Medical instruments

Abstract

An endoscopic instrument comprises a handle, an imaging probe extending distally from the handle and a tubular drape for surrounding the handle. Where the handle is non-sterile, the drape, the probe and the seal together form a sterile barrier around the handle. The drape comprises a drape ring that surrounds the handle and a seal acts between the drape ring and the probe. The probe can be turned about a longitudinal axis relative to the drape. The probe is attached to and can be turned with an inner part of the handle with respect to an outer sleeve of the handle. A sleeve angle sensor senses an angle of rotation or pivoting of the inner part relative to the outer sleeve, whereby a processor responsive to the sleeve angle sensor can counter-rotate a displayed image in accordance with the sensed angle.

Description

[0001] Medical instruments

[0002] This disclosure relates to medical instruments that have a camera or imager allowing a subject to be viewed on a video display such as a computer monitor.

[0003] As in the Applicant’s prior PCT patent application published as WO 2022 / 157393, this disclosure exemplifies medical instruments as scopes such as endoscopes or otoscopes for use when examining and performing surgery on ears. However, such instruments can also be used in other clinical applications such as ear, nose and throat (ENT) procedures, arthroscopy, laparoscopy, endoscopic neurosurgery and urology.

[0004] Effective access and visualisation are key to safe surgical procedures. In this respect, traditional ear surgery employing microscopic visualisation suffers from the disadvantage of a narrow field of view looking down into the ear canal. As a result, there can be poor visualisation of disease in the middle ear in regions that are difficult to access, such as the sinus tympani and facial recess. Whilst trans-canal surgery may be performed through a speculum by using a microscope and specialised surgical instruments, this again suffers from a narrow field of view. Thus, to improve the field of view, it is often necessary to expose the middle ear and attic area by performing a mastoidectomy. However, as the ears are surrounded by dense bone, mastoidectomy procedures are associated with increased operating times, potentially significant complications, longer hospital stays and protracted recovery.

[0005] Another disadvantage of microscopic visualisation in ear surgery is the substantial size of a surgical microscope. This compromises the surgeon’s dexterity, restricts the space available for surgical intervention and may have negative ergonomic consequences for the surgeon when using the microscope.

[0006] Given the drawbacks of microscopic visualisation, endoscopic ear surgery has become a growing clinical speciality. In comparison to a surgical microscope, an endoscope offers improved visibility and allows less invasive surgery. However, the ear presents particular challenges to the use of an endoscope, with a requirement for the imagesensing part of the endoscope to be as small as possible while maintaining image quality and allowing multiple angles of view.

[0007] More generally, there is a need to provide a panoramic endoscope for ear surgery that is compact, reliable and easy to keep clean in use and that provides effective visualisation. Embodiments described herein disclose endoscopes that have an imaging system integrated into a rotating or pivoting imaging head of an elongate probe to enable multiple angles of view.

[0008] Challenges arise from the ability to pivot an imaging head relative to the shaft of a probe or to rotate or pan the imaging head around the longitudinal axis of a probe. For example, the resulting image may not match a user’s perception of the field of view and so can disorient a user lacking a visual reference. Also, rotating the probe about its longitudinal axis by turning a handle attached to the probe could be undesirable if it requires a change of grip or displaces control elements on the handle from their expected positions.

[0009] Another challenge relates to cleaning, especially to keeping an imaging lens or window of the imaging head clean in use, as tissue or other contaminants adhering to the lens or window can obscure vision. Consequently, the endoscope may have to be removed from a subject’s ear canal repeatedly during surgery for cleaning. This interrupts and prolongs the surgical procedure and increases the risk of errors or inadvertent injury to the patient.

[0010] Further, as existing post-operative sterilisation processes cannot remove certain types of contamination, such as prions, the World Health Organisation recommends that all instruments used in surgery are discarded after surgery and so are of single-use design wherever possible. However, to reduce cost and waste, it is desirable to divide medical instruments into single-use components, such as a probe that enters the ear canal, and multi-use components, such as a handle that supports and actuates the probe. It is particularly desirable that single-use components are as simple, compact and inexpensive as possible. Also, it is necessary to maintain effective segregation between sterile components and non-sterile components of such instruments. This specification therefore discloses solutions for removably attaching and deploying a sterile drape that is deployable over a reusable handle, which may be non-sterile.

[0011] This specification describes endoscopes with both a 360° probe and a probe with two discrete positions, meaning that the former has an imaging head that can rotate through 360° whereas the latter has an imaging head that can pivot through a lesser angular range of, for example, nominally 0° to 45° although other angular ranges are possible. The probe with two discrete positions, exemplified as a 0° to 45° probe, provides variable angle functionality in two steps or optionally more than two steps or steplessly over its entire angle range, and could include a self-cleaning function.

[0012] Some endoscope systems described herein have detachable and interchangeable probes that, respectively, provide 360° and 0° to 45° functionality. Coupling mechanisms provide for convenient attachment of a probe to a handle and simple but foolproof release to avoid unintended separation of the probe from the handle. There is also a need to provide for mechanical, electrical and / or photonics interfaces between a handle and a detachable probe, while maintaining an effective seal between the sterile probe and a non-sterile handle.

[0013] Against this background, the invention resides in an endoscopic instrument that comprises: a handle; an imaging probe extending distally from the handle; a tubular drape for surrounding the handle, which may be releasably attached to a distal end of the handle; and a seal acting between the drape and the probe.

[0014] If the handle of the instrument is non-sterile, it must be surrounded by a sterile barrier. The drape, the probe and the seal can together form a sterile barrier around the handle. More specifically, the sterile barrier has four elements, namely: a drape surrounding the outside of the handle; a sterile probe capping the distal end of the handle; a seal or seals, integral to the probe, which allow mechanical movement driven through the handle / probe interface without compromising the sterile barrier of the probe, hence preventing fluids or other materials travelling within the probe and reaching the handle / probe interface; and a seal between the drape and the probe that completes the sterile barrier and optionally allows at least an outer part of the handle and the probe to turn relative to each other. In this way, fluids or other materials are prevented from traversing from the sterile to non-sterile parts of the device, or vice versa, thereby maintaining the sterile field.

[0015] The drape may comprise a drape ring that surrounds the handle, in which case the seal can act between the drape ring and the probe. The drape ring can be in fixed angular relation to the handle. For example, the drape ring and the handle may comprise complementary formations that are inter-engageable to lock the drape ring against rotation around the handle. The seal can be attached to the probe to act against the drape ring or can be attached to the drape ring to act against the probe. The seal can act longitudinally and / or radially against the probe and / or the drape ring.

[0016] The probe can be turned about a longitudinal axis relative to the drape, in which case the seal may be in sliding contact with the probe and / or with the drape. More particularly, the handle may comprise an outer sleeve and an inner part that can be turned with respect to the outer sleeve. In that case, the probe can be attached to and turned with the inner part of the handle with respect to the outer sleeve.

[0017] Conveniently, the seal and the probe can together seal a distal end interface of the handle. The seal can encircle a coupling interface between the handle and the probe and can also encircle mechanical, electrical and / or photonics interfaces between the handle and the probe. The probe may also comprise a probe seal for blocking migration of fluids or other materials through and along the probe, to or from the handle.

[0018] The drape may comprise a relatively narrow distal portion and a relatively wide proximal portion, optionally conjoined by a distally-tapering intermediate section between the distal portion and the proximal portion.

[0019] The drape can be stored in a compact configuration radially outboard of the handle and can be deployed from the compact configuration by proximal movement of the stored drape along the handle. The proximal portion of the drape can be stored in a more compacted form than the distal portion of the drape. The stored drape may be separated from the handle by a tubular wall that is movable axially relative to the handle.

[0020] More generally, a drape assembly of the invention comprises: an inner ring; and a tubular drape stored in a compact configuration radially outboard of the inner ring; wherein the stored drape is movable axially relative to the inner ring to deploy the drape from the compact configuration.

[0021] The stored drape can be separated from the inner ring by a tubular wall that is disposed radially outboard of the inner ring and that is movable axially relative to the inner ring. For example, the drape can be stored in an annular compartment disposed radially outboard of the inner ring, the tubular wall being an inner wall of that compartment. The proximal portion of the drape can be stored outboard of the tubular wall and the distal portion of the drape can be stored in a radial gap between the inner ring and the tubular wall. The drape can exit the radial gap and enter the annular compartment on a distal side of the annular compartment.

[0022] A removable barrier can close a lumen of the inner ring. The inner ring may have a stepped distal circumferential profile defining at least one circumferential sealing seat that faces distally and / or radially inwardly.

[0023] The invention also embraces an endoscopic instrument comprising a drape assembly of the invention in combination with a handle and an imaging probe extending distally from the handle. Conveniently, attachment of the probe to the handle effects a seal between the probe and the inner ring of the drape assembly.

[0024] The inner ring can be releasably attached to the handle. For example, the inner ring and the handle may comprise complementary formations that can engage to lock the inner ring against rotation around the handle.

[0025] Correspondingly, a method of deploying a tubular drape over a handle of an endoscopic instrument comprises moving the drape in a compact stored configuration proximally along and around the handle to deploy the drape from the stored configuration, a distal end of the drape being anchored to a distal end of the handle, for example by an inner ring that surrounds the handle and is sealed to the drape.

[0026] An imaging probe can be attached to the distal end of the handle, conveniently after deploying the drape, for which purpose the inner ring can be attached to the handle before deploying the drape. A lumen of the inner ring may be closed temporarily by a barrier such as a cap or a membrane during deployment of the drape, which barrier can be removed from the inner ring after deployment of the drape to allow the probe to be attached to the handle through the open lumen of the inner ring. A seal can then be effected between the imaging probe and the inner ring by attaching the imaging probe to the distal end of the handle. After use, the imaging probe can subsequently be removed from the handle before the drape and the inner ring is removed from the handle.

[0027] Where the handle comprises an inner part disposed within and movable relative to an outer sleeve, the invention embraces a handle for an endoscopic instrument, the handle comprising: an outer sleeve; an inner part disposed within the outer sleeve and rotatable or pivotable about a longitudinal axis relative to the outer sleeve, the inner part having a distal interface configured for attachment of an imaging probe to the handle; and a sleeve angle sensor for sensing a rotation angle or pivot angle of the inner part relative to the outer sleeve about the longitudinal axis.

[0028] The outer sleeve may comprise at least one control element that can be depressed to operate electronics carried by the inner part of the handle. In that case, the inner part may carry at least one pair of conductors that extend circumferentially in alignment with the or each control element to be connected electrically by depressing the or each control element.

[0029] At least two control elements may be disposed in mutually offset longitudinal positions along the outer sleeve of the handle, in which case the inner part of the handle can carry at least two pairs of conductors in mutually offset positions along the inner part, each of the pairs of conductors being in alignment with a respective one of the control elements.

[0030] Two control elements could be respective ends of a rocker. A fulcrum under the rocker may prevent simultaneous electrical connection of both of the conductor pairs aligned with the respective ends of the rocker. The or each control element can be surrounded by an elastic gaiter and can be depressed against resilient bias of the elastic gaiter.

[0031] The sleeve angle sensor can be a rotary sensor whose rotation is driven by relative angular movement between the inner part and the outer sleeve. For example, the sleeve angle sensor may comprise a potentiometer. Rotation of the sleeve angle sensor may be driven by a pinion gear on the inner part engaged with a rack formation within the outer sleeve. Alternatively, the sleeve angle sensor can be an optical sensor comprising an emitter and a detector opposed to a visual indicator or pattern that is characteristic of angular position around the longitudinal axis.

[0032] Correspondingly, an endoscope system of the invention comprises: an endoscopic instrument including a handle of the invention; a processor that is responsive to the sleeve angle sensor to counter-rotate an image in accordance with the sensed rotation angle or pivot angle, that image being generated by an imaging probe attached to the inner part of the handle; and a display for displaying the counter-rotated image which may thereby have corrected or improved orientation. A related method of operating an endoscopic instrument comprises: rotating or pivoting an imaging probe, and an inner part of a handle to which the imaging probe is attached, relative to an outer sleeve of the handle about a longitudinal axis; and sensing a rotation angle or pivot angle of the inner part relative to the outer sleeve about the longitudinal axis. In accordance with the sensed rotation angle or pivot angle, an image generated by the imaging probe can be counter-rotated and displayed. The sensed pivot angle can be displayed in addition to the counter-rotated image.

