Delivery device for injectable materials

Abstract: An apparatus for selecting the penetration depth of the end of a tubular delivery vehicle into a membrane, comprising: a body portion having the tubular delivery vehicle extending therefrom, said body portion having a receptacle therein in communication with said tubular delivery vehicle; a first member received on said body portion and fixed with respect to the tubular delivery vehicle; and a second member received on said fast member and selectively positionable thereon, said second member having a distal end portion disposed adjacent to the end of said delivery vehicle and adjustable with respect thereto by selectively positioning said second member on said first member.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to the field of injection devices wherein a quantity of an injectable material may be delivered into humans or other mammals. More particularly, the invention relates to delivery devices where the exact position at which the material enters the body must be closely controlled. An apparatus according to the preamble of claim 1 is known from WO-A-90/04988. Background Art Injectable materials for human and other mammalian uses are typically injected into the body through a delivery vehicle such as a hypodermic needle. This type of needle is generally a hollow tube terminating at one end in a sharp tip. The needle is typically coupled to one of several known delivery devices which feed the needle, such as a syringe body (to form a hypodermic syringe), or tubing leading to a bag or other container, in the case of larger volumes of injectable material. The hypodermic syringe body provides a stable, sterile environment in which a volume of the injectable material may be held for direct injection through the needle. It also provides a physical platform that an operator, such as a physician or nurse, may grip to control the depth and orientation of the needle during the injection of the injectable material into the human, or other mammalian body. In order to pass the injectable material from the syringe body through the needle, a plunger, having a piston formed on the forward end thereof, is reciprocally received within the syringe body. By pushing the plunger inwardly of the syringe body, the piston is forced inwardly of the syringe body to displace the injectable material in the syringe body through the needle. In US-A-3 605 744 there is disclosed an injection apparatus for per-injection and complete injection of medicant into tissue which apparatus comprises an elongated injector housing with an injector needle mounted therein. A spring biased plunger is provided to deliver a predetermined amount of medicant to the needle, which injected into the tissue in esponse to plunger movement. The penetration depth of the needle can be adjusted by a cam or the like. WO-A-90/04988 discloses a syringe guide with adjustment of the depth to which the needle penetrates, the guide comprising a body having one end provided with a sliding base which is adjustable in position by means of a screw, and whose other end includes a sliding part fixed to the syringe and loaded by a spring which, on relaxing, causes the needle to be plunged into the skin to a predetermined depth. GB-A-1 444 355 discloses a device for tattoo branding of animals adapted to be attached to a hand tool providing high speed reciprocating motion said devices comprising a slide to which is attached a cluster or comb of a plurality of juxtaposed substantially parallel steel needles extending in the direction of slide movement and made fast to such slide with their pointed ends projecting to varying extents in a manner such that the needles will always penetrate the animal skin to varying depths. One prior art use of hypodermic syringes is as a delivery system for collagen, sold under the trade names Zyplast® and Zyderm® by Collagen Corporation, Palo Alto California, which may be used for cosmetic or other purposes. In this application, the syringe is used to deliver a quantity of collagen interdermally to eliminate an undesirable cosmetic appearance of the skin at that location. For example, where, as a result of an unrelated surgery, body tissue does not fully support the overlying skin (epidermis), collagen may be injected under the epidermis, deep into the dermis, to provide a supporting mass. Likewise, where an individual has undesired wrinkles which are superficial, collagen may be injected just under the epidermis, to increase the volume of tissue under the epidermis surface to minimize or eliminate the wrinkles. Using a hypodermic syringe to inject the required amount of collagen at a particular location within the dermis requires a substantial degree of skill. In particular, the practitioner injecting collagen must simultaneously control the depth, orientation and position of the needle at a particular injection site, while providing an inward force on the plunger that is sufficient to force a controlled volumetric flow rate of high viscosity collagen out of the needle and into the exact location in the dermis that will provide the desired cosmetic effect. Each of the individual parameters of plunger force, needle depth, needle orientation and needle position independently contribute to the ultimate cosmetic effect of the injection. However, the structure of a typical hypodermic syringe can make simultaneous control of these different parameters difficult for even skilled practitioners. In particular, to force the collagen through the needle, the practitioner must articulate the thumb of the hand holding the syringe to the back of the rearwardly extending plunger while simultaneously wrapping two or more fingers about the syringe body or over the flange at the back of the syringe body. Then, the practitioner