Patent Publication Number: US-2023148837-A1

Title: Tip components of multi-camera endoscopes

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to multi-camera endoscopes. 
     BACKGROUND 
     An endoscope is a medical device used to image an anatomical site (e.g. a body cavity, a hollow organ). Unlike some other medical imaging devices, the endoscope is inserted into the anatomical site (e.g. through small incisions made on the skin of the patient). An endoscope can be employed not only to inspect an anatomical site and e.g. organs therein (and diagnose a medical condition in the anatomical site) but also as a visual aid in surgical procedures. Medical procedures involving endoscopy include laparoscopy, arthroscopy, cystoscopy, ureteroscopy, and hysterectomy. 
     SUMMARY 
     Aspects of the disclosure, according to some embodiments thereof, relate to multi-camera endoscopes. More specifically, but not exclusively, aspects of the disclosure, according to some embodiments thereof, relate to tip components of multi-camera endoscopes and methods of manufacture thereof. 
     Thus, according to an aspect of some embodiments, there is provided an elongated shaft for a multi-camera endoscope. The shaft includes a shaft body and a tip component mounted on a shaft distal portion (of the shaft body). The tip component includes, accommodated within a housing of the tip component:
         A front camera, a first side-camera, and a second side-camera positioned distally to the first side-camera. The side-cameras face oppositely, or substantially oppositely. The cameras are configured to jointly provide a field-of-view (FOV) of at least about 270 degrees.   A plurality of front illumination modules, two first side-illumination modules, and two second side-illumination modules. The two first side-illumination modules are respectively proximally and distally positioned relative to the first side-camera. The two second side-illumination modules are respectively proximally and distally positioned relative to the second side-camera. The illumination modules are configured to jointly illuminate the FOV.       

     The tip component includes a plurality of window elements of sapphire glass, which are soldered, using a noble-metal as solder material, within respective holes on the housing. Each of the cameras and the illumination modules is positioned behind a respective window element from the plurality of window elements. 
     According to some embodiments of the shaft, the noble metal includes gold and/or platinum. 
     According to some embodiments of the shaft, rims of the holes includes stainless steel. The window elements are soldered onto the rims. 
     According to some embodiments of the shaft, each of the window elements is set on a respective support ledge extending from a rim of the respective hole. The support ledges of at least some of the window elements, associated with the illumination modules, are segmented, thereby allowing provision of increased illumination by the illumination modules. 
     According to some embodiments of the shaft, segments pertaining to each of the segmented support ledges together circumferentially constitute less than 50% of a perimeter of the respective rim. 
     According to some embodiments of the shaft, the segments pertaining to each segmented support ledge consist essentially of four segments at most. 
     According to some embodiments of the shaft, a diameter D of the tip component measures between about 2 millimeters and about 15 millimeters. 
     According to some embodiments of the shaft, a characteristic scale d F  of the window element of the front camera measures between about 20% and about 50% of the diameter D of the tip component. 
     According to some embodiments of the shaft, at least some of the window elements, and holes corresponding thereto, are round or substantially round. 
     According to some embodiments of the shaft, the plurality of front illumination modules includes three illumination modules. A front surface of the housing may be flat, or substantially flat, and includes the window element of the front camera and three additional window elements. Each of the additional window elements has positioned behind thereto one of the front illumination modules, respectively. A relation between the diameter D, the characteristic scale d F , and a spacing y F  between the window element of the front camera and nearest window element from the additional window elements is given by y F ≈(D−3·d F )/4. 
     According to some embodiments, the characteristic scale d F  measures about 3.4 millimeters. 
     According to some embodiments, 0.1 mm≤d F ≤5 mm. According to some embodiments, 2 mm≤d F ≤5 mm. According to some embodiments, 3.2 mm≤d F ≤4.9 mm. According to some embodiments, 0.1 mm≤d F ≤1 mm. According to some embodiments, 0.1 mm≤d F ≤0.4 mm. 
     According to some embodiments, each of the additional window elements has a respective characteristic scale which is comparable to the characteristic scale d F . 
