(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/0019310 A1
`Hogendijk
`(43) Pub. Date:
`Jan. 29, 2004
`
`US 2004001931 OA1
`
`(54) BLOOD ASPIRATION SYSTEMAND
`METHODS OF USE
`(76) Inventor: Michael Hogendijk, Palo Alto, CA
`(US)
`Correspondence Address:
`NICOLA A. PISANO, ESQ.
`LUCE, FORWARD, HAMILTON & SCRIPPS,
`LLP
`11988 EL CAMINO REAL
`SUTE 200
`SAN DIEGO, CA 92130 (US)
`(21) Appl. No.:
`10/209,207
`(22) Filed:
`Jul. 29, 2002
`Publication Classification
`
`(51) Int. Cl." ......................... A61M 35/00; A61M 37/00
`
`(52) U.S. Cl. .................................................................. 604/1
`
`(57)
`
`ABSTRACT
`
`The present invention is directed to a blood aspiration
`System that is configured to enable various types of aspira
`tion through a working lumen of a catheter. The blood
`aspiration System facilitates natural aspiration by providing
`a circuit between a patients arterial and Venous vasculature,
`and also comprises a manually actuated pump configured to
`Selectively vary rates of aspiration in the working lumen.
`The blood aspiration System further comprises an external
`port that allows Suction-assisted aspiration or infusion
`through the working lumen, and further comprises a detach
`able filter that removes emboli prior to reperfusing blood
`into a patient's venous vasculature.
`
`
`
`50
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`55
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`Page 1
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`IPR2020-00126/-127/-128/-129/-130/-132/-134/-135/-136/-137/-138
`
`Medtronic Ex-1809
`Medtronic v. Teleflex
`
`

`

`Patent Application Publication
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`Jan. 29,2004 Sheet 1 of 8
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`Patent Application Publication
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`Jan. 29, 2004 Sheet 2 of 8
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`Patent Application Publication
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`Patent Application Publication Jan. 29, 2004 Sheet 5 of 8
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`Patent Application Publication Jan. 29, 2004 Sheet 6 of 8
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`Patent Application Publication
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`Jan. 29, 2004 Sheet 7 of 8
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`Patent Application Publication Jan. 29, 2004 Sheet 8 of 8
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`US 2004/001931.0 A1
`
`Jan. 29, 2004
`
`BLOOD ASPRATION SYSTEMAND METHODS
`OF USE
`
`FIELD OF THE INVENTION
`0001. The present invention relates to a blood aspiration
`System for use in conjunction with a catheter during a
`medical procedure, and more specifically, a System that is
`configured to provide a working lumen of the catheter with
`Substantially continuous natural aspiration and, optionally,
`pump-assisted aspiration.
`
`BACKGROUND OF THE INVENTION
`0002 Today there is a growing need to provide controlled
`access and vessel management during Such procedures as
`Stenting, atherectomy or angioplasty. Generally during these
`procedures there is a high opportunity for the release of
`embolic material. The emboli may travel downstream from
`the occlusion, lodging deep within the vascular bed and
`causing ischemia. The resulting ischemia may pose a Serious
`threat to the health or life of a patient if the blockage forms
`in a critical area, Such as the heart, lungs, or brain.
`0003. Several previously known methods and apparatus
`incorporate the use of an external Suction System in con
`junction with an aspiration catheter for removal of the clot
`and/or removal of embolic particles. However, several dis
`advantages arise when using an external Suction System as
`the Sole means for flow management within a vessel. First,
`it may be difficult to establish the proper aspirating pressure
`required at the treatment Site, and external preSSure adjust
`ments used with Suction pumps may lead to an incorrect
`amount of Suction for a given set of circumstances. If the
`amount of Suction is too low for the circumstances, then
`embolic particles may not be effectively removed and may
`travel downstream from the original occlusion, leading to
`further occlusive events. If the amount of Suction is too high,
`the vessel may collapse.
`0004 Moreover, if an external suction pump is utilized,
`retrieval of downstream emboli may require a flow rate that
`cannot be sustained by the vessel wall for more than a few
`Seconds, resulting in insufficient removal of emboli. Addi
`tionally, continuous use of an external Suction pump may
`result in excessive blood loSS, requiring infusion of non
`autologous blood and raising related Safety issues.
