SAFETY CANNULATING

Description

[0001] The invention relates to a safety cannula arrangement comprising: a) a cannula for puncturing human or animal tissue, wherein the cannula has a tip at a distal end section; b) a sliding body which is provided with the cannula at a distal end section and with a flexible tube at a proximal end section, wherein a flow connection extending through the sliding body exists between the tip of the cannula and a proximal end of the tube; c) a base body in which the sliding body can be moved from a working position in which the tip of the cannula is located outside the base body to a locking position in which the tip of the cannula is located inside the base body, wherein the base body is composed of at least three base body parts, a first base body part of which is sleeve-shaped and encloses a distal end section of the sliding body in its working position;a second base body part adjoins and is connected to the first base body part in a proximal direction, wherein the second base body part has a U-shaped, L-shaped, C-shaped, or lid-shaped cross-section, and a third base body part and the second base body part can be joined to form a hollow body open at both opposite end faces, wherein the third base body part has a lid-shaped, C-shaped, L-shaped, or U-shaped form and is connected to the second or the first base body part via a film hinge. d) an actuating element arranged between the base body and the sliding body, by means of which the sliding body can be moved from the operating position to the locked position, and e) a release mechanism arranged on the base body, by means of which the movement of the sliding body from the operating position to the locked position can be triggered.wherein the release mechanism has at least one release element which can be acted upon by a finger of a person using the safety cannula arrangement with a radially directed pressure force or by two fingers with a torque and which is provided with a locking element which, as a result of being acted upon with the pressure force or the torque, can be moved from a locking position, in which it is engaged with the sliding body and locks it in the operating position, to a release position, in which it is disengaged from the sliding body, so that the latter moves into the safety position,

[0002] For the purposes of the present invention, the term "proximal" refers to an arrangement or position directed towards the body of the person using the safety cannula assembly, in particular towards their hand holding the safety cannula assembly, whereas "distal" refers to an arrangement or position directed away from the body or hand. Consequently, a proximal end of an object, including the safety cannula assembly at issue here, is positioned closer to the person's body than a distal end.

[0003] Cannula sets are used in medicine, for example, for the withdrawal of body fluids, particularly for venous blood sampling or for the infusion of fluids into a vessel in the human body. In this context, safety cannula sets, which feature a protective mechanism for the cannula, serve to prevent needlestick injuries as effectively as possible while simultaneously offering maximum comfort to the person using the cannula set and preventing pain and trauma for the patient during use, including the activation of the needle guard.While with a passive needle guard the needle retracts automatically after blood collection or infusion is complete, without any further intervention from the user, with an active needle guard the user must consciously engage the needle to move it into its locked position. The present invention relates primarily to safety needle devices with active needle guards.

[0004] The "base body" within the meaning of the present application is defined as fulfilling a housing function and possessing an enclosed interior space in which the sliding element is at least partially housed in the operating position. In the safety position, i.e., after the sliding element has been repositioned, at least the cannula itself, including its tip, is completely enclosed within the interior of the base body in order to reliably prevent both needlestick injuries from the tip and contact with the rest of the needle, which may be contaminated or infectious bodily substance. In the present case, the term "base body" encompasses both one-piece and multi-piece designs, whereby in the case of a multi-piece design, the individual base body parts can be inserted, clipped, or otherwise connected to one another.The connection of several base body parts to one another using so-called film hinges is also conceivable within the scope of the present application. In this context, the walls of the base body do not have to be completely closed, but can also have openings, breaks, slots or other perforations, so that a hermetic seal of the interior from the environment is not necessarily required.

[0005] In the context of the present invention, an "actuating element" is understood to be an element that acts as a kind of "drive" capable of exerting the necessary force on the sliding body to move it from the operating position to the locking position. The "drive element" and the associated "energy storage device" can be separate. However, the combination of these two functions in a single component, particularly in the form of a "spring element," is especially advantageous. This element can store either mechanical energy (e.g., a helical spring) or pressure energy, such as in a pre-charged gas storage device.

[0006] In this application, a "sliding body" is understood to be a component that receives the cannula at a distal end and is connected to the tubing at a proximal end. The terms "cannula holder" or "needle carrier" are also commonly used. State of the art

[0007] From EP 2 108 394 B1, a protective cover arrangement for a cannula is known in which the base body is composed of three base body parts. A first base body part is formed by a distal, sleeve-shaped end section in which the cannula is housed in the retracted, i.e., secured, position of the sliding body, thus preventing needlestick injuries. The second base body part is integrally and rigidly connected (i.e., without a joint or hinge) to the sleeve-shaped first base body part and initially has the shape of a semi-cylindrical groove, then widens trapezoidally at the proximal end. Even in the widened section, the second base body part is groove- or trough-shaped, albeit with increased width. A proximal end wall has a semicircular cutout.The known arrangement further comprises a third base body part, which is connected to the second base body part via a film hinge running parallel to the longitudinal axis of the sliding body. The film hinge is located in the widened proximal end section of the second base body part. The third base body part has a groove- or trough-shaped form complementary to the end section of the second base body part. When the second and third base body parts are joined, they rest complementarily on each other in the wider end section of the second base body part and are fixed to each other by a snap-hook connection. The third base body part also has a semicircular recess in its proximal end wall, which aligns with the semicircular recess in the proximal end wall of the second base body part to form a circular opening for the flexible hose or...The sliding body itself is supplemented. A disadvantage of this known safety needle arrangement is that the base body is open in a central area between the sleeve-shaped first base body section and the distal end face of the third base body section, as it consists there only of the half-shell of the second base body section. Therefore, there is a risk that, after use of the device and moving the needle holder into the safety position, contamination of persons may occur through contact with the freely accessible cannula (outside its tip area) which is contaminated with bodily fluid. Furthermore, the known safety cannula arrangement lacks an actuating element by which the sliding body could be automatically moved from the working position to the safety position simply by manual release.A very similar safety cannula arrangement is also known from WO 2013 / 068855 A1, which originates from the same applicant.

