System for safety syringes

Abstract

A system for sequentially injecting liquids includes a syringe body defining a syringe proximal opening and a distal needle interface, and proximal and distal stop members forming proximal and distal chambers. The system also includes a first liquid in the distal chamber and a second liquid in the proximal chamber, and a plunger configured to be manually operated to distally insert the proximal stop member. The system further includes a needle hub assembly coupled to the syringe body, the needle assembly including a needle. The needle defines a needle interior, as well as a distal opening, an intermediate opening, and a proximal opening. The distal opening, the intermediate opening, and the proximal opening are fluidly coupled through the needle interior. By operating the plunger member to insert the proximal stop member, the first liquid is first ejected from the distal chamber, and then, sequentially, the second liquid is ejected from the proximal chamber.

Description

[Technical Field]

[0001] The present invention relates generally to injection systems, devices, and processes for facilitating varying levels of control over fluid injection, and more particularly to systems and methods for serial injection in healthcare settings. [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 used not only to inject fluids into patients, but also to withdraw or dispense fluids into containers (10), such as vials, bags, or other drug containment systems. In fact, due to regulatory restrictions and sterility concerns in some countries, such as the United States, the use of syringes (2) with vials (10) in certain patient environments means that such vials can only be used by a single patient and must then be discarded, generating significant medical waste from the vials and any remaining discarded medication and contributing to periodic shortages of certain critical medications.

[0003] Referring to FIG. 2A, three luer-type syringes (12) are shown, each having a distally disposed luer fitting configuration (14) that allows them to mate with other devices having similar mating configurations, 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 an intravenous bag. The luer fitting (14) of the syringe in FIG. 2A may be referred to as a "male" luer fitting, and the one in FIG. 2B (18) may be referred to as a "female" luer fitting, with one of their luer interfaces being threaded so that the two sides can be mated by relative rotation, which may be combined with a compressive load (in which case the configuration may be referred to as a "luer lock" configuration). In other words, one luer lock embodiment can utilize rotation, possibly combined with compression, to engage threads in a male fitting (14) configured to engage a flange on a female fitting (18), bringing the devices together to form a fluid-tight connection. In another embodiment, a tapered interface shape can be utilized to provide a luer engagement using compression without threads or rotation (such a configuration is sometimes referred to as a "slip-on" or "conical" luer configuration). While such luer connections are considered relatively safe for the practitioner, there is a risk of spillage / leakage of medication and damage to parts during assembly of the luer connection.

[0004] On the other hand, using a needle injection configuration carries the risk of the sharp needle contacting or pricking an unwanted person or structure. For this reason, so-called "safety syringes" have been developed. One embodiment of a safety syringe 20 is shown in FIG. 3, in which a tubular shield member 22 is spring-loaded 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-4B. With such a configuration, after the plunger 6 is fully inserted into the syringe body 4, the retractable needle 26 is configured to retract 28, 26 back into a safe position within the tubular body 4, as shown in FIG. 4B. Such a configuration that is configured to retract on its own may be associated with issues of blood splatter / aerosolization, safe storage of pre-loaded energy that may malfunction and activate before desired, loss of accuracy in delivering the total injection due to residual dead space within the spring compression volume, and / or loss of retraction rate control that may be associated with pain and patient anxiety.

[0005] Further complicating the syringe market is the increasing demand for pre-filled syringe assemblies, such as those shown in Figures 5A and 5B, which generally include a syringe body or "drug enclosure containing delivery system" (34), a plunger tip, plug, or stopper (36), and a distal seal or cap (35) that can fit over a luer-type interface (Figure 5A shows the cap 35 in place; in Figure 5B, the cap has been removed to illustrate the luer interface 14). A drug solution may reside 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) may comprise a standard butyl rubber material and may be coated with a biocompatible lubricious coating (e.g., polytetrafluoroethylene ("PTFE") or the like) to promote favorable sealing and relative motion characteristics relative to the associated syringe body structure and material. The proximal end of the syringe body (34) of FIG. 5B comprises a conventional one-piece syringe flange (38) that is integrally formed into the material of the syringe body (34). The flange (38) is configured to extend radially from the syringe body (34) and may be configured to surround the syringe body (34) fully or partially. A partial flange is known as a "clip flange," while a partial flange is known as a "clip flange." The other is known as a "full flange." The flange is used to provide support for grasping the syringe with the fingers and depressing the plunger to perform the injection. Syringe body 34 preferably comprises a transparent material, such as glass or a polymer. A plunger tip 36 may be positioned within syringe body 34 to form a volume within chamber or reservoir 40 and assist in the ejection of an associated fluid through the needle. Syringe body 34 may define a substantially cylindrical shape (i.e., such that a plunger tip 36 having a circular cross-sectional shape can establish a seal with syringe body 34) or may be configured to have other cross-sectional shapes, such as an ellipse.

[0006] Such assemblies are desirable because they can be volumetrically accurate, standardized, and manufactured by a small number of manufacturers worldwide, who can afford to meet all of the world's ever-changing regulations for filling, packaging, and drug / drug contact material selection and ingredient use. However, such simple configurations generally do not meet emerging global standards for single-use, safety, self-disabling, and needlestick protection. Therefore, certain suppliers are moving to more "vertical" solutions, such as those depicted in FIG. 5C (41), which attempt to meet all or at least some of the above standards with a single solution. As a result of attempting to meet these standards for many different scenarios, such products may have significant limitations (including some of those discussed above with reference to FIGS. 3-4B) and relatively high inventory and utilization costs.

[0007] Furthermore, the increasing number of injectable liquids (e.g., medications) adds the requirement that two or more components be injected sequentially (e.g., into a patient), preferably within a short time (e.g., a few seconds) of each other. Multiple components can be injected sequentially using separate injection devices (e.g., pre-loaded syringes) or by using the same injection device to sequentially draw multiple components from separate open containers and inject them sequentially. However, such sequential injections using separate injection devices or sequential withdrawal and injection of multiple components can result in multiple needle insertions into the patient, which can be inaccurate and result in component loss. Furthermore, sequential injections using separate injection devices or sequential withdrawal and injection of multiple components can unnecessarily expose the user to one or more uncapped needles. Furthermore, sequential injections using separate injection devices or sequential withdrawal and injection of multiple components can cause unacceptable delays between injections of multiple components.

[0008] In some cases, chemical reactions may occur between the components of a multi-component injection. The use of a conventional dual-chamber syringe, in which the components are mixed together inside the syringe, may not be compatible with these reactive components, as the mixed components may become unsuitable for injection. Some examples of this phenomenon include an increase in the viscosity of the combined medication when the components are mixed together, resulting in the medication being unable to be easily injected through a needle. Additionally, other reactions, such as exothermic reactions, endothermic reactions, etc., may occur that may prevent the use of conventional dual-chamber injection systems.

[0009] 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. 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 pass 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 dual-chamber injection systems experience increased 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. Additionally, the increased pressure increases the force that must be maintained on the plunger rod during mixing. To minimize the effects of pressure buildup, external bypass dual-chamber injection systems require the removal of the needle cap to open the syringe and install the needle before the fluids are transferred and mixed, or after mixing has occurred, to allow the pressure in the distal chamber to vent 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 shielded and vented pre-attached needle with built-in needle retraction into the dual-chamber injection system. The shielded and vented needle shield invention disclosed herein is applicable to external bypass dual-chamber injection systems. Additionally, it would be beneficial to incorporate a plunger position control methodology to maintain precise control of the distal stopper position during transfer and mixing.

[0010] Additionally, the increasing number of injectable liquids (e.g., medications) imposes yet another requirement that the time the injectable liquid is exposed to metal (e.g., the stainless steel of the needle) be minimized. Yet another requirement is the desirability of a system that is suitable for patient self-injection.

[0011] It is also desirable to incorporate needlestick protection technology into injection systems, where the ability to at least partially retract the needle tip within the syringe protects the person administering the injection and protects the patient from inadvertent needlestick injuries.

[0012] There is a need for an injection system that addresses the shortcomings of currently available configurations, and in particular, a need for a multi-chamber safety injection solution that can take advantage of the existing, relatively well-controlled supply chain of conventionally delivered pre-filled syringe assemblies such as those described with reference to Figures 5A and 5B.

[0013] Retracting the needle assembly moves the sharpened distal tip of the needle inside the needle hub or injection system body / syringe body, preventing accidental needle sticks.

[0014] Some existing injection and / or needle retraction systems include needle assemblies with openings that can become blocked if other portions of the needle assembly are crushed during assembly and / or use. Some existing injection and / or needle retraction systems include needle assemblies that can become structurally non-functional during assembly and / or use. Some existing injection and / or needle retraction systems include needle assemblies that can allow injectable agents and / or components of injectable agents to be inadvertently expelled from within the injection system body through a distal opening in the injection system body to the exterior of the injection system body.

[0015] There is a need for needle retraction systems and components thereof that address the shortcomings of currently available configurations. In particular, there is a need for needle assemblies having openings that resist blockage when other parts of the needle assembly are crushed during assembly and / or use by those other parts. There is also a need for needle assemblies that resist structural failure during assembly and / or use. There is a further need for needle assemblies that prevent inadvertent ejection of injectable material through the distal opening of the injection system body. Addressing these and other limitations of needle retraction systems allows for injection and / or needle retraction systems to be cost-effective and easily manufactured. Summary of the Invention

[0016] Some embodiments relate to injection systems, particularly multi-chamber sequential injection systems and multi-chamber safety injection systems that transition needles to a protective configuration to minimize accidental user injury and contamination from used needles.

[0017] 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 its distal end. The system also includes a proximal stop member and a distal stop member disposed within the syringe body, such that a proximal chamber is formed between the proximal stop member and the distal stop member, and a distal chamber is formed 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. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stop member into the syringe body. Additionally, the system includes a needle hub assembly coupled to the distal needle interface of the syringe body. The needle defines 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 are fluidly coupled through the needle interior. By operating the plunger member to insert the proximal stopper member distally relative to the syringe body, first a first liquid is expelled from the distal chamber through the needle, and then, sequentially, a second liquid is expelled from the proximal chamber through the needle.

[0018] In one or more embodiments, the needle includes a tubular member and a solid proximal end feature coupled thereto. The needle interior, the distal end opening, the intermediate opening, and the proximal opening can be formed in the tubular member. The solid proximal end feature can be coupled to the tubular member by welding. The weld can be a fillet weld configured to reduce shearing of the proximal stop member when the needle penetrates the proximal stop member compared to a needle without a fillet weld. The weld can be tapered proximally. The proximal opening can be adjacent to the weld. The solid proximal end feature can be cold-formed. The distal end of the solid proximal end feature can be disposed within the proximal end of the tubular member. The distal end of the solid proximal end feature and the proximal end of the tubular member can define an annular lumen fluidly coupling the proximal opening to the needle interior, the intermediate opening, and the distal end opening.

[0019] In one or more embodiments, the proximal opening has a rounded edge configured to reduce shearing of the proximal stop member when the needle penetrates the proximal stop member compared to a needle without a rounded edge. The proximal opening may be an elongated slot. The length of the elongated slot can provide tolerance for variations related to the proximal stop member and / or the distal stop member. The variations related to the proximal stop member and / or the distal stop member can be selected from the group consisting of distortion of the proximal surface of the distal stop member, the position of the proximal stop member relative to the elongated slot, and the position of the distal stop member relative to the elongated slot. The length of the elongated slot can be from about 1 / 32 inch to about 1 / 16 inch. The distance between the elongated slot and the solid proximal end can minimize back-leakage of the first liquid and the second liquid into the plunger. The elongated slot may be formed using a grinding wheel. The first and second sizes of the respective distal and proximal chambers can be changed by moving the proximal and distal stop members relative to the syringe body.

[0020] In one or more embodiments, the plunger member includes a needle retention 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 needle hub assembly can include a hub and a needle retention member configured to couple the needle to the hub. The needle can be at least partially retractable into the plunger when the plunger member is manipulated relative to the syringe body to convert the energy storage member latch member from a latched state to an unlatched state. The needle can be configured to fully pierce at least the distal stopper member so as to be at least partially retracted into the plunger. The energy storage member latch member can be configured to convert from the latched state to an unlatched state that at least partially retracts the needle into the plunger after the second liquid is expelled from the proximal chamber through the needle. The needle retention feature can be configured to actuate the conversion of the energy storage member latch member from the latched state to the unlatched state when the plunger member is manipulated to insert the proximal stopper member into the distal end of the syringe body.

[0021] In one or more embodiments, the distance between the proximal opening and the distal end of the syringe body is substantially equal to the length of the distal stop member, such that when the distal stop member is inserted into the distal end of the syringe body, the proximal stop member is inserted distally relative to the needle and the proximal opening is positioned within the proximal chamber. The proximal and distal stop members and the syringe body can be configured such that a distal force applied to the proximal stop member is transmitted to the distal stop member through the second liquid until the proximal stop member is inserted distally relative to the needle and the proximal opening is positioned within the proximal chamber.

[0022] In one or more embodiments, the system includes a first injection configuration having a proximal opening disposed within the distal chamber or the distal stopper member, and a second injection configuration having a proximal opening disposed within 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 end opening. The proximal stopper member and the distal stopper member can include a first polymer coating and a second polymer coating, respectively, on their respective distal and proximal surfaces, such that the proximal chamber is defined by the syringe body and the first and second polymer coatings. The distal stopper member can have a funnel tapering proximally and a space disposed at the tapered proximal end of the funnel. The intermediate opening can be adjacent to the distal end of the syringe body.

[0023] In another embodiment, a method for sequentially injecting 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 needle interface at its distal end. The system also includes a proximal stop member and a distal stop member disposed within the syringe body, such that a proximal chamber is formed between the proximal stop member and the distal stop member, and a distal chamber is formed 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. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stop member relative to the syringe body. Additionally, the system 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 through the needle interior. The method also includes advancing the plunger member to expel a first portion of the first liquid from the distal chamber through the needle interior and the distal end opening. The method also 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. Additionally, the method includes further advancing the plunger member to expel a second portion of the first liquid from the proximal chamber through the needle interior and the distal opening.

[0024] In one or more embodiments, the method also includes automatically retracting the distal needle tip into the needle hub or syringe body when the second portion of the first liquid is expelled through the distal end opening. The method may also include fully piercing at least the distal stopper member and retracting the needle at least partially into the plunger. The method may also include inserting the distal end of the needle into a patient before advancing the plunger member to expel the first portion of the first liquid from the distal chamber, thereby positioning the distal end opening of the needle within the patient before the first portion of the first liquid is expelled. The method may also include removing air from the distal chamber before inserting the distal end of the needle into the patient. Removing air from the distal chamber may 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. By advancing the plunger member, the proximal stopper member can be inserted distally relative to the syringe body, thereby exerting a distal force through the second liquid, inserting the distal stopper member distally relative to the syringe body, and expelling a first portion of the first liquid from the distal chamber through the interior of the needle and the distal end opening.

[0025] In one or more embodiments, the system has a first injection configuration in which the proximal opening is disposed within the distal chamber or the distal stop member, a second injection configuration in which the proximal opening is disposed within 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, and a third injection configuration in which the proximal and distal stop members contact each other and the proximal opening is blocked by the proximal and / or distal stop members. The system can be in the first injection configuration when the plunger member is advanced to expel a first portion of the first liquid from the distal chamber through the interior of the needle and the distal opening. The system can be in the second injection configuration when the plunger member is further advanced to expel the second liquid from the proximal chamber through the proximal opening, the interior of the needle and the distal opening. The system can be in a third injection configuration when the plunger member is advanced to expel a second portion of the first liquid from the distal chamber through the needle interior and distal end opening.

[0026] In one or more embodiments, the needle includes a tubular member and a solid proximal end feature coupled thereto, wherein the needle interior, the distal end opening, the intermediate opening, and the proximal opening are formed within the tubular member. The solid proximal end feature may be coupled to the tubular member by welding. The weld may be a fillet weld configured to reduce shearing of the proximal stop member when the needle penetrates the proximal stop member, compared to a needle without a fillet weld. The distal end of the solid proximal end feature may be disposed within the proximal end of the tubular member. The distal end of the solid proximal end feature and the proximal end of the tubular member may define an annular lumen fluidly coupling the proximal opening to the needle interior, the intermediate opening, and the distal end opening.

[0027] In one or more embodiments, the proximal opening has a rounded edge configured to reduce shearing of the proximal stop member when the needle penetrates the proximal stop member compared to a needle without a rounded edge. The proximal opening may be an elongated slot. The length of the elongated slot can provide tolerance for variations related to the proximal stop member and / or the distal stop member. The variations related to the proximal stop member and / or the distal stop member can be selected from the group consisting of distortion of the proximal surface of the distal stop member, the position of the proximal stop member relative to the elongated slot, and the position of the distal stop member relative to the elongated slot. The length of the elongated slot can be from about 1 / 32 inch to about 1 / 16 inch. The length of the elongated slot can minimize backflow of the first liquid and the second liquid into the plunger.

[0028] In one or more embodiments, the distal stop member has a funnel tapering in a proximal direction and a space disposed at the tapered proximal end of the funnel. The method can also include guiding the needle into the space at the tapered proximal end of the funnel, thereby aligning a needle proximal end feature with a needle retention feature within the plunger. The intermediate opening can be adjacent to the distal end of the syringe body.

[0029] In yet another embodiment, a system for continuously injecting liquids includes a syringe body defining a syringe proximal opening and a distal needle interface at its distal end. The system also includes a proximal stop member, an intermediate stop member, and a distal stop member disposed within the syringe body, such that a proximal chamber is formed between the proximal stop member and the intermediate stop member, an intermediate chamber is formed between the intermediate stop member and the distal stop member, and a distal chamber is formed between the distal stop member and the distal end of the syringe body. The system further includes a first liquid in the distal chamber, a second liquid in the intermediate chamber, and a third liquid in the proximal chamber. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stop member into the syringe body. Additionally, the system includes a needle hub assembly coupled to the distal needle interface of the syringe body, the needle assembly including a needle. The needle can define a needle interior, a distal opening, an intermediate opening, and a proximal opening. The distal opening, the intermediate opening, and the proximal opening can be fluidly coupled through an interior of the needle. By manipulating the plunger member to distally insert the proximal stopper member relative to the syringe body, the first liquid, the second liquid, and the third liquid can be sequentially expelled through the needle.

[0030] In one or more embodiments, by operating the plunger member to insert the proximal stopper member distally relative to the syringe body, the first liquid, the second liquid, and the third liquid are sequentially ejected through the needle in the following order: a first portion of the first liquid from the distal chamber, a second liquid from the intermediate chamber, a second portion of the first liquid from the distal chamber, and a third liquid from the proximal chamber.

[0031] In one or more embodiments, by operating the plunger member to distally insert the proximal stop member relative to the syringe body, the first liquid, the second liquid, and the third liquid are sequentially ejected through the needle in the following order: first liquid from the distal chamber, second liquid from the intermediate chamber, and third liquid from the proximal chamber. The needle can include a tubular member and a solid proximal end feature coupled thereto, and the needle interior, distal end opening, intermediate opening, and proximal opening can be formed within the tubular member. The solid proximal end feature can be coupled to the tubular member by welding. The weld can be a fillet weld configured to reduce shearing of the proximal and intermediate stop members when the needle penetrates them, compared to a needle without a fillet weld. The weld can be tapered proximally. The solid proximal end feature can be cold-formed. The distal end of the solid proximal end feature can be disposed within the proximal end of the tubular member. The distal end of the solid proximal end feature and the proximal end of the tubular member can define an annular lumen that fluidly couples the proximal opening to the needle interior, the intermediate opening, and the distal end opening.

[0032] In one or more embodiments, the proximal opening has a rounded edge configured to reduce shearing of the proximal stop member and the intermediate stop member when the needle penetrates the proximal stop member and the intermediate stop member, compared to a needle without a rounded edge. The proximal opening may be an elongated slot. The length of the elongated slot can provide tolerance for variations related to the proximal stop member, the intermediate stop member, and / or the distal stop member. The variations related to the proximal stop member and / or the distal stop member can be selected from the group consisting of distortion of the proximal surface of the distal stop member, distortion of the proximal surface of the intermediate stop member, the position of the proximal stop member relative to the elongated slot, the position of the intermediate stop member relative to the elongated slot, and the position of the distal stop member relative to the elongated slot. The length of the elongated slot may be from about 1 / 16 inch to about 1 / 8 inch. The distance between the elongated slot and the solid proximal end can minimize backflow of the first liquid, the second liquid, and the third liquid into the plunger. The elongated slots may be formed using a grinding wheel.

[0033] In one or more embodiments, the first size, second size, and third size of each of the distal chamber, intermediate chamber, and proximal chamber can be changed by moving the proximal stop member, intermediate stop member, and distal stop member relative to the syringe body. The plunger member can include a needle retention 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 needle hub assembly can include a hub and a needle retention member configured to couple the needle to the hub. The needle can be at least partially retractable into the plunger when the plunger member is manipulated relative to the syringe body to convert the energy storage member latch member from a latched state to an unlatched state. The needle can be configured to fully pierce at least the distal stop member and the intermediate stop member so as to be at least partially retracted into the plunger. The energy storage member latch member can be configured to convert from the latched state to an unlatched state that at least partially retracts the needle into the plunger after the third liquid is expelled from the proximal chamber through the needle. The needle retention feature needle can be configured to actuate a transformation of the energy storage member latch member from a latched state to an unlatched state when the plunger member is manipulated to insert the proximal stopper member into the distal end of the syringe body.

