Medical device accessory

Abstract

An accessory 10 for fitting over the distal end of a shaft of a medical device is provided which has a longitudinal axis 22 with a distal end and a proximal end. The accessory comprises a tubular body configured to receive a distal end of a shaft 70 of a medical device and to elastically grip the shaft 70 in use, at least one projecting element 24 extends outwardly from the tubular body, and a nose portion 26 projecting distally from the tubular body and beyond the distal end of the shaft in use. These projections can pull back or fatten folds within body tissue during endoscopic inspection.

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 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 scoping device. This type of cover is formed of a plastic material and forms a friction fit on the shaft of the medical device. In this type of cover the distal end of the shaft of the medical scoping device extends to the distal end of the cover and therefore may directly contact body tissues in use. Summary The present disclosure provides a accessory for fitting over the distal end of a shaft of a medical device as set out in claim 1. The accessory provides a variable offset distance of view between the end of the shaft and body tissues in use. Brief Description of the Drawings The present disclosure refers, by way of example only, to the accompanying drawings in which: Figure 1 shows a first embodiment of accessory; Figure 2 shows a second embodiment of accessory; Figure 3 shows a third embodiment of accessory; Figure 4 shows a fourth embodiment of accessory; Figure 5 shows a fifth embodiment of accessory; Figures 6 shows a sixth embodiment of accessory; Figure 7 shows a seventh embodiment of accessory; Figure 8 shows an eighth embodiment of accessory; Figure 9 shows a ninth embodiment of accessory; Figure 10 shows a tenth embodiment of accessory; Figure 11 shows an eleventh embodiment of accessory; Figure 12 shows a twelfth embodiment of accessory; Figures 13a and 13b show examples of textured surfaces on the projecting arms; Figure 14 shows the embodiment of Figure 1 in use on a shaft of a medical device and inserted into a body lumen. Detailed Description Figure 1 shows a first embodiment of an accessory 10 for fitting over the distal end of a shaft 70 of a medical device. The Figure includes a perspective view (shown top right), together with top, bottom, side, front and rear views of the accessory 10. The accessory 10 has first and second ends 14, 16, which in use are the distal and proximal ends respectively, and a longitudinal axis 22. The accessory 10 comprises a tubular body 12 and a nose portion 26 at the first end 14. The tubular body 12 has an outer circumferential surface 18, an inner circumferential surface 20. The accessory 10 further comprises one or more projecting elements 24 extending outwardly from the tubular body, as described further below. In use, the accessory 10 is fitted over the distal end of a shaft 70 of a medical device such as an endoscope, as described in more detail below. The distal tip of the shaft 70 is located within the tubular body 12 and is gripped by the tubular body 12. The second end 16 of the tubular body 12 is located proximally on the shaft 70. The nose portion 26 projects distally beyond the end of the shaft 70. The accessory 10 may be formed from a flexible, resilient material, such as a plastic or other polymer. This material forms the exterior surface of the tubular body 12, including the outer and inner circumferential surfaces 18, 20. The flexible, resilient material protects the shaft 70 and grips the shaft 70 to hold the accessory 10 in position. The tubular body 12 may also be textured or shaped, for example with ribs, on the outer and / or inner circumferential surfaces 18, 20. In the first embodiment, the nose portion 26 and the tubular body 12 are integrally formed with one another. However, in other embodiments as discussed further below, the tubular body 12 and the nose portion 26 may be separate parts which are joined together and therefore, the nose portion 26 may be formed of a different material to the tubular body 12. At the second end 16, the end face of the tubular body 12 may be perpendicular to the longitudinal axis 22. At the first end 14, in this embodiment, the nose portion 26 is shaped so that it is not perpendicular to the longitudinal axis 22. With reference to the side views of the accessory 10 as shown in Figure 1, an upper portion 14a of the first end face lies in a plane oblique to the longitudinal axis 22 such that it slopes downwardly in a distal direction. A lower portion 14b of the first end face lies in a curved plane and as seen in the side view the curvature is convex relative to the longitudinal axis 22. The lowermost part of the nose portion 26 therefore protrudes distally to the greatest extent. By way of example only, the outside diameter of the tubular body 12 may be in the range of 8.5-19 mm. The maximum combined length of the tubular body 12 and the nose portion 26 may be about 20 mm. The length of the nose portion 26 itself not including the tubular body 12 may be in the range of 1.5 - 5 mm. The accessory 10 is further provided with at least one axially extending slot 28. In this example, four slots 28 are provided which are equally spaced around the circumference of the accessory 10, at the top, bottom and on each side. However, the number of slots 28 and their size, position and spacing may vary. The slots 28 may be generally rectangular, or alternative shapes. Each slot 28 has a proximal portion located in the tubular body 12 and extends distally into the nose portion 26. The length of each slot 28 may vary depending on its position on the accessory 10. In Figure 1, the slot 28 at the top of the device is the shortest and the slot 28 at the bottom is the longest since bottom of the nose portion 26 extends