EP4355389A1

EP4355389A1 - Safety cannula assembly

Info

Publication number: EP4355389A1
Application number: EP22733600.5A
Authority: EP
Inventors: Viktor HAUPT
Original assignee: Walter Sarstedt Geraete und Verbrauchsmaterial fuer Medizin und Wissenschaft
Current assignee: Walter Sarstedt Geraete und Verbrauchsmaterial fuer Medizin und Wissenschaft
Priority date: 2021-06-16
Filing date: 2022-06-13
Publication date: 2024-04-24
Also published as: DE102021115548A1; BR112023026305A2; WO2022263350A1

Abstract

The invention relates to a safety cannula assembly (1) comprising: a) a cannula (17) for puncturing human or animal tissue, a distal end of said cannula (17) being provided with a tip (18); b) a sliding body (15), the distal end (16) of which is provided with the cannula (17) and the proximal end portion (19) of which is provided with a flexible tube (5), wherein there is a fluidic connection extending through the sliding body (15) between the tip (18) of the cannula (17) and a proximal end of the tube; c) a main body (2) having an interior space (72) in which the sliding body (15) is movably mounted; d) an adjusting element (21) which is located between the main body (2) and the sliding body (15) and by means of which the sliding body (15) can be displaced from a use position, in which the tip (18) of the cannula (17) is located outside the main body (2), to a safety position, in which the tip (18) of the cannula (17) is located inside the main body (2); and e) a trigger mechanism which is located on the main body (2) and by means of which it is possible to trigger the displacement of the sliding body (15) from the use position to the safety position, wherein the trigger mechanism comprises at least one trigger member to which a compressive force can be applied by means of a finger of a person using the safety cannula assembly (1) and which is provided with a locking element (61a, 61b) which can be displaced from a locking position, in which said locking element engages with the sliding body (15) and locks said sliding body in the use position, to a trigger position, in which said locking element is disengaged from the sliding body (15) so that said sliding body moves into the safety position, wherein a distance of the at least one locking element (61a, 61b) from a longitudinal axis of the sliding body (15) can be increased when the locking element (61a, 61b) is displaced from the locking position to the trigger position. In order to make the triggering of the retracting movement of the sliding body (15) safe and ergonomic, according to the invention the at least one trigger member (67a, 67b) and the associated locking element (61a, 61b) are located on different, preferably on opposite, sides of the longitudinal axis (7) of the sliding body (15).

Description

Safety Needle Assembly

description

introduction

The invention relates to a safety cannula arrangement comprising a) a cannula for puncturing human or animal tissue, the cannula having a tip in a distal end section, b) a sliding body which is connected to the cannula in a distal end section and to a flexible tube in a proximal end section is connected, wherein there is a flow connection extending through the sliding body between the tip of the cannula and a proximal end of the tube, c) a base body which is preferably provided on two opposite sides with a grip wing which has an interior space, and in in which the sliding body is movably mounted, d) an adjusting element arranged between the base body and the sliding body, by means of which the sliding body can be shifted from a usage position, in which the tip of the cannula is located outside of the base body, into a secure position, in which the tip is located the cannula inside lb of the base body, and e) a triggering mechanism arranged on the base body, by means of which the displacement of the sliding body from the position of use into the secured position can be triggered, the triggering mechanism having at least one triggering element which can be actuated by means of a finger of a person using the device with a compressive force can be acted upon and which is provided with a locking element which can be displaced from a locking position, in which it is in engagement with the sliding body and locks it in the position of use, into a release position, in which it is out of engagement with the sliding body, so that the latter moves into the securing position, wherein a distance of the at least one locking element from a longitudinal axis of the sliding body can be increased when the locking element is displaced from the locking position into the release position.

For the purposes of the present invention, the term "proximal" is to be understood as meaning an arrangement directed toward the body of the person using the safety needle arrangement (not the person whose tissue is being punctured), whereas "distal" means an arrangement correspondingly directed away from the body. Consequently, a proximal end of an object is located closer to the subject's body than a distal end.

Cannula arrangements within the meaning of this application are generally used to remove a body fluid, in particular blood, from a patient or to supply a fluid to the patient. Safety cannula assemblies are designed to provide the best possible post-use prevention of needle stick injuries while providing maximum comfort to the person using the cannula assembly and preventing pain and trauma to the patient during use of the cannula assembly, including activation of the needle guard. While a passive needle guard retracts the needle automatically after blood collection or infusion is complete, an active needle guard requires conscious interaction by the person using the cannula assembly to activate the needle guard. The present invention relates primarily to active needle guard safety cannula assemblies.

An actuating element within the meaning of the present invention is to be understood as an element that is able, as a kind of "drive", to exert the required force on the sliding body in order to convert it from the position of use into the secured position. Either the “drive element” and the associated “energy store” can be separate from one another. Particularly useful, however, is the combination of these two functions in one component, especially in the form of "spring elements" in which z. B. either mechanical energy is stored (e.g. coil spring or similar) and/or pressure energy, such as in a prestressed gas storage tank.

The base body according to the present invention is a type of housing that is used to accommodate at least part of the sliding body. For this purpose, the base body has an interior space for accommodating the sliding body and in particular the cannula tip in the secured position. In this context, walls of the base body do not have to be completely closed, but can also have the shape of a cage and, in particular, have openings, interruptions, slots or other perforations.

In this application, a “sliding body” should be understood to mean a component which receives the cannula at a distal end and is connected to the hose at a proximal end. A designation such as "cannula holder" or "needle carrier" is also common. State of the art

A needle arrangement is known from EP 3466464 A1, in which the sliding body is provided with a proximal thickening. In the area of this thickening, which is oval in cross section, a largest diameter is larger than a largest diameter of the base body, which is also oval in shape at its proximal end. The base body is also significantly thicker at its proximal end compared to the adjoining section extending in the distal direction. The release mechanism is arranged on the sliding body in the area of these thickenings. By pressing two surface-ribbed buttons diametrically opposite one another with respect to a longitudinal axis of the sliding body, two resilient tongues are moved inwards, as a result of which locking elements which engage in recesses in the thickened area of the base body can be disengaged. After these locking elements have been transferred from the locking position to the release position by radial pressure from the outside, the sliding body and thus also the cannula can move back in the proximal direction. The cannula and in particular its tip is thus shifted into the interior of the base body. A disadvantage of this known cannula arrangement is that the sliding body and thus the cannula must be manipulated, i.e. moved, by the person using the cannula arrangement during or before the retraction movement. As a result, there is a risk that unwanted movements or forces that are unpleasant or painful for the patient will occur in the area of the cannula tip, which is still located within the patient's tissue at this point in time.

A safety cannula arrangement of similar construction is disclosed in EP 3 169387 B1. Again, the proximal ends of the slider and body are thickened. In contrast to EP 3466464 A1 discussed above, the release mechanism in EP 3 169387 B1 is located at the proximal, thickened end of the base body. Corrugated pressure surfaces are in turn located on keys arranged diametrically to one another, which form resilient tongues and are provided with the hook-shaped locking elements at their proximal ends. By radially inward pressure on the keys, the locking elements are also displaced radially inward and thereby disengage from retaining surfaces located radially further outward at the edge of recesses in the thickened end section of the sliding body. A spring element arranged between the sliding body and the base body, when triggered, leads to a retraction movement of the sliding body together with the cannula arranged thereon. It is advantageous in this connection that the manipulation takes place on the (stationary) base body, whereas the retraction movement of the sliding body does not involve the person using the cannula arrangement touching or grasping it can be disturbed. Nevertheless, it is disadvantageous that the proximal end of the sliding body has a very large increase in diameter compared to the remaining part of the sliding body, as a result of which the retraction movement can be impeded by skin contact on the patient and the frictional forces caused thereby. This can also lead to an uncontrolled retraction movement and, as a result, to pain in the patient.

