. The electrical
`control may be provided with a solenoid 70 which is
`activated to first and second positions with control
`wires 74. The solenoid piston 76 acts through attach-
`
`6
`’
`ment pin 78 upon lifting lever 80 which is pivotably
`held mounted at 82 and appropriately spaced from the
`base plate 50 with mounting cylinder 84. A contact pad
`86 is formed at the opposite end of lifting lever 80 from
`attachment pin 78. Contact pad 86 contacts the lifting
`plate 72 upon retraction of solenoid piston 76. Contact
`pad 86 may have a rounded bearing cap 88 to permit
`reduced friction contact with the underside of lifting
`plate 72. Thus, when solenoid piston 76 is in its extended
`position as shown, the lever arm 52 is biased with spring
`56 to a downward or clamped closed position. Upon
`actuation of solenoid 70, piston 76 retracts and pivots
`about pivot mount 82 so that the contact pad 86, acting
`through rounded cap 88, lifts against lifting plate 72
`thereby raising the clamping arm portions 23 away from
`anvil 63 and out of the tube channel 26. A position latch
`mechanism 90 holds the lever arm in its upward position
`against the bias of spring 56 and also against the bias of
`solenoid spring 92, even when electrical power through
`wire 74 is discontinued.
`For safety purposes, position latch mechanism 90 is
`constructed and interconnected with the door latch 16
`so that if the door is opened to the infusion pump, latch
`90 mechanically forces the release of lifting arm 80 and
`pincher portion 23 again pinches the outlet tube to pre-
`vent further fluid flow, as such flow would then no
`longer be controlled by the pumping action of the infir-
`sion pump. A door sensor 94 is also provided and is
`interconnected through control wires 96 through a
`control circuit to control wires 74 of the solenoid so
`
`that upon opening of the door 14, as by unlatching latch
`mechanism 16, the solenoid 72 is electrically released.
`The construction and operation of the flow clip, the
`carrier receptacle 28 and a clip gripping mechanism 96
`can be further understood with reference to FIGS. 5
`and 6, in which FIG. 5 is a top partially exploded plan
`view of receptacle 28. FIG. 6 is an end view of recepta-
`cle 28. A pair of gripping arms 98 having gripping
`hooks 100 and tail portions 102 which gripping arms are
`pivotably held at 108 and 110 within opposed slots 104
`and 106 so that they pivot. The gripping arms 98 are
`biased as with a spring bias means 112 such that the
`gripping hooks 100 are exterior to a flow clip receiving
`chamber 114, which receiving chamber 114 is posi-
`tioned and sized to allow perpendicular sliding motion
`of a flow clip 42 thereinto. When flow clip 42 is inserted
`completely into the chamber 114, flow clip sides 124
`contact tail portions 102 of gripping arms 98 so that the
`gripping hooks 100 are moved inwardly against the
`flow clip carrier 40 and engage detent portions 116
`formed on opposed sides of the carrier 40 adjacent the
`slidable flow clip 42.
`FIG. 7 is a perspective view of the flow clip and
`carrier attached to a portion of an outlet tubing 38,
`which carrier, clip, and tubing is received and aligned
`within receptacle 28. FIGS. 8 and 9 are cross-sectional
`views of the flow clip. There is an orifice 118 through
`clip 42, which orifice 118 is sized and aligned for pas-
`sage of tube 38 therethrough perpendicular to the slid-
`ing direction of clip 42. The flow clip 42 further defines
`a narrow slit 120 extending from orifice 118, which
`narrow slit 120 has opposed inwardly facing surfaces
`122 and 124 which are sufficiently closely spaced such
`that the outlet tubing can be forced therebetween to
`thereby close off the tubing. Preferably, only a conve-
`nient amount of relative force between the tube and clip
`42, such as a force of less than about five pounds, is
`required to slide a tube into the slit. Upon sliding the
`
`ACTA EX. 1010-009
`
`ACTA Ex. 1010-009
`
`
`
`-
`
`7
`clip 42 toward the orifice 118, compression force on the
`tubing is released and it is in an open flow position.
`Sliding the clip 42 into channel 114 results in tubing
`38 engaging tube charmel 26 so that the clip is moved
`with respect to the tube to the orifice open position. The
`side walls 124 of clip 42 engage tail portions 102 of the
`gripping arms 98 and push the gripping hooks 100 into
`gripping detents 116. The contact between the sides 124
`of the clip 42 and the tail portions 102 of the gripping
`arms 98 keep the hooks 100 engaged while clip 42 is in
`its open flow position. In this position as described
`above, the tube pincher mechanism 22 is then activated
`as described with respect to FIGS. 3 and 4 until such
`time as cassette 30 is replaced.
`To remove cassette 30, it is necessary to release the
`gripping hooks 100 from detents 116. This is accom-
`plished by pulling the flow clip 42 outward with respect
`to carrier 40. Carrier 40 is automatically held in place
`with hooks 100 until the end 128 of clip 42 moves be-
`yond the tail portions 102 of gripping arms 98. Arms 98
`pivot automatically, due to bias spring 104, so that
`hooks 100 retract from detents 116 and carrier 40 is
`released. Sliding clip 42 relative to tubing 38 in this
`manner will force the tubing 38 into slit 120, clipping it
`closed between surfaces 122 and 123. Thus, before re-
`moving the cassette 30, the flow clip 42 must be placed
`into a closed flow position. Also, the tube pincher 22
`will be in a closed position due to the opening of door
`14. Button 24 can then be manually depressed to lift
`pincher arm 52 away from tube 38 to complete removal
`of cassette 30.
