Patent ID: 12200327

DETAILED DESCRIPTION

Turning first toFIG.2an assembled endoscope1according to the present invention is shown. The endoscope1has a proximal end with an operating handle2to be held in one hand by an operator. Accordingly, the operating handle is shaped in a manner ergonomically suitable for operator, in particular but not exclusively for the hand of the operator, as arms and joints may also play a role in the ergonomics. From the handle2an insertion tube3extends towards the distal end of the endoscope. At the distal end of the endoscope1the insertion tube3ends in a bending section4and a tip part5. The bending section4is in mechanical connection with an operating member6, digitally operable by the operator, e.g. by the thumb, thereby allowing the operator to bend the tip part5in a desired direction when advancing the insertion tube3towards a desired location, e.g. through a body cavity of a patient. As can also be seen the endoscope1comprises a flexible connection cable7with a connector8allowing the endoscope1to be connected to a monitoring device such as a monitor92shown inFIG.3forming part of an endoscope1and monitor92system.

Turning now toFIGS.1,1aand1b, an exploded view of the endoscope1is shown. As mentioned, the endoscope1has an operating handle2at the proximal end thereof i.e. at the left-hand side ofFIG.1a. The operating handle2is assembled from and comprises a number of handle parts to be described later. From the operating handle1, the insertion tube3comprising a number of insertion tube parts to be described later extends towards the distal end of the endoscope, i.e. towards the right-hand side ofFIG.1b.

As can be seen inFIG.1a, the operating handle2comprises at least two shell parts9,10forming the outer housing walls of the handle housing of the operating handle2. The two shell parts9,10form the outer housing walls and are shaped to provide an ergonomically suitable operating handle for an operator, gripping it with one hand. In addition to the two shell parts9,10a transition part11forming the transition from the operating handle to the insertion tube3, may be provided. This transition part may also form part of the handle housing. However, the two shell parts9,10constitute the major part of the housing in the embodiment shown.

The two shell parts9,10are adapted to engage and be held and be supported by a chassis12, in turn, adapted to support said at least two shells parts9,10by suitable engagement means, such as recesses and/or protrusions13interlocking with suitable complementary means14,15on the chassis12, better visible inFIGS.4and5. Furthermore the shell part10has pair of columns88of which only one is visible inFIG.1a. These columns88serve the attachment of the shell part10to the chassis12. The shell part has internal engagement means (not visible) adapted to engage the shell part9at the proximal end of the endoscope1, so as hold them together. At the other end the shell parts are held together by the transition part11.

Turning now to theFIGS.4,5and6, the chassis12will be described in greater detail. The chassis12preferably shell shaped, i.e. said chassis comprises an essentially shell shaped structure with a shell wall having an inner surface16and an outer surface17linked by an edge18, said essentially shell shaped structure defining an interior compartment19delimited by said inner surface16and the edge18of the shell wall, the edge thus defining main opening20of said interior compartment19. It will be understood that the chassis12can be designed mainly based on technical requirements, such as kinematic chains of movable parts, and thus be optimized for those technical requirements without having to inherit constraints from the ergonomic requirements of the handle2, i.e. the shape of the two shell parts9,10.

Best visible inFIGS.4and5are a number of different apertures and cut-outs formed in the chassis12. These apertures form vias for different purposes between the interior compartment19and the exterior of the chassis12.

The different cut-outs and apertures differ in shape, size, location and layout depending on their purposes, and may as mentioned be designed according to technical requirements, independently of the ergonomic requirements of the handle2.

Starting from the proximal end of the endoscope1there is an aperture21, as best seen inFIG.6. The aperture21accommodates a push button22, so that the push-button22extends from the interior compartment of the chassis12to the exterior, and on through an aperture in the shell part9to be accessible by an operator holding the handle2of the endoscope1. The push-button22is preferably biased towards an external position by means of two coil springs83guided by two guiding columns84fixed in the bottom two wells provided in the chassis12, preferably by gluing using UV-curable glue or resin transmitted through the transparent material of the chassis12. The two guiding columns83further serve to reduce friction between the coil springs83and the columns88. They are therefore preferably made of a material with relatively low friction, such as low-density polyethylene LDPE, e.g. Comothene® 4812.

