US20110282197A1 - Hand-Activated Syringe with Vacuum Chamber for Auto Refill - Google Patents

Abstract

A hand-activated syringe (14) is disclosed that uses a vacuum to retract a plunger (54) of the syringe (14) to draw fluid into a syringe body (18). A first seal (76) with the plunger (54) and a second seal (64) with the plunger (54) define a vacuum chamber (82). The spacing between the first seal (76) and the second seal (64) changes in response to the plunger (54) moving relative to the syringe body (18). Advancing the plunger (54) in a direction associated with a discharge stroke creates or increases a vacuum within the vacuum chamber (82) by increasing a spacing between the first seal (76) and the second seal (64). This vacuum thereafter may be used to retract the plunger (54) by decreasing a spacing between the first seal (76) and the second seal (64), and to thereby draw fluid into the syringe (14) from a fluid source (86).

Description

RELATED APPLICATIONS
• This application claims priority to U.S. Provisional Patent Application No. 61/149,718 filed on 4 Feb. 2009 entitled “HAND-ACTUATED SYRINGE WITH VACUUM CHAMBER FOR AUTO REFILL”.
FIELD OF THE INVENTION
• The present invention generally relates to filling hand-actuated syringes.
BACKGROUND
• Hand-held, hand-powered (e.g., hand-actuated) syringes may be used for cardiac catheter lab procedures and special angiographic procedures. For instance, the syringe may need to be filled with medical fluid (e.g., contrast media for use in medical imaging) one or more times for a given procedure. In this regard, a first syringe is typically interconnected with a bottle by using a combination of a syringe needle and a piercable membrane/diaphragm of the bottle, or by using a combination of a syringe luer fitting and a vented spike associated with the bottle. Once interconnected with the bottle, a user or clinician (typically a nurse) manually retracts the syringe plunger to draw medical fluid from within the bottle into the syringe. Upon being filled to a desired level, the syringe is disconnected from the bottle. A user (typically a physician) then injects the medical fluid from within the syringe into the patient (e.g., typically through a catheter already positioned in the patient's vasculature).
• Quite often, more medical fluid than is initially filled into the syringe is desired to complete the medical procedure (e.g., angiographic imaging). As such, another syringe is filled in the manner described above, or the same syringe is refilled in a similar fashion to that described above. In either case, it could be said that one or both time and materials (e.g., multiple syringes) are wasted.
SUMMARY
• As used herein, the phrase “fluidly isolated” or the like describes a relationship between components where fluid is, at least temporarily, not able to flow between the components. For example, where two components are fluidly isolated from each other, fluid at that time is unable to flow from one component to the other component. Such an inability to flow may be due to one or more valves being positioned to prevent such flow between the two components.
• As used herein, the phrases “fluidly interconnected, “in fluid communication with,” “fluidly communicates with,” or the like each describes a relationship between components where fluid is able to flow between the components in at least one circumstance. For example, “an injection device fluidly interconnected to a patient” describes a configuration where fluid is able to flow from the injection device, through any intermediate components (e.g., tubing, connectors), and to the patient (e.g., into the vasculature of the patient).
• A first aspect of the present invention is embodied by a syringe that includes a syringe body having a discharge port defined therein. In addition, the syringe includes a plunger that is movable relative to the syringe body and that includes a plunger head. The plunger head is disposed within the syringe body and is movable relative to the syringe body. There is a first seal with the plunger, where the plunger moves relative to this first seal.
• A number of feature refinements and additional features are applicable to the first aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of the first aspect. The following discussion is applicable to the first aspect, up to the start of the discussion of a second aspect of the present invention.
• The term “seal” is being used herein to define a region that prevents fluid from passing by the location of the seal. Unless otherwise specified, a seal may be defined in any appropriate manner. A seal may be defined by an interface between two or more components. In the case of the first aspect, there is a first seal with the plunger. As such, the first seal prevents fluid from passing by the plunger at the location of the first seal.