`0005 Furthermore, use of an external Suction pump
`generally requires drawing fluid from a patient's vessel and
`then reintroducing the fluid back into a filter using a three
`way Stopcock. This cumberSome technique may cause injury
`to blood cells and may limit the ability of the physician
`while performing the procedure.
`0006 Other methods for embolic removal have relied on
`more natural aspirating effects. For example, previously
`known devices have relied on the preSSure differential
`between the atmosphere and blood flow in a treatment vessel
`to cause a reversal of flow in the treatment vessel. However,
`Such natural aspiration techniques may provide insufficient
`flow to effectively remove emboli.
`0007. In view of these drawbacks of previously known
`Systems, it would be desirable to provide a blood aspiration
`System that allows a catheter to achieve a Substantially
`continuous rate of natural, physiologically-regulated aspira
`tion through a working lumen of the catheter.
`
`0008. It also would be desirable to provide a blood
`aspiration System that provides an appropriate rate of retro
`grade flow at a treatment Site to direct dislodged particles
`into a catheter for efficient removal without damaging the
`treatment vessel.
`0009. It further would be desirable to provide a blood
`aspiration System having an easy to use pump that Selec
`tively may be used, in conjunction with natural aspiration
`techniques, to further influence flow in a treatment vessel.
`0010. It yet further would be desirable to provide a blood
`aspiration System that provides a Suction/infusion port that
`optionally may be used to further influence aspiration in the
`catheter lumen and/or to infuse drugs or agents into the
`catheter lumen.
`0011. It still further would be desirable to provide a blood
`aspiration system that allows emboli to be filtered and blood
`reperfused into a patient's vessel to reduce blood loss.
`
`SUMMARY OF THE INVENTION
`0012. In view of the foregoing, it is an object of the
`present invention to provide a blood aspiration System that
`allows a catheter to achieve a Substantially continuous rate
`of natural, physiologically-regulated aspiration through a
`working lumen of the catheter.
`0013. It is also an object of the present invention to
`provide a blood aspiration System that provides an appro
`priate rate of retrograde flow at a treatment site to direct
`dislodged particles into a catheter for efficient removal,
`without damaging the treatment vessel.
`0014.
`It is a further object of the present invention to
`provide a blood aspiration System having an easy to use
`pump that Selectively may be used, in conjunction with
`natural aspiration techniques, to further influence flow in a
`treatment vessel.
`0015. It is still a further object of the present invention to
`provide a blood aspiration System that provides a Suction/
`infusion port that optionally may be used to further influence
`aspiration in the catheter lumen and/or to infuse drugs or
`agents into the catheter lumen.
`0016. It is yet a further object of the present invention to
`provide a blood aspiration system that allows emboli to be
`filtered and blood reperfused into a patient's vessel to reduce
`blood loss.
`0017. These and other objects of the present invention are
`accomplished by providing a blood aspiration System that is
`configured to enable three types of aspiration through a
`working lumen of a catheter. The blood aspiration System
`enables a Substantially continuous rate of natural, physi
`ologically-regulated aspiration through the working lumen
`using an arterial-venous shunt and, optionally, pump-as
`Sisted or Suction-assisted aspiration through the catheter
`lumen. This allows a physician to provide a Substantially
`continuous rate of retrograde flow in a treatment vessel
`during a medical procedure, while allowing a physician to
`further influence the rate of aspiration within the vessel.
`0018. In a preferred embodiment, the blood aspiration
`System of the present invention comprises a manifold having
`an inlet port in fluid communication with the working lumen
`of the catheter and an outlet port that preferably is coupled
`
`Page 10
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`

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`US 2004/001931.0 A1
`
`Jan. 29, 2004
`
`to a patient's venous vasculature. The blood aspiration
`System further comprises a manually actuated pump includ
`ing a housing having a lumen and a plunger disposed within
`the lumen. The manifold further preferably comprises a
`plurality of valves, described hereinbelow, that are config
`ured to channel flow through the manifold exclusively in one
`direction when the pump is actuated.
