Safety syringe system and method

Abstract

To provide a system for serially injecting liquids.SOLUTION: A system 100 includes a syringe body 34, proximal and distal stopper members 32, 36 disposed in the syringe body 34, first liquid in a distal chamber, second liquid in a proximal chamber, a plunger member, and a needle hub assembly coupled to a distal needle interface of the syringe body. The plunger member includes a needle retention feature, an energy-storage member and an energy-storage member latching member which are disposed in a plunger interior. The needle assembly includes a needle having a needle proximal end feature, a hub, and a needle latching member configured to couple the needle to the hub. Manipulating the plunger member to insert the proximal stopper member 32 distally relative to the syringe body 34 initially expels the first liquid and then the second liquid. The needle is at least partially retractable into the plunger interior.SELECTED DRAWING: Figure 7-7

Description

[Technical Field]

[0001] The present disclosure relates generally to injection systems, devices and processes for facilitating various levels of control over fluid injection, and more particularly to systems and methods relating to multi-chamber safety syringes in medical environments. [Background technology]

[0002] Millions of syringes, such as the one shown in FIG. 1A (2), are consumed daily in healthcare settings. A typical syringe (2) includes a tubular body (4), a plunger (6), and a needle (8). As shown in FIG. 1B, such syringes (2) can be utilized not only to inject fluids into patients but also to withdraw or expel fluids from or into containers such as vials, bags, or other drug containment systems (10). In fact, in some countries, such as the United States, due to concerns about maintaining sterility and regulatory constraints, if syringes (2) are used with vials (10) in certain patient settings, as shown, such vials must be used only with a single patient and then disposed of, resulting in significant medical waste from vials and remaining medication and contributing to periodic shortages of certain critical medications. Referring to FIG. 2A, three luer-type syringes (12) are shown, each having a distally disposed luer fitting configuration (14) for mating with other devices having a similar fitting configuration, such as the luer manifold assembly (16) shown in FIG. 2B. The luer manifold assembly of FIG. 2B can be used to administer liquid medications intravenously to a patient, with or without the use of an intravenous infusion bag. The luer fittings (14) of the syringes in FIG. 2A are sometimes referred to as "male" luer fittings, and the luer fittings (18) of FIG. 2B are sometimes referred to as "female" luer fittings, with one of the luer interfaces being threaded (in which case the configuration is sometimes referred to as a "luer lock" configuration) to couple the two through relative rotation, which may be combined with a compressive load. In other words, in one embodiment of a luer lock, rotation, possibly along with compression, is utilized to engage the threads of the male fitting (14), which are configured to engage a flange on the female fitting (18) to bring the device into a fluid-tight union. In another embodiment, a tapered interface shape may be utilized to provide the luer engagement using compression, without threads or rotation (such a configuration may be referred to as a "slip-on" or "conical" luer configuration).While such luer connections are perceived as relatively safe for the operator, there is a risk of spillage, leakage, or component damage during assembly of the luer connection. On the other hand, the use of needle injection configurations poses a risk of the sharp needle contacting or puncturing a person or unwanted structures. For these reasons, so-called "safety syringes" have been developed.

[0003] One embodiment of a safety syringe 20 is shown in FIG. 3, in which a tubular shield member 22 is spring-biased to cover the needle 8 when released from a locked position relative to the syringe body 4. Another embodiment of a safety syringe 24 is shown in FIGS. 4A and 4B. In this configuration, a retractable needle 26 is configured to retract (28, 26) into a safe position within the tubular body 4 after the plunger 6 is fully inserted into the syringe body 4, as shown in FIG. 4B. Such self-retracting configurations may be associated with issues of blood splatter / aerosolization, safe storage of pre-loaded energy that could result in premature activation, loss of precision in delivering a full dose injection due to residual dead space within the spring compression volume, and / or loss of retraction speed control, which may be associated with pain or patient discomfort.

[0004] The syringe market has become more complex due to the increasing demand for pre-filled syringe assemblies, such as those shown in FIGS. 5A and 5B, which generally comprise a syringe body or "drug containment and delivery system" (34), a plunger tip, plug or stopper (36), and a distal seal or cap (35) attached to a luer interface (FIG. 5A shows the cap 35 in place, while FIG. 5B has the cap removed to illustrate the luer interface 14). The liquid drug resides in a volume or drug reservoir (40) between the distal seal and the distal end (37) of the plunger tip (36). The plunger tip (36) can comprise a standard butyl rubber material and is coated with a biocompatible lubricious coating (e.g., polytetrafluoroethylene ("PTFE") or ethylene tetrafluoroethylene ("ETFE")) or the like to facilitate favorable sealing and relative motion characteristics relative to the associated syringe body structure and material. The proximal end of the syringe body (34) in FIG. 5B includes a conventional one-piece syringe flange (38) integrally formed with the material of the syringe body (34). The flange (38) is configured to extend radially from the syringe body (34) and to extend completely or partially around the circumference of the syringe body (34). The partial flange is known as a "clipped flange," while the other flange is known as a "full flange." The flange is used to grip the syringe with the fingers and provides support for depressing the plunger to perform the injection. The syringe body (34) preferably comprises a translucent material, such as glass or a polymer. A plunger tip (36) can be positioned within the syringe body (34) to form a contained volume within a chamber or reservoir (40) and aid in the evacuation of the associated fluid through the needle. Syringe body (34) may define a generally cylindrical shape (i.e., such that a plunger tip 36 having a circular cross-sectional shape establishes a seal with syringe body (34)), or may be configured to have other cross-sectional shapes, such as oval.

[0005] Such assemblies are desirable because they can be standardized and precisely mass-produced by the few manufacturers in the world who can afford to meet all of the world's ever-changing regulations regarding filling, packaging, and drug / drug interfacing material selection and component use. However, such simple configurations generally cannot meet new global standards for single-use, safety, self-disabling, and needlestick protection. For this reason, certain suppliers have turned to more "vertical" solutions, such as those shown in Figure 5C, which attempt to meet all or at least part of the standards in a single solution. However, as a result of attempting to meet those standards in many different scenarios, such products have significant limitations (including those discussed above with reference to Figures 3-4B) and can have relatively high inventory and usage costs.

[0006] Furthermore, as the volume of liquid (e.g., pharmaceutical) to be injected increases, the additional requirement arises of injecting two or more components sequentially (e.g., into a patient) preferably within a short interval (e.g., within a few seconds) of each other. Multiple components can be injected sequentially using separate injection devices (e.g., pre-loaded syringes), or the same injection device can be used to sequentially draw and inject multiple components from separate open containers. However, such sequential injections using separate injection devices or sequentially drawing and injecting multiple components not only entails inserting multiple needles into the patient, but can also be inaccurate and lead to component loss. Furthermore, sequential injections using separate injection devices or sequentially drawing and injecting multiple components into syringes can unnecessarily expose the user to one or more uncapped needles. Furthermore, sequential injections using separate injection devices or sequentially drawing and injecting multiple components can result in unacceptable delays between the injections of multiple components.

[0007] In some cases, chemical reactions may occur between components of a multi-component injection. The use of conventional dual-chamber syringes, such as those disclosed in U.S. Patent Application No. 14 / 696,342, in which components are mixed together in the syringe, may be incompatible with the reactive components, making the mixed components unsuitable for injection. Some examples of this phenomenon include an increase in the viscosity of the mixed drug when the components are mixed together, preventing the drug from being easily injected through a needle. Other reactions, such as exothermic or endothermic reactions, may also occur, preventing the use of conventional dual-chamber injection systems.

[0008] Existing dual-chamber injection systems (see, e.g., U.S. Pat. No. 4,874,381) utilize an external bypass channel formed in the outer wall of the syringe body. In this example, the external bypass channel is positioned so that distal movement of the plunger causes the distal stopper to move distally, exposing the external bypass channel to both the proximal and distal chambers, allowing liquid to move from the proximal chamber around the distal stopper to the distal chamber and mix with the drug component in the distal chamber. When the needle or syringe is capped for drug storage, these external bypass channel-based dual-chamber injection systems experience an increase in pressure in the distal chamber during transfer and mixing. This increased pressure creates resistance to transfer, making it difficult to transfer all of the liquid from the proximal chamber to the distal chamber. Furthermore, the increased pressure increases the force that must be maintained on the plunger rod during mixing. To minimize the effects of this increased pressure, external bypass dual-chamber injection systems require either removing the needle cap before transferring and mixing the fluids, or opening the syringe and attaching the needle after mixing has occurred to allow venting of pressure in the distal chamber during transfer and mixing. These requirements increase the risk of needlestick injuries and / or require additional steps by the user. It would be beneficial to incorporate a pre-attached needle with shielding and venting capabilities with integrated needle retraction into a dual-chamber injection system. The shielded and ventable needle shield embodiments disclosed herein are applicable to external bypass dual-chamber injection systems. Furthermore, it would be beneficial to integrate a plunger position control method to maintain precise control of the distal stopper position during transfer and mixing.

[0009] Furthermore, the increase in the amount of liquids (e.g., pharmaceuticals) that may be injected creates a further requirement to minimize the time that such liquids are exposed to metal (e.g., the stainless steel of the needle). Yet another requirement is the desirability of a system that is suitable for patient self-injection.

[0010] It is also desirable to incorporate anti-needlestick technology into injection systems. The ability to at least partially retract the sharp end of the needle within the syringe protects the injection personnel and the patient from inadvertent needlestick injuries.

[0011] There is a need for an injection system that addresses the shortcomings of currently available configurations, particularly a multi-chamber safety injection solution that can take advantage of the existing, relatively well-controlled supply chain of conventionally provided pre-filled syringe assemblies such as those described with reference to Figures 5A and 5B. Summary of the Invention

[0012] FIELD OF THE INVENTION Embodiments relate to injection systems. In particular, embodiments are directed to a multi-chamber safety injection system that transitions a needle into a protective configuration to minimize accidental injury to the user and contamination of used needles.

[0013] In one embodiment, a system for continuously injecting a liquid includes a syringe body defining a syringe proximal opening and a distal needle interface at a distal end. The system also includes a proximal stop member and a distal stop member disposed within the syringe body, forming a proximal chamber between the proximal stop member and the distal stop member, and a distal chamber between the distal stop member and the distal end of the syringe body. The system further includes a first liquid in the distal chamber and a second liquid in the proximal chamber. The system further includes a plunger member defining a plunger interior, the plunger member configured to be manually manipulated to distally insert the proximal stop member into the syringe body. The plunger member includes a needle retaining feature disposed within the plunger, an energy storage member disposed within the plunger, and an energy storage member latch member disposed within the plunger. The system further includes a needle hub assembly coupled to the distal needle interface of the syringe body. The needle assembly includes a needle having a needle proximal end feature, a hub, and a needle latch member configured to couple the needle to the hub. Manipulation of the plunger member to distally insert the proximal stop member relative to the syringe body expels a first liquid from the distal chamber through the needle, followed by a second liquid from the proximal chamber through the needle. In response to manipulation of the plunger member relative to the syringe body, an energy storage member latch member is transformed from a latched state to an unlatched state, thereby allowing the needle to be at least partially retracted within the plunger.