[0034] In one or more embodiments, the proximal stop member, intermediate stop member, and distal stop member and syringe body can be configured such that a distal force applied to the proximal stop member is transmitted to the intermediate stop member through the third liquid and to the distal stop member through the second liquid until the proximal stop member is inserted distally relative to the needle and the proximal opening is positioned within the intermediate chamber. The system can include a first injection configuration having a proximal opening disposed within the distal chamber or the distal stop member, a second injection configuration having a proximal opening disposed within the intermediate chamber to allow the second liquid to be transferred from the intermediate chamber through the proximal opening and the interior of the needle and out the distal opening, and a third injection configuration having a proximal opening disposed within the proximal chamber to allow the third liquid to be transferred from the proximal chamber through the proximal opening and the interior of the needle and out the distal opening. The proximal stop member and the intermediate stop member can include a first polymer coating and a second polymer coating 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. The distal stop member can have a funnel tapering in a proximal direction and a space disposed at the tapered proximal end of the funnel. The intermediate opening can be adjacent to the distal end of the syringe body.

[0035] In yet another embodiment, a method for sequentially injecting 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 needle interface at its distal end. The system also includes a proximal stop member, an intermediate stop member, and a distal stop member disposed within the syringe body, such that a proximal chamber is formed between the proximal stop member and the intermediate stop member, an intermediate chamber is formed between the intermediate stop member and the distal stop member, and a distal chamber is formed between the distal stop member and the distal end of the syringe body. The system further includes a first liquid in the distal chamber, a second liquid in the intermediate chamber, and a third liquid in the proximal chamber. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stop member into the syringe body. Additionally, the system includes a needle having 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 through the needle interior. The method also includes advancing the plunger member to expel a first portion of the first liquid from the distal chamber through the needle interior and the distal end opening. The method also includes further advancing the plunger member to expel a second liquid from the intermediate chamber through the proximal opening, the needle interior and the distal end opening. Moreover, the method includes further advancing the plunger member to expel a second portion of the first liquid from the proximal chamber through the needle interior and the distal end opening. Additionally, the method includes further advancing the plunger member to expel a third liquid from the proximal chamber through the proximal opening, the needle interior and the distal end opening.

[0036] In one or more embodiments, the method also includes automatically retracting the distal needle tip into the needle hub or syringe body when the second portion of the first liquid is expelled through the distal end opening.

[0037] In another embodiment, a method for sequentially injecting 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 needle interface at its distal end. The system also includes a proximal stop member, an intermediate stop member, and a distal stop member disposed within the syringe body, wherein a proximal chamber is formed between the proximal stop member and the intermediate stop member, an intermediate chamber is formed between the intermediate stop member and the distal stop member, and a distal chamber is formed 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 intermediate chamber. Additionally, the system includes a third liquid in the proximal chamber. In addition, the system includes a plunger configured to be manually operated to distally insert the proximal stop member into the syringe body, and a needle having a needle interior, a distal opening, an intermediate opening, and a proximal opening, wherein the distal opening, the intermediate opening, and the proximal opening are fluidly coupled through the needle interior. The method also includes advancing the plunger member to expel a 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 a second liquid from the intermediate chamber through the proximal opening, the needle interior and the distal end opening. Additionally, the system includes further advancing the plunger member to expel a third liquid from the proximal chamber through the proximal opening, the needle interior and the distal end opening.

[0038] In one or more embodiments, the method also includes automatically retracting the distal needle tip into the needle hub or syringe body when the third liquid is expelled through the distal end opening.

[0039] Some embodiments relate to injection systems. In particular, some embodiments relate to safety injection systems having a needle assembly with a channel therein that is resistant to crushing and structural failure. Other embodiments relate to safety injection systems having a needle assembly with a distal valve to prevent inadvertent ejection of injection material through a distal opening in the injection system body.

[0040] In one embodiment, the syringe assembly includes a syringe body having a syringe interior, a proximal end, a distal end, and a needle attachment interface disposed at the distal end. The assembly also includes a needle assembly having a proximal portion, an intermediate connector, and a distal portion. The assembly further includes a needle latch assembly configured to prevent proximal movement of the needle assembly in a closed state and to release the needle assembly to allow proximal movement of the needle assembly in an open state. The proximal portion has a crescent or dumbbell-shaped cross-section. The needle assembly is configured to retract into the syringe body after an injection using the syringe assembly.

[0041] In one or more embodiments, the proximal portion includes a plurality of lobes, two of which form an angle of approximately 90°. The proximal portion can include a section having a taper of approximately 12°-15°. The proximal portion can include a reduced diameter section and a proximal tip having a distal-facing overhang relative to the reduced diameter section of approximately 0.0075". The distal portion can include a sharpened distal tip.

[0042] In one or more embodiments, the assembly includes a proximal stop member and a distal stop member. The proximal and distal stop members and the syringe body define a proximal chamber, and the distal stop member and the syringe body define a distal chamber. The needle assembly can include a radially extending annular flange adjacent the proximal end of the intermediate connector. The distal portion can include a radially enlarged portion defining a longitudinal tube having a squircle cross-sectional shape. The distal portion can include a radially smaller portion having a rounded triangular cross-sectional shape.

[0043] In one or more embodiments, the distal stopper member includes a stopper insert including a pair of tabs. The syringe assembly can be configured to transfer a fluid from the proximal chamber to the distal chamber to mix with a component in the distal chamber, and later expel the mixed fluid and component from the distal chamber. The syringe assembly can be configured to expel a fluid from the distal chamber, and later expel the fluid from the proximal chamber. The proximal portion can have two separate compartments, each having a crescent or dumbbell-shaped cross-section.

[0044] In another embodiment, a syringe assembly includes a syringe body having a syringe interior and a proximal end and a distal end, and a needle assembly including a flow regulator disposed adjacent the distal end of the syringe body.

[0045] In one or more embodiments, the flow regulator includes a housing, the housing defining a liquid port and a compliant pin. The flow regulator can include a resilient seal configured to form a fluid-tight seal between the housing and the distal end of the syringe body. The resilient seal can be configured to close the liquid port when low pressure is present in the internal chamber of the syringe body. The resilient seal can be configured to open the liquid port when high pressure is present in the internal chamber of the syringe body. The assembly can include a stopper member having a stopper insert. The stopper insert can have an internal shape complementary to the external shape of the flow regulator.

[0046] Some embodiments relate to injection systems. In particular, some embodiments relate to safety injection systems having needle assemblies with channels therein that are resistant to crushing and structural failure. Some embodiments relate to multi-chamber sequential injection systems and multi-chamber safety injection systems that transition needles into a protective configuration to minimize accidental user injury and contamination from used needles.

[0047] In one embodiment, a system for sequentially injecting liquids includes a syringe body defining a syringe proximal opening and a distal needle interface at its distal end. The system also includes a proximal stopper member and a distal stopper member disposed within the syringe body, such that a proximal chamber is formed between the proximal stopper member and the distal stopper member, and a distal chamber is formed between the distal stopper 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. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stopper member into the syringe body. Additionally, the system includes a needle assembly having a proximal portion, an intermediate connector, and a distal portion. The proximal portion has a crescent or dumbbell-shaped cross-section. By operating the plunger member to distally insert the proximal stopper member into the syringe body, first, the first liquid is expelled from the distal chamber through the needle, and then, sequentially, the second liquid is expelled from the proximal chamber through the needle.

[0048] In one or more embodiments, the distal portion includes a sharp distal end. The proximal portion and the intermediate connector can have respective diameters that are substantially equal to one another. The proximal portion can include a solid proximal end feature, and the intermediate connector can include a tubular member. The solid proximal end feature can be cold-formed. The distal end of the solid proximal end feature can be disposed within the proximal end of the tubular member.

[0049] In one or more embodiments, the proximal portion defines a longitudinal channel on its surface. The length of the longitudinal channel may be substantially equal to the length of the distal stop member, such that when the distal stop member is inserted into the distal end of the syringe body, the proximal stop member is inserted distally relative to the needle and the proximal end of the longitudinal channel is positioned within the proximal chamber. The proximal and distal stop members and the syringe body can be configured such that a distal force applied to the proximal stop member is transmitted to the distal stop member through the second liquid until the proximal stop member is inserted distally relative to the needle and the proximal opening is positioned within the proximal chamber. The length of the longitudinal channel can provide tolerance for variations related to the proximal and / or distal stop members. The variations relating to the proximal stop member and / or the distal stop member may be selected from the group consisting of distortion of the proximal surface of the distal stop member, the position of the proximal stop member relative to the longitudinal channel, and the position of the distal stop member relative to the longitudinal channel.

[0050] In one or more embodiments, the distance between the longitudinal channel and the solid proximal end minimizes back leakage of the first and second liquids into the plunger. The longitudinal channel may be formed via stamping or injection molding.

[0051] In one or more embodiments, the system includes a first injection configuration in which a proximal end of a longitudinal channel is disposed within the distal chamber or the distal stop member, and a second injection configuration in which a proximal end of the longitudinal channel is disposed within the proximal chamber, thereby allowing a second liquid to be transferred from the proximal chamber through the longitudinal channel and out a distal end opening of the distal portion of the needle assembly. The first and second sizes of the respective distal and proximal chambers can be changed by moving the proximal and distal stop members relative to the syringe body.

[0052] In one or more embodiments, the system also includes a needle hub assembly having a hub and a needle retaining member configured to removably couple the needle to the hub. The plunger member can include a needle retention feature disposed within the plunger, an energy storage member disposed within the plunger, and an energy storage member latching member disposed within the plunger. The needle can be at least partially retractable into the plunger when the plunger member is operated relative to the syringe body to convert the energy storage member latching member from a latched state to an unlatched state. The needle can be configured to fully pierce at least the distal stopper member so as to be at least partially retracted into the plunger. The energy storage member latching member can be configured to convert from the latched state to an unlatched state that at least partially retracts the needle into the plunger after the second liquid is expelled from the proximal chamber through the needle. The needle retention feature can be configured to actuate the conversion of the energy storage member latching member from the latched state to the unlatched state when the plunger member is operated to insert the proximal stopper member into the distal end of the syringe body. The proximal stopper member and the distal stopper member can include a first polymer coating and a second polymer coating, respectively, on their respective distal and proximal surfaces, such that the proximal chamber is defined by the syringe body and the first polymer coating and the second polymer coating.

[0053] In another embodiment, a system for continuously injecting a liquid includes a syringe body defining a syringe proximal opening and a distal needle interface at its distal end. The system also includes a proximal stopper member and a distal stopper member disposed within the syringe body, such that a proximal chamber is formed between the proximal stopper member and the distal stopper member, and a distal chamber is formed between the distal stopper 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. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stopper member relative to the syringe body. Additionally, the system includes a fluid transfer assembly having a proximal portion and an intermediate connector. The proximal portion has a longitudinal channel formed on a surface thereof. The intermediate connector has a distal anchor member. By operating the plunger member to insert the proximal stopper member distally relative to the syringe body, first a first liquid is expelled from the distal chamber through the needle, and then, sequentially, a second liquid is expelled from the proximal chamber through the needle.

[0054] In one or more embodiments, the proximal portion is a solid metal elongate body and the intermediate connector is a polymer body having a recess configured to receive the distal end of the proximal portion. The fluid transfer assembly may be molded from a polymer as a unitary piece. The fluid transfer assembly may be molded from a metal as a unitary piece.

[0055] In one or more embodiments, the distal anchor member has a rectangular cross-sectional shape. The distal anchor member can include a slot having a biasing member disposed therein, the biasing member configured to exert a radially outward force against the inner wall of the distal needle interface. The distal anchor member can include a wavy wire member configured to exert a radially outward force against the inner wall of the distal needle interface. The distal anchor member can include a pair of flexible arms configured to exert a radially outward force against the inner wall of the distal needle interface. The distal anchor member can include a rubber sleeve configured to increase friction between the distal anchor member and the inner wall of the distal needle interface. The distal anchor member can also include proximal and distal openings configured to bypass the rubber sleeve.

[0056] In yet another embodiment, a system for sequentially injecting liquids includes a syringe body defining a syringe proximal opening and a distal needle interface at its distal end. The system also includes a proximal stopper member and a distal stopper member disposed within the syringe body, such that a proximal chamber is formed between the proximal stopper member and the distal stopper member, and a distal chamber is formed between the distal stopper 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. Additionally, the system includes a plunger configured to be manually operated to distally insert the proximal stopper member relative to the syringe body. Additionally, the system includes a fluid transfer assembly having a proximal portion and an intermediate connector. The intermediate connector has a distal anchor member. By operating the plunger member to distally insert the proximal stopper member relative to the syringe body, first, the first liquid is expelled from the distal chamber through the needle, and then, sequentially, the second liquid is expelled from the proximal chamber through the needle.

[0057] In one or more embodiments, the proximal portion defines a plurality of arms at its distal end, and the intermediate connector is a polymeric body having openings configured to receive the arms of the proximal portion. The arms can taper radially outward to couple the proximal portion to the intermediate connector. The arms can taper radially outward to exert a radially outward force against an inner wall of the distal needle interface.

[0058] In one or more embodiments, the distal anchor member includes a slot having a biasing member disposed therein. The distal anchor member can define a pair of bumps within the slot. The biasing member can define a pair of notches configured to receive the pair of bumps. The biasing member can be configured to exert a radially outward force against an inner wall of the distal needle interface. The proximal portion can have a longitudinal channel formed on a surface thereof.

[0059] In yet another embodiment, a system for continuously injecting a liquid includes a syringe body defining a syringe proximal opening and a distal needle interface at its distal end. The system also includes a proximal stop member and a distal stop member disposed within the syringe body, such that a proximal chamber is formed between the proximal stop member and the distal stop member, and a distal chamber is formed between the distal stop member and the distal end of the syringe body. The system further includes a powdered drug component in the distal chamber and a liquid drug component in the proximal chamber. Additionally, the system includes a plunger configured to be manually operated to insert the proximal stop member distally relative to the syringe body. In addition, the system includes a needle assembly having a proximal portion, an intermediate connector, and a distal portion. The system also includes a one-way valve partially disposed within the distal needle interface and configured to minimize migration of the powdered drug component from the distal chamber into the needle assembly.

[0060] In one or more embodiments, operating the plunger member to insert the proximal stopper member a first distance distally relative to the syringe body transfers the liquid drug component from the proximal chamber to the distal chamber to form a mixed liquid drug with the powdered drug component, and operating the plunger member to insert the proximal stopper member a second distance distally relative to the syringe body allows the mixed liquid drug to be expelled from the distal chamber and pass through the one-way valve and needle assembly.

[0061] In one or more embodiments, the distal portion includes a sharpened distal tip. The system can also include a needle retraction system disposed within the plunger member and configured to retract the needle assembly at least partially into the plunger member after injection. The one-way valve can include a proximal valve portion and a distal valve portion, the proximal valve portion including a sleeve extending distally from a center thereof.

[0062] In one or more embodiments, the sleeve is configured to have a tight tolerance with the distal valve portion of the needle assembly so that a powdered drug component cannot pass between the sleeve and the distal valve portion of the needle assembly. The tight tolerance can allow a liquid drug component to pass under pressure between the sleeve and the distal valve portion of the needle assembly. The sleeve can define a plurality of longitudinal channels on its surface.

[0063] In one or more embodiments, the proximal valve portion of the one-way valve defines an opening therethrough, such that when a liquid medicament is under pressure in the distal chamber, a liquid flow path is formed from the distal chamber through the opening, along the longitudinal channel between the proximal and distal valve portions of the one-way valve, through the needle assembly, and to the exterior of the system. The proximal and distal valve portions of the one-way valve can be configured to have a tight tolerance relative to one another to prevent powdered medicament components from passing between the proximal and distal valve portions of the one-way valve. The tight tolerance can allow the liquid medicament to pass between the proximal and distal valve portions of the one-way valve under pressure. The proximal valve portion can be rigid, and the distal valve portion can be flexible. When a liquid medicament is under pressure in the distal chamber, at least a portion of the distal valve portion can flex away from the proximal valve portion.

[0064] The foregoing and other embodiments of the present invention are described in the following detailed description. [Brief explanation of the drawings]

[0065] These and other aspects of the embodiments will be described in further detail with reference to the accompanying drawings, in which like elements in different figures are referred to by common reference numerals.

