Multi-chamber syringe with a plurality of plungers for continuously delivering fluid and method of use

Abstract

A multi-chamber syringe that continuously discharges a first fluid followed by a second fluid includes a container having a proximal end and a distal end including a fluid port for discharging the fluid within the container. The container defines a first chamber for containing the first fluid and a second chamber for containing the second fluid. The syringe also includes a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and a valve disposed within the container. The valve is configured to transition between a first position in which the flow of fluid from the first chamber through the valve is blocked and a second position in which the flow of fluid from the first chamber through at least one valve to the fluid port is permitted to discharge the first fluid from the container.

Description

Technical Field

[0001] Cross - reference to related applications This application claims priority to Indian Patent Application No. 202211036490, filed on June 24, 2022, entitled "Multi - chamber syringe and method of use having a plurality of plungers for continuously delivering fluids", the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] Field of the Invention The present invention generally relates to syringes for discharging a plurality of fluids, and more particularly to syringes for continuously discharging flush solutions and medical fluids.

Background Art

[0003] Description of the Related Art Vascular access devices (VADs) are commonly used medical devices and can include intravenous (IV) catheters such as peripheral catheters and central venous catheters. If not properly maintained or exposed to a non - sterile environment, VADs can become contaminated, blocked by thrombus, and / or spread infection. Many medical facilities implement sterilization procedures and protocols to ensure that VADs are used properly and do not lead to occlusion or infection. These protocols often include sterilization of VADs and flushing of catheters with flush solutions. Specifically, the implementation standards for VADs usually recommend that a flushing procedure be performed after catheter placement, before fluid injection, before and after drug administration, blood sampling, transfusion, and / or enteral nutrition administration.

[0004] These flushing procedures are intended to confirm the patency of the catheter, avoid drug incompatibilities, ensure that the full dose of the drug is administered to the patient, prevent thrombus formation, and minimize the risk of bloodstream infections caused by contamination of the VAD. Additionally, flushing can prevent blood deposition, blood residue, and accumulation of IV drugs within the catheter or other VAD devices. Such accumulations can lead to partial or complete occlusion of the fluid pathway within the catheter system, which may require the operator to perform certain expensive and potentially dangerous processes to decontaminate the affected catheter, or may require the operator to replace the occluded catheter with a new one. In many cases, such occlusions lead to treatment interruptions, which can interfere with patient care. The accumulation of residue within the catheter can also increase the risk of infection.

[0005] During administration of a drug or other medical fluid, the catheter or VAD is typically flushed both before and after delivering the fluid from a syringe or other drug delivery device to the VAD. In some cases, the catheter can be flushed using a syringe assembly pre-filled with various liquids (referred to herein as flush solutions). The size of the pre-filled syringe used to flush the catheter varies, for example, depending on the size and length of the catheter. Typically, pre-filled syringes for flushing a catheter or IV line contain a flush solution with a volume of about 1 mL, 3 mL, 5 mL, or 10 mL. Many different syringes commercially available from different manufacturers can be used to supply the flush solution through the patient's catheter or IV line, including, for example, the BD "PosiFlush" (registered trademark) pre-filled saline syringe from Becton Dickinson and Company.

[0006] To perform the flush procedure, the operator connects a pre-filled flush syringe to the VAD and advances the plunger rod within the barrel of the pre-filled syringe, which discharges the flush solution from the nozzle or fluid port of the pre-filled syringe into the VAD. After flushing, the pre-filled syringe is removed from the VAD and the operator may administer a dose of the medical fluid. Conventionally, the medical fluid is contained in a vial, drawn into a separate syringe, and the separate syringe is connected to the VAD after being filled with the medical fluid. Next, the medical fluid is injected into the VAD by advancing the plunger rod through the syringe containing the medical fluid. After the medical liquid has been injected into the VAD, the syringe is removed from the VAD and a second pre-filled flush syringe is used to flush the VAD. Flushing the VAD after administering the medical liquid confirms the patency of the catheter, delivers any residual medical liquid within the catheter to the patient, and ensures that a sufficient amount of the medical liquid is delivered to the patient.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Connecting a syringe or other device to a VAD, or removing a syringe or other device from a VAD, exposes a portion of the VAD to a non-sterile external environment, which increases the potential for the VAD to become contaminated and / or a source of bloodstream infection. To reduce the risk of bloodstream infection and ensure proper use and maintenance of the VAD, standard practice requires disinfecting and cleaning the fluid ports or connectors of the VAD each time a new syringe is connected to the VAD. Thus, reducing the number of syringes that must be connected to the VAD during a medication administration procedure simplifies the medication administration by reducing the number of times each part of the VAD is disinfected and cleaned. Reducing the number of syringes or other fluid delivery devices used during the procedure also reduces the chance that a portion of the VAD will become contaminated, thereby reducing the risk of bloodstream infection. The syringe and method of the present disclosure simplify the medication administration procedure by reducing the number of syringes used during such a procedure, thereby reducing the risk of contamination and bloodstream infection. **Means for Solving the Problems**

[0009] **Summary of the Invention** According to one aspect of the present disclosure, a multi-chamber syringe for continuously discharging at least a first fluid and subsequently a second fluid includes a container having a proximal end and a distal end, the distal end including a fluid port for discharging the first fluid and the second fluid from the container. The container defines a first chamber for containing the first fluid and a second chamber for containing the second fluid. The syringe also includes a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and at least one valve disposed within the container. The at least one valve is configured to transition between a first position in which flow of fluid from the first chamber through the valve is blocked and a second position in which flow of fluid from the first chamber through the at least one valve to the fluid port for discharging the first fluid from the container is permitted.

[0010] According to another aspect of the present disclosure, a pre-filled flushing syringe includes any of the syringes described above and a predetermined amount of a first fluid disposed within a first chamber of the pre-filled syringe. The valve is initially in a first position, thereby preventing the first fluid disposed within the first chamber from passing through at least one valve out of the first chamber.

[0011] According to another aspect of the present disclosure, a method of sequentially discharging fluid from one of the syringes described above includes moving the valve to a second position such that flow of fluid from the first chamber through the valve to the fluid port is permitted, moving a first plunger through the first chamber to discharge the first fluid from the first chamber through the fluid port, moving at least one valve to the first position such that flow of fluid from the second chamber through at least one valve to the fluid port is permitted, and moving a second plunger through the second chamber to discharge the second fluid from the second chamber through the fluid port.

[0012] According to another aspect of the present disclosure, a syringe includes a housing having an upper barrel and a lower barrel. The upper barrel includes an open proximal end, a distal end, a sidewall extending between the proximal end and the distal end, and a partition extending axially through the barrel and separating the barrel into a first chamber configured to contain a first fluid and a second chamber configured to contain a second fluid. The lower barrel is connected to the distal end of the upper barrel and includes a fluid port. The syringe also includes a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and a manually operable valve disposed within the lower barrel. The manually operable valve is configured to be movable between a first position in which flow of fluid from the second chamber through the valve to the fluid port is permitted to discharge the second fluid from the syringe and a second position in which flow of fluid from the first chamber through the valve to the fluid port is permitted to discharge the first fluid from the syringe.

[0013] According to another aspect of the present disclosure, a syringe includes a barrel having an open proximal end, a distal end including a frustoconical portion and a fluid port, a cylindrical sidewall between the proximal end and the distal end, and a partition extending axially through the barrel and separating the barrel into a first chamber configured to contain a first fluid and a second chamber configured to contain a second fluid. The syringe also includes a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and a compressible bellows disposed within the first chamber. The compressible bellows is configured to move between a non-biased position where fluid flow from the first chamber is blocked and a biased position where fluid flow from the first chamber to the fluid port is permitted.

[0014] Next, non-limiting, exemplary examples of embodiments of the present disclosure will be described in the following numbered items.

[0015] Item 1: A multi-chamber syringe for continuously discharging at least a first fluid and subsequently a second fluid, the syringe comprising a container including a proximal end and a distal end having a fluid port for discharging the first fluid and the second fluid from the container, the container defining a first chamber for containing the first fluid and a second chamber for containing the second fluid, a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and at least one valve disposed within the container and configured to transition between a first position where fluid flow from the first chamber through the at least one valve is blocked and a second position where fluid flow from the first chamber through the at least one valve to the fluid port is permitted for discharging the first solution from the container.

[0016] Item 2: A syringe of Item 1, wherein the first chamber and the second chamber extend axially of the container, and the longitudinal axis of the first chamber is substantially parallel to the longitudinal axis of the second chamber.

