Abstract
A cover (1) for a shaft of a medical scoping device comprises tubular member (2) arranged for application on the distal tip of the medical scoping device. The cover (1) comprises a plurality of projecting elements (3) spaced apart circumferentially around the tubular member (2), each projecting element having a base portion (13) and an arm portion. The projecting elements are pivotably mounted on the tubular member about a pivot axis. The base portion (13) comprises a detent (20), and the tubular member comprises a contact region, for example a protuberance (23), said contact region being located such that pivoting movement of the projecting element for moving the arm portion in a distal direction can effect impacting of the detent (20) on the contact region (23).
Claims
1-40. (canceled)
41. A cover for a shaft of a medical scoping device, the medical scoping device comprising a visualization system having a field of view, the cover comprising: a tubular member arranged for application over a distal end of the shaft of the medical scoping device and, in use, extending along a portion of the length of the distal end of the shaft of the medical scoping device; and a plurality of projecting elements arranged at positions spaced apart circumferentially around the tubular member, each projecting element comprising a base portion, a distal tip portion, and an intermediate portion, the intermediate portion being between the base portion and the distal tip portion; wherein at least one of the projecting elements is configured to move to a deflected position in which the distal tip portion of the projecting element is within the field of view of the visualization system of the medical scoping device.
42. The cover according to claim 41, wherein the distal tip portion of the at least one projecting element moves to the deflected position during the withdrawal of the medical scoping device through the body cavity.
43. The cover according to claim 41, wherein at least one of the distal tip portion and the intermediate portion of the at least one projecting element is resiliently deformable, and wherein the at least one projecting elements is deflected into the field of view of the visualization system of the medical scoping device at least in part through bending of the at least one of the distal tip portion and the intermediate portion of the projecting element.
44. The cover according to claim 41, wherein the at least one projecting element has a length and the length of the at least one projecting element is dimensioned so that the distal tip portion of the projecting element extends beyond a distal end of the medical scoping device when the projecting element is in the deflected position.
45. The cover according to claim 44, wherein the projecting elements are spaced apart in a ring around the tubular member, and wherein the ring is spaced from a distal edge of the tubular member by a distance that is less than the length of the projecting elements.
46. The cover according to claim 45, wherein the projecting elements are evenly spaced around the circumference of the tubular member.
47. The cover according to claim 45, wherein the ring is located no more than 10 mm from the distal edge of the tubular member.
48. The cover according to claim 45, wherein the length of the at least one projecting element is no more than 20 mm.
49. The cover according to claim 41, wherein an aspect ratio of a length of the projecting element and a width of the projecting element is no less than three.
50. The cover according to claim 41, wherein the cover has an overall diameter and the overall diameter of the cover is no more than 40 mm.
51. The cover according to claim 41, wherein the at least one projecting element has a width, and the width of the at least one projecting element is in the range of 1.5 mm to 3 mm.
52. The cover according to claim 41, wherein the cover has a length, and the length of the cover is in the range of 15 mm to 16 mm.
53. The cover according to claim 41, wherein the number of the projecting elements is at least six.
54. The cover according to claim 41, wherein the cover is of an elastomeric polymer selected from elastomeric polyesters, copolyesters, polyamides, polyolefins, silicones, polyetherketones, natural rubbers, synthetic rubbers, and styrene polymers, and copolymers or mixtures of any of the aforementioned.
55. The cover according to claim 54, wherein the elastomeric polymer is selected from styrene-olefin block copolymers and silicone rubbers.
56. The cover according to claim 41, wherein the cover comprises a polymer material of Shore A hardness from 40 to 60.
57. The cover according to claim 41, wherein the cover comprises a radio-opaque dye for identification during an examination of a human body.
58. The cover according to claim 41, wherein said distal tip portion of said at least one projecting element includes a bump.
59. A set of covers comprising a plurality of covers accordingly to claim 41, each cover of the set comprising a colored dye having a color, the color of the dye indicating the type of the cover.
