Patent Application
20180078715
The present invention relates to the detachment of fluid-transferring devices and connections from a corresponding hub, and especially when transferring fluid in a medical setting. The invention may find particular use in detaching a fluid transfer device such as a syringe, or other fluid transfer connection, from a hub that is connected to a living subject to/from whom fluid is being transferred.
In a medical setting it may be necessary or desirable to transfer fluid to/from a subject for a variety of reasons. For example, a hub connected to a needle or other cannula may be used to draw blood from a vein or to infuse fluid substances i.e. intravenous (IV) therapy. A drip is one type of IV therapy. IV therapy may be used to correct electrolyte imbalances, to deliver medications or nutrition, for blood transfusion or as fluid replacement to correct dehydration. IV therapy can also be used for chemotherapy of cancer patients. Fluid-transferring devices such as syringes may also be attached to a hub that connects a cannula for the addition or removal of fluid to/from a variety of bodily cavities, organs or vessels. For instance, the hub may be part of an entity providing a catheter to drain urine from the bladder or kidney, to remove fluid from an abscess, to extract liquid from joints or cysts, or to administer breathing gases through a tracheal tube. A typical endotracheal tube includes a cuff inflation tube with a hub for attachment of a syringe to enable inflation to seal the trachea and bronchial tree against air leakage and aspiration of fluids. A tracheostomy tube or urinary tract catheter might also use a cuff system with a hub for connection of a syringe or other device to inject fluid to inflate a cup or balloon that holds it in place. However fluid injections using a syringe connected to a needle are one of the most common health care procedures in the world.
When transferring fluids to/from a subject, the hub with its needle, catheter or other cannula inserted in the patient is often left in-situ while the fluid-transferring device may be removed and replaced, e.g. to empty/re-fill a syringe or to change over the IV therapy. Where two medical devices that carry small fluid volumes must be connected, a standard Luer fitting is the most common means of achieving a leak-free junction. One type of Luer fitting, commonly called a “Luer lock/lok”, uses an internally threaded collar surrounding a “Luer slip” friction fit (see below) tapered male tip of a syringe or the like. The projecting tip can be inserted into a corresponding female hub with an external thread, or other suitable protrusion for cooperating with the collar, and the collar screwed down on the hub to lock the connection. Such Luer lock fittings have the advantage of providing a secure connection that can not easily come loose, but two hands are needed to hold the hub while screwing the device in/out. A more rapid form of attachment may be preferred in some circumstances, for example in an emergency situation. Another type of Luer fitting, commonly called a “Luer slip”, simply uses a friction fit between a female hub and corresponding tapered male tip of a device without a threaded collar. A standard friction fit may be achieved by a 6% taper. A Luer slip attachment is common for infusing less viscous fluids, such as vaccinations, and transferring fluids where high pressures are not involved, for example when drawing blood.
A problem observed with both Luer lock and Luer slip connections is the risk of injury when detaching the fluid-transferring device from a hub on a cannula that is still connected to a patient. While a medical practitioner might take care to hold the hub and avoid injury when unscrewing a Luer lock connection, there is a temptation with a Luer slip connection to try to pull the device from the hub e.g. with one hand. However this can easily result in the hub being tugged away from the body and causing tissue damage. Often the device may not be pulled in a straight line with the cannula connected to the hub, but rotated, and this can twist the components. The tape used to hold the hub e.g. IV port in position is often loosened from the skin and its cannula e.g. needle may even be accidentally extracted. When emptying fluid from a body cavity, for example, keeping the needle hub still when detaching the syringe can be essential to avoid diffuse cutting inside the cavity or damage of the cavity wall. In addition there is a risk of unacknowledged contamination of both the hub and the Luer tip (not only the user) when holding the very small hub with the thumb and index fingers while pulling away the male tip, the tip sliding past the user's fingers as it is released.
Moreover tugging with a single hand does not usually apply enough force even to pull the device out of a friction fitting (such as a Luer slip) and, depending on the force used when connecting the Luer slip tip to the hub, the practitioner usually needs to hold or push the hub while also pulling the device so that it becomes detached. Typically the device will be rotated simultaneously while pulling away from the hub. This jerking can result in unwanted extraction of the needle or other component connected to the hub. The connection will often be pressurised by fluid. For example, a cuff connected to a tracheostomy tube, endotracheal tube or urinary catheter often has a tight connection of the male Luer tip with two-handed operation being required to loosen the connection while the sprung piston in the female Luer hub blocks the outflow of fluid (air or liquid) from the cuff.
Several medical procedures involve targeted introduction of an empty syringe connected to a cannula or other catheter. Such procedures require careful insertion of the cannula or catheter and also careful removal of the syringe if the catheter or cannula is left in situ. The process typically involves applying negative pressure in the syringe by pulling the plunger/piston back during the inward insertion movement of the cannula or catheter towards a target inside the patient. The objective is to verify that the correct target has been reached by drawing a body liquid, e.g. blood, cerebrospinal fluid, synovial fluid from joints, bile or urine into the syringe barrel where it can be observed. When the appropriate liquid is seen in the barrel, the user can be sure that the cannula or catheter tip is in the correct position. Some procedures involve the use of additional guiding tools, e.g. ultrasound guided cannula insertion. During such procedures the user must hold onto the ultrasound probe in addition to the syringe, and monitor the position of the cannula or catheter on a screen. After reaching the target with the tip, the operator typically needs to detach the syringe and its fluid transfer tip from the cannula or catheter hub. Using conventional methods this can inadvertently cause the cannula or catheter tip to dislocate from its intended targeted original position as two handed operation is required to remove the hub. Furthermore during such ultrasound-guided techniques for catheter tip placement, the ultrasound probe is typically put aside/inactivated before the disconnection and therefore the user loses the ability to accurately monitor the position of the cannula or catheter tip inside the body.
