Insertion device for an infusion set

Abstract

The invention relates to an insertion device for an infusion set (8) having an advancing means (3, 4) for moving the infusion set (8) from a proximal position into a distal position along a central axis (z). The insertion device also comprises a holding element (2), for holding the infusion set (8), and a push button (7). The push button (7) can be displaced along a central axis (z) by an actuation stroke (H) and is designed such that, when the push button (7) is actuated by the actuation stroke (H), the holding element (2) is moved radially outwards in order to at least partially release the infusion set (8) from the holding element (2).

Description

[0001] Insertion device for an infusion set

[0002] The present invention relates to an insertion device for an infusion set.

[0003] Infusion sets are known, for example, from W 002 / 070037 A2 and W02005 / 049117A2. Such infusion sets are used, for example, in insulin pump therapy, where insulin is transported from the insulin pump into the body of a diabetic patient using an infusion set. The infusion set comprises a cannula, which is preferably placed directly under or into the skin using an insertion device or puncture aid and held in place with a plaster.

[0004] An insertion device for such an infusion set is known, for example, from EP2979713B1. A disadvantage of this insertion device is that the infusion set is pushed out of the device without guidance, which creates the risk that the cannula will not penetrate sufficiently at a right angle to the puncture site. This can cause skin injuries to the patient.

[0005] It is therefore an object of the present invention to provide a simpler and safer insertion of an infusion set with such an insertion device.

[0006] This object is solved by the subject matter of independent claim 1. Advantageous embodiments emerge from the dependent claims.

[0007] In the following, proximal position of the insertion device means a position in which a propulsion device for advancing the infusion set into the skin is in a tensioned state, distal position of the insertion device means a position in which the propulsion device for advancing the infusion set into the skin is in a relaxed state.

[0008] The invention relates to an insertion device for an infusion set, comprising a propulsion mechanism for moving the infusion set from a proximal position to a distal position along a central axis (z). Furthermore, the insertion device comprises a holding element for holding the infusion set and a base part with a contact surface for placing the insertion device on an application site on the body of a patient, wherein the base part is received by the holding element. To hold the infusion set, the holding element comprises at least one holding arm, preferably two or a multiple of two holding arms. The holding arm is designed such that a holding wing provided on the infusion set can be snapped into and out of the holding arm. The holding arm is preferably elastic and / or tensionable.The insertion device further comprises a head part that is arranged to be rotatable relative to the base part about the central axis (z). Upon relative rotation between the head part and the base part in a first rotational direction, a guide element attached to the holding element can be guided by a counter-guide element provided on the base part, wherein the holding element is movable relative to the base part from a distal position to a proximal position along the central axis (z).

[0009] During a relative rotation between the head part and the base part in a second rotational direction, the guide element of the holding element can be guided by the counter-guide element provided on the base part, wherein the holding element can be moved relative to the base part from the proximal position to the distal position along the central axis (z). The holding element is movable along the axis (z) because the guide element of the holding element is in guiding engagement with the counter-guide element provided on the base part.

[0010] Preferably, the guide element of the holding element is designed as a guide cam, and the guide counter-element of the base part is designed as a guide cam. Alternatively, the guide element of the holding element can be designed as a guide cam, and the guide counter-element of the base part can be designed as a guide cam. A different guide element or a different guide counter-element can also be provided, for example, an external thread and a corresponding internal thread, provided that the guide element and the guide counter-element are in guiding engagement.

[0011] The retaining element is preferably connected to the head part in a rotationally fixed manner. The head part can rotate with the retaining element relative to the base part in a first rotational direction and / or a second rotational direction.

[0012] In addition, a lid can be connected to the head section in a rotationally fixed manner. Alternatively, the lid can be formed monolithically with the head section. The head section preferably accommodates the lid at its proximal end.

[0013] The propulsion device can preferably comprise an elastic means and a sliding element. Upon relative rotation between the head part and the base part in the first rotational direction, the elastic means can be tensioned, and upon relative rotation between the head part and the base part in the second rotational direction, the elastic means can be relaxed. The elastic means can be supported on the sliding element and on the head part or the cover, or alternatively, on the base part. The elastic means can thus be designed as a compression spring or a tension spring.