[0017] Item 3: A syringe of Item 1 or Item 2, wherein when at least one valve is in a first position, flow of fluid from the second chamber through at least one valve to a fluid port for discharging a second fluid from the container is permitted, and when at least one valve is in a second position, flow of fluid from the second chamber through at least one valve is blocked.

[0018] Item 4: A syringe of any one of Items 1 - 3, wherein when at least one valve is in a first position, moving the second plunger proximally through the second chamber draws the second fluid into the second chamber.

[0019] Item 5: A syringe of any one of Items 1 - 4, wherein the container comprises an upper barrel including the first chamber and the second chamber, and a lower barrel connected to the distal end of the upper barrel and surrounding at least one valve.

[0020] Item 6: A syringe of Item 5, wherein the upper barrel comprises an open proximal end, a distal end, an annular sidewall extending between the open proximal end and the open distal end, and an axially extending partition extending from the open proximal end to the distal end of the upper barrel and separating the first chamber from the second chamber.

[0021] Item 7: A syringe according to Item 5 or Item 6, further comprising at least one seal covering the open distal end of the upper barrel, the at least one seal having a first opening that permits a first fluid to flow from the first chamber to the at least one valve when at least one valve is in a second position, and a second opening that permits a second fluid to flow from the second chamber through the at least one valve when at least one valve is in a first position.

[0022] Item 8: A syringe according to Item 7, wherein the at least one seal comprises a proximal seal disposed between the distal end of the upper barrel and the at least one valve, and a distal seal disposed between the at least one valve and the distal end of the lower barrel.

[0023] Item 9: A syringe according to Item 7 or Item 8, wherein the first plunger and / or the second plunger comprises a stopper having a flat distal surface, and a protrusion extending from the flat distal surface and arranged to be inserted into the first opening or the second opening to completely discharge the first fluid from the first chamber or the second fluid from the second chamber.

[0024] Item 10: A syringe according to any of Items 5-9, wherein the upper barrel is connected to the lower barrel by ultrasonic welding.

[0025] Item 11: A syringe according to any of Items 1-10, wherein the upper barrel and the lower barrel comprise at least one of polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene.

[0026] Item 12: A syringe according to any of Items 1-11, wherein the first plunger comprises a first stopper within the first chamber, and a first plunger rod connected to the first stopper and extending from the first stopper through the proximal end of the container.

[0027] Item 13: The syringe of item 12, wherein the first plunger rod comprises a tab configured to contact a portion of the container when the first rod is moved through the first chamber, thereby providing feedback that an initial amount of the first fluid has been discharged from the first chamber.

[0028] Item 14: The syringe of item 12 or 13, wherein the second plunger comprises a second stopper within the second chamber and a second plunger rod connected to the second stopper and extending from the second stopper through the proximal end of the container.

[0029] Item 15: The syringe of item 14, wherein the first chamber and the second chamber have a semi-circular cross-sectional shape, and the first stopper and the second stopper have a semi-circular flat distal surface corresponding to the cross-sectional shape of the first chamber or the second chamber.

[0030] Item 16: The syringe of item 14 or 15, further comprising at least one removable cap that engages between the container and the first plunger rod and / or the second plunger rod, preventing movement of the plunger rod until at least one removable plunger cap is removed from the syringe.

[0031] Item 17: The syringe of any one of items 14 - 16, wherein the first stopper and / or the second stopper comprises a thermoplastic elastomer such as isoprene.

[0032] Item 18: The syringe of any one of items 14 - 17, wherein the first stopper and / or the second stopper comprises a proximal end, a distal end, and an outer surface extending between the proximal end and the distal end and sealingly contacting the inner surface of the container.

[0033] Item 19: A syringe according to any one of Items 14 - 18, wherein the first plunger rod and / or the second plunger rod is inserted into the cavity of the first stopper and / or the second stopper and engages with the first stopper and / or the second stopper, and the syringe comprises a connector portion for fixing the first stopper and / or the second stopper to the first plunger rod and / or the second plunger rod.

[0034] Item 20: A syringe according to any one of Items 14 - 19, wherein at least one valve comprises a body having a channel that is fluidly connected to the second chamber when the at least one valve is in a first position and fluidly connected to the first chamber when the at least one valve is in a second position.

[0035] Item 21: The syringe of Item 20, wherein the body comprises a rotary disk and a knob extending through an opening of the container for rotating the disk between a first position and a second position.

[0036] Item 22: The syringe of Item 21, wherein the disk is rotated between the first position and the second position by 80 degrees - 120 degrees.

[0037] Item 23: A syringe according to any one of Items 1 - 4, wherein the container comprises an annular side wall, a frustoconical portion extending from the annular side wall to a fluid port, and a partition extending through the barrel and separating the first chamber from the second chamber.

[0038] Item 24: The syringe of Item 23, wherein the first plunger comprises a first stopper having a substantially flat distal surface and a first plunger rod connected to the first stopper and extending proximally from the first stopper.

[0039] Item 25: The syringe of item 24, wherein the second plunger comprises a second stopper having a semi-conical distal face sized to be received within the frustoconical portion of the barrel, and a second plunger rod connected to the second stopper and extending proximally from the second stopper.

[0040] Item 26: The syringe of item 25, wherein the first plunger rod comprises a first tab disposed proximate the distal end of the first plunger rod and configured to contact the barrel, the first tab preventing the first plunger rod from being moved distally through the first chamber to discharge the first fluid from the first chamber.

[0041] Item 27: The syringe of item 26, wherein the second plunger rod comprises a second tab disposed proximate the proximal end of the second plunger rod and configured to contact and push down the first tab, whereby the first plunger rod can be moved through the first chamber.

[0042] Item 28: The syringe of any one of items 23 - 27, wherein at least one valve comprises a compressible body that blocks the flow of fluid from the first chamber to the fluid port in the expanded position and permits the flow of fluid from the first chamber to the fluid port in the compressed position.

[0043] Item 29: The syringe of item 28, wherein the barrel comprises at least one slot that defines a flow path for the flow of fluid from the first chamber to the fluid port, the at least one slot being arranged such that the flow of fluid through the at least one slot is blocked when the compressible body is in the expanded position and the flow of fluid to the fluid port through the at least one slot is permitted when the compressible body is in the compressed position.

[0044] Item 30: The syringe of item 29, wherein at least one slot is an opening extending through the partition of the barrel, and when the second stopper is in the most distal position within the second chamber, the second stopper seals a portion of at least one slot and prevents the first fluid from flowing into the second chamber.

[0045] Item 31: The syringe according to any one of items 28 - 30, wherein the compressible body comprises a semi-conical distal surface configured to be disposed in the frustoconical portion of the barrel and at least one radially extending rib configured to contact the inner surface of the cylindrical sidewall of the barrel to seal the first fluid within the first chamber.

[0046] Item 32: A pre-filled flushing syringe comprising the syringe according to any one of items 1 to 31 and a predetermined amount of a first fluid disposed within the first chamber of the pre-filled syringe, wherein at least one valve is initially in a first position, thereby preventing the first fluid disposed within the first chamber from passing through at least one valve out of the first chamber.

[0047] Item 33: The pre-filled syringe of item 32, wherein the first fluid is a physiological saline flush solution.

[0048] Item 34: The pre-filled syringe of item 32 or item 33, further comprising a removable plunger cap engaged between the first plunger and / or the second plunger and the container to prevent movement of the plunger until the cap is removed.

[0049] Item 35: A method of continuously discharging fluid from any one of syringes of Items 1-31, the method comprising moving at least one valve to a second position so that flow of fluid from a first chamber to a fluid port through at least one valve is permitted; moving a first plunger through the first chamber to discharge a first fluid from the first chamber through the fluid port; moving at least one valve to a first position so that flow of fluid from a second chamber to a fluid port through at least one valve is permitted; and moving a second plunger through the second chamber to discharge a second fluid from the second chamber through the fluid port.

[0050] Item 36: The method of Item 35, further comprising drawing a second fluid into the second chamber by moving a second plunger distally through the second chamber with at least one valve initially in the first position.

[0051] Item 37: The method of Item 36, wherein drawing the second fluid further comprises attaching a needle to the fluid port of a container, inserting the needle into the fluid container, and drawing the second fluid from the fluid container into the second chamber of the syringe.

[0052] Item 38: The method of any one of Items 35-37, wherein the syringe is provided partially pre-filled and contains a predetermined amount of a first fluid in the first chamber.

[0053] Item 39: The method of any one of Items 35-38, further comprising attaching at least one patient line to the fluid port of the syringe before discharging the second fluid from the second chamber through the fluid port.

[0054] Item 40: The method of any one of Items 35-39, wherein the first fluid includes a flush solution such as saline and / or a heparin lock flush solution, and the second fluid includes a therapeutic agent.

