Disposable medical insertion device

Abstract: Disclosed is an improved medical thrust device comprising: a thrust needle assembly (1) comprising a needle body (5) having a needle hub fixed to its needle (6); a hollow casing (11) at least opening at its top for slidably containing the thrust needle assembly, the opening top (14) of the hollow casing having inward projections on its inner circumference; a stopper (20) movably attached to the vicinity of the opening top of the hollow casing; and a protection cover (22) for enclosing at least the sharp point of the thrust needle, thereby permitting the thrust needle assembly to be retained in the hollow casing by putting the stopper in the shutting position, or permitting the thrust needle assembly to appear from the hollow casing by holding the needle hub of the inner needle between the inward projections of the opening top and the stopper, which is put in the shutting position. The inner needle can be retained in the casing or protection cover after removing it from the thrust spot, and the casing or protection cover containing the bacilli-contaminated needle therein can be thrown away as a disposable object.

Description: The present invention relates to a medical thrust device such as an indwelling thrust device or a syringe which is designed to subcutaneously thrust its needle into the blood vessel or bile duct for injection or removal of blood or body fluids, and more particularly to a disposal medical thrust device which is intended to be used once and then thrown away, thereby guaranteed to be free of contagion by injuring one's hand with the blood-smeared or bacilli-contaminated needle. Such a disposal medical thrust device includes a hard metal needle. A used needle is smeared with blood or body flood, which contains bacilli. Lest people should be infected with such bacilli, the blood-smeared needle body is used once and then thrown away. The precaution must be taken against every possible infection to doctors, nurses, assistants and collectors of waste materials. Therefore, the used needles must be contained in disposable casings, and advantageously the needle casings from which the needles are taken out are reused as such disposable casings. Once a used needle has been put in its casing there will be no fear for infection. When the used needle is being put in the casing with one hand holding the used needle and with the other hand holding the casing, the person often injures his hand with the sharp point of the bacilli-contaminated needle. In an attempt to prevent this dangerous incident it has been proposed an indwelling thrust device designed to have a needle cover responsive to removal of the needle from the thrust spot for automatically covering its sharp point, as for instance in Japanese Patent 3-191965(A). Specifically, the needle cover is in the form of expandable-and-shrinkable (telescoping or coiled-spring) body, and it has a cap on its top end, and its bottom end is attached to the hub of the needle, and the cap is fixed to the hub of the surrounding cannula. The sharp point of the needle is allowed to appear from the cannula by shrinking the expandable-and-shrinkable body, and then the needle is thrusted into a selected part of the human body. As the needle is removed from the thrust spot, the expandable-and-shrinkable body is allowed to expand so that the cap may cover the sharp point of the needle upon complete removal of the needle from the indwelling cannula. The expandable-and-shrinkable body is maintained in the shrinking position only by the friction between the expandable-and-shrinkable body and the surrounding cannula, and also by the friction between the needle and the surrounding expandable-and-shrinkable body, and therefore, once the expandable-and-shrinkable body has been put in the shrinking position it may be possible to allow the expandable-and-shrinkable body along with the surrounding cannula to extend beyond the sharp point of the needle before thrust or during thrust rather than removal from the thrust spot. Thus, extra caution is required in use. The expandable-and-shrinkable body must be long enough to cover the full length of the needle when it extends to its full length, and therefore, the radial size of the expandable-and-shrinkable body of telescoping type will be large. In case that the needle has a relatively long length, the outer radial size of the telescoping body when shrinked will be inhibitably large, radially extending a substantial size beyond the radial size of the cannula, thus causing an inconvenience in thrusting the needle into a selected part of the human body. Further, there has been proposed an injection needle storing container designed to have a long pore having a broad part and a narrow part on a cover plate of the container for removing a injection needle from a syringe body by hooking the needle hub with the pore, for instance in Japanese