(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/0204687 A1
`Mogensen et al.
`(43) Pub. Date:
`Oct. 14, 2004
`
`US 20040204687A1
`
`(54) INJECTOR DEVICE FOR PLACING A
`SUBCUTANEOUS INFUSION SET
`(76) Inventors: Lasse Wesseltoft Mogensen, Soborg
`(DK); Grete Kornerup, Ringsted (DK);
`Magnus Walter Goransson, Malmo
`(DK)
`
`(30)
`
`Foreign Application Priority Data
`
`Sep. 27, 2001 (DK)................................ PA 2001 O1411
`
`Publication Classification
`
`(51) Int. Cl." ...................................................... A61M 5700
`(52) U.S. Cl. .............................................................. 604/181
`
`Correspondence Address:
`BRINKS HOFER GILSON & LONE
`P.O. BOX 10395
`CHICAGO, IL 60610 (US)
`
`(21) Appl. No.:
`
`10/687,568
`
`(22) Filed:
`
`Oct. 15, 2003
`Related U.S. Application Data
`(63) Continuation-in-part of application No. PCT/DK02/
`00640, filed on Sep. 27, 2002.
`
`
`
`(57)
`
`ABSTRACT
`
`An injector device for transcutaneously placing a hollow
`cannula of a Subcutaneous infusion Set is disclosed. The
`injector device includes a plunger slidably received within
`the device housing for movement between an advanced
`position and a retracted position, the plunger having an
`insertion needle Secured thereto by a stable connection
`preventing loSS of the insertion needle during use of the
`device. The insertion needle receives and Supports the
`cannula of the Subcutaneous infusion Set in a position with
`the cannula oriented for transcutaneous placement upon
`movement of the plunger from the retracted position to the
`retracted position.
`
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`US 2004/0204687 A1
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`Oct. 14, 2004
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`INJECTOR DEVICE FOR PLACING A
`SUBCUTANEOUS INFUSION SET
`
`BACKGROUND OF THE INVENTION
`0001. This invention relates generally to an improved
`injector device for the placement of a Subcutaneous infusion
`Set on a patient. Examples of injector devices for the
`placement of a Subcutaneous infusion Set are disclosed in
`U.S. Pat. No. 6,093,172, U.S. Pat. No. 5,851,197 and WO
`99/33504, incorporated by reference herein.
`0002 Medical needles are widely used in the course of
`patient treatment, particularly for delivery of Selected medi
`cations. In one form, hollow hypodermic needles are
`employed for transcutaneous delivery of the medication
`from a syringe or the like, see U.S. Pat. No. 5,665,071. In
`another, as shown in U.S. Pat. No. 5,591,188 incorporated
`herein by reference, an insertion needle used in conjunction
`with an injector device is employed for transcutaneous
`placement of a Soft and relatively flexible tubular cannula,
`followed by removal of the insertion needle and subsequent
`infusion of medical fluid to the patient through the cannula.
`U.S. Pat. No. 5,681,323 relates to an insertion device for an
`emergency cricothyrotomy tube.
`0003. It is often necessary for a patient to transcutane
`ously place the medical needle himself. For example, dia
`betic patients frequently place a Subcutaneous infusion Set
`with a cannula for Subsequent programmable delivery of
`insulin by means of a medication infusion pump. Such
`Subcutaneous infusion Sets are disclosed, for example, in
`U.S. Pat. No. 4,755,173, U.S. Pat. No. 5,176,662; U.S. Pat.
`No. 5,257,980 and WO 98/58693 which are incorporated by
`reference herein.
`0004 Some patients are reluctant or hesitant to pierce
`their own skin with a medical needle, and thus encounter
`difficulties in correct needle placement for proper adminis
`tration of the medication. Such difficulties can be attribut
`able to insufficient manual skill to achieve proper needle
`placement or alternately to anxiety associated with antici
`pated discomfort as the needle pierces the skin. This prob
`lem can be especially significant with medications delivered
`via a Subcutaneous infusion Set, Since incorrect placement
`can cause kinking of the cannula and resultant obstruction of
`medication flow to the patient. Cannula kinking can be due
`to infusion Set placement at an incorrect angle relative to the
`patient's skin, and/or needle placement with an incorrect
`force and Speed of insertion.