• The location of the first seal is subject to a number of characterizations. The plunger head may move away from the first seal and toward the discharge port during a fluid discharge stroke—a movement of the plunger relative to the syringe body for purposes of discharging fluid from the syringe. The plunger head may be characterized as being between the discharge port and the first seal when the plunger is in its fully retracted position (e.g., where the fully retracted position may be associated with a maximum amount of fluid being within the syringe for use in a subsequent fluid discharge operation).
• The syringe may include a discharge chamber that is defined by a portion of an interior of the syringe body, along with the plunger head. A fluid to be discharged from the syringe may be contained within this discharge chamber. In one embodiment, it may be said that the discharge chamber is disposed on one side of the plunger head, while the first seal is disposed on an opposite side of the plunger head. This first seal may at least assist in defining a vacuum chamber, where this vacuum chamber and discharge chamber are thereby disposed on opposite sides of the plunger head within the syringe body. The phrase “vacuum chamber” means a chamber that is at a pressure that is less than the ambient pressure to which the syringe is exposed. The term “vacuum” encompasses any pressure that is less than ambient pressure. A vacuum pressure may also be referred to as negative pressure. A vacuum force may be a force that is exerted on an object by a negative pressure.
• A vacuum chamber may be provided within the interior of the syringe body, and may include first and second closed or sealed ends. The first closed end of the above-noted vacuum chamber may be defined at least in part by the first seal. The first seal may be realized in any appropriate manner. For instance, one or more sealing members (e.g., O-rings) may be mounted to the syringe body so as to remain in a fixed position relative to the syringe body, and may engage the plunger (e.g., a plunger push rod that extends from the plunger head and beyond the syringe body). That is, the interface between a stationary O-ring and a movable plunger may define the first seal.
• The second closed end of the vacuum chamber may be defined at least in part by the plunger head. Generally, there may be a second seal with the plunger, where this second seal moves along with the plunger (e.g., the second seal may be characterized as being maintained in a fixed position relative to the plunger, or stated another way this second seal may be characterized as staying in the same location with respect to the plunger head as the plunger head moves within and relative to the syringe body). The second seal may be realized in any appropriate manner. One or more sealing members (e.g., O-rings) may be mounted on the plunger (e.g., on the plunger head) and may engage an interior surface of the syringe body to define the second seal. In this case, the interface between such an O-ring(s) and the interior of the syringe body would define the second seal. Another option for defining the second seal is the interface between the plunger head itself and an interior of the syringe body. In each of these two instances, the location of the second seal will move along with the plunger.
• Based upon the foregoing, at least one seal for the noted vacuum chamber may move relative to the syringe body (e.g., the above-noted second seal), while at least one seal for the vacuum chamber may be maintained in a fixed position relative to the syringe body (e.g., the above-noted first seal). Another characterization is that the spacing between the first and second seals (and thereby the size of the vacuum chamber) may change by a movement of the plunger relative to the syringe body.
• A second aspect of the present invention is embodied by a syringe that includes a syringe body having a discharge port defined therein. This syringe also includes a plunger that is movable relative to the syringe body and that includes a plunger head. The plunger head is disposed within the syringe body and is movable relative to the syringe body. A discharge chamber of the syringe body is located on one side of the plunger head and is in fluid communication with the discharge port for the syringe body. Further, a vacuum chamber of the syringe body is located within the syringe body on another side of the plunger head and is fluidly isolated from the discharge chamber.
• A number of feature refinements and additional features are applicable to the second aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of the second aspect. The following discussion is applicable to the second aspect, up to the start of the discussion of a third aspect of the present invention.
