A PARENTERAL DEVICE

Abstract: A parenteral device (10) for the transfer of fluids to or from a living body. The device (10) comprises a body (11) having a chamber (18) and an opening (17) provided in the wall of the chamber (18). A hollow needle (19) is open at its outer end and is slidably mounted to the body (11) for axial movement therein. The needle (19) is movable between a first position in which it extends through said opening (17) such that its outer end extends beyond the body (11) and a second position in which the outer end of said needle is located innermost from said opening (17). A second aperture (21) in the wall of the needle (19) provides communication between the chamber (18) and the lumen of the needle (19) when in the first position.

Description: "A PARENTERAL DEVICE" THIS INVENTION relates to a parenteral device for the transfer of fluids to, or from a living body. Throughout this specification the term "parenteral device" shall be taken to include hypodermic syringes, cannulas and like devices which may be used for passively introducing or withdrawing fluids from a living body. It is the primary characteristic of parenteral devices that a sharp hollow needle be provided to facilitate the transfer of fluids to, or from a body. The difficulty created by the presence of such a needle arises from the possibility of injury which may be caused to a user or clinician when using the device or any person who may be required to handle the device before or subsequent to use. It will be appreciated however that the dangers resulting from possible injury are . surpassed by the dangers of infection that may arise from such injuries due to the presence of pathogens which may be present on the needle as a result of its usage. Furthermore this danger does not disappear at the conclusion of the utilisation of the parenteral device but is always present while the device remains in existence which has resulted in very careful disposal procedures being adopted in institutions where such parenteral devices are used. Such precautions, however, are not necessarily adopted where parenteral devices are used in out-of-clinic situations such as instances where the user is required to inject themselves with a parenteral. It is an object of this invention to provide a parenteral device which can reduce the possibility of injury and subsequent infection from a used device. In one form the invention resides in a parenteral device comprising a body having a chamber, an opening provided in the wall of the chamber, a hollow needle having a first aperture at or towards its outer end slidably mounted in the body to be movable axially in relation to the body and associated with the opening to be movable to a first position extending through said opening whereby its outer end extends beyond said body and a second position whereby the outer end of said needle is located within the body innermost from said opening, a second aperture provided in the needle providing communication between the chamber and the lumen of the needle when in the first position. The invention will be more fully understood in the light of the following description of one specific embodiment. The description is made with reference to the accompanying drawings of whichΞ Figure 1 is a schematic side elevation of a syringe according to the first embodiment having the needle in the first position; Figure 2 is a schematic sectional elevation of a syringe according to the first embodiment having the needle in the second position; Figure 3 is a sectional side elevation of a syringe according to the second embodiment having the needle in the first position; Figure 4 is a sectional side elevation of a syringe according to the second embodiment having the needle in the second position; Figure 5 is a sectional side elevation of a cannula according to the third embodiment having the needle in the second position; Figure 6 is a sectional side elevation of the cannula of the third embodiment having the needle in the first position; Figure 7 is a sectional side elevation of a cannula according to the fourth embodiment; Figure 8 is a cross-sectional view of the fourth embodiment of Figure 7 along line 8 8; Figure 9 is a cross-sectional view of the fourth embodiment along line 9 9; and Figure 10 is a cross-sectional elevation of the fourth embodiment along line 10 10. The first embodiment shown at figures 1 and 2 comprises a hypodermic syringe 10 which can be used for the injection of parenteral into a living body or alternatively for removal of fluids from a body. The syringe comprises a substantially cylindrical body 11 which slidably and sealingly accommodates a piston 12 which is movable axially through the body 11 and is caused to move by means of a plunger rod 13 which extends from the open end of the body 11. The inner face of the body and piston may be of non-circular configuration to establish rotational stability of the piston in the body. The plunger rod 13 is provided at its outer end with an abutment 14 which together with a flange 15 provided at the outer end of the body 11 facilitates manipulation of the plunger and movement of the piston by a user. The other end of the body 11 is closed and is provided with an off centre axially directed annular boss 16 having a central opening 17 which communicates with the interior of the body 11 between the closed end thereof a d the piston 12. As the piston 12 is caused