`0005 The present invention is aimed at providing an
`improved injector device, which may allow for a shortening
`of the total time required for the placement of an infusion
`Set. The present invention also aims at providing an
`improved Spring-type drive for urging a plunger within a
`housing to an advanced position.
`
`SUMMARY OF THE INVENTION
`0006. In accordance with the invention, an injector
`device has a plunger with a medical needle which may be
`hollow to allow for discharge of medication when priming
`the infusion Set, and which is adapted for the quick and easy
`transcutaneous placement through the skin of a patient of the
`cannula of a Subcutaneous infusion Set, the insertion needle
`extending through the infusion Set and protruding from the
`
`end of the cannula. The injector device is designed to place
`the cannula with the insertion needle extending there
`through, preferably with a controlled force and Speed of
`insertion, to ensure proper needle placement with minimal
`patient discomfort. The injector device may also allow
`placement of the insertion needle through the skin at a
`Selected insertion angle. After priming and placement of the
`infusion Set the injector device is removed and delivery of
`medication is initiated.
`0007 Preferably, the injector device is provided to the
`patient as a Sterile Sealed, Single use assembly including a
`Subcutaneous infusion Set with a housing already mounted
`on the insertion needle of the injector device, thereby
`reducing the number of components to be handled by the
`patient prior to the placement of the Subcutaneous infusion
`Set. The injector device assembly may be designed Such that
`no further packaging is required leading to Substantial cost
`reductions.
`0008 More particularly, the injector device comprises a
`device housing, preferably having an elongated bore, and a
`plunger slidably received therein for movement between an
`advanced position and a retracted position, the plunger
`having Substantially non-detachably Secured thereto an
`insertion needle adapted to receive and Support Said cannula
`in a position with the cannula oriented for transcutaneous
`placement upon movement of the plunger with Said needle
`from the retracted position to the advanced position. A drive
`urges the plunger with a controlled force and speed from the
`retracted position toward the advanced position to transcu
`taneously place Said cannula of Said Subcutaneous infusion
`Set received on Said insertion needle. The insertion needle on
`the plunger is removable from Said cannula while maintain
`ing the transcutaneous placement of the cannula. By is
`“Substantially nondetachably as used in the present appli
`cation is meant a connection, which will remainstable under
`normal conditions of use to allow the needle to remain on the
`plunger when retracting the injector device from a patient's
`skin.
`0009 Preferably, the injector comprises a spring-loaded
`plunger having a head for receiving the infusion Set in a
`position with the insertion needle projecting outwardly for
`transcutaneous placement through the skin of a patient. A
`front end of the housing is designed for being pressed
`against the skin of a patient, at a Selected needle insertion
`site; and in an orientation with the needle disposed at a
`correct or desired insertion angle. A trigger member is
`operable to release the plunger and thereby permit the drive
`Spring to carry the infusion Set toward the patient's skin with
`a controlled force and Speed, resulting in proper transcuta
`neous placement of the insertion needle with minimal
`patient discomfort.
`0010. The invention also relates to a novel spring-type
`drive for urging the plunger of an injector device to the
`advanced position, preferably for transcutaneously placing a
`Subcutaneous infusion Set, wherein the drive comprises a
`number of individual, elongated flexible plastics members,
`preferably extending around a respective part of the periph
`ery of the plunger, in the annular space between the plunger
`and a device housing. Each member is connected with the
`plunger and with the device housing. In the advanced
`position of the plunger, the plastics members are essentially
`plane and non-deformed. However, when moving the
`
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`Oct. 14, 2004
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`plunger to the retracted position, the plastics members are
`bend, Setting up the required force that seeks to drive the
`plunger to an advanced position. The novel Spring-type drive
`may also be implemented in injector devices of the type
`disclosed in U.S. Pat. No. 6,093,172, U.S. Pat. No. 5,851,
`197 and WO99/33504 where the plunger head does not have
`an insertion needle mounted thereon for receiving an infu
`Sion Set, but includes a receSS adapted for receiving as well
`as Supporting a Subcutaneous infusion Set.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0.011 The accompanying drawings illustrate the inven
`tion.
