WO2022229645A1

WO2022229645A1 - An engagement mechanism between an intrauretheral catheter and an insertion device

Info

Publication number: WO2022229645A1
Application number: PCT/GB2022/051084
Authority: WO
Inventors: Ronald L. Bracken; Aaron P WALSH; Kenneth Butcher
Original assignee: Ingenion Medical Limited
Priority date: 2021-04-29
Filing date: 2022-04-28
Publication date: 2022-11-03

Abstract

An engagement mechanism (2) for use in selective connection of an intraurethral catheter (1) and an insertion device (3) used for insertion of the catheter (1) into a urethra, the engagement mechanism (2) including: a first part (21) configured to be fitted to the catheter (1); and a second part (22) configured to be fitted to the insertion device (3), wherein the first and second parts (21,22) are configured to engage each other rotationally, and are configured to permit the passage of an extendible element therethrough.

Description

AN ENGAGEMENT MECHANISM BETWEEN AN INTRAURETHERAL CATHETER

AND AN INSERTION DEVICE

FIELD

Embodiments relate to an engagement mechanism for use in relation to intraurethral valves and valve systems, systems for the placement and/or removal of intraurethral valve systems, and the like. BACKGROUND

There is a desire, in general, to provide intraurethral valves which are capable of selectively controlling the flow of fluid therethrough. Such valves may be needed, for example, in relation to patients with urinary retention or incontinence deficiencies.

An example placement of such a valve in a male patient can be seen in figure 1 , which is an extract of figure 3 of US6066088 - reference numerals specifically referring only to prior art figures in the present description will be presented in parentheses along with an indication of the associated figure number (reference numerals are used without parentheses in the description to refer to embodiments, where appropriate, in order to aid understanding).

As can be seen, figure 1 shows a human male abdomen (30, figure 1) in cross-section. A valve (1 , figure 1) may be located within a patient’s bulbous urethra (26, figure 1) generally at bulge (17, figure 1) and generally upstream of the pendulous urethra (27, figure 1) - in terms of the normal flow of fluid through the urethra. The valve (1 , figure 1) is coupled to a retention mechanism by a catheter (16, figure 1) defining a lumen (21 , figure 1) - which as an outlet (25, figure 1) at the valve (1 , figure 1) and an inlet defined by retaining loops (28) of the retention mechanism. The retention mechanism is located in the bladder (29, figure 1) and includes the retaining loops (28, figure 1) which hold the retention mechanism in place relative to the bladder neck (22, figure 1).

The operation of the valve (1 , figure 1) between open and closed configurations is intended, therefore, to control the flow of fluid from the bladder (29, figure 1) through the outlet (25, figure 1) and to the pendulous urethra (27, figure 1). Important advances in this regard include the intraurethral magnetic valve of WO00/02499. Figure 1 of WO00/02499 is repeated as figure 2 of the present document for ease of reference. The document teaches an intraurethral magnetic valve (1 , figure 2) for insertion in the human urethra of a person suffering from incontinence. The intraurethral magnetic valve (1 , figure 2) includes a nonferromagnetic cylindrical housing (2, figure 2), a valve seat assembly (36, figure 2) attached to one end of the housing, a spherical magnetic valve element (14) disposed for universal movement in the housing, and a ring (10, figure 2) for retaining the valve element which is attached at the other end of the housing. The valve seat assembly (36, figure 2) has a nonferromagnetic valve seat (4, figure 2) and ferromagnetic ring (5, figure 2). The valve element (14, figure 2) is maintained in closed check position against the valve seat (4, figure 2) by attraction to the ferromagnetic ring (5, figure 2), restricting the flow of fluid through the valve (1, figure 2). An external magnet is used to impart magnetic torque and attraction to the valve element (14, figure 2) displacing it from the valve seat (4) and opening the valve for fluid flow. On removal of the external magnet, the valve element (14) returns to its closed check position on the valve seat (4, figure 2). The document also teaches a second embodiment in which the intraurethral magnetic valve (1, figure 2) includes a mechanism having a spring for relieving excessive fluid pressure, in which the valve seat assembly (36), rather than being attached to the housing (2, figure 2), is axially slidable within the housing against the force of the spring when excessive hydrostatic pressure is present to allow release of fluid through a passageway around the valve seat assembly (36, figure 2).

Such advanced intraurethral magnetic valves seek to allow selective release of fluid from the bladder through use of an external magnet, in other words, a magnet external to the patient’s body may be brought close to the internally fitted intraurethral magnetic valve to cause the actuation thereof from a closed configuration to an open configuration.

Still further developments of such intraurethral magnetic valves are described in W02020089623. Figures 4a-4c of W02020089623 are repeated as figures 3a-3c of the present document for ease of reference. The document teaches a valve with a valve main body (11 , figures 3a-3c) containing a spherical magnetic valve element (14, figures 3a-3c) and defining an inlet port (112, figures 3a- 3c) and an outlet port (25, figures 3a-3c). The spherical magnetic valve element (14, figures 3a-3c) is configured to close or open the outlet port (112, figures 3a-3c). To this end, a ferromagnetic ring (5, figures 3a-3c) is provided at the outlet port (25, figures 3a-3c). An external magnetic is used to actuate the valve and move the spherical valve element (14, figures 3a-3c) away from a valve seat at the outlet port. The valve seat in accordance with this document is formed from an elastomer material.

Irrespective of the specific intraurethral magnetic valve configuration, however, there is a need to insert the valve into position. Devices for the insertion of intraurethral magnetic valves have been discussed in, for example, W02008067557. Figures 1, 2 and 5 of W02008067557 are repeated as figures 4a-4c of the present document. W02008067557 teaches a valved catheter (1, figures 4a-4c) coupled to an insertion tool (8, figures 4a-4c). The valved catheter (1, figures 4a-4c) comprises a flexible catheter body (2, figures 4a-4c) holding a magnetic proximity valve (5, figures 4a and 4b) at one end and a malecot (3, figures 4a-4c) at the opposing end. A lumen (17, figures 4a-4c) is defined through the catheter (1, figures 4a-4c).

The insertion tool (8, figures 4a-4c) comprises an extendible element (9, figures 4a-4c) that extends through the lumen (17, figures 4a-4c) defined by the catheter (1, figures 4a and 4b), through the valve (5, figures 4a-4c), to the malecot (3, figures 4a-4c). The insertion tool (8, figures 4a-4c) includes a tensioning mechanism (8a, figures 4a-4c) for advancing and retracting the extendible element (9, figures 4a-4c) to operate the malecot (3, figures 4a-4c). The tensioning mechanism (8a, figures 4a-4c) may have a catheter segment (11, figures 4a-4c), a latch body (12, figures 4a-4c), a plunger (13, figures 4a-4c), a pretension means (14, figures 4a-4c), an inner latch (15, figures 4a-4c), and push button (16, figures 4a-4c), along with a biasing device (not shown in the figures included in the present document).

The insertion tool (8, figures 4a-4c) and the valved catheter (1, figures 4a-4c) are coupled together by the a valve engagement tip member (10, figures 4a-4c) and held together by the extendible element (9, figures 4a-4c) during implantation. After implantation, the extendible element (9, figures 4a-4c) is removed and this allows the valve engagement tip member (10, figures 4a-4c) to disengage from the valved catheter (1 , figures 4a-4c), leaving just the valved catheter (1, figures 4a-4c) in place.

The inter-engagement of the valve engagement tip member (10, , figures 4a-4c) and the valved catheter (1 , figures 4a-4c) is shown in figure 5 of W02008067557 (which is figure 4c of the present document). The valve engagement tip member (10, figures 4a-4c) and the corresponding parts of the valved catheter (1, figures 4a-4c) with which the tip member (10, figures 4a-4c) interacts, therefore, form an engagement mechanism between the catheter and the insertion device.

Advancement in the area of intraurethral valve placement can also be found in WO2011032150.

There is, therefore, a need for improved engagement mechanisms which provide more reliable and robust connection between the catheter and insertion device, but which still allow relatively straightforward disengagement after implantation of the catheter. The engagement mechanism must maintain engagement during the typical pulling, pushing, and twisting movements which occur during implantation but still allow for selective disengagement. This is a difficult balance to achieve.

This is particularly true in relation to valves such as those described in W02020089623 in which the valve is formed of a softer material (e.g. an elastomer), as it is generally harder to provide a reliable engagement with such softer materials. Moreover, removal of the catheter (which may be repeated periodically) may require a reliable and safe mechanism to engage the catheter for extraction. Some versions may, therefore, be for use in relation to valves such as those disclosed in W02020089623.

Aspects of the present technology seek to alleviate one or more problems associated with the prior art.

BRIEF DESCRIPTION OF THE INVENTION

An aspect of the technology provides an engagement mechanism for use in selective connection of an intraurethral catheter and an insertion device used for insertion of the catheter into a urethra, the engagement mechanism including: a first part configured to be fitted to the catheter; and a second part configured to be fitted to the insertion device, wherein the first and second parts are configured to engage each other rotationally, and are configured to permit the passage of an extendible element therethrough.

The first part may be a female part and may include an internal thread, and the second part may be a male part may have a lock member configured to engage the internal thread of the first part.

The lock member may be T-shaped or r-shaped.

The lock member may be an external thread.

The first part may include a wall defining an opening configured to receive a radial extension of the extendible element to inhibit rotational movement of the first part with respect to the extendible element, and wherein the first part may include a cavity adjacent the wall, such that the radial extension may be moveable into the cavity to allow rotational movement of the first part with respect to the extendible element.

The radial extension may be semi-circular in shape.

The first part may include a wall defining an opening configured to receive at least part of a keyed outer tube through which the extendible element is configured to pass, the opening may have at least one surface which is configured to abut a surface of the keyed outer tube to inhibit rotation of the first part with respect to the keyed outer tube, and wherein retraction of the keyed outer tube from the opening may permit rotation of the first part with respect to the keyed outer tube. The second part may define a channel which is configured to receive at least part of the keyed outer tube such that the second part and the keyed outer tube may be in a fixed rotational relationship. An engagement mechanism may further include an expandable member having an expanded configuration and an unexpanded configuration, the expandable member may be in the expanded configuration when the keyed outer tubed is at least partially received by the expandable member and may be in the unexpanded configuration when the keyed outer tubed is not at least partially received by the expandable member, wherein the expandable member in the expanded configuration may have an interlock surface which engages a first part interlock surface of the first part, and wherein the expandable member interlock surface may disengage the first part interlock surface in the unexpanded configuration, engagement of the interlock surface and the first part interlock surface inhibiting rotation of the keyed outer tube with respect to the first part. The extendible element may have a first section and a second section, wherein the first part may include a wall defining an opening configured to receive at least part of the second section of the extendible element, the opening may have at least one surface which is configured to abut a surface of the second section of the extendible element to inhibit rotation of the first part with respect to the extendible element, and wherein retraction of the second section of the extendible element from the opening may permit rotation of the first part with respect to the extendible element.

The second part may define a channel which is configured to receive at least part of the second section of the extendible element such that the second part and the extendible element are in a fixed rotational relationship.