[0066] [Figure 1] 1A and 1B are diagrams showing various aspects of conventional injection syringe configurations. [Figure 2] 2A and 2B are diagrams illustrating various aspects of conventional injection syringe configurations. [Figure 3] FIG. 3 is a diagram showing various aspects of conventional injection syringe configurations. [Figure 4] 4A and 4B are diagrams showing various aspects of conventional injection syringe configurations. [Figure 5] 5A to 5C are diagrams showing various aspects of conventional injection syringe configurations. [Figure 6]6A and 6B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 7] FIG. 7 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 8] 8A and 8B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 9] FIG. 9 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 10] 10A and 10B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 11] FIG. 11 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 12] FIG. 12 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 13] 13A and 13B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 14] FIG. 14 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 15] 15A and 15B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 16] FIG. 16 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 17]17A and 17B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 18] FIG. 18 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 19] 19A and 19B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 20] FIG. 20 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 21] 21A and 21B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 22] FIG. 22 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 23] 23A and 23B illustrate a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 24] FIG. 24 illustrates a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 25] 25A and 25B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 26] FIG. 26 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 27] 27A and 27B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 28]FIG. 28 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 29] 29A and 29B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 30] FIG. 30 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 31] 31A and 31B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 32] FIG. 32 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 33] 33A and 33B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 34] FIG. 34 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 35] 35A and 35B illustrate a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 36] FIG. 36 illustrates a method of continuous injection using a pre-filled triple-chamber continuous injection system according to some embodiments. [Figure 37] FIG. 37 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 38] FIG. 38 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 39]FIG. 39 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 40] FIG. 40 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 41] FIG. 41 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 42] FIG. 42 illustrates a multi-chamber injection system including a distal tubular member coupled to the distal end of a syringe body by a connector / retainer according to some embodiments. [Figure 43] 43A and 43B are perspective and side views of a safety injection system according to some embodiments. [Figure 44] 44A and 44B are perspective, exploded, detailed longitudinal cross-sectional, and detailed perspective views of a needle hub assembly according to some embodiments. [Figure 45] 45A and 45B are a perspective view, an exploded view, a detailed longitudinal cross-sectional view, and a detailed perspective view of a needle assembly according to some embodiments. [Figure 46] FIG. 46 illustrates a perspective view, an exploded view, a detailed longitudinal cross-sectional view, and a detailed perspective view of a needle assembly according to some embodiments. [Figure 47] 47A and 47B are perspective and side views of a proximal portion of a needle assembly according to some embodiments. [Figure 48] 48A and 48B are a perspective view, a detailed perspective view, and an axial cross-sectional view of the proximal portion of a needle assembly according to two embodiments. [Figure 49] 49A and 49B are perspective, detailed perspective, and axial cross-sectional views of the proximal portion of a needle assembly according to two embodiments. [Figure 50] 50A and 50B are a perspective view, a detailed perspective view, and an axial cross-sectional view of the proximal portion of a needle assembly according to two embodiments. [Figure 51] FIG. 51 is a schematic diagram of a logical pipe according to some embodiments. [Figure 52] 52A and 52B are detailed perspective views of the proximal portion and intermediate connector according to two embodiments. [Figure 53] FIG. 53 shows a side view, a detailed perspective view (front and rear), a perspective view, an axial view, and a perspective view of the proximal portion of a needle assembly showing its proximal tip, according to some embodiments. [Figure 54] 54A and 54B are a side view, a detailed perspective view (front and rear), a perspective view, an axial view, and a perspective view of the proximal portion of a needle assembly showing its proximal tip, according to some embodiments. [Figure 55] FIG. 55 shows a side view, a detailed perspective view (front and rear), a perspective view, an axial view, and a perspective view of the proximal portion of a needle assembly showing its proximal tip, according to some embodiments. [Figure 56] FIG. 56 shows a side view, a detailed perspective view (front and rear), a perspective view, an axial view, and a perspective view of the proximal portion of a needle assembly showing its proximal tip, according to some embodiments. [Figure 57] FIG. 57 shows a side view, a detailed perspective view (front and rear), a perspective view, an axial view, and a perspective view of the proximal portion of a needle assembly showing its proximal tip, according to some embodiments. [Figure 58] FIG. 58 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some embodiments. [Figure 59] FIG. 59 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some embodiments. [Figure 60] FIG. 60 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some embodiments. [Figure 61]FIG. 61 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some embodiments. [Figure 62] FIG. 62 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some other embodiments. [Figure 63] FIG. 63 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some other embodiments. [Figure 64] FIG. 64 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some other embodiments. [Figure 65] FIG. 65 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some other embodiments. [Figure 66] FIG. 66 shows longitudinal cross-sectional views of various steps of injection and needle capture using a safety injection system according to some other embodiments. [Figure 67] 67A and 67B are perspective and side views of a dual chamber safety injection system according to some embodiments. [Figure 68] 68A and 68B are perspective and exploded views of a fluid transfer assembly according to some embodiments. [Figure 69] 69A and 69B are perspective and side views of a proximal portion of a fluid transfer assembly according to some embodiments. [Figure 70] FIG. 70 shows a perspective view and a side view of a proximal portion of a fluid transfer assembly according to some embodiments. [Figure 71] Figures 71A, 71C, and 71D are detailed perspective views and axial views of a proximal portion of a fluid transfer assembly according to some embodiments. [Figure 72]72A and 72B are perspective, side, and axial cross-sectional views of a distal connector of a fluid transfer assembly according to some embodiments. [Figure 73] 73A, 73B, and 73C are perspective, side, and axial cross-sectional views of a distal connector of a fluid transfer assembly according to some embodiments. [Figure 74] 74A and 74B are detailed longitudinal and axial cross-sectional views of a fluid transfer distal connector inserted into the distal end of a syringe body according to some embodiments. [Figure 75] 75A and 75B are longitudinal cross-sectional and exploded views of a distal connector of a stopper member having a stopper insert according to some embodiments. [Figure 76] 76A, 76B, and 76C are detailed perspective views of a stopper member having a stopper insert according to some embodiments. [Figure 77] FIG. 77 is a schematic diagram of various steps of fluid transfer and injection using a dual chamber injection system according to some embodiments. [Figure 78] 78A and 78B are perspective and side views of a dual chamber safety continuous injection system according to some embodiments. [Figure 79] FIG. 79 is a detailed longitudinal cross-sectional view of a dual chamber safety continuous injection system according to some embodiments. [Figure 80] FIG. 80 is a schematic illustration of various steps of sequential injections using a dual chamber injection system according to some embodiments. [Figure 81] FIG. 81 is a detailed longitudinal cross-sectional view of a dual chamber safety continuous injection system according to some embodiments. [Figure 82] FIG. 82 is a schematic illustration of various steps of an injection using a dual chamber injection system according to some embodiments. [Figure 83]83A and 83B are detailed perspective views of a fluid transfer assembly and a proximal portion of the fluid transfer assembly, respectively, according to some embodiments. [Figure 84] FIG. 84 is a detailed perspective view of a proximal portion of a fluid transfer assembly according to some embodiments. [Figure 85] FIG. 85 is a schematic illustration of various steps of sequential injections using a dual chamber injection system according to some embodiments. [Figure 86] FIG. 86 is a perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 87] FIG. 87 is a detailed perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 88] FIG. 88 is a detailed perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 89] FIG. 89 is a detailed perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 90] FIG. 90 is a detailed perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 91] FIG. 91 is a detailed perspective view of a dual chamber injection system with a flow regulator according to some embodiments. [Figure 92] FIG. 92 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 93] FIG. 93 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 94] FIG. 94 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 95] FIG. 95 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 96] FIG. 96 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 97] FIG. 97 is a longitudinal cross-sectional view in various degrees of detail illustrating a method for safe sequential injection using a pre-filled dual chamber sequential safety injection system according to some embodiments. [Figure 98] FIG. 98 is a perspective view of a needle hub assembly according to some embodiments. [Figure 99] FIG. 99 is a perspective view of a needle assembly according to some embodiments. [Figure 100] FIG. 100 is a detailed perspective view of a needle proximal member of a needle assembly according to some embodiments. [Figure 101] FIG. 101 illustrates a perspective view and a longitudinal cross-sectional view of a needle proximal member according to some embodiments. [Figure 102] FIG. 102 illustrates a perspective view and a longitudinal cross-sectional view of a needle proximal member according to some embodiments. [Figure 103] 103A and 103B are axial cross-sectional views of the distal ends of two needle proximal members according to some embodiments. [Figure 104] FIG. 104 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 105] FIG. 105 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 106] FIG. 106 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 107]FIG. 107 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 108] FIG. 108 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 109] FIG. 109 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 110] FIG. 110 is a perspective and exploded perspective view of a fluid transfer assembly according to some embodiments. [Figure 111] FIG. 111 is a perspective and exploded perspective view of a fluid transfer assembly according to some embodiments. [Figure 112] 112A-112C are perspective, longitudinal, and axial cross-sectional views of a fluid transfer proximal member according to some embodiments. [Figure 113] FIG. 113 is a longitudinal cross-sectional view in various degrees of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 114] FIG. 114 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 115] FIG. 115 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 116] 116A-116C are longitudinal cross-sectional views in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 117] FIG. 117 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 118] FIG. 118 is a longitudinal cross-sectional view in various levels of detail illustrating a method of continuous injection using a pre-filled needle-free dual chamber continuous injection system according to some embodiments. [Figure 119] FIG. 119 is a perspective view of a fluid transfer assembly according to some embodiments. [Figure 120] FIG. 120 is a perspective view of a fluid transfer assembly according to some embodiments. [Figure 121] 121A-121C are longitudinal and axial cross-sectional views of a fluid transfer proximal portion according to some embodiments. [Figure 122] FIG. 122 is a perspective view of a fluid transfer assembly according to some embodiments. [Figure 123] FIG. 123 is a perspective view of a fluid transfer assembly according to some embodiments. [Figure 124] FIG. 124 is a detailed longitudinal cross-sectional view of an injection system including a fluid transfer interface / portion according to some embodiments. [Figure 125] 125A and 125B are perspective and exploded perspective views of fluid transfer interfaces / portions according to some embodiments. [Figure 126] 126A and 126B are perspective and top views of a fluid transfer distal anchor of a fluid transfer interface member / portion according to some embodiments. [Figure 127] 127A and 127B are perspective and side views of a biasing member of a fluid transfer junction / portion according to some embodiments. [Figure 128] FIG. 128 is a detailed longitudinal cross-sectional view of an injection system including a fluid transfer interface / portion according to some embodiments. [Figure 129] 129A and 129B are perspective, exploded perspective, and exploded side views of a fluid transfer interface / portion according to some embodiments. [Figure 130] FIG. 130 shows a perspective view, an exploded perspective view, and an exploded side view of a fluid transfer interface / portion according to some embodiments. [Figure 131]FIG. 131 is a detailed longitudinal cross-sectional view of an injection system including a fluid transfer interface / portion according to some embodiments. [Figure 132] 132A and 132B are perspective and side views of a fluid transfer interface / portion according to some embodiments. [Figure 133] FIG. 133 is a detailed longitudinal cross-sectional view of an injection system including a fluid transfer interface / portion according to some embodiments. [Figure 134] 134A and 134B are perspective, exploded perspective, and longitudinal cross-sectional views of fluid transfer junctions / portions according to some embodiments. [Figure 135] FIG. 135 shows a perspective view, an exploded perspective view, and a longitudinal cross-sectional view of a fluid transfer interface / portion according to some embodiments. [Figure 136] FIG. 136 is a longitudinal cross-sectional view of a fluid transfer assembly installed within a syringe body according to some embodiments. [Figure 137] FIG. 137 shows a perspective view and a longitudinal cross-sectional view of a fluid transfer assembly according to some embodiments. [Figure 138] FIG. 138 shows a perspective view and a longitudinal cross-sectional view of a fluid transfer assembly according to some embodiments. [Figure 139] 139A-139C are perspective, axial, and longitudinal cross-sectional views of a fluid transfer proximal member according to some embodiments. [Figure 140] FIG. 140 is a series of side views illustrating steps in the assembly of a fluid transfer assembly according to some embodiments. [Figure 141] FIG. 141 is a longitudinal cross-sectional view of a fluid transfer assembly installed within a syringe body according to some embodiments. [Figure 142] FIG. 142 is a perspective view illustrating steps in the assembly of a fluid transfer assembly according to some embodiments. [Figure 143] FIG. 143 is a longitudinal cross-sectional view of a fluid transfer interface / portion installed within a syringe body according to some embodiments. [Figure 144] 144A and 144B are a series of perspective and longitudinal cross-sectional views illustrating steps in the assembly of a fluid transfer junction / portion according to some embodiments. [Figure 145] 145A-145C are a series of perspective and longitudinal cross-sectional views illustrating steps in the assembly of a fluid transfer interface / portion according to some embodiments. [Figure 146] FIG. 146 shows a longitudinal cross-sectional view and a detailed longitudinal cross-sectional view of a dual-chamber safety injection system including a one-way valve according to some embodiments. [Figure 147] FIG. 147 shows a longitudinal cross-sectional view and a detailed longitudinal cross-sectional view of a dual-chamber safety injection system including a one-way valve according to some embodiments. [Figure 148] 148A-148C are perspective, side, and exploded views of the use of a one-way valve for use in a dual chamber safety injection system, according to some embodiments.

[0067] To better understand how the above and other advantages and objects of the various embodiments are achieved, a more detailed description of the embodiments will be given 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 represented by like reference numerals throughout. It will be understood that these drawings depict only certain exemplary embodiments, and therefore should not be considered limiting of the scope of the embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0068] Exemplary Pre-filled Multi-Chamber Continuous Injection Systems and Methods I. Dual Chamber Safety Injection System and Method 6A, 6B, and 7 show a longitudinal side view, a longitudinal cross-sectional view, and a detailed longitudinal cross-sectional view of a pre-filled dual-chamber sequential safety injection system (100) according to some embodiments. The pre-filled dual-chamber sequential safety injection system (100) includes a conventional, readily available pre-filled syringe body (34) having conventional, readily available 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). First and second liquids (252, 254) are contained within the distal and proximal chambers (42, 40), respectively. The proximal and distal stop members (32, 36) occlude the proximal and distal ends of the proximal chamber (40). Distal stop member 36 closes the proximal end of distal chamber 42. In some embodiments, the distal surface of proximal stop member 32 and the proximal surface of distal stop member 36 are each coated with a lubricious polymer coating (e.g., PTFE or ETFE), and the first and second polymer coatings of proximal and distal stop members 32, 36, together with syringe body 34, define proximal chamber 40. The lubricious polymer coating also serves to insulate the rubber of proximal and distal stop members 32, 36 from second liquid 254. The proximal and distal stop members (32, 36) may be oriented as shown in Figures 6A and 6B, or the distal stop (36) may be inverted so that the lubricious coating faces the distal chamber (42) so that the first liquid (252) in the distal chamber (42) contacts the lubricious coating for storage.

[0069] A needle hub assembly (606) is disposed at the distal end of the distal chamber (42). The needle hub assembly (606) includes a needle hub (608) and a needle spine assembly ("needle") (76) removably coupled thereto. In some embodiments, a needle cover member (not shown) may be placed on the needle hub assembly (606) for storage. The dual-chamber sequential safety injection system (100) facilitates sequential injection of a first liquid (252) from the distal chamber (42) and then injection of a second liquid (254) from the proximal chamber (40) upon sequential insertion of the plunger assembly (44) into the syringe body (34) to various degrees by a user. The plunger assembly (44) includes a plunger housing member (69) coupled to the proximal stopper member (32) and a plunger actuation interface (128). The first and second liquids (252, 254) located in the distal and proximal chambers (42, 40), respectively, may be any liquid or gel, such as a water-based or oil-based pharmaceutical solution.

[0070] The dual-chamber sequential safety injection system 100 has a crimped needle configuration in which the needle hub assembly 606 is attached in an injection-ready position when presented to a user after removal of a needle cover member (not shown), which may include a resilient sealing material on its inner surface for interfacing with the needle distal end 78 and / or distal hub 608 during storage. While the crimped needle is shown attached in place, the crimped 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 76 extending into the distal chamber 42 through the luer interface. Alternatively, the needle may be fixedly or removably attached to a flange on the cartridge body instead of the syringe.

[0071] The needle (76) includes a needle proximal end (50, see FIG. 7) and a needle distal end (78, see FIGS. 6A and 6B) that are coupled to opposing ends (i.e., the proximal and distal ends, respectively) of a needle interface member (83, see FIG. 7). The needle interface member (83) is a tubular member coupled to the sharp needle distal end (78), which also defines a distal opening (81). The needle interface member (83) also defines a proximal opening and an intermediate opening (85, 80). The intermediate opening (80) is located adjacent the distal end of the syringe body (34). The proximal opening (85) is located adjacent the proximal end of the needle interface member (83). The needle proximal end (50) is a solid proximal end feature.

[0072] As shown in FIG. 12 , the distal end 87 of the solid needle proximal tip 50 is disposed within the tubular needle interface member 83. The proximal end 89 of the tubular needle interface member 83 is welded to the solid needle proximal tip 50 by a fillet weld. The proximal end 89 of the tubular needle interface member 83 tapers proximally to facilitate the needle 76's penetration of a rubber stopper, such as the distal stopper member 36, while reducing or eliminating shearing / shredding of the rubber stopper (as described herein). Otherwise, shearing / shredding of the rubber stopper could interfere with the injection system and / or create undesirable rubber particles that could be injected into the patient. The proximal and distal edges 91 of the proximal opening 85 may also be rounded (e.g., by tumbling or grinding) to reduce or eliminate shearing / shredding of the rubber stopper during penetration.

[0073] 12, the distal end 87 of the solid needle proximal tip 50 and the tubular needle interface member 83 define an annular lumen 93. The annular lumen 93 fluidly couples the proximal opening 85 to the interior of the needle 76, the intermediate opening 80 (see FIG. 7), and the distal opening 81. Fluidly coupling the proximal opening 85 to the interior of the needle through the annular lumen 93 allows the proximal opening 85 to be positioned in close proximity to the proximal end 89 of the tubular needle interface member 83, thereby allowing for a more compact system design. Fluid coupling of the proximal opening (85) to the interior of the needle through the annular lumen (93) also allows a greater portion of the distal end (87) of the solid needle proximal end (50) to be positioned within the tubular needle interface member (83), thereby facilitating the manufacture of the pre-filled dual chamber continuous safety injection system (100).

[0074] As also shown in FIG. 12 , the proximal opening (85) is an elongated slot that can be formed in the tubular needle interface member (83) using a grinding wheel. The use of a grinding wheel facilitates mass production of the tubular needle interface member (83). The length of the proximal opening (85) is configured to provide tolerance for variations related to the proximal and / or distal stop members (32, 36). The variations related to the proximal and / or distal stop members (32, 36) can be distortion of the proximal surface of the distal stop member, the position of the proximal stop member relative to the elongated slot, and / or the position of the distal stop member relative to the elongated slot (as described herein). The length of the proximal opening (85) also minimizes or eliminates backflow of the first and second liquids (252, 254) into the plunger. In some embodiments, the length of the proximal opening (85) is between about 1 / 32 inch and about 1 / 16 inch. The proximal and distal edges (91) of the proximal opening (85) may also be rounded (e.g., by tumbling or grinding) to reduce or eliminate cutting / shredding of the rubber stopper during penetration thereof, as described herein.

[0075] Briefly, the additional components of the dual-chamber sequential safety injection system (100) include a retraction system, needle retention features, an energy storage member (e.g., a spring), and an energy storage member latch within the plunger member (44). In the embodiment shown in FIGS. 6A-24, a substantial portion of the safety needle retraction hardware resides within the plunger housing (69). The additional components also include a needle holder member (e.g., an O-ring, a needle latch, and / or a detent) within the needle hub (608). The additional components further include a funnel within the distal stop member (36) for guiding the needle proximal end (50) into the center of the distal stop member (36).

[0076] 6A-18 illustrate a safety sequential injection method using a pre-filled dual-chamber sequential safety injection system (100) described herein, according to some embodiments. FIGS. 6A, 6B, and 7 illustrate the pre-filled dual-chamber sequential safety injection system (100) in a first / ready-to-use configuration. The only difference between the first / ready-to-use configuration and the shipping configuration (not shown) is that the needle cover member (not shown) present in the shipping configuration is removed in the first / ready-to-use configuration. In the first / ready-to-use configuration, the proximal opening (85) is located within the distal chamber (42) along with the intermediate opening (80). Therefore, no fluid path exists between the proximal chamber (40) and the distal opening (81). Thus, any distal force applied to plunger actuation interface 128 is transferred through plunger member 44, proximal stop member 32, and the incompressible second liquid 254 in proximal chamber 40, causing distal stop member 36 to move distally relative to syringe body 34. The distal movement of distal stop member 36 relative to syringe body 34 increases pressure in distal chamber 42, which drives first liquid 252 from distal chamber 42 through intermediate and proximal openings 80, 85 and out distal opening 81.

[0077] 8A, 8B, and 9 show the pre-filled dual-chamber sequential safety injection system 100 after the distal stopper member 36 has been moved a first distance distally relative to the syringe body 34. The distal chamber 42 has been partially collapsed / reduced in size, and a portion of the first liquid 252 has been expelled from the pre-filled dual-chamber sequential safety injection system 100 through the distal opening 81. The distal movement of the distal stopper member 36 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to pierce the distal stopper member 36. As shown in FIG. 9 , the rubber material from which the distal stop member 36 is made is deformed / protruded proximally when the proximal end 50 of the needle 76 proximally penetrates the distal stop member 36 due to friction between the distal stop member 36 and the proximal end 50. This friction can be reduced by adding a lubricant to the various components of the pre-filled dual-chamber continuous safety injection system 100. The proximal opening 85 is still within the distal chamber 42 or is blocked by the distal stop member 36. Therefore, there is no flow path between the proximal chamber 40 and the distal opening 81, and distal forces applied to the plunger operating interface 128 are still transmitted to the distal stop member 36 as described above.

[0078] 10A, 10B, 11, and 12 show the filled dual-chamber sequential safety injection system 100 after the distal stopper member 36 has been moved distally a second distance (farther than the first distance) relative to the syringe body 34. The distal chamber 42 has been nearly completely collapsed / evacuated, and most of the first liquid 252 has been expelled from the filled dual-chamber sequential safety injection system 100 through the distal opening 81. Further distal movement of the distal stopper member 36 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to further penetrate the distal stopper member 36. As shown in Figures 11 and 12, the rubber material from which distal stop member 36 is made is deformed / ejected proximally when proximal end 50 of needle 76 penetrates distal stop member 36 proximally due to friction between distal stop member 36 and proximal end 50. Further penetration of proximal end 50 of needle 76 now positions proximal opening 85 within proximal chamber 40, also shown in Figures 11 and 12. Thus, a fluid path now exists between proximal chamber 40 and distal opening 81, and a distal force applied to plunger operating interface 128 now moves proximal stop member 32 distally relative to syringe body 34, expelling second liquid 254 from proximal chamber 40. Opening of the flow path between the proximal chamber (40) and the distal opening (81) places the pre-filled dual chamber continuous safety injection system (100) in a second configuration in which the second liquid (254) can be expelled from the proximal chamber (40).

[0079] As shown in Figure 12, the length of the proximal opening 85 provides tolerance for variations in the degree of deformation / ejection of the distal stop member 36 when the proximal end 50 of the needle 76 proximally penetrates the distal stop member 36. Notably, even if the distal stop member 36 is deformed / ejected more than expected, the proximal opening 85 remains fluidly coupled to the proximal chamber 40 at the distal opening 81. Figure 12 also shows that the proximal end 89 of the tubular needle interface member 83 is welded to the solid needle proximal end 50 with a fillet weld, tapering the proximal end 89 to facilitate penetration of the needle 76 through the distal stop member 36 while reducing or eliminating shearing / shredding of the distal stop member 36. Otherwise, cutting / shredding of the rubber stopper could interfere with the injection system and / or create undesirable rubber particles that could be injected into the patient. The proximal and distal edges 91 of the proximal opening 85 are also rounded (e.g., by tumbling or grinding) to reduce or eliminate cutting / shredding of the distal stopper member 36 during penetration thereof.

[0080] 13A, 13B, and 14 show the filled dual-chamber sequential safety injection system 100 after the proximal stopper member 32 has been moved distally a first distance relative to the syringe body 34. The proximal chamber 40 has been partially collapsed / reduced in size, and a portion of the second liquid 254 has been expelled from the filled dual-chamber sequential safety injection system 100 through the distal opening 81. As shown in FIG. 14, a flow path now exists between the proximal chamber 40 and the distal opening 81 because the proximal opening 85 is within the proximal chamber 40. The flow path between the proximal chamber (40) and the distal opening (81) allows a portion of the second liquid (254) to be expelled through the proximal opening (85), thereby allowing the proximal stop member (32) to move distally toward the distal stop member (36). The distal force applied to the plunger operating interface (128) is transferred to move the proximal stop member (32), so that the distal stop member (36) has substantially stopped moving at this point.

[0081] 15A, 15B, and 16 show the pre-filled dual-chamber sequential safety injection system 100 after the proximal stopper member 32 has been moved distally a second distance (farther than the first distance) relative to the syringe body 34. The proximal chamber 40 has been completely collapsed / expelled, and substantially all of the second liquid 254 has been expelled from the pre-filled dual-chamber sequential safety injection system 100 through the distal opening 81. Further distal movement of the proximal stopper member 32 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to penetrate the proximal stopper member 32 and enter the plunger assembly 44. Penetration of the proximal stopper member 32 causes the proximal end 50 of the needle 76 to be captured by the needle retention feature.

[0082] As shown in FIG. 16 , the length of the proximal opening (85) provides tolerance for variations in the position of the proximal and distal stop members (32, 36) when the proximal chamber (40) is collapsed. Notably, even if the proximal and distal stop members (32, 36) are positioned slightly differently when the proximal chamber (40) is collapsed, the proximal opening (85) will still be fluidly coupled to the proximal chamber (40) at the distal opening (81). The length of the proximal opening (85) is also configured to prevent back-leakage of the first and second liquids (252, 254) into the plunger assembly (44) by limiting the distance between the proximal opening (85) and the solid needle proximal end (50) so that the proximal opening (85) never enters the plunger assembly (44).

[0083] 17A, 17B, and 18 show the pre-filled dual-chamber sequential safety injection system 100 after the proximal stopper member 32 has been moved distally a third distance (farther than the first and second distances) relative to the syringe body 34. Further proximal movement of the proximal end 50 of the needle 76 toward the plunger assembly 44 activates the energy storage member latch, releasing the energy storage member (spring), which draws / retracts the needle 76 at least partially toward the plunger assembly 44, positioning the sharp distal end 78 of the needle 76 inside the syringe body 34. Retraction of the needle 76 places the pre-filled dual-chamber sequential safety injection system 100 in a safe configuration for disposal after injection.

[0084] Figures 19A-22 illustrate a later portion of a safety sequential injection method using a pre-filled dual-chamber sequential safety injection system 100' described herein, according to some embodiments. Figures 19A, 19B, and 20 illustrate the pre-filled dual-chamber sequential safety injection system 100' during a safety sequential injection method, at steps similar to those shown in Figures 15A, 15B, and 16 using the system 100. One difference between the pre-filled dual-chamber sequential safety injection systems 100, 100' is that the proximal end 50' and needle 76' of system 100' are longer than the corresponding proximal end 50 and needle 76 of system 100. Thus, the proximal opening 85 of system 100' enters the proximal chamber (not shown, see (40) in Figure 7) before the distal chamber 42 is substantially collapsed. 6A-14, only a first portion of the first liquid (252) is expelled from the distal chamber (42). As shown in FIG. 20, when the proximal chamber (40) is completely collapsed / expelled and substantially the entire amount of the second liquid (254) is expelled from the filled dual-chamber continuous safety injection system (100) through the distal opening (81), a second portion of the first liquid (252) remains in the distal chamber (42).

