External powered syringe driver and system and method using the same

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] This application relates to devices and methods for delivering a drug into a patient's body, and more particularly, to a syringe driver and an infusion device for use with an external air source, and to systems and methods for using such a driver.

[0002] Related application data This application claims the benefit of U.S. Provisional Application No. 63 / 149,204, filed on Feb. 12, 2021, the entire disclosure of which is hereby incorporated by reference in its entirety.

Background Art

[0003] There are numerous applications involving the delivery of pharmaceuticals or other drugs into a patient's body. For example, syringes are often used to deliver viscous fluids, such as oil tamponades, into a patient's eye during retinal detachment surgery. Such syringes can be connected to an external air source, such as a surgical console like the Alcon Constellation® system. Such consoles have a variable pneumatic source that provides a pressure, for example, of about 0 - 80 psi, which can be controlled by a surgeon using a foot pedal during use.

[0004] For example, after connecting a syringe containing a highly viscous silicone oil tamponade having a viscosity of about 1000 - 5000 cP to the pneumatic line of the console, it can be inserted into the patient's eye to deliver the oil to the posterior region of the eyeball. The syringe is introduced into the eye through a 23g or 25g trocar cannula. Thereafter, the oil can be delivered by advancing the syringe plunger using the pneumatic pressure from the console. Due to the high viscosity of the oil, the limited pressure obtained from the console, and the relatively small diameter of the cannula, the flow of the oil can be restricted by the constraints of the cannula.

[0005] However, when such systems are used to deliver low-viscosity drugs (e.g., 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 cause the resistance to fluctuate and / or the delivery rate to become unpredictable when the syringe is driven by a high-pressure external air source.

[0006] Therefore, improved devices and methods for delivering drugs into the patient's body would be useful. [Overview of the Initiative]

[0007] This application relates to devices and methods for delivering drugs into a patient's body, and more particularly to syringe drivers and infusion 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 comprising: a housing including a port communicating with a gas chamber within the housing and connectable to an external air source, and a cavity sized to accommodate a syringe containing a drug; and a drive piston having a first end positioned adjacent to the gas chamber and a second end including a plunger connectable to the syringe housed in the cavity, which moves from an initial first position to a second position when gas is supplied from the air source into the gas chamber. The device comprises a drive piston which is capable of advancing a plunger and dispensing a drug from a syringe, and a damping fluid chamber which includes a damping piston positioned between a first region and a second region filled with damping fluid in the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region, wherein the movement of the drive piston between a first position and a second position causes the damping fluid to flow from the first region to the second region through one or more passages or valves, thereby restricting the movement of the drive piston.

[0009] In another embodiment, a syringe driver is provided, the syringe driver comprising a housing having a proximal end including a port communicating with a gas chamber within the housing and connectable to an external air source, and a distal end including a cavity sized to accommodate a syringe containing a drug, and a drive piston having a first end positioned adjacent to the gas chamber and a second end including a plunger connectable to the syringe housed in the cavity, the drive piston being movable from an initial proximal position to a distal position when gas is supplied to the gas chamber from the air source. The device comprises a drive piston capable of advancing a plunger to deliver a drug from a syringe, and a damping fluid chamber comprising a damping piston positioned between a first region and a second region filled with damping fluid in the damping fluid chamber, and one or more passages or valves communicating between the first region and the second region, wherein the movement of the drive piston between a proximal position and a distal position causes the damping fluid to flow from the first region to the second region through one or more passages or valves, thereby restricting the movement of the drive piston.

[0010] In yet another embodiment, an injection device is provided, the injection device comprising a housing having a proximal end and a distal end, which communicates with a gas chamber within the housing and has a port that can be connected to an external air source; a drug chamber within the distal end, which includes a drug piston and an outlet port extending from the distal end; and a drive piston having a first end positioned adjacent to the gas chamber and a second end including a plunger connected to the drug piston, which is movable from an initial proximal position to a distal position when gas is supplied into the gas chamber from the air source. The device comprises a drive piston that advances a plunger and a drug piston to deliver a drug from the drug chamber through an outlet port, and a damping fluid chamber which includes a damping piston positioned 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 the movement of the drive piston between a proximal position and a distal position causes the damping fluid to flow from the first region to the second region through one or more passages or valves, thereby restricting the movement of the drive piston.

