JP2004526519A - Modular gas pressure needleless syringe - Google Patents

Abstract

A suitable needleless injector for injecting fluid through a surface includes a housing, a driver, an engine, and a trigger. The housing contains the fluid and the engine contains the compressed gas. When sufficient force is applied to the trigger, the compressed gas is released from the engine, pushing the driver through the interior of the housing and pushing the liquid out of the housing at a rate sufficient to pierce the surface and inject. In one embodiment, the needleless injector includes a mechanism to reduce recoil associated with the release of compressed gas from the engine. In another embodiment, the housing includes finger pads that provide stability and responsiveness for operating the device. Another embodiment includes a safety clamp on the housing to prevent accidental activation of the device.

Description

【Technical field】
[0001]
[Related application]
This application is related to Prior Art Document 1 filed on May 6, 2000. Further, the present application generally relates to prior art document 2 (now the prior art document 3) filed on December 19, 1998, which is related to the prior art document 4 (now the prior art document 4) filed on October 9, 1996. 5), which is a continuation-in-part of prior art document 6 (now prior art document 7) filed on September 25, 1996, which was filed on October 10, 1995, It is a continuation-in-part of prior art document 8, which has been abandoned. This application is also generally related to prior art document 9 filed on November 14, 1998 (currently prior art document 10) and U.S. Patent Application No. [Attorney Docket No. 69816-0250782] filed on March 14, 2001. (For example, see Patent Documents 1 to 10).
[Patent Document 1]
US patent application Ser. No. 09 / 566,928
[Patent Document 2]
U.S. patent application Ser. No. 09 / 215,769
[Patent Document 3]
U.S. Pat. No. 6,063,053
[Patent Document 4]
US Patent Application No. 08 / 727,911
[Patent Document 5]
U.S. Pat. No. 5,851,198
[Patent Document 6]
US patent application Ser. No. 08 / 719,459
[Patent Document 7]
U.S. Pat. No. 5,730,723
[Patent Document 8]
US patent application Ser. No. 08 / 451,470
[Patent Document 9]
US patent application Ser. No. 09 / 192,079
[Patent Document 10]
US Patent No. 6,080,130
[0002]
The present invention relates to needle-less injectors, and in particular, to perform modular needle-less injection using modular gas-pressured needle-less injectors and the same. About the method.
[Background Art]
[0003]
Traditionally, fluids such as drugs are injected subcutaneously or intradermally into a patient using a hypodermic syringe needle. The syringe body is filled with injectable fluid, and once the needle has penetrated the patient's skin, the plunger of the syringe is depressed to release the injectable fluid through the hole in the needle. Usually, the person performing the injection is a trained medical service provider, who subcutaneously by hand underneath the layer of skin for intradermal injection or under the layer of skin for subcutaneous injection. Insert the injection needle.
[0004]
Delivering a drug intradermally or subcutaneously by use of a hypodermic needle requires considerable skill and training to inject properly and safely. Moreover, the traditional method of intradermal injection requires that the needle actually make physical contact with the skin surface of the patient and penetrate it, which can be painful to the patient. Also, traditional needle syringes, such as hypodermic syringes, are expensive to manufacture and difficult to use in pre-contained dosages. Further, needled syringes have the disadvantage of increasing the risk of exposing the health care provider performing the injection and the public to contamination when such syringes are not properly disposed of.
[0005]
Jet injectors are generally configured to avoid some or all of these problems. However, conventional jet injectors are not only bulky and heavy and inconvenient to use, but existing conventional jet injectors can only deliver drugs subcutaneously under the patient's skin layer. Conventional jet injectors are somewhat dangerous to use because they can be released without pressing against the skin surface. At fluid delivery rates greater than about 800 feet per second (fps), conventional jet injectors can injure eyes within a distance of up to 15 feet. Moreover, it is widely known that improperly sterilized jet injectors infect the injection site. In addition, if the jet injector is not pressed against the injection site and is not properly positioned, the injection may wet the skin surface. Some of the fluid to be injected may remain on the skin surface after the injection and may not be properly injected into and / or through the skin surface, which may also cause problems with incorrect dosages There is.
[0006]
Needleless drug syringes are typically extended springs or compression-free to release fluid drug (by a push rod plunger) through a small opening (syringe nozzle) mounted vertically against the injection site and against the injection site. Use active gas. Fluid drugs are typically accelerated at high speeds, reaching speeds from about 800 feet per second (fps) to 1,200 fps (approximately 244 to 366 meters per second). Thus, by penetrating the fluid through the skin surface without using a needle, the drug is deposited in a flower-like pattern below the skin surface.
[0007]
However, it should be noted that a compression spring propelled jet injector does not have a linear delivery speed (a constant speed at which fluid is delivered). In addition to this problem, spring-propelled jet injectors with weakened (eg, degraded) springs often have a reduced fluid delivery rate during injection, resulting in inadequate penetration of fluid. Occurs. A reduced fluid velocity can cause improper dosing and bruising of the injection site when the injection surface is the skin of a human recipient.
[0008]
In a jet injector, if the inert gas is not released quickly and properly, the injection of fluid may be inadequate, as in devices utilizing compression springs. Conventional disposable needle-free injectors, such as the needle-free injectors shown in Prior Art Document 11 in which the patent issued to Parsons was published and Prior Art Document 12 in which the patent issued to Newman et al. Or present a breakable cylinder with a built-in gas that can be broken. Difficulty in maintaining strict tolerances for breakable members, as small changes in thickness can severely affect the pressure required to deploy gas from the gas chamber of the device. Problems arise. In addition, the fragments of the breakable member splatter at a high rate as the gas is released, and these fragments sometimes become jammed between the plunger driver and the housing, thereby preventing proper operation of the needleless syringe. . Attempts to prevent the formation of fine debris may mitigate some of this fear, but do not like to make the device more difficult to drive (see, for example, US Pat.
[Patent Document 11]
U.S. Pat. No. 4,913,699
[Patent Document 12]
U.S. Pat. No. 5,009,637
[0009]
Also, prior art documents 3 and 10 and other prior art documents 13 and 14 describe needle-free injectors incorporating a gas powered source, thus eliminating some of the limitations inherent in compression spring injectors. Addresses many of the problems associated with conventional jet injectors. The syringes described therein have a pre-filled and self-contained compressed gas to provide pressure for injecting the drug into the patient's skin surface without a needle (see, for example, US Pat. reference).
