HAND-ACTUATED SYRINGE WITH VACUUM CHAMBER FOR AUTO REFILL

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).

Claims

1-41. (canceled)

42. A method for operating a fluid delivery system, comprising: moving a plunger within a syringe body and in a discharge direction to discharge a gaseous fluid from said syringe body and while said syringe body is disconnected from a patient; creating a vacuum within said syringe body that biases said plunger in a retraction direction that is opposite of said discharge direction; exerting a separate biasing force on said plunger that also biases said plunger in the same said retraction direction; executing a first moving step comprising moving said plunger relative to said syringe body in said retraction direction using each of said vacuum and said biasing force, wherein said vacuum and said biasing force exert separate forces on said plunger that each tend to move said plunger in said retraction direction; 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 said discharge direction to discharge said fluid from said syringe body through said discharge port and to inject said fluid into said patient.

43. The method of claim 42, wherein said creating a vacuum step occurs during said moving a plunger step.

44. The method of claim 42, wherein said biasing force is selected from the group consisting of a pressure head in said fluid source, a spring force, a pressurization of said fluid source by a separate pressurizing source, or a combination thereof.

45. The method of claim 42, wherein said drawing step comprises directing said fluid through a check valve.

46. A method for operating a fluid delivery system, comprising: first moving a plunger in a first direction within a syringe body to create a vacuum within said syringe body; first moving said plunger in a second direction within said syringe body using a suction force from said vacuum and a separate force; drawing fluid from a fluid source, through a fill port of said syringe body, and into said syringe body using said step of first moving said plunger in said second direction; fluidly connecting a discharge port of said syringe body with a patient; and second moving said plunger in said first direction to discharge said fluid from said syringe body, through said fill port, and into said patient.

47. The method of claim 46, further comprising: releasing said plunger prior to said step of first moving said plunger in said second direction.

48. The method of claim 46, wherein said step of first moving said plunger in said first direction comprises: creating said separate force during said step of first moving said plunger in said first direction.

49. The method of claim 48, wherein said creating step comprises: using a biasing member that comprises a first end fixed relative to said plunger and a second end fixed relative to said syringe body.

50. The method of claim 49, wherein said step of using a biasing member comprises: increasing a magnitude of a biasing force of said biasing member during said step of first moving said plunger in said first direction, wherein said biasing force is said separate force.

51. The method of claim 50, wherein said step of first moving said first plunger in said second direction comprises using said biasing force.

52. The method of claim 46, wherein said separate force is a pressurizing source that is fluidly interconnected with said fluid source, and wherein said step of first moving said plunger in said second direction comprises: pressurizing said fluid source with said pressurizing source.

53. The method of claim 46, wherein said plunger comprises a plunger head that separates the syringe body into a discharge chamber and a vacuum chamber, and wherein said step of drawing fluid comprises: drawing said fluid into said discharge chamber.

54. The method of claim 53, wherein said vacuum is disposed in said vacuum chamber.

55. The method of claim 54, wherein said separate force is disposed in said vacuum chamber.

56. The method of claim 55, wherein said step of first moving said plunger in said first direction comprises: creating said separate force while moving said plunger in said first direction within said syringe body.

57. The method of claim 56, wherein said creating step comprises: using a biasing member that comprises a first end fixed relative to said plunger and a second end fixed relative to said syringe body.

58. The method of claim 57, wherein said step of biasing includes: increasing a magnitude of a biasing force of said biasing member during said step of first moving said plunger in said first direction, wherein said biasing force is said separate force.

59. The method of claim 57, wherein said step of first moving said first plunger in said second direction comprises using said biasing force.

60. The method of claim 54, wherein said separate force is disposed in said discharge chamber.

61. The method of claim 54, wherein said separate force is a pressurizing source that is fluidly interconnected with said fluid source, and wherein said step of first moving said plunger in said second direction comprises: pressurizing said fluid source with said pressurizing source.

62. A fluid delivery system, comprising: a fluid source comprising a medical fluid; a syringe comprising: a syringe body comprising a discharge port and a fill port; 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; a first conduit extending between said fluid source and said fill port; a second conduit configured to extend between a patient and said discharge port at a time when said first conduit extends between said fluid source and said fill port; a first valve associated with said fill port; and a second valve associated with said discharge port, wherein said second valve is disposed in a closed position while said medical fluid from said fluid source is loaded into said discharge chamber through said first conduit by said first valve being in an open position, and wherein said first valve is configured to be disposed in a closed position to fluidly isolate said fluid source from said interior of said is syringe body while said medical fluid is being directed out of said discharge chamber, through said discharge port, through said second conduit, and into said patient by said second valve being in an open position and at which time said first conduit continues to extend between said fluid source and said fill port.

