FR2881053A1 - Syringe needle protecting device comprises a tubular body, an injection piston assembled in a sliding motion, protective support, a mobile needle cover and a deployment element - Google Patents

Abstract

The end of the tubular body is fixed by the needle. The deployment element (37) includes a pneumatic element for displacing the needle cover (35), from its retracted position towards its deployed position and the pneumatic element comprises: a thrust chamber delimited by a cavity; a displacement piston (40) sliding in the cavity interdependent of the reference body and the needle cover; a pressurization body; and a support guard is assembled between the pressurization positions. The needle cover is assembled between the retracted position and the deployed position. The pressurization body comprises an actuation surface of the injection piston (23) to move the piston from its rest position to its pressurization position. The deployment element further comprises a blocking element, which is releasable when the pressurization body reaches a release position. The support (33) comprises immobilization element of the pressurization body. The pressurization chamber having a transverse section in the displacement areas of the pressurization body, which is higher than the transverse section of the thrust chamber of the needle cover.

Description

The present invention relates to a needle protection device

  for a syringe comprising a needle, a tubular body at the end of which is fixed the needle, and an injection piston slidably mounted in the body, the device comprising:

  - A protective support, adapted to be secured to the body of the syringe; a needle protector movably mounted relative to the protector support between a retracted position and an extended position; means for deploying the needle protector.

  This device is particularly applicable to hypodermic syringes for o injection of liquid into the body of a subject.

  EP-A-0 966 983 discloses a device of the aforementioned type, conventionally comprising a protective support which receives the injection syringe.

  The needle protector is movable relative to the carrier under the action of a deployment spring interposed between the protector support and the needle protector.

  To achieve such a device, the spring must first be applied between the protector support and the needle protector. Then, during the transport of the device, before mounting on a syringe, the device is armed, that is to say that the operating spring of the protector is compressed.

  The use of such a spring in the device is not entirely satisfactory. During the injection, the spring is disposed around the syringe and thus at least partially masks its contents. Moreover, because of the stiffness of the spring, the release of the deployment of the needle protector is abrupt. The use of the needle protection device is therefore not completely easy.

  An object of the invention is therefore to provide an easy needle protection device.

  For this purpose, the subject of the invention is a protection device of the aforementioned type, characterized in that the deployment means comprise pneumatic means for moving the needle protector from its retracted position to its deployed position.

  The device according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination: the pneumatic displacement means comprise at least one thrust chamber delimited by: a cavity formed in one of a reference member and the needle protector; and - a displacement piston sliding in the cavity, integral with the other of the reference member and the needle protector; the pneumatic displacement means comprise at least one pressurizing member of the or each thrust chamber, mounted movable relative to the protective support between a proximal rest position and a distal pressurization position; the pressurizing member comprises at least one operating surface of the injection piston, to move the injection piston with respect to the body when the pressurizing member moves from its rest position to its pressurizing position; - The deployment means comprise locking means of the needle protector in its retracted position, the locking means being releasable when the pressurizing member reaches a release position, beyond its rest position; the support comprises means for immobilizing the pressurizing member in its pressurized position; the reference member is formed by the protective support; The cavity is formed in the protector support, the displacement piston being integral with the needle protector; the pressurizing member and the protector support delimit a variable volume pressurizing chamber during the displacement of the pressurizing member from its rest position to its pressurized position; pressurizing being connected to the thrust chamber; a cross section of the pressurizing chamber in the displacement region of the pressurizing member is greater than a cross section of the pushing chamber in the region of displacement of the needle shield; the reference member is formed by the pressurizing member; and - the piston is integral with the pressurizing member, the cavity being formed in the needle protector.

  The invention further relates to an injection assembly, characterized in that it comprises: to - a syringe having a needle, a tubular body at the end of which is fixed the needle, and an injection piston slidably mounted in the body; and a needle protection device as defined above, the support being integral with the body.