[0008] Furthermore, EP 2 509 674 B1 describes a base body of a safety cannula assembly in which two base body halves are connected by means of a film hinge extending transversely to a longitudinal axis of the base body and leaving an opening for the cannula between two hinge sections. When the two base body parts are joined, a longitudinally extending slot is located in each of the opposite narrow sides of the base body. A handle wing connected to the needle carrier passes through this slot and is axially displaceable together with the needle carrier. An actuating element for automatically transferring the sliding element from the operating to the safety position is not provided in the known safety needle assembly.

[0009] Furthermore, WO 2011 / 100039 A1 discloses a safety cannula arrangement in which no tube is connected to the rear end of the sliding body or cannula carrier, but rather the needle protrudes from both sides of the sliding body, and the rear, free end of the needle serves as a direct connection point for a blood collection tube. Therefore, according to WO 2011 / 100039 A1, the sliding body is designed to have a sufficiently large diameter for the insertion of the blood collection tube and is open at the proximal end to allow insertion.

[0010] The safety function of the previously known cannula arrangement results from the fact that, after completion of the blood collection process and after disconnection and withdrawal of the blood collection tube from the base body, a receiving body for the sliding body and the double cannula stored therein, which was previously in a "waiting position" outside the base body, is moved in a direction transverse to the longitudinal axis of the cannula into the space for the blood collection tube, which is no longer located there, such that a release element then enables a retraction movement of the cannula together with the sliding body when a receiving cross-section of the receiving body has been pushed over the proximal free end of the cannula, thus enabling a retraction movement of the sliding body together with the cannula inside the receiving body.The receiving body and the base body are arranged in a mutually inclined (kinked) arrangement, which is harmless due to the sufficiently small angle between the two longitudinal axes for the required movement of the sliding body on a curved path.

[0011] The release element and the locking principle implemented thereby comprise a keyhole whose narrow cross-section locks the sliding body in the operating position, while its enlarged cross-section allows the sliding body to pass through in the release position. Although WO 2011 / 100039 A1 discloses a film hinge for connecting two base body parts, the previously known design is not suitable for realizing a plurality of base body parts and connecting them each by means of a film hinge.

[0012] US Patent 5,746,215 A describes a safety cannula arrangement in which the cannula must first be withdrawn from an initial safety position into a working position by means of an externally accessible slider. During this withdrawal from the base body, a spring element is extended and thus pre-tensioned. After completion of the blood draw or puncture, this spring element contracts again upon pressure on a release mechanism, thereby returning the sliding body and cannula to the safety position.

[0013] EP 2 985 049 A1 describes a removable butterfly needle protective cover comprising a base body for receiving a butterfly needle, which is formed as a one-piece injection-molded part. The butterfly needle has a needle section, a wing section projecting from the base body, and a handle section attached to the wing section. One end of the handle section is connected to the needle section, and the other end is provided for connection to a hose. The butterfly needle is movable between a working state with the needle tip protruding and a secured state without the needle tip protruding. According to EP 2 985 049 A1, the base body comprises a needle tip protective head, an upper cover, and a lower cover. The needle tip protective head is designed as a cylinder with an axially through-hole.The upper and lower covers are formed by elongated components that extend axially from the base body and each have a distal and a proximal end. The distal ends of the upper and lower covers are connected to the cylindrical protective head of the base body by film hinges.

[0014] Finally, EP 1 448 260 A1 discloses a cover housing for a winged cannula, in which the housing (base body) is composed of two complementary half-shells connected by a film hinge. The connection of the two half-shells is achieved via a film hinge running parallel to the longitudinal axis of the cover housing or the needle carrier. Snap hooks are arranged on a longitudinal side of the housing opposite the film hinge to secure both housing halves in the closed position. This previously known housing design also has slots on two opposite longitudinal sides extending in the direction of the longitudinal axis, which allow displacement of the sliding element together with the retaining wings arranged thereon and projecting in opposite directions. Task

[0015] The invention aims to propose a safety cannula assembly that simplifies the assembly process, particularly the positioning of the actuating element and the generation of its preload. At the same time, the manufacturing effort should be reduced. Solution

[0016] Starting from a safety cannula arrangement of the type described above, the underlying problem is solved by the actuating element being supported with its distal end on a support surface of the first basic body part.

[0017] The cannula assembly according to the invention, which is preferably a blood collection device, offers significant advantages during assembly, particularly when inserting the sliding element into the base body. For this purpose, the first base body part and the adjoining second base body part, both arranged axially one behind the other in the direction of the longitudinal axis of the base body and sliding element respectively, are first provided, or—in the case of a film hinge connection between the first and second base body parts—brought into a linear alignment with each other. Then, the sliding element and the actuating element are joined together and inserted as a unit into the first and second base body parts, or alternatively, the (untensioned) actuating element is first inserted into the first and second base body parts, and only in a subsequent step is the sliding element added, thereby bringing the actuating element into the pre-tensioned state.