[0085] 21A, 21B, and 22 show the pre-filled dual-chamber sequential safety injection system 100' after the proximal and distal stop members 32, 36 have been moved a certain distance distally relative to the syringe body 34. The distal movement of the proximal and distal stop members 32, 36 relative to the syringe body 34 expels a second portion of the first liquid 252 from the distal chamber 42 through the intermediate opening 80. The expulsion / injection pattern of the embodiment shown in FIGS. 19A-22 is a first portion of the first liquid 252 in the distal chamber 42, followed by substantially all of the second liquid 254 in the proximal chamber 40, and finally a second portion of the first liquid 252 in the distal chamber 42. After the second portion of first liquid 252 is expelled, needle 76' is at least partially retracted into plunger assembly 44 as shown in Figures 17A, 17B, and 18 and described above. Although specific portions of first liquid 252 are shown in Figures 19A-22, the dimensions of various portions of needle 76' can be varied to adjust the portions of first liquid 252.

[0086] Figures 23A, 23B, and 24 show a pre-filled dual-chamber sequential safety injection system (100") in a first / ready-to-use configuration, according to some embodiments. Various components of the pre-filled dual-chamber sequential safety injection system (100") may be identical to the corresponding components of the pre-filled dual-chamber sequential safety injection system (100) shown in Figures 6A-18. One difference between the prefilled dual-chamber sequential safety injection systems (100, 100") is that the system (100") shown in Figures 23A, 23B, and 24 has a larger distal chamber (42") compared to the distal chamber (42) of the system (100) shown in Figures 6A-18. Accordingly, the system (100") is configured to inject more of the first liquid (252) from the larger distal chamber (42"). In fact, the distal chamber (42") is larger because more of the first liquid (252) is added during the manufacturing of the system (100"). The system (100") can be used to sequentially inject a first liquid and a second liquid (252, 254) in a manner similar to that shown in Figures 6A-18 and described above.

[0087] As shown in the pre-filled dual chamber sequential safety injection system (100, 100', 100"), the various components of the system (100, 100', 100") and their positions can be varied to adjust the amount of the first and second liquids (252, 254) injected, including the portion of the first liquid (252) that can be injected before and after the second liquid (254).

[0088] II. Triple-Chamber Injection Systems and Methods 25A, 25B, and 26 are longitudinal side, longitudinal cross-sectional, and detailed longitudinal cross-sectional views of a pre-filled triple-chamber sequential injection system (200) according to some embodiments. The pre-filled triple-chamber sequential injection system (200) includes a conventional, readily available pre-filled syringe body (34) having conventional, readily available proximal, intermediate, and distal stop members (32, 33, 36) disposed therein. The proximal, intermediate, and distal stop members (32, 33, 36) together with the syringe body (34) define proximal, intermediate, and distal chambers (40, 41, 42). First, second, and third liquids (252, 253, 254) are contained within the distal, intermediate, and proximal chambers (42, 41, 40), respectively. The proximal and intermediate stop members (32, 33) close the proximal and distal ends of the proximal chamber (40). The intermediate and distal stop members (33, 36) close the proximal and distal ends of the intermediate chamber (41). The distal stop member (36) closes the proximal end of the distal chamber (42). In some embodiments, various surfaces of the proximal, intermediate, and distal stop members (32, 33, 36) are each coated with a lubricious polymer coating (e.g., PTFE or ETFE), such that the coating, together with the syringe body (34), defines the distal, intermediate, and proximal chambers (42, 41, 40). The lubricious polymer coating also serves to insulate the rubber of the proximal, intermediate, and distal stop members (32, 33, 36) from the first, second, and third liquids (252, 253, 254), respectively. The proximal, intermediate, and distal stop members (32, 33, 36) may be oriented as shown in Figures 6A and 6B, or the distal stop member (36) may be inverted.

[0089] A needle hub assembly 606 is disposed at the distal end of the distal chamber 42. The needle hub assembly 606 includes a needle hub 608 and a needle spine assembly ("needle") 76 coupled thereto. In some embodiments, a needle cover member (not shown) may be placed on the needle hub assembly 606 for storage. The pre-filled triple-chamber sequential injection system 200 facilitates sequential injection of a first portion of a first liquid 252 from the distal chamber 42, followed by injection of a second liquid 253 from the intermediate chamber 41, followed by injection of a remaining portion of the first liquid 252 from the distal chamber 42, and then injection of a third liquid 254 from the proximal chamber 40, as the plunger assembly 44 is sequentially inserted into the syringe body 34 by a user to various degrees. The plunger assembly (44) is coupled to the proximal stopper member (32) and includes a plunger operating interface (128). The first, second, and third liquids (252, 253, 254) located in the distal, intermediate, and proximal chambers (42, 41, 40), respectively, may be any liquid or gel, such as an aqueous or oil-based pharmaceutical solution.

[0090] The prefilled triple-chamber sequential injection system 200 has a crimped needle configuration in which the needle hub assembly 606 is attached in an injection-ready position when presented to a user after removal of a needle cover member (not shown), which may include a resilient sealing material on its inner surface for interfacing with the needle distal end 78 and / or distal hub 608 during storage. While the crimped needle is shown attached in place, the crimped 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 76 extending into the distal chamber 42 through the luer interface. Alternatively, the needle may be fixedly or removably attached to a flange on the cartridge body instead of the syringe.

[0091] The needle (76) includes a needle proximal end (50, see FIG. 26) and a needle distal end (78, see FIGS. 6A and 6B) that are coupled to opposing ends (i.e., the proximal and distal ends, respectively) of a needle interface member (83, see FIG. 7). The needle interface member (83) is a tubular member coupled to the sharp needle distal end (78), which also defines a distal opening (81). The needle interface member (83) also defines a proximal opening and an intermediate opening (85, 80). The intermediate opening (80) is located adjacent the distal end of the syringe body (34). The proximal opening (85) is located adjacent the proximal end of the needle interface member (83). The needle proximal end (50) is a solid proximal end feature.

[0092] The pre-filled triple-chamber sequential safety injection system (200) includes many of the same components as the pre-filled dual-chamber sequential safety injection system (100) shown in Figures 6A-18 and is assembled similarly to the pre-filled dual-chamber sequential safety injection system (100). For example, the tubular needle interface member (83) is welded to the solid needle proximal end (50) by a fillet weld configured to facilitate the needle (76) penetrating a rubber stopper, such as the distal stopper member (36), while reducing or eliminating cutting / shredding of the rubber stopper (described herein). The proximal and distal edges of the proximal opening (85) may also be rounded (e.g., by tumbling or grinding) to reduce or eliminate cutting / shredding of the rubber stopper during penetration thereof.

[0093] The elongated slot can be formed in the tubular needle interface member (83) using a grinding wheel. The use of a grinding wheel facilitates mass production of the tubular needle interface member (83). The length of the proximal opening (85) is configured to provide tolerance for variations associated with the proximal stop member, the intermediate stop member, and / or the distal stop member (32, 33, 36). The variations associated with the proximal stop member, the intermediate stop member, and / or the distal stop member (32, 33, 36) can be distortion of the proximal surface of the distal stop member, distortion of the proximal surface of the intermediate stop member, the position of the proximal stop member relative to the elongated slot, the position of the intermediate stop member relative to the elongated slot, and / or the position of the distal stop member relative to the elongated slot (as described herein). In some embodiments, the length of the proximal opening (85) is between about 1 / 16 inch and about 1 / 8 inch. The proximal and distal edges of the proximal opening (85) may also be rounded (e.g., by tumbling or grinding) to reduce or eliminate cutting / shredding of the rubber stopper during penetration thereof, as described herein.

[0094] Additional components further include a funnel within the distal stop member (36) for guiding the needle proximal end (50) into the center of the distal stop member (36).

[0095] 25A-36 illustrate a method of sequential injection using a pre-filled triple-chamber sequential injection system (200) described herein, according to some embodiments. FIGS. 25A, 25B, and 26 show the pre-filled triple-chamber sequential injection system (200) in a first / ready-to-use configuration. The only difference between the first / ready-to-use configuration and the shipping configuration (not shown) is that the needle cover member (not shown) present in the shipping configuration is removed in the first / ready-to-use configuration. In the first / ready-to-use configuration, the proximal opening (85) is located within the distal chamber (42) along with the intermediate opening (80). Therefore, there is no fluid flow path between the intermediate and proximal chambers (41, 40) and the distal opening (81). Thus, any distal force applied to plunger operating interface 128 is transferred through plunger member 44, proximal stop member 32, incompressible third liquid 254 in proximal chamber 40, intermediate stop member 33, and incompressible second liquid 253 in intermediate chamber 41, causing distal stop member 36 to move distally relative to syringe body 34. The distal movement of distal stop member 36 relative to syringe body 34 increases pressure in distal chamber 42, which drives first liquid 252 from distal chamber 42 through intermediate and proximal openings 80, 85 and out distal opening 81.

[0096] 27A, 27B, and 28 show the filled triple-chamber serial injection system 200 after the distal stopper member 36 has been moved a first distance distally relative to the syringe body 34. The distal chamber 42 has been partially collapsed / reduced in size, and a portion of the first liquid 252 has been expelled from the filled triple-chamber serial injection system 200 through the distal opening 81. The distal movement of the distal stopper member 36 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to pierce the distal stopper member 36. As shown in FIG. 28 , the rubber material from which the distal stop member 36 is made is deformed / protruded proximally when the proximal end 50 of the needle 76 proximally penetrates the distal stop member 36 due to friction between the distal stop member 36 and the proximal end 50. This friction can be reduced by adding a lubricant to the various components of the pre-filled triple-chamber sequential injection system 200. The proximal opening 85 is still within the distal chamber 42 or is blocked by the distal stop member 36. Therefore, there is no flow path between the intermediate chamber 41 and the distal opening 81, and distal forces applied to the plunger operating interface 128 are still transmitted to the distal stop member 36 as described above.

[0097] 29A, 29B, and 30 show the filled triple-chamber serial injection system 200 after the distal stopper member 36 has been moved distally a second distance (farther than the first distance) relative to the syringe body 34. The distal chamber 42 has been further collapsed, and a first portion of the first liquid 252 has been expelled from the filled triple-chamber serial injection system 200 through the distal opening 81. Further distal movement of the distal stopper member 36 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to further penetrate the distal stopper member 36. As shown in FIG. 30 , the rubber material from which distal stop member 36 is made is deformed / protruded proximally when proximal end 50 of needle 76 proximally penetrates intermediate stop member 33 due to friction between distal stop member 36 and proximal end 50. As also shown in FIG. 30 , penetration of proximal end 50 of needle 76 through distal stop member 36 now positions proximal opening 85 within intermediate chamber 41. Thus, a fluid path now exists between intermediate chamber 41 and distal opening 81, and a distal force applied to plunger operating interface 128 now moves intermediate stop member 33 distally relative to syringe body 34, expelling second liquid 253 from intermediate chamber 41. Opening of the flow path between the intermediate chamber (41) and the distal opening (81) places the filled triple-chamber continuous injection system (200) in a second configuration in which the second liquid (253) can be expelled from the intermediate chamber (41).

[0098] Figures 31A, 31B, and 32 show the filled triple-chamber sequential injection system 200 after the intermediate stopper member 33 has been moved distally relative to the syringe body 34 until it contacts the distal stopper member 36. The intermediate chamber 41 (see Figure 26) has collapsed, and substantially all of the second liquid 253 has been expelled from the filled triple-chamber sequential injection system 200 through the distal opening 81. Further distal movement of the intermediate stopper member 33 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to pierce the intermediate stopper member 33. As shown in Figure 32, the rubber material from which intermediate stop member 33 is made is deformed / protruded proximally when proximal end 50 of needle 76 penetrates proximally through distal stop member 36 due to friction between intermediate stop member 33 and proximal end 50. As also shown in Figure 32, proximal opening 85 is now blocked by intermediate and distal stop members 33, 36 due to the proximal end 50 of needle 76 penetrating intermediate stop member 33. Thus, the only open flow path in system 200 is from distal chamber 42 through distal opening 80 to the distal opening, and a distal force applied to plunger operating interface 128 at this point moves intermediate and distal stop members 33, 36 distally relative to syringe body 34, expelling a second portion of first liquid 252 from distal chamber 42. Reopening of the flow path between distal chamber 42 and distal opening 81 places pre-filled dual-chamber sequential safety injection system 100 in a third configuration in which a second portion of first liquid 252 can be expelled from distal chamber 42.

[0099] Figures 33A, 33B, and 34 show the filled triple-chamber sequential injection system 200 after the intermediate and distal stop members 33, 36 have been moved distally relative to the syringe body 34 until the distal stop member 36 contacts the distal end of the syringe body 34. The distal chamber 42 (see Figure 26) has collapsed, and substantially all of the first liquid 252 has been expelled from the filled triple-chamber sequential injection system 200 through the distal opening 81. Further distal movement of the intermediate stop member 33 relative to the syringe body 34 also causes the proximal end 50 of the needle 76 to pierce the intermediate stop member 33. 34, the proximal end 50 of the needle 76 has now penetrated the intermediate stop member 33, so that the proximal opening 85 is now positioned within the proximal chamber 40. Thus, a fluid path now exists between the proximal chamber 40 and the distal opening 81, and a distal force applied to the plunger operating interface 128 now moves the proximal stop member 32 distally relative to the syringe body 34, expelling the third liquid 254 from the proximal chamber 40. Opening the fluid path between the proximal chamber 40 and the distal opening 81 places the pre-filled dual-chamber continuous safety injection system 100 in a fourth configuration in which the third liquid 254 can be expelled from the proximal chamber 40.

[0100] Figures 35A, 35B, and 36 show the filled triple-chamber sequential injection system 200 after the proximal stopper member 32 has been moved distally relative to the syringe body 34 until it contacts the intermediate stopper member 33. The proximal chamber 40 (see Figure 26) has collapsed, and substantially all of the third liquid 254 has been expelled from the filled triple-chamber sequential injection system 200 through the distal opening 81. Figures 35A, 35B, and 36 show the completed state of the sequential injection method using the filled triple-chamber sequential injection system 200.

[0101] The ejection / injection pattern of the embodiment shown in Figures 25A-36 is a first portion of the first liquid 252 in the distal chamber 42, followed by substantially all of the second liquid 253 in the intermediate chamber 41, followed by a second portion of the first liquid 252 in the distal chamber 42, and finally substantially all of the third liquid 254 in the proximal chamber 40. While a specific portion of the first liquid 252 is shown in Figures 25A-36, the dimensions of various portions of the needle 76 can be altered to adjust the portion of the first liquid 252. The various components of the system 200 and their positions can be altered to adjust the amount of the first, second, and third liquids 252, 253, 254 injected, including the portion of the first liquid 252 that can be injected. Although the system 200 shown in Figures 25A-36 did not include a safety needle retraction system, the triple chamber serial injection system can be modified to include a safety needle retraction system. Although the system 200 shown in Figures 25A-36 includes three chambers, some embodiments of the injection system can include four or more chambers.

[0102] Exemplary Distal Tube Connector / Retainer Figures 37-42 show a multi-chamber injection system 3700 including a distal tubular member 3783 coupled to the distal end 3782 of a syringe body 3734 by a connector / retainer 3784. The distal end 3782 of the syringe body 3734 may be a luer lock connector for coupling to a needle (not shown). Figure 37 shows the distal end 3782 of the syringe body 3734 with a cap 3786 attached. Figure 38 shows the distal end 3782 of the syringe body 3734 without the cap 3786.

[0103] Figure 39 shows the connector / retainer 3784 in more detail. The connector / retainer 3784 includes a diamond-shaped portion 3788 and a flat portion 3790. The diamond-shaped portion 3788 is resiliently compressible to fit proximally inside the distal end 3782 of the syringe body 3734. Figures 41 and 42 show the insertion of the connector / retainer 3784, with its coupled distal tubular member 3783, into the distal end 3782 of the syringe body 3734 during assembly. When placed inside the distal end (3782) of the syringe body (3734), the diamond-shaped portion (3788) is biased to expand to increase friction between the inner surface of the distal end (3782) of the syringe body (3734) and the diamond-shaped portion (3788) to resist longitudinal (e.g., proximal) movement of the connector / retainer (3784) and the distal tubular member (3783) connected thereto relative to the syringe body (3734).

[0104] The flat portion 3790 of the connector / retainer 3784 is larger in at least one dimension compared to the opening in the distal end 3782 of the syringe body 3734. Thus, the flat portion 3790 of the connector / retainer 3784 interferes with the distal end 3782 of the syringe body 3734 to limit distal movement of the connector / retainer 3784 and its coupled distal tubular member 3783 relative to the syringe body 3734.

[0105] As shown in Figure 40, once assembled, a flow path 3792 opens between the interior of syringe body 3734 and its exterior past connector / retainer 3784.

[0106] The connector / retainer 3784 may be cut or stamped as a single piece from a flat metal sheet (e.g., stainless steel), with the distal end of the diamond-shaped portion 3788 midway between the cut / stamped piece. The cut / stamped piece can then be bent to form the diamond-shaped portion 3788. The material from which the cut / stamped piece is cut / stamped provides elastic qualities to the diamond-shaped portion 3788. The two pieces forming the flat portion 3790 can overlap one another. The free end of the flat portion 3790 may include one or more tongues configured to fit within a distal opening at the distal end of the distal tubular member 3783 to facilitate coupling (e.g., by welding) the connector / retainer 3784 to the distal tubular member 3783.

[0107] III. Exemplary Safety Injection Systems 43A and 43B illustrate a single-chamber crimped needle safety injection system (600) according to some embodiments. The safety injection system (600) includes a needle hub assembly (610) coupled to a syringe body (620) and a plunger member (630) coupled to a stopper member (640) disposed within the syringe body (620). The needle hub assembly (610) includes a needle assembly (650), such as those described below. The safety injection system (600) includes a needle retraction system disposed substantially within the plunger member (630). The needle retraction system applies a proximal force to the needle assembly 650 after the injection is completed, drawing the needle assembly 650 at least partially into the needle hub assembly 610 and / or syringe body 620, thereby positioning the sharp distal tip 652 of the needle assembly 650 within the needle hub assembly 610 and / or syringe body 620 to prevent accidental needle sticks. In some embodiments, the proximal force is between about 2 pounds and about 3 pounds.

[0108] Exemplary Needle Assembly 44A-58 illustrate various needle assemblies and their features according to various embodiments.

[0109] Figure 44A shows a needle hub assembly (610) with a rigid needle shield (612) attached, according to some embodiments. Figure 44A also shows the proximal end of a needle assembly (650). Figure 44B shows a needle assembly (650), according to some embodiments.

[0110] Figure 45A is an exploded view of the needle assembly 650 shown in Figure 44B. The needle assembly 650 includes a proximal portion 660 and a distal portion 654, each configured to be partially disposed within the respective proximal and distal ends of an intermediate connector 670. The distal end of the distal portion 654 includes a sharpened distal tip 652 configured to pierce the target tissue for injection. The intermediate connector 670 includes an annular recess 672 configured to interfere with a needle latch to prevent the needle assembly 650 from being retracted proximally before the injection is completed.

[0111] The proximal portion (660) includes a proximal tip (680) at its proximal end and one or more longitudinal channels (662) extending from its distal end. Figure 45B is a longitudinal cross-sectional view of an intermediate connector (670) with the proximal and distal portions (660, 654) partially disposed therein, according to some embodiments. Figure 45B shows that the proximal portion (660) includes two longitudinal channels (662) formed in approximately opposing surfaces of the proximal portion (660). The longitudinal channels (662) form two flow paths that enter the intermediate connector (670) from outside the needle assembly (650), then enter the distal portion (654), pass through a proximal opening (656) in the distal portion (654), and exit the sharp distal tip (652) of the distal portion (654).

[0112] 46 shows the proximal end of the intermediate connector 670 with the distal end of the proximal portion 660 inserted therein until only the proximal end of the longitudinal channel 662 remains outside the intermediate connector 670. This proximal end of the longitudinal channel 662 forms an opening 664 that fluidly couples the interior and exterior of the needle assembly 650.

[0113] 47A and 47B are perspective and side views of a proximal portion 660 of a needle assembly 650 according to some embodiments. The proximal portion 660 may be formed by stamping a single piece of flat sheet metal or metal wire to form the various features of the proximal portion 660 described herein. Forming the proximal portion 660 by stamping reduces manufacturing complexity and cost.

[0114] Figures 48A and 48B are perspective views of two proximal portions (660A, 660B) according to two embodiments. Figures 49A and 49B are detailed perspective views of the distal end of each of the proximal portions (660A, 660B). Figures 50A and 50B are axial cross-sectional views of the distal end of each of the proximal portions (660A, 660B).

[0115] As best shown in Figures 50A and 50B, the axial cross-sections of the distal ends of each of the proximal portions (660A, 660B) form a crescent and dumbbell shape, respectively. The crescent and dumbbell shapes define one and two longitudinal channels (662A, 662B), respectively. The longitudinal channels (662A, 662B) have rounded / circular cross-sections, which minimize fluid flow restriction through the longitudinal channels (662A, 662B). A circular cross-section is a highly efficient cross-section for fluid flow due to minimized fluid interaction with the channel walls, which would otherwise impose a zero velocity boundary condition on the flowing fluid. Therefore, minimizing wall exposure minimizes the amount of shear resistance experienced by the fluid during flow. The Hagen-Poiseuille equation:

[0116] According to TIFF0007799324000001.tif12170, the resistance of logic pipe 1400 (see Figure 51) is r 4Because ρ is inversely proportional to ρ, the fluid flow resistance of a single round channel (662A) (see FIG. 50A) can be lower compared to a double channel (662B) (see FIG. 50B) even if the cross-sectional area is maintained.

