Medical device accessory

Abstract

A cover 10 for fitting over a distal end of a shaft of a medical device, such as an endoscope, the cover comprising a tubular body 12 with at least one projecting element 24 extending outwardly. In us

Description

Field The present disclosure relates to an accessory for use with a medical device, such as an endoscope. Background US 2019 / 0183328 describes a cover for the shaft of a medical device, in particular for fitting over the distal tip of an endoscope. The cover is a tubular member with proximal and distal ends and inner and outer circumferential surfaces. Axially extending ribs may be provided on the inner and outer circumferential surfaces. A plurality of projecting elements is provided on the outer surface of the cover which in use extend radially outwardly from the cover. These can pull back or flatten folds of body tissue to facilitate the inspection of a body cavity or carrying out other medical procedures with the medical device. This type of cover is formed of a plastic material and forms a friction fit on the shaft of the medical device. However, as the external dimensions of a shaft of a medical device may vary slightly, for example with different models, there is a need to provide a cover which can adapt to shafts of different sizes while maintaining a secure fit on the shaft. Summary The present disclosure provides a cover for a medical device as set out in claim 1 and a holder for such a cover as set out in claim 10. A method for fitting the cover to the distal end of a shaft of a medical device is set out in claim 18. Brief Description of the Drawings The present disclosure refers, by way of example only, to the accompanying drawings in which: Figure 1 is a perspective view of one embodiment of accessory, in a first, closed position; Figure 2 is a side view of the accessory of Figure 1; Figure 3 is a plan view of the accessory of Figure 1; Figure 4 shows perspective, side and plan views of a spring member; Figure 5 shows a perspective view and a plan view of the accessory of Figure 1-4 in a second, open position; Figure 6a shows a perspective view from above and a plan view of one embodiment of a holder for the accessory of Figure 1; Figure 6b shows a plan view of a second embodiment of a holder; Figures 7 shows a perspective view from below and a side view of the holder of Figure 6a; Figure 8 shows a plan view and a perspective view from above of the holder of Figures 6a and 7, with the accessory fitted therein; Figures 9a-d illustrate fitting a shaft into an accessory fitted in a holder; and Figures 10a-10i illustrate alternative forms of spring member. Detailed Description As shown in Figures 1-3, an accessory 10 for a medical device comprises a cover for fitting, in particular, over the distal end of the shaft 70. The cover comprises a tubular body 12 with first and second ends 14, 16, an outer circumferential surface 18, an inner circumferential surface 20 and a longitudinal axis 22. The accessory 10 also includes one or more projecting elements 24 projecting radially outwardly, as described further below. The tubular body 12 is open at its first and second ends 14, 16. The tubular body 12 also comprises a slot 26 extending axially between the first end 14 and the second end 16. The tubular body 12 is flexible and resilient such that it can be bent or deformed to open up the axial slot 26. This increases the width of the slot 26 and to increase the internal diameter of the tubular body 12, as shown in Figure 5. The tubular body 12 preferably comprises a spring member 28 which, when at rest and in an un-tensioned state, retains the tubular body 12 in a first, closed position as in Figures 1 -3, in which the tubular body 12 has a first internal diameter and the axial slot 26 has a first width. The first width may be very small, or substantially zero with the sides of the slot 26 contacting each other. The first internal diameter is sufficient to allow the tubular body 12 to encircle and grip a shaft 70. The tubular body 12 may be deformed into a second, open position by bending to open up the axial slot 26 in a circumferential direction to a second width, larger than the first width, as shown in Figure 5. This places the spring member 28 in tension and the tubular body 12 in a second position in which the tubular body 12 has a second internal diameter, larger than the first internal diameter. The spring member 28 biases the tubular body 12 towards the first, closed position. Once a deflecting force acting to open up the axial slot 26 is removed, the accessory 10 will return to its first, closed position, in which the tubular body 12 returns to its first internal diameter and the axial slot 26 returns to its first width. In the embodiment shown, the spring member 28 comprises a spring plate. The plate may be a rectangle of resilient material, which is bent round into a tubular shape, leaving an axially extending opening 30 between its free ends, as shown in Figure 4, so that in plan view it is generally C-shaped. Preferably, the spring member 28 is formed of metal, such as spring steel, which maintains its tension over time (if only loaded within its elastic range). However, other resilient materials may be used which have a high yield strength so that the spring member 28 will return to the initial tubular shape when a deflecting force acting to open up the axial opening 30 is removed. The spring member 28 