WO 2016/007438 A1 describes a safety pin arrangement in which the triggering mechanism is designed in the form of a tongue that is resiliently mounted in the radial direction. The tongue protrudes with a button or push button section through an adapted recess in the base body and can thus be actuated from the outside with a finger by a person using the safety cannula arrangement. By applying a radially inwardly directed force to the button section, a locking element in the form of a step located on the tongue is disengaged from the wall of the previously described recess in the base body. On the one hand, the tongue dips into an adapted pocket in the sliding body, which means that, in the next step, it is also possible to dip axially into the free inner cross-section of the base body. An adjusting element designed as a helical spring brings about a retraction movement of the sliding body, together with the cannula arranged thereon, in the proximal direction. A disadvantage of this prior art is that the design and manufacture of the slide body with the elongated tongue of the triggering mechanism is complicated. Accidental triggering of the needle guard is possible due to the small trigger that is freely accessible from the outside, although this can already occur due to stresses caused by transport. The force introduced by triggering is not symmetrical and is transferred to the tip of the needle. This inevitably leads to irritation in the patient.

Another safety pin with a proximally thickened sliding body and a triggering mechanism arranged thereon and, in turn, a thickened proximal end section of the base body is known from WO 2015/058402 A1. The disadvantages are essentially the same as those of the device according to EP 3466464 A1.

In addition, WO 2009/021263 A1 discloses a safety cannula arrangement in which the triggering mechanism is located on the base body, which is provided with a resilient tongue in a distal end section on the diametrically opposite side operating person can be shifted inside. During this radially inward displacement, the tongues of the base body take with them two resilient tongues of the sliding body, which run approximately parallel to them. As a result, they are also shifted radially inwards. At their rear ends, the springs of the sliding body are provided with locking elements on the face side, which bear against the walls of a cutout in the base body. This contact is canceled by the inward displacement of the resilient tongues of the sliding body, as a result of which the sliding body is released and is displaced in the proximal direction by the force of a coil spring, thereby moving the cannula into the secured position. With this previously known device and its special type of triggering mechanism, the construction of both the base body and the sliding body is complicated. Due to the thickening of the sliding body in a proximal section and a radial step formed at the transition area to the flexible hose, there is a risk that the retraction movement of the sliding body and hose will be impeded by skin contact on the patient.

In addition, US Pat. No. 5,575,777 discloses a device for placing a catheter, in which energy-absorbing components, e.g. in the form of a viscous material, are arranged inside the main body of the device in order to reduce the speed of the needle carrier during the retraction movement. The needle carrier is associated with a retraction mechanism, which in turn has a release and locking mechanism. The latter has a combined release and locking element, which is referred to as a "slider" or "trigger" and is formed by a "slide" that can be moved radially, i.e. in a plane perpendicular to the longitudinal axis of the main body or the cannula. The slider is provided with a keyhole-shaped opening in its central area. In the locking position, the slide is in engagement with the cannula holder, specifically in the area of a circumferential groove at the distal end of the cannula holder. The front end of the cannula holder, which is thicker than this circumferential groove, prevents the cannula holder, which is prestressed by spring tension, from being transferred from the use position to the safety position. In this state, the walls of the circumferential groove are supported on wall sections of the slide, which delimit the “keyhole” in its approximately rectangular, narrow area on both sides.

If the slide is now manually moved transversely to the longitudinal axis of the needle by pressing an external release element, the thickened front end gets into the area of the larger, approximately circular section of the keyhole, so that the front end of the cannula holder disengages from the slide and as a result which triggers the retreat movement.

In the previously known device in the form of a placement aid for a catheter is not a blood sampling device with which a patient Body fluid, especially blood, can be removed. There is also no intended flow through the cannula itself in the sense of a liquid withdrawal or infusion. Rather, the proximal end of the cannula opens into a chamber which is closed at its distal end with a hydrophilic filter in order to prevent the escape of air but not the escape of blood that flows into the patient's skin when the cannula is punctured , to allow. Therefore, converting this catheter placement device into a safety needle assembly for blood collection is not practical.

Other safety cannulas with a basically comparable structure are known from US Pat. No. 6,547,762 and EP 2638924 A1.

Finally, EP 1 479408 A1 also describes a needle protection arrangement in which the release mechanism is in turn arranged on the needle carrier and leads there to a disadvantageous thickening at the proximal end--as already described above. With the exception of the locking elements on the springy tongues of the triggering mechanism on the needle carrier side, the triggering mechanism - viewed in the axial direction - is located completely "next to" the base body, i.e. in a section between the hose connection and the proximal end of the base body. What is also disadvantageous about this needle protection arrangement is that either the fingers of the person operating the triggering mechanism have to follow the retraction movement of the sliding body as synchronously as possible, or that the fingers have to be taken away from the latter immediately after the triggering mechanism has been actuated in order to allow a free and through the fingers of the user Person to allow free rearward movement of the slider.

task

Based on the prior art described above, the invention is based on the object of proposing a safety cannula arrangement that is easy to use, requires little design and production effort and causes pain or trauma in the patient during or after the triggering of the retraction mechanism for the sliding body minimized.

solution

Based on a safety cannula arrangement of the type described above, the above object is achieved in that the at least one release element and the associated locking element are preferably arranged on different, preferably opposite, sides of the longitudinal axis of the sliding body in the release and/or locking position. The safety cannula assembly is preferably a blood sampling device.

The arrangement of the triggering element and locking element on opposite sides of the longitudinal axis of the sliding body makes it possible for a radially inward (i.e. towards the longitudinal axis) directed pressure on the triggering element and a movement of this triggering element, likewise radially inward, to be effected in a very simple manner can be converted into a movement of the associated locking element in a direction pointing radially away from the longitudinal axis (or at least with a movement component in this direction). “Associated locking element” is to be understood as meaning any coupling between a triggering element and a locking element that interacts with it, in particular a mechanical forced coupling, in particular the connection via an intermediate element that transmits compressive forces and/or shearing forces and/or torques and is integral with the triggering element and/or can be connected to the locking element.

The displacement of the locking element radially outwards as a result of a radially inward movement of the triggering element is particularly advantageous because a radially outward movement of the locking element makes it possible to enlarge and/or change the shape of a free cross section in an interior space of the base body in a simple manner will. This increase in cross-section or change in shape in turn makes it possible to create the necessary free space for the retraction movement of the sliding body. This means that the locking element is displaced from an engaged position with the sliding body, in which it is arranged closer to the longitudinal axis of the sliding body, to a release position (release position), in which it is radially further outward, i.e. further from the longitudinal axis of the sliding body removed, is arranged. With the triggering principle according to the invention, a radially inward movement of the triggering element is thus converted into a radially outward movement of the associated locking element, which allows a simple and space-saving design of the locking mechanism to be achieved in the radial direction. In particular, the sliding body can be kept completely free of the triggering mechanism and the triggering elements, which enables a slim and simple design. The safety cannula arrangement according to the invention is thus manipulated solely on the base body and not on the sliding body, which is why this can move backwards freely after actuation of the triggering mechanism and in particular without being touched by the fingers of the person using the safety cannula arrangement.

In addition, the slim design of the sliding body without protruding components a trigger mechanism allows an unhindered retraction movement and in particular prevents unwanted, braking contact with the patient's skin.

The at least one release element and the associated at least one locking element are preferably arranged on different sides of a plane that runs both parallel to a longitudinal axis of the cannula and perpendicular to a plane defined by a ground surface of the cannula tip.

The safety cannula arrangement preferably has at least one grip wing on the base body. An arrangement of two grip wings arranged on opposite sides of the base body is particularly preferred.

According to one embodiment of the invention, it is provided that—in a cross section oriented perpendicularly to the longitudinal axis of the sliding body—one release element and one locking element are arranged on diametrically opposite sides of the longitudinal axis. Thus, two pairs, each consisting of a release element and an associated locking element, interact with one another on opposite sides. This symmetry makes the structure of the safety cannula arrangement according to the invention particularly simple and operation safe and intuitive. Of course, instead of two pairs, four pairs of triggering element and associated locking element can also be formed. In principle--even if this is not preferred--the arrangement of three pairs--each offset by 120° in the circumferential direction--is conceivable.