[0014] In one or more embodiments, the first and second sizes of the distal and proximal chambers, respectively, can be changed by relative movement of the proximal and distal stop members with respect to the syringe body.

[0015] In one or more embodiments, the needle defines a needle interior, a distal opening, an intermediate opening, and a proximal opening, the distal opening, the intermediate opening, and the proximal opening being fluidly coupled via the needle interior. The distance between the proximal opening and the distal end of the syringe body may be approximately equal to the length of the distal stopper member, such that when the distal stopper member is inserted into the distal end of the syringe body, the proximal stopper member is inserted distally relative to the needle to position the proximal opening in the proximal chamber. The proximal and distal stopper members and the syringe body may be configured such that a distal force applied to the proximal stopper member is transmitted to the distal stopper member via the second liquid until the proximal stopper member is inserted distally relative to the needle to position the proximal opening in the proximal chamber. The system can have a first injection configuration in which the proximal opening is disposed within the distal chamber, and a second injection configuration in which the proximal opening is disposed within the proximal chamber, thereby permitting transfer of a second liquid from the proximal chamber through the proximal opening and the interior of the needle and out the distal opening, and a distal stop member can close the intermediate opening when the system is in the second injection configuration.

[0016] In one or more embodiments, the needle is configured to retract at least partially into the plunger, completely through at least the distal stop member. In other embodiments, the needle may be configured to retract to a position where the distal tip of the needle is disposed within the syringe body. The proximal and distal stop members may include first and second polymer coatings on their respective distal and proximal surfaces, such that a proximal chamber is defined by the syringe body and the first and second polymer coatings.

[0017] In one or more embodiments, the distal stop member has a proximally tapered funnel and a space disposed at the tapered proximal end of the funnel. The funnel may be configured to guide the needle proximal end feature into the space at the tapered proximal end of the funnel, thereby aligning the needle proximal end feature with a needle retaining feature within the plunger. The funnel may be configured to align the needle proximal end feature with a needle retaining feature within the plunger during assembly of the system and / or during manipulation of the plunger member to distally insert the proximal stop member into the syringe body.

[0018] In one or more embodiments, the energy storage member latch member is configured to transform from a latched state to an unlatched state to at least partially retract the needle into the plunger after the second liquid is expelled from the proximal chamber through the needle. The needle retaining feature may be configured to actuate the transformation of the energy storage member latch member from the latched state to the unlatched state in response to manipulation of the plunger member to insert the proximal stop member into the distal end of the syringe body.

[0019] In one or more embodiments, the distal stop member has a detent to resist passage of the needle proximal end feature. The detent may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to passage of the needle proximal end feature. The detent can be modified to adjust the distal force required to overcome the resistance. The detent can have a "U" shape. The detent can include bent wire. The detent can have a flattened cross section. The detent can have a needle proximal end feature receiving feature. The needle proximal end feature receiving feature can have a chamfered surface. The detent can include an annealed stainless steel alloy. The needle proximal end feature can have an angle of about 30 degrees.

[0020] In one or more embodiments, the needle has a shoulder to resist passage through the detent. The shoulder and detent may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to the shoulder passing through the detent. The detent can be modified to adjust the distal force required to overcome the resistance. The shoulder may have an angle of about 50 degrees.

[0021] In one or more embodiments, the needle has a groove to provide resistance to passage through the detent. The groove and detent may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to the groove passing through the detent. The detent can be modified to adjust the distal force required to overcome the resistance.

[0022] In another embodiment, a method for sequentially infusing a first liquid and a second liquid into a patient includes providing a system including a syringe body defining a syringe proximal opening and a distal end. The system also includes proximal and distal stop members disposed on the syringe body, forming a proximal chamber containing the second liquid between the proximal and distal stop members and a distal chamber containing the first liquid between the distal stop member and the distal end of the syringe body. The system further includes a plunger member defining a plunger interior and configured to be manually manipulated to distally insert the proximal stop member into the syringe body. The system further includes a needle having a needle interior, a distal end opening, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the needle interior. The method also includes advancing the plunger member to expel the first liquid from the distal chamber through the needle interior and the distal end opening. The method further includes further advancing the plunger member to expel the second liquid from the proximal chamber through the proximal opening, the needle interior, and the distal opening. The method further includes automatically retracting the distal needle tip into the needle hub or syringe body as the first and second liquids are injected into the patient.

[0023] In one or more embodiments, the method also includes inserting the distal end of the needle into the patient before advancing the plunger member to expel the first liquid from the distal chamber, thereby positioning the distal end opening of the needle against the patient before expelling the first liquid. The method also includes removing air from the distal chamber before inserting the distal end of the needle into the patient. Removing air from the distal chamber can include holding the syringe body in a substantially vertical position and manipulating the plunger member to distally insert the proximal stopper member relative to the syringe body.

[0024] In one or more embodiments, advancing the plunger member inserts the proximal stopper member distally relative to the syringe body, thereby exerting a distal force through the second liquid to insert the distal stopper member distally relative to the syringe body, thereby expelling the first liquid from the distal chamber through the needle interior and the distal end opening.

[0025] In one or more embodiments, the system has a first injection configuration in which the proximal opening is located in the distal chamber, and a second injection configuration in which the proximal opening is located in the proximal chamber, thereby allowing a second liquid to be transferred from the proximal chamber through the proximal opening and the interior of the needle and out the distal opening. The system is in the first injection configuration when the plunger member advances to expel the first liquid from the distal chamber through the interior of the needle and the distal opening. The system is in the second injection configuration when the plunger member further advances to expel the second liquid from the proximal chamber through the proximal opening, the interior of the needle, and the distal opening. When the system is in the second injection configuration, the distal stop member may block the intermediate opening. The method may further include the steps of: completely passing the needle at least through the distal stop member; and at least partially retracting the needle into the plunger. In other embodiments, the method may include retracting the needle to a position where the distal tip of the needle is disposed within the syringe body.

[0026] In one or more embodiments, the distal stop member has a proximally tapered funnel and a space disposed at the tapered proximal end of the funnel, and the method further includes the step of funnel directing the needle into the space at the tapered proximal end of the funnel, thereby aligning a needle proximal end feature with a needle retaining feature within the plunger.

[0027] In one or more embodiments, the needle further includes a needle proximal end feature, and the distal stop member includes a detent. The method further includes the step of the detent resisting passage of the needle proximal end feature. Advancing the plunger member to expel the first liquid from the distal chamber through the needle interior and the distal end opening can include applying a distal force to the plunger member to overcome the resistance to passage of the needle proximal end feature through the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0028] In one or more embodiments, the needle further includes a shoulder and the distal stop member includes a detent. The method further includes the step of the detent resisting passage of the shoulder. Further advancing the plunger member to expel the second liquid from the proximal chamber through the proximal opening, the needle interior, and the distal end opening can include applying a distal force to the plunger member to overcome the resistance of the shoulder to passage of the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0029] In one or more embodiments, the needle further includes a groove and the distal stop member includes a detent. The method further includes the step of the detent resisting passage of the groove. Further advancing the plunger member to expel the second liquid from the proximal chamber through the proximal opening, the needle interior, and the distal end opening can include applying a distal force to the plunger member to overcome the resistance of the groove to passage of the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0030] In yet another embodiment, a system for continuously injecting a liquid includes a syringe body defining a syringe proximal opening and a distal interface at a distal end. The system also includes a proximal stop member and a distal stop member disposed on the syringe body, forming a proximal chamber between the proximal stop member and the distal stop member, and a distal chamber between the distal stop member and the distal end of the syringe body. The system further includes a first liquid in the distal chamber and a second liquid in the proximal chamber. The system further includes a plunger member configured to be manually operated to distally insert the proximal stop member into the syringe body. The system further includes a hub assembly coupled to the distal interface of the syringe body. The hub assembly includes a transfer pipe having a transfer pipe proximal end and a transfer pipe distal end, a hub, and a connector fluidly coupled to the transfer pipe distal end. By manipulating the plunger member to insert the proximal stopper member distally into the syringe body, first a first liquid is expelled from the distal chamber through the transfer pipe, and then successively a second liquid is expelled from the proximal chamber through the transfer pipe.

[0031] In one or more embodiments, the first and second sizes of the distal and proximal chambers, respectively, can be changed by relative movement of the proximal and distal stop members with respect to the syringe body.

[0032] In one or more embodiments, the transfer pipe defines a transfer pipe interior, a distal end opening at the distal end of the transfer pipe, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the transfer pipe interior. The distance between the proximal opening and the distal end of the syringe body may be approximately equal to the length of the distal stopper member, and when the distal stopper member is inserted into the distal end of the syringe body, the proximal stopper member may be distally inserted into the transfer pipe to position the proximal opening in the proximal chamber. The proximal and distal stopper members and the syringe body may be configured such that a distal force applied to the proximal stopper member is transmitted to the distal stopper member via the second liquid until the proximal stopper member is distally inserted into the transfer pipe to position the proximal opening in the proximal chamber.

[0033] In one or more embodiments, the system has a first injection configuration in which the proximal opening is disposed within the distal chamber, and a second injection configuration in which the proximal opening is disposed within the proximal chamber, thereby allowing transfer of a second liquid from the proximal chamber through the proximal opening and the interior of the transfer pipe and out the distal end opening. When the system is in the second injection configuration, a distal stop member may block the intermediate opening. The proximal and distal stop members may include first and second polymer coatings on their respective distal and proximal surfaces, and the proximal chamber may be defined by the syringe body and the first and second polymer coatings.

[0034] In one or more embodiments, the distal stop member has a proximally tapered funnel and a space disposed at the tapered proximal end of the funnel. The funnel may be configured to guide the proximal end of the transfer pipe into the space at the tapered proximal end of the funnel, thereby aligning the transfer pipe with the distal stop member. The funnel may be configured to align the transfer pipe with the distal stop member during assembly of the system and / or during manipulation of the plunger member to distally insert the proximal stop member into the syringe body.

[0035] In one or more embodiments, the distal stop member has a detent that resists passage of the transfer pipe proximal end. The detent may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to passage of the transfer pipe proximal end. The detent can be modified to adjust the distal force required to overcome the resistance. The detent can have a "U" shape. The detent can include bent wire. The detent can have a flattened cross section. The detent can have a transfer pipe proximal end receiving feature. The transfer pipe proximal end receiving feature can have a chamfered surface. The detent can include an annealed stainless steel alloy. The transfer pipe proximal end can include a transfer pipe proximal end feature having an angle of about 30 degrees.