An engagement mechanism may further include an expandable member having an expanded configuration and an unexpanded configuration, the expandable member may be in the expanded configuration when the second section of the extendible element is at least partially received by the expandable member and may be in the unexpanded configuration when the extendible element is not at least partially received by the expandable member, wherein the expandable member in the expanded configuration may have an interlock surface which engages a first part interlock surface of the first part, and wherein the expandable member interlock surface may disengage the first part interlock surface in the unexpanded configuration, engagement of the interlock surface and the first part interlock surface inhibiting rotation of the extendible element with respect to the first part.

The interlock surface and/or the first part interlock surface may include a plurality of teeth. An engagement mechanism may further include a lock washer configured to be located between at least part of the first and second parts and to inhibit rotational movement between the first and second parts. The first or second part may include at least one rib configured to engage a part of the other of the first or second part to inhibit rotational movement between the first and second parts.

The part of the other of the first or second parts may include at least one slot, the or each slot being configured to receive a respective one of the at least one rib.

The first and/or second parts may have a central longitudinal axes and may be configured such that the extendible element passes through the first and second parts along the central longitudinal axes. The first and/or second parts may have a central longitudinal axes and may be configured such that the extendible element passes through the first and second parts along an axis which is offset from the central longitudinal axes.

The first part may include a channel through which the extendible element passes and the second part may include an opening through which the extendible element passes, the channel and/or opening may be configured to permit rotational movement of the first part with respect to the second part through a part of a circle and to inhibit further rotation of the first part with respect to the second part by abutment of the extendible element against a surface defining at least part of the channel or opening.

The second part may include a moveable member configured to be moved radially outwardly by the extendible element to engage at least one retaining protrusion of the first part so as to inhibit rotation of the first part with respect to the second part. Another aspect provides a first part of an engagement mechanism suitable for use as the first part of the engagement mechanism.

Another aspect provides a second part of an engagement mechanism suitable for use as the first part of the engagement mechanism.

Another aspect provides a combination of an intraurethral catheter and the first part, wherein the intraurethral catheter includes a magnetically operated valve.

The magnetically operated valve may include a spherical magnetic valve element. The axis along which the first part may be configured to pass the extendible element is aligned with an aperture defined by a valve seat of the magnetically operated valve. The magnetically operated valve may include a valve seat insert which provides the valve seat, wherein the valve seat insert may include one of a retaining protrusion or a retaining recess, and the first part may include the other of a retaining protrusion or a retaining recess, the retaining protrusion and retaining recess being configured to engage each other to inhibit rotational movement between the valve seat insert and the first part.

The insertion device may include the extendible element.

Another aspect provides a combination of a catheter, an insertion device, an extendible element, and the engagement mechanism.

The catheter may further include one or more tethers which are wrapped in a helix around the insertion device, and wherein the insertion device may further include a clip or band to hold the or each tether in place. BRIEF DESCRIPTION OF THE FIGURES

In order that the present disclosure may be more readily understood, preferable embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIGURE 1 is a view taken from US6066088;

FIGURE 2 is a view taken from WO00/02499;

FIGURES 3a-3c are views taken from W02008067557;

FIGURES 4a-4c are views taken from W02008067557; FIGURES 5a-5c show views of a version of the disclosed technology;

FIGURES 6a-6c show views of a version of the disclosed technology;

FIGURES 7a-7c show views of a version of the disclosed technology;

FIGURES 8a & 8b show views of a version of the disclosed technology;

FIGURES 9a & 9b show views of a version of the disclosed technology; FIGURES 10a-10e show views of a second part of a version of the disclosed technology;

FIGURES 11a-11f show views of a second part of a version of the disclosed technology;

FIGURES 12a & 12b show views of a version of the disclosed technology (with an additional thread member);

FIGURE 13 show views of a version of the second part of the disclosed technology (with ribs); FIGURES 14a & 14b show views of a version of the disclosed technology (using an extendible element with a radial extension);

FIGURES 15a & 15b show views of a version of the disclosed technology (with a modified thread); FIGURES 16a & 16b show views of a version of the disclosed technology (having a covered wall);

FIGURES 17a & 17b show views of a version of the disclosed technology (having a covered wall);

FIGURES 18a & 18b show views of a version of the disclosed technology (having a ribs and slots);

FIGURES 19a & 19b show views of a version of the disclosed technology (having an expandable member);

FIGURES 20a & 20b show views of a version of the disclosed technology (having a lock washer); FIGURE 21 shows a view of a version of the disclosed technology (having a keyed outer tube); FIGURE 22 shows a view of a version of the disclosed technology (having a two section extendible element);

FIGURES 23a & 23b show views of a version of the disclosed technology (having a two section extendible element);

FIGURES 24a & 24b show views of a version of the disclosed technology (having an offset extendible element);

FIGURES 25a & 25b show views of a version of the disclosed technology (having an offset, oval, extendible element);

FIGURES 26a & 26b show views of a version of the disclosed technology (having an offset, oval, extendible element);

FIGURES 27a & 27b show views of a version of the disclosed technology (having an offset extendible element);

FIGURES 28a & 28b show views of a version of the disclosed technology (having an offset extendible element);

FIGURES 29a & 29b show views of a version of the disclosed technology (having an interlocking valve seat insert and first part);

FIGURE 30 shows a view of a version of the disclosed technology (having a moveable member); FIGURE 31 shows a view of a version of the disclosed technology (having a spiral wound tether(s)); and

FIGURE 32 shows a view of a version of the disclosed technology (in particular, the catheter). DETAILED DESCRIPTION OF THE DISCLOSURE

With reference to figure 32 by way of example, aspects of the present technology may be particularly useful in relation to an intraurethral catheter 1 which is configured for insertion into a urethra (which may be a male or female, human or animal, urethra).

The catheter 1 has a first end which, when inserted, it located within the urethra and a second end which, when inserted, is located at or towards the bladder. The first end catheter 1 may be formed of a soft material and may be formed from an elastomer. The second end of the catheter 1 may include a malecot which is configured to expand within the bladder to help hold the catheter 1 in place. The catheter 1 , when inserted, may be configured to drain the bladder through a lumen 11 defined through the catheter 1.

The catheter 1 may include a valve 12 and the valve 12 may be located at the first end of the catheter 1.

The catheter 1 may include a malecot 13 or other holding system which is configured to help to hold the catheter 1 in place following insertion (i.e. implantation). The holding system (e.g. the malecot 13) may include a member which is configured to pass into the bladder and then expand to inhibit movement of the holding system (e.g. the malecot 13) back through the urethra and out of the bladder (during normal use). The holding system (e.g. the malecot 13) may further allow for the passage of fluid from the bladder through the urethra when expanded and may take the forms discussed above in relation to the background section of this document. References herein to a malecot 13 are for convenience and refer to any suitable holding system, for example. The malecot 13 may be located at a second end of the catheter 1.

Returning to the valve 12 (an example of which can be seen in figure 5c, for example) which may be at the first end of the catheter 1 , the valve 12 may include a valve main body 121 defining an internal valve volume 1211 in which is positioned a valve element 122 (which may be a spherical magnetic valve element 122). The internal valve volume 1211 has a length along a longitudinal axis of the valve main body 121. The longitudinal axis of the valve main body 121 extends from an inlet port 123 of the valve 12 to an outlet port 124 of the valve 1 . The internal valve volume 1211 has a width along an axis perpendicular to the longitudinal axis of the valve main body 121. The valve 12 may include a valve seat against which the valve member 14 is configured to seal (selectively) with the valve seat defining an aperture through which, in use, urine may pass (when the valve 12 is in an open configuration and through which the flow of urine is inhibited or substantially prevented when the valve 12 is in a closed configuration).

In some aspects of the technology, the internal valve volume 1211 may be generally cylindrical in shape and the width thereof may be a diameter, for example.

The inlet port 123 and the outlet port 124 may both have a width (e.g. a diameter) which is less than that of the internal valve volume 1211.

The internal valve volume 1211 is sized to receive the valve element 122, for example, as depicted in figure 5c. The internal valve volume 1211 may be sized to permit movement of the valve element 122 between a closed configuration and an open configuration - as described herein. Towards the outlet 124, there is a ferromagnetic ring 125. The ferromagnetic ring 125 defines a passage through which fluid may pass. The ferromagnetic ring 125 is depicted in the valve 12 in figure 5c, for example. The ferromagnetic ring 125 may be generally tubular in form or may be ring-like, for example.

In some aspects of the technology, the valve main body 121 is formed from an elastomer material (such as silicone) and may be formed from only the elastomer material. This elastomer material may be selected for its biocompatibility and/or the ability to impregnate the material with antimicrobial and/or antifungal agent. The ferromagnetic ring 125 may be formed of a ferrous metal or ferrous metal alloy. Therefore, the valve body 11 may be formed from a relatively flexible material compared to the ferromagnetic ring 125. In some aspects of the technology, application of a force to the valve main body 121 may cause the valve main body 121 to deform elastically and for the internal valve volume width (in the direction of the force) to be reduced.

In some aspects of the technology, the ferromagnetic ring 125 may be embedded in at least part of the valve main body 121 with the valve main body 121 at least partially formed around the ferromagnetic ring 125. In such aspects of the technology, the formation of the valve main body 121 (or at least the part in which the ferromagnetic ring 125 is embedded) may be a moulding process around the ferromagnetic ring 125 - which may, therefore, be placed inside a mould before elastomer material for the valve main body 121 (or part thereof) is delivered to the mould (e.g. injected into the mould). Other methods of fixing the ferromagnetic ring 125 to the valve main body 121 are envisaged without limitation. For example, the valve main body 121 may be a generally tubular member into which the ferromagnetic ring 125 is inserted along with a valve seat insert 126 (the valve seat insert 126 may be an insert which provides the valve seat, for example).

The valve seat insert 126 may be held in place within the valve main body 121 by, for example, an interference fit and/or an adhesive. The valve seat insert 126 may include a recess (which may be annular) configured to receive at least part of the ferromagnetic ring 125. In some versions, the ferromagnetic ring 125 may be located (i.e. is beatable) within this recess and adjacent an inner surface of the valve main body 121 - the recess and the valve main body 121 defining an open ended annular chamber, for example. In some versions, a seal member 127 may be provided and may, for example, substantially close the open ended annular chamber. The seal member 127 may be configured to help to hold the ferromagnetic ring 125 in place and/or to reduce the exposure of the ferromagnetic ring 125 to fluids which may pass through the valve 12 (such as liquids including urine). The recess of the valve seat insert 126 may be located in a part of the valve seat insert 126 which is downstream of the normal direction of the flow of urine through the valve 12, compared to the valve seat, following insertion. The recess may be shielded from direct exposure to the majority of the urine flowing through the valve 12 by at least part of the valve seat insert 126, for example.

In some versions of the technology, therefore, the valve seat insert 126 is in the form of a plug which is received within the valve main body 121 and through which there is an opening (e.g. defined by the valve seat) providing fluid communication between the inlet port 123 and the outlet port 124. That opening being selectively closable by the valve element 122 as discussed herein.