A coupling, namely a forced mechanical coupling, between the release element and the locking element can be achieved in a particularly simple manner if the at least one release element and the associated locking element—in a cross-section running perpendicularly to the longitudinal axis of the sliding body—through the base body—together have a U-shape or C-shape form. In this context, it is particularly useful if the at least one release element is located on a first leg of the U or C and the associated locking element is located on a second leg of the U or C.

A further development of the safety needle arrangement according to the invention provides that each triggering element is connected to the base body via at least one joint element, with the joint element preferably being elastically and/or plastically deformable relative to the base body when the triggering element is shifted from the locking position to the triggering position. A joint element allows relative movement between Trigger member and body without requiring a great deal of effort from the person using the safety cannula assembly.

An advantageous embodiment of the joint element is that it is designed as a beam. A plurality of joint elements are preferably designed as beams running parallel to one another, which should preferably be arranged equidistantly from one another. In this way, a type of flat lattice structure is created, which is also suitable in particular as a base body side wall and nevertheless has the elasticity required for actuating the triggering mechanism.

According to a particularly advantageous development of the invention, the at least one joint element is connected with a proximal end to a proximal end section of the base body and is provided with the locking element at a distal end. In such a configuration, the non-positive connection runs through the base body—preferably through a rigid and sufficiently rigid side wall—to the proximal end, in order to form a bearing point for the joint element there. A transverse force applied to the release element is thus conducted via the joint element (with elastic deformation of the same) to the bearing point of the joint element at the proximal end, from where it is transferred via a side wall in the direction of the rest of the base body. In this way, a sufficiently large distance between the at least one locking element, which is arranged at the distal end of the joint element, and a proximal end of the base body can be achieved. In particular, a connection area for the flexible hose can be arranged in this way within the base body in the release section.

Furthermore, it is provided that several joint elements, preferably joint elements in the form of beams, are connected at their distal ends by means of a pressure rod running perpendicularly to the beams, which in turn connects a release element to the associated locking element. The release element, the interposed pressure rod and the locking element connected to it can—viewed in a plane perpendicular to the longitudinal axis of the base body—form a U-shape or C-shape.

If the triggering element has a triggering surface which is arranged at an angle of approx. 90° to a plane within which the at least one articulated element is movable and/or a pressure rod connecting several articulated elements is arranged, this results in an arrangement that is particularly useful in the training a base body having a channel-like interior is advantageous. More preferably, the trigger surface Elevation, in particular one in the form of a hump, which can be felt with a finger of a person using the arrangement.

In a further embodiment of the invention, the base body is approximately cuboid in the area of the triggering mechanism, with two L-arrangements, each consisting of a triggering surface and a plurality of joint elements, preferably forming a rectangle in a cross section running perpendicular to the longitudinal axis of the base body. Said cuboid shape elegantly allows the diametrically opposite arrangement of the triggering surfaces, which in turn allow ergonomic operability.

To simplify assembly, it is proposed that the base body have two base body parts which are arranged at least essentially mirror-symmetrically to a plane running through a longitudinal axis of the base body when its base body parts are in the assembled state and/or - when viewed in section - point-symmetrically to this longitudinal axis, with preferably the two body parts are positively connected to each other by means of snap hooks or locking lugs.

A particularly simple way of engaging between the sliding body and the at least one locking element is when this is in contact with the proximal end face of the sliding body in the position of use. More preferably, said proximal face of the sliding body is formed by a sleeve portion into which a distal end of the tube is inserted, or by a radial step in the sliding body.

In order to guarantee a limitation of the retraction movement after the actuation element has been triggered, the at least one locking element can bear against a step of the sliding body in the secured position. As an alternative to such a dual function of a locking element, another stop element for the slider, z. B. also for a flange formed thereon, be present on the base body. Preferably, the step on the sliding body for stopping the locking element in the securing position is formed by a flange projecting radially over a preferably rotationally symmetrical outer casing of the sliding body.

Furthermore, an embodiment of the invention consists in that the flange has an end face at its distal end, which forms a support surface for the adjusting element, which is preferably designed as a helical spring. In this case, the aforementioned flange has a dual function, which simplifies the design of the sliding body. It is particularly advantageous if the adjusting element is supported with its distal end on a support surface of the first base body part.

The cannula arrangement according to the invention offers great advantages during assembly, in particular when inserting the sliding body into the base body. For this purpose, the first base body part and the adjoining second base body part, which are both arranged axially one behind the other when viewed in the direction of the longitudinal axis of the base body or sliding body, are provided or - in the case of a film hinge connection between the first and the second base body part - in a linear aligned to each other. The sliding body and the adjusting element are then joined together and placed as a unit in the first and second base body part, or the (unstressed) adjusting element is first inserted into the first and second base body part and only in a next step is the sliding body added and with it the adjusting element transferred to the prestressed state.

The sleeve-shaped first part of the main body offers a great advantage, in particular with regard to a secure and precisely fitting positioning of the actuating element in the main body. Particularly in the case of a helical spring as the actuating element, this can be aligned and used coaxially with the sleeve-shaped first body part and is then securely fixed at its distal end during the process of being converted into the prestressed state, preventing it from slipping or evading and jumping away.

As the last step in the assembly sequence, the third base body part is then connected to the second base body part, as a result of which the base body is completed and is present in its final form.

To simplify handling or to offer alternative handling in addition to gripping the housing-like part of the base body, it is proposed that the base body be provided with a gripping wing on each of two opposite sides. The grip wings can be made of a rubber-elastic material so that they can be pressed against one another in a known manner by gripping them with two fingers in an area above the base body until they are in contact with one another.

A further development of the invention consists in the fact that the distal end of the adjusting element is supported on a step formed in an interior space of the first base body part or on an end wall forming a distal termination of the first base body part. This ensures a particularly simple and secure fixation of the actuating element during its transfer into the prestressed state. Further developing the arrangement according to the invention, the grip wings can be connected to a sleeve-shaped connecting part that is pushed onto the base body. An overlapping area between the connecting part and the base body can preferably enclose both at least one axial section of the first base body part and one axial section of the second base body part and the third base body part. In this way, the sleeve-shaped connecting part not only ensures a secure and firm connection of the grip wings to the base body, but also stabilizes it in the manner of a collar or clamp, which, due to the assembly of the base body from several base body parts, additionally secures the assembled state.

A first variant of the design of the first and second body parts consists in these two parts being rigidly connected to one another. There is therefore no articulation between these two base body parts, in particular there is no film hinge between these two base body parts. In this variant, the alignment of the first base body part to the second is always automatically ensured and during assembly, a degree of freedom that would have to be eliminated by appropriate fixing and guiding of the components is eliminated from the outset.

As an alternative to the aforementioned variant, it is also possible to connect the first base body part and the second base body part to one another via a film hinge. In this case, a hinge axis of the living hinge should be aligned perpendicular to and at a distance from the longitudinal axis of the sliding body.

With regard to the third base body part, two basic cases of connection to the other base body parts are conceivable: on the one hand, the third base body part and the second base body part can be connected to one another by means of a film hinge. The hinge axis of the film hinge can be aligned parallel or perpendicular to the longitudinal axis of the sliding body. In this variant, the second base body part forms the central element of a “triple chain” formed from the three base body parts, which are connected via two film hinges, with the second base body part being connected to both film hinges.

As an alternative to the embodiment mentioned above, the possibility also comes into consideration that the third base body part and the first base body part are connected to one another by means of a film hinge. In this case - as is already the case in the case of the connection between the first and the second base body part - the hinge axis of the film hinge should be aligned perpendicular to and at a distance from the longitudinal axis of the sliding body. In the latter case, a symmetrical Create an arrangement in which the first body part forms the middle link of the "chain of three" and the two end links of the chain are formed by preferably identically designed body parts. In this configuration, the second and third base body parts are preferably synchronously pivoted about the respective film hinge axes towards the longitudinal axis of the sliding body previously inserted into the first base body part and brought into contact and fixed against one another during the joining process.