On the outer surface17of the shell wall of the chassis12two lugs with holes89are provided. These serve to engage the columns88on the shell part10for attaching it to the chassis, as described above.

In the shell wall two elongate apertures23in the form of slits are provided. The two elongate apertures23are preferably arranged as a pair, one on either side of the aperture23. The two elongate apertures23serve as guide means for the push-button by accommodating a respective protrusion24provided on the surface of the push-button22.

In the vicinity of the two elongate apertures23, a first and a second pair of apertures25,26in the form of essentially cylindrical through holes are provided. The first pair of essentially cylindrical apertures serve as pivotal bearings for trunnions27of a control lever28for maneuvering the bending section5via a pair of Bowden pulls29. As can best be seen inFIGS.1and2, the control lever28is attached to the control knob6, and at least the control knob extends to the outside of the endoscope handle2through a slit30in the shell part10to be accessible by a thumb of the an operator. It should be noted that it is not essential for the function as bearings for the trunnions27of the control knob, that the holes are though holes, but because the chassis is preferably injection moulded, through holes may be much easier manufactured than e.g. blind holes.

It will be understood that due to the slit30and other necessary openings in the shell parts9,10, the handle housing does not protect the internal components fully. Though some protection against spray and splash is provided by the shell parts9,10there is basically fluid communication between the exterior and the interior of the handle housing. This is largely intended, as sealing these openings would be unnecessarily complicated and costly.

The second pair of apertures26are preferably also circular through holes and have the same diameter. They need not be circular, however, as their purpose is allowing the insertion of a tool, such as a rod in order to immobilise the control lever28during assembly of the endoscope, more specifically when attaching the proximal ends of the cables31of the two Bowden pulls29to the control lever28. Accordingly, the control lever28has a through hole32, corresponding in size to the apertures26, and adapted to align with these in one position of the control lever28, thereby allowing the insertion of the tool through all three holes,26,32, so as to block movement of the control lever28with respect to the chassis12. The position of the three holes26,32are selected so as to block the control lever28in a position later corresponding to a neutral position of the control lever28and knob6, in which the bending section4is straight.

With the control lever28blocked during assembly the cables31Bowden pull may be attached to the control lever28in a well defined manner. This is preferably done by threading the respective free end of each cable31through suitable passages in the control lever28, forming a loop43by looping the free ends back to the respective cable and crimping the free end onto the cable31using a barrel33. The barrel33may be of the open barrel type, to avoid the hazel of sliding the barrel33on onto the cable31prior to crimping. Evidently, other attachments for the loop43, such as protrusions, may also be used. Furthermore, entirely different attachments methods without loops are also envisaged, albeit not preferred.

To facilitate this assembly process a cross-shaped aperture34is located in the vicinity of the bottom of the chassis12, i.e. away from the main opening20defined by the edge18. Likewise a cut-out35in the wall from the edge18is provided. The cross-shaped aperture34and the cut-out35allows access to the cables31various tools, such as holding and crimping tools during the assembly.

As can best be seen inFIG.5the cross-shaped aperture34a further, essentially rectangular aperture is generally aligned with a further rectangular access aperture36and a pentagonal aperture37in the direction towards the proximal end of the endoscope1. The cross-shaped aperture34, the rectangular aperture36and the pentagonal aperture37are separated by respective bridges38and39. These bridges38,39do not follow the general curvature of the outer surface17of the chassis12but are indented to form a generally V-shaped groove40connecting the cross-shaped aperture34to the pentagonal aperture37via the rectangular aperture36. As can be seen fromFIG.7, this V-shaped groove40in the outer surface17provides the outer surface17with a means for guiding one or more movable parts, in particular the cable31of the Bowden pull between two apertures, such as the cross-shaped aperture34and the pentagonal aperture37along the outer surface17outside of the interior compartment19. This in turn allows the unsupported free end of the cable31of the Bowden pull to follow a straight line. At the same time, because the unsupported free end of the cable31passes from the interior compartment19of the chassis12to the exterior via the cross-shaped aperture34, the cable31becomes easily accessible for the assembly tools, in particular the crimping tool. The cross-shape of the cross-shaped aperture, in turn, facilitates the use of the tools by providing the necessary space for opening and closing the tools, be it a crimping tool or a holding tool.