Ease of disconnection can be a problem not only when detaching a device from a hub connected to a patient but also when it is desired to fill/empty a device such as a syringe via a fluid hub in a quick and convenient manner. For example, when filling a syringe using a needle inserted in a vial, each time that the syringe is removed it requires two hands to firmly grasp the needle hub and the syringe to separate them while the needle remains in the vial. As mentioned above, there is again a risk of contamination as the user grasps the hub and the tip comes into contact with the fingers holding the hub.
Another situation where a user might come into contact with a needle hub is when using a blood collection tube. The blood tubes are evacuated plastic or glass containers sealed with an elastomeric septum that is piercable by a double-ended needle to draw venous blood. Due to the piercing force and pressure differential, a secure connection to the needle assembly is required and therefore a threaded Luer lock connection is normally used rather than a Luer slip. U.S. Pat. No. 5,201,716 proposes an alternative blood specimen collection system that does not require the needle assembly to be grasped and twisted during disconnection. In this system a needle assembly is mounted with an interference fit rather than a threaded connection. A pivotally mounted lever assembly is spring-biased to hold the needle assembly in position, i.e. to provide an additional level of security over the friction fit. If the lever is actuated against its spring bias then there is only an interference fit holding the needle assembly in place. The lever can be pivoted to simultaneously release the spring bias and to apply a forward ejection force to the needle assembly.
In any situation where one hand is holding a needle hub while pulling a device away there is a risk of needlestick injury and contamination. Needle caps frequently being mislaid or forgotten can exacerbate this. This also applies when separating a needle or other contaminated component from a syringe or similar device for disposal purposes, with many needlestick injuries occurring when trying to remove sharps to throw into a bin. Usually the person handling a syringe will try to cover a contaminated needle with a cap after use, before grasping the hub to separate the needle from the syringe barrel for disposal. However, when mounting a needle cap onto the contaminated needle a person will use the large muscle groups in the arms and shoulders that work less precisely and, combined with poor depth of vision, this often results in a needlestick injury to the fingers holding the needle cap. It would be better if a needle hub could be safely released without needing to cap the needle or handle the connection.
There are various fluid transfer procedures in the medical setting that may require a very secure connection between a fluid transfer tip (e.g. provided by a syringe) and a corresponding hub. The hub may be connected to a needle or catheter inserted into an artery, vein, cavity or organ of a patient. In the field of cardiology, angiography and angioplasty, procedures may inject fluids (liquid and/or air) into narrow channels at high pressure. Manual syringes and manifold sets are used for percutaneous coronary interventions and coronary diagnostic procedures such as angiography. A cardiac angiographic kit typically comprises a catheter hub for connection, a catheter body of chosen size, length and stiffness, and a tip with a single end-hole to eject fluids. The catheter body is inserted into the coronary vessels, ventricles and/or peripheral vasculature. A syringe may be connected to the catheter hub to inject contrast agents or saline at pressures ranging between 250 and 800 psi, and even up to 1000 or 1200 psi (84 bar). The catheter hub has an external thread to provide a standard Luer lock connection.
Luer lock connectors have become universal, not only for joining syringes to hubs, but also for connecting small-bore medical tubing and hoses for liquids and/or gases. Luer lock connections are commonly used for vascular IV lines but also find use in other medical treatment or diagnostic systems. Tubing and hoses may use a Luer lock connection for cuff inflation systems, feeding tubes, catheters, and hoses for vascular, enteral, respiratory, neuraxial and urethral/urinary systems.
The screw connection of a Luer lock hub is often considered necessary to withstand high pressures. However a syringe, hose or other fluid transfer device must be rotated to connect, and disconnect, its Luer lock collar to/from the hub. This can take time and requires a two-handed operation. Furthermore, when a user grips the hub to unscrew the connection there is a risk of contamination, especially where the hub includes a needle that may carry blood on its shaft. It would improve the efficiency and workflow of medical procedures if a fluid transfer device could be disconnected from a Luer lock hub more easily.
There are various devices known in the art to assist in the removal of a Luer slip hub from a fluid transfer device. Many of these devices utilise a lever member capable of pushing the hub away from the tip of the fluid transfer device. In such embodiments the positioning of the lever member on the fluid transfer device can lead to accidental release of the hub, as the lever typically requires a small amount of force to be applied to it in order to remove the hub. This accidental release could be dangerous in instances where a needle is attached to the hub as this could result in a needlestick injury.
Arrangements for removing a Luer slip hub may also be used to remove a Luer-lock hub from a fluid transfer device. Some examples of this are taught in WO 2014/020090. These fluid transfer devices typically include a threaded collar attached to a lever member. Such a lever member is capable of moving the threaded collar away from the Luer-lock hub allowing it to be released. However The Applicant has now appreciated the potential for improvement of the arrangements taught in the above-mentioned application. In particular it has been recognised that in some circumstances there might be a tendency with such devices when screwing the Luer-lock hub to the device for the lever member to pull forward and away from the fluid transfer tip. This could cause the threaded collar to move away from the fluid transfer tip and so result in a poor connection between the hub and transfer tip which could lead to the loss of fluid during use of the fluid transfer device.
