WO1989005118A1

WO1989005118A1 - A device for taking blood samples

Info

Publication number: WO1989005118A1
Application number: PCT/NO1988/000090
Authority: WO
Inventors: Arild Jensen; Torfinn Johansen
Original assignee: Arild Jensen; Torfinn Johansen
Priority date: 1987-12-07
Filing date: 1988-12-06
Publication date: 1989-06-15
Also published as: NO164511C; NO881494D0; NO881494L; NO164511B

Abstract

A device for taking blood samples, comprising a cannula (1) and a substantially cylindrical holder (6) whose one end has an aperture (7) for insertion of the cannula, while the other end of the holder is open for insertion of a container for a blood sample. The end of the holder where the cannula can be inserted comprises a movable element (11) having a relatively to the holder axial, through going aperture for the insertion of the cannula, and in the vicinity of this aperture the element has at least one locking element (13) adapted to be placed in a locking position axially outside of at least one radial protrusion (4) on the cannula (1). In addition the element (11) has, in the vicinity of the aperture, at least one edge or surface (14) which by movement of the element in a direction which brings the locking element (13) away from the locking position comes into engagement with the under side of the protrusion (4) or with one or more additional protrusions on the cannula, in order to disengage the cannula from the holder (6) by continued movement of the element.

Description

A device for taking blood samples.

The present invention relates to a device for taking blood samples, comprising a cannula and a substantially cylindrical holder whose one end has an aperture for insertion of the cannula, while the other end of the holder is open for insertion of an end of a container for collecting blood.

For taking blood samples are most frequently used disposable cannulae which approximately in the middle have a threaded thick¬ ening adapted to be screwed into a cylindrical holder which in one end has a correspondingly threaded aperture for the cannula. The container for collecting the blood usually consists of a small glass bulb which in one end is closed by an elastomeric element, for instance a membrane, nd by insertion of the contain¬ er into the open end of the holder the membrane is perforated by the inserted end of the cannula. After the taking of the blood sample the container is pulled out of the holder, and simultan¬ eously the container is pulled off the cannula, whereupon the cannula can be screwed off the holder and thrown away.

Screwing the used cannula off the holder is usually carried out manually, and this brings about the risk that the person per¬ forming the unscrewing can get pricked on the cannula, which implies a risk of transferring infectious diseases such as hepatitis or transferring for instance HIV.

An object of the present invention is to achieve a device which among else eliminates the above mentioned drawback, and more spe¬ cifically an object is to achieve a device which permits removal of used cannulae from the holder in a simple manner which sub¬ stantially reduces the risk that somebody gets pricked on the cannula.

According to the invention the above object is achieved by means of a device specified in the succeeding claims.

The device according to the invention permits that the cannula can be locked in an inserted position in the holder by means of a movable element at one end of the holder, and that disengagement of the cannula from the holder only

SUBSTITUTE SHEET makes it necessary to move the element away from its locking position, in order to cause that the cannula loosens and is - moved at least partly out of the holder.

In addition to substantially reducing the risk of getting pricked the device brings about the advantages that both the fastening of the cannula in the holder and the disengagement _ of the cannula from the holder are substantially simpler -and faster to perform than screwing the cannula in order to fasten and disengage it, respectively.

The invention will hereinafter be explained more detailed with reference to the accompanying drawings.

In practice the invention can comprise a movable element which is either shiftable, turnable or pivotable.

Fig. 1 shows a longitudinal section through a device according to the invention, comprising a shiftable element.

Fig. 2 shows in a perspective view from above the shiftable element included in the device shown in Fig.l .

Fig. 3 shows the same element seen in a perspective view frorr- below.

Fig. 4 shows a longitudinal section through a part of a device according to the invention, comprising another embodiment of the shiftable element and of the thickening on the cannula.

Fig. 5 shows another embodiment of a shiftable element include in the invention, seen in a perspective view from above.

Fig. 6 shows the element of Fig. 5 seen in a perspective view from below.

Fig. 7 shows still another embodiment of a shiftable element seen in a perspective view from above.

Fig. 8 shows the element of Fig. 7 seen in a perspective view from below. Fig. 9 shows a turnable element seen in a perspective view.

Fig. 10 shows a longitudinal section through a part of a device according to the invention, comprising a turnable element as shown in Fig. 9.

In the Figs, have been used the same reference numerals for equal or mutually equivalent parts.