the furthest distance distally. The width of the slots 28 may be the same or may vary. The projecting elements may comprise a plurality of arms 24 projecting radially outwardly from the tubular body 12. The arms 24 may be identical to each other and equally spaced around the tubular body 12, but other configurations are also possible. Eight arms may be provided as illustrated in Figure 1, although fewer or more arms may also be provided. Although not shown, in alternative embodiments adjacent arms may be joined together by connecting webs, or a plurality of individual arms may be replaced by a continuous annular collar around the tubular body 12. In a relaxed state, each arm 24 has an arcuate form which is convex with respect to the longitudinal axis 22. A first end 30 of each arm 24 is joined to or integral with the tubular body 12. A second end 32 of each arm 24 is free and projects beyond the second end 16 of the tubular body 12. The second end 32 of each arm 24 may be provided with a flange 34 directed radially inwardly back towards the longitudinal axis 22. The flange 34 may be provided with a textured surface to enhance the grip of the flange 34 against body tissues when in use. For example, an inner face 36 of the flange 34 may comprise a series of ridges 38. Figure 13a shows an example with straight ridges 38, while Figure 13b shows an alternative with chevron-shaped ridges 38. The projecting arms 24 may be made from a resilient polymer material, such as a silicone. The arms 24 therefore have some stiffness and are self-supporting, while allowing some flexing as they contact body tissue when in use. Each arm 24 may be supported by a strut 40 which extends between the tubular body 12 and the underside of the arm 24. Each strut 40 may include one or more hinge points 42 allowing each strut 40 to fold and straighten as the arm 24 moves towards and away from the tubular body 12. The struts 40 limit how far each arm 24 can flex away from the tubular body 12. In use, a shaft 70 of a medical device is inserted into the second end 16 of the tubular body 12 and advanced until the distal end of the shaft 70 is located within the tubular body 12. Typically, the shaft 70 will be inserted until its distal tip is just behind or slightly overlapping the proximal ends of the slots 28. The inner surface 20 of the tubular body 12 may be provided with a visual indicator, e.g. a line or arrow, or a physical stop, e.g. a raised protrusion or ridge (not shown), to indicate how far into the tubular body 12 the shaft 70 should be inserted. However, the user may be able to alter the position of the shaft 70 within the tubular body 12 to some extent to suit a specific procedure. Since the slots 28 extend axially into the nose portion 26 at least part of the slots 28 will remain open and not be blocked by the shaft 70 which does not project into the nose portion 26. The nose portion 26 protrudes distally beyond the distal tip of the shaft 70. In this state, the resilient tubular body 12 securely grips the shaft 70 and the accessory 10 is ready for use and the medical device may 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. The arms 24 help to stabilize and centre the distal end of the shaft 70 in the body lumen. As the shaft 70 is gradually withdrawn, the arms 24 contact folds of tissue and act to gently pull back and flatten them, to allow a clearer view of and access to the body tissues. The arms 24 may flex away from the tubular body 12, as shown in Figure 14, limited by the struts 40. The flanges 34 and ridges 38 help the arms 24 to grip the tissues. 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 and disposed of. Since the nose portion 26 protrudes distally beyond the distal tip of the shaft 70, the distal tip of the shaft 70 is offset from the distal end 14 of the accessory 10 and is therefore spaced from the body tissues. In the case of a medical device such as an endoscope, this enables a clearer view through the medical device. Due to the shape of the nose portion 26, the amount of offset between the distal tip of shaft 70 and the body tissues can be varied by changing the orientation of the medical device and which part of the accessory 10, i.e. the lower or upper part or one side, contacts the body tissues. The nose portion 26 itself may also be used to hold and manipulate folds of tissue and may help in tunnelling inside the lower and upper gastrointestinal tract. The nose portion 26 may also be used to scoop up and retrieve foreign bodies from within a body cavity. Some medical procedures involve the use of water or other fluid which is supplied through the medical device. This may be used to clean a lens or viewing window at the distal of the medical device and to irrigate the site under observation. The slots 28 in the tubular body 12 help fluid supplied through the medical device to escape more quickly from the accessory 10 so that fluid does not collect in front of the lens and obscure the field of view. Since the slots 28 extend axially, even if the exact position of the shaft 70 within the tubular body 12 varies slightly, at least part of the slots 28 remain exposed to allow fluid to escape. Typically, in use, a lens at the distal tip of the shaft 70 of a medical device will be positioned near to the top of the accessory 10 (with reference to the orientation in the perspective and side views of Figure 1). Therefore, the slot or slots 28 at the top may be the widest to permit faster removal of fluid from the region in front of the lens. The nose portion may be formed from an opaque material and the inner surface of the nose portion 26 may be formed with a dark colour so that it can be used for magnification endoscopy purposes. A darker colour will absorb distorted light and remove redouts in the endoscopic view. Further embodiments of an accessory 10 are described below with reference to Figures 2-12. Like Figure 1, these