Instrument For The Parenteral Penetration Of A Needle

Abstract

The apparatus comprises a body having a configuration such that it may readily be gripped in one hand; a support which is mounted for rectilineal sliding motion within the said body; a container which is detachably mounted within the sliding support; a hollow needle which is connected to the said container and adapted to communicate with the interior of this latter and means adapted to communicate with the interior of this latter and means adapted to cause the sliding support to carry out a movement of displacement within the body in the direction of forward motion of the hollow needle at high speed and with sufficient force to ensure penetration of the needle into the organ considered.

Description

This invention is concerned with instruments which are intended to permit parenteral penetration of a needle and more particularly although not exclusively to instruments for taking blood samples from large animals and especially from cows.

Up to the present time, simple hypodermic needles of conventional type were employed for this purpose in the majority of applications and in some cases were mounted on syringes which accordingly served as handles. The vein was punctured and blood was drawn by means of the syringe or alternatively allowed to flow directly from the needle into a test tube. A more recent practice has consisted in the use of tubes formed of plastic material in which it is possible to mount either a plug fitted with a hollow needle for carrying out the blood sampling operation or a stopper for transporting samples which have thus been collected.

All these instruments are of somewhat rudimentary design and are subject to a number of drawbacks ; in fact, the veterinary surgeon must possess a certain degree of manual skill in order to perform the operation easily, accurately and rapidly to prevent the animal from feeling any pain and consequently from exhibiting defensive movements which frequently slow down or otherwise interfere with the operation. Blood samples are usually taken from a vein in the neck of the animal so that the hollow needle must first pass through the hide, that is to say through a thickness of approximately one-half cm, and then penetrate into the vein to exactly the right depth to ensure that the tip of the needle in fact remains within the interior of the vein and does not pierce the opposite wall of this latter.

The aim of this invention is to provide an apparatus for carrying out operations of this type accurately and with considerably greater ease without requiring any particular skill on the part of the practitioner.

To this end, the apparatus in accordance with the invention comprises : a body having a configuration such that it may readily be gripped in one hand, a support which is mounted for rectilineal sliding motion within the said body, a container which is detachably mounted within the sliding support, a hollow needle which is connected to the said container and adapted to communicate with the interior of this latter and means adapted to cause the sliding support to carry out a movement of displacement within the body in the direction of forward motion of the hollow needle at high speed and with sufficient force to ensure penetration of the needle into the organ considered.

In an advantageous embodiment, the means for causing the displacement of the sliding support are elastic means such as a spring, the instrument being additionally provided with a latch for retaining the sliding support in the retracted position and with external releasing means carried by the body and adapted to disengage the latch from the sliding support in order that the said elastic means may be permitted to propel the said support together with the needle which is secured thereto.

It will readily be appreciated that a blood sample can very easily be taken from an animal by means of an instrument of this type. In fact, when the container which consists, for example, of a tube of plastic material is mounted within the interior of the instrument, the user has plenty of time to apply the instrument against the region in which the needle is to be inserted. It is then only necessary to actuate the external releasing means referred-to above in order to cause the needle to be propelled instantaneously and automatically under the requisite force and to the desired depth through the hide or skin and into the vein from which a blood sample is to be taken. The blood then flows into the tube under the action of gravity and of the blood pressure.

The invention is also directed to instruments of this type for taking samples of liquid which are not under pressure and also for carrying out injections which can be applied not only to animals but also to human beings if so desired.

To this end, in accordance with another property of the invention, the container is constituted by a cylinder in which is mounted a piston, the said piston being rigidly fixed to one extremity of a rod while the other extremity of the said rod is accessible from the exterior of the instrument body even when the piston has reached its position of maximum penetration within the cylinder. Thus, once the needle has been introduced into the organ concerned, it is possible according to requirements either to cause the piston to withdraw when a sample has to be taken or on the contrary to cause said piston to advance if an injection is to be performed.

Further properties and advantages of the invention will become apparent from the following description and from the accompanying drawings in which few embodiments of an instrument according to the invention for the parenteral penetration of a needle are shown by way of non-limitative examples.