[0055] Item 41: A method according to any of the methods of items 35 - 40, wherein the first plunger comprises a plunger rod having a tab configured to contact a portion of the container when the first plunger rod is moved through the first chamber, thereby providing feedback that an initial amount of the first fluid has been discharged from the first chamber, and moving the first plunger through the first chamber to discharge the first fluid from the first chamber through the fluid port comprises discharging the initial amount of the first fluid by moving the first plunger through the first chamber until the tab contacts the container before discharging the second fluid, discharging the remaining amount of the first fluid from the first chamber by continuing to move the first plunger through the first chamber after the second fluid has been discharged from the second chamber.

[0056] Item 42: A syringe, the syringe comprising a housing comprising: (i) an upper barrel having an open proximal end, a distal end, and a sidewall extending between the proximal end and the distal end, and a partition axially extending through the barrel and separating the barrel into a first chamber configured to contain a first fluid and a second chamber configured to contain a second fluid; (ii) a lower barrel connected to the distal end of the upper barrel and including a fluid port; a first plunger for discharging the first fluid from the first chamber; a second plunger for discharging the second fluid from the second chamber; and a manually operable valve disposed within the lower barrel, the valve being configured to be moved between a first position in which flow of fluid from the second chamber through the valve to the fluid port is permitted to discharge the second fluid from the syringe and a second position in which flow of fluid from the first chamber through the valve to the fluid port is permitted to discharge the first fluid from the syringe.

[0057] Item 43: A syringe according to item 42, wherein the first chamber and the second chamber extend axially through an upper barrel, and the longitudinal axis of the first chamber is substantially parallel to the longitudinal axis of the second chamber.

[0058] Item 44: A syringe according to item 42 or 43, wherein when a manually operable valve is in a first position, the flow of fluid from the first chamber through the valve is blocked, and when the valve is in a second position, the flow of fluid from the second chamber through the valve is blocked.

[0059] Item 45: A syringe according to item 44, further comprising at least one seal covering the open distal end of the upper barrel, the at least one seal having a first opening that permits the first fluid to flow from the first chamber to the valve when the valve is in the second position, and a second opening that permits the second fluid to flow from the second chamber through the valve when the valve is in the first position.

[0060] Item 46: A syringe according to item 45, wherein the at least one seal comprises a proximal sheet disposed between the distal end of the upper barrel and the valve, and a distal sheet disposed between the valve and the distal end of the lower barrel.

[0061] Item 47: A syringe according to any of items 42 - 46, wherein the upper barrel is connected to the lower barrel by ultrasonic welding.

[0062] Item 48: A syringe according to any of items 42 - 47, wherein the first plunger comprises a first stopper within the first chamber and a first rod connected to the first stopper and extending from the first stopper through the proximal end of the upper barrel.

[0063] Item 49: The syringe of item 48, wherein the first plunger rod comprises a tab extending from the first plunger rod that contacts a portion of the upper barrel when the first plunger rod is moved from the first chamber, thereby providing feedback that an initial amount of the first fluid has been discharged from the first chamber.

[0064] Item 50: The syringe of any one of items 42 - 49, wherein the manually operable valve comprises a body having a through-hole defining a flow path, the through-hole being fluidly connected to the second chamber when the valve is in a first position and fluidly connected to the first chamber when the valve is in a second position.

[0065] Item 51: The syringe of item 50, wherein the body comprises a rotating disk and a tab extending through an opening in the lower barrel for rotating the disk between a first position and a second position.

[0066] Item 52: A syringe comprising a barrel having an open proximal end, a distal end comprising a frustoconical portion and a fluid port, a cylindrical sidewall between the proximal end and the distal end, a partition extending axially through the barrel and separating the barrel into a first chamber configured to contain a first fluid and a second chamber configured to contain a second fluid, a first plunger for discharging the first fluid from the first chamber, a second plunger for discharging the second fluid from the second chamber, and a compressible bellows disposed within the first chamber and configured to move between a non-biased position where flow of fluid from the first chamber is blocked and a biased position where flow of fluid from the first chamber to the fluid port is permitted.

[0067] Item 53: The syringe of item 52, wherein the first chamber and the second chamber extend axially through the barrel and the longitudinal axis of the first chamber is substantially parallel to the longitudinal axis of the second chamber.

[0068] Item 54: A syringe according to item 52 or 53, wherein the first plunger comprises a first stopper having a substantially flat distal surface within the first chamber, and a first rod connected to the first stopper and extending from the first stopper through the proximal end of the barrel.

[0069] Item 55: A syringe according to item 54, wherein the second plunger comprises a second stopper having a semi-conical distal surface within the second chamber, and a second rod connected to the second stopper and extending from the second stopper through the proximal end of the barrel.

[0070] Item 56: A syringe according to item 55, wherein the barrel comprises at least one slot for flowing a first fluid from the first chamber to a fluid port, and the at least one slot is arranged such that when the compressible bellows is in an unbiased position, the flow of fluid to the at least one slot is prevented, and when the compressible bellows is in a biased position, the flow of fluid to the fluid port through the at least one slot is allowed.

[0071] Item 57: A syringe according to item 56, wherein the at least one slot is an opening extending through a partition of the barrel, and when the second stopper is in the most distal position within the second chamber, the second stopper seals a part of the at least one slot to prevent the first fluid from flowing into the second chamber.

[0072] Item 58: A syringe according to any one of items 52 - 57, wherein the compressible bellows comprises a semi-conical distal surface configured to be disposed in a frustoconical portion of the barrel, and at least one radially extending rib configured to contact an inner surface of a cylindrical sidewall of the barrel to seal the first fluid within the first chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0073]

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DETAILED DESCRIPTION OF THE INVENTION

[0074] Description of the Invention The following description is provided to enable one of ordinary skill in the art to make and use the described embodiments, which are contemplated for carrying out the present invention. However, various modifications, equivalents, variations, and alternatives will be readily apparent to those of ordinary skill in the art. All such modifications, changes, equivalents, and alternatives are intended to be included within the spirit and scope of the present invention.

[0075] For the following description, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal", and their derivatives will be relevant to the present invention as they are oriented in the drawings. As used herein, the term "proximal" refers to a part or end of a device, such as a syringe or catheter, that is grasped, manipulated, or used by an operator or other user. The term "distal" refers to the end or part of the device that is farthest from the part of the device that is grasped, manipulated, and used by the operator. For example, the "proximal end" of a catheter or IV line refers to the end that includes a liquid port connected to a liquid container, such as an IV bag or syringe. The "distal end" of a catheter or IV line refers to the end that is connected to a patient. However, it should be understood that the present invention may contemplate alternative variations and sequences of steps, unless explicitly specified to the contrary. Also, the specific devices and processes shown in the accompanying drawings and described in the following specification are merely exemplary embodiments of the present invention. Accordingly, the specific dimensions and other physical characteristics related to the embodiments disclosed herein should not be considered limiting.

[0076] Referring to the figures, the present disclosure is directed to multi-chamber syringes 10, 210 that discharge a first fluid F1 and a second fluid F2 from a container or barrel through the fluid ports or nozzles of the syringes 10, 210, for example, into a vascular access device (VAD). The first fluid F1 can be a flush solution such as saline and / or a heparin lock flush solution. An example of a saline flush solution is 0.9% sodium chloride USP for injection. An example of a heparin lock flush solution is 0.9% sodium chloride containing 100 USP units of sodium heparin per mL or 10 USP units of sodium heparin per mL. Other flush solutions known in the art can also be used with the syringes 10, 210 of the present disclosure. The second fluid F2 can be a medical fluid, which, as used herein, can refer to a drug, a total parenteral nutrition (TPN) solution, or other therapeutic agents used in the treatment of chronic or acute conditions known in the art. Exemplary therapeutic agents can include, for example, drugs, chemicals, biological or biochemical substances that achieve a desired therapeutic effect when delivered to a patient in a therapeutically effective amount.

[0077] In some examples, the syringes 10, 210 are configured to perform two steps or aspects of an injection procedure, specifically, injecting a medical fluid and then injecting a flush solution. In other examples, the syringes 10, 210 are configured to perform three steps or aspects of an injection procedure, specifically, injecting a first quantity of a flush solution (the first fluid F1) to prepare and / or confirm patency of the patient line (referred to herein as a primary flush or a pre-flush), followed by injecting a quantity of a medical fluid (the second fluid F2), followed by injecting a second quantity of a flush solution (the first fluid F1) to flush the patient line and confirm that all of the medical fluid has passed from the patient line into the patient (referred to herein as a post-flush). The syringes 10, 210 of the present disclosure can also be used to continuously deliver a different second drug or therapeutic agent after a first drug or therapeutic agent.

