Single piece scope shaft construction

Abstract

A shaft for a surgical tool, such as an endoscope is made using a single piece of tubing having an articulated portion located between a main portion and a distal portion. The main portion includes a first plurality of cuts through a sidewall of the single piece of tubing configured to permit articulation of the main portion in two or more planes of motion. The articulated portion includes a second plurality of cuts through the sidewall of the single piece of tubing configured to permit articulation of the main portion in one plane of motion. The distal portion includes a third plurality of cuts through the sidewall of the single piece of tubing configured to permit no articulation of the main portion.

Description

SINGLE PIECE SCOPE SHAFT CONSTRUCTIONFIELD OF THE DISCLOSURE

[0001] The technical field of this disclosure relates generally to endoscopic devices and methods, and more specifically to construction of the shaft sections of single-use flexible ureteroscopes.BACKGROUND

[0002] Endoscopes can be used for a variety of different diagnostic and interventional procedures, including colonoscopy, bronchoscopy, thoracoscopy, laparoscopy, ureteroscopy and video endoscopy. Endoscopes typically have a control handle which is configured to allow a user to control a position of a distal end during the procedure. There are a number of different types of endoscopes depending on the internal structure to be examined. For example in the case of the urinary tract, the endoscope, known as a ureteroscope, the flexible tube is designed to be of sufficiently small diameter to be inserted into the ureter to detect any undesirable objects, such as the presence of kidney stones, polyps or tumors.

[0003] A conventional imaging endoscope used for such procedures comprises a flexible tube that having a proximal end at a control handle with a fiber optic light guide that directs illuminating light from an external light source to the distal tip where it illuminates, e.g., tissue or occlusive objects to be examined. Additional optical components are sometimes incorporated to adjust the spread of the light exiting the fiber bundle and the distal tip. The endoscope may include an objective lens at the distal tip and a fiber optic imaging light guide that communicates with a camera at the proximal end of the endoscope. Alternatively, an imaging camera chip may be located at the distal tip. Also LED illumination source(s) might be placed at the distal tip of the scope next to camera chip and control electric current delivered over the thin wires through the shaft. In addition, most endoscopes include one or more working channels through which irrigation fluid and / or medical devices such as biopsy forceps, laser optical fiber, snares, fulguration probes, and other surgical or diagnostic tools may be passed.

[0004] To navigate the endoscope through complex and tortuous paths with minimum pain, side effects, risk, or sedation to the patient, modern endoscopes include means for deflecting the distal tip of the endoscope to follow the pathway of the structure under examination, with minimum deflection or friction force upon the surrounding tissue. Control cables similar to bicycle brake cables are carried within the endoscope body. These cables connect a flexibleportion of the distal end to a set of controls at the handle. The operator can steer the endoscope by manipulating the controls during insertion to direct it to a region of interest.

[0005] For most doctors, having precise control of the distal head section is a highly important feature of a surgical tool, such as an endoscope. Fast and precise translation of each manipulation at the control handle directly affects the accuracy of surgical procedure as well as overall treatment time and total clinical outcome.

[0006] It is within this context that aspects of the present disclosure arise.BRIEF DESCRIPTION OF THE FIGURES

[0007] The teachings of the present disclosure can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

[0008] FIG. 1 depicts a scope shaft according to aspects of the present disclosure.

[0009] FIG. 2A is a flattened plan view of a main portion of the single piece scope shaft of FIG. 1 cut along line A-A of FIG. 1.

[0010] FIG. 2B is a cross-sectional view taken along line B-B of FIG. 2A.

[0011] FIG. 3A is a flattened plan view of an articulated portion of the single piece scope shaft of FIG. 1 cut along line B-B of FIG. 1.

[0012] FIG. 3B is a cross-sectional view taken along line B-B of FIG. 3A.

[0013] FIG. 4A is a flattened plan view of a distal portion of the single piece scope shaft of FIG. 1 cut along line C-C of FIG. 1.

[0014] FIG. 4B is a cross-sectional view taken along line B-B of FIG. 4A.

[0015] FIG. 5A depicts an example of a distal end of a scope shaft according to aspects of the present disclosure.

[0016] FIG. 5B depicts an example of a portion of a scope shaft with indents for articulation control cables according to aspects of the present disclosure.

[0017] FIG. 5C depicts an alternative example of a distal end of a scope shaft according to aspects of the present disclosure.

[0018] FIG. 5D depicts an alternative example of a distal end of a scope shaft according to aspects of the present disclosure.

[0019] FIG. 5D depicts another example of a distal end of a single-piece scope shaft according to aspects of the present disclosure.

[0020] FIG. 5E depicts another example of a distal end of a single-piece scope shaft according to aspects of the present disclosure.