[0033] The invention also provides an imaging probe for an endoscopic instrument, the probe comprising: an elongate probe shaft having a longitudinal axis; an imaging head that is pivotable about a pivot axis transverse to the longitudinal axis; and an angulation mechanism that is connected to the imaging head by a link extending within the probe shaft, the link being movable longitudinally to pivot the imaging head about the pivot axis. For example, longitudinal movement of the link can pivot the imaging head by a crank action acting about the pivot axis. The shaft can also contain optical fibres and / or a flexible PCB connected to the imaging head that bend in response to pivoting of the imaging head.

[0034] The angulation mechanism may comprise a cam shaft having a cam profile that acts on an armature fixed to or integral with the link and that is arranged to effect longitudinal movement of the armature and the link in response to rotation of the cam shaft. The cam shaft can turn about an axis that is substantially parallel to the longitudinal axis of the probe shaft. A probe seal around the cam shaft and / or the armature can be arranged to block migration of fluids or other materials through the probe.

[0035] The armature may be biased toward the cam profile by a spring acting between the armature and a structure of the probe, which spring may bias the armature into contact with the cam profile. The cam profile can act on the armature via a cam follower that is biased into contact with the cam profile by a spring acting between the armature and the cam follower.

[0036] A proximal coupling of the cam shaft may be exposed at a proximal end interface of the probe. The proximal coupling can comprise a circumferentially-extending alignment ramp that terminates in an interlocking formation. An endoscopic instrument may comprise an imaging probe of the invention and a handle to which the imaging probe can be attached, the handle containing a rotary drive that comprises a drive shaft engageable with the cam shaft of the imaging probe. The drive shaft can turn about an axis that is substantially parallel to the longitudinal axis of the probe shaft.

[0037] A distal coupling of the drive shaft may be exposed at a distal end interface of the handle. The distal coupling may comprise a circumferentially-extending alignment ramp that terminates in an interlocking formation.

[0038] At least one angular position sensor may be disposed beside the drive shaft. The angular position sensor could, for example, comprise a pair of microswitches angularly spaced about the drive shaft, in which case the drive shaft could carry a lobe that is movable by rotation of the drive shaft into actuating contact with the respective microswitches.

[0039] The angular position sensor may instead comprise at least one Hall-effect sensor, in which case the drive shaft can carry a least one magnet that is movable into signaltriggering alignment with the at least one Hall-effect sensor. The angular position sensor can instead comprise an optical sensor comprising an emitter and a detector opposed to a visual indicator or pattern that is characteristic of angular position around the longitudinal axis.

[0040] The instrument may include, or be combined with, a processor that is responsive to the or each angular position sensor to drive a display that shows the sensed angular position.

[0041] A related method of pivoting an imaging head of an endoscopic instrument relative to an elongate probe shaft of the instrument may comprise effecting longitudinal movement of a link that extends along the probe shaft to the imaging head, that movement of the link pivoting the imaging head about a pivot axis transverse to a longitudinal axis of the probe shaft.

[0042] Longitudinal movement of the link may be effected by turning a cam shaft within the probe, for example by turning a drive shaft coupled to the cam shaft, the drive shaft being implemented in a handle that is removably coupled to the probe. Conveniently, interlocking formations of the cam shaft and the drive shaft can self-align upon coupling the handle to the probe. The angular position of the drive shaft relative to the handle can be sensed, and the sensed angular position can be displayed in addition to an image generated by the imaging head.

[0043] A handle of an endoscopic instrument may comprise: a distally-opening passage in a distal end of the handle for receiving a proximally-extending shank of a probe; and a mechanism for releasably attaching the probe to the handle via the shank, wherein the mechanism comprises: at least one pin that is biased toward the passage to protrude into the passage for engaging the shank; and an armature that is movable distally within the handle and has at least one inclined cam surface arranged to bear against a correspondingly inclined surface of the at least one pin to push the pin away from the passage against the bias. The armature can be moved distally under the action of a release button at a proximal end of the handle, for example encircling a cable that extends proximally from the handle.

[0044] An imaging probe for an endoscopic instrument may comprise: an elongate probe shaft having a longitudinal axis; an imaging head that is pivotable about a pivot axis transverse to the longitudinal axis; a flushing channel extending along the probe shaft for conveying a flow of a flushing fluid toward the imaging head; and a diverter surface opposed to a distal end of the flushing channel for diverting the flow of the flushing fluid onto the imaging head. The imaging head may be pivotable to orient a lens or window of the imaging head toward the diverter surface.

[0045] Where an angulation link extends within the probe shaft, the link being movable longitudinally to pivot the imaging head about the pivot axis by a crank action or otherwise, the diverter surface may be movable longitudinally with the angulation link relative to the pivot axis. The diverter surface could instead be fixed to the probe shaft.

[0046] An endoscopic instrument may comprise the imaging probe and a handle to which the imaging probe can be attached, the handle comprising a flushing control element that is operable to start or stop the flow of the flushing fluid toward the imaging head.

[0047] An imaging probe for an endoscopic instrument may comprise: an imaging head including an imager such as a camera; a coupling interface for coupling the probe to a handle of the instrument; a mechanical interface for conveying drive from the handle to move the imaging head relative to a shaft of the probe; a power interface for conveying power from the handle to the imager; and a data interface for conveying image data from the imager to the handle. An electronic interface can implement the power interface and / or the data interface and can communicate with the imager via a power and control data interface.

[0048] A first photonics interface may be configured to convey illuminating light to the imaging head from a light source external to the probe. There may also be a second photonics interface, which can be configured to convey illuminating light to the imaging head from a light source external to the probe.

[0049] A light guide interface can communicate with the first and second photonics interfaces, the light guide interface being configured to convey the illuminating light from the first photonics interface to the imaging head and to convey the image data from the imager to the second photonics interface, whereby the second photonics interface implements the data interface.

[0050] A light guide interface can communicate with the first photonics interface, the light guide interface being configured to convey the illuminating light from the first photonics interface to the imaging head and to convey the image data from the imager to a data transceiver communicating with the electronic interface, whereby the electronic interface implements the data interface.

[0051] A handle for an endoscopic instrument may comprise: a coupling interface for coupling the handle to a probe of the instrument; a mechanical interface for conveying drive to the probe; a power interface for conveying power to the probe; and a data interface for receiving image data from the probe. The handle may further comprise a first photonics interface configured to convey illuminating light to the probe. The handle may comprise a source of the illuminating light or may be configured to convey the illuminating light from a source external to the handle.

[0052] The handle may further comprise a second photonics interface. The second photonics interface can also be configured to convey illuminating light to the probe. For example, the first photonics interface may be connected to a source of visible light and the second photonics interface may be connected to a source of infrared light.

[0053] The second photonics interface may instead be connected to a data transceiver to receive the image data from the probe, whereby the second photonics interface can implement the data interface. Nevertheless, an electronic interface can implement the power interface and / or the data interface.

[0054] A probe for an endoscopic instrument may comprise: a proximal interface for attachment to a handle; an elongate shaft; and a grip formation disposed between the proximal interface and the shaft, the grip formation comprising: a distal nose cone adjoining a proximal end of the shaft; a grip ring disposed proximally of the nose cone and having a diameter greater than a diameter of the nose cone; and a shank disposed proximally of the grip ring and having a diameter less than the diameter of the grip ring.

[0055] The proximal interface may have a diameter greater than the diameter of the grip ring. The diameter of the shank may be greater than the diameter of the nose cone.

[0056] A distally-facing distal ledge may extend between the nose cone and the grip ring. A proximally-tapering surface may extend between the grip ring and the shank. A distally- facing proximal ledge may extend between the shank and the proximal interface.

[0057] An endoscope system of the invention may comprise an endoscopic instrument of the invention and a camera control system, and may further comprise a display. The camera control system may comprise a source of illuminating light.

[0058] In order that the invention can be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which:

[0059] Figure 1 is a perspective view of an endoscope comprising a single-use probe;

[0060] Figure 2 is a perspective view of an endoscope system including an endoscope that comprises an endoscope handle with interchangeable single-use probes, shown in exploded view;

[0061] Figure 3 is an enlarged detail side view of the endoscope of Figure 2, showing a distal end of the endoscope handle and a proximal end of a probe coupled to the handle;

[0062] Figures 4a and 4b are schematic side views showing how the endoscope of Figure 3 is apt to be held by differently-sized hands; Figures 5a and 5b are schematic side views, in longitudinal section, showing how a probe can be coupled to and released from an endoscope handle;

[0063] Figures 6a and 6b are side views of an endoscope, with Figure 6b showing the probe rotated relative to the handle;

[0064] Figures 7a and 7b are cross sections through the handle of the endoscope shown in Figures 6a and 6b respectively, those cross sections being on lines A- A and B-B of Figures 6a and 6b;

[0065] Figures 8a and 8b are cross sections through the handle of the endoscope shown in Figures 6a and 6b respectively, those cross sections being on line A-A of Figures 6a and 6b;

[0066] Figures 9a, 9b and 9c are schematic views of a human computer interface of an endoscope system accompanied by corresponding perspective views of an endoscope probe, the interface displaying orientations of the probe and viewing angles of an imaging head of the probe;

[0067] Figure 10 is a side view of an endoscope;

[0068] Figure 11 is a cross section through the handle of the endoscope shown in Figure 10, that cross section being on line C-C of Figure 9;

[0069] Figure 12 is an enlarged detail side view of the handle of the endoscope shown in Figure 10, with an outer sleeve of the handle being shown in longitudinal section;

[0070] Figure 13 is an enlarged detail side view of a rocker, being a control element on the handle of the endoscope shown in Figure 10;

[0071] Figures 14a and 14b are enlarged detail side views, in longitudinal section, showing a distal end of an endoscope handle and a proximal end of a probe coupled to the handle, further showing a mechanism for adjusting the viewing angle of a distal head of the probe; Figures 15a and 15b are enlarged detail side views, in longitudinal section, showing a proximal end of a probe containing another mechanism for adjusting the viewing angle of a distal head of the probe;

[0072] Figure 16 is an enlarged detail perspective view of the interior of a probe;

[0073] Figure 17 is a perspective view of a distal end of an endoscope handle and a proximal end of a probe to be coupled to the handle, showing mechanical, electrical and photonics interfaces between the handle and the probe;

[0074] Figure 18 is an end view of a proximal end of a probe, showing an additional photonics interface;

[0075] Figure 19 is a perspective view of a mechanical interface between a drive shaft of a handle and a cam shaft of a probe;

[0076] Figures 20a to 23 are perspective views of various sensing arrangements for determining angular displacement of a motor that drives the mechanism of Figures 15a and 15b;

[0077] Figures 24 and 24b are perspective views, and Figure 24c is an end view corresponding to Figure 24a, showing a distal imaging head of a probe at different viewing angles;

[0078] Figures 25a and 25b are enlarged detail side views, in longitudinal section, showing a linkage within a probe for adjusting the viewing angle of a distal imaging head;

[0079] Figures 26a and 26b correspond to Figures 25a and 25b but show a flushing arrangement for cleaning a lens or window of the imaging head;

[0080] Figures 27a and 27b are enlarged detail side views, in longitudinal section, showing a fibre bundle connection extending within a probe to a distal imaging head;

[0081] Figures 28a and 28b correspond to Figures 27a and 27b but show a flexible PCB connection extending within a probe to a distal imaging head; Figure 29 is an enlarged detail perspective view of the distal end of a probe, showing a pivot arrangement that mounts an imaging head to a shaft of the probe;

[0082] Figures 30 to 36 are block diagrams of various endoscope systems;

[0083] Figures 37 and 38 are schematic side views, in longitudinal section, of different drape cassettes that are attachable to an endoscope;

[0084] Figures 39a to 39d show the drape cassette of Figure 37 being used to deploy a drape over the handle of an endoscope; and

[0085] Figures 40 to 43 are enlarged detail side views, in longitudinal section, showing sealing arrangements between a handle and a probe of an endoscope.

[0086] Figure 1 shows an endoscope 10 that comprises a single-use sterile elongate probe 24 coupled to a reusable handle 34, which can therefore be non-sterile. As will be explained below, the handle 34 can be covered with a drape 347 to provide a sterile barrier. Optionally, the handle 34 could be sterilised after use by autoclaving or by chemical immersion.

