Endoscope with a flexural distal tip

Abstract

An endoscope has a narrow, metal cannula for insertion into the body of a patient. The distal tip of the endoscope has substantially the same outer diameter as the rest of the cannula when no tool is being passed through its working channel. When a tool is passed through the cannula the distal tip expands to a larger diameter to accommodate the tools outer diameter. The endoscope distal tip includes one or more compliant flexure mechanisms formed by cuts in the metal that facilitate its expansion when a tool is inserted and retraction due to the resiliency of the metal when a tool is withdrawn. The endoscope has an imaging sensor with a direction of view the is substantially unchanged when a tool is inserted.

Description

ENDOSCOPE WITH A FLEXURAL DISTAL TIPREFERENCE TO RELATED APPLICATION

[0001] This application incorporates by reference and is a continuation-in-part of U.S.Patent Appl. Ser. No. 16 / 268,819.

[0002] This application incorporates by reference and claims the benefit of the filing date of each of the above-identified patent application, as well as of any applications that it incorporates by reference, directly or indirectly, and the benefit of which it claims, including U.S. provisional applications, U.S. non-provisional applications, and International applications.

[0003] This patent application claims the benefit of and incorporates by reference the following provisional applications:U.S. Provisional Patent Appl. Ser. No. 63 / 524,101 filed June 29, 2023; andU.S. Provisional Patent Appl. Ser. No. 63 / 447,290 filed February 21, 2023.

[0004] Said U.S. Patent Appl. Ser. No. 16 / 268,819, and U.S. Patent App. Ser. No.16 / 268,909 (now U.S. Pat. 11,712,149), each claim the benefit of and incorporates by reference U.S. Provisional Patent Application Ser. No. 62 / 630,718, filed on February 14, 2018.FIELD

[0005] This invention relates to endoscopic medical devices. More particularly some embodiments relate to an endoscope assembly. More particularly some embodiments relate to medical endoscope cannulas for insertion through a relatively narrow body opening such as the cervix for imaging inside a body cavity such as the uterus, where such cannulas contain a working channel through which a tool introduced.BACKGROUND

[0006] For medical endoscopes intended for insertion into a narrow body opening, it is often desirable for the outer diameter of the portion being inserted, i.e. the cannula, to be as small as possible. Cannula diameter tends to have a direct relation to patient pain and comfort. Thus, a smaller diameter cannula will tend to minimize pain of the patient during the insertion process. In the example of the hysteroscope, the cannula will be inserted into the uterus through a natural body opening called cervix which is very small. Generally, dilation of the cervix will be needed if the diameter of the cannula exceeds 5mm. Such dilation can be quite traumatic, causing great pain of the patient if not anesthetized. On the other hand, the distal tip of the cannula has to be thick enough to accommodate the imaging optics, the illumination elements, and channels for fluid inflow / outflow as well as for surgical tool introduction, thus designing a slim cannula tip with all necessary functionalities can be challenging.SUMMARY

[0007] According to some embodiments, an endoscope cannula assembly comprises: an axially extending, hollow outer tube and an axially extending, hollow inner tube inside the outer tube; wherein one of said outer and inner tubes has a distal portion formed by cuts therein into a flexure structure configured to resiliently expand in response to a radially outward force applied thereto and to flex back when the force is removed, said flexure structure comprising: a proximal flexure segment that comprises first and second axially extending parts formed by axially extending cuts into said distal portion and a series of rib arc structural members formed by partial circumferential cuts into said axially extending parts whereby said first flexure segment is rigid in the axial direction and resiliently flexible in the radially outward direction; a distal flexuresegment that is positioned distally from the proximal flexure segments and is formed by serpentine cuts into said distal portion leaving axially extending flexible ribbons connected at their axial ends whereby the distal flexure segment is configured to expand in response to a radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; said cannula assembly further comprising a supporting bracket secured at said distal portion and extending radially inwardly therein and a sensor assembly secured to the supporting bracket and comprising a camera module and illumination elements; and an axially extending working channel inside said inner tube; wherein said working channel is configured to accept a surgical tool that has a cross-section greater than hollow space inside said distal portion between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket to thereby push the supporting bracket radially outwardly and expand said proximal and distal flexure segments; and wherein said distal portion is configured to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion of the proximal and distal flexure segments.

[0008] According to some embodiments, the endoscope cannula assembly can further include one or more of the following: (a) said distal portion is a distal portion of said outer tube; (b) said distal portion is a distal portion of said inner tube that extends distally from the outer tube; (c) the inner and outer tubes have central longitudinal axes spaced from each other to thereby leave space between an inner wall of the outer tube and an outer wall of the inner tube as a fluid flow channel; (d) a first valve fluidly coupled to said working channel and a second valve fluidly coupled to said fluid flow channel; (e) a bridging tube between said valves, wherein said valves and bridging tube are configured to selectively enable irrigation fining flow into the working channel and drainage flow out of the fluid channel or irrigation fluid flow into both saidworking channel and fluid flow channel; (f) a rigid conduit configured for insertion into said working channel to exert said radially outward force on said supporting bracket and having an internal channel for insertion of a surgical instrument that need not be rigid; (g) a handle assembly to which a proximal portion of the cannula assembly is rotatably secured and a rotation knob coupled to said cannula assembly to rotate the cannula assembly about a longitudinal axis thereof relative to said handle assembly; and (h) the outside diameter of the cannula assembly is less than 5 mm at a portion thereof configured for insertion into a patient.

[0009] According to some embodiments, an endoscope cannula assembly comprises: a first, axially extending, hollow tube that has a distal portion made of a metal and comprises a flexure structure formed by cuts into said distal portion and configured to expand radially outwardly and flex back due to resiliency of said metal: wherein said cuts include a serpentine cut forming a flexure segment comprising axially extending flexible ribbons connected at axial ends to thereby form a serpentine continuous strip of metal with ends connected to said distal portion of the hollow tube and configured to expand said distal portion of the hollow tube radially outwardly in response to radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; a supporting bracket at said distal portion, extending radially inwardly therein and a sensor assembly secured to the supporting bracket and comprising a camera module and illumination elements; an axially extending working channel inside said tube; and wherein said working channel is configured to accept a surgical tool that has a crosssection greater than hollow space inside said distal portion of the hollow tube that is between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket and thereby generates radially outward force expanding said flexure structure.