[0014] Preferably, in the proximal position of the propulsion device, the sliding element can be rotated from a first position to a second position, wherein in the first position the sliding element is held by the holding element and in the second position the sliding element can be released from the holding element, so that the sliding element is axially movable along the central axis (z) relative to the holding element.

[0015] The sliding element is preferably arranged offset relative to the retaining element in the distal and proximal positions of the propulsion device by an angle of rotation, preferably by an angle of rotation of approximately 10°, approximately 12°, or approximately 15°. A different angle of rotation may also be provided.

[0016] The sliding element has a safety surface, preferably a projection, in particular a ramp-shaped projection. The safety surface, in particular the projection, serves to hold the infusion set in the holding element, in particular to hold it better. The safety surface, in particular the projection of the sliding element, can be in abutting contact with the holding wing of the infusion set in the first position of the sliding element in order to pretension the holding arm of the holding element radially inward and to hold the infusion set. Thus, in the first position of the sliding element, the snap connection between the holding wing of the infusion set and the holding arm of the holding element is secured. The snap connection between the holding element and the infusion set holds the infusion set better in the insertion device.The patient can remove a covering of the plaster in the insertion device with the inserted infusion set without the infusion set being released prematurely from the insertion device or the infusion set being damaged. The safety surface, in particular the projection of the sliding element, can move into the second position of the sliding element by rotation relative to the holding element, wherein the safety surface, in particular the projection of the sliding element, is arranged radially offset relative to the holding arm. Thus, in the second position of the sliding element, the infusion set can be pushed out of the holding arm of the holding element more easily, since the infusion set is no longer additionally held in the holding arm via the sliding element, but rather the infusion set is only held in the holding element via the snap connection between the holding wing of the infusion set and the holding arm of the holding element.

[0017] The sliding element can have a ring support for pushing the infusion set out of the holding element or can be designed as a ring support. The ring support can be sleeve-shaped. The ring support can be at least partially ring-shaped. The ring support can come into abutting contact with the infusion set, in particular with a housing, in particular a cap-shaped housing of the infusion set. Thus, the infusion set can be guided and pushed out of the insertion device.

[0018] The lid preferably accommodates a push button. The push button can be displaceable along the central axis (z) by an actuation stroke (H). Furthermore, the push button can be designed such that, upon actuation of the push button by the actuation stroke (H), the sliding element can be rotated relative to the holding element about the central axis (z) by the angle of rotation, preferably by a rotation angle of approximately 10°, approximately 12°, or approximately 15°, into the second position.

[0019] The push button can be displaceable along the central axis (z) by an actuation stroke (H) and can be designed such that, upon actuation of the push button by the actuation stroke (H), the holding element (2) is moved radially outward to at least partially release the infusion set from the holding element. The snap connection between the holding wing of the infusion set and the holding arm of the holding element can thus be released.

[0020] The holding element and the push button can each have sliding surfaces which are designed such that when the push button is actuated by the actuating stroke (H), the holding element is moved radially outwards in order to at least partially release the infusion set from the holding element.

[0021] The push button can preferably have a snap arm, in particular a snap hook on the snap arm, which can move the holding arm of the holding element radially outward to at least partially release the infusion set from the holding arm. This movement can be a spreading movement, a radially outward pretensioning movement, or a deflection movement. For this purpose, the snap hook on the push button and / or the holding arm of the holding element can have sliding surfaces, in particular inclined sliding surfaces. The sliding surfaces can come into sliding contact.

[0022] Preferably, this movement can take place at least partially before and / or during the pressing of the ring support onto the infusion set.

