Patent ID: 12201268

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.1,1aand1ban 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.1. 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.1.

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. Turning now toFIGS.1,1aand1ban 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.

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) at 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 part

Turning now to theFIGS.4,5and6the 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 lay-out 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. Cosmothene® 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 manoeuvring the bending section5via an arrangement of 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.

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 pull wires31of 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 pull wire31of the Bowden pull arrangement to follow a straight line. At the same time, because the unsupported free end of the pull wire31passes from the interior compartment19of the chassis12to the exterior via the cross-shaped aperture34, the pull wire31becomes 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.

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. 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. Starting from the distal end of the insertion tube3there is provided a working channel formed by 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

A transparent plastic material is advantageous in that it more efficiently allows dispersion of light and hence better allows parts to be joined and/or sealed using an UV curable glue or resin, i.e. an adhesive 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 guide tubes60of the Bowden pulls29to the operating handle is sufficient to secure the Bowden pulls29in position. Hence it has been realised that in a simply cost reducing and efficient embodiment of a single use endoscope, an outer surface of the outer guide tubes60can be adhered to the operating handle in order to secure the Bowden pulls29in position. I.e. a part of the outer surface of the outer guide tube adjacent to the most proximal part of the outer guide tube is adhered to the operating handle. 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-wire31of the Bowden pull29is negligible in a disposable endoscope1. The pull-wires31are 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. Preferably, the outer guide tubes60are made of a coiled wire. Preferably a coiled stainless steel wire, which also has shown to hardly undergo any stretching during shelf life and use as required for a single-use endoscope.

FIG.7shows in more detail the recesses61provided along the inner surface of the operating handle2. In the embodiment shown recesses61are provided in a chassis12which is a part of the operating handle. Evidently, the recesses may be provided on the inner surfaces of the shell parts9,10forming the shell structure of the operating handle2. Likewise, the proximal end of the outer guide tubes60of the Bowden pulls29may be glued directly to the operating handle without the provision of recesses61. The recesses61are provided in one side of the operating handle2and are formed by upright standing wall sections63forming the elongate recesses61extending in the proximal-distal longitudinal direction of the operating handle2, wherein the outer guide tubes are positioned as shown inFIG.8. The recesses61may share a wall section63and the side wall of the operating handle may form part of the recesses61. The recesses61are elongate with a length I as indicated inFIGS.7and8. To keep the outer guide tubes60in the desired position in the recesses61they are adhered and thereby affixed to the recesses, preferably the adhesive is an UV curable glue or resin, i.e. one that hardens under the influence of ultraviolet light. Dots of applied adhesive64are indicated inFIG.8. It is preferred that the adhesive is applied in the most distal ⅔ of the recesses indicated with ⅔ l inFIGS.7and8. This provides more tolerance to the length of the outer guide tubes and ensures that they are affixed to the operating handle even if they are provided to the shorter side within the tolerances. Evidently, the adhesive may be applied in many different manners as long as it serves the purpose of affixing the outer guide tube60to the operating handle2so that the pull-wire may be keep its tension during self-life and use. Hence the adhesive may be applied before or after the outer tube is positioned as desired and even application of adhesive both before and after positioning of the outer guide tube is possible.

As indicated with h inFIGS.7and8the operating handle2has a height h and the proximal end of the two recesses61are located at different locations along the height h. Thereby the recesses also serves a guide means of the pull-wires31towards the control lever28. As indicated inFIG.1athis is desirable because the pull-wires31are fastened to the control lever28at different heights.

It has also shown advantageous to adhere the outer guide tubes60of the Bowden pulls29to an outer surface of the working channel in order to improve the bending properties of the distal tip4. This is indicated inFIG.2where62indicated points where the guide tube is affixed to the working channel by means of an adhesive, preferably to the second tubular member73. In the embodiment three points between the operating handle and the bending section4are indicated, but at least one point would suffice. Again an UV curable glue or resin, i.e. an adhesive that hardens under the influence of ultraviolet light, which is used for gluing other parts of the operating handle, and especially the proximal ends of the outer guide tubes to the operating handle, is suitable as adhesive to glue the parts together.

The embodiments described in the above description of how to implement the solutions of the invention are only examples. The skilled person will realize that numerous variations to the solutions may be presented without departing from the scope of the invention. In particular, the solutions may be implemented in endoscopes differing in construction from those used in the exemplary embodiments. Also, the skilled person will realize that e.g. material choices and dimensions may vary. The skilled person will also understand that the above description of the exemplary embodiments refer to those embodiments in a neutral relaxed state, i.e. when the endoscopes are not in use, and not influenced by external forces.