`0012 FIG. 1 is a perspective schematic vertical cross
`Sectional view illustrating an injector device embodying the
`novel features of the invention,
`0013 FIG. 2 is a schematic cross-sectional view of the
`injector device shown in FIG. 1, with the end cap removed,
`0.014
`FIG. 3 is a schematic cross-sectional view of the
`injector device of FIG. 1, with the plunger in the advanced
`position and after placement of the Subcutaneous infusion
`Set,
`0015 FIG. 4 is a view similar to FIG. 4 with end cap
`placed for protection of the protruding insertion needle,
`0016 FIG. 5 is an exploded perspective view illustrating
`the plunger and housing parts of the injector device,
`0017 FIG. 6 is a highly schematic vertical partly cross
`Sectional view illustrating an injector device according to a
`Second embodiment of the invention, prior to use,
`0018 FIG. 7 is a view similar to FIG. 6, illustrating the
`injector device being made ready for use,
`0019 FIG. 8 is a view similar to FIG. 6 of the infusion
`Set being primed,
`0020 FIG. 9 is a view similar to FIG. 6 with the plunger
`being retracted and the injector device made ready for
`transcutaneous placement of the infusion Set,
`0021 FIG. 10 is a view similar to FIG. 6, with the
`infusion Set being placed on a patient,
`0022 FIG. 11 is a view similar to FIG. 6, with the
`injection device being removed from the infusion Set placed
`on the patient,
`0023 FIG. 12 is a horizontal perspective, cross-sectional
`view of the device shown in FIGS. 6-11, showing the
`Spring-type drive with the plunger in the advanced position,
`as seen along line 12-12 in FIG. 8,
`0024 FIG. 13 is a perspective view illustrating an injec
`tor device according to a third embodiment of the invention,
`prior to use,
`0.025
`FIG. 14 is a perspective, partly cross-sectional
`view of the device of FIG. 13,
`0026 FIG. 15 is a view similar to FIG. 14, showing the
`plunger in the advanced position,
`0.027
`FIG. 16 is a exploded perspective view illustrating
`the various parts of the injector device of FIGS. 13-15,
`
`0028 FIG. 17 is a perspective view of an infusion set
`suitable for use with the injector device of the invention,
`0029 FIG. 18 is a cross-sectional view showing how
`priming of an infusion Set may be carried out using a hollow
`insertion needle,
`0030 FIG. 19 shows in an exploded view a presently
`preferred embodiment of the injector device assembly, Simi
`lar to the embodiment of FIGS. 6-12, wherein the plunger
`has an insertion needle Secured thereto.
`0031 FIGS. 20a and 20b show in a perspective view the
`injector device of FIG. 19 with the plunger in the advanced
`position
`0032 FIGS. 21a and 21b show in a perspective view the
`injector device of FIG. 19 with the plunger in the retracted
`position,
`0033 FIGS. 21c-e are views similar to FIG. 20a, 21a
`and 21b with part of the housing being cut away,
`0034 FIGS. 22a and 22b show an injector device with
`out an insertion needle Secured to the plunger,
`0035 FIGS. 23a and 23b show a schematic cross-sec
`tional view through the infusion set of FIG. 17, without and
`with an insertion needle, respectively, and
`0036 FIG. 24 shows the injector device of FIG. 19 with
`a glucose Sensor.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`0037. An injector device shown schematically in FIG. 1
`by the reference numeral 10 is provided for quick and easy
`placement of a Subcutaneous infusion Set 14, and may then
`be discarded safely. The infusion set 14 with a cannula 26
`extending therefrom is shown Schematically only.
