Flexible endoscope

Abstract

An endoscope includes a handle connected to a flexible, steerable, kink-resistant insertion tube. An endoscope insertion tube may include a shaft, a lower durometer section proximate to a distal end of the shaft, and a higher durometer section positioned between the lower durometer section and a medium durometer section. The endoscope insertion tube may further include a fourth thermoplastic laminate section proximate to a proximal end of the shaft and having a higher durometer. A method of making an endoscope insertion tube may include inserting a mandrel with one, two, or more lateral slots and a liner into a shaft, wherein the liner is positioned between the mandrel and the shaft, bonding a bonded portion of the liner to an inner surface of the shaft, separating other portion(s) of the liner from the shaft, and inserting a first deflection wire in a gap between the shaft and the unbonded portion(s) of the liner.

Claims

1. An endoscope insertion tube comprising: a shaft having an outer surface, an inner surface, a proximal end, a distal end, and a lumen; a plastic housing fixed to at least a portion of the outer surface of the shaft; a shaft liner, wherein an inner surface of the shaft liner defines a single inner lumen and wherein at least a portion of an outer surface of the shaft liner is fixed to the inner surface of the shaft; a working channel and optics positioned in the inner lumen of the shaft liner; at least one gap between the shaft and the shaft liner; and a deflection wire, wherein at least a portion of the deflection wire is positioned within the gap such that said portion of the deflection wire is within the lumen of the shaft and exterior to the inner lumen of the shaft liner, the plastic housing comprising a first section having at least a first durometer, a second section having at least a second durometer, a third section having at least a third durometer, and a fourth section having at least a fourth durometer; wherein at least a portion of the first section is proximate to a proximal end of the shaft and wherein at least a portion of the fourth section is proximate to a distal end of the shaft; wherein the fourth section is distal to the third section and the third section is distal to the second section; wherein the fourth durometer is less than the first durometer, the second durometer, and the third durometer; and wherein the second durometer is less than the first durometer and the third durometer; and wherein the shaft has a length and comprises a braided material having a variable PIC rate, defined as a number of rotations of braid per centimeter along the length of the shaft, and the shaft has first, second, third, and fourth portions corresponding to the first, second, third, and fourth sections of the plastic housing, and wherein the first portion of the shaft has a PIC rate that is different than PIC rates of the second, third, and fourth portions.

2. The endoscope insertion tube of claim 1, wherein the shaft liner has a substantially uniform thickness.

3. The endoscope insertion tube of claim 1, wherein the inner lumen of the shaft liner is hollow.

4. An endoscope insertion tube comprising: a braided shaft having an inner surface and a lumen; a shaft liner having an inner lumen, wherein at least a portion of the shaft liner is fixed to the inner surface of the shaft; a working channel and optics positioned in the inner lumen of the shaft liner; at least two deflection wires, wherein at least a portion of each deflection wire is positioned within the lumen of the shaft and exterior to the inner lumen of the shaft liner; a thermoplastic laminate laminated to at least a portion of the outer surface of the shaft, the thermoplastic laminate comprising: a first section having at least a first durometer, a second section having at least a second durometer, a third section having at least a third durometer, and a fourth section having at least a fourth durometer; wherein at least a portion of the first section is proximate to a proximal end of the shaft and wherein at least a portion of the fourth section is proximate to a distal end of the shaft; wherein the fourth section is distal to the third section and the third section is distal to the second section; wherein the fourth durometer is less than the first durometer, the second durometer, and the third durometer; and wherein the second durometer is less than the first durometer and the third durometer; and wherein the shaft has a length and comprises a braided material having a variable PIC rate, defined as a number of rotations of braid per centimeter along the length of the shaft, and the shaft has first, second, third, and fourth portions corresponding to the first, second, third, and fourth sections of the thermoplastic laminate laminated to the outer surface of said sections of the shaft, and wherein the first portion of the shaft has a PIC rate that is different than PIC rates of the second, third, and fourth portions.

5. The endoscope insertion tube of claim 4, wherein the shaft liner has a thickness, defined by a greatest difference between an outer diameter of the shaft liner and an inner diameter of the shaft liner at the portions of the shaft liner fixed to the shaft, that is about less than or equal to a thickness of the shaft.

6. The endoscope insertion tube of claim 4, wherein the inner lumen of the shaft liner is hollow.

7. The endoscope insertion tube of claim 4, further comprising: a light source, an image sensor, and a handle, wherein the handle is attached to a first end of the shaft and operably coupled to the deflection wires, wherein the light source and image sensor are positioned proximate to a distal end of the shaft, and wherein the image sensor comprises an analog sensor.

