Lid for medical implant

Abstract

A lid for a medical implant that has first and second parts and a mechanism for engaging the implant. The second part is rotatable relative to the first part such that, in use, rotation of the second part relative to the first part causes the engaging mechanism to engage with and attach the lid to the implant.

Claims

1. A lid for a medical implant, the lid comprising: a first part; a second part having a side; and engaging means located in the second part or integrally formed with the second part; wherein; the second part is configured to be assembled with the first part; in use when the second part is assembled with the first part, the second part is rotatable relative to the first part, or the first part is rotatable relative to the second part; and relative rotation of the first part or the second part in use causes the first part to engage the engaging means and causes the engaging means to be moved, with respect to the side of the second part, such that said engaging means engages with the implant and thereby attaches the lid to the implant.

2. The lid as claimed in claim 1, wherein the first part, the second part and the engaging means are arranged such that, in use when the lid is detached from the implant, rotation of the second part relative to the first part, or rotation of the first part relative to the second part, causes the first part to press against the engaging means such that said engaging means is moved with respect to the side of the second part and engages with the implant and thereby attaches the lid to the implant.

3. The lid as claimed in claim 1, wherein the engaging means comprises at least one pin.

4. The lid as claimed in claim 1, wherein the first part is a cap.

5. The lid as claimed in claim 1, wherein the second part is a base, the base being ring shaped.

6. The lid as claimed in claim 1, wherein the first part is snap fitted into the second part.

7. The lid as claimed in claim 1, wherein the first and second part comprise complementary guide means.

8. The lid as claimed in claim 7, wherein the complementary guide means comprise one or more grooves provided on the first part or the second part, and one or more complementary protruding parts provided on the other of the first part and the second part, whereby the one or more protruding parts are arranged to extend into the one or more grooves, thereby allowing the first and second parts to rotate relative to each other.

9. The lid as claimed in claim 1, wherein the first and second parts are arranged such that as the second part is rotated relative to the first part, or the first part is rotated relative to the second part, the first part is also made to move axially with respect to the second part.

10. The lid as claimed in claim 1, wherein the first part comprises or has connected thereto a rotation means for rotating the first part relative to the second part, and wherein the rotation means is a movable member or slider arranged to radially move or slide in a groove or recess provided in the first part.

11. The lid as claimed in claim 10, wherein the rotation means is movable between a first position in which the second part may be rotated relative to the first part, or the first part may be rotated relative to the second part, and a second position in which the second part may not be rotated relative to the first part, or the first part may not be rotated relative to the second part.

12. The lid as claimed in any preceding claim 1, wherein the lid further comprises a seal.

13. The lid as claimed in claim 12, wherein the seal is provided in or is part of the first part.

14. The lid as claimed in claim 12, wherein the seal is a sealing ring.

15. The implant attached to the lid of claim 1.

16. A method of manufacturing the lid as claimed in claim 1, the method comprising: providing the first part, the second part and the engaging means, the engaging means located in the second part or integrally formed with the second part; and assembling the first part, the second part and the engaging means to form the lid such that the second part is rotatable relative to the first part, or vice versa, and, in use, rotation of the second part relative to the first part, or vice versa, causes the engaging means to be moved, with respect to the side of the second part, whereby said engaging means engages with the implant and thereby attaches the lid to the implant.

17. A method of attaching the lid as claimed in claim 1, the lid comprising the second part assembled with the first part, to the implant, the method comprising: placing the lid over a protruding end of the implant; and then rotating the second part relative to the first part, or vice versa, such that the engaging means moves with respect to the side of the second part, whereby said engaging means engages with the implant and thereby attaches the lid to the implant.

18. A method of removing the lid as claimed in claim 1, the lid comprising the second part assembled with the first part, to the implant, the method comprising: rotating the second part relative to the first part, or vice versa, such that the engaging means moves with respect to the side of the second part, whereby said engaging means disengages from the implant; and then removing the lid from the implant.