An outlet port 124 end of the valve 12 may be tubular (and may have a generally circular cross- section, although other cross-sectional shapes are possible) and may extend beyond the valve seat insert 126 or other part of the valve 12 providing the valve seat. This tubular end of the valve 12 may be defined by the valve main body 121 , for example. This tubular end of the valve 12 may be configured to receive or provide at least part (e.g. a first part 21) of an engagement mechanism 2

In some versions of the technology, the valve 12 may not be at the first end of the catheter 1 , in which case the at least part (e.g. the first part 21) of the engagement mechanism 2 may be provided at the first end of the catheter 1 which may not be at the valve 12. In other words, the catheter 1 may extend beyond the valve 12 and the aforementioned tubular end may be part of the catheter 1 which is not part of the valve 12 or this end may be deemed to be a part of the valve 12 even if the valve seat is some distance away along the catheter 1. The depicted versions of the catheter 1 show the at least part (e.g. the first part 21) of the engagement mechanism 2 in combination with the valve 12 - with this part of the engagement mechanism 2 provided in the tubular end of the valve 12 - however, this need not be the case and the same teachings apply to versions in which the tubular end is, in fact, a tubular end of the catheter 1. The description of the versions below should be construed accordingly.

The engagement mechanism 2 may be configured to secure the intraurethral catheter 1 to an insertion device 3 which may be an insertion device similar to those discussed in the background section of this document, for example. The insertion device 3 may be configured to be secured to the intraurethral catheter 1 for insertion (or implantation) of the intraurethral catheter 1. The insertion device 3 may, therefore, be generally elongate and may be configured to be at least partially received within the urethra during the insertion process. A width or diameter of the insertion device 3 may, therefore, be generally the same as a width or diameter of the intraurethral catheter 1.

The malecot 13 (or other holding system, see above) may be operated into a collapsed state for insertion. For this purpose, and/or for stiffening the catheter 1 (and potentially also the insertion device 3) for insertion, an extendible element 4 may be provided, such as a wire or tube (or in some versions as described herein a nested set of telescoping members such as a tube and at least one wire or other tube). This extendible element 4 may be used in the same manner as described above in the background section of this document. The extendible element 4 may, therefore, extend from the malecot 13 through the catheter 1 (including through the valve 12) and to the insertion device 3. The extendible element 4 may pass through the lumen 11 , for example, of the catheter 1. The extendible element 4 may pass through the inlet and outlet ports 123,124 of the valve 12 and through an aperture defined by the valve seat (i.e. the extendible element 4 may pass through the aperture through which urine may pass during operation of the valve 12 following insertion). The extendible element 4 may, therefore, hold the valve 12 in an open configuration - preventing the valve element 122 from sealing against the valve seat (i.e. preventing the valve 12 from adopting the closed configuration).

The insertion device 3 may include one or more mechanisms for pushing or pulling the extendible element 4 and/or for latching the extendible element 4 in a position in which it is tensioned or compressed. These one or more mechanisms may be substantially as described above in the background section of this document. The one or more mechanisms may be provided at an end of the insertion device 3 which is remote from the catheter 1 during insertion. As such the one or more mechanisms may be controllable by a user to change, for example, the stiffness of the catheter 1 and/or the expansion or collapse of the malecot 3 (or other holding system). The one or more mechanisms may include, for example, one or more spools, resilient biasing arrangements (such as springs, which may be helical springs), one or more levers, one or more buttons, and/or the like.

Therefore, a first end of the insertion device 3 is, during insertion, adjacent the catheter 1 and a second end (which may include the aforementioned one or more mechanisms) may be remote from the catheter 1 .

The first end of the insertion device 3 may, therefore, include at least part of the engagement mechanism 2 (e.g. a second part 22) which is configured to engage the part of the engagement mechanism 2 of the catheter 1. Accordingly, the first and second parts 21 ,22 of the engagement mechanism 2 may engage with each other to help to secure the catheter 1 and the insertion device 3 together.

The engagement mechanism 2 may be configured such that the extendible element 4 may pass therethrough and may be configured to allow for axial movement of the extendible element 4 therethrough. The first end of the insertion device 3 may, therefore, include a tubular main body 31 (through which the extendible element 4 may pass) and the second part 22 of the engagement mechanism 2 (again, through or past which the extendible element 4 may pass).

The first end of the catheter 1 may, likewise, define a lumen 11 (through which the extendible element 4 may pass) and may include the first part 21 of the engagement mechanism 2 (again, through or past which the extendible element 4 may pass).

The first part 21 of the engagement mechanism 2 may be provided as an insert which is at least partially received by the catheter 1 and which may be received by, for example, the lumen 11 and/or the tubular end of the valve 12. The catheter 1 lumen 11 and/or the tubular end of the valve 12 may have a generally circular internal cross-section and so the first part 21 of the engagement mechanism 2 may have a generally circular external cross-section. The first part 21 may be sized and shaped to be received by the lumen 11 and/or the tubular end of the valve 12. In some versions, however, the first part 21 is integrally formed with the valve 12 and/or another part of the catheter 1.

The second part 22 of the engagement mechanism 2 may be provided as an insert which is at least partially received by the tubular main body 31 of the insertion device 3. In some versions, however, the second part 22 is integrally formed with the tubular main body 31.

In some versions, including those depicted, the first part 21 is generally a female part and the second part 22 is generally a male part. However, this need not be the case. Accordingly, it may be that the roles of the first and second parts 21 ,22 as described herein may be reversed in some versions - with the first part 21 being a generally male part and the second part being a generally female part.

However, comfort for the subject in which the catheter 1 is implanted may be improved by providing the first part 21 as a generally female part, as the first part 21 may then be contained within the catheter 1 (i.e. covered around at least part of its circumference by the material used to form the catheter 1 and/or the valve main body 121). In some versions the first part 21 (and the second part 22) may be formed from a harder material than the material which covers at least part of the first part 21 (i.e. the material from which the catheter 1 and/or the valve main body 121 are formed) - so having the first part 21 as a female part may provide a softer outer layer around the first part 21 which may improve comfort.

In some versions, the first part 21 does not extend substantially, or at all, beyond an end of the catheter 1 (e.g. beyond an end of the lumen 11 and/or the tubular end of the valve 12). The second part 22 may extend beyond the end of the tubular main body 31 of the insertion device 3 sufficient to engage the first part 21 and this may require the first part 21 to extend into the catheter 1 (e.g. into an end of the lumen 11 and/or the tubular end of the valve 12).

The first part 21 and second part 22 have a first configuration in which disengagement of the two parts 21 ,22 is inhibited or substantially prevented and a second configuration in which disengagement of the two parts 21 ,22 is permitted (e.g. by manual manipulation of the insertion device 3 to draw the insertion device 3 away from the catheter 1).

During insertion (i.e. implantation) of the catheter 1 the first and second parts 21 ,22 are in their first configuration. Once the catheter 1 is in place, the first and second parts 21 ,22 are put into their second configuration to allow for removal of the insertion device 3, leaving the catheter 1 in place.

As will be appreciated, the holding of the catheter 1 and insertion device 3 together during insertion is important to enable the user to navigate the catheter 1 into position safely and successfully.

Once in place, however, the insertion device 3 is no longer needed (although may be used, in some versions for extraction of the catheter 1) and needs to be removed from the catheter 1.

During the insertion process, the catheter 1 and insertion device 3 will be subjected to, respective, different pushing, pulling, and twisting forces, which risk the premature disengagement of the catheter 1 and the insertion device 3. However, once in place, the insertion device 3 needs to be disengaged reliably and the user has no direct access, at this point, to the catheter 1. Providing a balance between keeping the catheter 1 and insertion device 3 engaged (i.e. in the first configuration of the two parts 21 ,22) and yet allowing for reliable disengagement (i.e. changing the configuration of the two parts 21 ,22 to the second configuration) is difficult.

In versions disclosed herein, the first and second parts 21 ,22 of the engagement mechanism 2 are operated between the first and second configurations through relative rotation of the first part 21 relative to the second part 22 (which would typically be achieved by application of a manual rotation force to the insertion device 3 and hence to the second part 22 with the first part 21 being generally in a substantially stable rotational position within the urethra).

The second part 22 may have a central longitudinal axis which is generally aligned with a central longitudinal axis of the catheter 1 and insertion device 3 when held straight. The first part 21 may have a correspondingly aligned central longitudinal axis. In some versions, operation of the first and second parts 21 ,22 between the first and second configurations requires relative rotation of the first part 21 with respect to the second part 22 and this rotation is about an axis of rotation. The axis of rotation may be aligned with the central longitudinal axes of the first and/or second parts 21 ,22. In some versions, the first part 21 includes a radially outwardly extending projection and the second part 22 includes a radially inwardly extending projection. The two projections are sized and shaped to permit, in one relative rotational position of the first and second parts 21 ,22, the outwardly extending projection to pass the inwardly extending projection in a direction parallel to the axis of rotation. However, in another relative rotational position of the first and second parts 21 ,22, the outwardly extending projection and inwardly extending projection are inhibited or substantially prevented from passing each other in a direction parallel to the axis of rotation (i.e. the inwardly and outwardly extending projections may abut or otherwise engage each other). In other words, the second part 22 may be inserted into the first part 21 (such that the inwardly and outwardly extending projections pass each other), then the second part 22 may be rotated with respect to the first part 21 (such that the projections engage and inhibit or substantially prevent removal of the second part 22 from the first part 21). Likewise, from this position, the second part 22 may be rotated to the position in which the projections are permitted to pass each other such that the second part 22 can be removed from the first part 21.

In some versions, the projection(s) of the first and/or second part 21 , 22 may be moveable between an extended and a retracted position - with the projections configured to pass each other when in the retracted position and to engage when in the extended position. Actuation of the projection(s) between their extended and retracted positions may be achieved by linear movement of, for example, the extendible element 4. In other words, the second part 22 may be inserted into the first part 21 (such that the inwardly and outwardly extending projections pass each other (i.e. with at least one of the projections in a retracted position), then the at least one projection may be moved to its extended position (such that the projections engage and inhibit or substantially prevent removal of the second part 22 from the first part 21). Likewise, from this position, the projection(s) may be moved to their retracted position so that the projections are permitted to pass each other such that the second part 22 can be removed from the first part 21.

Some versions may, therefore, be referred to as providing a rotationally operated engagement and others may be referred to as providing a linearly operated engagement.

In some versions, particularly in relation to linearly operated engagements, in which the extendible element 4 may be used to cause a projection to move between an extended and a retracted position, the user can, through use of the insertion device 3, control the linear movement of the extendible element 4 to control the movement of the projection between the extended and retracted positions and this control may be with a relatively low risk of accidental operation. This provides the user with greater control than might otherwise be the case but can mean a more complex engagement mechanism 2. In some versions, particularly in relation to rotationally operated engagements, the engagement mechanism 2 can be relatively simple in its construction but there is a greater risk of accidental operation.

In some versions, therefore, there are provided one or more arrangements to inhibit operation of the rotationally operated engagements until a threshold force is applied or until another operation then permits the operation of the rotationally operated engagement to occur.

Various implementations of the technology disclosed herein and discussed above are now described with reference to specific depicted versions. However, it will be appreciated that these are not isolated embodiments but are to be read as providing teachings which may be combined with teachings which centre on other versions.

With that in mind, figures 5a-5c show different views of a version of the engagement mechanism 2.

Wth reference to figures 5a and 5c, the catheter 1 includes the valve 12. The valve element 122 can be seen (which may be a spherical valve element 122, for example) and a valve seat insert 126 is provided which provides the valve seat. The valve seat, as described above, defines an aperture therethrough which is selectively closable by the valve element 122. In figure 5c, the extendible element 4 can be seen extending through the valve 12 and, in particular, through the aperture defined by the valve seat and this is preventing the valve element 122 from moving against the valve seat to close the valve 12. Also visible in figure 5c is the ferromagnetic ring 125 (to which the valve element 122 is attracted) and the seal member 127 (as described above).