Fig. 1 shows an embodiment of a device according to the invention which comprises a shiftable element in the form of a slide 11. The slide is situated at the end of a holder 6. A cannula 1 extends through the slide 11 and that end of the holder 6 where the slide is situated. On the cannula 1 is a thickening 2, which may for instance be fastened by having a narrow hole for the cannula. From the opposite end of the holde is inserted a container 15, in the form of a small bulb or flask of glass or plastic. The container has a closure 16 through which the cannula can penetrate, and in Fig. 1 the closure is shown as a plug, though it may also be a membrane.

The holder 6 has an aperture 7 for insertion of the cannula 1, and the aperture is defined by a conical socket 8 to which a portion of the thickening 2 on the cannula is adapted. In the example the thickening 2, moreover, has an outer collar 3 which may be elliptic or oval and is situated in a corresponding elliptic or oval aperture 9 in the end of the holder 6. Thereby the cannula can only be inserted in the holder in two positions, i.e. such that the tapered edge which defines the outer cannula opening lies in a plane parallel with the longitudinal direction of the slide 11. This is merely a practical arrangement in order to achieve that the cannula can be forced into a vein with the tapered edge facing inclined outwardly from the part of the body into which the cannula is to be introduced and that simultaneously the slide 11 will be situated parallelly with the skin and does not prevent the holder 6 in being laid closely against the skin when the cannula is being introduced. This is, however, a detail of little importance. The slide 11 is situated in a duct 10 crosswisely of the holder 6 and. can be shifted in this crosswise direction. In the following part of the description- is also ^referred to Figs. 2 and 3, showing the slide of Fig. 1. In order to lock the cannula 1 in the inserted position in the holder 6 the thickening has an inner collar 4, and a locking edge 13 on the slide 11 projects outside of the collar 4 when the slide is in the locking position, where it is shown in Fig. 1.

In order to unlock the cannula 1 and to force it at least partly out of the holder 6 the slide 11 is shifted to the left as shown in Fig. 1. Thereby the locking edge 13 will be brought away from its locking position, and moreover two sloping surfaces 14, one of which appearing from Fig. 2, will be moved below the collar 4 and thereby detach the cannula 1 from the holder 6. If the cannula is not forced completely out thereby, it will fall out of the holder when this is held with the cannula directed downwardly or sloping downwardly. The slide 11 has a relatively to the holder 6 through going aperture 12 (Figs. 2 and 3) in order to give room for the thickening 2 on the cannula.

For the insertion of a new cannula the slide 11 is placed in an approximately middle position, whereby the cannula can be inserted without being prevented by the slide 1, whereupon the slide 11 is shifted to the locking position shown in Fig. 1, During the disengagement the two sloping surfaces 14 will push against the collar 4 on mutually opposite sides, whereby no bending moment occurs in the cannula 1, and preferably the sloping surfaces 14 are situated in such a manner that at the beginning of the disengagement they act against diametrically opposite portions of the collar 4.

The slide may be provided with stop lugs 5 which restricts its shifting relatively to the holder 6. The slide can be made of a sufficiently resilient material to enable it to be pressed together in order that one of the sets of lugs 5 (to the left in Fig. 2 and to the right in Fig. 3) can be forced through the duct 10 in the holder 6. In addition the lugs prevent the slide 11 from sliding inadvertently out of the duct 10. Fig. 4 illustrates another embodiment of the device according to the invention, and shows only that end of a holder 6 in which a cannula 1 has been inserted. The cannula 1 has a thickening 2 which comprises a collar 4, and the thickening 2 has been inserted in a conical aperture 7 defined by a socket 8 in the holder 6, in the same manner as shown in Fig. 1. Differently from the embodiment of Fig. 1 the collar 4 has a conical shape, whereby it replaces the sloping surfaces 14 shown in Fig. 1. The slide 11 has edges 14 in order to disengage the cannula 1 from the holder 6 by cooperating with the underside of the collar 4. A locking edge 13 on the slide 11 acts in the same manner as shown in Fig. 1, in that it is placed outside of the collar 4.

Figs. 5 and 6 show in perspective views, seen from above and from below, respectively, a modification of the slide 11 shown in Figs. 2 and 3. The slide 11 shown in Figs. 5 and 6 comprises a locking edge 13, stop lugs 5, an aperture 12 and sloping edge 14, the latter being, contrarily to the curved sloping edges shown in Figs. 2 and 3, planar.

Figs.7 and 8 show an element that can be used in the embodi¬ ment of the device shown in Fig. 4, i.e. a slide 11. This slide also comprises a locking edge 13, an aperture 12 and lugs 5, and two edges 14 extending inclined relatively to the longitudi nal direction of the slide 11 can be brought into engagement with the conical surface on the collar 4, shown in Fig. 4. There is, however, nothing to prevent that the edges 14 can be replaced by chamfers.