[0011] In yet another embodiment, an injection device is provided for use with an external air source, the injection device comprising a housing having a proximal end and a distal end, the housing having a port communicating with a gas chamber within the housing and connectable to an external air source; a drug chamber within the distal end, the drug chamber having a drug piston and an outlet port extending from the distal end; and a drive piston having a first end positioned adjacent to the gas chamber and a second end having a plunger connected to the drug piston, the drive piston being movable from an initial proximal position to a distal position when gas is supplied into the gas chamber from the air source, thereby moving the plunger and The device comprises a drive piston that advances a drug piston to deliver a drug from the drug chamber through an outlet port, a damping fluid chamber within the drive piston, a damping piston mounted on a shaft fixed axially 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 for the damping piston communicating between the first region and the second region, wherein the movement of the drive piston between a first position and a second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby restricting the movement of the drive piston.

[0012] In yet another embodiment, a system for injection is provided, comprising an injection device and a pressurized gas supply source connectable to a port, wherein the injection device comprises a housing having a proximal end and a distal end, the housing having a port communicating with a gas chamber within the housing and connectable to an external air source, the drug chamber within the distal end having a drug piston and an outlet port extending from the distal end, and a drive piston having a first end positioned adjacent to the gas chamber and a second end having a plunger connected to the drug piston, the drive piston being movable from an initial proximal position to a distal position when gas is supplied into the gas chamber from the air source, The device comprises a drive piston that advances a plunger and a drug piston to deliver a drug from the drug chamber through an outlet port, a damping fluid chamber within the drive piston, a damping piston mounted on a shaft fixed axially 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 for the damping piston communicating between the first region and the second region, wherein the movement of the drive piston between a first position and a second position causes the damping fluid to flow from the first region to the second region through the one or more passages, thereby restricting the movement of the drive piston.

[0013] In yet another embodiment, a method for performing an injection is provided, the method comprising the steps of providing a syringe driver, the syringe driver comprising a housing having a proximal end and a distal end including a port communicating 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 comprising 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, and inserting a syringe containing one or more drugs into the cavity of the housing The procedure includes the steps of coupling the drug piston of the syringe to a drive piston in the housing and positioning the outlet port of the syringe adjacent to 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 dispensing the drug from the syringe, wherein the 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 restricting the movement of the drive piston.

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

[0015] This invention is best understood by reading the following detailed description in conjunction with the attached drawings. Please note that, in accordance with common practice, the various features and design elements in the drawings are not to a fixed scale. Conversely, the dimensions of the various features and design elements have been arbitrarily enlarged 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. Figures 1B and 1C are side views of the syringe driver shown in Figure 1A. [Figure 2] Figures 2A and 2B are cross-sectional views of the syringe driver shown in Figures 1A to 1C. [Figure 3] Figure 3 is a cross-sectional view of the syringe driver shown in Figures 1A to 1C, illustrating its operation when the driver is driven by an external air source. Figure 3A is a detailed view of the damping piston of the syringe driver shown in Figure 3. [Figure 4] Figure 4 is a schematic diagram of the syringe driver shown in Figures 1A to 1C. [Figure 5] Figure 5 is a schematic diagram of an alternative to the syringe driver. [Modes for carrying out the invention]

[0016] Before describing the examples, it should be understood that the present invention is not limited to the specific examples described and can, of course, be modified. Furthermore, since the scope of the present invention is limited only by the appended claims, it should be understood that the terms used herein are intended solely to describe specific examples and are not intended to limit them.

[0017] Where a range of values ​​is provided, unless the context explicitly indicates otherwise, it should be understood that each intermediate value between the upper and lower limits of that range, up to one-tenth of the unit of the lower limit, is also specifically disclosed. Each small range between any stated value or intermediate value within the stated range and any other stated value or intermediate value within that stated range is included in the scope of the invention. The upper and lower limits of those small ranges may be independently included in or excluded from that range, and if either or both limits are included in a small range, or neither is included, each range is also included in the invention, subject to the limits that are specifically excluded within the stated range. If a stated range includes one or both limits, the range excluding one or both of those included limits is also included in the invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Any methods and materials similar to or equivalent to those described herein may be used in carrying out or testing the present invention, but several possible exemplary methods and materials are described herein.