Patent 64-52480(A) and 1-136665(A). A used injection needle is inserted into the broad part of the pore and shifted to the narrow part keeping a flange of the needle hub lower side of the cover plate and the syringe body is shifted upward to drop and store the separated injection needle into the container. WO-A-95/23003, which is used as a basis for the preamble of claim 1, relates to intravenous catheter insertion devices which employ a sharp needle to introduce an intravenous catheter into a body vessel of a patient. The sharp needle end is positioned to extend from within the catheter such that the needle and catheter can be introduced into the body vessel which is pierced by the sharp needle. Following use of the intravenous catheter insertion device to introduce and implace an intravenous catheter into a patient's body vessel, the needle is withdrawn from within the catheter and the device is separated from the catheter such that only the catheter remains within the body vessel. The device comprises a self-contained coupling means for preventing separation of the catheter from the device until the needle is substantially transposed into a safety receptacle to thereby permit the used needle to be safely handled and discarded. However, the used injection is exposed without cover before disposing into the container and accordingly it is not enough to guarantee to be free from infection. Also, it is afraid that long term storing may cause an accident to fall the container and the stored needles spring out of the hole. Therefore, there has been an ever increasing demand for a disposal medical thrust device guaranteed to be free of injuring one's hand with the bacilli-contaminated needle, still assuring that it can be handled with ease. One object of the present invention is to provide a disposal medical thrust device achieving this demand. This object is achieved with the features of the claims. In particular, a medical thrust device according to the invention comprises a casing having at least an opening top with inner projections formed inside, a needle assembly slidably fitted in the casing, a stopper movable between an opening position and a shutting position and a protection cover for enclosing at least a sharp point of the thrust needle, in which the hollow space of the casing is shut at least partly to separate into the forward, shortened and rearward, extended hollow sections. The needle assembly can be selectively put by the stopper in a first, self-containing position in which the needle assembly is contained in the rearward, extended hollow section of the casing with the stopper in the shutting position, or in a second, thrusting position in which the needle appears from the casing with the rear hub of the needle assembly caught between the inner projections of the opening top of the casing and the stopper, which is put in the opening position. In case of indwelling thrust devices they are usually in the first, self-containing position for circulation in market and storage in warehouses, and the devices will be put in the second, thrusting position for use. In the thrusting position in which the needle appears from the opening top of the casing, the substantial length of the thrust device is allotted to the holding of the device with one hand, thus facilitating the handling of the thrust device. When thrusting is completed and the needle is removed from the cannula, the stopper is put in the opening position, thereby allowing the needle to fall in the casing or the protection cover to be contained and prevented from projecting from the casing by the stopper, which is now put in the shutting position. Thus, the thrust device can be used once and then thrown away safely without fear of injuring one's hand with the bacilli-contaminated needle. Additionally the thrust device has a protection cover to cover at least the sharp point of the needle, thereby preventing the injuring of one's hand prior to use by permitting the uncovering of the sharp point of the needle just prior to thrust. The protection cover is press-fitted on the hub of the cannula or on the forward end of the hollow casing, thus enclosing the needle assembly. In case that the needle assembly is allowed to appear from the casing while being shipped, circulated in the market or stored in warehouses, the protection cover will prevent the exposing of the sharp point of the needle. Thus, the protection cover works as a needle case in shipping, circulating in the market or being warehoused, whereas the casing works as a disposable case after use. Advantageously the casing may be of a telescoping structure, and then it can be extended to contain the bacilli-contaminated needle when thrown away. Prior to use it can be shrinked to a shortened size, thereby reducing a substantial dead space which otherwise, would be occupied by the indwelling thrust device in shipping, circulation in the