to move towards or away from the closed end, so the volume of the chamber 18 is caused to vary. The boss 16 may have a suitable configuration in order to accommodate a "Luer" or like fitting which may be used for the transfer of parenteral into the chamber 18 from an ampoule or like container. Alternatively the boss 16 may be formed with a sharpened top and suitably shaped to be used to take up fluid from a sealed ampoule. The piston 12 and plunger rod 13 slidably accommodate a hollow needle 19 which is mounted to one end of a control rod 20 whereby the needle 19 is movable axially in relation to the plunger rod 13 through the piston 12. The location of the needle is such that it is aligned with the central passage way 17 in the boss 16 provided on the body 11 whereby on axial movement of the control rod 20 the needle 19 is movable through the central passageway 17. The outer end of the hollow needle 19 is provided with an opening for the transfer of fluid out of the lumen of the needle while the inner end of the needle is provided with a laterally directed second opening 21. The axially directed passageway in the piston which accommodates the control rod 20 and needle 19 is provided with an appropriate sealing means to prevent leakage of fluid from the chamber 18 to the axial passageway 22. In addition, the plunger rod 13 supports a tubular sealing element 23 which slidably and sealingly accommodates the control rod 20 and needle 19 to further prevent any leakage from the chamber 18 and also to prevent contamination of the needle 19 when retracted and accommodated within the tubular support element 23. The outer end of the control rod 20 is provided with an over-turned portion which co-operates with a radial slot 25 in the flange 15 of the body 11 and a downwardly oblique slot 26 in the body 11 which communicates " with the radial slot 25 and which facilitates retention of the downturned portion 24 of the control rod 23 in the body 11 and the location of the needle in its first position as shown at figure 1 at which it extends through the central passageway 17 and the boss 16. On outward axial movement of the control rod 20 once disengaged from the slots 25 and 26 in the body 11 the lower end of the downturned portion 24 becomes engaged with the outer axial face of the flange 15 and a stop 27 provided thereon to retain the control rod 23 at its outermost extension in relation to the body as shown at figure 2 at which position the needle 19 is in its second position whereby it is retracted into the body 11 and is clear of the central passageway 17. The axial movement of the control rod 20 and the needle 19 is independent of the axial movement of the plunger rod 13 whereby the needle 19 may be located in either its first position as shown at figure 1 or its second position as shown at figure 2 and the piston can be located at any position within the body 11 and moved within the body 11. Therefore when the needle 19 is in its second position at which it is retracted within the body 11 the boss 16 may be fitted with a "Luer" of like fitting for the introduction of a parenteral into a body 11 from an ampoule or like receptacle by operation of the plunger rod 13. Once filled with a parenteral the needle 19 may be moved to its first position after removal of the "Luer" fitting for the administration of the parenteral. Subsequent to the administration of the parenteral the needle 19 is moved to its second position at which time the syringe can be safely discarded. If it is desired to prevent the inadvertent movement of the needle 19 beyond the body 11 of the syringe, the syringe or control rod may be deformed to prevent any further axial movement of the control rod 20 and the needle 19 in the body 11. If desired the first embodiment may be modified whereby the needle 19 and boss 16 are located centrally in the piston and body 11 respectively. The second embodiment shown at figures 3 and 4 also relate to a hypodermic syringe and the same reference numerals have been used for identical components. The syringe 10 according to the embodiment comprises a substantially cylindrical body 11 which is closed at one end and is open at the other end. The body supports a piston 12 which is sealingly received within the body 11 and is slidable axially therein. The piston 12 is associated with a plunger rod 13 which extends from the open end of the body 11 and is associated with an enlarged end which together with an outwardly directed flange provided at the open end of the body 11 facilitates manipulation of the plunger. The body 11 is associated with a tubular housing 30 located on the exterior wall of the body 11 and which extends axially along the wall. The lower end of the tubular housing 30 is formed with a boss 16 which extends beyond the lower end of the body 11 which if desired may be configured to facilitate engagement with a "Luer" or like fitting as described in relation to the first embodiment. The boss 16 is formed with a central passageway 17 which opens into the interior of the housing 30 and communicates with a lateral passageway 26 provided in the side wall of the body 11 adjacent the closed end thereof to facilitate communication between the chamber 18 provided, between the piston 12 and the closed end of the body 11 and the interior of the tubular housing 30. The tubular housing 30 slidably accommodates a needle 19 which is mounted to the lower end of a control rod 