[0036] In one or more embodiments, the transfer pipe has a shoulder to resist passage through the detent. The shoulder and detent may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to the shoulder passing through the detent. The detent can be modified to adjust the distal force required to overcome the resistance. The shoulder may include an angle of about 50 degrees.

[0037] In one or more embodiments, the transfer pipe has grooves to provide resistance to passage through the detent. The grooves and detents may be configured such that a distal force of about 2 pounds to about 5 pounds applied to the plunger member overcomes the resistance to the grooves passing through the detent. The detents can be modified to adjust the distal force required to overcome the resistance.

[0038] In yet another embodiment, a method for sequentially injecting a first liquid and a second liquid includes providing a system. The system includes a syringe body defining a syringe proximal opening and a distal end. The system also includes proximal and distal stop members disposed on the syringe body, forming a proximal chamber containing the second liquid between the proximal and distal stop members and a distal chamber containing the first liquid between the distal stop member and the distal end of the syringe body. The system further includes a plunger member defining a plunger interior and configured to be manually manipulated to distally insert the proximal stop member into the syringe body. The system further includes a transfer pipe having a transfer pipe interior, a distal end opening, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the transfer pipe interior. The system further includes a connector fluidly coupled to the transfer pipe interior. The method also includes advancing the plunger member to expel a first liquid from the distal chamber through the transfer pipe interior and the distal end opening, and further advancing the plunger member to expel a second liquid from the proximal chamber through the proximal opening, the transfer pipe interior and the distal end opening.

[0039] In one or more embodiments, the method further includes connecting a coupling member to an IV bag, thereby fluidly coupling the interior of the transfer pipe with the IV bag, before advancing the plunger member to expel the first liquid from the distal chamber. The method can also include removing air from the distal chamber before connecting the coupling member to the IV bag. Removing air from the distal chamber can include holding the syringe body in a substantially vertical position and manipulating the plunger member to distally insert the proximal stopper member relative to the syringe body.

[0040] In one or more embodiments, advancing the plunger member inserts the proximal stopper member distally relative to the syringe body, thereby exerting a distal force through the second liquid to insert the distal stopper member distally relative to the syringe body, thereby expelling the first liquid from the distal chamber through the interior of the transfer pipe and the distal end opening.

[0041] In one or more embodiments, the system has a first injection configuration in which the proximal opening is located in the distal chamber and a second injection configuration in which the proximal opening is located in the proximal chamber, thereby allowing a second liquid to be transferred from the proximal chamber through the proximal opening and the interior of the transfer pipe and out the distal opening. The system is in the first injection configuration when the plunger member advances to expel the first liquid from the distal chamber through the interior of the transfer pipe and the distal opening. The system is in the second injection configuration when the plunger member further advances to expel the second liquid from the proximal chamber through the proximal opening, the interior of the transfer pipe and the distal opening. A distal stopper member may close the intermediate opening when the system is in the second injection configuration.

[0042] In one or more embodiments, the distal stop member has a proximally tapered funnel and a space disposed at the tapered proximal end of the funnel, and the method further includes the step of funnel directing the transfer pipe proximal end into the space at the tapered proximal end of the funnel, thereby aligning the transfer pipe proximal end with the distal stop member.

[0043] In one or more embodiments, the transfer pipe further includes a transfer pipe proximal end, and the distal stop member includes a detent. The method further includes the step of resisting passage of the transfer pipe proximal end through the detent. Advancing the plunger member to expel the first liquid from the distal chamber through the transfer pipe interior and the distal end opening can include applying a distal force to the plunger member to overcome the resistance to passage of the transfer pipe proximal end through the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0044] In one or more embodiments, the transfer pipe further includes a shoulder and the distal stop member includes a detent. The method further includes the step of the detent resisting passage of the shoulder. Further advancing the plunger member to expel the second liquid from the proximal chamber through the proximal opening, the transfer pipe interior, and the distal end opening can include applying a distal force to the plunger member to overcome the resistance of the shoulder to passage of the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0045] In one or more embodiments, the transfer pipe further includes a groove and the distal stop member includes a detent. The method further includes the step of the detent resisting passage of the groove. Further advancing the plunger member to expel the second liquid from the proximal chamber through the proximal opening, the transfer pipe interior, and the distal end opening can include applying a distal force to the plunger member to overcome the resistance of the groove to passage of the detent. The distal force can be between about 2 pounds and about 5 pounds.

[0046] In one embodiment, a system for mixing and injecting pharmaceutical products includes a syringe body defining a proximal opening at a proximal end and a distal needle interface at a distal end. The system also includes proximal and distal stop members disposed on the syringe body, forming a proximal drug chamber between the proximal and distal stop members and a distal drug chamber between the distal stop member and the distal end of the syringe body. The system further includes a plunger member defining a plunger interior and configured to be manually manipulated to distally insert the proximal stop member into the syringe body. The system further includes a needle hub assembly coupled to the distal needle interface of the syringe body. The needle assembly includes a needle having a needle proximal end feature and a sharpened needle distal end, and a hub. The system further includes a needle cover having a threaded surface for removably coupling the needle cover to the hub. The needle cover has a sealing configuration in which the needle cover prevents fluid flow through the needle distal end and a venting configuration in which the needle cover allows fluid flow through the needle distal end.

[0047] In one or more embodiments, pulling the needle cover distally relative to the syringe body moves the needle cover from the sealing configuration to the venting configuration. The first and second sizes of the distal and proximal drug chambers, respectively, can be changed by relative movement of the proximal and distal stop members relative to the syringe body.

[0048] In one or more embodiments, the plunger member includes a needle retaining feature disposed within the plunger, an energy storage member disposed within the plunger, and an energy storage member latch member disposed within the plunger, wherein, in response to manipulation of the plunger member relative to the syringe body, the energy storage member latch member is transformed from a latched state to an unlatched state, thereby allowing the needle to be at least partially retracted within the plunger.

[0049] In one or more embodiments, the needle assembly also includes a needle latch member configured to couple the needle to the hub. The distal and proximal drug chambers can contain first and second components, respectively, of a drug that are mixed together prior to injection into a patient.

[0050] In one or more embodiments, the system has a transport configuration in which the needle proximal end feature is disposed within the distal drug chamber. The system also has a transfer configuration in which the needle proximal end feature at least partially penetrates the distal stop member and is at least partially disposed within the proximal drug chamber. The system also has a mixing configuration in which the proximal and distal stop members contact each other, thereby transferring a first drug component from the proximal drug chamber to the distal drug chamber and mixing the first drug component with a second drug component in the distal drug chamber.

[0051] In one or more embodiments, the needle further comprises a distal opening disposed at the needle distal end, an intermediate opening disposed in the distal drug chamber when the system is in the transport, transfer, and mixing configurations, and a proximal opening disposed in the proximal drug chamber when the system is in the transport and transfer configurations. The proximal opening may be a slot.

[0052] In one or more embodiments, the needle cover has flexible fingers configured to permit distal movement of the needle cover relative to the hub in the sealed configuration and to prevent distal movement of the needle cover relative to the hub in the vented configuration. The hub may have a threaded surface configured to interact with the threaded surface and flexible fingers of the needle cover when the needle cover is in the vented configuration, thereby preventing distal movement of the needle cover relative to the syringe body without rotation of the needle cover relative to the syringe body.

[0053] In one or more embodiments, rotating the needle cover relative to the syringe body in a first direction transitions the needle cover from the sealing configuration to the venting configuration. The hub can also include an interference member configured to removably couple the needle cover to the hub. Distal movement of the plunger member relative to the syringe body can cause the distal stop member to move distally relative to the needle such that the needle proximal end feature penetrates the distal stop member.

[0054] In another embodiment, a system for mixing and injecting pharmaceutical products includes a syringe body defining a proximal opening at a proximal end and a distal needle interface at a distal end. The system also includes a proximal stop member and a distal stop member disposed on the syringe body, forming a proximal drug chamber between the proximal stop member and the distal stop member, and a distal drug chamber between the distal stop member and the distal end of the syringe body. The system also includes a plunger member defining a plunger interior, the plunger member having a threaded surface such that when the plunger member is rotated relative to the syringe body in a first direction, the plunger member advances and inserts the proximal stop member into the syringe body. The system further includes a needle hub assembly coupled to the distal needle interface of the syringe body. The needle assembly includes a needle having a needle proximal end feature and a sharpened needle distal end, and a hub. The system further includes a needle cover removably coupled to the hub.

[0055] In one or more embodiments, the first and second sizes of the distal and proximal drug chambers, respectively, can be varied by relative movement of the proximal and distal stop members with respect to the syringe body. The plunger member can include a needle retaining feature disposed within the plunger, an energy storage member disposed within the plunger, and an energy storage member latch member disposed within the plunger. In response to relative manipulation of the plunger member with respect to the syringe body, the energy storage member latch member is transformed from a latched state to an unlatched state, thereby allowing the needle to be at least partially retracted within the plunger.

[0056] In one or more embodiments, the needle assembly also includes a needle latch member configured to couple the needle to the hub. The distal and proximal drug chambers can contain first and second components, respectively, of a drug that are mixed together prior to injection into a patient.

[0057] In one or more embodiments, the system has a transport configuration in which the needle proximal end feature is disposed within the distal drug chamber. The system also has a transfer configuration in which the needle proximal end feature at least partially penetrates the distal stop member and is at least partially disposed within the proximal drug chamber. The system further has a mixing configuration in which the proximal and distal stop members contact each other, thereby transferring a first drug component from the proximal drug chamber to the distal drug chamber and mixing the first drug component with a second drug component in the distal drug chamber.

[0058] In one or more embodiments, the needle further comprises a distal opening disposed at the needle distal end, an intermediate opening disposed in the distal drug chamber when the system is in the transport, transfer, and mixing configurations, and a proximal opening disposed in the proximal drug chamber when the system is in the transport and transfer configurations. The proximal opening may be a slot.

[0059] In one or more embodiments, the threaded surface of the plunger member has a double helix thread. The threaded surface of the plunger member may have a relatively large pitch thread. The threaded surface of the plunger member may have an 8.5 mm pitch.

[0060] In one or more embodiments, the threaded surface of the plunger member may be configured such that rotating the plunger member relative to the syringe body in a first direction advances the plunger member and inserts the proximal stop member into the syringe body until the proximal stop member contacts the distal stop member. Alternatively, rotating the plunger member relative to the syringe body in a first direction advances the plunger member and inserts the proximal stop member into the syringe body just short of contacting the distal stop member.

[0061] In one or more embodiments, the system further includes a flange coupled to the proximal end of the syringe body, the flange having a threaded surface that interacts with the threaded surface of the plunger member to advance the plunger member and insert the proximal stop member relative to the syringe body during rotation of the plunger member relative to the syringe body. The surface of the flange can include a removed wall. Rotating the plunger member relative to the syringe body in a first direction can move the distal stop member distally relative to the needle, causing the needle proximal end feature to penetrate the distal stop member.

