Externally powered syringe driver and systems and methods using same - Patents.com

Abstract

A syringe driver and injection device are provided. The driver includes a housing, the housing including a port communicating with a gas chamber therein and connectable to an external air source, and a cavity for receiving a syringe containing a medicament. A drive piston in the housing includes a first end disposed adjacent the gas chamber and a second end including a plunger connectable to the syringe. A damping mechanism is provided in the housing coupled to the drive piston and including a damping piston in a damping fluid chamber such that when gas provided from an external source into the gas chamber advances the drive piston to deliver the medicament from the syringe, damping fluid in the damping fluid chamber flows through an orifice or valve from a first region to a second region, thereby limiting movement of the drive piston.

Description

[Technical field]

[0001] The present application relates to devices and methods for delivering medication into a patient's body, and more particularly to syringe drivers and injection devices for use with an external air source, and systems and methods for using such drivers.

[0002] Related Application Data This application claims the benefit of co-pending U.S. Provisional Application No. 63 / 149,204, filed February 12, 2021, the entire disclosure of which is expressly incorporated herein by reference. [Background technology]

[0003] There are many applications involving the delivery of medicines or other agents into the body of a patient. For example, injectors are often used to deliver viscous fluids, such as oil tamponade, into a patient's eye during retinal detachment surgery. Such injectors may be connected to an external air source, for example, a surgical console such as the Constellation® system manufactured by Alcon. Such consoles may have a variable air pressure source providing, for example, a pressure of about 0-80 psi, which may be controlled by a foot pedal by the surgeon during use.

[0004] For example, a syringe containing a high viscosity silicone oil tamponade, with a viscosity of approximately 1000-5000 cP, can be connected to the console's air pressure line and then inserted into the patient's eye to deliver the oil to the posterior region of the eye. The syringe is introduced into the eye through a 23 g or 25 g trocar cannula. The oil can then be delivered by advancing the syringe plunger using air pressure from the console. Due to the high viscosity of the oil, the limited pressure available from the console, and the relatively small diameter of the cannula, the flow of the oil may be restricted by the constraints imposed by the cannula.

[0005] However, when such systems are used to deliver agents with low viscosity (e.g., a viscosity of about 1 centipoise (lcP) or less), variations in syringe plunger friction, variations in downstream cannula size, and / or other variations in flow resistance and tissue resistance can result in variable resistance and / or unpredictable delivery rates when the syringe is driven by a high pressure external air source.

[0006] Therefore, improved devices and methods for delivering pharmaceutical agents into the body of a patient would be useful. Summary of the Invention

[0007] The present application is directed to devices and methods for delivering medication into a patient's body, and more particularly to syringe drivers and injection devices for use with an external air source, as well as systems and methods for using such drivers.

[0008] According to one embodiment, a syringe driver for use with an external air source is provided, the syringe driver including a housing including a port in communication with a gas chamber within the housing and connectable to an external air source, a cavity sized to receive a syringe containing a medicament, and a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connectable to a syringe contained within the cavity, the drive piston adapted to move from an initial first position to a second position upon delivery of gas from the air source into the gas chamber. a drive piston capable of moving a plunger forward to expel a drug from the syringe; and a damping fluid chamber including a damping piston disposed between a first region and a second region of the damping fluid chamber filled with a damping fluid, and one or more passages, valves or the like communicating between the first region and the second region, such that movement of the drive piston between the first position and the second position causes the damping fluid to flow from the first region to the second region through the one or more passages or valves, thereby limiting movement of the drive piston.

[0009] According to another embodiment, a syringe driver is provided, the syringe driver including a housing including a proximal end including a port in communication with a gas chamber within the housing and connectable to an external air source, and a distal end including a cavity sized to receive a syringe containing a medicament, and a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connectable to a syringe contained within the cavity, the drive piston being movable from an initial proximal position to a distal position upon delivery of gas from an air source into the gas chamber. a drive piston capable of moving a plunger forward to expel a drug from the syringe; and a damping fluid chamber including a damping piston disposed between a first region and a second region of the damping fluid chamber filled with a damping fluid, and one or more passages, valves or the like communicating between the first region and the second region, such that movement of the drive piston between a proximal position and a distal position causes the damping fluid to flow from the first region through the one or more passages or valves to the second region, thereby limiting movement of the drive piston.