     According to some embodiments of the shaft, respective diameters of the window elements of the first and second side-cameras measure between about 2.5 millimeters and about 5 millimeters. Respective diameters of the window elements of the first and second side-illumination modules measure between about 3.5 millimeters and about 5.5 millimeters. Respective distances between each of the window elements of the side-cameras and the two window elements of the illumination modules, which are adjacent thereto, measure between about 0.5 mm and about 1.5 mm. 
     According to some embodiments of the shaft, the window elements of the cameras are all comparable in size. The window elements of the side illumination modules are all comparable in size. 
     According to some embodiments of the method, characteristic scales of the window elements of the side-cameras measure between about 30% to about 120% of the characteristic scale of the window element of the front camera. 
     According to some embodiments of the shaft, the window elements of the side-cameras have a smaller characteristic scale than the window elements of the side-illumination modules. 
     According to some embodiments of the shaft, each of the window elements has a thickness measuring between about 0.2 millimeters and about 1 millimeter. 
     According to some embodiments of the shaft, the gold-soldering between each of the window elements and the rim of the respective hole fluidly seals a gap between the window element and the rim. The fluid-sealing provided by the gold-soldering is configured to withstand autoclave sterilization. 
     According to some embodiments of the shaft, a width w of the gap measures between about 0.02 millimeters and about 0.1 millimeters. 
     According to some embodiments of the shaft, optical axes of the cameras span a plane comprising a longitudinal axis of the elongated shaft. 
     According to some embodiments of the shaft, the optical axis of the second side-camera is perpendicular to the longitudinal axis of the elongated shaft. The optical of the first side-camera is tilted by up to 5 degrees relative to the optical axis of the second side-camera and towards the optical axis of the front camera. 
     According to some embodiments of the shaft, the housing includes a first part, a second part, and a third part. The first part includes the front surface, the front camera, and the plurality of front illumination modules. The second part include a cover section, including the holes of the first side-camera and first side-illumination modules, and the first side-camera and first side-illumination units. The third part includes a hull, the second side-camera and second side-illumination units. The hull is open on a distal end thereof and a proximal end thereof, and includes an elongated opening on a first side-surface thereof, on which the cover section is configured to be fitted, and, on second side-surface thereof, the holes of the second side-camera and the second side-illumination modules. The hull is configured to accommodate the cameras and the illumination modules. 
     According to some embodiments of the shaft, each of the first part and second part is soldered, welded, and/or glued to the third part. 
     According to some embodiments of the shaft, each of the cameras is mounted on a respective printed circuit board (PCB). 
     According to some embodiments of the shaft, each of the illumination modules includes one or more light-emitting diodes (LEDs). 
     According to an aspect of some embodiments, there is provided a method for affixing windows on a shaft of a multi-camera endoscope. The method includes:
         Providing a housing of a tip component of a shaft of a multi-camera endoscope. The housing includes at least a pair of holes arrangements. Each of the holes arrangements includes at least two holes for a window element for a camera and for at least one window element for at least one illumination module.   For each of the holes:
           Fitting a respective window element on a support ledge extending centrally from a rim of the hole.   Soldering the window element onto the rim of the hole, thereby affixing the window element onto the housing.   
               

     The support ledges of at least some of the illumination module window elements are segmented, thereby allowing provision of increased illumination by the illumination modules. 
     According to some embodiments of the method, at least some of the window elements comprise sapphire glass and at least some of the window elements are soldered onto the rim of the respective hole using solder material comprising a noble metal. 
     According to some embodiments of the method, the noble metal comprises gold and/or platinum. 
     According to some embodiments of the method, segments pertaining to each of the segmented support ledges together circumferentially constitute less than 50% of a perimeter of the respective rim. 
     According to some embodiments of the method, the segments pertaining to each of the segmented support ledges consist of four segments at most. 
     According to some embodiments of the method, the soldering fluidly seals gaps between the window elements and the rims of the holes and is configured to withstand autoclave sterilization. 
     According to some embodiments of the method, each of the illumination modules includes one or more LEDs. 
     Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims included herein. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In case of conflict, the patent specification, including definitions, governs. As used herein, the indefinite articles “a” and “an” mean “at least one” or “one or more” unless the context clearly dictates otherwise. 