8. The endoscope insertion tube of claim 7, wherein the image sensor comprises electrical lines coupled to an analog-to-digital converter, wherein at least a portion of the electrical lines are positioned within the inner lumen of the shaft liner, and wherein the analog-to-digital converter is positioned proximate to the first end of the shaft.

9. The endoscope insertion tube of claim 4, further comprising at least four gaps between the shaft and shaft liner and at least four tubular deflection channel liners positioned within the gaps.

10. The endoscope insertion tube of claim 4, wherein the inner lumen of the shaft liner is non-circular.

11. The endoscope insertion tube of claim 4, wherein the inner lumen of the shaft liner has plural indentations.

12. The endoscope insertion tube of claim 4, further comprising a cap attached to a distal end of the shaft, wherein the at least two deflection wires are attached to the cap.

13. The endoscope insertion tube of claim 1, further comprising: the shaft liner has at least two bonded sections and at least two unbonded sections, wherein at least two bonded sections are fixedly attached to at least a portion of the inner surface of the shaft; at least a second gap, wherein one gap is between the shaft and each of at least two unbonded sections of the shaft liner; wherein an interior of the shaft liner defines a non-circular inner lumen; at least two deflection channel liners, wherein one deflection channel liner is positioned in each of at least two gaps, and wherein an interior of each deflection channel liner defines a deflection channel; at least a second deflection wire, wherein each deflection wire has a proximal end and a distal end, wherein at least a portion of the at least two deflection wires are positioned in each of at least two deflection channels; wherein at least a portion of at least two deflection wires are positioned within the lumen of the shaft and exterior to the inner lumen of the shaft liner; at least two optics channels positioned within the inner lumen proximate to the distal end of the shaft; at least a portion of at least one light source positioned within an optics channel and proximate to a distal end of the endoscope insertion tube; at least a portion of at least one image sensor positioned within an optics channel and proximate to the distal end of the endoscope insertion tube; and a cap attached to the distal end of the at least two deflection wires.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, which are not true to scale, serve to illustrate exemplary embodiments, forms, and aspects of the invention and to explain principles and advantages thereof:

(2) FIG. 1A is a side elevation view of an embodiment described herein.

(3) FIG. 1B is a detail view of FIG. 1A

(4) FIG. 2 is a perspective view of the embodiment of FIG. 1.

(5) FIG. 3A is a cross-sectional view taken along line 3-3 of FIG. 2.

(6) FIG. 3B is a cross-sectional view of another embodiment described herein.

(7) FIG. 4 is a perspective end view of the embodiment of FIG. 1.

(8) FIG. 5A is a cross-sectional view of another embodiment described herein.

(9) FIG. 5B is a cross-sectional view of another embodiment described herein.

(10) FIG. 5C is a cross-sectional view of another embodiment described herein.

(11) FIG. 6A is a side elevation view of a handle 200.

(12) FIG. 6B is a side elevation view of a handle 200.

DESCRIPTION

(13) Flexible endoscopes, components thereof, and methods of making same are described. In the interest of clarity and conciseness, not all features of an actual implementation—e.g., dimensions, tolerances, etc. —are described in this disclosure. As used in this disclosure, the terms “about” or “approximately” apply to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). It will be appreciated that in the development of a product or method embodying the invention, the developer must make numerous implementation-specific decisions to achieve the developer's specific goals, such as compliance with manufacturing and business-related constraints, that will vary from one implementation to another. Moreover, it will be appreciated that such a development effort may be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

(14) An apparatus embodying features of the present invention is shown in FIGS. 1A and 1B. A flexible endoscope 10 comprises an endoscope insertion tube 100 connected to a handle 200. The insertion tube 100 has a distal end 108 and a proximal end 106 relative to the handle 200.

(15) In one form of the invention, endoscope insertion tube 100 remains at a neutral position 102 until a user actuates a trigger 220 (see FIGS. 1A and 6A), causing the distal end 108 to deflect and assume a deflected position 104. In one plane, the angle of deflection of the distal end 108 may range from 0 degrees at the neutral position 102 to preferably plus or minus 270 or more preferably 300 or more degrees when fully deflected (i.e., in either direction), and all angles in between. In some embodiments, deflection may be in two or three dimensions. When the trigger 220 is released, the handle 200 a biasing force may return the trigger to its neutral position, moving the distal end 108 towards neutral position 102. The ability to articulate the distal end 108 of the endoscope insertion tube 100 enhances steerability.