[0010] According to yet another embodiment, there is provided an injection device comprising a housing including a proximal end including a port in communication with a gas chamber within the housing and connectable to an external air source, a distal end, a medicament chamber in the distal end including a medicament piston and an exit port extending from the distal end, and a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston being movable from an initial proximal position to a distal position upon supply of gas from an air source into the gas chamber. a drive piston which advances the plunger and drug piston to expel drug from the drug chamber through the outlet port; and a damping fluid chamber which includes a damping piston disposed between a first region and a second region of the damping fluid chamber filled with damping fluid, and one or more passages, valves or the like communicating between the first and second regions, such that movement of the drive piston between a proximal position and a distal position causes damping fluid to flow from the first region through the one or more passages or valves to the second region, thereby limiting movement of the drive piston.

[0011] According to yet another embodiment, there is provided an injection device for use with an external air source, the injection device comprising a housing including a proximal end including a port in communication with a gas chamber within the housing and connectable to an external air source, and a distal end, a medicament chamber in the distal end including a medicament piston and an exit port extending from the distal end, a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston being movable from an initial proximal position to a distal position upon supply of gas from an air source into the gas chamber, thereby actuating the plunger and a drive piston for advancing the drug piston to expel the drug from the drug chamber through the outlet port; a damping fluid chamber in the drive piston; a damping piston mounted on a shaft axially fixed relative to the housing and disposed in the damping fluid chamber between a first region and a second region of the damping fluid chamber filled with damping fluid; and one or more passages in the damping piston communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes damping fluid to flow through the one or more passages from the first region to the second region, thereby limiting movement of the drive piston.

[0012] According to yet another embodiment, a system for performing an injection is provided, the system comprising an injection device and a pressurized gas source connectable to a port, the injection device comprising a housing including a proximal end including a port in communication with a gas chamber within the housing and connectable to an external air source, a distal end, a medicament chamber within the distal end including a medicament piston and an exit port extending from the distal end, a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston being movable from an initial proximal position to a distal position upon supply of gas from the air source into the gas chamber, the damping fluid chamber in the drive piston; the damping piston mounted on a shaft axially fixed relative to the housing and positioned within the damping fluid chamber between a first region and a second region filled with damping fluid in the damping fluid chamber; and one or more passages in the damping piston communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes damping fluid to flow through the one or more passages from the first region to the second region, thereby limiting movement of the drive piston.

[0013] According to yet another embodiment, a method for performing an injection is provided comprising the steps of providing a syringe driver, the syringe driver comprising a housing having proximal and distal ends including ports in communication with a gas chamber within the housing, a drive piston, and a damping mechanism, the damping mechanism including a damping fluid chamber, the damping fluid chamber including a damping piston disposed within the damping fluid chamber between a first region filled with damping fluid and a second region of the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region; and inserting a syringe containing one or more medicaments into a cavity of the housing. the method includes coupling a drug piston of the syringe to a drive piston in the housing and positioning an outlet port of the syringe adjacent the distal end, connecting an external air source to the port, connecting a cannula to the outlet port, introducing the cannula into the patient's body, and activating the external air source to move the drive piston from an initial first position to a second position, thereby advancing the plunger and expelling the drug from the syringe, wherein movement of the drive piston between the first and second positions causes damping fluid to flow from the first region to the second region through one or more passages or valves, thereby limiting movement of the drive piston.

[0014] Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0015] The invention is best understood by reading the following detailed description in conjunction with the accompanying drawings, in which: It should be understood that, according to common practice, the various features and design elements of the drawings are not drawn to scale. Conversely, dimensions of the various features and design elements have been arbitrarily expanded or reduced for clarity. The drawings include the following figures: [Figure 1] Figure 1A is a perspective view of an example of a syringe driver, and Figures 1B and 1C are side views of the syringe driver of Figure 1A. [Diagram 2] 2A and 2B are cross-sectional views of the syringe driver of FIGS. 1A to 1C. [Diagram 3] Figure 3 is a cross-sectional view of the syringe driver of Figures 1A-1C illustrating operation of the driver when driven by an external air source. Figure 3A is a detailed view showing a damping piston of the syringe driver of Figure 3. [Figure 4] FIG. 4 is a schematic diagram of the syringe driver of FIGS. 1A to 1C. [Diagram 5] FIG. 5 is a schematic diagram of an alternative embodiment of a syringe driver. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Before describing the embodiments, it is to be understood that the invention is not limited to particular embodiments described, as such may, of course, vary, and the scope of the present invention will be limited only by the appended claims, and the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0017] Where a range of values ​​is provided, each intervening value between the upper and lower limits of that range, to the tenth of the unit of the lower limit, is understood to be specifically disclosed unless the context clearly dictates otherwise. Each smaller range between any stated or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the scope of the invention. The upper and lower limits of those smaller ranges may each be independently included or excluded in the range, and when either or both limits are included in the smaller range or neither are included, each range is also encompassed within the invention, subject to the limit specifically excluded in the stated range. When a stated range includes one or both limits, ranges excluding one or both of those included limits are also included in the invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, some possible exemplary methods and materials are described herein.