may be configured in different ways if desired. For example, while Figure 4 shows a solid plate, the spring member may be formed of a perforated sheet with one or more openings, in order to reduce weight. Various examples are shown in Figures 10a-h, in which the spring member 28 comprises a number of circumferentially extending bands 28a, with gaps between them, joined by one or more axially extending connecting bars 28b. A connecting bar 28b may be formed at a location opposite to the axial slot 26 as in Figures 10a-10c. A pair of connecting bars 28b may be provided at the ends of the spring plate 28, defining the opening 30 between them, as in the examples of Figures 10e and 10f. Multiple connecting bars 28b may be provided, spaced around the circumference as in Figure 10d. In Figures 10g and 10h, the spring plate 28 is provided with an array of perforations, such a circular or square / rectangular openings 28c. Alternatively, the spring member 28 may comprise a series of separate C-shaped bands 28d, stacked one above the other in an axial direction, as in Figure 10i. The spring member 28 may be completely encased within a softer, flexible coating material 32, such as a plastic or other polymer. The spring member 28 and the coating material 32 may be moulded together in one piece. This softer coating material 32 forms the exterior surface of the tubular body 12, including the outer and inner circumferential surfaces 18, 20. The softer coating material 32 protects the shaft 70 and may enhance the grip of the tubular body 12 on the shaft 70. The coating material 32 may also be textured or shaped, for example with ribs on the outer and / or inner circumferential surfaces 18, 20. The annular projecting element 24 may be located at or near to the first end 14, and may comprise a plurality of arms projecting radially outwardly from the tubular body 12. The arms may be identical to each other and equally spaced around the tubular body 12, but other configurations are also possible. Connecting webs (not shown) may join adjacent arms to one another. Alternatively, the projecting element 24 may comprise an annular collar extending around the circumference of the tubular body 12, except for across the axial slot 26. In all embodiments, the projecting element 24 may be made of a resilient polymer material, such as a silicone. The projecting element 24 therefore has some stiffness and is self-supporting so that it maintains its shape, while allowing some flexing as it contacts body tissue when in use. In use, the accessory 10 is fitted over the distal end of a shaft 70 of a medical device such as an endoscope, as shown in Figure 9d. The first end 14 is located at the distal-most end of the shaft 70. The second end 16 is located proximally on the shaft 70. The accessory 10 may be provided in a holder which facilitates fitting the accessory to a shaft 70 of a medical device. As shown in Figures 6a, 6b and 7, the holder may comprise a container 40 in which an accessory 10 may be stored prior to use. The container 40 may be generally cylindrical and comprises a flat circular base 42 and a perimeter wall 44, together defining an enclosure in which the cover can be located. An annular lip 48 may extend around the upper edge of the perimeter wall 44. In use, a peel-off cover (not shown) for the container 40 may be adhered to the lip 48. One or more additional walls may be provided between the base 42 and the perimeter wall 44. In this example, a short vertical wall 46a is provided around the flat base wall 42 and a sloping wall 46b is provided between the vertical wall 46a and the perimeter wall 44. The base 42 and the short vertical wall 46a together define a shallow recess 50 in the base of the container 40 for receiving the first end 14 of the accessory 10 in use. The sloping wall 46b supports the projecting elements 24 of the accessory 10 in use. The container 40 is further provided with features to locate the accessory 10 in the container 40 in its second, open position. In particular, a blocking element 52 is provided, which projects into the enclosure and at least part of which fits within the axial slot 26 of the tubular body 12 when it is in its second, open position. This prevents the accessory 10 springing back into its closed position under the action of the spring member 28. At least one locating element 54 may be arranged opposite to the blocking element 52, to help correctly position the accessory 10 against the blocking element 52. The blocking element 52 comprises a main body in the form of a generally rectangular column projecting radially into the container 40 from the perimeter wall 44 and upwardly from the base of the container 40 (in this example including the base 42, and additional walls 46a, 46b). The main body of the blocking element 52 comprises a pair of side walls 56 joined by an upper surface 58. On its radially inner side, the blocking element 52 is formed with a narrowed nose portion 60 formed by side walls 66 which are joined to the side walls 56 of the main body by a shoulder 62. The end face 64 of the nose portion 60, which joins the side walls 66 and faces radially inwardly, has a concave arcuate form. As shown in Figure 6a, the side walls 66 of the nose portion 60 may be parallel to each other and to the side walls 56 of the main body of the blocking element 52. Alternatively, in a variant of the container 40 as shown in Figure 6b, the side walls 