(16) In one form, the endoscope insertion tube 100 comprises a plastic laminate comprising four sections: (i) a relatively high durometer proximal section 112, preferably beginning at the proximal end 106 and continuing for most of the length of the endoscope insertion tube 100; (ii) an intermediate durometer middle section 114; (iii) a relatively high durometer middle section 116; and (iv) a relatively low durometer distal section 118, proximate to the distal end 108 of endoscope insertion tube 100. The specific durometer used may depend on the application, but preferred ranges for each of the sections are:

(17) first section 112 . . . preferably about 50-140 durometers or more durometers and more preferably about 65-130 and even more preferably about 70-120 durometers;

(18) second section 114 . . . preferably about 40-100 durometers and more preferably about 45-75 durometers and even more preferably about 50-60 durometers;

(19) third section 116 . . . preferably about 50-140 durometers or more durometers and more preferably about 65-130 and even more preferably about 70-120 durometers;

(20) fourth section 118 . . . preferably about 15-55 durometers or less and more preferably about 20-50 durometers and even more preferably about 30-40 durometers.

(21) Regardless of the foregoing preferred ranges, however, the second section 114 preferably has a durometer less than the durometers of the first and third sections 112, 116 and the fourth section 118 preferably has a durometer less than the durometers of the first, second, and third sections 112, 114, 116. The durometers of the first and third sections 112, 116 may be the same or different. Further embodiments may have one, two or three sections or even five or more sections, each with the same of different durometers.

(22) In addition or alternatively, the second section 114 may be more flexible (i.e., less rigid) than the first and third sections 112, 116 and the first, second, and third sections 112, 114, 116 may be less flexible (i.e., more rigid) than the fourth section 118. The flexibility or rigidity of the first and third sections 112, 116 may be the same or different.

(23) In addition or alternatively, when in a deflected position 104, the second section 114 may have a smaller bend radius than the first and third sections 112, 116, and the fourth section 118 may have a smaller bend radius and shorter deflection tangent than the second section 144. The bend radius of the first and third sections 112, 116 may be the same or different.

(24) In one embodiment, the length of the first section 112 may be about 50-70 cm, the second section 114 may be about 1-3 cm, the third section 116 may be about 1-3 cm, and the fourth section 118 may be about 4-6 cm.

(25) In one embodiment, the laminate may be made of a plastic or a thermoplastic, such as polyether block amide (also known as Pebax®), polytetrafluoroethylene (“PTFE”), or nylon. Different sections of laminate may comprise the same or different materials as other sections, including combinations of the foregoing materials.

(26) Turning to FIGS. 2 and 3, the distal end 108 of the endoscope insertion tube 100 is shown without a cap 160. The endoscope insertion tube 100 comprises a tubular shaft 120, preferably comprising an alloy and more preferably comprising a steel alloy. In one preferred embodiment, the shaft 120 comprises flexible braided flat steel wires. Additionally or alternatively, the shaft 120 may comprise wires comprising titanium nickel alloy.

(27) In one form, as best seen in FIG. 4, the distal section 118 of the plastic laminate terminates proximate to the distal end 108, leaving an exposed portion 122 of the shaft 120. A marker 158 may be positioned on or near the exposed portion 122. In an alternative form, the distal section 118 may extend to cover the shaft 120 up to the cap 160.

(28) Different durometers and flexibility in two different sections of the endoscope insertion tube 100 may be achieved, for example, by using different thicknesses of the material bonded to an outer surface of the shaft 120. For example, the higher durometer proximal section 112 may have a thermoplastic laminate thickness (and hence outer diameter) that is greater than the thermoplastic laminate thickness (and outer diameter) of the lower durometer distal section 118.

(29) In addition or alternatively, different durometers and flexibility in an intermediate section of the endoscope insertion tube 100 may be achieved by overlapping two neighboring laminate sections. For example, as shown in FIG. 5C, two laminate sections may overlap. FIG. 5C shows a cross-section of an end of middle section 114 overlapping an end of proximal section 112. In some forms, two or more or all of the laminate sections may have at least some overlap with one or both neighboring sections. The order of overlap is reversible, so another form may have an end of section 112 overlapping an end of section 114. If the overlapping laminate sections have different durometers, then the overlapping section may have an intermediate durometer, i.e., less than the higher durometer section and greater than the lower durometer section.