[0019] It should be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to a "compound" includes a plurality of such compounds, and a reference to a "polymer" includes a reference to one or more polymers and equivalents thereof known to those skilled in the art.

[0020] In this specification, a certain range is indicated by the term "about" before the numerical values. The term "about" is used in this specification to literally support the exact numerical value that it precedes, and a numerical value that is close to or approximately close to the numerical value that it precedes. When determining whether a numerical value is close to or close to a specifically stated numerical value, the unstated numerical value that is close or close may be a numerical value that is substantially equivalent to the specifically stated numerical value in the context in which it is presented.

[0021] Referring to the drawings, FIGS. 1A-1C show an example of an injection device 8 including a syringe driver 10 for use with an external air source (not shown) and a syringe or other container 80 containing one or more agents for delivery, for example, to a patient's eye or another site within the patient's body. As further described elsewhere herein, the syringe 80 can be loaded into the syringe driver 10, which can be connected to an external air source, such as a surgical console (not shown), which can be actuated to deliver the agents into the patient's body. For example, the devices, systems and methods herein can be used for the controlled delivery of therapies, such as subretinal tissue plasminogen activator, subretinal gene therapy, retinal adhesives, etc., to the posterior of a patient's eye. Such treatments may involve delivering relatively low viscosity agents, e.g., fluids having a viscosity of 1 centipoise (1 cP) or less, and / or agents having variable viscosities (e.g., in the case of retinal adhesives). Due to the low viscosity of such fluids, the overall flow rate using conventional injectors can be highly variable and / or unpredictable. The devices, systems and methods herein can provide attenuation that provides the primary resistance to the flow of the delivered agent, provide a throttling action that provides a safe upper limit to the flow rate of the agent, and / or allow delicate control of the delivery rate, as described elsewhere herein, for example. Alternatively, the injection devices herein can be used for other applications, such as to deliver silicone oil tamponade or other highly viscous materials, e.g., materials having a viscosity of about 1000-5000 cP, to the posterior region of a patient's eye during retinal detachment surgery, as described elsewhere herein.

[0022] 2A and 2B, the syringe driver 10 includes a housing 20 including a proximal end 22 and a distal end 24 defining a longitudinal axis 26, and one or more chambers or cavities therein. For example, as shown, the housing 20 may be an elongated tubular body including one or more internal partitions or other structures for supporting its internal components. The housing may be formed using conventional materials and compositions, for example, formed from plastic, metal and / or composite materials. The housing 20 may have a size, e.g., diameter and / or length, corresponding to manipulation of the injection device 8, and may optionally include texturing and / or other features (not shown) to facilitate holding and / or otherwise manipulating the injection device 8 during use.

[0023] The housing 20 can include a port 30 at the proximal end 22 connectable to an external air source (not shown) that communicates with a gas chamber 28 within the housing 20. For example, as shown, a plug 32 can be inserted into and / or otherwise attached to the proximal end 22 of the housing 20 and include the port 30 and a gas inlet passage 34 extending from the port 30 to a distal end 36 of the plug 32 to define a proximal wall of the gas chamber 28. The gas chamber 28 can include a tubular inner wall 29 attached within the housing 20, or alternatively, the wall of the gas chamber 28 can be formed directly into the housing 20 itself and / or defined by a surface of the housing itself.

[0024] The proximal end 22 of the housing 20 and the plug 32 may include cooperating connectors for securing the plug within the proximal end 22. For example, as shown, the proximal end 22 may include an annular ridge 23 and the plug 32 may include a corresponding recess 31 into which the ridge 23 is received to permanently (or optionally removably) attach the plug 32 to the housing 20. Additionally or alternatively, the plug 32 may be attached to the housing 20 using one or more of adhesive bonding, fusion, welding, or the like. Alternatively, the port 30 and gas inlet passage 32 may be integrally formed with the housing 20, for example, by molding or otherwise integrally forming an end wall at the proximal end 22 that includes the port 30.

[0025] The port 30 may include one or more connectors that allow for connection to the port 30 of a tube in communication with an external air source, e.g., a surgical console (not shown), for providing pressurized air or other compressible gas to operate the syringe driver 10, as described elsewhere herein. For example, as shown in FIGS. 1B-2B, the port 30 may include, for example, a male nipple that may be inserted into the end of a tube to thereby provide a substantially airtight interference fit. Alternatively, the port 30 and / or the tube from the air source (not shown) may be provided with a luer fitting, one or more threads and / or other connectors to provide the desired connection.