must press the plunger inwardly of the syringe body to physically displace the collagen in the syringe body, and thus, force the collagen out of the needle. As a result, during the period in which the practitioner must exercise precise control over the location of the needle tip, the needle tip is positioned several inches from the nearest portion of the practitioner's hand. Additionally, the syringe effectively pivots about the practitioner's fingers. Therefore, any movement of the practitioner's thumb on the plunger that is not collinear with the plunger will result in an equal and opposite movement of the needle tip. Such movement, when the needle is already positioned at a precise location in the dermis, will move the tip out of position and the collagen will be mis-delivered. The locating of the needle tip at the proper depth within the dermis is also difficult for the practitioner. To engage the tip of the needle at the proper injection depth, the practitioner may move the needle inwardly and outwardly with respect to the surface of the skin (epidermis). However, there is no visual reference point, other than the end of the syringe body, from which the practitioner can easily determine the extent that the needle extends into the dermis. Thus, the needle tip may be placed too deep, or too shallow, for the intended application. Additionally, as the practitioner depresses the plunger to displace collagen from the needle, the entire syringe may rock back and forth and thus vary the depth of the needle tip at the injection site. To further complicate the collagen injection regimen, a practitioner typically does not inject a preselected quantity of collagen to create a desired cosmetic effect, but instead typically determines the total injection quantity by monitoring the effect of the injected collagen on the injection site during the injection. As the injection site begins to take on the desired appearance, the practitioner must closely control the quantity of collagen leaving the needle to ensure that the overall quantity of collagen ultimately entering the injection site does not exceed the quantity necessary to provide the desired cosmetic effect. It should be appreciated that the person (practitioner) injecting the collagen must have good, steady control of the fingers, hand and arm and also have excellent eye-hand coordination to be an effective provider of cosmetic collagen injections. These qualities are not always present in individuals, and this has limited the availability of collagen therapy to patients. In addition to the cosmetic applications for injectable collagen described above, there are newly developed applications for treatment of urinary incontinence and rectal incontinence. These latter applications require delivery of larger quantities of injectable collagen to a precise location within the body. And, although a catheter rather than a needle may be used at the point of injection in some instances (treatment of urinary incontinence for example), accurate delivery of quantity of injectable material is very important. Therefore, there exists a need in the art to provide a delivery device for materials, including collagen and other injectable materials which provides for an easily usable means of determining the depth of penetration of the needle into the dermis for cosmetic applications, to ensure proper delivery of collagen, or other materials, to a desired injection site. SUMMARY OF THE INVENTION The present invention provides an apparatus for selecting the penetration depth of the end of a tubular delivery vehicle into a membrane as defined in claim 1. The apparatus provides a visual and/or physical indication of the extent of needle penetration into the dermis to allow the practitioner of the delivery device to ensure delivery of the injectable material to the proper location within the dermis at the injection site. Preferably, the depth gauge is mounted about the syringe needle, and is adjustable on threads provided on the distal end of the syringe body. The extension of the needle past the end of the depth gauge is calibrated to equate with the preferred depth below the surface of the skin at which the product in the syringe is to be delivered. The practitioner of the delivery device can thus precisely deliver the injectable material into a specific location under the epidermis. The depth guide may be used in conjunction with any needle or tube type delivery device where the portion of the needle or tube extending from a baseline position is critical to the delivery of the material to a desired location. These and other features of the invention will be apparent from the following description of the embodiments, when read in conjunction with the following drawings, wherein: BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a delivery device which is equipped with the apparatus for selecting the penetration depth of the present invention; Figure 2A is an enlarged view of the needle depth guide of the delivery device of the present invention; and Figure 2B is an enlarged view of the needle depth gauge of Figure 6A moved to a second position. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is useful in the delivering of a fluid or other injectable material into desired locations in humans and other mammals, such as the injection of collagen, or the injection of other viscous fluids or injectable materials through a needle or other delivery vehicle/conduit, such as a catheter, into humans and other mammals. The invention is also particularly well suited to the injection of such materials where different portions of the volume of the material in a delivery device such as a syringe are injected into one or more injection sites in a single patient during multiple insertions of the needle or catheter into that single patient. In addition, the invention is equally well suited to situations where the quantity of material introduced during each injection is critical or is determined by monitoring the effect of the material on the patient as it is injected. Referring now to Figure 1, a perspective view of a delivery device 10 and a pneumatic supply 100 is shown. The delivery device 10 generally includes a conformable body 12 having a syringe 40 with injectable material such as collagen selectively receivable therein. The body 12 is configured to fit easily in a practitioner's hand, such that a trigger 14 thereon may be easily actuated between an "off", preferably extended, position and an "on", preferably depressed, position. The body 12 of the delivery device 10 preferably includes a separable syringe housing 16 and a valve housing 18 connected at a fitting 20, such as a bayonet or j-lock fitting, which permits easy separation and re-connection of the syringe housing 16 and the valve housing 18. The syringe housing 16 includes a front opening 26 through which the distal end portion 41 of a syringe 40 projects, and the valve housing 18 includes a rear fitting portion 22, preferably configured as a quick disconnect luer fitting, to allow quick connection, and disconnection, of a pneumatic supply 100 to the body 12. The trigger 14 is connected to the syringe housing 16 about a pivot point within the syringe housing 16 and may be moved about the pivot point between an extended, or no flow, condition and a depressed, or flow condition. The trigger 14 may also be positioned between the extended and retracted positions to vary the flow rate of the collagen delivered to an injection site as will be further described herein. The body 12, in conjunction with the positioning of the trigger 14 thereon, provides a delivery device which may be firmly gripped in an operator's hand and easily maneuvered to provide control of the position of a needle 48 positioned on the distal end portion 41 of the syringe body 40 which extends from the front of the syringe housing 16. In the device shown, the valve housing 18 is configured as a generally cylindrical member, and the syringe housing 16 includes a reduced diameter portion 17 which terminates in a semi-spherical portion 19 forming the forward end of the syringe housing 16. Thus, when a practitioner holds the delivery device 10 in his or her hand, the practitioner's thumb and index finger will engage the interface of the semi-spherical portion 19 and reduced diameter portion 17, while the remaining fingers of the hand can extend around, and thus grip, the cylindrical valve housing 18 portion of the body 12. Alternatively, the practitioner may wrap his or her fingers about the body 12, with the thumb extending forwardly such that the last digit of the thumb is positioned over the trigger 14. Thus, a single hand operable device for delivering a collagen dispersion into an injection site is provided. Further, as the fingers of the practitioner's hand are located adjacent the front, or needle end of the delivery device 10, and the practitioner's thumb is not extending rearwardly to press the projecting end of a plunger, the likelihood that the needle 48 will move into an undesired location as the collagen is injected is significantly decreased. In the device shown in Figure 1, the syringe 40 is a standard injection syringe, wherein the plunger has been removed. Syringe 40 includes an outer body portion with an outwardly extending flange on the rear end thereof and a luer fitting 50, with a needle 48 extending therefrom, located on the distal end portion 41 thereof. As is also shown in Figure 1 a pneumatic supply 100, such as a CO 2 bottle 102 (shown in phantom), is connected to a regulator 104. The CO 2 bottle 102 is received in a housing 108, and the housing 108 is sized to permit the practitioner to slip the entire pneumatic supply 100 into a pocket or clip the pneumatic supply 100 to an article of clothing. The regulator 104 is a standard spring biased piston configuration (not shown) wherein a spring loads a piston against an orifice in communication with the CO 2 source. The piston moves on and off the orifice to regulate the pressure of the CO 2 on the downstream side of the valve. An adjustment knob 150 is provided on the exterior of the regulator 104,. which when turned can increase or decrease the spring compression. A relief valve 114 is also provided on the pneumatic supply 100. The relief valve is one typical of those in the art, which spring loads a valve on a seat. If the pressure at the relief valve 114, which is located intermediate the regulated outlet from the CO 2 bottle and the delivery device 10, exceeds a pre-detemnined limit, the relief valve 114 will vent the pressurized fluid to atmosphere. A length of tubing 122 extends from the regulator 104 to the fitting on the fitting portion 22 of the delivery device body 12 to deliver regulated fluid to a control valve system. Referring now to Figures 2A and 2B, the configuration of the needle depth guide 300 is shown. The needle depth guide 300 is used to allow a practitioner to select a specific extension of the needle tip beyond the end of the depth guide which corresponds to the desired depth of the injection, and then insert the needle until the skin, or other membrane into which the injection is being made, contacts the depth guide. In Figure 2A, the needle 48 extends the minimum distance from the depth guide 300, and in Figure 2B, the needle extends the maximum distance from the depth guide 300. The preferred depth guide 300 configuration includes a cap 302 which is received over the extending luer fitting 50 of the syringe 40, and an adjustable ferrule 306. The cap 302 includes a plurality of extending tines 308 which are spaced about