Figures also show a perspective view (shown top right), together with top, bottom, side, front and rear views of the accessory 10. It will be appreciated that the features of the various embodiments may be combined and interchanged as required. Many of the features of each accessory 10 are the same as those described above and the same reference numerals are used. The differences between the various embodiments are set out below. In a second embodiment shown in Figure 2, the end face 14c at the first end 14 of the accessory 10 all lies in a flat plane which is oblique to the longitudinal axis and without a curved portion. Five slots 28 are shown, with two in the upper part of the accessory 10, one on each side and one at the bottom. In this and the subsequent embodiments the struts 40 are omitted, but they could be added if desired. A third embodiment shown in Figure 3 is similar to that in Figure 2, but in this case the slots 28 are elliptical in shape rather than rectangular. A fourth embodiment shown in Figure 4 is similar to that in Figure 3, but in this case the distal end 14 has a crenellated end face 14d formed by a series of alternating raised and recessed portions. This may increase grip against a body tissue and may also lead to less interference in the image provided on a video screen to the medical personnel carrying out the procedure. A fifth embodiment shown in Figure 5 is similar to that in Figure 4, but only five projecting arms 24 are provided. In the sixth embodiment shown in Figure 6, the nose portion 26 comprises a transparent cap attached to the tubular body 12. In this example, the transparent cap is in the form of a hemispherical dome 44. This form of accessory 10 may be used in the upper gastrointestinal (Gl) tract for observation and to dilate strictures and stenoses. The smooth dome shape facilitates smooth entry into the narrow area of the upper Gl tract. In this example, the slots 28 may be omitted as no fluid may be used in the procedure. In a seventh embodiment shown in Figure 7, the nose portion 26 also comprises a transparent cap attached to the tubular body 12. In this embodiment, the cap has a shallow conical tip 46 at the distal end, and a frustoconical portion 48 adjacent to the tubular body 12. As with the sixth embodiment, this form of accessory 10 may be used in the upper gastrointestinal (Gl) tract for observation and to dilate strictures and stenoses. The shallow conical tip 46 assists with smooth entry into the narrow area of the upper Gl tract. In this example slots 28 are provided which may be used for supplying gas, e.g. air or CO2, used for insufflation to inflate the body lumen for ease of movement of the medical device and to ensure a clearer view. Some slots 28 may be in the tubular body 12, such as that shown on the top of the accessory 10, while some may be in part of the tubular body 12 and part of the nose portion 26, such as those shown on the sides. In an eighth embodiment shown in Figure 8, the nose portion 26 comprises a transparent collar 50 attached to the tubular body 12. The collar 50 may be open at the distal end 14. The collar 50 in this example is frustoconical, tapering inwardly in a distal direction. Alternatively, in a ninth embodiment shown in Figure 9, the transparent collar 50 may be cylindrical. In a tenth embodiment shown in Figure 10, the transparent collar 50 may be frustoconical but tapering outwardly in a distal direction. In eleventh and twelfth embodiments shown in Figures 11 and 12, the nose portion 26 also comprises a collar 50 shaped to provide a specific depth and direction of view. The collar 50 may be transparent or opaque, and it may be generally frustoconical, tapering inwardly in a distal direction. The distal end face 14e may be in a plane oblique to the longitudinal axis 22 as in Figure 11, or perpendicular to the longitudinal axis 22 as in Figure 12. In both cases, a lower side of the distal end 14 has a flattened portion 14f. Thus, the distal opening of the collar 50 is the shape of a circle with a segment removed. This shape allows easy access for surgical devices inserted through an instrument channel of the medical device and the flattened surface 14f can rest against the surface of a body lumen to provide great stability when using such surgical devices. In all these embodiments, the slots 28, when present, may be shaped and positioned as required. The number of arms 24 may be varied. The struts 40 for the arms 24 are not shown, but they could be provided if required. Where the nose portion 26 comprises a cap or collar joined to the tubular body 12, the nose portion 26 may be formed of a harder material than the tubular body 12 to assist with advancing the device through narrow areas and would also assist in keeping the cap rigid during the procedure Thus, the present disclosure provides an improved accessory 10 for a shaft 70 of a medical device which provides for a variable offset distance between the shaft 70 and the body tissues. The accessory 10 is compatible with many different types of procedure, including procedures which use water (or other liquids) for irrigation, or gas for insufflation. The nose portion 26 assists in accessing tight or narrow locations. The arms 24 provide for enhanced grip and manipulation of tissue folds. 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” is 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. An accessory for fitting over the distal end of a shaft of a medical device, the accessory having a longitudinal axis and a distal end and a proximal end along the axis, the accessory comprising a tubular body configured to receive a distal end of a shaft of a medical device and to elastically grip the shaft in use, at least one projecting element extending outwardly from the tubular body, and a nose portion projecting distally from the tubular body and beyond the distal end of the shaft in use.