`0019. In operation, the outlet port preferably is coupled to
`a venous return sheath, which is adapted to be disposed in
`a remote vein. When the venous return sheath is disposed in
`the remote vein, and when an occlusive element of the
`catheter is deployed in a patient's artery, a preSSure differ
`ential between venous and arterial pressure will cause blood
`to flow in a retrograde fashion in the artery. This natural,
`physiologically-regulated aspiration through the manifold
`preferably occurs before, during and after a medical proce
`dure performed through the working lumen of the catheter to
`effectively remove thrombi and/or emboli from the vessel.
`0020. The manifold preferably comprises a slide valve
`disposed between the inlet port and the outlet port. The slide
`Valve preferably comprises a block having a bore that
`selectively directs fluid flow between the inlet port and the
`outlet port when the plunger is in an advanced position.
`When the plunger is retracted, a Spring pushes the block
`proximally to cause the Slide valve to be in a closed position
`whereby natural aspiration is temporarily inhibited.
`0021 Additional aspiration selectively may be provided
`through the working lumen of the catheter using the pump.
`When the Slide valve is in the closed position and natural
`aspiration is temporarily inhibited, the retraction of the
`plunger draws fluid into a pump chamber formed between a
`first check valve and the plunger. AS fluid is drawn into the
`pump chamber, increased rates of aspiration within the
`working lumen of the catheter are provided. The physician
`then may distally advance the plunger to cause fluid to flow
`from the pump chamber, through a Second check valve and
`into the outlet port.
`0022. If desired, suction-assisted aspiration also selec
`tively may be applied using a Suction/infusion port coupled
`to the manifold. Alternatively, a Syringe may be coupled to
`Suction/infusion port to infuse Saline, drugs or other thera
`peutic agents to the treatment Site.
`0023 The apparatus of the present invention further
`preferably comprises a detachable filter chamber coupled to
`the manifold. Blood exiting through the outlet port of the
`manifold flows into the filter chamber and through a filter,
`prior to being reperfused into a remote vein. The filter
`chamber is detachable from the manifold to allow filtered
`emboli to be Studied and characterized.
`0024 Methods of using the apparatus of the present
`invention also are provided.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0.025
`Further features of the invention, its nature and
`various advantages will be more apparent from the accom
`panying drawings and the following detailed description of
`the preferred embodiments, in which:
`0.026
`FIGS. 1A-1B provide side and side sectional views
`of a blood aspiration System in accordance with principles of
`the present invention;
`
`0027 FIG. 2 provides a side view of a catheter apparatus
`that may be used in conjunction with the blood aspiration
`system of FIG. 1;
`0028 FIG. 3 provides a side view illustrating features of
`a detachable filter chamber of the present invention;
`0029 FIGS. 4A-4C are, respectively, side views of a
`check valve of the present invention in open and closed
`positions, and a croSS-Sectional view along line A-A of FIG.
`4A,
`0030 FIGS. 5A-5C are perspective views illustrating
`Slide valves that may be used in accordance with the present
`invention; and
`0031 FIGS. 6A-6C describe a preferred method of using
`the apparatus of FIG. 1 in accordance with the principles of
`the present invention.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`0032. The present invention is directed to a blood aspi
`ration System that is configured to enable natural aspiration
`through a working lumen of a catheter and, optionally,
`pump-assisted aspiration through the working lumen. The
`blood aspiration System enables a Substantially continuous
`rate of natural, physiologically-regulated aspiration through
`the working lumen by enabling fluid communication
`between the working lumen and a patient's venous vascu
`lature. The blood aspiration system further comprises a
`manually actuated pump provided to allow increased rates of
`aspiration through the working lumen. The provision of
`Substantially continuous retrograde flow and, optionally,
`Selectively increased rates of retrograde flow at a treatment
`Site facilitates removal of emboli during an interventional
`procedure while minimizing trauma to the treatment vessel.
