Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/30—Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
  • A61M5/3007—Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules with specially designed jet passages at the injector's distal end
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M5/3129—Syringe barrels
  • A61M2005/3132—Syringe barrels having flow passages for injection agents at the distal end of the barrel to bypass a sealing stopper after its displacement to this end due to internal pressure increase

Definitions

• Present invention is directed to a jet injector for injecting a liquid medical drug through the skin of a person to be treated comprising a housing to be pressurized and holding said medical drug and which is defined by an enclosing periphery wall and a bottom wall having an internal surface facing the interior of the housing and an opposite external surface, the bottom wall has at least one through passage extending between said internal and external surfaces and through which, when the injector is used, said medical drug is expelled from the housing and transformed into a thin jet stream penetrating the skin of said person.
• the invention is also directed to a method for operating such an injector.
• This invention is also directed to a method for producing a jet injector for injecting a liquid medical drug through the skin of a person to be treated comprising a housing to be pressurized and holding said medical drug and which is defined by an enclosing periphery wall and a bottom wall having at least one through passage.
• Existing needleless jet injectors for injection of a liquid medical drug creates a jet stream penetrating the skin of a person to be treated by the inherent force of said stream.
• Those injectors generally include a high pressure housing having one or more openings for an exit jet stream. Said opening or openings are quite narrow, typically in the order of some tenth of a millimetre. Such openings are very difficult to produce with close tolerances, both rationally and reproduceably, eg by injection moulding of plastic material. Besides, it is difficult to produce openings having such a design and smoothness that the exit jet stream will be coherent and accurately confined to achieve best possible skin penetration effect.
• PCT application WO 01/05454 is directed to a needleless syringe comprising an injector with nested elements, the inner elements of which having a number of small chanels formed on their periphery surfaces for conducting a medical drug from a pressurized chamber, through said number of chanals and to the skin of a patient so that a plurality of drug streams penetrate the- skin.
• the mouth of each chanal is in contact with the skin and the drug streams are injected directly into the skin, ie without any gaps therebetween.
• the fineness of said drug streams are determined by the size of the chanals and the section area of the chanals has a minimal dimension. If the dimension is too small the flow resistance in the chanals will be too high and reduces the flow rate of the drug jeopardizing the desired penetration effect.
• a further object of present invention is to provide a jet injector having an outlet which not will be contaminated by the skin of a person during injection.
• step (v) in addition to or instead of step (ii) machining portions of the wall of the mould forming said periphery surface such that recesses are created in the wall of the mould, eg by milling, cutting, engraving, spark machining or etching;
• Fig. 1 is a fragmentary, longitudinal section view of a jet injector according to one embodiment of present invention
• Fig. 2 is a perspective view of an insert arranged to be inserted in a housing of jet injector according to Fig. 1;
• Fig. 3 is a cross section view along line A-A;
• Fig. 4 is an enlarged view of a portion of the insert and a surrounding wall portion according to the embodiment of Fig. 1 and 2 illustrating the flow of an expelled medical drug, whereby the gap between these portions is exaggerated for clarity reasons;
• Fig. 5 is a view similar to that of Fig. 3 and showing a second embodiment of the invention
• Fig. 6 is a fragmentary, longitudinal section view of the embodiment in Fig. 5;
• Fig. 7 is a view similar to that of Fig. 1 showing a third embodiment of the invetion;
• Fig. 8 is an enlarged detail view of a part of the wall portion according to the embodiment in Fig. 7;
• Fig. 9 is a view similar to that of Fig. 3 and showing a fourth embodiment of present invention;
• Fig. 10 is an enlarged detail view of a part of the insert according to a fifth embodiment of the invention.
• Fig. 11 is a view similar to that of Fig. 3 schematically depicting a sixth erobodiment of present invention.
• Fig. 12 in a view similar to that of Fig. 1 illustrates a seventh embodiment of the invention.
• Fig. 13 in a view similar to that of Fig. 2 illustrates an eighth embodiment of the invention.