In these drawings :

FIG. 1 is a front view of a first embodiment of an instrument in accordance with the invention ;

FIG. 2 is a profile view which corresponds to FIG. 1 ;

FIG. 3 is a sectional view taken along line III--III of FIG. 1 ;

FIG. 4 shows an alternative form of the container of FIG. 3 ;

FIG. 5 shows another form of construction of a container which is intended for use in the instrument of FIG. 1 to 3 ;

FIG. 6 shows another form of construction of the container.

The instrument for parenteral penetration of a needle as illustrated in FIG. 1 to 3 comprises essentially a body 1, a s1iding tubular support 2, a container 3, a hollow needle 4, a mouthpiece 5, a propulsion spring 6 and a latch 7.

The instrument body 1 may be formed of plastic material or of metal and, in this example of construction, is of elongated shape and has a configuration such as to afford a convenient grip for the user. The body which is illustrated is accordingly provided with hollowed-out portions such as those which are designated by the reference numeral 11 and in which the operator's fingers may be placed in order to ensure a perfect grip.

The sliding support 2 is constituted by a tubular member which is capable of sliding axially within a bore 14 of the body 1 and in the inner extremity of which is screwed an end-cap 15 having a diameter which is slightly larger than the external diameter of the sliding support 2 so as to serve as guide for said support within an enlarged portion 17 of the bore of the instrument body 1. The central portion of the end-cap 15 is provided on its external face with a boss 20 on which is fixed the socket connector 21 of the hollow needle 4. An axial bore 23 is pierced right through the end-cap 15 and provides a communication between the hollow needle 4 and the interior of the container 3 which is mounted in the sliding support 2. The mouthpiece 5 is screwed into the extremity of the body 1 in which is located the hollow needle 4. Said mouthpiece is pierced by a central bore 24 and provided with a rounded rib 25 which is located in a diametral plane and has a generally concave or crescent shape ; said rib is intended to be closely applied against the skin of the animal in the zone of a vein from which a blood sample is to be taken.

The propulsion spring 6 is a helical compression spring, one extremity of which is applied against the peripheral portion of the inner face of the end-cap 15 whilst the other extremity of the spring is applied against the annular shoulder 26 which is formed as a result of the difference in diameter between the two portions 14 and 17 of the bore of the instrument body 1.

The sliding support 2 can be maintained in the retracted position which is illustrated and in which the extremity of the hollow needle has been withdrawn into the central bore 24 of the mouthpiece 5 ; this is achieved by means of the latch 7 which is pivotally mounted on a pin 28 within a longitudinal slot 27 of the body, the extremity of said latch being engaged in an annular groove or notch 31 which is formed in the sliding support 2. The latch 7 can be disengaged from the notch 31 by means of external releasing means constituted in this example by a pushbutton 33 which is integral with one extremity of an extension arm 34 of the latch 7 and which is urged outwards by a small helical compression spring 35, said spring being applied against the bottom of the slot 27 of the body 1.

The container 3 which is intended to collect the blood sample is constituted in this form of construction by a tube of plastic material, for example. One extremity of said tube is closed while the other open extremity is applied against the inner face of the end-cap 15. The tube 3 can be freely inserted in the sliding support 2 at the open outer extremity of this latter and is held in position within said support by means of two small catches 41 which are pivotally mounted on pins 42 within two slots 43 respectively which are formed in the outer extremity of the sliding support 2, said extremity being enlarged for this purpose. The extremities of said catches are urged against one end of an annular enlargement or boss 45 formed on a corresponding portion of the tube 3 and are maintained elastically in this position by means of springs 46 which are fitted within corresponding holes of the sliding support. The boss 45 of the tube is applied elastically against the extremities of the two catches 41 by means of another helical compression spring 48, the two extremities of which are applied respectively against the other end of the boss 45 and against an annular shoulder 49 which is formed in the corresponding portion of the bore of the sliding support 2. The two catches 41 are provided respectively with extensions in the form of two pushbuttons 51 which can be gripped together between the operator's thumb and forefinger in order to draw the pushbuttons together and thus displace the two catches 41 outwards so as to free the boss 45 and consequently the container 3, thereby permitting the ejection of this latter under the action of the spring 48.