[0010] According to some embodiments, the endoscope cannula assembly described in the immediately preceding paragraph can further include one or more of the following: (a) said distal portion is configured to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion; (b) said distal portion of the tube further comprises axially extending parts that are axially spaced from said flexible ribbons and are formed by axially extending cuts into said distal portion; (c) said distal portion of the tube further includes a series of rib arc structural members formed by partial circumferential cuts into said axially extending parts that are axially spaced from said flexible ribbons, whereby said axially extending parts are rigid in the axial direction and resiliently flexible in the radially outward direction; (d) a second hollow inner tube that is inside said first tube, wherein said working channel is inside said inner tube and said inner tube has an outside diameter less than the inside diameter of the first tube to thereby leave a fluid flow channel between the first and second tubes; (e) a first valve fluidly coupled to said working channel and a second valve fluidly coupled to said fluid flow channel; (f) a bridging tube between said valves, wherein said valves and bridging tube are configured to selectively enable irrigation fining flow into the working channel and drainage flow out of the fluid channel or irrigation fluid flow into both said working channel and fluid flow channel; (g) a rigid conduit that is configured for insertion into said working channel to exert said radially outward force on said supporting bracket and has an internal channel for insertion of a surgical instrument that need not be rigid; (h) a second tube that surrounds the first tube, wherein said distal portion is a distal portion of said second tube; (i) the inner and outer tubes have central longitudinal axes spaced from each other; (j) a handle assembly to which a proximal portion of the cannula assembly is rotatably secured and a rotation knob coupled to said cannula assembly to rotate the cannula assembly about a longitudinal axis thereof relative to saidhandle; and (k) the outside diameter of the endoscope cannula assembly is less than 5 mm at a portion thereof configure for insertion into a patient.

[0011] According to some embodiments, a method of imaging an internal space in a patient comprises: inserting into an internal space in a patient a hollow tube that has a distal portion made of a metal and comprises a flexure structure formed by cuts into said distal portion and configured to expand radially outwardly and flex back due to resiliency of said metal: wherein said cuts include a serpentine cut forming a flexure segment comprising axially extending flexible ribbons connected at axial ends to thereby form a serpentine continuous strip of metal with ends connected to said distal portion of the hollow tube and configured to expand said distal portion radially outwardly in response to radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; providing a supporting bracket secured at said distal portion and extending radially inwardly therein and a sensor assembly secured to the supporting bracket and comprising a camera module and illumination elements, and an axially extending working channel inside said tube; and inserting a surgical tool distally in said working channel that has a cross-section greater than hollow space inside said distal portion between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket and thereby generates radially outward force expanding said flexure structure.

[0012] According to some embodiment, the method further comprises one or mor of: (a) configuring said distal portion to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion; (b) providing at said distal portion of the tube axially extending parts that are axially spaced from said flexible ribbons and are formed by axially extending cuts into said distal portion; (c) providing at said distal portion of the tube aseries of rib arc structural members formed by partial circumferential cuts into said axially extending parts that are axially spaced from said flexible ribbons, whereby said axially extending parts provided with said rib arc structural elements are rigid in the axial direction and resiliently flexible in the radially outward direction.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which principles of the invention are utilized, and the accompanying drawings of which:

[0014] FIG. l is a sectional view of a hysteroscope having a cannula with an expandable distal tip, according to some embodiments;

[0015] FIGs. 2A and 2B illustrate further detail of the distal tip of the cannula assembly, according to some embodiments;

[0016] FIG. 3 is a perspective view illustrating further detail of the distal portion of an outer tube that includes a flexure structure, according to some embodiments;

[0017] FIGs. 4A-4D are top views illustrating further details of compliant mechanisms for use with flexural structures in a distal tip of an endoscope, according to some embodiments;

[0018] FIGs. 5A and 5B are perspective views of a supporting bracket and a portion of an inner tube, respectively, used with a flexural distal tip of an endoscope, according to some embodiment;

[0019] FIGs. 6A and 6B are sectional views illustrating a tool partially inserted into the working channel of an endoscope having a flexural distal tip, according to some embodiments;

[0020] FIGs. 7A and 7B are sectional views illustrating a tool fully inserted into the working channel of an endoscope having a flexural distal tip, according to some embodiments;

[0021] FIGs. 8A and 8B are perspective and sectional views, respectively, of a flexural distal tip of an endoscope, according to some embodiments;

[0022] FIG. 9 is a sectional view of endoscope flexural distal tip, according to some other embodiments;

[0023] FIGs. 10A, 10B and 10C are sectional views of an auxiliary conduit that is used to facilitate the introduction of flexible tools through an endoscope having a flexural distal tip, according to some embodiments; and

[0024] FIGs. 11 A and 1 IB are schematic diagrams illustrating a fluid system for providing endoscope fluid inflow and outflow, according to some embodiments.DETAILED DESCRIPTION

[0025] A detailed description of examples of preferred embodiments is provided below.While several embodiments are described, it should be understood that the new subject matter described in this patent specification is not limited to any one embodiment or combination of embodiments described herein, but instead encompasses numerous alternatives, modifications, and equivalents. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding, some embodiments can be practiced without some or all of these details. Moreover, for the purpose of clarity, certain technical material that is known in the related art has not been described in detail in order to avoidunnecessarily obscuring the new subject matter described herein. It should be clear that individual features of one or several of the specific embodiments described herein can be used in combination with features of other described embodiments or with other features. Further, like reference numbers and designations in the various drawings indicate like elements.

[0026] As used herein, the terms distal and proximal refer to locations referenced from the apparatus and can be opposite of anatomical references. For example, a distal location of a probe may correspond to a proximal location of an elongate member of the patient, and a proximal location of the probe may correspond to a distal location of the elongate member of the patient.

[0027] While some exemplary embodiments are directed at hysteroscopes, one of skill in the art will appreciate that this is not intended to be limiting, and the devices described herein may be used for other therapeutic or diagnostic procedures and in other anatomical regions of a patient’s body.