In this version as depicted, and some other versions, the valve 12 is generally located at the end of the catheter 1 and there is a tubular end of the valve 12 providing the end of the catheter 1. This need not be the case (as described) and the valve 12 may be located further up the catheter 1 (i.e. closer to the other end of the catheter 1).

The first part 21 of the engagement mechanism 2 is visible in figures 5a and 5c. In this version, and some others, the first part 21 is received within the tubular end of the valve 12. Indeed, in the depicted version (and some other versions), the tubular end of the valve 12 extends beyond the end of the first part 21 such that the first part 21 is recessed within the end of the catheter 1 (and in the depicted and some other versions, within the valve 12).

The first part 21 is in the form of a plug which is provided within the end of the catheter 1 . During manufacture, the valve seat insert 126, if provided, may be inserted into the valve main body 121 and then, afterwards, the first part 21 may be inserted into the valve main body 121 and so into the tubular end of the valve 12. The first part 21 may be held within the catheter 1 by an interference fit, for example. In some versions, an adhesive may be used to assist in securing the first part 21 within the catheter 1 (e.g. within the valve 12).

In some versions, the first part 21 may have an exposed side which faces outwardly from the end of the catheter 1 and a covered side which faces in the opposite direction. In the depicted version, and some others, the exposed side can be seen in figure 5a (and figure 5c), whilst the covered side can be seen in figure 5c and is the side which faces the valve seat insert 126 (or another part of the valve 12).

The covered side of the first part 21 may be shaped to engage at least part of the valve seat insert 126. For example, as described herein, the ferromagnetic ring 125 may be provided within the recess defined (at least in part) by the valve seat insert 126. In the depicted version of figure 5c (and some others), this may be around an outer circumference of the valve seat insert 126 but other recess locations are also envisaged. The first part 21 may include, in the covered side, one or more engagement members 211 configured to be at least partially received by the recess in the valve seat insert 126 in which the ferromagnetic ring 125 is provided. Therefore, in figure 5c and some other versions, the one or more engagement members 211 may include a circumferential rib which extends from the covered side of the first part 21 and which is at least partially received within the recess in the valve seat insert 126. This may help to seal the ferromagnetic ring 125 and inhibit the risk of urine (for example) contacting the ferromagnetic ring 125 or even degrading the seal member 127. The first part 21 between the covered and exposed sides may have an outer wall 212 which may provide the first part 21 with a generally cylindrical shape. The outer wall 212 may be configured (e.g. sized and shaped) to engage an inner surface of the tubular end of the valve 12 or another inner surface of the catheter 1 (e.g. in versions in which the valve 12 is located differently to that depicted in figure 5c, for instance). The outer wall 212 may include one or more ridges or ribs which are configured to engage the aforementioned inner surface to assist in holding the first part 21 in place.

The exposed side of the first part 21 may define a first part aperture 213 (i.e. an aperture through at least part of the first part 21). In particular, the first part 21 may include an exposed wall 214 which defines the first part aperture 213. This first part aperture 213 can be seen in figures 5a and 5c for example, with a particular shape. In particular, as depicted and in some other versions, the first part aperture 213 has two semi-circular sections which together provide the first part aperture 213 (and which are arranged with the flat sides of the two semi-circular sections adjacent each other). The two semi-circular sections may be of different sizes (e.g. different diameters). In some versions, such as depicted in figures 5a-5c, a smaller of the two semi-circular sections of the first part aperture 213 is located generally centrally through the exposed wall 213 and the larger of the two semi-circular sections of the first part aperture 213 is radially offset from the smaller of the two sections in the exposed wall 214. A cavity 215 may be defined within the first part 21 and that cavity 215 may be at least partially defined by the exposed wall 214 and the outer wall 212 (and may be partially defined by a part of the valve seat insert 126 or another part of the valve 12 or catheter 1).

The first part aperture 213 may be at least partially aligned with the aperture defined by the valve seat (e.g. of the valve seat insert 216) such that the extendible element 4 can pass through the first part aperture 213 and through the aperture defined by the valve seat.

The second part 22 is shown, for example, in figures 5b and 5c. In this version, and some others, the second part 22 is at least partially received by the tubular main body 31 of the insertion device 3. The second part 22 includes a generally cylindrical portion 221 which is received by the insertion device 3. An outer surface of the generally cylindrical portion 221 may include one or more ribs, barbs, or ridges to help to keep the second part 22 secured to the insertion device 3 (i.e. to keep the generally cylindrical portion 221 received within the tubular main body 31 of the insertion device 3. The second part 22 may include a flange 222 which has a larger diameter than the generally cylindrical portion 221 such that the flange 222 cannot pass into the tubular main body 31. Accordingly the flange 222 may hinder or substantially prevent the second part 22 from being pushed into the insertion device 3 to a greater extent than intended. The flange 222 diameter may also be larger than an internal diameter of the end of the catheter 1 - such as the tubular end of the valve 12, for example (see figure 5c).

In some versions, such as depicted in figures 5b and 5c, the second part 22 may include a generally frusto-conical portion 223 which extends from the flange 222 away from the generally cylindrical portion 221. In some versions, such as depicted in figures 5b and 5c, the second part 22 may include an insertion portion 224 which may be cylindrical in shape and which may extend from the end of the frusto-conical portion 223. The insertion portion 224 may be configured to be received, at least in part, by the first part aperture 213. In particular, the insertion portion 224 may be configured to be received by the smaller semi-circular section of the first part aperture 213 and may have a diameter which is generally equal to (or marginally less than) a width of the smaller semi-circular section of the first part aperture 213 such that the exposed wall 214 may engage the insertion portion 224 in this region. A lock member 225 may extend from the insertion portion 224 and may extend radially away from the longitudinal axis of the second part 22. The lock member 225 is sized and shaped to fit through the first part aperture 213 and, in particular, through the larger semi-circular section thereof (with the insertion portion 224 being received by the smaller semi-circular section thereof). Accordingly, the lock member 225 may pass into the cavity 215 of the first part 21 to be received by that cavity. With the lock member 225 so received, rotation of the second part 22 with respect to the first part 21 , brings the lock member 225 out of alignment with the first part aperture 213. If retraction of the second part 22 from the first part 21 is then attempted, the lock member 225 will abut or otherwise engage an inner surface of the exposed wall 214 to hinder or substantially prevent disengagement of the first part 21 and the second part 22.

As can be seen from figures 5b and 5c, for example, the extendible element 4 may pass through a channel 226 defined through one or more of the flange 222, the generally frusto-conical portion 223, the insertion portion 224, and the lock member 225 (and into the tubular main body 31 of the insertion device 3). The extendible element 4 may, therefore, be provided extending from the insertion device 3 through the second part 22. The extendible element 4 may then be threaded through the valve 12 and into the catheter 1 , through the first part 21 , as depicted for example. The second part 22 may then be engaged with the first part 21 as described above.

Disengagement of the first and second parts 21 ,22 may be achieved by rotation of the second part 22 relative to the first part 21 such that the lock member 225 is once again aligned with the first part aperture 213 to permit the lock member 225 to pass through the first part aperture 213 as the first and second parts 21 ,22 move further apart and disengage.

Rotation of the second part 22 with respect to the first part 21 is about the axis of rotation which may also pass through the channel 226 and the aperture defined by the valve seat, for example.

After placement of the catheter 1 , the extendible element 4 may be removed from the catheter 1 and the first and second parts 21 ,22 may be disengaged (which may occur in any order or at the same time in some versions). The valve element 122 will then be free to move to engage the valve seat and close the valve 12, for example.

As can be seen, for example, the insertion portion 224 may have a length which is generally equal to (or marginally greater than) a depth of the exposed wall 214 (such that the edge of the exposed wall 214 at the first part aperture 213 is retained between the lock member 225 and the end of the generally frusto-conical portion 223).

The generally frusto-conical portion 223 is configured (e.g. sized and shaped) to be received within the end of the catheter 1 (e.g. within the tubular end of the valve 12) and the flange 222 may abut the end of the catheter 1 (e.g. the end of the tubular end of the valve 12). As the end of the catheter 1 (e.g. the end of the tubular end of the valve 12) may be formed from an elastomer, for example, the abutment of the flange 222 and the end of the catheter 1 (e.g. the end of the tubular end of the valve 12) may press the locking member 225 into engagement with the inner surface of the exposed wall 214. This pressing force may be predetermined by virtue of a length of extension of the generally frusto-conical portion 223 from the flange 222 relative to the distance from the end of the catheter 1 (e.g. the end of the tubular end of the valve 12) to the inner surface of the exposed wall 214, for example. This force may help to resist relative rotational movement of the first part 21 and the second part 22 during the insertion process, until disengagement of the first and second parts 21 , 22 is required.

The first part aperture 213 has been described in relation to figures 5a-5c as having two semicircular sections but this is just one example. Another example is shown in figures 6a-6c and the description above in relation to figures 5a-5c applies equally to this version, with the exception of the shape of the first part aperture 213. In this version, the first part aperture 213 is centrally located through the exposed wall 214 (i.e. so that the axis of rotation passes through the first part apertures 213), but has a stadium shape (i.e. a rectangle with rounded ends). In this version, the lock member 225 is stadium shaped too such that it may pass through the first part aperture 213 so that the lock member 225 is received by the cavity 215. Rotation of the second part 22 with respect to the first part 21 brings parts of the lock member 225 out of alignment with the first part aperture 213 such that they abut an inner surface of the exposed wall 214. This hinders or substantially prevents disengagement of the first and second parts 21 ,22. Again, however, rotation of the second part 22 with respect to the first part 21 will bring the locking member 225 back into alignment with the first part aperture 213 so that the locking member 225 can pass therethrough - so allowing disengagement of the first and second parts 21 ,22 as they are moved apart.

In the version of figures 6a-6c, therefore, the lock member 225 may be said to be T-shaped or part- mushroom shaped. Indeed, the lock member of figures 5a-5c may also be referred to as part- mushroom shaped or may be referred to as r-shaped.

As mentioned above, figures 6a-6c correspond with figures 5a-5c, with figure 6a showing the catheter 1 and first part 21 , figure 6b showing the insertion device 3 and second part 22, and figure 6c showing a cross-section through the engaged first and second parts 21 ,22 (with the extendible element 4 passing therethrough).

The version of figures 6a-6c, and others using a T-shaped lock member 225, compared to the version in figures 5a-5c may allow engagement of the first and second parts 21 ,22 in multiple relative orientations of the two parts 21 ,22 (i.e. in two different relative orientations). In versions such as those described in relation to figures 5a-5c and/or figures 6a-6c, and some other versions, the area of engagement between the first and second parts 21 ,22 may be about 3mm² to 5mm² and may be 3mm² to 4mm², for example.

As will be appreciated, therefore, the exposed wall 214 and the lock member 225 are examples (see above) of respective protrusions (the exposed wall 214 being an inwardly extending projection and the lock member 225 being an outwardly extending projection).

One or more detents, stops, ridges, recesses, ribs, or the like, may be provided on the engaging surfaces of the first and second parts 21 ,22 to resist relative rotation (e.g. to increase a predetermined threshold rotational force required to disengage the first and second parts 21 ,22 and/or to limit the extent of rotational movement between the two parts 21 ,22).