     Unless specifically stated otherwise, as apparent from the disclosure, it is appreciated that, according to some embodiments, terms such as “processing”, “computing”, “calculating”, “determining”, “estimating”, “assessing”, “gauging” or the like, may refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data, represented as physical (e.g. electronic) quantities within the computing system&#39;s registers and/or memories, into other data similarly represented as physical quantities within the computing system&#39;s memories, registers or other such information storage, transmission or display devices. 
     Embodiments of the present disclosure may include apparatuses for performing the operations herein. The apparatuses may be specially constructed for the desired purposes or may include a general-purpose computer(s) selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions, and capable of being coupled to a computer system bus. 
     The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method(s). The desired structure(s) for a variety of these systems appear from the description below. In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present disclosure as described herein. 
     Aspects of the disclosure may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types. Disclosed embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Some embodiments of the disclosure are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some embodiments may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an embodiment in more detail than is necessary for a fundamental understanding of the disclosure. For the sake of clarity, some objects depicted in the figures are not drawn to scale. Moreover, two different objects in the same figure may be drawn to different scales. In particular, the scale of some objects may be greatly exaggerated as compared to other objects in the same figure. 
       In the figures: 
         FIG.  1    is a schematic, perspective view of an endoscope, according to some embodiments; 
         FIGS.  2 A and  2 B  are schematic, perspective side-views of a distal section of a shaft of an endoscope, which is a specific embodiment of the endoscope of  FIG.  1   ; 
         FIG.  2 C  is a schematic, cross-sectional view of the distal section of the shaft of  FIG.  2 A , according to some embodiments; 
         FIG.  3    is a schematic, exploded view of a shaft distal section of an endoscope, which is a specific embodiment of the endoscope of  FIG.  2 A ; 
         FIG.  4 A  is schematic, exploded view of a first part of a tip component of the shaft distal section of  FIG.  3   , according to some embodiments; 
         FIG.  4 B  is a schematic, exploded view of a second part of the tip component of the shaft distal section of  FIG.  3   , according to some embodiments; 
         FIG.  4 C  is a schematic, exploded view of a third part of the tip component of the shaft distal section of  FIG.  3   , according to some embodiments; 
         FIG.  5    is a schematic, cross-sectional view of the second part of  FIG.  4 B , according to some embodiments; 
         FIG.  6 A  is a schematic, perspective view of a hull, which forms part of a second part of a tip component of an endoscope, which is a specific embodiment of the endoscope of  FIG.  3   ; 
         FIG.  6 B  is a schematic, side-view of the hull of  FIG.  6 A , according to some embodiments; 
         FIG.  7    is a schematic cross-sectional view of a window element mounted within a side-hole on a tip component of an endoscope, which is a specific embodiment of the endoscope of  FIG.  2 A ; 
         FIG.  8    is a schematic, perspective view of a side-surface of a tip component of a specific embodiment of the shaft of  FIG.  2 A , the side-surface including a hole with full circumferential support for a window element; 
         FIG.  9    is a schematic, perspective view of a side-surface of a tip component of a specific embodiment of the shaft of  FIG.  3   , the side-surface including a hole with partial circumferential support for a window element; 
         FIG.  10    is a schematic, perspective, semi-transparent view of a hull of a second part of the tip component, which is a specific embodiment of the tip component of  FIG.  9   , according to some embodiments; 
         FIG.  11 A  schematically depicts a front holes arrangement on the tip component of the endoscope of  FIG.  2 A , according to some embodiments; 
         FIGS.  11 B and  11 C  schematically depict a first side-holes arrangement and a second side-holes arrangement, respectively, on the tip component of the endoscope of  FIG.  2 A , according to some embodiments; and 
         FIG.  12    is a schematic, cross-sectional view of a first side-section of the endoscope of  FIG.  2 A , according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The principles, uses, and implementations of the teachings herein may be better understood with reference to the accompanying description and figures. Upon perusal of the description and figures present herein, one skilled in the art will be able to implement the teachings herein without undue effort or experimentation. In the figures, same reference numerals refer to same parts throughout. 