[0028] There are some known designs for a compact endoscope distal tip having a slim cannula. For some proposed structures the distal tip is somewhat flexible such that it keeps a low profde or small cross-section when initially inserted through the narrow bodily orifice. After the cannula distal tip passes through the orifice and arrives inside a wide cavity, the operator or user introduces the surgical tool through a working channel resulting in the expansion or lateral movement of portions of the cannula distal tip. Upon completion of the procedure, the tool is withdrawn from the working channel, and the distal tip of the cannula is designed to recover to its original size or position before the cannula is withdrawn from the patient body.

[0029] U.S. Pat. No. 11,141,045 discusses an endoscope with an expandable distal tip where a flexible working channel is wrapped up with an elastomeric outer sheath. When a surgical tool is introduced through the working channel toward the distal tip, the initially-collapsed cross-section of the working channel will stretch to an enlarged-profile state and the elastomeric outer sheath will be expanded resultingly. The expanded outer sheath creates a radially inward tension on the working channel such that the working channel sleeve will collapse toward or to its original low-profile state when the surgical tool is withdrawn by the user.

[0030] U.S. Pat. No. 11,432,717 discusses a design of expandable distal tip having two- segments “offset” shape. The distal end is also enclosed within an expandable outer sleeve made of elastomeric material, and the working channel is a metal sleeve with its distal portion cut to form a hinge. When a surgical tool advances through the working channel and sticks out, it will push and deflect the living hinge. As a result, the elastomeric outer sleeve is expanded by the deflected hinge with a tendency to constrict back. Once the tool is withdrawn from the working channel, the outer sleeve automatically constricts under its elastomeric force to collapse the hinge back toward its original position.

[0031] U.S. Pat. No. 11,529,048 discusses another design of an endoscope distal tip having an expandable profile. The entire image sensor assembly is mounted on a flexible arm structure consisting of two living hinge portions. In the original state, the sensor assembly and the flexible hinges are all restrained within the outer sheath with tension. After inserting the endoscope distal tip into the patient cavity, the user then moves the outer sheath toward the proximal end to unleash the flexible arm such that it will fully stretch out under its inherent spring force, resulting in the sideway displacement of the sensor assembly and hence the clearance of pathway for the surgical tool introduced through the working channel.

[0032] According to some embodiments, an endoscope cannula is described that has a compact design including a relatively small diameter including the diameter of its distal tip. According to some embodiments, the described design includes an expandable distal tip. In someembodiments, the expandability of the distal tip is achieved by cutting a flexure structure into the distal portion of the tubing wall where an image sensor assembly is mounted. The working mechanism of the expandable tip can be described as follows.

[0033] When no surgical tool is inserted in the working channel of the endoscope, the image sensor assembly adhered to the flexure structure at the distal tip is positioned in lateral space that would at least partially be occupied by the working channel. Therefore, the image sensor assembly, which can include a camera module, associated lenses and electronic as well as one or more lighting components, does not use any additional cannula diameter.

[0034] When a tool advances along the working channel toward the distal tip, it clears its pathway by pushing the sensor assembly sidewards or laterally (radially outwardly) with respect to the central longitudinal axis of the cannula. A translational offset displacement of the sensor assembly results and consequently a flexural structure is expanded. The expanded flexure, in turn, creates a contractive tension that help press the sensor assembly firmly against the inserted tool. This way, the sensor assembly rides stably on the tool, eliminating or reducing vibration during the operation.

[0035] When the procedure that includes the tool has finished, the operator withdraws the tool from the working channel, and the flexure automatically contracts (radially inwardly) to its non-stressed state making the sensor assembly move back to its original position.

[0036] With this flexural structure of the distal tip, the cannula of the endoscope can be designed with a very low profile (i.e. small outer diameter) while still maintaining a relatively large cross-section of the working channel (for instance, a 9 Fr working channel inside a cannula with less than about 5.0 mm overall outer diameter). Such characteristics are highly desirable and beneficial for hysteroscopy as well as other minimally invasive endoscopic operations.

[0037] FIG. 1 is a cross section view of a hysteroscope having a cannula with an expandable distal tip, according to some embodiments. The endoscope 100 includes a handle assembly 11 and a cannula assembly 15. The handle assembly 11 includes, among other things, a number of components and control elements. A rotation knob 112 that allows the user to rotate the cannula assembly 15 around its longitudinal axis as shown by dashed arrow 102 so that the orientation of the image sensor assembly mounted at the distal tip 120 of cannula can be adjusted as shown by dashed arrow 104. At the center of the rotation knob 112, there’s a small inlet 111 through which the user can insert a surgical instrument or tool into the working channel of the cannula 15.

[0038] Handle assembly 11 also include inflow and outflow fluid connectors 113 and 114, respectively, such that inflow and outflow can be control using valves. As used herein the term "inflow" refers to fluid flowing into the patient (i.e. out of the distal tip 120 and cannula assembly 15), and "outflow" refers to fluid flowing out of the patient (i.e. into the distal tip 120 and cannula assembly 15). The inflow fluid coming from a peristaltic pump or a saline bag flows into the hysteroscope through the connector 113 and then goes through the fluid tubing 115 to the inflow channel of the cannula 15, and finally arrives at the uterine cavity. For the outflow, the intrauterine fluid is drained through the outflow channel of the cannula down to the outflow tubing 116, and then comes out via the outflow connector 114 at the bottom of the handle assembly.

[0039] The cannula assembly 15 includes an inner tube 20, an outer tube 10, and an image sensor assembly mounted at the distal tip 120. The distal tip 120 of the outer tube 10 or inner tube 20 includes structural characteristics which make it flexible. The distal tip 120 is capable of expanding and contracting laterally (i.e., perpendicular to the longitudinal axis of the cannula), as will be described in further detail infra.

[0040] FIGs. 2A and 2B illustrate further detail of the distal tip of the cannula assembly, according to some embodiments. FIG. 2A is a perspective view of the expandable distal tip 120, while FIG. 2B is the cross-section view of the expanding distal tip 120.