market or storage in warehouses. In place of using a relatively large-sized casing as a disposable container a relatively small-sized disposable case may be used. Then, the hub of the needle assembly may be composed of a head hub-section and a tail hub-section. The head hub-section is sized so as to permit it to pass through the reduced space defined by the inward projections of the opening top of the casing whereas the tail hub-section is sized so as to prevent it from passing through the reduced space of the top opening. The tail hub-section and the casing are equipped with anti-rotation means, and likewise, the head hub-section and the disposable case are equipped with anti-rotation means. After the bacilli-contaminated needle is allowed to fall in the casing, the disposable case is fitted on the needle assembly to cover the same, and then the disposable case is rotated to separate the needle-and-head hub-section from the tail hub-section, thus permitting the disposable case, which covers the needle and the head hub-section, to be removed from the casing and thrown away. Thus, the bacilli-contaminated needle can be thrown away safely as a relatively small-sized waste material. The protection tube may be sized and used as a disposable case. The stopper is designed to reciprocate between the opening and shutting position. The invention may be applied to syringes, in which the hollow casing is made opened at its bottom to allow insertion of syringe body therefrom. The protection cover is made closing at the top and the opening bottom end is made detachable to each of the forward and rear end of the hollow casing, respectively. The stopper may have an additional small through hole for the injection nozzle of the syringe to be inserted therethrough. In this case the needle assembly is allowed to appear from the casing being enclosed by the protection cover while being shipped, circulated in the market or stored in warehouses, thereby the protection cover works as a needle case not only in shipping, circulating in the market or being warehoused but also works as a disposable case after use in the form of being connected to the rear end of the hollow casing. Other objects and advantages of the present invention will be understood from the following description of indwelling thrust devices according to preferred embodiments of the present invention, which are shown in accompanying drawings. Fig.1 is a longitudinal section of an indwelling type thrust device according to a first embodiment; Fig.2 is a cross section of the thrust device taken along the line 2-2 in Fig.1; Figs.3A, 3B, 3C and 3D show how the thrust device can be used; Fig.4 is a longitudinal section of an indwelling type thrust device according to a second embodiment; Figs.5A, 5B, 5C show how the thrust device can be used; Fig.6 is a longitudinal section of an indwelling type thrust device according to a third embodiment; Figs.7 and 8 show how the thrust device can be used; Figs. 9 and 10 show enlarged cross sections of the thrust device taken along the lines 9-9 and 10-10 in Fig.6, respectively; Fig.11A is a longitudinal section of a selected part of an indwelling type thrust device, and Fig.11B is a cross section of the selected part of the thrust device, showing a different form of stopper; Fig.12A is a longitudinal section of a selected part of an indwelling type thrust device, and Fig.12B is a cross section of the selected part of the thrust device, showing another different form of stopper; Fig.13A is a longitudinal section of a selected part of an indwelling type thrust device, and Fig.13B is a cross section of the selected part of the thrust device, showing still another different form of stopper; Fig.14 is a longitudinal section of a syringe type thrust device according to a fifth embodiment; Fig.15 is a cross section of the thrust device taken along the line 15-15 in Fig.14; Fig.16 shows how the thrust device can be used; Figs.1 to 10 show indwelling type thrust devices according to different embodiments of the present invention. Every indwelling thrust device includes a thrust needle assembly 1 comprising an indwelling cannula body 2 and a thrust needle body 5. The indwelling cannula body 2 comprises a cannula 3 of a soft synthetic resin material, having a hard cylindrical hub 4 integrally or separately connected to its base end, and the thrust needle body 5 comprises a thrust metal needle 6 fitted in the indwelling cannula 3, and the thrust metal needle 6 has a sharp point 7 at one end and a hard synthetic resin hub 8 attached to the other end. The structure described so far is well known. Referring to Fig.1, the hub 8 of the thrust metal needle 6 is composed of a tapered head-section 8a of relatively small diameter and a tail-section 8b of relatively large diameter. The thrust metal needle 6 is inserted in the cannula 3 with its sharp point 7 appearing therefrom. The tail hub-section 8b