60. A medical scoping device comprising a visualization system and a cover according to claim 41.
61. A cover for a shaft of a medical scoping device, the medical scoping device comprising a visualization system having a field of view, the cover comprising: a tubular member arranged for application over a distal end of the shaft of the medical scoping device and, in use, extending along a portion of the length of the distal end of the shaft of the medical scoping device; and a plurality of projecting elements arranged at positions spaced apart circumferentially around the tubular member, each projecting element comprising a base portion, a distal tip portion, and an intermediate portion, the intermediate portion being between the base portion and the distal tip portion; wherein at least one of the projecting elements comprises at least one bump and is configured to bend to a deflected position in which the at least one bump is within the field of view of the visualization system of the medical scoping device.
62. The cover according to claim 61, wherein the at least one bump comprises a measurement scale.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a perspective view of cover according to a first embodiment of the invention for use in sigmoidoscopy.
[0039] FIG. 2 is a side view of the cover of FIG. 1;
[0040] FIG. 3 is a bottom view of the cover of FIG. 1 and includes a detail view showing a portion of the base of a projecting element and the adjacent portion of the tube;
[0041] FIG. 4 is a view of the cover of FIG. 1 from above, showing a detail of a portion of the cover at the base portion of a projection element;
[0042] FIG. 5 is a vertical section through the cover of FIGS. 1 to 4 along the line V-V shown in FIG. 4;
[0043] FIG. 6 is a vertical section through the cover of FIGS. 1 to 4 along the line VI-VI shown in FIG. 4, further showing in section a detail of a portion of the cover showing the base portion of the projecting element and the adjacent portion of the tube in section;
[0044] FIG. 7 is a horizontal section along the line VII-VII of FIG. 2;
[0045] FIG. 8 is a perspective view of cover according to a second embodiment of the invention for use in enteroscopy;
[0046] FIG. 9 is a bottom view of the cover of FIG. 8 and includes a detail view showing a portion of the base of a projecting element and the adjacent portion of the tube;
[0047] FIG. 10 is a view of the cover of FIG. 1 from above, showing a detail of a portion of the cover at the base portion of a projection element;
[0048] FIG. 11 is a section through a cover according to FIGS. 1 to 7 in the rest position;
[0049] FIG. 12 is a section through the cover of FIG. 11 showing the projecting elements in a forward position;
[0050] FIG. 13 is a schematic view of a cover according to the invention as used in a first stage of colonoscopic examination;
[0051] FIG. 14 is a schematic view of the cover of FIG. 13 during a main visualisation stage of a colonoscopic examination;
[0052] FIG. 15 is a perspective view of a projecting element for use in a cover according to a third embodiment of the invention;
[0053] FIG. 16 is a partial side view of the cover of the third embodiment of the invention in which the projecting elements are in an extreme distal position; and
[0054] FIG. 17 is a section through the cover shown in FIG. 16 along the line A-A shown in FIG. 16
[0055] The invention is described hereafter with reference to first and second illustrative embodiments of the invention comprising a tip cover device for sigmoidoscopy (FIGS. 1 to 7) and a tip cover device for enteroscopy (FIGS. 8 to 10). The invention may be applied in cover devices suitable for other types of internal examination, for example endoscopy, colonoscopy, and any other technique in which a visualisation device is advanced into a bodily orifice for examination.
[0056] FIGS. 1 to 7 show, as a first illustrative embodiment of the invention, a scope cover of dimensions suitable for mounting on the end of a sigmoidoscope. The cover 1 is formed in one piece from a resiliently deformable polymer material. Dimensions referred to herein are, except where otherwise stated, when the cover or parts thereof are in their rest positions, that is, are not subject to any applied deformation.
[0057] With reference to FIGS. 1 to 7, the cover 1 has a tubular member 2 generally indicated by reference numeral 2 and eight projecting elements 3. The projecting elements 3 are joined to the tubular member 2 by a mounting structure described further below. The projecting elements are evenly spaced around the circumference of the tubular member 2 at 45° intervals.
[0058] The tubular member 2 comprises a circumferential outer surface 4, a circumferential inner surface 5, a distal edge 6 and a proximal edge 7. The axial length of the tubular member 2 may vary in size relative to the diameter of the tubular member 2. Irrespective of whether the axial length is longer or shorter than the diameter of the cover, the direction extending parallel to the axis of the tubular member 2 is referred to herein as the longitudinal direction.