In other versions, such as depicted in figures 7a-7c, the lock member 225 may be provided as a thread member and the first part aperture 213 may be formed as a correspondingly threaded aperture (still as defined by the exposed wall 214 which might be otherwise referred to as the exposed thread 214 or simply a thread of the first part 21 , although the exposed wall may extend over a greater depth of the first part 21 than in the versions described in relation to figures 5a-5c and 6a-6c).

Accordingly, the lock member 225 may be a helical lock member (providing the thread member) and the first part aperture 213 may be a helical aperture (providing the threaded aperture).

The lock member 225 (and first part aperture 213) may have a trapezoidal profile and this may be an Acme profile, for example.

The lock member 225 may extend through about 180° (or less) around the second part 22, and with the first part 21 providing a corresponding extension for the first part aperture 213.

In versions such as those described in relation to figures 7a-7c, and some other versions, the area of engagement between the first and second parts 21 ,22 may be about 5mm² to 8mm² and may be 6mm² to 7mm², for example.

Providing a helical lock member and helical aperture for the lock member 225 and first part aperture 221 may, for example, mean that the predetermined threshold rotational force to disengage the first and second parts 21 , 22 is higher than in versions such as those in figures 5a- 5c, and 6a-6c, for example. Again, the description in relation to figures 5a-5c and figures 6a-6c applies equally to the version of figures 7a-7c other than with respect to the shape of the lock member 225 and the first part aperture 213.

In some other versions, such as depicted in figures 8a and 8b, a hybrid configuration may be adopted. So, for example, the T-shaped lock member 225 described generally above in relation to figures 6a-6c may be implemented in combination with a helical first part aperture 213 like that described above in relation to figures 7a-7c.

In some such hybrid versions, therefore, the T-shaped lock member 225 is configured to engage with a threaded aperture defined by the exposed wall 214. This configuration may also be described as having a threaded aperture for the first part aperture 213 which is defined by one or more thread members (e.g. provided by exposed wall or thread 214) extending inwardly from an inner surface of the first part 21. The first part 21 may be generally tubular in shape in such an alternative description of the configuration.

Again, for the avoidance of doubt, one or more detents, stops, ridges, recesses, ribs, or the like, may be provided on the engaging surfaces of the first and second parts 21 ,22 to resist relative rotation (e.g. to increase a predetermined threshold rotational force required to disengage the first and second parts 21 ,22 and/or to limit the extent of rotational movement between the two parts 21 ,22). Indeed, in figures 8a and 8b, a stop 216 can be seen at the end of a thread member.

The description above in relation to figures 5a-5c, figures 6a-6c, and figures 7a-7c apply equally to the version of figure 8a and 8b, other than with respect to the shape of the lock member 225 (for which the description of the lock member 225 in relation to figures 6a-6c applies) and the first part aperture 213 (in relation to which the description of the first part aperture 213 for figures 7a-7c applies).

The thread members of figures 8a and 8b, and other versions, may extend around 150°. There may be two such thread members provided, which may oppose each other across a diameter of the first part 21 , as depicted, for example in figures 8a and 8b. As will be appreciated, the T- shaped lock member 225 means that there are two possible initial orientations of the first and second parts 21 ,22 from which the first and second parts 21 ,22 may be secured to each other.

Figure 9a shows another view, a cross-section, of a version similar to that of figures 7a-7c or 8a and 8b, which includes a first part 21 having a threaded aperture as the first part aperture 213. The description of the first part 21 (and the valve 12 and/or end of the catheter 1) provided above in relation to figures 7a-7c and 8a and 8b, generally applies equally to figure 9a, with the exception that the extendible element 4 is not shown. Figure 9b shows variation of the versions discussed above in relation to figures 9a, and 7a-7b, with the first and second parts 21 ,22 engaged (and the extendible element 4 present too). The above description, however, applies equally to this version. In this version, the generally cylindrical portion 221 of the second part 22 includes a circumferential outwardly projecting barb 221a (which, as mentioned above, helps to hold the second part 22 in place with respect to the insertion device 3).

As discussed above, the first part 21 may be secured within the catheter 1 (e.g. with the tubular end of the valve 12) by an interference fit but an adhesive may additionally be used between the first part 21 and the catheter 1 (e.g. the tubular end of the valve 12) and this adhesive may be applied around the outer wall 212 of the first part 21 , for example. Likewise, an adhesive may also (or alternatively) be used to help to secure the second part 22 with respect to the insertion device 3. Accordingly, an adhesive may be applied to the generally cylindrical portion 221 of the second part 22 for this purpose (e.g. in addition to the barbs 221a or similar feature to assist with the connection between the two pieces). The fit between the first part 21 and the catheter 1 (e.g. with the tubular end of the valve 12) may be tight, as may the fit between the second part 22 and the insertion device 3 tubular main body 31. Moreover, a relatively tight fit between the lock member 225 and the exposed wall 214 forming the threaded first part aperture 213 may be required to ensure there is a sufficiently large predetermined threshold rotational force before the first and second parts 21 ,22 rotate with respect to each other and can be disengaged.

Figures 10a-1 Oe show various views of a version of the second part 22. Although the description above applies equally to this version, the features of this version (and other versions) will be covered for the avoidance of doubt.

As can be seen from figure 10a, for example, which is an end-on view of the second part 22 of this version, the second part 22 may include a lock member 225 in the form of a thread member and the lock member 225 may extend around the insertion portion 224 of the second part 22. The lock member 225 may extend around 360° of the insertion portion 224 and may comprise a single thread member, for example. Towards an end of the locking member 225 closest to the generally frusto-conical portion 223 there may be a stop member 227 which may be configured, in use, to abut against a stop 216 of the first part 21 , for example. Such a stop member 227 may be provided in relation to other versions of the second part 22 including a lock member 225 in the form of a thread member. The stop member 225 can be seen in figures 10b and 10c, for example.

As described in relation to other versions, the second part 22 there may be a generally frusto- conical portion 223 from which the insertion portion 224 extends and a flange 222 may be provided at an opposing end of the generally frusto-conical portion 223 to the insertion portion 224. A generally cylindrical portion 221 may be provided extending from the flange 222, for receipt by the insertion device 3 (e.g. by the tubular main body 31 of the insertion device 3). There may, as depicted for example, be a barb 221a provided around a part of the generally cylindrical portion 221 and configured to resist removal of the second part 22 from the insertion device 3. As described above, an adhesive may also be used (e.g. around the generally cylindrical portion 221) to help to secure the second part 22 to the insertion device 3.

The total length of the second part 22 may be around 10-15mm and may be about 11mm. The lock member 225 may project from the insertion portion 223 by a distance of about 2mm (e.g. about 1 7mm). The lock member 225 may be, at its base (nearest the insertion portion 224) be about 1 mm in depth (or about 1 2mm) and a tip of the lock member 225 may have a radius of about 0.2mm. A thread pitch of the lock member 225 may be about 2.5mm.

Also as described above, the second part 22 may define a channel 226 there through - which leads into the tubular main body 31 of the insertion device 3 when fitted thereto and through which the extendible element 4 may pass.

Through the insertion portion 224 and/or at least at the end of the insertion portion 224, the channel 226 may be of a size such that the extendible element 4 may pass therethrough but this part of the channel 226 may guide the extendible element 4 as it passes through to the catheter 1. The channel 226 at the insertion portion 224 (or at least the end thereof) may be narrower than the channel 226 in, for example, the generally cylindrical portion 223.

Figures 11a- 11f show different views of a version of the first part 21 and that version may be configured to engage the version of the second part 22 depicted in figures 10a-10e, for example.

Again, the description above applies equally to this version of the first part 21.

This version of the first part 21 , along with some others, has a generally tubular form - see figures 11f and 11 e, for example. The outer diameter of the first part 21 may be larger at one end and smaller at the opposing end. The change in diameter may be gradual (i.e. a taper) and/or may include one or more steps (as shown in figures 11e and 11 f, for example). The end with the smaller diameter may be the exposed end of the first part 21 , for example.

The exposed wall 214 in the version shown in figures 11a- 11f is provided in the form of an internal thread and so may, instead, be referred to as the internal thread 214 of the first part 21. This internal thread 214 may include the stop 216 as previously discussed and may not be provided through 360°. A total length of the first part 21 may be about 5mm and the outer diameter of the first part 21 may be about 6mm. In the depicted version of figures 11 a-11 f, the step change in the outer diameter may be about halfway along the length of the first part 21 and may be about 0.2mm change in diameter.

Even with the inter-engaging thread design of, for example, figures 10a-10e and 11 a-11 f, the first and second parts 21 ,22 may still disengage (through forced relative rotation) in use in some instances. This may be especially the case as the extendible element 4 is pushed through in order to collapse the malecot 13 (or other holding system), for example.

Therefore, devices and systems may be needed in order to reduce the risk of the first and second parts 21 ,22 rotating with respect to each other in an unintended manner. These devices and systems are described with passing reference to particular versions of the first and/or second parts 21 ,22 but it will be appreciated that this is for convenience only and they may be applied to other versions.

With reference to figures 12a and 12b, the first part 21 may, in some versions be provided with an additional thread member 217. The additional thread member 217 may be provided to engage a second side of a part of the lock member 225, wherein the first side of the part of the lock member 225 configured to engage a part of the exposed wall 214 (which may be in the form of a thread member). Therefore, the additional thread member 217 may be configured to sandwich a part of the lock member 225 (which may be a thread member of the second part 22) between itself and the exposed wall 214 (which may be in the form of a thread member of the first part 21). The additional thread member 217 may be provided towards an end of the threaded first part aperture 213, for example. The additional thread 2107 may be an extension of the thread provided by the exposed wall 214, for example. The lock member 225 may, in some embodiments, be extended to provide a longer thread member in some versions (e.g. to extend more than 360° around the insertion portion 224).

The use of the additional thread 217 may increase the predetermined threshold rotational force required to rotate the first and second parts 21 ,22 with respect to each other and mean that further rotations may be needed to disengage the two parts 21 ,22 completely.

In some versions, the internal thread 214 and/or the lock member 225 may, through a first length thereof, have a rougher surface than through a second length thereof, such that from a fully engaged position of the first and second parts 21 ,22 the initial rotation is harder (due to the engagement of the rougher surface(s)) than the final rotation prior to disengagement. With reference to figure 13, in a version of the second part 22 the flange 222 may include one or more ribs 222a which may, for example, extend in a generally radial direction. The or each rib 222a (of which there may be two as depicted, for example) may engage the end of the catheter 1 (e.g. the tubular end of the valve 12). The or each rib 222a may, therefore, increase the friction between the first and second parts 21 ,22 when engaged with each other and increase the predetermined threshold rotational force required for rotation of the first part 21 with respect to the second part 22, for example. In some versions, the end of the catheter 1 (e.g. the tubular end of the valve 12) and/or the first part 21 may be provided with one or more slots 218 (see below), each slot 228 being configured to receive a respective rib 222a.

In some versions, see figures 14a and 14b for example, rotation between the first and second parts 21 ,22 may be inhibited through use of the extendible element 4. In particular, the extendible element 4 (which is otherwise an elongate generally uniform member in the region of the first and second parts 21 ,22) may include a radial extension 41 which is configured to be received by a corresponding opening 219a defined by the first part 21. The opening 219a may be shaped and sized to receive the radial extension 41 and to inhibit rotation between the first part 21 and the extendible element 4 (by abutment of the radial extension 41 and the first part 21). The extendible element 4 may be held in a substantially constant rotational position with respect to the insertion device 3 by, for example, the mechanism used to move the extendible element 4 axially (as described in relation to the background section of this document). Therefore, rotation of the first part 21 with respect to the second part 22 may be inhibited or substantially prevented.