[0023] Furthermore, the sliding element comprises a recess for receiving a retaining tab provided on the infusion set. The patient can hold the infusion set using the retaining tab of the infusion set. The retaining tab can be elongated. However, other shapes can also be provided. The recess of the sliding element is designed such that the retaining tab can preferably be inserted in one orientation or in two orientations, wherein these two orientations are arranged offset from one another by 180° in the circumferential direction. This ensures easy insertion of the infusion set into the insertion device.

[0024] The invention is described below with reference to several figures. The features disclosed herein advantageously further develop the invention, both individually and in combination. They show:

[0025] Figures 1 a and 1b: Exploded views of an embodiment of an insertion device.

[0026] Figure 2: a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in an initial position, wherein the longitudinal sectional view corresponds to the section line A-A shown in Figure 1a or in Figure 1b.

[0027] Figure 3: a longitudinal sectional view of the embodiment of the insertion device according to Figure 1 a or 1 b with an inserted infusion set, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1 a or in Figure 1 b.

[0028] Figure 4: a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in a loaded position, the longitudinal sectional view corresponding to the section line AA shown in Figure 1a or in Figure 1b.

[0029] Figure 5: a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in a triggered position, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or in Figure 1b.

[0030] Figure 6: a longitudinal sectional view of the embodiment of the insertion device according to Figure 1 a or 1 b with the infusion set inserted into the skin of a patient, the longitudinal sectional view corresponding to the section line AA shown in Figure 1 a or in Figure 1 b.

[0031] Figures 1a and 1b show exploded views of an embodiment of an insertion device according to the invention. The injection device comprises a sliding element (3) and a holding element (2) for holding an infusion set (8), wherein the infusion set (8) can comprise a cannula (8c) for piercing the skin of a patient and a plaster (8d) for securing the infusion set to the patient's skin. For this purpose, the holding element (2) comprises at least two holding arms (2a), wherein the at least two elastic holding arms (2a) are each arranged offset from one another by 180° in the circumferential direction. The holding arms (2a) are designed such that two holding wings (8a) arranged on the infusion set (8) can snap into and out of the holding arms (2a). So that the infusion set (8) can be inserted into the insertion device, the sliding element (3) has a recess (3g) at its distal end.A retaining tab (2b) attached to the infusion set (8) can be received in the recess (3g). Furthermore, the insertion device comprises a head part (5) and a base part (1), wherein the base part (1) accommodates the retaining element (2). The base part.

[0032] (1) comprises a contact surface (1a) for placing the insertion device onto an application site on the patient's body. Longitudinal webs (1b) for axially guiding the holding element (2) along a central axis (z) are arranged on the inner surface of the base part (1). An annular groove (1c) is provided at the proximal end and on the outer surface of the base part (1). A snap-in element (5a) is attached to the distal end and on the inner surface of the head part (5). The snap-in element (5a) of the head part (5) is snapped into the annular groove (1c) of the base part (1) such that the head part (5) is rotatable relative to the base part (5). The holding element (1) has a guide element in the form of a guide curve (2b), which engages with a guide counter-element in the form of a guide cam (1d) provided on the base part (1).During a relative rotation between the head part (5) and the base part (1) in a first direction of rotation, the guide curve (2b) of the holding element (2) can be guided by the guide cam (1d) provided on the base part (1), wherein the holding element (2) can be moved relative to the base part (1) from a distal position to a proximal position along the central axis (z). The holding element (2) can be guided due to or by means of the guide pair (1d; 2b). During a relative rotation between the head part (5) and the base part (1) in a second direction of rotation, the guide curve (2b) of the holding element (2) can also be guided by the guide cam (1d) provided on the base part (1), wherein the holding element (2) can be moved relative to the base part (1) from the proximal position to the distal position along the central axis (z). The holding element (2) is connected to the head part (5) in a rotationally fixed and axially movable manner.For this purpose, the holding element (2) comprises a rib (2c) on the outer surface of the casing, which rib engages with a groove (5b) provided on the inner surface of the casing of the head part (5). The insertion device further comprises a propulsion device. The propulsion device comprises an elastic means in the form of a compression spring (4) and the sliding element (3). The compression spring (4) is tensionably mounted between the sliding element (3) and a cover (6). The cover (6) is axially fixedly connected to the head part (5) via a snap connection. For this purpose, the cover (6) has a cover groove (6a) at its proximal end, which engages with an annular web (5c) provided on the head part (5). The sliding element (3) has an annular support (3a) for pressing the infusion set (8) out of the insertion device, in particular for pressing it out in a guided manner.Furthermore, a sliding element stop (3b) is provided on the sliding element (3), which can come into contact with a holding element stop (2e) attached to the inner surface of the casing of the holding element (2). Due to the contact between the sliding element stop (3b) and the holding element stop (2e), the sliding element (3) is firmly connected axially to the holding element (2). This prevents the sliding element (3) from independently moving out of contact with the holding element.