[0059] The circumferential inner surface 5 has a multiplicity of parallel interior ridges 8 extending longitudinally, which are separated into eight groups of three, which groups are spaced apart about the circumference of the inner surface. The interior ridges serve to improve the grip of the cover when mounted on a scoping device tip, which may especially be useful where the tip is exposed to bodily fluids or other fluids which can have a lubricating effect that has the potential to lead to dislodging of a cover that is not firmly attached.
[0060] The circumferential outer surface 4 comprises outer surface ridges 9 extending longitudinally from a location in the vicinity of the distal edge 6 towards the proximal edge 7. The outer surface ridges 9 are arranged in eight pairs, the pairs being spaced apart evenly around the circumference of the tubular member 2. Embraced between each said pair 9′, 9″ of ridges and the adjacent pairs on each side are channels 10. With reference to the detail in FIG. 3, each channel 10 is defined by a lateral wall surface 11 of a ridge 9′ of one pair, and an opposed lateral wall surface 12 of a ridge 9″ of the adjacent pair, the channel 10 having a channel base. The channel serves to receive an associated projecting element in some orientations as hereafter described. The longitudinal outer surface ridges 9 are wider and deeper than the inner surface ridges 8, and in addition to serving to mount the projecting elements 3 the pairs of outer ridges 9 impart additional structural stability with stretching capability of the tube portion in the radial direction as will be described further below, thereby facilitating application to, and removal from, a scoping device.
[0061] The structure of one projecting element 3, and associated channel 10 will now be described in more detail. The cover of FIGS. 1 to 7 comprises seven further projecting elements and associated channels which are of like structure and configuration.
[0062] The projecting element 3 has a base portion 13 via which the projecting element is mounted on the cover and an arm 14 which extends from the base portion. The arm 14 comprises an intermediate portion 15 and a tip portion 16 terminating in free end 17. The projecting element is of monolithic structure, and the intermediate portion 15 and tip portion 16 are therefore designated for reasons of convenience and do not constitute visibly distinct portions. As previously mentioned, the projecting element 3 is also integrally formed with the rest of the cover in the embodiment described.
[0063] The projecting element 3 is connected to the tubular member 2 via a pair of mountings provided on opposite sides of the base portion 13 of the projecting element. A first mounting of said pair comprises a first connector portion 18 extending laterally from a first side of the base portion 13 joining the base portion at one side to the lateral wall surface 11 of ridge 9′. A second mounting of said pair comprises a second connector portion 19 extending laterally from the opposite side of the base portion 13 to the adjacent lateral wall surface 12 of ridge 9″. The connector portions 18 and 19 permit pivoting of the projecting element 3 relative to the rest of the cover 1 by means of twisting deformation of the first and second connector portions.
[0064] The connector portions 18, 19 define a pivot axis which extends through the intervening part of the base portion 13 of the projecting element from one connector portion 18 to the other connector portion 19. Pivoting of the projecting element about the pivot axis can occur in two directions. Pivoting movement of the free end 17 towards the proximal direction enables the projecting element to adopt a proximal position in which the projecting element is received at least partly within the channel 10. That position may be adopted on application of force in the proximal direction during insertion of the scope (as shown in FIG. 12) or when folds of the intestinal wall are encountered during advancing of the scope within narrow parts of the body cavity being examined. Pivoting of the free end 17 in the distal direction, as may occur on withdrawal of the scope through the area of the intestine to be visualised, can cause partial eversion of the projecting element from the position shown in FIG. 1 to a forward position in which the free ends of the projecting elements are at an angle of greater than perpendicular relative to the proximal direction. The base portion 13 comprises a detent 20 which is on the opposite side of the pivot axis from the arm 14 of the projecting element. As a result, when the arm 14 comprising the intermediate portion 15 and tip portion 16 is pivoted towards the distal direction, the detent 20 is pivoted downwardly towards the surface of the tubular member 2. The detent 20 includes a contoured contact region 21 which, after a certain degree of pivoting, impacts upon the outer surface of the tubular member 2, within the base of the channel 10. The base of the channel 10 is configured in the embodiment shown to have a contoured region in the vicinity of the base portion 13 of the projecting element 3. The contoured region includes a recessed region 22 and a raised region forming a protuberance 23. The protuberance 23 provides a contact region which obstructs the locus of movement of the detent 20 when the projecting element 3 is pivoted towards the distal direction. In the embodiment shown, the protuberance 23 is essentially level with the part of the floor of the channel 10 that is proximal of the projecting element, and the recessed region 22 around it is recessed relative to the floor of the channel 10. It is also possible, however, for the contact region to be provided on a protuberance 23 at a level that is higher than the proximally located floor of the channel 10. The presence of recessed regions 22 defining between them a protuberance 23, can be advantageous in simplifying mouldability, especially for injection moulding processes where removal from a mould in the line of draw may be facilitated.