• Moving the plunger relative to the syringe body in a direction associated with a fluid discharge stroke for the syringe may decrease the volume of the discharge chamber, may increase the volume of the vacuum chamber, or both. There may be a first seal with the plunger (e.g., a plunger push rod), where the plunger may move relative to this first seal. There may be a second seal with the plunger (e.g., a plunger head), where this second seal may move along with the plunger. These first and second seals may each define a boundary for the vacuum chamber, and may be in accordance with the first and second seals discussed above in relation to the first aspect. Each of the various features discussed above in relation to the first aspect may be used by this second aspect, individually or in any combination.
• A number of feature refinements and additional features are separately applicable to each of the first and second aspects of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of each of the first and second aspects. The following discussion is separately applicable to each of the first and second aspects, up to the start of the discussion of a third aspect of the present invention.
• The syringe may be a hand-held, hand-powered or hand-activated syringe of any appropriate type. For instance, the syringe may include a plunger push rod that extends from the plunger head and beyond an end of the syringe body (e.g., opposite of the discharge port) such that it may be engaged by a user's thumb. An end of the plunger push rod that extends beyond the syringe body may include an appropriate actuation surface for engagement by an operator (e.g., thumb-actuated). The syringe may also be in the form of what is commonly known as a “control syringe”—a configuration where at least one loop extends from the barrel of the syringe for receiving a user's finger(s), and where a loop extends from an end of the plunger for receiving a users thumb. Yet another option for the syringe is to have a pair of levers that are movably interconnected (e.g., by a pivot pin), where one lever is also movably interconnected with the syringe body (e.g., by a pivot pin), and where the other lever is movably interconnected with the plunger (e.g., by a pivot pin) such that that a single hand of a user may engage and manipulate the levers to change the position of the plunger relative to the syringe body. In any case, user-applied forces may be used to advance the plunger for a fluid discharge stroke in the case of each of the first and second aspects.
• The syringe may include a first check valve to control flow out of the syringe body. In one embodiment, this first check valve is located within a discharge nozzle of the syringe. Other locations may be appropriate. The syringe body may include a fill port, and the syringe may further include a second check valve for this fill port (e.g., to control flow into the syringe body through the fill port). As such, a valve may fluidly isolate the syringe from a fluid source during a fluid discharge from the syringe (e.g., the second check valve), a valve may fluidly isolate a patient (interconnected with the discharge port of the syringe) from a fluid source during a syringe loading or refilling operation (e.g., the first check valve), or both.
• Vacuum forces may provide the sole force for retracting the syringe plunger to load fluid into the syringe. However, one or more other forces may be used to facilitate retraction of the syringe plunger. For instance, one or more biasing members may be used to bias the plunger to/toward a fully retracted position. Any appropriate biasing member may be utilized, for instance, a spring. In this regard, one end of a biasing spring may be fixed to the plunger in an appropriate manner, while an opposite end of the spring may be fixed to the syringe body in an appropriate manner. Each biasing member may be fluidly isolated from fluid to be discharged from the syringe.
• The syringe may be used for any appropriate application, for instance to inject fluid into a patient (e.g., via tubing mounted to a discharge nozzle of the syringe, and/or by a catheter or other access device inserted into the vasculature of the patient). A fluid delivery system of the invention may utilize a fluid source and any syringe described herein. The fluid source of such a fluid delivery system may be fluidly interconnected with a fill port of the syringe, and a check valve (e.g., the second check valve mentioned above) may be used to control the flow into the syringe from the fluid source. In one embodiment, a pressure head of the fluid source may be used to supplement or augment the vacuum force to retract the plunger for purposes of loading fluid into the syringe. In one embodiment, the fluid source is pressurized (e.g., by a pressurizing source), and this pressure may be used to supplement or augment the vacuum force to retract the plunger for purposes of loading fluid into the syringe. Any one or more of the supplemental forces described herein may be used with the vacuum force to retract the plunger for purposes of loading fluid into the syringe, including in any appropriate combination.