[0021] FIG. 6 depicts examples of different configurations of a scope shaft in the vicinity of the distal portion according to aspects of the present disclosure.DETAILED DESCRIPTION

[0022] Although the following detailed description contains many specific details for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, examples of embodiments of the invention described below are set forth without any loss of generality to, and without imposing limitations upon, the claimed disclosure.

[0023] In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top," "bottom," "front," "back," "leading," "trailing," etc., is used with reference to the orientation of the figure(s) being described. Because components of embodiments of the present disclosure can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0024] It is desirable for a scope shaft to have single piece construction with no joints that can cause backlashes and wobbling as well as increasing the shaft wall thickness and presenting reliability issues. However, contradictory requirements, mostly for flexibility and rigidity, present design challenges, reliability issues and cost constraints, especially for single-use instruments.

[0025] According to aspects of the present disclosure, a shaft for an endoscope, or similar instrument, may be made from a single length of metal tubing, e.g., a stainless steel hypotubing, to ensure best torque transition from an operating handle to a distal end. Slots are cut into the metal tubing, e.g., by laser cutting, to impart flexibility to the shaft. The slots are cut in such a way that the tubing remains in one piece. No separate links formed during laser cutting,such that there are no joints between sections of the tubing having different flexibility characteristics. That also ensures maximum space for irrigation fluid. The outside diameter of the tubing may be in the range of 2mm to 5mm and wall thickness of the tubing may be in the range of 50 to 200 micrometers. The shaft generally includes three sections: a relatively stiff main section, a flexible articulating section, and a distal head section. Each section has a different arrangement of slots configured to provide the section with a correspondingly different degree of flexibility and function.

[0026] As shown in FIG. 1 , a shaft 100 in accordance with aspects of the present disclosure includes a single piece of tubing 101 having a main portion 102, an articulated portion 104, and a distal portion 106. The articulated portion 104 is located between the main portion 102 and the distal portion 106. It is noted that the lengths of the different sections are not shown to scale in FIG. 1. For example, the articulated portion 104 is significantly longer than distal portion 106. The single piece tubing 101 may include one or more working channels of sufficient inner diameter to accommodate optical fibers, medical devices such as biopsy forceps, snares, fulguration probes, and other surgical or diagnostic tools. In some implementations, the single piece of tubing 101 may be, e.g., a single piece of metal tubing. The choice of metal tubing depends somewhat on the intended application for the shaft. For many medical applications the tubing may be a suitable grade of stainless steel such as medical grade stainless steel or surgical grade stainless steel. Medical grade stainless steels include, but are not limited to SAE 316 and SAE 316L stainless steel, also referred to as marine grade stainless. In particular, SAE 316L is a chromium, nickel, molybdenum alloy of steel that exhibits relatively good strength and corrosion resistance. 316L is the low carbon version of 316 stainless steel. Surgical stainless steel is a grade of stainless steel used in biomedical applications. Common "surgical steels" include, but are not limited to, austenitic SAE 316 stainless and martensitic SAE 440, SAE 420, and 17-4 stainless steels.

[0027] One of the main advantages of constructing the shaft from the single piece tubing 101 is reduced “cold working” capability together with maintaining spring back function. The specific cut pattern in the articulated portion may be configured to allow relatively easy flexing in opposite directions without an increase in stiffness and consecutive breakage that is characteristic common feature of steel “cold working”.

[0028] The main portion 102 includes a first plurality of cuts 108 through a sidewall of the single piece of tubing 101. The cuts 108 are configured to permit articulation of the main portion 102 in two or more planes of motion. The articulated portion 104 includes a second plurality of cuts110 through the sidewall of the single piece of tubing 101 configured to permit articulation of the articulated portion 104 in one plane of motion. This section may include variable of cuts pattern to allow, e. g. gradual increase in flexibility (or decrease in stiffness) towards distal section, which might be preferable for navigation within the human body for certain clinical procedures. The distal portion 106 may include a third plurality of cuts 112 through the sidewall of the single piece of tubing 101 configured to permit no articulation of the distal portion 106.

[0029] Between the three main functional portions 102, 104, 106 there might optionally be additional interface sections. For example, the tubing 101 may include passive articulation between the main portion 102 and the articulated portion 104 to reduce stress at the interface during navigating and gaining access to certain areas, as well as functional features e.g., slots for welding of guide wires and spring tubes.