[0065] In the covers shown in FIGS. 1 to 7 and FIGS. 8 to 10, the rest position of the projecting elements 3 is such that the arm portions are directed slightly proximally, for example at an angle of about 70 to 80° relative to the proximal direction. The detent 20 on the base portion 13 of the projecting element 3, and the protuberance 23 on the tubular member 2 are so arranged relative to one another that contact occurs when the projecting element has been pivoted to be approximately perpendicular or slightly greater than perpendicular relative to the proximal direction. In practice, that may correspond to pivoting the projecting element 3 by about 30° forward from the rest position shown in FIG. 1. Since the cover is of a resiliently deformable material, further advancing of the base portion 13 of the projecting element 3 is permitted by deformation of the detent 20 and/or of the region of contact on protuberance 23. The degree of resistance may increase with the degree of deformation of the contact regions, and further movement may eventually be stopped. In at least some embodiments it is preferred that the advancing of the arm in the distal direction is limited to 120° or less, relative to the proximal direction. For the avoidance of doubt, since the intermediate portion 15 and tip portion 16 of the arm are flexible, bending in the distal direction will be able to occur in those parts, and will occur preferentially in comparison to further bending at the base portion 13 which is subject to the resistance imposed by the contact between the base portion 13 and the cover 2 at protuberance 23. Thus, reference to an angular position relative to the proximal direction is to be taken to refer to the angle of the part of the arm 14 closest to the base portion 13, whilst the remainder of the arm 14 may be subject to additional forward bending.
[0066] As shown in FIG. 7, in the rest position the cover comprises longitudinally regions made up of alternating grip regions 24 and expansion regions 25. The grip regions 24 include the inner grip ridges 8 which serve to enhance security of gripping of the cover. Alternating with, and slightly displaced radially outwards relative to, the grip regions 24 are the expansion regions 25 that are located under the pairs of external longitudinal ridges 9. The expansion regions and adjacent grip regions are so joined to one another by inclined web portions 26 that they permit a certain degree of radial expansion of the tubular member 2. Webs 27 of material between each ridge of the outer pairs 9′, 9″ of ribs also permit a degree of stretching in the distal region of the cover. By comparison, in the channels 10 between adjacent pairs of outer ribs 9, the degree of stretching in the distal region of the cover is limited by the mounting of the projecting elements 3 in the channels between adjacent pairs of outer ribs 9 in that region.
[0067] In practice, the cover of FIGS. 1 to 7 for use on a sigmoidoscope may have an internal diameter of from 8 to 10 mm (not including the gripping ridges) when at rest. When mounted on the tip of a scope, the cover will adopt an internal diameter approximating to the external diameter of the scope. The cover may, by way of example, have a total axial length of 15 to 16 mm, an overall diameter of 39 to 40 mm. The projecting elements may have a length of 12 to 16 mm. The width of the projecting elements may advantageously be in the region of 1.5 to 3 mm, for example 1.8 to 2.5 mm. The inner longitudinal ridges may be, for example, about 0.2 mm wide. The outer ridges are thicker, for example about 0.4 mm in width, and are separated by a web of about 0.3 mm in width.