• A third aspect of the present invention is embodied by a method for loading fluid into a syringe. In this method, a vacuum is created within a body of the syringe, and a plunger of the syringe is moved relative to the syringe body in a first direction using this vacuum. A medical fluid (e.g., contrast media for use in a medical imaging procedure) is drawn into the syringe body due to this movement of the syringe plunger in the first direction.
• A number of feature refinements and additional features are applicable to the third aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of the third aspect. The remainder of this discussion is applicable to at least this third aspect. Initially, the syringe in accordance with each of the first and second aspects may be used in this third aspect.
• The vacuum may be created by moving the plunger relative to the syringe body in a second direction. The syringe plunger may be moved in one direction (e.g., a second direction) to create the vacuum, and the syringe plunger may be moved in an opposite direction (e.g., the noted first direction) by the vacuum force to draw fluid into the syringe body. The noted first and second directions may be opposite of each other. The vacuum may be created by advancing the plunger without any medical fluid having been previously loaded into the syringe body (e.g., an empty configuration for the syringe). For instance, it may be such that only air or another gas is being discharged from the syringe by movement of the plunger that generates a vacuum (e.g., a movement in the noted second direction). However, the vacuum may be created while advancing the plunger relative to the syringe body to discharge medical fluid from the syringe. In one embodiment, the medical fluid that is discharged from the syringe by an advancement of the plunger (and which generates the vacuum) is of the same type as a medical fluid that is loaded into the syringe by a vacuum-assisted movement of the syringe plunger.
• The entire force that retracts the plunger to load fluid into the syringe may be provided by a vacuum. Other forces may be used in combination with this vacuum to retract the syringe plunger. For instance, a movement of the plunger that creates the vacuum may also increase a spring force that acts on the syringe plunger, and that assists in retracting the plunger to draw fluid into the syringe. More generally, a biasing force may be exerted on the plunger and which biases the same toward/to its fully retracted position. The magnitude of this biasing force may increase as the plunger moves in a direction that also increases the absolute value of the force created by the vacuum. A pressure head may be used to retract the syringe plunger. Pressurizing a fluid source may also be used to retract the syringe plunger. Any one or more of these supplemental forces may be used with a vacuum to retract the plunger, individually or in any combination.
• A first check valve may be opened when advancing the plunger relative to the syringe body in a direction that creates a vacuum (e.g., a check valve that controls a flow out of the syringe), a second check valve may be closed when advancing the plunger relative to the syringe body in a direction that creates a vacuum (e.g., a check valve that controls a flow from a fluid source into the syringe), or both. A first check valve may be closed when moving the plunger relative to the syringe body in a direction that draws fluid into the syringe body (e.g., a check valve that controls a flow out of the syringe), a second check valve may be opened when moving the plunger relative to the syringe body in a direction that draws fluid into the syringe body (e.g., a check valve that controls a flow from a fluid source into the syringe), or both.
• A number of feature refinements and additional features are separately applicable to each of above-noted first, second, and third aspects of the present invention. These feature refinements and additional features may be used individually or in any combination in relation to each of the above-noted first, second, and third aspects of the present invention. Any feature of any other various aspects of the present invention that is intended to be limited to a “singular” context or the like will be clearly set forth herein by terms such as “only,” “single,” “limited to,” or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular (e.g., indicating that a power injector includes “a syringe” alone does not mean that the power injector includes only a single syringe). Moreover, any failure to use phrases such as “at least one” also does not limit the corresponding feature to the singular (e.g., indicating that a power injector includes “a syringe” alone does not mean that the power injector includes only a single syringe). Finally, use of the phrase “at least generally” or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a syringe barrel is at least generally cylindrical encompasses the syringe barrel being cylindrical).