[0078] The syringes 10, 210 of the present disclosure enable an operator, such as a medical technician, nurse, physician assistant, physician, or other trained or untrained clinician or healthcare provider, to administer, for example, a drug and then administer a flush solution without having to exchange syringes between the delivery of a first fluid and a second fluid. Thus, pre-flush, drug injection, and post-flush can be performed immediately one after another, avoiding the delays caused by switching different syringes or infusion devices.

[0079] In some examples, the syringes 10, 210 are provided as partially filled syringes, and the chambers of the syringes 10, 210 are filled with a flush solution during manufacture. The partially pre-filled syringes 10, 210 may include caps, clips, retainers, and / or other packaging to hold the plunger rod in a predetermined position and ensure that the flush solution does not leak from the partially pre-filled syringes 10, 210 during unexpected times such as during transportation.

[0080] The syringes 10, 210 of the present disclosure are also configured to enable an operator to aspirate a medical fluid into the syringes 10, 210 before fluid delivery to a patient. For example, the operator can insert the nozzle or needle of the syringes 10, 210 into a vial containing the medical fluid, and then aspirate the medical fluid into the fluid chamber of the syringes 10, 210 by moving the plunger rod of the syringes 10, 210 in the proximal direction. After the medical fluid is aspirated into the fluid chamber of the syringes 10, 210, the syringes 10, 210 are connected to the fluid port of the VAD, and the delivery of the first fluid F1 and the subsequent delivery of the second fluid F2 can occur by discharging the first fluid and the second fluid in sequence.

[0081] The syringes 10, 210 of the present disclosure simplify the fluid administration procedure by eliminating the need to flush or disinfect a portion of the VAD between the delivery of the first fluid and the second fluid, providing a significant time savings compared to conventional fluid administration methods. The syringes 10, 210 of the present disclosure also reduce the risk of infection and allow for subsequent flushing of the VAD immediately following the administration of the medical fluid, which can prevent occlusion of the drug within the VAD. Further, the syringes 10, 210 of the present disclosure have little or zero dead space, which means that all of the medical fluid contained within the first chamber of the syringes 10, 210 is flushed from the syringes 10, 210 when a second fluid (e.g., flush solution) moves through the syringes 10, 210 into the VAD. Multi-chamber syringe for continuous drug administration Figures 1A - 4B show examples of a multi-chamber syringe 10 for sequentially discharging a first fluid F1 contained in a first fluid chamber 12 and a second fluid F2 contained in a second fluid chamber 14. For example, the syringe 10 can be configured to perform a two-stage fluid delivery that discharges a predetermined amount of the second fluid F2 from the second chamber 14, followed by discharging a predetermined amount of the first fluid F1 from the first chamber 12. In other examples, the syringe 10 can be configured to perform a three-stage fluid delivery that includes discharging a predetermined amount of the first fluid F1 from the first chamber 12, followed by discharging a predetermined amount of the second fluid F2 from the second chamber 14, followed by discharging the remaining amount of the first fluid F1 from the first chamber 12.

[0082] As described above, in some examples, the first fluid F1 can be a flush solution such as saline, and / or an anticoagulant such as heparin. The type and amount of the flush solution contained in the first chamber 12 can be varied, for example, according to the particular type of catheter or IV line being used. In some examples, the syringe 10 is partially pre-filled to contain, for example, from about 1 mL to 20 mL of the first fluid F1, or preferably, from about 5 mL to about 10 mL of the first fluid F1. The second fluid F2 can be a medical fluid such as a drug or other therapeutic agent intended to be delivered to a patient through a VAD such as a catheter or IV line.

[0083] In some examples, the syringe 10 comprises a container 16 or housing that defines or surrounds the first chamber 12 and the second chamber 14. The container 16 can comprise an open proximal end 18 and a distal end 20 with a fluid port 22 or nozzle for discharging the fluids F1, F2 from the container 16. The fluid port 22 of the container 16 can be a connector such as a luer connector, a threaded connector, or a snap connector configured to be connected to a needle, for example, to access the interior of a medical vial containing a medical fluid. The fluid port 22 can also be configured to be connected, directly or indirectly, to a fluid port, valve, or other end access portion of the VAD. For example, a common type of fluid port of the VAD is a pierceable septum or a septum with a slit made of rubber or other elastomeric material, which allows the insertion of a sharp or blunt needle cannula to inject fluid into or withdraw fluid from the VAD catheter. Another common fluid port of the VAD is a valve, which does not require a needle to access the VAD. Instead, the valve can be actuated by the frustoconical tip of the syringe barrel 16 to provide fluid communication between the interior of the container 16 and the VAD.

[0084] In some examples, the first chamber 12 and the second chamber 14 are parallel or substantially parallel cavities or spaces that extend axially through the container 16. For example, the longitudinal axis L1 of the first chamber 12 (shown in FIG. 3A) can be parallel or substantially parallel to the longitudinal axis L2 of the second chamber 14 (shown in FIG. 3A). As used herein, "substantially parallel" means that the axis L1 is approximately parallel to the axis L2. For example, the axis L1 can be tilted by a small amount, such as less than 5 degrees, with respect to the axis L2. The chambers 12, 14 can be of any convenient shape determined based on the dimensions of the container 16 of the syringe 10 and / or other components. For example, the first chamber 12 and the second chamber 14 can have a semi-circular cross-sectional shape, as well as an elliptical, circular, square, triangular, or rectangular shape.

[0085] In some examples, the container 16 is a syringe barrel, such as a barrel of a conventional fluid delivery syringe used in medical procedures, which is manufactured, for example, by an injection molding process. For example, the container 16 or barrel can be substantially similar in shape, size, and configuration to a barrel of a syringe used to administer a flush solution to a VAD, as known in the art. The container 16 or barrel can be a cylindrical or elliptical columnar structure formed from a rigid thermoplastic material, such as polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, acrylonitrile butadiene styrene, or other injection molding or moldable resin materials known in the art. An exemplary barrel for a flush syringe is described, for example, in Patent Document 1 entitled "Flush Syringe Assembly with Controlled Pulsatile Flushing", which is hereby incorporated by reference in its entirety.

[0086] In other examples, the container 16 can be formed from a plurality of separately molded parts that are joined to form the container 16. For example, the container 16 can include an upper barrel 24 that surrounds the first chamber 12 and the second chamber 14, and a lower barrel 26 connected to the upper barrel 24. Similar to many conventional syringe barrels, the upper barrel 24 and the lower barrel 26 of the container 16 can be formed from at least one of polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or acrylonitrile butadiene styrene.

[0087] In some examples, the upper barrel 24 of the container 16 includes an open proximal end 28, a distal end 30, and an annular side wall 32 extending between the open proximal end 28 and the distal end 30. The distal end 30 of the upper barrel 24 can be open or substantially closed, but can include an opening that permits fluid contained within the chambers 12, 14 to pass through the distal end 30 of the upper barrel 24 from the chambers 12, 14. The upper barrel 24 also includes a partition 34, such as an axially extending wall or septum, that extends from the open proximal end 28 to the distal end 30 of the upper barrel 24 and separates the first chamber 12 from the second chamber 14. In some examples, the partition 34 is disposed centrally within the container 16 and separates the container 16 into a first chamber 12 and a second chamber 14 having the same or substantially the same fluid volume. In other examples, the partition 34 can be offset or separated from the longitudinal axis of the container 16, which means that the chambers 12, 14 can contain different fluid volumes. The lower barrel 26 of the container 16 can include an open proximal end 36, a closed distal end 38 that includes the fluid port 22 of the container 16, and an annular side wall 40 extending between the proximal end 36 and the distal end 38. The upper barrel 24 can be joined to the lower barrel 26 by any suitable fastener or adhesive known in the art. In some examples, the upper barrel 24 and the lower barrel 26 are joined by ultrasonic welding. For example, as shown in FIGS. 4A and 4B, the proximal end 36 of the lower barrel 26 can be joined to the distal end 30 of the upper barrel 24 at an ultrasonic weld joint 70 (shown in FIG. 4B).

[0088] In some examples, syringe 10 further includes a seal, herein referred to as proximal seal 42, that covers distal end 30 of upper barrel 24 to seal the fluids within chambers 12, 14 of container 16. Proximal seal 42 can be a substantially flat sheet made of a liquid-impermeable material such as silicone that is slightly smaller than the cross-section of upper barrel 24. Proximal seal 42 is disposed at distal end 30 of upper barrel 24 and can be held in place by valve 44 disposed distally of seal 42 or by contact between seal 42 and, for example, the inner surface of sidewall 40 of lower barrel 26. In some examples, proximal seal 42 includes a first opening 46 (most clearly shown in FIG. 2B) that permits first fluid F1 to flow from first chamber 12 through valve 44 to fluid port 22. Proximal seal 42 can also include a second opening 48 (most clearly shown in FIG. 2B) that permits second fluid F2 to flow through valve 44 from second chamber 14. Syringe 10 can also include a distal seal 50 that is similar or identical in size and shape to proximal seal 42 and is disposed between valve 44 and distal end 38 of lower barrel 26.

