US2512568A - Hypodermic injection device - Google Patents

Description

June 20,1950 J. A. SAFFIR HYPODERMIC INJECTION DEVICE 2 Sheets-Sheet 1 Filed Aug. 13, 1946 ,QiIIIIILZI} I June 20, 1950 J. A. sAFFlR HYPODERMIC INJECTION DEVICE 2 Sheets-Sheet 2 Filed Aug. 13, 1946 24,64 Ff/A/ WA X if PAEA/T/A/ WAX A Patented June 20, 1950 UNITED STATES PATENT OFFICE Claims.

This invention relates to the art of hypodermic injection devices. More particularly it pertains to devices adapted to administer therapeutic substances by subcutaneous or intramuscular injection, and to devices adapted for withdrawing samples from the animal system, such as blood specimen. In its preferred embodiments, the invention is directed to hypodermic injection devices which afiord optimum conditions of sterility and control during the interval of administering the therapeutic substance or withdrawing the specimen.

Despite the effectiveness of hypodermic injection devices in general use, certain difilculties and objectionable features prevail in their adaptation. Thus the available devices which are practicable do not permit early enough detection of entry into a vein. Since it is necessary for the blood to transit the entire length of the steel needle before it is visible to the eye of the physician, there is no way of observing the interval at which the blood commences to flow.

It is therefore not infrequent that the penetration of the needle, otherwise referred to herein as the cannula, has been carried through one or more veins without there being any indication of the position of the needle tip at any time. The results of such excessive penetration and trauma are unnecessary hemorrhage at the point of incision as well as an objectionable discoloration, frequently with painful discomfort at the area of injury by the needle.

Other limitations are the brittleness manifested by ferrous needles and the tendency on occasion to break as a result of the puncturing or penetrating operation, leavingneedle fragments embedded beneath the skin and underlying tissue. Such accidents may be of serious consequence, necessitating resort to surgery for removal of the needle fragments. Other hazards which may occur with hard steel needles are illustrated by the unintentional and frequently harmful penetration of the peridental membrane or periosteum and into the bone structure for a comparatively short distance, depending upon the pressure applied.

It is an object of this invention to obviate such difliculties and uncertainties as hereinabove indicated.

Another object is to provide a hypodermic injectlon device which will permit observation, at least for the length of the cannula or needle, during the interval that a therapeutic substance is being administered or a specimen is being withdrawn.

Another object is to attain a needle which will manifest a minimum hazard as a result of breakage, and which lends itself to expedient sharpening.

An additional object is to produce a hypodermic injection device wherein the needle or cannula is adapted to permit observation during usage and is integral with the body portion of the barrel, merely a plunger or piston being necessary for reciprocation within said body portion or barrel.

A further object is to furnish an injection device wherein the needle and barrel portions are integral with each other, the latter also comprising the ampule.

An important object is to devise a non-metal hypodermic injection device, both as to the barrel portion and the needle or cannula.

Another object is the obtention of a non-metal hypodermic injection device" which lends itself to maintaining sterile conditions of usage and is adapted for self-medication.

Other objects, advantages, and features of the invention will become apparent from the following description read in connection with the accompanying drawings in which similar elements are designated by like numerals:

Fig. l is a longitudinal section of a. hubless tubular needle comprising a single element in the form of a unitary segment of plastic or synthetic resinous material, with its attachment to a Cock type of syringe device, shown by a fragmentary dotted line indication.

Fig. 2 relates to a cross-sectional view taken along the line 2-2 of Fig. 1.

Fig. 3 presents in longitudinal section a cannula provided with a threaded hub portion, and its attachment to a Cook type of syringe, the latter being shown in fragmentary portion by dotted lines.

Fig. 4 provides a showing in longitudinal section of a plastic or resinous needle for attachment to a Luer type of syringe.

Fig. 5 is directed to a longitudinal sectional view of a Luer type injection device, the barrel and tubular needle being integrally formed and of plastic or synthetic resinous derivation.