63. The fluid delivery system of claim 62, wherein said syringe further comprises at least one biasing member that biases said plunger toward a fully retracted position.

64. The fluid delivery system of claim 63, wherein said at least one biasing member is disposed in said vacuum chamber.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0029] FIG. 1 is a schematic of one embodiment of a fluid delivery system having a vacuum-assisted refill syringe.

[0030] FIGS. 2A-C present a refill sequence for the vacuum-assisted refill syringe used by the fluid delivery system of FIG. 1.

[0031] FIG. 3 illustrates the vacuum-assisted refill syringe used by the fluid delivery system of FIG. 1, with an optional supplemental return spring.

DETAILED DESCRIPTION

[0032] One embodiment of a fluid delivery system is illustrated in FIG. 1 and is identified by reference numeral 10. The fluid delivery system 10 includes a syringe 14 and a fluid source 86. Generally, the fluid delivery system 10 is configured to automatically refill the syringe 14 with fluid from the fluid source 86. The term refill encompasses providing any appropriate volume to the syringe 14, and specifically does not require that the entire fluid-containing volume of the syringe 14 be occupied by fluid from the fluid source 86 as a result of a refilling operation.

[0033] The syringe 14 includes a syringe body 18 and a plunger or push rod assembly 54 that extends within and that is movable relative to the syringe body 18. The syringe body 18 may be of any appropriate size, shape, configuration, and/or type. The syringe body 18 may be formed from any appropriate material or combination of materials. In one embodiment, the syringe body 18 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 body 18). However, the syringe body 18 could be defined by two or more separately fabricated structures that are appropriately joined together.

[0034] The syringe body 18 includes a flange 42, a barrel 22 (e.g., cylindrical), a transition section 26 (e.g., in the form of a truncated cone; frustumly-shaped), and a discharge nozzle 30. The discharge nozzle 30 includes a discharge port 34. Fluid may be discharged from the syringe 14 through this discharge port 34. A check valve 50a may be disposed within the discharge nozzle 30, or more generally between the discharge port 34 and the push rod assembly 54. Preferably, all flow out of the syringe 14 is directed through the check valve 50a.

[0035] The syringe body 18 may also include a fill or refill port 46. A discharge from the fluid source 86 may be directed into the syringe 14 through this fill port 46. The fill port 46 may be disposed at any appropriate location relative to the syringe body 18. In the illustrated embodiment, the fill port 46 is disposed on the transition section 26 of the syringe body 18. Generally, it may be desirable for the fill port 46 to be located at or near the end of the discharge stroke of the push rod assembly 54. In any case, a check valve 50b may be disposed within the fill port 46, or more generally between the fluid source 86 and the interior of the syringe barrel 22. Preferably, all flow into the syringe 14 (from the fluid source 86) is directed through the check valve 50b.

[0036] The push rod assembly 54 extends within the syringe body 18, and furthermore is movable relative to the syringe body 18. The push rod assembly 54 includes a plunger head 58 and a plunger push rod 66 that extends from the plunger head 58. One or more annular sealing members 62 may be formed on a perimeter of the plunger head 58 and may engage an interior surface of the syringe body 18. Each such sealing member 62 may be of any appropriate size, shape, configuration, and/or type. Each sealing member 62 may be integrally-formed with the push rod assembly 54 as shown, although one or more sealing members could be separately formed and mounted on the plunger head 58 (e.g., an O-ring). Any sealing member that was separately mounted to the plunger head 58 would then become part of the plunger head 58.

[0037] Generally, the interface between the perimeter of the plunger head 58 and the interior of the syringe body 18 defines a second seal 64. Any appropriate shape for the perimeter of the plunger head 58 may be utilized to define the second seal 64 (e.g., different shapes of sealing members 62 may be appropriate; a cylindrical surface defining the perimeter of the plunger head 58 could be pressed against the interior of the syringe body 18 to define the second seal 64). In any case, fluid should be prevented from flowing past the second seal 64.

[0038] Since the plunger head 58 moves relative to the syringe body 18, so too does the second seal 64 and as indicated by the double-headed arrow A in FIG. 1. That is, the second seal 64 may be characterized as moving along with the push rod assembly 54 during use of the syringe 14. The second seal 64 may be characterized as being maintained in a fixed position relative to the push rod assembly 54. The second seal 64 may be characterized as staying in the same location with respect to the plunger head 58 as the plunger head 58 moves within and relative to the syringe body 18.