     In the description and claims of the application, the words “include” and “have”, and forms thereof, are not limited to members in a list with which the words may be associated. 
     As used herein, the term “about” may be used to specify a value of a quantity or parameter (e.g. the length of an element) to within a continuous range of values in the neighborhood of (and including) a given (stated) value. According to some embodiments, “about” may specify the value of a parameter to be between 99% and 101% of the given value. In such embodiments, for example, the statement “the length of the element is equal to about 1 millimeter” is equivalent to the statement “the length of the element is between 0.99 millimeters and 1.01 millimeters”. 
     As used herein, according to some embodiments, the terms “substantially” and “about” may be interchangeable. 
     As used herein, a first quantity and a second quantity may be said to be “comparable” when the first quantity is about equal to the second quantity. Similarly, a first parameter and a second parameter may be said to be “comparable” (in magnitude) when a magnitude of the first parameter is about equal to a magnitude of the first parameter. 
     For ease of description, in some of the figures a three-dimensional cartesian coordinate system (with orthogonal axes x, y, and z) is introduced. It is noted that the orientation of the coordinate system relative to a depicted object may vary from one figure to another. Further, the symbol ⊙ may be used to represent an axis pointing “out of the page”, while the symbol ⊗ may be used to represent an axis pointing “into the page”. 
       FIG.  1    schematically depicts an endoscope  100 , according to some embodiments. Endoscope  100  includes an elongated shaft  102 , configured to be inserted into an anatomical site (e.g. an anatomical cavity), and a handle  104 , configured to be held by a user (e.g. a surgeon) of endoscope  100  and to facilitate guiding and manipulation of shaft  102  (particularly the distal section thereof) within the anatomical site. Shaft  102  further includes an (elongated) shaft body  108  and a (distal) tip component  110  mounted on a shaft body distal end  112 . A shaft body proximal portion  114  is connected to, or configured to be connected to, handle  104 , thereby mounting shaft  102  on handle  104 . 
     According to some embodiments, each of shaft body  108  and tip component  110  may have a round or substantially round transverse cross-section. According to some embodiments, tip component  110  may be of a greater diameter than shaft  102  or at least a shaft body distal portion  116  (which includes shaft body distal end  112 ), as described in PCT application publication No. WO2019035118 to A. Levy et al., which is incorporated herein by reference in its entirety. According to some such embodiments, a tip proximal portion  118  (i.e. a proximal portion of tip component  110 ) may be tapered (i.e. incline in the proximal direction), terminating in a rim  120 . 
     According to some embodiments, shaft  102  may have a diameter measuring between about 2 millimeters and about 15 millimeters. Tip component  110  may measure between about 1 millimeter and about 25 millimeters in length. According to some embodiments, tip component  110  may have a narrower diameter than the rest of shaft  102 . 
     According to some embodiments, tip component  110  may be permanently attached to shaft body  108 , e.g. using an adhesive or by soldering. Alternatively, according to some embodiments tip component  110  may be detachably mounted on shaft body  108 . For example, tip component  110  may be screwed onto shaft body  108 . Tip component  110  includes a front surface  122 , a first side-surface  124 , and a second side-surface (not visible in  FIG.  1   ), positioned oppositely to first side-surface  124 . Front surface  122  includes a front windows arrangement  132 . First side-surface  124  includes a first side-windows arrangement  134 . Optionally, in embodiments including three cameras (as elaborated on below), the second side-surface includes a second side-windows arrangement. Each of the windows arrangements (i.e. front windows arrangement  132 , first side-windows arrangement  134 , and the second side-windows arrangement (when included)) may include a plurality of windows, as described below. 
     Tip component  110  includes at least two cameras and a plurality of illumination modules. Each of the illumination modules is associated with a respective camera from the at least two cameras. In particular, each camera may be associated with a plurality of illumination modules. Each camera, and the one or more illumination modules associated therewith, are positioned behind a respective windows arrangement from the windows arrangements (i.e. front windows arrangement  132 , first side-windows arrangement  134 , and the second side-windows arrangement (when included)) such that the camera is positioned behind a respective window (dedicated to the camera) from the respective windows arrangement and each of the one or more illumination modules is positioned behind a respective window (dedicated to the illumination module) from the respective windows arrangement. 