19. The lid as claimed in claim 1, wherein the lid is arranged such that, in use, when the lid is placed over a protruding end of the implant and the engaging means is disengaged, rotation of the first part relative to the second part in a first direction causes a movement of the engaging means with respect to the side of the second part, whereby said engaging means engages with the implant and thereby attaches the lid to the implant.

20. The lid as claimed in claim 19, wherein the lid is arranged such that, in use when the engaging means is engaged with the implant, rotation of the first part relative to the second part in a second direction causes a movement of the engaging means with respect to the side of the second part, whereby said engaging means disengages from the implant and thereby detaches the lid from the implant.

21. The lid as claimed in claim 1, wherein the lid is arranged such that, in use, when the second part is rotated with respect to the first part (or vice versa), the engaging means is made to: protrude into an engagement recess or cavity provided on the implant; or protrude over, around or through an engagement protrusion provided on the implant.

22. The lid as claimed in claim 1, wherein the lid is arranged such that, in use when the first part is assembled with the second part, rotation of the first part relative to the second part causes the engaging means to be moved radially inwards, with respect to the side of the second part, such that said engaging means engages with the implant and thereby attaches the lid to the implant.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the present invention will now be shown by way of example only and with reference to the accompanying drawings, in which:

(2) FIG. 1 shows a perspective view of an ostomy implant;

(3) FIG. 2 shows a side view of the ostomy implant of FIG. 1;

(4) FIG. 3 shows an exploded perspective view of components of a lid according to an embodiment of the invention;

(5) FIGS. 4(a)-(c) show a top, side and perspective view, respectively, of the lid shown in FIG. 3;

(6) FIGS. 5(a)-(h) show a perspective, bottom, side, cross-sectional, top, side, cross-sectional and a further cross-sectional view, respectively, of the cap of the lid shown in FIG. 3;

(7) FIGS. 6(a)-(d) show a bottom, top, side and end view, respectively, of the slider of the lid shown in FIG. 3;

(8) FIGS. 7(a)-(i) show a perspective, bottom, cross-sectional, side, further side, detail, further detail, further cross-sectional and further cross-sectional view, respectively, of the base of the lid shown in FIG. 3;

(9) FIGS. 8(a) and (b) show side and end views, respectively, of a pin of the lid shown in FIG. 3;

(10) FIGS. 9(a)-(c) show a top, cross-sectional and side views, respectively, of the sealing ring of the lid shown in FIG. 3;

(11) FIGS. 10(a)-(c) show steps for inserting the pins of FIG. 8 into the base of FIG. 7;

(12) FIGS. 11(a)-(e) show steps for inserting the sealing ring of FIG. 9 into the cap of FIG. 5;

(13) FIGS. 12(a)-(c) show steps for inserting the slider of FIG. 6 into the cap of FIG. 5;

(14) FIG. 13 shows how to insert the assembled cap of FIG. 12 into the assembled base of FIG. 10;

(15) FIG. 14 shows a perspective view of a lid following the step of FIG. 13;

(16) FIGS. 15(a)-(d) shows steps for finalising the assembly process of the lid following the step of FIG. 13;

(17) FIG. 16 is a flow diagram showing the steps for assembly of the lid;

(18) FIGS. 17(a)-(d) show steps for fitting a lid of FIG. 3 onto an implant;

(19) FIGS. 18(a)-(e) show steps for removing a lid of FIG. 3 from an implant; and

(20) FIG. 19 shows a perspective view of an implant fitted with a lid of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

(21) FIG. 3 shows an exploded perspective view of the components of a lid 10 according to an embodiment of the invention.

(22) The components of the lid 10 consist of: a substantially ring-shaped base 11, a substantially circular cap 12, a slider 13, a sealing ring 14 and three pins 15. The respective components 11, 12, 13, 14, 15, of the lid 10 are described in more detail below.