[Patent Document 13]
U.S. Pat. No. 5,851,198
[Patent Document 14]
US Patent No. 5,730,723
[0010]
However, gas pressure sources for needle-free injectors that use a pop valve or release tab valve to release the inert gas contained in each gas chamber can only be released once, and therefore quality control. Present the difficulties of the test method. Furthermore, many syringe operations require the user to depress the trigger, relying primarily on the repulsion of the injection surface to initiate the injection. On surfaces where the underlying surface of the syringe is sensitive, applying such pressure may be inconvenient. In addition, slippery injection surfaces can cause such devices to slide out of position during injection, causing injuries and inadequate fluid delivery during use.
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0011]
Accordingly, it is an object of one embodiment of the present invention to provide a gas pressure needle-free injector that, for practical purposes, eliminates the above-mentioned limitations.
[Means for Solving the Problems]
[0012]
In one embodiment of the present invention, a needle-free injector suitable for injecting fluid through an injection surface includes a housing, a trigger, an engine, and a driver. The housing contains the fluid and the engine contains the compressed gas. When a sufficient amount of force is applied to the trigger, the compressed gas is released from the engine and pushes the driver through the interior of the housing, pushing the liquid out of the housing at a velocity sufficient to penetrate the injection surface.
[0013]
In another embodiment of the present invention, a needleless injector includes a mechanism for reducing recoil associated with the release of compressed gas from the engine. A grip is included on the engine to mechanically couple the engine to a needleless syringe element affixed to the housing, thereby preventing the engine from separating from the housing when the compressed gas is released from the engine. be able to. Also, a retainer hook on the inner surface of the trigger, corresponding to a latch retainer mechanism on the outer surface of the housing, further prevents the engine from separating from the housing.
[0014]
In yet another embodiment of the present invention, the needle-free injector housing includes a finger rest that provides stability during the injection and provides a responsiveness to drive the needle-free injector. Thus, the user need not rely solely on repulsion from the injection surface to initiate the injection. A finger rest configured to receive the user's finger without anxiety substantially without slippage may be included on both sides of the housing.
[0015]
In yet another embodiment of the present invention, a reusable valve is attached to the needleless syringe engine. The valve includes a rubber head that holds the engine stationary element, and when the trigger is depressed, the head is disengaged from the stationary element to release compressed gas from the engine, and the driver is pushed further to push liquid out of the housing. Can be extruded. A spring may be included in the valve to maintain a proper hermetic seal with the canister containing the compressed gas.
[0016]
In yet another embodiment of the invention, a safety clamp is included on the outer surface of the needleless syringe housing to prevent accidental activation of the device. The safety clamp must be removed before use, but can be made of a sufficiently flexible material so that the user can simply remove the clamp from the housing with the help of the grips on it .
BEST MODE FOR CARRYING OUT THE INVENTION
[0017]
As shown in the drawings for purposes of illustration, the present invention is implemented in a gas pressure needleless syringe. In a preferred embodiment of the present invention, a gas pressure needle-free injector is adapted to be pre-filled with a drug for single use. This needleless syringe is preferably used for humans or other animals. However, it is recognized that other embodiments of the present invention may be used in other applications requiring a needleless injector, such as when passing injectable material through a porous membrane or the like.
[0018]
Embodiments of the present invention can also be used for the injection of other fluids or injection antigens, such as proteins, vitamins, hormones, drugs, vaccines, drugs, lyophilized drugs, drug mixtures or the like. It is intended to be within the scope of the term "liquid" as used herein. In a preferred embodiment, the liquid used in accordance with the present invention has been degassed prior to filling into a needle-free injector, or has been filed on March 14, 2001, US Patent Application No. [Attorney Docket No. 69816-0250782]. Have sufficient chemical properties so that the liquid is degassed immediately upon filling or shortly after filling. In neither of these preferred embodiments, there is substantially no gas pocket created in the internal cavity containing the liquid during storage of the needleless syringe prior to use.
[0019]
To facilitate the description of the various elements of the present invention, the following spatial coordinate system is applied to them. As shown in FIG. 1c, a central axis is defined through the entire length of the gas pressure needleless injector 100. This central axis 1 has one end at the proximal end 2 of the needleless syringe 100 and is defined as the end of the device that contacts the injection surface during normal operation of the syringe. The other end of the central axis is at the distal end 3 of the syringe 100 and is defined as the end of the device furthest from the injection surface when positioning the syringe perpendicular to the injection surface. Thus, the various elements of the device of the present invention can be described with reference to their central axis as well as their proximal and distal portions, respectively.
[0020]
As shown in FIG. 1, the gas pressure needleless syringe 100 includes a housing 201. This housing 201 may be of any suitable shape, but in a preferred embodiment it is substantially cylindrical about a central axis. The housing 201 preferably varies in inner diameter along its length to accommodate the components located and operative when the syringe 100 is fully assembled. The housing 201 shown in FIG. 2a has four such inner diameters, namely, an ampoule diameter 202, a plunger diameter 203, an ejector diameter 204, and a drive diameter 205, respectively. Although embodiments of the present invention preferably do not include an ampoule, a mechanical element that is separate from and separate from the housing 201, the housing 201 may be used for various purposes such as liquid filling. It can function as an ampoule.
[0021]
The outer surface 206 of the proximal end surface of the housing 201 may be flat, but in a preferred embodiment it is shaped to maximize the efficiency of the syringe. Optimum efficiency is that substantially all of the liquid contained in syringe 100 is pumped through the injection surface and, after the injection is complete (see FIGS. 1d and 1e), on the injection surface or proximal to housing 210. This is a case where substantially no liquid remains on the outer surface portion 206 of the end surface. To that end, in the embodiment shown in FIG. 2a, when the outer surface portion 206 of the proximal end surface of the housing 201 contacts the injection surface, the outer surface portion 206 of the proximal end of the housing 201 will pass through the surface to be injected. It is made to pinch and extend. Therefore, the outer surface portion 206 at the proximal end of the housing 201 preferably has a conical shape around the central axis and further has a raised rim 207 around its circumference.
[0022]
The inner surface 208 at the proximal end of the housing 201 can be of any suitable shape. It may be substantially conformal to the shape of the outer surface 207 or may have a configuration separate from the outer surface. In one embodiment, the inner surface 208 is flat, but preferably, as shown in FIG. 2a, the inner surface 208 is substantially conical and at least one opening 209 is at or near the crown 210. The needleless syringe 100 shown in FIG. 1 has only one opening.
