WO2007003874A1

WO2007003874A1 - Introducing device with wheel operator

Info

Publication number: WO2007003874A1
Application number: PCT/GB2006/002023
Authority: WO
Inventors: Kadiyali Madhava Srivatsa
Original assignee: Kadiyali Madhava Srivatsa
Priority date: 2005-07-05
Filing date: 2006-06-05
Publication date: 2007-01-11
Also published as: GB0513720D0

Abstract

A cannula introducing device comprises a body (10), a needle (12) projecting from the front end of the body, a wheel (18) mounted in or to the body and having a rim engageable by the user to turn the wheel, and a plunger (16) at the front end of the body, arranged to be advanced upon rotation of the wheel, in order to advance a cannula (22) disposed over the needle.

Description

Introducing Device with wheel operator

The present invention relates to medical devices and more particularly to devices for introducing a cannula, or a catheter, or a guide wire for a catheter, into a patient's blood vessel.

A number of devices have been used or proposed hitherto for introducing a cannula, or a catheter, or a guide wire for a catheter, into a patient's blood vessel. Such devices are generally of complicated construction, or relatively difficult to use reliably and safely. Moreover, it is sometimes desirable to insert a relatively long cannula into a blood vessel, and this is particularly difficult to achieve with hitherto known devices.

In accordance with the present invention, there is provided a cannula introducing device which comprises a body, a needle projecting from a front end of said body, a wheel mounted in or to said body and having a rim engageable by the user to turn said wheel, and a plunger at the front end of said body and arranged to be advanced upon rotation of said wheel.

In use, a cannula is positioned over the needle of the device, with the tip of the needle projecting from the forward end of the cannula. The tip of the needle is inserted into the patient's blood vessel, then the user turns the wheel to advance the plunger and push the cannula over the needle and into the blood vessel.

The wheel may comprise a reel around which an elongate flexible element is wound, the elongate flexible element having a free end coupled to the plunger so that rotation of the reel serves to wind or to unwind the elongate flexible element to advance the plunger. The elongate flexible element may be relatively long, to advance the cannula a relatively long distance, and the needle and cannula itself may be correspondingly relatively long. In another embodiment, the plunger may be mounted to the forward end of an elongate e.g. rigid driver member, the wheel being coupled to this driver member (e.g. by teeth on the wheel engaging serrations on the driver member) to displace it longitudinally of itself to advance the plunger.

Preferably the wheel is arranged for rotation, to advance the plunger, by the user engaging a portion of its rim to displace that portion in a direction away from the front end of the body and towards an opposite, rear end of the body.

Preferably the device further comprises a blood collecting chamber for collecting blood received through the needle. The needle may be mounted to the blood collecting chamber, with the blood collecting chamber and needle arranged for displacing rearwardly, relative to the device body, upon continuing rotation of the wheel, after at least partial advancement of the plunger. This arrangement halves the rotation of the wheel required in order to advance the plunger the same distance relative to the needle. The wheel may have a secondary wheel coupled to it, with the blood collecting chamber coupled to the secondary wheel for displacement thereby. The arrangement may comprise an endless band or belt trained around the secondary wheel and around a further wheel, with the blood collecting chamber coupled to one run of the band or belt, extending between the secondary and further wheels: an elongate driver element for the plunger may be coupled to a second such run of the band or belt.

Also in accordance with the present invention, there is provided a cannula introducing device which comprises a body, a needle projecting from a front end of said body, a plunger at the front end of said body, operating means engageable by a user for advancing said plunger, and a blood collecting chamber to which said needle is mounted, said blood collecting chamber and needle being arranged for displacement rearwardly, relative to said body, upon continuing operation of said operating means, after at least partial advancement of said plunger.

In this device, the operating means may comprise a wheel having a rim engageable by the user to turn the wheel for advancing the plunger and displacing the blood collecting chamber and the needle. The operating means, for engagement by the user, may however take alternative forms: for example, it may comprise an element which is movable along an elongate path, e.g. in a sliding action and preferably in a direction away from the front end of said body and towards a rear end thereof.

Further in accordance with the present invention, there is provided a catheter or guide wire introducing device which comprises a body having a needle projecting from a front end thereof, a reel mounted in or to said body, and a catheter or a guide wire wound around said reel and having a free end thereof engaged into the rear end of said needle, said reel having a rim engageable by the user to turn said reel and unwind said catheter or guide wire and advance said catheter or guide wire through said needle. hi use of this device, the needle tip is first inserted into the patient's blood vessel and then the user turns the reel to unwind the catheter or guide wire and advance it through the needle and into the patient's blood vessel, hi the case of the guide wire, when this is in position, a catheter may be threaded over it and into the blood vessel, after which the guide wire may be withdrawn.