  The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings, in which: FIG. 1 is a sectional view along a median plane of a first injection assembly according to the invention, with a needle protector occupying its retracted position; - Figure 2 is a view similar to Figure 1, during the injection of a product in a patient; - Figure 3 is a view similar to Figure 1, after the product injection, the needle protector occupying its deployed position; FIG. 4 is a view similar to FIG. 1 of a second injection assembly according to the invention; FIG. 5 is a view similar to FIG. 2 of the second assembly according to the invention; FIG. 6 is a view similar to FIG. 1 of a third assembly 30 according to the invention; - Figure 7 is a view similar to Figure 2 of the third assembly according to the invention; FIG 8 is a view similar to Figure 3 of the third set according to the invention.

  The first injection assembly 11 according to the invention, represented in FIG. 1, comprises a syringe 13 and a protection device 15.

  In all that follows, the terms proximal and back are synonymous, as are the terms distal and before. The terms inside and outside mean the volume defined by the syringe 13 or the protective device 15.

  Syringe 13 is a standard shaped glass syringe for single use. It contains a liquid to be injected, intramuscularly or subcutaneously, to a patient. It comprises for this purpose a body 17 of longitudinal axis X-X ', an injection needle 19 integral with the distal end 21 of the body 17 and a piston 23.

  The piston 23 conventionally comprises a rod 25 provided, at its distal end, with a buffer 27, and provided, at its proximal end, with a support head 29 on which is intended to rest the thumb of the hand of the practitioner in the absence of the device 15.

  The body 17 of the syringe has in its proximal portion a collar defining circumferentially two diametrically opposed lugs 31, normally intended, in particular in the absence of the device 15, to form bearing surfaces for the index and middle fingers of the practitioner when handling the syringe 13 and the injection of the liquid therein.

  The protection device 15, of general axis X-X 'essentially comprises, as represented in FIG. 1: a support 33 of generally tubular shape; a protective sleeve 35 mounted to move coaxially with respect to the support 33; and pneumatic means 37 for moving the sleeve 35 relative to the support 33.

  The pneumatic displacement means 37 comprise a thrust chamber 38 of the sleeve 35, delimited by an annular cavity 39 formed in the support 33, and by a displacement piston 40, integral with the sleeve 35.

  They further comprise a pressurizing chamber 41, connected to the thrust chamber 38, the chamber 41 being delimited by a cover 42 slidably mounted relative to the support 33 and by a proximal surface 43 of the support 33.

  The support 33 comprises an inner peripheral wall 45, an intermediate peripheral wall 47, connected to the inner wall 45 by a peripheral portion 49 connecting the proximal ends of the walls 45 and 47. It also comprises an outer peripheral wall 51, connected at the intermediate wall 47 by their distal ends.

  The inner, intermediate and peripheral walls 45, 47 and 51 are coaxial with axis X-X 'and of generally cylindrical shape.

  The inner wall 45 internally defines a conduit for receiving the syringe body 17, of transverse dimension slightly greater than the external diameter of the body 17 of the syringe 13. The inner wall 45 has a distal end 53 converging towards the axis XX 'and through which the injection needle 19 protrudes. As illustrated in FIG. 1, the distal end 53 of the inner wall 45 is of diameter substantially equal to the outer diameter of a protective cap 55 placed around the needle 19 during the transport of the injection assembly 11.

  The proximal end of the inner wall 45 defines an inner peripheral shoulder 57 on which rests an O-ring seal 59, of diameter substantially equal to the outside diameter of the neck of the syringe 13.

  The lugs 31 of the body 17 of the syringe 13 are held in abutment on the shoulder 57 by means of a locking lip 61 which protrudes rearwardly from the connecting section 49.

  The intermediate wall 47 has a length substantially equal to that of the inner wall 45.

  The intermediate wall 47 defines, with the inner wall 45, an inner annular space forming the cavity 39 of the thrust chamber 38. The cavity 39 opens at the distal end 65 of the walls 45, 47, and is partially closed by the connecting section 49 at the proximal end of these walls 45, 47.

  A plurality of connecting conduits 67 are formed in the connection section 49, along axes parallel to the axis X-X ', to connect the pressurizing chamber 41 to the thrust chamber 38. open into the internal cavity 39 and the proximal surface 43 of the support 33, at the section 49.

  Furthermore, the intermediate wall 47 defines, at its proximal end, a peripheral housing 71 of U-shaped cross section opening radially outwardly. This housing 71 receives an O-ring seal 73 whose outer peripheral surface projects slightly beyond the intermediate wall 47.