[0041] Referring to FIG. 2A, a portion of the distal wall of the outer tube 10 is fabricated to form a flexure structure 50 that includes one or more compliant mechanisms. As used herein, the term compliant mechanism refers to a flexible mechanism that achieves force and motion transmission through resilient body deformation. The flexure structure 50 gains at least some of its mobility from deflection of flexible members rather than from movable joints and / or hinges. According to some embodiments, structure 50 includes no movable joints and / or hinges. According to some embodiments, the flexure structure 50 is not completely detached from the main body of the outer tube 10 but partially and integrally connected to the proximal portion of tube 10. Such use of compliant mechanisms provides several benefits over structures that rely on more rigid links connected by one or more movable joints. Such benefits can include reduced part count, reduced complexity in manufacturing and assembly, reduced cost, increased precision in motion and predictability. Compliant mechanisms such as flexure structure 50 also can be more scalable so that one design can more easily be adapted to other sized and / or applications.According to some embodiments, flexure structure 50 is further divided into three segments: segments 51, 52 and 53, which are positioned sequentially along the longitudinal direction of proximal to distal. According to some embodiments, segments 51, 52 and 53 of flexure structure 50 are seamlessly interconnected as a continuous piece of flexure.

[0042] According to some embodiments, image sensor assembly 130 includes camera module 40, LED illumination element 42, and supporting bracket 30 onto which camera module 40 and LED element 42 are directly mounted. According to some embodiments, although onlyone LED element 42 is shown in FIG 2 A for clarity, other numbers of LED elements, such as two or three, can be provided according to the application. The supporting bracket 30 is also designed with openings 301 at its front distal surface for fluid inflow. According to some embodiments, supporting bracket 30 is bonded to distal flexure segment 53 of tube 10 so that both a portion of segment 53 and bracket 30 can move laterally together.

[0043] When no tool is inserted in working channel 24, the lower portion of supporting bracket 30 will be resting on a cut of the inner tube 20. In this scenario, the bracket 30 will not completely block the passageway of working channel 24, but there’s still a fluid opening 22 which allows for the fluid communication between the inner tube 20 and fluid opening 22.

[0044] Referring to FIG. 2B, central longitudinal axis 21 of inner tube 20 and central longitudinal axis 12 of outer tube 10 have a lateral offset. A fluid channel 23 is formed in an upper portion of tube 10 that is not occupied by tube 20. According to some embodiments, fluid channel 23 is configured for inflow purposes and is in fluid communication with distal opening 301, shown in FIG. 2A, in supporting bracket 30. The working channel 24 inside the inner tube 20 forms the second fluid channel that can be configured for fluid flowing in the opposite direction to fluid channel 23. The working channel 24 is isolated from the channel 23 by the wall of the inner tube 20 and sensor supporting bracket 30. Working channel 24 is also in fluid communication with distal opening 22 below the supporting bracket 30.

[0045] Also shown in FIG. 2B is camera module 40 connected to electrical cable 402. Cable 402 is routed through the fluid channel 23 all the way down to the cable connector at the bottom of the handle assembly 11 (shown in FIG. 1). Also shown in FIG. 2B is the working channel 24 that has an inner diameter along the main body of the cannula ranging from about 3.0 mm to about 4.0 mm, and the outer tube 10 that has an outer diameter ranging from about 4.5 mm toabout 6 mm. According to some embodiments, the inner tube 20 has an inner diameter of about 3.0 mm and the outer tube 10 has an outer diameter of about 4.5 mm. Other dimensions may be used depending on the particular application. For example, products having a larger inner diameter working channel may have a correspondingly larger outer tube diameter.

[0046] FIG. 3 is a perspective view illustrating further detail of the distal portion of the outer tube 10 that includes a flexure structure 50, according to some embodiments. According to some embodiments, outer tube 10 is made of a metallic material. In many applications, a relatively hard metal material is suitable for tube 10. According to some embodiments, stainless steel is a suitable material for tube 10, although other materials can be suitable, such as titanium, titanium alloys, and nickel-based alloys, according to the application. Flexure structure 50 includes segments 51, 52 and 53. According to some embodiments, segments 51, 52 and 53 are continuously and seamlessly connected as an integral part of the distal portion of tube 10.

[0047] Flexure segment 51 consists of a series of interconnected structural members 519 resembling rib arcs. According to some embodiments, these rib arcs are formed by cutting out a plurality of circumferential slots such as slots 513 and 514 and two longitudinal slots 511 and 512 on each side of the tube 10. Note that longitudinal slot 512, shown in dashed line, is symmetrically positioned on the opposite side of tube 10. As illustrated in FIG. 3, a feature of circumferential slot 513 is that it connects with the longitudinal slot 511 but is not connected with longitudinal slot 512, as shown by dashed portion 513'. Similarly, for circumferential slot 514, the situation is reversed in that it is not connected with the longitudinal slot 511 but connects with the longitudinal slot 512, as shown by dashed portion 514'. According to some embodiments the circumferential slots in segment 51 have a relatively narrow longitudinal (axial direction) width. According to some embodiments the axial direction width of thecircumferential slots of segment 51 is about 0.2 mm. The width of the slots can in general be related to the cutting tools used in manufacture. According to some embodiments a laser cutting tool can be used to reduce the slot widths to 0.1 mm or smaller. The thickness of the wall of tube 10, according to some embodiments ranges from about 0.1 mm to about 0.15 mm. Accordingly, the flexure segment 51 forms a compliant mechanism that has very good flexibility in the vertical direction, shown by dashed arrow 350, but a relatively high rigidity along the axial direction of tube 10, shown by dashed arrow 352.

[0048] The middle segment 52 is a rigid portion bridging the proximal segment 51 and distal segment 53. As shown in FIG. 2B, the sensor supporting bracket 30 can extend axially from the very distal end of segment 53 to the space beneath the middle segment 52. According to some embodiments, at the center of segment 52 there can be an optional opening 523, as is shown in both FIG. 2B and FIG.3. The opening 523 is connected with the fluid channel 23 via an internal channel inside the sensor supporting bracket 30 and serves as an additional outlet of the inflow channel for irrigating the uterus.