[0039] The plunger push rod 66 extends beyond a first end 38 of the syringe body 18 (where the first end 38 is opposite of the discharge port 34 in the illustrated embodiment). An actuation surface 70 is provided on an exposed end of the plunger push rod 66. A user may position a digit (e.g., a thumb) on this actuation surface 70 to advance the push rod assembly 54 toward the discharge nozzle 30 to discharge fluid from the syringe 14. Therefore, the syringe 14 may be characterized as being hand-actuated or hand-powered.

[0040] One or more sealing members 74 may be fixed relative to the syringe body 18 (e.g., mounted to the syringe body 18), and may engage the push rod assembly 54 to define a first seal 76. The push rod assembly 54 moves relative to this first seal 76the first seal 76 may stay in the same location as the push rod assembly 54 is moved. In the illustrated embodiment, the sealing member 74 is at least generally disposed at the first end 38 of the syringe body 18, and engages the plunger push rod 66. Each such sealing member 74 may be of any appropriate size, shape, configuration, and/or type (e.g., an O-ring).

[0041] The plunger head 58 may be characterized as separating the interior of the syringe body 18 into a fluid or discharge chamber 78 and a vacuum chamber 82. The discharge chamber 78 may be characterized as being disposed on one side of the plunger head 58, while the vacuum chamber 82 may be characterized as being disposed on the opposite side of the plunger head 58. Generally, the discharge chamber 78 is disposed on the side of the plunger head 58 that fluidly communicates with the discharge port 34, while the vacuum chamber 82 is disposed on the opposite side of the plunger head 58 (e.g., on the back side of the plunger head 58). Therefore, the vacuum chamber 82 extends between the second seal 64 (e.g., defined by the engagement of the movable plunger head 58 with the interior of the syringe body 18) and the first seal 76 (e.g., defined by the engagement of the sealing member 74 with the push rod assembly 54, specifically the plunger push rod 66 in the illustrated embodiment).

[0042] The spacing between the first seal 76 and the second seal 64 changes in response to movement of the push rod assembly 54 relative to the syringe body 18. When the push rod assembly 54 is moved toward the discharge port 34 (in the direction associated with a fluid discharge stroke), the spacing between the first seal 76 and the second seal 64 increases (e.g., by a movement of the second seal 64 relative to the stationary first seal 76). This reduces the size of the discharge chamber 78 (e.g., to provide a fluid discharge from the syringe 14) and increases the size of the vacuum chamber 82. When the push rod assembly 54 is moved away from the discharge port 34 (in the direction associated with a fluid-loading operation), the spacing between the first seal 76 and the second seal 64 decreases (e.g., by a movement of the second seal 64 relative to the stationary first seal 76). This increases the size of the discharge chamber 78 (e.g., to accommodate the loading of fluid therein) and decreases the size of the vacuum chamber 82.

[0043] The fluid source 86 is fluidly interconnected with the syringe 14 by a fill or refill line 90 that extends to the refill port 46 of the syringe 14. Any appropriate fluid may be utilized by the fluid source 86 (e.g., contrast media; a flushing agent such as saline or any other biocompatible media). The fill line 90 may be in the form of a conduit of any appropriate type (e.g., medical tubing).

[0044] The vacuum chamber 82 may provide the sole or primary force that moves the push rod assembly 54 in a manner that fills or refills the syringe 14 with fluid from the fluid source 86. FIGS. 2A-C present one embodiment of a refill sequence that uses a vacuum force to retract the syringe push rod assembly 54. The push rod assembly 54 is in its fully retracted position in FIG. 2A. A user may engage the actuation surface 70 of the push rod assembly 54, and push the push rod assembly 54 in the direction of the discharge port 34 and as shown in FIG. 2B (e.g., a movement in the direction of the arrow B). This increases the size of the vacuum chamber 82 and simultaneously reduces the size of the discharge chamber 78 (e.g., by increasing the spacing between the first seal 76 and the second seal 64, where the first seal 76 remains stationary relative to the push rod assembly 54 and where the second seal 64 moves along with the push rod assembly 54). The check valve 50b should preclude any fluid from being discharged into the fluid source 86 at this time. Moreover, this motion of the push rod assembly 54 should cause the check valve 50a to open such that fluid is discharged from the syringe 14 (a certain differential pressure may be required to open the check valve 50a). In FIGS. 2A and 2B, this fluid may be in the form of air, such that a patient should not be fluidly interconnected with the syringe 14 at this time. In any case, the noted motion should also progressively reduce the pressure within the vacuum chamber 82 (e.g., the pressure within the vacuum chamber 82 should become more negative as the push rod assembly 54 is advanced on a fluid discharge stroke), or stated another way the absolute value of the negative pressure within the vacuum chamber 82 should increase by a movement of the push rod assembly 54 toward the discharge port 34.