[0087] The probe 24 comprises an elongate shaft 23, whose nominal diameter may be 3.5mm or less, or 6.5mm or less, and a distally-tapering proximal cone 22 adjoining a proximal end of the shaft 23. As will be explained, the probe 24 has a variable-angle imaging head 26 at its distal tip, the head 26 comprising an imager such as a camera 230 or other image sensor or image receiver. The viewing angle or viewing axis of the head 26 is adjustable relative to the central longitudinal axis of the probe 24, causing the head 26 to pivot about a pivot axis that is orthogonal to the longitudinal axis of the probe 24.

[0088] In this example, the viewing axis or angle of the head 26 is adjustable between 0° and 45°, the former being aligned with or parallel to the longitudinal axis of the probe 24 and the latter being at an angle of 45° to that axis. This range of adjustment is suitable for simple sinuplasty and for functional endoscopic sinus surgery (FESS). In other examples, the viewing axis or angle of the head 26 can be adjusted through a different angular range, for example through ranges of 30° to 70°, such as 60°. The viewing axis or angle of the head 26 can even be adjusted through 360° to provide panoramic visualisation for complex FESS. In the latter case, the probe 24 is apt to provide for selfcleaning of a lens or window of the head in situ as disclosed in WO 2021 / 013963, which is exclusively licenced to the Applicant, and in WO 2022 / 157393 filed by the Applicant, whose contents are incorporated herein by reference. In any case, adjustment of the viewing angle within a given angular range can be stepwise or continuous.

[0089] A rocker 15 on the handle 34 allows a user to control the viewing angle of the head 26. For example, tilting the rocker 15 back by pressing its proximal end 12 can toggle or change the viewing angle to, or toward, 45° whereas tilting the rocker 15 forward by pressing its distal end 14 can toggle or change the viewing angle to, or toward, 0°.

[0090] The handle 34 of the endoscope 10 has a largely cylindrical outer shape to allow a user to hold the endoscope 10 comfortably in the hand and to turn the probe 24 easily to pan the head 26 around the longitudinal axis of the probe 24, hence increasing the user’s field of view. In this respect, when using the probe 24 with an angle of view oriented other than at 0° to the longitudinal axis, it may be clinically useful to turn the probe 24 around its longitudinal axis to look in different directions within the surgical site. For example, in normal sinus surgery usage, such as when operating on the maxillary sinus, the probe 24 may be turned through 90° to the left or the right, hence clockwise or anticlockwise about the longitudinal axis.

[0091] The handle 34 has a tubular outer sleeve 98 and an inner part 134 that can turn within the outer sleeve 98, with the probe 24, about a longitudinal axis of the handle 34 being a co-linear extension of the longitudinal axis of the probe 24. Thus, the outer sleeve 98 of the handle 34 serves as a horizon orientation datum that allows the user to maintain a visual and tactile reference for ‘up’ by keeping a top surface of the outer sleeve 98 facing upwards while turning the probe 24 about its longitudinal axis. This ‘up’ reference allows the system to maintain a natural horizon, hence preventing user disorientation.

[0092] In this example, there are two additional buttons 16, 32 on the handle 34 and different functions can be assigned to those buttons 16, 32. For example, one button 16 could be a media button 16 that is pressed to take a photograph and / or to stop or start a video and / or to tag a point in a video whereas the other button 32 can be pressed to clean or flush a camera lens 228 or window of the head 26. In this respect, the probe 24 has a Luer connector 20 to allow flushing liquid to flow distally along an internal cannula of the probe 24. The flushing liquid flushes and cleans debris or fluid off the lens 228 or window of the head 26 and off any components within the probe 24 that may be exposed to the flushing liquid.

[0093] Radially-protruding finger scallops 18 at a proximal end of the probe 24 define a fluted profile that helps a user to turn the probe 24 manually about its longitudinal axis relative to the outer sleeve 98 of the handle 34. Fingers of the user’s hand can engage the scallops 18 to turn the probe 24 even when the same hand holds the endoscope 10. As the scallops 18 could impede normal grip if they extended fully around the circumference or longitudinal axis of the probe 24, the scallops 18 are provided only at an upper portion of the probe 24 and so only extend part of the way around the circumference. The scallops 18 are designed not to intrude on the user’s grip when the probe 24 is turned through 90° in either circumferential direction.

[0094] A proximal end of the probe 24 is received telescopically by a distal end of the handle 34, with a male formation of the probe 24 fitting into a female formation of the handle 34. A drape ring 30 of a drape assembly 344 is shown at the junction between the probe 24 and the handle 34, and a circumferential seal 28 is disposed between the probe 24 and the drape ring 30. The drape ring 30, the drape cassette 56 and the seal 28 will be described in detail later.

[0095] Figure 2 shows an endoscope system 36 in which an endoscope handle 34 is connected to a camera control unit (CCU) 58, which drives a medical monitor 38 in turn. The handle 34, the CCU 58 and the monitor 38 are all designed for re-use in multiple medical procedures. In this example, interchangeable probes 50, 52 can be coupled selectively to the handle 34. For example, one probe 50 can have a viewing angle range of 0° to 45°, as before, whereas the other probe 52 can have a different viewing angle of, for example, 360°.

[0096] In this example, the probes 50, 52 do not have scallops like those shown in Figure 1 but instead have knurled twist rings 54 near their proximal ends to help a user to grip and turn the probe 24 about its longitudinal axis relative to the outer sleeve 98 of the handle 34. Also, this example depicts a release button 48 on each twist ring 54. The release button 48 is pressed to unlatch the probe 50, 52 from the handle 34 to allow the probe 50, 52 to be interchanged or discarded at the end of a surgical procedure. Other probe release arrangements are possible; one such arrangement will be described below with reference to Figures 5a and 5b. Again, a drape cassette 56 is disposed at or near the junction between the probe 24 and the handle 34 and a proximal end of the probe 24 is received telescopically by a distal end of the handle 34, with a male formation of the probe 24 fitting into a female formation of the handle 34.

[0097] Referring now also to Figures 3, 4a and 4b, the probes 24 shown in Figures 1 and 2 have proximal nose cone arrangements, or grip formations, that allow the endoscope 10 to be held as comfortably by users with small hands as by users with large hands. In either case, the endoscope 10 is generally held in a modified precision grip with the pads of the little finger and the ring finger in distal positions to provide precision, supported by the thumb at a proximal position and often the index figure helping to grip the endoscope 10 at a proximal position too.

[0098] Figure 3 shows that the grip formation of the probe comprises the aforementioned distally-tapering cone 22 defining a dominant cone shape that flares proximally or extends radially, at an angle of between 60° and 90° to the longitudinal axis of the probe, to an enlarged grip ring, thus forming a distal ledge on the distal side of the grip ring. A reverse cone shape 62 is formed on the proximal side of the grip ring where the shape tapers proximally to a narrow shank 60 that flares proximally or extends radially again to the twist ring 54, corresponding to the fluted scallops of the probe of Figure 1 , at an angle of between 60° and 90° to the longitudinal axis of the probe, thus forming a proximal ledge on the distal side of the twist ring 54.

[0099] By virtue of this grip formation shape, a smaller hand can grip the shank 60 between the thumb and index finger as shown in Figure 4a. Conversely, a larger hand can grip the distal end of the handle 34 between the thumb and the index finger and can place one or more fingers against the shank 60 or the reverse cone shape 62, as shown in Figure 4b, to provide a secure grip without slipping. In each case, the grip formation provides two ledges that flare between different diameters. A user’s finger or fingers can rest against the distal and / or proximal ledges together or individually, allowing a multitude of grip possibilities for hands of different sizes.

[0100] Turning next to Figures 5a and 5b, these drawings show a mechanism 64 being part of a coupling interface for coupling a probe 24 to a handle 34 and subsequently for releasing the probe 24 from the handle 34. In this mechanism 64, a proximal end of the probe 24 has a proximally-extending spigot or shank 76 that has a largely circular cross-section and a rounded, chamfered or otherwise tapered proximal tip 74. The shank 76 has rounded notched cut-outs 83 in mutual opposition in its side wall, close to the proximal tip 74. Alternatively, the notches 83 could be defined by the ends of a transverse through-hole that extends through the shank 76.

[0101] When the probe 24 is being coupled to the handle 34, the shank 76 is inserted into a distally-facing hole or passage 202 in a central distal structure 72 of the handle 34. When the shank 76 is inserted fully into the passage 202, the notches 83 receive respective pins 80 that are disposed in mutual opposition around the passage 202. The pins 80 are biased radially inwardly in mutual opposition by springs 82, 84 that act between the structure 72 and the pins 80, hence being urged into the notches 83 to lock in a snap-fit action as shown in Figure 5a. Conversely, when the shank 76 is being inserted into the passage 202, the rounded proximal tip 74 of the shank 76 presses the pins radially outwardly against the bias of the springs 82, 84 and so allows the shank 76 to be pushed proximally past the pins 80.

[0102] The probe 24 can be released by depressing a release button 66 as shown in Figure 5b. This moves a sliding armature 68 distally within the handle 34 against the bias of a spring 84 that acts between the armature 68 and the structure 72. The armature 68 has inclined cam surfaces 70 that bear against correspondingly inclined surfaces of the pins 80. That interaction pushes the pins 80 radially outwardly to disengage them from the notches 83, hence unlocking the probe 24 for removal from the handle 34.

[0103] Conveniently, the release button 66 may be at a proximal end of the handle 34 as shown, hence requiring a deliberate and conscious release action to mitigate any risk of accidental release of the probe 24. For example, the release button 66 could be defined by a ring protruding from the proximal end of the handle 34, that ring encircling a cable 370 that extends from the proximal end of the handle 34 to connect the handle to the CCU 58.

[0104] If the probe 24 is turned in such a way that the viewing axis of the imaging head 26 departs from an upward inclination, the horizon as viewed through the camera 230 will be inclined at an angle different to what would naturally be expected. This can be disorientating as mentioned above. To solve this, Figures 6a to 7b show more details of the outer sleeve 98 of the handle 34 defining a horizon orientation datum, and how the outer sleeve 98 interacts with a sleeve angle sensor 96 on the inner part 134 of the handle 34. In this example, the sleeve angle sensor 96 is a potentiometer, such as a three-turn, five-turn or ten-turn potentiometer. The potentiometer is operably connected to a pinion gear 94 that is engaged with a circular rack 92 formed on the radially inner side of the outer sleeve 98.

[0105] With the outer sleeve 98 maintained in an upright position by keeping a marker 86 on the handle 34 facing upwardly as shown in Figures 6a and 6b, the probe 24 can be turned through about 175° in either angular direction about the longitudinal axis 90 of the probe 24 as shown in Figure 6b. The rocker 15 or other control elements, such as buttons 16, 32, can also or instead serve as such a marker 86 on the handle 34. An orientation marker 88 on the probe 24 indicates the degree of rotation of the probe 24. To avoid exceeding the angular limits of the potentiometer 96, angular movement of the probe 24 relative to the outer sleeve 98 is limited by an inner stop 102 on the inner part 134 of the handle 34 coming into contact with an outer stop 100 on the outer sleeve 98. The inner stop 102 and the outer stop 100 are shown in Figures 7a and 7b, the latter showing the probe 24 turned through about 30° relative to the outer sleeve 98.

[0106] As the probe 24 turns relative to the outer sleeve 98 as shown in Figure 7b, the pinion wheel 94 is turned by its interaction with the rack 92, hence correspondingly acting on the potentiometer 96. Consequently, the electrical resistance of the potentiometer 96 increases or decreases depending upon the direction and extent of rotation. This change in resistance corresponds to the change in the angle of the probe 24 and so can provide an angular feedback signal to the CCU 58. In response to that signal, software in the CCU 58 rotates the image, in real time, in the opposite direction to the probe 24 by the same angular amount, thus counteracting rotation of the probe 24 to maintain a natural horizon in the image.

[0107] Optionally, the inner stop 102 and the outer stop 100 can be omitted to allow the probe 24 to be turned until the potentiometer 96 reaches its angular limits. Also optionally, other technical solutions can implement the sleeve angle sensor 96. Such solutions could include direct optical monitoring of a pattern on the inner sleeve to provide absolute measurement, optical monitoring of a spoked wheel to calculate angular position, a hall effect sensor, or a digital encoder.