`0038. The injector device 10 includes a plunger 30 hav
`ing thereon a medical insertion needle 12 with a pointed end
`12A. The plunger 30 is arranged for longitudinal sliding
`movement within a device housing 28 between a forward
`advanced position (FIGS. 3 and 4) and a rearward retracted
`position (FIGS. 1 and 2). The device housing 28 may have
`a circular, Square or any desired cross-sectional shape. The
`device housing 28 and the plunger 30 are preferably formed
`of a plastics material in a moulding process.
`0039 The infusion set 14 is used to infuse medical fluids
`Such as insulin to a patient, and generally includes a housing
`with an internal chamber (not shown) that receives medica
`tion via infusion tubing. An enlarged base 24 of the infusion
`set 14 is provided on the housing for stable affixation thereof
`to the skin of the patient. The enlarged base 24 may carry an
`adhesive and be provided with a release sheet 14 which is
`removed to expose the adhesive prior to placement of the
`infusion set. Alternatively, the base 24 may be sized to allow
`the infusion set to be fixed to the patient by an adhesive
`patch. The infusion Set has a protruding Soft and flexible
`cannula 26, which communicates with the internal chamber,
`and a passage Sealed by a Sealing membrane extends through
`the housing opposite the cannula 26. The medical insertion
`needle 12 of the injector device 10 extends through the
`passage, into the internal chamber and through the cannula
`26, when the infusion set 14 is mounted in position on the
`injector device. After transcutaneous placement of the can
`
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`nula 26, the injector device 10 with the insertion needle 12
`is retracted from the infusion Set 14 to permit medication
`delivery through the cannula 26 to the patient.
`0040 Examples of subcutaneous infusion sets suitable
`for use with the injector device of the present invention, and
`in particular in conjunction with the insertion needle of the
`injector device, are shown and described in U.S. Pat. Nos.
`4,755,173, 5,176,662 and 5,257,980, European patent no.
`956 879 and in international patent application no.
`98/58693, which are incorporated by reference herein. Such
`infusion Sets generally include a hollow cannula part. The
`insertion needle shown in those publications may be obvi
`ated through the present invention. Alternatively, the injector
`device according to the invention may be used to transcu
`taneously place a cannula associated with other types of
`infusion Sets.
`0041. The invention provides a ready to use injector
`device, which may be molded from a Suitable plastics
`material. An -injector device assembly including the injector
`device and a Subcutaneous infusion Set will effectively
`Simplify the placement of an infusion Set as the assembly, as
`delivered from the factory, provides an infusion Set already
`mounted on the insertion needle 12. The time required for
`the placement of an infusion Set is reduced.
`0042. The injector device 10 includes a trigger-type
`actuator mechanism for transcutaneous placement, with a
`controlled speed and force, of the insertion needle 12 which
`is secured to the plunger 30, with the insertion needle 12
`oriented at an angular position relative to the skin of the
`patient in principally the manner as shown in international
`patent application no. 99/33504 incorporated herein by
`reference.
`0043. The plunger 30 has a recessed head 32 (FIG. 3) at
`a lower or forward end thereof shaped for receiving the
`housing of the Subcutaneous infusion Set 14. Centrally in the
`recess, the head 32 is provided with the metal insertion
`needle 12, which is Securely connected thereto. The inser
`tion needle 12 may connected to the plunger in any Suitable
`manner Such as in the process of molding the plunger 30, or
`the insertion needle 12 may be press-fit in the plunger 30.
`The receSS in the plunger head 32 need not provide Support
`for the infusion Set 14 in the Sense of providing resistance to
`removal of the infusion set 14. Such support may be
`provided Solely by the frictional engagement of the insertion
`needle 12 with the cannula 26 or preferably with the sealing
`membrane within the internal chamber of the infusion set 14.