20. The upper end of the control rod 20 extends beyond the upper end of the tubular housing 30 and is provided with an enlarged portion 24 which can be gripped by a user to cause axial movement of the needle 19 and control rod 20 within the tubular housing 30. The body 11 is provided with a stop member 32 which is intended to engage the upper end of the control rod 20 when the needle is in the first position extending from the boss 17 as shown at figure 3 to prevent inadvertent axial displacement of the needle into the housing 30. The outer end of the needle 19 is provided with a first aperture to facilitate the flow of parenteral from the needle 19 when in use. The inner end of the needle 19 is provided with a laterally directed second aperture 21. When the needle 19 is in its first position at which it extends from the boss 16 through the central opening 17 as shown as figure 3 the second aperture 21 in the needle communicates with the passageway 31 provided in the said wall of the body 11 to facilitate the flow of parenteral from the chamber 18 into the needle 19. Suitable seals are provided on the internal walls of the housing 30 to either side of the passageway 31 to prevent leakage of a parenteral between the walls of the housing 30 and the needle 19 and control rod 20. Furthermore, the control rod 20 and needle may be provided with an external configuration to facilitate sealing with the side internal walls of the secondary housing 30. When the needle 19 is in its fully retracted position at which it is fully accommodated within the secondary housing 30 the enlarged upper end of the control rod 20 extends through an aperture 34 provided in the flange 15 whereby it becomes lockingly engaged with the flange 34 to prevent inadvertent axial displacement of the needle and control rod from the second position as shown at figure 4. It should be appreciated that any suitable form of retaining the control rod in either of its positions may be used. When in the second position the free end of the needle 19 is positioned clear of the central passageway 17 and the boss 16 which facilitates the delivery of body fluids into a specimen receptacle or the application of a "Luer" fitting to the boss 16 for the drawing of parenteral into the chamber 18 from an ampoule or similar container. In the case of both the first and second embodiments, the boss 16 may be configured to eliminate the need of a "Luer" fitting whereby the boss 16 may be inserted directly into an ampoule or container for the charging of the chamber 18 with parenteral. In addition, in both the first and second embodiments, the needle when in second position need not be drawn clear of the central passageway 17 and the boss 16 in order that the central passageway 17 is sealed and thus the chamber 18 is sealed with the needle in the retracted state. This latter feature is of importance where the syringe is used to draw samples which are required to be stored in the syringe during transportation to a testing station or like or where the syringe is required to be supplied by the manufacturers pre-filled with a parenteral. In the case of the second embodiment, the body 11 and/or secondary housing 30 and/or the control rod 20 may be such that they may be distorted on locating the needle 19 and control rod 20 in the second position to prevent any axial displacement of the needle from the used syringe. In relation to the second embodiment the sealing provided between the needle 19 and the interior of the secondary housing 30 may be such that the flow of parenteral from the chamber 18 to the needle 19 may be shut off by rotating the needle 19 about its central axis. Furthermore the body 11 may be formed with two compartments each being provided with its own piston and plunger but with a common secondary housing 30 whereby the chamber of each may be brought into communication with the lumen of the needle by rotation of the needle about its central longitudinal axis or alternatively by axial displacement of the needle between one of two positions. A further alternative may comprise the provision of a plurality of secondary housings 30 each accommodating their own retractable needle 19 and being connectable with a common chamber 18. The third embodiment at figures 5 and 6 relates to a cannula 50 which can be used for the passive extraction or administration of fluids to a living body. The cannula comprises a substantially tubular element 51 which is closed at one end and is adapted at the other end 52 to be connected to tubing which is associated with a receptacle containing a parenteral or which is intended to receive body fluids. The tubular element 51 is associated with a secondary tubular housing 53 which is mounted to one side of the tubular element 51 in substantially parallel relationship therewith and which is provided with an axial opening 54 at the end adjacent the closed end of the tubular element 51. The interior wall of the tubular element 51 is formed with a passageway 55 adjacent the opening 54 which opens into the interior of the tubular secondary tubular housing 53. The interior of the secondary tubular housing 53 slidably supports a hollow needle 56 which is mounted to one end of a control rod 57. The control rod 57 is located within the secondary tubular housing 53 and is provided at its innermost end with a laterally projecting protruberance 58 which is slidably receivable in an axial slot 59 provided