US 3356089 A
Description (OCR text may contain errors)
Dec. 5, 1967 2 Sheets-Sheet 1 Filed March 1, 1965 S C Y R OM M T R R NF 0 E. v w W D A R A W 0 H VI 8 NBA,
NM I H N Nm Dec. 5, 1967 I H. R. FRANCIS INJECTION NEEDLE GUIDE 2 Sheets-Sheet 2 Filed March 1, 1965 I NVENTOR.
HOWARD R. FRANCIS ATTORNEY United States Patent 3,356,089 INJECTION NEEDLE GUIDE Howard R. Francis, Provo, Utah 84601 Filed Mar. 1, 1965, Ser. No. 436,004 5 Claims. (Cl. 128-221) ABSTRACT OF THE DISCLOSURE A hypodermic unit for use in relatively inaccessible locations, having a needle sheath attached to a lighttransmitting cylindrical outer barrel with external graduations, and an intermediate medication barrel with an interior plunger and having a long needle joined to the forward end of the medication barrel and generally closely surrounded by the sheath so that controlled advancing and retracting of the medication barrel selected distances within the outer barrel by reference to the graduations on the outer barrel will (a) extend the needle tip outside the sheath for selected depth penetration of a relatively inaccessible location of a patients body and (b) dispose the needle tip within the sheath, respectively. Once the needle tip has penetrated the body, advancing of the plunger a selected distance relative to the medication barrel will expel a known quantity of medication into the patient.
This invention relates in general to certain new and useful improvements in hypodermic syringes and, more particularly, to hypodermic syringes adapted for use in paracervical or pudendal anesthesia, paracentesis, or similar surgical procedures.
The conventional type of hypodermic syringe usually consists of a barrel, piston-like plunger, and a hypodermic needle, the length of which ordinarily ranges from one to three inches. Such needles are usually inserted into the patients upper arm or buttocks and, prior to insertion, the area of the skin surrounding the place of penetration will be sponged off with alcohol or other suitable antiseptics to render the area reasonably sterile. Inasmuch as the area is relatively accessible and the manipulative techniques are conventional, there is very little likelihood that the doctor, nurse, or medical technician using such a hypodermic syringe will violate asepsis. There are, however, a number of surgical situations in which it is highly desirable to use a hypodermic syringe having an extremely long needle for insertion into relatively inaccessible areas of the patients body.
For example, in paracervical or pudendal anesthesia, a local anesthetic is injected at selected locations around the patients cervix. This type of anesthesia is used by many obstetricians to avoid the liability of a general anesthetic which tends to reduce the cooperative activity of the patient in bearing down during delivery and also is felt by some to be somewhat dangerous to the fetus. The administration of paracervical anesthesia by means of a conventional hypodermic syringe is quite diflicult for a number of reasons.
In the first place, when the patient is in delivery position with her legs supported in obstetrical crutches, the entire cervical region is not particularly accessible for the application of a conventional hypodermic syringe having a needle of the usual length. Moreover, because of discomfort associated with labor the patient often has difiiculty holding still and, accordingly, it is impossible to attain any degree of precision in the insertion of the hypodermic needle into the tissue surrounding the cervix. Furthermore, it is relatively easy for an unprotected needle to penetrate the vaginal wall or even fetal tissue in the attempt to approach the site of intended injection. Finally, an obstetrician, under circumstances of actual delivery,
is using surgical gloves which very often are punctured by the hypodermic needle if it slips or is otherwise misdirected, thereby causing contamination.
In the administration of paracervical anesthesia, it is also extremely desirable for the obstetrician to know, within reasonable limits of accuracy, the depth to which the needle is inserted, but this cannot be readily estimated when using conventional hypodermic syringes. A somewhat similar problem is encountered in paracentesis, which procedure involves a surgical puncture of an anatomical cavity. In such procedures, it is extremely desirable to know the depth to which the needle has entered into the cavity. Furthermore, for purposes of paracervical anesthesia, paracentesis, or for any other surgical procedure requiring the use of a long hypodermic needle, it is also desirable to maintain the needle within an aseptic sheath or enclosure until the actual moment of puncture.
It is, therefore, the primary object of the present invention to provide a novel hypodermic syringe having a long sheathed needle which can be maintained within the sheath until the actual moment of puncture and then manually projected from the sheath into the patients flesh in a manner which maintains a maximum degree of asepsis.
It is another object of the present invention to provide a hypodermic syringe of the type stated having a relatively long needle Which can be inserted into the patients flesh to a known and measured depth.
It is a further object of the present invention to provide a hypodermic syringe of the type stated which can be constructed of relatively inexpensive materials without sacrifice of efficiency or utility, so that the entire needle can be considered as disposable or, in other worths, used once and then discarded.