`A rear end of the plunger 30 has a trigger-type actuator
`assembly 34 cooperating with the rear end of the device
`housing 28, and includes a stem, which is longitudinal Split
`to define a pair of trigger arms 38 which have out-turned
`trigger fingerS 58 on the Sides thereof. The trigger actuator
`assembly 34 is adapted to hold the plunger 30 in a retracted
`position, against the force of a compressed helical drive
`spring 36. The trigger arms 38 of the actuator assembly 34
`are adapted for fingertip depression to release the plunger 30
`for Spring-loaded travel toward the advanced position, and
`for corresponding transcutaneous placement of the insertion
`needle 12, and of the cannula 26 travelling therewith,
`through the patient's skin. In an alternative embodiment, S
`release of the plunger 30 may be caused by pressing manu
`ally on diametrically opposed outside areas of the device
`housing 28 to deform the housing 28 and thereby effect
`release of the trigger arms 38.
`
`0044 FIGS. 1-5 illustrate construction details of the
`injector device housing 28, lo wherein the lower or nose end
`thereof defines a flat and generally planar peripheral Surface
`25 for placement against the Skin of a patient with a
`longitudinal axis of the device housing 28 oriented generally
`perpendicular to the patient's skin. A hollow bore of the
`device housing 28 has a size and shape for reception of the
`infusion set 14, with the insertion needle 12 extending
`through the cannula 26 and extending together with the
`cannula 26 in a direction for placement on a patient. A
`releasable cover sheet 42 (FIGS. 1 and 2) is preferably
`secured to the device housing 28 at the nose end thereof to
`indicate the sterility of the infusion set 14. The device
`housing 28 may also include a narrow slot (not shown)
`extending parallel with the insertion needle 12 to accom
`modate slide-fit reception of a coupling element projecting
`laterally from the infusion Set housing for coupling of the
`infusion Set with a pump (not shown), and longitudinally
`extending track slots 52 (FIG. 3). The plunger 30 includes
`ribs 50 for guided reception within the track slots 52 formed
`in the device housing 28 to control the movement of the
`plunger 30 between the advanced position and the retracted
`position. The plunger 30 ribs 50 define a surface 51 near the
`head 32 adapted to cooperate with a peripheral inner edge 29
`at the nose end of the device housing 28 to limit movement
`of the plunger, thereby defining the advanced position of the
`plunger 30.
`004.5 Thus, the forward or nose end of the device hous
`ing 28 accommodates movement of the Subcutaneous infu
`Sion Set 14 between the retracted position disposed Substan
`tially at the rearward most end of the device housing 28, and
`the advanced position.
`0046. As will be understood, the trigger-type actuator
`assembly 34 generally functions to releasably retain the
`plunger 30 in the retracted and cocked position, ready for
`rapid and Spring-loaded actuation upon depression of the
`trigger arms 38 to place the infusion Set 14 on the patient.
`More particularly, the trigger assembly 34 is initially locked
`against a shoulder 66 formed on the device housing 28 by
`means of the trigger fingers 58. The drive spring 36 com
`prises a coil Spring positioned about the Stem on the plunger
`30 and reacts between a rearward face 64 of the plunger head
`32, and an internal shoulder 66' on the device housing 28.
`The drive spring 36 normally biases the plunger 30 toward
`the advanced position. During manufacture of the injector
`device assembly, the infusion Set 14 is Seated in the receSS
`formed in the plunger head 32, either before or after the
`plunger 30 is moved to the retracted position. In this
`retracted plunger position, the drive Spring 36 is retained in
`a compressed and cocked condition, with the cannula 26 of
`the infusion set 14 being received on the insertion needle 12.
`The releasable cover sheet 42 is then applied to the device
`housing 28 at the nose end thereof.
`0047. In use of the injector device 10 with the infusion set
`14, the cover sheet 42 is first removed and the injector device
`10 is placed firmly against the patient's skin, with the
`infusion Set 14 Supported in the proper orientation and at a
`predetermined distance from the skin. A cap 94, which
`prevents accidental projection of the infusion Set 14 by
`preventing access to the trigger arms 38, is removed. Simple
`depression of the arms 38 releases the cocked plunger for
`Spring-loaded travel rapidly albeit with a controlled Speed
`and force of insertion, to ensure penetration of the patient's
`
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`skin with minimal discomfort, and in a manner which
`properly places the insertion needle and cannula 26.