in the wall of the secondary tubular housing 53 to allow for axial displacement of the control rod 57 and consequently the needle 56 between a first position as shown at figure 6 at which the needle extends beyond the closed end of the tubular element 51 and a second position as shown at figure 5 at which the needle is fully accommodated within the secondary tubular housing 53. The hollow needle is provided with a first opening 60 at its outer end and a second opening at or near its inner end which communicates with the passageway 55 in the wall of the tubular element 51 when the needle is in its first position as shown at figure δ. Suitable sealing means are provided on the interior wall of the secondary tubular housing 53 in the region of the passageway 55 and or on the external face of the needle 56 in the region of the second aperture 61 to ensure there is no leakage of any fluids between the internal wall of the secondary tubular housing 53 and the needle 56. If desired the needle 56 and control rod 57 may be rotatable in the secondary tubular housing 53 about the central longitudinal axis of the needle 56 and the seal provided between the interior wall of the secondary tubular housing 53 and the needle 56 may be such that with rotation of the needle the second aperture therein may be brought into and out of communication with the passageway 55 to allow a flow of fluid therebetween and/or prevent such fluid flow. In addition, the slidable relationship between the protruberance 58 on the control rod 57 within the slot 59 may be such that the needle is retained in either of its end positions to prevent inadvertent displacement from either position. Furthermore, the body of the cannula may be formed of a material which facilitates the permanent distortion of the tubular element 51 when the needle 19 is in its retracted position and which prevents displacement of the needle from a used cannula. The cannula of the embodiment shown at figures 5 and 6 incorporates a feature which may be preferred however which is not essential. The feature comprises an annular chamber 62 at a position spaced from the closed end of the tubular element 51 which is provided with an opening 63 which can be connected to tubing 64. The annular chamber 62 is provided with a second passageway 65 which opens into the interior of the secondary tubular housing 53 and which can be brought into communication with the second opening 61 provided in the needle 19. Suitable indexing is provided on the slot 59 to ensure retention of the control rod 57 in a position at which such communication can be provided. The function of the annular chamber is to provide for an alternative admission of a second fluid into a body or alternatively the extraction of body fluids prior to or subsequent to the administration of a parenteral, or alternatively sampling of fluids which have been discharged through the tubular element 51 of the cannula. The fourth embodiment shown at figures 6, 7, 8, 9 and 10 is also directed to a cannula and common reference numerals have been used in some instances to those of the third embodiment in relation to identical components. The cannula of the fourth embodiment comprises a tubular housing 53 which slidably receives a control rod 57 having a hollow needle 56 mounted to one end thereof which is movable through an opening 54 provided in one end of the tubular housing 53. The side walls of the tubular body 51 are provided with two separate fluid flow ducts 70 and 71 which open into the interior of the tubular housing 53 through separate passageways 72 and 73 which are angularly displaced from each other about a central longitudinal axis and each of which are provided with their own outlet and or inlet 74 and 75. The needle 56 is provided at its outer end with a first aperture 60 and at its inner end with a second laterally opening aperture 61. The control rod 57 is provided with a laterally extending portion 5S which extends through an axial slot 59 provided in the side wall of the tubular housing 53. At the end of the slot 59, corresponding to the position at which the needle is in its first position as shown at figure 7 where it extends beyond the opening 54 in the body 51 and the second aperture 61 in the needle is brought into communication with either passageway 72 or 73 of either duct 70 or 71 respectively by rotation of the control rod 57. This is achieved by means of a circumferential slot provided in the end of the axial slot 59 not shown which permits rotation of the protruberance 58. By means of the fourth embodiment the cannula may be used to service two different purposes without the need for replacing the cannula by another to facilitate an exchange of such purposes. It should be appreciated that each of the embodiments may be modified whereby the needle of each is spring biased to either its first or second position and is associated with a latching means whereby on release of the latching means the needle will move under the influence of the spring pressure to its first or second position respectively. Each of the embodiments described above provide a parenteral device whereby the exposure of the needle can be minimised during use and disposal without the need for a needle cap and which can reduce the need for special disposal procedures previously reguired of the needle of such devices. It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiment described above.