[0026] 2A and 2B, the housing 20 also includes a cavity 40 adjacent the distal end 24 that is sized to receive a syringe 80 or other container for one or more medicaments intended for delivery into the patient's body. As shown, the housing 20 can include an internal partition 42 that is proximally offset from the distal end 24 a distance sufficient to allow insertion of the syringe 80, thereby, for example, limiting insertion of the syringe 80 into the housing 20.

[0027] In the illustrated example, the syringe 80 includes a barrel 82 including a proximal end 84, a substantially closed distal end 86, and a drug chamber 88 for receiving a drug. A syringe piston 90 is slidably disposed within the proximal end 84 and is coupled to the syringe driver 10 as described elsewhere herein such that a drug is provided through an outlet 92 at the distal end 86. The distal end 86 may include an outlet port 94, including, for example, a luer fitting and / or other connector, to which a needle or other tubular cannula (not shown) may be connected for delivery of the drug. Alternatively, the needle or other cannula may be permanently attached and / or integral to the distal end 86 of the barrel 82. In another alternative, the syringe 80 may be integrated within the housing of the syringe driver, for example, by forming the drug chamber directly in the driver housing and forming or attaching an outlet port (not shown) to the distal end of the housing.

[0028] The housing 20 and / or the syringe 80 can include one or more connectors for securing the syringe 80 received within the cavity 40, e.g., allowing the syringe 80 to be removably or permanently housed within the cavity 40. For example, one or more detents, threads, or the like (not shown) can be provided on the syringe 80 and the housing 20, e.g., on the interior partition 42 and proximal end 84 of the syringe 80, and / or within the distal end 24 of the housing 20 and on the distal end 86 of the barrel 80. For example, a desired syringe 80 can be selected and simply inserted into the cavity 40, and the connectors can automatically secure the syringe 80, preparing the injection device 8 for use.

[0029] Optionally, as shown in FIGS. 1A and 1B, housing 20 includes one or more windows or other transparent surfaces, such as window 25, that allow a user to visually observe syringe 80 within cavity 40, e.g., to monitor the flow of medication from injection device 8 during delivery.

[0030] 2A and 2B, a drive piston 50 is provided within the housing 20 and includes a first or proximal end 52 disposed adjacent the gas chamber 28 and a second or distal end 54 including a plunger 56 connectable to a drug piston 90 of a syringe 80 received within the cavity 40. In the illustrated example, the interior partition 42 includes a passageway 43 through which the second end 54 of the drive piston 50 is slidably received to provide the plunger 56 within the syringe cavity 40. As illustrated, the drug piston 90 can include a recess 91 within which the plunger 56 is received when the syringe 80 is inserted into the cavity 40 such that subsequent distal movement of the drive piston 50 causes a corresponding distal movement of the drug piston 90. Additionally or alternatively, the plunger 56 and / or the drug piston 90 may include one or more connectors to further couple them to one another, e.g., one or more detents, threads, etc. (not shown) that permanently or removably connect the piston 90 and the plunger 56.

[0031] As shown in FIGS. 3 and 4, and described elsewhere herein, when gas is supplied into gas chamber 28 from an external air source, as indicated by arrow 100, drive piston 50 moves distally, e.g., to the left, as indicated by arrow 102, from an initial proximal position (e.g., as shown in FIG. 3) to a distal position (not shown), thereby advancing plunger 56 distally and dispensing medication from syringe 80, as indicated by arrow 104.

[0032] 2A and 2B, in the illustrated example, the proximal end 52 of the drive piston 50 includes an outer O-ring 53 that is slidable along the inner wall 29 of the gas chamber 28 to provide, for example, a substantially airtight seal. Thus, pressurized gas introduced into the gas chamber 28 from an external air source can generate a pressure within the gas chamber 28 that exerts a distal force on the proximal end 52 of the drive piston 50. Additionally, as the drive piston 50 advances distally, the O-ring 53 can slide along the inner wall 29 and the distal end 54 of the drive piston, thereby guiding the drive piston 50 as it advances, for example, alone or in combination with the passage 43 through the internal partition 42. Optionally, the housing 20 can include one or more additional partitions or supports, such as the internal support 44, that can further support and / or guide the drive piston 50.

[0033] Syringe driver 10 also includes a damping mechanism configured, for example, to provide an upper limit on the rate at which drive piston 50 advances from the proximal position when the air source is actuated. For example, a damping fluid chamber 60 may be provided within housing 20 including a damping piston 70 operably coupled to drive piston 50 for restricting the flow of damping fluid within damping fluid chamber 60 to provide resistance to advancement of drive piston 50.