[0023]
The at least one opening 209 provides fluid communication between the interior 214 of the housing 201 and the surface to be injected through. The number of openings 209 may vary depending on the delivery parameters of the liquid to be injected. One such parameter is the depth to which liquid must penetrate the recipient's tissue when injecting a medicament into a human using the device. For example, in one embodiment, it may be desirable to inject the liquid just below the outermost skin layer of the recipient, and a multi-aperture may be best suited for that purpose. Alternatively, a single opening may be most desirable for injections that need to penetrate deeper for maximum efficacy.
[0024]
A discharge passage 211 may be provided through the housing 201 from the inner wall 212 to the outer wall 213, preferably in the housing 201 section of the ampoule diameter 202. This discharge passage 211 allows gas to escape from the interior 214 of the housing 201, preferably only after an injection has been given. Thus, most preferably, the discharge passage 211 is located at the location of the piston 500 after injection (see FIGS. 1d and 1e), i.e., at a point in the housing 201 immediately distal to that location. In these most preferred embodiments, after discharging substantially all of the liquid contained in the housing 201 from the needle-free injector 100, gas flows through the discharge passage 211 until the piston 500 rests in its final position. It cannot escape from the interior 214 of 201.
[0025]
Prior to the injection, the liquid contained in the needle-free injector 100 is applied to the inner surface 208 of the proximal end of the housing 201, the inner wall 212 of the housing 201, and the area bounded by the proximal end 403 of the plunger 400. It is preferably housed in the interior 214 of the housing 201 (see FIGS. 1a and 2a).
[0026]
As shown in FIG. 2 a, the housing 201 further includes a finger receiver 215. In a preferred embodiment, two such finger receivers 215 are formed on both sides of the outer wall 213 of the housing 201. Most preferably, these finger catches 215 are located directly opposite each other. In a preferred embodiment, each finger receiver 215 has an arc 216 on its proximal side to fit the appropriate finger placement to inject by itself or to assist a medical professional or the like in injecting. Having. In the most preferred embodiment, the arc 216 of the finger rest 215 includes a non-slip, textured surface 217.
[0027]
When an individual who injects himself uses the needleless syringe 100, in order to stabilize the apparatus, the individual's thumb and middle finger are applied to the arcs 216 of the finger holders 215 on both sides of the housing 201, and the distance of the syringe 100 is increased. The index finger is operatively pressed against the trigger 800 at the end. In another manner in which the user can inject the injection himself, which is also the preferred manner when operating the needleless syringe 100 by someone other than the person receiving the injection, but in order to stabilize the device, the housing The index finger and the middle finger are arranged on the arc 216 of the finger receiver 215 on both sides, and the thumb is operatively pressed against the trigger 800 at the distal end of the syringe 100.
[0028]
Housing 201 further includes at least one latch retainer mechanism 218 near the distal end. The at least one latch retainer mechanism 218 comprises a set of a plurality of serrated ridges surrounding the outer wall 213 of the housing 201 about its central axis. More preferably, there are two latch retainer mechanisms 218 comprising two sets of a plurality of serrated ridges 219 opposing each other on outer wall 213 of housing 201, but any suitable number of latch retainer mechanisms is provided. 218 can also be used. Preferably, as shown in FIG. 1b, the housing 201 has its proximal end defined by a ridge 221 and its distal end defined by at least one latch retainer mechanism 218 and the proximal end of the trigger 800. It further includes a clamping recess 220.
[0029]
The ampule cap 300 shown in FIG. 3 can be further attached to the proximal end of the housing 201, and the ampoule cap keeps the outer surface portion 206 of the proximal end face of the housing 201 sterile during storage of the needleless syringe 100. Serve to maintain. Further, when using the degassed liquid in accordance with the present invention, the ampoule cap 300 may have at least one opening 209 in the proximal end of housing 201 and surrounding Provide the necessary hermetic seal between the atmosphere. Referring again to FIG. 3, the outer surface 302 of the ampoule cap 300 may be of any convenient configuration, but preferably, the inner surface 301 of the ampoule cap 300 substantially co-exists with the outer surface 206 at the proximal end of the housing 201. It is configured to be shaped.
[0030]
The plunger 400 shown in FIG. 4 can be attached to the housing 201. Since the plunger 400 has a diameter equal to or slightly larger than the ampoule diameter 202 of the housing 201, it is preferable that the plunger 400 is press-fitted inside the housing 201. Plunger 400 is preferably made of a material that is sufficiently elastic so as to provide an air and liquid tight seal with inner wall 212 of housing 201 by press fitting. The plunger 400 is preferably cylindrical to resemble the shape of the inner wall 212 of the housing 201, although other shapes may be appropriate, especially when the inner wall 212 of the housing 201 is non-cylindrical. Furthermore, the wall 401 of the plunger 400 can have several ridges 402 disposed thereon. Preferably, there are at least two such ridges 402, and more preferably, three ridges 402. Such a ridge 402 provides stability to the plunger 400 such that during injection, there is no rotational movement about any axis other than the central axis, and the direction of movement is substantially along the central axis. And remains linear.
[0031]
The proximal end 403 of the plunger 400 may be of any suitable shape, including a flat surface, but in a preferred embodiment it approximates the shape of the inner wall 208 of the proximal end of the housing 201. However, due to the elastic properties of the plunger material, the proximal end 403 of the plunger 400 can conform to a different surface shape than itself when mechanically pressing the plunger against such a surface. Thus, the shape of the proximal end 403 of the plunger 400 need not resemble the shape of the inner wall 208 of the proximal end of the housing 201, but when the proximal end is pressed against the inner wall during or after the injection. , Can be conformal to the shape of the inner wall 208. However, in the most preferred embodiment, the proximal end 403 of the plunger 400 is substantially conical in shape.
[0032]
The distal end 404 of the plunger 400 may also be of any suitable shape and is received by the proximal end of the piston 500. In a preferred embodiment, the plunger 400 is symmetrical in shape along a plane perpendicular to the central axis. Thus, in a preferred embodiment, the distal end 404 of the plunger 400 is substantially conical in shape.
[0033]
The piston 500 shown in FIG. 5 can be attached to the housing 201. The piston 500 is preferably substantially cylindrical along its central axis, particularly toward embodiments where the inner wall 212 of the housing 201 is non-cylindrical, but towards its distal end, although other shapes are suitable. A flared portion 501 is provided. Preferably, the proximal end 502 of the piston 500 is shaped such that it mechanically receives the distal end 404 of the plunger 400. Thus, in the most preferred embodiment, the proximal end 502 of the piston 500 is a generally conical recess. In a preferred embodiment, the piston 500 further includes a chamber 503 extending from the top of the conical recess 502 along the central axis of the piston 500.