[0108] Figures 8a and 8b exemplify a sleeve angle sensor 96 that employs optical monitoring using an optical sensor 110 mounted on the inner part 134 of the handle 34. The optical sensor 110 comprises an emitter 106 and a detector 104 and is opposed to a strip 106 that extends circumferentially around the interior of the outer sleeve 98. The strip 106 bears a visual indicator or pattern that is characteristic of the longitudinal position along the strip 106 and thus of the angular position around the pivot axis of the outer sleeve 98 where the strip 106 is curved circumferentially around that axis. In this example, the strip 106 bears a visual indicator in the form of a longitudinally-tapering marking. The width or thickness of that marking at a given longitudinal position along the strip 106 is detected by the optical sensor 110 to determine the angular position of the optical sensor 110, and hence the angular position of the inner part 134 relative to the outer sleeve 98 of the handle 34.

[0109] In principle, it would be possible to reverse the arrangement shown in Figures 8a and 8b, with the optical sensor 110 instead being mounted on the outer sleeve 98 of the handle 34 and the strip 106 encircling the inner part 134 of the handle 34.

[0110] Figures 9a, 9b and 9c show a human computer interface (HCI) 112 of an endoscope system 122 and corresponding views 124 of the probe 24 of an endoscope 10 when viewing an object within the field of view of the imaging head 26. These drawings show how the HCI 112, driven by the CCU 58, responds to a sleeve angle sensor 96 and optionally to other sensors in the handle 34, such as an accelerometer 300 or a gyroscope.

[0111] The HCI 112 displays the viewing angle 116 of the imaging head 26 relative to the longitudinal axis of the probe 24, being 0° in Figures 9a and 9c and 45° in Figure 9b. That angle 116 is displayed numerically in this example but could be displayed graphically in other examples, for example as a wheel icon that apparently rotates toward or away from the user as the imaging head 26 pivots relative to the shaft 23 of the probe 24.

[0112] The HCI 112 also displays the angular position of the probe 24 relative to the outer sleeve 98 of the handle 34 about the longitudinal axis of the probe 24, as sensed by the sleeve angle sensor 96. In this example, the relevant angle is displayed to the user by angular displacement of a marker 120 around an image 118 of the field of view of the imaging head 26, as shown by Figure 9c. However, the CCU 58 causes the HCI 112 to rotate the image 118 to keep the image 118 upright, providing more natural visual mapping for the user and giving the user confidence in the displayed view.

[0113] Also shown in the HCI of Figures 9a, 9b and 9c is a tool carousel 114 that allows a user easily to select functions to control using a simple interface. Optionally, the HCI 112 could show a three-dimensional representation of an endoscope 10 to communicate the orientation of the probe 24 and the angle of view of the imaging head 26 relative to the longitudinal axis of the probe 24.

[0114] The control elements on the handle 34, exemplified in Figure 1 by the rocker 15 and additional buttons 16, 32, act on and so must interface with electronic components that are disposed in the inner part 134 of the handle and in the probe 24. This presents a problem because the inner part 134 of the handle 34 turns with the probe 24 relative to the outer sleeve 98 of the handle 34, to which the control elements are mounted. In this respect, it is clearly desirable for the control elements to remain in fixed relation to the exterior of the handle 34 so that they remain in predictable locations, serve as visual markers of orientation and continue to fall naturally to hand, even if the probe 24 is turned about its longitudinal axis. Figures 10 to 12 show how that problem is solved.

[0115] Specifically, Figures 11 and 12 show that the inner part 134 of the handle 34 is encircled by conductor pairs 136, 138 that extend circumferentially. In this example, the conductor pairs 136, 138 are defined on flexible PCBs 132 that wrap around the inner part 134 of the handle 34. The conductor pairs 136, 138 lie in respective planes that are orthogonal to the longitudinal axis and aligned longitudinally with the respective control elements, namely the proximal and distal ends of the rocker 15 and the two additional buttons 16, 32. The rocker 15 and the buttons 16, 32 surmount conductive pads 126 that bridge and hence connect the respective underlying conductor pairs 136, 138 when depressed.

[0116] The conductive pads 126 are biased away from the associated conductor pairs 136, 138 by the resilience of elastic gaiters 130 that surround and lift the rocker 15 and the buttons 16, 32. The gaiters 130 prevent fluid ingress around the rocker 15 and the buttons 16, 32 and also urge the rocker 15 into a central position in which the conductive pads 126 of the rocker 15 do not make contact with either of the associated pairs of conductors 136, 138. Optionally, as shown in Figure 12, a portion of the rocker 15 protrudes between and below the conductive pads 126 to define a fulcrum that prevents both ends of the rocker 15 being depressed at the same time.

[0117] As another option to prevent both ends of a rocker 15 being depressed at the same time, Figure 13 shows that a portion 99 of the outer sleeve 98 can arch or protrude under a rocker 15 to define a sliding surface 101 serving as a virtual fulcrum about which the rocker 15 can rock. Figure 13 also shows an elastic gaiter 130 around the rocker 15, sealed to and bridging between the outer sleeve 98 and the rocker 15. The resilience of the gaiter 130 returns the rocker 15 to its mid point in which neither of the conductive pads 126 beneath the rocker 15 will contact the associated conductor pair.

[0118] Figures 14a to 15b show angulation mechanisms 140, 172 for driving pivotal movement of the imaging head 26 of the probe 24 to a selected viewing angle, hence onto a selected viewing axis. The angulation mechanisms 140, 172 turn rotational movement into a linear push-pull movement that effects angular motion of the imaging head 26. A motor 174 and drive shaft 178 in the handle 34 are mated to the probe 24 via a mechanical interface 144. Angular position is monitored in the handle 34 using various position sensors 176, some examples of which will be described later with reference to Figures 20a to 23.

[0119] The probe comprises an outer tube 166, 192 and an inner tube 164, 190 in sliding telescopic co-axial relation. The outer tube 166, 192 is fixed in position with the nose cone 158, 188 at the proximal end of the probe 24 whereas the inner tube 164, 190 can reciprocate longitudinally within the outer tube 166, 192. Within the nose cone 158, 188, a proximal end portion of the inner tube 164, 190 is received within and fixed to a sleeve or armature 156.

[0120] In the mechanism 140 of Figures 14a and 14b, a nose cone 158 contains a cam shaft 168 that turns about an axis substantially parallel to, and laterally offset from, the central longitudinal axis of the probe 24. The cam shaft 168 has a proximally-facing cam profile 170 that is inclined relative to the axis of rotation. The cam profile 170 is shaped to interact with a sliding armature 154 as the cam shaft 168 turns. For this purpose, the armature 154 has a cam follower 150 extending laterally from its proximal end.

[0121] The armature 154 has a circumferential flange that bears against a compression spring 152 that also acts against an internal wall of the nose cone opposed to the flange. The spring 152 and the wall surround the armature 154, which is a sliding fit within an aperture in the wall. The action of the spring 152 urges the armature 154 and hence the inner tube 164 distally with respect to the outer tube 166 of the probe 24.

[0122] The cam follower 150 bears against the cam profile 170 under the action of the spring 152. Thus, turning the cam shaft 168 causes the cam profile 170 to force the cam follower 150, and hence the armature 154 and an inner tube 164 of the probe 24 attached to the armature 154, in a proximal direction against the bias of the spring 152. As will be explained below, the inner tube 164 of the probe 24 forms part of a linkage that acts on the head 26 to pivot the head 26 in response to longitudinal or axial movement of the inner tube 164.

[0123] When the imaging head 26 is at 0° relative to the central longitudinal axis of the probe 24, corresponding to Figure 14a, the spring 152 pushes the inner tube 164 into a distal position. Conversely, when the spring 152 is compressed by proximal movement of the armature driven by the cam shaft 168, the inner tube 164 moves to the proximal position shown in Figure 14b to move the imaging head 26 to an angle of 45° relative to the central longitudinal axis of the probe 24.

[0124] A proximal end of the cam shaft 168 protrudes from a proximal face of the nose cone 158 to form a mechanical interface 144 or coupling whereby a complementary rotary drive in the handle 34 can control movement of the inner tube 164 and hence of the imaging head 26. Figures 14a and 14b also show photonic 146 and electronic interfaces 148 that convey power and data between the probe 24 and the handle 34. Such interfaces are also shown in Figures 17 and 18, to be described below.

[0125] The probe 24, the nose cone 158 and the various interfaces 144, 146, 148 are configured to form a barrier to prevent any fluid or other material traversing in either direction between the sterile surgical field and the non-sterile handle. Within the probe 24, a sterile barrier between the mechanical interface 144 and the armature 156 is exemplified by a seal 142 around the cam shaft 168.

[0126] In the mechanism 172 of Figures 15a and 15b, the handle 34 is shown as containing a motor 174, a position sensor 176 and a drive shaft 178 that serve as a rotary drive, akin to a rotary drive that could be used with the mechanism 140 of Figures 14a and 14b. The distal end of the drive shaft 178 is exposed at a distal face of the handle 34 to couple with a cam shaft 182 in the nose cone 188 of the probe 24. In this case, the drive shaft 178 has a male profile and the cam shaft 182 has a complementary female profile. Again, the cam shaft 182 turns about an axis substantially parallel to, and laterally offset from, the central longitudinal axis of the probe 24.

[0127] The cam shaft 182 has a proximally-facing cam profile 184 that is inclined relative to the axis of rotation and that is shaped to interact with a sliding armature 194 as the cam shaft 182 turns. The armature 194 is urged distally by the bias of a primary spring 180 that acts against a flange encircling the armature 194. Again, the armature 194 has a cam follower 196 that bears against the cam profile 184 of the cam shaft 182. In this instance, however, the cam follower 196 is not fixed to the armature 194 and is urged distally against the cam profile 184 by the bias of a secondary spring 198 that acts between the cam follower 196 and the flange around the armature 194. The secondary spring 198 ensures that the cam follower 196 is held in sliding contact with the cam profile 184 throughout.

[0128] Turning the cam shaft 182 causes the cam profile 184 to force the cam follower 196 proximally against the bias of the secondary spring 198. This forces the armature 194, and hence the inner tube 190 of the probe 24 attached to the armature 194, proximally against the bias of the primary spring 180. As before, longitudinal or axial movement of the inner tube 190 causes the head 26 of the probe 24 to pivot as required.

[0129] As the armature 194 moves proximally under the action of the cam profile 184 on the cam follower 196 and the secondary spring 198, the primary spring 180 and the secondary spring 198 both compress. The primary spring 180 will compress preferentially as the secondary spring 198 exerts stronger longitudinal bias than the primary spring 180. This means that the cam can be configured to over-drive the cam follower 196, safe in the knowledge that the secondary spring 198 will compress before any damage could be caused by over-driving the armature 194. This is advantageous as it allows for looser manufacturing tolerances, thus reducing manufacturing cost.

[0130] In the example shown in Figures 15a and 15b, the nose cone 188 of the probe 24 contains a sterile barrier in the form of a seal 142 around the armature 194.

[0131] In a variant of the mechanism 172 shown in Figures 15a and 15b, it would be possible instead for a single spring to be used instead of two springs disposed in series on opposite sides of the flange of the armature 194. For example, a single spring could act against a cam follower 196 that is fixed to the armature 194.

[0132] Figure 16 shows provisions for grounding the metal outer tube 166 of the probe 24 to the system chassis defined by the CCU 58. This grounding must be achieved through the electronic interface 148 between the probe 24 and the handle 34. Within the probe 24, the electronic interface 148 comprises a PCB 199 that has a contact pad 201. A conductive combined cam follower and sliding armature 203 is biased by a conductive spring 205. The spring 205 also presses a conductive flange or washer 207 against the contact pad 201 of the PCB 199.

[0133] Figure 17 shows components of mechanical 144, electrical 148 and photonics interfaces 146 located at the junction between the distal end of a handle 34 and the proximal end of a probe 24. Those interfaces 144, 146, 148 are completed when the probe 24 and the handle 34 are assembled together to bring the interface components 144, 146, 148 into mutual opposition, contact or engagement. Also evident in Figure 17 are the aforementioned spigot or shank 76 at the proximal end of the probe 24 and the corresponding passage 202 in the handle 34 forming part of the mechanism for coupling the probe to the handle 34.

[0134] Specifically, in this example: the electrical interface 148 is defined by rows of electrical conductors or connectors 204, for example, between two and twelve connectors 204; the mechanical interface 144 is defined by a drive shaft 178 that protrudes from the handle 34 and a complementary socket 200 of a cam shaft 182 in the probe 24; and the photonics interface 146 is defined by an LED in the handle 34 that is opposed to an end of an optical fibre bundle within the probe 24. In a variant, Figure 18 shows the proximal end of a probe 24 that has components of dual photonics interfaces 146.