(23) FIGS. 4(a)-(c) show top, side and perspective views, respectively, of the lid 10 of FIG. 3.

(24) FIGS. 5(a)-(h) show a perspective, bottom, side, cross-sectional, top, side, cross-sectional and a further cross-sectional view, respectively, of the cap 12 of the lid 10 shown in FIG. 3.

(25) The cap 12 is circular and is formed of a circular top part 28 and a ring-shaped side part 29.

(26) In the top part 28 there is a first groove 20 which runs from one side of the top part 28, across the centre of the top part 28, to the opposite side of the top part 28. The upper surface 28a of the top part 28 slightly projects over the two sides of the first groove 20 forming a small recess 22 along either side of the groove 20.

(27) Within the first groove 20, in its base (which is otherwise flat), there is a second groove 21. The second groove 21 is narrower than the first groove 20 and runs from the one side of the top part 28 where the first groove 20 starts, across the centre of the top part 28, and almost, but not quite, to the opposite side of the top part 28. The centrelines of the first and second grooves 20 and 21 are co-linear.

(28) On the otherwise flat base of the second groove 21, and spaced along its centreline, there are two upwardly-projecting bumps 23a and 23b. The bumps 23a and 23b do not project any higher than the depth of the second groove 21, so they do not project up into the first groove 20. These bumps 23a and 23b are provided and positioned so as to give a definite “click” sound and feel feedback to the user, when the slider is pushed all the way into each of its two end positions. The “click” sound and feel feedback is provided as the bumps 23a and 23b pass over a corresponding bump 31 provided on the bottom surface of the slider 13 (see below).

(29) On the upper surface 28a of the top part 28 there are two logos 27a and 27b marking locked and unlocked positions of the lid 10.

(30) The side part 29 projects downwards from the circumferential edge of the top part 28.

(31) Within the outer surface of the side part 29 are provided three identical and equally circumferentially spaced apart grooves 24. Each groove 24 consists of an upwardly-extending part 24a and a circumferentially-extending part 24b. The upwardly-extending part 24a extends upwards from the bottom of the side part 29 towards, but not as far as, the top part 28. The groove 24 then continues in the circumferentially-extending part 24b from the top of the upwardly-extending part 24a circumferentially around the side part 29. Each groove 24 does not extend as far around the side part 29 as the next groove 24 so that a gap without any groove is present between the grooves 24.

(32) The upwardly-extending part 24a of each groove 24 is shallower than the circumferentially-extending part 24b of each groove 24. Thus, there is a small step “down” (or radially inwards with respect to the cap 12) from the upwardly-extending part 24a to the circumferentially-extending part 24b, which starts just above it. In addition, there is a small ridge 24d provided along the top end of the upwardly-extending part 24a before the drop “down” into the circumferentially-extending part 24b.

(33) In the circumferentially-extending part 24b of each groove 24 there is a thin ridge 24c along most but not the entire length of the centreline of the circumferentially-extending part 24b. The ridge 24c does not extend as far as either end of the circumferentially-extending part 24b.

(34) When the lid 10 is assembled, the three ridges 24c are in contact with three corresponding circular guide projections 44 located on the inside of the base part 11 (see below).

(35) As each circumferentially-extending part 24b extends around the side part 29, it also extends slightly upwardly, such that each circumferentially-extending part 24b slopes upwards around the side part 29.

(36) On the underside of the top part 28, and inside the side part 29, there is a radially inner groove 25 and a radially outer groove 26. The radial outer groove 26 is bounded or formed by the radially inner surface of the side part 29 and a first circular wall 26a. The radial inner groove 25 is bounded or formed by the first circular wall 26a and a second circular wall 25a.

(37) FIGS. 6(a)-(d) show a bottom, top, side and end view, respectively, of the slider 13 of the lid 10 shown in FIG. 3.