• Present invention concerns a jet injector for delivering a liquid medical drug or preparation to a person to be treated by creating or forming a jet stream of the liquid drug, which jet stream has an accurate fineness and force to penetrate the skin of said person and enter his body.
• an jet injector generally comprises a housing or reservoir 1 holding a medical drug 2 to be dispensed, when pressurized in an arbitrary way known by a man skilled in the art, eg by means of a piston device (not shown) .
• the housing 1 is defined by an enclosing periphery wall 3, an unillustrated top portion (not part of the invention) and a bottom wall 4.
• the bottom wall 4 has an internal surface 5 facing the interior of the housing 1 and an opposite external surface 6.
• a through passage 7 (cf Fig. 4) is provided in the bottom wall 4 extending between said internal and external surfaces 5 and 6, resp., and when using the injector said medical drug 2 is expelled from the housing 1.
• the through passage 7 is a gap between a through hole or aperture—8 (cf Fig. 5) and an insert 9 placed-inside the aperture 8.
• a through hole or aperture—8 cf Fig. 5
• an insert 9 placed-inside the aperture 8.
• the insert 9 has an essentially cone-shaped body 10 and is arranged to be inserted into the housing such that a portion 13 of said essentially cone-shaped body 10, the periphery surface 39 of which is generally congruent to the aperture wall 12, is received in the aperture 8.
• Said body 10 tapers in a direction away from the passage 7 and terminates in a sharp point or tip 14 at a distance from the bottom wall 4 outside the housing and positioned on said symmetry axis 11. It is preferred that the tip is sharp although it is also possible to have it slightly truncated for edge release of the liquid. Since both the through passage 7 and the body 10 have substantially cone-shaped outer surfaces the width of the passage can easily be adjused by relative axial displacement or positioning between these parts. Said through passage or gap 7 between the aperture wall 12 and said portion 13 of the essentially cone- shaped body 10 serves as a flow confining restriction to develop a high pressure in the medical drug expelled from said housing 1, when using the jet injector.
• the remaining portion 15 of the essentially cone-shaped body ie the portion between its portion 13 opposite the aperture wall 12 and its point 14, has a periphery surface 40 receiving or catching the medical drug flowing from the passage 7 and guiding it towards said point 14 to create or form a coherent, thin jet stream emerging from the point 14.
• At least an area including the point 14 of said body 10 has a concave periphery surface, or concave periphery line when seen in cross-section through the axis, and preferably all of the periphery surface of said body portion 15 between the external surface 6 of the bottom wall 4 and the point 14 is concave," cf Fig. 4. This figure illustrates schematically the flow of said expelled drug.
• a stream or substreams 16 of a medical drug pressurized in said passage 7 flow(-s) along the periphery surface 40 of said portion 15 attracted to said surface by the so called Coanda effect.
• the substreams coalesence or are focused before reaching the point 14 creating a substantially homogeneous flow 17 arriving to the point 14 and forming a coherent, thin jet stream 18 emerging from said point 14.
• the fineness of said jet stream is related to said flow confining restriction, ie the pressure of the stream (-s) 16.
• the curvature of the concave surface or line can vary somewhat.
• the surface is designed so as to give a decreasing angle between the converging streams towards the tip and preferably an almost parallel or substantially parallel flow at the very tip, e.g. by letting the tangential lines of the surface close to the tip substantially coincide.
• the converging concave lines of the cross-section can for exmple be be segments of a circle but it is preferred that the curvature changes towards to tip, which can be obtained if instead the lines are shaped as segments of an oval, parabolic or hyperbolic curve or intermediates therbetween.
• the segments are mirror images with respect to the axis 11, preferably also arranged to give a decreasing curvature towards the tip and most preferably placed so as to give the abovesaid substantially parallel lines at the tip.
• a positioning element 19 protrudes from said bottom wall 4 and preferably but not mandatory terminates at a level beyond or at said point 14 of the essentially cone-shaped body 10.