With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.
In the accompanying drawings:
FIG. 1 is a side elevational view of a hypodermic syringe constructed in accordance with and embodying the present invention;
FIG. 2 is a longitudinal sectional view taken along line 22 of FIG. 1;
FIGS. 3, 4, 5, and 6 are transverse sectional views taken along lines 3-3, 44, 55, and 66, respectively, of FIG. 1;
FIG. 7 is a side elevational view of the sheath and graduated outer barrel forming a part of the present invention;
FIG. 8 is an exploded side elevational view of the barrel and needle forming a part of the present invention;
FIG. 9 is an exploded side elevational view of the plunger forming a part of the present invention;
FIG. 10 is a transverse sectional view taken along line 1010 of FIG. 9; and
FIG. '11 is a fragmentary sectional view taken along line 11-11 of FIG. 10.
Referring now in more detail and by reference characters to the drawings, which illustrate a preferred embodiment of the present invention, A designates a hypodermic syringe consisting of four major parts or components, namely, a graduated outer barrel 1, a medication barrel or cylinder 2, a needle 3, and a piston-like plunger 4. Preferably the outer barrel 1, cylinder 2, and plunger 4 are molded from a transparent synthetic resin, such as, for example, a polystrene, polyvinyl, or methylmethacrylate resin. The actual molding or other methods by which these parts can be fabricated are conventional and, therefore, are not described herein in detail. It is sufiicient for present purposes to point out that the plastic components may preferably be made by injection molding and, where it is necessary for one plastic part J to be joined rigidly to another, conventional adhesives, well known to the art, may be employed.
The outer barrel 1 integrally includes a tubular section 5 which is open at one end and, at such end, is provided with an external annular collar 6. Internally, the tubular section 5 is as smooth and precisely cylindrical as possible. This can be readily achieved without undue expense for manufacturing cost by the use of well polished, precisely-machined molding dies constructed in accordance with well-known die-making practice. At its other or so-called closed end, the tubular section 5 is integrally provided with a frusto-conical end wall 9, which is, in turn, integrally joined at its forward end (reference being made to the left-hand side of FIG. 1) with a coaxial tubular extension 8. Integrally joined to the forward end of the tubular extension 8 is a tapered section 7 which extends forwardly and merges into an elongated tubular sheath 10, integrally provided at its forward end with an enlarged spherical bulb 11 having a smallbored coaxial aperture 12 formed in its forwardmost portion. As will be seen by reference to FIGS. 1 and 7, the tubular section 5, the tubular extension 8, the tubular sheath 10, and the aperture 12 are all in coaxial alignment along a common centerline which is the longitudinal centerline of the hypodermic syringe A.
Adhesively or otherwise rigidly secured within the tapered section 7 and projecting coaxially into the rear end of the tubular sheath is a guide sleeve 13 integrally consisting of a somewhat conical rear-end portion 14 and forward extension portion 15 which terminates in a diametrically reduced tip 16. The guide sleeve 13 is preferably molded of a synthetic resin or so-called plastic which is the same as the material used for the other plastic parts of the hypodermic syringe A and is formed with a tubular bor 17 which is also coaxial with the longitudinal centerline of the hypodermic syringe A and is of substantially the same internal diametral size as the aperture 12.
The cylinder 2 consists of a tubular member 18 which is formed of a transparent plastic such as one of the aforementioned synthetic resins and is internally provided with a cylindrical surface 19. At its rear end, the tubular member 18 is completely open and adjacent to its rear end, is externally provided with two diametrically opposite 'U-shaped finger loops 20, 21, which are cemented or otherwise rigidly secured thereto. At its other or forward end, the tubular member 18 is provided with a circular plug-shaped closure member 22 which has an annular skirt 23 sized for snug-fitting disposition within the forward end of the tubular member 18. The skirt 23 is marginally joined to the outer periphery of a forwardly projecting conical end wall 24, which, in turn, integrally merges into a forwardly projecting externally tapered hub-receiving fitting 25 having an axial bore 26 that merges at its rearward end into the internally tapered face of the conical end wall 24. Integrally formed with, and projecting annularly outwardly around the forward end of the skirt 23, is a collar 27, the external diametral size of which is substantially equal to the external diametral size of the tubular member 18. Provided for snug-fitting disposition externally around the skirt 23 is an O-ring 28 which is slightly larger in external diametral size than the external diametral size of the collar 27 and tubular member 18. Thus, when the O-ring 28 is slipped over the skirt 23, and the latter is inserted into the forward end of the tubular member 18, the O-ring 28 will fit snugly and slidably within the interior surface of the tubular section 5 of the outer barrel 1, in the manner of a piston ring. It will, of course, be evident that the external surface of the skirt 23 is tightly cemented to the forward end of the tubular member 18 so as to form a liquidtight pressure-resistant seal therewith, all as best seen in FIG. 2.