     According to some embodiments, a front camera of the at least two cameras may face along, or substantially along, the distal direction (as indicated by a dashed arrow A). According to some embodiments, wherein the at least two cameras include three cameras, a first side-camera may face transversely (along one of the two opposite transverse directions indicated by a dashed double-headed arrow B), or substantially transversely. That is, the first side-camera may point, or substantially point, along a radial direction, and away from first side-surface  124 . A second side-camera may face oppositely, or substantially oppositely, to the first side-camera. According to some embodiments, the two side-cameras may be positioned such that they are not back-to-back. 
     According to some embodiments, each of the illumination modules includes one or more light emitting diodes (LEDs). 
     According to some embodiments, the illumination modules include the distal tips of respective optical fibers. According to some such embodiments, handle  104  may include one or more light sources connected to one or more optical fibers extending through handle  104  and shaft  102 . The optical fibers are configured to guide the light produced by the light sources from handle  104  to tip component  110 , wherefrom the guided light may be shone such as to illuminate the field-of-view of the cameras. According to some embodiments, the light sources may be external to handle  104 , being positioned, for example, in a main control unit (not shown). In such embodiments, a cable, which includes one or more optical fibers, may be used to guide the light, generated by the light sources in the main section, to handle  104 . According to some embodiments, the cable may be a multi-purpose cable, such as a utility cable  140  described below. 
     Handle  104  may include a user control interface (not shown) configured to allow a user to control endoscope  100  functions. In particular, the user control interface may be functionally associated with the cameras and the illumination modules. According to some embodiments, the user control interface may allow, for example, to control zoom, focus, record/stop recording, and/or freeze frame functions of the cameras and/or to adjust the intensity of light provided by the illumination modules collectively and/or individually. The user control interface may include one or more buttons, knobs, switches, a touch panel, and/or the like. 
     According to some embodiments, endoscope  100  may be (i) directly maneuvered by a user through the manipulation of handle  104 , as well as (ii) indirectly maneuvered, via robotics, e.g. using a robotic arm or other suitable gripping means configured to allow manipulation of handle  104 . 
     The main control unit may be functionally associated with endoscope  100  via utility cable  140 . The main control unit may include electronic circuitry (e.g. one or more processors and memory components) configured to process (digital data) from the cameras, such as to display the captured images and video(s) on a monitor. In particular, the processing circuitry may be configured to process the digital data received from each of the cameras, such as to produce therefrom a combined video file/stream providing a continuous and consistent (seamless) panoramic view of an anatomical site wherein endoscope  100  is inserted. 
     According to some alternative embodiments, the main control unit may be functionally associated with endoscope  100  through wireless communication. 
       FIGS.  2 A and  2 B  are schematic perspective side-views of a (shaft) distal section  206  of a shaft  202  of an endoscope  200 , which is a specific embodiment of endoscope  100 . Endoscope  200  includes shaft  202  and a handle (not shown), such as handle  104 . Shaft  202  is a specific embodiment of shaft  102  and includes a shaft body  208  and a tip component  210 , which are specific embodiments of shaft body  108  and tip component  110 . Also indicated is a housing  228  of tip component  210 , which is configured to accommodate internal components, such as cameras, illumination units, electronics, and so on. Shaft distal section  206  includes tip component  210  and a shaft body distal portion  216  of shaft body  208 . Also indicated are a front surface  222 , a first side-surface  224 , and a second side-surface  226  of tip component  210 . 
     Making reference also to  FIG.  2 C ,  FIG.  2 C  is a schematic, longitudinal cross-sectional view of shaft distal section  206 , according to some embodiments. According to some embodiments, and as depicted in  FIG.  2 C , tip component  210  includes three cameras and three illumination units: a front camera  242 , a first side-camera  244 , a second side-camera  246 , a front illumination unit  252 , a first side-illumination unit  254 , and a second side-illumination unit  256 . According to some embodiments, front illumination unit  252  may include three illumination modules, while each of side-illumination units  254  and  256  may include two illumination modules. 