is loaded with a filter 9, which permits the passing-through of air, but prevents the passing-through of blood or other body fluids. A casing 11 is an elongated hollow cylinder of a hard synthetic resin material, having a closed bottom 12 and an opening top 14. The opening top 14 has inward projections 15 formed on its inner circumference 13. Also, the hollow cylinder 11 has opposite guide slots 16 formed inside in a plane perpendicular to the axis of the hollow cylinder 11 in the vicinity of the opening top 14. A round-sided rectangular stopper plate 20 has a hole 21 formed close to one side, and the hole 21 has a diameter almost equal to the inner diameter of the casing 11. The stopper plate 20 is slidably inserted in the opposite guide slots 16 of the hollow cylinder 11 so as to move between the shutting position in which the closing wall section 22 of the stopper plate 20 closes the casing 11 in the vicinity of the opening end 14 and the opening position in which the hole 21 of the stopper plate 20 is put in alignment with the longitudinal hollow space of the casing 11. The stopper plate 20 is positioned so as to separate the full length of the longitudinal hollow space of the casing 11 into the tail-section which is somewhat longer than the length of the indwelling needle assembly 1 and the head-section which is long enough to hold the tail hub-section 8b of the needle hub 8 tightly between the closing wall section 22 of the stopper plate 20 and the inward projections 15 of the opening top of the casing 11. As seen from Figs. 1 and 3, the indwelling thrust device according to the first embodiment has a protection cover 24 of hard synthetic resin press-fitted on the cannula hub 4. The protection cover 24 encloses the cannula 3 to extend a short distance beyond the sharp point 7 of the needle 6. As seen from Fig.1, the thrust needle assembly 1 is put in the casing 11 with the needle hub 8 sitting on the bottom wall 12 of the casing 11, and the stopper plate 20 is put in the shutting position. The indwelling thrust device when put in this position can be shipped, warehoused or circulated in the market. In use, the stopper plate 20 is moved to the opening position, and then the casing 12 is turned with its opening end 14 down, thereby allowing the thrust needle assembly 1 to fall down by gravity, passing through the hole 21 of the stopper plate 20 and the reduced space defined by the inward projections 15 of the opening top 14 of the casing 11, as shown in Fig.3(A). The hole 21 of the stopper plate 20 and the longitudinal hollow space of the casing 11 are somewhat larger than the tail hub-section 8b of the needle hub 8, thereby allowing the thrust needle assembly 1 to fall slowly in the casing 11, or preventing the quick falling of the thrust needle assembly 1. When the tail hub-section 8b of the needle hub 8 is caught by the inward projections 15 of the opening top 14 of the casing 11, the stopper plate 20 is put in the shutting position, thereby holding the tail hub-section 8b of the needle hub 8 between the closing wall section 22 of the stopper plate 20 and the inward projections 15 of the opening top of the casing 11. Then, the protection cover 24 is removed so that the indwelling thrust device may be ready for use, as shown in Fig.3(B). The person holds the indwelling thrust device by pinching the cannula hub 4 with thumb and index finger and by holding the casing 11 with the other fingers or otherwise, by gripping the casing 11 with all fingers, and he thrusts the sharp point of the needle into a selected part of the human body. The stopper plate 20 extends a short distance from the casing 11 in one direction, thus causing no hindrance to thrusting operation. After the thrust needle body 5 is removed from the thrust spot, leaving the cannula body 2 behind, the stopper plate 20 is put in the opening position in which the head-section communicates with the tail-section of the casing 11, and then the casing 11 is turned upright with its opening top 14 up, thus allowing the thrust needle body 5 to fall slowly onto the bottom wall 12 of the casing 11 through the top opening 14 and the hole 21 (see Fig.3 C). When the thrust needle body 5 is sit on the bottom wall 12 of the casing 11, the stopper plate 20 is put in the shutting position, thereby preventing the thrust needle body 5 from slipping off from the casing 11 (see Fig.3 D). The first embodiment described so far is defined in claims 1, 2 and 3. The casing 11 is advantageously used as a container for pre- and post-use of needle, thus permitting the bacillie-contaminated needle to be thrown away as a waste material without using another extra casing for that purpose. The indwelling thrust device can be selectively put in either condition of permitting use or throwing-away of the device simply by moving and putting the stopper plate in the shutting or opening position, and by turning the device upside