[0062] The above and other embodiments of the present disclosure are described in the detailed description that follows. [Brief explanation of the drawings]

[0063] The above and other features of the embodiments will be described in more detail with reference to the accompanying drawings, in which like elements in different drawings are designated by common reference numerals.

[0064] [Figure 1] 1A and 1B illustrate various features of a conventional syringe configuration. [Figure 2] 2A and 2B illustrate various features of a conventional syringe configuration. [Figure 3] FIG. 3 illustrates various features of a conventional syringe design. [Figure 4] 4A and 4B illustrate various features of a conventional syringe configuration. [Figure 5] 5A-5C illustrate various features of a conventional syringe configuration. [Figure 6] 6A-6Q illustrate various features of a syringe-based dual chamber safety injection system in a protective configuration where the end / tip of the distal needle is retracted after use, according to some embodiments. [Figure 7] 7A-7L illustrate various features of a syringe-based dual chamber safety injection system during steps of a method for continuously injecting liquids using the system, according to some embodiments. [Figure 8] 8A-8C illustrate various features of two embodiments of a syringe-based dual chamber safety injection system. [Figure 9] 9A-9C illustrate various features of a syringe-based dual chamber safety injection system during steps of a method for continuously injecting liquids using the system, according to some embodiments. [Figure 10] 10A and 10B illustrate various features of a syringe-based dual chamber safety injection system during steps of a method for continuously injecting liquids using the system, according to some embodiments. [Figure 11]11A and 11B illustrate various features of a syringe-based dual chamber safety injection system according to some embodiments. [Figure 12] 12A-12C illustrate various features of a distal stopper member having a stopper bushing with a detent for use in a syringe-based dual-chamber safety injection system according to some embodiments, during steps of a method for continuously injecting liquids using the system. [Figure 13] 13A-13C illustrate various features of a stopper member bushing with a detent for use in a syringe-based dual chamber safety injection system according to some embodiments. [Figure 14] 14A-14C illustrate various features of a detent for use with a stopper member bushing for use with a syringe-based dual chamber safety injection system according to some embodiments. [Figure 15] FIG. 15 is a graph plotting stress versus strain for materials from which detents can be made for use with stopper member bushings used in syringe-based dual chamber safety injection systems according to some embodiments. [Figure 16] FIG. 16 illustrates various harpoon shapes for use with stopper member bushings in conjunction with detents for use with syringe-based dual chamber safety injection systems according to some embodiments. [Figure 17] FIG. 17 illustrates various shoulder shapes for use on stopper member bushings in conjunction with detents for use with syringe-based dual chamber safety injection systems according to some embodiments. [Figure 18] FIG. 18 illustrates various features of the needle spine assembly of a syringe-based dual chamber safety injection system according to some embodiments. [Figure 19] FIG. 19 illustrates various features of the needle spine assembly of a syringe-based dual chamber safety injection system according to some embodiments. [Figure 20]FIG. 20 illustrates a dual chamber safety injection system with a shielded and ventable needle cover in a sealed and vented configuration, respectively, according to some embodiments. [Figure 21] FIG. 21 illustrates a dual chamber safety injection system with a shielded and ventable needle cover in a sealed and vented configuration, respectively, according to some embodiments. [Figure 22] FIG. 22 shows in detail a threaded plunger member and finger flange for use in a dual chamber safety injection system according to some embodiments. [Figure 23] FIG. 23 illustrates a finger flange for use in a dual chamber safety injection system according to some embodiments. [Figure 24] FIG. 24 illustrates a dual chamber safety injection system in a transfer configuration with a shielded and ventable needle cover, according to some embodiments. [Figure 25] FIG. 25 details the proximal and distal stop members and the proximal opening of the needle for use in a dual chamber safety injection system according to some embodiments. [Figure 26] FIG. 26 illustrates a needle for use with a dual chamber safety injection system according to some embodiments. [Figure 27] FIG. 27 shows in detail the proximal end of a needle for use in a dual chamber safety injection system according to some embodiments. [Figure 28] FIG. 28 illustrates a dual chamber safety injection system in a venting and mixing configuration with a shielded and ventable needle cover, according to some embodiments. [Figure 29] FIG. 29 illustrates a dual chamber safety injection system in a mixed configuration with the shielded and ventable needle cover removed for injection, according to some embodiments. [Figure 30] FIG. 30 details the proximal end of a shielded and ventable needle cover in a sealed configuration for use in a dual chamber safety injection system according to some embodiments. [Figure 31] FIG. 31 details the proximal end of a shielded and ventable needle cover removed from the distal end of a needle hub for use in a dual chamber safety injection system according to some embodiments. [Figure 32] FIG. 32 is a cross-sectional view detailing the proximal end of a shielded and ventable needle cover in a sealed configuration for use in a dual chamber safety injection system according to some embodiments. [Figure 33] FIG. 33 is a cross-sectional view detailing the proximal end of a shield and ventable needle cover in a venting configuration for use in a dual chamber safety injection system according to some embodiments. [Figure 34] FIG. 34 details the proximal end of a shielded and ventable needle cover removed from the distal end of the needle hub for use in a dual chamber safety injection system according to some embodiments.

[0065] To better understand how the above and other advantages and objects of the various embodiments are obtained, a more detailed description of the embodiments will be provided with reference to the accompanying drawings. It should be noted that the drawings are not drawn to scale, and elements of similar structure or function are designated by similar reference numerals throughout. It should be understood that the drawings depict only certain exemplary embodiments, and therefore should not be considered to limit the scope of the embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0066] Exemplary Prefilled Dual Chamber Safety Infusion System 6A and 6B, a perspective view and a longitudinal cross-sectional view of a pre-filled dual-chamber safety injection system (100) are shown, each having a conventional pre-filled syringe body (34) with conventional proximal and distal stop members (32, 36) disposed therein. The proximal and distal stop members (32, 36), together with the syringe body (34), define proximal and distal chambers (40, 42). The proximal and distal stop members (32, 36) occlude the proximal and distal ends of the proximal chamber (40). The distal stop member (36) occludes the proximal end of the distal chamber (42). In some embodiments, the distal end of the proximal stopper member (32) and the proximal end of the distal stopper member (36) are each coated with a lubricious polymer coating (e.g., PTFE or ETFE), and the first and second polymer coatings of the proximal and distal stopper members (32, 36), together with the syringe body (34), define a proximal chamber (40). The lubricious polymer coating serves to isolate the rubber of the proximal and distal stopper members (32, 36) from the second liquid (254). The proximal and distal stopper members (32, 36) can be oriented as shown in FIGS. 6A and 6B, or the distal stopper (36) can be inverted so that the lubricious coating faces the distal chamber (42) and the first liquid (252) in the distal chamber (42) contacts the lubricious coating for storage.

[0067] The needle coupling assembly (606) is disposed at the distal end of the distal chamber (42) with the needle cover member (63) attached for storage. The dual-chamber safety injection system facilitates sequential injection of a first liquid (252) from the distal chamber (42) followed by a second liquid (254) from the proximal chamber by a user sequentially inserting the plunger assembly (44) into the syringe body (34) to varying degrees. The plunger assembly (44) includes a proximal stopper member (32), a plunger housing member (69), and a plunger operating interface (128). The first and second liquids disposed in the distal and proximal chambers (42, 40), respectively, may be any liquid or gel, such as an aqueous or oil-based medicinal solution.

[0068] The dual-chamber safety injection system (100) has a staked needle configuration in which, when provided to a user, the needle assembly, including the needle spine assembly ("needle") (76) and the needle coupling assembly (606), is mounted in a fixed position ready for injection after removal of the needle cover member (63), which may have an elastomeric sealing material on its interior surface that contacts the needle distal end (78) and / or the needle distal housing portion (610, see FIGS. 6C and 6D) during storage. Alternatively, the needle cover member (63) may include a vent (shown and described below) that allows pressure resulting from the movement of the liquids (252, 254) to escape from the interior of the syringe body (34) while preventing contamination from entering the syringe body (34). Although the staked needle is depicted as being fixed in place, the staked needle can be removably coupled to the syringe body (34) using a luer slip or luer lock interface (not shown), with the proximal end (50) of the needle member extending through the luer interface into the distal chamber (42). Alternatively, the needle may be fixedly or removably attached to a flange on the cartridge body instead of the syringe. Such a cartridge injection system is disclosed in U.S. Patent Application No. 15 / 801,281. In the embodiment shown in Figures 6A-7L, a significant portion of the safety needle retraction member resides within the plunger housing.

[0069] As shown in Figures 6C and 6D, upon initial assembly (i.e., in a factory or fabrication facility, rather than on-site in a "staked needle" configuration), the proximal housing assembly (608) is configured to snap-fit ​​over the slightly recessed radial portion (602) of the syringe body (i.e., using a snap ring element (604) that constitutes the proximal housing assembly or a snap ring element coupled to the proximal housing assembly) that is formed in the syringe body during manufacture of the syringe body.

[0070] Figures 6E-6O are various views of an exemplary needle spine assembly ("needle") (76) and various portions thereof, as shown in Figures 6A-6D, according to some embodiments. Figures 6E / 6F, 6G / 6H, 6I / 6J, 6K / 6L, and 6M / 6N are corresponding pairs of side and longitudinal cross-sectional views of the needle spine assembly (76) and various portions thereof. Figure 6O is a perspective view of the needle spine assembly (76) according to some embodiments.

[0071] The needle spine assembly (76) includes a needle proximal end (50) and a needle distal end (78) coupled to opposite ends (i.e., the proximal and distal ends, respectively) of a needle interface member (83). The needle interface member (83) is configured with a necked or radially reduced portion (111) configured to engage with a latch member (612) and a movable block member (614) (see Figures 6P and 6Q), thereby maintaining the needle interface member (83), the needle proximal end (50), and the needle distal end (78) proximally fixed relative to the syringe body (34) during injection. After the plunger assembly is fully inserted relative to the smaller diameter flange (33) (i.e., after or about the time when the second liquid (254) contained in the proximal chamber (40) of the syringe body (34) has been completely expelled), the movable block member (614) is advanced relative to the distal housing portion (610), thereby displacing the multiple (two shown) cantilevered latch members (616) of the latch member (612) by the movable block member (614). Specifically, the needle spine assembly (76) is urged distally by the full advancement of the plunger assembly, thereby advancing the movable block member (614) and moving the cantilevered latch members (616). Moving the cantilevered latch members (616) allows the needle distal end (78), joining member (83), and proximal end (50) to be retracted via their couplings, thereby safely positioning the sharp needle tip (48) within the plunger housing member (69). Alternatively, needle tip 48 can be retracted to a position proximal to the exterior surface of distal housing portion 610 to safely shield the sharp tip from the user. In other words, cantilevered latch member 616 maintains the position of needle tip 48 during injection and needle / syringe assembly until pushed out by movable blocking member 614 upon full plunger insertion, as further described in U.S. Patent Application No. 15 / 801,259.After the cantilevered latch member (616) is pushed out by the movable block member (614), the needle (76) is freed to automatically retract when triggered by further distal movement of the needle spine assembly (76), as described in U.S. Patent Application Nos. 14 / 696,342 and 62 / 416,102.