For reasons of symmetry and to simplify assembly, in the latter case the two film hinges should be at the same distance from the tip of the cannula, viewed in the axial direction. Likewise - for the same reasons - the two film hinges should each have the same distance from the longitudinal axis of the sliding body.

Further developing the invention, it is also provided that the first main body part

- Rotationally symmetrical in a distal section and/or

- Is cuboid in a proximal section, wherein preferably a film hinge is arranged on opposite proximal edges of the cuboid proximal section. Such a configuration enables the distal end of the actuating element or sliding body to be securely accommodated in the rotationally symmetrical distal section and the sliding body to be secured against rotation in the cuboid proximal section, provided that the sliding body has a cross-sectional shape that prevents twisting within the preferably rectangular, in particular square cross-section having proximal cuboid section prevents.

A preferred embodiment of the safety cannula arrangement according to the invention is that the rotationally symmetrical section of the first main body part has a cylindrical tip section and a likewise cylindrical transition section for receiving the adjusting element compressed in the position of use, with a removable tubular cannula protection preferably being pushed onto the tip section.

In addition, it is also proposed that the second base body part and the third base body part be together in an assembled state

- form a gripping area adjoining the film hinges in the proximal direction, which is preferably on its outer casing Ribs or a variety of elevations to increase grip and / or

- form a release area (36) adjoining the grip area in the proximal direction, which has a release mechanism and/or

form a closure area arranged at a proximal end of the base body, in which the second base body part and the third base body part are positively connected to one another by means of snap hooks and/or latching lugs.

In addition, a development of the invention also provides that the first base body part forms a distal end of the base body.

It is particularly advantageous if the stop surface of the sliding body is arranged on the at least one rotation-blocking body of the sliding body to limit the axial movement during the transfer of the sliding body into the securing position.

The sliding body according to the invention is thus distinguished by a particularly simple structure and favorable manufacturability. In particular, the invention can advantageously be replaced where the locking elements for fixing the sliding body in the position of use are not used at the same time as a rotation blocking body. Such a dual function of the locking elements is provided in a large number of known safety cannula arrangements. According to the concept of the invention, the anti-rotation body can thus be formed by a separate component (in addition to the locking elements of the triggering mechanism) and typically also be spaced, preferably axially spaced, from the locking elements. The anti-rotation body and stop surface of the sliding body, on the other hand, are formed by the same component or are formed on the same component, so that this dual function creates a design that is particularly favorable in terms of installation space and complexity. The invention is open to the manner in which the anti-rotation is achieved by the anti-rotation body of the slider. All geometries that prevent the sliding body from twisting about its longitudinal axis but nevertheless allow it to move axially in the base body for the purpose of moving it into the securing position are conceivable.

According to an advantageous embodiment of the invention, it is provided that the base body is provided with a grip wing on each of two opposite sides, whereby the handling is improved or an alternative way of handling (compared to the handling of the actual base body itself) is made available.

Ergonomics are further improved if a grip area for handling the device during the puncture is preferably arranged exclusively on the base body, with ribs or a plurality of elevations to increase grip being present in the grip area. In particular, this avoids the situation where the safety needle arrangement also has to be handled in the area of the needle holder, which is disadvantageous because the latter moves relative to the base body when the triggering mechanism is actuated.

To further develop the invention, it is proposed that the sliding body be in the form of a hollow cylinder and the anti-rotation body of the sliding body be a projection or flange protruding radially outwards over an outer lateral surface of the hollow cylinder, which preferably - viewed in the direction of the longitudinal axis of the sliding body - has a square shape Has outline whose corners are preferably rounded. The square shape of the outline of the projection or flange has advantages with regard to the assembly of the safety cannula arrangement, since it allows an exact positioning of the cannula tip relative to the base body in a very simple manner—with a known alignment of the cannula tip to the sliding body. Preferably, such a square-shaped projection or flange with a square-shaped cross-section cooperates in a portion of the interior of the body to achieve the required rotational locking. In principle, however, the projection or flange can also have a polygonal or elliptical shape.

In addition to the double function of blocking rotation and forming a stop surface, the blocking body arranged on the sliding body can also fulfill a third function. This is because the actuating element can be supported on a distal end face of the rotation-blocking body arranged on the sliding body, opposite the stop face for limiting the retraction movement. The construction is particularly simple and cheap in this way.

According to a further development of the safety cannula arrangement according to the invention, the stop surface of the base body can be formed by at least one projection extending radially inwards from a wall of the base body enclosing the interior space of the base body. The projection can be formed, for example, by a step in the base body wall or a typically distal base body end wall, which can also only be a partially formed end wall. Finally, a particularly advantageous embodiment consists in the fact that there are two of the aforementioned projections, which are arranged diametrically opposite one another and - viewed in the direction of the longitudinal axis of the sliding body - each have the shape of a triangle, in particular with an arcuately curved contour, with each Projection connects two wall sections of the base body arranged in an L-shape to one another in a cross-section in a corner region. In a two-part design of the base body in the area of the rotation blocking device, the projections serving as stops also fulfill a stiffening function by preventing unwanted deformation of the wall sections arranged in an L-shape, which are connected to one another, and thus making it easier to maintain the rectangular cross-section of the base body in this area.

In addition, it is particularly advantageous that a maximum diameter or a maximum width of the sliding body extending perpendicularly to the longitudinal axis of the sliding body in an exit section of the sliding body that is in the securing position and adjoins the proximal end of the main body in the proximal direction is at most 80%, preferably at most 70%, more preferably at most 60%, of a maximum diameter or a maximum width of the base body extending perpendicular to the longitudinal axis of the sliding body.

The invention thus creates a particularly slim sliding body, which is therefore “low-resistance” during the retraction movement, in which there is a risk that it will get caught on the patient’s skin or on other objects or be slowed down as a result of the retraction movement from the base body. is particularly low. In particular, there are no elastically deformable locking elements, such as resilient tongues or the like, present on the sliding body according to the invention, which provoke a particularly great risk of getting caught. For this reason, with the safety needle assembly according to the present invention, a proper retraction movement of the sliding body is ensured with an extremely high probability after the blood collection or infusion has been completed, so that pain or trauma to the patient is avoided as much as possible.

The arrangement of the locking elements inside the base body also prevents unintentional triggering of the retraction mechanism of the sliding body. In addition, the arrangement of the triggering elements and the locking elements of the triggering mechanism on the base body enables a simple structural design of the sliding body and also enables ergonomic operability when triggering the retraction movement. In order to create the greatest possible stability of the free section of the cannula in the position of use of the safety cannula arrangement, a distance measured in the direction of the longitudinal axis between a bearing point arranged furthest in the distal direction and a bearing point of the sliding body arranged furthest in the proximal direction should be at least 100%, preferably at least 120%, more preferably at least 140%, even more preferably at least 160% of the length of the base body measured in the direction of the longitudinal axis, with the bearing points each being suitable for dissipating transverse forces acting on the sliding body, which can be directed in any radial direction (In relation to the longitudinal axis of the cannula or the base body). A large distance between the bearing points results in a good dissipation of transverse forces from the sliding body into the base body, so that the receiving and mounting of the sliding body in the base body can be carried out in a particularly play-free manner. This in turn results in a particularly advantageous function during the puncture, since transverse forces exerted by the user on the cannula via the main body and the sliding body can be transferred very directly and without "elasticity" or "wobbling" to the puncture site and in particular the vessel to be punctured. There is thus a system with high "stiffness" in the transverse direction, which increases the accuracy of the puncture. This applies in particular to so-called "rolling veins", which are characterized by the fact that they try to avoid a lateral force exerted by the cannula before the puncture by moving sideways. The stiffer the overall system is—viewed in a direction transverse to the longitudinal axis of the sliding body—and the less play there is in this direction, the greater the probability of actually being able to perform the puncture at the desired location.