`0033 Referring now to FIG. 1, features of a blood
`aspiration System constructed in accordance with principles
`of the present invention are described. Blood aspiration
`system 20 preferably comprises manifold 50 having inlet
`port 54 and outlet port 55, and further comprises pump 60
`coupled to manifold 50. Blood aspiration system 20 prefer
`ably further comprises arterial line 30, venous line 40, and
`filter chamber 70, which are coupled to manifold 50 and
`pump 60 as described hereinbelow.
`0034 Blood aspiration system 20 may be used in con
`junction with a catheter, e.g., as illustrated in FIG. 2 by
`catheter 21 having proximal and distal ends and working
`lumen 23 extending therebetween. Catheter 21 preferably is
`coupled to blood outlet port 27, which is in fluid commu
`nication with working lumen 23, inflation port 25, which
`may be used to inflate occlusion member 22, and hemostatic
`port 26, which may be used to advance instruments into
`working lumen 23. In operation, blood outlet port 27 is
`coupled to blood inlet port 34 of arterial line 30 of FIG. 1
`to establish fluid communication between working lumen 23
`and lumen 33 of arterial tubing 32.
`0035) Lumen 33 of arterial tubing 32 preferably is
`coupled to inlet tubing 56 of manifold 50 at manifold inlet
`port 54, as shown from a side sectional view in FIG. 1B.
`Inlet tubing 56 of manifold 50 also is in fluid communication
`with Suction/infusion port 52, and further is in fluid com
`
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`
`Jan. 29, 2004
`
`munication with first check valve 80 and slide valve 100, as
`described in greater detail hereinbelow.
`0036) Manifold outlet port 55 preferably is coupled to
`threaded cap 75 of filter chamber 70. As described in greater
`detail hereinbelow, blood flowing into filter chamber 70
`from manifold outlet port 55 flows through filter entrance 71
`and through filter 72. Filtered blood then exits filter chamber
`70 through filter exit port 73, which preferably is coupled to
`venous line 40. Filter exit port 73 allows for fluid commu
`nication between filter chamber 70 and lumen 43 of venous
`tubing 42. Blood flowing through venous tubing 42 then
`exits through blood outlet port 44, which may be coupled to
`a venous return sheath (not shown) that is adapted to be
`inserted into a patient's venous vasculature. A Suitable
`venous return sheath is described in commonly-assigned
`U.S. patent application Ser. No. 09/418,727, now U.S. Pat.
`No. 6,423,032, which is incorporated herein by reference in
`its entirety.
`0037. In accordance with principles of the present inven
`tion, blood aspiration System 20 may be used in conjunction
`with catheter 21 of FIG. 2 during a medical procedure to
`provide a Substantially continuous rate of natural, physi
`ologically-regulated aspiration through working lumen 23.
`0.038. In particular, catheter 21 may be disposed in a
`patient's artery and occlusive element 22 may be deployed
`to occlude flow in the artery. The natural aspiration may be
`provided through working lumen 23 when a venous return
`sheath (not shown), which is coupled to blood outlet port 44,
`is introduced into a remote vein. Once this arterial-venous
`circuit is established, negative pressure in Venous line 40
`during diastole will establish a low rate continuous flow of
`blood through working lumen 23 of catheter 21, to the
`patient's vein Via the venous return line.
`0.039
`Specifically, the arterial-venous circuit allows
`blood flow in the patient’s artery that is distal of occlusive
`element 22 to flow in a retrograde fashion through working
`lumen 23 and blood outlet port 27 of FIG. 2, through arterial
`line 30 and manifold inlet port 54, through slide valve 100
`(when slide valve 100 is in an open position), through
`manifold outlet port 55, filter chamber 70, venous line 40,
`through the venous return sheath coupled to blood outlet
`port 44 and back into the remote vein. This method, which
`utilizes the difference between venous and arterial preSSure,
`may be used to provide a Substantially continuous rate of
`aspiration at a treatment site before, during and after a
`medical procedure to ensure that emboli generated during
`the procedure are directed into working lumen 23 for Safe
`removal. Emboli are captured by filter 72 so that filtered
`blood may be reperfused into the remote vein.