[0019] In this specification and the appended claims, the singular forms "a," "an," and "the" refer to multiple subjects unless the context clearly indicates otherwise. For example, a reference to "compound" includes multiple such compounds, and a reference to "polymer" includes one or more polymers and their equivalents known to those skilled in the art.

[0020] In this specification, certain ranges are indicated by the term “approximately” preceding a number. The term “approximately” is used herein to literally support the exact number preceding the term, as well as numbers that are close to or nearly close to the number preceding the term. When determining whether a number is close to or approximates a specifically stated number, an unstated number that is close or approximates may be substantially equivalent to the specifically stated number in the context in which it is presented.

[0021] Referring to the drawings, Figures 1A–1C show an example of an infusion device 8 comprising a syringe driver 10 for use with an external air source (not shown) and a syringe or other container 80 containing one or more drugs for delivery to, for example, the patient's eye or another part of the patient's body. As will be further described elsewhere in this specification, 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 activated to deliver drugs into the patient's body. For example, the devices, systems and methods described herein can be used to control and deliver therapies such as subretinal tissue plasminogen activator, subretinal gene therapy, and retinal adhesives to the posterior part of the patient's eye. Such procedures may involve the delivery of relatively low-viscosity drugs, e.g., fluids with a viscosity of less than 1 centipoise (1 cP), and / or drugs with variable viscosity (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 described herein can provide damping that gives primary resistance to the flow of the drug being delivered, resulting in a throttling effect that provides a safe upper limit on the drug flow rate, as described elsewhere herein, and / or allows for fine control of the delivery flow rate. Alternatively, the infusion devices described herein can be used for other applications, for example, during retinal detachment surgery, to deliver silicone oil tamponade or other highly viscous materials, such as materials having a viscosity of about 1000–5000 cP, to the posterior region of the patient's eye, as described elsewhere herein.

[0022] Referring further to FIGS. 2A and 2B, the syringe driver 10 includes a housing 20 having a proximal end 22 and a distal end 24 that define 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 that includes one or more internal partitions or other structures for supporting its internal components. The housing can be formed using conventional materials and stock, for example, it can be formed from plastic, metal, and / or composite materials. The housing 20 can have a size corresponding to the operation of the injection device 8, for example, a diameter and / or length, and optionally can include texturing and / or other features (not shown) for facilitating holding and / or otherwise operating the injection device 8 during use.

[0023] The housing 20 can include a port 30 at the proximal end 22 that can be connected 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 is inserted and / or otherwise attached to the proximal end 22 of the housing 20 and includes the port 30 and a gas inlet passage 34 that extends from the port 30 to the distal end 36 of the plug 32 and can define the proximal wall of the gas chamber 28. The gas chamber 28 can include a tubular inner wall 29 attached within the housing 20, alternatively, the walls of the gas chamber 28 may be directly formed on the housing 20 itself and / or may be defined by the surface of the housing itself.

[0024] The proximal end 22 of the housing 20 and the plug 32 can include cooperating connectors for fixing the plug within the proximal end 22. For example, as shown, the proximal end 22 can include an annular ridge 23, and the plug 32 can 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, one or more of adhesion by an adhesive, fusing, welding, etc. can be used to attach the plug 32 to the housing 20. Alternatively, the port 30 and the gas inlet passage 32 can be integrally formed with the housing 20, for example, by molding or otherwise integrally forming an end wall that includes the port 30 at the proximal end 22.

[0025] The port 30 can include one or more connectors that enable connection of a tube, for example, to an external air source such as a surgical console (not shown), to supply 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 can include a male nipple that can 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) can be provided with a luer fitting, one or more threads, and / or other connectors to provide the desired connection.