Fig. 6 pertains to a, longitudinal sectional view of an injection device, derived from synthetic resin, as an integral unit including the needle and the barrel, the latter also functioning as the Fig. 8 indicates in longitudinal sectional view the injection device of Figs. 6 and 7, with the ampule-barrel portion compressed after use of the device.

Fig. 9 comprises in longitudinal section a device similar to that shown in Figs. 6-8, but with a modified form of sheath, also indicated by sectional view.

Fig. 10 is drawn to a cross-sectional view taken along line ill-l0 of Fig. 9.

Fig. 11 pertains to a collapsible multiple compartment barrel type of hypodermic injection device, the needle and syringe being of a synthetic plastic and formed as a single element, the device being internally provided with a protective coating.

Fig. 12 is a cross-sectional view of Fig. 11 taken along line |2-l2.

Fig. 13 relates to another modification of integral plastic needle and collapsible barrelampule device, shown in longitudinal section, with a resilient cover over the collapsible portion.

Fig. 14 is directed to a longitudinal sectional view of the device shown in Fig. 13, with the barrel-ampule portion indicated in its collapsed form.

Referring more particularly to the features of invention embodied in the modification shown by the various figures of the drawing, the hollow, fluid transmitting needle or cannula of Fig. 1 is of hubless construction and comprises the injection end I, capsule or ampule piercing end 2, and collar 3 for anchoring the needle to the syringe, or injection device which is of the Cook type. The needle and collar combination is desirably a one-piece transparent or translucent element comprising a unitary mass of resinous material, and is in effect seamless compared with prior art devices which involve a separable needle and collar. The production of the needle may be in accordance with the known practices in the art of molding, such as molding by extrusion or casting, or even by electrophoresis.

It is a usual requisite that the material from which the needle is fabricated is of the hard resin variety, but the properties of the needle may be altered to satisfy predetermined requisites. Preferably the hardness should be less than that which will penetrate bone. structure and relative to which peridental membrane or periosteum will manifest substantial resistance to penetration. Nevertheless it should, in its molded or polymerized form, manifest suilicient hardness to permit or lend itself to sharpening in the form of a sharp edge of point, characteristic of the hypodermic needle adapted to pierce and penetrate the skin and adjacent underlying tissue.

The resinous material within the contemplation of the invention herein is of organic derivation and should desirably be comparatively inert to water at sterilizing temperature as well as to chemical or therapeutic agents. It will however be understood that a reasonable latitude in the inertness characteristic of the resin is contemplated, especially in view of the protective treatment or covering which may be applied, as indicated hereinbelow. Illustrative of organic resins that may be utilized in forming the hollow, fluid transmitting needle disclosed in the various fi ures oi the drawings are the so-called chemical-resistant phenolics, hard polystyrenes, methyl methacrylates, melamine resins, and hard allyl resins, as well as the urea resins and the polyamides, otherwise referred to as the "nylon type of resin. As previously indicated, these resins are preferably translucent or transparent in order to permit observation of the prevailing conditions in the needle while the hypodermic injection device is being used.

The needle of Fig. 3 manifests the same characteristics as that shown in Fig. 1 with respect to transparency or translucency, unitary portion or mass of resin, method of fabrication, and choice of resins which may be used. This unitary needle modification includes a threaded hub 4 for securing the needle to the barrel of a Cook type of syringe and is accordingly seamless.

While any one of the specified types of resins may be used in making the needle shown in Figs. 1-3 or any other needle such as those illustrated by'the other figures of the drawing, it is within the purview of the disclosure to embody a plurality of resins. For example referring to Figs. 1-3, the injection portion of the needle and the collar 3 or threaded hub 4 may be a, polystyrene, while the ampule penetrating end may be a melamine resin. It is ordinarily most expedient and economically practicable however to form the entire needle and its appurtenances from one material, optimum types being polystyrene and methyl methacrylate.

Referring to Fig. 4, the needle comprises a one-piece device of transparent synthetic resin designated as 5, the portion 6 thereof terminating in the injection end I. The hub or attached portion 8 is provided with indentation 9 to facilitate grasping the device. It will be clear that such a unitary combination of needle and hub affords an economical device of minimum weight and maximum expediency.'