The level of the liquid which accumulates within the tube can be observed through a longitudinal slot 54 of the instrument body 1 and a corresponding longitudinal slot 55 of the sliding support 2 ; said support is maintained in a constant angular position with respect to the body 1 by means of a stud 56 which is fixed radially in the body 1 and one extremity of which is engaged within the longitudinal slot 55 of the sliding support 2.

The pierced end-cap 15 is additionally provided with a duct 57 for connecting the container 3 to the atmosphere in order that the air which is present within said container may be discharged progressively as it is replaced by the liquid which is being collected.

The operation of the instrument is as follows :

Assuming that the apparatus is equipped with a hollow needle and a tube as illustrated in the drawings for the purpose of taking a blood sample, the instrument body 1 is gripped firmly in one hand and placed against the animal, the rib 25 of the mouthpiece 5 being carefully applied so as to be placed astride the vein from which the blood specimen is to be taken. When the instrument has thus been accurately centered, it is only necessary to press the pushbutton 33 in order that the needle should penetrate instantaneously under the action of the propulsion spring 6 through the skin and the wall of the vein considered. The operator maintains the instrument without moving while the blood flows into the container under the combined effects of gravity and of the blood pressure. He observes the level of liquid through the slots 54 and 55 and then quickly withdraws the instrument as soon as a sufficient quantity of blood has been collected. The operator then removes the filled container 3 by pressing the two catch-buttons 51 simultaneously and closes the tube 3 by means of a conventional plug (not shown in the drawings) which he places over the open end of the tube. The operator replaces this tube with a fresh empty tube, resets the instrument by exerting a tractive effort on the outer extremity of the sliding support 2 until the latch 7 again engages in the annular groove 31 of the sliding support and the instrument is in readiness for further operation.

When it proves necessary to collect a liquid which is not under pressure or which has too high a viscosity to flow freely through the needle into the container, especially when a relatively fine needle is employed as is the case, for example, when taking a sample from an organ of the human body or alternatively when it is necessary to carry out an injection instead of a sampling operation, the simple tube 3 which is shown in FIG. 3 is in that case replaced by a tube 3A (as shown in FIG. 4) which is fitted with a leak-tight piston 61. Said piston is slidably mounted within said container and rigidly fixed to a rod 62, the outer extremity of which is adapted to carry an operating knob 63 which still remains accessible from the exterior of the sliding support 2 even when the piston 61 is in its position of maximum penetration as shown in the drawings.

In order to make use of a tube of this type, the procedure is the same as that which was described earlier in connection with the insertion of the needle. However, depending on whether it is necessary to carry out a sampling operation or an injection operation, insertion of the needle is carried out when the piston has reached its position of maximum penetration as shown in FIG. 4 or alternatively and on the contrary when the piston is withdrawn and the tube is filled with liquid to be injected.

Once the needle has been inserted into the organ under consideration, there is then exerted either a tractive effort on the knob 63 in order to carry out the sampling operation or on the contrary a thrust in order to carry out an injection.

This syringe tube 3A is positioned and removed in the same manner as the simple tube 3 of FIG. 3.

In order to satisfy aseptic requirements, the tube 3 of FIG. 3 can be replaced by the tube 3B of FIG. 5 or the tube 3A of FIG. 4 can be replaced by the tube 3C of FIG. 6 ; the hollow needle 4 is incorporated directly with said tubes and is in that case used only once.

For the purpose of mounting the tube 3B or the tube 3C within the instrument, use is made of an end-cap 15A (as shown in FIG. 5) which is slightly modified with respect to the end-cap 15 of FIG. 3, which is also screwed into the inner extremity of the sliding support 2, but which has a central opening 65 of relatively large diameter in order to accommodate the narrowed upper extremity of the container 3C as shown in FIG. 5.

The utilization of the instrument in conjunction with the tube 3B of FIG. 5 or with the tube 3C of FIG. 6 is carried out in the same manner as in the case of the tube 3 of FIG. 3 or 3A of FIG. 4 respectively.

When use is made of a syringe tube such as the tube 3A of FIG. 4 or the tube 3C of FIG. 6, the movement of penetration of the piston 61 can be followed visually through the slots 54 and 55 of the instrument.