[0034] 2A and 2B, the damping fluid chamber 60 is disposed within the drive piston 50, e.g., adjacent the proximal end 52, with the distal end 54 of the drive piston 50 extending distally from the damping fluid chamber 60. The damping piston 60 is disposed at an intermediate position within the damping fluid chamber 50, thereby separating the damping fluid chamber 60 into a first region 60a and a second region 60b. As shown in FIGS. 3 and 4, the first region 60a can initially contain the damping fluid 62, e.g., filled with an incompressible oil or other liquid having a viscosity substantially higher than the viscosity of the agent within the syringe 80, e.g., about 10-100,000 cP.

[0035] As best shown in FIG. 3A, the damping piston 70 includes one or more orifices or other passages 72 extending therethrough, for example, to provide communication between the first and second regions 60a, 60b of the damping fluid chamber 60, allowing the damping fluid 62 to flow between the regions 60a, 60b. The damping piston 70 may be axially fixed relative to the damping fluid chamber 60, for example, such that the damping piston 70 remains substantially stationary as the drive piston 50, and thus the damping fluid chamber 60, advances, for example, during delivery of a drug. It will be appreciated that the damping mechanism may alternatively be reversed, for example, the damping piston 70 may move with the drive piston 50 while the damping fluid chamber 60 remains stationary (not shown).

[0036] As a result, axial movement of one of the damping fluid chamber 60 and the damping piston relative to the other causes the damping fluid 62 to flow between the first and second regions 60a, 60b, as shown, for example, in FIG. 3A by arrows 106. For example, as shown in FIGS. 3 and 4, distal movement of the drive piston 50, for example from the proximal position shown, causes the damping fluid chamber 60 to move distally while the damping piston 70 remains stationary. This relative movement reduces the volume of the first chamber 60a, thereby creating a pressure that causes the damping fluid 62 to flow from the first region 60a to the second region 60b through the passageway(s) 72. The relatively high viscosity of the damping fluid 62 and the relatively small cross-sectional area of ​​the passageway(s) 72 restrict the flow of the damping fluid, which may limit the rate of axial movement of the drive piston 50, as further described elsewhere herein.

[0037] 2A and 2B, the damping piston 70 may be attached to a shaft 74 including a proximal or first end 76 that is fixed relative to the plug 32 on the housing 20 and a distal or second end 78 that is located distal to the damping fluid chamber 60. The damping fluid chamber 60 may include one or more seals, such as O-rings 66, to receive the shaft 74 passing therethrough and provide a fluid seal to prevent leakage of the damping fluid 62 from the damping fluid chamber 60 while allowing relative axial movement. Thus, the shaft 74, and thus the damping piston 70, remain stationary relative to the housing 20 as the drive piston 50, and thus the damping fluid chamber 60, move distally.

[0038] It will be appreciated that one or more parameters of the damping mechanism may be altered to provide a desired resistance to limit the rate of axial movement of the drive piston 50. For example, by varying one or more of a) the viscosity of the damping fluid, b) the number and / or cross-sectional orifice size of the one or more passages 72, c) the diameter or other cross-section of the damping fluid chamber 60, and d) the diameter or other cross-section of the drive piston 50 as desired, the maximum volumetric flow rate of drug delivered from the syringe 80 can be adjusted for a given air pressure, e.g., from an external air source.

[0039] Optionally, other damping configurations may be provided. For example, one or more passages may be provided in the wall of the drive piston 50 and / or other structures (not shown) within the housing 20, i.e., to provide a narrow path between the first and second regions 60a, 60b. Alternatively, instead of providing one or more orifices or passages 72 in the damping piston 70, for example, valves (not shown) communicating between the first and second regions 60a, 60b, such as pressure relief valves, spring-loaded disks, spring-loaded ball valves, etc., may be provided within the damping piston 70 and / or other components within the housing 20 to restrict the flow of damping fluid 62 between the first and second regions 60a, 60b of the damping fluid chamber 60 in a desired manner.

[0040] Additionally or alternatively, a damping mechanism can be provided in parallel or in series with the drive piston and syringe piston, as desired. For example, referring to FIG. 5, an alternative configuration is shown in which a damping mechanism is provided in series between the drive piston 150 and the syringe piston 90. As shown, the syringe driver 110 is provided to include an air chamber 128 that can be connected to an external air source (not shown), for example, via port 130, to apply a distal force to the proximal end 152 of the drive piston 150, similar to the injection device 8. The distal end 154 of the drive piston 150 is coupled to the syringe piston 90 of the syringe 80, and similar to the injection device 8, distal movement of the drive piston 150 causes a corresponding distal movement of the syringe piston 90 to deliver the medicament in the interior 88 of the syringe 80.