[0117] Even with the longitudinal channels 662A, 662B formed therein, the proximal portions 660A, 660B have sufficient bending moment of inertia to improve stiffness and resistance to bending. In fact, the proximal portions 660A, 660B resemble a steel I-beam and have similar stiffness characteristics. Resistance to bending is particularly important when the proximal portions 660A, 660B pierce the stopper member 640. Minimizing bending as the proximal portions 660A, 660B pierce the stopper member 640 improves the likelihood that the proximal tip 680 of the proximal portion 664 will be captured, allowing retraction of the needle assembly 650 (see FIGS. 58-62 and 63-66).

[0118] The diameters of proximal portions 660A and 660B are also relatively large (e.g., approximately 0.026 inches compared to a cold-formed proximal portion having a diameter of approximately 0.020 inches). The larger diameter of proximal portion 660 results in a higher overall bending moment of inertia and greater resistance to bending, which also improves the probability of capture. Proximal portions 660A and 660B are also very close in diameter to intermediate portion 670, which may have a diameter of approximately 0.036 inches. The similar diameters allow needle assembly 650 to be more easily retracted through the stopper member during retraction compared to a needle assembly made with a cold-formed proximal portion, because the proximal opening of intermediate portion 670 is less likely to catch on the stopper member during retraction due to the relatively small diameter difference between intermediate portion 670 and proximal portion 660.

[0119] 52A and 52B are detailed perspective views of the distal ends of each of the proximal portions (660A, 660B), showing cutaway sections of the intermediate connector (670) within which the respective distal ends are partially disposed. As shown in FIGS. 52A and 52B, the crescent and dumbbell cross-sectional shapes of the proximal portions (660A, 660B) provide a substantial amount of contact between the outer diameter of the proximal portions (660A, 660B) and the inner diameter of the tubular intermediate connector (670). This substantial contact reduces the amount of welding force required to join the proximal portions (660A, 660B) and the tubular intermediate connector (670). This reduced amount of welding force also minimizes the probability of blockage of the channels (662A, 662B) resulting from crushed weld metal in the proximal portions (660A, 660B) and the tubular intermediate connector (670).

[0120] Figures 53-57 show the proximal tip (680) of the proximal portion (664) in more detail. The proximal tip (680) includes a pyramidal-shaped proximal piercing tip (682), a slightly tapered intermediate portion (684), and a toroidal-shaped distal flange (686). As shown in Figure 56, the pyramidal-shaped proximal piercing tip (682) includes four faces / lobes 683. As shown in Figure 53, the edges defining the lobes 683 of the pyramidal-shaped proximal piercing tip (682) form a tip with an approximately 90° angle when viewed from the side. Compared to the more obtuse 90° angle of the tip, the intermediate portion (684) has a more acute taper of approximately 12°-15°. The more acute taper of the intermediate portion (684) reduces the force required to pierce the stopper member.

[0121] The pyramidal proximal piercing tip 682 and the slightly tapered intermediate section 684 form the composite tip shape of the proximal tip 680. The 90° pyramidal proximal piercing tip 682 may be convex and configured to hook / grab onto the distal surface of the stopper member 640, which may be coated with a slippery hard coating in some embodiments, without slipping off the distal surface of the stopper member 640. The 12°-15° intermediate section 684 is configured to require a lower piercing force for the proximal tip 680 to penetrate and pierce the stopper member 640. The transition between the pyramidal proximal puncture tip (682) and the intermediate portion (684) is smoothed and therefore configured to minimize snagging or sticking of the funnel component during capture of the proximal tip (680) of the proximal portion (664) to allow retraction of the needle assembly (650) (see Figures 58-62 and 63-66).

[0122] The proximal portion 660 of the needle assembly 650 also includes a reduced diameter portion 664 immediately distal to the proximal tip 680. In embodiments in which the proximal portion 660 of the needle assembly 650 is formed by stamping, the radial overhang between the outer diameter of the toroidal distal flange 686 and the reduced diameter portion 664 may be up to about 0.0075 inches. This relatively large overhang (e.g., compared to a cold-formed proximal tip) increases the probability and safety of the proximal tip 680 of the proximal portion 664 becoming trapped, allowing retraction of the needle assembly 650 (see Figures 58-62 and 63-66).

[0123] IV. Exemplary Safety Injection Systems Figures 58-62 illustrate injection and needle capture using a safety injection system 2100 according to some embodiments. Figure 58 illustrates the safety injection system 2100 in a pre-injection configuration, including a needle assembly 650 having a proximal portion 660 similar to the embodiment shown in Figures 53-57. The safety injection system 2100 includes a needle retraction system.

[0124] In Figure 59, the proximal tip (680) of the proximal portion (660) is about to pierce the stopper member (640), which is shown to have a convex distal surface. The 90° pyramidal proximal piercing tip (682) of the proximal tip (680) is configured to hook / grab onto the distal surface (642) of the stopper member (640) without slipping off. As mentioned above, the distal surface (642) of the stopper member (640) may also be coated with a slippery hard coating.

[0125] 60 illustrates continued distal movement of the stopper member 640 relative to the needle assembly 650. The needle retraction system, according to some embodiments, includes a funnel 632 configured to guide the proximal tip 680 into the needle catch cup 634. The smoothed transition between the pyramidal proximal piercing tip 682 and the intermediate portion 684 is configured to minimize snagging or sticking of the funnel 632 during capture of the proximal tip 680 of the proximal portion 664 by the needle catch cup 634.

[0126] 61 and 62 illustrate continued distal movement of the stopper member 640 relative to the needle assembly 650. Interaction between the proximal tip 680 and the funnel 632 guides the proximal tip 680 into the needle catch cup 634. The relatively large radial overhang (approximately 0.0075 inches) between the profile of the toroidal distal flange 686 of the proximal tip 680 and the reduced diameter portion 664 increases the probability and safety of capture of the proximal tip 680 by the needle catch cup 634. The relatively large radial overhang also allows for a wider opening in the needle catch cup 634 without compromising placement of the proximal tip 680 after capture. The wider opening and slightly tapered middle portion (684) allow the proximal tip (680) to be inserted into the needle catch cup (634) without triggering the needle retraction mechanism (e.g., a spring release latch).

[0127] Figures 63-66 illustrate an injection and needle capture using a safety injection system 2600 according to some embodiments. Figure 63 illustrates a safety injection system 2600 including a needle assembly 650 having a proximal portion 660 similar to the embodiment shown in Figures 53-57. The safety injection system 2600 includes a needle retraction system. The difference between the safety injection system 2100 shown in Figures 58-62 and the safety injection system 2600 shown in Figures 63-66 is that the safety injection system 2600 includes a pair of self-actuating tabs 634' forming a funnel 632' instead of the needle catch cup 634 shown in the safety injection system 2100. Additionally, the pair of self-actuating tabs 634' are shaped to be trigger components to reduce the number of components (e.g., for assembly).

[0128] Figure 63 shows a safety injection system 2600 in a pre-injection configuration, including a needle assembly 650 having a proximal portion 660 similar to the embodiment shown in Figures 53-57. The safety injection system 2600 includes a needle retraction system.

[0129] Figures 64-66 illustrate injection and needle capture following distal movement of the stopper member 640 relative to the needle assembly 650. Interaction between the proximal tip 680 and the funnel 632' guides the proximal tip 680 proximally to the pair of self-energizing tabs 634'. The relatively large radial overhang (approximately 0.0075 inches) between the outer diameter of the toroidal distal flange 686 of the proximal tip 680 and the reduced diameter portion 664 increases the probability and safety of capture of the proximal tip 680 by the self-energizing tabs 634'. The self-energizing tabs 634' are separated by two slots 636 (see Figure 65) that are parallel to the sidewalls and longitudinal axis of the needle catch member. Due to the parallel configuration of slot 636 relative to the sidewall of the needle catch member, tab 634' is self-biasing in that when proximal tip 680 is pulled distally relative to tab 634', tab 634' clamps around reduced diameter portion 664 of needle assembly 650. Rotation of tab 634' and the portion of funnel 632' distal to slot 636 contributes to this self-biasing feature. The needle catch also includes a pair of windows 638 that facilitate rotation of tab 634'.

[0130] The larger radial overhang also allows for a wider opening between the self-energizing tabs 634' without compromising the placement of the proximal tip 680 after capture. In embodiments with a larger radial overhang (e.g., 0.0075 inches), the self-energizing tabs 634' are configured to capture the proximal tip 680 with a pull-out force on the order of 12 pounds. The wider opening and slightly tapered middle portion 684 allow the proximal tip 680 to be inserted between the self-energizing tabs 634' without triggering the needle retraction mechanism (e.g., a spring release latch).

[0131] V. Exemplary Dual-Chamber Injection System 67A-77 illustrate a dual-chamber injection system 3600 having a fluid transfer assembly 3650 according to some embodiments. The fluid transfer assembly 3650 is similar to the needle assembly 650 described herein in that it has one or more channels 3662 and a proximal tip 3680 similar to the corresponding channels 662 and proximal tip 680 in the needle assembly 650 described herein. The dual-chamber injection system 3600 includes a needle connector 3610 formed at the distal end of a syringe body 3620 and a plunger member 3630 coupled to a proximal stopper member 3640 disposed within the syringe body 3620. A distal stopper member 3690 is also disposed within the syringe body 3620. Although not shown here, the dual-chamber injection system 3600 may include a needle retraction system. The needle retraction system is disposed substantially within the interior of the plunger member (3630).

[0132] Figures 68A and 68B illustrate a fluid transfer assembly (3650) according to some embodiments. Figure 68B is an exploded view of the fluid transfer assembly (3650) shown in Figure 68A. The fluid transfer assembly (3650) includes a proximal portion (3660) configured to be partially disposed within the proximal end of an intermediate connector (3670). The fluid transfer assembly (3650) also includes a distal connector (3700) configured to receive the distal end of the intermediate connector, which in turn is configured to be partially disposed within the proximal end of the distal connector (3700). The intermediate connector (3670) includes a radially extending annular flange (3674) configured to interface with a distal stop member (3690).

[0133] 69A-71D show the proximal portion (3660) of the fluid transfer assembly (3650) and its various components according to some embodiments. The proximal portion (3660) of the fluid transfer assembly (3650) includes a proximal tip (3680), a longitudinal channel (3662), and a radially extending annular flange (3674). The proximal tip (3680) in the fluid transfer assembly (3650) is similar to the proximal tip (680) in the needle assembly (650) described herein. In particular, the proximal tip 3680 includes a pyramidal proximal piercing tip 3682, a slightly tapered intermediate portion 3684, and a toroidal distal flange 3686 (see FIG. 71A ) that are structurally and functionally similar to the respective pyramidal proximal piercing tip 682, slightly tapered intermediate portion 684, and toroidal distal flange 686 of the proximal tip 680. As in the proximal tip 680, the transition between the pyramidal proximal piercing tip 3682 and the intermediate portion 3684 in the proximal tip 3680 is smoothed. Thus, the proximal tip 3680 is configured to minimize snagging or sticking of the funnel 3696 during penetration of the proximal tip 3680 through the distal stop member 3690 (see FIGS. 75A-77 ).

[0134] As shown in FIG. 71B, the longitudinal channel (3662) in the proximal portion (3660) of the fluid transfer assembly (3650) has a rounded / circular cross-section, which minimizes fluid flow restriction through the longitudinal channel (3662).

[0135] As shown in Figures 71C and 71D, the radially extending annular flange 3674 is configured to temporarily interfere with a pair of tabs 3698 in the stopper insert 3694 to hold the distal stopper member 3690 and the fluid transfer assembly 3650 relative to one another in a transfer configuration (see Figures 75A-77) when a sufficient amount of force is applied to the plunger member 3630 to transfer fluid through the longitudinal channel 3662 in the fluid transfer assembly 3650. The pair of tabs 3698 are also configured to allow the radially extending annular flange 3674 to pass therethrough when additional force is applied to the plunger member 3630 after transfer of fluid across the longitudinal channel 3662 is completed. The longitudinal channel 3662 is configured such that fluid flow is stopped after the annular flange 3674 moves proximally of the tabs 3698.

[0136] 72A-74B illustrate various embodiments of a distal connector 3700. The distal connector 3700 includes a radially enlarged proximal portion 3710 and a distal portion 3720. The radially enlarged proximal portion 3710 is configured to receive the distal end of the intermediate connector 3670 of the fluid transfer assembly 3650. As shown in FIG. 73C, the opening 3712 in the proximal portion 3710 has a squircle cross-sectional shape. Thus, when the intermediate connector 3670, which is tubular and has a circular cross-sectional shape, is inserted into the opening 3712 in the proximal portion 3710 (see FIG. 74A), a mechanical fit is formed between the distal end of the intermediate connector 3670 and the proximal portion 3710 of the distal connector 3700.

[0137] As shown in Figures 73B and 74B, the distal portion 3720 is configured to fit into the distal opening of the syringe body 3620 and couple the fluid transfer assembly 3650 thereto. The exterior of the distal portion 3720 has a rounded triangular cross-section. Thus, when the distal connector 3700 is inserted into the opening 3622 in the distal end of the syringe body 3620 (see Figure 74A), a mechanical fit is formed between the distal portion 3720 of the distal connector 3700 and the distal end of the syringe body 3620. Figure 74B also shows that three channels 3730 are formed between the exterior of the distal portion 3720 of the distal connector 3700 and the distal end of the syringe body 3620. These channels (3730) allow fluid to pass from the interior of the syringe body (3620) to the exterior of the syringe body (3620).

[0138] 75A-76C illustrate a distal stopper member 3690 for use with a dual-chamber injection system, according to some embodiments. The distal stopper member 3690 includes a readily available rubber stopper 3692 and a stopper insert 3694 disposed therein. The stopper insert 3694 includes a pair of resiliently deformable tabs 3698 (see FIGS. 76A-76B) that form part of a distally facing funnel 3696. As described herein, the tabs 3698 are configured to temporarily interfere with the radially extending annular flange 3674 of the fluid transfer assembly 3650 to hold the distal stop member 3690 and the fluid transfer assembly 3650 relative to one another in a transfer configuration (see FIG. 77 ) when a sufficient amount of force is applied to the plunger member 3630 to transfer fluid through the longitudinal channel 3662 in the fluid transfer assembly 3650. The tabs 3698 are also configured to allow the radially extending annular flange 3674 to pass therethrough when additional force is applied to the plunger member 3630 after transfer of fluid across the longitudinal channel 3662 is complete.

[0139] 77 illustrates various steps in fluid transfer and injection 4000 using a dual chamber injection system, such as system 3600 described herein. In step 4010, the system is in a transport configuration with proximal tip 3680 positioned against the distal surface of rubber stopper 3692.

[0140] In step 4020, sufficient force is applied to the plunger assembly 3630 to drive the distal stopper member 3690 distally relative to the proximal tip 3680, causing the proximal tip 3680 to puncture the rubber stopper 3692. With the transfer tube assembly 3650 and distal stopper member 3690 in the position shown in step 4020, the system is in a fluid transfer configuration in which the proximal and distal chambers are fluidly coupled via the longitudinal channel 3662 in the needle assembly 3650. As described herein, interference between the tab 3698 of the stopper insert 3694 and the radially extending annular flange 3674 of the needle assembly 3650 maintains the fluid transfer configuration while fluid is transferred from the proximal chamber to the distal chamber by continuing to apply force to the plunger member 3630.

[0141] In step 4030, the proximal stop member 3640 is moved distally until it contacts the distal stop member 3690, thereby completing the fluid transfer, at which point an increased force can be applied to the distal stop member 3690 since the fluid transfer has ceased.

[0142] In step (4040), the increased force applied to the distal stopper member (3690) overcomes the interference between the tab (3698) of the stopper insert (3694) and the radially extending annular flange (3674) of the needle assembly (3650), causing the distal stopper member (3690) to move distally relative to the fluid transfer member (3650) and expel fluid from the distal chamber outside the syringe body (3620).

[0143] In step 4050, the discharge of fluid from the distal chamber to the exterior of syringe body 3620 is completed. Distal stopper member 3690 has moved 4020 toward the distal end of the syringe body.

[0144] VI. Exemplary Continuous Safety Injection Systems 78A-85 illustrate sequential safety injection systems 4200, 4400 having needle assemblies 4650, 4750 according to some embodiments. The needle assemblies 4650, 4750 are similar to the needle assembly 650 described herein in that they have one or more channels 4662 and proximal tips 4680 similar to the corresponding channels 662 and proximal tips 680 in the needle assembly 650 described herein. The sequential safety injection systems 4200, 4400 include a needle hub assembly 4610 coupled to a syringe body 4620 and a plunger member 4630 coupled to a proximal stopper member 4640 disposed within the syringe body 4620. A distal stopper member 4690 is also disposed within the syringe body 4620. The continuous safety injection system 4600 also includes a needle retraction system that is disposed substantially within the plunger member 4630.

[0145] FIG. 79 illustrates a sequential safety injection system 4200 according to some embodiments. The sequential safety injection system 4200 includes a needle assembly 4650 having a proximal portion 4660 and a distal portion 4654, each configured to be partially disposed within the respective proximal and distal ends of an intermediate connector 4670. The needle assembly 4650 is similar to the needle assembly 650 described herein in that it includes one or more channels and a proximal tip similar to the corresponding channel 662 and proximal tip 680 in the needle assembly 650 described herein. The intermediate connector 4670 includes an annular recess 4672 configured to interfere with a needle latch to prevent the needle assembly 4650 from being retracted proximally before the injection is completed. The intermediate connector 4670 also includes a vent opening 4676 for releasing pressure buildup during injection.

[0146] 80 illustrates various steps in a sequential injection 4300 using a dual-chamber injection system such as system 4200 described herein. In step 4310, the system is in a shipping configuration with the proximal tip of the needle assembly positioned against the distal surface of the rubber stopper of distal stopper member 4290.

[0147] In step 4320, sufficient force is applied to the plunger assembly to drive distal stopper member 4290 distally relative to the proximal tip, causing the proximal tip to pierce the rubber stopper. The distal movement of distal stopper member 4290 expels fluid from the distal chamber through a longitudinal channel in needle assembly 4650.

[0148] In step 4030, distal stop member 4290 moves distally until it reaches the distal end of syringe body 4620, thereby completing fluid transfer from the distal chamber. Fluid transfer from the distal chamber also ceases because the longitudinal channel is no longer fluidly connected to the distal chamber. Instead, movement of distal stop member 4290 places the longitudinal channel in fluid communication with the proximal chamber.

[0149] In step 4040, the proximal stop member 4240 is moved distally until it contacts the distal stop member 4290, thereby completing fluid transfer from the proximal chamber. Thus, the system 4200 is used to sequentially inject fluid, first from the distal chamber and then from the proximal chamber. After injection of fluid from both the distal and proximal chambers, the needle retraction system can apply a proximal force to the needle assembly 4650 to at least partially pull the needle assembly 4650 inside the needle hub assembly 4610 and / or syringe body 4620, thereby disposing the sharp distal tip of the needle assembly 4650 within the needle hub assembly 4610 and / or syringe body 4620 and preventing an accidental needle stick.

[0150] Figures 81 and 82 illustrate a dual-chamber safety injection system 4400 according to some embodiments. The difference between the safety injection system 4400 illustrated in Figures 81 and 82 and the sequential safety injection system 4200 illustrated in Figures 79 and 80 is that the safety injection system 4200 includes a distal slot 4676 in the intermediate connector 4670, while the safety injection system 4400 does not include a distal slot in the intermediate connector 4670. No fluid medication / injection agent is stored in the distal chamber of the dual-chamber safety injection system 4400. The sequence 4500 of steps 4510-4540 illustrated in Figure 82 is designed to minimize interactions between the stainless steel components of the needle assembly 4650 and the medication stored in the proximal chamber of the dual-chamber safety injection system 4400 during long-term storage of the pre-filled dual-chamber sequential safety injection system 4400. The drug and stainless steel components only come into contact momentarily during injection. The dual-chamber safety injection system 4400 may include only a polymer latching mechanism to further minimize interaction between the injectable and the metal. Steps 4510-4540 shown in FIG. 82 are substantially identical to steps 4310-4340 shown in FIG. 80, except that no fluid drug / injectable is stored in the distal chamber of the dual-chamber safety injection system 4400. Thus, steps 4520 and 4530 introduce only the needle assembly 4650 into the proximal chamber for injecting fluid therein (immediately after introduction of the needle assembly 4650).

[0151] Figures 83A-85 illustrate various components of a needle assembly 4550 for use with a sequential safety injection system (e.g., systems 4200, 4400 described herein), according to some embodiments. The difference between needle assembly 4550 shown in Figures 83A-85 and needle assembly 4650 shown in Figures 78A-82 is that needle assembly 4550 includes two longitudinally separated longitudinal channels 4562A, 4562B (see Figures 83B and 84) instead of a single longitudinal channel.

[0152] Figure 83A illustrates a needle assembly 4550 for use with a safety continuous injection system according to some embodiments. The needle assembly 4550 includes a proximal portion 4560 and a distal portion 4554, each configured to be partially disposed within the respective proximal and distal ends of an intermediate connector 4570. The needle assembly 4550 is similar to the needle assembly 650 described herein in that it includes one or more channels and a proximal tip similar to the corresponding channel 662 and proximal tip 680 in the needle assembly 650 described herein. The intermediate connector 4570 includes an annular recess 4572 configured to interfere with a needle latch to prevent the needle assembly 4550 from being retracted proximally before the injection is completed.

[0153] Figure 83B shows the proximal portion 4560 of the needle assembly 4550 according to some embodiments. The proximal portion 4560 has a distal longitudinal channel 4562A and a proximal longitudinal channel 4562B. The proximal portion 4560 also has a proximal tip 4580 similar to the proximal tip 680 described herein. Figure 84 shows the proximal portion 4560, showing the proximal longitudinal channel 4562B in more detail. The distal longitudinal channel 4562A is configured to provide an exit port from the distal chamber to the exterior of the syringe body 4520. The proximal longitudinal channel 4562B is configured to provide an exit port from the proximal chamber to the exterior of the syringe body 4520.