down or down side up, without requiring access to the bacilli-contaminated needle by one's hand. Referring to Figs. 4 and 5, the indwelling thrust device according to the second embodiment uses a protection cover 25 of hard synthetic resin, which protection cover 25 is press-fitted on the opening top 14 of the casing 11. The protection cover 25 is composed of head and tail cylindrical sections. The head cylindrical section has a relatively short diameter, and is closed at its top end, whereas the tail cylindrical section has a relatively long diameter, and is open at its bottom. The thrust needle assembly 1 is held by holding the tail hub-section 8b of the needle hub 8 between the closing wall section 22 of the stopper plate 20 and the inward projections 15 of the opening top 14 of the casing 11. The substantial length of the thrust needle assembly 1 projecting from the casing is enclosed in the protection cover 25. In this embodiment the thrust needle assembly 1 projects from the casing 11, using the protection cover 25 as wrapping case. The casing 11 can be used as a disposable container. The casing 11 can be designed to be fixed or unadjustable in length as in the first embodiment, but advantageously it is designed to be adjustable in length. Specifically in order to reduce the whole size of the device to possible minimum when being shipped, warehoused or circulated in the market the casing 11 is of telescoping structure, and is composed of telescoping head- and tail-sections 11a and 11b. The head-section 11a is a bottomless hollow cylinder of relatively short diameter whereas the tail-section 11b is a bottomed hollow cylinder of relatively large diameter. The indwelling thrust device can be shrinked by pushing the head-section 11a into the tail-section 11b when being shipped, warehoused or circulated in the market (see Fig.4). When the device is used for the medical treatment, the protection cover 25 is removed to expose the substantial length of the thrust needle assembly (see Fig.5A). After the thrust needle body 5 is removed from the thrust spot, leaving the cannula body 2 behind, the stopper plate 20 is put in the opening position in which the head-section communicates with the tail-section of the casing 11, and then the device is extended to its full length by pulling the tail-section 11b backward. Thereafter, the casing 11 is turned upright with its opening top 14 up, thus allowing the thrust needle body 5 to fall slowly toward the bottom wall 12 of the casing 11 through the top opening 14 and the hole 21 (see Fig.5B). When the thrust needle body 5 is sit on the bottom wall 12 of the casing 11, the stopper plate 20 is put in the shutting position, thereby preventing the thrust needle body 5 from slipping off from the casing 11 (see Fig.5C). The second embodiment described above is defined in claims 4 and 5. The indwelling thrust device can be put easily in ready-for-use condition simply by removing the protection cover, and can be put in disposable condition by single-hand operation without requiring access to the bacilli-contaminated needle by hand. The first embodiment uses a casing 11 large enough to contain the thrust needle assembly 1, and the second embodiment uses an expandable casing 11 which can be extended to its full length to contain the bacilli-contaminated needle 6. Therefore, these embodiments are inevitably increased in size. In an attempt to permit the size of the medical thrust device to be reduced to possible minimum when being thrown away as a waste material a medical thrust device according to the third embodiment is so designed as to permit the protection cover to be used as a disposable container for the bacilli-contaminated needle. For that purpose the protection cover, needle hub and casing of the medical thrust device according to the first embodiment are modified as described below. Figs.6 to 10 show a medical thrust device according to the third embodiment. As seen from Fig.6, the needle hub 8 is composed of a head hub-section 81 and a tail hub-section 84. The tapering head hub-section 81 has longitudinal ribs 83 formed at regular intervals on its cone surface, and has the bottom end of the needle 6 press-fitted therein. As shown in Fig.6, it has a tapering recess 82 made in its bottom. The tail hub-section 84 is detachably press-fitted in the bottom recess 82 of the head hub-section 81 at the tapering forward end 85. The head hub-section 81 is sized so as to pass through the reduced space defined by the inward projections 15 of the opening end 14 of the casing 11. The tail hub-section 84 has ribs 86 formed circumferentially at regular intervals on its bottom end. The tail hub-section 84 is sized so as to be caught by the inward projections 15 of the opening end 14 of the casing 11. The protection cover 26 is an elongated hollow, bottom-less cylinder of hard, synthetic resin, and is closed at its top by a top wall 