Medical scope accessory

Abstract

A cover 10 for covering the distal end of a shaft of a medical scoping device 50, comprising a tubular body 12, having a first end, a second end 16, and a longitudinal axis extending between the first

Description

Field The present disclosure relates to an accessory for use with a medical scope, such as an endoscope. Background US 2019 / 0183328 describes a cover for the shaft of a medical scoping 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 scope. This type of cover is formed of a plastic material and forms a friction fit on the shaft of the medical scoping device. Although the tubular cover has some elasticity, it is still relatively stiff and has some thickness. The thickness of the cover may add several mm to the diameter of the distal tip of the shaft and may affect the insertion capability of the medical scoping device. Summary The pressent disclosure provides a cover for covering the distal end of a shaft of a medical scoping device as set out in claim 1. A method for fitting the cover to the distal end of a shaft of a medical scoping device is set out in claim 11. The cover of the present disclosure is lightweight and flexible, with a low profile and smooth inner and outer surfaces. The cover can be axially shortened by rolling up and provided in a smaller package that conventional accessories. Brief Description of the Drawings The present disclosure refers, by way of example only, to the accompanying drawings in which: Figure 1 is a schematic side view of the distal end of a shaft of a medical scoping device fitted with an accessory in accordance with one embodiment; Figure 2 is a side view of the accessory of Figure 1 in a partially extended state, when not fitted to a shaft; Figure 3 is a side view of the accessory of Figure 1 in its compressed state before fitting to the shaft; Figure 4 shows an example of the accessory, with the projecting element removed for clarity, when first fitted on to a shaft and still in its axially compressed state; Figure 5 is a perspective view of an example of the accessory, fitted on to the distal end of a shaft of a medical scoping device and in its extended state, with part of the projecting element omitted for clarity; Figure 6 is a front view of an example of the accessory and the projecting element; Figure 7 is a side view of one finger of the projecting element; Figure 8 is a front view of the finger of Figure 7; Figure 9 is a perspective view of another example of the accessory, in its extended state, showing only part of the projecting element; Figure 10 is a schematic perspective view of yet another example of the accessory, in its extended state. Detailed Description As shown in Figures 1-3, an accessory 10 for a shaft 50 of a medical scoping device comprises a cover for fitting over the distal end of the shaft 50. The cover comprises a tubular body 12 with an outer circumferential surface, an inner circumferential surface and a longitudinal axis 20. The tubular body 12 is open at its first and second ends. The outer and inner circumferential surfaces are smooth and the tubular body 12 does not include any axially extending ribs. A first ring 14 is provided at the first end of the tubular body 12. A second ring 16 may be provided at the second end of the tubular body 12. The accessory 10 also includes an annular projecting element 24, as described further below. In use, the accessory 10 is fitted over the distal end of a shaft 50 of a medical scoping device such as an endoscope, as shown in Figure 1. The first end ring 14 is located at the distal-most end of the shaft 50 and will therefore be referred to as the distal end ring 14. The second end ring 16 (when present) is located proximally on the shaft 50 and will therefore be referred to as the proximal end ring 16. The accessory 10 may be formed from a resiliently deformable polymer material so that it can be removably fitted on to the shaft 50 of a medical scoping device. In particular, the tubular body 12 is formed from a very thin, flexible and elastic membrane. For example, the tubular body 12 may be formed of a latex material, polyurethane or similar. In use, as described below, the tubular body 12 is extended axially and pulled taut to provide a smooth, low-profile cover around the shaft 50 as shown in Figure 1. When not supported by a shaft 50, the tubular body 12 is so thin that it does not possess sufficient rigidity to maintain a smooth cylindrical shape. Instead, it will be very flexible and floppy as illustrated in Figure 2. The distal end and proximal end rings 14, 16 are each formed to be thicker and stiffer than the tubular body 12, although they retain some elasticity. The proximal end ring 16 is shaped and dimensioned to engage around the shaft 50 of the endoscope, helping to anchor the accessory 10 in place. The distal end ring 14 is shaped and dimensioned to engage around the distal-most edge of the shaft 50. The distal end and proximal end rings 14, 16 may be formed of the same material as the tubular body 12, but with a greater thickness to provide greater stiffness. Alternatively, the distal end and proximal end rings 14, 16 may be formed of a different material, such as a silicone polymer, attached to the tubular body 12, for example by over moulding. In some embodiments, the distal end ring 14 may comprise first and second (or more) adjacent rings 14a, 14b as seen in Figure 4 (from