In one embodiment of the present invention, the catheter is provided with an enlarged termination or hub which is removably engaged with the reel: the needle is longitudinally split and the body comprises two parts which can be opened, to allow the catheter to be removed from the needle once it has been fully unwound from the reel and its termination or hub disengaged from the reel. Preferably the termination is arranged for engagement into the enlarged rear end of a cannula. Preferably the device includes a plunger arranged to be displaced along the needle, to advance the cannula into the blood vessel, after the tip of the needle has been inserted into the blood vessel and before the catheter is advanced into the blood vessel. Preferably the body of the device includes an operating element engageable by the user and coupling means between this operating member and the plunger, the operating element being displaceable in a direction away from the front end of the body, for moving the plunger forwardly.

In another embodiment of the present invention, the rear end of the catheter is provided with a flexible termination which is able to pass through the needle, after the catheter has been fully unwound from the reel, and upon the device being retracted. Preferably the termination is arranged to engage into the rear end of the cannula. Preferably the cannula is provided with a connector having a stem inserted into an orifice in the side of the cannula and arranged to be displaced radially inwards, when the catheter termination is engaged into the rear end of the cannula, to engage into an orifice in the side of a connector portion of the catheter termination.

Embodiments of the present invention will now be described by way of examples only and with reference to the accompanying drawings, in which:

FIGURE 1 is a top plan view, partly hi section, of an embodiment of cannula introducing device in accordance with the present invention, shown with a cannula disposed over the projecting needle of the device and the assembly in an initial condition ready for use;

FIGURE 2 is a side view of the assembly shown in Figure 1;

FIGURE 3 is a similar side view of the assembly, shown in a final condition after use;

FIGURE 4 is a top plan view, partly in section, of an embodiment of guide wire introducing device in accordance with the present invention;

FIGURE 5 is a side view of the device of Figure 4; FIGURE 6 is a side view, partly in section, of an embodiment of catheter introducing device in accordance with the present invention;

FIGURE 7 is a view of the device of Figure 6, once opened up to release a termination or hub with which the rear end of the catheter is provided;

FIGURE 8 is a side view, partly in section, of another embodiment of catheter introducing device in accordance with the present invention;

FIGURE 9 is a side view, partly in section, of a cannula through which the catheter is being passed;

FIGURE 10 is a similar view of the cannula once a terminal seal of the catheter has entered the rear of the cannula;

FIGURE 11 is a side view, partly in section, of a further embodiment of cannula introducing device in accordance with the present invention, shown with a cannula disposed over the proj ecting needle of the device and the assembly in an initial condition ready for use;

FIGURE 12 is a similar side view of the assembly, shown hi a final condition after use;

FIGURE 13 is a view, corresponding to Figure 11, of a modified device; and

FIGURE 14 is a view, corresponding to Figure 11, of another modified device.

Referring to Figures 1 to 3 of the drawings, there is shown a cannula introducing device which comprises a body 10 having a hollow needle 12 proj ecting from a forward end thereof, the interior of the needle 12 communicating with a blood collecting chamber 14 within the body 10, adjacent its forward end. The device further comprises a plunger or needle guard 16, in the form of a flat plate, initially disposed against the front end of the body 10 and having a central aperture through which the needle 12 extends. The body 10 is of generally flat, rectangular shape and has an internal compartment in which a wheel 18, in the form of a reel, is mounted for rotation around its axis: the reel 18 is disposed generally parallel to the opposite sides of the body 10, with its rim projecting from one longitudinal edge of the body 10, and forms an operating element for the device.

An elongate flexible element or wire 20 is wound on the reel 18 and has a free end portion 21 which extends through a passage formed longitudinally of the body 10 and out from the front end of the body 10, where it is connected to the plunger or needle guard 16. It will be appreciated that the user may grip the body 10 in one hand, and engage the projecting rim of the reel 18 with the index finger of that hand, and then retract the index finger in order to turn the reel 18 on its axis (in the clockwise direction, as viewed in Figures 2 and 3): this has the effect of unwinding the element or wire 20 from the reel 18, the end portion 21 thus being extended longitudinally of itself and so advancing the plunger or needle guard 16 along the needle 12.