66 of the nose portion 60 may be non-parallel and may diverge away from each other in a radially inward direction from the shoulder 62 towards the end face 64. This may help to retain the nose portion 60 more securely within the slot 26 of the accessory 10 when the accessory 10 is fitted in the container 40 as discussed further below. On the opposite side of the container 40, in this example a pair of locating elements 54 is provided. Each locating element 54 comprises a raised projection protruding upwardly from the sloping wall 44b and base 42 and extending a small distance into the recess 50. The blocking element 52 projects upwardly to a first height, which is typically about the same as the axial length of an accessory 10 to be housed in the container 40. The locating element(s) 54 project upwardly to a second height, which is less than the first height of the blocking element 52, typically about half of the first height. In use, an accessory 10 is deflected into its open position and fitted into the container 40. The tubular body 12 is fitted between the blocking element 52 and the locating elements 54. The first end 14 of the tubular body 12 is received in the recess 50. The projecting elements 24 are supported on the sloping wall 46b. The nose portion 60 of the blocking element 52 is located in the slot 26. The curved end face 64 of the nose portion 62 follows the curvature of the inner circumferential surface 20 of the tubular body 12 in order to form a smooth circular opening into which the shaft 70 may be inserted. The locating elements 54 fit either side of one of the projecting elements 24. Depending on the configuration of the projecting elements 24, the number, shape and position of the locating elements 54 may be altered to suit. In this way, the accessory 10 is held securely in the container 40 in its open position, until it is required for use. The accessory 10 may be stored in a sterile condition in the container 40 with a cover (not shown) applied across the top of the container 40 and adhered to the lip 48 to seal the container 40. When the accessory 10 is required for use, the cover is removed. As shown in Figures 9a and 9b, the distal end of a shaft 70 of a medical device is inserted into the tubular body 12. Since the tubular body 12 is being held in the open position, the inside diameter of the accessory 10 is larger than the outside diameter of the shaft 70 and the shaft 70 can be easily inserted. The shaft 70 may then be tilted to one side as shown in Figure 9c, away from the blocking element 52 and towards the locating elements 54, in order to remove the nose portion 60 of the blocking element 52 from the slot 26. Since the height of the locating elements 54 is less than the height of the blocking element 52, this tilting movement is possible. Once the nose portion 60 is removed from the axial slot 26, the spring member 28 urges the tubular body 12 back into its first, closed position with a reduced internal diameter. In this state, the accessory 10 grips the shaft 70 and together they can be removed from the container 40, leaving the accessory 10 in position on the shaft 70 and ready for use as shown in Figure 9d. The container 40 can then be disposed of. When the accessory 10 is fitted on a shaft 70, the medical device may then be inserted into a patient’s body. Normally when examining the colon, for example, the shaft 70 of the medical device is advanced relatively quickly to the furthest point requiring examination and then gradually withdrawn more slowly, with most of the visual examination carried out during the withdrawal. As the shaft 70 is gradually withdrawn, the projecting elements 24 act to gently pull back and flatten folds of tissue, to allow a clearer view of the body tissues through the device. At the end of the procedure the shaft 70 is completely withdrawn from the patient’s body. The accessory 10 can then be removed from the shaft 70, for example by manually bending the tubular body 12 to open the axial slot 26 so that the accessory 10 can slide off the shaft 70. The accessory 10 can then be disposed of. Thus, the present disclosure provides an improved accessory 10 for the shaft 70 of a medical device. The accessory 10 can be securely stored in a container 40 ready for fitting to a shaft 70 and once in position, grips the shaft 70 securely. As noted above, in this disclosure the term “medical device” may refer to an endoscope, but this term is also intended to refer to any device suitable for insertion into a biological cavity or lumen in order to carry out visualisation thereof and / or treatment. Accordingly, the term “medical device” are intended to encompass any or all of endoscopes, gastroscopes, colonoscopes, enteroscopes, sigmoidoscopes, panendoscopes, but this list is non-exhaustive. Endoscopy involves inspecting the inside of a body lumen or cavity and includes procedures known as arthroscopy, cystoscopy, gastroscopy, uteroscopy and colonoscopy. Enteroscopy involves examination of the small intestine including the duodenum, jejunum and ileum. Such devices are elongate flexible probes which may be inserted into the body directly or via a cannula or other guide device. Medical devices can also include rigid surgical endoscopes or endotherapy devices such as biopsy forceps and polypectomy snares. The cover of the present disclosure may be used in conjunction with all of the aforementioned types of medical device.