(38) The slider 13 is dimensioned so as to extend across a diameter of the lid 10, when assembled. As such, the slider 13 is substantially rectangular but has slightly curved ends 38a 38b to match the circumference of the lid 10. The slider 13 has a curved upper surface 37 with the curvature of this surface 37 extending along the length of the slider 13 (i.e. when assembled, across the diameter of the lid 10).

(39) On the bottom surface of the slider 13 and towards one end 38b, there are two parallel ridges 30a, 30b of equal length extending along a short length of the slider 13. Extending between the two ridges 30a, 30b is a curved bump 31. The ridges 30a, 30b extend slightly further along the length of the slider 13 than the bump 31.

(40) Around the mid-point of the slider 13, and on its bottom surface, is a curved groove 32 extending from one edge 39a of the slider 13 towards but not as far as the opposite edge 39b. The curved groove 32 has a radius of curvature on its inner edge corresponding to that of the outer circumference of the cap 12.

(41) At one end of the upper surface 37 of the slider 13 there is marked a double-ended arrow 24, showing the directions in which the slider 13 is to be slid, in use. At the other end of the upper surface 37, there is a ridged area 33 with ridges for facilitating the sliding of the slider 13, in use.

(42) Along each edge 39a, 39b of the slider 13, from its bottom side, there is a projecting part 36b, 36a, respectively. The projecting part 36b is broken, or has a gap 36b′, at one point where it extends over the curved groove 32. The projecting parts 36a, 36b are dimensioned so as to fit in the recesses 22 present inside the first groove 20 of the cap 12.

(43) FIGS. 7(a)-(i) show a perspective, bottom, cross-sectional, side, further side, detail, further detail, further cross-sectional and further cross-sectional view, respectively, of the base 11 of the lid 10 shown in FIG. 3

(44) The base 11 is ring shaped and has a side part 40 and a radially inwardly extending part 42 which extends radially inwardly from a lower (in use) circumferential edge of the side part 40.

(45) On the outer surface of the side part 40 there are gripping regions 41 with ridges to facilitate gripping of the base 11, for example in use, e.g. for rotating the base 11.

(46) The base 11 is dimensioned so that the cap 12 can fit inside it exactly.

(47) On the upper or inner surface of the radially inwardly extending part 42 there is a circumferential groove 45 formed by the inner surface of the side part 40 and a circular ridge 45a extending upwardly from the inner circumference of the inwardly extending part 42. The ridge 45a is dimensioned so as to fit in the radially outer groove 26 of the cap 12, when the lid 10 is assembled.

(48) At three equally circumferentially spaced apart positions along the circumferential groove 45 there are three straight grooves 43 which are slightly deeper than the circumferential groove 45. Above the centre point of each of these straight grooves 43, and extending from the inner surface of the side part 40, there are three circular guide projections 44. These circular guide projections 44 are dimensioned so as to fit in, and slide along, the groove 24 of the cap.

(49) These circular guide projections 44 are provided on short flexible arms and, as the base 11 or cap 12 is rotated, the guide projections 44 are arranged to travel over the ridges 24c provided in the grooves 24, as described above. As the guide projections move over the ridges 24c, this produces a slight breaking action to (or frictional force exerted against) the rotation between the cap 12 and the base 11, this provides a nice and solid “quality” feeling to a user of the lid. At the two rotational end positions, i.e. when the guide projections 44 are at either end of the grooves 24, the ridges 24c disappear and the breaking action does too, thereby creating distinct end positions, with the frictional force provided by the ridge 24c meaning that the cap 12 and the base 11 do not unintentionally rotate against each other.

(50) In the radially inwardly extending part 42 beneath each circular guide projection 44, there is a rectangular hole 47. These holes 47 are not related to the function of the lid 10, but are present due to the injection moulding process used to make the lid 10. These holes 47 are needed for movable anvils in the injection moulding tooling to create the circular guide projections 44 described above.

(51) At either end of each straight groove 43, on a radially inner side, there is a resilient tongue 49 which can act as a weak spring.