The needle 3 integrally includes a steel hub-member 29 having an internally tapered socket 30 adapted to fit seatingly upon the tapered surface of the fitting 25. At its forward end, the hub 29 is provided with a diametrally reduced coaxial tubular extension 31 which rigidly embraces the rear end of an elongated steel cannula 32, the forward end of which is beveled and sharpened to facilitate penetration of the flesh. Moreover, the cannula 32 is of such external diametral size that it will fit snugly, but, nevertheless, slidably, through the bores 12 and 16, substantially as shown in FIG. 2.
The plunger 4 includes an elongated cylindrical member 33 having an external diametral size substantially equal to the internal diametral size of the cylindrical surface 19 so as to fit snugly and slidably therein. The tubular member 33 is also preferably fabricated of a transparent plastic material, such as one of the previously mentioned synthetic resins, and is integrally provided at its rearward end with a diametrally enlarged annular collar 34 provided with a pair of diametrally opposite rectangular ears 35, 36, having rearwardly opening rectilinear recesses 37, 38, for snugly accommodating the opposite ends of a diametrally extending cross-bar 39 which is integrally provided on its rearward face with a rearwardly projecting finger-loop 40. The cross-bar 39 is tightly cemented or otherwise rigidly secured at its ends in the recesses 37, 38, so that the finger-loop 40 may be utilized for manipulating the plunger 4.
At its forward end, the plunger 4 is provided with a diametrally reduced annular shoulder 41, the interior surface of which defines a diametrally reduced opening 42. Provided for disposition within the forward end of the tubular member 33 is a piston-forming rubber plug 43 having a forward conical end 44 which is tapered to the same angle as the tapered skirt 23 of the closure member 22 which forms a part of the cylinder 2.
The conical end 44 terminates in a diametrally enlarged annular ring or shoulder 45 which is, in turn, connected by means of a diametrally reduced cylindrical portion 46 and a second annular ring or shoulder 47, the rings or shoulders 45, 47, being of such external diametral size as to form a piston-like sliding seal against the cylindrical surface 19 of the cylinder 2 when the plunger 4 is operatively inserted therein. At its rearward end, the plug 43 includes a diametrally reduced skirt 48, the external diametral size of which is substantially equal to the internal. diametral size of the opening 42. At its rearward end, the skirt 48 is provided with a collar-portion 49, the external diametral size of which is substantially equal to the inter-- nal diametral size of the tubular member 33. The axial! length of the skirt 48 is very slightly smaller than the axial' tions of the plug 43 are inserted through the opening 42,.
the collar-portion 49 will seat snugly against the interiorfaces thereof and hold the plug 43 firmly in operative posi-- tion at the forward end of the tubular member 33.
It will be noted by reference to FIGS. 1 and 7, that the: tubular section 5 of the outer barrel 1 is provided with a. series of graduations and half-graduations respectively indicating centimeters and half-centimeters of axial distance. As shown, the scale of graduations encompasses a distance of four centimeters. The fourth full-centimeter graduation is coincident with the line of juncture between the frusto-conical end wall 9 and the forward end of the tubular section 5. It will, of course, be understood in this connection, that the number of graduations and the distances therebetween can be varied to reflect any selected scale and to measure off any desired distance within appropriate limits. Approximately 1.5 to 2.0 cm. have been found to be particularly suitable for hypodermic syringes which are to be used for paracervical anesthesia. On the other hand, hypodermic syringes which are intended for paracentesis will possibly require up to 4 cm. as are provided for in the present model described. Other possible uses might require even deeper penetration in which case the outer barrel 1 and cannula 32 will be correspondingly longer also.
The cannula 32 is of such axial length that, when the forward annular margin end of the cylinder 2 is shifted to the zero calibration, the cannula 32 will be entirely withdrawn into the sheath and the pointed end thereof will be withdrawn into the bore 12 of the spherical bulb 11. On the other hand, when the cylinder 2 is pushed forwardly through the outer barrel 1 until the forward margin end is at its forwardmost position, that is to say, the position in line with the four centimeter graduation on the scale, the pointed end of the cannula 32 will extend four centimeters beyond the aperture 12.