[0018] The sleeve-shaped first part of the base offers a significant advantage, particularly with regard to the secure and precise positioning of the actuating element within the base body. Especially when using a coil spring as the actuating element, it can be aligned and inserted coaxially with the sleeve-shaped first part of the base body and is then securely fixed at its distal end during the process of transitioning to the pre-tensioned state, preventing slippage, displacement, or dislodgement.

[0019] As the final step in the assembly sequence, the third basic body part is then connected to the second basic body part, thereby completing the basic body and giving it its final form.

[0020] To simplify handling, or to offer an alternative to grasping the housing-like part of the base body, it is proposed that the base body be provided with a grip wing on each of two opposite sides. The grip wings can be made of a rubber-elastic material and, in a known manner, pressed against each other by grasping with two fingers in an area above the base body until they make contact. Using two grip wings increases ease of use. However, using only one grip wing or even no grip wing at all is also conceivable.

[0021] A further development of the invention consists in the actuating element being supported at its distal end against a step formed in an interior of the first base body part or against 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 transition into a pre-tensioned state.

[0022] Further developing the arrangement according to the invention, the handle wings can be connected to a sleeve-shaped connecting element that is pushed onto the base body. Preferably, an overlapping area between the connecting element and the base body can enclose at least one axial section of the first base body part as well as one axial section each of the second and third base body parts. In this way, the sleeve-shaped connecting element not only ensures a secure and firm connection of the handle wings to the base body, but also stabilizes it like a cuff or clamp, which, due to the base body being composed of several base body parts, provides additional security for the assembled state.

[0023] One possible design for the first and second body parts involves rigidly connecting them. This eliminates any articulation between the two parts, specifically the presence of a film hinge. With this design, the alignment of the first and second body parts is always automatically ensured, and a degree of freedom that would otherwise be required during assembly through fixing and guiding the components is eliminated from the outset.

[0024] As an alternative to the aforementioned method, it is also possible to connect the first and second base body parts using a film hinge. In this case, one hinge axis of the film hinge should be perpendicular to and at a distance from the longitudinal axis of the sliding body.

[0025] Regarding the third base body part, two fundamental connection options to the other base body parts are conceivable: Firstly, the third base body part and the second base body part can be connected to each other 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 middle element of a "three-part chain" formed by the three base body parts, which is connected via two film hinges, with the second base body part being connected to both film hinges.

[0026] As an alternative to the embodiment described above, it is also possible for the third base body part and the first base body part to be connected to each other by means of a film hinge. In this case, as is already the case with the connection between the first and second base body parts, the hinge axis of the film hinge should be oriented perpendicular to and at a distance from the longitudinal axis of the sliding body. In the latter case, a symmetrical arrangement can be created in which the first base body part forms the middle link of the "three-part chain" and the two end links of the chain are formed by base body parts that are preferably identically designed.In this configuration, during the joining process, the second and third base body parts are preferably pivoted synchronously around their respective film hinge axes onto the longitudinal axis of the sliding body previously inserted into the first base body part, brought into contact with each other, and fixed against each other.

[0027] For reasons of symmetry and to simplify assembly, in the latter case the two film hinges should be the same distance from the tip of the cannula when viewed axially. Likewise, for the same reasons, the two film hinges should each be the same distance from the longitudinal axis of the sliding body.

[0028] Further developing the invention, it is also provided that the first basic body part rotationally symmetrical in a distal section and / or cuboidal in a proximal section The design preferably incorporates a film hinge on opposite proximal edges of the cuboid proximal section. This configuration enables the secure placement of the distal end of the actuating element or sliding body within the rotationally symmetrical distal section and prevents rotation of the sliding body within the cuboid proximal section, provided the sliding body has a cross-sectional shape that prevents rotation within the preferably rectangular, and in particular square, proximal cuboid section.

[0029] A preferred embodiment of the safety cannula arrangement according to the invention is characterized in that the rotationally symmetrical section of the first base body part has a cylindrical tip section and a similarly cylindrical transition section for receiving the actuating element compressed in the operating position, wherein preferably a removable tubular cannula guard is pushed onto the tip section.

[0030] Finally, it is also proposed that the second basic body part and the third basic body part be in a joined state together form a grip area extending proximally to the film hinges, which is preferably equipped on its outer shell with ribs or a plurality of protrusions to increase grip, and / or form a release area extending proximally to the grip area, which has a release mechanism, and / or form a locking 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 each other by means of snap hooks and / or locking lugs.

[0031] Furthermore, a further development of the invention provides that the first basic body part forms a distal end of the basic body. Example of implementation

[0032] The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing:

[0033] It shows: Figs. 1 and 2: A safety cannula assembly from two different perspectives with a distally attached cannula guard, Fig. 3: an exploded view of the safety cannula assembly, Fig. 4: a perspective view of the base body with the cannula protruding from it, Fig. 5: as Figure 4 , however, in a partial section of the base body, Fig. 6: a free-cut first base body part with a sliding body inserted therein, Fig. 7: the sliding body with cannula, adjusting element and a section of a flexible tube, Fig. 8: as Figure 7 , however without the actuating element, Fig. 9: a perspective view of the base body with the second and third base body parts folded to the side, Fig. 10: a perspective view of the first and second base body parts, Fig. 10a: as Fig. 10 , however, from a different perspective, Figs. 11 and 12: a longitudinal section through the safety cannula assembly according to the Figure 1 and 2with the sliding body in the operating position, Fig. 12a: a detail enlargement from Fig. 12 Figs. 13 to 16: each a section along line II through the safety cannula arrangement according to the Figure 1 and 2 in different positions of the release elements and locking elements, Fig. 17: a perspective view of the safety pin in a section along line II-II in the Figure 1 and 2 , Fig. 18: a release mechanism in a section along line III-III as in Figure 1 In the proximal direction, Fig. 19: a longitudinal section through the safety pin arrangement according to the Figure 1 and 2 in the locking position of the sliding body, Fig. 19a: a detail enlargement from Fig. 19 Fig. 20: a section through the safety cannula assembly according to the Figure 1 and 2 along line IV-IV with the sliding body in the locking position in the distal direction of view, Fig. 21: as Figure 18 , however, in the locking position of the sliding body, and Fig. 22: a cross-section through the safety cannula arrangement according to the Figure 1 and 2 along line VV in the distal direction of view.