(30) In one form, the endoscope insertion tube 100 comprises a liner 130 having a bonded portion 132 fixed to a portion of an inner surface of the shaft 120 and an unbonded portion 133, which is not fixed to the shaft 120 (see, e.g., FIG. 5, where unbonded portions 133 are proximate to slots 134 of mandrel 135). The interior of the liner 130 may define the boundaries of an inner lumen 150. One or more gaps between the liner 130 and the shaft 120 may be used as deflection channels 142.

(31) In some forms, as shown in FIGS. 3A and 3B, a shaft liner 130 and one or more gaps between the liner 130 and the shaft are positioned within a lumen (not labeled) of the shaft 120. The shaft liner 130 may have an inner lumen 150.

(32) The shaft 120 comprises a lumen comprising the liner, the space between the shaft liner and the shaft,

(33) As shown in FIG. 3B, a deflection wire 140 may be positioned in one or more deflection channel liners 143 or in each of them. The liner 143 may be a plastic or more preferably a thermoplastic, such as PTFE.

(34) As shown in FIGS. 2, 3A, and 5A, a second liner 143 may be positioned within the gap (between liner 130 and shaft 120), wherein an interior of the second liner 143 may define the deflection channel 142.

(35) A wide range of possibilities exist for what may be positioned within the inner lumen 150, which will depend on the application(s) for which the insertion tube is used. In one form, at least one working channel 152 and at least one optics channel 155 may be positioned within the inner lumen 150. One optics channel 155 may house an imaging optics bundle 156 comprising a complimentary metal-oxide semiconductor (“CMOS”) or other suitable image sensor, such as a camera or charge-coupled device sensor. The imaging optics bundle 156 may further comprise a solid core optical fiber connected to the image sensor. One or more optics channels 155 may house one or more light sources, such as an illuminated optical fiber or a light emitting diode (“LED”). Alternatively, an LED may be positioned at the distal end 108 of the shaft without an accompanying optics channel 155. In some embodiments, two working channels 152 may be positioned within the inner lumen 150.

(36) Preferred embodiments, in which wall thickness has been minimized by positioning deflection wires 140 within the lumen 150 of the shaft 120, allow an efficient use of space within the lumen 150. The outer diameter of the insertion tube 100 may be the size of typical ureteroscopes (e.g., 2-3 mm), but full-sized optical components and working channel 152 may be used. Smaller optics may produce an inferior image and a smaller working channel may not allow for use of common tools and may also slow irrigation flow.

(37) Turning to FIG. 4, an endoscope insertion tube 100 may comprise a marker 158 and cap 160. The marker 158 may comprise a material that is radio opaque, such as a high density metal. One or more markers 158 may be positioned anywhere along the length of the endoscope insertion tube 100; one preferable location is proximate to the distal end 108 of the endoscope insertion tube 100, so that users are able to visualize or otherwise detect the approximate location of the distal end 108 within a patient.

(38) The cap 160 may be attached, such as by welding or other suitable means, to the distal ends of the deflection wires 140. In some embodiments, the deflection channels 142 are not in fluid communication with the lumen 150. The cap 160 may comprise one or more apertures for the distal ends of the working channel 152 and optics channels 155 to interface with the environment proximate to the distal end 108 of the endoscope insertion tube 100.

(39) In some forms, the marker 158 and optics channels 155 are about 3-4 mm or less in length. The length of the rigid marker 158 is preferably minimized because it enlarges the deflection tangent of a preferentially bendable portion (e.g., sections 114, 116, and 118) of the insertion tube 100.

(40) FIG. 6 shows a handle 200 for steering the insertion tube 100. In one embodiment, the handle 200 comprises a tip 202, luer lock 210, and trigger 220. A tip 202 of the handle 200 connects to the proximal end 106 of endoscope insertion tube 100. A trigger 220 actuates the deflection wires 140.

(41) The handle 200 may also comprise a light pin 230, imaging optics bundle termination 256, and eyepiece 258. A light pin 230 illuminates the one or more illuminating optics bundles 157. The images captured and transmitted through the imaging optics bundle 156 are displayed on an eyepiece 258, which is connected to an imaging optics bundle termination 256. The eyepiece 258 may be removable or permanently attached.

(42) One embodiment of the invention is a method of making an endoscope insertion tube 100 using a mandrel 135. As shown in FIG. 5, a primary mandrel 135, a liner 130, and two secondary mandrels 141 may be inserted into a shaft 120.