[0089] Syringe 10 also includes a plurality of plungers configured to move through chambers 12, 14 of container 16, through fluid port 22 at distal end 20 of container 16, to draw second fluid F2 into second chamber 14, and / or to expel fluids F1, F2 from chambers 12, 14. For example, syringe 10 can include a first plunger 52 that moves through first chamber 12 and a second plunger 54 that moves through second chamber 14. First plunger 52 can include a first stopper 56 (most clearly shown in FIG. 2A) within first chamber 12 and a first plunger rod 58 connected to first stopper 56 and extending from first stopper 56 through proximal end 18 of container 16. Second plunger 54 can include a second stopper 60 within second chamber 14 and a second plunger rod 62 connected to second stopper 60 and extending from second stopper 60 through proximal end 18 of container 16.

[0090] The first and second stoppers 56, 60 can have many features of conventional syringe stoppers or plungers known in the art. For example, the stoppers 56, 60 can be formed from a thermoplastic elastomer material such as polypropylene or polyethylene, as well as synthetic rubber or natural rubber (e.g., isoprene). The first stopper 56 and / or the second stopper 60 can include a proximal face 64 or proximal end, a distal face 66 or distal end, and an outer peripheral surface 68 extending between the proximal face 64 and the distal face 66. The outer peripheral surface 68 can be configured to seal in contact with the inner surface of the side wall 32 of the upper barrel 24 to move the fluids F1, F2 through the chambers 12, 14 of the container 16. In some examples, the distal end or distal face 66 of the stoppers 56, 60 can be substantially flat. Further, the distal face 66 of the stoppers 56, 60 can be semi-circular corresponding to the cross-sectional shape of the first chamber 12 and / or the second chamber 14. In some examples, as most clearly shown in FIG. 2A, the stoppers 56, 60 can also include protrusions 72 configured to be inserted into and engage the openings 46, 48 of the proximal seal 42 to eliminate the dead space within the openings 46, 48. For example, the first stopper 56 can include a protrusion 72 that passes through the first opening 46 when the first stopper 56 is in the most distal position within the first chamber 12, which ensures that all of the first fluid F1 is discharged from the first chamber 12 to the valve 44. Similarly, the second stopper 60 can include a protrusion 72 arranged to be inserted into the second opening 48 when the second stopper 60 is in the most distal position, ensuring that all of the second fluid F2 is discharged from the second chamber 14.

[0091] As described above, the second stopper 60 can be configured to move through the second chamber 14 to aspirate fluid into the container 16. For example, as indicated by arrow P in FIG. 3B, movement of the second stopper 60 in the proximal direction through the second chamber 14 aspirates the second fluid F2 into the second chamber 14 through the fluid port 22 of the container 16. As will be described in more detail below, as indicated by arrow D in FIG. 3D, movement of the first stopper 56 in the distal direction through the first chamber 12 discharges the first fluid F1 from the first chamber 12. Similarly, movement of the second stopper 60 in the distal direction through the second chamber 14 (indicated by arrow D in FIG. 3E) discharges the second fluid F2, such as a medical fluid, from the second chamber 14.

[0092] The plungers 52, 54 may also include plunger rods such as a first plunger rod 58 connected to the first stopper 56 and a second plunger rod 62 connected to the second stopper 60. The plunger rods 58, 62 can be injection molded parts formed from a rigid thermoplastic material, such as, for example, polyester, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, or other thermoplastic materials known in the art. The plunger rods 58, 62 may include a distal end 78 that engages one of the stoppers 56, 60. For example, the distal ends 78 of the plunger rods 58, 62 may include an annular connector 80 that is inserted into a corresponding cavity 82 (shown in FIG. 1B) or slot in the proximal surface 64 of the stoppers 56, 60. The plunger rods 58, 62 also include a proximal end 84 that projects proximally from the proximal end 18 of the container 16 and a body that extends between the proximal end 84 and the distal end 78 of the plunger rods 58, 62. The proximal ends 84 of the plunger rods 58, 62 may include a thumb press plate 88 for operating the plunger rods 58, 62 to move the stoppers 56, 60 through the container 16. The bodies of the plunger rods 58, 62 may have various cross-sectional shapes and configurations within the scope of the present disclosure. For example, the body may have a generally cross-shaped cross-section. In other examples, the cross-section of the plunger rods 58, 62 may be an I-beam shape, a hollow circle, a hollow square, a hollow rectangle, or an L-shape. In some examples, the syringe 10 may also include a removable plunger cap 90 (shown in FIG. 3A), which engages between the thumb press plate 88 of one or both of the plunger rods 58, 62 and the proximal end 18 of the container 16 and prevents movement of the plunger rods 58, 62 until the removable plunger cap 90 is removed from the syringe 10. For example, as shown in FIG. 3A, the removable cap 90 may be engaged with the first plunger rod 58 and limit movement through the first chamber 12 of the first plunger rod 58.

[0093] In some examples, the first plunger rod 58 may further include a tab 92 configured to contact a portion of the container 16 when the first plunger rod 58 is moved through the first chamber 12. The tab 92 may be disposed on the plunger rod 58 and provides a tactile feedback that an initial amount of the first fluid F1 has been discharged from the first chamber 12. As described in more detail herein, the tactile feedback provided by the tab 92 assists the practitioner in performing the three-stage liquid discharge procedure. In particular, the practitioner may push the first plunger rod 58 and the first stopper 56 through the first chamber 12 of the container 16 until the practitioner feels the tactile feedback from the tab 92, and the tactile feedback indicates that an initial amount of the first fluid F1, such as a flush solution, sufficient to prepare and confirm the patency of the patient line has been discharged from the container 16. Next, the practitioner may move the second plunger rod 62 and the second stopper 60 through the second chamber 14 to discharge a second fluid F2, such as a medical fluid, into the patient line. Finally, the practitioner applies sufficient force to the first plunger rod 52 to cause the tab 92 to deform or bend, enabling the first plunger rod 52 and the stopper 56 to move through the first chamber 12 and discharging the remaining amount of the first fluid F1 from the first chamber 12.

[0094] Syringe 10 may also include a valve 44 disposed within container 16 and configured to control the continuous flow of fluid from first chamber 12 and second chamber 14. Valve 44 may be disposed within lower barrel 26 of container 16 between proximal seal 42 and distal seal 50. Valve 44 may be configured to permit the flow of fluid from either first chamber 12 or second chamber 14, through valve 44, to fluid port 22 of container 16. More specifically, valve 44 has a first position (shown in FIGS. 3A-3C and 3E) in which the flow of fluid from first chamber 12 through valve 44 is blocked, and a second position (shown in FIGS. 3D and 3F) in which the flow of fluid from first chamber 12 through valve 44 to fluid port 22 is permitted to discharge first fluid F1 from container 16. Further, in some examples, when valve 44 is in the first position, the flow of fluid from second chamber 14 through valve 44 to fluid port 22 is permitted to discharge second fluid F2 from container 16. Similarly, when valve 44 is in the second position, the flow of fluid from second chamber 14 through valve 44 is blocked. Also, when valve 44 is in the first position, moving second plunger 54 proximally through second chamber 14 draws second fluid F2 into second chamber 14.

[0095] Continuing to refer to FIGS. 1A-3F, in some examples, valve 44 may comprise a body 74 having a channel 76, which is fluidly connected to the second chamber 14 when the valve 44 is in the first position and fluidly connected to the first chamber 12 when the valve 44 is in the second position. The body 74 may be a cylindrical structure such as a rotating disk. In some examples, the body 74 or the rotating disk may be an injection molded part made of rigid plastic. The body 74 or the rotating disk may also include a tab or knob 94 configured to be grasped by an operator to rotate the body 74 or the disk and move the valve 44 between the first and second positions. As shown in FIG. 1A, the tab or knob 94 may extend through an opening 96 in the side wall 40 of the lower barrel 26. The operator may grasp or push the tab or knob 94 to rotate the body 74 in a first direction (indicated by arrow A1 in FIG. 1A), which moves the body 74 toward the first position. Conversely, the operator may grasp or push the tab or knob 94 to rotate the knob in a second direction (indicated by arrow A2 in FIG. 1A), which moves the body 74 of the valve 44 to the second position. In some examples, the tab or knob 94 may be rotated through a predetermined angular distance, such as from 80 degrees to 120 degrees, or preferably about 100 degrees, to move the body 74 or the rotating disk between the first and second positions.