Even in disconnection arrangements for removing hub where a threaded collar is not involved, for example a Luer slip hub, there may be other reasons for maintaining the front portion of the disconnecting member in a fully pulled back position until a user is ready to disconnect the hub. For example, in a fluid transfer device as seen in WO 2013/164358 a catch may be arranged to hold the hub after it has been released from its friction fitting, and controlling the range of movement of the disconnecting member may help to ensure proper functioning of such a catch.
The present invention seeks to address or mitigate at least some of the problems mentioned above.
When viewed from a first aspect the present invention provides a fluid transfer device comprising:
a body member;
a fluid transfer tip, the fluid transfer tip comprising a tapered friction fitting for a corresponding hub;
a disconnecting member having a front portion and a rear portion; and
engagement features operating between the disconnecting member and the body member which engage with one another to inhibit the front portion of the disconnecting member from moving relative to the fluid transfer tip;
the device being arranged such that upon application of a force to the rear portion of the disconnecting member, the disconnecting member deforms so that the engagement features are no longer in engagement with one another, thereby allowing the front portion of the disconnecting member to move relative to the fluid transfer tip and subsequently release the hub from the friction fitting.
Thus it will be seen by those skilled in the art that a fluid transfer device provides a novel mechanism for reducing the risk of accidental release of the hub from the fluid transfer tip. The engagement features ensure that the hub is only removed when a sufficient force is applied to the rear portion of the disconnecting member. The engagement features help to reduce the risk that if a user should inadvertently apply pressure to the disconnecting member, this will accidentally release the hub. Only purposeful operation can act to disconnect the hub. As the disconnecting member is “locked” in an engaged position until a user applies sufficient force to deform the disconnecting member and disengage the engagement features, this can prevent the disconnecting member from moving inadvertently during transport.
It will be appreciated that the disconnecting member is preferably mounted to the body member so as to allow movement of its front portion relative to the fluid transfer tip. Any suitable mounting arrangement may be provided between the body member and the disconnecting member. This is described further below.
In a set of embodiments the disconnecting member is provided by i.e. comprises a lever member. An advantage of using a lever member to disconnect the tip from a corresponding hub is that it can amplify an input force to provide a greater output force, i.e. providing leverage to push a hub away from the tip. In a set of embodiments the lever member is pivotally mounted relative to the fluid transfer tip. The mechanical advantage of a lever member can increase the force applied so that the device can be released without necessarily holding the hub, thereby enabling single-handed operation. This carries several advantages—for example the ability to maintain sterility during procedures. In the case of cannula or catheter insertion procedures, such as those previously described, it advantageously allows a user easily to detach the hub when the cannula or catheter tip is correctly positioned without disturbing its position. In ultrasound-guided procedures it also allows the entire procedure up to and including detachment of the hub to be conducted without looking away from the ultrasound monitor or needing to let go of the ultrasound probe.
The lever member may comprise an output part consisting of the front portion and an input part consisting of the rear portion. The front portion may generally extend in a plane at an angle of about 90 degrees to the rear portion, i.e. a L-shaped lever. As is described in more detail below, the front portion and the rear portion may be integrally formed in a three-dimensional shape, for example integrally moulded from a plastics material. The rear portion may be partly cylindrical in shape, extending at least partly around an axis that is parallel to the fluid transfer tip and substantially perpendicular to the plane of the front portion.
Advantageously the disconnecting member is designed such that any potential user can apply an appropriate force to overcome the engagement features. The disconnecting member could be formed integrally with the body member—e.g. using a living hinge. In another set of embodiments the disconnecting member is a separate part from the body member.
Any suitable form of engagement features may be used. For example complementary mutually engaging coarse surfaces could be provided on the disconnecting member and body member. In a set of embodiments however the engagement features comprise at least one protrusion and at least one complementary recess. Protrusions and recesses are considered advantageous as they may provide a positive indication to the user when they are in a locked position. For example when a user applies a force to the disconnecting member it will be evident if the features are locked together as the disconnecting member will not be moved when a smaller force is applied.
The protrusion may, for example, be located on the body member of the fluid transfer device or on an adapter fitted thereto. The recess may be located on the disconnecting member. However it will be appreciated that the arrangement of engagement features could be the other way around or indeed any combination thereof could be provided—e.g. with some protrusions on one part and other protrusions on the other part. It will be appreciated that there may be any number of engagement features depending on the application of the device. For example the device may be provided with more engagement features to increase the force necessary to move the connecting member.
In a set of embodiments the engagement features are designed such that there is a smooth transition from engagement to non-engagement. This may be achieved through chamfered or rounded edges on the engagement features. Such a smooth transition may be advantageous in some circumstances to prevent an excessive force being applied to the hub.
In a set of embodiments the engagement features are visible to the user. Such embodiments may be advantageous in ensuring the user is aware of the state of the disconnecting e.g. lever member when connecting a hub to the fluid transfer device. The disconnecting member may be clear or translucent thus enabling the user to see through the surface of the disconnecting member to determine whether the engagement features are in engagement with one another. Alternatively the engagement features may extend through an external surface of the disconnecting member. For example a protrusion on the body member having a non-circular cross-section could extend through a corresponding aperture on the disconnecting member enabling it to be seen by the user.
In a set of embodiments in which the disconnecting member comprises a lever member, the engagement parts are positioned behind a point at which the lever member pivots. Where the lever member is pivotally connected at two or more points, a pivot axis may be defined between those points and the engagement points may therefore be positioned behind the pivot axis relative to the front portion. This ensures that the force applied to the lever initially goes towards deforming the lever member and separating the engagement features instead of causing the lever member to become detached from its pivot points.