`0.048. Following placement of the infusion set 14 the
`injector device with insertion needle 12 is withdrawn
`quickly and easily from the cannula. Thereafter, the injector
`device can be discarded and the infusion Set 14 can be used
`in a normal manner to deliver a Selected medication through
`the infusion tubing and cannula 26 to the patient. AS shown
`in FIG. 4, the safety cap 94 may conveniently be adapted to
`cooperate with an annular recess 33 formed in the head 32
`of the plunger 30 for providing protection against the needle
`12.
`0049. It is noted that the removable cap 94, when sealed
`to the device housing 28 at the end opposite the plunger
`head, together with the cover sheet 42 enable the injector
`device 10 together with the infusion set 14 mounted on the
`insertion needle 12 to be Sterilised in a conventional Ster
`ilisation proceSS using e.g. ethylene oxide, where the Ster
`ilising agent flows through the membrane formed by the
`cover sheet 42. By proper choice of the materials used for
`making the injector device, the injector device may then
`remain Sterile under normal conditions of Storage, making
`any external packaging unnecessary.
`0050. An alternative embodiment of the invention is
`shown schematically in FIGS. 6-12, wherein components
`corresponding in function to those described previously with
`respect to FIGS. 1-5 are identified by common reference
`numerals increased by 100. FIGS. 6-12 serve the purpose of
`explaining the principles involved in that embodiment, and
`the figures Show Schematic, partial cross-sectional views of
`the injector device.
`0051 FIGS. 6-12 show an injector device assembly
`including a modified injector device 110 constructed from a
`reduced number of parts and having an alternative drive
`mechanism for advancing:the plunger. The modified injector
`device 110 comprises a generally cylindrical hollow device
`housing 128, a plunger 130 and a trigger-type actuator 134
`formed integrally with the plunger 130. A cover 194, pref
`erably a flexible membrane, covers the top of the injector
`device 110 and a further cover 142 covers the bottom end of
`the injector device 110.
`0.052 The plunger 130 has a generally cylindrical form
`with a head 132 and a central pin 129 including a metal
`insertion needle 112 Secured thereto in a molding process, by
`preSS-fit, or by any other method providing a Suitable
`resistance to loSS of the insertion needle during use of the
`device. The pin 129 stops at a distance from a pair of
`outwardly turned legs 138" at the head 132, to accommodate
`for the infusion set 114 in the head 132 of the plunger 130.
`The insertion needle 112 extends through the infusion set
`114 in a similar manner as described with reference to FIGS.
`1-6. An infusion Set tubing 113 having a typical length of
`between about 50 cm and 120 cm and connected to the
`infusion Set 114 is wound up in the lower part of an annular
`space 115 between the device housing 128 and the plunger
`130 to form part of the assembly.
`0.053 More specifically, the device housing 128 again has
`a forward or nose end defining a flat and generally planar
`Surface 125 for firm placement against the skin of a patient.
`The plunger 130 additionally includes a pair of resilient
`trigger arms 138 which are connected with the pair of
`
`outwardly turned legs 138' and which have out-turned
`trigger fingers 158 at the sides thereof. The trigger arms 138
`are adapted and sized for partial radial compression toward
`each other as they ride within the device housing when the
`plunger 130 is displaced from the advanced position (FIG.
`6) to the retracted position (FIG.9). As the retracted position
`is reached, the trigger arms 138 are Spring-loaded by the
`resiliency to move first inwardly and then outwardly
`whereby the trigger fingers engage the upper Surface of a
`shoulder 166 of the device housing 128. In this position the
`trigger fingers 158 retain the plunger 130 in the retracted
`position.