27. It has longitudinal ribs 29 formed at regular intervals on its inner circumference, and is radially sized to be fit in the reduced space defined by the inward projections 15 of the opening top 14 of the casing 11. The casing 11 has ribs 18 circumferentially formed at regular intervals on the bottom wall 12. As seen from Fig.6, the protection cover 26 encloses the cannula 3 and the needle 6, and all of these parts are integrated together by press-fitting the bottom end of the protection cover 26 on the ribs 83 of the head hub-section 81 of the needle hub 8. The so integrated thrust needle assembly 1 is inserted in the casing 11 until it has reached the bottom wall 12 of the casing 11, allowing the thrust needle assembly 1 to partly appear from the opening top 14 of the casing 11 while being held tightly by the inward projections 15 of the opening top 14 of the casing 11. Thus, the medical thrust device in this position can be shipped, warehoused or circulated in the market. In use, the protection cover 26 is pulled out from the casing 11 until the tail hub-section 84 of the thrust needle assembly 1 has been caught by the inward projections 15 of the opening top 14, and then, the stopper plate 20 is pushed to the shutting position to hold the tail hub-section 84 between the closing wall section 22 of the stopper plate 20 and the inward projections 15 of the opening top 14 of the casing 11, thus holding stably the thrust needle assembly 1 at the top of the casing 11. The protection cover 26 is removed so that the indwelling thrust device may be ready for use. After the inner thrust needle body 5 is removed from the thrust spot, leaving the cannula body 2 behind, the stopper plate 20 is put in the opening position in which the head-section communicates with the tail-section of the casing 11, and then the casing 11 is turned upright with its opening top 14 up, thus allowing the inner thrust needle body 5 to fall slowly onto the bottom wall 12 of the casing 11 through the top opening 14 and the hole 21 of the stopper plate 20. This proceeding is similar to what is described with reference to Figs.3A, 3B and 3C. When the inner thrust needle body 5 is sit on the bottom wall 12 of the casing 11, the protection cover 26 is inserted into the casing 11 to press-fit its open bottom on the ribs 83 of the head hub-section 81 while rotating the protection cover 26, thus causing the longitudinal ribs 29 of the protection cover 26 and the hubs 86 of the tail hub-section 84 to engage with the ribs 83 of the head hub-section 81 and the ribs 18 of the bottom wall 12, respectively (see Fig.7). Then, the protection cover 26 is rotated along with the head hub-section 81 while the tail hub-section 84 is connected to the casing 11 so that the tail hub-section 84 remains still. As a result the tapering forward end 85 of the tail hub-section 84 is loosely fitted in the tapering recess 82 of the bottom of the head hub-section 81 so that the head hub-section 81 may be separated from the tail hub-section 84 (see Fig.8). The protection cover 26 is positively connected by permitting the ribs 83 of the head hub-section 81 to cut in the inner circumference of the protection cover 26, thereby integrally connecting the head hub-section 81 to the protection cover 26. Then, the protection cover 26 holding the thrust needle assembly therein is removed from the casing 11 to be thrown away as a disposable waste. The medical thrust device according to the third embodiment as described above is defined in claim 6, permitting the protection cover 26 to be used as a disposable case for throwing the bacilli-contaminated needle away. The protection cover 26 is relatively small in size, accordingly reducing the amount of waste material. As described earlier, the bacilli-contaminated needle is allowed to fall in the casing 11, and the protection cover 26 is inserted into the casing 11 to cover the bacilli-contaminated needle. Therefore, there is no fear for injuring one's hand with the sharp point of the bacilli-contaminated needle in throwing away the dangerous object. The medical thrust devices according to the first, second and third embodiments of the present invention are appropriate for the needle of standard length. The size of these devices, particularly of their casings or protection covers will increase inhibitably with the increase of the needle length beyond 15 centimeters. Different forms of stopper other than the round-ended rectangular plate can be used. Figs.11A and 11B show a flexible, rectangular stopper plate 50 of soft synthetic resin, the opposite longitudinal sides of which rectangular stopper plate 50 are slidably fitted both in the opposite longitudinal guide slots 34 on the top side of the casing 11, and in the opposite vertical guide slots 35 on the inner, opposite lateral side walls of the casing 11. The rectangular stopper plate 50 can be put selectively in opening or shutting