  The wall 47 delimits externally, at its proximal end, a shoulder 101 of rear stopper of the cap 42 and, at its distal end, a peripheral recess 103 for snapping the cap 42.

  The outer wall 51 delimits with the intermediate wall 47 an outer annular space 75, closed at the distal end of the walls 47, 51 and opening at the proximal end of these walls 47, 51. This space 75 forms a guide slide of the hood 42, as will be described below.

  Furthermore, the outer wall 51 has, at its proximal end, gripping lugs 77 which protrude radially outwards. The ears 77 are intended to form bearing surfaces for the forefinger and middle finger of the practitioner during the manipulation of the protection device 15.

  The sleeve 35 comprises a body 79 of generally tubular shape 25 and of length at least equal to the length of the needle 19.

  The sleeve 35 comprises at its proximal end an annular pad snapped onto the body 79, and forming the displacement piston 40. The proximal surface 83 of this buffer 40 defines a thrust surface of the sleeve 35 which sealingly closes the cavity 39 of the thrust chamber 38.

  The sleeve 35 further comprises, in the vicinity of its proximal end, resilient locking blades 85 integral with the body 79. Each blade 85 comprises a proximal free end 86 which is held in abutment on the inner wall 45 by solicitation. of the blade 85 towards the axis X-X '.

  The sleeve 35 further comprises, at its distal end 87, a portion converging towards the X-X 'axis while moving distally, which has a central opening 89 through which the needle 19 passes.

  The central opening 89 has an inside diameter greater than the outside diameter of the cap 55.

  The sleeve 35 is slidably received in the inner annular space 39. It is thus movable between a retracted position shown in FIG. 2, in which the annular buffer 40 is disposed in the vicinity of the connecting section 49, and an extended position , shown in Figure 3, wherein the annular pad 40 is disposed adjacent the distal ends of the inner walls 45 and intermediate 47.

  Thus, in the retracted position of the sleeve 35, the chamber 38 has a volume less than the volume it has when the sleeve 35 is in its extended position.

  In the retracted position of FIG. 1, the needle 19 is engaged in the central opening 89 of the sleeve 35 and protrudes beyond this opening 89.

  In the extended position of FIG. 3, the needle 19 is completely received in the interior volume delimited by the sleeve 35. In this position, the free ends 86 of the locking blades 85 of the body 79 are inserted into an outer peripheral shoulder 91 delimited at the distal end 53 of the inner wall 45. The cooperation between the blades 89 and the shoulder 91 prevents the displacement of the sleeve 35 to its retracted position.

  The cover 42 comprises a substantially cylindrical side wall 93 and a proximal wall 95 which closes the proximal edge of the wall 93. The walls 93 and 95 internally delimit the pressurizing chamber 41.

  The side wall 93 of the cover has a shape complementary to that of the outer annular space 75 and is received in this space. The seal 73 bears against the wall 93 and the proximal surface 43 of the support 33 seals the pressurization chamber 41, with the exception of the ducts 67.

  The internal volume formed by the pressurizing chamber 41, the ducts 67 and the thrust chamber 38 is sealed.

  The side wall 93 also has, at its distal end, a bead 97 annular inner holding position.

  The proximal wall 95 of the cover 42 internally has a surface 99 for receiving the piston 23, which bears on the support head 29. The piston 23 is substantially completely received in the chamber 41 for pressurizing.

  to The cover 42 is slidably received in the outer annular space 75, which forms means for guiding this cover 42. The cover 42 is thus movable in translation along the axis XX 'between a proximal position of rest, shown in FIG. 1, in which the proximal wall 95 is away from the proximal surface 43, and a distal pressurizing position of the chamber 41, shown in FIG. 2, in which the proximal wall 95 is disposed in the vicinity of the proximal surface 43.

  The section of the proximal surface 43 defined at the periphery of the joint is greater than the section of the thrust surface 83 of the piston 40, so that a cross section of the pressurizing chamber 41 in the region of displacement of the support 33 relative to the cover 42 is greater than a cross section of the thrust chamber 38 in the region of displacement of the sleeve 35 relative to the support 33.