which the projecting element 24 has been omitted for clarity) and Figure 5 (which shows only part of the projecting element 24). Preferably, in a direction from the first end to the second end, each ring is successively thinner and more flexible. Thus, the distal-most ring 14a may have the greatest thickness and stiffness, with the second ring 14b having a smaller thickness and stiffness, and the tubular body 12 having the smallest thickness and stiffness. In this way extra stability is given to the distal end of the accessory 10 and the thickness / stiffness decreases in stages to the tubular body 12. The distal end ring 14 may have an internal surface shaped to engage against the profile of the distal-most edge of the shaft 50 for a secure fit. For example, the inner surface of the ring 14 may have a stepped or curved profile to suit the outer profile of the shaft 50. The distal end ring 14 may be shaped such that one part 14’ will overlap the outer periphery of the end face 52 of the shaft 50 and another part 14” will fit around the circumference of the shaft 50 as illustrated in Figure 5. The tubular body 12 is sufficiently thin and flexible that, before fitting to the shaft 50, the axial length of the accessory 10 can be shortened by rolling up the tubular body 12 from the second end towards the distal end ring 14, thus bringing the distal end and proximal end rings 14, 16 closer together, as shown in Figure 3. For example, the tubular body 12 may be rolled up by first turning the proximal end ring 16 over on the outer circumferential surface of the tubular body 12, and then repeatedly rolling over to axially shorten the accessory 10. Thus, the accessory 10 can be provided in a smaller package than conventional accessories, such as that shown in US 2019 / 0183328. In the axially shortened state, the accessory 10 can be fitted on to the distal end of the shaft 50 as shown in Figure 4 (from which the projecting element 24 has been omitted for clarity). The shaft 50 is inserted into the accessory 10 from the second end. The distal end ring 14 (or first distal end ring 14a) is securely seated around the distal-most end of the shaft 50. The proximal end ring 16 is located proximally on the shaft 50, but still close to the distal end ring 14 because the tubular body 12 is still rolled up. The tubular body 12 and the proximal end ring 16 are then unrolled in a proximal direction along the shaft 50, causing the tubular body 12 to extend axially. The tubular body 12 is extended proximally along the shaft 50 until it is stretched out smoothly with its inner circumferential surface adjacent to the outer surface of the shaft 50. As the tubular body 12 is slightly stretched in its extended state, it lightly grips the shaft 50 to stay in position. The distal and proximal end rings 14, 16 also grip against the circumference of the shaft 50, maintaining the tubular body 12 in the axially extended state and securing the accessory 10 on the shaft 50. The annular projecting element 24 may comprise a collar encircling the accessory 10. The projecting element 24 may be secured to the distal end ring 14. Where two or more adjacent distal end rings 14a, 14b etc. are provided, the projecting element 24 may be provided on any of them. In one embodiment, as shown in Figures 5-9, the projecting element 24 comprises a collar created by a series of elongate elements 26, referred to herein as fingers, joined together by connecting webs 28. For illustrative purposes, Figure 5 shows just two adjacent fingers 26 with one connecting web 28. However, preferably the projecting element 24 extends all the way around the distal end ring 14. In one example as shown in Figure 6, eight fingers 26 are provided. The fingers 26 are equally spaced around the circumference of the tubular body 12 and joined by eight webs 28. However, a different number of fingers 26 and webs 28 and a different spacing are also possible. In the example shown in Figure 5, the base of each finger 26 is joined to the first distal end ring 14a of the tubular body 12. In the example shown, the fingers 26 are identical to each other, and the webs 28 are also identical to each other. However, the size and shape of the fingers 26 and / or of the webs 28 could be varied. It is also possible for the webs 28 to be omitted. Each finger 26 comprises a base portion 30 which is attached to or integrally formed with the distal end ring 14a, and a tip portion 32 which is spaced from the distal end ring 14a. The base portion 30 may extend substantially radially, such that it is substantially perpendicular to the longitudinal axis 20. Alternatively, the base portion 30 may extend at an angle of less than 90° to the longitudinal axis 20, so that it tilts slightly towards the proximal end of the accessory 10. The tip portion 32 extends at a shallower angle to the longitudinal axis 20, so that it has a much more pronounced tilt towards the proximal end of the accessory 10. There is a smooth transition between the base portion 30 and the tip portion 32 so that the finger 26 is arcuate and the projecting element 24 curves away from the distal-most tip of the shaft 50 in use. Each finger 26 may taper as shown in Figures 7 and 8, so that it becomes narrower from the base portion 30 towards the tip portion 32. Each web 28 comprises a membrane attached to or integrally formed with the distal end ring 14a and two adjacent fingers 26. The tip