In addition, it makes sense that a distance measured in the direction of the longitudinal axis between a bearing point arranged furthest in the distal direction and a bearing point of the sliding body arranged furthest in the proximal direction should be at least 70%, preferably at least 80%, more preferably at least 90%, even further is preferably at least 95% of the length of the sliding body measured in the direction of the longitudinal axis, the bearing points being suitable in each case for dissipating transverse forces acting on the sliding body, which run in any radial direction. The considerations and advantages mentioned above with regard to the distance between the bearing points in relation to the length of the base body apply here. The length of the base body is typically greater than the length of the sliding body, since in particular a connection point between a proximal end of the cannula holder and a distal end of the hose is arranged inside the base body. Further developing the invention, it is proposed that the bearing point arranged furthest in the distal direction and/or the bearing point arranged furthest in the proximal direction directly adjoin the distal or proximal end of the sliding body and/or extend to this end. In such an embodiment, the entire length of the sliding body is used as the bearing point spacing, ie as the bearing length, so that the system is particularly rigid or stable when subjected to the action of lateral forces.

A further development of the principle according to the invention is that a bearing point arranged on a proximal end of the sliding body, preferably the bearing point arranged furthest in the proximal direction, is formed by at least one projection of the base body that extends into an interior space of the base body and on which a stop surface for Limitation of the sliding body is formed from the position of use into the secured position. In this case there is a particularly favorable double function of the said projection on the base body, as a result of which the construction is correspondingly simplified.

If the sliding body is free of elastically deformable elements or links that interact and/or can be displaced in the course of the actuation of the triggering mechanism, not only is a particularly simple design of the sliding body created, but also the risk that the displacement of the Sliding body in the securing position from the base body exiting sliding body section hooked on objects or the patient's skin and hindered the retraction movement.

Finally, an advantageous embodiment of the invention consists in the triggering mechanism being arranged on two main body parts and being formed jointly by them, with the two main body parts preferably being joined with a movement relative to one another which has a movement component perpendicular to the longitudinal axis of the sliding body. In contrast to the prior art, as formed by WO 2016/007438 A1, the joining of two base body parts in this embodiment according to the invention does not take place by axially sliding or plugging one into the other, but by a movement transverse or perpendicular to the longitudinal axis of the sliding body or by a folding or pivoting movement about a pivot axis running perpendicularly to the longitudinal axis, which can be the case in particular when at least one film hinge is formed between two main body parts.

example The invention is explained in more detail below using an exemplary embodiment which is illustrated in the drawing:

It shows:

1 and 2: A safety cannula arrangement from two different perspectives with a distally attached cannula protection,

Fig. 3: an exploded view of the safety cannula assembly,

4: a perspective view of the base body with the cannula protruding therefrom,

5: like FIG. 4, but in a partial section of the base body, FIG

sliding body,

Fig. 7: the sliding body with cannula, adjusting element and a section of a flexible hose,

8: like FIG. 7, but without the adjusting element, FIG. 9: a perspective view of the base body with the second and third base body part folded away to the side,

Figure 10: A perspective view of the first and second

body part,

10a: like FIG. 10, but from a different perspective FIGS. 11 and 12: a longitudinal section through the safety cannula arrangement according to FIGS. 1 and 2 with the sliding body in the position of use,

Fig. 12a: an enlargement of a detail from Fig. 12

Fig. 13 to 16: each a section along the line l-l through the

Safety cannula arrangement according to Figures 1 and 2 in different positions of the triggering elements and locking elements,

17: a perspective view of the safety pin in a section along line II-II in FIGS. 1 and 2, 18: a release mechanism in a section along the line III-III as in FIG. 1 in the proximal viewing direction,

19: a longitudinal section through the safety pin arrangement according to FIGS. 1 and 2 in the safety position of the sliding body,

Fig. 19a: an enlargement of a detail from Fig. 19

20: a section through the safety cannula arrangement according to FIGS. 1 and 2 along the line IV-IV with the sliding body in the safety position in the distal viewing direction,

21: like FIG. 18, but in the securing position of the sliding body, and

22: A cross section through the safety cannula arrangement according to FIGS. 1 and 2 along the line V-V in the distal viewing direction.

In the delivery state shown, a safety cannula arrangement 1 shown in different perspectives in Figures 1 and 2 has a base body 2 forming an elongated housing, a wing module 3 arranged thereon, a tubular cannula protector 4 pushed over a distally protruding cannula, and a flexible cannula shown cut off for the sake of simplicity Tube 5 to recognize. The hose 5 shown cut off, which is connected to a proximal end section of a sliding body not visible in FIGS. 1 and 2, has a length of approx to other means of handling blood collection. The base body 2 is provided in a gripping area 9 on two opposite sides with a plurality of transverse ribs 6 running perpendicular to a longitudinal axis 7 of the base body (or also the safety cannula arrangement as a whole or the sliding body), the overhang of which is rounded off from the cuboid basic geometry of the grip area 9 of the base body 2 initially decreases, starting from a maximum overhang at the transverse ribs 6 adjacent to the wing module 3 towards the proximal end of the grip area 9 of the base body 2, and then increases again. The transverse ribs 6 running equidistantly and parallel to one another are connected to one another and stabilized on each side by a longitudinal rib 8 arranged in a plane of symmetry of the base body 2 . In this way, a particularly safe and ergonomic grip is made possible for two fingers of a person using the safety cannula arrangement 1 gripping the grip area 9 of the base body 2 from opposite sides, and handling is thus simplified. From the exploded view according to Figure 3 it can be seen that the base body 2 is composed of three base body parts 10, 11 and 12, namely a sleeve-shaped first base body part 10, which extends furthest in the distal direction, and two half-shell-shaped base body parts (second base body part 11 and third body part 12). The second base body part 11 and the third base body part 12 are each connected to the first base body part 10 via a film hinge 13, 14 and are therefore articulated about a hinge axis of the film hinge 13, 14 relative to the first base body part 10. The two base body parts 11 and 12 have an identical shape, but are arranged symmetrically relative to a plane of symmetry which is arranged parallel to the two film hinges 13, 14 and runs through the longitudinal axis 7 of the base body.

An essentially hollow-cylindrical sliding body 15 is arranged in an interior space of the base body 2 and is mounted so that it can move in the axial direction (ie the direction of the longitudinal axis 7) relative to the base body 2. A cannula 17, which is provided at its distal end with a tip 18 formed by a ground surface, is inserted in a sealing manner into a distal end section 16 of the sliding body 2. A distal end section 20 of the tube 5 is inserted in a sealing manner into a proximal end section 19, which is designed as a sleeve section. For this reason, the sliding body 15, the cannula 17 and the tube 5 form a unit which is firmly connected to one another, the components of which--apart from the flexibility of the tube 5--cannot be displaced relative to one another. In order to store the sliding body 15 in the position of use under prestress in the base body 2 and in this way to provide a drive for a proximally extending retraction movement of the sliding body 15 relative to the base body 2, an adjusting element 21 is externally mounted on the distal end section 16 of the sliding body 15 Form of a helical spring pushed, which with its distal end 22 in the first body part 10 and with its proximal end 23 on a cross-sectionally rectangular flange 24 which projects beyond an outer surface of the sliding body 15, is supported.