[0033] (2), a snap fastener (2d) provided on the inner surface of the holding element (2) can snap into a first groove (3c) provided on the outer surface of the sliding element (3). In addition, a stop contact can be provided between a first sliding element web (3e) provided on the sliding element (3) and a first holding element web (2h) attached to the holding element (2) in order to limit relative rotation between the sliding element (3) and the holding element (2) in a first direction of rotation. In order to limit relative rotation between the sliding element (3) and the holding element (2) in a second direction of rotation, a stop contact is provided between a second sliding element web (3e') provided on the sliding element (3) and a second holding element web (2h') attached to the holding element (2).When the second sliding element web (3e') is in abutting contact with the second holding element web (2h'), the sliding element (3) is in abutting contact with the holding element (2), such that the sliding element (3) is axially displaceable relative to the holding element (2). For this purpose, the holding element (2) has a guide groove (2f) on the inner surface of the casing, wherein the sliding element stop (3b) can slide with the first and second sliding element webs (3e, 3e') along the guide groove (2g). The snap catch (2d) of the holding element (2) can thereby be engaged in a second groove (3c). 1 ) of the sliding element (3), wherein the second groove (3c 1 ) is arranged offset in the circumferential direction from the first groove (3c) of the sliding element. The sliding element (3) further comprises a control cam (3d) which can come into guiding engagement with the guide cam (1d) of the base part (1). Upon relative rotation of the head part

[0034] (5) and the base part (1), the sliding element (3) can be rotated relative to the holding element (2) via the guide cam (1d) of the base part (1) and via the control curve (3d) of the sliding element (3). The sliding element (3) moves relative to the holding element (2) from a first to a second position. The guide curve (2b) of the holding element (2), the guide cam (1d) of the base part (1), and the control curve (3d) of the sliding element (3) are designed and arranged such that the sliding element (3) can be rotated relative to the holding element (2). The angle of rotation between the sliding element (3) and the holding element (2) can preferably be approximately 10°. Other angles of rotation can also be provided, for example approximately 12° or 15°. The insertion device further comprises a push button (7) which is received by the cover (6). The push button (7) has a snap arm (7a) projecting in the distal direction. The snap arms (7a) are in sliding contact with the cover

[0035] (6) provided lid webs (6b). A snap hook (7b) attached to the respective snap arm (7a) forms a stop with the distal end of the lid web (6b), so that the relative axial movement in the proximal direction of the push button (7) relative to the lid (6) is limited. The snap arm (7a), in particular the snap hook (7b) of the snap arm (7a) of the push button, is displaceable along the central axis (z) by an actuation stroke (H) and is designed such that when the push button (7) is actuated by the actuation stroke (H), the holding element (2) is moved radially outwards in order to at least partially release the infusion set (8) from the holding element (2).A sliding surface (7e), in particular an inclined sliding surface (7e), is provided on the snap hook (7b) of the push button (7), which sliding surface can come into sliding contact with a sliding surface (2g), in particular an inclined sliding surface (2g), provided on the snap arm (2a) of the holding element (2), wherein when the push button is actuated by the actuating stroke (H), the snap arm (2a) of the holding element (2) is moved radially outwards in order to at least partially release the infusion set (8), in particular the holding wing (8a) of the infusion set (8), from the holding arm (2a) of the holding element. The relative axial movement in the distal direction of the push button (7) relative to the cover (6) is controlled between a spring element located at the proximal end of the push button.