Prior to actual use, the cylinder 2, with the needle 3 operatively attached, is withdrawn entirely from the outer barrel 1 and filled with a suitable quantity of any desired local anesthetic. This may be done in the conventional manner of filling any hypodermic syringe. The cylinder 2, with its associated needle 3 and plunger 4, is then reinserted into the outer barrel 1 until the forward margin end is aligned with the zero calibration scale. Thereupon, the obstetrician placed the spherical bulb 11 at about an 8:00 oclock position to one side of the cervix. Since the sharp point of the cannula 32 is not exposed, there is virtually no possibility of violating asepsis in this procedure and the obstetrician does not need to concern himself with the danger of puncturing either his glove or finger when he is holding the flesh of the patient in firm stationary position preparatory to emplacing the pointed end of the cannula 32. After proper placement adjacent to'the cervix, the cannula is extended about one and onehalf centimeters to 2 cm. by forcing the cylinder 2 forwardly within the outer barrel 1 by that distance as measured along the scale of calibrations. About 6-10 cubic centimeters of an anesthetic are then injected. The hypodermic syringe A is then withdrawn and, after about one or two contractions of the uterus, the same procedure is followed on the other side of the cervix at about 3:00 to 4:00 oclock position. Should an episiotomy be required for easy delivery of the fetus, the cannula 32 can be extended to whatever length is necessary and anesthetic can be injected into the Wall of the vagina in the appropriate positions to anesthetize the pudendal nerve.
By reason of the fact that the hypodermic syringe A is constructed of relatively inexpensive plastic components, it can be manufactured very inexpensively and, thus, may be discarded after one use. The hypodermic syringe A, constructed in accordance with the present invention, therefore, becomes a disposable syringe which can be sterile-packed at time of manufacture, so that the doctor or hospital is relieved of the necessity of sterilizing the hypodermic syringe A at or prior to time of actual use. This, obviously, results in material economies, both in terms of time and materials. As a matter of fact, actual experience has shown that precision-made glass syringes of conventional design are highly susceptible to breakage and survive only a small number of actual uses. This fact, coupled with the high initial cost and the substantial expenses involved in cleaning and sterilizing such syringes after each usage, clearly establishes that disposable hypodermic syringes constructed in accordance with the present invention are much more economical.
It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the hypodermic syringes may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.
Having thus described my invention, what I claim and desire to secure by Letters Patent is:
1. A hypodermic syringe comprising a hollow lighttransmitting smooth bore outer barrel open at one end, a cylinder adapted to receive a plunger and having a smooth exterior surface slideably mounted in the barrel through and extending beyond the open end of the barrel and visible through the wall of the barrel, means interposed between the bore of the barrel and the exterior surface of the cylinder to frictionally restrain the cylinder in any selected one of a number of incrementally distinct positions relative to the barrel, a long hypodermic needle sheath having inside and outside diameters each several times smaller than the inside and outside diameters of the barrel, respectively, and being mounted at one end thereof on a second generally closed end of the barrel, a long needle mounted on the forward end of the cylinder and always extending through and well beyond the small opening and loosely extending through at least almost the entire length of the enclosing needle sheath, said barrel carrying graduations so that the cylinder may be selectively positioned within the barrel relative to the barrel graduations (a) for locating the needle tip slightly within the sheath at the leading end of the sheath to accommodate precise location and removal of the leading end of the sheath adjacent the body of a patient prior to and following penetration, respectively, and (b) for advancing the needle tip from the selectively positioned leading end of the sheath a distance corresponding to the barrel graduations caused to be traversed by the cylinder to inject only the needle tip to a desired depth into the patient at said precise location.
2. A syringe as defined in claim 1 wherein the leading end of the needle sheath is bulbous in configuration.
3. A syringe as defined in claim 1 wherein said frictionally restraining means comprises an O-ring to accommodate relative sliding movement of the barrel and the cylinder and to frictionally maintain any selected relative position of the barrel and the cylinder.
4. A syringe as defined in claim 1 further comprising a guide sleeve disposed in the vicinity of the small opening to snugly though slideably receive and guide the needle to accommodate generally axial to and fro movement of the needle relative to the sheath in spaced relation thereto.
5. A syringe as defined in claim 1 wherein the trailing end of the cylinder has two opposed finger-grips each having front and back abutment surfaces for forcibly advancing and retracting the cylinder within the barrel as desired.
References Cited UNITED STATES PATENTS 561,059 5/ 1896 Mitchell 128-218 2,571,653 10/ 1951 Bastien 1282l8 2,876,770 3/1959 White 128215 2,922,420 l/ 1960 Cheng 128-221 2,923,295 2/1960 Guerriero 128-215 3,028,862 4/1962 Prater 128218 FOREIGN PATENTS 532,170 10/1954 Belgium.
RICHARD A. GAUDET, Primary Examiner.
D, L. BAKER, Assistant Examiner,