[0096] As will be described in more detail herein, the syringe 10 can initially be provided in a partially filled state with a first fluid F1, such as a flush solution, within the first chamber 12, as shown in FIG. 3A. In this initial or partially filled position, the first stopper 56 is disposed within the first chamber 12 near the proximal end 18 of the container 16, and the first chamber 12 accommodates a volume of the first fluid F1 of from about 1 mL to 20 mL, preferably from about 5 mL to 10 mL. The valve 44 is in the first position and prevents the first fluid F1 within the first chamber 12 from being discharged from the first chamber 12. The second stopper 60 can be inserted at any position within the second chamber 14. When ready for use, the operator can move the second stopper 60 to its most distal position, abutting against the distal end 30 of the upper barrel 24, and the projection 72 extending from the distal face 66 of the second stopper 60 at least partially projects from the first opening 46 of the proximal seal 42. Next, the operator can move the second stopper 60 in the proximal direction (indicated by arrow P in FIG. 3B) to aspirate a second fluid F2, such as a medical fluid, into the second chamber 14, thereby completely filling the syringe 10, as shown in FIG. 3C. When the syringe 10 is completely filled with both the first fluid F1 and the second fluid F2, the operator can use the plungers 52, 54 and the valve 44 to sequentially control the discharge of the first fluid F1 and the second fluid F2 from the syringe 10, as will be described in detail later. Method for discharging fluid from a multi-chamber syringe As described above, the syringe 10 is used for continuous fluid discharge, such as discharging an initial amount of flush solution, followed by a fixed amount of medical fluid, and then discharging the remaining amount of flush solution from the syringe 10 to the VAD. A flowchart showing the procedure of the continuous fluid discharge process using the syringe 10 is shown in FIG. 5.

[0097] As shown in FIG. 5, in step 110, the operator first obtains a partially filled syringe 10, in which the first chamber 12 of the syringe 10 is filled with a predetermined amount of a first fluid F1 such as a flush solution. For example, the partially filled syringe 10 may contain from about 1 mL to about 20 mL, preferably from about 5 mL to 10 mL, of the first fluid F1 or flush solution. The valve 44 is in the first position, preventing the outflow of the first fluid F1 or flush solution from the first chamber 12. The syringe 10 in the initial or partially filled position is shown in FIG. 3A. In step 112, the operator prepares the syringe 10 for use, for example, by removing all packaging from the syringe 10 and, if any, removing the plunger cap 90 that holds the plunger rods 58, 62 in place. The operator may also move the second plunger rod 62 distally, as indicated by arrow D in FIG. 3A, to fully abut the second stopper 60 of the syringe 10 at its most distal position. In step 114, the operator places the container 16 in fluid communication with the interior of a container that holds the medical fluid to be delivered to the patient. For example, the operator may attach a needle (not shown) to the fluid port 22 at the distal end 20 of the container 16 and insert the needle into a medical container or vial that holds the medical fluid to be injected into the patient.

[0098] In step 116, the operator aspirates the medical fluid into the second chamber 14 of the container 16. For example, the operator may grasp the second plunger rod 62 and move the second plunger rod 62 proximally, as indicated by arrow P in FIG. 3B, which moves the second stopper 60 proximally, thereby aspirating or drawing in the fluid into the second chamber 14, as indicated by arrow A3 in FIG. 3B. In FIG. 3C, the syringe 10 is shown in its fully filled position with the first fluid F1 in the first chamber 12 and the second fluid F2 in the second chamber 14.

[0099] When the dosage of the medical fluid administered to the patient is drawn into the second chamber 14, at step 118, the operator removes a needle (not shown) from the fluid port 22 of the container 16 and connects the fluid port 22 to the VAD. For example, the operator may insert the nozzle of the container 16 into the corresponding port or valve of the VAD, thereby establishing fluid communication between the chambers 12, 14 of the container 16 and the lumen of the VAD.

[0100] At step 120, when the syringe 10 is properly connected to the VAD, the operator may perform a primary flush or pre-flush of the patient line. To perform the primary flush or pre-flush, the operator first moves the valve 44 to a second position, for example, by grasping the knob 94 (shown in FIGS. 1A, 1B, and 2C), which establishes fluid communication between the first chamber 12 and the fluid port 22 of the container 16. Specifically, as shown in FIG. 3C, the valve 44 can be rotated in the direction of arrow A2, as a result of which the channel 76 moves from a state of fluid communication with the second chamber 14 to a state of fluid communication with the first chamber 12. Next, the operator grasps the first plunger rod 58 and pushes the first plunger rod 58 in the distal direction (indicated by arrow D in FIG. 3D), which causes the first stopper 56 to move distally through the first chamber 12 and, as shown by arrow A4 in FIG. 3D, pushes the first fluid F1 out of the first chamber 12. The operator continues to move the first stopper 56 distally through the first chamber 12 until the tab 92 of the first plunger rod 58 contacts the container 16, as shown in FIG. 3D. As described above, the contact between the tab 92 and the container 16 provides tactile feedback to the operator, indicating that a predetermined initial amount of the first fluid F1 has been discharged from the syringe 10 through the patient line.

[0101] When the primary flash or pre-flash is executed, at step 122, the operator then discharges the second fluid F2 aspirated from the container 16, such as a medical vial, into the second chamber 14 into the patient line. To discharge the second fluid F2, the operator first moves the valve 44 to the first position, as indicated by arrow A1 in FIG. 3D, which establishes fluid communication between the second chamber 14 and the fluid port 22 of the container 16 through the valve 44. Next, the operator grasps the second plunger rod 62 and pushes the second plunger rod 62 distally (as indicated by arrow D in FIG. 3E), which causes the second stopper 60 to move distally through the second chamber 14. The distal movement of the second stopper 60 causes the second fluid F2 (e.g., a medical fluid) in the second chamber 14 to be discharged from the container 16 into the VAD through the fluid port 22 or nozzle of the container 16, as indicated by arrow A5 in FIG. 3E. The operator continues to move the second plunger rod 62 distally until the second stopper 60 abuts the proximal seal 42 at the distal end 30 of the upper barrel 24. In FIG. 3E, the second stopper 60 is shown in this most distal position.

[0102] In step 124, following the discharge of the second fluid F2 from the container 16, the operator then performs a second flush or post-flush to ensure that the entire amount of the second fluid F2 has passed from the container 16 through the patient line, to remove debris from, and / or within, the patient line. To perform the second flush or post-flush, the operator returns the valve 44 to the second position as indicated by arrow A2 in FIGS. 3E and 3F, which establishes fluid communication from the first chamber 12, through the valve 44, to the fluid port 22 of the container 16. Next, the operator grasps the first plunger rod 58 and presses the first plunger rod 58 in the distal direction (indicated by arrow D in FIG. 3F) with sufficient force to deform the tab 92, as a result of which the first plunger rod 58 can be inserted further distally within the first chamber 12. When the tab 92 is depressed or deformed, the operator continues to press the first plunger rod 58 in the distal direction, which causes the first stopper 56 to move distally through the first chamber 12 and discharge the first fluid F1 from the first chamber 12 through the fluid port 22, as indicated by arrow A6 in FIG. 3F. The operator continues to move the first plunger rod 58 in the distal direction until the first stopper 56 abuts the proximal seal 42 at the distal end 30 of the upper barrel 24, which indicates that the entire remaining amount of the first fluid F1 or flush solution has been discharged from the first chamber 12 and the fluid port 22 into the patient line. In FIG. 3F, the syringe 10 is shown in this final or end-of-use position following the discharge of the entire amounts of the first fluid F1 and the second fluid F2 from the container 16, and the distal faces 66 of the first stopper 56 and the second stopper 60 contact or are substantially in contact with the distal end 30 of the upper barrel 24 and / or the proximal seal 42. Multi-chamber syringe including a stopper with an enclosed fluid passageway Figures 6A - 7D show another example of a multi - chamber syringe 210 for continuously delivering a first fluid F1, such as a flush solution, and a second fluid F2, such as a medical fluid. Syringe 210 may include many of the components and features of syringe 10 shown in FIGS. 1A - 4B. In particular, syringe 210 includes a container that surrounds or defines a first chamber 212 and a second chamber 214. The container may be a syringe barrel 216 having an open proximal end 218, a distal end 220 that includes a fluid port 222, and a side wall 224 that extends between the proximal end 218 and the distal end 220 of the barrel 216. Barrel 216 may also include a partition 234 or a septum that separates the interior of barrel 216 into a first chamber 212 and a second chamber 214. For example, as shown in FIG. 7A, the first chamber 212 and the second chamber 214 are parallel or substantially parallel cavities or spaces that extend axially through barrel 216. For example, the longitudinal axis L1 (shown in FIG. 7A) of the first chamber 212 may be parallel or substantially parallel to the longitudinal axis L2 (shown in FIG. 7A) of the second chamber 214.