  In the proximal position of the cover 42, the pressurizing chamber 41 has a volume greater than the volume it has when the cover 42 25 occupies its distal position.

  In the proximal rest position shown in FIG. 1, the cover 42 protrudes rearwardly with respect to the support 33. The bead 97 at the distal end of the cover 42 abuts against the proximal shoulder 101.

  On the other hand, the O-ring 73 seals against the inner surface of the side wall 93. In this position, the injection piston 23 protrudes rearwardly with respect to the body 17 of the syringe 13.

  In the distal pressurization position shown in FIGS. 2 and 3, the annular space 75 receives, over substantially its entire length, a part of the lateral wall 93. Furthermore, the bead 97 of the cover is received in the peripheral recess 103 The cover 42 is thus locked in its distal position.

  In this position, the piston 23 is inserted substantially completely into the body 17 of the syringe 13 and abuts against the distal end 21 of the body 17 in the vicinity of the injection needle 19 The assembly of the injection assembly 11 will now be described.

  Initially, as shown in FIG. 1, the sleeve 35 is mounted on the support 33 and is held in its retracted position by the blades 85. Then, the support 33 is assembled on the syringe 13, which is pre-filled with a liquid to inject into a patient. The syringe 13 is equipped with the cap 55 which encloses the distal end 21 of the syringe body 17.

  Then, the cover 42 is mounted at the rear of the support 33 in its proximal rest position, the proximal wall 95 of the cover 42 resting on the bearing head 29 of the piston 23.

  The operation of the injection assembly will now be described. When the practitioner is ready to inject the liquid contained in the syringe 13, he removes the cap 55 by pulling it axially forward. Then, as shown in FIG. 2, it stitches the needle 19 in the skin 105 of a patient and injects the liquid contained in the syringe 13 by exerting a push with its thumb on the proximal wall 93 of the cover 42, its index and its middle finger remaining in contact with the lateral gripping lugs 77 of the support 33.

  When moving the cover 42 from its proximal position of rest to the distal compression position, the cover 42 presses on the piston 23 and causes the injection of liquid into the patient.

  Simultaneously, the volume of the pressurizing chamber 41 decreases. Due to the tightness of the volume formed by the chamber 41, the channels 67, and the thrust chamber 38, the volume of the chamber 38 increases by displacement of the sleeve 35 forward, until the end distal 87 of the sleeve 35 abuts the skin 105 of the patient.

  In this intermediate position of the sleeve 35, the displacement of the sleeve 35 towards its deployed position is prevented and the pressure in the chamber 41 increases significantly. The pressure is transmitted to the thrust chamber 38 via the channels 67, the volume of the chamber 38 can no longer increase because of the support of the sleeve 35 on the skin 105 of the patient.

  At the end of the injection, when the cover 42 reaches its distal position, the pad 27 comes into contact with the distal end 21 of the body 17 and substantially all of the liquid has been injected into the patient. In this position, the distal bead 97 of the cover 42 is received in the peripheral recess 103 of the wall 47 and prevents movement of the cover 42 back to its proximal rest position.

  Then, the practitioner removes the needle 19 from the patient. The force exerted on the thrust surface 83 of the sleeve 35, resulting from the pressure in the thrust chamber 38 causes the displacement of the protective sleeve 35 from its intermediate position to its deployed position, the cover 42 being retained, so that that the volume of the chamber 41 can not increase.

  In this deployed position, the protective sleeve 35 is held in position by the cooperation between the blades 85 and the shoulder 91 which avoids any risk of contamination of the practitioner during removal of the needle 19.

  Thus, thanks to the pneumatic means 37 for moving the protective sleeve 35, the needle protection device 15 according to the invention does not require the insertion of a stress spring between the support 33 and the sleeve 35, which facilitates its mounting process.

  Moreover, if the protective device 15 is made of transparent material, the syringe 13 is completely visible in the absence of a spring. Likewise, the triggering of the deployment of the protective sleeve 35 is less abrupt than when this triggering results from the presence of a spring. The protective device 15 is therefore easy to use.

  Since the cross-section of the pressurizing chamber 41 is greater than the cross section of the thrust chamber 38, the force applied to the proximal surface 83 of the piston 40 during the deployment of the sleeve 35 is high in comparison with the force to be applied. by the practitioner to move the cover 42 to its distal position. As a result, the deployment of the sleeve 35 is facilitated, without the need for the user to generate a high deployment force.