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

[0027] In the illustrated example, the syringe 80 includes a barrel 82 with a proximal end 84, a substantially closed distal end 86, and a drug chamber 88 for containing the drug. The syringe piston 90 is slidably positioned within the proximal end 84 and coupled to the syringe driver 10, as described elsewhere herein, so that the drug is supplied from an outlet 92 at the distal end 86. The distal end 86 may include an outlet port 94, for example, a Luer fitting and / or other connector, to which a needle or other tubular cannula (not shown) can be connected for drug delivery. Alternatively, a needle or other cannula can be permanently attached to and / or integrated with the distal end 86 of the barrel 82. In another alternative example, the syringe 80 may be integrated into the housing of the syringe driver by forming the drug chamber directly into the driver housing and forming or mounting an outlet port (not shown) at the distal end of the housing.

[0028] The housing 20 and / or syringe 80 may include one or more connectors for securing the syringe 80 received in the cavity 40, thereby allowing the syringe 80 to be removably or permanently housed in the cavity 40, for example. For example, one or more retainers, threads, etc. (not shown) may be provided on the syringe 80 and housing 20, for example, on the internal partition 42 and proximal end 84 of the syringe 80, and / or inside the distal end 24 of the housing 20 and on the distal end 86 of the barrel 80. For example, by simply selecting the desired syringe 80 and inserting it into the cavity 40, the connectors can automatically secure the syringe 80 and prepare the injection device 8 for use.

[0029] Optionally, as shown in Figures 1A and 1B, the housing 20 may include one or more windows or other transparent surfaces, such as window 25, which allows the user to visually observe the syringe 80 in the cavity 40 and, for example, monitor the flow of drug from the infusion device 8 during delivery.

[0030] Continuing to refer to Figures 2A and 2B, the drive piston 50 is provided within the housing 20 and includes a first end or proximal end 52 positioned adjacent to the gas chamber 28 and a second end or distal end 54 which includes a plunger 56 connectable to the drug piston 90 of the syringe 80 received in the cavity 40. In the illustrated example, the internal partition 42 includes a passage 43 through which the second end 54 of the drive piston 50 is slidably received, providing the plunger 56 into the syringe cavity 40. As shown, the drug piston 90 may include a recess 91, through which the plunger 56 is received when the syringe 80 is inserted into the cavity 40, so that subsequent distal movement of the drive piston 50 causes distal movement corresponding to the drug piston 90. Additionally or alternatively, the plunger 56 and / or the drug piston 90 may include one or more connectors for further coupling them to each other, such as one or more retaining clips, threads, etc. (not shown) for permanently or removablely connecting the piston 90 and the plunger 56.

[0031] As shown in Figures 3 and 4 and as described elsewhere in this specification, when gas is supplied into the gas chamber 28 from an external air source, as indicated by arrow 100, the drive piston 50 moves distally from an initial proximal position (shown, for example, in Figure 3) to a distal position (not shown), for example to the left, as indicated by arrow 102, thereby causing the plunger 56 to advance distally and supply the drug from the syringe 80, as indicated by arrow 104.

[0032] Returning to Figures 2A and 2B, in the illustrated example, the proximal end 52 of the drive piston 50 includes an outer O-ring 53 that slides along the inner wall 29 of the gas chamber 28, for example, to provide a substantially airtight seal. Thus, pressurized gas introduced into the gas chamber 28 from an external air source can generate pressure within the gas chamber 28 that applies a distal force to the proximal end 52 of the drive piston 50. Furthermore, 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, on its own or in combination with a passage 43 that penetrates the internal partition 42. Optionally, the housing 20 may include one or more additional partitions or supports, such as an internal support 44, that can further support and / or guide the drive piston 50.

[0033] The syringe driver 10 also includes a damping mechanism configured to provide an upper limit on the speed at which the drive piston 50 moves forward from its proximal position when the air source is activated. For example, a damping fluid chamber 60 may be provided within the housing 20, and within it, a damping piston 70 operably coupled to the drive piston 50 to restrict the flow of damping fluid in the damping fluid chamber 60 and provide resistance to the forward movement of the drive piston 50.

[0034] For example, as shown in Figures 2A and 2B, the damping fluid chamber 60 is located within the drive piston 50, for example, adjacent to 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 positioned in the middle of 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 Figures 3 and 4, the first region 60a may initially contain the damping fluid 62, which is filled with an incompressible oil or other liquid having a viscosity substantially higher than the viscosity of the drug in the syringe 80, for example, a viscosity of about 10 to 100,000 centipoise (10 to 100,000 cP).