Claims

1. A cover for fitting over the distal end of a shaft of a medical device, the cover comprising:a tubular body with a first end, a second end, inner and outer circumferential surfaces, an internal diameter and at least one projecting element extending outwardly, an axial slot in the tubular body extending between the first end and the second end, wherein the tubular body is movable between a first position in which the slot has a first width and the tubular body has a first internal diameter, and a second position in which the width of the slot and the internal diameter of the tubular body are increased, wherein the tubular body is resiliently biased from the second position into the first position.

2. A cover as claimed in claim 1, wherein the tubular body further comprises at least one spring element.

3. A cover as claimed in claim 2, wherein the spring element comprises a resilient spring plate located between the inner and outer circumferential surfaces of the tubular body.

4. A cover as claimed in claim 3, wherein the spring plate is perforated.

5. A cover as claimed in claim 4, wherein the spring plate comprise a plurality ofcircumferentially extending bands joined by at least one axially extending connecting bar.

6. A cover as claimed in claim 2 or claim 3, wherein the spring element comprises a plurality of separate circumferentially extending bands.

7. A cover as claimed in any of claims 2-6, wherein the spring element is formed of metal.

8. A cover as claimed in any of claims 2-7, wherein the spring element is embedded within a flexible coating material.

9. A cover as claimed in any of claims 2-8, wherein the spring element is moulded in one piece with a flexible coating material.

10. A holder for a cover as claimed in any of claims 1 -9, wherein the holder comprises a base and a side wall together defining an enclosure for receiving the cover, and further comprising a blocking member projecting into the enclosure and configured to fit within the axial slot in the tubular body when the tubular body is in the second position, to maintain the tubular body in the second position.

11. A holder as claimed in claim 10, wherein the blocking member comprises a main body with a nose portion, wherein the nose portion is narrower than the main body and is configured to fit into the axial slot in the tubular body.

12. A holder as claimed in claim 10 or claim 11, further comprising at least one locating member projecting into the enclosure opposite to the blocking member.

13. A holder as claimed in claim 12, wherein the blocking member extends upwardly from the base to a first height, the or each locating member extends upwardly from the base to a second height, and the first height is greater than the second height.

14. A holder as claimed in any of claims 10-13, wherein the nose portion comprises parallel side walls.

15. A holder as claimed in any of claims 10-13, wherein the nose portion comprises diverging side walls.

16. A holder as claimed in any of claims 10-15, wherein the nose portion comprises a concave end face.

17. An assembly comprising a cover as claimed in any of claims 1 - 9 fitted into a holder as claimed in any of claims 10-16.

18. A method for fitting a cover as claimed in any of claims 1 - 9 to the distal end of a shaft of a medical device, wherein the cover is fitted into a holder as claimed in any of claims 10-16 such that the blocking member locates in the axial slot of the tubular body to maintain the cover in the second position, and the method comprises inserting the distal end of a shaft of a medical device into the tubular body, tilting the shaft to remove theblocking member from the axial slot and to permit the tubular body to return to the first position and to grip the shaft, and removing the shaft and cover from the holder.

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