[0049] Flexure segment 53 is formed by cutting out portions of tube 10 such that two compliant serpentine portions 533 and 534 are positioned at each side of the tubing wall 10. The two compliant serpentine portions 533 and 534 form compliant mechanisms that can be described as serpentine flexure elements due to their snake-like or meandering pattern.Compliant serpentine portions 533 and 534 are connected with the top portion 531 and the bottom portion 535 respectively of flexure segment 53, and the top and bottom portions 531, 535 are connected with the main body portion of the tube 10 at flexure segment 53. Compliant serpentine portions 533 and 534 are relatively narrow in width such that they are flexible along the circumferential or lateral direction (such as shown by dashed arrow 350). As a result, the toppiece 531 can be lifted upwards in the vertical direction shown by dashed arrow 350, by a radially outward force acting on the sensor supporting bracket 30. After flexible expansion, compliant serpentine portions 533 and 534 create a constriction force that tends to pull the top piece 531 downwards to its original position. Further details of the expansion mechanism of compliant serpentine portions 533 and 534 are provided infra. Note that compliant serpentine portions 533 and 534 can be formed such that they securely wrap around the sensor supporting bracket 30 but according to some embodiments they are not bonded or glued together.

[0050] FIGs. 4A-4D are top views illustrating further details of compliant serpentine portions 533 and 534, according to some embodiments. FIG.4A illustrates the unstressed state of a portion of compliant serpentine portion 533. As is shown, a basic building block of the compliant mechanism is the curved portion 5321 and straight portion 5322. The curved portion 5321 provides the flexibility of the mechanism while the straight portion 5322 can remain straight when the structure is stretched under tension.

[0051] FIG. 4B shows how a portion of compliant serpentine portion 533 resiliently deforms and expands when a radially outward force or load is applied, as indicated by arrows 5331 and 5332, which is exactly what happens when the sensor bracket 30 is being pushed upward by a tool being inserted into the working channel. The curved portion 5321 in FIG. 4B is deformed into a reflex angle. As a result, the compliant serpentine portion 533 is expanded and the compliant serpentine flexure element creates radially inward tension forces, i.e. in the opposite directions to the load directions indicated by arrows 5331 and 5332.

[0052] It should be noted that the shape of the compliant serpentine flexure elements shown herein are examples for illustration purpose and can have many variations. FIG. 4C and FIG. 4D show two further examples.

[0053] FIG. 4C illustrates a compliant serpentine element design used to form portions 533 and or 534, according to some embodiments. In this example the curved portion 5321 is thinner (i.e., narrower in width) than the straight portion 5322. This type of arrangement can be useful to increase range of motion of the structure while still maintaining sufficient flexibility and stiffness characteristics. Like in FIG. 3, the serpentine flexure design shown in FIG. 4C also connects with the top piece 531 of flexure segment 53 and with the main proximal portion of tube 10 at the bottom portion 535 of flexure segment 53.

[0054] FIG. 4D illustrates another variation of a compliant serpentine mechanism design similar to those shown in FIGs 4A-4C. In the case for FIG. 4D, the mechanism includes two compliant serpentine elements 5335 and 5336 arranged next to each other in the axial direction. In this design, two elements 5335 and 5336 are attached to each other at multiple connection points 5323, as shown. Also shown in FIGs. 4C and 4D are some examples of dimensions that have been found suitable for some applications. In FIGs. 4C and 4D the curved portions have width that ranges from about 0.2 mm to about 0.3 mm, and the gaps between adjacent straight portions is about 0.2 mm but can range from about 0.1 mm to about 0.3 mm. The width of the gaps between some features, such as between the adjacent straight portions of the serpentine structures, may depend on the fabrication technology used. In general, small gaps / slots are preferred but there are often other considerations such as availability of laser cutting technology.

[0055] FIGs. 5A and 5B are perspective views of the supporting bracket and the distal portion of the inner tube that is in close contact with the supporting bracket, respectively, according to some embodiments. FIG. 5A illustrates the shape of the supporting bracket 30 of the image sensor assembly 130 (shown in FIG. 2A). As shown, a large portion from the lower side of bracket 30 is concave. The lower portion of bracket 30 includes two curved surfaces 302and 304. Bracket 30 may also include the two wing-shaped portions 303 and 306, according to some embodiments. FIG. 5B shows the distal portion 202 of the inner tube 20. Distal portion 202 has a generally cylindrical or elliptic outer shape 204. Distal portion 202 includes a large cutout region that forms two ramped edges 212 and 214 and optionally two upward-directed tabs 206 and 208. The inner surfaces of wing-shaped portions 303 and 306 of support bracket 30 in FIG. 5A are shaped to mate with the outer surface 204 of the distal portion 202 of inner tube 20 in FIG. 5B. The curved surfaces 302 and 304 of bracket 30 are shaped to match ramped edges 212 and 214, respectively, of distal portion 202 of inner tube 20. Shaping and arranging bracket 30 and distal portion 202 in this manner has been found to aid in limiting the bracket 30 from moving side-to-side, in the directions shown by dashed arrow 330, as the bracket 30 is moved up and down, in the direction shown by dashed arrow 332, by insertion and withdrawal of a tool though the working channel. If further limitation of movement is desirable, two slots 306 and 308 can be formed on bracket 30, shown in FIG. 5A, that accept tabs 206 and 208, respectively, on distal portion 202 of inner tube 20, shown in FIG. 5B. The described tab and slot arrangement allows bracket 30 to be reliably seated on the cut edge of distal portion 202. The arrangement allows relative motion between parts 30 and 202 in up / down directions (arrow 332) and restricts relative motion in the left / right direction (arrow 330).

[0056] The central bottom surface 320 of bracket 30 is formed with a downward-facing concave shape (i.e., a circular arc at each lateral cross-section) but along the longitudinal direction (from proximal to distal end) the surface 320 ramps down smoothly. As such, when a tool is inserted into the working channel 24, its front head will gently push against the surface 304 and force the supporting bracket 30 to move upward relative to the distal portion of tube 202 (arrow 332 in FIG. 5A). When the inserted tool reaches the flat, distal surface 321, bracket 30will be “riding” on the tool stably, as described in further detail infra. On the upper surface of bracket 30 is a notch 305 that is dimensioned to accommodate cable 402 (shown in FIG. 2B) and also for fluid communication between fluid channel 23, top side opening 523, and front opening 301 (both shown in FIG. 2A). Note that some embodiments may have an inflow opening on the top such as opening 523 and others may have an inflow opening on the front, such as opening 301, and still others may have inflow openings at both locations and or other locations.