portion 32 of each finger 26 may extend beyond the free edge 34 of the web 28. The free edge 34 of each web 28 may be arcuate as shown, or straight. In the example shown in Figure 9, the tip portions 32 of the fingers 26 are joined by a hoop 36. Where such a hoop 36 is provided, the webs 28 could be omitted, so that the fingers 26 are only connected by the hoop 36. The connecting hoop 36 has larger diameter that the tubular body 12 and is not connected to the tubular body 12, so that it floats around the tubular body 12 supported by the fingers 26. The connecting hoop 36 will typically have a larger diameter than the distal end and proximal end rings 14, 16. The projecting element 24 is formed from one or more flexible, resilient materials. It is sufficiently stiff to remain in the outwardly extended position around the tubular body 12 but is able to flex and bend as it contacts body tissue in use. When the accessory 10 is fitted on a shaft 50, the medical scoping device may then be inserted into a patient’s body. Normally when examining the gastrointestinal tract, for example, the shaft 50 of the medical scoping 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 50 is gradually withdrawn, the projecting element 24 acts to gently pull back and flatten folds of tissue, to allow a clearer view of the body tissues through the scoping device. The webs 28 prevent the fingers 26 from being pushed apart and distributes the force applied to the body tissue more evenly. The webs 28 may also wipe the tissue as the shaft 50 is withdrawn to help remove any debris. At the end of the procedure the shaft 50 is completely withdrawn from the patient’s body. The accessory 10 can then be removed from the shaft 50, for example by gripping the proximal end ring 16 and using it to peel the device off the shaft 50, or by rolling up the proximal end ring 16 back towards the distal end ring 14, thus rolling up the tubular body 12, and then pulling the whole device off the distal end of the shaft 50. The accessory 10 can then be disposed of. In another embodiment as shown in Figure 10, the projecting element 24 is in the form of a cage surrounding the distal end of the accessory 10. The cage is formed from a series of elongate elements 38, referred to herein as ribs. In one example, twelve ribs 38 are provided, equally spaced around the circumference of the tubular body 12. However, a different number of ribs 38 and a different spacing are also possible. In the example shown, the ribs 38 are identical to each other. However, the size and shape of the ribs 38 could be varied. The base of each rib 38 is joined to the distal end ring 14 of the tubular body 12 (or one of the distal end rings if there are two or more). Each rib 38 comprises a base portion 40 attached to or integrally formed with the distal end ring 14, and a tip portion 42 spaced from the distal end ring 14. The base portion 40 may extend substantially radially, such that it is substantially perpendicular to the longitudinal axis 20. Alternatively, the base portion 40 may extend at an angle of less than 90° to the longitudinal axis 20, so that it tilts slightly towards the proximal end of the accessory 10. The tip portion 42 extends proximally and may be angled inwardly towards to the longitudinal axis 20. The ends of the tip portions 42 are joined by a connecting hoop 44. The connecting hoop 44 has larger diameter that the tubular body 12 and is not connected to the tubular body 12, so that it floats around the tubular body 12 supported by the ribs 38. The connecting hoop 44 may have a larger diameter than the distal end and proximal end rings 14, 16. There is a smooth transition between the base portion 40 and the tip portion 42 so that the rib 38 is arcuate and the projecting element 24 curves away from the distal-most tip of the shaft 50 in use. In use, the cage helps to hold body tissue away from the distal end of the shaft 50 to allow a clearer view through the scoping device. In all embodiments, the projecting element 24 may be made a resilient polymer material, such as a silicone. The projecting element is stiffer and more self-supporting than the thin membrane of the tubular body 12 so that it maintains its shape while allowing some flexing as it contacts body tissue. The elongate elements are arcuate and have a convex curvature with respect to the longitudinal axis between the first and second ends of the accessory 10. Thus, the present disclosure provides an improved accessory 10 for the shaft 50 of a medical scoping device, in the form of a lightweight and flexible cover. The cover can be rolled up and provided in a smaller package than conventional accessories and fitted to a shaft by unrolling along the shaft. Once in use on a shaft 50 of a medical scope the cover has smooth inner and outer surfaces. The projecting element 24 helps to pull back folds of tissue to facilitate the inspection procedure. As noted above, in this disclosure the term “medical scoping device” or “medical scope” may refer to an endoscope, but these terms are 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 terms “medical scoping device” and “medical scope” 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 scoping devices are elongate flexible probes which may be inserted into the body directly or via a cannula or other guide device. Medical scoping 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 scoping device.