[0034]
Outside the distal section of the piston is a flared portion 501, which preferably terminates in an enlarged cup rim 504. In a most preferred embodiment, the distal section of the piston further comprises a hollow enlarged cup 505. This enlarged cup 505 is different from the chamber 503 that extends from the proximal end 502 of the piston 500 along the central axis of the piston, since the chamber 503 does not extend completely through the piston 500 to the enlarged cup 505. No gas communication.
[0035]
Referring to FIGS. 2 a and 5, the distal section of the piston 500 is press fit into the housing 201 portion of the piston diameter 203 and the diameter of the enlarged cup rim 504 of the piston 500 is substantially equal to the piston diameter 203 of the housing 201. Is equal to Alternatively, the diameter of the enlarged cup rim 504 may be slightly smaller than the piston diameter 203 of the housing 201. When using the needleless injector 100, the expansion cup 505 is radially expandable due to the force of the compressed gas pushing it. Accordingly, a substantial hermetic seal is formed between the enlarged cup rim 504 and the inner wall 212 of the housing 201, thus serving to optimize the performance of the piston 500.
[0036]
The effusive device 600 shown in FIG. 6 can be attached to the housing 201. It is preferable that the spouter 600 is fixed to the spouter diameter 204 portion of the housing 201 along the inner wall 212 thereof. Bonding can be performed by high frequency welding or other suitable means. Most preferably, the ejector 600 is secured to the housing 201 only after the plunger 400 and the piston 500 are mounted in the housing 201.
[0037]
The effusive device 600 preferably further includes at least one groove 601 that provides gas communication between the distal end 602 of the effluent device 600 and the base of the effluent cup 603. The at least one groove 601 is sized and positioned to optimize a particular injection delivery parameter. As exemplarily shown in FIG. 7, in a preferred embodiment, the effusive device 600 can include two to eight grooves 601 that can be the same diameter or different diameters, Further, the orientation may be symmetric or asymmetric around the central axis of the ejector 600. The choice of various combinations of grooves 601 in the effusive device 600 affects the delivery performance of the needleless injector 100, for example, changes the initial acceleration of the driver of the needleless injector 100. The driver speed for the preferred embodiment of the present invention is shown in FIG. Notably, the compressed gas engine of the present invention allows for a substantially constant delivery rate during most of the injection.
[0038]
Referring to FIG. 6 b, a valve stem receiving recess 604 located at the central axis of the effusive device may further be included at the distal end 602 of the effusive device 600. Effluent 600 further includes a securing ring 605 around its outer circumference. Preferably, the retaining ring 605 is angled at its distal surface 606, while its proximal surface 607 is flat.
[0039]
A trigger 800 shown in FIG. 8 can be further attached to the housing 201. The trigger 800 is preferably substantially cylindrical to conform to the shape of the outer wall 213 of the housing 201. The distal end of the trigger 800 can have a recess 801 therein, but in a preferred embodiment, the recess 801 has an additional texture to position it without slipping when operating the needleless injector 100. Can be attached.
[0040]
The trigger 800 preferably includes at least one retainer hook mechanism 802 used to secure the trigger 800 to the housing 201 and to reduce the recoil associated with the deployment of the compressed gas contained in the engine housing 1000. Without such a safety feature, the forces generated by releasing the gas contained within engine housing 1000 could cause the engine assembly to separate from the remaining components of needleless injector 100, Injections can be inappropriate and hurt the user.
[0041]
The at least one retainer hook mechanism 802 includes a housing, since the retainer hook mechanism 803 at the proximal end of the retainer hook mechanism 802 preferably locks around a continuous serrated ridge 219 with a latch retainer mechanism 218. Operatively engages at least one latch retainer mechanism 218 located near the distal end of 201. In the preferred embodiment, there are two retainer hook mechanisms 802 located opposite one another on the trigger 800, which spatially correspond to the two latch retainer mechanisms 218 on the outer wall 213 of the housing 201.
[0042]
The at least one retainer hook mechanism 802 and the at least one latch retainer mechanism 218 preferably prevent the trigger 800 from rotating about its central axis. In one most preferred embodiment, the side 804 of the at least one retainer hook mechanism 802 fits around the side 222 of the at least one latch retainer mechanism 218 to prevent rotation.
[0043]
The safety clamp 900 shown in FIG. 9 can be further attached to the housing 201. This safety clamp 900 prevents accidental ejection of the needleless injector 100. The safety clamp 900 is preferably substantially semi-cylindrical in shape and conformal to the outer wall 213 of the housing 201 and is located in a clamping recess 220 around the outer wall 213 of the housing 201, The ridge 221 defines its proximal end and the proximal end of at least one latch retainer mechanism 218 and trigger 800 defines its distal end (see FIG. 1b). The safety clamp 900 preferably does not completely surround the housing 201, but rather at least surrounds at least half of the housing 201, which facilitates removal and prevents the clamp 900 from easily falling off the needleless injector 100. it can. Most preferably, the safety clamp 900 is made from a sufficiently flexible material so that the temporary deformation of the clamp 900 allows it to be removed from the outer wall 213 of the housing 201. A grip 901 and foot 902 can be included on the safety clamp 900 to assist in this removal.
[0044]
Preferably, the engine assembly 101 shown in FIG. The engine assembly 101 can further include an engine housing 1000 shown in FIG. The engine housing 1000 is preferably made of a material that is impermeable to the compressed gas contained therein and has a hollow inner chamber 1003. Most preferably, engine housing 1000 is comprised of stainless steel or a similar metal. Preferably, the needle-free injector 100 is driven using a compressed inert gas, which is housed inside the engine housing 1000 before use. The most preferred gas is carbon dioxide, but other suitable gases can be used as well. In a most preferred embodiment, the engine assembly 101 can be overfilled (ie, contain excess compressed gas therein) and used at a variable height without disturbing the performance characteristics of the needleless injector 100. .
[0045]
Engine housing 1000 is preferably substantially cylindrical in shape to conform to inner wall 212 of housing 201, although other shapes can be used. Referring to FIG. 10, engine housing 1000 can have a large diameter portion 1001 and a small diameter portion 1002, with the small diameter portion 1002 being proximal to the large diameter portion 1001. The distal end of engine housing 1000 includes a circular recess 1004 that can be pressed against trigger 800 (see FIG. 1b). The proximal end of the engine housing 1000 includes an opening 1005 and, in a preferred embodiment, a sealing ridge 1006 surrounding the opening 1005.