[0072] Figures 6E-6O illustrate features of the needle spine assembly (76), including the elements of the needle assembly, but not the needle coupling assembly (606). As shown in Figures 6F and 6H, the needle proximal end (50) includes a coupling member (86) at its distal end and a pointed proximal end (84). A needle interface member (83) couples the coupling member (86) to the needle distal end (78). The needle distal end (78), the coupling member (86) of the needle proximal end (50), and the needle interface member (83) can be held together by an interference fit, welding, and / or adhesive. The needle proximal end (50) is coupled to the needle interface member (83), such that the interior of the needle interface member (83) is closed at its proximal end, preventing fluid flow through the proximal end of the needle interface member (see Figure 6H). The proximal end (84) of the needle proximal tip (50) in the illustrated embodiment forms a "harpoon"-type geometry configured to pierce and retain a compliant member and can engage the compliant member for retraction of the needle spine assembly (76) into the plunger housing member (69). The use of the proximal end (84) to retract the needle spine assembly (76) into the plunger housing member (69) is further described in U.S. Patent Application Nos. 15 / 801,259 and 15 / 801,304. The needle proximal tip (50) may be formed from metal rod and metal ring using, for example, welding, laser cutting, stamping, and / or machining techniques.

[0073] As shown in Figures 6G-6N, the needle interface member (83) and needle distal end (78) can provide a fluid pathway selectively connecting the proximal and distal chambers (40, 42) to the exterior of the system (100). This fluid pathway can include one or more proximal openings (85) at the proximal end of the needle interface member (83) adjacent the needle proximal end (50), as shown in Figures 6G-6N. In the embodiment shown in Figures 6E-6O, there are two proximal openings (85). In other embodiments, there can be a fewer (e.g., one) or a greater (e.g., three) number of proximal openings (85). The fluid pathway can include one or more intermediate openings (80) distal to the one or more proximal openings (85). In the embodiment shown in Figures 6E-6O, there is one intermediate opening (80). In other embodiments, there can be more (e.g., two) intermediate openings (80). The proximal and intermediate openings (85, 80) may be formed by cutting (eg, holes or slots) into the sidewall of the hollow joining member (83).

[0074] The distal portion (78) of the needle spine assembly (76) includes a sharpened hypodermic needle tip (48, see FIGS. 6M and 6N) formed at the distal-most end of the distal portion (78). The fluid pathway may also include one or more distal openings (81) at the needle tip (48). In the embodiment shown in FIGS. 6E-6O, there is one distal opening (81). In other embodiments, there may be more (e.g., two) distal openings (81). The distal openings (81) may be formed by scraping or cutting the distal end of the distal portion (78) or by cutting (e.g., holes or slots) into the sidewall of the hollow joining member (83).

[0075] The proximal, intermediate, and distal openings (85, 80, 81) are all in fluid communication with the interior (82) of the needle spine assembly (76). The interior (82) of the needle spine assembly (76) extends from the proximal opening (85) to the distal opening (81). Changing the relative positions of the needle spine assembly (76) and the proximal and distal stop members (32, 36) selectively couples the proximal and distal chambers (40, 42) to the exterior of the system (100) via the interior (82) of the needle spine assembly (76). In the embodiment shown in Figures 7A-7I, the intermediate opening (80) is always located within the distal chamber (40) during injection. When the proximal openings (85) are also disposed within the distal chamber (40) (FIGS. 7A-7C), or when one or more of the proximal openings (85) are blocked by the distal stopper member (36), the distal chamber (42) is fluidly coupled to the exterior of the system (100) via one or more of the proximal openings (85) and / or intermediate opening (80), the interior (82) and distal opening (81) of the needle spine assembly (76). FIGS. 7A-7C show a first injection configuration in which a first liquid (252), but not a second liquid (254), can be injected via the interior (82) and distal opening (81) of the needle spine assembly (76). When one or more of the proximal openings are disposed within the proximal chamber (42) and the intermediate opening (80) is blocked by the distal stop member (36) (FIGS. 7G-7I), the proximal chamber (40) is fluidly coupled to the exterior of the system (100) via one or more proximal openings (85), the interior (82) of the needle spine assembly (76), and the distal opening (81). FIGS. 7G-7I illustrate a second injection configuration in which a second liquid (254), rather than the first liquid (252), can be injected through the interior (82) of the needle spine assembly (76) and the distal opening (81). As shown in FIG. 7I, the distal stop member (36) prevents fluid flow (e.g., the flow of the second fluid (254)) into the intermediate opening (80).

[0076] 7A-7I illustrate one embodiment of a prefilled dual chamber safety injection system (100) having the needle spine assembly (76) shown in FIGS. 6E-6O at various steps in a method of continuous injection.

[0077] 7A-7C show the dual-chamber safety injection system 100 (side view, longitudinal section, and detailed longitudinal section) in a first step of a method for sequential injection, with the system 100 in a first injection configuration. In the first step shown in FIGS. 7A-7C, the needle cover member 63 (see FIGS. 6A and 6B) has been removed, rendering the system 100 ready for use. The distal chamber 42 may optionally be "bubble-cleared" by holding the syringe body in a substantially vertical position and manipulating the plunger member to distally insert the proximal stopper member relative to the syringe body. During bubble clearance, air within the distal chamber 42 rises to the top of the distal chamber 42, where the small opening 80 is located, and exits the system 100 through the intermediate opening 80, the interior 82 of the needle spine assembly 76, and the distal opening 81.

[0078] 7C also shows that the distal stop member 36 includes a distal stop bushing 310 that defines a positioning funnel 314 for guiding the proximal end 84 of the needle proximal tip into a fixed position (within the space 316 at the tapered proximal end of the distal stop bushing 310) during injection. In other embodiments, the positioning funnel 314 is configured to guide the proximal end 84 of the needle proximal tip into a fixed position during assembly of the dual chamber safety injection system 100. Further details regarding the positioning funnel 314 are described in U.S. Patent Application Serial No. 15 / 801,259.

[0079] Figures 7D-7F show the dual-chamber safety injection system (100) in a second step of a method for sequential injection (side view, longitudinal section, and detailed longitudinal section), with the system (100) in a first injection configuration. In the second step shown in Figures 7D-7F, the proximal stop member (32) is moved distally relative to the syringe body (34) by applying a distal force to the plunger member, as described in U.S. Patent Application No. 15 / 801,259. The portion of the needle interface member (83) having the proximal opening (85) does not pass through the distal stop member (36) into the proximal chamber (40), so the proximal chamber (40) is a substantially closed chamber. Therefore, the distal movement of the proximal stop member (32) distally displaces the incompressible second liquid (254) in the proximal chamber (40) and the distal stop member (36) the same distance. Distal movement of the distal stop member (36) increases the pressure within the distal chamber (42), thereby expelling a portion of the first liquid (252) from the distal chamber (42) and the system (100) through the proximal opening (85) and / or the intermediate opening (80), the interior (82) of the needle spine assembly (76), and the distal opening (81).

[0080] In some embodiments, the needle tip (48) and distal opening (81) are positioned within (e.g., pierced by) the patient before a distal force is applied to the plunger member to inject the first liquid (252) into the patient. A sharpened needle tip (48, see FIGS. 6M and 6N) facilitates such injection.

[0081] 7F shows that the proximal end (84) of the needle proximal tip is guided into position during injection through the middle of the distal stop member (36) by a positioning funnel (314) defined by the distal stop bushing (310). Further details regarding the positioning funnel (314) are described in U.S. Patent Application No. 15 / 801,259.

[0082] Figures 7G-7I illustrate the dual-chamber safety injection system (100) (side view, longitudinal section, and detailed longitudinal section) during a third step of a method for sequential injection, showing the system (100) at the end of a first injection configuration and the beginning of a second injection configuration. In the third step shown in Figures 7G-7I, the distal stopper member (36) advances to the distal end of the syringe body (34), thereby collapsing the distal chamber (42; see Figures 7D-7F) and expelling substantially all of the first liquid (252; see Figures 7D-7F) previously contained therein. The distal stopper member (36) effectively blocks the intermediate opening (80) by separating it from the second liquid (254) in the proximal chamber (40).

[0083] As shown in FIG. 7I, the portion of the needle interface member (83) having the proximal opening (85) passes through the distal stop member (36) and enters the proximal chamber (40). Therefore, the proximal chamber (40) is no longer closed because it is open through the proximal opening (85). This places the system (100) in a second injection configuration. The distance between the most distal proximal opening (85) and the distal end of the syringe body (34) is substantially equal to the length of the distal stop member (36). Therefore, when the distal stop member (36) is inserted into the distal end of the syringe body (34), the proximal opening (85) is positioned within the proximal chamber (40).

[0084] 7J-7L illustrate the dual-chamber safety injection system 100 (side view, longitudinal section, and detailed longitudinal section) during a fourth step of the method for continuous injection, with the system 100 positioned at the end of the second injection configuration. In the fourth step shown in FIGS. 7J-7L, the proximal stop member 36 advances to its proximal end at the distal end of the syringe body 34, thereby collapsing the proximal chamber 40 (see FIGS. 7G-7I) and expelling substantially all of the second liquid 254 (see FIGS. 7G-7I) previously contained therein. At the completion of the fourth step shown in Figures 7J-7L, after the patient has been injected, the proximal end (84) has penetrated both the proximal and distal stop members (32, 36) and is mated with a coupling feature in the plunger rod for at least partially retracting the needle spine assembly (76) into the plunger rod, as described in U.S. Patent Application No. 15 / 801,259. In some embodiments, the system (100) retracts the needle spine assembly (76) to a position where the distal tip (48) of the needle spine assembly is disposed within the syringe body (34).

[0085] Exemplary Prefilled Dual Chamber Continuous and Safe Infusion System Figures 8A-8C show two embodiments of dual-chamber safety injection systems (800, 810). The first system (800) has a total injection volume of 1 mL. The second system (810) has a total injection volume of 3 mL. The first system (800) uses a long glass syringe (834) with a total volume of approximately 1 mL, as shown in Figure 8B. The proximal and distal chambers (840, 842) of the first system (800) each have a maximum capacity of approximately 0.5 mL.

[0086] The second system (810) uses a standard glass syringe (844) with a total volume of approximately 3 mL, as shown in Figure 8C. The proximal and distal chambers (850, 852) of the second system (810) each have a maximum capacity of approximately 1.5 mL.