Claims: THE CLAIMS defining the invention are as follows: 1. A parenteral device comprising a body having a chamber, an opening provided in the wall of the chamber, hollow needle having the first aperture at its outer end and being slidably mounted to the body to be movable axially therein, said needle being associated with an opening whereby it is movable to a first position and extending through said opening whereby its outer end extends beyond the body and a second position whereby the outer end of said needle is located innermost from said opening, a second aperture in the wall of the needle providing communication between the chamber and the lumen of the needle when in the first position. 2. A parenteral device as claimed at claim 1 wherein said body comprises a syringe having a piston slidably accommodated within the body said needle being slidably and sealingly engaged by said piston. 3. A parenteral device as claimed at claim 2 wherein the needle is slidably accommodated by a tubular seal associated with the piston and which encloses the needle when in the second position. 4. A parenteral device as claimed at claim 1 wherein the needle is accommodated within a secondary tubular housing separate from said chamber said opening being provided in said secondary tubular housing and a second opening extends from the chamber into the secondary tubular housing and communicates with said second aperture when the needle is in the second position. 5. A parenteral device as claimed at any one of the preceding claims wherein when the needle is in its second position, said first opening is in direct communication with the chamber. 6. A parenteral device as claimed at any one of the preceding claims wherein sealing means are provided between the interior wall of the secondary tubular housing and the exterior face of the needle to each side of the second opening. 7. A parenteral device as claimed at any one of claims 4, 5 or 6 wherein a plurality of chambers open into the tubular secondary housing through second openings at spaced locations and seals are provided between the interior wall of the secondary tubular housing and the needle to isolate said second openings, said needle being movable to a plurality of first positions to bring the second aperture into communication with each second opening. 8. A parenteral device as claimed at claims 7 wherein said secondary openings are axially and/or circumferentially spaced from each other. 9. A parenteral device as claimed in any one of the preceding claims wherein a releasable retention means is provided to retain the needle in its two end positions. 10. A parenteral device as claimed at claim 8 wherein one wall of said chambers comprises a duct adapted to be connected to a receptacle. 11. A parenteral device as claimed in any one of the preceding claims wherein the needle is spring biased to its first or second position and latching means are provided to retain it in its first or second position. 12. A parenteral device as claimed at any one of the preceding claims wherein the needle is sealingly engaged with the body in the region of the opening when in the second position to sealingly close the chamber . 13. A parenteral device as claimed at claim 1 and claim 4 to 11 as dependant on claim 1 wherein the parenteral device comprises a cannula. 14. A parenteral device substantially as herein described with reference to the accompanying drawings.

Inventors: WHISSON MAXWELL EDMUND, WHISSON, MAXWELL, EDMUND
Applicants: WHISSON MAXWELL EDMUND, WHISSON, MAXWELL, EDMUND
Application year: 1988
Main classification: A61M5
IPC codes: A61M5