InFIGS.4and5a further pair apertures41in the form of essentially cylindrical through holes can be seen. Similar to the apertures25, the further pair of apertures41serve as bearings of trunnions42carrying a pinion44. The pinion44is adapted to be in engagement with a curved rack45having a first free end46and a second end with trunnions47held loosely in suitable receptacles inside the push button22. The rack45as such is loosely held in a guideway comprising a first side85, a second side86and a curved bottom87adapted to keep the rack45in engagement with the pinion44, cf.FIG.6. The first side85and the second side86as well as the curved bottom87are preferably formed integrally with the remainder of the chassis12, e.g. in an injection moulding process. The first side is preferably constituted by a plane surface of a thickened part of the wall, i.e. a raised part of the inner surface16of the chassis12.

Rotation of the pinion44may be effected by an operator moving the push-button22, e.g. depressing it using an index finger, upon which the push-button transfers motion to the curved rack, in turn rotating the pinion44.

On the pinion44, two lever arms48and49of different lengths are provided. These arms48and49are in rigid connection with the pinion44. Via a number of intermediate parts50,51,52,53and54a desired operation of a tool55at the tip part4at the distal end of the endoscope1may be effected when the pinion44is rotated. The manner in which the operation of the tool55is to be effected may depend on the details of the tool. Variations in requirements can be controlled in dependence on the differences in lengths of the lever arms48and49, and possibly articulations of the intermediate part50, at the design stage of the endoscope1with a tool for a specific purpose.

As can best be seen inFIGS.4and6a number of apertures56are arranged to form openings from shelves57on the inner surface16of the chassis12to the outer surface17of the chassis12. These openings are adapted to form undercut receptacles for protruding barbs58on a mounting plate59best seen inFIGS.9,10and13. The mounting plate59is preferably injection moulded from the same transparent plastic material as the chassis12. Using a transparent plastic material is advantageous in that it allows parts to be joined and/or sealed using an UV curable glue or resin, i.e. one that hardens under the influence of ultraviolet light. In respect of glue or resin, be it UV curable or not, it has been found that simply gluing the proximal end portions of the outer tubes60of the Bowden pulls29in suitable recesses61provided along the inner surface16of the shell wall is sufficient to secure the Bowden pulls29in position. This is primarily, because, as it has been realized, adjustment is not needed. Adjustment, in turn, is not necessary because any slacking of the pull cable31of the Bowden pull29is negligible in a disposable endoscope1. The pull cables31are not under any substantial tension during shelf life and will hardly undergo any mentionable stretching during the one short occasion the disposable endoscope1is in use.

The mounting plate59when attached to the chassis12, and possibly secured thereto by preferably UC curing resin or glue, forms a partial lid over the main opening20, and hence partially encloses the interior compartment19. Closing the interior compartment partially on all four sides, rather than only three, adds rigidity to the chassis12as it hinders lateral compression, i.e. of the shell walls towards each other. Accordingly, the chassis12and in particular the walls parts thereof may be made with a reduced strength, i.e. thinner or with more or larger apertures than would otherwise be possible.

As the name suggest, the reinforcing of the chassis12it not the main purpose of the mounting plate59. Rather, the mounting plate59is adapted to carry electronic circuitry of the endoscope1, e.g. on a printed circuit board62, as can best be seen inFIG.10. In the following the electronic circuitry on the printed circuit board62will be referred to as main electronics. This is mainly to distinguish from other electronics located at or embedded in the tip4of the insertion tube3of the endoscope1which will accordingly be termed tip electronics. Both for the term main electronics and the term tip electronics it should be borne in mind that this description relates to a non-limiting exemplary embodiment, and that no functionality requirements should be attributed to these terms.