In the modification of Fig. 5, the Luer type injection device l0 involves a cylindrical type body of barrel portion II which is integrally formed as a one-piece device, or single unitary member, with needle 6. To facilitate gripping the barrel, a flanged end I! is provided which may be slightly curved. Piston i3 may be of metal, rubber or of hard synthetic resin of a type similar to that utilized in molding the needlebarrel combination. This piston corresponds with the type conventionally used, and may be supplied with a handle or knob end 14 as well as guard means (not shown) at the point of barrel entrance by the piston. This device similarly provides the features of transparency or translucency, economy and practicability referred to hereinabove.

It is particularly noteworthy that this construction tends to enhance the safety factor of the device in the art of hypodermic medication, since it obviates the tendency of needle breakage at any point, including the zone where the needle is fitted to the hub or collar in prior art devices, which point or zone is generally considered to be an area of weakness. The unitary or one-piece cast or molded device of the present invention substantially eliminates the points or areas at which shearing Stresses tend to exist and cause breakage.

An optimum type of hypodermic injection device is that contemplated by Figs. 6 to 14. In the modification shown by Figs. 6 to 9, the device I5 comprises needle l6 and ampule ll. As in the previous modifications, the needle should in its optimum adaptation be transparent or translucent and derived from a hard resin which is essentially unaffected by the various methods of sterilization, or by chemical or therapeutic agents which may be contained within the ampule.

The ampule portion which in effect comprises the barrel part of the device is fabricated from a flexible or resilient type of material, such as rubbe:- or resin, and in its optimum embodiment is translucent or transparent. It will however be understood that the entire device, including both the needle and the ampule-barrel combination may be formed from the same material, the flexi- \bility or resiliency of the ampule being determined by the comparative thinness while the tubular needle is substantially thicker and accordingly rigid.

Similarly the variation in properties as between the hard needle and the resilient syringe may be attained through the known expedients in the resin art for altering the properties of a given resin. Thus by resort to regulated or controlled variations in plasticizing a given resin, its properties may be widely altered from that of the hard type desirable for the cannula to that of the resilient or elastic type desirable for the ampule and/or barrel. Illustrative of resins which may be utilized for both the needle and ampule are the cellulose acetate or cellulose nitrate resins, the vinyl acetate-chloride conjoint polymers, polystyrene, methyl methacrylate as well as others.

The two portions, namely the needle and ampule-barrel combination, are integrally molded or combined to form a one-piece lightweight resinous hypodermic injection device. This device is of general application, and also lends itself to self medication, in view of the simplicity of its structure and manner of utilization, such as for self hypodermic medication with insulin. Moreover became of the economy features of this device which involves a comparatively low cost, it is practical to supply this syringe directly from the laboratory, appropriately sterilized and containing the predetermined medication under the conditions Or instructions that it is to be restricted to a single use and then discarded in the interest of sterile medication.

For purposes-of distributing this device in its sterile condition, it may be provided with a close fitting sheath or cover l8 conforming with the shape of the device. While this cover or sheath may be made from diversified types of material manifesting flexibility and/or resiliency, including metal foil, paper, various waxes such as paraflin, it is desirably formed from a resilient synthetic resin or from rubber. As shown in Fig. 6, this sheath l8 terminates in end portion l9 which totally overlies the ampule or barrel ll of the syringe, and is provided with a beaded or curved edge 20 to facilitate its removal. Before using this hypodermic injection device, sheath or cover It is removed, as by stretching end I9 off the barrel or ampule l1 and then displacing the sheath from the needle, or by removing in any expedient manner the protective material used.