In accordance with the invention the hub may be retained on the tip purely by the friction fitting. The fluid transfer device may therefore be used to disconnect a Luer slip hub. In a set of embodiments however the disconnecting member comprises locking means for holding the hub. This may help the hub to be held onto the fluid transfer tip more securely. In such embodiments the engagement features are particularly advantageous as they can ensure a tight locking connection with the hub.
In a set of embodiments the locking means is provided by a latch or other positive connection. For example, a suitable positive connection may be achieved by engaging a pair of male/female parts. This ensures that there is a strong positive connection with the hub and only allows removal of the hub when the lever member is depressed. Some non-limiting examples of a latch may include a single protrusion, a series of protrusions or a saw-tooth profile.
In a further set of embodiments the locking means comprises a screw thread provided on a lever member providing the disconnecting member. This provides a mechanism for locking a suitably configured hub, e.g. a standard Luer lock hub, onto the device. The hub may be connected by relative rotation between it and the body member, as is conventional, to ensure a tight screw connection. Such a Luer lock connection may be suited to high pressure fluid transfer procedures.
In such arrangements the lever member may be arranged such that movement of the front portion of the lever member relative to the body member causes the screw thread to pivot away and release the screw fit so that a hub can be disconnected from the device without an unscrewing action. The usual two-handed operation of unscrewing can thus be replaced by a simple one-handed operation of the lever member.
It is not essential that the hub also carries a screw thread. For example if the screw thread on the lever member does not extend all the way around the hub, the hub may be engaged though a simple annular flange, such as is found on a standard Luer slip hub, with the screw thread engaging the flange to provide a positive connection in addition to the friction fitting. Other hub designs may also be positively engaged by the screw thread, as is explained further below.
The Applicant has appreciated that locking the lever member in position, by means of the engagement features, is also beneficial when using threaded or flanged hubs with a threaded collar on the lever member. When screwing a screw threaded hub or hub with a flange onto a device without the lever member locked in position, there may be a tendency for the lever member to be pulled forward, due to the threaded hub pulling on the collar, in such a way that the collar might slip off the thread or flange. In this case when screwing the hub in further it would not be possible to obtain a desirably tight connection between the hub and male connector tip. With the engagement features of the present invention this problem may be overcome. The engagement features may prevent the lever member from moving in reaction to the pulling force referred to above. Consequently as the hub is screwed onto the collar the lever member is kept in an engaged position, with the threaded collar held close to the male connector tip, and a tight fit can be made with the male connector tip. Furthermore, when the disconnecting member is in the locked position, and the engagement features are in engagement with one another, a pulling force provided by the collar as the hub is screwed in to the collar, pulls the sidewalls of the disconnecting member inwards and further tightens the engagement of the engagement features thus preventing the disconnecting member from moving.
The screw thread mounted on the lever member can be considered a kind of latch, as pivoting the lever member releases the latch so that the screw thread is separated from a corresponding thread on an outer surface of the connected hub. This leaves the hub connected by the friction fitting alone. Simply releasing the screw fit is not enough to disconnect the hub from the fluid transfer tip; the hub cannot fall away from the tip under gravity due to the friction fitting. The lever member of preferred embodiments of the invention has the additional function of also releasing the hub from the friction fitting. This may be achieved in a single smooth action by the lever member, for example a front surface of the front portion, moving relative to the fluid transfer tip to push away the hub and release the friction fitting. In a preferred set of embodiments the lever member is pivotally connected to the body member of the device with one end, such as a front surface, moveable between first and second positions relative to the fluid transfer tip. Such a pivotal connection may apply more generally to other forms of disconnecting member.
As is mentioned above, a hub may be connected to the fluid transfer device by pushing and rotating the hub, thus engaging the thread on the hub with the threaded collar or other screw thread provided on the lever member. For example, a standard Luer lock hub may be rotated by up to 270° to ensure connection of its outer screw thread with the screw thread mounted on the lever member. During this process the lever member may remain locked in its engaged position while the hub is being connected. However, the Applicant has recognised that the time and/or manual dexterity required to rotate a hub to form the screw fit may not always be desirable. In accordance with embodiments of the invention however, an over-threshold force can be applied to the rear portion of the lever member to pivot the screw thread or other locking means provided on the front portion of the lever member away from the tip. A hub can then be pushed onto the male connector tip. A final, short rotation of the hub may then allow the screw thread to engage. This may provide an improvement over standard Luer lock connections as it may only require a turn through 90° (or less), rather than 180° or 270°, to complete the screw fit connection.
In a set of embodiments the screw thread on the lever member is only partial. For example the screw thread may be an internal thread carried by a partial or hemi-cylindrical collar. As such a collar only extends around one side of the fluid transfer tip, e.g. up to 180° around the circumference of the fluid transfer tip, the screw fit may be released simply by pivoting the lever member to move the collar away from the fluid transfer tip and hub connected thereto.
More generally, it is preferable that the screw thread provided on the lever member takes the form of an internally threaded collar. Such a collar may be provided on the lever member to at least partially surround the fluid transfer tip. In order to ensure a secure Luer lock connection, the internally threaded collar may extend substantially 360° around the circumference of the fluid transfer tip. However a 360° collar can make it more difficult for the lever member to operate to release the screw fit, as the collar must be moved away from the fluid transfer tip on all sides. The internally threaded collar may be separable into multiple segments that are arranged to be moved apart by pivoting the lever member to disengage the engagement features and thereby release the screw fit with the hub.