(43) In some forms, as shown in FIGS. 5A-C, the mandrel 135 may have two slots 134 on opposing sides of the mandrel. Each slot 134 is preferably a concave groove or indentation along at least a portion of the length of the mandrel, wherein the slot 134 is sized to form a deflection channel 142 between the liner 130 and shaft 120 that can accept a deflection wire 140. In alternative forms, the mandrel 135 may have only one slot 134 or two, three, four, or more slots 134, corresponding to a predetermined number of deflection channels 142 for deflection wires 140. For a mandrel 135 with plural slots 134, they may be spaced regularly or irregularly across the circumference of the mandrel 135. In some forms, one or more slots 134 may be shaped to substantially conform to at least a portion of the exterior of secondary mandrels 144. One or more secondary mandrels 144 may be nested within a slot 134 (see, e.g., FIG. 5A).

(44) In addition or alternatively, the height 137 and/or width 138 of the cross-section of the mandrel 135 could vary along its length. In one preferred embodiment, for example, the width (i.e., diameter across one or more slots 134) may be a certain value along the higher durometer proximal section 112 and the width be less at one or more of the middle and distal sections 114, 116, 118. The width 138 of the mandrel 135 is preferably measured at the base of slots 134 (see arrows for feature 138 in FIGS. 5A-C). In this form, the sections 114,116,118 will have enhanced preferential deflection relative to section 112. In addition or alternatively, the height 137 may be a certain value at a section of the proximal section 112 and the height 137 may be greater at one or more of the middle and distal sections 114, 116, 118. These forms may also have an enhanced deflection tangent for the distal end 108 of the insertion tube 100.

(45) In addition or alternatively, the depth of the slot 134 may vary at different sections along the length of the mandrel 135, creating a variable cross section. This variable cross section could impart a variable moment of inertia (i.e., resistance to bending) to the insertion tube 100. In one form, the mandrel 135 may have deeper slots 134 at a section near the proximal end 106 of endoscope insertion tube 100, which may permit the proximal ends of deflection wires 140 to be positioned proximate to a center point of the inner lumen 150. The mandrel 135 may also have shallower slots 134 at a section near the distal end 108 of the endoscope insertion tube 100, which may permit the distal ends of deflection wires 140 to be positioned farther from the center point of the inner lumen 150. In addition or alternatively, this configuration may enhance the effect of the variable durometer laminate on the middle and distal sections 114, 116, 118 of the insertion tube 100.

(46) Secondary mandrels 141 are positioned between the shaft 120 and the liner 130 to keep open what will become the deflection channels 142.

(47) As shown in FIGS. 1, 2, and 5C one or more laminate sections 110 may be positioned over the shaft 120. One preferred method of bonding plastic laminate 110 to the shaft 120 is through the use of an additional heat shrinkable tube (not shown) comprising any suitable thermoplastic material, such as fluorinated ethylene-propylene (“FEP”). Once the plastic laminate sections 110 are in position around outside surface of the shaft 120, the tube is positioned around the sections 110.

(48) The primary mandrel 135, liner 130, secondary mandrels 141, shaft 120, laminate sections 110, and shrink tube may be heated to bond the shaft 120 to the liner 130 and laminate sections 110. A laminator may be used to apply dry heat forced air convection over the insertion tube assembly. The temperature and time may vary according to the differing durometers of each section of the insertion tube 100. The heat may simultaneously shrink the outer tube and melt the plastic layer(s). If a shrink tube is used, it is removed after the insertion tube assembly cools.

(49) In an alternative form, a plastic housing 110 may be cast on the exterior of the shaft 120. Casting a plastic housing 110 onto shaft 120 may be achieved by emerging the shaft 120 into liquid plastic, such as a molten thermoplastic, thereby adding thin layers (each less than about 0.01-0.1 mm) until a desired thickness is achieved.

(50) In some forms, the shaft 120 comprises braided wire, such as steel or an alloy thereof, and the plastic laminate sections 110 may be laminated to the shaft 120. The plastic laminate 110 may at least partially melt into and/or through interstices of the braided shaft 120 and may attach to the shaft liner 130, fixing at least a portion of the shaft liner 130 to the inner surface of the shaft 120. The melted plastic laminate 110 may also attached to one or more deflection channel liners 143. The melted plastic laminate 110 may also file most of the gap around and between the mandrels 144 (see FIGS. 5A-C) and the shaft 120.

(51) The braid may have a variable PIC rate (i.e., rotations of braid per centimeter) such that it is more rigid in the proximal section 112 than one or more of the other sections 114, 116, 118. In addition or alternatively, the braid may be reinforced with a coil (not shown). In addition or alternatively, the braid may be electroplated over at least section 112 to further increase its rigidity. In some forms, the braid may not be electroplated except for section 112.