[0036] (7) provided push-button disc (7c) and a lid shoulder (6c) attached to the proximal end of the lid (6). The push-button (7) further comprises a push-button bevel (7d) which can interact with a sliding element edge (3h) of the sliding element (3) provided at a sliding element opening (3f) in order to rotate the sliding element (3) relative to the holding element (2). Figure 2 shows a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in an initial position, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or Figure 1b. The holding element (2), the push-button (7) and the propulsion device (3, 4) are in the distal position, wherein no infusion set has yet been inserted into the insertion device. The guide cam (1d) of the base part (1) is in abutting contact with the proximal end of the control cam (2b) of the holding element (2).The sliding element stop (3b) of the sliding element rests on the holding element stop (2e) of the holding element (2), so that the sliding element (3) is axially firmly connected to the holding element (2). The snap catch (2d) of the holding element (2) projects into the first groove (3c) of the sliding element (3), so that the sliding element (3) cannot independently come into contact with the holding element (2). The compression spring (4) is mounted between the cover (6) and the sliding element (3) such that the sliding element (3) and the holding element (2) are held in the distal position. The compression spring (4) can be relaxed or, preferably, pretensioned.

[0037] Figure 3 shows a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b with the inserted infusion set, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or Figure 1b. The patient inserts the infusion set (8) with the holding tab (8b) through the recess (3g) of the sliding element (3). The recess (3g) of the sliding element (3) is designed such that the holding tab (8b) can be inserted in two orientations, which are offset from one another by 180° in the circumferential direction. The holding wings (8a) of the infusion set (8) snap into the holding arms (8a) of the holding element (2). The infusion set (8) is inserted into the insertion device. The sliding element (3), in particular the ring support (3a) of the sliding element (3) and the infusion set (8), have a distance along the central axis (z).A projection (3i) provided on the sliding element is in abutting contact with the retaining wing (8a) of the infusion set in the first position in order to hold the infusion set (8), in particular the retaining wing (8a) of the infusion set (8), in the retaining arm (2a). The projection (3i) of the sliding element (3) biases the retaining arm (2a) of the retaining element (2) radially outward. The projection (3i) of the sliding element (3) is ramp-shaped.

[0038] Figure 4 shows a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in a loaded position, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or Figure 1b. The patient rotates the head part (5) relative to the base part (1) of the insertion device in the first direction of rotation. The guide curve (2b) of the holding element (2) is guided by the guide cam (1d) arranged on the base part (1), so that the holding element (2) is moved relative to the base part (1) from the distal position to the proximal position along the central axis (z). The guide cam (1d) of the base part (1) comes into abutting contact with the distal end of the control curve (2b) of the holding element (2).The distal end of the control cam (2b) of the holding element (2) and the guide cam (1d) of the base part (1) are designed such that the guide cam (1d) of the base part (1) can hold the holding element (2) in the proximal position. The sliding element stop (3b) of the sliding element (3) rests on the holding element stop (2e) of the holding element (2), so that the sliding element (3) is moved with the holding element (2) into the proximal position. The spring (4), which is mounted between the sliding element (3) and the cover (6), is tensioned or further tensioned in the process.