A desirable modification of sheath or jacket is shown in Figs. 9 and 10. This sheath 22 may be derived from any of'the materials referred to hereinabove in connection with sheath l8, and

is formed with an intermediate projecting portion 23 which is of a dimension that fits within and substantially fills the lumen of cannula IS. The remainder of the sheath 22 is shaped to closely conform in a binding resiliency with the outer surface of the cannula or needle, and may terminate at 24 along the lower portion of the ampule or barrel to which it similarly clings in a mildly binding manner. It will thus be seen that both sheaths l8 and 22 are adapted to maintain the sterility of the hypodermic injection device and to retain the medicament therein until the device is utilized. While sheath l8 prevents the therapeutic agent from-flowing out of the needle, sheath or jacket 22, by virtue of projection 23, retains the medicament within the body of the ampule or syringe, preventing it from flowing into the needle. Desirable materials for this sheath are polystyrene and the cellulose acetates 0r nitrates.

In administering a therapeutic substance or in operating the device modification shown in Figs. 6

to 8, the barrel or ampule ll may be depressed as indicated at 2| in Fig. 8. It is desirable to withdraw the device from the area of penetration before the finger is removed from 2|, in order to avoid aspirating any of the drug or serum which has been administered. This is in the nature of a precaution against any tendency for the collapsed ampule or barrel I! to rebound from its depressed point as shown at 2|.

Figs. 11 and 12 are directed to another desirable embodiment of a one-piece unitary combination of flexible or collapsible barrel and transparent hard needle or cannula similar to that of Figs. 6-10. This modification 24' includes needle 25 having injection end 26, the opposing end of the cannula being merged with ampule or barrel 21. This barrel is adapted for administering two types of medicaments, one contained in ampule 28 and the other in ampule 29.

The opposing wall portions of the ampule or barrel contact at 35 to provide a tentative seal between respective chambers or compartments 28 and 29. This temporary closure is attained primarily as a result of the form in which the barrel portion is molded and the inherent tendency of the resilient or rubber-like material, which may actually be rubber, to retain its form. In the optimum embodiment of the device, the barrel and/or ampule is transparent and desirably of synthetic organic resinous material. Pressure on the end 36 of the ampule serves to establish intercourse between the two compartments 28, 29 and enables the injection of the ampule contents. The precaution of removing the device from the zone at which it has been used, before the pressure applied to end 38 is withdrawn, in order to obviate the aspirating of medicament, is applicable with this modification as in the case of the device shown in Figs. 6 to 8.

The modification contemplated by Figs. 13 and 14 is similar in its fundamental characteristics and materials utilized to that described with respect to Figs. 6 to 12. The unitary or one-piece combination device 3| includes the needle 32 and the flexible ampule-barrel portion 33. In its optimum adaptation it is transparent or translucent at least to the extent of the needle, and preferably in its entirety. As a protective housing for the ampule, it may be effectively provided with a rubber jacket 34 which is snapped over the ampule and manifests a mildly binding grip thereover. In addition to protecting the ampule, this jacket facilitates gripping the barrel portion of the device for collapsing the same. Alternatively to providing jacket 34 as a separate cover for ampule 33, the ampule may be coated, as by electrophoresis, with a film of rubber.

In lieu of a rubber jacket 34, the ampule-barrel 33 may be embraced by a resilient or rubberlike resinous cover. Similarly 33 may comprise a resilient or elastic laminated synthetic resinous material derived from layers of the same or different resins.

It will be understood that the reinforced adaptation of ampule and/or barrel illustratively described in Figs. 13 and 14 may likewise be applicable to the barrel or ampule shown in the modification of Figs. 6 to 12. Similarly, the application of a protective sheath as considered in connection with Figs. 6-10 may also be resorted to for any of the other modifications of hypodermic device disclosed. Likewise, the operating precautions to prevent re-aspirating of therapeutic substance, as described in respect to Figs. 6 to 12, pertain to the manipulative technique of the modification in Figs. 13-14. I

The scope of the disclosure contemplates hypodermic devices, exemplified by any of the modifications herein, which are in effect laminated articles derived from compatible synthetic resinous material or combinations of resinous material with other materials, such as rubber. To attain the desired translucency or transparency, properties of the optimum embodiments of the invention, the materials determining the laminated article should have similar indices of refraction.