[0034] From one into the Figure 1 and 2 The safety cannula assembly 1, shown from different perspectives, comprises, in its delivered state, an elongated base body 2, a wing module 3 attached to it, a tubular cannula guard 4 pushed over a distally projecting cannula, and a flexible tube 5 shown cut off for simplicity. The cut-off tube 5, which connects to a proximal end section of a [missing information] in the Figure 1 and 2The base body 2, which is connected to a non-visible sliding body, has a length of approximately 5 cm to 30 cm and is equipped at its proximal end with an adapter that ensures connectivity to other blood collection handling devices. The base body 2 is provided in a grip 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 of the safety cannula assembly as a whole or of the sliding body). The projection of these ribs over the otherwise rounded cuboidal geometry of the grip area 9 of the base body 2 decreases from a maximum projection 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 equidistant and parallel transverse ribs 6 are connected 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 secure and ergonomic grip is provided for two fingers grasping the grip area 9 of the base body 2 from opposite sides by a person using the safety cannula assembly 1, thus simplifying handling.

[0035] From the exploded view according to Figure 3It can be seen that the base body 2 is composed of three base body parts 10, 11, and 12: a sleeve-shaped first base body part 10, which extends furthest distally, and two hemispherical base body parts (second base body part 11 and third base 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 pivotally movable 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 are identically shaped but arranged symmetrically relative to a plane of symmetry that is parallel to the two film hinges 13, 14 and runs through the longitudinal axis 7 of the base body.

[0036] A substantially hollow cylindrical sliding body 15 is arranged in an interior space of the base body 2 and is mounted to be movable in the axial direction (i.e., 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 beveled surface, is inserted into a distal end section 16 of the sliding body 2 in a sealing manner. A distal end section 20 of the tube 5 is inserted into a proximal end section 19, which is designed as a socket section. For this reason, the sliding body 15, the cannula 17, and the tube 5 form a rigidly connected unit, the components of which—apart from the flexibility of the tube 5—are not displaceable relative to one another.In order to support the sliding body 15 in the operating position under preload in the base body 2 and in this way to provide a drive for a proximal retraction movement of the sliding body 15 relative to the base body 2, an actuating element 21 in the form of a helical spring is externally slid onto the distal end section 16 of the sliding body 15, which is supported with its distal end 22 in the first base body part 10 and with its proximal end 23 on a flange 24 with a rectangular cross-section, which projects over an outer surface of the sliding body 15.

[0037] The following will be used as an example to illustrate the Figures 4 to 10 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: From Figure 4It can be seen 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 contains, firstly, a rotationally symmetrical section (apart from two locking lugs 25 for fixing the wing module 26) and, adjoining it in the proximal direction, an approximately cuboid-shaped section 27. The rotationally symmetrical section 26 is in turn subdivided into a cylindrical tip section 28, onto which the in Figure 4 Cannula protection not shown 4 (see Fig. 1 and 2 ) is pushed on, and a cylindrical transition section 29, which is conically chamfered at its distal end, in which the distal end section 16 of the sliding body 15, not visible here, is located together with the adjusting element 21 pushed onto it. As can be seen with regard to the Figures 3As can be seen from 1 and 2, the wing module 3 has a central connecting part 30, to whose two opposite longitudinal sides a handle wing 31 is integrally attached (see also Figure 17), from a distal end of the base body 2, the connecting part 31 of the wing module 3 is pushed onto the base body 2. An axially measured length 32 of the connecting part 31 of the wing module 3 corresponds to a length 33 of an overlap area 34, which extends over both the first base body part 10 and the joined (second and third) base body parts 11 and 12 and can be subdivided into sections 34d and 34p, of which the distal section 34d overlaps the first base body part 10 and the proximal section 34p overlaps the second and third base body parts 11 and 12. In the area of ​​the first base body part 10, the overlap area 34 completely contains the cuboid section 27 and partially the approximately cylindrical transition section 29, up to the locking lugs 25 located there.The connecting part 30 of the wing module 3 thus also bridges, in particular, the area of ​​the two film hinges 13, 14 and a gap located there between the first base body part 10 and the second and third base body parts 11 and 12. Starting from a proximal end of the overlap area 34, the grip area 9, described above, extends proximally and is formed jointly by both base body parts 11 and 12. Further proximally is a circumferential groove area 35, and further proximally thereafter is a release area 36, ​​in which a release 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 locking area 38, in which the second base body part 11 and the third base body part 12 are positively connected to each other by means of snap hooks.Opening of the base body 2 by means 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 locking area 38 and on the other hand by the sliding connecting part 30 of the wing module 3.