[0154] 85 illustrates various steps in a sequential injection 4800 using a dual-chamber injection system having a needle assembly 4550 described herein. In step 4810, the system is in a shipping configuration in which the proximal tip 4580 of the needle assembly 4550 is positioned against the distal surface of the rubber stopper of the distal stopper member 4690.

[0155] In step 4820, sufficient force is applied to plunger assembly 4630 to drive distal stopper member 4690 distally relative to proximal tip 4580, causing proximal tip 4580 to puncture the rubber stopper. Distal movement of distal stopper member 4690 expels fluid from the distal chamber through distal longitudinal channel 4562A in needle assembly 4550.

[0156] In step 4830, distal stop member 4690 moves distally until it reaches the distal end of syringe body 4620, thereby completing fluid transfer from the distal chamber. Fluid transfer from the distal chamber also ceases because proximal longitudinal channel 4562B is fluidly connected to the proximal chamber. At this point, fluid transfer from the proximal chamber can begin via proximal longitudinal channel 4562B.

[0157] In step 4040, proximal stop member 4840 contacts distal stop member 4690, thereby moving distally until fluid transfer from the proximal chamber through proximal longitudinal channel 4562B is complete. Thus, the system is used to sequentially inject fluid first from the distal chamber and then from the proximal chamber. After injection of fluid from both the distal and proximal chambers, the needle retraction system can apply a proximal force to needle assembly 4550 to at least partially pull needle assembly 4550 inside needle hub assembly 4610 and / or syringe body 4620, thereby disposing the sharp distal tip of needle assembly 4550 within needle hub assembly 4610 and / or syringe body 4620 and preventing accidental needle sticks.

[0158] VII. Exemplary Injection Systems with Valves 86-91 illustrate an injection system 4900 having a flow regulator 4950 according to some embodiments. FIG. 86 illustrates the injection system 4900, which is a dual-chamber injection system having the flow regulator 4950. The injection system 4900 includes a tube 4910 coupled to a syringe body 4920 and a plunger member 4930 coupled to a proximal stop member 4940 disposed within the syringe body 4920. The needle hub assembly 4910 also includes a distal stop member 4990 disposed within the syringe body 4920. The proximal and distal stop members 4940, 4990 define a proximal chamber 4942. The distal stopper member 4990 and the distal end of the syringe body 4920 define a distal chamber 4992. The proximal and distal chambers 4942, 4992 can contain liquids and / or lyophilized powders configured to be mixed prior to injection.

[0159] While using a dual-chamber injection system to mix drug components, pressure can build up in the distal chamber, which can cause some of the drug components to be unintentionally / prematurely expelled from the distal chamber in existing systems. The flow regulator 4950 in the injection system 4900 described herein minimizes and / or prevents unintentional / premature injection of drug components from the distal chamber 4992 during mixing, and unintentional migration of drug components from the distal chamber through the distal opening during shipping.

[0160] 88 shows in more detail a flow regulator (4950) installed within an injection system (4900) according to some embodiments. The flow regulator (4950) includes a housing (4952) defining a harpoon mount (4954) configured to couple (e.g., via a mechanical fit) to the distal end of the transfer tube (4910). The housing (4952) also defines a fluid port (4956) configured to provide an exit port from the distal chamber (4992) to the exterior of the syringe body (4920). The flow regulator (4950) also includes an elastic seal (4958). The housing (4952) also defines a compliant pin (4960) configured to engage the inner diameter of the distal opening (4922) of the syringe body (4920). Compliant pin (4960) is hollow to provide a selectively open flow path between fluid ports (4956), through compliant pin (4960) and out distal opening (4920).

[0161] 88 and 89 are detailed longitudinal cross-sectional views of the flow regulator 4950 installed in the injection system 4900, showing the components of the flow regulator 4950 in a closed configuration (FIG. 88) and an open configuration (FIG. 89). The resilient seal 4958 in the flow regulator 4950 is configured and / or biased to remain closed at pressures below a predetermined pressure (e.g., 5 psi) in the distal chamber 4992. Pressures above the predetermined pressure in the distal chamber 4992 force the resilient seal 4958 open.

[0162] FIG. 88 shows the flow regulator 4950 in a closed configuration. Low pressure within the distal chamber 4992 biases the elastomeric seal 4958 to close the fluid port 4956 defined by the housing 4952 (see paths A and B). Furthermore, the elastomeric seal 4958 provides a fluid-tight seal between the housing 4952 and the distal end of the syringe body 4920 (see path C). Thus, with the flow regulator 4950 located within the distal chamber 4992 and under low pressure, all possible fluid paths (A, B, and C) are closed, preventing inadvertent / premature expulsion of the drug component from the distal chamber 4992.

[0163] FIG. 89 shows the flow regulator 4950 in an open configuration. Higher pressure within the distal chamber 4992 (e.g., during injection) forces the elastomeric seal 4958 away from the fluid port 4956 defined by the housing 4952, opening paths A and B. However, the elastomeric seal 4958 continues to provide a fluid-tight seal between the housing 4952 and the distal end of the syringe body 4920 (see path C). Thus, with the flow regulator 4950 located within the distal chamber 4992 and under high pressure, two of the three flow paths (A and B) are opened, allowing the mixed medication to exit the distal chamber 4992.

[0164] 90 and 91 illustrate the end of an injection using the dual-chamber injection system 4900 described herein. When the injection of the mixed medication from the distal chamber 4992 has ended, the distal stopper member 4990 is at the distal end of the syringe body 4920. The guide 4994 of the distal stopper member 4990 and the complementary conical shape of the flow regulator 4950 minimize the space lost when adding the flow regulator 4950 to the system 4900. The flow regulator 4950 described herein minimizes and / or prevents unintended / premature injection of the medication components from the distal chamber 4992.

[0165] VIII. Exemplary Prefilled Dual Chamber Continuous Safety Injection Systems and Methods 92-94 show a longitudinal side view and two increasingly detailed longitudinal cross-sectional views of a pre-filled dual-chamber sequential safety injection system (100''') according to some embodiments. The pre-filled dual-chamber sequential safety injection system (100''') includes a conventional, readily available pre-filled syringe body (34) having conventional, readily available 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). First and second liquids (252, 254) are contained within the distal and proximal chambers (42, 40), respectively. The proximal and distal stop members (32, 36) occlude the proximal and distal ends of the proximal chamber (40). Distal stop member 36 closes the proximal end of distal chamber 42. In some embodiments, the distal surface of proximal stop member 32 and the proximal surface of distal stop member 36 are each coated with a lubricious polymer coating (e.g., PTFE or ETFE), and the first and second polymer coatings of proximal and distal stop members 32, 36, together with syringe body 34, define proximal chamber 40. The lubricious polymer coating also serves to insulate the rubber of proximal and distal stop members 32, 36 from second liquid 254. The proximal and distal stopper members (32, 36) may be oriented as shown in Figures 92-94, or the distal stopper (36) may be inverted so that the lubricious coating faces the distal chamber (42) so that the first liquid (252) in the distal chamber (42) contacts the lubricious coating for storage.

[0166] A needle hub assembly 606′ is disposed at the distal end of the distal chamber 42. The needle hub assembly 606′ includes a needle hub 608 and a needle assembly (“needle”) 76″ removably coupled thereto. In some embodiments, a needle cover member (not shown) may be placed on the needle hub assembly 606′ for storage. The pre-filled dual-chamber sequential safety injection system 100′″ facilitates sequential injection of a first liquid 252 from the distal chamber 42 and then injection of a second liquid 254 from the proximal chamber 40 upon sequential insertion of the plunger assembly 44 into the syringe body 34 to various degrees by a user. The plunger assembly 44 includes a plunger housing member 69 coupled to the proximal stopper member 32 and a plunger actuation interface 128. The first and second liquids (252, 254) located in the distal and proximal chambers (42, 40), respectively, may be any liquid or gel, such as a water-based or oil-based pharmaceutical solution.

[0167] The prefilled dual-chamber sequential safety injection system 100''' has a crimped needle configuration in which the needle hub assembly 606' is attached in an injection-ready position when presented to a user after removal of a needle cover member (not shown), which may include a resilient sealing material on its inner surface for interfacing with the needle distal member 78 and / or distal hub 608 during storage. Although the crimped needle is shown attached in place, the crimped needle can be removably coupled to the syringe body 34 (e.g., using a luer slip or luer lock interface (not shown)), with the proximal member 50 of the needle assembly 76'' extending into the distal chamber 42 through the luer interface. Alternatively, the needle may be fixedly or removably attached to a flange on the cartridge body instead of the syringe.

[0168] Needle assembly 76" includes a needle proximal member (50; see FIGS. 93 and 94) and a needle distal member (78; omitted in FIGS. 93 and 93, see FIG. 92) coupled to opposing ends (i.e., the proximal and distal ends, respectively) of needle interface member 83 (see FIGS. 94 and 94). Needle interface member 83' is a tubular member coupled to needle distal member 78, which also defines a sharpened distal end 81 having a distal opening 82. Needle assembly 76" defines a proximal longitudinal channel 85' and an intermediate opening 80'. Intermediate opening 80' is disposed adjacent the distal end of syringe body 34. Proximal longitudinal channel 85' is defined by proximal needle member 50". In some embodiments, the needle proximal member (50'') is a solid proximal end feature.

[0169] As shown in FIG. 94, the proximal member distal anchor (87) (89) of the needle proximal member (50") is disposed within the proximal end of the tubular needle interface member (83'). In some embodiments, the needle proximal member (50") is coupled to the proximal end (89) of the tubular needle interface member (83') by an interference fit between the proximal member distal anchor (87) and the proximal end (89) of the tubular needle interface member (83'). In other embodiments, the proximal end (89) of the tubular needle interface member (83') is welded to the needle proximal member (50"). In some embodiments, the weld is a "lap" weld through the needle interface member (83') to the needle proximal member (50'"). The cross section of the needle proximal member (50'') at the weld can be rectangular, crescent, or dumbbell shaped, so that the components are fastened together but allow fluid to flow across the joint through the interior of the needle joint member (83').

[0170] In some embodiments, the needle proximal member 50'' is formed by stamping a single piece of flat sheet metal or metal wire to form the various features of the needle proximal member 50''. Forming the needle proximal member 50'' by stamping reduces manufacturing complexity and cost. The outer diameters of the needle proximal member 50'' and the needle interface member 83' are substantially small, facilitating retraction of the needle assembly 76'' while minimizing snagging of the proximal and distal stop members 32, 36.

[0171] Briefly, the additional components of the pre-filled dual-chamber sequential safety injection system (100''') include a retraction system within the plunger member (44), a needle retention feature, an energy storage member (e.g., a spring), and an energy storage member latch. In the embodiment shown in FIGS. 92-97, a substantial portion of the safety needle retraction hardware resides within the plunger housing (69). The additional components also include a needle holder member (e.g., an O-ring, a needle latch, and / or a detent) within the needle hub (608). The additional components further include a funnel within the distal stop member (36) for guiding the needle proximal member (50'') into the center of the distal stop member (36).

[0172] 92-97 illustrate a method for safe sequential injection using the pre-filled dual chamber sequential safety injection system (100''') described herein, according to some embodiments.

[0173] 92-94 show the prefilled dual-chamber sequential safety injection system 100''' in a first / ready-to-use configuration. The only difference between the first / ready-to-use configuration and the shipping configuration (not shown) is that the needle cover member (not shown) present in the shipping configuration is removed in the first / ready-to-use configuration. In the first / ready-to-use configuration, the proximal longitudinal channel 85' is disposed within the distal chamber 42 along with the intermediate opening 80'. Therefore, no fluid flow path exists between the proximal chamber 40 and the distal opening 82. Therefore, any distal force applied to the plunger operating interface 128 is transferred through the plunger member 44, the proximal stopper member 32, and the incompressible second liquid 254 within the proximal chamber 40, moving the distal stopper member 36 distally relative to the syringe body 34. Distal movement of distal stopper member (36) relative to syringe body (34) increases pressure in distal chamber (42), thereby driving first liquid (252) from distal chamber (42) through intermediate opening (80'), tubular needle joint member (83'), and distal needle member (78) to exit distal opening (82) of distal needle member (78).

[0174] FIG. 95 shows the filled dual-chamber sequential safety injection system 100''' after the distal stopper member 36 has been moved distally a first distance relative to the syringe body 34. The distal chamber 42 has been partially collapsed / reduced in size, and a portion of the first liquid 252 has been expelled from the filled dual-chamber sequential safety injection system 100''' through the distal opening 82. The distal movement of the distal stopper member 36 relative to the syringe body 34 also causes the needle proximal member 50'' of the needle assembly 76'' to penetrate the distal stopper member 36. The proximal longitudinal channel 85' is still within the distal chamber 42 or is blocked by the distal stopper member 36. Therefore, there is no flow path between the proximal chamber (40) and the distal opening (82), and distal forces applied to the plunger operating interface (128) are still transmitted to the distal stop member (36) as described above.

[0175] FIG. 96 shows the filled dual-chamber sequential safety injection system (100′″) after the distal stopper member (36) has been moved distally a second distance relative to the syringe body (34) (farther than the first distance shown in FIG. 95). The distal chamber (42, see FIG. 95) has been nearly completely collapsed / evacuated, and most of the first liquid (252, see FIG. 95) has been expelled from the filled dual-chamber sequential safety injection system (100′″) through the distal opening (82). Further distal movement of the distal stopper member (36) relative to the syringe body (34) also causes the needle proximal member (50″) of the needle assembly (76″) to further penetrate the distal stopper member (36). The further penetration of the needle proximal member (50″) of the needle assembly (76″) now positions the proximal longitudinal channel (85′) within the proximal chamber (40). Thus, a flow path now exists between the proximal chamber 40 and the distal opening 82, and a distal force applied to the plunger operating interface 128 now moves the proximal stop member 32 distally relative to the syringe body 34 and the distal stop member 36, expelling the second liquid 254 from the proximal chamber 40. The opening of the flow path between the proximal chamber 40 and the distal opening 82 places the pre-filled dual-chamber sequential safety injection system 100''' in a second configuration in which the second liquid 254 can continue to be expelled from the proximal chamber 40 after the first liquid 252 has been mostly expelled from the distal chamber 42.

[0176] FIG. 96 also shows the filled dual-chamber sequential safety injection system (100'") after the proximal stopper member (32) has been moved distally a first distance relative to the syringe body (34), with the filled dual-chamber sequential safety injection system (100'") in a second configuration. The proximal chamber (40) has been partially collapsed / reduced in size, and a portion of the second liquid (254) has been expelled from the filled dual-chamber sequential safety injection system (100'") through the distal opening (82). As shown in FIG. 100, a flow path now exists between the proximal chamber (40) and the distal opening (82) because the proximal longitudinal channel (85') is within the proximal chamber (40). The flow path between the proximal chamber (40) and the distal opening (82) allows a portion of the second liquid (254) to be expelled through the proximal longitudinal channel (85′), thereby allowing the proximal stop member (32) to move distally toward the distal stop member (36). The distal stop member (36) has now substantially stopped moving, as the distal force applied to the plunger operating interface (128) is transferred to move the proximal stop member (32).

[0177] FIG. 97 shows the filled dual-chamber sequential safety injection system 100''' after the second liquid (254, see FIG. 96) has been substantially expelled from the proximal chamber (40, see FIG. 96) by continued distal movement of the proximal stopper member 32, with the filled dual-chamber sequential injection safety system 100''' in the second configuration. Further proximal relative movement of the needle proximal member 50'' of the needle assembly 76'' toward the plunger assembly 44 activates the energy storage member latch, releasing the energy storage member (spring), which pulls / retracts the needle assembly 76'' at least partially toward the plunger assembly 44, positioning the sharp distal end 81 of the needle distal member 78 of the needle assembly 76'' inside the syringe body 34. Retraction of the needle assembly (76'') places the pre-filled dual chamber sequential safety injection system (100''') in a safe configuration for disposal after injection.

[0178] Exemplary Needle Assembly 98-103B show a needle assembly (76'') for use with a pre-filled dual chamber sequential safety injection system (100''') according to some embodiments.

[0179] Figure 98 shows a needle hub assembly 606' with a rigid needle shield 612 attached, according to some embodiments. Figure 98 also shows the needle proximal member 50'' and needle interface member 83' of needle assembly 76''.

[0180] FIG. 99 illustrates a needle assembly 76″ according to some embodiments. The needle assembly 76″ includes a needle proximal member 50″ and a needle distal member 78, each configured to be partially disposed within the respective proximal and distal ends of a needle interface member 83′. The needle proximal member 50″ includes a proximal tip 84 at its proximal end configured to be captured for retraction of the needle assembly 76″ after injection. The distal end of the needle distal member 78 includes a sharpened distal tip 81 configured to pierce the target tissue for injection. The sharpened distal tip 81 defines a distal opening 82 for injection. The needle interface member 83′ includes an annular recess 72 configured to interfere with the needle latch to prevent proximal retraction of the needle assembly 76″ before the injection is completed.

[0181] FIG. 100 shows the proximal tip 84 of the needle proximal member 50'' in more detail. The proximal tip 84 includes a faceted proximal piercing tip 86 that facilitates piercing of the proximal and distal stop members 32, 36. The needle proximal member 50'' of the needle assembly 76'' also includes a reduced diameter section 88 immediately distal to the proximal tip 84. The reduced diameter section 88 increases the probability and safety of capturing the proximal tip 84 of the needle proximal member 50'' and allowing retraction of the needle assembly 76''.

[0182] FIG. 101 shows a needle proximal member (50") according to some embodiments. The needle proximal member (50") includes a proximal tip (84) at its proximal end, a proximal longitudinal channel (85') between its proximal and distal ends, and two distal longitudinal channels (90) extending from its distal end.

[0183] Figure 102 is a longitudinal cross-sectional view of the needle proximal member (50''). The needle proximal member (50'') includes two distal longitudinal channels (90) formed in generally opposing surfaces of the needle proximal member (50''). As shown in Figure 99, when the needle proximal member (50'') is partially disposed within the needle interface member (83'), the distal longitudinal channels (90) form two flow paths that extend from outside the needle assembly (76'') into the needle interface member (83'), then into the needle distal member (78) and out the sharpened distal end (81) of the needle distal member (78).

[0184] Figure 99 shows a fully assembled needle assembly (76'') by inserting the distal end of the needle proximal member (50'') into the needle interface member (83') until only the proximal end of the distal longitudinal channel (90) remains outside the needle interface member (83'). This proximal end of the distal longitudinal channel (90) forms an intermediate opening (80') in the needle assembly (76'') that fluidly couples the interior and exterior of the needle assembly (76'').

[0185] 103A and 103B are axial cross-sections of the respective distal ends of needle proximal members (50″, 50B) according to some embodiments. The distal end of the needle proximal member (50″) shown in FIG. 103A has a dumbbell-shaped cross-section similar to the needle proximal member (50″) shown in FIGS. 101 and 16. The distal end of the needle proximal member (50B) shown in FIG. 103B has a crescent-shaped cross-section. The dumbbell and crescent shapes define two and one distal longitudinal channels (90, 90B), respectively. The distal longitudinal channels (90, 90B) have rounded / circular cross-sections, which minimize fluid flow restriction through the distal longitudinal channels (90, 90B). A circular cross-section is an efficient cross-section for fluid flow due to minimized fluid interaction with the channel walls, which would otherwise impose a zero-velocity boundary condition on the flowing fluid. Therefore, by minimizing wall exposure, the amount of shear resistance experienced by the fluid during flow is minimized. Hagen-Poiseuille equation:

[0186] According to TIFF0007799324000002.tif13170, the resistance of the logic pipe is R 4 Because the cross-sectional area is inversely proportional to the radius, the fluid flow resistance of a single round channel (90B) (see Figure 103B) can be lower compared to a double channel (90) (see Figure 103A) even if the cross-sectional area is maintained.

[0187] Even with the distal longitudinal channels 90, 90B formed therein, the needle proximal members 50'', 50B have sufficient bending moment of inertia to improve stiffness and resistance to bending. In fact, the needle proximal members 50'', 50B resemble a steel I-beam and have similar stiffness characteristics. Resistance to bending is particularly important when the needle proximal members 50'', 50B pierce the stopper member 640. Minimizing bending as the needle proximal members 50'', 50B pierce the stopper member 640 improves the probability that the proximal tip 84 of the needle proximal members 50'' will be captured, allowing retraction of the needle assembly 76''.

[0188] The diameter of the needle proximal member (50'', 50B) is also relatively large (e.g., approximately 0.026 inches compared to a cold-formed proximal member having a diameter of approximately 0.020 inches). The larger diameter of the needle proximal member (50'') results in a higher overall bending moment of inertia and greater resistance to bending, which also improves the probability of capture. The needle proximal member (50'', 50B) is also very close in diameter to the needle interface member (83'), which may have a diameter of approximately 0.036 inches. The similar diameters allow the needle assembly (76'') to be more easily retracted through the stopper member during retraction compared to a needle assembly made with a cold-formed proximal member, as the needle interface member (83') is less likely to catch on the stopper member during retraction due to the relatively small diameter difference between the needle interface member (83') and the needle proximal member (50'').

[0189] IX. Exemplary Prefilled Needle-Free Dual Chamber Continuous Injection Systems and Methods 104-106 show a longitudinal cross-sectional view and two increasingly detailed longitudinal cross-sectional views of a pre-filled, needle-free, dual-chamber sequential injection system 1800 according to some embodiments. The pre-filled, needle-free, dual-chamber sequential safety injection system 1800 is similar to the pre-filled, dual-chamber sequential injection system 100 shown in FIGS. 92-94. There are two main differences between the systems 1800 and 100. First, the dual-chamber sequential injection system 1800 shown in FIGS. 104-106 does not include a "needle" extending outside the syringe body 1834, like the needle distal member 78 in the dual-chamber sequential injection system 100 shown in FIGS. 92-94. Second, the dual-chamber sequential injection system 1800 shown in FIGS. 104-106 does not include a needle retraction system, like the one in the dual-chamber sequential injection system 100 shown in FIGS. 92-94. Therefore, the dual chamber sequential injection system (1800) is not a "safe" injection system.