[0041] Unlike syringe driver 10, syringe driver 110 includes a damping fluid chamber 160 that is substantially stationary relative to the drive housing and thus drive piston 150. For example, the damping fluid chamber may be attached to the housing or formed by a surface of the housing. A damping piston 170 is provided within damping fluid chamber 160, for example, separating damping fluid chamber 160 into first and second regions 160a, 160b and directly coupled to drive piston 150. One or more orifices or pressure relief valves 172 are provided, for example, within damping piston 170, drive piston 150, and / or housing 1120, to allow damping fluid in first region 160a to flow therethrough to second region 160b.

[0042] Thus, unlike syringe driver 10, in syringe driver 110, distal movement of drive piston 150 causes corresponding distal movement of damping piston 170, which pressurizes the damping fluid in first region 160a and causes the damping fluid to flow through one or more passages 172 to second region 160b, thereby restricting the flow of medication, similar to syringe driver 10.

[0043] 3 and 4, an exemplary method of using the injection device 8, for example, for performing an injection into a patient's eye or other target location, will now be described. First, a syringe 80 containing one or more medicaments can be inserted into the cavity 40 of the housing 20 such that a medicament piston 90 of the syringe 80 is coupled to the distal end 54 of the drive piston 50. An outlet port 94 of the syringe 80 can include, for example, a luer fitting or other connector extending from the distal end 24 and can be disposed adjacent to the distal end 24 of the housing 20. A cannula, for example, a needle or other elongated tubular member sized for introduction into the target location, can be connected to the outlet port 94. For example, to deliver a medicament to the posterior region of the patient's eye, a trocar or other tubular device sized to receive a cannula connected to the outlet port 94 can be placed in the eye, for example, by conventional methods.

[0044] An external air source, e.g., a surgical console, can be connected, e.g., using conventional methods, to the inlet gas port 30 of the syringe driver 10. A cannula on the outlet port 94 can be introduced into the patient's body via a trocar, e.g., into the patient's eye, with the tip of the cannula positioned adjacent the posterior region.

[0045] Once the tip is positioned at the target location, an external air source is activated to supply pressurized gas to port 30 and gas chamber 28 to advance the drive piston from an initial proximal position toward a distal position, thereby advancing plunger 56 and drug piston 90 to deliver drug from syringe 80 into the target area. For example, the surgical console may include a foot pedal that the surgeon or other practitioner may activate to increase air pressure as needed to control the rate of advancement of drive piston 50 and the flow rate of drug. However, due to the inclusion of a damping mechanism, movement of the drive piston between the proximal and distal positions causes damping fluid to flow through one or more passages 72 in damping piston 70 from a first region 60a to a second region 60b of damping fluid chamber 60, thereby limiting the rate at which drive piston 50 advances even if the surgeon applies excessive air pressure.

[0046] Movement of the drive piston 50 is impeded by pressure in the damping fluid chamber 60 acting on the damping piston 70 resulting from resistance to flow of the damping fluid 62 through one or more passages 72 between the regions 60a, 60b. The velocity of the drive piston 50 and plunger 56, and hence the volumetric flow rate of the drug from the syringe 80, is at its maximum when the forces are balanced between the air side (from the pressure of the external air source) and the damping fluid side (from the pressure generated in the damping fluid chamber 60). Thus, the damping mechanism may provide the primary resistance to the flow of the delivered drug, i.e., may provide a throttling action that provides a safe upper limit on the flow rate of the drug due to the relatively high viscosity of the damping fluid versus other resistances associated with the injection device, the drug and / or the patient's anatomy, and / or may allow for delicate control of the delivery rate.

[0047] Additionally, in describing representative embodiments, the specification may present a method and / or process as having a particular order of steps. However, unless the method or process relies on the particular order of steps described herein, the method or process should not be limited to the particular order of steps described. As one of ordinary skill in the art would recognize, other orders of steps are possible. Thus, the particular order of steps described herein should not be construed as limiting the scope of the claims.

[0048] While the invention is susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It is to be understood, however, that the invention is not limited to the particular forms or methods disclosed, but on the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.