position by pushing the stopper plate 50 backward or forward along the top surface of the casing 11. Figs.12A and 12B show another flexible, rectangular stopper plate 52 of soft synthetic resin, which has oblique threads 53 formed on its upper surface. An operating ring 39 is rotatably fitted in the circumferential slot 38, which is formed on the outer surface 13 of the casing 11. The operating ring 39 has spiral threads 40 formed inside, and these spiral threads 40 engage with the oblique threads 53 of the stopper plate 52. Opposite longitudinal guide slots 41 are formed on the top surface of the casing 11, and opposite vertical guide slots 35 are formed on the inner, opposite side walls of the casing 11. These longitudinal guide slots 41 and vertical guide slots 35 are continuous via a lateral slot 42, which is formed on the top surface of the casing 11. The opposite longitudinal sides of the rectangular stopper plate 52 are slidably fitted in the longitudinal guide slots 41 on the top surface of the casing 11, and in the vertical guide slots 35 on the inner, opposite side walls, passing through the lateral slot 42 of the casing 11. The rectangular stopper 52 can move in and out of the hollow space of the casing 11 between the shutting position and the opening position. These stopper plates can be used equally in medical thrust devices according to the first, second and third embodiments described above, but a simpler stopper may be used in a medical thrust device according to the fourth embodiment, in which the stopper need not be put in the shutting position to confine the needle in the casing. Figs.13A and 13B show such a simple stopper 54, which is a rectangular plate of hard, synthetic resin. As shown in Fig.13A, the rectangular plate 54 is fitted in the lateral slot 45, which is made in the ceiling of the casing 11. The rectangular plate 54 extends a mid distance in the hollow space of the casing 11 to hold the needle hub 8 of the thrust needle assembly 1 between the stopper 54 and the inward projections 15 of the opening top 14 of the casing 11. The stopper 54 may be pushed in the hollow space of the casing 11, thereby confining the bacilli-contaminated needle in the casing to prevent it from slipping off from the casing 11. If the needle is long enough to extend beyond the stopper 54, the bacilli-contaminated needle can be bent by pushing the stopper 54 in the hollow space of the casing 11, thereby positively holding the used needle in the casing 11 to assure even more safety in throwing the disposable object away. Figs.14 shows a syringe type thrust device according to a fifth embodiment of the present invention. The thrust device in this embodiment uses a hollow casing 101 which is bottomless to allow insertion of a syringe 110 therethrough and is relatively short. The syringe 110 is composed with a hollow barrel 111 and plunger 112 slidably inserted into the hollow barrel. The hollow barrel 111 has a cylindrical connector 113 on its top end to be fitted into the needle hub 8 of the thrust needle body 5. It uses a stopper 105 having an additional small through hole 108 between the hole 106 for the opening section and the closing wall section 107. A protection cover 120 is press-fitted on the opening top 102 of the casing 101, and is closed at its top end. The thrust needle body 5 is held by holding the tail hub-section 8b of the needle hub 8 between the the stopper plate 105 and the inward projections 103 of the opening top 102 of the casing 101, in which the connector 113 of the syringe 110 passes through the small through hole 108 of the stopper 105 to be fitted into the needle hub 8. The substantial length of the thrust needle body 5 projecting from the casing is enclosed in the protection cover 120. In this embodiment the protection cover 120 is used as wrapping case when being shipped, warehoused or circulated in the market (see Fig.14). The protection cover 120 is used also as a disposable container together with the casing 101 by connecting the bottom opening end to the screwed rear end 104 of the casing 101 (see Figs.16). As may be understood from the above, a medical thrust device according to the present invention is designed so as to permit the needle to be confined in its casing, and to permit the needle to appear from its casing, and also it is designed so as to permit its casing to be used as a disposable container, in which the used needle can be put in without fear of injuring one's hand with the sharp point of the bacilli-contaminated needle. Also, it is designed so as to have a protection cover to enclose at least the sharp point of the needle, thereby guaranteed to be free of injuring people with the sharp point of the needle prior to thrust. The protection cover may be used as a disposable container. The casing extends behind the needle in use, thus conveniently permitting the holding of the device by the casing with hand.