(52) A recess 46 is provided in the side part 40 above one of the circular guide projections 44. The recess 46 is dimensioned such that the slider 13 can be slid through it.

(53) FIGS. 8(a) and (b) show side and end views, respectively, of the pins 15 of the lid 10 shown in FIG. 3. The pins 15 are straight with a circular cross section and curved ends. Three pins 14 are provided for each lid 10 and they are dimensioned so as to fit in the three straight grooves 43 of the base 11.

(54) FIGS. 9(a)-(c) show a top, cross-sectional and side views, respectively, of the sealing ring 14 of the lid 10 shown in FIG. 3. The sealing ring 14 is circular and dimensioned so as to fit in the radially inner groove 25 of the cap 12. The ring 14 has a flat side 14b and a curved side 14c. Two small projections 14a are provided opposite each other on the sealing ring 14 and extend perpendicularly from the flat side 14b of the ring 14. The small projections 14a do not serve any purpose once the lid 10 is assembled but merely serve to identify the flat side 14b of the ring 14 more clearly, so that it can be inserted into the inner groove 25 of the cap 12 in the correct orientation.

(55) Before the lid 10 is assembled from its component parts 11, 12, 13, 14, 15 and then packaged, it is cleaned and disinfected. The cleaning process includes ultrasonic cleaning-disinfection with 70% ethanol for 3-5 minutes. After this, and before assembly and packing, all parts 11, 12, 13, 14, 15 are dried by heat (maximum 70° C.) or in room air in a protected area to avoid condensation in the packaging. Cleaning is performed in a clean and controlled environment, in conjunction with assembly and packaging in sealable bags.

(56) When the lids 10 are produced in volume, the lid parts 11, 12, 13, 14, 15 will be moulded in a clean-room environment directly. This means no cleaning (as described above) will be necessary before (or after) assembly.

(57) The assembly process for the lid 10 will now be described.

(58) FIGS. 10(a)-(c) show steps for inserting the three pins 15 into the base 11 for assembly of the lid 10.

(59) First, as shown in FIG. 10(a), the base 11 is placed with its radially inwardly extending part 42 located at the bottom. A pin 15 is then placed in each of the three straight grooves 43, as shown in FIG. 10(b). The final configuration of the base 11 and pins 15 after performing these steps is shown in FIG. 10(c).

(60) FIGS. 11(a)-(e) show steps for inserting the sealing ring 14 into the cap 12 for assembly of the lid 10.

(61) First, cap 12 (as shown in FIG. 11(a)) is placed with its radially inner groove 25 facing upwards, as shown in FIG. 11(b). The sealing ring 14 is then placed into the radially inner groove 25 with its flat side 14b facing downwards into the groove 25, and its curved side 14c facing upwards out of the groove 25, as shown in FIGS. 11(c) and (d). The final configuration of the cap 12 and sealing ring 14 after performing these steps is shown in FIG. 11(e).

(62) In an alternative embodiment, the cap 12 and sealing ring 14 are formed together using a two-step injection moulding process (forming first the cap 12 and then the sealing ring 14 on the cap 12) so that the method shown in FIGS. 11(a)-(e) is not required.

(63) FIGS. 12(a)-(c) show steps for inserting the slider 13 into the cap 12 for assembly of the lid 10.

(64) First, as shown in FIG. 12(a), the cap 12 is placed with its upper surface 28a facing upwards and the slider 13 is placed with its upper surface 37 facing upwards. The end 38a of the slider 13 is then slid into the first groove 20 of the cap 12 along axis L. The slider 13 is slid into the first groove 20 at the end of the first groove 20 where the second groove 21 extends to right to the circumferential edge of the cap 12. As the slider 13 is slid into the first groove 20, the projecting parts 36a, 36b of the slider 13 slide through the recesses 22 along either side of the groove 20.