[0103] Unlike the previous examples, syringe barrel 216 may be a single molded part that is similar in structure to the barrels of conventional fluid delivery syringes. Also, the distal end 220 of syringe barrel 216 may include a tapered portion 221 (shown in FIGS. 6D and 7A - 7D) that extends from the side wall 224 of barrel 216 to fluid port 222 to direct fluid from chambers 212, 214 to fluid port 222.

[0104] The syringe 210 further includes a first plunger 252 for discharging the first fluid F1 from the first chamber 212 and a second plunger 254 for discharging the second fluid F2 from the second chamber 214. Similar to the previous example, the first plunger 252 includes a first stopper 256 and a first plunger rod 258 shown in FIG. 8A. The second plunger 254 includes a second stopper 260 and a second plunger rod 262 shown in FIG. 8B. The first stopper 256 includes a proximal surface 264, a distal surface 266, and an annular outer peripheral surface 268 extending between the proximal surface 264 and the distal surface 266. The distal surface 266 of the first stopper 256 is flat. In contrast, the second stopper 260 includes a partially conical or frustoconical distal surface 266 that corresponds to the curvature or angle of the tapered portion 221 of the distal end 220 of the barrel 216. In particular, the partially or semi-conical distal surface 266 of the second stopper 260 can be configured to push the second fluid F2 through the tapered portion 221 of the second chamber 214, which ensures that all or substantially all of the second fluid F2 is directed towards the fluid port 222 and that no or only a small amount of the second fluid F2 remains in the second chamber 214 after the use of the syringe 210 is completed.

[0105] Similar to the previous example, syringe 210 also includes a valve 244 that controls the continuous discharge of the first fluid F1 and the second fluid F2 from the syringe 210. Different from the previous example, valve 244 is an automatic valve that opens and closes by a force acting on valve 244 (such as the force indicated by arrow F in FIG. 6C) when the first plunger rod 258 and the first stopper 256 move through the first chamber 212. Also, in the case of syringe 210, valve 244 controls only the fluid flow of the first fluid F1 from the first chamber 212. Specifically, when valve 244 is in the first position or the closed position (shown in FIGS. 7A-7C), the fluid flow from the first chamber 212 through valve 244 to the fluid port 222 of the barrel 216 is prevented. When valve 244 is in the second position or the open position (shown in FIGS. 6D and 7D), the fluid flow from the first chamber 212 through valve 244 to the fluid port 222 is allowed. In the case of syringe 210 of FIGS. 6A-7D, the fluid flow from the second chamber 214 is not controlled by valve 244, which means that the second fluid F2 is allowed to flow from the second chamber 214 whenever the second plunger rod 262 moves the second stopper 260 through the second chamber 216 with sufficient force to move the fluid F2 through the fluid port 222 of the barrel 216.

[0106] As shown in FIGS. 6A - 7D, and FIGS. 9A and 9B, valve 244 includes a compressible body 274 or bellows which, in an unbiased or extended position, blocks the flow of fluid from the first chamber 212 to the fluid port 222 and, in a biased or compressed position, allows the flow of fluid from the first chamber 212 to the fluid port 222. Similar to stoppers 256, 260, the compressible body 274 can be formed from a thermoplastic elastomer material such as polypropylene or polyethylene, and a synthetic or natural rubber (such as isoprene). The compressible body 274 of valve 244 includes a semi - body or partially frustoconical portion 276 that is disposed in the tapered or frustoconical portion 221 of barrel 216. The compressible body 274 can also include a partial or semi - cylindrical portion 278 that extends proximally from the frustoconical portion 276. The semi - cylindrical portion 278 can include one or more peripheral ribs 280 configured to contact and seal against the inner surface of the sidewall 224 of barrel 216, ensuring that the first fluid F1 passes through valve 244 only when valve 244 is in the compressed or open position.

[0107] In some examples, the barrel 216 includes a structure such as a channel or groove for guiding the first fluid F1 through the valve 244 when the body 274 is compressed. For example, as most clearly shown in FIGS. 6B and 6C, the barrel 216 may include a slot 282 that defines a flow path for fluid flow from the first chamber 212 to the fluid port 222. The slot 282 may be arranged such that fluid flow through the slot 282 is blocked when the compressible body 274 is in the extended position. As shown in FIG. 6D, when the compressible body 274 is in the compressed position, fluid flow through the slot 282 to the fluid port 222 is permitted. In some examples, as shown in FIGS. 6B and 6C, the slot 282 is an opening, notch, or through-hole that extends through the partition 234 of the barrel 216. When the compressible body 274 of the valve 244 is in the expanded state, the compressible body 274 prevents the fluid F1 from passing through the slot 282 and / or from passing from the first chamber 212 to the second chamber 214. The compressible body 274 also prevents any second fluid F2 from flowing into the first chamber 212 through the slot 282 and / or from mixing with the first fluid F1. When the second stopper 260 is in the most distal position within the second chamber 214 (e.g., as shown in FIGS. 7A, 7C, and 7D), the second stopper 260 seals a portion of the slot 282 and prevents the first fluid F1 from flowing into the second chamber 214. For example, the distal surface 266 of the second stopper 260 disposed in the frustoconical portion 221 of the barrel 216 may contact the partition 234 to seal the slot 282 and separate the first chamber 212 from the second chamber 214.

[0108] Similar to the previous example, syringe 210 can be provided in a partially filled state (shown in FIG. 7A) where initially, the first chamber 212 is filled with a first fluid F1 such as a fluid solution and the second chamber 214 can be empty. The second chamber 214 is filled by moving the second plunger rod 260 in the proximal direction (indicated by arrow P in FIG. 7B) and drawing the second fluid F2 into the second chamber 214 through the fluid port 222 from a container such as a medical vial, as indicated by arrow A8 (FIG. 7B). When the syringe 210 is completely filled with the first fluid F1 in the first chamber 212 and the second fluid F2 in the second chamber 214 (as shown in FIG. 7B), the second fluid F2 is discharged from the syringe 210 by moving the second plunger rod 262 in the distal direction (indicated by arrow D in FIG. 7C) and discharging the second fluid F2 from the second chamber 214, as indicated by arrow A9 in FIG. 7C. The operator continues to move the second plunger rod 262 through the second chamber 214 until the second stopper 260 abuts against the distal end 220 of the barrel 216, ensuring that all or almost all of the second fluid F2 is discharged from the second chamber 214. In FIG. 7C, the second stopper 260 is shown in the most distal position.

[0109] After discharging the second fluid F2 from the second chamber 214, the operator performs a post-flush by discharging the first fluid F1 from the first chamber 212. To discharge the first fluid F1, the operator grasps the first plunger rod 258 and pushes the first plunger rod 258 in the distal direction (indicated by arrow D in FIG. 7D), which causes the first stopper 256 to move through the first chamber 212. The movement of the first stopper 256 through the first chamber 212 increases the fluid pressure within the first chamber 212, causing the compressible body 274 of the valve 244 to compress. As described above, the compressible body 274 is shown in the compressed position in FIG. 6D. When the body 274 compresses, the fluid flows through channels or flow paths such as the slot 282 within the partition 234 shown in FIGS. 6B-6D. The operator continues to push the first plunger rod 258 and the first stopper 256 through the first chamber 212 until the distal surface 266 of the first stopper 256 contacts, or nearly contacts, the compressible body 274, thereby ensuring that all or nearly all of the first fluid F1 within the first chamber 212 passes through the valve 244 through the slot 282 and flows to the fluid port 222, where the first fluid F1 is discharged from the syringe 210. Thus, the syringe 210 provides a continuous discharge of the first fluid F1 following the second fluid F2. In FIG. 7D, the syringe 210 is shown in its final position where both the first fluid F1 and the second fluid F2 have been discharged from the syringe 210.