[0030] The main section 102 propagates from an operating handle end towards the distal section 106. By way of example, the main section 102 may be between 500 mm and 750 mm in length. The main section 102 is configured to be sufficiently flexible to negotiate anatomical curvatures of biological tissue with low induced strain, yet sufficiently rigid to translate direct force during insertion. The main section is cut to ensure omni-directional bending, e.g., in two or more planes, with spring-back effect. To facilitate such bending, the first plurality of cuts includes a plurality of staggered interrupted arcuate cuts 108 along a circumference of the single piece of tubing 101, as shown in the lower left image of FIG. 1. The cuts may be formed by laser cutting. Each of the arcuate cuts creates a narrow gap in the tubing over a portion of the tubing’s circumference. The staggering of the cuts may be appreciated by referring to FIG. 2A, which depicts a portion of the tubing 101 that has been cut along line A-A of Fig. 1 and laid flat. Generally, the cuts may be non-tapered. However, in some implementations, bending may be further facilitated by tapering the cuts 108 as shown by the dashed lines in FIG. 2B. In this example, the cuts 108 are wider at the outside diameter of the tubing than at the inside diameter.

[0031] The second plurality of cuts 110 are configured to ensure bending of the articulating section 104 in one plane. The articulating section 104 has no dis-jointed links, but rather has frequent cutouts defined by the cuts 110 with bendable “bridges” 112, which may have variable thickness. Such a pattern provides earlier bending of the most distal parts of the articulating section 104 first, and smooth uniform end curvature of the whole articulating section. By way of example, and not by way of implementation, the articulating section 104 may be configured to bend within one plane under controlled force of the operator with deflection angle up to 270degrees. In some implementations, the length of the articulating section may be, e.g., 60 mm to 80mm with the resulting bend curvature being about 20mm diameter.

[0032] As shown in the upper left image of FIG. 1 , the second plurality of cuts includes a plurality of interrupted rounded rectangular cuts 110 along a circumference of the single piece of tubing. Some or all of the interrupted rounded rectangular cuts may be characterized by a rounded rectangular shape interrupted by bridge portions 112 at opposite corners of the rounded rectangular shape. As may be seen in the upper left image of FIG. 1 , the interrupted rounded rectangular cuts 110 may be configured to define a spine 111 of uninterrupted material along a portion of the length of the single piece tubing. The configuration of the cuts 110 in the articulated section may be appreciated by referring to FIG. 3A, which depicts a portion of the tubing 101 that has been cut along line B-B of Fig. 1 and laid flat. As may be seen in FIG. 3A, rounded rectangular cuts 110 may be arranged in circumferential pairs that define two parallel spines 111 of uninterrupted tubing material along the length of the articulated section. The spines 111 limit bending of the articulated section to a single plane. One or more, or even all of the interrupted rounded rectangular cuts 110 may be characterized by a tapered cross-section that is wider at an outside diameter of the single piece of tubing 101 than at an inside diameter of the single piece of tubing.

[0033] The degree of articulation of the articulated portion 104 may be adjusted changing the linear frequency of the rounded rectangular cuts. By way of example, a larger frequency of cuts 114 near the distal portion 106 compared to the frequency of cuts 110 near the main portion 102 allows for a smaller radius of curvature near the distal portion. The frequency of cuts along the length of the articulated portion 104 may be varied to allow for a transition in the degree of curvature from larger radius near the main section 102 to a smaller radius near the distal section 106, as may be seen in the lower left image in FIG. 1.

[0034] As may be seen in the upper right image of FIG. 1 , the interrupted rounded rectangular cuts 114 may be configured to define a spine 113 of uninterrupted material along a portion of the length of the single piece tubing. The higher frequency spacing and configuration of the cuts 114 in the distal section may be appreciated by referring to FIG. 4A, which depicts a portion of the tubing 101 that has been cut along line C-C of Fig. 1 and laid flat. As may be seen in FIG. 4A, rounded rectangular cuts 110 may be arranged in circumferential pairs that define two parallel spines 113 of uninterrupted tubing material along the length of the articulated section. The spines 113 limit bending of the articulated section to a single plane. Some or all of the cuts 114 may optionally be characterized by a tapered cross-section that is wider at an outsidediameter of the single piece of tubing 101 than at an inside diameter of the single piece of tubing, as shown by the dashed lines in FIG. 4B.

[0035] As shown in FIG. 5B, the articulating portion 104 may include one or more indents 118 configured to receive articulation cables (shown in Fig. 5C). Indentations for guiding the pull wires might be designed as separate features or as part of the articulating function, e.g., as seen in FIG. 6.

[0036] The distal section 106 is the most distal piece of the single-piece tubing 101 , i.e., the piece furthest from the operating handle end. The distal section 106 is positioned right after articulating section 104.

[0037] As may be seen in the upper right image of FIG. 1 , the interrupted rounded rectangular cuts 114 may be configured to define a spine 113 of uninterrupted material along a portion of the length of the single piece tubing. The higher frequency spacing and configuration of the cuts 114 in the distal section may be appreciated by referring to FIG. 4A, which depicts a portion of the tubing 101 that has been cut along line C-C of Fig. 1 and laid flat. As may be seen in FIG. 4A, rounded rectangular cuts 110 may be arranged in circumferential pairs that define two parallel spines 113 of uninterrupted tubing material along the length of the articulated section. The spines 113 limit bending of the articulated section to a single plane. Some or all of the cuts 114 may be characterized by a tapered cross-section that is wider at an outside diameter of the single piece of tubing 101 than at an inside diameter of the single piece of tubing, as shown in FIG. 4B.