  In a second injection assembly 111 according to the invention, shown in FIGS. 4 and 5, the support 33 is devoid of an intermediate wall 47.

  Furthermore, the thrust chamber 38 is delimited by the annular space 113 defined between the outer wall 51 and the inner wall 45 of the support 33. This space 113 is partially closed by the connecting section 49 and opens at the distal end 65 of the wall 45. The sleeve 35 is received in this annular space 113, so that the annular buffer 40 closes the chamber 38.

  The sleeve 35 further comprises locking lugs 115, integral with the body 79, and which protrude rearwardly through the annular pad 40 and the channels 67.

  Each lug 115 comprises a locking head 117 disposed in abutment on the proximal surface 43 of the support 33, outside the channel 67.

  Each head 117 is movable transversely between a position bearing on the surface 43 and a laterally offset position towards the inside away from this surface 43.

  The maximum transverse dimension of each head 117 is smaller than the maximum transverse dimension of the channel 67 in which the lug 115 is engaged, so that the head 117 passes through the channel 67 when it is released from the surface 43.

  The sleeve 35 further comprises two lateral guide slots 119 formed in the body 67 parallel to the axis X-X ', on either side of this axis X-X'. Each slot 119 receives a guiding pin 121, integral with the inner wall 45, and protruding radially outwardly in the vicinity of the distal end 65. Each pin 121 abuts against the proximal end 123 of the slot 121 in which it is inserted, when the sleeve 35 occupies its deployed position.

  Furthermore, the cover 42 is slidably mounted on the outer wall 51. It comprises a ring 125 for releasing the locking lugs 115, which protrudes internally in the pressurizing chamber 41 from the proximal wall 95, around the receiving surface 99 of the bearing head 29. The release ring 125 comprises an inner lateral surface 127 inclined away from the axis XX 'from the proximal wall 95.

  The operation of the second injection assembly 111 differs from the first assembly 11 in that, during the displacement of the cover 42 towards its distal position, the sleeve 35 is retained in its retracted position by the locking lugs 115. its distal position, and that the liquid in the syringe 13 has been substantially totally injected into the patient, the practitioner exerts an additional thrust on the cover 42 to release the locking lugs 115.

  The lateral surface 127 of the release ring 125 then comes into contact with the heads 117 of the lugs 115 and thus pushes these heads 117 towards the axis X-X ', away from the proximal surface 43 of the support 33. sleeve 35 is then released and goes into its deployed position as described above. During this movement, the heads 117 enter successively into the channels 67, then into the annular space 113.

  In the third injection assembly 151 according to the invention, represented in FIGS. 6 to 8, the support 33 comprises a single cylindrical lateral wall 45 disposed in abutment around the body 17 of the syringe 13. The wall 45 comprises, on its proximal end, a peripheral radial portion 49 extending outwardly and delimiting the proximal surface 43 of the support 33. This section 49 receives the ears 31 of the syringe 13.

  Furthermore, the sleeve 35 is slidably mounted on the outer surface of the wall 45. It comprises, at its proximal end, fastening pawls 153 protruding longitudinally rearward, which are engaged on the peripheral edge 155 of the section. radial 49.

  Furthermore, this assembly 151 comprises two thrust chambers 38 delimited respectively by two lateral cylinders 157 secured to the sleeve 35. The cylinders 157 extend on either side of the axis X-X ', parallel to this axis and are connected to the body 79 of the sleeve 35 by radial walls 159.

  Each cylinder 157 opens at the proximal end of the sleeve 33, and is closed off by a distal wall 161 which delimits in the cylinder 157 a thrust surface 83 of the sleeve 35.

  The chamber 38 is further delimited by two lateral pistons 163, integral with the cover 42. These pistons are coaxial respectively with the cylinders 157.

  Each piston 163 comprises a rod 165 which protrudes forwardly from the proximal wall of the cover 42, and a head 167 sealingly inserted into a corresponding cylinder 157.

  The cover 42 has no side wall so that the protection device 15 does not have a pressurizing chamber.