[0135] As will be explained, the electrical interface 148 can serve as a power interface and / or as a data interface 318 between the probe 24 and the handle 34. Also, one of the dual photonics interfaces 146 serves as a data interface between the probe 24 and the handle 34.

[0136] Figure 19 shows a distal coupling of the drive shaft 178 and a complementary proximal coupling of the cam shaft 182. Each coupling comprises diametrically-opposed circumferentially-extending alignment ramps 179 that terminate in diametrically- opposed interlocking formations 181. In this example, the interlocking formations 181 comprise notches on the proximal coupling of the cam shaft 182 that receive lugs on the distal coupling of the drive shaft 178 but that arrangement could of course be reversed. Sliding interaction with the alignment ramps 179 effects self-alignment between the couplings, which rotate relative to each other until alignment and engagement of the interlocking formations 181 prevents further relative rotation.

[0137] Figures 20a to 23 show various examples of position sensors 176 for monitoring the angular position of a drive shaft 178 of a motor 174 in the handle 34. As noted above, the angular position of the drive shaft 178 determines the viewing angle, or the angle of the viewing axis, of the imaging head 26 relative to the longitudinal axis of the probe 24.

[0138] In Figures 20a and 20b, a collar 210 on the drive shaft 178 has a radially-protruding lobe 208 that is positioned to interact with microswitches 206 fixed to the inner part 134 of the handle 34. Actuators of the microswitches 206 face inwardly in mutual opposition about the drive shaft 210. As the drive shaft 210 turns, the collar 210 also turns to bring the lobe 208 into or out of actuating contact with the respective actuators 206. In this way, the outputs of the microswitches 206 provide binary angular position data to the control electronics of the endoscope system 36, 122.

[0139] Figure 20a shows the lobe 208 pressed against the actuator of one of the microswitches 206 and Figure 20b shows the lobe 208 pressed against the actuator of the other microswitch 206. In this example, the drive shaft 178 turns through 60° as the lobe 208 moves between the actuators of the microswitches 206. The angulation mechanisms 140, 172 of Figures 14a to 15b can be arranged to convert that 60° angular movement of the drive shaft 178, and hence of the cam shaft 168, 182, into 45° pivoting of the head.

[0140] Figures 21a and 21 b show a variant in which Hall-effect sensors 212 replace the microswitches 206 of Figures 20a and 20b and are similarly fixed to the inner part 134 of the handle 34. The lobe 208 of Figures 20a and 20b is replaced by a magnet 214 on the collar 210. A small air gap maintains clearance between the magnet 214 and the sensors 212 as the drive shaft 178 and the collar 210 turn.

[0141] The magnet 214 turns to face the respective Hall-effect sensors 212 as the drive shaft 178 turns. Figure 21a shows the magnet 214 facing one of the sensors 212, which is therefore triggered to produce a corresponding output signal. Conversely, Figure 21b shows the magnet 214 facing the other sensor 212, which is therefore triggered to produce a corresponding output signal. The output signals of the sensors 212 thereby provide angular position data to the control electronics of the endoscope system 36, 122.

[0142] In the example shown in Figures 21a and 21 b, the drive shaft 178 turns through 180° as the magnet 214 moves between the Hall-effect sensors 212. The angulation mechanisms 140, 172 of Figures 14a to 15b can be arranged to convert that 180° angular movement of the drive shaft 178, and hence of the cam shaft 168, 182, into 45° pivoting of the head 26.

[0143] Figures 22a and 22b show a variant of a Hall-effect system in which a single Hall-effect sensor 216 fixed to the inner part 134 of the handle 34 is disposed to one side of the drive shaft 178 in alignment with the collar 210. In this instance, the collar 210 carries magnets 218, 220 in diametric opposition about the collar 210 and therefore with 180° angular separation about the drive shaft 178 that is disposed within the collar 210. Again, there is a small air gap to allow clearance between the magnets 218, 220 and the sensor 216 as the drive shaft 178 and the collar 210 turn.

[0144] The magnets 218, 220 are arranged to present respectively different poles to the Halleffect sensor 216 as the drive shaft 178 turns. Specifically, one magnet 218 has an outwardly-facing north pole whereas the other magnet 220 has an outwardly-facing south pole. Figure 22a shows the north pole of the first magnet 218 facing the sensor 216, which therefore produces a low output signal. Conversely, Figure 22b shows the south pole of the second magnet 220 facing the sensor 216, which therefore produces a high output signal. The level of the output signal of the single sensor 216 thereby provides angular position data to the control electronics of the endoscope system 36, 122.

[0145] In the example shown in Figures 22a and 22b, the drive shaft 178 turns through 180° as the magnets 218, 220 swap to face the Hall-effect sensor 216. Again, the angulation mechanisms 140, 172 of Figures 14a to 15b can be arranged to convert that 180° angular movement of the drive shaft 178, and hence of the cam shaft 168, 182, into 45° pivoting of the head 26.

[0146] Figure 23 exemplifies absolute optical monitoring of the angular position of the drive shaft 178. This variant allows continuous 360° measurement and control of the drive shaft position required for a 360° probe. For this purpose, an optical sensor 222 mounted on the inner part 134 of the handle 34 comprises an emitter and a detector and is opposed to a strip 224 that extends circumferentially around the drive shaft 178. The strip 224 bears a visual indicator that is characteristic of the longitudinal position along the strip 224 and thus of the angular position around the pivot axis of the drive shaft where the strip 224 is curved circumferentially around that axis. In this example, the visual indicator takes the form of a longitudinally-tapering marking extending along the strip 224. The width or thickness of that marking at a given longitudinal position along the strip 224 is detected by the optical sensor 222 to determine the angular position of the strip 224, and hence the angular position of the drive shaft 178 relative to the inner part 134 of the handle 34.

[0147] In principle, it would be possible to reverse the arrangement shown in Figure 23, with the optical sensor 222 instead being mounted on the drive shaft 178 and the strip 224 being mounted on the inner part 134 of the handle 34 around the shaft 23.

[0148] Figures 24a, 24b and 24c show an imaging head 26 in the distal end of a tubular shaft 23 of the probe 24. The imaging head 26 holds a camera 230 and light emitters 226, which may be optical fibres or optionally LEDs mounted in the head 26 beside the camera 230. The head 26 is shown at 45° to the longitudinal axis of the shaft 23 in Figures 24a and 24c, and at 0° to the longitudinal axis of the shaft 23 in Figure 24b. The head 26 remains within the diameter of the shaft 23 throughout its range of angular movement. As noted above by way of example, the outer diameter of the shaft 23 may be 3.5mm. In this example and as also shown in longitudinal section in Figures 25a and 25b, the head 26 has a generally spherical or part-spherical body. However, the head 26 could have other shapes, such as the generally cuboidal shapes shown in the longitudinal sectional views of Figures 27a to 28b. Like numerals are used for like features in Figures 24a to 28b.

[0149] The head 26 holds a camera 230, which comprises a lens 228, an image sensor and optical fibres 226. The image sensor is connected to an electrical cable, such as a micro co-axial cable or other cable, via an intermediate flexible printed circuit board (PCB). The optical fibres 226 bend to allow the imaging head to move through its range of angular movement. The PCB and cable can also bend to accommodate such pivotal movement of the head.

[0150] Figures 25a and 25b show an angulation mechanism 232 in a distal end portion of the probe 24. Specifically, the inner tube 240 of the probe 24 comprises an inner tube extension 234 that is pivotably connected to the imaging head 26 via a head interlock 236. Longitudinal or axial movement of the inner tube 240 and the inner tube extension 234 within the outer tube 242 of the probe 24 drives a crank action via the interlock 236 that causes the head 26 to pivot about the pivot axis. The viewing axis of the head 26 is at 0° to the longitudinal axis of the shaft 23 in Figure 25a and at 45° to the longitudinal axis of the shaft 23 in Figure 25b. Beneficially, the inner tube extension 234 is offset laterally to one side of the central longitudinal axis to allow space within the outer tube 242 to accommodate bending of cables, optical fibres or a PCB connecting to the head 26.

[0151] In the example shown in Figures 25a and 25b, the inner tube extension 234 is interlocked with both the inner tube 240 and the imaging head 26; alternatively, the inner tube extension 234 could be an integral part of the inner tube 240 extending distally to the head interlock 236. Such an integral arrangement is shown in Figures 27a to 28b.

[0152] Figures 26a and 26b correspond to Figures 25a and 25b but show a flushing arrangement for cleaning a lens 228 or window of the imaging head 26 with a flow of a flushing fluid such as water. For this purpose, a flushing channel 246 extends along the shaft 23 of the probe 24 to convey the flow toward the imaging head 26, and a diverter surface 244 is opposed to a distal end of the flushing channel 246 to divert the flow onto the imaging head 26.

[0153] Specifically, Figures 26a and 26b show a diverter surface 244 defined by a splash plate 244 or diverter vane that is integrated into the distal end of the inner tube extension 234. In this case, therefore, the diverter surface 244 is movable longitudinally with respect to the shaft 23 of the probe 24. The splash plate 244 directs fluid pumped along the inner tube 240 across the camera lens 228 or window and optical fibres. The imaging head 26 can be pivoted away from the 0° viewing axis as shown in Figure 26b to orient a lens 228 or window of the imaging head 26 toward the diverter surface 244 defined by the splash plate 244.

[0154] In a variant of the arrangement shown in Figures 26a and 26b, the outer tube 242 may instead be shaped to form a splash plate 244 or diverter vane. In that case, the diverter surface defined by the splash plate 244 or diverter vane may be fixed to the shaft 23 of the probe 24.

[0155] Figures 27a and 27b show a bundle of optical fibres 248 extending within the shaft 23 of the probe 24 and connecting to the head 26 via a sealed electronic joint 250 at a distal end of the bundle 248. The fibres 248 are substantially straight when the viewing axis of the head 26 is at 0° to the longitudinal axis of the shaft 23 as shown in Figure 27a. Conversely, the fibres 248 bend along their length when the viewing axis of the head 26 is at 45° to the longitudinal axis of the shaft 23 as shown in Figure 27b. Similarly, Figures 28a and 28b show a flexible PCB 252 extending within the shaft 23 of the probe 24, in a different longitudinal plane to the bundle of optical fibres 248 shown in Figures 27a and 27b. Again, the PCB 252 connects to the head 26 via a sealed electronic joint 254 at a distal end of the PCB 252. In this instance, though, the PCB 252 is bent along its length when the viewing axis of the head 26 is at 0° to the longitudinal axis of the shaft 23 as shown in Figure 28a and the PCB 252 straightens along its length when the viewing axis of the head 26 is at 45° to the longitudinal axis of the shaft 23 as shown in Figure 28b.

[0156] Figure 29 shows the distal end of a probe 24 in which the pivot axis of the imaging head 26 is defined by diametrically-opposed pins 254. The tubular wall of the shaft 23 of the probe 24 has diametrically-opposed slots 256 that open to the distal end of the shaft 23 to receive the respective pins 254. The slots 256 are J-shaped to lock the pins 254 at the base of the J shape in alignment with the pivot axis.

[0157] The pins 254 have mutually-inclined flats that bear against respective edges of the slots 256 to serve as stops 258, 260 that delimit pivotal movement of the imaging head 26. In this example, one of the stops 258 corresponds to the 45° position of the imaging head 26 whereas the other stop 260 corresponds to the 0° position of the imaging head 26.

[0158] Figures 30 to 36 are exemplary block diagrams of endoscope systems 262, 268, 320, 322, 324, 332, 340, comprising a CCU 58, a handle 34 and a probe 24. The systems 262, 268, 324, 332, 340 shown in Figures 30, 31 and 34 to 36 employ a simple probe 24 whose head 26 moves through a restricted viewing angle range of, for example, 0° to 45°. Conversely, the systems 320, 322 shown in Figures 32 and 33 employ a more complex probe 24 whose head moves through a wider or unrestricted viewing angle range of, for example, 360°.

[0159] The CCU 58 is connected to the handle 34 by a cable 264 that can convey power from the CCU 58 to the handle 34 and data from the handle 34 to the CCU 58. The cable 264 is shown as being received in a socket 266 of the CCU 58 but that arrangement could, of course, be reversed. Interfaces between the handle 44 and the probe 24 are also shown, these being a mechanical interface 144, an electronic interface 148 and at least one photonics interface 146, 147. Figure 31 shows that a source of illumination can be implemented in the CCU 58 rather than in the handle 34 or the probe 24. The source of illumination may, for example, be a single laser, an RGB laser arrangement or an LED 270. In this instance, the cable connecting the handle 34 to the CCU 58 is a combined electric and photonic cable 272.