[0035] As best illustrated in Figure 3A, the damping piston 70 includes one or more orifices or other passages 72 extending through it, thereby, for example, connecting 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 can be fixed axially to the damping fluid chamber 60, for example, so that the damping piston 70 remains substantially stationary as the drive piston 50, and consequently the damping fluid chamber 60, advance, for example, during drug delivery. Alternatively, the damping mechanism may be reversed, for example, so that the damping piston 70 moves with the drive piston 50 while the damping fluid chamber 60 remains stationary (not shown).

[0036] As a result, the 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 and 60b, for example, as indicated by arrow 106 in Figure 3A. For example, as shown in Figures 3 and 4, distal movement of the drive piston 50, for example, distal movement from the illustrated proximal position, 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 generating pressure that causes the damping fluid 62 to flow from the first region 60a to the second region 60b through one or more passages 72. Because the viscosity of the damping fluid 62 is relatively high and the cross-sectional area of ​​one or more passages 72 is relatively small, the flow of the damping fluid is restricted, and thereby the axial speed of the drive piston 50 may be restricted, as will be further described elsewhere in this specification.

[0037] As shown in Figures 2A and 2B, the damping piston 70 can be mounted on a shaft 74, which includes a proximal end or first end 76 fixed relative to a plug 32 on the housing 20, and a distal end or second end 78 located distal to the damping fluid chamber 60. The damping fluid chamber 60 may include one or more seals, such as O-rings 66, which are configured to receive the shaft 74 passing through the damping fluid chamber 60, allowing relative axial movement, while providing a fluid seal to prevent damping fluid 62 from leaking out of the damping fluid chamber 60. Thus, as the drive piston 50, and consequently the damping fluid chamber 60, moves distally, the shaft 74, and consequently the damping piston 70, remain stationary relative to the housing 20.

[0038] It will be understood that one or more parameters of the damping mechanism can be modified to provide a desired resistance to limit the axial movement speed of the drive piston 50. For example, by modifying one or more of the following as needed: a) the viscosity of the damping fluid, b) the number of one or more passages 72 and / or the size of the cross-sectional orifices, 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, the maximum volumetric flow rate of the drug supplied from the syringe 80 can be adjusted, for example, with respect to a given air pressure from an external air source.

[0039] Optionally, other damping configurations can be provided. For example, one or more passages can 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, a valve (not shown) connecting the first and second regions 60a, 60b, such as a pressure relief valve, a spring-loaded disc, or a spring-loaded ball valve, can 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 may be provided in parallel or in series with the drive piston and syringe piston, as needed. Referring to Figure 5, for example, an alternative configuration is shown in which the damping mechanism is provided in series between the drive piston 150 and the syringe piston 90. As shown in the figure, the syringe driver 110, like the infusion device 8, is provided to include an air chamber 128 which may be connected to an external air source (not shown), for example, via a port 130, to apply a distal force to the proximal end 152 of the drive piston 150. The distal end 154 of the drive piston 150 is coupled to the syringe piston 90 of the syringe 80, and, like the infusion device 8, distal movement of the drive piston 150 results in corresponding distal movement of the syringe piston 90, thereby delivering the drug inside the syringe 88.

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

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

[0043] Next, with reference to Figures 3 and 4, exemplary methods of using the injection device 8, for example, for performing injection into a patient's eye or other target location, will be described. First, a syringe 80 containing one or more drugs can be inserted into the cavity 40 of the housing 20 such that the drug piston 90 of the syringe 80 is coupled to the distal end 54 of the drive piston 50. The exit port 94 of the syringe 80 may include, for example, a Luer fitting or other connector extending from the distal end 24 and may be located adjacent to the distal end 24 of the housing 20. A cannula may be, for example, a needle or other elongated tubular member of a size for introduction into a target location and may be connected to the exit port 94. For example, to deliver a drug to the posterior region of a patient's eye, a trocar or other tubular device of a size to accept a cannula connected to the exit port 94 may be placed inside the eye, for example, by conventional methods.