Claims

1. 1. A syringe driver for use with an external air source, comprising: a housing including a port in communication with a gas chamber within the housing and connectable to the external air source, and a cavity sized to receive a syringe containing a medicament; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connectable with a syringe contained within the cavity, the drive piston being movable from an initial first position to a second position upon supply of gas from an air source into the gas chamber, thereby advancing the plunger to expel a medicament from the syringe; a damping fluid chamber, the damping fluid chamber including a damping piston disposed within the damping fluid chamber between a first region and a second region filled with damping fluid of the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes the damping fluid to flow through the one or more passages or valves from the first region to the second region, thereby limiting movement of the drive piston.

2. 2. The syringe driver according to claim 1, The damping fluid chamber is disposed within the drive piston such that the damping fluid chamber moves with the drive piston as the drive piston moves from the first position to the second position, thereby allowing the damping fluid to flow between the first region and the second region.

3. 1. A syringe driver for use with an external air source, comprising: a housing including a proximal end including a port in communication with a gas chamber within the housing and connectable to the external air source, and a distal end including a cavity sized to receive a syringe containing a medicament; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connectable with a syringe contained within the cavity, the drive piston being movable from an initial first position to a second position distal to the first position upon supply of gas into the gas chamber from an air source, thereby advancing the plunger to expel a medicament from the syringe; a damping fluid chamber, the damping fluid chamber including a damping piston disposed within the damping fluid chamber between a first region and a second region filled with damping fluid of the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes the damping fluid to flow through the one or more passages or valves from the first region to the second region, thereby limiting movement of the drive piston.

4. 4. The syringe driver according to claim 3, the damping fluid chamber is disposed within the drive piston such that as the drive piston moves from the first position to the second position, the damping fluid chamber moves distally with the drive piston, thereby allowing the damping fluid to flow between the first region and the second region.

5. 5. The syringe driver according to claim 2, a damping piston fixed relative to the housing such that the damping piston remains substantially stationary as the drive piston and damping fluid chamber move, thereby allowing the damping fluid to flow between the first region and the second region.

6. The syringe driver according to claim 5, A syringe driver as claimed in any preceding claim, wherein the dampening piston is mounted on a shaft that is fixed relative to the housing.

7. 4. The syringe driver according to claim 3, A syringe driver, wherein a distal end of the drive piston extends distally from the damping fluid chamber into the cavity.

8. 4. The syringe driver according to claim 1, a damping fluid chamber that is substantially stationary relative to the housing, and a damping piston that is coupled to the drive piston such that when the drive piston moves from the first position to the second position, the damping piston moves distally to allow the damping fluid to flow between the first region and the second region.

9. 9. The syringe driver according to claim 8, 13. A syringe driver comprising: a damping piston attached to the drive piston between a first end and a second end of the drive piston.

10. 10. The syringe driver according to claim 9, The syringe driver of claim 1, wherein the damping fluid chamber is located between the gas chamber and the cavity in the housing.

11. The syringe driver according to any one of claims 1 to 7, 11. A syringe driver comprising: a first actuator for actuating a piston in a first position; a second actuator for actuating a piston in a second position; and a damping fluid having a viscosity that limits flow rate through the one or more passages or valves to limit the speed at which the drive piston moves between the first position and the second position.

12. The syringe driver according to any one of claims 1 to 7, The one or more passages or valves include one or more passages in the damping piston that communicate between the first and second regions.

13. The syringe driver according to any one of claims 1 to 7, A syringe driver, wherein the one or more passages or valves include a valve that restricts flow between the first and second regions.

14. 14. The syringe driver of claim 13, The syringe driver, wherein the one or more passages or valves are one of a pressure relief valve, a spring loaded ball valve, and a spring loaded disk.

15. 5. The syringe driver according to claim 2, The one or more passages or valves are disposed in the drive piston and provide communication between the first region and the second region.

16. 1. A syringe driver for use with an external air source, comprising: a housing including a port in communication with a gas chamber within the housing and connectable to the external air source, and a cavity sized to receive a syringe containing a medicament; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connectable with a syringe contained within the cavity, the drive piston being movable from an initial first position to a second position upon supply of gas from an air source into the gas chamber, thereby advancing the plunger to expel a medicament from the syringe; a damping fluid chamber within the drive piston; a damping piston mounted on a shaft axially fixed relative to the housing and positioned in the damping fluid chamber between a first region and a second region of the damping fluid chamber filled with damping fluid; and one or more passages in the damping piston communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby limiting movement of the drive piston.

17. The syringe driver according to any one of claims 1 to 7 or 16, The syringe driver, wherein the damping fluid has a viscosity of about 100-100,000 centipoise (10-100,000 cP).