BRIEF DESCRIPTION OF THE FIGURES
• FIG. 1 is a schematic of one embodiment of a fluid delivery system having a vacuum-assisted refill syringe.
• FIGS. 2A-C present a refill sequence for the vacuum-assisted refill syringe used by the fluid delivery system ofFIG. 1.
• FIG. 3 illustrates the vacuum-assisted refill syringe used by the fluid delivery system ofFIG. 1, with an optional supplemental return spring.
DETAILED DESCRIPTION
• One embodiment of a fluid delivery system is illustrated inFIG. 1 and is identified byreference numeral10. Thefluid delivery system10 includes asyringe14 and afluid source86. Generally, thefluid delivery system10 is configured to automatically refill thesyringe14 with fluid from thefluid source86. The term “refill” encompasses providing any appropriate volume to thesyringe14, and specifically does not require that the entire fluid-containing volume of thesyringe14 be occupied by fluid from thefluid source86 as a result of a refilling operation.
• Thesyringe14 includes asyringe body18 and a plunger or pushrod assembly54 that extends within and that is movable relative to thesyringe body18. Thesyringe body18 may be of any appropriate size, shape, configuration, and/or type. Thesyringe body18 may be formed from any appropriate material or combination of materials. In one embodiment, thesyringe body18 is an integrally-formed structure (e.g., of one-piece construction; such that there are no joints of any kind between adjacent portions/sections of the syringe body18). However, thesyringe body18 could be defined by two or more separately fabricated structures that are appropriately joined together.
• Thesyringe body18 includes aflange42, a barrel22 (e.g., cylindrical), a transition section26 (e.g., in the form of a truncated cone; frustumly-shaped), and adischarge nozzle30. Thedischarge nozzle30 includes adischarge port34. Fluid may be discharged from thesyringe14 through thisdischarge port34. Acheck valve50amay be disposed within thedischarge nozzle30, or more generally between thedischarge port34 and thepush rod assembly54. Preferably, all flow out of thesyringe14 is directed through thecheck valve50a.
• Thesyringe body18 may also include a fill or refillport46. A discharge from thefluid source86 may be directed into thesyringe14 through thisfill port46. Thefill port46 may be disposed at any appropriate location relative to thesyringe body18. In the illustrated embodiment, thefill port46 is disposed on thetransition section26 of thesyringe body18. Generally, it may be desirable for thefill port46 to be located at or near the end of the discharge stroke of thepush rod assembly54. In any case, acheck valve50bmay be disposed within thefill port46, or more generally between thefluid source86 and the interior of thesyringe barrel22. Preferably, all flow into the syringe14 (from the fluid source86) is directed through thecheck valve50b.
• Thepush rod assembly54 extends within thesyringe body18, and furthermore is movable relative to thesyringe body18. Thepush rod assembly54 includes aplunger head58 and aplunger push rod66 that extends from theplunger head58. One or moreannular sealing members62 may be formed on a perimeter of theplunger head58 and may engage an interior surface of thesyringe body18. Each such sealingmember62 may be of any appropriate size, shape, configuration, and/or type. Each sealingmember62 may be integrally-formed with thepush rod assembly54 as shown, although one or more sealing members could be separately formed and mounted on the plunger head58 (e.g., an O-ring). Any sealing member that was separately mounted to theplunger head58 would then become part of theplunger head58.
• Generally, the interface between the perimeter of theplunger head58 and the interior of thesyringe body18 defines asecond seal64. Any appropriate shape for the perimeter of theplunger head58 may be utilized to define the second seal64 (e.g., different shapes of sealingmembers62 may be appropriate; a cylindrical surface defining the perimeter of theplunger head58 could be pressed against the interior of thesyringe body18 to define the second seal64). In any case, fluid should be prevented from flowing past thesecond seal64.
• Since theplunger head58 moves relative to thesyringe body18, so too does thesecond seal64 and as indicated by the double-headed arrow A inFIG. 1. That is, thesecond seal64 may be characterized as moving along with thepush rod assembly54 during use of thesyringe14. Thesecond seal64 may be characterized as being maintained in a fixed position relative to thepush rod assembly54. Thesecond seal64 may be characterized as staying in the same location with respect to theplunger head58 as theplunger head58 moves within and relative to thesyringe body18.