[0046]
The engine assembly 101 preferably further includes a valve body 1100 shown in FIG. It is preferable that the overall shape of the valve element 1100 is substantially cylindrical, and it is more preferable that at least a part of the valve element 1100 be inside the engine housing 1000. Most preferably, the valve body 1100 has a sealing rim 1101 pressed against a sealing ridge 1006 surrounding an opening 1005 at the proximal end of the engine housing 1000 around its outer periphery. Most preferably, a sealing ring 1200 covers around the sealing rim 1101 and the sealing ridge 1006 to secure the valve body 1100 and the engine housing 1000 to each other (see FIG. 1b).
[0047]
This sealing ferrule 1200 is shown in FIG. 12 and is mechanically bent around the sealing rim 1101 and the sealing ridge 1006 in front of its distal portion 1201. The proximal portion 1202 of the sealing ferrule 1200 is substantially the same diameter as the outside of the valve body 1100, such that merely bending the distal portion thereof mechanically couples the valve body 1100 to the engine housing 1000. It has become. In FIG. 1, the distal portion 1201 of the sealing ring 1200 is shown in a bent state. The valve body 1100 preferably has a recess 1102 around its circumference adapted to fit a gasket 1103 (shown in FIG. 1b). The gasket 1103 helps to ensure that a gas-tight seal between the interior of the engine housing 1000 containing the gas and the atmosphere inside the needleless injector 100 is maintained.
[0048]
Referring to FIG. 11, the interior of valve body 1100 is preferably hollow and consists of several distinct parts. The distal interior 1104 of the valve body 1100 can include a threaded engagement 1105, which preferably extends from the distal end of the valve body 1100 to the distal end of the first axial cavity 1106. The first axis cavity 1106 is bounded at its proximal end by a shoulder 1107, which extends from the second axis cavity 1108 to the first axis cavity 1106, which is preferably smaller in diameter than the first axis cavity 1106. Can be separated. In a preferred embodiment, this shoulder 1107 is an angled edge. In a similarly preferred embodiment, at least one stem guide 1109 protrudes from the wall of the second axial cavity 1108. In one most preferred embodiment, there are at least three such stem guides 1109 that substantially prevent any movement of the stem 1400 in any direction other than along the central axis of the needleless injector 100 during the injection. It plays the role of prevention.
[0049]
The proximal end of the second axis cavity 1108 preferably terminates in a diverter receiving chamber 1110 of sufficient diameter that it surrounds the distal end 602 of the diverter 600. Most preferably, after injection with the needleless injector 100, the distal end 602 of the ejector 600 rests inside the ejector receiving chamber 1110.
[0050]
The proximal end of the effluent receiver chamber 1110 preferably has at least one grip 1111 extending therefrom. The at least one grip 1111 preferably locks around another suitable element of the needleless injector 100 when the grip element 1112 is located inside the grip 1111. However, in an alternative embodiment, the at least one gripper 1111 can have its gripping element 1112 located outside of the gripper 1111 so that it can be locked inside another element. In the most preferred embodiment, two grips 1111 are arranged opposite each other, each of which includes a gripping element 1112 located inside the grip 1111. In these most preferred embodiments, upon injection, these two grips 1111 slide over the locking ring 605 of the ejector 600 and lock around it. The combination of the retaining ring 605 and the gripper 1111 helps to reduce the recoil associated with the deployment of the compressed gas contained in the engine assembly 101 and injects until the gripper 1111 slides through the retaining ring 605. Preferably does not deploy, thus ensuring that the user depresses trigger 800 completely and properly.
[0051]
The valve element 1100 preferably further includes a threaded valve guide 1300, as shown in FIG. The threaded valve guide 1300 preferably has a cylindrical shape and is threaded around its outer wall 1301, and the valve guide is connected to a thread engagement portion 1105 to thereby form the inside of the valve body 1100. It can be screwed into the distal portion 1104. Most preferably, a thread on the outer wall 1301 of the threaded valve guide 1300 extends along the entire outer wall 1301 from the distal end to the proximal end of the threaded valve guide 1300. The threaded valve guide 1300 also includes a cylindrical internal cavity 1302 whose proximal end is unobstructed. However, its distal end is preferably covered by a stem guide pane 1303. Preferably, the stem guide pane 1303 is provided with at least one vent opening 1304, whereby the internal cavity 1302 of the threaded valve guide 1300 and the engine housing 1000 at the distal end of the threaded valve guide 1300. Gas communication between the hollow interior chambers 1003 is enabled. Also preferably, the stem guide pane 1303 includes a central axis with a hole 1305 slightly larger in diameter than the stem 1400 located therein. Most preferably, the stem guide pane 1303 further includes a spring seat 1306 on its proximal surface comprising at least one ridge 1307 that maintains the valve spring 1500 in place.
[0052]
The valve element 1100 preferably further includes a valve stem 1400 shown in FIG. The valve stem 1400 preferably comprises a substantially cylindrical rod 1401 having a flat proximal end 1402 and a preferably pressed or hammer-forged distal end 1403. FIG. 14a shows the distal end 1403 after hammering and FIG. 14b before hammering. Also most preferably, a spring ridge 1404 extending radially from the rod 1401 and a generally conical valve secured to the proximal and outer surfaces of the spring ridge 1404 and the portion of the rod 1401 immediately proximal of the spring ridge 1404. A head 1405 is included. Most preferably, the valve head 1405 is made of a rubber material, such as a silicone-based rubber, which is flexible and semi-permeable enough to be used according to the needleless syringe 100. In the most preferred embodiment, the angle between the proximal surface of the valve head 1405 and the central axis is substantially equal to the angle of a shoulder 1107 disposed between the first axial cavity 1106 and the second axial cavity 1108 of the valve disc 1100. Is the same as
[0053]
The valve element 1100 may further include a valve spring 1500 shown in FIG. The valve spring 1500 is made of wire and is preferably semi-conical in shape, with its proximal end 1501 having a smaller diameter than its distal end 1502. The proximal end 1501 of the valve spring 1500 is preferably pressed against the distal surface of the spring ridge 1404 on the valve stem 1400, while the distal end 1502 of the valve spring 1500 is located near the valve stem guide pane 1303. Preferably, it is pressed against a position surface and held in place in a semi-radial direction by a spring seat 1306.
[0054]
Furthermore, the valve of the present invention can be repeatedly opened and closed without damage, so that the valve can be opened and closed at least once before filling the engine assembly 101 with compressed gas for quality control testing. Can be inspected. Defective valves are problematic in any device utilizing such a mechanism, but in the case of needleless injectors useful in medical applications where such defects can lead to improper drug dosage, That is especially important.