Figs. 9 and 10 illustrate an embodiment of a device according to the invention where the movable element is turnable, and Fig. 9 shows the element itself while Fig. 10 shows one end of a holder 6 comprising a conical aperture 7 defined by a socket 8. Moreover, the end of the holder 6 has a mounting 17 by which the element 11' is held in such a manner that it is turnable relatively to the holder 6, and the turnability is limited by not shown lugs on the holder coming into engagement with surfaces 18 shown in Fig. 9. The mounting 17 and a correspon¬ ding mounting on the element 11' may have recesses which permit axial movement of the element 11' towards the end of the holder 6, whereupon the element 11' is turned in order to establish interlocking between the mountings. The surfaces 18 and the not shown lugs on the holder are situated in such a manner that the element 11' can only be turned between such terminal positions that the interlocking between the mountings is maintained. The thickening 2 on the cannula 1 has locking protrusions 4' , and in the inserted position the thickening is locked against turning relatively to the holder 6, by means of not shown means, such as for instance a rib in the aperture 7 and a corresponding groove in the thickening 2, or vice versa The cannula 1 with the thickening 2 is inserted in the holder 6 such that the mentioned rib enters the mentioned groove and such that the protrusions 4' enter the recesses in the element 11' between the sloping surfaces 14' and the protrusions 13' , whereupon the element 11' is turned in order to bring the protrusions 13' to positions outside of the locking protrusions 4' on the thickening 2.

In order to disengage the cannula 1 the element 11' is turned in the opposite direction, whereby the sloping surfaces 14' come into engagement with the underside of the locking protru¬ sions 4' . By continued turning of the element 11' the cannula 1 is forced out of the holder 6.

The holder 6, the element 11, 11' and the thickening 2 may for instance be made of plastic, without this being mentioned as any limitation.

Claims

Claims .

1. A device for taking blood samples, comprising a cannula (1) and a substantially cylindrical holder (6) whose one end has an aperture (7) for insertion of the cannula,while the other end of the holder is open for insertion of a container (15) for a blood sample, c h a r a c t e r i z e d i n that the end of the holder (6) in which the cannula (1) can be inserted comprises a movable element (11, 11') having a relatively to the holder axial, through going aperture for the insertion of the cannula, that the element in the vicinity of this aperture has at least one locking element (13, 13') adapted to be placed in a locking position axially outside of a radial protrusion (4) on the cannula (1) , and that the element (11, 11') in the vicinity of the aperture has at least one edge (14, 14') which by movement of the element in a direction which brings the lockin element (13, 13') away from the locking position comes into engagement with the axially inner side of the radial protrusio or protrusions (4, 4') on the cannula or with one or more additional protrusions on the cannula, whereby continued movement of the element (11, 11') causes that the cannula is disengaged from the holder (6) .

2. A device according to claim 1, c h a r a c t e r i z e d i n that the movable element (11) is a shiftable slide guided in a crosswise duct (10) in one end of the holder (6) .

3. A device according to claim 2, c h a r a c t e r i z e d i n that the slide (11) has two surfaces or edges (14) which during disengagement of the cannula act against approximately diametrically opposite portions of the protrusion or protrusions (4) .

4. A device according to claim 3, c h a r a c t e r i z e d i n that the slide (11) has at least one sloping surface (14) which causes disengagement of the cannula (1) .

5. A device according to claim 2, c h a r a c t e r i z e d i n that the slide (11) has at least one edge (14) for cooperation with an approximately conical surface on the protrusion (4) on the cannula (1) .

6. A device according to claim 1, c h a r a c t e r i z e d i n that the movable element (11') is turnably mounted on the holder (6) , whereby means are provided for preventing turning of the cannula (1) relatively to the holder when the cannula has been inserted in the latter, and that the cannula has at least one radial protrusion (4') adapted to cooperate with at least one locking protrusion (13') and a surface or edge (14') on the element (11') , whereby turning of the element causes locking and unlocking, respec¬ tively, of the cannula.

7. A device according to claim 6, c h a r a c t e r i z e d i n that a groove in the cannula (1) or in a socket (8) of the holder in which the cannula is inserted cooperates with a rib or a lug on the socket (8) or on the cannula, in order to prevent turning of the cannula relatively to the holder.

8. A device according to claim 6 or 7, c h a r a c t e r i z e d i n that the turnably mounted element (11') approximately has the form of a sleeve, on which two locking protrusions (13') protrude in the same circumferential direction at one end of the sleeve and are situated diametrically opposite of each other, whereby the locking protrusions define recesses whose axially lower limitation is formed by the surface (14') acting to disengage the cannula (1) .