The opening 219 may be defined by a covered wall 219 which may be part of the first part 21 and located at the covered end thereof.

The radial extension 41 may be generally in the shape of a semicircle, for example. The opening 219a may also be of the same shape as the radial extension 41. Other shapes are also envisaged.

The cavity 215 may be sufficiently large to permit axial movement of the radial extension 41 into the cavity and then rotation of the radial extension 41 (the extendible element 4 and the second part 22) with respect to the first part 21. In versions including an internal thread as part of the first part 21 , the thread may be sufficiently spaced apart from the covered wall 219 to allow the radial extension 41 to be received by the cavity 215 when the first and second parts 21 ,22 are engaged.

In some versions, the covered wall 219 may not be part of the first part 21 but may be a separate piece in the same location as described above.

By way of an introduction, some versions may incorporate an extended thread for the lock member 225 as shown in figures 15a and 15b. Of note in this and some other versions are the flat end of the second part 22 which may better permit rotation of, for example, the radial extension 41 in the cavity 215 at the end of the second part 22 - when the second part 22 is received by the first part 21. Of further note is that the generally frusto-conical portion 223 need not be provided in all versions. Instead, for example, the insertion portion 224 may extend directly from the flange 222 (without the intermediate feature of the generally frusto-conical portion 223). This lack of a generally frusto-conical portion 223 may also be true for other versions disclosed herein (whether or not specific examples may be depicted with or without the feature). Likewise, the generally frusto-conical portion 223 may be present in versions even if specific examples are depicted without the feature.

Such a version is depicted in figures 16a and 16b, for example. This is a version which is mentioned above in which the covered wall 219 is provided separately from the first part 21. In this, and some other versions, the covered wall 219 may be provided as a cap which is configured to fit over an end of the first part 21 (i.e. the covered end). Accordingly, the end of the first part 21 may include a portion of reduced diameter over which an outer rim 219b of the covered wall 219 is configured to fit. As described above, the covered wall 219 may define the opening 219a configured to receive the radial extension 41. This version, as depicted, also uses the thread configuration of figures 15a and 15b but this need not be the case and others of the versions presented herein may be used. The covered wall 219 may be welded or secured to the first part 21 using an adhesive, for example.

Versions in which there is a radial extension 41 on the extendible element 4 may present an increased risk of injury when the extendible element 4 is removed (an issue which may be partially resolved by removal of the extendible element 14 from the urethra at the same time as the insertion device 3).

Some versions may use other configurations rather than a radial extension 41 for the same purpose but with, in some cases, for example, reduced risk of injury.

With that in mind, figures 17a and 17b show a version which may use a keyed outer tube 42 through which the extendible element 4 is configured to pass. In some versions, the keyed outer tube 42 forms a part of the extendible element 4, with the extendible element 4 including the keyed outer tube 42 and an inner wire or tube (the an extendible element 4 with different sections along its length as described herein, see below).

The keyed outer tube 42 has an external cross-section with one or more surfaces against which the covered wall 219 can engage to inhibit or substantially prevent relative rotation between the keyed outer tube 42 and the first part 21 (the keyed outer tube 42 may also be prevented from rotation relative to the second part 22 by, for example, engagement of the one or more surfaces against a part of the second part 22 such as the insertion portion 224 (through which it passes)).

The keyed outer tube 42 may have a triangular, square, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, or decagonal outer cross-sectional shape. The outer cross-sectional shape may be a regular shape, or an irregular shape. The keyed outer tube 42 may have an internal cross-sectional shape which is different to the outer cross-sectional shape and may be circular.

The keyed outer tube 42 is configured to receive the extendible element 4 in some versions or the inner wire or tube in others, and to permit axial movement thereof through the keyed outer tube 42.

In versions which include the inner wire or tube, then this inner wire or tube may perform the function of the extendible element 4, for example in relation to the collapsing of the malecot 13 or other holding system and/or stiffening of the catheter 12.

The various versions disclosed herein may be used with different forms of extendible element 4 and keyed outer tube 42, and reference to these features in relation to all disclosed versions should be considered in light of the more detailed discussion of variations of these particular features which are discussed below (e.g. with reference to figures 21 onwards).

The covered wall 219, which may be provided as a cap (as depicted in figures 17a and 17b, for example, and described above), has an opening 219a which is shaped and sized so that a surface of the covered wall 219 which defines the opening 219a is configured to engage at least part of the outer surface of the keyed outer tube 42 such that rotation of the covered wall 219 (and so the first part 21) with respect to the keyed outer tube 42 is inhibited or substantially prevented. The opening 219a may be shaped to correspond with the keyed outer tube 42 (so that a shape of the opening 219a is the same as the shape of the keyed outer tube 42).

In some versions, at least part of the covered wall 219, such as part of the rim 219b, may be provided with a flat portion which engages a corresponding flat portion of the rest of the first part 21 to inhibit rotational movement between the covered wall 219 and the rest of the first part 21 (the covered wall 219, as will be appreciated, may be considered to be part of the first part 21 or a separate element or component).

The keyed outer tube 42 may be configured to extend through the second part 22 and the channel 226 may, at least through a part thereof, be shaped and sized so that a surface of the second part 22 which defines the channel 226 is configured to engage at least part of the outer surface of the keyed outer tube 42 such that rotation of the second part 22 with respect to the keyed outer tube 42 is inhibited or substantially prevented. The at least a part of the channel 26 may be shaped to correspond with the keyed outer tube 42 (so that a shape of the at least a part of the channel 26 is the same as the shape of the keyed outer tube 42).

Thus, the first and second parts 21 ,22 may be held in a fixed relative rotational position by use of the keyed outer tube 42 which extends through both the first and second parts 21 ,22.

The keyed outer tube 42 may be configured for axial movement (i.e. retraction or extension with respect to the first 21 and/or second 22 parts). The keyed outer tube 42 may, therefore, be slidingly received by the first and second parts 21 ,22. Movement of the keyed outer tube 42 in this manner may be achieved by manual pushing or pulling of the keyed outer tube 42 and this may be via a mechanism of the insertion device 3 provided for this purpose, for example (such a mechanism may be a button, for example, the axial movement of which may drive axial movement of the keyed outer tube 42, and there may be a direct abutment between the button and the keyed outer tube 42, for example).

Axial movement of the keyed outer tube 42 to retract the keyed outer tube 42 from the covered wall 219 may disengage the keyed outer tube 42 from the covered wall 219 (with the keyed outer tube 42 leaving the opening 219a). As engagement of the keyed outer tube 42 and the covered wall 219 was holding the first part 21 in a fixed rotational position with respect to the keyed outer tube 42, the disengagement then allows the first part 21 to rotate with respect to the keyed outer tube 42 (and so with respect to the second part 22). The keyed outer tube 42 may remain at least partially received by the second part 22 (i.e. within the channel 226) during this disengagement from the first part 21 and the rotation. In some versions, the keyed outer tube 42 can be completely retracted from both the first and second parts 21 ,22 (and may or may not be retracted from the insertion device 3 too). Rotation of the first part 21 with respect to the second part 22 may be achieved, for example (in this and other versions), by rotation of the insertion device 3 with respect to the first part 21 (and so with respect to the catheter 1 , for example).

As such, the use of the keyed outer tube 42 in such versions allow the rotational movement of the first and second parts 21 ,22 to be selectively inhibited or substantially prevented.

Another version is shown in figures 18a and 18b which includes an arrangement for inhibiting undesired rotational movement between the first and second parts 21 ,22 (e.g. for increasing the predetermined threshold rotational force required for rotational movement between the two parts 21 ,22). The arrangement, as will be appreciated, can be used in other versions disclosed herein. For example, even though figures 18a and 18b do not show a keyed outer tube 42, this arrangement may be used in such versions. The version of figures 18a and 18b has been alluded to above in relation to the versions described with reference to figure 13, for example. In this, and other, versions, the second part 22 includes the flange 222 with one or more ribs 222a (see above). The depicted, and some other versions, include two ribs 222a for example.

The version as depicted in figures 18a and 18b, for example but also in other versions, the first part 21 may include one or more corresponding slots 218, which may be positioned to cooperate with the one or more ribs 222a (although this need not be the case). With the first and second parts 21,22 engaged (e.g. substantially fully engaged in versions using a lock member 225 in the form of a threaded member and/or threaded first part aperture 213, as well as some other versions) at least one of the one or more ribs 222a may be at least partially received by at least one of the one or more slots 218. This may, therefore, inhibit the rotational movement of the first part 21 with respect to the second part 22 (i.e. increase the predetermined threshold rotational force required to rotate the two parts 21 ,22 with respect to each other). In some versions, the or each rib 222a corresponds in shape, size and/or position, with the or each slot 218. In some such versions, the or each rib 222a is at least partially received by a respective slot 218 when the first and second parts 21,22 are engaged (e.g. fully engaged, as explained above, for example).

The or each slot 218 may be provided in the exposed wall 214 and may extend through at least a part of the depth thereof. The or each slot 218 may also extend radially through part of the first part 21 (such as the exposed wall 214). In some versions the or each rib 222a and the or each slot 218 are elongate (e.g. as depicted).

However, other shapes of slot 218 and/or rib 222a are envisaged. For example a rib 222a may be a circular protrusion and a slot 218 may be a circular recess. The or each rib 222a and the or each slot 218 need not be the same size and/or shape as each other in some versions. Figures 19a and 19b show a variation of a version using a keyed outer tube 42, for example. The variation used in this version may be implemented in combination with the other features taught herein, for example.

Wth reference to figures 19a and 19b by way of example, the first part 21 may include an expandable member 2191 which may be considered to be a variation of the covered wall 219 (i.e. the expandable member 2191 may be considered to be the covered wall 219).

The expandable member2191 may comprise a body 2191a which is configured to extend around at least part of the keyed outer tube 42. The body 2191a may, therefore, define an aperture configured to receive at least part of the keyed outer tube 42 and which is shaped such that a surface of the body 2191a engages at least one surface of the keyed outer tube 42 to inhibit or substantially prevent rotational movement between the expandable member 2191 and the keyed outer tube 42 (when so received). The aperture defined by the body 2191a may, therefore, be shaped to correspond with the external cross-sectional shape of the keyed outer tube 42 (as described above).

The body 2191a of the expandable element 2191 may include an interlock surface 2191b. In the depicted and some other versions, the interlock surface 2191b may be at least part of an outer circumferential surface of the body 2191a but the interlock surface 2191b may be another surface (such as an end face). The interlock surface 2191b is a surface of the expandable element 2191 which is configured to engage (or interlock) with a surface of the rest of the first part 21 such as an inner surface of the outer wall 212 of the first part 21. For example, the inner surface of the outer wall 212 towards the covered end of the first part 21 may be a first part interlock surface 212a.

The interlock surface 2191b and the first part interlock surface 212a are configured to engage each other and may have respective features (such as teeth (which may be radially extending teeth)) which interlock with each other. When interlocked in this manner, rotational movement of the expandable member 2191 and the rest of the first part 21 (e.g. at least the outer wall 212) is inhibited or substantially prevented.