• Theplunger push rod66 extends beyond afirst end38 of the syringe body18 (where thefirst end38 is opposite of thedischarge port34 in the illustrated embodiment). Anactuation surface70 is provided on an exposed end of theplunger push rod66. A user may position a digit (e.g., a thumb) on thisactuation surface70 to advance thepush rod assembly54 toward thedischarge nozzle30 to discharge fluid from thesyringe14. Therefore, thesyringe14 may be characterized as being hand-actuated or hand-powered.
• One ormore sealing members74 may be fixed relative to the syringe body18 (e.g., mounted to the syringe body18), and may engage thepush rod assembly54 to define afirst seal76. Thepush rod assembly54 moves relative to thisfirst seal76—thefirst seal76 may stay in the same location as thepush rod assembly54 is moved. In the illustrated embodiment, the sealingmember74 is at least generally disposed at thefirst end38 of thesyringe body18, and engages theplunger push rod66. Each such sealingmember74 may be of any appropriate size, shape, configuration, and/or type (e.g., an O-ring).
• Theplunger head58 may be characterized as separating the interior of thesyringe body18 into a fluid ordischarge chamber78 and avacuum chamber82. Thedischarge chamber78 may be characterized as being disposed on one side of theplunger head58, while thevacuum chamber82 may be characterized as being disposed on the opposite side of theplunger head58. Generally, thedischarge chamber78 is disposed on the side of theplunger head58 that fluidly communicates with thedischarge port34, while thevacuum chamber82 is disposed on the opposite side of the plunger head58 (e.g., on the “back” side of the plunger head58). Therefore, thevacuum chamber82 extends between the second seal64 (e.g., defined by the engagement of themovable plunger head58 with the interior of the syringe body18) and the first seal76 (e.g., defined by the engagement of the sealingmember74 with thepush rod assembly54, specifically theplunger push rod66 in the illustrated embodiment).
• The spacing between thefirst seal76 and thesecond seal64 changes in response to movement of thepush rod assembly54 relative to thesyringe body18. When thepush rod assembly54 is moved toward the discharge port34 (in the direction associated with a fluid discharge stroke), the spacing between thefirst seal76 and thesecond seal64 increases (e.g., by a movement of thesecond seal64 relative to the stationary first seal76). This reduces the size of the discharge chamber78 (e.g., to provide a fluid discharge from the syringe14) and increases the size of thevacuum chamber82. When thepush rod assembly54 is moved away from the discharge port34 (in the direction associated with a fluid-loading operation), the spacing between thefirst seal76 and thesecond seal64 decreases (e.g., by a movement of thesecond seal64 relative to the stationary first seal76). This increases the size of the discharge chamber78 (e.g., to accommodate the loading of fluid therein) and decreases the size of thevacuum chamber82.
• Thefluid source86 is fluidly interconnected with thesyringe14 by a fill or refillline90 that extends to therefill port46 of thesyringe14. Any appropriate fluid may be utilized by the fluid source86 (e.g., contrast media; a flushing agent such as saline or any other biocompatible media). Thefill line90 may be in the form of a conduit of any appropriate type (e.g., medical tubing).
• Thevacuum chamber82 may provide the sole or primary force that moves thepush rod assembly54 in a manner that fills or refills thesyringe14 with fluid from thefluid source86.FIGS. 2A-C present one embodiment of a refill sequence that uses a vacuum force to retract the syringepush rod assembly54. Thepush rod assembly54 is in its fully retracted position inFIG. 2A. A user may engage theactuation surface70 of thepush rod assembly54, and push thepush rod assembly54 in the direction of thedischarge port34 and as shown inFIG. 2B (e.g., a movement in the direction of the arrow B). This increases the size of thevacuum chamber82 and simultaneously reduces the size of the discharge chamber78 (e.g., by increasing the spacing between thefirst seal76 and thesecond seal64, where thefirst seal76 remains stationary relative to thepush rod assembly54 and where thesecond seal64 moves along with the push rod assembly54). Thecheck valve50bshould preclude any fluid from being discharged into thefluid source86 at this time. Moreover, this motion of thepush rod assembly54 should cause thecheck valve50ato open such that fluid is discharged from the syringe14 (a certain differential pressure may be required to open thecheck valve50a). InFIGS. 2A and 2B, this fluid may be in the form of air, such that a patient should not be fluidly interconnected with thesyringe14 at this time. In any case, the noted motion should also progressively reduce the pressure within the vacuum chamber82 (e.g., the pressure within thevacuum chamber82 should become “more negative” as thepush rod assembly54 is advanced on a fluid discharge stroke), or stated another way the absolute value of the negative pressure within thevacuum chamber82 should increase by a movement of thepush rod assembly54 toward thedischarge port34.