[0057] FIGs. 6A and 6B are sectional views from two perpendicular directions illustrating a tool 60 partially inserted into the working channel 24 of an endoscope having a flexural distal tip, according to some embodiments. FIG. 6A is a sectional view where the inserted tool 60 is in the working channel (i.e., inside the inner tube 20) but has not reached the image sensor bracket 30. Shown in FIG. 6A is a cross section view of flexural distal tip 120, including flexure segment 51, segment 52 and flexure segment 53. As described, supra, the flexural properties of segments 51 and 53 can be formed by cutting, e.g. laser cutting, a designed pattern into the material of the distal portion of the outer tube 10. The sensor supporting bracket 30 is attached to flexure segment 53. According to some embodiments, as shown in FIG. 6A, the bracket 30 can also be attached to a portion of segment 52. The dashed arrow 400 denotes the DOV (Direction of View) of the image sensor 40 mounted on bracket 30. A tool 60 is shown being inserted in the working channel formed by tube 20. In FIGs. 6A, 6B, 7A and 7B, for purposes of clarity the tool 60 is not shown in section but rather in side views. Also, for purposes of clarity in FIGs. 6 A and 7A, various notches are drawn in the upper wall of tube 10, while the configuration, locations, and dimensions of the slots and or cuts will actually depend on the particular design implemented for the flexural segments 51 and 53. FIG. 6B is the front view of the distal end 120 corresponding to the same relative tool location within the working channel asdepicted in FIG. 6A. As can be seen, the image sensor bracket 30 is resting on the partially-cut distal tip of the inner tube 20, while being wrapped around by the top piece 531 and serpentine portions 533 and 534 of the flexure segment 53. Also shown, in dashed lines, are tabs 206 and 208 that are fully inserted into slots 306 and 308 formed in bracket 30.

[0058] FIGs. 7A and 7B are sectional views illustrating a tool fully inserted into the working channel of an endoscope having a flexural distal tip, according to some embodiments. As shown in FIG.7A, the sensor bracket 30 is now lifted upwards relative to the bottom side of the distal tip in a direction parallel to the direction of the dashed arrow 332. The upwards motion is caused by the insertion of tool 60 while the tension force indicated by arrows 540 resists it. The tension force 540 is caused by flexure segment 53 and more specifically, by compliant serpentine portions 533 and 534. The tension force 540 presses the bracket 30 downward such that the bracket 30 stably rides on the tool. Note that while the distal tip 120 is in its expanded state as shown in FIGs. 7A and 7B, the DOV 400 of the image sensor 40 remains unchanged (parallel to the longitudinal axis of the cannula, according to some embodiments). Due to the rising of the supporting bracket 30, the rib arcs of flexure segment 51 are also expanded in a piece-by-piece gradual fashion. FIG. 7B shows a front view of the expanded distal tip in this situation where you can see the sensor supporting bracket 30 is now lifted up relative to, and supported by the tool 60, meanwhile compliant serpentine portions 533 and 534 of the flexure segment 53 are expanded radially outwardly, against radially inward tension force. The amount of expansion of the distal tip 120, and the amount of lifting of the upper portion of the distal tip, including bracket 30 and image sensor 40 relative to the tool 60 and distal portion 202 of inner tube 20, will depend on the outer dimensions of the particular tool 60 that is inserted in the working channel. As an example, in FIG. 7B, the non-expanded location of the imaging sensor isdepicted by dashed circle 40'. In the example shown, the mid-point of the imaging sensor is raised in a direction parallel to arrow 332 by an amount ranging from about 1.5 mm to about 3.0 mm. Also shown in FIGs. 6B and 7B, is the inner diameter of the tube 20, including distal portion 202 is about 3.0 mm in this example. Also shown in FIG. 6B is the thickness of outer tube 10 being in a range from about 0.1 mm to about 0.15 mm. The overall thickness (outer diameter) of the cannula, and distal tip 120, which is shown in FIG. 6B is about 4.5 mm in this example.

[0059] FIGs. 8A and 8B are perspective and section views, respectively, of a flexural distal tip of an endoscope, according to some embodiments. In this example, a thin outer sleeve 152 is shown to be wrapping around the outer surface of outer tube 10. According to some embodiments, sleeve 152 can be made of elastomeric bio-compatible materials such as silicone, thermoplastic polyurethane or TPU, polyolefin, etc. Other materials can be used according to other embodiments. A benefit of using sleeve 152 is that uneven surfaces of the whole cannula are reduced or eliminated, including at the distal tip where the flexure segments 51 and 53 are positioned, otherwise the edges of the slots in flexure segments 51 and or 53 may have a risk of scrapping the tissue of the cervical canal when the endoscope is inserted / withdrawn from the patient body. Also, sleeve 152 can reduce or prevent undesirable leakage of fluid through the cutting slots of the flexure segments 51 and 53. According to some embodiments, when the flexural properties of the distal tip are adequately provided by the compliant flexural elements such as serpentine elements 533 and 534 in segment 53, then the sleeve 152 can be made to be quite thin and flexible since it does not need to provide radially inward tension force to pull back the supporting bracket, for example when the tool is being withdrawn. According to some embodiments, the thickness of sleeve 152 is in a range from about 0.05 mm to about 0.1 mm, asshown in FIG. 8B, to make the profile of the cannula as small as possible. By contrast, some known designs for devices rely on an elastomeric body force to return an expanded distal tip to its unexpanded state when the tool is withdrawn, and the thickness of the elastomeric body could be in the range of 0.3 mm to 0.5 mm to provide the adequate returning force. In some known endoscope designs having expandable distal tips where an elastomeric material is positioned at a far distal edge, the elastomeric material may be prone to snagging or hooking certain portions of a tool, when the tool is being withdrawn. In such cases the elastomeric material might have to be quite thick to resist these effects. For example, some tools such as some tissue resection devices have a cutting blade window configuration. In such cases the edge(s) of the blade window may be prone to be snagged by a distal end positioned elastomeric material.

[0060] FIG. 9 is a sectional view of endoscope flexural distal tip, according to some other embodiments. In this example, the entire flexure-based structure is implemented on the inner tube rather than on the outer tube. Accordingly, the image sensor assembly is mounted to the flexural distal end of the inner tube. As shown in FIG 9, compliant flexure structure 70 is cut out on the wall of the inner tube 72 rather than on the outer tube 73. The sensor supporting bracket 75 is adhered to the flexure structure 70, and an elastomeric sleeve 74 wraps around the flexure 70 for the same purpose(s) as mentioned supra with respect to FIGs. 8A and 8B.