Claims: A medical thrust device comprising a thrust needle assembly (1), which has a needle (6) and a needle hub (8) fixed to said needle: and a hollow casing (11) for slidably containing said thrust needle assembly therein, wherein said hollow casing has an opening (14) at its top having an inward projection (15) on its inner circumference, and said medical thrust device further comprises a stopper (20) which is movably attached to said hollow casing so as to move between an opening position and shutting position, in which inner space of said hollow casing is closed, characterized in that the stopper is positioned on said hollow casing so as to separate the full length of hollow space of said hollow casing into a tail-section somewhat longer than said thrust needle assembly and a head-section having a length so as to hold hub-section (8b) of said needle hub (8) tightly between a closing wall section (22) of said stopper (20) and said inward projection (15) of the opening top of said hollow casing (11), when the stopper (20) is in the shutting position, and in that said medical thrust device has a protection cover (24, 25, 26) for enclosing at least a sharp point of said needle. A medical thrust device according to claim 1, wherein said device being an indwelling thrust device wherein said thrust needle assembly (1) further comprising an indwelling cannula body (2) having a cannula hub (4) fixed to its cannula (3) and detachably attached to the needle hub (8), the thrust needle (6) being covered with the cannula body (2), and the hollow casing (11) is closing at its bottom (12). A medical thrust device according to claim 2, wherein the protection cover (24; 25; 26) has means to detachably connect its bottom end to the cannula hub (4) while the thrust needle assembly (1) is retained in the hollow casing (11) with the stopper (20) put in the shutting position. A medical thrust device according to claim 2, wherein the protection cover (24; 25; 26) is closing at the top and has means to detachably connect its bottom end to the forward end of the holhow casing (11) while the thrust needle assembly (1) appears from the hollow casing (11) with the needle hub (8) between the inward projection (15) of the opening top (14) of the hollow casing (11) and the stopper (20), which is put in the shutting position, thereby permitting the thrust needle assembly (1) appeared from the hollow casing (11) to be shut up in the protection cover (24; 25; 26). A medical thrust device according to claim 2, wherein the needle hub (8) comprises a head hub-section (8a) and a tail hub-section (8b), these hub-sections being detachable from each other, the head hub-section (8a) being sized so as to permit the passing of the head hub-section (8a) through the opening space defined by the inward projection (15) of the opening top (14) of the hollow casing (11) whereas the tail hub-section (8b) being sized so as to prevent the passing of the tail hub-section (8b) through the opening space defined by the inward projection (15) of the opening top (14), the protection cover (24; 25; 26) being detachably connected to the head hub-section (8a) to enclose the thrust needle assembly (1), the tail hub-section (18b) and hollow casing (11) being equipped with anti-rotation means, and the head hubsection (8a) and the protection cover (24; 25; 26) being equipped with rotation-resistive means, the protection cover (24; 25; 26) having the thrust needle assembly (1) contained therein being caught by the inward projection (15) of the opening top (14) of the casing to partly appear from the opening top (14) of the hollow casing (11), while the stopper (20) is put in the opening position. A medical thrust device according to claim 1, wherein said device is a syringe (110) wherein the hollow casing (101) is open at its bottom, the protection cover (120) is closing at the top and has means to detachably connect its bottom end to the forward and rear end of the hollow casing (101), respectively, and wherein it further comprises a syringe body having a hollow barrel (111) and a plunger (112) slidably fitted into the hollow barrel (111), the stopper (105) having an additional small through hole (108) to be passed through by a cylindrical connector (113) at front of the hollow barrel (111) to be connected to the needle hub (8), while the thrust needle assembly (1) appears from the hollow casing (101) with the needle hub (8) between the inward projection (103) of the opening top (102) of the hollow casing (101) and the stopper (105), thereby permitting the thrust needle assembly (1) appeared from the hollow casing (101) to be shut up in the protection cover (120).

Inventors: HIGASHIINOUE AKIHIRO, NAKAJIMA HIROAKI, HIGASHIINOUE, AKIHIRO, NAKAJIMA, HIROAKI
Applicants: TOGO MEDIKIT CO LTD, TOGO MEDIKIT CO. LTD.
Application year: 1997
Main classification: A61M5
IPC codes: A61M25, A61M5