`0040. With retrograde flow established in the selected
`artery via the venous return sheath, a medical procedure may
`be performed through hemostatic port 26 and working
`lumen 23 of catheter 21. At any time before, during or after
`the medical procedure, additional aspiration may be pro
`vided at the treatment site via a Syringe (not shown) coupled
`to Suction/infusion port 52. It is preferred that the additional
`Suction provided by the Syringe only be used in conjunction
`with the above-described natural aspiration technique for a
`limited period of time, e.g., at the time a vascular lesion is
`being traversed or disrupted, to ensure that trauma to the
`vessel wall due to the external Suction is reduced. Alterna
`tively, the Syringe may be used to temporarily establish
`
`antegrade flow, e.g., to infuse contrast agents, drugs, lytic
`agents or other therapeutic agents, when Slide valve 100 is
`in a closed position, as described hereinbelow.
`0041. In accordance with principles of the present inven
`tion, blood aspiration system 20 further comprises pump 60
`having housing 61 and plunger 62 disposed within lumen 66
`of housing 61, as shown in FIG. 1B. Plunger 62 comprises
`a proximal end having handle 63, which is configured to be
`grasped by a physician, and a distal end having tip 64.
`Plunger 62 is configured So that there is a Small amount of
`friction between an outer Surface of plunger 62 and an
`interior surface of housing 61. The friction holds plunger 62
`in place within housing 61 without the need for an external
`force. However, the small amount of friction may be over
`come when an external force is applied, e.g., when plunger
`62 is retracted by a physician for purposes described here
`inbelow.
`0042. Referring now to FIG. 3, filter chamber 70 is
`shown detached from manifold 50 preferably by unscrewing
`threaded cap 75 from its engagement with a grooved interior
`section (not shown) of manifold outlet port 55. At this time,
`emboli captured within filter 72 may be studied and char
`acterized for diagnostic purposes. Filter chamber 70 then
`may be reattached to manifold 50 by screwing threaded cap
`75 into engagement with the grooved interior Section of
`manifold outlet port 55.
`0043 Referring now to FIG. 4, features of first and
`second one-way check valves 80 and 90 of FIG. 1B are
`described. In FIG. 4A, components of first check valve 80
`are identical to those provided for second check valve 90,
`and reference numerals 80-88 that are used to illustratively
`describe first check valve 80 corresponds to numerals 90-98
`that are used to describe the operation of Second check valve
`90 in FIGS. 6A-6C hereinbelow.
`0044) First check valve 80 preferably comprises inlet port
`81 having taper 86 disposed at a first end of the valve and
`exit ports 83 disposed at a second end, as shown in FIG. 4A.
`First check valve 80 preferably comprises ball 82 that is
`contained within plurality of ball guides 84, which allow
`longitudinal movement of ball 82 within the valve. Aper
`tures 88 are formed between ball guides 84, ball 82 and an
`exterior Surface of check valve 80, as shown in a cross
`Sectional view in FIG. 4C.
`0045 First check valve 80 is configured to permit flow
`through the valve in only one direction, as illustrated by the
`arrows in FIG. 4A. When flow occurs in this direction, fluid
`flow passes through inlet port 81 to push ball 82 towards the
`Second end of the valve. With ball 82 at the second end, fluid
`passes around ball 82, through apertures 88 and out exits
`ports 83. When flow occurs in the opposite direction, how
`ever, ball 82 is configured to prohibit flow from passing
`through the valve. Specifically, when fluid enters through
`exit ports 83 in the direction shown in FIG. 4B, ball 82 is
`pushed toward the first end and plugs against taper 86 and/or
`inlet port 81 to prohibit flow through inlet port 81. In this
`manner, first and second check valves 80 and 90 are used,
`respectively, to prohibit a reversal of flow through manifold
`inlet port 54 and direct flow in a direction toward manifold
`outlet port 55 when pump 60 is actuated, as described
`hereinbelow.