[0045] When the push rod assembly 54 has reached the end of a desired fluid discharge stroke and the user releases the push rod assembly 54, the suction forces within the vacuum chamber 82 should move the push rod assembly 54 toward (e.g., back to) its fully retracted position (e.g., in the direction of the arrow C in FIG. 2C). That is, the negative pressure within the vacuum chamber 82 should retract the push rod assembly 54. Retraction of the push rod assembly 54 decreases the size of the vacuum chamber 82 and simultaneously increases the size of the discharge chamber 78 (e.g., by decreasing the spacing between the first seal 76 and the second seal 64, where the first seal 76 remains stationary relative to the push rod assembly 54 and where the second seal 64 moves along with the push rod assembly 54). The retraction of the push rod assembly 54 should open the check valve 54b to draw fluid from the fluid source 86 into the syringe 14 via the fill port 46 and as shown in FIG. 2C. It should be appreciated that this retraction of the push rod assembly 54 may be initiated from various different positions within the syringe barrel 22 (e.g., the plunger head 58 need not be at or near the transition section 26 when the user releases the push rod assembly 54, such that it is thereafter retracted via the negative pressure in the vacuum chamber 82).

[0046] With fluid having been loaded in the syringe 14 in the above-noted manner (e.g., FIG. 2C), a patient may be fluidly interconnected with the syringe 14 in any appropriate manner (e.g., via medial tubing mounted on the discharge nozzle 30 of the syringe 14, 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 the actuation surface 70 of the push rod assembly 54, and push the push rod assembly 54 in the direction of the discharge port 34 (e.g., in the direction of arrow B in FIG. 2B). This again progressively increases the size of the vacuum chamber 82 and progressively reduces the pressure within the vacuum chamber 82. This also progressively reduces the size of the discharge chamber 78 such that fluid is discharged out of the syringe 14 through the discharge port 34 in the above-noted manner. When the desired amount of fluid has been discharged from the syringe 14, the user may release the push rod assembly 54, and the suction forces within the vacuum chamber 82 should again move the push rod assembly 54 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 the vacuum chamber 82 should again retract the push rod assembly 54, where this retraction should open the check valve 54b to draw fluid from the fluid source 86 into the syringe 14 via the fill port 46. This fill/discharge cycle may be repeated any number of times.

[0047] The syringe 14 could be configured such that the push rod assembly 54 is initially disposed in an extended position within the syringe body 18 (e.g., at its minimum spacing with the discharge port 34), and then retained or locked in this position in any appropriate manner. That is, there would be a vacuum or a negative pressure within the vacuum chamber 82 at this time. A user could release the push rod assembly 54 to allow fluid to be initially loaded into the syringe 14 from the fluid source 86 in the above-noted manner, namely where the suction force within the vacuum chamber 82 would retract the push rod assembly 54 (e.g., to the fully retracted position shown FIG. 2C). Thereafter, any number of discharge/fill cycles could be repeated in accordance with the foregoing.

[0048] One or more forces could be utilized to supplement the vacuum force for retracting the syringe push rod assembly 54, to in turn load fluid into the syringe 14 from the fluid source 86 in the above-noted manner. For instance, the pressure head within the fluid source 86 may contribute to retracting the push rod assembly 54 to load fluid into the syringe 14 from the fluid source 86. The pressure source 86 could also be pressurized, for instance by a pressurizing source 94 that is fluidly interconnected with the fluid source 86. Another option is illustrated in FIG. 3, where one or more biasing members (e.g., a spring) are used to bias the push rod assembly 54 toward/to its fully retracted position. Generally, one end of the biasing member 100 may be fixed relative to the push rod assembly 54 (e.g., its plunger head 58), while another end of the biasing member 100 may be fixed relative to the syringe body 18 (e.g., by a spring anchor 104). In this case, advancing the push rod assembly 54 on a discharge stroke increases the magnitude of the spring force in the biasing member 100 (or stated another way, increases the magnitude of the biasing force). Once the push rod assembly 54 is released, this spring or biasing force, along with the suction force that has developed within the vacuum chamber 82, retracts the push rod assembly 54 to draw fluid into the syringe body 18 from the fluid source 86.

[0049] 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.