[0038] In Figure 5The figure shows how the sliding element 15 is arranged in the interior of the base body 2. The second base body part 11 is not shown; only the "lower" third base body part 12 is depicted. The distal end section 16 of the sliding element 15, as well as the actuating element 21, are not visible because they are concealed within the sleeve-shaped first base body part 10. A snap hook 39 is visible in the locking area 38. This snap hook engages with a corresponding recess in the second base body part 11 when the two base body parts 11 and 12 are joined, forming a non-destructive locking mechanism. The release area 36 and the handle area 9 of each of the two base body parts 11 and 12 are connected to each other exclusively via a connecting web 40. This web 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 here that the entire second and third basic body parts 11, 12 (as well as the basic body 2 consisting of the three basic body parts 10, 11, 12 in total) including the film hinges 13, 14 is manufactured as a single-piece injection-molded part. Figure 5 Furthermore, a further snap hook 41 can be seen on the base body part 12, wherein this snap hook 41 is arranged in the grip area 9 and also interacts with an adapted recess in the second base body part 11 and holds the two base body parts 11 and 12 together (in addition to the snap hooks 39 and the connecting part 30 of the wing module 3).

[0039] In Figure 6The sliding body 15, including the cannula 17 inserted therein and the tube 5 inserted at its proximal end, is shown, with only the first base body part 10 depicted. The sliding body 15 has a sleeve section 42, which is larger in diameter than a central section and extends proximally to it. This sleeve section 42 is formed from a shorter transition section 43 and a cylindrical insertion section 44, which extends proximally to it. The insertion section 44 has an inner cylindrical bore that is adapted to an outer diameter of the flexible tube 5, and the tube is tightly bonded into this bore.

[0040] With regard to Figure 7It becomes apparent that the sleeve section 42 is provided with four release grooves 45, evenly distributed around its circumference and extending in the direction of the longitudinal axis of the sliding body 15, for the locking tongues of the base body 2, which will be explained below. The release 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 rises ramp-like to a circumferential boundary line 48 between the insertion area 44 and the conical transition section 43. The function of the release grooves 45 in conjunction with the aforementioned locking tongues will be explained later.

[0041] While in Figure 7 For the sake of clarity, the compressed actuating element 21 is shown on a distal end section 49 of the sliding body 15; this is otherwise analogous to the representation according to Figure 8 This is not the case. 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.

[0042] The individual areas of the basic body 2 and the mirror-symmetrical arrangement of the identically shaped basic body parts 11 and 12 can be very clearly illustrated by the Figure 9 The figure shows the base body 2 with base body parts 11 and 12 folded laterally from the first base body part 10. In this state, the base body 2 is removed from the injection mold as an injection-molded part. The following can be clearly seen from the figure: Figure 9 Remove the grip area 9, the adjoining notch area 35, the adjoining release area 36, ​​and the closure area 38 forming the proximal end. On the in Figure 9In the third basic body part 12 shown on the left, a recess 53 is visible in which the snap hook 39 (see Fig. 5 ) is lockable. A further recess 54 is also visible in the grip area 9, which serves for the locking reception of the corresponding snap hook 41 on the grip area 9 of the third base body part 12. Thus, there are a total of two snap hooks 39 and two recesses 53 in the locking area 38, and two snap hooks 41 and two recesses 54 in the grip area 9. On each of the two base body parts 11 and 12, there is therefore one snap hook 39, 41 and one recess 53, 54 in both the grip area 9 and the locking area 38.

[0043] Figure 10This allows a view into the channel-shaped third base body part 12, since, on the one hand, the second base body part 11, which is also channel-shaped and arranged above it in the assembled state, has been removed, and on the other hand, the sliding body 15 along with the cannula 17 and tube 5 is not inserted. It can be seen that a base 55 and two opposing half-walls 56, 57 of the base body part 12 are arranged at right angles to each other, 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 both base body parts 11 and 12 when joined and define a median plane parallel to the longitudinal axis 7 in the contact area of ​​the two base body parts 11, 12, which also forms a plane of symmetry. Furthermore, in Figure 10The snap hooks 41 in the handle area 9 and 39 in the locking area 38, arranged on opposite sides with respect to the longitudinal axis 7, are also visible.

[0044] In the Figure 11 , 12 and 12aThe diagram shows a longitudinal section of the safety cannula assembly 1 in the operating state of the sliding body 15 from different perspectives. A distal end face 58 of the sliding body 15 is essentially flush with a distal end face 59 of the first base body part. In this position, the cannula 17 projects with a free length 60 beyond the distal end face 59 of the base body part 10. The actuating element 21 is in a pre-tensioned state, so that the sliding body 15 tends to move proximally relative to the base body 2. This movement is prevented by two locking elements 61a, 61b, which are part of the release mechanism 37 and interact with a proximal end face 62 of the sliding body 15 in its sleeve section 42. The end face 62 of the sliding body 15, in conjunction with the smaller diameter hose 5, forms a step 63, which is also located in the Figures 6 to 8This is clearly visible. In the operating position of the sliding body 15 – viewed in the axial direction – this step is located in the notch area 35, 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 without play in the base body 2 in the operating position, which is essential for a proper puncture procedure.

[0045] From a synthesis of Figures 13 to 16 The operation of the release mechanism 37 becomes clear in Figure 18. The proximal end face 62, which forms the aforementioned step 63 in the transition from the hose 5 to the socket section 42 of the sliding body 15, is secured by two diametrically opposed locking elements 61a, 61b (see also Figure 18). Fig. 10 a)The sliding body 15 is held back so that it remains in the operating position 45. The release grooves are visible in the sleeve section 42 of the sliding body 15, resulting in a circular contour of the end face 62 in cross-section, interrupted by four recesses at 90° intervals.