[0061] FIGs. 10A, 10B and 10C are sectional views of an auxiliary conduit that can be used to facilitate the introduction of flexible tools through an endoscope having a flexural distal tip, according to some embodiments. An auxiliary conduit allows for the insertion of flexible tools that might not be sufficiently stiff to push the distal end of the tool through the flexural distal tip. FIG. 10A shows an example of a conduit 80 that is both rigid and hollow. Conduit 80 includes a base 82 and an elongated, rigid tube 81 having a distal tip 85. The tube 81 is mounted or bondedto base 82. The base 82 is designed with a passageway and opening in the shape of a bell mouth to facilitate the accommodation of an inserted tool. According to some embodiments, conduit 80 may be used in cases where a tool to be inserted is not sufficiently rigid to allow for a pushing force to reliably expand the flexure structure(s) at the distal tip of the endoscope cannula. As shown in FIG. 10B, the user initially inserts the rigid conduit 80 into the working channel, which expands the flexure structure of the cannula and eventually the distal tip 85 of the conduit protrudes slightly out of the distal end 120 of the endoscope. The user can then introduce the desired flexible tool 83 through the conduit, as shown in FIG.10C. The tool 83 has a distal tip 87 that protrudes from the distal tip 85 of conduit 80.

[0062] FIGs. 11A and 11B are schematic diagrams illustrating a fluid system for providing endoscope fluid inflow and outflow, according to some embodiments. In some cases, for endoscopes having a relatively narrow (slim) cannula it is desirable to provide an increased maximum fluid inflow rate (i.e. out of the cannula and into the patient's body) that would otherwise be solely provided by the dedicated and limited inflow fluid channel. For example, during some procedures when the endoscope is initially inserted, a relatively high rate of fluid inflow may desirable for a quick uterine distention. Unfortunately, in cases where the endoscope has a relatively narrow (small) overall diameter, such as below about 5 mm, and where the endoscope has an expandable distal tip, such as the flexural distal tip endoscope described herein, a narrow fluid inflow channel may be smaller than desired for a rapid distention of the uterus at the beginning of the procedure. According to some embodiments, fluid channel 23, shown in FIG. 2B is dedicated to inflow and with a relatively confined space. According to some embodiments, the described fluid system design can be configured to substantially increase the inflow rate while not requiring the operator or user to learn and or perform any additionaloperational steps or manipulations. In FIGs. HA and 1 IB, valve 113 is, as far as the user is concerned the inflow control valve, and valve 114 is the outflow control valve. Valves 113 and114 have levers 1132 and 1142 respectively. For the convenience of explanation and as is the convention of many valve products, each valve 113 and 114 is in the "ON" position when the lever is parallel to the fluid flow direction, and is in the "OFF" position when the lever is perpendicular to the fluid flow direction. In FIGs. 11 A and 1 IB due to the vertical orientation of fluid tubes 91 and 97, valves 113 and 114 are both "ON" when its lever is vertical and "OFF" when horizontal. The inflow-control valve 113 is a two-port valve and provides fluid communication between tabs 1134 and 1136 which are both parallel to the control lever 1132. The outflow-control valve 114 is a three-port valve and allows fluid communication between tabs 1144 and 1146.

[0063] FIG. 11A shows a continuous flow mode in which the inflow valve 113 and outflow valve 114 are both switched to “ON”. The inflow-control valve 113 being at “ON” position means the inflow from the irrigation tube 91 can go through the tube 93, the internal inflow tube115 and finally go into the fluid channel 23 depicted in FIG. 2B. Similarly, the outflow-control valve 114 at its “ON” status will disconnect the bridging tube 94 from the drainage tube 97 but allows the outflow stream to flow through the internal outflow tube 116 to the drainage tube 97.

[0064] FIG. 1 IB shows the valve lever configuration where the user wants only fluid inflow. The user has positioned lever 1132 of inflow-control valve 113 to its "ON" position, and the user has positioned lever 1142 of outflow-control valve 114 to its “OFF” position. With this lever position combination, the bridging tube 94 is connected with the internal outflow tube 116, and the drainage tube 97 is disconnected with the tube 116. Consequently, part of the inflow stream will travel through the bridging tube 94 and go through the tube 116 and finally reach theworking channel, which substantially increases the overall inflow rate for irrigating the intrauterine cavity. A benefit of the described fluid system is that it does not rely on the user making unfamiliar and or additional steps or manipulations to gain the benefit of the improved flow rate.

[0065] The embodiments disclosed herein can be combined in one or more of many ways to provide improved diagnosis and therapy to a patient. The disclosed embodiments can be combined with prior methods and apparatus to provide improved treatment, such as combination with known methods of urological, or gynecological diagnosis, surgery and surgery of other tissues and organs, for example. It is to be understood that any one or more of the structures and steps as described herein can be combined with any one or more additional structures and steps of the methods and apparatus as described herein, the drawings and supporting text provide descriptions in accordance with embodiments.

[0066] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims, which can be revised during prosecution, define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

CLAIMSWhat is claimed is:

1. An endoscope cannula assembly comprising: an axially extending, hollow outer tube and an axially extending, hollow inner tube inside the outer tube; wherein one of said outer and inner tubes has a distal portion formed by cuts therein into a flexure structure configured to resiliently expand in response to a radially outward force applied thereto and to flex back when the force is removed, said flexure structure comprising: a proximal flexure segment that comprises first and second axially extending parts formed by axially extending cuts into said distal portion and a series of rib arc structural members formed by partial circumferential cuts into said axially extending parts whereby said first flexure segment is rigid in the axial direction and resiliently flexible in the radially outward direction; a distal flexure segment that is positioned distally from the proximal flexure segments and is formed by serpentine cuts into said distal portion leaving axially extending flexible ribbons connected at their axial ends whereby the distal flexure segment is configured to expand in response to a radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; said cannula assembly further comprising a supporting bracket secured at said distal portion and extending radially inwardly therein and a sensor assemblysecured to the supporting bracket and comprising a camera module and illumination elements; and an axially extending working channel inside said inner tube; wherein said working channel is configured to accept a surgical tool that has a crosssection greater than hollow space inside said distal portion between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket to thereby push the supporting bracket radially outwardly and expand said proximal and distal flexure segments; and wherein said distal portion is configured to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion of the proximal and distal flexure segments.