`0046 Referring now to FIG. 5, perspective views depict
`ing alternative configurations of slide valve 100 of FIG. 1B
`
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`

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`
`Jan. 29, 2004
`
`are shown. In FIG.5A, slide valve 100 comprises block 101
`having an oval-shaped configuration and first end 103,
`second end 105, and bore 108 extending laterally though a
`central region of block 101. Bore 108 is sized to permit
`blood flow therethrough without imposing Significant
`trauma upon blood vessels. Slide valve 100 further com
`prises first solid section 102 disposed between first end 103
`and bore 108, and second solid section 104 disposed
`between second end 105 and bore 108.
`0047 Block 101 of slide valve 100 preferably is disposed
`within compartment 58 of manifold 50 so that block 101 is
`configured for longitudinal movement within the compart
`ment. When block 101 comprises an oval-shaped configu
`ration, it is preferred that compartment 58 also comprises an
`oval configuration to accommodate the block and prevent
`circumferential rotation of the block within the compart
`ment. As described hereinbelow with respect to FIG. 6, first
`end 103 is configured to engage a Spring disposed within
`compartment 58, while second end 105 is configured to
`engage tip 64 of plunger 62.
`0048 Referring to FIG. 5B, alternative slide valve 110 is
`shown as comprising block 111 having first end 103, first
`Solid section 112, second Solid section 114, Second end 115,
`and bore 118 extending laterally through a central region of
`block 111. In the embodiment of FIG. 5B, slide valve 110
`includes rod 116 that extends longitudinally from second
`end 116, whereby rod 116 is configured to engage tip 64 of
`plunger 62. Slide valve 110 further includes bore 117
`disposed in first end 113 that extends partially into first solid
`section 112 of block 111, as shown in FIG. 5B. Bore 117 is
`configured to receive an end portion of a Spring for purposes
`described hereinafter.
`0049. In FIG. 5C, block 121 of alternative slide valve
`120 is illustrated as having a rectangular configuration. In
`this embodiment, rectangular block 121 preferably is con
`figured for longitudinal movement within a rectangular
`compartment of manifold 50. It will be appreciated by those
`skilled in the art that, while FIGS. 5A-5C illustrate slide
`Valves having oval and rectangular-shaped configurations,
`other configurations of the block may be provided to achieve
`the functions described hereinafter.
`0050 Referring now to FIGS. 6A-6C, a preferred method
`of using apparatus 20 of FIG. 1 to selectively vary the rate
`of aspiration provided through working lumen 23 of catheter
`21 is described. In FIG. 6A, the arrows indicate the direction
`in which blood flows when natural, physiologically-regu
`lated flow is provided through working lumen 23 when slide
`valve 100 is provided in an open position.
`0051 AS described hereinabove, an arterial-venous shunt
`allows blood flow in the patients artery that is distal of
`occlusive element 22 to flow in a retrograde fashion through
`working lumen 23, through manifold inlet tubing 56, bore
`108 and manifold outlet tubing 57, through filter chamber 70
`and Venous return line 40, and back into a remote vein.
`0.052 Slide valve 100 is held in the open position,
`whereby bore 108 is aligned with inlet and outlet tubing 56
`and 57 of manifold 50, when plunger 62 is in an advanced
`position within housing 61, as shown in FIG. 6A. Specifi
`cally, plunger 62 is advanced distally So that tip 64 pushes
`against second end 105 of valve 100 to cause first end 103
`to compress Spring 59, which is disposed within compart
`
`ment 58. Wall friction between plunger 62 and an interior
`wall of housing 61 holds the plunger in the advanced
`position, i.e., the force of Spring 59 cannot overcome the
`wall friction, so that bore 108 remains aligned with tubing
`Sections 56 and 57.
`0053 When slide valve 100 is in the open position shown
`in FIG. 6A, first and second check valves 80 and 90 are
`effectively closed. With respect to second check valve 90,
`blood flowing from outlet tubing 57 into exit ports 93 will
`push ball 92 against inlet port 91 to close valve 90. With
`respect to first check valve 80, ball 82 is depicted in a closed
`position covering inlet port 81 in FIG. 6A. It should be
`noted that ball 82 actually may be pushed forward by flow
`from inlet tubing 56, so that small levels of fluid may enter
`into pump chamber 65. However, So long as plunger 62
`remains in the advanced position, flow entering into pump
`chamber 65 through valve 80 is confined to a small region
`within pump chamber 65 and, therefore, valve 80 is effec
`tively closed because little or no flow can occur through the
`valve.