[0046] The locking elements 61a, 61b have a triangular or trapezoidal shape when viewed axially and each have a control edge 64a, 64b against an outer surface 65 of the hose 5.

[0047] Out of Figure 18It can be seen that the locking elements 61a, 61b are each coupled to a release element 67a, 67b via a compression rod 66a, 66b. The release elements 67a, 67b are each provided with a projection 68a, 68b in the form of a hemispherical knob. In a side view of the base body 2, the release elements 67a, 67b form two approximately square surfaces, each with the central projection 68a, 68b, with the compression rods 66a, 66b extending at an angle of 90° to these surfaces. The locking elements 61a, 61b, in turn, extend at an angle of approximately 90° to the compression rods 66a, 66b, resulting in an overall C-shape or U-shape. The release elements 67a, 67b and the locking elements 61a, 61b each form a free leg of the U or C, whereas the compression bars 66a, 66b form a "base element" of the U or C.

[0048] If, after completion of the blood withdrawal or infusion performed using the safety cannula assembly 1, the sliding body 15 is to be moved into the locking position in which the cannula 17 is completely enclosed within the base body 2, the user of the safety cannula assembly 1 applies a radial pressure force, directed in the direction of arrows 69a, 69b, to the projections 68a, 68b of the release elements 67a, 67b simultaneously with two fingers of one hand. Starting from the Figure 13 In the depicted locking position, in which the locking elements 61a, 61b block the sliding body 15 by engagement (stop against the end face 62), the Figure 13 The upper locking element 61a moves to the right by pressing on the left release element 68a, whereas the one in Figure 13 The lower locking element 61b is moved to the left by pressure on the right release element 68b. Figure 14A state is shown in which, through corresponding displacement of the release elements 68a, 68b, which form a rigid unit, and the associated locking elements 61a, 61b, a gap 70 has formed between the latter and the outer surface 65 of the tube 5. However, this gap 70 is not yet large enough to prevent the end face 62 from contacting the locking elements 61a, 61b. For this reason, the cannula holder 15 remains in the operating position in this position of the release mechanism or the release elements 67a, 67b. Figure 15 shows a further intermediate state in which the distances 70 between the locking elements 61a, 61b and the outer surface 65 of the hose 5 are larger, but still cause an overlap between the locking elements 61a, 61b and the end face 62 of the sliding body 15 and thus its blockage.

[0049] In the Figure 16In the position shown, the release elements 67a, 67b with their associated button-shaped projections 68a, 68b are displaced outwards just far enough that the cross-section of the sliding body 15, defined by a circular outline 71 (envelope), is completely released in the area of ​​the sleeve section 42. The locking elements 61a, 61b are now disengaged from the sliding body 15, allowing the latter to move in a proximal direction, driven by the actuating element 21, which causes the cannula 17 to retract into the interior of the base body 2.

[0050] Accordingly, the Figures 19 and 19a The sliding body 15 is in the locking position, in which the cannula 17, including its tip 18, is arranged within an interior space 72 of the base body 2. The actuating element 21, in the form of a helical spring, is now in a more relaxed state compared to the operating position of the sliding body 15.

[0051] To prevent the entire sliding body 15, and thus also the cannula 17 itself, from exiting at the proximal end of the base body, the locking position of the sliding body 15 is defined by a stop surface 73 arranged on it. The stop surface 73 located on the sliding body 15 interacts with a stop surface 74 of the base body 2, which is formed at the proximal end of the base body 2, specifically at the proximal end of the closure area 38, which is jointly formed by the second base body part 11 and the third base body part 12.

[0052] As can be seen from the sectional view according to Figure 20As a result, both the second and the third base body parts 11, 12 have a U-shaped cross-section, wherein the two U-shaped cross-sections of the walls are nested 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, 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; rather, two corner areas are filled and each is defined by an arc 75 extending towards the longitudinal axis 7 of the base body 2, inscribing a quarter circle in the respective corner of the U or C. Figure 20The edges of an imaginary square, into which the stop elements 76, bounded by the arc lines 75, are placed in the corners, are shown with dashed lines for better clarity.

[0053] As from Figure 20 As can be seen, the radius of a circle passing through the (slightly rounded) corners of the square flange 24 when viewed along the longitudinal axis 7 is larger than the radius of a circle formed by a continuation of the two arcs 75. For this reason, the square flange 24 cannot pass through the free cross-section in the area of ​​the stop surfaces 74 formed on the stop elements 76, thus preventing any movement of the sliding body 15 at this point. (From the sectional view according to...) Figure 21This fact can also be clearly seen. The square flange 24 rests against the stop surfaces 76 of the base body parts 11, 12 in the area of ​​its rounded sections 77. In the Figure 21 In the depicted state, the cannula carrier 15 is in the secured position, in which the sleeve section 42 at the proximal end of the sliding body 15 has emerged from the base body 2.