(65) As the slider 13 is slid through the first groove 20, resistance is felt as the curved bump 31 under the slider 13 meets the bumps 23b and then 23a in the second groove 21 of the cap 12. Some additional force is therefore required to cause the curved bump 31 to pass over the bumps 23b and then 23a in the second groove 21.

(66) After the bump 31 on the slider 13 has passed over the bump 23a in the second groove 21, the ends of the parallel ridges 30a, 30b abut against the closed end 21a of the second groove 21 and the slider 13 cannot be slid any further across the cap 12. The ridges 30a, 30b and the ends 21a of the second groove 21 are positioned such that at this point, i.e. when the parallel ridges 30a, 30b abut against the closed end 21a of the second groove 21, the curved groove 32 on the underside of the slider 13 extends around the outer circumference of the cap 12, as shown in FIGS. 12(b) and (c). The slider 13 should be slid into this position, i.e. where the ends of the parallel ridges 30a, 30b abut against the closed end 21a of the second groove 21 and the curved groove 32 on the underside of the slider 13 extends around the outer circumference of the cap 12 before the further steps of assembly of the lid 10 described below are performed.

(67) FIG. 13 shows how to insert the assembled cap 12 (i.e. with the slider 13 and sealing ring 14 inserted in it) into the assembled base 11 (i.e. with the pins 15 inserted in it).

(68) The assembled cap 12 is positioned with its upper surface 28a facing upwards and the assembled base 11 is positioned, for example on a level surface, with its radially inwardly extending part 42 located at the bottom or facing downwards. The cap 12 is positioned such that the upwardly-extending parts 24a of the grooves 24 in the cap 12 are each located directly above a circular guide projection 44 in the base 11. The assembled cap 12 (with slider 13) is further positioned such that the slider 13 slightly overlaps the recess 46 in the side part 40 of the base 11.

(69) The assembled cap 12 and the assembled base 11 are then pressed or snapped together, by pressing the cap 12 into the base 11, such that the circular guide projections 44 in the base 11 pass over the ridges 24d at the top end of each upwardly-extending part 24a, and into the circumferentially-extending parts 24b.

(70) As the assembled cap 12 (i.e. including the slider 13) has been positioned such that the slider 13 slightly overlaps the recess 46 in the side part 40 of the base 11, part of the top edge 48 of the base 11 is fitted into the curved groove 32 on the underside of the slider 13.

(71) FIG. 14 shows a perspective view of a lid 10 comprising the base 11, cap 12 and slider 13 (as well as the pins 15 and sealing ring 14, which are not visible) following the steps associated with FIG. 13 described above.

(72) FIGS. 15(a)-(d) shows the steps for finalising the assembly process of the lid 10 following the steps of FIG. 13 described above.

(73) First, the cap 12 and slider 13 are rotated clockwise with respect to the base 11, when viewed from above, by pushing the slider 13 along path P, as shown in FIG. 15(a). By pushing the slider 13, the cap 12 is rotated as far as it can be, i.e. until the circular guide projections 44 reach the upper ends of the circumferentially-extending parts 24b of the grooves 24 (opposite to the ends where the circumferentially-extending parts 24b meet the upwardly-extending parts 24a) and are thus prevented moving further.

(74) As the cap 12 is rotated in this way, it is also drawn further down into the base 11 due to the slope of the circumferentially-extending parts 24b in the cap 12.

(75) When the cap 12 has been rotated as far as it can be, i.e. when the circular guide projections 44 reach the upper ends the circumferentially-extending parts 24b of the grooves 24, the slider 13 is located inside the recess 46 of the base 11, as shown in FIG. 15(b).

(76) Next, as shown in FIG. 15(c), the slider 13 is pushed inwards, along arrow A through the recess 46 and first groove 20, until it is prevented from moving further by abutting against the side part 40 of the base 11. At this point, the slider 13 is positioned across the entire diameter of the lid 10, within the first groove 20, as shown in FIG. 15(d). The longitudinal length of the slider 13 is equal to the outer diameter of the base 11 such that, at this point, the slider 13 does not project outwardly from base 11 at all.