Concerning perfecting details of the invention, where the medicament is a substance which manifests some reactive tendency toward the material from which the device is fabricated, or where the material of the hypodermic device is not entirely inert and may absorb water or be afiected by the therapeutic substance utilized, the internal surface of the device is desirably coated with a substance which will minimize any such detrimental effect upon the therapeutic substance or the device. By way of illustration referring to Figs. 11 and 12, the internal surface of the hypodermic injection means is shown coated with an inert substance Ill adapted to prevent direct contact between the medicament and the walls of the device. Such a coating may be parafiln wax as well as various synthetic resins which are essentially unaffected by the therapeutic substance contemplated, the choice of coating material beins subject to substantial variations within the skill of the art dependent upon the compatibility between the hypodermic device and the medicament.

For example, where the hypodermic injection device comprises a urea resin, which manifests a water absorption tendency, and the therapeutic substance is in the form of an aqueous solution of predetermined concentration, the desirability of an inert film to prevent contact of the medicament with the urea resin wall surface is quite apparent. Unless some liner or coating of inert material is provided to prevent contact of the medicament with the urea resin, the device will be adversely aflfected and the characteristics of the medicament will be altered at least with respect to its concentration. Under such circumstances, effective protection will be provided by a film of polystyrene or the styrene monomer, or paraflln wax previously referred to, on the internal wall surface of the device.

The presence of the inert liner on the inner surface of the device will not detrimentally affect the functioning thereof. For example, the coating film or liner may actually improve the seal existing at 35, in the modification of Fig. 11. Thus a coating of parafiin wax on the inner wall surface of barrel-ampule 21 may result inasupplementary seal augmenting the inherent tendency of the walls to contact at 35, and this temporary seal may be easily broken upon compressing end 36 of the ampule.

Themannerofapplyingtheinertlinertothe injection device or previously to the material from which it is made, such as to sheets of the resinous material, may be subject to substantial diversification. Thus the protective film may be expediently supplied, in accordance with any preferred practice, including spraying, dipping or varnishing. Desirably the film material should be in an appropriate physical state to effect requisite coating, either by maintaining appropriate temperature conditions or by resort to a suitable vehicle. As a preferred expediency.

the inert coating material may be supplied by a glolvent vehicle which is removable by evapora- .As an example of an effective manner or internally coating the hypodermic device with the inert protective substance, a solution of the coating material may be aspirated into the device to effect over-all contact with the internal surface. following which the excess of the solution is expeiled. This comprises washing the internal surface with a solution of the material intended to form the coating film. Upon drying either under atmospheric conditions or at reasonable temperatures, the vehicle is dissipated, resulting in a thin protective layer. Alternatively a comparatively fine needle spray is inserted through the cannula or otherwise, and the coating material in its solvent vehicle is sprayed through the said needle in accordance with the usual practice, as by resort to air or inert gas pressure, with the result that a spray film is deposited on the internal wall surface.

As previously indicated, the choice of resins utilized in forming the needle or the barrel portion of the syringe injection device may be subjected to substantial variation, dependent upon the properties contemplated for the device and in view of other attendant conditions. such as the water absorption characteristics of the resin or its reactivity with the medicament. Moreover, the modifications of the hypodermic in- Jection device within the purview of the invention, and particularly those involving a fiexible or resilient barrel or ampule-barrel combination, such as shown in Figs. 6 to 14, where different types of resins are used for the cannula or needle and for the barrel, should desirably be such as are amenable to interpolymerization. Thus a polystyrene needle and a flexible or elastic vinyl polymer barrel are quite compatible from the standpoint of inter-polymerization. Other examples of interpolymerizable resins are methyl methacrylate with styrene or their derivatives; and vinyl resins with methyl methacrylate.

Similarly adaptable is the same chemical type of resin for both the needle and the barrel. Thus, the latter may be of a thinness which provides a resiliency or elasticity 'sufiicient to function as a barrel of the ampule type dmcribed. Despite the variation in physical properties between the comparativel rigid needle and the resilient bulb or barrel portion of the device, expedient blending or interpolymerization at the jointure between the two portions is attainable, because of the similar chemical characteristics of the material utilized.