The structure of the base body 2 from its base body parts 10 to 12 and the interaction of the base body 2 with the sliding body 15 are explained in more detail below with reference to FIGS. 4 to 10:

It can be seen from FIG. 4 that the base body 2, viewed in the axial direction, can be divided into different areas. Starting from a distal end of the base body 2, the sleeve-shaped first base body part 10 initially contains a rotationally symmetrical (apart from two latching lugs 25 for fixing the wing module 26) and an approximately cuboid section 27 adjoining it in the proximal direction. The rotationally symmetrical section 26 is in turn divided into a cylindrical tip section 28, onto which the cannula protection 4 (not shown in FIG. 4) (see FIGS. 1 and 2) is pushed. and a cylindrical transition section 29 which is tapered at its distal end and in which the distal end section 16 (not visible here) of the sliding body 15 together with the actuating element 21 pushed onto it is located. As can be seen by looking at Figures 3 and 1 and 2, the wing module 3 is connected to a central connecting part 30, on the two opposite longitudinal sides of which a grip wing 31 is connected in one piece (see also Figure 17), from a distal end of the base body 2 postponed to this one. A length 32 of the connecting part 31 of the wing module 3 measured in the axial direction corresponds to a length 33 of an overlapping area 34, which extends both over the first main body part 10 and the joined (second and third) main body parts 11 and 12 and into the sections 34d and 34p, of which the distal section 34d overlaps the first body part 10 and the proximal section 34p overlaps the second and third body parts 11, 12. In the area of the first base body part 10, the overlapping area 34 completely contains the cuboid section 27 and partially the approximately cylindrical transition section 29 up to the latching lugs 25 there a gap area located there between the first main body part 10 and the second and third main body parts 11 and 12. Starting from a proximal end of the overlapping area 34, the grip area 9 already described above adjoins in the proximal direction, which is shared by both main body parts 11 and 12 is formed. Further in the proximal direction there is a circumferential notch area 35 and further in the proximal direction adjoining this is a triggering area 36 in which a triggering mechanism 37 , which will be explained in more detail later, is located. Finally, a proximal end section of the base body 2 is formed by a closure area 38 in which the second base body part 11 and the third base body part 12 are positively connected to one another by means of snap hooks. An opening of the base body 2 by way of a folding movement of the two base body parts 11 and 12 is thus prevented on the one hand by the snap hooks in the closure area 38 and on the other hand by the connecting part 30 of the wing module 3 being pushed over.

Figure 5 shows how the sliding body 15 is arranged in the interior of the base body 2, for which the second base body part 11 is not shown, but only the "lower" third base body part 12. The distal end section 16 of the sliding body 15 is the same as the actuating element 21 is not visible because it is in the sleeve-shaped first body part 10 are concealed. A snap hook 39 can be seen in the closure area 38, which interacts with an adapted recess in the second base body part 11 when the two base body parts 11 and 12 are in the assembled state and forms a closure that cannot be released without destroying it. In each of the two body parts 11, 12, the release area 36 and the handle area 9 are connected to one another exclusively via a connecting web 40, which is connected to the handle area 9 at its proximal end and to the release area 36 at its distal end. For the sake of completeness, it should be noted at this point that the entire second and third base body part 11, 12 (as well as the base body 2 consisting of the three base body parts 10, 11, 12 as a whole) including the film hinges 13, 14 are produced as a one-piece injection molded part. Figure 5 also shows a further snap hook 41 on the base body part 12, with this snap hook 41 being arranged in the grip area 9 and also interacting with an adapted recess in the second base body part 11 and the two base body parts 11 and 12 (in addition to the snap hooks 39 and the connecting part 30 of the wing module 3) holds together.

FIG. 6 shows the sliding body 15 together with the cannula 17 inserted therein and the hose 5 pushed in at the proximal end, only the first base body part 10 being shown. The sliding body 15 has a sleeve section 42 which is larger in diameter than a middle section and adjoins it in the proximal direction, which is formed from a shorter transition section 43 and an insertion section 44 which adjoins it in the proximal direction and is cylindrical in basic shape. The fitting portion 44 has an inner cylindrical bore which is matched to an outer diameter of the flexible hose 5 and into which the hose is tightly bonded.

Looking at FIG. 7 it can be seen that the sleeve section 42 is provided with four stress relief grooves 45 for blocking tongues of the base body 2 explained further below, distributed evenly over the circumference of the sleeve section 42 and running in the direction of the longitudinal axis of the sliding body 15. The stress relief grooves 45 have a longer section 46, in which they have a greater depth and a groove base running parallel to the longitudinal axis 7, and a shorter distal section 47, in which the groove base ramps to a peripheral boundary line 48 between the insertion area 44 and the conical Transition section 43 increases. The function of the relieving grooves 45 in connection with the aforesaid blocking tongues will be explained later. While in FIG. 7 the compressed actuating element 21 is shown on a distal end section 49 of the sliding body 15 for the sake of clarity, this is not the case in the otherwise analogous representation according to FIG. This makes it clear that a diameter 50 in the distal end section 49 of the sliding body 15 is larger than a diameter 51 in a middle section 52 of the sliding body 15.

The individual areas of the base body 2 and the mirror-symmetrical arrangement of the identically shaped base body parts 11 and 12 can be seen very clearly in FIG. In this state, the base body 2 is removed from the injection mold as an injection molded part. The grip area 9, the adjoining notch area 35, the adjoining release area 36 and the closure area 38 forming the proximal end can be seen clearly in FIG. A recess 53 can be seen on the third base body part 12 shown on the left in FIG. 9, in which the snap hook 39 (see FIG. 5) can be received in a locking manner. A further recess 54 in the gripping area 9 can also be seen, which is used for lockingly receiving the corresponding snap hook 41 on the gripping area 9 of the third body part 12 . There are therefore a total of two snap hooks 39 and two recesses 53 in the closure area 38 and two snap hooks 41 and two recesses 54 in the handle area 9. Each of the two main body parts 11 and 12 is therefore both in the handle area 9 and in the closure area 38 a snap hook 39, 41 and a recess 53, 54 each.

Figure 10 allows an insight into the trough-shaped third base body part 12, since on the one hand the trough-shaped second base body part 11 arranged above it in the assembled state was removed and on the other hand the sliding body 15 together with the cannula 17 and tube 5 is not inserted. It can be seen that a bottom 55 and two opposing half-walls 56, 57 of the base body part 12 are arranged at right angles to one another, resulting in a square cross-section of the interior when the two base body parts 11, 12 are joined. The two longitudinal ribs 8 of the base body part 12 arranged on opposite sides are formed jointly by the two base body parts 11 and 12 in the joined state and define in the contact area of the two base body parts 11, 12 a central plane running parallel to the longitudinal axis 7, which also forms a plane of symmetry. In addition, the snap hooks 41 in the handle area 9 and 39 in the closure area 38, which are arranged on opposite sides--in relation to the longitudinal axis 7--can also be seen in FIG. FIGS. 11, 12 and 12a each show a longitudinal section of the safety cannula arrangement 1 in the operational state of the sliding body 15 from different perspectives. A distal end face 58 of the sliding body 15 terminates essentially flush with a distal end face 59 of the first base body part. In this position, the cannula 17 protrudes with a free length 60 beyond the distal end face 59 of the base body part 10 . The adjusting element 21 is in a pretensioned state, so that the sliding body 15 tends to move in the proximal direction relative to the base body 2 . This movement is prevented by two locking elements 61a, 61b, which are part of the triggering mechanism 37 and interact with a proximal end face 62 of the sliding body 15 in the socket section 42 thereof. The end face 62 of the sliding body 15, in conjunction with the hose 5, which has a smaller diameter, forms a step 63, which is also clearly visible in FIGS. This step is in the position of use of the sliding body 15 - viewed in the axial direction - in the notch area 35 and specifically at its proximal end, which is defined by the locking elements 61a, 61b of the release mechanism 37. The sliding body 15 is thus fixed in the position of use without play in the axial direction in the base body 2, which is essential for a proper puncture process.

A synopsis of FIGS. 13 to 16 and 18 makes it clear how the release mechanism 37 works. The proximal end face 62, which forms the said step 63 in the transition from the tube 5 to the sleeve section 42 of the sliding body 15, is held back by two diametrically opposite locking elements 61a, 61b (see also Fig. 10 a), so that the sliding body 15 in the position of use 45 remains. In the socket section 42 of the sliding body 15, the stress relief grooves are visible, resulting in a circular contour of the end face 62 interrupted by four indentations at 90° intervals in cross section.

The locking elements 61a, 61b have--when viewed axially--a triangular or trapezoidal shape and rest with a respective control edge 64a, 64b on an outer lateral surface 65 of the hose 5.