[0068] In use, the cover will, when mounted on a scope tip, generally be in a slightly radially expanded configuration, which enhances grip of the cover on the device. In that configuration, the spacing between the base portion 13 and the nearest part of tubular member 2 will be reduced as compared with that shown in the drawings. It may even be possible for the base portion 13 to be in contact with the tubular member 2, provided that the contact does not impede forward pivoting of the projecting element or interaction of the detent 20 with the protuberance 23. The application and removal of the cover 1 to a scoping device is facilitated by stretching of the proximal region of the tubular member 2, where the structure of outer ridges 9, webs 27 and the inclined web portions 26 enhances resilient radial deformation of the tubular member 2. In practice, that is advantageous in that, if the cover is placed on a relatively large-diameter scoping device, the rib pairs 9′ 9″ are able to pull apart and open up preferentially deforming to maintain the integrity and function of the mountings of the projecting elements and the interaction of the base portion of the projecting elements with the adjacent portions of the tubular member 2. However, the cover is equally usable on a scoping device of relatively small diameter—the rib pairs 9′, 9″ and intervening web 27 do not need to deform to maintain the integrity and function of the mountings of the projecting elements and the interaction of the base portion of the projecting elements with the adjacent portions of the tubular member 2. Whilst the embodiment described has two parallel ribs 9′, 9″ defining intervening web 27 it will be appreciated that other structures that focus stretching at regions circumferentially spaced from the mountings of the projecting elements are also possible.
[0069] With reference to FIGS. 8 to 10, there is shown an enteroscope cover 101 suitable for mounting over the tip of an enteroscope. The enteroscope cover 101 is of generally similar structure to the sigmoidoscope cover 1. In the cover 101, however, the structure of the projecting elements differs, being somewhat shorter than those of the cover of FIG. 1. Otherwise, the features of the cover 101 are essentially the same as corresponding features of cover 1 as described above and are indicated by the same reference numerals. Although not visible in the drawings, the projecting elements 103 may be slightly wider than those of the cover 1 as well as being slightly shorter. With the exception of the projecting elements, suitable dimensions for the cover 101 may be the same as, or similar to, those for cover 1. The dimensions of the cover can readily be adapted for use with colonsocopes, gastroscopes, and any other type of endoscope.
[0070] As previously mentioned, the sigmoidoscope cover of FIGS. 1 to 7 or the enteroscope cover of 8 to 10 is formed of a resiliently deformable material. In the embodiments described in FIGS. 1 to 10, the covers were made of a thermoplastic elastomer, for example Cawiton PR10942E (trade mark), a styrene-ethylene butylene styrene block copolymer of Shore A hardness 46 available from Wittenburg B.V. and suitable for medical use. The covers can be made by any suitable process, with injection moulding being one suitable process for many of the suitable materials. Methods of injection moulding suitable polymers are well-known and widely practised in the art.
[0071] In use of the cover devices of the invention, advantageous control of the forward movement of the arms is achieved, as illustrated in FIGS. 11 and 12 and with reference to FIGS. 13 and 14. FIG. 11 shows the cover of FIGS. 1 to 7 in the rest position. In practice, it is usual for a scoping device for visualisation of a part of the gastrointestinal system to be advanced relatively quickly through the cavity to be examined until the furthest point requiring examination is reached. The device is then withdrawn more slowly with most of the visual examination being carried out during withdrawal. Since the cover preferably surrounds the tip of the scope very close to the lens system, the clinician's field of view primarily includes the region in front of the distal end 6 of the cover. As the device is withdrawn, the projecting elements encounter structures on the wall of the cavity being examined, such as colonic folds 201 in the case of colonoscopy, and/or encounter bends 202 in the cavity walls (see FIGS. 13 and 14). The relative movement of the scope with reference to those features of the cavity during withdrawal results in the application of a force on the projecting elements tending to push them towards the distal direction with reference to the rest of the cover 1. The projecting elements 3 are able to pivot relatively freely until the contact region 21 of the detent 20 impacts on the tubular member 2 at protuberance 23. As the cover is formed of a resiliently deformable material, the protuberance provides some resistance to further forward movement of the base portion 13 whilst not completely preventing some further forward movement. The movement of the arm 14 is, however, unimpeded, so that further deformation occurs preferentially at intermediate portion 15 and tip portion 16. As a result the projecting elements are able to open up structures for examination whilst minimising any tendency for the free ends 17 to contact the distal edge of the tubular member 2 or to fold over closely against the distal tip of the scope thereby disproportionately and undesirably obstructing the field of view of the scope. The distal edge 6 is bevelled and that further reduces the tendency for undesired contact between the distal edge and the projecting elements.