The manner of molding the respective portions of the devices within the purview of this invention is subject to a diversification of procedures within the preference and skill of one versed in the molding art. Similarly whether the parts of, the device are molded from a resin monomer, or from an intermediate stage resin 9 and the article subsequently polymerized to the .ilnal stage, is likewise within the prerogative of discretion and the skill in the art of molding resinous materials, particularly synthetic resins, as well as other types of suitable materials.

In lieu of the more or less fixed element of hardness and attendant brittleness characteristic of steel needles, the hypodermic needle of the present invention, whether it be opaque or transparent or translucent, derived from plastic compositions, preferably a synthetic organic resin or of the type disclosed herein, is susceptible to a controlled variation in the hardness characteristics dependent upon the chemical types and the physical form of the resin utilized. Thus the hardness of the needle, while desirably less than that of steel, can be made quite ample, and

varied with the particular field to which the hypodermic injection device is to be adapted. It has been found that a Brinell hardness in excess of 16 or a Barcol surface hardness in excess of 22 may be adaptable for use as a cannula. Indicative of the hardness values applicable to some of the resins within the purview of this disclosure are the Brinell numbers shown in the Handbook of Chemistry and Physics, 27th edition, Chemical Rubber Publishing Co., in the table on pages 1222 to 2135, designated as "Properties of Commercial Plastics." Among the values indicated are the following ranges: polystyrene 20-30: copolyvinyl chloride acetate i25; acrylateand methacrylate 18-20 mm., 500 kg); urea-formaldehyde 48-54 (10 mm., 500 kg).

The yieldable or somewhat resilient properties of the resins result in a cannula which is desirably less frangible than steel, and the hazard of accidental breakage is thereby substantially curtailed. Of distinct importance is the tolerance of the human system to various types of plastics, which are actually utilized in connection with body restorations, such as sections of the skull or other bones; for example, methyl methacrylate when used in this manner causes no irritation whatsoever.

In contradistinction, a broken steel needle which remains imbedded may involve serious difficulties and even necessitate surgery. For

example, a needle broken in'the region of the mandibular nerve on the medial surface of the ascending ramus of the mandible may prove fatal from surgical attempts at removal. The significance thereof is indicated by the fact that this site is quite frequently the point of hypodermic injection for securing anesthesia where lower teeth are to be extracted. Similarly, the yieldable and less frangible properties of the cannula molded from resinous material afford an element of protection against penetration of bone or similar structure, such as neridental membrane and periosteum. Accordingly objectionable penetration of bone, periosteum or peridental membrane, together with the attendant possibilities of injury and pain, which may follow from the pressure applied to a hard metal needle. is substantially minimized.

While the steel needles of the prior art present a problem in obtaining appropriate sharpness and require special tools and stones to attain satisfactory puncturing or penetrating characteristics, the resin needle of the present invention, irrespective of whether it is opaque or transparent or translucent, lends itself to expedient sharpening by resort to available means and devices, since the resins manifest a comparatively low resist- 10 ance to abrasion. By way of illustration, polystyrene or methyl methacrylate needles are quite susceptible to efficient, satisfactory sharpening for the purpose contemplated. The importance of a properly sharpened hypodermic needle and the objection to a blunt needle, in view of the pain and discomfort attributable to the latter, are quite obvious.

In addition to the enhanced eifectiveness and adaptability of the hypodermic injection devices within the scope of the invention, the structural simplicity and economy involved are emphasized by the modifications shown in the drawings. Thus, the combination of the needle and the hub or collar for securing the needle to the syringe, that. is to the barrel portion of the device, is molded or otherwise formed as a unitary element essentially free from seams. This is in contrast to the prior art devices which secure the needleto the syringe barrelby a collar or hub that is separable and distinct from the needle. The

- danger of slippage of the separable elements may render a needle useless, and this situation is, to all intents and purposes, eliminated by the unitary, seamless combination described. This combination, in addition, affords a facility of assembly and manufacture which comprises a distinct advantage over the prior art practice of making the needle and the attaching hub or collar as separable elements. Accordingly, the

adaptation of the needle disclosed in Figs. 1-3 to a Cook type hypodermic syringe, or the needle of Fig. 4 to a Luer type hypodermic syringe results in material improvements of such injection devices.