the perimeter of the lower portion of the cap 302 and an extending threaded portion 310. The ferrule 306 includes an internally threaded first portion 312 and an extending tubular guide 314 which terminates in an open end 304. The extending tines 308 position and secure the cap 302 on the ribbed luer fitting 50 of the syringe 40. Preferably the luer fitting 50, with the needle depth guide 300 thereon, is supplied to the practitioner separately from the syringe 40, and the practitioner connects the luer fitting 50 over the distal end portion 41 of the syringe 40. By turning the ferrule 306 on the threaded portion 310 of the cap 302, the position of the end 304 of the tubular guide 314 may be changed with respect to the distal end of the needle 48, and thus the extension of the needle 48 beyond the end 304 of the tubular portion 314 may be adjusted. The extension of the needle 48 past the end 304 of the tubular portion 314 may be used to set the depth below the skin to which the needle 48 penetrates. Thus, for a cosmetic application, when a specific quantity of collagen, or other material, is delivered to the dermis with the delivery device, the practitioner adjusts the depth guide 300 so that the desired needle 48 penetration depth under the epidermis is equal to the extension of the needle 48 beyond the end of the tubular guide 314. Preferably, the depth guide 300 is configured to allow the distal end portion of the needle 48 to extend between about 0.030 and 0.160 inches from the end of the tubular guide 314 to ensure that the collagen, or other material, is delivered to the appropriate layer of the dermis. By turning the ferrule 306 on the threaded portion 310 of the cap 302, these dimensions for the extension of the needle end past the open end 304 of the tubular guide 314 may be provided. When the ferrule 306 is fully inwardly turned over the threaded portion 310 of the cap 302, the threaded first portion 312 engages the outer end of the cap 302 which provides the stop to ensure that no more than 0.160 inches of needle 48 will extend past the open end 304 of the tubular guide 314. Likewise, the threads on the threaded portion 310 terminate such that the ferrule 306 cannot be turned in a direction counter from the fully retracted position to a position wherein less than 0.030 inches of needle 48 extend past the end 304 of the tubular portion 314. It is specifically contemplated that the practitioner will set the needle depth by turning the ferrule to obtain the desired needle 48 extension, and then permit the end 304 of the tubular portion 314 to touch the patient's epidermis. However, the end 304, when calibrated by the practitioner to represent a reference point for the amount of needle 48 extending therepast, may move the needle tip within the patient with fine control by using the end 304 as a reference point. Although the delivery device 10 has been principally described with reference to the delivery of collagen to dermal locations, the delivery device 10 may also be used to control the delivery of collagen, and other injectable materials, to other locations and through delivery vehicles other than needles. For example, the device could be used to provide control over catheter delivered collagen to locations such as the urinary sphincter, or other more internal locations within the body.

Claims: An apparatus for selecting the penetration depth of the end of a tubular delivery vehicle (48) into a membrane, comprising: a body portion (50) having the tubular delivery vehicle (48) extending therefrom, said body portion having a receptacle therein in communication with said tubular delivery vehicle; and a second member (306) received on a first member (302) and selectively positionable thereon, said second member having a distal end portion disposed adjacent to the end of said delivery vehicle (48) and adjustable with respect thereto by selectively positioning said second member on said first member, characterized in that the first member (302) is received on said body portion (50) and fixed with respect to the tubular delivery vehicle (48). The apparatus of Claim 1, wherein said first member (302) includes threads thereon, and said second member (306) includes mating threads thereon. The apparatus of Claim 1 or 2 wherein said tubular delivery vehicle is a hypodermic needle (48). The apparatus of Claim 1,2 or 3 wherein said body member includes a luer fitting (50), and said first member (302) is selectively receivable on said luer fitting. The apparatus of any one of the preceding claims, wherein said distal end portion extends around the delivery vehicle (48). The apparatus of any one of the preceding claims, wherein: said first member (302) includes a threaded portion (310); and said second member (306) includes an internally threaded portion (312) received over said threaded portion and an extending tubular portion (314) extending circumferentially about said tubular delivery vehicle (48). The apparatus of Claim 6, wherein said second member (306) may be positioned at a first position with respect to said threaded portion (310) at which said tubular delivery vehicle (48) extends a maximum distance from said second member, at a second position with respect to said threaded portion at which said tubular delivery vehicle extends a minimum distance from said second member, and at intermediate positions between said first position and said second position. The apparatus of any one of the preceding claims, wherein said membrane is a human dermis.

Inventors: DROSTE AMY M, FEUHRER JAMES J, FISHER ROBERT J, KURJAN CHRISTINE M, DROSTE, AMY M., FEUHRER, JAMES J., FISHER, ROBERT J., KURJAN, CHRISTINE M.
Applicants: COLLAGEN AESTHETICS INC, COLLAGEN AESTHETICS,INC.
Application year: 1995
Main classification: A61M5
IPC codes: A61M5, A61F2