  The cover 42 further comprises a ring 169 for releasing the locking pawls 153 which protrudes distally from the proximal wall 95.

  The operation of this injection assembly 151 differs from that shown in FIGS. 4 and 5 in that the side pistons 163 directly increase the pressure in the thrust chambers 38, without passing through an intermediate pressurizing chamber.

  As a result, during the displacement of the cover 42 towards its pressurized position, the volume of the thrust chambers 38 decreases and the pressure in these chambers 38 increases. During this movement, the locking pawls 153 retain the sleeve 35 in its retracted position, against the force produced on the thrust surfaces 83 by pressurizing the thrust chambers 38.

  When the release ring 169 comes into contact with the pawls 153, it moves the pawls 153 laterally away from the axis XX 'and releases them from the support 33. The pressure which applies to the thrust surfaces 83, inside the chambers 38, causes the displacement of the side cylinders 157 forwards, and consequently the displacement of the sleeve 35 towards its deployed position.

Claims (13)

  A needle protection device (15) for a syringe (13) comprising a needle (19), a tubular body (17) at the end (21) of which the needle (19) is attached, and a piston (23) of injection slidably mounted in the body (17), the device (15) comprising: - a support (33) protector, adapted to be secured to the body (17) of the syringe (13); a needle protector (35) movably mounted relative to the protector support (33) between a retracted position and an extended position; means (37) for deploying the needle protector (35); characterized in that the deployment means comprises pneumatic means (37) for moving the needle protector (35) from its retracted position to its deployed position.   2. Device (15) according to claim 1, characterized in that the pneumatic displacement means (37) comprise at least one thrust chamber (38) delimited by: - a cavity (39, 38) formed in one of a reference member (33; 42) and needle protector (35); and a displacement piston (40; 167) sliding in the cavity (39; 38), integral with the other of the reference member (33; 42) and the needle protector (35).   3. Device (15) according to claim 2, characterized in that the pneumatic displacement means (37) comprise at least one member (42) for pressurizing the or each thrust chamber (38), mounted movably by relative to the protector support (33) between a resting proximal position and a distal pressurizing position.   4. Device (15) according to claim 3, characterized in that the pressurizing member (42) comprises at least one actuating surface (99) of the injection piston (23), to move the piston of injection (23) with respect to the body (17) when the pressurizing member (42) moves from its rest position to its pressurized position.   5. Device (15) according to any one of claims 3 to 4, characterized in that the deployment means (37) comprises means (115) for locking the needle protector (35) in its retracted position, the locking means (115) being releasable when the pressurizing member (42) reaches a release position, beyond its rest position.   6. Device (15) according to any one of claims 3 to 5, characterized in that the support (33) comprises means (97, 103) for immobilizing the pressurizing member (42) in its pressurization position.   7. Device (15) according to one of claims 2 to 5, characterized in that the reference member (33; 42) is formed by the protective support (33).   8. Device (15) according to claim 7, characterized in that the cavity (39) is formed in the protective support (33), the displacement piston (40) being integral with the needle protector (35).   9. Device (15) according to one of claims 7 and 8, taken in combination with claim 3, characterized in that the pressurizing member (42) and the protective support (33) define a chamber ( 41) of variable volume pressure during displacement of the pressurizing member (42) from its rest position to its pressurized position, the pressurizing chamber (41) being connected to the chamber thrust (38).   10. Device (15) according to claim 9, characterized in that a cross section of the pressurizing chamber (41) in the region of displacement of the pressurizing member (42) is greater than one section. cross-section of the thrust chamber (38) in the region of displacement of the needle protector (35).   11. Device (15) according to any one of claims 3 to 6, characterized in that the reference member (33; 42) is formed by the pressurizing member (42).   12. Device (15) according to claim 11, characterized in that the piston (167) is integral with the pressurizing member (42), the cavity (38) being formed in the needle protector (35). .   13. Injection assembly (11; 111; 151), characterized in that it comprises: - a syringe (13) comprising a needle (19), a tubular body (17) at the end (21) of which the needle (19) is fixed, and an injection piston (23) slidably mounted in the body (17); and a needle protection device (15) according to any one of the preceding claims, the support (33) being integral with the body (17).