[0044] An external air source, such as a surgical console, can be connected to the inlet gas port 30 of the syringe driver 10, for example, using a conventional method. The cannula on the outlet port 94 can be introduced into the patient's body via a trocar, for example, into the patient's eyeball, with the tip of the cannula positioned adjacent to 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, thereby advancing the drive piston from its initial proximal position to its distal position, which in turn advances the plunger 56 and drug piston 90 to deliver the drug from the syringe 80 into the target area. For example, the surgical console may include a foot pedal that can be activated by the surgeon or other operator to increase the air pressure as needed to control the forward speed of the drive piston 50 and the flow rate of the drug. However, because a damping mechanism is provided, the movement of the drive piston between the proximal and distal positions causes the damping fluid to flow through one or more passages 72 of the damping piston 70 from a first region 60a to a second region 60b of the damping fluid chamber 60, thereby limiting the speed at which the drive piston 50 advances, even if the surgeon applies excessive air pressure.

[0046] The movement of the drive piston 50 is hindered by the pressure within the damping fluid chamber 60 acting on the damping piston 70, resulting from the resistance of the flow of damping fluid 62 through one or more passages 72 between regions 60a and 60b. When the force balances between the air side (from the pressure of the external air source) and the damping fluid side (from the pressure generated within the damping fluid chamber 60), the speed of the drive piston 50 and plunger 56, and thus the volumetric flow rate of the drug from the syringe 80, reaches its maximum. For this reason, the damping mechanism can provide the primary resistance to the flow of the drug being delivered, i.e., because the viscosity of the damping fluid is relatively high compared to other resistances related to the infusion device, the drug, and / or the patient's anatomical structure, it can result in a throttling effect that provides a safe upper limit on the drug flow rate and / or allows for fine control of the delivery flow rate.

[0047] Furthermore, when describing representative embodiments, this specification may present methods and / or processes as steps in a specific order. However, unless the method or process depends on a specific order of steps described herein, the method or process should not be limited to a specific order of steps described herein. As those skilled in the art will understand, other orders of steps are also possible. Therefore, a specific order of steps described herein should not be construed as limiting the scope of the claims.

[0048] While the present invention is capable of various modifications and alternative forms, specific examples are shown in the drawings and described in detail herein. However, it should be understood that the present invention is not limited to any particular form or method disclosed, but rather encompasses all modifications, equivalents, and alternatives that fall within the scope of the appended claims.

Claims

1. A syringe driver for use with an external air source, A housing comprising a port communicating with a gas chamber within the housing and connectable to an external air source, and a cavity sized to accommodate a syringe containing a drug, A drive piston comprising an elongated member having a first end slidably disposed within the gas chamber and a second end including a plunger connectable to a syringe housed within the cavity, wherein when gas is supplied from an air source into the gas chamber, generating pressure within the gas chamber, and this pressure applies a distal force that advances the first end within the gas chamber, the drive piston is movable from an initial first position to a second position, thereby advancing the second end and the plunger of the drive piston to dispense a drug from the syringe. A damping fluid chamber comprising: a damping piston disposed within the damping fluid chamber between a first region filled with damping fluid in the damping fluid chamber 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, wherein the movement of the drive piston between the first and second positions causes the damping fluid to flow from the first region to the second region through the one or more passages or valves, thereby restricting the movement of the drive piston; A syringe driver characterized in that the damping fluid chamber is positioned inside the drive piston in close proximity to the first end, and when the drive piston moves from a first position to a second position, the damping fluid chamber moves together with the drive piston, causing the damping fluid to flow between the first region and the second region.

2. A syringe driver for use with an external air source, A housing comprising a proximal end including a port that communicates with a gas chamber within the housing and can be connected to an external air source, and a distal end including a cavity sized to accommodate a syringe containing a drug, A drive piston having a first end slidably disposed within the gas chamber and a second end including a plunger connectable to a syringe housed within the cavity, wherein when gas is supplied to the gas chamber from an air source, generating pressure within the gas chamber, and this pressure applies a distal force that advances the first end within the gas chamber, the drive piston is movable from an initial first position to a second position distal to the first position, thereby advancing the second end and the plunger of the drive piston to dispense a drug from the syringe. A damping fluid chamber comprising: a damping piston disposed within the damping fluid chamber between a first region filled with damping fluid in the damping fluid chamber 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, wherein the movement of the drive piston between the first and second positions causes the damping fluid to flow from the first region to the second region through the one or more passages or valves, thereby restricting the movement of the drive piston; A syringe driver characterized in that the damping fluid chamber is positioned inside the drive piston in close proximity to the first end, and when the drive piston moves from a first position to a second position, the damping fluid chamber moves together with the drive piston, causing the damping fluid to flow between the first region and the second region.