In use, the plunger or needle guard 16 is initially in the retracted position shown in Figures 1 and 2, in contact with the front end of the body 10 of the device. A cannula 22 is positioned over the needle 12, for its rear end to abut the plunger 16 and the tip of the needle 12 to project from the forward end of the cannula 22. It will be noted that the cannula 22 comprises a tubular stem having an enlarged, conical rear end. The user grips the body 10 of the device in one hand and brings the assembly up to the patient to insert the tip of the needle 12 carefully into a blood vessel, causing blood to flow through the needle 12 and into the chamber 14: when the user sees that blood has entered the chamber 14, he engages the projecting rim of the reel 18 with his index finger and, by repeated retractions of this finger, turns the reel 18 to unwind the element or wire 20 and so advance the plunger or needle guardl6; the plunger 16 accordingly pushes the cannula 22 forwardly along the needle 12, so that the forward end of the cannula passes over the tip of the needle 12 and into the blood vessel.

Once the cannula 12 is in position in the patient's blood vessel, and referring to Figure

3 of the drawings, the body 10 can be retracted to withdraw the needle 12, firstly from the patient's blood vessel and then from the cannula: throughout this movement, the rotation of the reel 18 is continued, so that the plunger 16 continues to advance and, finally, reaches a position in which it covers the sharp tip of the needle 12. With the tip of the needle covered by the plunger 16, it is prevented from causing needle stick injuries. Moreover, at least the end portion 21 of the element or wire 20 is formed with a series of ratchet serrations 21a which co-operate with a tooth or projection, formed on the body 10 at or adjacent the front end of the passage therein through which the element or wire 20 extends, to prevent the plunger 16 being retracted, once it has been advanced: this arrangement prevents the device being re-used, with the risk of spreading infection.

It will be appreciated that the device which has been described with reference to Figures 1 to 3 of the drawings is of relatively simple construction yet easy to use, whilst minimising the risk of movement of the tip of the needle 12 as the cannula 22 is advanced over the needle and into the patient's blood vessel. Further, the element or wire 20 wound on the reel 18 may be quite long, and the arrangement therefore enables a relatively long cannula to be advanced over a relatively long needle.

Referring to Figures 4 and 5 of the drawings, there is shown a device for introducing a guide wire into a patient's blood vessel. The device comprises a body 10, a projecting needle 12, a blood-collecting compartment 14 and a rotary reel 18, as the device of Figures 1 to 3. The device differs, however, from the device of Figures 1 to 3, in that a guide wire 24 is wound around the reel 18 with its free end entering the needle 12. In use, the device is brought up to the patient for the tip of its needle 12 to enter the blood vessel, causing blood to flow through the needle 12 and into the compartment 14; when the user sees that blood has entered the compartment 14, he uses his index finger to turn the reel 18, as described above in relation to the device of Figures 1 to 3, to advance the guide wire 24 through the needle 12 and into and along the blood vessel. Then the body 10 is retracted to withdraw the needle 12, leaving the guide wire in position: a catheter can then be threaded over the guide wire and into the blood vessel, after which the guide wire may be withdrawn.

Referring to Figures 6 and 7 of the drawings, there is shown a device for introducing a catheter into a patient's blood vessel. The device comprises a body 10, a projecting needle 12, a blood-collecting compartment 14, a plunger or needle guardl 6 and a rotary reel 18, all as the device shown in Figures 1 to 3. The device further comprises an operating knob 26 which is mounted in a guide groove which extends along the edge of the body 10, from which the rim of the reel 18 projects: the operating knob 26 projects from this edge of the body and can be displaced, by the user' s index finger, along the guide groove, away from the front end ofthe body lO. An elongate coupling element 28, such as a wire, is connected at one end thereof to the operating knob 26 and extends along the guide groove and then through a passage 29 which is formed in the body 10, the passage 29 firstly curving around the rear end of the body 10 to the opposite edge of the body 10 and then extending parallel to the latter edge of the body 10 to the front end fo the body, where the other end of the coupling element or wire 28 is connected to the plunger 16.

In use of the device of Figures 6 and 7, the body 10 is brought up to a patient and the tip of the needle 12, projecting from a cannula 22, is inserted into a blood vessel. When the user sees blood entering the compartment 14, he retracts the operating knob 26 to displace the coupling element or wire 28 longitudinally of itself and so advance the plunger 16, and thereby push the tip of the cannula into the blood vessel. He then turns the reel 18, using his index finger in the manner described above, to advance a catheter 30, which is wound around the reel 18, through the needle 12 and cannula 22, and into the blood vessel. The rearward end of the catheter 30 has an enlarged termination or hub 31, which is engaged in a radial groove 18a in one side of the reel 18. The body 10, needle 12, plunger or needle guard 16 and coupling element 28 (at least at the forward end thereof) are all longitudinally split, the two opposite side parts of the body 10 being hinged together along the edge opposite the edge from which the rim of the reel 18 projects. When the catheter has been advanced as far as possible (i.e. it has been unwound to its fullest extent from the reel 18), the body is opened, at the same time opening apart the opposite sides of the needle 12 and plunger 16: the device in this condition is shown in Figure 7. The termination or hub 31 is then disengaged from the reel 18 and the catheter removed from the needle 12 and plunger 16, enabling the catheter 30 to be advanced to a final position, in which the termination 31 is engaged in the enlarged rear end of the cannula 22. The catheter termination 31 is formed with a passage to enable it to be used for withdrawing blood from the patient or introducing fluid or medication into the patient's blood vessel.