It can be seen from FIG. 18 that the locking elements 61a, 61b are each coupled to a release element 67a, 67b via a push rod 66a, 66b. The trigger members 67a, 67b are each provided with an elevation 68a, 68b in the form of a hemispherical button. In a side view of the base body 2, the release members 67a, 67b form two approximately square surfaces, each with the central elevation 68a, 68b, the pressure rods 66a, 66b running at an angle of 90° thereto. The locking elements 61a, 61b in turn extend in one Angle of about 90 degrees to the pressure rods 66a, 66b, resulting in a C-shape or U-shape overall. The release elements 67a, 67b and the locking elements 61a, 61b each form a free leg of the U or C, while the pressure rods 66a, 66b form a “base element” of the U or C.

If, after the end of the blood withdrawal or infusion carried out by means of the safety cannula arrangement 1, the sliding body 15 is to be transferred to the securing position in which the cannula 17 is completely accommodated within the main body 2, the user of the safety cannula arrangement 1 exercises a radial movement with two fingers of one hand at the same time compressive force running in the direction of the arrows 69a, 69b on the elevations 68a, 68b of the triggering members 67a, 67b. Starting from the locking position shown in FIG. 13, in which the locking elements 61a, 61b block the sliding body 15 by engaging (abutting against the end face 62), the upper locking element 61a in FIG. 13 moves to the right by pressing on the left release element 68a, whereas the lower locking element 61b in FIG. 13 moves to the left through pressure on the right-hand triggering element 68b. FIG. 14 shows a state in which a distance 70 has formed between the latter and the outer lateral surface 65 of the hose 5 as a result of a corresponding displacement of the triggering elements 68a, 68b forming a rigid unit and the locking elements 61a, 61b connected thereto. However, this distance 70 is not large enough to cancel out a stop of the end face 62 on the locking elements 61a, 61b. For this reason, the cannula holder 15 still remains in the position of use in this position of the triggering mechanism or the triggering members 67a, 67b. Figure 15 shows another intermediate state in which the distances 70 between the locking elements 61a, 61b and the lateral surface 65 of the hose 5 are larger, but there is still an overlap between the locking elements 61a, 61b and the end face 62 of the sliding body 15 and thus cause its blockage.

In the position of the triggering elements 67a, 67b with their associated button-shaped elevations 68a, 68b shown in Figure 16, the associated locking elements 61a, 61b are displaced outwards just far enough that the cross section of the sliding body 15 defined by a circular outline 71 (envelope) in the area of the sleeve portion 42 is fully released. The locking elements 61a, 61b are now disengaged from the sliding body 15, so that the latter, driven by the actuating element 21, can move in the proximal direction, which leads to the cannula 17 being retracted into the interior of the base body 2. Accordingly, FIGS. 19 and 19a show the sliding body 15 in the secured position, in which the cannula 17 including its tip 18 is arranged within an interior space 72 of the base body 2. FIG. The actuating element 21 in the form of the helical spring is now in a more relaxed state than the position of use of the sliding body 15 .

In order to prevent the entire sliding body 15 and thus also the cannula 17 itself from escaping at the proximal end of the base body, the securing position of the sliding body 15 is defined by a stop surface 73 arranged on it. The stop surface 73 on the sliding body 15 interacts with a stop surface 74 of the base body 2, which is formed on the proximal end of the base body 2, namely on the proximal end of the closure area 38, which is formed jointly by the second base body part 11 and the third base body part 12 is.

As can be seen from the sectional view according to FIG. 20, both the second and the third base body part 11, 12 have a U-shaped cross section, with the two U-shaped cross sections of the walls pointing in a direction perpendicular to the plane of symmetry of the base body 2, i.e. in a direction perpendicular to the two film hinges, i.e. the pivoting during the joining process, are nested in one another and thus define an essentially square free cross section in the interior 72 of the base body 2. However, the cross-sectional shape in the area of the stop surfaces 74 of the base body parts 11 and 12 is not exactly square, but two corner areas are filled in and towards the longitudinal axis 7 of the base body 2 by a curved line 75, which inscribes a quadrant in the relevant corner of the U or C. In FIG. 20, the edges of an imaginary square, into which the stop elements 76 delimited by the curved lines 75 are introduced in the corners, are shown in broken lines for the sake of better clarity.

As can be seen from Figure 20, the radius of a circle that runs through the (slightly rounded) corners of the square-shaped flange 24 when looking in the direction of the longitudinal axis 7 is larger than the radius of a circle that runs through a continuation of the two curved lines 75 is formed. For this reason, the square flange 24 cannot pass through the free cross section in the area of the stop surfaces 74, which are formed on the stop elements 76, so that displacement of the sliding body 15 is terminated at this point. This situation can also be clearly seen from the sectional view according to FIG. The square flange 24 rests in the area of its rounded sections 77 on the stop surfaces 76 of the base body parts 11, 12. In the state shown in Figure 21 is the Cannula holder 15 in the secured position, in which the sleeve section 42 at the proximal end of the sliding body 15 has exited the base body 2 from this.

It can be seen from FIG. 22 that the interior space 72 in the cuboid section 27 of the first base body part 10, which is generally sleeve-shaped, is square (with rounded corners). The cross section of the square flange 24 is adapted to this cross-sectional shape in such a way that, on the one hand, a smooth movement in the axial direction of the sliding body 15 under the action of the force of the actuating element 21 is possible, but, on the other hand, a rotation of the sliding body 15 about the longitudinal axis 7 is reliably prevented. The flange 24 thus fulfills the function of a rotation blocking body of the sliding body 15 and, correspondingly, the cuboid section 27 of the first base body part 10 a rotation blocking body of the base body 2. While on the square-shaped flange 24 of the sliding body 15, the proximal stop surface 73 for limiting the retraction movement of the sliding body 15 is arranged , the square-shaped flange 24 has a double function in that its further stop surface 78, which is not visible in FIG. 22 but is illustrated in FIGS. 7 and 8, serves to support the actuating element 21.

In addition to limiting the retraction movement of the sliding body 15 in the proximal direction, it is also important to prevent the sliding body 15, once it has assumed the securing position, from being intentionally or unintentionally advanced back in the distal direction in order to expose the cannula 17 again and the Safety needle assembly 1 may reuse what should be avoided or prevented at all costs. The blocking tongues 79 already discussed above, which are designed as resilient elements of the base body 2 and are each arranged within a window 80 surrounding the blocking tongues 79 on three sides, are used for this purpose. This circumstance can be clearly seen in FIGS. 19 and 19a, in which the sliding body 15 is in the secured position. One end face 81 of the blocking tongues 79 rests against the stop face 78 of the square flange 24, which is oriented in the distal direction, so that this even has a triple functionality (end stop for the retraction movement, support of the actuating element 21 and stop face for the blocking tongues 79). Since the blocking tongues 79 are elastically connected to the respective base body part 11, 12, they deviate elastically radially outwards when the sliding body 15 passes through during the retraction movement, in order to move radially inwards again after passing the square-shaped flange 24 due to their pretension and the To achieve blocking effect in connection with the flange 24. Since the diameter of the sliding body 15 is smaller in the distal end portion 49 than in the central region 52, a sufficiently large Overlapping of the blocking tongues 79 with the projection of the flange 24 over the adjacent cylindrical surface (viewed in the radial direction) ensured.

As can be seen from Figure 9, the blocking tongues 79 are shaped during the injection molding production of the base body parts 11 and 12 in such a way that, starting from a connection cross section with the associated base body part 11, 12 towards their free ends, they are on the longitudinal axis 7 of the base body 2 or sliding body 15 run too inclined. In order to reliably maintain this radially inward pretension even during a possibly longer storage time of the safety cannula arrangement 1 , the previously explained relaxation grooves 45 are formed in the sleeve area 42 of the sliding body 15 . During storage when the sliding body 15 is in use, these allow the blocking tongues 79 to be aligned inclined towards the longitudinal axis 7 exactly in the form required later in the secured position of the sliding body 15 to block a renewed extension movement of the sliding body 15. In this way, compared to a design of the sleeve section 42 without such stress relief grooves 45, material fatigue and a loss of the radially inwardly directed prestress are prevented, which could otherwise lead to a failure of the blocking tongues 79, so that the cannula 17 cannot be extended again would certainly be prevented.