[0038] The distal section may end in a distal head 117, which may be configured as shown in FIG. 5A - FIG. 5E. The distal head 117 may be formed from the distal end of the single piece tubing 101 , or attached thereto. The distal head 117 may include an objective lens at the distal tip and a fiber optic imaging light guide. Alternatively, an imaging camera chip may be located at the distal tip. In addition, the distal head may be configured to accommodate medical devices such as biopsy forceps, snares, fulguration probes, and other surgical or diagnostic tools may be passed. In some implementations, a miniature camera chip with illumination LEDs may be mounted to the distal head, as well as distal end of the working channel. Cutouts at the distal head section may provide fluidic outlets used for irrigation or aspiration. Also, they can be used as “windows” for different sensors, like remote pressure or temperature sensors.

[0039] There are a number of different possible configurations for the distal portion 106.Generally, this portion is configured for no articulation. The distal head section 117 may also beconfigured as a “carrier” for an attached component with additional functional elements, described previously. The distal head 117 may include cutouts and / or projections to facilitate attachment of such components.

[0040] Aspects of the present disclosure provide a flexible shaft that it is sufficiently rigid for ease of insertion. A single steel tube from the operating handle to the distal head provides best translation of the toque force during manipulation as well as nearly total absence of nondesirable “memory” effect of the curving shaft sections. The absence of joints (with component overlaps) gives maximum open space for internal components and functions of the shaft. It also significantly simplifies manufacturing and assembly.

[0041] While the above is a complete description of the preferred embodiment of the present invention, it is possible to use various alternatives, modifications, and equivalents. Therefore, the scope of the present invention should be determined not with reference to the above description but should, instead, be determined with reference to the appended claims, along with their full scope of equivalents. Any feature described herein, whether preferred or not, may be combined with any other feature described herein, whether preferred or not. In the claims that follow, the indefinite article “A,” or “An” refers to a quantity of one or more of the item following the article, except where expressly stated otherwise. The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means for.”

Claims

Claims1 . A shaft, comprising: a single piece of tubing having a main portion and a distal articulated portion, wherein the main portion includes a first plurality of cuts through a sidewall of the single piece of tubing configured to permit articulation of the main portion in two or more planes of motion, wherein the articulated portion includes a second plurality of cuts through the sidewall of the single piece of tubing configured to permit articulation of the articulated portion in one plane of motion, wherein the distal portion includes a third plurality of cuts through the sidewall of the single piece of tubing configured to permit no articulation.

2. The shaft of claim 1 , wherein the first plurality of cuts includes a plurality of staggered interrupted arcuate cuts along a circumference of the single piece of tubing.

3. The shaft of claim 1 , wherein the second plurality of cuts includes a plurality of interrupted rounded rectangular cuts along a circumference of the single piece of tubing.

4. The shaft of claim 3, wherein one or more cuts of the plurality of interrupted rounded rectangular cuts are characterized by a tapered cross-section that is wider at an outside diameter of the single piece of tubing than at an inside diameter of the single piece of tubing.

5. The shaft of claim 3, wherein the plurality of interrupted rounded rectangular cuts includes one or more cuts characterized by a rounded rectangular shape interrupted by bridge portions at opposite corners of the rounded rectangular shape.

6. The shaft of claim 3, wherein the plurality of interrupted rounded rectangular cuts is configured to define a spine of uninterrupted material along a portion of the length of the single piece tubing.

7. The shaft of claim 1 , wherein the second plurality of cuts is characterized by a frequency of cuts that varies along a length of the single piece of tubing.

8. The shaft of claim 1 , wherein the second plurality of cuts is characterized by larger frequency of cuts near the distal portion compared to a frequency of cuts near the main portion.

9. The shaft of claim 1 , wherein a frequency of cuts along a length of the articulated portion is varied to allow for a transition in the degree of curvature from a larger radius near the main portion to a smaller radius near the distal portion.

10. The shaft of claim 1 , wherein the distal portion includes one or more indents configured to receive an articulation cable.

11. The shaft of claim 1 , wherein the single piece of tubing is a single piece of metal tubing.

12. The shaft of claim 1 , wherein the single piece of metal tubing is a single piece of stainless steel tubing.

13. The shaft of claim 1 , wherein the single piece of metal tubing is a single piece of medical grade stainless steel tubing.

14. The shaft of claim 1 , wherein the single piece of metal tubing is a single piece of surgical grade stainless steel tubing.

15. The shaft of claim 1 , wherein the articulating section is configured to bend within one plane under controlled force with a deflection angle up to 270 degrees.

Images