(77) FIG. 16 is a flow diagram showing the steps for assembly of the lid 10 from its component parts 11, 12, 13, 14, 15.

(78) At step 50, the pins 15 are inserted into the base 11, as shown in FIGS. 10(a)-(c) and described above.

(79) At step 51, the sealing ring 14 is inserted into the cap 12, as shown in FIGS. 11(a)-(e) and described above. In an alternative embodiment, in which the cap 12 and sealing ring 14 are/have been formed together (e.g. in a two-step injection moulding process, as described above), this step 51 is not needed.

(80) At step 52, the slider 13 is inserted into the cap 12, as shown in FIGS. 12(a)-(c) and described above.

(81) In FIG. 16, step 51 is performed before step 52 but in other embodiments step 52 is performed before step 51, and in yet other embodiments steps 51 and 52 are performed in parallel.

(82) In FIG. 16, step 50 is performed in parallel with steps 51 and 52 but in other embodiments steps 50, 51 and 52 are performed in series in any order, e.g. 50 then 51 then 52; or 51 then 52 then 50. The other sequences of these steps would also be possible.

(83) After steps 50-52 have been performed (in whichever order, and in series or in parallel), step 53 is performed in which the cap 12 (with the slider 13 and sealing ring 14) is inserted into the base 11 (with pins 15), as shown in FIGS. 13 and 14 and described above.

(84) Next, at step 54, the cap 12 is rotated with respect to the base 11, as shown in FIGS. 15(a) and (b) and described above.

(85) Finally, at step 55, the slider 13 is slide into the groove 20 in the cap 12, as shown in FIGS. 15(c) and (d) and described above, and is ready for packaging, use or storage.

(86) Once the lid 10 has been assembled in this way, it can be provided to a patient for fitting onto an implant 1.

(87) FIGS. 17(a)-(d) show steps for fitting the lid 10 onto an implant 1.

(88) Starting from a lid 10 with the slider 13 slid in across the cap 12, before the lid 10 can be fitted on an implant 1, the slider 13 must be slid outwardly along the groove 30 in the cap 12. The cap 12 must then be rotated anti-clockwise with respect to the base 11 when viewed from above (or vice versa), such that the cap 12 rises up out of the base 11 slightly, and the slider 13 is only slightly overlapping the recess 46. The lid 10 is then ready to be fitted onto an implant 1.

(89) As shown in FIG. 17(a) a user holds the projecting end of the slider 13 and places the lid 10 over the exterior section 4 of the implant 1.

(90) The slider 13 is then used to hold the cap 12 stationary while the base 11 is rotated in an anti-clockwise direction with respect to the cap 12 when viewed from above, as shown by the arrow in FIG. 17(b) (alternatively, the slider 13 could be used to rotate the cap 12 in a clockwise direction with respect to the base 11 when view from above, while the base 11 is held stationary) until the slider 13 is positioned completely in the recess 46 of the base 11.

(91) As the base 11 is rotated anti-clockwise with respect to the cap 12 (or vice versa), the cap 12 is drawn down into the base 11 by virtue of the circular guide projections 44 being made to slide along upwardly sloping circumferentially-extending parts 24b of the grooves 24 around the cap 12.

(92) As the cap 12 is drawn down into the base 11 in this way, the side part 29 of the cap 12 moves down into the circumferential groove 45 inside the base 11, thereby forcing the three pins 15 located in the three straight grooves 43 around the circumferential groove 45 radially inwardly, against the resilient tongues 49 and slightly upwardly into the groove 6 around the exterior circumference of the exterior section 4 of the implant 1. This engaging of the pins 15 against the inner upper surface of the groove 6 of the implant 1 secures and holds the lid 10 onto the implant 1 and prevents users from being able to simply move or pull the lid 10 straight off of the implant 1, intentionally or unintentionally.