Such a fluid transfer connection benefits from the screw fit of a standard Luer lock connection, which is trusted to withstand pressurised fluid transfer procedures, and the quality of the connection is ensured as the lever member is locked in position by the engagement features. The connection also enables the Luer lock connection to be released by operating the lever member instead of unscrewing the tip from a corresponding hub. This can be a simple one-handed gesture rather than a two-handed twisting movement. The separable collar allows the lever-operated disconnection mechanism to cooperate with a standard Luer lock hub.
In a set of embodiments the locking means is carried by a collar provided on the disconnecting member such that the hub can be mounted to the tip by initially applying a force to the disconnecting member to disengage the engagement features and move the collar away from the tip, and when the hub has been pushed onto the friction tip, the disconnecting member can be returned to a position whereby the locking means on the collar engages with the hub. Such an embodiment is advantageous as it allows the user to easily mount the hub on the device without having to overcome the locking means when attaching the hub. This is particularly advantageous when the locking means is provided by a latch which might require significant force to push the hub past the latch.
A potential problem with pushing a hub away from a tip is that it may be forcibly disconnected. If the hub is carrying a needle or other sharp object then this could pose an injury risk. In a set of embodiments therefore the device further comprises a catch means arranged to catch the hub after it has been released from the friction fitting. Further movement of the disconnecting member (e.g. against a resilient bias) may cause the catch means to catch the hub. In this way the hub may be caught as it becomes disconnected but then controllably separated from the device. The engagement features can ensure that the disconnecting member always starts from its engaged position and the front portion is then moveable through its full range of movement when a user applies a force to the rear portion, which helps to ensure that the hub is fully released from the friction fitting before the catch means comes into contact with the hub.
The catch means may be subsequently released by resiliently biased movement of the disconnecting member, e.g. back to its resting state, with the front portion pulled back along the fluid transfer tip. Preferably the catch means is automatically released by such resiliently biased movement of the disconnecting member. Once the catch means is released the hub may be free to fall away from the tip under gravity rather than under a force applied by movement of the disconnecting member. This can provide much better control of the hub as it is separated from the device, avoiding the risk of forced ejection of the hub. For example, a user can decide when to allow release of the catch means after moving the device away from a medical procedure and positioning the hub to drop into a waste bin. This is especially important when disposing of a needle hub in a sharps bin. A single-handed user operation can have the effect of loosening the friction fit, catching the hub, and then subsequently releasing the hub for it to gently fall away from the device. For example, a user may only need to squeeze a resiliently-biased lever member and then let go.
The catch means is preferably arranged to move relative to the fluid transfer tip so as to catch the hub as it is pushed towards a distal end of the fluid transfer tip by movement of the front portion of the disconnecting member. Preferably the catch means is arranged to automatically come into contact with the hub after its release from the friction fitting. The catch means may comprise any member that engages against the hub to hold it back e.g. using mechanical interlocking, friction, adhesion, etc. For example, the catch means may comprise at least one grabbing member e.g. one or more finger(s) extending towards the distal end of the fluid transfer tip. In other examples, the catch means may comprise at least one gripping pad or adhesive surface e.g. arranged to retain the hub after it has been released from the friction fitting. The catch means may simply engage against a surface of the hub, for example where the hub is an IV port and a syringe of saline solution is connected to the hub. Where the hub is provided with a rim, for example a needle hub, then this can aid the catch mechanism e.g. the catch means may be shaped to engage over the rim.
In one set of embodiments the catch means may be independent of the disconnecting member, for example provided by the fluid chamber and/or fluid transfer tip. However it is desirable that the catch means does not interfere with movement of the disconnecting member. In another set of embodiments the catch means is preferably provided by, e.g. carried by, the disconnecting member. This may make it easier to ensure that the catch means only operates once the front portion of the disconnecting member is moving or has moved relative to the fluid transfer tip to release the hub from the friction fitting. For example, the catch means may comprise at least one grabbing member or latch finger extending from the disconnecting member towards the distal end of the fluid transfer tip. In embodiments where the disconnecting member comprises a lever member, pivotal movement of the the lever member may cause the catch means to swing into contact with the hub only after the front portion has acted to release the hub from the friction fitting. In embodiments where the disconnecting member comprises a screw thread, the catch means may be arranged opposite the screw thread.
In a set of embodiments the disconnecting member is moveable between two positions: a first position wherein the front portion proximal to the fluid transfer tip e.g. male connector tip is close to the base of the tip and a second position wherein the front portion moves towards a distal end of the fluid transfer tip e.g. male connector tip. In a further set of embodiments the disconnecting member is resiliently biased such that it returns to its first position when no force is applied to the disconnecting member, in particular when no force is applied to the rear portion of the disconnecting member. In other words, the disconnecting member is biased into the first position by a resilient bias. This may be advantageous as it means that the device may always be in a state whereby a hub can be attached. In embodiments involving a catch means, preferably the catch means is arranged to be automatically released by the disconnecting member moving from the second position back to the first position under the resilient bias. In a further set of embodiments the resilient bias is provided by the disconnecting member itself. This is advantageous as the lever member can be designed such that the deformation of the lever member, required to separate the engagement parts, acts to resiliently bias the disconnecting member back to its first, locked, positioned. In a set of embodiments the disconnecting member is made from an elastically deformable material. In a preferred set of embodiments the disconnecting member is made from plastic which can provide an inexpensive, sterile and disposable product for single use in a medical setting. Moulding the disconnecting member from a plastics material may also facilitate integration of the engagement features with the resilient bias.