3. In the syringe driver according to claim 1 or 2, A syringe driver characterized in that the damping piston is fixed to the housing inside the drive piston and includes one or more passages or valves, and the damping piston remains substantially stationary when the drive piston and damping fluid chamber move, so that the damping fluid flows through the drive piston between the first region and the second region.

4. In the syringe driver described in claim 3, A syringe driver characterized in that the damping piston is attached to a shaft fixed to the housing.

5. In the syringe driver according to claim 2, A syringe driver characterized in that the second end of the drive piston extends distally from the damping fluid chamber into the cavity.

6. In the syringe driver according to any one of claims 1 to 5, A syringe driver characterized in that the damping fluid has a viscosity that limits the flow rate through the one or more passages or valves in order to limit the speed at which the drive piston moves between the first position and the second position.

7. In the syringe driver according to any one of claims 1 to 5, A syringe driver characterized in that the one or more passages or valves include one or more passages in the damping piston that connect the first and second regions.

8. In the syringe driver according to any one of claims 1 to 5, A syringe driver characterized in that the one or more passages or valves include a valve that restricts the flow between the first and second regions.

9. In the syringe driver according to claim 8, A syringe driver characterized in that the one or more passages or valves have one of the following: a pressure relief valve, a spring-loaded ball valve, and a spring-loaded disc.

10. In the syringe driver according to claim 1 or 2, A syringe driver characterized in that the one or more passages or valves are arranged on the drive piston and connect the first region and the second region.

11. In the syringe driver according to any one of claims 1 to 5, A syringe driver characterized in that the damping fluid has a viscosity of 0.01 to 100 Pascal seconds (0.01 to 100 Pa·s).

12. An injection device for use with an external air source, A housing comprising a proximal end including a port that communicates with a gas chamber within the housing and is connectable to an external air source, and a distal end, The drug chamber within the distal end includes a drug piston and an outlet port extending from the distal end, A drive piston comprising an elongated member having a first end slidably disposed within the gas chamber and a second end including a plunger connected to the drug piston, wherein when gas is supplied from an air source into the gas chamber, generating pressure within the gas chamber, and this pressure applies a distal force that advances the first end within the gas chamber, the drive piston is movable from an initial first position to a second position, thereby causing the second end of the drive piston to advance, and the plunger and drug piston to advance, thereby discharging the drug from the drug chamber through the outlet port. A damping fluid chamber comprising: a damping piston disposed within the damping fluid chamber between a first region filled with damping fluid in the damping fluid chamber 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, wherein the movement of the drive piston between the first and second positions causes the damping fluid to flow from the first region to the second region through the one or more passages or valves, thereby restricting the movement of the drive piston; An injection device characterized in that the damping fluid chamber is positioned inside the drive piston in close proximity to the first end, and when the drive piston moves from a first position to a second position, the damping fluid chamber moves together with the drive piston, causing the damping fluid to flow between the first region and the second region.

13. In the injection device according to claim 12, An infusion device characterized in that the housing comprises a cavity adjacent to the distal end, and the infusion device further comprises a syringe housed in the cavity, including the drug chamber, the drug piston, and the outlet port.

14. In the injection device according to claim 13, An injection device characterized in that the housing and the syringe are provided with one or more connectors for securing the syringe within the cavity.

15. In the injection device according to claim 12, An injection device characterized in that the damping piston is fixed to the housing such that the damping piston remains substantially stationary when the drive piston and damping fluid chamber move, thereby allowing the damping fluid to flow between the first region and the second region.

16. In the injection device according to claim 12, An injection device characterized in that the distal end of the drive piston extends distally from the damping fluid chamber into the cavity.