`0054) A drive spring 136 is mounted within the device
`housing 128 to drive the plunger towards the nose of the
`device housing in the retracted position of the plunger 130,
`upon release of the trigger arms 138. The drive spring 136
`is formed integrally with the device housing 128 and the
`plunger 130 in a molding process and may conveniently be:
`formed of the same plastics material as the plunger 130 and
`the device housing 128. The Spring is shown in closer details
`in FIG. 12. The spring 136 essentially comprises a number
`of elongated plastics Strips 136, each extending around a
`respective part of the periphery of the plunger 130, in the
`annular space 115 between the plunger 130 and the device
`housing 128. The drawing Show an embodiment incorpo
`rating two Such Strips that each extends around about one
`fourth of the periphery of the plunger 130. Each strip 136 is
`integrally connected at one end 136" with the plunger 130
`and with the device housing 128 at the other end 136'. In the
`advanced position of the plunger shown in FIGS. 6-8 and
`10-12, the strips 136 are preferably essentially plane and
`non-deformed. However, when moving the plunger 130 to
`the retracted position shown in FIG. 9, the strips 136 of the
`Spring are bend, Setting up the required force that seeks to
`drive the plunger 130 towards the nose of the device housing
`128. It is noted that this proceSS normally gives rise to a
`rotational movement of the plunger 130 about its central
`axis, which is coincident with the insertion needle 112.
`0055 Operation of the injector device assembly shown in
`FIGS. 6-12 is as follows. Since the injector device is
`preferably delivered to the patient in an uncocked State to
`Simplify the process of manufacture, the plunger 130 must
`first be moved to the retracted position. To allow for retrac
`tion of the plunger 130, the upper cover 194, which spans
`across the device housing 128 and the lower cover 142 are
`first removed, as shown in FIG. 7. The lower cover 142 may
`be hingedly connected to the device housing 128. In this
`process, the infusion Set 114 is exposed with the pointed end
`112A of the insertion needle 112 projecting from the end of
`the soft flexible cannula 126. The infusion set tubing 113 is
`then connected to a Suitable pump, and the infusion Set 114
`is primed (drop marked 300 in FIG. 8) by allowing medi
`cation to exit through the narrow annular space between the
`cannula 126 and the insertion needle 112 or, if a hollow
`needle is used, through the needle, as shown in FIG. 18. The
`injector device 110 is then cocked by displacing the plunger
`130 with respect to the device housing 128 as illustrated by
`the arrow in FIG. 9, until the fingers 158 engage the upper
`shoulder 166 of the device housing 120 indicating that the
`injector device is now ready for use. A release sheet 114 is
`then removed exposing an adhesive material on the bottom
`Side of the infusion housing 114, and the patient or the
`nursing perSonnel then places the injector device on the
`patient’s skin. The plunger 130 is released by application of
`
`Page 25 of 30
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`US 2004/0204687 A1
`
`Oct. 14, 2004
`
`an inwardly directed manual force on the arms 138 to
`transcutaneously place the insertion needle 112 and the
`cannula 126. In an alternative embodiment, release of the
`plunger 130 may be caused by pressing manually on dia
`metrically opposed outside areas of the device housing 128
`to deform the housing 128 and thereby effect release of the
`trigger arms 138.
`0056. The injector device 110 is then removed, leaving
`the infusion set 114 on the patient's skin, illustrated by
`reference numeral 116, and the bottom cover 142 is then
`repositioned at the original place shown in FIG. 11 for
`protection of the insertion needle 112 which projects par
`tially from the nose end of the device housing 128.
`0057 The removable upper cover 194 and the bottom
`cover 142, when sealed to the device housing 128, allow the
`injector device 110 together with the infusion set 14
`mounted on the insertion needle 112 to be sterilised in a
`conventional Sterilisation proceSS using e.g. ethylene oxide.
`For this purpose one or both covers 142, 194 may comprise
`a permeable membrane allowing through-flow of the Steril
`ising agent. By choosing Suitable materials, the injector
`device may then remain Sterile for a long time under normal
`conditions of Storage whereby no f