[0054] Out of Figure 22It can be seen that the interior 72 in the cuboid section 27 of the overall sleeve-shaped first base body part 10 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, smooth axial movement of the sliding body 15 is possible under the influence of the actuating element 21, while on the other hand, rotation of the sliding body 15 about the longitudinal axis 7 is reliably prevented. The flange 24 thus fulfills the function of a rotational locking element for the sliding body 15, and correspondingly, the cuboid section 27 of the first base body part 10 fulfills the function of a rotational locking element for the base body 2. While the proximal stop surface 73 for limiting the retraction movement of the sliding body 15 is arranged on the square flange 24 of the sliding body 15, the square flange 24 has a dual function insofar as its Figure 22not visible, however in the Figure 7 and 8 The further stop surface 78 is illustrated to serve as support for the actuating element 21.

[0055] 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 locking position, from being intentionally or unintentionally advanced again in the distal direction to expose the cannula 17 and potentially reuse the safety cannula assembly 1, which must be avoided at all costs. For this purpose, the locking tongues 79 mentioned above serve, which are designed as spring elements of the base body 2 and are each arranged within a window 80 that surrounds the locking tongues 79 on three sides. This fact can be seen in the Figures 19 and 19aThe sliding body 15 is in the locked position. Each end face 81 of the locking tongues 79 rests against the distally oriented stop surface 78 of the square flange 24, thus giving the flange a triple function (end stop of the retraction movement, support of the actuating element 21, and stop surface for the locking tongues 79). Since the locking tongues 79 are elastically connected to the respective base body parts 11, 12, they deflect elastically radially outwards as the sliding body 15 passes through during the retraction movement. After passing the square flange 24, their preload causes them to move radially inwards again, thus achieving the locking effect in conjunction with the flange 24.Since the diameter of the sliding body 15 in the distal end section 49 is smaller than in the central area 52, a sufficiently large overlap of the blocking tongues 79 with the projection of the flange 24 over the adjacent cylindrical surface (viewed in the radial direction) is ensured.

[0056] As can be seen from Figure 9As can be seen, the locking tongues 79 are shaped during the injection molding of the base body parts 11 and 12 such that, starting from a connecting cross-section with the associated base body part 11, 12, they extend towards their free ends, inclined towards the longitudinal axis 7 of the base body 2 or sliding body 15. To reliably maintain this radial inward preload even during potentially extended storage of the safety cannula assembly 1, the previously described release grooves 45 are molded into the socket area 42 of the sliding body 15. These grooves allow the locking tongues 79 to be aligned inclined towards the longitudinal axis 7 during storage of the sliding body 15, precisely in the shape required later in the locking position of the sliding body 15 to block any further extension 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 a renewed extension of the cannula 17 would not be reliably prevented.

[0057] Regarding the design of the triggering mechanism 37, with regard to Figure 18 as well as additionally the Figures 10, 10Sections a and 4 further explain the following: As already mentioned, the base body 2 in the release area 36 is approximately cuboid in shape, with each release element 67a, 67b and the associated compression rod 66a, 66b, in conjunction with hinge elements designed as beams 82, three of which are connected by the respective compression rod 66a, 66b, together forming an L-shaped wall arrangement. Due to the small cross-sections of the beams 82, they can be deformed relative to the proximal closure area 38 by pressure on the release elements 67a. When pressure is applied to the release elements 67a, 67b, a connecting cross-section 83 arranged between them and the closure area 38 also acts as a further (rotary) hinge. A release surface formed by the release elements 67a, 67b is clearly arranged at an angle of 90° to a plane within which the beams 82 and the compression bar 66a, 66b connecting them are arranged.The respective locking elements 61a, 61b extend at an angle of 90° to the latter plane of the beams 82 and the respective associated compression member 66a, 66b. Overall, this results in a U- or C-arrangement in the cross-section. Reference symbol list

[0058] 1 Safety cannula assembly 2 Base body 3 Wing module 4 Cannula guard 5 Tube 6 Transverse rib 7 Longitudinal axis 8 Longitudinal rib 9 Grip area 10 First base body part 11 Second base body part 12 Third base body part 13 Film hinge 14 Film hinge 15 Sliding body 15 Sheath area 16 Distal end section 17 Cannula 18 Tip 19 Proximal end section 20 Distal end section 21 Actuating element 21 Support surface 22 Distal end 23 Proximal end 24 Flange 25 Locking lug 26 Rotationally symmetric section 27 Cuboid section 28 Tip section 29 Transition section 30 Connecting part 31 Grip wing 32 Length 33 Length 34 Overlap area 34d Section 34p Section 35 Notch area 36 Release area 37 Release mechanism 38 Locking area 39 Snap hook 40 Connecting web 41 Snap hook 42 Sleeve section 43 Transition section 44 Insertion section 45 Release groove 46 Section 47 Section 48 Boundary line 49 End section 50 Diameter 51 Diameter 52 Middle area 53 Recess 54 Recess 55 Bottom 56 Half wall57 Half-wall 58 End face 59 End face 60 Free length 61a, 61b Locking element 62 Proximal end face 63 Step 64a, 64b Control edge 65 Shell surface 66a, 66b Compression bar 67a, 67b Release element 68a, 68b Raise 69a, 69b Arrow 70 Spacing 71 Outline 72 Interior 73 Stop surface 74 Stop surface 75 Arc line 76 Stop element 77 Section 78 Stop surface 79 Blocking tongue 80 Window 81 End face 82 Beam 83 Connecting cross-section 84 Rotation locking device