The first part interlock surface 212a may, for example, be a surface which defines at least part of the cavity 215. The expandable member 2191 may be configured to be at least partially received within the cavity 215

The expandable member 2191 is configured to adopt an expanded and an unexpanded condition. With the expandable member 2191 at least partially received by the first part 21 (e.g. by the cavity 215), and in its expanded condition, the interlock surface 2191b and the first part interlock surface 212a may interlock (i.e. engage each other) as described above. However, with the expandable member2191 in the unexpanded condition, and the expandable member2191 received in the same manner in the first part 21, the interlock surface 2191b and the first part interlock surface 212a may not be interlocked (i.e. they may be disengaged) such that rotational movement between the expandable member 2191 and the rest of the first part 21 may be permitted. Alternatively or additionally, in the unexpanded condition, the interlock surface 2191b and the first part interlock surface 212a may interlock (i.e. engage each other) as described above but the expandable member 2191 may be permitted to rotate with respect to the keyed outer tube 42.

Changing the condition of the expandable member 2191 may be achieved by removal (or insertion) of the keyed outer tube 42 from receipt by the aperture defined by the body 2191a. The expandable member 2191 may be configured to flex inwardly (reducing its diameter, for example) when the keyed outer tube 42 is removed from the aperture defined by the body 2191a (and may flex outwardly (increasing its diameter, for example) when the keyed outer tube 42 is received by the aperture defined by the body 2191a). To achieve this, the expandable member 2191 may be generally annular (i.e. the body 2191a may be generally annular) but there may be a break in the body 2191a such that the body 2191a forms a broken circle or e-shape. The opposing ends of the body 2191a (which face each other across the gap formed by the c-shape, for example) may, in the unexpanded condition for the expandable member 2191 , be closer together than when the expandable member 2191 is in the expanded condition.

Thus, with the keyed outer tube 42 received by the expandable member 2191 in the manner described, the expandable member 2191 is restricted from rotation with respect to the keyed outer tube 42 and the outer wall 212 of the first part 21 is restricted from rotation with respect to the expandable member 2191. In relation to this and other versions, any threads of a threaded first part aperture 213 may be in a fixed rotational relationship (e.g. extending from) the outer wall 213 and so are also restricted from rotation with respect to the keyed outer tube 42. Also as described herein, the second part 22 may be restricted from rotation with respect to the keyed outer tube 42, so restricting rotational movement of the first and second parts 21 ,22 with respect to each other.

The keyed outer tube 42 may be axially moved to retract it from the expandable member 2191 and so allow the expandable member 2191 to adopt the unexpanded condition. This then permits rotational movement of the first part 21 with respect to the second part 22 (as the expandable member 2191 no longer restricts this rotation).

The expandable member 2191 may be described as a gear member, for example.

In some versions, see figures 20a and 20b by way of example, there may be provided a lock washer 229 which may be part of the first part 21 , the second part 22, or a separate element or component. As will be appreciated, this lock washer 229 may be implemented into any of the other versions disclosed in this document.

The lock washer 229 is configured to abut a part of the first part 21 (or the catheter 1) and a part of the second part 21 (or the insertion device 3). In the depicted and some other versions, the lock washer 229 may abut the flange 222 and the exposed wall 214.

The lock washer 229 may be made from a relatively soft material (compared to the first and second parts 21 ,22 for example) and may be made from silicone, for example. The lock washer 229 may be configured to increase the predetermined threshold rotational force required to rotate the first part 21 with respect to the second part 22. In some versions which include the lock washer 229, the lock washer 229 may fit (at least partially) within the end of the catheter 1 (e.g. within the tubular end of the valve 12). In some versions, the first part 21 may be provided such that it is relatively close to the end of the catheter 1 so that the lock washer 229 may engage part of the first part 21 (as described above) and still be substantially outside of the catheter 1 (e.g. the tubular end of the valve 12). In some versions, the lock washer 229 is further configured to abut at least part of the catheter 1 (e.g. the tubular end of the valve 12). As will be appreciated, the coefficient of friction between the lock washer 29 and the end of the catheter 1 may be higher than between the lock washer 229 and the first part 21. This may help to provide the required predetermined threshold rotational force as discussed above.

We turn now to variations in the versions of the extendible element 4 including the keyed outer tube 41. It will be appreciated that the keyed outer tube 42 need not be keyed if the interference fit between the parts is adequate for the required predetermined threshold rotational force. The keyed outer tube 42 may, therefore, throughout be replaced by an outer tube 42 which need not be keyed.

Figure 21 , by way of example, shows the keyed outer tube 42 with the extendible element 4 passing therethrough. As described herein, the keyed outer tube 42 may be considered to be part of the extendible element 4, with a wire or tube passing therethrough. In order, however, to align with the background section of this document, the extendible element 4 and keyed outer tube 42 are described as separate components because the extendible element 4 primarily performs the functions of the corresponding element discussed in the background section.

The other components shown in figure 21 are incidental and provided for context rather than as an indication of a limitation to use of the outer tube 42 and extendible element 4 in relation to versions including those components, in the depicted form or otherwise. The same is true for the other figures used in relation to the disclosure of different versions of the outer tube 42 and/or extendible element 4

This version permits independent extension and retraction of the keyed outer tube 42 and the extendible element 4. However, there is increased complexity in operation as the two need to be controlled independently.

In some versions, the keyed outer tube 42 and extendible element 4 may be combined into a multisection extendible element 4 - see figure 22, for example. In this and some other versions, a first section 43 of the extendible element 4 has a first diameter and a second section 44 of the extendible element 4 has a second diameter. The first diameter may be smaller than the second diameter. The first section 43 may, therefore, be a narrow section and the second section 44 may be a wide section. In some versions, the first section 43 is not keyed (and may have a circular external cross-sectional shape) and the second section 44 is keyed. An external cross-sectional shape of the second section 44 may be any of the shapes described herein in relation to the keyed outer tube 42, for example.

The first and second sections 43,44 of the extendible element 4 may be configured to be operated in unison (i.e. axial movement of the second section 44 may cause axial movement of the first section 43). The first and second sections 43,44 may be connected for movement together. The first and second sections 43,44 may be integrally formed. The second section 44 may be a sleeve which is fitted (or moulded) over a length of the first section 43. The first and second sections 43,44 may be welded together. Such versions may be simpler to manufacture, for example, than the versions using a keyed outer tube 42.

The extendible element 4 may be formed from steel (e.g. stainless steel) or a plastics material, for example.

With reference to, for example, figures 23a and 23b, in some versions in which the extendible element 4 has first and second sections 43,44, with a keyed second section 44 and a first section 43 which is not keyed, the diameters of the first and second sections 43,44 may be substantially equal (or the first section 43 diameter may be marginally less than the second section 44 diameter). This may help to reduce interference between the second section 44 and the valve seat insert 126.

As can be seen in figure 23b (and, indeed, in figure 22), the extendible element 4 longitudinal axis may be aligned with a central longitudinal axis of the catheter 1 (e.g. of the valve 12) in some versions. So aligned, the extendible element 4 may pass through the aperture defined by the valve seat, for example.

As the aperture defined by the valve seat is offset with respect to the central longitudinal axis of the catheter 1 in some versions, there is a risk of the extendible element 4 damaging or moving the valve seat insert 126, for example.

Therefore, in some versions - such as described with reference to figures 24a and 24b, for example - the extendible element 4 longitudinal axis may be radially offset, at least in the region of the valve seat (and valve set insert 126 in some versions), from the central longitudinal axis of the catheter 1. This may be achieved by providing the channel 226 in the second part 22 through a radially offset position with respect to the central longitudinal axis of the second part 22 (see figure 24b, for example). In some versions, in which there may be a covered wall 219 defining the opening 219a, the opening 219a may be likewise radially offset position with respect to the central longitudinal axis of the first part 22. Accordingly, the extendible element 4 may be guided along an offset path.

Moreover, as the axis of rotation of the first part 21 relative to the second part 22 is aligned with the central longitudinal axis of the first part 22 and the second part 21 , the provision of an offset extendible element 4 in this manner may help to resist relative rotational movement of the first part 21 with respect to the second part 22 (i.e. increasing the predetermined threshold rotational force required to rotate the first part 21 with respect to the second part 22).

As discussed above, the outer cross-sectional shape of the second section 44 could be a number of different shapes. In some versions - see figures 25a and 25b - the outer cross-section shape may be oval. Indeed, the first section 43 may also be this shape (and may also be the same size of cross-section too, for example). As can be seen, for example, the extendible element 4 may pass along the central longitudinal axis of the first and/or second parts 21 ,22; however, a central longitudinal axis of the extendible element 4 may be offset (e.g. radially) therefrom.

A variation of the versions described in relation to figures 25a and 25b is described with reference to figures 26a and 26b. In this version, the extendible element 4 may be generally as described; however, rather than provide a correspondingly shaped opening 219a and/or at least part of the channel 226 (which may be the case in relation to figures 25a and 25b), the opening 219a and/or at least part of the channel 226 may be square in shape. This may be simpler to manufacture. Yet more versions of the disclosed technology are considered in relation to figures 27a, 27b, 28a, and 28b. These versions, and some other versions, use an extendible element 4 with a circular external cross-sectional shape. The extendible element 4 may have this shape along substantially the entire length thereof which is located within the valve 12, first part 21 , and second part 22 when in use. The opening 219a and/or at least part of the channel 226, however, may not be of the same cross-sectional shape and/or size as the extendible element 4. In the depicted and some other examples, the opening 219a and/or at least part of the channel 226 are generally D-shaped (i.e. semi-circular). In some versions, the opening 219a and/or at least part of the channel 226 have a width which is greater than a diameter of the extendible element 4. In some versions, the opening 219a and/or at least part of the channel 226 have a height which is greater than a diameter of the extendible element 4. This arrangement may be such that the extendible element 4 can pass therethrough and may pass through the aperture defined by the valve seat such that no substantive contact is made between the extendible element 4 and the valve seat insert 126, for example. This arrangement may be such that the first and second parts 21 ,22 are permitted to rotate with respect to each other through a predetermined part of a complete rotation (e.g. through about 90°) thereafter the extendible element 4 may abut part of the covered wall 219 and/or the second part 22 to inhibit or substantially prevent further rotation (which might lead to disengagement of the first and second parts 21 ,22). Accordingly, the first and second parts 21 ,21 may be substantially prevented from disengaging each other.

The primary difference between the version of figures 27a/b and figures 28a/b is in the size of the opening 219a and/or at least part of the channel 226. As will be appreciated, in these and some other versions, the opening 219a and/or at least part of the channel 226 are shaped and sized such that the extendible element 4 is permitted to pass along the opening 219a and/or at least part of the channel 226 in a lateral movement to allow for rotation of the second part 22 with respect to the first part 21 (at least until the extendible element 4 abuts an end of the opening 219a and/or at least part of the channel 226 such that further rotational movement is restricted or substantially prevented).

As will be understood, the opening 219a and/or at least part of the channel 226 in these and some other versions is offset from the central longitudinal axis of the first part 21 (and/or the catheter 1), and/or the second part 22 (and/or the insertion device 3) such that rotation of the first part 21 with respect to the second part 22 is resisted, as described above.