• When thepush rod assembly54 has reached the end of a desired fluid discharge stroke and the user releases thepush rod assembly54, the “suction forces” within thevacuum chamber82 should move thepush rod assembly54 toward (e.g., back to) its fully retracted position (e.g., in the direction of the arrow C inFIG. 20). That is, the negative pressure within thevacuum chamber82 should retract thepush rod assembly54. Retraction of thepush rod assembly54 decreases the size of thevacuum chamber82 and simultaneously increases the size of the discharge chamber78 (e.g., by decreasing the spacing between thefirst seal76 and thesecond seal64, where thefirst seal76 remains stationary relative to thepush rod assembly54 and where thesecond seal64 moves along with the push rod assembly54). The retraction of thepush rod assembly54 should open the check valve54bto draw fluid from thefluid source86 into thesyringe14 via thefill port46 and as shown inFIG. 2C. It should be appreciated that this retraction of thepush rod assembly54 may be initiated from various different positions within the syringe barrel22 (e.g., theplunger head58 need not be at or near thetransition section26 when the user releases thepush rod assembly54, such that it is thereafter retracted via the negative pressure in the vacuum chamber82).
• With fluid having been loaded in thesyringe14 in the above-noted manner (e.g.,FIG. 2C), a patient may be fluidly interconnected with thesyringe14 in any appropriate manner (e.g., via medial tubing mounted on thedischarge nozzle30 of thesyringe14, along with a catheter or any other vasculature access device that is directed into the vasculature of the patient). Moreover, a user may again engage theactuation surface70 of thepush rod assembly54, and push thepush rod assembly54 in the direction of the discharge port34 (e.g., in the direction of arrow B inFIG. 2B). This again progressively increases the size of thevacuum chamber82 and progressively reduces the pressure within thevacuum chamber82. This also progressively reduces the size of thedischarge chamber78 such that fluid is discharged out of thesyringe14 through thedischarge port34 in the above-noted manner. When the desired amount of fluid has been discharged from thesyringe14, the user may release thepush rod assembly54, and the “suction forces” within thevacuum chamber82 should again move thepush rod assembly54 toward (e.g., back to) its fully retracted position (e.g., in the direction of arrow C in FIG.2C). That is, the negative pressure within thevacuum chamber82 should again retract thepush rod assembly54, where this retraction should open the check valve54bto draw fluid from thefluid source86 into thesyringe14 via thefill port46. This fill/discharge cycle may be repeated any number of times.
• Thesyringe14 could be configured such that thepush rod assembly54 is initially disposed in an extended position within the syringe body18 (e.g., at its minimum spacing with the discharge port34), and then retained or locked in this position in any appropriate manner. That is, there would be a vacuum or a negative pressure within thevacuum chamber82 at this time. A user could release thepush rod assembly54 to allow fluid to be initially loaded into thesyringe14 from thefluid source86 in the above-noted manner, namely where the “suction force” within thevacuum chamber82 would retract the push rod assembly54 (e.g., to the fully retracted position shownFIG. 2C). Thereafter, any number of discharge/fill cycles could be repeated in accordance with the foregoing.
• One or more forces could be utilized to supplement the vacuum force for retracting the syringepush rod assembly54, to in turn load fluid into thesyringe14 from thefluid source86 in the above-noted manner. For instance, the pressure head within thefluid source86 may contribute to retracting thepush rod assembly54 to is load fluid into thesyringe14 from thefluid source86. Thepressure source86 could also be pressurized, for instance by a pressurizingsource94 that is fluidly interconnected with thefluid source86. Another option is illustrated inFIG. 3, where one or more biasing members (e.g., a spring) are used to bias thepush rod assembly54 toward/to its fully retracted position. Generally, one end of the biasingmember100 may be fixed relative to the push rod assembly54 (e.g., its plunger head58), while another end of the biasingmember100 may be fixed relative to the syringe body18 (e.g., by a spring anchor104). In this case, advancing thepush rod assembly54 on a discharge stroke increases the magnitude of the spring force in the biasing member100 (or stated another way, increases the magnitude of the biasing force). Once thepush rod assembly54 is released, this spring or biasing force, along with the suction force that has developed within thevacuum chamber82, retracts thepush rod assembly54 to draw fluid into thesyringe body18 from thefluid source86.
• The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.