[0039] Figure 5 shows a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b in a triggered position, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or Figure 1b. The patient presses the push button (7) in the distal direction. The push button bevel (7d) of the push button (7) interacts with the sliding element edge (3h) of the sliding element opening (3f) of the sliding element (3) in such a way that the sliding element (3) is rotated relative to the holding element (2), preferably by an angle of rotation of approximately 10°. The projection (3i) provided on the sliding element is in the second position and thus in external abutment contact with the holding wing (8a) of the infusion set (8). The holding arm (2a) of the holding element (2) is no longer pretensioned radially outward by the projection (3i) of the sliding element (3). The holding arm (2a) of the holding element (2) is relaxed.The snap (2d) of the holding element (2) comes into the second groove (3c) when the insertion device is triggered. 1) of the sliding element (3). The sliding element stop (3b) of the sliding element (3) comes into external contact with the holding element stop (2e) of the holding element (2). The first and second sliding element webs (3e, 3e') of the sliding element are in guiding engagement with the guide groove (2g) of the holding element (2) in such a way that the sliding element (3) can be moved relative to the holding element (2) via the spring force of the tensioned spring (4). In this process, the ring support (3a) of the sliding element (3) presses onto the infusion set (8) or onto a cap-shaped housing of the infusion set with the aid of the spring force of the spring (4), so that the holding wings (8a) of the infusion set (8) snap out of the holding arms (2a) of the holding element (2) and the infusion set (8) is moved distally.In addition, the holding arm (2a) of the holding element (2) and the snap hook (7b) of the push button (3) each have sliding surfaces (2g; 7e) which are designed such that, upon actuation of the push button (7), the holding arm (2a) of the holding element (2) is moved radially outwards by the actuation stroke (H) in order to at least partially release the infusion set (8), in particular the holding wing (8a) of the infusion set (8), from the holding element (2), in particular the holding arm (2a) of the holding element (2). The infusion set, with the cannula (8c) provided on the infusion set, can be inserted into the patient's skin.

[0040] Figure 6 shows a longitudinal sectional view of the embodiment of the insertion device according to Figure 1a or 1b with an infusion set inserted into the patient's skin, wherein the longitudinal sectional view corresponds to the section line AA shown in Figure 1a or Figure 1b. The cannula (8c) of the infusion set (8) is inserted into the patient's skin. The push-button disc (7c) of the push-button (7) is in abutting contact with the cover shoulder (6c) of the cover (6). The sliding element (3) comes into abutting contact with the guide cam (1d) of the base part (1). The annular support (3a) of the sliding element (3) is in abutting contact with the infusion set (8), in particular with the cap-shaped housing of the infusion set (8). The spring (4), which is mounted between the cover (6) and the sliding element (3), is relaxed.The insertion device can now be removed from the patient's skin, with the infusion set (8) remaining on the patient's skin via the plaster (8d) provided on the infusion set.

[0041] To return the insertion device to the initial position shown in Figure 2, the patient rotates the head part (5) relative to the base part (1) of the insertion device in the second direction of rotation. The guide curve (2b) of the holding element (2) is guided by the guide cam (1d) arranged on the base part (1), so that the holding element (2) is moved relative to the base part (1) from the proximal position to the distal position along the central axis (z). The guide cam (1d) of the base part (1) comes into abutting contact with the proximal end of the guide curve (2b) of the holding element (2). The proximal end of the guide curve (2b) of the holding element (2), the guide cam (1d) of the base part (1) and the control curve (3d) of the sliding element (3) are designed and arranged such that the sliding element (3) can be rotated relative to the holding element (2), preferably by the angle of rotation of approximately 10°.The sliding element (3) carries the push button (7) along the sliding element edge (not visible) of the sliding element (3) and along the push button bevel (7d). The snap hook (7b) of the push button (7) comes into contact with the distal end of the lid web (6b) of the lid (6). The retaining element (2) is in the distal position, allowing a new infusion set (8) to be inserted into the insertion device.

[0042] Reference symbol:

[0043] 1 base part

[0044] 1 a contact surface

[0045] 1 b Longitudinal web

[0046] 1c annular groove

[0047] 1d guide cam

[0048] 2 holding element

[0049] 2a Holding arm

[0050] 2b Guide curve

[0051] 2c rib

[0052] 2d Snap e Holding element stop f Guide groove g Sliding surface h First holding element web h' Second holding element web Sliding element a Ring support b Sliding element stop c First groove c' Second groove d Control curve e First sliding element web' Second sliding element web f Sliding element opening g Recess h Sliding element edge i Securing surface, projection Compression spring Head part a Snap b Longitudinal groove c Ring web Cover a Cover groove b Cover web c Cover shoulder 7 Push button