[0087] 9A-9C illustrate a prefilled dual-chamber safety injection system (900) during various steps of a continuous injection according to one embodiment. During the continuous injection step shown in FIG. 9A, the system (900) is in the first injection configuration described above. In the first injection configuration, the proximal and distal stop members (932, 936), needle spine assembly (976), and syringe body (934) are positioned such that the proximal opening (985) is located within the distal chamber (942) and the proximal chamber (940) is closed. Therefore, the first liquid (952) in the distal chamber (942) can exit the system (900) via one of two fluid paths (910, 912), which include the proximal opening (985) and the intermediate opening (980), respectively. In the first configuration, the second liquid (952) cannot exit the system (900). Instead, the incompressible second liquid (952) transfers the force applied to the proximal stop member (932) to the distal stop member (936).

[0088] 9B shows the system (900) in the second injection configuration described above, in which the distal stop member (936) is moved to the distal end of the syringe body (934), thereby collapsing the distal chamber (942; see FIG. 9A), and expelling substantially all of the first liquid (952; see FIG. 9A) from the system (900). In the second injection configuration, the proximal and distal stop members (932, 936), the needle spine assembly (976), and the syringe body (934) are positioned such that the proximal opening (985) is positioned within the proximal chamber (940), thereby opening the proximal chamber (940). This allows the second liquid (954) within the proximal chamber (940) to exit the system (900) via the fluid pathway (910), which includes the proximal opening (985). In the second configuration, the distal stop member (936) substantially blocks the intermediate opening (980) by isolating the intermediate opening (980) from the second liquid (954) in the proximal chamber (940).

[0089] Figure 9C shows the system 900 after the proximal stop member 932 has been moved distally to a position where it abuts the proximal end of the distal stop member 936. This collapses the proximal chamber 940 (see Figure 9B) and expels substantially all of the second liquid 954 (see Figure 9B) from the system 900. After the first and second liquids 952, 954 (see Figure 9A) have been expelled from the system 900, slight further distal movement of the plunger member moves the needle spine assembly 976 distally, thereby releasing the needle latch and permitting proximal retraction of the needle 976, so that the distal tip 948 is positioned and protected within the syringe body 934. The release of the needle latch retraction of the needle 976 is further described in U.S. Patent Application No. 15 / 801,259.

[0090] Figures 10A and 10B illustrate a prefilled dual-chamber safety injection system (1000) according to another embodiment during various steps of a continuous injection. The difference between the system (1000) shown in Figures 10A and 10B and the system (900) shown in Figures 9A-9C is that the needle spine assembly (1076) is sized and positioned relative to the proximal and distal stop members (1032, 1036) and the syringe body (1034) such that the proximal end (1084) of the needle (1076) is located within the distal chamber (1042) in the storage / transport configuration shown in Figure 10A. In this embodiment, a funnel guides the proximal end (1084) of the needle (1076) through the distal stop member (1036), as described in U.S. Patent Application No. 15 / 801,259.

[0091] As shown in FIG. 10B , in the second injection configuration, the proximal opening (1085) is disposed within the proximal chamber (1040), thereby opening the proximal chamber (1040). The distance between the proximal opening (1085) and the distal end of the syringe body (1034) is approximately equal to the length of the distal stopper member (1036). Therefore, when the distal stopper member (1036) is inserted into the distal end of the syringe body (1034), the proximal opening (1085) is disposed within the proximal chamber (1040). The use of a shorter needle spine assembly (1076) allows the needle spine assembly (1076) to be retracted into the shorter plunger member, as described in U.S. Patent Application No. 15 / 801,259.

[0092] Exemplary Distal Bushing System with Detents in Dual Chamber Safety Injection 11A and 11B illustrate a prefilled dual-chamber safety injection system (1100) according to some embodiments. This system (1100) differs from the other prefilled dual-chamber safety injection systems described above in that the distal stopper member (1136) is not a continuous injection system, but rather a mixed injection system such as that described in U.S. Patent Application No. 15 / 801,259. In these systems, liquid is transferred from the proximal chamber (1140) to the distal chamber (1142) to rehydrate lyophilized components (not shown) in the distal chamber (1142) before the rehydrated mixture is injected into the patient. Various features and advantages of such a system are described in U.S. Patent Application No. 15 / 801,259.

[0093] The system 1100 includes a stopper bushing 1110 having a detent 1112 disposed therein. The detent 1112 is configured to interact with the pointed proximal end 1184 of the needle spine assembly 1176 and a shoulder 1116 at the junction between the needle proximal end 1150 and the needle interface member 1183 to provide resistance to distal movement of the distal stopper member 1136 relative to the needle spine assembly 1176. The interaction between the detent 1112 and the proximal end 1184 maintains the distal stopper member 1136 in a usable position during storage and shipping, such as the configuration shown in FIGS. 11A and 11B. This interaction maintains the position of the distal stopper member 1136 even in the presence of a vacuum or partial vacuum (e.g., for lyophilized components) within the distal chamber 1142. Without detent 1112 and with a vacuum in distal chamber 1142, distal stop member 1136 would eventually move distally relative to needle spine assembly 1176 and be pierced thereby, rendering the system unusable for continuous infusion.

[0094] The interaction between the detent (1112) and the shoulder (1116) maintains the distal stop member (1136) in a transfer position during transfer of liquid from the proximal chamber (1140) to the distal chamber (1142). This interaction allows the user to apply a wider range of forces to the plunger member to transfer liquid while minimizing the risk of premature movement of the distal stop member (1136).

[0095] 12A-12C illustrate the interaction between the detent 1112, the pointed proximal end 1184 of the needle spine assembly 1176, and the shoulder 1116 of the needle spine assembly 1176 in the prefilled dual-chamber safety injection system 1100 shown in FIGS. 11A and 11B. As shown in FIG. 12A, the distal stop member 1136 includes a stop bushing 1110 having a detent 1112 and defining a positioning funnel 1114. In FIG. 12A, the positioning funnel 1114 guides the proximal end 1184 of the needle spine assembly 1176 into position adjacent the detent 1112.

[0096] 12B illustrates a storage / shipment configuration of the system 1100. In this configuration, the pointed proximal end 1184 of the needle spine assembly 1176 is disposed adjacent to and partially within the detent 1112. Various characteristics (e.g., geometry, material, etc.) of the proximal end 1184 and the detent 1112 can be modified to adjust the force required to push the proximal end 1184 past the detent 1112. These characteristics are described in more detail below. In one embodiment, the force required to push the proximal end 1184 past the detent 1112 is between about 2 pounds and about 5 pounds. As described above, even if a vacuum or partial vacuum in distal chamber 1142 urges distal stop member 1136 distally, the interaction between proximal end 1184 and detent 1112 prevents premature movement of distal stop member 1136 relative to needle spine assembly 1176. This allows prefilled dual chamber system 1100 to be stored while minimizing the risk of premature movement of distal stop member 1136, which could render system 1100 unusable.

[0097] 12C illustrates the transfer configuration of the system 1100. In this configuration, the distal stop member 1136 is pushed distally past the pointed proximal end 1184 of the needle spine assembly 1176 by a user-applied force on the plunger member. The proximal opening 1185 is disposed within the proximal chamber 1140, thereby allowing liquid to move from the proximal chamber 1140 to the distal chamber 1142. A vacuum within the distal chamber 1142 draws liquid from the proximal chamber 1140, while a user-generated force applied to the proximal stop member 1132 via the plunger member assists in the liquid movement. In this configuration, the shoulder 1116 of the needle spine assembly 1176 is disposed adjacent to the detent 1112. Various characteristics (e.g., geometry, material, etc.) of the shoulder 1116 and detent 1112 can be altered to adjust the force required to push the shoulder 1116 past the detent 1112. These characteristics are described in detail below. In one embodiment, the force required to push the shoulder 1116 past the detent 1112 is between about 2 pounds and about 5 pounds. The shoulder is formed at the junction between the needle proximal end 1150 and the needle interface member 1183. Due to the interaction between the shoulder 1116 and the detent 1112, pressure applied to the plunger member assists in the transfer of liquid from the proximal chamber 1140 to the distal chamber 1142 while the system 1100 is held in the transfer configuration shown in FIG. 12C . The force required to overcome the interference between shoulder 1116 and detent 1112 provides the user with more freedom to depress the plunger member to assist in fluid transfer, thereby increasing the likelihood of complete fluid transfer.

[0098] Figures 13A-13C show a stopper bushing 1110 for use with the prefilled dual-chamber safety injection system 1100 shown in Figures 11A and 11B. The stopper bushing 1110 has a detent 1112 inserted into a slot in the bushing 1110 along an axis perpendicular to the longitudinal axis of the needle spine assembly. As shown in Figure 13C, the detent can be made of a bent wire in a "U" shape.

[0099] FIGS. 14A-14C illustrate detents 1412, 1412′ for use with the stopper bushing of a prefilled dual-chamber safety injection system according to various embodiments. The detents 1412, 1412′ are formed from a sheet of metal material and therefore have a flattened cross-section. Each detent 1412, 1412′ has a “U” shape and includes a notch 1418 configured to accommodate a rounded shape, such as the pointed proximal end and shoulder, of the needle spine assembly. The detent 1412′ shown in FIG. 14B includes a chamfered / adjusted pass-through surface 1420 around the periphery of the notch 1418 of the detent 1412′ adjacent the pointed proximal end of the needle spine assembly when in the storage / transport configuration described above. The chamfered pass-through surface 1420 can be altered to adjust the amount of force required to pass through the detent 1412′.

[0100] FIG. 14C shows the pointed proximal end (1484) of the needle spine assembly (1476) positioned within the notch (1418) of the detent (1412), such as when in a storage / shipping configuration.

[0101] In one embodiment, the resistance provided by the detent 1412 as it slides over the pointed proximal end 1484 of the needle spine assembly 1476 is variable. The detent 1412 resists passage by the proximal end 1484 during storage (e.g., several years). A user applies a preset amount of force, causing the proximal end 1484 to slide through the detent 1412. Thereafter, the detent 1412 offers minimal resistance to movement of the needle spine assembly 1476 through the detent 1410 until the detent 1412 reaches the shoulder 1116 (see FIG. 12C ). Once the detent 1412 abuts the shoulder, the resistance increases to positively stop the advancement of the detent 1412 (and distal stop member) relative to the needle 1478. After the aforementioned fluid transfer, the user applies another preset amount of force to push detent 1412 past the shoulder. After the shoulder is cleared, friction due to the interaction between detent 1412 and needle 1476 is minimized, facilitating injection and needle retraction.

[0102] The preset force magnitude can be adjusted to accommodate a combination of the system's functional requirements and the user's aesthetic preferences. If the actuation force is too small, it may work, but the user may find it difficult to apply the force lightly enough, leading to overdoing it. If the force is too large, the user may find the system "too difficult" to activate. Fortunately, the preset force magnitude can be "tuned" within a predetermined range by modifying the properties of various components.