Claims

1. A cover for covering the distal end of a shaft of a medical scoping device, the cover comprising a tubular body, having a first end, a second end and a longitudinal axis extending between the first and second ends, a first ring at the first end of the tubular body, wherein the first ring is thicker than the tubular body, and an annular member projecting radially outwardly from the first ring, wherein the tubular body is sufficiently thin and flexible that the cover can be shortened axially by rolling up of the tubular body from the second end towards the first end.

2. A cover as claimed in claim 1, wherein the first end ring comprises an internal surface which is shaped to engage the profile of the distal tip of the shaft.

3. A cover as claimed in claim 1 or claim 2, wherein the first end ring comprises two or more adjacent rings and, in a direction from the first end to the second end, each ring is successively thinner and more flexible.

4. A cover as claimed in any of claims 1 to 3, wherein the annular member comprises a plurality of elongate elements each comprising a base portion projecting from the first ring and a tip portion extending from the base portion towards the second end.

5. A cover as claimed in claim 4, wherein each elongate element is joined to each adjacent elongate element by a connecting web.

6. A sheath as claimed in claim 5, wherein the tip portions of the elongate elements project beyond the connecting webs.

7. A cover as claimed in any of claims 4 to 6, wherein the tip portions of the elongate elements are joined by a hoop and wherein the hoop is not attached to any other part of the cover.

8. A cover as claimed in any of claims 4 to 7, wherein the elongate elements are arcuate and have a convex curvature with respect to the longitudinal axis.

9. A cover as claimed in any of claims 4 to 8, wherein each elongate element tapers from the base portion towards the tip portion.

10. A cover as claimed in any of claims 1 to 9, wherein the tubular body further5 comprises a second ring at the second end of the tubular body, wherein the second ring is thicker than the tubular body.

11. A method for fitting a cover as claimed in any preceding claim to a shaft of a medical scoping device when the cover is in an axially shortened state, comprising10 inserting a distal end of the shaft into the cover from the second end, locating the first ring around the distal-most end of the shaft, unrolling the tubular body proximally along the shaft to move the second end away from the first ring until the tubular body is fully extended and the second end grips the shaft.

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