[0053] 7a Snap arm

[0054] 7b Snap hook

[0055] 7c push button disc

[0056] 7d snap fastener bevel

[0057] 7e sliding surface

[0058] 8 Infusion set

[0059] 8a Retaining wing

[0060] 8b retaining tab

[0061] 8c Cannula

[0062] 8d pavement z central axis

[0063] AA cutting axis

[0064] H Actuating stroke

Claims

Patent claims 1. An insertion device for an infusion set comprising: - a propulsion device (3, 4) for moving the infusion set (8) from a proximal position to a distal position along a central axis (z), - a holding element (2) for holding the infusion set (8), - a base part (1) which receives the holding element (2) and has a contact surface (1 a) for placing the insertion device on an application site on the body of a patient, - a head part (5), wherein the base part (1) and the head part (5) are rotatable relative to each other about the central axis (z), wherein the holding element (2) is connected to the head part in a rotationally fixed and axially movable manner and the head part (5) has a push button at its proximal end, - wherein a guide element provided on the holding element is in guiding engagement with a guide counter-element provided on the base part such that upon a relative rotation between the head part (5) and the base part (1) in a first direction of rotation, the holding element (2) is movable relative to the base part (1) from a distal position into a proximal position along the central axis (z) and that upon a relative rotation between the head part (5) and the base part (1) in a second direction of rotation, the holding element (2) is movable relative to the base part (1) from the proximal position to the distal position along the central axis (z), - characterized in that the push button (7) is displaceable along the central axis (z) by an actuating stroke (H) and is designed such that when the push button (7) is actuated by the actuating stroke (H), the holding element (2) is moved radially outwards in order to at least partially release the infusion set (8) from the holding element (2).

2. Insertion device according to claim 1, characterized in that the holding element (2) and the push button (3) each have sliding surfaces (2g; 7e) which are designed such that when the push button (7) is actuated by the actuating stroke (H), the holding element (2) is moved radially outwards in order to at least partially release the infusion set (8) from the holding element (2).

3. Insertion device according to claim 2, characterized in that the sliding surfaces (2g; 7e) are inclined.

4. Insertion device according to one of the preceding claims, characterized in that the holding element (2) has a holding arm (2a) for holding the infusion set (8), wherein the holding arm (2a) of the holding element (2) is movable radially outwards.

5. Insertion device according to one of the preceding claims, characterized in that the push button (7) has a snap arm (7a) with a snap hook (7b), wherein a sliding surface (7e), in particular an inclined sliding surface (7e) is provided on the snap hook (7b), which sliding surface moves the holding element (2) radially outwards by the actuation stroke (H) when the push button (7) is actuated in order to at least partially release the infusion set (8) from the holding element (2).

6. Insertion device according to claim 4 and claim 5, characterized in that a sliding surface (2g), in particular an inclined sliding surface (2g), is provided on the holding arm (2a) of the holding element, wherein upon actuation of the push button (7) by the actuation stroke (H), the holding element (2) moves radially outwards in order to at least partially release the infusion set (8) from the holding element (2).

7. Insertion device according to one of the preceding claims, characterized in that the propulsion device (3, 4) has an elastic means (4) and a sliding element (3).

8. Insertion device according to claim 7, characterized in that the sliding element (3) has a securing surface (3i), in particular a projection (3i) in order to hold the infusion set (9) in the holding element (2).

9. Insertion device according to claim 7 or 8, characterized in that the sliding element (3) has a ring support (3a) for pressing the infusion set (8) out of the holding element (2).

10. Insertion device according to claim 7, characterized in that the elastic means (4) is designed as a compression spring (4).

11. Insertion device according to one of claims 7 to 10, characterized in that the sliding element (3) has a recess (3g) to accommodate a retaining tab (8b) provided on the infusion set (8).

12. Insertion device according to one of the preceding claims, characterized in that the guide element of the holding element (2) is designed as a guide curve (2b) and the guide counter element of the base part (1) is designed as a guide cam (1d).

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