• a position beyond the tip may serve to keep a distance between the tip and the target surface, e.g. to let the stream form before hitting the target, whereas a- position "at or behind the tip may serve to allow the tip to contact the target surface, e.g. to act as a short needle for severing the target tissue and reduce the penetrating requirements on the liquid jet.
• the positioning element 19 is intended to be placed on the skin of the person to be treated when injecting the medical drug.
• the periphery wall 3, the bottom wall 4 and the positioning element 19 of the jet injector are made in one piece of resin, preferably polycarbonate resin, ie by injection moulding.
• the relatively large aperture 8 in the bottom wall 4 is rather easy to manufacture with accurate tolerances, either during said moulding or afterwards by machining, compared to the small borings in the art for transferring a medical drug.
• the insert 9 comprises an essentially cone-shaped body 10, the base 20 of which is positioned substantially at the level of said internal surface 5 of the bottom wall 4, when the injector is assembled, cf Fig. 4. However, and preferably, the insert 9 also comprises a head body 21, cf Figs.
• the head body 21 and the essentially cone-shaped body 10 are made in one piece of resin, suitably polycarbonate plastic, ie by injection moulding.
• the head body 21 has a periphery surface 22 matching the inner surface 23 of said periphery wall 3, a bottom surface 24 having a configuration adapted to said internal surface 5 of the bottom wall 4 and a number of flutes 25 formed in the head body 21 and connecting the interior of the housing 1 with said aperture 8, directly or indirectly as will be discussed below, said flutes 25 extending along the peripheral surface 22, the bottom surface 24 and terminating at said internal surface 5 inside the aperture area.
• said through passage -7 is a number of grooves 26 formed-in -said upper portion 13 of the essentially cone-shaped body 10 extending between the lower portion 15 of the body 10 and the ends of said flutes 25, thereby communicating the interior of the housing 1 with said portion 15 and ultimately with the jet stream forming point 14.
• a number of grooves are formed in the aperture wall 12 extending from its internal surface 5 to its external surface 6, not shown.
• a key means (not shown but known to a man skilled in the art) is arranged to position the outlets of the flutes 25 in register with the inlets of the grooves 26.
• Each flute 25 has a section area larger than that of a groove 26, said flutes 25 passing pressurized medical drug from the interior of the housing 1 into relevant ones of said grooves 26.
• said passage 7 is configurated substantially like a ring- shaped gap instead of a plurality of grooves.
• a number of spacing means are provided between said insert 9 and said bottom wall 4 and/or between said insert 9 and said aperture wall 12, whereby a ring-shaped gap is formed between the periphery surface 39 of said essentially cone-shaped body and the aperture wall 12.
• said spacing means are protrusions 27 projecting from the peripheral surface 39 of the upper portion 13 of said essentially cone-shaped body 10 engaging the wall 12 of said aperture 8.
• the protrusions 27 are at least three in number extending substantially from the internal surface 5 to the external surface 6 of the wall 4, when the insert 9 is mounted.
• the protrusions 27 are preferably arranged in pairs, cf Fig. 6.
• the protrusions are provided on and projecting from-th -wall 12 of said aperture 8 engaging said peripheral surface 39 of the upper portion 13 (cf Fig.
• the protrusions 27 are bosses, pins, studs, ribs, ridges or the like integrated in the surface/wall from which they project.
• Fig. 7 depicts spacing means as protrusions provided between the bottom surface 24 of said head body 21 and the internal surface 5 of said bottom wall 4. In this embodiment also said restriction is achieved as a ring-shaped gap between the aperture wall 12 and said periphery surface 39 of the essentially cone-shaped body 10.
• Fig. 8 illustrates, in an enlarged scale, protrusions 27 projecting from said internal surface 5 of the bottom wall 4
• Fig. 9 illustrates, in a similar scale, protrusions 27 projecting from the bottom surface 24 of said head body 21.
• Fig. 10 depicts an alternative where protrusions 27 are integral with the head body 21 of the insert 9. The protrusions may otherwise be similar those mentioned in connection with Fig. 8 and 9.
• Fig. 11 depicts schematically still another embodiment of present invention.