As is clearly understood, the invention is not limited to the embodiments which have been described in the foregoing with reference to the accompanying drawings and which have been given solely by way of example. Depending on the applications which are contemplated, modifications can accordingly be made without thereby departing either from the scope or the spirit of the invention.

Claims

What I claim is :

1. An instrument for the parenteral penetration of a needle, such as for taking a blood sample from a large animal, comprising an elongated tubular body having an exterior configuration so that it can be readily gripped in one hand, said tubular body having an axially extending bore therethrough with the bore having a first end and a second end, an open-ended tubular support having a forward end and a rearward end and positioned within and axially displaceable through the bore in said tubular body between a first position where its forward end is spaced between the first and second ends of said tubular body and a second position where its forward end is displaced from the first position toward the first end of said tubular body, an end-cap secured to the forward end of said tubular support and providing a partial closure for the forward end thereof, said end-cap having a vent hole therethrough aligned with the opening through said tubular support, means located adjacent the first end of said tubular body defining a stop for the forward end of said tubular support in its second position, a container closed at one end and removably fitted within said tubular support so that its open end abuts said end-cap and the vent hole in said end-cap communicates with the interior of said container, propulsion spring means positioned within the bore in said tubular body and bearing against said tubular body at one end and against one of said tubular support and end-cap at the other end for propelling said tubular support from its first position to its second position, latch means mounted in said tubular body for retaining said tubular support in its first position against the action of said propulsion spring and for releasing said tubular body so that it can be propelled by said spring from its first to its second position, and a hollow needle secured to one of said end-cap and said container and the passageway through said hollow needle communicating with the interior of said container, said hollow needle being arranged to be retained interiorly of said tubular body in the first position of said tubular part and to project from the first end of said tubular body when said tubular support is displaced to its second position.

2. An instrument, as set forth in claim 1, wherein said container has an annular shoulder formed on its exterior surface adjacent its closed end, means associated with said tubular support for releasably holding said container within said tubular support, said means comprising a catch mounted on said tubular support and arranged to engage the shoulder on said container, and a catch release member in cooperating engagement with said catch for releasing said catch so that said container can be removed from said tubular support.

3. An instrument, as set forth in claim 2, wherein an annular boss is formed on and extends laterally outwardly from the exterior surface of said container for an axially extending length thereof and forms at one end the shoulder with which said catch engages and its other end another shoulder, and an ejecting spring means positioned between said tubular support at one end and the another shoulder on said annular boss at the other end.

4. An instrument in accordance with claim 1, wherein said hollow needle is rigidly fixed to said container.

5. An instrument in accordance with claim 1, wherein said container comprises a cylinder, a piston reciprocably mounted in said cylinder, a piston rod having one end rigidly secured to said piston and the other end accessible from the exterior of said tubular body even when said piston has reached its position of maximum penetration within said cylinder.

6. An instrument, as set forth in claim 1, wherein said means defining a stop for the forward end of said tubular support comprises a mouthpiece secured to the first end of said tubular body and having an opening through which said hollow needle projects when said tubular support is displaced into its second position, said mouthpiece having a rounded external rib with a generally concave crescent shape located in a diametrical plane extending across the first end of said tubular body and the opening to which said hollow needle extends being formed at the center of said rib.

7. An instrument, as set forth in claim 1, wherein an annular boss is arranged about and extends outwardly from said container, an ejecting spring means is arranged about said container with one end bearing against said annular boss on said container and the other end bearing against said tubular support, and a catch mounted on said tubular support and arranged to engage the opposite end of said annular boss from the one contacted by said ejecting spring means, and a catch release member in cooperating engagement with said catch for releasing said catch so that said container can be removed from said tubular support.

8. An instrument, as set forth in claim 1, wherein each of said tubular support and said tubular body have a longitudinal slot therethrough and said longitudinal slots arranged in register for viewing the level of liquid within said container.

9. An instrument, as set forth in claim 1, wherein said end-cap has another opening therethrough communicating with the interior of said container, and said hollow needle is fixed to said end-cap with its passageway communicating with another opening through said end-cap so that a passage extends from said hollow needle through said end-cap into said container.