While the disconnecting member may take many different forms, preferably the disconnecting member comprises a front surface that is substantially transverse to the axis of the tip and the front surface is arranged to move along the tip from a first position to a second position when a force to disengage the engagement features is applied to the disconnecting member. In order for the disconnecting member to transfer force efficiently, it is preferable for it to be relatively stiff. The disconnecting member may be stiffened by forming it as a three-dimensional shell—i.e. with a shape that extends significantly in all three dimensions.
In a set of embodiments the disconnecting member comprises a front surface that is substantially transverse to the axis of the tip and one or more side surfaces that extend in a direction substantially parallel to the axis of the tip. The front surface may be provided by the front portion and the one or more side surfaces may be provided by the rear portion. The side surfaces may form a shroud extending at least partly around an axis defined by the tip—e.g. by at least 90 degrees. The shroud preferably extends back from the front surface, away from the fluid transfer tip. The three-dimensional extent of the member can help to ensure that it is stiff even if formed of a plastics material yet is still deformable to allow the engagement features to separate. In such embodiments, when a force is applied to the disconnecting member, i.e. to the rear portion of the disconnecting member, it causes the side surfaces of the disconnecting member to expand, thus disengaging the engagement features and allowing the disconnecting member to move relative to the body member.
In a further set of embodiments separate resilient means are provided between the disconnecting member and the body member. This may be in the form of a spring or any piece of elastically deformable material. For example, the resilient bias may be provided by a spring member arranged so as to push the front portion of the disconnecting member into the first position in the absence of a force being applied to the the rear portion. Such a spring member may be integrated with the disconnecting member or mounted between the disconnecting member and the body member. This may be advantageous in embodiments where the disconnecting member comprises a screw thread for holding the hub, to ensure that the disconnecting member returns to its original, locked (i.e. first) position to ensure the screw thread connection is secure, irrespective of any resilience of the disconnecting member itself. An advantage of the engagement features preventing movement of the front portion in the absence of a force being applied is that the resilient means, e.g. spring, is only overcome during use of the device. The engagement features effectively lock the disconnecting member in the first position so that the spring is unlikely to experience wear if the device is exposed to minor forces, e.g. during transit. This can prolong the lifetime of the resilient bias so that the device can be reused reliably with multiple hubs.
The body member comprising at least one of the engagement features may be integral with or separate from the fluid transfer tip. In one set of embodiments the body member includes an integral mounting arrangement for the disconnecting member. The mounting arrangement may comprise one or more axles for pivotally mounting the disconnecting member, preferably a disconnecting member in the form of a lever member. In embodiments where the body member is integral with the fluid transfer tip, it may be positioned behind the fluid transfer tip, for example carried by a fluid chamber that is integrated with the tip. The body member and its engagement feature(s) may therefore be positioned behind the front surface of the disconnecting member that moves relative to the fluid transfer tip. Preferably the body member includes a mounting arrangement for the rear portion of the disconnecting member.
In a set of embodiments it is envisaged that at least one of the engagement features may be integrally provided with the mounting arrangement between the body member and the disconnecting member. For example, the body member may comprise one or more axles for pivotally mounting the disconnecting member (e.g. in the form of a lever member) and the axles may be shaped so as to provide an engagement feature. This may reduce the complexity involved in moulding the body member from a plastics material. For instance, the axles or other mounting arrangement may have a protrusion or recess formed in an outer surface thereof so as to provide the body member with an engagement feature.
In one set of embodiments the fluid transfer device comprises a fluid chamber in communication with the fluid transfer tip and the body member is integrated with the fluid chamber. For example, the body member may comprise an axle integrated with the fluid chamber for pivotally mounting a disconnecting member in the form of a lever member. In a set of embodiments one of the engagement features is integrated with the fluid chamber. In such examples, the fluid transfer device may comprise a syringe and the syringe barrel may have an axle moulded on its outer surface to pivotally mount the lever member along with an engagement feature moulded on its outer surface to engage the corresponding feature on the lever member. The fluid chamber, such as the barrel of a syringe, may therefore be designed to mount a disconnecting member so that the device can be supplied with the disconnecting member pre-mounted ready for use.
In another set of embodiments the disconnecting member could even be integrated with the body member, for example as a lever member pivotally mounted by an integral hinge and held in a locked position by means of complementary engagement features on the body member and the lever member respectively. The lever member and body member could, for example, be formed as a single plastics moulding, e.g. with the lever member pivotally mounted by a living hinge or the like.
However, in another set of embodiments it may be desirable to retrofit a disconnecting member to an existing fluid transfer device or connection. For example, it may be desirable to mount a lever member (or other disconnecting member) to a standard syringe or other device/connection—via a suitable body member which may grip the syringe etc—so as to enjoy various of the benefits outlined above but without changing the design of the device/connection. In such embodiments it is preferable that the disconnecting member is mounted by a separate body member, i.e. a body member that is separate from the fluid transfer tip or fluid chamber in communication with the fluid transfer tip. The body member may be attached to a fluid transfer device or connection by any suitable means. So as to avoid interference with the fluid transfer tip, the body member may be attached to the aft end of the tip, or behind the tip, e.g. by an attachment collar which grips the body. In a set of embodiments the body member comprises means for gripping a barrel, hose or other suitable portion of a fluid transfer device. The gripping means, could, for example, comprise one or more elastically compliant fingers made from a high friction material such as synthetic rubber.