18. 1. An injection device for use with an external air source, comprising: a housing including a proximal end in communication with a gas chamber within the housing and including a port connectable to the external air source, and a distal end; a medicament chamber in the distal end, the medicament chamber including a medicament piston and an exit port extending from the distal end; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston movable from an initial proximal position to a distal position upon supply of gas into the gas chamber from an air source, thereby advancing the plunger and medicament piston to expel medicament from the medicament chamber through the exit port; an damping fluid chamber, the damping fluid chamber including a damping piston disposed within the damping fluid chamber between a first region and a second region filled with damping fluid of the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region, wherein movement of the drive piston between the proximal position and the distal position causes the damping fluid to flow through the one or more passages or valves from the first region to the second region, thereby limiting movement of the drive piston.

19. 20. The injection device of claim 18, An injection device, characterized in that the housing has a cavity adjacent the distal end, the injection device further comprising a syringe accommodated within the cavity, the syringe including the drug chamber, the drug piston and the exit port.

20. 20. The injection device of claim 19, An injection device, wherein the housing and the syringe include one or more connectors for securing the syringe within the cavity.

21. 20. The injection device of claim 18, An injection device characterized in that the damping fluid chamber is disposed within the drive piston such that when the drive piston moves from a proximal position to a distal position, the damping fluid chamber moves distally with the drive piston such that the damping fluid flows between the first region and the second region.

22. 22. The injection device of claim 21, An injection device characterized in that the damping piston is fixed relative to the housing such that the damping piston remains substantially stationary as the drive piston and damping fluid chamber move, thereby allowing the damping fluid to flow between the first region and the second region.

23. 22. The injection device of claim 21, An injection device, wherein a distal end of the drive piston extends distally from the damping fluid chamber into the cavity.

24. 20. The injection device of claim 18, An injection device characterized in that the damping fluid chamber is substantially stationary relative to the housing, and the damping piston is coupled to the drive piston such that when the drive piston moves from a proximal position to a distal position, the damping piston moves in a distal direction to cause the damping fluid to flow between the first region and the second region.

25. 25. The injection device of claim 24, An injection device, comprising: a damping piston attached to the drive piston between a first end and a second end of the drive piston.

26. 26. The injection device of claim 25, The injection device, wherein the damping fluid chamber is located between the gas chamber and the cavity in the housing.

27. An injection device according to any one of claims 18 to 26, 11. An injection device comprising: a damping fluid having a viscosity that limits flow rate through the one or more passages to limit the speed at which the drive piston moves between the first position and the second position.

28. An injection device according to any one of claims 18 to 26, The one or more passages or valves include one or more passages in the damping piston communicating between the first and second regions.

29. An injection device according to any one of claims 18 to 26, An injection device, wherein the one or more passages or valves include a valve that restricts flow between the first and second regions.

30. 30. The injection device of claim 29, An injection device, wherein the one or more passages or valves are one of a pressure relief valve, a spring loaded ball valve, and a spring loaded disk.

31. 1. A system for performing an injection, comprising: An injection device according to any one of claims 18 to 26, and a source of pressurized gas connectable to the port.

32. 1. An injection device for use with an external air source, comprising: a housing including a proximal end in communication with a gas chamber within the housing and including a port connectable to the external air source, and a distal end; a medicament chamber in the distal end, the medicament chamber including a medicament piston and an exit port extending from the distal end; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston movable from an initial proximal position to a distal position upon supply of gas into the gas chamber from an air source, thereby advancing the plunger and medicament piston to expel medicament from the medicament chamber through the exit port; a damping fluid chamber within the drive piston; an injection device comprising: a damping piston mounted on a shaft axially fixed relative to the housing and positioned in the damping fluid chamber between a first region and a second region of the damping fluid chamber filled with damping fluid; and one or more passages in the damping piston communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby limiting movement of the drive piston.

33. 1. A system for performing an injection, comprising: An injection device; a source of pressurized gas connectable to the port; The injection device comprises: a housing including a proximal end in communication with a gas chamber within the housing and including a port connectable to an external air source, and a distal end; a medicament chamber in the distal end, the medicament chamber including a medicament piston and an exit port extending from the distal end; a drive piston having a first end disposed adjacent the gas chamber and a second end including a plunger connected to the medicament piston, the drive piston movable from an initial proximal position to a distal position upon supply of gas into the gas chamber from an air source, thereby advancing the plunger and medicament piston to expel medicament from the medicament chamber through the exit port; a damping fluid chamber within the drive piston; a damping piston mounted on a shaft axially fixed relative to the housing and disposed in the damping fluid chamber between a first region and a second region of the damping fluid chamber filled with damping fluid; and one or more passages in the damping piston communicating between the first region and the second region, wherein movement of the drive piston between the first position and the second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby limiting movement of the drive piston.

Images