[0103] Figure 15 shows a stress versus strain graph (1500) for the stainless steel from which the detent is made. Using annealed stainless steel causes the detent material to sit on a flat yield plateau (1510), which causes the detent to permanently "bend" or yield after passing over the proximal end or shoulder, limiting the gripping force of the detent after the proximal end or shoulder passes through it. By selecting different materials, the resilience of the detent to the deformation required to clear the proximal end and / or shoulder can be altered, thereby adjusting the force required to push those components past the detent.

[0104] Figure 16 illustrates the geometry of the proximal end (1684) of the needle spine assembly (1676) and its effect on the force required to push the proximal end (1684) past the detent. To fine-tune the resistance force over the arrowhead proximal end (1684) and over the shoulder (1716, see Figure 17), the bevel angle on each can be adjusted individually as needed. Ignoring friction as an approximation, the effect of the bevel angle on the resistance force (X) is shown by the equation in Figure 17. The tangent function can have values ​​from zero to a very large number, so theoretically, any force can be achieved. Adding friction adds even more force to the value calculated using the equation. Values ​​of approximately 30 degrees for the arrowhead proximal end (1684) and approximately 50 degrees for the shoulder (1716) provide a resistance force that many users find acceptable.

[0105] Figures 18 and 19 illustrate a solid needle proximal tip 1850 for use with a dual-chamber safety injection system according to some embodiments. The use of a solid proximal tip simplifies and reduces manufacturing costs. The needle proximal tip 1850 is formed from a shouldered solid metal stem and a longer needle interface member 1883. This eliminates the need to drill side holes in the hollow stem and the need to provide a plug at the point end. The solid needle proximal tip 1850 design uses a longer needle interface member 1883 with a proximal opening 1885 near the proximal end 1884 to provide a fluid passage between the chambers. The weld between the needle interface member 1883 and the solid needle proximal tip 1850 is smooth and rounded to minimize resistance to passage of the detent 1812 (see Figure 19). Needle interface member 1883 is formed with a wide groove 1822 to capture detent 1812 and hold the distal stopper member in place for fluid transfer to the transfer configuration.

[0106] Threaded plunger member While dual-chamber safety injection systems are known, users must exercise extreme caution when applying distal force to the plunger member to move the proximal stop member distally to transfer fluid from the proximal chamber to the distal chamber. Applying too little or too much distal force to the plunger member can result in incomplete transfer of fluid from the proximal chamber to the distal chamber. Applying too much force to the plunger member can cause the distal stop member to move too far distally, thereby blocking the fluid transfer opening and rendering the system unusable. Applying too little force to the plunger member can result in incomplete transfer of fluid until more force is applied, which can cause the distal stop member to move too far distally, blocking the fluid transfer opening and rendering the system unusable. The threaded plunger member embodiments described herein address the above issues. By addressing these issues, dual-chamber safety injection systems are more user-friendly and enable accurate and safe delivery of mixed injectates.

[0107] Figure 20 illustrates a dual-chamber safety injection system 2000 according to some embodiments. The system 2000 includes a threaded plunger member 2002, a threaded flange 2004, a slotted needle proximal opening 2006, and a two-position shieldable and ventable needle cover 2008. The system 2000 shown in Figure 20 is in a shipping configuration prior to use. In the shipping configuration, the shieldable and ventable needle cover 2008 is in a sealed configuration (described below).

[0108] FIG. 21 illustrates the dual-chamber safety injection system (2000) shown in FIG. 20 in a fluid transfer configuration. In the fluid transfer configuration, the shielded and ventable needle cover (2008) is pulled distally onto the needle hub (2009), transitioning the shielded and ventable needle cover (2008) to the vent configuration (described below). The plunger member (2002) is then rotated clockwise (2010) relative to the syringe body, causing the plunger member (2002) and the proximal and distal stop members (via threaded interaction with the finger flanges (2004)) to controllably move distally relative to the syringe body. Distal movement of the distal stop member a controlled amount allows the proximal end of the needle to penetrate the distal stop member. This positions the proximal needle opening within the proximal chamber, allowing fluid to move from the proximal chamber to the distal chamber, mixing with the injectate contained in the distal chamber.

[0109] FIG. 22 shows in detail the threaded plunger member 2002 and finger flange 2004 of the dual-chamber safety injection system 2000 shown in FIG. 20. The thread 2012 of the threaded plunger member 2002 has a relatively large helical thread pitch to allow for greater axial movement of the plunger member 2002 per rotation of the plunger member 2002. The thread pitch may be between 5 mm and 25 mm. Preferably, the thread pitch is 8.5 mm. The thread 2012 may form a single helix or a multiple helix. The multiple helix may be a double helix, a triple helix, a quadruple helix, or the like. Preferably, the thread 2012 is a double helix.

[0110] Figure 23 shows in detail the finger flange (2004) and the threads thereof that correspond to the threads (2012) of the plunger member (2002) (see Figure 22). One wall (2014) of the threads of the finger flange (2004) is removed to facilitate the transition between rotation of the plunger member (2002) to thread the proximal end of the needle through the distal stop member and / or transfer fluid from the proximal chamber to the distal chamber, and application of a distal force to the plunger member (2002) to complete the fluid transfer and / or expel / inject the mixed fluid from the distal chamber.

[0111] FIG. 24 illustrates the dual-chamber safety injection system (2000) shown in FIG. 20 at a later stage in the fluid transfer configuration compared to FIG. 34. In the embodiment shown in FIG. 24, fluid transfer is still incomplete because there is still space between the proximal and distal stops (and thus still fluid in the proximal chamber). However, the threaded surface of the plunger member (2002) is sufficiently distal to the finger flange (2004). Therefore, in this embodiment, rotation of the plunger member achieves only penetration of the proximal end of the needle through the distal stop. To complete fluid transfer, a distal force (2016) must be applied to the plunger member (2002). In other embodiments, the plunger member (2002) is provided with a threaded surface such that rotation of the plunger member (2002) can complete fluid transfer.

[0112] Figure 25 shows in detail the proximal opening (2006) of the needle of the dual chamber safety injection system (2000) shown in Figure 20. The proximal opening (2006) is a slot that maintains an open fluid path between the proximal and distal chambers even when the proximal and distal stop members approach and contact each other, terminating fluid transfer.

[0113] Figure 26 shows in detail the needle of the dual chamber safety injection system (2000) shown in Figure 20. The slotted proximal opening (2006) is visible in Figure 26.

[0114] Figure 27 shows in more detail the proximal end of the needle of the dual-chamber safety injection system (2000) shown in Figure 20. Both the slotted proximal opening (2006) and the intermediate opening (2018) are visible in Figure 27. The size of the slotted proximal opening (2006) prevents excessive pressure from building up in the proximal chamber that might otherwise cause the distal stop member to move distally prematurely. In fact, with a sufficiently long slotted proximal opening (2006), the proximal and distal ends of the slotted proximal opening (2006) can form a fluid path around the proximal stop member in addition to the fluid path that includes the intermediate opening (2018). Alternatively or additionally, the intermediate opening (2018) can also be a slot.

[0115] Figure 28 shows the dual-chamber safety injection system (2000) shown in Figure 20 in a mixing configuration. The proximal and distal stop members come together to terminate fluid transfer. Once fluid has been transferred from the proximal to the distal chamber, the system (2000) can be agitated (e.g., by shaking) to mix the infusate in the distal chamber. A shielded and ventable needle cover (2008) is used to protect the needle and the user during mixing and agitation.

[0116] Figure 29 shows the removal of needle cover 2008 by unscrewing 2020 to allow dual chamber safety injection system 2000 to be injected.

[0117] Shielded and ventilated needle covers In the case of a pre-attached needle, without a ventable needle cover, fluid movement from the proximal chamber to the distal chamber can cause pressure to build up in the distal chamber. The increased pressure in the distal chamber can cause backflow from the distal chamber to the proximal chamber, which can lead to an inaccurate ratio of infusate in the proximal and distal chambers after mixing. Again, the user must be careful to overcome the pressure building up in the distal chamber by applying a constant distal force to the plunger member. Even if the user applies such force, when the needle cover is eventually removed, the increased pressure in the distal chamber can cause a portion of the mixed infusate to be prematurely expelled. The shielding and ventable needle cover embodiments described herein address the above-mentioned issues. Addressing these issues makes dual-chamber safety injection systems more user-friendly and enables accurate and safe delivery of mixed infusates.

[0118] Figure 30 shows a shielded and ventable needle cover 2008 in a sealed configuration for use with the dual-chamber safety injection system 2000 shown in Figure 20. The needle cover 2008 includes an adapter 2022 having multiple (e.g., three) flexible fingers 2024. Figure 30 shows the hub 2026 of the needle assembly on the syringe, which interacts with various components of the needle cover 2008, as described below.

[0119] Figure 31 shows the shieldable and ventable needle cover 2008 shown in Figure 30 removed from the hub 2026, illustrating various components of the needle cover 2008 and the hub 2026. The needle cover 2008 includes a plurality of flexible fingers 2024 and a threaded inner surface 2028. The hub 2026 includes a threaded outer surface 2030 configured to correspond to and interact with the threaded inner surface 2028 of the needle cover 2008.

[0120] Figure 32 is a cross-sectional view of the shielded and ventable needle cover (2008) shown in Figure 30 in a sealed configuration. In the sealed configuration, the distal end (2032) of the needle is occluded by the inner material of the needle cover (2008).

[0121] Figure 33 is a cross-sectional view of the needle cover 2008 in the shielding and venting configuration shown in Figure 32. As described above, pulling (2009) the needle cover 2008 distally transitions the needle cover 2008 from the sealing configuration to the venting configuration. Moving the needle cover 2008 distally on the hub 2026 moves the flexible fingers 2024 into engagement with the threaded outer surface 2030 of the hub 2026. The needle cover 2008 also includes a proximal flange 2034. The interaction between the flexible fingers 2024, the proximal flange 2034, and the threaded outer surface 2030 prevents further distal pulling (or pushing) of the needle cover 2008 along the longitudinal axis of the system 2000. This locks the needle cover (2008) into a vented configuration, which allows fluid (i.e., gas) to exit the needle distal end (2032) and out of the needle cover (2008) without obstructing the distal end (2032). In this configuration, the needle remains covered or shielded from the user, but the vented needle cover (2008) can reduce pressure within the distal chamber by venting fluid (i.e., gas) from the distal chamber. Shielding the needle covers the sharp needle tip and prevents needlestick injuries to the user during mixing and shaking of the dual-chamber syringe. After mixing, the needle cover (2008) can be removed from the hub (2026) by rotating (2020) the needle cover (2008) relative to the hub (2026), as shown in FIG. 29.