Where, as in Fig. 5, the Luer type of syringe is modified to comprise a one-piece integral combination of barrel or cylinder'with the needle, with at least the needle and preferably the combination manifesting transparent or translucent characteristics, a significantly improved device is afforded. This combination in effect comprises a needle with one end expanded to form the barrel and is therefore essentially seamless. Merely a piston is required to form a complete hypodermic injection device, and this piston may be either of metal, or synthetic resinous material manifesting rigid properties, such as that of the needle-barrel combination. Thus themodiflcation of Fig. 5 provides a low cost structure which is not only more eflicient than that of the prior art, but also results in a substantial curtailment of accidental hazards.

The devices of the type illustrated in Figs. 6 to 14 are predicated upon a unitary, seamless combination of cannula or needle with resilient barrel which may be adapted to function as a medicament-containing ampule. In effect, an extremely simple,sturdy, minimum weight, economical and practical hypodermic injection device, in the form of an integral or single unitary member, is provided which affords optimum effectiveness in adaptation and use, and at the same time obviates the attendant hazards and uncertainties applicable to prior art devices. Moreover, these desirable embodiments of the invention make possible a substantia ly improved standard of sterile medication because of the practicability of restricting these devices to a single use and subsequent discard. Under these circumstances, the device may be filled at an appropriate laboratory under controlled conditions of sterility, and shipped or distributed under circumstances which will maintain the requisite sterility until used, as by the effective adaptation of sheaths or covers 2,s12,sea

, ll pursuant to the present disclosure. l 'ollowin g use, as previously noted, the device may be discarded without presenting any serious economic problem.

It will accordingly be noted that the invention is predicated on a novel type of hypodermic syringe or injection device which embraces among its features a structurally novel type of needle.

bus the needle of the present invention desira ly comprises or is derived from an organic resin, and the light-transmitting embodiment thereof represents a preferred modification. Contrary to the uncertain technique which necessitates that the physician await the dripping of blood from the end of his needle to ascertain that it is in a blood vessel, the preferred modifications of basically novel needle of the present invention may afl'ord direct visibility of the lumen, thereby affording the advantage of constant observation during use of the hypodermic device. The course of the therapeutic agent being administered can, therefore, be clearly followed, as well as the flow of blood from the area in which an incision has been made. Moreover, the presence of any extraneous material in or clogging of the lumen may be easily detected in the needle or device of the present invention, while this is essentially not possible with the prior art device. The not unusual evidences of corrosion in ferrous type needles are substantially eliminated.

Pursuant to the invention a novel, structurally simple, sturdy hypodermic injection device is provided which affords an enhanced efficiency of operation. While the details of disclosure of the various flgures of the drawings are directed to optimum adaptations of the invention, it will be understood that these showings are primarily illustrative in scope and are not to be taken by way of restriction or limitations.

Thus the impact and flexural strength charac- 40 teristics of the resins utilized for the needle or other portions of the injection devices within the purview of this invention may be substantially increased by reinforcing the resins with glass cloth or glass fibers, as well as other types of fibers, including those of synthetic resin derivation. The length and dimension of the fibers as well as the concentration may be subject to substantial variation, dependent upon the properties contemplated and the procedure involved in fabricating the device. In order to maintain the desired translucency or transparency, the index of refraction of the flbers should substantially correspond with that of the resin, and the concentration should not materially exceed 35%, relative to the resin content. Optimum concentrations are within the range of 7% to 25%. and optimum'dimensions include a length in the approximate range of to and a diameter in the approximate range of 0.00022" to 0.00048".