2. An accessory as claimed in claim 1, wherein the nose portion comprises an end face at least part of which is oblique to the longitudinal axis.

3. An accessory as claimed in claim 1 or claim 2, wherein the nose portion comprises an end face at least part of which is curved relative to the longitudinal axis.

4. An accessory as claimed in claim 1, wherein the nose portion comprises an end face which is perpendicular to the longitudinal axis.

5. An accessory as claimed in claim 1 or claim 2, wherein the nose portion comprises an end face comprising a series of alternating raised and recessed portions.

6. An accessory as claimed in any preceding claim, wherein the nose portion is integral with the tubular body.

7. An accessory as claimed in any of claims 1 -5, wherein the nose portion is joined to the tubular body and is formed of a different material to the tubular body.

8. An accessory as claimed in claim 7, wherein the nose portion is transparent.

9. An accessory as claimed in claim 8, wherein the nose portion is a hemisphericaldome.

10. An accessory as claimed in claim 8, wherein the nose portion comprises a conical tip.- IQ-11. An accessory as claimed in any of claim 1 -8, wherein the nose portion comprises an annular collar.

12. An accessory as claimed in any preceding claim, further comprising at least one axially extending slot in the tubular body and extending into the nose portion.

13. An accessory as claimed in any preceding claim, wherein the at least one flexible projecting element comprises a plurality of arms each having a first end joined to or integral with the tubular body and a second free end projecting proximally beyond the proximal end of the accessory.

14. An accessory as claimed in claim 13, wherein each arm further comprises a flange at the second end of the arm directed radially inwardly towards the longitudinal axis.

15. An accessory as claimed in claim 14, wherein each flange is provided with a textured surface.

16. An accessory as claimed in any of claims 13-15, wherein a strut extends between the tubular body and each arm.

17. An accessory as claimed in claim 16, wherein each strut comprises at least one hinge point allowing the strut to fold.

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