[0122] FIG. 34 illustrates a shielded and ventable needle cover 2008′ and hub 2026′ according to another embodiment. The needle cover 2008′ has a threaded inner surface 2028′. The hub 2026′ includes a threaded outer surface 2030′ configured to correspond to and interact with the threaded inner surface 2028′ of the needle cover 2008′. The needle cover 2008′ and hub 2026′ are configured such that, when the needle cover 2008′ is rotated relative to the hub 2026′, the needle cover transitions from a sealed configuration to a vented configuration. The hub 2026′ also includes an interference member 2036 that forms a connection between the needle cover 2008′ and the hub 2026′ in the vented configuration. However, it is possible to remove needle cover 2008' from hub 2026' by overcoming the interference fit between interference member 2036 and needle cover 2008'.

[0123] Although the prefill dual chamber safety injection system described and illustrated herein includes a syringe with a staked needle, the various configurations / embodiments described herein (e.g., continuous injection, detent dual chamber, threaded plunger member, and shielded and ventable needle cover) can be used with cartridges and auto-injectors, and needleless injection systems with luer connectors and transfer piping, such as those described in U.S. Patent Application Nos. 15 / 801,281 and 15 / 801,259.

[0124] Various exemplary embodiments of the present disclosure are described herein. These examples are referred to in a non-limiting sense. They are provided to illustrate the more broadly applicable features of the present disclosure. Various changes may be made in the described disclosure, and equivalents may be substituted, without departing from the true spirit and scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process acts or steps to the objective, spirit or scope of the present disclosure. Moreover, as will be understood by those skilled in the art, each of the individual variations described and exemplified herein has individual components and features that can be readily separated from or combined with the features of any of the other embodiments without departing from the scope or spirit of the present disclosure. All such modifications are intended to be within the scope of the claims associated with this disclosure.

[0125] Any of the described devices for performing a subject diagnostic or interventional procedure may be provided in a packaged combination for use in performing such an intervention. These supply "kits" may further include instructions for use and may be packaged in a sterile tray or container as commonly employed for such purposes.

[0126] The present disclosure includes methods that may be performed with a subject device. The methods may include the act of providing such a suitable device. Such providing may be performed by an end user. That is, the act of "providing" merely requires the end user to obtain, access, approach, place, set up, activate, power on, or take other action to provide the required device in the subject method. Methods described herein may carry out the recited events in any order that is logically possible or in the sequence of events recited.

[0127] Exemplary features of the present disclosure, along with details regarding material selection and manufacturing, have been described above. Other details of the present disclosure may be understood in connection with the above-cited patents and publications, as well as generally known or understood by those skilled in the art. For example, those skilled in the art will understand that one or more lubricious coatings (e.g., hydrophilic polymers such as polyvinylpyrrolidone-based compositions, fluoropolymers such as tetrafluoroethylene, PTFE, ETFE, hydrophilic gels, or silicones) may be used in connection with various portions of the device, such as relatively large interface surfaces of movably coupled portions, as needed, to facilitate, for example, low-friction manipulation or advancement of such objects relative to other portions of the instrument or nearby tissue structures. The same will be true for method-based features of the present disclosure with respect to additional actions commonly or logically employed.

[0128] Furthermore, while the present disclosure has been described with reference to several examples optionally incorporating various features, it is not intended to be limited to those described or disclosed as contemplated with respect to each variation of the present disclosure. Various modifications can be made to the described disclosure, and equivalents (whether described herein or not included for brevity) can be substituted without departing from the true spirit and scope of the disclosure. Furthermore, when a range of values ​​is provided, it is understood that all intervening values ​​between the upper and lower limits of that range, as well as other stated or intervening values ​​within the stated range, are encompassed within the scope of the present disclosure.

[0129] It is also contemplated that any feature of the described inventive variations may be described and claimed independently or in combination with any one or more of the features described herein. Reference to a singular item includes the possibility of a plurality of the same items. More specifically, as used in this specification and the claims related thereto, the singular forms "a," "an," "said," and "the" include plural referents unless otherwise indicated. In other words, the use of articles allows for "at least one" of the subject items in the above description, as well as in the claims related to this disclosure. It should be noted that such claims may be drafted to exclude any element. Thus, this statement is intended to function as a preceding statement using exclusive terms such as "solely," "only," etc., in connection with the recitation of claim elements, or a preceding statement using a "negative" limitation.

[0130] Without using such exclusive language, the term "comprising" in any claim relating to this disclosure shall be construed as allowing for the inclusion of any additional elements, regardless of whether a given number of elements are recited in such claim or whether the addition of features would be considered to change the nature of the elements recited in such claim. Except as specifically defined herein, all technical and scientific terms used herein shall be given the broadest and most commonly understood meaning possible while maintaining the validity of the claims.

[0131] The breadth of the present disclosure is not limited to the examples and / or subject matter specification provided, but rather is limited only by the scope of the language of the claims associated with this disclosure.

Claims

1. 1. A system for continuously infusing a liquid, comprising: a syringe body defining a syringe proximal opening and a distal interface at a distal end of the syringe body; a proximal stop member and a distal stop member disposed on the syringe body, the proximal stop member and the distal stop member forming a proximal chamber therebetween and a distal chamber therebetween at a distal end of the syringe body; a first liquid in the distal chamber; and a second liquid in the proximal chamber; and a plunger member configured to insert the proximal stopper member distally relative to the syringe body; a hub assembly coupled to the distal interface of the syringe body, a transfer pipe having a transfer pipe proximal end and a transfer pipe distal end; a hub assembly including a hub; inserting the plunger member and the proximal stopper member distally relative to the syringe body to first expel the first liquid from the distal chamber through the transfer pipe, and then sequentially expel the second liquid from the proximal chamber through the transfer pipe; the transfer pipe defines a transfer pipe interior, a distal end opening at a distal end of the transfer pipe, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the transfer pipe interior; the distal stop member has a U-shaped detent for increasing the resistance of the transfer pipe proximal end passing through the distal stop member compared to a stop member without a detent; The system, wherein the detent comprises a bent wire.

2. 2. The system of claim 1, wherein the detent is configured such that a distal force of about 2 to about 5 pounds applied to the plunger member overcomes resistance to the proximal end of the transfer pipe passing through the detent.

3. 3. The system of claim 2, wherein the detent is modifiable to adjust the distal force required to overcome the resistance.

4. 1. A system for continuously infusing a liquid, comprising: a syringe body defining a syringe proximal opening and a distal interface at a distal end of the syringe body; a proximal stop member and a distal stop member disposed on the syringe body, the proximal stop member and the distal stop member forming a proximal chamber therebetween and a distal chamber therebetween at a distal end of the syringe body; a first liquid in the distal chamber; and a second liquid in the proximal chamber; and a plunger member configured to insert the proximal stopper member distally relative to the syringe body; a hub assembly coupled to the distal interface of the syringe body, a transfer pipe having a transfer pipe proximal end and a transfer pipe distal end; a hub assembly including a hub; inserting the plunger member and the proximal stopper member distally relative to the syringe body to first expel the first liquid from the distal chamber through the transfer pipe, and then sequentially expel the second liquid from the proximal chamber through the transfer pipe; the transfer pipe defines a transfer pipe interior, a distal end opening at a distal end of the transfer pipe, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the transfer pipe interior; the distal stop member has a U-shaped detent for increasing the resistance of the transfer pipe proximal end passing through the distal stop member compared to a stop member without a detent; The system, wherein the detent comprises an annealed stainless steel alloy.

5. 10. The system of claim 1, The system, wherein the transfer pipe proximal end includes a transfer pipe proximal end feature having an angle of approximately 30 degrees.

6. 10. The system of claim 1, A system wherein the first and second sizes of the distal and proximal chambers, respectively, can be varied by relative movement of the proximal and distal stop members with respect to the syringe body.

7. 10. The system of claim 1, The system is characterized in that the proximal stopper member, the distal stopper member, and the syringe body are configured such that a distal force applied to the proximal stopper member is transmitted to the distal stopper member via the second liquid until the proximal stopper member is inserted distally into the transfer pipe and the proximal opening of the transfer pipe is positioned in the proximal chamber.

8. 10. The system of claim 1, the system having a first injection configuration in which the proximal opening of the transfer pipe is disposed within the distal chamber, and a second injection configuration in which the proximal opening of the transfer pipe is disposed within the proximal chamber; This allows the second liquid to be moved from the proximal chamber through the proximal opening of the transfer pipe and the interior of the transfer pipe out the distal end opening of the transfer pipe.

9. 10. The system of claim 1, The system, characterized in that the proximal and distal stop members include first and second polymer coatings on their respective distal and proximal surfaces, and the proximal chamber is defined by the syringe body and the first and second polymer coatings.

10. 10. The system of claim 1, The system, wherein the distal stop member has a proximally tapered funnel and a space disposed at the tapered proximal end of the funnel.

11. 11. The system of claim 10, The system, characterized in that the funnel is configured to guide a transfer pipe proximal end feature into a space at a tapered proximal end of the funnel, thereby aligning the transfer pipe proximal end feature inside the plunger.

12. 12. The system of claim 11, The system, wherein the funnel is configured to align the transfer pipe proximal end feature within the plunger during assembly of the system.

13. 12. The system of claim 11, The system, characterized in that the funnel is configured to align the transfer pipe proximal end feature within the plunger during insertion of the plunger member to insert the proximal stopper member distally relative to the syringe body.

14. 1. A system for continuously infusing a liquid, comprising: a syringe body defining a syringe proximal opening and a distal interface at a distal end of the syringe body; a proximal stop member and a distal stop member disposed on the syringe body, the proximal stop member and the distal stop member forming a proximal chamber therebetween and a distal chamber therebetween at a distal end of the syringe body; a first liquid in the distal chamber; and a second liquid in the proximal chamber; and a plunger member configured to insert the proximal stopper member distally relative to the syringe body; a hub assembly coupled to the distal interface of the syringe body, a transfer pipe having a transfer pipe proximal end and a transfer pipe distal end; a hub assembly including a hub; inserting the plunger member and the proximal stopper member distally relative to the syringe body to first expel the first liquid from the distal chamber through the transfer pipe, and then sequentially expel the second liquid from the proximal chamber through the transfer pipe; the transfer pipe defines a transfer pipe interior, a distal end opening at a distal end of the transfer pipe, an intermediate opening, and a proximal opening, the distal end opening, the intermediate opening, and the proximal opening being fluidly coupled via the transfer pipe interior; The system is a first injection configuration, the proximal opening being disposed within the distal chamber; a second injection arrangement, the proximal opening being disposed within the proximal chamber, whereby the second liquid is transferred from the proximal chamber through the proximal opening and the interior of the transfer pipe and out the distal end opening; The distal stop member closes the intermediate opening when the system is in the second injection configuration. the distal stop member has a U-shaped detent for increasing the resistance of the transfer pipe proximal end passing through the distal stop member compared to a stop member without the detent; The system, wherein the detent comprises a bent wire.

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