[0072] More specifically, on withdrawal, the projecting elements, acted on by the cavity wall, are urged towards the distal direction. That results initially in relatively free movement towards the distal direction as the base portion is pivoted through a first proximal angular range. However, once the detent 20 reaches a position where it is in contact with the contact region 21 at protuberance 23, the deformation or bending of the intermediate and distal portions of the projecting elements assumes greater importance as further pivoting of the base portion at the mountings is resisted as a result of the contact between the detent 20 and protuberance 23 and relies on deformation or compression of one or both of detent 20 and protuberance 23. However, further distal deflection is still able to occur through bending or deformation of the projecting elements 3 themselves.
[0073] Use of a cover of the invention is illustrated with reference to FIGS. 13 and 14 in which colonoscopy is referred to by way of illustration. The distal end tip 200 of the medical scoping device comprises a channel through which a light source, image relaying mean and air suction are supplied. The medical scoping device distal tip 200 with the cover 1 is inserted via the anus into the colon of an individual under investigation. On inserting the medical scoping device with cover into the patient the projecting elements 3 are moved from an at rest position to a second position (referred to herein as a proximal position) where they are flattened towards the medical scoping device shaft. During intubation, the projecting elements 3 are designed to collapse into the channels 10 during insertion through the anus. This exposes a smooth low friction surface of the cover to the mucosa to aid intubation.
[0074] The flexible shaft of the medical scoping device 200 is advanced in a distal direction through the colon towards the bend or loop region of the colon (FIG. 14) whilst insufflating the colon immediately forwards of the distal tip of the scoping device 200. The projecting elements once passed the anus revert to their resting first position. As the scope passes further up the colon and encounters the loop region the projecting elements engage with the colon wall in a soft grip (where the projecting elements can fan out and the endoscopist can perform a controlled proximal withdrawal flattening the colonic folds for good visualisation). The projecting elements 3, 103 of the cover of the present invention act to gently open and flatten the colonic folds for inspection during withdrawal.
[0075] In that manner, the projecting elements can be used to straighten out loops in the colon for more thorough examination and/or reduce the need for acute tip deflection and/or open out structures such as folds for examination. In accordance with the present invention these objectives are achievable with improved visualisation through reducing encroachment of the projecting elements into the field of vision. Improved visualisation is important for identifying small pre-malignant and malignant lesions that can be hidden or difficult to view when performing conventional endoscopy.
[0076] The projecting elements of the cover also serve to gently stabilise the tip of the scoping device within the lumen of the colon or small intestine immediately prior to and during therapeutic procedures. This has the advantage of permitting the endoscopist the reassurance that the tip will remain in position from the stage of visualising a lesion or polyp until completion of the therapeutic procedure.
[0077] In use, the projecting elements are designed to pivot forwards so that they become flared outwards on withdrawal. They keep the instrument tip in the central part of the bowel lumen as the instrument moves backwards, gently holding the mucosa to prevent the tip from flipping backwards, they maintain position during therapy and improve all-round visualisation, whilst the possibility of obstruction of the main field of vision in front of the scope tip by one or more projecting elements is reduced.
[0078] On withdrawing the scope especially through the anus the projecting elements are able, notwithstanding the limitation on movement of the base portion of the projecting elements, to be moved into a forward position. This is achievable as a result of the flexibility of the arm comprising the intermediate portion 15 and tip portion 16, which permit bending at the intermediate portion and distal portion such that the arm is positioned parallel or nearly parallel to the distal direction. With the arms in that position, the scope can be comfortably withdrawn.