When viewed from a second aspect the invention provides a connector for a fluid transfer device comprising a fluid transfer tip comprising a tapered friction fitting for a corresponding hub, the connector providing:
a body member;
a disconnecting member having a front portion and a rear portion; and
engagement features operating between the disconnecting member and the body member which engage with one another to inhibit the front portion of the disconnecting member moving relative to the body member;
the device being arranged such that upon application of a force to the rear portion of the disconnecting member, the disconnecting member deforms so that the engagement features are no longer in engagement with one another, thereby allowing the front portion of the disconnecting member to move relative to the fluid transfer tip and subsequently release the hub from the friction fitting.
It will be understood that such a retrofitting adapter or connector may be attached around the fluid transfer tip or any other part of a fluid transfer connection or device, such as a syringe, in any situation where operation of the disconnecting member e.g. lever member may assist in locking and subsequently disconnecting a hub to/from the tip. The adapter or connector, and in particular the body member, may be attached before or after inserting the tip into a hub. Such an adapter or connector could be optionally attached to a fluid transfer device or connection by a user when it is determined that the friction fitting is too tight to be easily disconnected by pulling the tip away from the hub, or at least not without risking damage or injury. The connector mechanism could also be optionally attached where the fluid transfer device (or connection) is connected to a hub carrying a needle and protection from needle spike is desired.
In embodiments of a connector or adapter according to the second aspect of the invention, the body member may comprise at least one of the engagement features and the disconnecting member may comprise at least another one of the engagement features. As is described above, the engagement features may comprise at least one protrusion and at least one complementary recess. In at least some examples the protrusion is located on the body member and the recess is located on the disconnecting member. The engagement features may be arranged such that there is a smooth transition from engagement to non-engagement. The engagement features can therefore provide a locking function against undesired movement of the disconnecting member, but a smooth response when a user applies a force to operate the disconnecting member.
Any of the features described hereinabove in relation to the disconnecting member and/or body member may equally be applied to embodiments of a connector or adapter according to the second aspect of the invention. Certain of these embodiments will be described further below, but in a non-exclusive way, and additional or alternative embodiments will be apparent from the foregoing description.
It will be appreciated that the disconnecting member is preferably mounted to the body member so as to allow movement of its front portion relative to the body member, which can be used to retrofit the connector to any device comprising a fluid transfer tip. Any suitable mounting arrangement may be provided between the body member and the disconnecting member.
In a set of embodiments the body member comprises an integral mounting arrangement for the disconnecting member. The disconnecting member may be removably mounted to the body member or formed integrally with the body member. In a particular set of embodiments the disconnecting member comprises a lever member and the mounting arrangement comprises one or more axles for pivotally mounting the lever member to the body member.
In a set of embodiments the body member comprises means for gripping a barrel, hose or other suitable portion of a fluid transfer device. The body member, or at least its internal surface, may optionally be shaped to match the external surface of a fluid transfer device. For example, the body member may have a generally cylindrical shape so as to match a typical fluid transfer device in the form of a syringe or blood collection tube holder.
In a set of embodiments the disconnecting member comprises a screw thread arranged for holding the hub on the fluid transfer tip. In such embodiments the connector or adapter is particularly suited to the connection and disconnection of a hub that has a Luer lock fitting. As is described in more detail above, the screw thread may be an internal thread carried by a partial or hemi-cylindrical collar.
In a set of embodiments the disconnecting member comprises a catch means arranged for catching the hub after it has been released from the friction fitting. In such embodiments the connector or adapter is particularly suited to the connection and disconnection of a hub that carries a needle. In embodiments where the disconnecting member comprises a screw thread, preferably the catch means is arranged opposite the screw thread. Optionally the disconnecting member is mounted to the body member so as to be resiliently biased such that the front portion moves back and the catch means is automatically released when the force is removed from the rear portion of the disconnecting member. This means that a single-handed operation of the disconnecting member can release a hub from the friction fitting, catch the hub so that it is not forcibly ejected, and subsequently release the hub to fall away under gravity at a time dictated by the user.
As is mentioned above, the body member may be cylindrical to fit around a typical fluid transfer tip or onto a typical fluid chamber e.g. the barrel of a syringe. In a set of embodiments the disconnecting member comprises a front surface that is substantially transverse to the axis of the body member and one or more side surfaces that extend in a direction substantially parallel to the axis of the body member. The disconnecting member, for example in the form of a lever member, may therefore comprise a three-dimensional shell with a shape that extends significantly in all three directions. This can ensure that the disconnecting member is relatively stiff even if moulded from a plastics material.
In one set of embodiments of either aspect of the invention the disconnecting member is removably mounted to the body member. This means that a user may remove and discard the disconnecting member if it is not required or if it is preferable to operate the device (or connection) without any interference from the disconnecting member.
The fluid transfer device may comprise any type of device used to transfer fluid—liquid and/or gas—either to or from a fluid receptacle. The fluid receptacle may be inanimate or it may be part of a living subject, for example a bodily cavity, organ or vessel, such as a vein or artery. The present invention may find a wide range of uses, for example it could be employed for containers of dangerous or hazardous liquids—e.g. glue—where it is desirable to be able to detach a cap or disconnect a hub whilst avoiding contact with a user's hand. In a preferred set of embodiments however the fluid transfer device is a medical device. The fluid transfer device may comprise one or more devices such as a syringe, pre-filled syringe, IV delivery device e.g. “drip”, transfusion device, fluid pump, stopcock, aspirator, suction device, container for a blood collection tube, or hose. Alternatively the fluid transfer device could comprise a luer lock/luer slip male/female “bridge extension”, which would enable the one-hand use functionality described herein to be added to an existing device. The device may be made to meet the relevant medical standard(s), for example ISO 7886 for sterile hypodermic syringes.