`0054 Referring now to FIG. 6B, a physician proximally
`retracts handle 63 of plunger 62 to draw fluid into pump
`chamber 65. In a retracted position, tip 64 of plunger 62 no
`longer contacts second end 105 of slide valve 100. Spring 59
`then expands to push block 101 of FIG. 5A in a distal
`direction and cause first solid segment 102 of valve 100 to
`block an opening between inlet and outlet tubing 56 and 57.
`In this closed position, slide valve 100 prohibits fluid
`entering through manifold inlet port 54 from flowing
`directly into filter chamber 70.
`0055 With slide valve 100 in the closed position, fluid is
`diverted through first check valve 80. Accordingly, by
`retracting plunger 62 proximally, fluid may be aspirated
`from a blood vessel through working lumen 23 of catheter
`21 and diverted into pump chamber 65. The rate of aspira
`tion in the vessel may be controlled by proximally retracting
`plunger 62 a known distance within housing 61 using indicia
`69 disposed on housing 61, as shown in FIG. 1A.
`0056 Referring now to FIG. 6C, plunger 62 is advanced
`distally by a physician to cause fluid in pump chamber 65 to
`be forced through second check valve 90. Specifically, when
`plunger 62 is advanced distally, fluid flow pushes ball 92 of
`valve 90 in a distal direction, i.e., away from inlet port 91,
`to permit fluid flow through exit ports 93 of valve 90. Fluid
`then flows through outlet tubing 57 into filter chamber 70,
`through filter 72, through venous line 40, and through a
`venous return sheath (not shown) into a remote vein. This
`technique advantageously allows filtered blood to be reper
`fused directly into a patient's body. When plunger 62 is
`advanced distally, first check valve 80 is forced into a closed
`position because ball 82 is pushed against inlet port 81.
`0057. In accordance with principles of the present inven
`tion, the use of two opposing check valves 80 and 90 ensures
`that fluid is directed through manifold 50 exclusively in one
`direction when pump 60 is actuated, i.e., fluid may flow from
`inlet tubing 56 into pump chamber 65 and then may flow
`into outlet tubing 57. However, fluid may not flow in a
`reverse direction from pump chamber 65 back towards
`catheter 21 because first check valve 80 will close. Similarly,
`fluid from filter chamber 70 may not flow in a reverse
`direction into pump chamber 65 because Second check valve
`90 will close. It should be noted that slide valve 100 will
`
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`US 2004/001931.0 A1
`
`Jan. 29, 2004
`
`remain in the closed position when pump 60 is actuated So
`long as plunger 62 is not fully advanced to cause tip 64 to
`engage second end 105 of valve 100.
`0.058 Using the techniques described hereinabove, it is
`possible to achieve variable rates of aspiration through
`working lumen 23 of catheter 21 using pump 60. In opera
`tion, a physician Selectively may retract and advance plunger
`62 a desired amount, using markings 69, for as many cycles
`as desired. This allows a physician to achieve Selectively
`higher rates of aspiration in a vessel at a location distal of
`occlusion element 22 without the need for an external
`Suction device. However, if desired, Suction-assisted aspi
`ration and/or infusion may be applied through Suction/
`infusion port 52 when slide valve 100 is in a closed position,
`as described hereinabove.
`0059 While preferred illustrative embodiments of the
`invention are described above, it will be apparent to one
`skilled in the art that various changes and modifications may
`be made therein without departing from the invention. The
`appended claims are intended to cover all Such changes and
`modifications that fall within the true spirit and scope of the
`invention.
`
`1. Apparatus Suitable for providing variable rates of
`aspiration to a working lumen of a catheter, the apparatus
`comprising:
`a manifold having an inlet port and an outlet port, wherein
`the inlet port is in fluid communication with the work
`ing lumen of the catheter; and
`a pump coupled to the manifold, the pump having a
`housing defining a lumen and a plunger disposed within
`the lumen,
`wherein the pump may be Selectively actuated to vary the
`rate of aspiration provided between the inlet