[0055]
During injections using a needleless injector, several mechanisms operate to reduce the recoil associated with the release of compressed gas from the engine housing. A grip on the valve body operatively couples to a retaining ring on the outer surface of the effusive device, and a retainer hook on the retainer hook mechanism operatively locks to each successive saw tooth of the latch retainer mechanism. I do. Such a safety feature not only functions to avoid the risk of injury, but also ensures proper delivery of liquid through the injection surface.
[Example]
[0056]
Needleless syringe operation
Prior to use, a needleless syringe according to the present invention is assembled, but all components thereof are gamma sterilized except for the engine assembly. For quality control purposes, the engine assembly is inspected by opening and closing valves, and then the engine housing is filled with the appropriate compressed gas. The interior of the housing between the housing proximal end and the plunger proximal end is then filled with 0.5 ml of liquid. Next, the needleless syringe is assembled and stored for a certain period of time.
[0057]
When ready for use (see FIG. 1a), the user removes the ampoule cap from the proximal end of the housing. Subsequently, the user also removes the safety cap by bending and / or deforming the cap. The user is going to give the injection himself, and selects and uses the following configuration. That is, the index finger and the middle finger of the user are applied to the arc of the finger receiver to stabilize the device, and the thumb is operatively pressed against the trigger. The proximal end of the needleless syringe is then positioned substantially perpendicular to the injection plane.
[0058]
The user then depresses the trigger until the proximal end of the trigger presses against the ridge defining the proximal end of the clamping recess. During this movement of the trigger, the retainer hook and the latch retainer mechanism cooperate as the retainer hook locks through the continuous serration with the latch retainer mechanism.
[0059]
When the trigger is axially moved forward, the engine housing, the valve body and the threaded valve guide also move. Thus, the gripper at the proximal end of the valve body is advanced, as the distal end of the valve body simultaneously slides into the valve body receiving cavity of the valve body, part of which penetrates and rests therein. And lock around the eruption fixing ring. However, at the same time, the stem moves with the trigger, and once the stem mechanically contacts the stem receiving recess in the effusive device, the stem remains stationary with respect to the housing. As the gripper slides over and passes over the locking ring of the ejector, the valve stem and the ejector come into such mechanical contact.
[0060]
Upon mechanical contact between the stem and the ejector, the valve spring is compressed and the valve is opened because the valve head is separated from the shoulder between the first and second axial cavities of the valve body. The compressed gas (previously housed in the engine housing, the internal cavity of the threaded valve guide, and the first axial cavity of the valve body) then passes through the gap formed between the valve head and the shoulder at once. The gas passes through the second axial cavity all at once, through the stem guide, through the effluent receiver chamber, and through at least one groove in the effusion device. The gas then fills the space defined by the effusive cup and the enlarged cup of the piston, which are close together or pressed together before the gas separates the two elements. When gas is introduced into this space, the piston is squeezed proximally to urge the plunger into the interior of the housing and correspondingly push liquid out of the syringe through at least one opening in the proximal end of the syringe. Enter and / or penetrate the surface. The piston and the plunger cooperate as a driver. Once the plunger presses against the proximal end of the housing, excess gas can escape through the exhaust passage in the housing. The user then discards the needleless syringe and the injection is complete.
[0061]
While the above description refers to particular embodiments of the present invention, it will be readily apparent to those skilled in the art that many changes may be made without departing from the spirit thereof. The appended claims are intended to cover such modifications as would fall within the true spirit and scope of the invention. Therefore, the embodiments disclosed herein are to be considered in all respects as illustrative and non-limiting, and the scope of the present invention is indicated by the appended claims rather than the foregoing description. It is intended that the present invention cover all modifications that come within the meaning and range of equivalents of the claims.
[Brief description of the drawings]
[0062]
FIG. 1a is a perspective view of a needleless syringe prior to administering an injection according to one embodiment of the invention, shown without rotation about the central axis of the syringe.
FIG. 1b is a side cross-sectional view of a needleless syringe according to one embodiment of the present invention, shown rotated 90 ° about a central axis.
FIG. 1c is a side perspective view of a needleless syringe according to one embodiment of the present invention, shown without rotation about a central axis.
FIG. 1d is a side perspective view of a needleless syringe after being injected according to one embodiment of the present invention, shown rotated 180 ° about the central axis of the syringe.
FIG. 1e is a side partial cross-sectional view of a needleless syringe after being injected according to one embodiment of the present invention, shown rotated 90 ° about a central axis.
FIG. 2a shows a needleless syringe housing according to one embodiment of the present invention, showing a side rotated 180 ° about a central axis.
FIG. 2b is a perspective view showing the proximal end of a needle-free injector according to one embodiment of the present invention.
FIG. 2c is a perspective view showing the distal end of a needleless syringe according to one embodiment of the present invention.
FIG. 3a is a side perspective view showing an ampule cap of a needleless syringe according to one embodiment of the present invention.
FIG. 3b is a side sectional view showing an ampoule cap of the needleless syringe according to an embodiment of the present invention;
FIG. 3c is a proximal end perspective view showing an ampoule cap of a needleless syringe according to one embodiment of the present invention.
FIG. 4a is a side perspective view showing a plunger of a needleless syringe according to one embodiment of the present invention.
FIG. 4b is a side sectional view showing a plunger of a needleless syringe according to an embodiment of the present invention.
FIG. 4c is a proximal end cross-sectional view showing a plunger of a needleless injector according to one embodiment of the present invention.
FIG. 5a is a side perspective view showing a piston of a needleless syringe according to one embodiment of the present invention.
FIG. 5b is a side sectional view showing a piston of a needleless syringe according to an embodiment of the present invention.
FIG. 5c is a proximal end perspective view showing a piston of a needleless syringe according to one embodiment of the present invention.
FIG. 5d is a distal end perspective view showing a piston of a needleless syringe according to one embodiment of the present invention.
FIG. 6a is a side perspective view showing a sparger of a needleless injector according to an embodiment of the present invention.
FIG. 6b is a side cross-sectional view illustrating a squirt device of a needle-free injector according to an embodiment of the present invention.
FIG. 6c is a proximal end perspective view of a dispenser of a needleless injector according to one embodiment of the present invention.
FIG. 6d is a perspective view of the distal end showing a dispenser of a needleless injector according to one embodiment of the present invention.
FIG. 7a illustrates various configurations of a groove in a squirt device of a needleless injector according to an embodiment of the present invention.
7a and 7b illustrate various configurations of a groove in a sparger of a needleless injector according to an embodiment of the present invention.
FIG. 7c illustrates various configurations of a groove in a squirt device of a needleless injector according to an embodiment of the present invention.
FIG. 7d illustrates various configurations of grooves in the effusive device of a needleless injector according to an embodiment of the present invention.