17. In the injection device according to any one of claims 12 to 16, An injection device characterized in that the damping fluid has a viscosity that limits the flow rate through the one or more passages in order to limit the speed at which the drive piston moves between the first position and the second position.

18. In the injection device according to any one of claims 12 to 16, An injection device characterized in that the one or more passages or valves include one or more passages of the damping piston that communicate between the first and second regions.

19. In the injection device according to any one of claims 12 to 16, An injection device characterized in that the one or more passages or valves include a valve that restricts the flow between the first and second regions.

20. In the injection device according to claim 19, An injection device characterized in that the one or more passages or valves have one of the following: a pressure relief valve, a spring-loaded ball valve, and a spring-loaded disc.

21. A system for performing injections, An injection device according to any one of claims 12 to 16, A system characterized by comprising a source of pressurized gas that can be connected to the aforementioned port.

22. An injection device for use with an external air source, A housing comprising a proximal end including a port that communicates with a gas chamber within the housing and is connectable to an external air source, and a distal end, The drug chamber within the distal end includes a drug piston and an outlet port extending from the distal end, A drive piston comprising an elongated member having a first end slidably disposed within the gas chamber and a second end including a plunger connected to the drug piston, wherein when gas is supplied to the gas chamber from an air source, pressure is generated within the gas chamber, and this pressure applies a distal force that advances the first end within the gas chamber, the drive piston is movable from an initial first position to a second position, causing the second end of the drive piston to advance, and the plunger and drug piston to advance, thereby discharging the drug from the drug chamber through the outlet port. The damping fluid chamber in the drive piston, The device comprises: a damping piston mounted on a shaft fixed axially to the housing, positioned 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 for the damping piston communicating between the first region and the second region, wherein the movement of the drive piston between a first position and a second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby restricting the movement of the drive piston; An injection device characterized in that the damping fluid chamber is positioned inside the drive piston in close proximity to the first end, and when the drive piston moves from a first position to a second position, the damping fluid chamber moves together with the drive piston, causing the damping fluid to flow between the first region and the second region.

23. A system for performing injections, Injection device and It is equipped with a source of pressurized gas that can be connected to a port, The injection device, A housing comprising a proximal end including a port that communicates with a gas chamber within the housing and is connectable to an external air source, and a distal end, The drug chamber within the distal end includes a drug piston and an outlet port extending from the distal end, A drive piston comprising an elongated member having a first end slidably disposed within the gas chamber and a second end including a plunger connected to the drug piston, wherein when gas is supplied to the gas chamber from an air source, pressure is generated within the gas chamber, and this pressure applies a distal force that advances the first end within the gas chamber, the drive piston is movable from an initial first position to a second position, causing the second end of the drive piston to advance, and the plunger and drug piston to advance, thereby discharging the drug from the drug chamber through the outlet port. The damping fluid chamber in the drive piston, The device comprises: a damping piston mounted on a shaft fixed axially to the housing, positioned 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 for the damping piston communicating between the first region and the second region, wherein the movement of the drive piston between a first position and a second position causes the damping fluid to flow through the one or more passages from the first region to the second region, thereby restricting the movement of the drive piston; The system is characterized in that the damping fluid chamber is positioned inside the drive piston in close proximity to the first end, and when the drive piston moves from a first position to a second position, the damping fluid chamber moves together with the drive piston, causing the damping fluid to flow between the first region and the second region.

24. The injection device according to any one of claims 12 to 16 and 22 is further, An injection device characterized in that it includes a pressurized gas supply source connected to the port as the external air source, and the pressurized gas supply source is configured to deliver high-pressure gas into the port and the gas chamber, thereby advancing the drive piston from a first position to a second position, which in turn advances the plunger and the drug piston, and delivers the drug from the syringe.

25. An injection device according to claim 24, wherein the pressurized gas supply source has an actuator, and when the drive piston moves between the first position and the second position and the damping fluid moves from the first region to the second region through the one or more passages or valves, the actuator is configured to increase the gas pressure to control the speed at which the drive piston moves forward and the flow rate of the agent, thereby limiting the speed at which the drive piston moves forward.

26. An injection device according to claim 24, characterized in that the actuator has a foot pedal.

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