[0079] FIG. 15 shows a projecting element 3′ that may be used in a further embodiment of the cover of the invention. Projecting element 3′ is essentially the same as the projecting element 3 as described with reference to FIGS. 1 to 12 above. However, the upper distal surface is provided with a measurement scale 28 comprising four spaced elongate ridges. The measurement scale as shown extends along at least a part of said projecting element in a direction from the base portion towards the distal tip portion of the projecting element. Whilst the measurement scale 28 is shown in FIG. 15 as comprising four spaced elongate ridges it will be appreciated that the measurement scale may be of any suitable form (for example printed) and may extend in a different direction. FIG. 16 shows a distal portion of the cover when in use. The projecting elements 3′ are in a measuring, position, in which the free ends are deflected into the field of view. Since the distal pivoting of the base portion of the projecting elements is limited to, for example about 140° relative to the proximal direction, the deflection of the projecting elements into the field of view is achieve at least in part through bending of the intermediate and distal portions of the projecting element. The projecting elements 3′ are shown schematically in FIGS. 16 and 17 as being deflected distally with their tips including measurement scales 28 deflected radially inwardly beyond the distal edge of the tubular member. With reference to FIG. 17, which is a section along line A-A in FIG. 16, when the projecting elements are in that position, the measurement scales 28 are comfortably within the field of vision of a scoping device visualisation system in which visualisation takes place from the distal end of the scoping tip portion positioned in the axial channel 18. However, any tendency of the tips of the projecting elements 3′ with measurement scales 28 to collapse towards the distal tip surface of the scope is reduced as a result of the limitation on distal pivoting provided by the interaction of the detent 20 and contact region 21 (not visible in FIG. 16). Whilst the measurement scale can be visualised when the projecting elements 3′ are inclined at no more than 180°, for example no more than 160° or 140° relative to the proximal direction, visualisation and accuracy of measurement may be further enhanced when the projecting element is deflected further, as shown in FIGS. 16 and 17.
[0080] In FIGS. 16 and 17 and also in each of FIGS. 11 and 12 respectivaly, for ease of illustration, the cover device is shown with all projecting elements deflected distally to the same extent. In practice, it is possible for the degree of distal deflection to be different in different projecting elements 3, 3′, for example according to the proximity to, and local configuration of, the cavity wall. If desired, the distal tip carrying the cover may be so manoeuvred relative to the colon wall such that one or more of the projecting elements 3, 3′ is intentionally caused to be deflected by a greater amount than other projecting elements 3, 3′.
[0081] Distal deflection of the projecting elements 3, 3′ is a consequence of interaction between the free ends and the surrounding wall regions of the cavity being examined during the withdrawal of the distal tip of the scope through the body cavity. Radial inward deflection may be induced for one or more of the projecting elements 3, 3′ by means of manoeuvring the endoscope relative to adjacent structures within the cavity being examined, for example, by controlling the position and motion of the distal tip portion 200 remotely such that one or more said projecting elements contacts a wall region of the cavity, the relative movement of the distal tip of the scope 200 and the cavity wall serving to deflect the projecting element(s) 3, 3′. In the embodiment of FIGS. 16 and 17, each of the projecting elements 3′ is provided with its own measuring scale 28. Whilst in principle the invention includes devices in which a single measuring scale is provided on one of a plurality of projecting elements, providing measuring scales on all projecting elements enables measurement to be carried out with any projecting element 3′ so that the device can readily be used to measure a polyp at any angular location of the inner wall of the body cavity without the need for significant pivoting of the endoscope tip to bring a single measurement scale into a suitable angular location. Embodiments having a measurement scale advantageously enable assessment of the size of an anatomical abnormality in an elongate body cavity, which abnormality may at least in part be visually obscured by a movable obstruction. In practice this may be achieved by advancing towards said abnormality a scoping device 200 having a distal tip portion comprising the cover, if necessary manoeuvring the distal tip portion such that one or more of the projecting elements 3′ contacts said movable obstruction so as to move said obstruction relative to said abnormality to be assessed; further manoeuvring said distal tip portion such that a said projecting element is positioned adjacent to said abnormality; assessing a dimension of said abnormality by comparison of said object with a said measurement scale 28 on the adjacent projecting element; and optionally surgically removing said abnormality.
[0082] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.