FIG. 7e illustrates various configurations of grooves in a squirt device of a needleless injector according to an embodiment of the present invention.
FIG. 7f illustrates various configurations of a groove in a squirt device of a needleless injector according to an embodiment of the present invention.
FIG. 7g illustrates various configurations of grooves in the effusive device of a needleless injector according to an embodiment of the present invention.
FIG. 7h illustrates various configurations of a groove in a squirt device of a needleless injector according to an embodiment of the present invention.
FIG. 7i illustrates various configurations of a groove in a squirt device of a needleless injector according to an embodiment of the present invention.
FIG. 8a is a side perspective view showing a trigger that has not been rotated about a central axis of a needleless injector according to one embodiment of the present invention.
FIG. 8b is a side cross-sectional view showing a needleless syringe according to an embodiment of the present invention rotated by 90 °.
FIG. 8c is a proximal end perspective view showing a needleless injector according to one embodiment of the present invention.
FIG. 8d is a distal end perspective view showing a needleless syringe according to one embodiment of the present invention.
FIG. 9a is a proximal end perspective view showing a safety clamp of a needleless syringe according to one embodiment of the present invention.
FIG. 9b is a side perspective view showing a safety clamp of a needleless injector according to one embodiment of the present invention.
FIG. 10a is a side perspective view showing an engine housing of a needleless syringe according to one embodiment of the present invention.
FIG. 10b is a side sectional view showing the engine housing of the needle-free injector according to one embodiment of the present invention.
FIG. 10c is a proximal end perspective view showing the engine housing of the needleless injector according to one embodiment of the present invention.
FIG. 10d is a distal end perspective view showing the engine housing of the needleless injector according to one embodiment of the present invention.
FIG. 11a is a side perspective view showing a valve body of a needleless syringe according to an embodiment of the present invention. FIG. 11C is a cross-sectional view showing the side, and FIG. 11C is a perspective view showing the proximal end.
FIG. 11b is a side sectional view showing a valve body of the needleless injector according to one embodiment of the present invention.
FIG. 11c is a proximal end perspective view showing the valve body of the needleless injector according to one embodiment of the present invention.
FIG. 12a is a side perspective view of a needleless syringe according to one embodiment of the present invention, showing the sealing ferrule before being mechanically mounted around a valve body and an engine housing.
FIG. 12b is a side cross-sectional view of the needleless syringe according to one embodiment of the present invention, showing the sealing ferrule before being mechanically mounted around the valve body and the engine housing.
FIG. 12c is a proximal end perspective view of the needleless syringe according to one embodiment of the present invention, showing the sealing ferrule prior to mechanical attachment around the valve body and the engine housing.
FIG. 13a is a side perspective view showing a threaded stem guide of a needleless injector according to an embodiment of the present invention, partially in cross-section.
FIG. 13b is a side cross-sectional view, partly in cross-section, showing the threaded stem guide of the needleless injector according to one embodiment of the present invention.
FIG. 13c is a proximal end perspective view showing a threaded stem guide of a needleless injector according to an embodiment of the present invention, partially in section.
FIG. 13d is a distal end perspective view showing a threaded stem guide of a needleless injector according to an embodiment of the present invention, partially in cross-section.
FIG. 14a is a side perspective view showing a valve stem of a needleless injector according to one embodiment of the present invention.
FIG. 14b is a side sectional view showing a valve stem of a needleless injector according to an embodiment of the present invention.
FIG. 14c is a proximal end perspective view showing the valve stem of a needleless injector according to one embodiment of the present invention.
FIG. 15a is a side perspective view showing a valve spring of a needleless injector according to one embodiment of the present invention, in a relaxed state.
FIG. 15b is a side perspective view showing the valve spring of the needleless injector according to an embodiment of the present invention in a compressed state.
FIG. 16 is a diagram illustrating driver speed for one embodiment of the present invention during an injection.
[Explanation of symbols]
[0063]
1 center axis
2 proximal end
3 distal end
100 gas pressure needleless syringe
101 Engine assembly
201 Housing
202 Ampoule diameter
203 piston diameter
204 Ejector diameter
205 drive diameter
206 outer surface
207 wheel
208 Inner wall
209 opening
210 Top
211 discharge passage
212 inner wall
213 Exterior wall
214 inside
215 finger catch
216 arc
217 Surface with texture
218 Latch Cage Mechanism
219 Serrated Ridge
220 Clamp recess
300 ampoule cap
301 inside
302 outer surface
400 plunger
401 wall
402 Ridge
403 Proximal end
404 distal end
500 piston
501 end spread part
502 proximal end
502 dent
503 chamber
504 Enlarged cup wheel edge
505 magnifying cup
600 Eruptor
601 groove
602 distal end
603 spout cup
604 Valve stem receiving recess
605 Fixing ring
606 distal surface
607 Proximal plane
800 trigger
801 recess
802 Cage hook mechanism
803 Cage hook mechanism
804 side
900 safety clamp
902 feet
1000 engine housing
1003 Internal chamber
1001 Large diameter part
1002 small diameter part
1004 circular dent
1005 opening
1006 Sealed ridge
1100 valve body
1101 Sealed edge
1103 Gasket
1104 distal interior
1104 medial distal section
1105 Thread engagement part
1106 First axis cavity
1107 shoulder
1108 Second axis cavity
1109 Valve stem guide
1110 Ejector receiving chamber
1111 gripper
1112 gripping element
1200 Hermetic Fitting Wheel
1201 distal part
1202 Proximal
1300 Threaded Valve Guide
1301 Exterior wall
1302 Cylindrical internal cavity
1303 Valve stem guidance pane
1304 Ventilation opening
1305 hole
1306 Spring seat
1307 Ridge
1400 valve stem
1401 Cylindrical rod
1402 flat proximal end
1403 distal end
1404 Spring Ridge
1405 valve head
1500 Valve spring
1501 Proximal end
1502 distal end

Claims (50)

A needleless syringe suitable for injecting fluid through a surface,
A housing containing the fluid and further comprising at least one opening;
At least one latch retainer mechanism disposed on an outer surface of the housing;
An engine mounted inside the housing and further containing gas;
A driver that pushes the fluid out of the housing and is slidably disposed inside the housing;
A trigger coupled to the housing;
At least one retainer hook mechanism positioned on the trigger and aligned with the latch retainer mechanism. 2. The system of claim 1, wherein the at least one retainer hook mechanism and the at least one latch retainer mechanism are operatively associated to move the trigger only axially in the direction of the at least one opening. Needle syringe. The needleless syringe of claim 1, wherein the engine further comprises a valve. The needle-free injector further comprises a disperser fixed to the housing,
The effusive device has at least one groove disposed therein;
Further, the valve