[0190] The pre-filled, needle-free, dual-chamber sequential injection system 1800 includes a conventional, readily available, pre-filled syringe body 1834 having conventional, readily available proximal and distal stop members 1832, 1836 disposed therein. The proximal and distal stop members 1832, 1836, together with the syringe body 1834, define proximal and distal chambers 1840, 1842. First and second liquids 1852, 1854 are contained within the distal and proximal chambers 1842, 1840, respectively. The proximal and distal stop members 1832, 1836 occlude the proximal and distal ends of the proximal chamber 1840. The distal stop member 1836 closes the proximal end of the distal chamber 1842. In some embodiments, the distal surface of the proximal stop member 1832 and the proximal surface of the distal stop member 1836 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 stop members 1832, 1836, together with the syringe body 1834, define the proximal chamber 1840. The lubricious polymer coating also serves to insulate the rubber of the proximal and distal stop members 1832, 1836 from the second liquid 1854. The proximal and distal stopper members (1832, 1836) may be oriented as shown in Figures 104-106, or the distal stopper (1836) may be inverted so that the lubricious coating faces the distal chamber (1842) so that the first liquid (1852) in the distal chamber (1842) contacts the lubricious coating for storage.

[0191] The dual-chamber sequential injection system 1800 shown in FIGS. 104-106 does not include a "needle" extending outside the syringe body 1834. Instead, the dual-chamber sequential injection system 1800 includes a fluid transfer assembly 1876. The fluid transfer assembly 1876 of the prefilled, needleless, dual-chamber sequential injection system 1800 facilitates sequential injection of a first liquid 1852 from the distal chamber 1842 and then injection of a second liquid 1854 from the proximal chamber 1840 as the plunger assembly 1844 is sequentially inserted into the syringe body 1834 by a user to varying degrees. The plunger assembly 1844 includes a plunger housing member 1869 coupled to the proximal stopper member 1832 and a plunger actuation interface 1828. The first and second liquids (1852, 1854) located in the distal and proximal chambers (1842, 1840), respectively, may be any liquid or gel, such as a water-based or oil-based pharmaceutical solution.

[0192] The fluid transfer assembly (1876) of the pre-filled needle-free dual chamber continuous injection system (1800) is configured for use with a connector (e.g., a luer lock or luer slip interface coupled to a needle or fluid transfer tube (not shown) having a sharpened end).

[0193] The fluid transfer assembly 1876 includes a fluid transfer proximal member 1850 (see FIGS. 105 and 106) coupled to the proximal end of a fluid transfer interface 1883 (see FIGS. 105 and 106). The fluid transfer proximal member 1850 is a metal spike having a proximal channel 1885 formed therein. The fluid transfer interface 1883 is configured to be coupled to the distal end of the fluid transfer proximal member 1850 and to secure the fluid transfer assembly 1876 within the distal opening of the syringe body 1834. The fluid transfer interface 1883 includes a fluid transfer distal anchor 1891, which includes an open core 1892 to provide a fit for the fluid transfer distal anchor 1891. The fluid transfer interface (1883) may be coupled to the fluid transfer proximal member (1850) by mechanical engagement. The fluid transfer interface (1883) can secure the fluid transfer assembly (1876) to the syringe body (1834) by mechanical engagement between the fluid transfer distal anchor (1891) and the distal end of the syringe body (1834). The fluid transfer interface (1883) can define one or more channels therein to provide an intermediate opening (1880) between the interior and exterior of the syringe body (1834) / distal chamber (42). The intermediate opening (1880) is disposed adjacent the distal end of the syringe body (1834). A proximal longitudinal channel (1885) is defined by the proximal fluid transfer member (1850). In some embodiments, the fluid transfer proximal member (1850) is a solid proximal end feature.

[0194] In some embodiments, the fluid transfer proximal member 1850 is formed by stamping a single piece of flat sheet metal or metal wire to form various features of the fluid transfer proximal member 1850. Forming the fluid transfer proximal member 1850 by stamping reduces manufacturing complexity and cost.

[0195] 104-109 illustrate a method for safe sequential injection using the pre-filled needle-free dual chamber sequential injection system (1800) described herein, according to some embodiments.

[0196] 104-106 show the pre-filled needleless dual chamber sequential injection system 1800 in a first / ready to use configuration. The only difference between the first / ready to use configuration and the shipping configuration (not shown) is that the syringe body cap (not shown) present in the shipping configuration has been removed in the first / ready to use configuration.

[0197] In the first / ready-to-use configuration, the proximal longitudinal channel 1885 is disposed within the distal chamber 1842 along with the intermediate opening 1880. Thus, no flow path exists between the proximal chamber 1840 and the distal opening 1882. Thus, any distal force applied to the plunger actuation interface 1828 is transferred through the plunger member 1844, the proximal stop member 1832, and the incompressible second liquid 1854 within the proximal chamber 1840, moving the distal stop member 1836 distally relative to the syringe body 1834. As the distal stopper member (1836) moves distally relative to the syringe body (1834), the pressure in the distal chamber (1842) increases, thereby driving the first liquid (1852) from the distal chamber (1842) through an intermediate opening (1880) formed between the fluid transfer joint member (1883) and the distal end of the syringe body (1834) and out the distal end of the syringe body (1834) (e.g., to a Luer connector).

[0198] 107 and 108 show the pre-filled needle-free dual-chamber serial injection system 1800 after the distal stopper member 1836 has been moved distally relative to the syringe body 1834 until the distal stopper member 1836 nearly contacts the distal end of the syringe body 1834. The distal chamber 1842 (see FIG. 105) has been nearly completely collapsed / evacuated, and most of the first liquid 1852 (see FIG. 105) has been expelled from the pre-filled needle-free dual-chamber serial injection system 1800 through the distal end of the syringe body 1836. The distal movement of the distal stopper member 1836 relative to the syringe body 1834 also causes the fluid transfer proximal member 1850 of the fluid transfer assembly 1876 to penetrate the distal stopper member 1836. The proximal longitudinal channel 1885 is now disposed within the proximal chamber 1840 by the fluid transfer proximal member 1850 of the fluid transfer assembly 1876. Thus, a fluid path now exists between the proximal chamber 1840 and the intermediate opening 1880, and a distal force applied to the plunger operating interface 1828 now moves the proximal stop member 1832 distally relative to the syringe body 1834 and the distal stop member 1836, expelling the second liquid 1854 from the proximal chamber 1840. Opening the flow path between the proximal chamber (1840) and the distal opening (1882) places the pre-filled needleless dual-chamber continuous injection system (1800) in a second configuration in which the second liquid (1854) can continue to be discharged from the proximal chamber (1840) after the first liquid (1852) has been mostly discharged from the distal chamber (1842).

[0199] Figure 109 shows the filled needle-free dual-chamber continuous injection system (1800) after the second liquid (1854, see Figure 107) has been substantially expelled from the proximal chamber (1840, see Figure 96) by distal movement of the proximal stopper member (1832), and the filled needle-free dual-chamber continuous injection system (1800) is in a second configuration.

[0200] Exemplary Fluid Transfer Assembly 110-112C show a fluid transfer assembly 1876 for use with a pre-filled, needle-free, dual-chamber sequential injection system 1800 according to some embodiments.

[0201] 110 and 111 are perspective and exploded views of a fluid transfer assembly 1876 according to some embodiments. The fluid transfer assembly 1876 includes a fluid transfer proximal member 1850 configured to be partially disposed within and coupled to a proximal end of a fluid transfer interface 1883. The fluid transfer proximal member 1850 includes a proximal piercing tip 1884 at its proximal end configured to pierce the distal stopper member 1836. The fluid transfer interface 1883 includes a fluid transfer distal anchor 1891 configured to secure the fluid transfer assembly 1876 to the distal opening of the syringe body 1834 via an interference fit.

[0202] 112A-112C are perspective, longitudinal, and axial cross-sectional views of a fluid transfer proximal member (1850) according to some embodiments. The fluid transfer proximal member (1850) includes a proximal piercing tip (1884) at its proximal end and a proximal longitudinal channel (1885) between its proximal and distal ends.

[0203] The diameter of the fluid transfer proximal member 1850 is also relatively large (e.g., about 0.026 inches to about 0.040 inches, compared to a cold-formed proximal member having a diameter of about 0.020 inches). The larger diameter of the fluid transfer proximal member 1850 results in a higher overall bending moment of inertia and greater resistance to bending, which also improves the probability of capture. Due to its relatively large diameter and solid construction, the fluid transfer proximal member 1850 has a sufficient bending moment of inertia to improve stiffness and resistance. Resistance to bending is particularly important when the fluid transfer proximal member 1850 pierces the distal stopper member 1836. Minimizing bending of the fluid transfer proximal member 1850 when piercing the distal stopper member 1836 facilitates proper functioning of the pre-filled, needle-free, dual-chamber sequential injection system 1800 during sequential injections.

[0204] Figures 113-121C illustrate a pre-filled needle-free dual-chamber sequential injection system 2700 and a fluid transfer assembly 2776 for use therewith, according to some embodiments. The pre-filled needle-free dual-chamber sequential injection system 2700 and fluid transfer assembly 2776 are similar to the pre-filled needle-free dual-chamber sequential injection system 1800 and fluid transfer assembly 1876 shown in Figures 104-112C. The difference between these two systems 2700, 1800 and assemblies 2776, 1876 is that the fluid transfer assembly 2776 shown in Figures 113-121C is molded or formed as a single piece (e.g., from a polymer or metal sheet or wire). The fluid transfer assembly 2776 still includes a fluid transfer proximal portion 2750 and a fluid transfer interface portion 2783. Molding or forming the fluid transfer assembly 2776 as a single piece simplifies manufacturing and assembly of the system. Forming the fluid transfer assembly 2776, including the fluid transfer interface 2783, from metal minimizes system failure from stress-induced tearing of the fluid transfer distal anchor portion 2791 of the fluid transfer interface 2783, which can occur in structures formed from polymers.

[0205] 113-115 show a longitudinal cross-sectional view and two progressively more detailed longitudinal cross-sectional views of a pre-filled, needle-free, dual-chamber, sequential safety injection system 2700 according to some embodiments. The pre-filled, needle-free, dual-chamber, sequential safety injection system 2700 is similar to the pre-filled, dual-chamber, sequential injection system 100 shown in FIGS. 92-94. The pre-filled, needle-free, dual-chamber, sequential injection system 2700 includes a conventional, readily available, pre-filled syringe body 2734 having conventional, readily available, proximal and distal stop members 2732, 1836 disposed therein. The proximal and distal stop members 2732, 1836, together with the syringe body 2734, define proximal and distal chambers 2740, 1842. First and second liquids (2752, 1854) are contained within distal and proximal chambers (2742, 1840), respectively. Proximal and distal stop members (2732, 1836) close the proximal and distal ends of the proximal chamber (2740). A distal stop member (2736) closes the proximal end of the distal chamber (2742). In some embodiments, the distal surface of the proximal stop member (2732) and the proximal surface of the distal stop member (2736) 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 stop members (2732, 1836), together with the syringe body (2734), define the proximal chamber (2740). The lubricious polymer coating also serves to insulate the rubber of the proximal and distal stopper members 2732, 1836 from the second liquid 2754. The proximal and distal stopper members 2732, 1836 may be oriented as shown in Figures 104-106, or the distal stopper 2736 may be inverted so that the lubricious coating faces the distal chamber 2742, such that the first liquid 2752 in the distal chamber 2742 contacts the lubricious coating for storage.

[0206] The dual-chamber sequential injection system 2700 shown in FIGS. 113-115 does not include a "needle" extending outside the syringe body 2734. Instead, the dual-chamber sequential injection system 2700 includes a fluid transfer assembly 2776 that is molded or formed as a single piece, as described above. The fluid transfer assembly 2776 of the prefilled, needleless, dual-chamber sequential injection system 2700 facilitates sequential injection of a first fluid 2752 from the distal chamber 2742 and then injection of a second fluid 2754 from the proximal chamber 2740 when the plunger assembly 2744 is sequentially inserted into the syringe body 2734 by a user to various degrees. The plunger assembly 2744 includes a plunger housing member 2769 coupled to the proximal stopper member 2732 and a plunger actuation interface 2728. The first and second liquids (2752, 1854) located in the distal and proximal chambers (2742, 1840), respectively, may be any liquid or gel, such as a water-based or oil-based pharmaceutical solution.

[0207] The fluid transfer assembly (2776) of the pre-filled needle-free dual chamber continuous injection system (2700) is configured for use with a connector (e.g., a Luer lock or Luer slip interface coupled to a needle or fluid transfer tube (not shown) having a sharpened end).

[0208] The fluid transfer assembly 2776 includes a fluid transfer proximal portion 2750 (see FIGS. 114 and 115) and a fluid transfer interface 2783 (see FIGS. 114 and 115). The fluid transfer proximal portion 2750 has a proximal channel 2785 molded or formed therein. The fluid transfer interface 2783 is configured to secure the fluid transfer assembly 2776 within a distal opening of the syringe body 2734. The fluid transfer interface 2783 includes a fluid transfer distal anchor 2791, which includes a cylindrical open core 2792 to provide a fit for the fluid transfer distal anchor 2791. The fluid transfer interface (2783) can secure the fluid transfer assembly (2776) to the syringe body (2734) by an interference fit between the fluid transfer distal anchor (2791) and the distal end of the syringe body (2734). The fluid transfer interface (2783) can define one or more channels therein to provide an intermediate opening (2780) between the interior and exterior of the syringe body (2734) / distal chamber (2742). The intermediate opening (2780) is disposed adjacent the distal end of the syringe body (2734). A proximal longitudinal channel (2785) is defined by the proximal fluid transfer portion (2750).

[0209] 113-118 illustrate a method for safe sequential injection using the pre-filled needle-free dual chamber sequential injection system (2700) described herein, according to some embodiments.

[0210] 113-115 show the pre-filled needleless dual chamber sequential injection system 2700 in a first / ready to use configuration. The only difference between the first / ready to use configuration and the shipping configuration (not shown) is that the syringe body cap (not shown) present in the shipping configuration has been removed in the first / ready to use configuration.

[0211] In the first / ready-to-use configuration, the proximal longitudinal channel 2785 is disposed within the distal chamber 2742 along with the intermediate opening 2780. Thus, there is no flow path between the proximal chamber 2740 and the distal opening 2782. Thus, any distal force applied to the plunger actuation interface 2728 is transferred through the plunger member 2744, the proximal stop member 2732, and the incompressible second liquid 2754 within the proximal chamber 2740, causing the distal stop member 2736 to move distally relative to the syringe body 2734. As the distal stopper member (2736) moves distally relative to the syringe body (2734), the pressure in the distal chamber (2742) increases, thereby driving the first liquid (2752) from the distal chamber (2742) through an intermediate opening (2780) formed between the tubular fluid transfer junction (2783) and the distal end of the syringe body (2734) and out the distal end of the syringe body (2734) (e.g., to a Luer connector).

[0212] 116 and 117 show the pre-filled needle-free dual-chamber serial injection system 2700 after the distal stopper member 2736 has been moved distally relative to the syringe body 2734 until the distal stopper member 2736 nearly contacts the distal end of the syringe body 2734. The distal chamber 2742 (see FIG. 114) has been nearly completely collapsed / evacuated, and most of the first liquid 2752 (see FIG. 114) has been expelled from the pre-filled needle-free dual-chamber serial injection system 2700 through the distal end of the syringe body 2736. The distal movement of the distal stopper member 2736 relative to the syringe body 2734 also causes the fluid transfer proximal portion 2750 of the fluid transfer assembly 2776 to penetrate the distal stopper member 2736. The proximal longitudinal channel 2785 is now disposed within the proximal chamber 2740 by the fluid transfer proximal portion 2750 of the fluid transfer assembly 2776. Thus, a fluid path now exists between the proximal chamber 2740 and the intermediate opening 2780, and a distal force applied to the plunger actuation interface 2728 now moves the proximal stop member 2732 distally relative to the syringe body 2734 and the distal stop member 2736, expelling the second liquid 2754 from the proximal chamber 2740. Opening the flow path between the proximal chamber (2740) and the distal opening (2782) places the pre-filled needleless dual-chamber continuous injection system (2700) in a second configuration in which the second liquid (2754) can continue to be discharged from the proximal chamber (2740) after the first liquid (2752) has been mostly discharged from the distal chamber (2742).

[0213] Figure 118 shows the filled needle-free dual-chamber continuous injection system (2700) after the second liquid (2754, see Figure 107) has been substantially expelled from the proximal chamber (2740, see Figure 96) by distal movement of the proximal stopper member (2732), and the filled needle-free dual-chamber continuous injection system (2700) is in a second configuration.

[0214] 119-121C show a fluid transfer assembly (2776) for use with a pre-filled, needle-free, dual-chamber sequential injection system (2700) according to some embodiments.

[0215] 119 and 120 are perspective views of a fluid transfer assembly 2776 according to some embodiments. The fluid transfer assembly 2776 includes a fluid transfer proximal portion 2750 and a fluid transfer interface 2783. The fluid transfer proximal portion 2750 includes a proximal piercing tip 2784 at its proximal end configured to pierce the distal stopper member 2736. The fluid transfer interface 2783 includes a fluid transfer distal anchor 2791 configured to secure the fluid transfer assembly 2776 to the distal opening of the syringe body 2734 via an interference fit.

[0216] 121A-121C show perspective and axial cross-sectional views of a fluid transfer assembly 2776 according to some embodiments. The fluid transfer proximal portion 2750 includes a proximal piercing tip 2784 at its proximal end and a proximal longitudinal channel 2785 between its proximal and distal ends. The fluid transfer distal anchor 2791 has a triangular cross-sectional shape to provide a flow path from the intermediate opening 2780 to the exterior of the syringe body 2734. The fluid transfer distal anchor 2791 also defines a cylindrical open core 2792 to provide a fit for the fluid transfer distal anchor 2791, allowing the fluid transfer distal anchor 2791 to deform slightly to create an interference fit with the distal opening of the syringe body 2734.

[0217] The diameter of the fluid transfer proximal portion 2750 is also relatively large (e.g., about 0.026 inches to about 0.040 inches, compared to a cold-formed proximal portion having a diameter of about 0.020 inches). The larger diameter of the fluid transfer proximal portion 2750 results in a higher overall bending moment of inertia and greater resistance to bending, which also improves the probability of capture. Due to its relatively large diameter and solid construction, the fluid transfer proximal portion 2750 has a sufficient bending moment of inertia to improve stiffness and resistance. Resistance to bending is particularly important when the fluid transfer proximal portion 2750 pierces the distal stopper member 2736. Minimizing bending of the fluid transfer proximal portion 2750 when piercing the distal stopper member 2736 facilitates proper functioning of the pre-filled, needle-free, dual-chamber sequential injection system 2700 during sequential injections.

[0218] 122-123 show perspective views of a fluid transfer assembly 2776' for use with the prefilled, needleless, dual-chamber sequential injection system 2700, according to some embodiments. The fluid transfer assembly 2776' is similar to the fluid transfer assembly 2776 shown in FIGS. 119-121C. The difference between the two fluid transfer assemblies 2776', 2776 is that the distal end of the fluid transfer proximal portion 2750' has an additional rib and draft 2792' to facilitate penetration of the distal stopper member 2736. Another difference is that the proximal piercing tip 2784' is beveled to facilitate penetration of the distal stopper member 2736.

[0219] Exemplary Fluid Transfer Distal Anchor Although the fluid transfer assembly (1876, 2776, 2776') is described herein with a fluid transfer distal anchor (1891, 2791, 2791') having a simple triangular cross section, some embodiments of the fluid transfer assembly may be used with other fluid transfer distal anchors configured to secure the fluid transfer assembly to a distal opening of a syringe body. The fluid transfer distal anchors described herein may be used with any fluid transfer assembly, including the fluid transfer assembly (1876, 2776, 2776') described herein.

[0220] 124-127B show an injection system 3900 including a fluid transfer interface 3983 according to some embodiments. The remaining parts of the fluid transfer assembly have been omitted for clarity. The fluid transfer interface 3983 includes a fluid transfer distal anchor 3991 at its distal end.

[0221] The fluid transport distal anchor 3991 defines a slot 3993 and includes a biasing member 3994 disposed within the slot 3993. The fluid transport distal anchor 3991 also defines two pegs 3995 (see FIGS. 124, 126A, and 126B) configured to maintain the biasing member 3994 within the slot 3993. The biasing member (3994) (see Figures 127A and 127B) is a spring-like metal loop configured to interfere with the inner diameter of the distal end (3995) of the syringe body (3934) (see Figure 124) to create a tight fit that holds the fluid transfer distal anchor (3991) within the distal end (3995) of the syringe body (3934) while minimizing stress on the remainder of the fluid transfer distal anchor (3991).

[0222] 128-130 show an injection system 4100 including a fluid transfer interface 4183 according to some embodiments. The remaining parts of the fluid transfer assembly have been omitted for clarity. The fluid transfer interface 4183 includes a fluid transfer distal anchor 4191 at its distal end.

[0223] The fluid transfer distal anchor 4191 takes the form of a wavy wire segment that is configured to interfere with the inner diameter of the distal end 4195 of the syringe body 4134 (see FIG. 128) to create an interference fit that holds the fluid transfer distal anchor 4191 within the distal end 4195 of the syringe body 4134. The wavy wire fluid transfer distal anchor 4191 can be press fit into the remainder of the fluid transfer interface member / portion 4183.

[0224] 131-132B show an injection system 4600 including a fluid transfer interface 4683 according to some embodiments. The remaining portions of the fluid transfer assembly have been omitted for clarity. The fluid transfer interface 4683 includes a fluid transfer distal anchor 4691 at its distal end.