• Said cone-shaped body 10, and specially its upper portion 13, is manufactured with coarse tolerances and so is the aperture 8 creating gaps occuring between the periphery surface 39 of the upper portion 13 of said essentially cone-shaped body 10 and the surrounding wall 12 of said aperture 8. These gaps 28 cooperate to constitute a passage 7 for transferring medical drug from said housing 1 to said jet stream forming portion 15 of the insert 9.
• Figs. 12 and 13 embodiments equipped with flexible walls are shown constituting a flow confining restriction passage, the magnitude of the restriction is related to the pressure in said housing 1.
• the insert 9 is a solid and homogeneous body.
• said insert 9 is a hollow body confined by a pliable, elastic thin- -walled shell 29.
• the head body—21 -of the insert 9 has a diameter smaller than the inner diameter of the housing 1 forming a ring-shaped chanal 30 therebetween.
• the bottom wall 24 of the head body 21 forms an angle with said symmetry axis 11 more acute than the angle between the internal surface 5 of said bottom wall 4 and the symmetry axis to establish a flow path from the housing 1 to the aperture 8.
• Fig. 13 shows a further embodiment of present invention working with flexible walls. The essential difference between this embodiment and the previous ones is that a central port of the bottom wall 4 is configurated like a truncated funnel or hopper instead of plate having a converging aperture.
• a pliable elastic wall 33 formed as a truncated funnel and converging outwardly from said housing 1 is depending from the bottom wall 4 and is terminated in a bottom surface 34 forming a sharp edge in contact with the essentially cone-shaped body 10.
• the elastic wall 33 is integrated with the bottom wall 4 and in its upper portion a number of blind grooves or recesses 36 are formed.
• a solid insert 9 with or without a head body 21 is to be positioned inside said wall 33.
• the medical drug in the housing 1 will flow into said grooves 36 causing the flexible wall 33 to deflect outwardly, in the direction of the arrows 37, the junction between the bottom wall 4 and said flexible wall 33 serving as a pivot.
• the lower portion of said wall 33 will be separated from the essentially- cone-shaped body 10 temporarily forming a passage 7 therebetween letting the medical drug through.
• Present invention is also directed to methods for producing a jet injector discussed above (excluding the embodiments of Figs. 11 and 12).
• a method for producing, for example, a jet injector illustrated in Figs. 5-10 includes following steps.
• step (v) In addition to or instead of step (ii) machin portions of the wall of the mould forming said periphery surface 39 such that recesses are created in the wall of the mould, eg by milling, cutting, engraving, spark machining or etching.
• step (v) In addition to or instead of step (iii) machin said periphery surface 39 such that grooves 26 extend from the internal surface 5 of said bottom wall 4 to its external surface 6, when said insert 9 is positioned into said aperture 8 according to step (vi) .
• the insert 9 of the jet injector in Fig. 12 is preferably produced by-blow- oulding.
• a related gas inlet (not shown) is provided in the upper (horisontal) wall of the shell 29. After having removed the insert from the mould said inlet is airtight sealed in a per se known appropriate way.

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• Health & Medical Sciences (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2002
  • 2002-07-03 SE SE0202063A patent/SE0202063D0/sv unknown
• 2003
  • 2003-06-27 AU AU2003239097A patent/AU2003239097A1/en not_active Abandoned
  • 2003-06-27 MX MXPA05000254A patent/MXPA05000254A/es unknown
  • 2003-06-27 BR BR0312412-6A patent/BR0312412A/pt not_active IP Right Cessation
  • 2003-06-27 CA CA002491302A patent/CA2491302A1/en not_active Abandoned
  • 2003-06-27 EP EP03733812A patent/EP1556106A1/en not_active Withdrawn
  • 2003-06-27 WO PCT/SE2003/001125 patent/WO2004004810A1/en active Application Filing
  • 2003-06-27 JP JP2004519444A patent/JP2005531387A/ja not_active Withdrawn
  • 2003-06-30 TW TW92117852A patent/TW200402314A/zh unknown

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