(52) In addition or alternatively, heating the plastic laminate sections 110 melts and bonds the plastic laminate 110 to the shaft 120 without a heat shrinkable tube.

(53) During the heating step, at least a bonded portion 132 of the liner 130 bonds to an inner surface of the shaft 120 and an unbonded portion 133 is separated from the inner surface of the shaft 120 by the secondary mandrel 141, creating a gap that may be used as a deflection channel 142.

(54) In some embodiments, the primary mandrel 135 may be coated with PTFE, which will coat the inner lumen 150.

(55) In operation, an endoscope insertion tube 100 is connected to a handle 200. The proximal section 112, which in some embodiments may form most of the length of insertion tube 100, may be coiled in packaging. The insertion tube 100 may be uncoiled and proximal optical connections (not shown) to the imaging optics bundle 156 and illumination optics bundle 157 may be operably connected, through the handle 200, to the eyepiece 258 and light pin 230, respectively. The working channel 152 may be connected to irrigation.

(56) In one application, the endoscope insertion tube 100 may be back loaded on a guide wire that is placed with a cystoscope or introduced to the ureter using an access sheath. To locate abnormalities, such as a kidney stone, the insertion tube 100 may be guided through the renal collecting system using the imaging provided by imaging means and x-ray imaging provided by fluoroscopy. A variety of small tools can be passed through the working channel. For example, a laser may be used to break the stone or it may be removed with a basket.

(57) The embodiments and examples shown in the drawings and described above are exemplary of numerous others that may be made within the scope of the appended claims. It is contemplated that numerous other configurations may be used, and the material of each component may be selected from numerous materials other than those specifically disclosed.

(58) No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. For example, an embodiment comprising a singular element does not disclaim plural embodiments; i.e., the indefinite articles “a” and “an” carry either a singular or plural meaning and a later reference to the same element reflects the same potential plurality. A structural element that is embodied by a single component or unitary structure may be composed of multiple components. Ordinal designations (first, second, third, etc.) merely serve as a shorthand reference for different components and do not denote any sequential, spatial, or positional relationship between them. Words of approximation such as “about,” “approximately,” or “substantially” refer to a condition or measurement that, when so modified, is understood to not necessarily be absolute or perfect but would be considered close enough by those of ordinary skill in the art to warrant designating the condition as being present or the measurement being satisfied. For example, a numerical value or measurement that is modified by a word of approximation, such as “about” or “approximately,” may vary from the stated value by 1, 2, 3, 4, 5, 6, 7, 10, 12, and up to 15%.

(59) The foregoing description of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form(s) disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined only by the following claims, as amended, and their equivalents.

DESCRIPTION OF REFERENCED NUMERALS

(60) 10 . . . flexible endoscope

(61) 100 . . . endoscope insertion tube

(62) 102 . . . neutral position

(63) 104 . . . deflected position

(64) 106 . . . proximal end of endoscope insertion tube 100

(65) 108 . . . distal end of endoscope insertion tube 100

(66) 110 . . . thermoplastic laminate

(67) 111 . . . laminate section

(68) 112 . . . higher durometer proximal section

(69) 114 . . . intermediate durometer middle section

(70) 116 . . . higher durometer middle section

(71) 118 . . . lower durometer distal section

(72) 120 . . . shaft

(73) 122 . . . exposed portion of shaft

(74) 130 . . . shaft liner

(75) 132 . . . bonded portion of liner 130

(76) 133 . . . unbonded portion of liner 130

(77) 134 . . . slot of mandrel 135

(78) 135 . . . primary mandrel

(79) 136 . . . surface of mandrel 135

(80) 137 . . . height of mandrel 135

(81) 138 . . . width of mandrel 135

(82) 140 . . . deflection wire

(83) 142 . . . deflection channel

(84) 143 . . . deflection channel liner

(85) 144 . . . secondary mandrel

(86) 150 . . . inner lumen of shaft liner 130

(87) 152 . . . working channel

(88) 155 . . . optics channel

(89) 156 . . . imaging optics bundle

(90) 157 . . . illuminating optics bundle

(91) 158 . . . marker

(92) 160 . . . cap

(93) 200 . . . handle

(94) 202 . . . tip

(95) 210 . . . luer lock

(96) 220 . . . trigger

(97) 230 . . . light pin

(98) 256 . . . imaging optics bundle termination

(99) 258 . . . eyepiece