[0160] Otherwise, the CCU 58 comprises the same components in each of Figures 30 to 36 but not all of those components need to be used or to be present in each case. At the heart of the CCU 58, a controller 274 exemplified by a single-board computer 274 or system on module (SOM) device takes inputs from, and sends outputs to, a user control interface 276, an ethernet / wireless interface 278 and a USB interface 280. The controller 274 communicates with the ethernet / wireless interface 278 and the USB interface 280 directly and optionally also via an electronic health records interface 282 as shown. Optionally, the controller 274 also communicates with the ethernet / wireless interface 278 via an artificial intelligence and augmented reality (AI / AR) interface 284. The controller 274 also takes inputs from and sends outputs to the handle 34 via the cable 264, 272 and the socket 266, 286 both directly and via in-system programmable (ISP) devices and video circuits 288, and can also output illumination signals to the handle 34 via an illumination driver 290. Where a source of illumination is implemented in the CCU 58 as shown in Figure 31 , that source is connected to the illumination driver 290.

[0161] The handle 34 comprises an electronic control module 292 that may also integrate video and power functions. The control module 292 takes electrical power from the CCU 58 via the electrical cable 264 in this example but could instead be powered internally or from another power source. The control module 292 takes inputs from, and sends outputs to, a user control interface 294 of the handle 34. Optionally, an ID chip 296 or EPROM communicating with the control module 292 bears a unique ID of the handle 34.

[0162] The control module 292 receives video data from the probe 24 via the electronic interface 148. The control module 292 also controls an LED 298 in the handle 34 to output illuminating light to the probe 24 via a first photonics interface 146.

[0163] The handles 34 of the systems 262, 268, 320, 322, 324, 332, 340 shown Figures 30 to 36 each have an optional accelerometer sensor 300. The handle 34 of the system 332 shown in Figure 35 further comprises an optional gyroscope sensor 300 that could also be added to the handles 34 of the systems 262, 268, 320, 322, 324, 340 shown in Figures 30 to 34 and 36. The accelerometer 300 and / or the gyroscope supplies a corresponding signal to the control module 292 whereby the system can determine and respond to acceleration and orientation of the handle 34. For example, the system can use accelerometer 300 and / or gyroscope data to facilitate the application of artificial intelligence and / or augmented reality solutions.

[0164] Optionally, as shown in the systems 262, 268, 320, 332, 340 of Figures 30 to 32, 35 and 36, the handle 34 has a second photonics interface 147 that communicates with the control module 292 via a data transceiver 302. The second photonics interface 147 supports optional use of a probe 24 that has a wireless interface with the imaging head 26, such as the aforementioned 360° probe 24, where light can be used for data transmission across the wireless interface. Such solutions are disclosed in the Applicant’s PCT application published as WO 2022 / 157393, whose contents are incorporated herein by reference. They are also outlined graphically in the system 320 of Figure 32, which include a 360° probe 24 instead of a 0° to 45° probe 24 as noted above.

[0165] Figure 36 shows the option of using a second photonics interface 147 to convey IR to the probe from an IR LED 342 in the handle 34 for near-infrared (NIR) fluorescence imaging.

[0166] A 360° probe 24 can be attached to the handle 34 and used wherever the handle 34 has a second photonics interface 147 and a data transceiver 302 as shown in Figures 30 to 32 and 35. Conversely, Figure 33 shows how a second photonics interface 147 can be obviated by placing the data transceiver 302 in the probe 24 rather than in the handle 34. Data from a 360° probe 24 can then travel across the electronic interface 148 between the probe 24 and the handle 34. In another approach, a second photonics interface 147 is omitted from the simplified handle 34 of the system 324 shown in Figure 34, which is therefore configured only for use with a simple probe 24 whose head moves through a restricted angular range of, for example, 0° to 45°.

[0167] With input from an angle sensor 304 such as the aforementioned microswitches or Halleffect sensor(s), the control module 292 controls a motor 174 that drives pivotal movement of the imaging head 26 of the probe 23 and provides feedback to a user as to the selected angle of the head 26. Drive from the motor 174 is conveyed to the probe 24 across the mechanical interface 144. The motor 174 is present in the handles 34 shown in Figures 30 to 32, 35 and 36 but the handles 34 of Figures 33 and 34 are further simplified by replacing the motor 174 with a manual actuator 175, such as a thumbwheel, that drives the cam shaft of a probe 24 coupled to the handle 34.

[0168] In the handle 34 of the system 332 shown in Figure 35, the user control interface 294 is shown as being on a horizon orientation sleeve 338 that also comprises a sensor interface 326. The horizon orientation sleeve 338 corresponds to the outer sleeve 98 of the handle 34, where the inner part 134 of the handle 34 is pivotable with the probe 24 relative to the outer sleeve 98. A sleeve angle sensor 96, responsive to the sensor interface 326, determines the angle between the outer sleeve 98 and the inner part 134 of the handle 34 and supplies a corresponding signal to the control module 292. Optionally, as noted above, the sleeve angle sensor 96 is a potentiometer that is connected to the outer sleeve 98 through gears and serves to monitor the angular position of the outer sleeve 98 relative to the inner part 134 of the handle 34. As the inner part 134 of the handle 34 is rigidly connected to the probe 24, this also serves to monitor rotation of the probe 24 around its longitudinal axis relative to the outer sleeve 98.

[0169] The probes of the systems 262, 268, 320, 322, 324, 332, 340 shown in Figures 30 to 36 each comprise an actuation or angulation mechanism 308 that responds to mechanical drive across the mechanical interface 144 to effect viewing angle variation 310 of the head 26. The head 26 of each probe 24 further comprises a camera module 312 and illumination 314 to illuminate the field of view of the camera module 312. Optionally, each probe 24 of the systems 262, 268, 320, 322, 324, 332, 340 shown in Figures 30 to 36 also comprises a probe ID chip 306 or EPROM communicating with the electronic interface148 and bearing a unique ID of the probe 24.

[0170] In the 0° to 45° probes 24 shown in Figures 30, 31 and 34 to 36, the first photonics interface 146 conveys light directly to the head to illuminate the field of view of the camera module 312. Also, the camera module 312 communicates directly with the electronic interface 148 and from there with the control module 292 of the handle 34.

[0171] In the 360° probes 24 shown in Figures 32 and 33, the camera module 312 of the head 26 communicates wirelessly via a light guide interface 316 and / or a power and control data interface 318. The light guide interface 316 receives light from the first photonics interface 146 and supplies light to the illumination in the head 26. Reciprocally, in Figure 32, the light guide interface 316 conveys data from the head 26 to the control module 292 of the handle 34 via the second photonics interface 147 and the data transceiver 302. Alternatively, in Figure 34, the light guide interface 316 conveys data from the head 26 to the control module 292 of the handle 34 via the data transceiver 302 and the electronic interface 148. Conversely, the power and control data interface 318 conveys to the head 26 power and control data received from the control module 292 of the handle 34 via the electronic interface 148.

[0172] Turning next to Figures 37 and 38, these drawings show further details of annular drape assemblies 344 like those featured in Figures 1 and 2.

[0173] A drape cassette 56 and the probe(s) 24 are provided in a sterile condition to be opened in the sterile surgical field, whereas the handle 34 is provided in a non-sterile condition. The drape cassette 56 contains a tubular flexible drape 347 that is deployable to provide a sterile barrier between the handle 34 and the sterile field and to allow controls on the handle 24 to be manipulated through the drape 347. The drape 347 has a relatively narrow distal portion 348 whose diameter is a close fit around the handle 34 and flares through a distally-tapered intermediate section 350 into a relatively wide proximal portion 346 around a cable 370 that extends proximally from the handle 34.

[0174] The drape assemblies 344 of Figures 37 and 38 are in two parts that are mutually spaced in a radial direction, namely an inner part that comprises a tubular drape ring 30 and an outer part that is movable proximally around, along and beyond the handle 34 to extend around and along the cable 370. This proximal movement of the outer part relative to the drape ring 30 deploys the drape 347 from within the drape cassette 56 in preparation for a surgical procedure. Specifically, a sterile user pushes the outer part of the drape cassette 56 proximally to deploy the drape 347 over the handle 34 using a hand that remains in the sterile field outside the drape 347.

[0175] The drape 347 is packed in a compactly furled, gathered, concertinaed or folded configuration within the drape cassette 56, specifically within radially inner and outer chambers of the drape cassette 56. The drape 347 may be more tightly packed in the outer chamber than in the inner chamber. The outer chamber is defined within an outer housing 362 that forms the outer part of the drape cassette 56 and that has radially inner and outer tubular walls. The inner chamber is disposed on the radially inner side 364 of the inner wall of the outer housing 362.

[0176] The narrower distal portion 348 and the tapered intermediate section 350 of the drape

[0177] 347 are held within the inner chamber whereas the wider proximal portion 346 of the drape 347 is held within the outer chamber. The narrower distal portion 348 of the drape 347 unfolds and deploys from the inner chamber first. Advantageously, as the handle 34 is draped first with the distal portion 348 of the drape 347, this allows a sterile user to hold the handle 34 through the drape 347 while the proximal portion 346 of the drape 347 is pulled over the remainder of the cable 370.

[0178] The drape cassette 56 shown in Figure 37 is designed to be connected to the handle 34 before the probe 24 is connected to the handle 34. Specifically, the drape cassette 56 is attachable to and then remains fixed to the outer sleeve 98 of the handle 34. As the drape cassette 56 is connected to the handle 34 rather than to the probe 24, it is straightforward to remove the probe 24 from the handle 34 when a surgical procedure is finished or if interchanging probes 24 during the procedure.

[0179] The drape ring 30 in the inner part of the drape cassette 56 receives and fits closely around a distal end portion of the handle 34 as a sliding press fit. In this example, a longitudinally-extending locating feature or spline 352 on the inside of the drape ring 30 engages a complementary locating feature 353 on the outside of the handle 34 to prevent rotation of the drape 347 around the handle 34. Alternatively, a feature similar in shape to a bevel gear could extend into the proximal inner edge of the drape ring 30 and a complementary locating feature on the outside of the handle 34 to prevent rotation of the drape 347 around the handle 34. This option has the advantage of being largely self-aligning.

[0180] A distal end of the drape ring 30 is stepped radially outwardly to define seat surfaces 356, 360 that face distally and radially inwardly to seal against a probe 24 to be fitted to the handle 34. The distally-facing seat surface 356 is defined by a shoulder and the inwardly-facing seat surface 360 is defined within a distally-extending lip or flange.

[0181] The drape ring 30 shown in Figure 37 supports a removable lid or cap 354 on the distal side of the drape ring 30. The cap 354 extends across and closes the lumen of the drape ring 40 to serve as a barrier that helps a sterile user to attach the drape ring 30 to the handle 34 without risking contact with the non-sterile interface at the distal end of the handle 34. In this example, the cap 354 is substantially rigid and engages resiliency with the distally-extending lip or flange of the drape ring 30. Optionally the cap 354 may extend radially to hold or stabilise the drape cassette 56 in a similar way to the ring 366, which allows the drape assembly 344 to form a rigid body for ease of assembling onto the handle. In another example of such a barrier, the cap 354 could be replaced by a peel-off film 355 that is bonded to the drape ring 30.

[0182] The drape ring 30 is surrounded concentrically by a close-fitting drape ring shell 358 that locks a distal end of the drape 347 to the drape ring 30 and proximally abuts the outward step of the drape ring 30. Alternatively, the drape ring 30 can be formed in one part, in which case the drape 347 can be fixed to the drape ring 30 by adhesive or by plastic welding.

[0183] The inner and outer chambers surround the drape ring 30 and the drape ring shell 358 concentrically. The inner chamber is an annular gap defined between the inner part of the drape cassette 56 and the inner wall of the outer housing 362.

[0184] The drape 347 traverses the inner chamber distally on a corrugated zig-zag path that extends distally from the proximal end of the drape ring shell 358 and exits the inner chamber through a distal opening. The drape 347 then reverses direction to enter the outer chamber through a distally-facing annular slot in the outer housing 362 and traverses the outer chamber proximally on a corrugated zig-zag path.