A valve stem having a circular ridge,
A valve head fixed to the valve stem and the circular ridge,
A valve stem guide fixed to the engine;
The needleless syringe according to claim 3, comprising a spring having a first end against the circular ridge and a second end against the valve stem guide. 5. The needleless syringe of claim 4, wherein the valve opens when the trigger is depressed. The needleless syringe according to claim 1, wherein the driver comprises a piston and a plunger. The plunger is symmetric;
The needleless syringe of claim 6, wherein the plunger forms a substantially hermetic seal with the housing. The plunger is
A conical front end,
The rear end of the cone,
The needleless syringe according to claim 6, comprising a cylindrical body. The needleless syringe of claim 8, wherein the plunger further comprises at least one ridge surrounding the cylindrical body. 7. The needleless syringe of claim 6, wherein the piston comprises an expansion cup. Further comprising an ampoule cap detachably attached to the housing,
The needleless syringe of claim 1, wherein the ampoule cap forms a hermetic seal over the opening in the housing. The needleless syringe of claim 1, wherein the housing further comprises an exhaust passage. The needleless syringe of claim 1, further comprising an end having a surface on which the trigger does not slide. The effusive device further comprises a fixing ring,
The needleless syringe of claim 4, wherein the engine further comprises at least one grip. Further comprising a safety clamp detachably attached to the housing,
2. The needleless syringe of claim 1, wherein the safety clamp prevents the trigger from moving axially of the at least one opening relative to the housing. The needleless syringe of claim 1, wherein the housing further comprises at least one finger receiver. The housing further comprises two finger receivers arranged opposite to each other;
2. The needleless syringe of claim 1, wherein the finger rest further comprises a non-slip surface. A needleless syringe suitable for injecting fluid through a surface,
A housing containing the fluid and further comprising at least one opening;
An engine mounted inside the housing and further containing gas;
A driver that pushes the fluid out of the housing and is slidably disposed inside the housing;
A trigger coupled to the housing;
A valve attached to the engine,
Depressing the trigger causes the valve to open,
Needleless syringe, wherein the valve can withstand repeated opening. The valve is
A valve stem having a circular ridge,
A valve head fixed to the valve stem and the circular ridge,
A valve stem guide fixed to the engine;
19. The needleless syringe of claim 18, comprising a spring having a first end against the circular ridge and a second end against the stem guide. The needleless syringe further comprises a squirt device fixed to the housing,
19. The needleless syringe of claim 18, wherein the effusive device has at least one groove disposed therein. 19. The needleless syringe of claim 18, wherein the driver comprises a piston and a plunger. The plunger is symmetric;
22. The needleless syringe of claim 21, wherein the plunger forms a substantially hermetic seal with the housing. The plunger is
A conical front end,
The rear end of the cone,
22. The needleless syringe of claim 21, comprising a cylindrical body. 24. The needleless syringe of claim 23, wherein the plunger further comprises at least one ridge surrounding the cylindrical body. 22. The needleless syringe of claim 21, wherein the piston comprises an expansion cup. Further comprising an ampoule cap detachably attached to the housing,
19. The needleless syringe of claim 18, wherein the ampoule cap forms a hermetic seal over the opening in the housing. 19. The needleless syringe of claim 18, wherein the housing further comprises an exhaust passage. 19. The needleless syringe of claim 18, wherein the trigger further comprises an end having a non-slip surface. The trigger further comprises at least one retainer hook mechanism;
19. The needleless syringe of claim 18, wherein the housing further comprises at least one latch retainer mechanism. The effusive device further comprises a fixing ring,
21. The needleless syringe of claim 20, wherein the engine further comprises at least one grip. Further comprising a safety clamp detachably attached to the housing,
19. The needleless syringe of claim 18, wherein the safety clamp prevents the trigger from moving axially of the at least one opening relative to the housing. 19. The needleless syringe of claim 18, wherein the housing further comprises at least one finger receiver. The housing further comprises two finger receivers arranged opposite to each other;
19. The needleless syringe of claim 18, wherein the finger rest further comprises a non-slip surface. A needleless syringe suitable for injecting fluid through a surface,
A housing containing the fluid and further comprising at least one opening;
An engine mounted inside the housing and further containing gas;
A driver that pushes the fluid out of the housing and is slidably disposed inside the housing;
A trigger coupled to the housing;
At least one gripper disposed on the engine. 35. The needleless syringe of claim 34, wherein the engine further comprises a valve. The needle-free injector further comprises a disperser fixed to the housing,
The effusive device has at least one groove disposed therein;
Further, the valve
A valve stem having a circular ridge,
A valve head fixed to the valve stem and the circular ridge,
A valve stem guide fixed to the engine;
36. The needleless syringe of claim 35, comprising a spring having a first end against the circular ridge and a second end against the stem guide. 37. The needleless syringe of claim 36, wherein the valve opens when the trigger is depressed. 35. The needleless syringe of claim 34, wherein the driver comprises a piston and a plunger. 39. The needleless syringe of claim 38, wherein the plunger is symmetric, and the plunger forms a substantially hermetic seal with the housing. The plunger is
A conical front end,
The rear end of the cone,
39. The needleless syringe of claim 38, comprising: a cylindrical body. 41. The needleless syringe of claim 40, wherein the plunger further comprises at least one ridge surrounding the cylindrical body. 39. The needleless syringe of claim 38, wherein the piston comprises a dilation cup. Further comprising an ampoule cap detachably attached to the housing,
35. The needleless syringe of claim 34, wherein the ampoule cap forms a hermetic seal over the opening in the housing. 35. The needleless syringe of claim 34, wherein the housing further comprises an exhaust passage. 35. The needleless syringe of claim 34, wherein the trigger further comprises an end having a non-slip surface. The trigger further comprises at least one retainer hook mechanism;
35. The needleless syringe of claim 34, wherein the housing further comprises at least one latch retainer mechanism. The effusive device further comprises a fixing ring,
37. The needleless syringe of claim 36, wherein the needleless syringe further comprises at least two grips. Further comprising a safety clamp detachably attached to the housing,
35. The needleless syringe of claim 34, wherein the safety clamp prevents the trigger from moving axially of the at least one opening relative to the housing. 35. The needleless syringe of claim 34, wherein the housing further comprises at least one finger receiver. The housing further comprises two finger receivers arranged facing each other;
35. The needleless syringe of claim 34, wherein the finger rest further comprises a non-slip surface.

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