Figure 8 shows a device similar to the device of Figures 6 and 7 and like parts are denoted by like reference numerals: the body 10, needle 12 and plunger 16 are not, however, longitudinally split. Also, the catheter 30 has a termination which comprises a connector 32 and a funnel-shaped, flexible seal 33. The catheter can be unwound completely from the reel 18, then the device retracted so that the seal 33 passes through the needle 12, the seal 33 being able to compress sufficiently in the radial direction to allow this. The catheter 30 is then advanced fully, for its termination to fit into the enlarged rear end of the cannula 22 (Figure 9): a plug 34 is then inserted into the end of the cannula 22, to seal it (Figure 10). The cannula 22 is provided with an orifice in the side of its stem, into which the stem of a connector 35 is fitted: once the termination of the catheter has become engaged into the rear end of the cannula, the connector 35 is pushed inwards, radially of the cannula 22, for the inner end of its stem to engage into an orifice 32a of the connector portion 32 of the catheter termination. The side-connector 35 may be used for the withdrawal of blood samples from the patient, or the introduction of fluid or medication into the patient's blood vessel.

Figures 11 and 12 show a cannula introducing device similar to the device of Figures 1 to 3, like parts being denoted by like reference numerals, but differing therefrom in the following respects. Firstly, the plunger or needle guard 16 is mounted to the forward end of an elongate member 20 which is engaged by the wheel 18, so that when the wheel 18 is rotated in the manner previously described, the elongate member or driver 20 is advanced longitudinally of itself to advance the needle guard 16: this modification is also applicable to the devices of Figures 4 to 8. Secondly, the blood collecting chamber 14 is arranged for displacement longitudinally of the body 10 of the device and the needle 12 is mounted to the forward end of the chamber 14: the wheel 18 is coupled to a smaller, inner wheel 18a which is coupled to the chamber 14 for retracting the latter, hi use of this device, the assembly shown in Figure 11 is brought up to the patient to insert the tip of the needle 12 into a blood vessel, as described above for the device of Figures 1 to 3 : when the user sees blood entering the chamber 14, he engages the projecting rim of the wheel 18 with his index finger and, by repeated retractions of this finger, turns the wheel 18 to advance the driver member 20 and hence the needle guard 16; the needle guard 16 thus pushes the cannula 22 forwardly along the needle 12, for the tip of the cannula 22 to pass over the tip of the needle 12 and enter the blood vessel. As the user further rotates the wheel 18, this rotates the inner wheel 18a to retract the blood collecting chamber 14 and withdraw the needle 12 from the blood vessel, leaving the cannula with its tip firmly positioned within the blood vessel: this further rotation of the wheel 18 may produce further advancement of the needle guard 16 as the needle 12 is withdrawn, in which case the user also moves the body 10 of the device rearwardly to compensate. Figure 12 shows the final condition of the device, in which the tip of the needle 12 is covered by the needle guard 16 to protect against needle stick injuries. A particular advantage of this device is that the displacement which may be made of the wheel 18, for the plunger to be advanced the same distance relative to the needle, is halved relative to the device of Figures 1 to 3.

Figure 13 shows a modification of the device of Figures 11 and 12, in which an endless band 41 is trained around the inner wheel 18a and also around a wheel 19 disposed rearwardly of the wheel assembly 18,18a, with the blood collecting chamber 14 mounted to the upper run of the band 41. When the rotation of the wheel 18 is transmitted to the inner wheel 18a as described above, this drives the belt 41 to retract the chamber 14 and the needle 12. Figure 14 shows a further modification, for reducing the thickness of the body 10 of the device: in this modification, the driver member 20 for the needle guard 16 is mounted to the lower run of the band 41, rotation of the wheel 18 causing advancement of the driver member 20 and needle guard 16 via the band 41; the chamber 14 is coupled to the band 41 preferably in such a manner that the retraction of the chamber 14 and needle 12 does not commence until after the needle guard 16 has been advanced sufficiently for the tip of the cannula to enter the patient's blood vessel.