[0225] The fluid transfer distal anchor 4691 takes the form of a pair of long, flexible plastic arms configured to interfere with the inner diameter of the distal end 4695 of the syringe body 4634 (see FIG. 131 ), creating an interference fit that holds the fluid transfer distal anchor 4691 within the distal end 4695 of the syringe body 4634 with very low static stress. The length of the flexible plastic arms 4691 and their relatively small interference with the inner diameter of the distal end 4695 of the syringe body 4634 allows the flexible plastic arms 4691 to operate in their elastic range, thereby ensuring that a radial spring force is applied while minimizing static stresses in the glass distal end 4695 of the syringe body 4634 and within the body of the fluid transfer distal anchor 4691 and the risk of stress tearing.

[0226] 133-135 show an injection system 4700 including a fluid transfer interface 4783 according to some embodiments. The remaining portions of the fluid transfer assembly have been omitted for clarity. The fluid transfer interface 4783 includes a fluid transfer distal anchor 4791 at its distal end.

[0227] The fluid transfer distal anchor 4791 includes a recessed portion 4793 and a rubber sleeve 4794 disposed within the recessed portion 4793 and configured to interfere with an inner diameter of the distal end 4795 of the syringe body 4734 (see FIG. 133) to create an interference fit that retains the fluid transfer distal anchor 4791 within the distal end 4795 of the syringe body 4734. The fluid transfer distal anchor 4791 also includes proximal and distal openings 4796, 4797 for bypassing the seal created by the rubber sleeve 4794 and the distal end 4795 of the syringe body 4734 (see FIG. 145).

[0228] Exemplary Fluid Transfer Assembly 136-140 illustrate a fluid transfer assembly 5076 according to some embodiments. FIG. 136 is a longitudinal cross-sectional view illustrating the fluid transfer assembly 5076 installed within a syringe body 5034 according to some embodiments. The fluid transfer assembly 5076 can be used within pre-filled, needle-free, dual-chamber, continuous injection systems according to some embodiments, such as the pre-filled, needle-free, dual-chamber, continuous injection systems 1800 and 2700 shown in FIGS. 104-109 and 113-118, respectively. Like the fluid transfer assemblies 1876 and 2776, the fluid transfer assembly 5076 is configured for use with dual-chamber, continuous injection systems that do not include a "needle" extending outside the syringe body 5034. Furthermore, the fluid transfer assembly 5076 is not configured for use with a needle retraction system, such as that found in the dual-chamber, continuous injection system 100 shown in FIGS. 92-94.

[0229] The fluid transfer assembly 5076 is configured to be used with a conventional, readily available pre-filled syringe body 5034 and conventional, readily available proximal and distal stop members (not shown) disposed therein.

[0230] The fluid transfer assembly 5076 facilitates sequential injection of a first fluid from the distal chamber and then a second fluid from the proximal chamber in the pre-filled, needle-free, dual-chamber sequential injection system as the plunger assembly is sequentially inserted by a user to various degrees into the syringe body 5034. The sequential injection system and various system components are similar to those in the pre-filled, needle-free, dual-chamber sequential injection systems 1800, 2700 shown in Figures 104-109 and 113-118, respectively.

[0231] The fluid transfer assembly 5076 is configured to be used with a connector (e.g., a luer lock or luer slip interface coupled to a needle or fluid transfer tube (not shown) having a sharpened end). The fluid transfer assembly 5076 includes a fluid transfer proximal member 5050 coupled to a proximal end of a distal fluid transfer distal anchor 5091.

[0232] 137 and 138 illustrate a fluid transfer assembly 5076 according to some embodiments. The fluid transfer assembly 5076 includes a fluid transfer proximal member 5050 that is partially disposed within the proximal end of a fluid transfer interface 5083, which in turn is partially disposed within the proximal end of a fluid transfer distal anchor 5091. The fluid transfer proximal member 5050 includes a proximal tip 5084 at its proximal end that is configured to pierce a distal stopper member during sequential injections. The fluid transfer proximal member 5050 may be a solid metal body, and the fluid transfer interface 5083 may be a metal tube. The fluid transfer proximal member 5050 may be coupled to the fluid transfer interface 5083 by welding.

[0233] The proximal end of the fluid transfer junction member 5083 is a split tube that defines two arms 5082 that both connect the fluid transfer junction member 5083 to the fluid transfer distal anchor 5091 and connect the fluid transfer assembly 5076 to the syringe body 5034.

[0234] As shown in Figures 139A-139C, the fluid transfer proximal member 5050 includes a longitudinal opening 5052 and a cross beam 5054 partially defined therein. The longitudinal opening 5052 is configured to receive two arms 5082 on either side of the cross beam 5054 during assembly, as shown in Figure 140. After the arms 5082 are inserted past the cross beam 5054, the arms 5082 are plastically deformed outward to couple the fluid transfer interface member 5083 to the fluid transfer distal anchor 5091 and prevent the two components from disassembling without introducing resting stress into the fluid transfer distal anchor 5091. The outward plastic deformation of the two arms 5082 mechanically prevents the fluid transfer interface member 5083 and the fluid transfer distal anchor 5091 from disassembling without introducing resting stress into the fluid transfer distal anchor 5091. The outwardly deformed arms 5082 interfere with the inner diameter of the distal end 5096 of the syringe body 5034 (see FIG. 136), creating an interference fit that couples the fluid transfer assembly 5076 to the distal end 5096 of the syringe body 5034 while minimizing stress on the remainder of the fluid transfer distal anchor 5091, which may be formed from a polymer.

[0235] 141 and 142 illustrate a fluid transfer assembly 5176 according to some embodiments. FIG. 141 is a longitudinal cross-sectional view illustrating the fluid transfer assembly 5176 installed within a syringe body 5134 according to some embodiments. The fluid transfer assembly 5176 is similar to the fluid transfer assembly 5076 shown in FIGS. 136-140 in that the fluid transfer assembly 5176 does not include a "needle" extending outside the syringe body 5134 and is configured for use with a dual-chamber continuous injection system configured for use with a non-retraction system. The fluid transfer assembly 5176 also includes a fluid transfer proximal member 5150 coupled to the proximal end of the distal fluid transfer distal anchor 5191. The difference between the fluid transfer assemblies 5076, 5176 shown in FIGS. 136 and 141 is that the fluid transfer proximal member 5150 extends distally to define a pair of arms 5182 instead of being connected to a distally dividing tubular member.

[0236] The fluid transfer distal anchor 5191 shown in FIG. 141 is identical to the fluid transfer distal anchor 5091 shown in FIG. 136. During assembly, the arms 5182 are inserted past the cross beam 5154 and are plastically deformed outward to couple the fluid transfer proximal member 5150 to the fluid transfer distal anchor 5191 and prevent the two components from disassembling without introducing static stresses into the fluid transfer distal anchor 5191. The outwardly deformed arms 5182 also interfere with the inner diameter of the distal end 5196 of the syringe body 5134 (see FIG. 141 ), creating an interference fit that couples the fluid transfer assembly 5176 to the distal end 5196 of the syringe body 5134 while minimizing stress on the remainder of the fluid transfer distal anchor 5191, which may be formed from plastics and polymers.

[0237] Exemplary Fluid Transfer Distal Anchor 143-145C illustrate an injection system 5200 including a fluid transfer interface / portion 5283 according to some embodiments. The remaining portions of the fluid transfer assembly have been omitted for clarity. As shown in FIGS. 143 and 144A, the fluid transfer interface / portion 5283 includes a fluid transfer distal anchor 5291 at its distal end.

[0238] The fluid transfer distal anchor 5291 defines a slot 5293, and the fluid transfer interface member / portion 5283 includes a diamond-shaped biasing member 5294 disposed within the slot 5293. The fluid transfer distal anchor 5291 also defines two bumps 5295 (see FIGS. 143 and 145A-145C), and the biasing member 5294 defines two notches 5297 configured to receive the two bumps 5295 and maintain the biasing member 5294 within the slot 5293 (see FIGS. 143 and 145B-145C). The biasing member 5294 (see Figures 144B and 145A) is a spring-like diamond-shaped metal loop configured to interfere with the inner diameter of the distal end 5296 of the syringe body 5234 (see Figure 143) to create an interference fit that holds the fluid transfer distal anchor 5291 within the distal end 5296 of the syringe body 5234 while minimizing stress on the remainder of the fluid transfer distal anchor 5291.

[0239] 144B and 145A show the diamond-shaped biasing member 5294 before insertion into the slot 5293 defined by the fluid transport distal anchor 5291. FIG. 145B shows the insertion of the diamond-shaped biasing member 5294 into the slot 5293 defined by the fluid transport distal anchor 5291. In FIG. 145B, the diamond-shaped biasing member 5294 is in a "free" state in which it can pass between two bumps 5295 defined by the fluid transport distal anchor 5291.

[0240] 145C, after the diamond-shaped biasing member 5294 is inserted into the slot 5293 defined by the fluid transfer distal anchor 5291, the diamond-shaped biasing member 5294 is squeezed / compressed to plastically deform the diamond-shaped biasing member 5294 such that pairs of notches 5297 engage pairs of bumps 5295. The engagement of the notches 5297 with the pairs of bumps 5295 mechanically couples the diamond-shaped biasing member 5294 to the fluid transfer distal anchor 5291 without introducing any resting stress to the fluid transfer distal anchor 5291. FIG. 145C shows the fully assembled fluid transfer interface member / portion 5283 as shown in FIG. 144A.

[0241] When the fluid transfer interface member / portion 5283 is inserted into the distal end 5296 of the syringe body 5234 (see FIG. 143), the diamond-shaped biasing member 5294 interferes with the inner diameter of the distal end 5296 of the syringe body 5234, creating an interference fit that holds the fluid transfer distal anchor 5291 within the distal end 5296 of the syringe body 5234.

[0242] X. Exemplary Dual-Chamber Injection System 146-148C show a dual-chamber safety injection system 5300 having a syringe body 5320 having a one-way valve 5400 disposed within its distal end, according to some embodiments. The dual-chamber safety injection system 5300 also includes a needle assembly 5350 extending through the one-way valve 5400, and proximal and distal stop members 5340, 5390 disposed within the syringe body 5320. The proximal and distal stop members 5340, 5390 define proximal and distal chambers 5360, 5370 within the syringe body 5320. The dual-chamber safety injection system 5300 also includes a plunger member 5330 including a needle retraction system. The needle retraction system is disposed substantially within the plunger member 5330.

[0243] In some embodiments, a liquid drug component is disposed in the proximal chamber 5360 and a powdered (e.g., lyophilized) drug component is disposed in the distal chamber 5370. The dual chamber safety injection system 5300 is configured such that application of a distal force to the plunger member 5330 moves the proximal stopper member 5340 distally to transfer the liquid drug component from the proximal chamber 5360 to the distal chamber 5370. The dual chamber safety injection system 5300 is then agitated (e.g., inverted) to mix the liquid drug component and the powdered drug component to form a mixed liquid drug. Continued application of a distal force to the plunger member 5330 then moves the proximal and distal stopper members 5340, 5390 distally to expel the mixed liquid drug from the distal chamber 5370 through the needle assembly 5350. After the mixed liquid drug is expelled from the distal chamber 5370, a needle retraction system within the plunger member 5330 at least partially retracts the needle assembly 5350 inside the plunger member 5330 to position the sharp distal end of the needle assembly 5350 inside the syringe body 5320.

[0244] The one-way valve 5400 is shown in detail in Figures 148A-148C. As shown in Figure 148C, the one-way valve 5400 includes a rigid (e.g., plastic) proximal portion 5410 having a circular base 5412 defining a pair of lateral openings 5414 and having a sleeve 5416 extending distally from its center. The sleeve 5416 defines a plurality of longitudinal channels 5418 on its outer surface.

[0245] The one-way valve 5400 also includes a flexible / pliable (e.g., rubber) distal portion 5420 having a central opening 5422 configured to receive a sleeve 5416. As shown in FIG. 147 , the sleeve 5416 has an inner diameter that is only slightly larger than the outer diameter of the portion of the needle assembly 5350 that passes through it. This tight tolerance prevents powdered medication ingredient from inadvertently passing through the one-way valve 5400 and entering and clogging the needle assembly 5350. The tolerances between the side openings 5414 of the one-way valve 5400 and the proximal and distal portions 5410, 5420 are also tight enough to prevent powdered medication ingredient from passing through. The flexible distal portion 5420 extends around the circular base 5412 of the rigid proximal portion 5410 to snugly fit and block the two side openings 5414, preventing any powdered medication ingredient from passing through. On the other hand, the one-way valve 5400 allows the mixed liquid medicament to pass under pressure (described below) through the side opening 5414 between the proximal and distal portions 5410, 5420 of the one-way valve 5400, along a plurality of longitudinal channels 5418 on the sleeve 5416, through the middle opening 5352 (see FIG. 147 ) into the needle assembly 5350, and out of the dual-chamber safety injection system 5300. Thus, the one-way valve 5400 prevents powdered medicament components from passing through it and entering and clogging the needle assembly 5350, while allowing liquid (e.g., the mixed liquid medicament) to pass through (e.g., under pressure exerted by the plunger member) and exit the dual-chamber safety injection system 5300 through the needle assembly 5350.

[0246] In the default assembled state, the proximal and distal portions 5410, 5420 of the one-way valve 5400 contact each other at the distal face of the circular base 5412, closing off the two side openings 5414 and preventing the powdered drug components from exiting the distal chamber 5370. However, after the liquid drug has been mixed and is ready for injection, a distal force applied to the plunger member 5330 creates pressure within the distal chamber 5370, which causes the mixed liquid drug to be expelled under pressure. Pressure in the distal chamber causes the flexible distal portion 5420 of the one-way valve 5400 to separate from the rigid proximal portion 5410 of the one-way valve 5400, thereby unblocking the two side openings 5414 and allowing the mixed liquid drug to pass under pressure through the one-way valve 5400, along multiple longitudinal channels 5418 on the sleeve 5416, through the middle opening 5352, into the needle assembly 5350 (see FIG. 147), and out of the dual chamber safety injection system 5300 for transport.

[0247] Although the pre-filled dual chamber safety injection systems shown and described herein include syringes with crimped needles, the various configurations / embodiments described herein (e.g., sequential injection, detent dual chamber, threaded plunger member, and shielded vented needle cover) can be used with cartridges, autoinjectors, and needleless injection systems having luer connectors, transfer piping.

[0248] Various exemplary embodiments of the present invention are described herein. These examples are referred to in a non-limiting sense. These examples are provided to illustrate broader applicable aspects of the present invention. Various modifications may be made to the described invention, and equivalents may be substituted, without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process operation, or step to the objective, spirit, or scope of the present invention. Moreover, those skilled in the art will recognize that each of the individual variations described and illustrated herein have distinct components and features that can be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. All such modifications are intended to be within the scope of this disclosure and the associated claims.

[0249] Any of the described devices for performing the subject diagnostic or interventional procedures may be provided in packaged combinations for use in performing such interventions. These supply "kits" may further include instructions for use and be packaged in a disinfectant disc or container such as is commonly available for such purposes.

[0250] The present invention includes methods that can be implemented using the subject devices. The methods can include the act of providing such a suitable device. Such provisioning can be performed by an end user. In other words, the act of "providing" only requires the end user to perform the actions of obtaining, accessing, approaching, locating, setting up, activating, powering on, or other operations that provide the device required for the subject method. The methods described herein can perform the recited events in any order that is logically possible, and can perform the events in the order recited.

[0251] Exemplary embodiments of the present invention, including details regarding material selection and manufacturing, have been described above. As with other details of the present invention, these may be understood with reference to the above-referenced patents and publications, as well as those 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 the relatively large interfaces of the movable coupling portions, as desired, for example, to facilitate low-friction manipulation or advancement of such objects relative to other portions of the instrument or adjacent tissue structures. The same may be true with respect to method-based aspects of the present invention with respect to additional operations as commonly or logically utilized.

[0252] Additionally, while the present invention has been described with reference to several examples that optionally incorporate various features, the present invention is not limited to what has been described or shown as being contemplated in connection with each variation of the present invention. Various modifications can be made to the invention as described, and equivalents (whether described or not included herein for purposes of brevity) can be substituted without departing from the true spirit and scope of the invention. Additionally, when a range of values ​​is given, it is understood that all intervening values ​​between the upper and lower limits of that range, and any other stated or intervening values ​​within that stated range, are encompassed within the invention.

[0253] It is also contemplated that any optional features of the described inventive variations may be set forth 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 appended claims, the singular forms "a," "an," "said," and "the" include plural references unless specifically stated otherwise. In other words, the use of articles permits "at least one" of the subject items in the above description and in the claims associated with this disclosure. It is further noted that such claims may be drafted to exclude any optional element. Accordingly, this statement is intended to serve as a predicate to the use of exclusive terminology such as "solely," "only," and the like, or the use of a "negative" limitation in connection with the recitation of claim elements.

[0254] Unless such exclusive terminology is used, the term "comprising" in any claim associated with this disclosure shall permit the inclusion of any additional elements, regardless of whether a given number of elements are recited in such claim or whether the addition of elements 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.

[0255] The scope of the present invention is not intended to be limited to the examples provided and / or details of the present subject matter, but rather is intended to be limited only by the scope of the language of the claims associated with this disclosure.

Claims

1. 1. A system for continuously injecting a liquid, comprising: a syringe body defining a syringe proximal opening and a distal needle interface at a distal end thereof; a proximal stop member and a distal stop member disposed within the syringe body, wherein a proximal chamber is formed between the proximal stop member and the distal stop member, and a distal chamber is formed between the distal stop member and the 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 be manually manipulated to insert the proximal stopper member distally relative to the syringe body; a needle hub assembly coupled to the distal needle interface of the syringe body, the needle hub assembly including a needle; the needle having a solid proximal portion and a tubular intermediate portion; the tubular intermediate portion defining a needle interior; the needle defines a distal end opening, an intermediate opening adjacent the tubular intermediate portion, and a proximal channel, the proximal channel being an elongated groove formed in an outer surface of the proximal portion and extending longitudinally of the needle; the distal end opening and the intermediate opening are fluidly coupled through an interior of the needle; by operating the plunger member to insert the proximal stopper member distally relative to the syringe body, first dispensing the first liquid from the distal chamber through the needle, and then sequentially dispensing the second liquid from the proximal chamber through the needle; the proximal stop member, the distal stop member, and the syringe body are configured such that a distal force applied to the proximal stop member is transmitted to the distal stop member through the second liquid until the proximal stop member is inserted distally relative to the needle and a proximal end of the proximal channel is positioned within the proximal chamber; The system wherein the second liquid is delivered to the distal chamber via the proximal channel and from the distal chamber to the distal end opening.

2. the needle comprising a tubular member and a solid proximal end feature coupled thereto; The system of claim 1 , wherein the needle interior, the distal end opening, and the intermediate opening are formed in the tubular member.

3. The system of claim 2 , wherein the solid proximal end feature is coupled to the tubular member by welding.

4. 4. The system of claim 3, wherein the weld is a fillet weld configured to reduce shearing of the proximal stop member when the needle penetrates the proximal stop member compared to a needle without a fillet weld.

5. The system of claim 3 , wherein the weld tapers proximally.

6. The system of claim 2 , wherein a distal end of the solid proximal end feature is disposed within the proximal end of the tubular member.

7. The system of claim 1 , wherein the length of the elongated groove provides tolerance for variations associated with the proximal stop member and / or the distal stop member.

8. 8. The system of claim 7, wherein the variations associated with the proximal stop member and / or the distal stop member are selected from the group consisting of distortion of the proximal surface of the distal stop member, the position of the proximal stop member relative to the elongated groove, and the position of the distal stop member relative to the elongated slot.

9. The system of claim 7 , wherein the length of the elongated groove is between about 1 / 32 inch and about 1 / 16 inch.

10. The system described in claim 1, wherein the length of the elongated groove minimizes backflow of the first liquid and the second liquid into the plunger member.

11. 2. The system of claim 1, wherein the first and second sizes of the distal and proximal chambers, respectively, can be changed by moving the proximal and distal stop members relative to the syringe body.

12. The plunger member a needle retaining feature disposed within the plunger; an energy storage member disposed within the plunger; an energy storage member latch member disposed within the plunger; The needle hub assembly Hub and a needle retaining member configured to couple the needle to the hub; 2. The system of claim 1, wherein the needle is at least partially retractable within the plunger when the plunger member is manipulated relative to the syringe body to convert the energy storage member latch member from a latched state to an unlatched state.

13. The system of claim 12 , wherein the needle is configured to fully pierce at least the distal stop member such that the needle is at least partially retracted within the plunger.

14. 13. The system of claim 12, wherein the energy storage member latch member is configured to transform from the latched state to the 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.

15. 13. The system of claim 12, wherein the needle retaining feature is configured to actuate a transformation of the energy storage member latch member from the latched state to the unlatched state upon manipulation of the plunger member to insert the proximal stop member into the distal end of the syringe body.

16. The system described in claim 1, wherein the length of the proximal channel is 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 and the proximal end of the proximal channel is positioned within the proximal chamber.

17. The system according to claim 1, a first injection arrangement, wherein the proximal channel is disposed within the distal chamber or the distal stopper member; and a second injection arrangement, wherein the proximal channel is disposed within the proximal chamber, thereby allowing the second liquid to be transported from the proximal chamber through the proximal channel and the interior of the needle and out the distal end opening.

18. The system described in claim 1, wherein the proximal stopper member and the distal stopper member include a first polymer coating and a second polymer coating, respectively, on their respective distal and proximal surfaces, such that the proximal chamber is defined by the syringe body and the first polymer coating and the second polymer coating.

19. The distal stopper member is a proximally tapering funnel; 10. The system of claim 1, further comprising a space disposed at the tapered proximal end of the funnel.

20. The system described in claim 1, wherein the intermediate opening is adjacent to the distal end of the syringe body.

21. The system described in claim 1, wherein the proximal channel is spaced from the interior of the needle.

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