(93) In addition, as the cap 12 is drawn down into the base 11, the sealing ring 14 on the underside of the cap 12 is compressed against the upper surface of the exterior section 4 of the implant 1 thereby forming a leak-proof seal between the implant 1 and the lid 10.

(94) Once the lid 10 has been secured and sealed in this way, the slider 13 is slid back across the rest of the lid 10, through groove 20, as shown in FIG. 17(c), so that it is no longer protruding radially outwardly from the rest of the lid 10, as shown in FIG. 17(d).

(95) In order to remove a lid 10 from an implant 1, the reverse procedure is performed, as shown in FIGS. 18(a)-(d).

(96) The lid 10 starts with the slider 13 in a “slid in” position with respect to the rest of the lid 10, as shown in FIG. 18(a). The slider 13 is then pulled outwards through the groove 20 in the cap 12, as shown in FIG. 18(b). When fully drawn out, the slider 13 is then used to hold the cap 12 stationary while the base 11 is rotated in a clockwise direction with respect to the cap 12 (or, alternatively, the base 11 is held stationary and the slide 11 is used to rotate the cap 12 in an anti-clockwise direction with respect to the base 11). This rotation causes the cap 12 to move upwards and slightly out of the base 11 such that the side part 29 no longer forces or holds the pins 15 in the groove 6 around the implant 1 and the resilient tongues 49 cause the pins 15 to be retracted from the groove 6. In addition, the sealing ring 14 is no longer compressed down against the upper surface of the exterior section 4 of the implant 1.

(97) The user can then lift the lid 10 off of the implant 1 with little or no resistance.

(98) After removal of the lid 10 in this way from an implant 1, it should be washed, as shown in FIG. 18(e).

(99) FIG. 19 shows a perspective view of an implant 1′ (not implanted in a patient) fitted with a lid 10.

(100) The lid 10 is reusable but with a limited life. It can be used by a patient for up to two weeks before a new lid 10 must be used.

(101) The lid 10 is dimensioned to fit an implant with an outer diameter corresponding to an inner diameter of the lid 10. However, the lid 10 can be fitted onto implants 1, 1′ with differing axial lengths and/or different internal structures.

(102) The slider 13, the cap 12 and the base 11 are all made of plastic by injection moulding.

(103) The pins 15 are made of stainless steel.

(104) In an alternative embodiment, the pins 15 are made of plastic. This can ensure that the pins 15 wear out long before the edge of the groove 6 in the implant 1, 1′ over which the pins 15 move.

(105) The sealing ring 14 is made of a medical grade soft polymer.

(106) Each lid 10 is provided to a user in a disinfected state in a semi-sealed individual bag (i.e. the bags are perforated along one side to be easy to tear open. However, the lid 10 does not need to be sterile.

(107) The lid 10 (except the pins 15 and sealing ring 14) is skin-coloured and is intended to be inconspicuous.

(108) The lid 10 is designed such that one lid size can fit different implant sizes. For example, implants can be provided with different inner diameters (i.e. the diameter of the opening through the implant), e.g. optimised for different sizes (thicknesses/diameters) of ileum. However, as the implants (particularly their exterior sections) have the same outer diameter, the same lid 10 may fit implants with different inner diameters.

(109) The sealing ring 14 is located sufficiently close to the outer diameter of the lid 10 such that the lid 10 may fit implants even with a relatively large inner diameter (and, consequently, a relatively thin exterior section top surface against which the sealing ring 14 can be compressed).

(110) The lid 10 can also fit implants with different axial lengths, providing that the outer diameter of the exterior section of the implant is the same.

(111) The fact that the same lid 10 may fit implants of different sizes is advantageous because there is no need to make different sized lids for implants with different inner diameters and/or axial lengths. This makes manufacturing simpler, saves time and costs, and is safer (there is no chance of putting a wrong sized lid 10 on an implant).