`
`Carrier 40 may be inserted into receptacle 20 whether
`the flow clip is in a closed or open position; if in a closed
`position, the engagement of hooks 100 will take place
`upon pushing flow clip 42 completely into slide cham-
`ber 114. Arms 98 will automatically be pushed into
`detents 116. If, however, flow clip 42 is in the open
`position upon insertion, pivot mechanism 130 has suffi-
`cient resiliency to allow hooking arms 98 to move out-
`wardly until hooks 100 drop into detents 116, thereby
`effecting carrier latching once again.
`With reference again to FIG. 3, tubing engagement
`sensors 132 and 134 are provided. Sensors 132 and 134
`may be a light source and a light receptor photocell,
`respectively,
`to detect the presence of a tubing 38
`within tubing channel 26. Blockage of direct light indi-
`cates engagement of a tube 38 and carrier 40 within
`receptacle 28.
`Removal of flow clip 40 from receptacle 28 is assisted
`by a spring 138 in a channel 136, as shown in FIG. 5,
`formed at the back of chamber 114. Spring arm 138
`biases the flow clip slightly in an outward direction to
`facilitate ease of removal and to further facilitate firm
`engagement against hooks 100.
`A schematic diagram of a control circuit 140 is de-
`picted in FIG. 10. In the control circuit 140, there is a
`door sensor 94 which provides a signal to central pro-
`cessor 142. Sensor 132 also provides a signal to the
`central processor to indicate insertion of carrier 40.
`Pincher position sensor 66 signals a closed or open tube
`pincher position. If desired, an air sensor 144 may be
`provided to detect air bubbles or voids in the flow tube
`38. Each of these sensors detect essentially either a
`“yes” or a “no” condition. Door sensor 94 signals
`whether the door 14 is opened or whether it is closed.
`Flow carrier sensor 132 signals whether the carrier is
`properly loaded or whether it is not. Position sensor 66
`signals whether the tube pincher is in a closed or an
`
`5,437,635
`
`8
`open position. Air sensor 144 signals whether there is
`air in the fluid flow or no air. These signals are provided
`to the central processor 142 which acts upon the pro-
`vided information according to a program 148 which,
`for example, may be contained in software, on a com-
`puter chip, may be entered by an operator through a
`keyboard, or the like. The signal from door sensor 94 is
`preferably acted upon by the central processor 142
`according to a program to electrically enable the sole-
`noid 70 for energization by control wires 74 and also to
`enable the infusion pumping mechanism. The signal
`from carrier sensor 132 is also used to enable the infu-
`sion pumping mechanism such that if either the door 14
`is unlatched or the carrier 40 is not properly loaded into
`the flow carrier receptacle 28, then pumping action will
`not be initiated and/or an appropriate alarm signal will
`be given to the operator so that corrective action can be
`taken. Once the carrier 40 is properly loaded and the
`door is properly closed, then the signal from pincher
`position sensor 66 is received by the central processor
`142 to energize the solenoid 70 from a closed to an open
`position or from an open to a closed position according
`to the program 148. The pincher position sensor 66
`confirms that the desired action takes place and if con-
`firmation is not received, an appropriate alarm signal
`may be activated. Further, if the pincher position sensor
`66 detects that the pincher is in a closed position, then
`the pump mechanism may be disabled to avoid over-
`pressurizing the cassette and overworking the pump
`mechanism due to inordinately high pressures caused by
`the closed tube pincher.
`The air sensor 144 can also be used to provide the
`central processor 142 with information, and if air is
`sensed for a significant period of time, then the central
`processor can respond by disabling the pump and by
`activating the solenoid control
`to close the tube
`pincher, to allow the pincher arm 23 to close. Further,
`an appropriate alarm may be energized to notify the
`operator of the occlusion condition so that corrective
`measures may be taken.
`Thus, what has been disclosed is a tube flow limiter
`mechanism having a tube pincher mechanism and a
`safety flow clip which cooperate to provide a mecha-
`nism which reduces the possibility for unchecked free
`fluid flow and which is conveniently operable and sub-
`stantially manually actuated to secure non-flow condi-
`tion unless manually actuated to open the flow or actu-
`ated through electrical control to allow flow there-
`through.
`Other alterations and modifications of the invention
`will likewise become apparent to those of ordinary skill
`in the art upon reading the present disclosure, and it is
`intended that the scope of the invention disclosed herein
`be limited only by the broadest interpretation of the
`appended claims to which the inventors are legally
`entitled.
`What is claimed is:
`
`1. A flow limiter mechanism in an infusion pump of
`the type having a channel for receiving a flow tube
`connected to a disable pumping cassette, said flow lim-
`iter mechanism comprising:
`a) a tube pincher operatively associated with said
`receiving channel, said tube pincher having a
`clamped position to stop flow in said flow tube
`received in said receiving channel, and said tube
`pincher having an unclamped position to allow
`flow in said flow tube, and which tube pincher is
`mechanically retractable to an unclamped position;
`
`ACTA EX. 1010-010
`
`ACTA Ex. 1010-010
`
`
`
`5,437,635
`
`10
`tion and for releasing said clip carrier when said
`flow clip is in said closed clipping position.
`5. A flow limiter mechanism as in claim 1 wherein
`
`9
`b) electrical controls for selectably operating said
`tube pincher from said clamped position to said
`unclamped position while said flow tube connected
`to said disposable cassette is received in said receiv-
`ing channel of said infusion pump;
`c) a flow clip attached to said flow tube manually
`operable between opened and closed clipping posi-
`tions prior to receiving said flow tube into said
`receiving channel; and
`d) means cooperatively associated between said flow
`clip and said receiving channel for preventing re-
`moval of said flow tube from said receiving chan-
`nel when