[0110] Referring to FIGS. 10A and 10B, in some examples, the plungers 252, 254 of the syringe 210 may include a locking mechanism to ensure that the plunger rods 258, 262 are used in the correct order. For example, as shown in FIGS. 10A and 10B, the first plunger 252 may include a first tab 284 disposed proximate to the distal end of the first plunger rod 258 and / or proximate to the stopper 256. As used herein, "proximate to the distal end" and / or "proximate to the stopper 256" may mean that the first tab 284 extends from a portion of the first plunger rod 258 that is closer to the distal end of the plunger rod 258 than to the proximal end of the plunger rod 258. As shown in FIG. 10A, the first tab 284 extends radially from the plunger rod 258 and is disposed to contact a portion of the barrel 216, preventing the first plunger rod 258 from being moved distally through the first chamber 212 to expel the first fluid F1 from the first chamber 212 before the second fluid F2 is expelled from the second chamber 214. Similarly, the second plunger 254 may include a second tab 286 extending from the second plunger rod 262. The second tab 286 may be disposed proximate to the proximal end of the second plunger rod 262. For example, the second tab 286 may be disposed on the second plunger rod 262 at a location closer to the proximal end of the plunger rod 262 than to the distal end of the plunger rod 262. The second tab 286 is configured to contact the first tab 282 and push down on the first tab, such that the first plunger rod 258 may be moved through the first chamber 212.

[0111] More specifically, in use, the plunger rods 258, 262 are in their most proximal positions in FIG. 10A, which means that the syringe 210 is filled with a first fluid F1 in the first chamber 212 and a second fluid F2 in the second chamber 214. In this position, as shown in FIG. 10A, due to the contact between the first tab 284 and the partition 234 of the barrel 216, the operator cannot insert the first plunger rod 258 further into the first chamber 212. As described above, the operator first moves the second plunger rod 262 distally through the second chamber 214 (shown by arrow D in FIG. 10A). Moving the second plunger rod 262 distally (shown by arrow D) through the second chamber 214 causes the second tab 286 to contact the first tab 284. As shown in FIG. 10B, the contact between the first tab 284 and the second tab 286 pushes down the first tab 284. When the first tab 284 is pushed down, the operator can move the first plunger rod 258 distally (shown by arrow D in FIG. 10B) through the first chamber 212, which, as described above, results in the first fluid F1 being discharged from the first chamber 212.

[0112] Examples of the multi-chamber syringe and method of the present disclosure are shown in the accompanying figures and described in detail above, but other examples will be apparent to and readily made by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to be illustrative rather than limiting. The invention described above is defined by the appended claims, and all changes to the invention that come within the meaning and range of equivalents of the claims are to be embraced within their scope.

Claims

1. A multi-chamber syringe for the continuous discharge of at least a first fluid followed by a second fluid, said syringe comprising: a container having a proximal end and a distal end provided with a fluid port for discharging said first fluid and said second fluid from said container, said container defining a first chamber for containing said first fluid and a second chamber for containing said second fluid, said container; a first plunger for discharging said first fluid from said first chamber; a second plunger for discharging said second fluid from said second chamber; at least one valve disposed within said container, said at least one valve being configured to transition between a first position in which the flow of fluid from said first chamber through said at least one valve is blocked and a second position in which the flow of fluid from said first chamber through said at least one valve to said fluid port is permitted; A syringe characterized by comprising the above.

2. The syringe according to claim 1, wherein said first chamber and said second chamber extend axially through said container, and the longitudinal axis of said first chamber is substantially parallel to the longitudinal axis of said second chamber.

3. The syringe according to claim 1, wherein when said at least one valve is in said first position, the flow of fluid from said second chamber through said at least one valve to said fluid port is permitted for discharging said second fluid from said container, and when said at least one valve is in said second position, the flow of fluid from said second chamber through said at least one valve is blocked.

4. The syringe according to claim 1, wherein said container comprises an upper barrel having said first chamber and said second chamber, and a lower barrel connected to the distal end of said upper barrel and surrounding said at least one valve.

5. The syringe according to claim 4, wherein the upper barrel comprises an open proximal end, a distal end, an annular side wall extending between the open proximal end and the open distal end, and an axially extending partition extending from the open proximal end to the distal end of the upper barrel and separating the first chamber from the second chamber.

6. The syringe according to claim 5, further comprising at least one seal covering the open distal end of the upper barrel, the at least one seal having a first opening that permits the first fluid to flow from the first chamber to the at least one valve when the at least one valve is in the second position, and a second opening that permits the second fluid to flow from the second chamber through the at least one valve when the at least one valve is in the first position.

7. The syringe according to claim 6, wherein the first plunger and / or the second plunger comprises a stopper having a flat distal surface and a protrusion extending from the flat distal surface and configured to be inserted into the first opening or the second opening to completely discharge the first fluid from the first chamber or the second fluid from the second chamber.

8. The syringe according to claim 1, wherein the first plunger comprises a first stopper within the first chamber and a first plunger rod connected to the first stopper and extending from the first stopper through the proximal end of the container.

9. The syringe according to claim 8, wherein the first plunger rod comprises a tab configured to contact a portion of the container when the first plunger rod is moved through the first chamber, thereby providing feedback that an initial amount of the first fluid has been discharged from the first chamber.

10. The syringe according to claim 1, wherein the at least one valve comprises a body having a channel that fluidly connects to the second chamber when the at least one valve is in the first position and fluidly connects to the first chamber when the at least one valve is in the second position.

11. The syringe according to claim 10, wherein the body comprises a rotating disk and a knob extending through an opening of the container for rotating the rotating disk between the first position and the second position.

12. The syringe according to claim 1, wherein the container comprises an annular side wall, a frustoconical portion extending from the annular side wall to the fluid port, and a partition extending through the barrel and separating the first chamber from the second chamber.

13. The syringe according to claim 12, wherein the first plunger comprises a first stopper having a substantially flat distal surface and a first plunger rod connected to the first stopper and extending proximally from the first stopper. The second plunger comprises a second stopper having a semi-conical distal surface sized to be received within the frustoconical portion of the barrel and a second plunger rod connected to the second stopper and extending proximally from the second stopper.

14. The syringe according to claim 13, wherein the first plunger rod comprises a first tab disposed proximate the distal end of the first plunger rod, the first tab being configured to contact the barrel to prevent the first plunger rod from moving distally through the first chamber and discharging the first fluid from the first chamber. The second plunger rod comprises a second tab disposed proximate the proximal end of the second plunger rod, the second tab being configured to contact the first tab and push the first tab downward, whereby the first plunger rod can be moved through the first chamber.

15. A syringe according to claim 12, wherein said at least one valve comprises a compressible body that blocks the flow of fluid from said first chamber to said fluid port in the extended position and allows the flow of fluid from said first chamber to said fluid port in the compressed position.

16. A syringe according to claim 15, wherein said barrel comprises at least one slot that defines a flow path for the flow of fluid from said first chamber to said fluid port, and said at least one slot is arranged such that when said compressible body is in the extended position, the flow of fluid through said at least one slot is blocked, and when said compressible body is in the compressed position, the flow of fluid through said at least one slot to said fluid port is allowed.

17. A pre-filled flushing syringe, said pre-filled flushing syringe comprising a container having a proximal end and a distal end including a fluid port for discharging a first fluid and a second fluid from said container, said container defining a first chamber for containing said first fluid and a second chamber for containing said second fluid, said container; a first plunger for discharging said first fluid from said first chamber; a second plunger for discharging said second fluid from said second chamber; at least one valve disposed within said container, said at least one valve configured to transition between a first position in which the flow of fluid from said first chamber through said at least one valve is blocked and a second position in which the flow of fluid from said first chamber through said at least one valve to said fluid port is allowed for discharging said first fluid from said container; a predetermined amount of a first fluid disposed within said first chamber of said pre-filled syringe; wherein said at least one valve is initially in said first position, thereby preventing the first fluid disposed within said first chamber from passing through said at least one valve from said first chamber.

18. The pre-filled syringe according to claim 17, wherein the first fluid is a physiological saline flush solution.

19. A syringe, wherein the syringe comprises a housing, the housing comprising: (i) an upper barrel having an open proximal end, a distal end, a side wall extending between the proximal end and the distal end, and a partition extending axially through the barrel and separating the barrel into a first chamber configured to contain a first fluid and a second chamber configured to contain a second fluid; and (ii) a lower barrel connected to the distal end of the upper barrel and having a fluid port. a first plunger for discharging the first fluid from the first chamber; a second plunger for discharging the second fluid from the second chamber; a manually operable valve disposed within the lower barrel and configured to be movable between a first position that permits flow of fluid from the second chamber through the valve to the fluid port for discharging the second fluid from the syringe and a second position that permits flow of fluid from the first chamber through the valve to the fluid port for discharging the first fluid from the syringe.

20. The syringe according to claim 19, wherein the first chamber and the second chamber extend axially through the upper barrel, and the longitudinal axis of the first chamber is substantially parallel to the longitudinal axis of the second chamber.

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