Claims

1. A safety cannula assembly (1) comprising a) a cannula (17) for puncturing human or animal tissue, wherein the cannula has, in a distal end section, a tip (18), b) a sliding body (15) which, in a distal end section (49), is provided with the cannula (17) and, in a proximal end section (46), with a flexible tube (5), wherein a flow connection extending through the sliding body (15) exists between the tip (18) of the cannula (17) and a proximal end of the tube (5), c) a base body (2), in which the sliding body (15) is displaceable from a use position, in which the tip (18) of the cannula (17) is located outside the base body (2), into a safety position, in which the tip (18) of the cannula (17) is located inside the base body (2), wherein the base body (2) is composed of at least three base body parts (10, 11, 12), of which - a first base body part (10) is designed in the form of a sleeve and surrounds a distal end section (49) of the sliding body (15) in its use position, - a second base body part (11) adjoins the first base body part (10) in the proximal direction and is connected thereto, wherein the second base body part (11) is formed in a U-shaped, L-shaped, C-shaped or cover-shaped manner in cross-section and - a third base body part (12) and the second base body part (11) can be assembled to form a hollow body open at both opposite end faces, wherein the third base body part (12) is formed in a cover-shaped, C-shaped, L-shaped or U-shaped manner and is connected to the second base body part (11) or to the first base body part (10) via a film hinge (13, 14), d) an actuating element (21) arranged between the base body (2) and the sliding body (15), by means of which the sliding body (15) can be displaced from the use position into the safety position, and e) a release mechanism (37) arranged on the base body (2), by means of which the displacement of the sliding body (15) from the use position into the safety position can be triggered, wherein the release mechanism (37) has at least one release member (67a, 67b) which can be acted upon by a person using the safety cannula assembly (1) with a radially directed pressing force or with a torque and which is provided with a locking element (61a, 61b) which, as a result of the pressing force or torque being applied, is displaceable from a locking position, in which it engages with the sliding body (15) and locks it in the use position, into a release position, in which it is disengaged from the sliding body (15) in such a manner that the sliding body moves into the safety position, characterized in that the actuating element (21) is supported with its distal end against a support surface (21s) of the first base body part (10).

2. The safety cannula assembly (1) according to claim 1, characterized in that the base body (2) is provided on each of two opposite sides with a grip wing (31).

3. The safety cannula assembly (1) according to claim 1 or 2, characterized in that the actuating element (21), with its distal end, is supported against a step formed in an interior space of the first base body part (10) or against an end wall forming a distal end of the first base body part (10).

4. The safety cannula assembly (1) according to any one of claims 1 to 3, characterized in that the grip wings (31) are connected to a sleeve-shaped connecting part (30) which is pushed onto the base body (2), wherein preferably an overlap region (34) between the connecting part (30) and the base body (2) encloses both at least one axial section (27, 29) of the first base body part (10) and in each case at least one axial section (34p) of the second base body part (11) and of the third base body part (12).

5. The safety cannula assembly (1) according to any one of claims 1 to 4, characterized in that the first base body part (10) and the second base body part (11) are rigidly connected to one another and integrally formed.

6. The safety cannula assembly (1) according to any one of claims 1 to 4, characterized in that the first base body part (10) and the second base body part (11) are connected to one another via a film hinge (13), wherein a hinge axis of the film hinge (13) is oriented perpendicularly to, and spaced apart from, the longitudinal axis (7) of the sliding body (15).

7. The safety cannula assembly (1) according to any one of claims 1 to 6, characterized in that the third base body part (12) and the second base body part (11) are connected to one another by means of a film hinge, the hinge axis of which is oriented parallel to or perpendicular to the longitudinal axis (7) of the sliding body (15).

8. The safety cannula assembly (1) according to any one of claims 1 to 6, characterized in that the third base body part (12) and the first base body part (10) are connected to one another by means of a film hinge (14), the hinge axis of which is oriented perpendicularly to, and spaced apart from, the longitudinal axis (7) of the sliding body (15).

9. The safety cannula assembly (1) according to claims 6 and 8, characterized in that the two film hinges (13, 14), viewed in the axial direction, are at the same distance from the tip (18) of the cannula (17).

10. The safety cannula assembly (1) according to claim 9, characterized in that the two film hinges (13, 14) are each at the same distance from the longitudinal axis (7) of the sliding body (15).

11. The safety cannula assembly (1) according to any one of claims 1 to 10, characterized in that the first base body part (10) - is rotationally symmetrical in a distal section (26), and / or - is cuboid-shaped in a proximal section (27), wherein preferably a film hinge (13, 14) is arranged in each case on opposite proximal edges of the cuboid-shaped proximal section (27).

12. The safety cannula assembly (1) according to claim 11, characterized in that the rotationally symmetrical section (26) of the first base body part (10) has a cylindrical tip section (28) and a preferably likewise cylindrical transition section (29) for receiving the actuating element (21) compressed in the use position, wherein preferably a removable tubular cannula protector (4) is pushed onto the tip section (28).

13. The safety cannula assembly (1) according to any one of claims 1 to 12, characterized in that the second base body part (11) and the third base body part (12), in an assembled state, together form - a grip region (9) adjoining the film hinges (13, 14) in the proximal direction, which is preferably provided on its outer surface with ribs (6, 8) or with a plurality of projections for increasing grip, and / or - a release region (36) adjoining the grip region (9) in the proximal direction, which comprises a release mechanism (37), and / or - a closure region (38) arranged at a proximal end of the base body (2), in which the second base body part (11) and the third base body part (12) are connected to one another by means of snap hooks (39) and / or latching projections in a form-fitting manner.

14. The safety cannula assembly (1) according to any one of claims 1 to 13, characterized in that the first base body part (10) forms a distal end of the base body (2).