Claims (31)

1. A fluid delivery system, comprising:

a fluid source;

a syringe comprising:

a syringe body comprising a discharge port and a fill port, wherein said discharge port is connectable to a patient;

a plunger movable relative to said syringe body and comprising a plunger head that is disposed within said syringe body; and

a first seal with said plunger, wherein said plunger moves relative to said first seal; and

a conduit extending between said fluid source and said fill port, and including while said discharge port remains available for connection to a patient.

2. The fluid delivery system ofclaim 1, wherein said plunger head moves away from said first seal and toward said discharge port for a fluid discharge stroke.

3. The fluid delivery system ofclaim 1, wherein said plunger head is located between said discharge port and said first seal when said plunger is in a fully retracted position.

4. The fluid delivery system ofclaim 1, wherein said syringe further comprises a discharge chamber defined by an interior of said syringe body and said plunger head, and wherein said first seal is disposed on an opposite side of said plunger head in relation to said discharge chamber.

5. The fluid delivery system ofclaim 4, wherein said syringe further comprises a vacuum chamber disposed on an opposite side of said plunger head in relation to said discharge chamber.

6. The fluid delivery system ofclaim 1, wherein said syringe further comprises a second seal with said plunger head, and wherein said second seal moves along with said plunger.

7. The fluid delivery system ofclaim 1, wherein said syringe further comprises a vacuum chamber disposed within said syringe body and comprising first and second closed ends, and wherein said first closed end comprises said first seal, and wherein said second closed end comprises said plunger head.

8. The fluid delivery system ofclaim 7, wherein said syringe further comprises a second seal fixed relative to and moveable with said plunger, and wherein said vacuum chamber extends between said first and second seals.

9. A fluid delivery system, comprising:

a fluid source;

a syringe comprising:

a syringe body comprising a discharge port and a fill port, wherein said discharge port is connectable to a patient;

a plunger movable relative to said syringe body and comprising a plunger head that is disposed within said syringe body;

a discharge chamber on a first side of said plunger head and that fluidly communicates with said discharge port; and

a vacuum chamber on a second side of said plunger head and that is fluidly isolated from said discharge chamber; and

a conduit extending between said fluid source and said fill port and including while said discharge port remains available for connection to a patient.

10. The fluid delivery system ofclaim 9, wherein a volume of said discharge chamber decreases and a volume of said vacuum chamber increases by a movement of said plunger in a direction of a fluid discharge stroke.

11. The fluid delivery system ofclaim 10, wherein a pressure within said vacuum chamber decreases by a movement of said plunger in a direction of a fluid discharge stroke.

12. The fluid delivery system ofclaim 9, wherein a volume of said discharge chamber decreases and a volume of said vacuum chamber increases by a movement of said plunger toward said discharge port.

13. The fluid delivery system ofclaim 12, wherein a pressure within said vacuum chamber decreases by a movement of said plunger toward said discharge port.

14. The fluid delivery system ofclaim 9, wherein said syringe further comprises:

a first seal with said plunger, wherein said plunger moves relative to said first seal; and

a second seal with said plunger, wherein said second seal moves with said plunger, wherein said first and second seals are spaced from each other.

15. The fluid delivery system ofclaim 14, wherein said first seal is defined by an interface between an O-ring and said plunger, wherein said O-ring is mounted to said syringe body.

16. The fluid delivery system ofclaim 14, wherein said second seal is defined by an interface between said plunger head and an interior of said syringe body.

17. The fluid delivery system ofclaim 14, wherein said first and second seals each define a boundary for said vacuum chamber.

18. The fluid delivery system ofclaim 1, wherein said syringe further comprises:

a first check valve associated with said discharge port.

19. The fluid delivery system ofclaim 18, wherein a flow out of said syringe body is directed through said first check valve and then said discharge port.

20. The fluid delivery system ofclaim 18, wherein said syringe further comprises:

a second check valve associated with said fill port.

21. The fluid delivery system ofclaim 1, wherein said syringe further comprises a spring that interacts with said plunger.

22. The fluid delivery system ofclaim 21, wherein said spring biases said plunger away from said discharge port.

23. The fluid delivery system ofclaim 21, wherein said spring biases said plunger toward a retracted position relative to said syringe body.

24. The fluid delivery system ofclaim 1, wherein said plunger moves toward said discharge port in response to a manual force.

25. The fluid delivery system ofclaim 1, wherein said syringe further comprises at least one biasing member that biases said plunger toward a fully retracted position.

26-27. (canceled)

28. The fluid delivery system ofclaim 1, wherein said fluid source is pressurized.

29. The fluid delivery system ofclaim 1, further comprising:

a pressurizing source fluidly interconnected with said fluid source.

30. The fluid delivery system ofclaim 1, wherein a pressure head exists with regard to said fluid source.

31. A method for operating a fluid delivery system, comprising:

creating a vacuum within a syringe body;

exerting a biasing force on said plunger that supplements a force provided by said creating step;

executing a first moving step comprising moving a plunger relative to said syringe body in a first direction using each of said vacuum and said biasing force;

drawing fluid into said syringe body from a fluid source and through a fill port of said syringe body using said first moving step;

fluidly connecting a discharge port of said syringe body with a patient; and

executing a second moving step comprising moving said plunger relative to said syringe body in a second direction to discharge said fluid from said syringe body through said discharge port and to inject said fluid into said patient.

32-41. (canceled)

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