2. The endoscope cannula assembly of claim 1, in which said distal portion is a distal portion of said outer tube.

3. The endoscope cannula assembly of claim 1, in which said distal portion is a distal portion of said inner tube that extends distally from the outer tube.

4. The endoscope cannula assembly of claim 1, in which the inner and outer tubes have central longitudinal axes spaced from each other to thereby leave space between an inner wall of the outer tube and an outer wall of the inner tube as a fluid flow channel.

5. The endoscope cannula assembly of claim 4, further including a first valve fluidly coupled to said working channel and a second valve fluidly coupled to said fluid flow channel.

6. The endoscope cannula assembly of claim 5, further including a bridging tube between said valves, wherein said valves and bridging tube are configured to selectively enable irrigation fluing flow into the working channel and drainage flow out of the fluid channel or irrigation fluid flow into both said working channel 24 and fluid flow channel.

7. The endoscope cannula assembly of claim 1, further including a rigid conduit configured for insertion into said working channel to exert said radially outward force on said supporting bracket and having an internal channel for insertion of a surgical instrument that need not be rigid.

8. The endoscope cannula assembly of claim 1, further including a handle assembly to which a proximal portion of the cannula assembly is rotatably secured and a rotation knob coupled to said cannula assembly to rotate the cannula assembly about a longitudinal axis thereof relative to said handle assembly.

9. The endoscope cannula assembly of claim 1 having an outside diameter less than 5 mm at a portion thereof configured for insertion into a patient.

10. An endoscope cannula assembly comprising:a first, axially extending, hollow tube that has a distal portion made of a metal and comprises a flexure structure formed by cuts into said distal portion and configured to expand radially outwardly and flex back due to resiliency of said metal: wherein said cuts include a serpentine cut forming a flexure segment comprising axially extending flexible ribbons connected at axial ends to thereby form a serpentine continuous strip of metal with ends connected to said distal portion of the hollow tube and configured to expand said distal portion of the hollow tube radially outwardly in response to radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; a supporting bracket at said distal portion, extending radially inwardly therein and a sensor assembly secured to the supporting bracket and comprising a camera module and illumination elements; an axially extending working channel inside said tube; and wherein said working channel is configured to accept a surgical tool that has a crosssection greater than hollow space inside said distal portion of the hollow tube that is between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket and thereby generates radially outward force expanding said flexure structure.

11. The endoscope cannula assembly of claim 10, wherein said distal portion is configured to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion.

12. The endoscope cannula assembly of claim 10, in which said distal portion of the tube further comprises axially extending parts that are axially spaced from said flexible ribbons and are formed by axially extending cuts into said distal portion.

13. The endoscope cannula assembly of claim 12, in which said distal portion of the tube further includes a series of rib arc structural members formed by partial circumferential cuts into said axially extending parts that are axially spaced from said flexible ribbons, whereby said axially extending parts are rigid in the axial direction and resiliently flexible in the radially outward direction.

14. The endoscope cannula assembly of claim 10, further including a second hollow inner tube that is inside said first tube, wherein said working channel is inside said inner tube and said inner tube has an outside diameter less than the inside diameter of the first tube to thereby leave a fluid flow channel between the first and second tubes.

15. The endoscope cannula assembly of claim 14, further including a first valve fluidly coupled to said working channel and a second valve fluidly coupled to said fluid flow channel.

16. The endoscope cannula assembly of claim 15, further including a bridging tube between said valves, wherein said valves and bridging tube are configured to selectively enable irrigation fluing flow into the working channel and drainage flow out of the fluid channel or irrigation fluid flow into both said working channel and fluid flow.

17. The endoscope cannula assembly of claim 10, further including a rigid conduit that is configured for insertion into said working channel to exert said radially outward force on said supporting bracket and has an internal channel for insertion of a surgical instrument that need not be rigid.

18. The endoscope cannula assembly of claim 10, further including a second tube that surrounds the first tube, wherein said distal portion is a distal portion of said second tube.

19. The endoscope cannula assembly of claim 18, in which the inner and outer tubes have central longitudinal axes spaced from each other.

20. The endoscope cannula assembly of claim 10, further including a handle assembly to which a proximal portion of the cannula assembly is rotatably secured and a rotation knob coupled to said cannula assembly to rotate the cannula assembly about a longitudinal axis thereof relative to said handle.

21. The endoscope cannula assembly of claim 10 having an outside diameter less than 5 mm at a portion thereof configure for insertion into a patient.

2. A method of imaging an internal space in a patient comprising: inserting into an internal space in a patient a hollow tube that has a distal portion made of a metal and comprises a flexure structure formed by cuts into said distal portion and configured to expand radially outwardly and flex back due to resiliency of said metal: wherein said cuts include a serpentine cut forming a flexure segment comprising axially extending flexible ribbons connected at axial ends to thereby form a serpentine continuous strip of metal with ends connected to said distal portion of the hollow tube and configured to expand said distal portion radially outwardly in response to radially outward force applied thereto and to flex back when the radially outward force acting thereon is removed; providing a supporting bracket secured at said distal portion and extending radially inwardly therein and a sensor assembly secured to the supporting bracket and comprising a camera module and illumination elements, and an axially extending working channel inside said tube; and inserting a surgical tool distally in said working channel that has a cross-section greater than hollow space inside said distal portion between the supporting bracket and the inside of the distal portion such that said surgical tool in motion in the distal direction engages said supporting bracket and thereby generates radially outward force expanding said flexure structure.

23. The method of claim 22, including configuring said distal portion to maintain a consistent direction of view (DOV) of said camera module during said radially outward expansion.

24. The method of claim 23, including providing at said distal portion of the tube axially extending parts that are axially spaced from said flexible ribbons and are formed by axially extending cuts into said distal portion.

25. The method of claim 24, including providing at said distal portion of the tube a series of rib arc structural members formed by partial circumferential cuts into said axially extending parts that are axially spaced from said flexible ribbons, whereby said axially extending parts provided with said rib arc structural elements are rigid in the axial direction and resiliently flexible in the radially outward direction.

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