While I have described my invention in accordance with desirable embodiments, it is obvious that many changes may be made in the details of construction, and in the combination of parts and materials, without departing from the spirit of the invention as defined in the following claims. Moreover relative to the terminology in the appended claims, the expression "light-transmitting" is intended to generically include within its scope the characteristic of complete transparency, as well as any extent of translucency or partial transparency which affords an element of visibility sufficient to reveal the presence of liquid within the portion of the hypodermic syringe or injection device referred to.

Having thus set forth my invention, I claim:

1. A hypodermic injection device comprising a barrel and a needle, said barrel and needle being of organic resinous material, at least said needle being light-transmitting, said needle and barrel being integral and the needle having a sharp 118 adapted to pierce and penetrate the skin and ad- Jacent underlying tissue.

2. A hypodermic injection device comprising a rigid barrel and a needle, said barrel and needle being of organic resinous material, at least said needle being light-transmitting, said needle and barrel being integral and the needle 'having a sharp edge adapted to pierce and penetrate the skin and adjacent underlying tissue.

3. A hypodermic injection device comprising a needle and a barrel, said device being entirely of synthetic resin derivation and comprising a single unitary member, the needle being substantially rigid and light-transmitting and the barrel being comparatively flexible.

4. A hypodermic injection device comprising a needle and a barrel adapted for use as an ampule, said device being entirely of synthetic resin derivation, the needle being substantially rigid and transparent and the barrel being comparatively resilient and transparent, said needle and barrel comprising a single unitary substantially seamless member, being interpolymerized at their jointure.

5. A device as in claim 4, wherein the needle and the barrel are derived from a resin of the group consisting of polystyrene, methyl methacrylate and the vinyl chloride-vinyl acetate eonjoint polymer.

6. A hypodermic injection device comprising a needle and a barrel adapted for use as an ampule, said device being entirely of synthetic resin derivation, the needle being substantially rigid and transparent and the barrel being comparatively resilient, and a removable protective sheath overlying and closely fitted to the surface of at least the needle portion of said device, said sheath providing a closure for the open end of the needle, thereby maintaining requisite sterility and preventing loss of medicament.

'l. A hypodermic injection device comprising a needle and a barrel adapted for use as an ampule, said device being entirely of synthetic resin derivation, the needle being substantially rigid and transparent and the barrel being comparatively resilient, and a removable protective sheath overlying and closely fitted to the surface of at least the needle portion of the device and providing a closure for the open end of said needle, said sheath including a projection inserted within and substantially filling the lumen of said needle, said sheath thereby maintaining requisite sterility and preventing discharge of medicament from said barrel.

8. A hypodermic injection device comprising a needle and a barrel as a single unitary member, said barrel having a plurality of chambers with a restricted intermediate portion between them adapted for temporary closure, said device being entirely of synthetic resin derivation, the needle being substantially rigid and transparent and the barrel being comparatively flexible.

9. A hollow, fluid transmitting needle for a hypodermic injection device, said needle consisting entirely of an organic resinous material, said needle having a sharp edge at an end thereof also of said resinous material and adapted to pierce and penetrate the skin and adjacent underlying 1 t ssue.

1'3 10; ii-hollow. fluid transmitting needle tore hypodermic iniection- *deyiceg. consisting entirely of, light-transmitting and organic resinous material, said needle having a, sharp edge at an end thereof also of saidresinou's material and adapted to pierce and penetrate the skin and adjacent underlying tissue. I

JACOB A. SAFFIR.

REFERENCES ci'mn The following references are of record in the file of this patent:

UNITED STATES PATENTS Name D te- Number Name Date Hart June 16, 1914 Dickinson Mar. 2, 1915 Brown Mar. 28, 1916 Lozier Mar. 12, 1940 Smith Oct. 8, 1940 Erhard Oct. 29, 1940 Mou'le July 21, 1942 Henderson Nov. 6, 1945 women m'rnn'rs 9 Country Date Germany -1. Jan. 22, 19991 Germany Apr. 15, 1926' Great Britain May 8, 1939

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