It will be appreciated that the devices which have been described are of simple construction yet easy and reliable to use and, furthermore, enable cannula, catheters or guide wires of relatively long length to be inserted into a blood vessel in a simple and effective manner.

Claims

1) A cannula introducing device which comprises a body, a needle proj ecting from a front end of said body, a wheel mounted in or to said body and having a rim engageable by the user to turn said wheel, and a plunger at the front end of said body and arranged to be advanced upon rotation of said wheel.

2) A device as claimed in claim 1 , in which said wheel comprises a reel around which an elongate flexible element is wound, said elongate flexible element having a free end coupled to said plunger, rotation of said reel serving to unwind said elongate flexible element to advance said plunger.

3) A device as claimed in claim 1 , in which said plunger is mounted to a forward end of an elongate driver member, said wheel being coupled to said elongate driver member to displace said member longitudinally of itself to advance said plunger.

4) A device as claimed in any preceding claim, in which said wheel is arranged for rotation, to advance said plunger, by the user engaging a portion of its rim to displace that portion in a direction away from the front end of said body and towards an opposite, rear end of said body.

5) A device as claimed in any preceding claim, further comprising a blood collecting chamber for collecting blood received through said needle.

6) A device as claimed in claim 5, in which said needle is mounted to said blood collecting chamber, and said blood collecting chamber and needle are arranged for displacing rearwardly, relative to said body, upon continuing rotation of said wheel, after at least partial advancement of said plunger.

7) A device as claimed in claim 6, in which said wheel has a secondary wheel coupled thereto, and said blood collecting chamber is coupled to said secondary wheel for displacement thereby.

8) A device as claimed in claim 7, further comprising an endless band trained around said secondary wheel and around a further wheel, said blood collecting chamber being coupled to one run of said band.

9) A device as claimed in claim 8, in which an elongate driver member for said plunger is coupled to a second run of said band.

10) A device as claimed in any preceding claim, in which said plunger forms a protective cover or guard for the tip of said needle, when said needle is in a fully-advanced position relative to said body.

11) A cannula introducing device which comprises a body, a needle proj ecting from a front end of said body, a plunger at the front end of said body, operating means engageable by a user for advancing said plunger, and a blood collecting chamber to which said needle is mounted, said blood collecting chamber and needle being arranged for displacement rearwardly, relative to said body, upon continuing operation of said operating means, after at least partial advancement of said plunger.

12) A device as claimed in claim 11, in which said operating means comprises a wheel mounted in or to said body and having a rim engageable by the user to turn said wheel for advancing said plunger and for displacing said blood collecting chamber and needle.

13) A device as claimed in claim 12, in which said wheel has a secondary wheel coupled thereto, and said blood collecting chamber is coupled to said secondary wheel for displacement thereby.

14) A device as claimed in claim 13, further comprising an endless band trained around said secondary wheel and around a further wheel, said blood collecting chamber being coupled to one run of said band extending between said secondary and further wheels. 15) A device as claimed in claim 14, in which an elongate driver member for said plunger is coupled to a second run of said band.

16) A device as claimed in any one of claims 11 to 15, in which said plunger forms a protective cover or guard for the tip of said needle, when said plunger is in a fully advanced position relative to said body.

17) A catheter or guide wire introducing device which comprises a body having a needle projecting from a front end thereof, a reel mounted in or to said body, and a catheter or a guide wire wound around said reel and having a free end thereof engaged into the rear of said needle, said reel having a rim engageable by the user to turn said reel and unwind said catheter or guide wire and advance said catheter or guide wire through said needle.

18) A device as claimed in claim 17, in which the catheter is provided with an enlarged termination which is removably engaged with said reel, said needle is longitudinally split and said body comprises two parts which can be opened to allow the catheter to be removed from the needle once it has been fully unwound from said reel and its said termination disengaged from said reel.

19) A device as claimed in claim 18, further comprising a plunger arranged to be displaced along said needle.

20) A device as claimed in claim 19, further comprising an operating element which is displaceable in a direction away from the front end of said body, and towards an opposite, rear end of said body, for moving said plunger forwardly.

21) A device as claimed in claim 17, in which the rear end of said catheter is provided with a flexible termination which is able to pass through said needle, after the catheter has been fully unwound form said reel, and upon the device being itself retracted.

22) A device as claimed in any one of claims 17 to 21, in combination with a cannula having an enlarged rear end into which said termination is arranged to engage. 23) A device as claimed in claim 22, in which said cannula is provided with a connector having a stem inserted into an orifice in the side of the cannula and arranged to be displaced radially inwards, when said termination is engaged into the rear end of the cannula, to engage into an orifice in the side of a connector portion of said termination.