[0185] The alternative drape cassette 56 shown in Figure 38 is designed to be assembled with a probe 24 before the assembly of the probe 24 and the drape cassette 56 is attached to the handle 34. For this purpose, the drape cassette 34 has a drape ring 30 that is designed to receive and engage with the proximal end of the probe 24. The drape cassette 56 is pushed over the proximal end of the probe 24 until the drape ring 30 clicks into engagement with the probe 24. Yet, the probe 24 can turn freely within the drape ring 30 so as not to hamper rotation of the probe 24 relative to the outer sleeve 98 of the handle 24.

[0186] The tapered section 350 of the drape 347 extends distally and outwardly across the inner chamber from the narrower distal portion of the drape and exits the inner chamber through a distal opening. The wider proximal portion of the drape 347 then reverses direction to enter the outer chamber through a distally-facing annular slot in the outer housing 362 and traverses the outer chamber proximally on a corrugated zig-zag path.

[0187] In the drape cassette 56 of Figure 38, the drape ring 30 is joined to the outer part of the drape cassette 56 by a deformable annular disc or ring 366 that extends radially inwardly from a proximal end of the outer housing 362 to a proximal end of the drape ring 30. Additionally, the distal end of the drape ring 30 is surrounded by an annular lip or flange 368 that extends radially outwardly from the drape ring 30. The narrower distal portion of the drape 347 is received between the deformable ring 366 and the flange 368.

[0188] When the outer part of the drape cassette 56 of Figure 38 is moved proximally along the handle to deploy the drape 347, the inner edge of the deformable ring 366 deflects distally relative to the outer part while sliding along the handle 34. The drape ring 30 and the flange 368 are left behind to anchor the distal end of the drape 347 relative to the outer sleeve 98 of the handle 34. The flange 368 can be torn off and discarded after deployment of the drape 347 if desired.

[0189] Figures 39a shows a drape cassette 56 of Figure 37 being attached telescopically to the distal end of an endoscope handle 34 with the cap 354 fixed in place on the drape ring 30. Figures 39b and 39c then show steps of deployment of the drape 347 as the outer part of the drape cassette 56 is advanced proximally along and beyond the handle 34. The cap 354 can remain in place on the drape ring 30 until deployment of the drape 344 is complete. The narrower distal portion 348 of the drape 347 deploys first over the handle 34, noting that less force is required to unfold that portion than the wider proximal portion 346 of the drape 347.

[0190] Deployment of the distal portion 348 of the drape 347 over the handle 38 is shown in Figure 39b and subsequent deployment of the wider proximal portion 346 of the drape 344 following the tapered section 350 of the drape 347 is shown in Figure 39c. Figure 39c shows a substantially rigid cap 354 after removal from the drape ring 30 and also shows the alternative of a peel-off film 355 barrier after removal from the drape ring 30. With the handle 34 fully draped and the cap 354 or film 355 removed, Figure 39d then shows a probe 24 being attached to the distal end of the handle 34, which can be held through the drape 347 by a sterile user.

[0191] The probe 24 shown in Figure 39d has a circumferential elastomeric seal arrangement 372 at its proximal end, variants of which will now be described with reference to Figures 40 to 43. When the probe 24 is attached to the draped handle 34, the seal 372 ensures that a continuous sterile barrier is formed in the operating field. The seal 372 abuts or is attached to the drape ring 30 to maintain this sterile barrier yet allows the probe 24 to be turned about its longitudinal axis relative to the drape ring 30 and the outer sleeve 98 of the handle 24. Figures 40 to 42 show various seal arrangements in which the seal 372 is fixed to the probe 24 and seals against a seat surface of the drape ring 30. Conversely, Figure 43 shows that it is possible to reverse the seal arrangement to fix the seal 372 to the drape ring 30 and to seal against a seat surface of the probe 24 instead.

[0192] In Figures 40 and 43, the seal 376, 384 exerts sealing pressure longitudinally, in a direction parallel to the direction of coupling, against either a seat surface 374 of the drape ring 30, as shown in Figure 40, or against a seat surface of the probe 24 as shown in Figure 43. For example, Figure 40 shows a seal 376 fixed to the probe 24 and bearing against the distally-facing seat surface 374 defined by the shoulder of the aforementioned stepped distal end of the drape ring 30. For such seals to be effective, the mechanism coupling the probe 24 to the handle 24 should exert a constant and consistent longitudinal pressure to compress the seal to a necessary extent around its full circumference.

[0193] Figures 41 and 42 show an alternative approach of exerting sealing pressure laterally, in a direction perpendicular to the direction of coupling. In this case, the seal 378, 382 bears radially outwardly against the inwardly-facing seat surface defined within the distally-extending lip or flange of the aforementioned stepped distal end of the drape ring 30. The seal 378 of Figure 41 has a double sealing edge on its radially outer side whereas the seal 382 of Figure 42 has a single sealing edge on its radially outer side.

[0194] The approach exemplified in Figures 41 and 42 is advantageous because the radial pressure on the sealing face or edge of the seal 382, 284 can easily be controlled by specifying appropriate dimensions and material properties. Again, it will be apparent that this approach could also be applied to a reverse arrangement in which the probe 24 is provided with an inwardly-facing seat surface to seal against a seal fixed to the drape ring 30.

Claims

Claims1 . An endoscopic instrument comprising: a handle; an imaging probe extending distally from the handle; a tubular drape for surrounding the handle; and a seal acting between the drape and the probe.

2. The instrument of Claim 1 , wherein the drape is releasably attached to a distal end of the handle.

3. The instrument of Claim 1 or Claim 2, wherein the drape comprises a drape ring that surrounds the handle and the seal acts between the drape ring and the probe.

4. The instrument of Claim 3, wherein the drape ring is in fixed angular relation to the handle.

5. The instrument of Claim 4, wherein the drape ring and the handle comprise complementary formations that are inter-engageable to lock the drape ring against rotation around the handle.

6. The instrument of any of Claims 3 to 5, wherein the seal is attached to the probe and acts against the drape ring.

7. The instrument of any of Claims 3 to 5, wherein the seal is attached to the drape ring and acts against the probe.

8. The instrument of Claim 6 or Claim 7, wherein the seal acts longitudinally against the probe and / or the drape ring.

9. The instrument of Claim 6 or Claim 7, wherein the seal acts radially against the probe and / or the drape ring.

10. The instrument of any preceding claim, wherein the probe can be turned about a longitudinal axis relative to the drape.

11. The instrument of Claim 10, wherein the seal is in sliding contact with the probe or with the drape.

12. The instrument of Claim 10 or Claim 11 , wherein the handle comprises an outer sleeve and an inner part that can be turned with respect to the outer sleeve.

13. The instrument of Claim 12, wherein the probe is attached to and can be turned with the inner part of the handle about the longitudinal axis with respect to the outer sleeve.

14. The instrument of any preceding claim, wherein the seal and the probe together seal a distal end interface of the handle.

15. The instrument of any preceding claim, wherein the handle is non-sterile and the drape, the probe and the seal together form a sterile barrier around the handle.

16. The instrument of any preceding claim, wherein the seal encircles a coupling interface between the handle and the probe.

17. The instrument of Claim 16, wherein the seal encircles mechanical, electrical and / or photonics interfaces between the handle and the probe.

18. The instrument of any preceding claim, wherein the probe comprises a probe seal for blocking migration of fluids or other materials through the probe, to or from the handle.

19. The instrument of any preceding claim, wherein the drape comprises a relatively narrow distal portion and a relatively wide proximal portion.

20. The instrument of Claim 19, wherein the drape further comprises a distally-tapering intermediate section between the distal portion and the proximal portion.

21. The instrument of any preceding claim, wherein the drape is stored in a compact configuration radially outboard of the handle and is deployable from the compact configuration by proximal movement of the stored drape along the handle.

22. The instrument of Claim 21 , wherein the stored drape is separated from the handle by a tubular wall that is movable axially relative to the handle.

23. A drape assembly comprising: an inner ring; and a tubular drape stored in a compact configuration radially outboard of the inner ring; wherein the stored drape is movable axially relative to the inner ring to deploy the drape from the compact configuration.

24. The assembly of Claim 23, wherein the stored drape is separated from the inner ring by a tubular wall that is disposed radially outboard of the inner ring and is movable axially relative to the inner ring.

25. The assembly of Claim 23 or Claim 24, wherein the drape comprises a relatively narrow distal portion and a relatively wide proximal portion.

26. The assembly of Claim 25, wherein the drape further comprises a distally-tapering intermediate section between the distal portion and the proximal portion.

27. The assembly of Claim 25 or Claim 26, wherein the proximal portion of the drape is stored outboard of the tubular wall and the distal portion of the drape is stored in a radial gap between the inner ring and the tubular wall.

28. The assembly of any of Claims 25 to 27, wherein the proximal portion of the drape is stored in a more compacted form than the distal portion of the drape.

29. The assembly of any of Claims 23 to 28, wherein the drape is stored in an annular compartment disposed radially outboard of the inner ring, the tubular wall being an inner wall of the compartment.

30. The assembly of Claim 29 when dependent on Claim 27, wherein the drape exits the radial gap and enters the annular compartment on a distal side of the annular compartment.

31. The assembly of any of Claims 23 to 30, further comprising a removable barrier that closes a lumen of the inner ring.

32. The assembly of any of Claims 23 to 31 , wherein the inner ring has a stepped distal circumferential profile defining at least one circumferential sealing seat that faces distally and / or radially inwardly.

33. An endoscopic instrument comprising: the drape assembly of any of claims 23 to 32; a handle; and an imaging probe extending distally from the handle.

34. The instrument of Claim 33, wherein the inner ring is releasably attached to the handle.

35. The instrument of Claim 33 or Claim 34, wherein the inner ring and the handle comprise complementary formations that can engage to lock the inner ring against rotation around the handle.

36. The instrument of any of Claims 33 to 35, wherein the probe is attachable to the handle, thereby effecting a seal between the probe and the inner ring.

37. The instrument of Claim 36, wherein the seal is fixed to the probe and acts against the inner ring.

38. The instrument of Claim 36, wherein the seal is fixed to the inner ring and acts against the probe.

39. The instrument of any of Claims 36 to 38, wherein the seal acts longitudinally against the probe and / or the inner ring.

40. The instrument of any of Claims 36 to 39, wherein the seal acts radially against the probe and / or the inner ring.

41. A method of deploying a tubular drape over a handle of an endoscopic medical instrument, the method comprising moving the drape in a compact stored configuration proximally along and around the handle to deploy the drape from the stored configuration, a distal end of the drape being anchored to a distal end of the handle.

42. The method of Claim 41 , comprising attaching an imaging probe to the distal end of the handle.

43. The method of Claim 42, comprising subsequently removing the probe from the handle and then removing the drape from the handle.

44. The method of any of Claims 41 to 43, comprising anchoring the distal end of the drape to the handle by an inner ring that surrounds the handle and is sealed to the drape.

45. The method of Claim 44 when dependent on Claim 42 or Claim 43, comprising effecting a seal between the imaging probe and the inner ring by attaching the imaging probe to the distal end of the handle.

46. The method of Claim 44 or Claim 45, comprising attaching the inner ring to the handle before deploying the drape.

47. The method of any of Claims 41 to 46, wherein a lumen of the inner ring is temporarily closed by a barrier during deployment of the drape, which barrier is removed from the inner ring after deployment of the drape.

48. The method of any of Claims 41 to 47, wherein the drape is held in the compact stored configuration around a tubular wall disposed radially outboard of the handle and is deployed by proximal movement of the tubular wall along the handle.

49. The method of Claim 48, wherein the tubular wall is disposed radially outboard of the inner ring before the drape is deployed.

50. The method of Claim 48 or Claim 49, wherein the tubular wall is a radially inner wall of an annular compartment in which the drape is held in the compact stored configuration and from which the drape is deployed.

51. A handle for an endoscopic instrument, the handle comprising: an outer sleeve; an inner part disposed within the outer sleeve and rotatable or pivotable about a longitudinal axis relative to the outer sleeve, the inner part having a distal interface configured for attachment of an imaging probe to the handle; and a sleeve angle sensor for sensing a rotation angle or pivot angle of the inner part relative to the outer sleeve about the longitudinal axis.

52. The handle of Claim 51, wherein the outer sleeve comprises at least one control element that can be depressed to operate electronics carried by the inner part of the handle and the inner part carries at least one pair of conductors that extend circumferentially in alignment with the at least one control element to be connected electrically by depressing the at least one control element.