With regard to the design of the triggering mechanism 37, the following should be stated with regard to FIG. 18 and additionally also FIGS. 10, 10a and 4:

As already mentioned, the base body 2 is approximately cuboid in the triggering area 36, with one triggering element 67a, 67b and the associated pressure rod 66a, 66b in connection with articulated elements designed as beams 82, three of which are connected by the respective pressure rod 66a, 66b. together form an L-shaped wall arrangement. Due to the small cross sections of the bars 82, these can be deformed relative to the proximal closure area 38 by pressure on the release members 67a. When pressure is applied to the release members 67a, 67b, a connection cross-section 83 arranged between these and the closure area 38 also acts as a further (pivoting) joint. A triggering surface formed by each of the triggering members 67a, 67b runs as can be seen at an angle of 90° to a plane within which the bars 82 and the pressure rods 66a, 66b connecting them in each case are arranged. The respective locking elements 61a, 61b in turn extend at an angle of 90° to the last-mentioned plane of the beams 82 and of the respectively associated pressure rod 66a, 66b. Overall, this results in a U or C arrangement in cross section. Reference List

1 safety needle assembly

2 basic bodies

3 wing module

4 needle protection

5 hose

6 transverse rib

7 longitudinal axis

8 longitudinal rib

9 grip area

10 first body part 11 second body part 12 third body part

13 film hinge

14 film hinge

15 sliding body 15m lateral surface

16 distal end section

17 cannula

18 tip

19 proximal end section

20 distal end section 21 adjusting element 21s support surface 22 distal end

23 proximal end

24 flange

25 detent

26 rotationally symmetrical section

27 cuboid section

28 lace section

29 transition section

30 connector

31 grip wings

32 length

33 length

34 Overlap Area 34d section

34p section

35 notch area

36 trigger area

37 release mechanism

38 closure area

39 snap hooks

40 connecting bridge

41 snap hooks

42 sleeve section

43 transition section

44 male portion

45 relaxation groove

46 section

47 section

48 boundary line

49 end section

50 diameter

51 diameter

52 midrange

53 recess

54 recess

55 floor

56 half wall

57 half wall

58 face

59 face

60 free length

61a, 61b locking element 62 proximal end face 63 step

64a, 64b control edge 65 outer surface

66a, 66b pressure bar 67a, 67b release element 68a, 68b elevation 69a, 69b arrow 70 distance

71 outline

72 interior

73 stop surface 74 stop surface

75 arc line

76 stop element

77 section

78 stop surface 79 locking tongue

80 windows

81 face

82 bars

83 Connection cross-section 84 Anti-rotation device

Claims

patent claims

A safety cannula arrangement (1) comprising a) a cannula (17) for puncturing human or animal tissue, the cannula (17) being provided with a tip (18) at a distal end. b) a slide (15) provided with the cannula (17) at its distal end (16) and with a flexible tube (5) at its proximal end portion (19), a extending through the slide (15). There is a flow connection between the tip (18) of the cannula (17) and a proximal end of the tube, c) a base body (2) which has an interior (72) in which the sliding body (15) is movably mounted, d) an adjusting element (21) arranged between the base body (2) and the sliding body (15), by means of which the sliding body (15) can be moved from a position of use in which the tip (18) of the cannula (17) is outside the base body (2). , can be displaced into a securing position in which the tip (18) of the cannula (17) is located within the base body (2), and e) a triggering mechanism which is arranged on the base body (2) and by means of which the displacement of the sliding body (15) from the use position to the safety position can be released, the triggering mechanism having at least one triggering member which can be subjected to a compressive force by means of a finger of a person using the safety cannula arrangement (1) and which is provided with a locking element (61a, 61b) which can be moved from a locking position in which it is engaged with the sliding body (15) and locks it in the position of use, can be displaced into a release position in which it is disengaged from the sliding body (15) so that the latter moves into the securing position, with a spacing of the at least one locking element (61a, 62b) can be enlarged from a longitudinal axis of the sliding body (15) when the locking element (61a, 61b) is displaced from the locking position into the release position. characterized in that the at least one release member (67a, 67b) and the associated locking element (61a, 61b) on different, preferably are arranged on opposite sides of the longitudinal axis (7) of the sliding body (15).

2. Safety needle arrangement (1) according to claim 1, characterized in that - in a cross section oriented perpendicularly to the longitudinal axis (7) of the sliding body - on diametrically opposite sides of the longitudinal axis (7) there is one release element (67a, 67b) and one Locking element (61a, 61b) are arranged.

3. Safety needle arrangement (1) according to claim 1 or 2, characterized in that the at least one release element (67a, 67b) and the associated locking element - in a cross section running perpendicularly to the longitudinal axis (7) of the sliding body (15) through the base body ( 2) - forming a U-shape or C-shape together, with the at least one release element (67a, 67b) preferably being on a first leg of the U or C and the associated locking element (61a, 61b ) is located.

4. Safety needle arrangement (1) according to one of Claims 1 to 3, characterized in that each release element (67a, 67b) is connected to the base body (2) via at least one articulated element, the articulated element being elastic and flexible relative to the base body (2). /or is plastically deformable when the release member (67a, 67b) is shifted from the locking position to the release position.

5. Safety cannula arrangement (1) according to one of Claims 1 to 4, characterized in that the at least one joint element is a bar (82), preferably that several joint elements are designed as bars (82) running parallel to one another and preferably spaced equidistantly from one another.

6. Safety cannula arrangement (1) according to one of claims 1 to 5, characterized in that the at least one joint element is connected with a proximal end to a proximal end section of the base body (2) and has the locking element (61a, 61b) at a distal end .

7. Safety cannula arrangement (1) according to one of Claims 1 to 6, characterized in that several joint elements, preferably each designed as a bar (82), are connected at their distal ends by means of a pressure rod (66a, 66b) running perpendicularly to the bar (82). ) are connected, the in turn connects a release element (67a, 67b) to the associated locking element (61a, 61b).

8. Safety needle assembly (1) according to any one of claims 1 to 7, characterized in that the triggering member (67a, 67b) has a triggering surface which is arranged at an angle of approximately 90° to a plane within which the at least one joint element movable and/or a pressure bar (66a, 66b) connecting several articulated elements is arranged, with the triggering surface also preferably having an elevation (68a, 68b), in particular one in the form of a hump, which can be activated by a finger of a person using the safety cannula arrangement (1). is palpable.

9. Safety needle arrangement (1) according to one of Claims 1 to 8, characterized in that the base body (2) is approximately cuboid in the region of the triggering mechanism, with preferably - in a cross section running perpendicular to the longitudinal axis (7) of the base body (2). - Two L-arrangements each consisting of a trigger surface and a plurality of joint elements together form a rectangle.

10. Safety needle arrangement (1) according to one of claims 1 to 9, characterized in that the base body (2) has two base body parts (11, 12) which are at least essentially mirror-symmetrical to a longitudinal axis (7) of the base body (2) in the assembled state of its base body parts (11, 12) are arranged extending level, wherein preferably the two base body parts (11, 12) are positively connected to each other by means of snap hooks or locking lugs.

11. Safety cannula arrangement (1) according to one of claims 1 to 10, characterized in that the at least one locking element (61a, 61b) in the position of use rests against a proximal end face (62) of the sliding body (15).

12. Safety cannula arrangement (1) according to one of claims 1 to 11, characterized in that a proximal end face (62) of the sliding body (15) is formed by a sleeve section (42) into which a distal end of the tube (5) is inserted .

13. Safety cannula arrangement (1) according to one of claims 1 to 12, characterized in that the at least one locking element (61a, 61b) bears against a step of the sliding body (15) in the secured position.

14. Safety cannula arrangement (1) according to claim 13, characterized in that the step for contacting the locking element (61a, 61b) in the secured position is formed by a radially projecting flange over a preferably rotationally symmetrical outer casing of the sliding body (15).

15. Safety cannula arrangement (1) according to claim 14, characterized in that the flange (24) has an end face at its distal end which forms a support surface (21s) for the adjusting element (21), which is preferably designed as a helical spring.