Some embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:
There may be seen in
The tapered tip 6 is inserted into the hub 14 and forms a friction fit that is fluid-tight. In each of the embodiments, a lever member 12 is provided that can be manually operated to move relative to the male tip 6 between a first position, proximal to the syringe barrel 4 and a second position spaced from the first position towards the distal end of the male tip 6 so as to push against the hub 14. Operation of the lever member 12 therefore acts to disconnect the syringe hub 14 from the tip 6 without a user needing to pull or tug the syringe hub 14 to release the friction fit of the Luer slip connection.
In the embodiment of
The lever member 12 comprises a front surface 18 and rearwardly extending surface. The rearwardly extending surface comprises a top surface 20 and side surfaces 22. In the embodiment shown in
There is shown in
The adapter 10 comprises two axle portions 32 integrally moulded at its forward end. These mount the lever member 12 to the adapter 10 so that it can pivot about an axis defined by the axle portions 32. The adapter 10 further comprises protrusions 34 extending from a rear part thereof. The protrusions 34 have chamfered edges 36 which ensure that they pass smoothly into and out of corresponding recesses on the lever member 12 as will be explained hereinbelow.
As seen in
In the embodiments shown the protrusions 34 and recesses 38 are positioned centrally about the axis of the fluid transfer device 2, however it will be appreciated that depending on the application they could be positioned away from the centre axis and further towards the top or the bottom of the adapter 10.
Because the lever member 12 is locked into position unless pressure is applied to the rear portion 20, when the hub 14 is screwed into the threaded collar 24, the collar 24 (which is an integral part of the lever member 12) resists the tendency to be drawn up by the hub 14 which would otherwise give rise to a tendency to slip off the flange 40 (see
The adapter 42 also comprises an integral male connector tip 6′ and the adapter 42 shown in
Also shown is a base plate 52 on the opposite side of the adapter 42 to the axle portions 32′. This has a curved rear portion 54. The base plate 52 is provided to allow the user to grip the adapter 42 securely. This assists both when positioning the female hub 14 on the male tip 6′ and when releasing the hub 14.
Once the hub 14 is fully screwed into position it is in a locked position. It is held in place by the friction fit provided by the male tip 6, and by the screw fit of the threaded collar 24 (i.e. a so-called Luer Lock connection). This locked position can be seen in
When the user has finished using the device and wishes to remove the female hub 14, they simply apply pressure to the top surface 20 of the lever member 12. This process can be seen in
When the user wishes to remove the female hub 14 completely for safe disposal, they can release the applied pressure to the lever member 12. This process is illustrated in
Also visible in
As described above, the hub 14 is typically attached to the device by pushing it onto the tip 6 whilst at the same time screwing it into the threaded collar 24. As an alternative method it is also possible first to depress the lever member rear portion 20, which disengages the protrusions 34 and recesses 38 and causes the lever member to pivot. The threaded collar 24 is pivoted away from the tip 6. The hub 14 can then be pushed onto the tip 6 and the lever member 12 can be released. The resilience of the lever member 12 causes it to return to its original locked position. The threaded collar 24 also returns to engage the flange 40 of the hub. The hub 14 can then be rotated a small amount to screw it into its final position. This method is advantageous as it requires minimal turning of the hub which may be difficult in instances where the hub is attached to a needle, or in instances where the hub is already attached to a living subject.
Also shown in
In the embodiments shown the protrusions and axles are located on the adapter or fluid transfer device. However it is appreciated the both the axles and/or protrusions may be provided on the lever member and corresponding recesses may be provided on the adapter or fluid transfer device. Indeed there are many other possible ways in which engagement features could be provided to inhibit movement between the lever member and adapter.
It will be appreciated that it is not essential for an adapter to be provided—the invention could be implemented using a specially designed fluid transfer device. Moreover it is not essential to use a pivoting lever member—other forms of disconnecting member are contemplated such as a linearly sliding disconnecting member.
Whilst the lever members seen in previous Figures all have a threaded collar mounted on the front surface of the lever member which may lock onto the hub, it will be appreciated that this may not always be the case.
There may be seen in
The tapered tip 6 is inserted into the hub 14 and forms a friction fit that is fluid-tight. As will be appreciated from the description above, the lever member 112 can be manually operated to move relative to the male tip 6 between a first position, proximal to the syringe barrel 4 and a second position spaced from the first position towards the distal end of the male tip 6 so as to push against the hub 14. Operation of the lever member 112 therefore acts to disconnect the syringe hub 14 from the tip 6 without a user needing to pull or tug the syringe hub 14 to release the friction fit of the Luer slip connection.
In the embodiment of
The lever member 112 comprises a front surface 118 and rearwardly extending surface. The rearwardly extending surface comprises a top surface 120 and side surfaces 122. The lever member 112 in this Figure differs from the lever member 12 of
The adapter 10 has the general form of an annular band 28 enabling it to be fitted onto the syringe 2. The band 28 has a smooth inner surface 30. This inner surface 30 could be tapered or stepped to allow the adapter 10 to be fitted on to syringe barrels or other devices which have different diameters. In this embodiment the adapter 10 is held on due to the frictional force between the adapter 10 and the outer surface of the syringe barrel 4.
The adapter 10 comprises two axle portions 32 integrally moulded at its forward end. These mount the lever member 112 to the adapter 10 so that it can pivot about an axis defined by the axle portions 32. The adapter 10 further comprises protrusions 34 extending from a rear part thereof.
As seen in
Also shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 1506050.2 | Apr 2015 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/057943 | 4/11/2016 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14692798 | Apr 2015 | US |
| Child | 15565298 | US |