53. The handle of Claim 52, comprising at least two control elements in mutually offset positions along the outer sleeve of the handle, wherein the inner part of the handle carries at least two pairs of conductors in mutually offset positions along the inner part, each of the pairs of conductors being in alignment with a respective one of the control elements.

54. The handle of Claim 53, wherein the at least two control elements are respective ends of a rocker.

55. The handle of Claim 54, comprising a fulcrum under the rocker that prevents simultaneous electrical connection of both of the conductor pairs aligned with the respective ends of the rocker.

56. The handle of any of Claims 52 to 55, wherein the at least one control element is surrounded by an elastic gaiter and can be depressed against resilient bias of the elastic gaiter.

57. The handle of any of Claims 51 to 56, wherein the sleeve angle sensor is a rotary sensor whose rotation is driven by relative angular movement between the inner part and the outer sleeve about the longitudinal axis.

58. The handle of Claim 57, wherein the sleeve angle sensor comprises a potentiometer.

59. The handle of Claim 57 or Claim 58, wherein rotation of the sleeve angle sensor is driven by a pinion gear on the inner part engaged with a rack formation within the outer sleeve.

60. The handle of any of Claims 51 to 56, wherein the sleeve angle sensor is an optical sensor comprising an emitter and a detector opposed to a visual indicator or pattern that is characteristic of angular position around the longitudinal axis.

61. An endoscope system comprising: an endoscopic instrument comprising the handle of any of Claims 51 to 60; a processor that is responsive to the sleeve angle sensor to counter-rotate an image in accordance with the sensed rotation angle or pivot angle, that image being generated by an imaging probe attached to the inner part of the handle; and a display for displaying the counter-rotated image.

62. A method of operating an endoscopic instrument, the method comprising: rotating or pivoting an imaging probe, and an inner part of a handle to which the imaging probe is attached, relative to an outer sleeve of the handle about a longitudinal axis; and sensing a rotation angle or pivot angle of the inner part relative to the outer sleeve about the longitudinal axis.

63. The method of Claim 62, further comprising:in accordance with the sensed rotation angle or pivot angle, counter-rotating an image generated by the imaging probe; and displaying the counter-rotated image.

64. The method of Claim 63, further comprising displaying the sensed pivot angle in addition to the counter-rotated image.

65. An imaging probe for an endoscopic instrument, the probe comprising: an elongate probe shaft having a longitudinal axis; an imaging head that is pivotable about a pivot axis transverse to the longitudinal axis; and an angulation mechanism that is connected to the imaging head by a link extending within the probe shaft, the link being movable longitudinally to pivot the imaging head about the pivot axis.

66. The imaging probe of Claim 65, wherein the angulation mechanism comprises a cam shaft having a cam profile that acts on an armature fixed to or integral with the link and that is arranged to effect longitudinal movement of the armature and the link in response to rotation of the cam shaft.

67. The imaging probe of Claim 66, wherein the armature is biased toward the cam profile by a spring acting between the armature and a structure of the probe.

68. The imaging probe of Claim 67, wherein the spring biases the armature into contact with the cam profile.

69. The imaging probe of any of Claims 66 to 68, wherein the cam profile acts on the armature via a cam follower that is biased into contact with the cam profile by a spring acting between the armature and the cam follower.

70. The imaging probe of any of Claims 66 to 69, wherein a proximal coupling of the cam shaft is exposed at a proximal end interface of the probe.

71. The imaging probe of Claim 70, wherein the proximal coupling comprises a circumferentially-extending alignment ramp that terminates in an interlocking formation.

72. The imaging probe of any of Claims 66 to 71 , wherein the cam shaft turns about an axis that is substantially parallel to the longitudinal axis of the probe shaft.

73. The imaging probe of any of Claims 66 to 72, comprising a probe seal around the cam shaft and / or the armature, the probe seal being arranged to block migration of fluids or other materials through the probe.

74. The imaging probe of any of Claims 65 to 73, wherein longitudinal movement of the link pivots the imaging head by a crank action acting about the pivot axis.

75. The imaging probe of any of Claims 65 to 74, wherein the shaft also contains optical fibres and / or a flexible PCB connected to the imaging head that bend in response to pivoting of the imaging head.

76. An endoscopic instrument comprising: the imaging probe of any of Claims 65 to 75; and a handle to which the imaging probe can be attached, the handle containing a rotary drive that comprises a drive shaft engageable with the cam shaft of the imaging probe.

77. The instrument of Claim 76, wherein the drive shaft turns about an axis that is substantially parallel to the longitudinal axis of the probe shaft.

78. The instrument of Claim 76 or Claim 77, wherein a distal coupling of the drive shaft is exposed at a distal end interface of the handle.

79. The instrument of Claim 78, wherein the distal coupling comprises a circumferentially-extending alignment ramp that terminates in an interlocking formation.

80. The instrument of any of Claims 76 to 79, comprising at least one angular position sensor disposed beside the drive shaft.

81. The instrument of Claim 80, wherein the at least one angular position sensor comprises a pair of microswitches angularly spaced about the drive shaft and the drive shaft carries a lobe that is movable by rotation of the drive shaft into actuating contact with the respective microswitches.

82. The instrument of Claim 80, wherein the at least one angular position sensor comprises at least one Hall-effect sensor and the drive shaft carries a least one magnet that is movable into signal-triggering alignment with the at least one Hall-effect sensor.

83. The instrument of Claim 80, wherein the at least one angular position sensor comprises an optical sensor comprising an emitter and a detector opposed to a visual indicator or pattern that is characteristic of angular position around the longitudinal axis.

84. The instrument of any of Claims 80 to 83, further comprising a processor that is responsive to the at least one angular position sensor to drive a display that shows the sensed angular position.

85. A method of pivoting an imaging head of an endoscopic instrument relative to an elongate probe shaft of a probe of the instrument, the method comprising turning a cam shaft within the probe to effect longitudinal movement of a link that extends along the probe shaft to the imaging head, that movement of the link pivoting the imaging head about a pivot axis transverse to a longitudinal axis of the probe shaft.

86. The method of Claim 85, comprising turning the cam shaft by turning a drive shaft coupled to the cam shaft, the drive shaft being implemented in a handle that is removably coupled to the probe.

87. The method of Claim 86, comprising self-aligning interlocking formations of the cam shaft and the drive shaft upon coupling the handle to the probe.

88. The method of any of Claims 85 to 87, comprising sensing the angular position of the drive shaft relative to the handle.

89. The method of Claim 88, comprising displaying the sensed angular position in addition to an image generated by the imaging head.

90. A handle of an endoscopic instrument, the handle comprising: a distally-opening passage in a distal end of the handle for receiving a proximally-extending shank of a probe; and a mechanism for releasably attaching the probe to the handle via the shank, wherein the mechanism comprises: at least one pin that is biased toward the passage to protrude into the passage for engaging the shank; and an armature that is movable distally within the handle and has at least one inclined cam surface arranged to bear against a correspondingly inclined surface of the at least one pin to push the pin away from the passage against the bias.

91. The handle of Claim 90, wherein the armature is movable distally under the action of a release button at a proximal end of the handle.

92. The handle of Claim 91 , wherein the release button encircles a cable that extends proximally from the handle.

93. An imaging probe for an endoscopic instrument, the probe comprising: an elongate probe shaft having a longitudinal axis; an imaging head that is pivotable about a pivot axis transverse to the longitudinal axis; a flushing channel extending along the probe shaft for conveying a flow of a flushing fluid toward the imaging head; and a diverter surface opposed to a distal end of the flushing channel for diverting the flow of the flushing fluid onto the imaging head.

94. The imaging probe of Claim 93, wherein the imaging head is pivotable to orient a lens or window of the imaging head toward the diverter surface.

95. The imaging probe of Claim 93 or Claim 94, further comprising an angulation link extending within the probe shaft, the link being movable longitudinally to pivot the imaging head about the pivot axis, wherein the diverter surface is movable longitudinally with the angulation link relative to the pivot axis.

96. The imaging probe of Claim 95, wherein longitudinal movement of the link pivots the imaging head by a crank action acting about the pivot axis.

97. The imaging probe of Claim 93 or Claim 94, wherein the diverter surface is fixed to the probe shaft.

98. An endoscopic instrument comprising: the imaging probe of any of Claims 93 to 97; and a handle to which the imaging probe can be attached, the handle comprising a flushing control element that is operable to start or stop the flow of the flushing fluid toward the imaging head.

99. An imaging probe for an endoscopic instrument, the probe comprising: an imaging head including an imager; a coupling interface for coupling the probe to a handle of the instrument; a mechanical interface for conveying drive from the handle to move the imaging head relative to a shaft of the probe; a power interface for conveying power from the handle to the imager; and a data interface for conveying image data from the imager to the handle.

100. The imaging probe of Claim 99, comprising an electronic interface that implements the power interface and / or the data interface.

101. The imaging probe of Claim 100, wherein the electronic interface communicates with the imager via a power and control data interface.

102. The imaging probe of any of Claims 99 to 101 , further comprising a first photonics interface configured to convey illuminating light to the imaging head from a light source external to the probe.

103. The imaging probe of any of Claims 99 to 102, comprising a second photonics interface.

104. The imaging probe of Claim 103, wherein the second photonics interface is configured to convey illuminating light to the imaging head from a light source external to the probe.

105. The imaging probe of Claim 103 when dependent on Claim 102, further comprising a light guide interface communicating with the first and second photonics interfaces, the light guide interface being configured to convey the illuminating light from the first photonics interface to the imaging head and to convey the image data from the imager to the second photonics interface, whereby the second photonics interface implements the data interface.

106. The imaging probe of Claim 102 when dependent on Claim 100 or Claim 101 , further comprising a light guide interface communicating with the first photonics interface, the light guide interface being configured to convey the illuminating light from the first photonics interface to the imaging head and to convey the image data from the imager to a data transceiver communicating with the electronic interface, whereby the electronic interface implements the data interface.

107. A handle for an endoscopic instrument, the handle comprising: a coupling interface for coupling the handle to a probe of the instrument; a mechanical interface for conveying drive to the probe;a power interface for conveying power to the probe; and a data interface for receiving image data from the probe.

108. The handle of Claim 107, further comprising a first photonics interface configured to convey illuminating light to the probe.

109. The handle of Claim 108, comprising a source of the illuminating light.

110. The handle of Claim 108, configured to convey the illuminating light from a source external to the handle.

111. The handle of any of Claims 107 to 110, comprising a second photonics interface.

112. The handle of Claim 111 , wherein the second photonics interface is configured to convey illuminating light to the probe.

113. The handle of Claim 112 when dependent on Claim 108, wherein the first photonics interface is connected to a source of visible light and the second photonics interface is connected to a source of infrared light.

114. The handle of Claim 111 , wherein the second photonics interface is connected to a data transceiver to receive the image data from the probe, whereby the second photonics interface implements the data interface.

115. The handle of any of Claims 107 to 114, comprising an electronic interface that implements the power interface and / or the data interface.

116. An endoscopic instrument comprising the imaging probe of any of Claims 99 to 106 and / or the handle of any of Claims 107 to 115.

117. An endoscope system comprising the instrument of Claim 116 and a camera control system.

118. The system of Claim 117 comprising the handle of Claim 108 or Claim 112, wherein the camera control system comprises a source of the illuminating light.

119. The system of Claim 117 or Claim 118, further comprising a display.

120. A probe for an endoscopic instrument, the probe comprising: a proximal interface for attachment to a handle; an elongate shaft; and a grip formation disposed between the proximal interface and the shaft, the grip formation comprising: a distal nose cone adjoining a proximal end of the shaft; a grip ring disposed proximally of the nose cone and having a diameter greater than a diameter of the nose cone; and a shank disposed proximally of the grip ring and having a diameter less than the diameter of the grip ring.

121. The probe of Claim 120, wherein the proximal interface has a diameter greater than the diameter of the grip ring.

122. The probe of Claim 120 or Claim 121 , wherein the diameter of the shank is greater than the diameter of the nose cone.

123. The probe of any of Claims 120 to 122, wherein a proximally-tapering surface extends between the grip ring and the shank.

124. The probe of any of Claims 120 to 123, wherein a distally-facing distal ledge extends between the nose cone and the grip ring.

125. The probe of any of Claims 120 to 124, wherein a distally-facing proximal ledge extends between the shank and the proximal interface.

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