In modern camera endoscopes1the tip part4forming the distal end of the insertion tube3comprises a camera, such as a CCD camera, and illumination means, such as an LED, allowing the operator to see his actions on a monitor92connected to the endoscope1. This necessitates supply and signal cables or wires7,63to be drawn between the tip part4and the monitor92. In the tip part4space is very limited and apart from the camera and illumination means there no or little room for electronics, such as an amplifier. The signals from the imaging chip of the camera may thus not be amplified at the source. Therefore the weak electrical analogue signals from the camera which are prone to disturbance by electrical noise picked up by signal wires, cables etc. on the way to the monitor92. To overcome this, the main electronics acts as an intermediate between the tip electronics electrical power supply and amplification. Thus the weak signals from the camera arriving on the wires63may be amplified and otherwise modified, e.g. digitally encoded before they are transmitted to the monitor92via the flexible external connection cable7. The present invention thus takes advantage of the fact that in the handle2of the endoscope1there is much better room for the amplification and signal processing means than anywhere else in the signal path from the tip part4at the distal end of the insertion tube3to the monitor92.

Furthermore, with the main electronics being located on the mounting plate59in conjunction with the chassis12it becomes possible to accommodate the electronics according to technical requirements, without much consideration to ergonomic properties and the general layout of the handle2. One particular technical requirement is the protection of the electronics against undesired contact with fluids such as water, which may disturb or ruin the electronics, in particular aqueous saline solutions. Other electrolytes may also pose problems, but main problem is water which in many clinical situations is ubiquitous. The traditional approach in multiple-use endoscopes as well as in single use, i.e. disposable endoscopes1has been to seal the outer housing. This, however, is difficult and costly because the integrity of the housing needs to be breached in order to allow the passage of movable operating parts, such as in the endoscope1according to the present invention the push-button22and the control button6.

Accordingly, the present invention realizes that by fitting a suitable cover64a sealed compartment for the main electronics may be provided within the handle, thus obviating the need for sealing the outer housing of the handle2. The skilled person will understand that this applies, not only to the operating handle with a chassis12on which the preferred embodiments are based, but to operating handles for endoscopes in general. Thus the mounting plate59could also be mounted and directly within a shell part of an operating handle without a chassis12, thereby protecting the main electronics, and possibly reinforcing the shell part mechanically.

The cover64has an edge65which essentially lies in a single plane except for a passage66for the cables7,63to enter and exit the compartment. The edge65is thus adapted to engage a plane surface of the mounting plate59in close vicinity of the edge68of the mounting plate59. As can be seen the edge68is preferably raised along the circumference of the mounting plate thus facilitating the positioning, attaching and sealing of the cover64with respect to the mounting plate59. This attaching and sealing of the cover64with respect to the mounting plate59is preferably also performed using UV curable glue or resin, and accordingly the cover64is therefore also made of transparent plastic material, e.g. injection moulded like the chassis12and mounting plate59. The chassis12, mounting plate59and the cover64are preferably all made of the same material, thus facilitating the choice of a glue or resin with suitable adhesive and cohesive properties. This glue or resin may also be used to seal directly around the cable7and wires63at the passage66. Preferably, the mounting plate59has a receptacle69in the shape of a half-pipe, serving to receive and hold the cable7and wires63as well as serve to limit the amount of UV curable glue or resin used when sealing the compartment around the cable7and wires63.

In a preferred embodiment, however, the glue or resin does not seal directly around the cable7and wires63. Instead the wires63are drawn from the compartment to the tip part4of the insertion tube3of the endoscope1within a wire or cable conduit70, seen only inFIG.1. Consequently, the sealing at the passage66will be around the conduit70and the cable7. The conduit70, in turn, is sealed at the tip part4at the distal end of the insertion tube3of the endoscope1, thereby providing a sealed compartment extending all the way to the tip part4, where it is preferably moulded in together with the camera housing. This sealed compartment protects the wires63, which are relatively thin, against mechanical stress while preserving the sealing properties.