In these and some other versions, the first part 21 and the valve seat insert 126 are intended to be in a fixed rotational relationship with each other. In some versions, particularly those using an offset extendible element 4, there may be a tendency for the first part 21 and the valve seat insert 126 to rotate with respect to each other. This may also be a problem in relation to other versions.

Therefore, with reference to figures 29a and 29b, for example, the valve seat insert 126 may include a retaining protrusion 126a and the first part 21 may include a corresponding retaining recess 212b which is configured to receive the retaining protrusion 126a such that rotational movement of the valve seat insert 126 with respect to the first part 21 is inhibited or substantially prevented. The retaining protrusion 126a may extend from a surface of the valve seat insert 126 adjacent the first part 21. The retaining recess 212b may be located in the outer wall 212 or in the covered wall 219, for example. The retaining protrusion 126a may extend in a direction parallel with a longitudinal axis of the valve seat member 126 and/or the first part 21. In some versions the retaining protrusion 126a is part of the first part 21 and the retaining recess 212b is part of the valve seat insert 126.

In some versions, with reference to figure 30 for example (which is an example of a linearly operated engagement), the second part 22 includes at least one moveable member 224a which may be part of the insertion portion 224, for example. The at least one moveable member 224a may be configured to be pushed (and held) outwardly by the extendible element 4 passing through the channel 226. In other words, the at least one moveable member 224a may be splayed outwardly by the extendible element 4 and, indeed, this may define at least part of the channel 226. In the depicted and some other versions, the at least one moveable member 224a is a segment of the insertion portion 224.

The at least one moveable member 224a may be configured, when pushed or splayed outwardly, to engage one or more abutment members 219c of the first part 21. The or each abutment member 219c may be part of the covered wall 219, for example, and/or may extend radially inwardly from the outer wall 212.

With the at least one moveable member 224a engaging the one or more abutment members 219c, rotation of the first part 21 relative to the second part 22 may be inhibited or substantially prevented.

In some versions, there may be a plurality of moveable members 224a and abutment members 219c. In some versions, each moveable member 224a may be configured to be engaged between two abutment members 219c (one on either side thereof). In some versions, the or each moveable member 224a and/or the or each abutment member 224a may have a substantially triangular cross-sectional shape.

Such versions may be used and another manner in which to inhibit rotational movement of the first and second parts 21 ,22 with respect to each other (e.g. in versions in which the first part aperture 213 is a threaded aperture and/or in which the lock member 225 is a thread member).

The extendible member 4 may be retracted from the part of the second part 22 adjacent the moveable member(s) 224a such that they are no longer held in their outward position. The abutment member(s) 219c may be shaped (e.g. with angled surfaces) to encourage movement of the or each moveable member 224a towards an inward (i.e. retracted) position on a rotational force being applied to the second part 22 relative to the first part 21 such that the or each abutment member 219c and moveable member 224a disengage. Accordingly, the first and second parts 21 ,22 may then be permitted to rotate with respect to each other.

Figure 31 depicts an insertion tool 3 as generally described herein coupled to the end of the catheter 1.

The catheter 1 may include one or more tethers 14. The or each tether 14 may extend from the catheter 1 through the urethra after insertion/implantation of the catheter 1. The or each tether 14 may be secured at one end of the catheter 1 and the or each tether 14 may extend out of the urethra. Thus, the or each tether 14 may be used to help to pull the catheter 1 for extraction purposes.

The or each tether 14 may be secured, at one end, to a fixed position on the catheter 1. In some versions, wrapping the or each tether 14 may be wrapped around a length of the insertion device 3 (e.g. the tubular main body 31 thereof) and this wrapping may be in a helical manner as shown, for example. This wrapping may help to inhibit rotation of the catheter 1 (and so the first part 21) with respect to the insertion device 3 (and so the second part 22). As described above, therefore, this may help to prevent unintended disengagement of the first and second parts 21 ,22.

In some versions, a clip or band 126b may be provided around at least part of the insertion device 3 (e.g. around at least part of the tubular main body 31) which is configured to clamp the or each tether 14 to the insertion device 3. This clip or band 126b may, therefore, inhibit or substantially prevent the or each tether 14 from unwrapping from around the insertion device 3.

As will be understood, various versions provide an engagement mechanism 2 which has two parts 21 ,22 which engage each other. In many of the disclosed versions, the two parts 21 ,22 rotationally engage each other. Various versions of the described technology are concerned with providing a predetermined threshold rotational force for disengaging the first and second parts 21 ,22. Multiple aspects of the technology may be combined in combination, as will be appreciated.

The first part 21 is configured to be fitted to the catheter 1 (and may then form a part thereof). The second part 22 is configured to be fitted to the insertion device 3 (and then form a part thereof).

The catheter 1 and insertion device 3 may be provided (i.e. supplied for use) in an engaged (i.e. connected) configuration - i.e. with the first and second parts 21 ,22 engaged.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The invention may also broadly consist in the parts, elements, steps, examples and/or features referred to or indicated in the specification individually or collectively in any and all combinations of two or more said parts, elements, steps, examples and/or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein.

Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure. Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.

Claims

1. An engagement mechanism for use in selective connection of an intraurethral catheter and an insertion device used for insertion of the catheter into a urethra, the engagement mechanism including: a first part configured to be fitted to the catheter; and a second part configured to be fitted to the insertion device, wherein the first and second parts are configured to engage each other rotationally, and are configured to permit the passage of an extendible element therethrough.

2. An engagement mechanism according to claim 1 , wherein the first part is a female part and includes an internal thread, and the second part is a male part has a lock member configured to engage the internal thread of the first part.

3. An engagement mechanism according to claim 2, wherein the lock member is T-shaped or r-shaped.

4. An engagement mechanism according to claim 1 or 2, wherein the lock member is an external thread.

5. An engagement mechanism according to any preceding claim, wherein the first part includes a wall defining an opening configured to receive a radial extension of the extendible element to inhibit rotational movement of the first part with respect to the extendible element, and wherein the first part includes a cavity adjacent the wall, such that the radial extension is moveable into the cavity to allow rotational movement of the first part with respect to the extendible element.

6. An engagement mechanism according to claim 4, wherein the radial extension is semicircular in shape.

7. An engagement mechanism according to any of claims 1 to 4, wherein the first part includes a wall defining an opening configured to receive at least part of a keyed outer tube through which the extendible element is configured to pass, the opening having at least one surface which is configured to abut a surface of the keyed outer tube to inhibit rotation of the first part with respect to the keyed outer tube, and wherein retraction of the keyed outer tube from the opening permits rotation of the first part with respect to the keyed outer tube.

8. An engagement mechanism according to claim 7, wherein the second part defines a channel which is configured to receive at least part of the keyed outer tube such that the second part and the keyed outer tube are in a fixed rotational relationship.

9. An engagement mechanism according to claim 7 or 8, further including an expandable member having an expanded configuration and an unexpanded configuration, the expandable member being in the expanded configuration when the keyed outer tubed is at least partially received by the expandable member and being in the unexpanded configuration when the keyed outer tubed is not at least partially received by the expandable member, wherein the expandable member in the expanded configuration has an interlock surface which engages a first part interlock surface of the first part, and wherein the expandable member interlock surface disengages the first part interlock surface in the unexpanded configuration, engagement of the interlock surface and the first part interlock surface inhibiting rotation of the keyed outer tube with respect to the first part.

10. An engagement mechanism according to any of claims 1 to 4, wherein the extendible element has a first section and a second section, wherein the first part includes a wall defining an opening configured to receive at least part of the second section of the extendible element, the opening having at least one surface which is configured to abut a surface of the second section of the extendible element to inhibit rotation of the first part with respect to the extendible element, and wherein retraction of the second section of the extendible element from the opening permits rotation of the first part with respect to the extendible element.

11. An engagement mechanism according to claim 10, wherein the second part defines a channel which is configured to receive at least part of the second section of the extendible element such that the second part and the extendible element are in a fixed rotational relationship.

12. An engagement mechanism according to claim 10 or 11 , further including an expandable member having an expanded configuration and an unexpanded configuration, the expandable member being in the expanded configuration when the second section of the extendible element is at least partially received by the expandable member and being in the unexpanded configuration when the extendible element is not at least partially received by the expandable member, wherein the expandable member in the expanded configuration has an interlock surface which engages a first part interlock surface of the first part, and wherein the expandable member interlock surface disengages the first part interlock surface in the unexpanded configuration, engagement of the interlock surface and the first part interlock surface inhibiting rotation of the extendible element with respect to the first part.

13. An engagement mechanism according to claim 9 or 12, wherein the interlock surface and/or the first part interlock surface includes a plurality of teeth.

14. An engagement mechanism according to any preceding claim, further including a lock washer configured to be located between at least part of the first and second parts and to inhibit rotational movement between the first and second parts.

15. An engagement mechanism according to any preceding claim, wherein the first or second part includes at least one rib configured to engage a part of the other of the first or second part to inhibit rotational movement between the first and second parts.

16. An engagement mechanism according to any preceding claim, wherein the part of the other of the first or second parts includes at least one slot, the or each slot being configured to receive a respective one of the at least one rib.

17. An engagement mechanism according to any preceding claim, wherein the first and/or second parts have a central longitudinal axes and are configured such that the extendible element passes through the first and second parts along the central longitudinal axes.

18. An engagement mechanism according to any preceding claim, wherein the first and/or second parts have a central longitudinal axes and are configured such that the extendible element passes through the first and second parts along an axis which is offset from the central longitudinal axes.

19. An engagement mechanism according to claim 18, wherein the first part includes a channel through which the extendible element passes and the second part includes an opening through which the extendible element passes, the channel and/or opening being configured to permit rotational movement of the first part with respect to the second part through a part of a circle and to inhibit further rotation of the first part with respect to the second part by abutment of the extendible element against a surface defining at least part of the channel or opening.

20. An engagement mechanism according to any preceding claim, wherein the second part includes a moveable member configured to be moved radially outwardly by the extendible element to engage at least one retaining protrusion of the first part so as to inhibit rotation of the first part with respect to the second part.

21. A first part of an engagement mechanism suitable for use as the first part of the engagement mechanism according to any of claims 1 to 20.

22. A second part of an engagement mechanism suitable for use as the first part of the engagement mechanism according to any of claims 1 to 20.

23. A combination of an intraurethral catheter and the first part according to claim 21 , wherein the intraurethral catheter includes a magnetically operated valve.

24. A combination according to claim 23, wherein the magnetically operated valve includes a spherical magnetic valve element.

25. A combination according to claim 23 or 24, wherein the axis along which the first part is configured to pass the extendible element is aligned with an aperture defined by a valve seat of the magnetically operated valve.

26. A combination according to any of claims 23 to 25, wherein the magnetically operated valve includes a valve seat insert which provides the valve seat, wherein the valve seat insert includes one of a retaining protrusion or a retaining recess, and the first part includes the other of a retaining protrusion or a retaining recess, the retaining protrusion and retaining recess being configured to engage each other to inhibit rotational movement between the valve seat insert and the first part.

27. A combination of an insertion device and the second part of claim 22, wherein the insertion device includes the extendible element.

28. A combination of a catheter, an insertion device, an extendible element, and the engagement mechanism of any of claims 1 to 20.

29. A combination according to claim 28, wherein the catheter further includes one or more tethers which are wrapped in a helix around the insertion device, and wherein the insertion device further includes a clip or band to hold the or each tether in place.