On the opposite side of the mounting plate59away from the compartment and the printed circuit board62, two perpendicular flanges77are provided. These confer additional rigidity to the mounting plate59but their main purpose is to serve as protective barriers for a flexible hose71of a working channel of the endoscope1. Like many prior art endoscopes, the endoscope1of the present invention comprises a working channel e.g. allowing liquid or fluid to be delivered to or extracted from the body cavity into which the endoscope has been advanced.

Starting from the distal end of the insertion tube3of the working channel as a first tube segment72attached to and preferably embedded in the tip part4at one end. The second end of the first tube segment72is connected to a first end of a second tube segment73by means of a short length of rigid tubing74. Rigid in this sense is to mean more rigid than the second tube segment73which, in turn, is more rigid than the first tube segment72which has to comply with the flexibility requirements of the bending section5. Similarly, the first tube segment72is more rigid than the flexible hose71. In this respect it is preferred to make the flexible hose71of a first polyurethane elastomer and to make the first tube72of another polyurethane elastomer. Both polyurethane elastomers could be Pellethane®, which is available in different variants. The second tube segment73may also comprise polyurethane. The second end of the second tube segment73is connected to a T-joint75in connection with a connector76or lead-in mounted on chassis12in connection with a circular aperture91and serving to connect a hose of a suction or irrigation means to the working channel so as to extract or deliver aforesaid liquid or fluid to the body cavity into which the endoscope has been advanced.

However, in the endoscope1according to the present invention the working channel serves not only fluids or liquids, but also serves as a working channel for the tool55, which means that a sealing is necessary where the motion of the lever arms48and49are transferred to the movable intermediate parts53and54which are largely accommodated within the first tube72and the second tube73of the working channel. This sealing is achieved by the use of the flexible hose71which is fixed at one end at the intermediate part51and at the other end at the T-shaped joint75. The hose71may have a smooth surface in a relaxed state or it could be corrugated to form a bellows. The hose71is of a highly flexible thin-walled material as compared to the first tube72and the second tube73of the working channel, because it has to be able to comply with the relative motions between the intermediate parts50,51,52which is a compound translatory and rotational movement in two dimensions with respect to the chassis12.

This compound translatory and rotational movement in two dimensions with respect to the chassis12make the hose71prone to damage from other movable parts of the endoscope1. This is in particular the case for the cables31of the Bowden pulls29and certainly the crimps33even though some protection is achieved by guiding the cables31outside of the chassis12in the V-shaped grooves40. As mentioned above, this protection is further increased by at least one of the flanges77.

This compound translatory and rotational movement in two dimensions with respect to the chassis12is quite substantial, and to accommodate for the movement of the intermediate part50in one direction the rectangular aperture36is provided in the wall of the chassis12. In the other direction the bottom78of the mounting plate between the flanges77serves as a strike plate to limit motion of the intermediate part50so as to be abutted by the claw like end79thereof which clamps and holds the intermediate member52inside the hose71. This limitation of the motion prevents the section of the hose71located between the claw like end79and the intermediate part51to which the hose71is attached to be overstretched and rupture. The flanges77serve also to guide and control the movements of the hose71and claw like end79, in particular in the lateral direction.

The entire insertion tube3is sealingly encapsulated in a flexible outer tube. The outer tube comprises a first outer tube section80and a second outer tube section81joined with a sleeve82. Similarly to the working channel the first outer tube section80is more flexible than the second tube section81in order to comply with the movements of the bending section5. The second tubular member73is however still quite flexible. More specifically, the second tubular member73and a second outer tube section81surrounding it are so flexible that they allow a loose knot to be tied on the insertion tube3. The alternative is a rigid or semi-rigid endoscope where the insertion portion is rigid, only slightly bendable or hinged, and which does not allow a knot to be tied on the insertion tube. Preferably, the first outer tube section80is made from the very same material as the hose71, either of them simply cut to a suitable length from a stock of tubular material for the respective purpose.

Returning now toFIG.1a, a protective tubular member90can be seen. The intermediate part11has a slightly frustoconical section adapted to receive one end of the protective tubular member90. The protective tubular member does not form part of the endoscope1as such but serves as a protective means during storage.