     Each of cameras  242 ,  244 , and  246  includes a lens assembly and an image sensor: Front camera  242  includes a front lens assembly  260  and a front image sensor  262 , first side-camera  244  includes a first side-lens assembly  264  and a first side-image sensor  266 , and second side-camera  246  includes a second side-lens assembly  268  and a second side-image sensor  270 . According to some embodiments, each of image sensors  262 ,  266 , and  270  is a CMOS (complementary metal-oxide semiconductor) image sensor, but it will be understood that other options are possible. In particular, according to some alternative embodiments, one or more of the image sensors may be CCD (charge-coupled device) image sensors. 
     According to some embodiments, and as depicted in  FIG.  2 C , first side-camera  244  and second side-camera  246  are not positioned back-to-back. That is, first side-camera  244  is positioned within tip component  210  at a distance D 1  from front surface  222  of tip component  210 , and second side-camera  246  is positioned at a distance D 2  from front surface  222 , with D 2 &lt;D 1 . According to some such embodiments, first side-camera  244  and second side-camera  246  may be positioned adjacently to one another along the longitudinal axis L of shaft  202 , thereby saving space and helping to restrict the lateral dimensions (i.e. the diameter) of shaft distal section  206 . The longitudinal axis L extends along the length of shaft  202  (and therefore in parallel to the x-axis). According to some such embodiments, the diameter of shaft distal section  206  may be smaller than about 11 millimeters. According to some embodiments, the distance D 1  may be between about 10 millimeters and about 27 millimeters, and the distance D 2  may be between about 10 millimeters and about 17 millimeters. According to some embodiments, the distance D 1  is between about 4 millimeters and about 15 millimeters, and the distance D 2  is between about 4 millimeters and about 15 millimeters, but at the same time D 2  may be smaller than D 1 . 
     According to some embodiments, and as depicted in  FIGS.  2 A- 2 C , front lens assembly  260  may be embedded in or on front surface  222 , such as to face forward along the direction defined by the positive x-axis, i.e. the distal direction. First side-lens assembly  264  may be embedded in or on first side-surface  224 , such as to face sideways, along a direction, which as shown in  FIG.  2 C , is slightly tilted relative to the direction defined by the positive y-axis. That is, an optical axis O 1  of first side-lens assembly  264  may be slightly tilted (e.g. on a plane parallel to the xy-plane) relative to the y-axis (as indicated by an angle θ, defined by the optical axis O 1  and the longitudinal axis L, which is slightly greater than 90 degrees in  FIG.  2 C ). As a non-limiting example, according to some embodiments, θ may be between 90.5 degrees and 95 degrees. Second side-lens assembly  268  may be embedded in or on second side-surface  226 , such as to face sideways, along the direction defined by the negative y-axis. (So that an optical axis O 2  of second side-lens assembly  268  is parallel to they-axis, or, what is the same thing, perpendicular to the longitudinal axis L). 
     Also indicated is an angle α between optical axis O 2  and longitudinal axis L. According to some embodiments, not depicted in  FIG.  2 C , optical axis O 2  may be slightly tilted relative to longitudinal axis L. As a non-limiting example, according to some embodiments, α may be between 90.5 degrees and 95 degrees. 
     According to some embodiments, cameras  242 ,  244 , and  246  are configured to provide, in combination, a continuous field-of-view (FOV) of at least about 270 degrees. More specifically, the horizontal FOV provided by the cameras may be at least about 270 degrees, wherein the horizontal plane may be parallel to the xy-plane. According to some such embodiments, the optical axes of cameras  242  (not shown),  244  (i.e. optical axis O 1 ), and  246  (i.e. optical axis O 2 ) all lie on plane parallel to the xy-plane. The positioning of the cameras within tip component  210  may be selected such as to minimize the space occupied by the cameras and reduce the diameter of tip component  210  and shaft distal section  206 , while affording a continuous FOV at least about 270 degrees. 
     According to some alternative embodiments, not depicted in the figures, first side-camera  244  and second side-camera  246  are positioned back-to-back. 
     Each of cameras  242 ,  244 , and  246 , and illumination units  252 ,  254 , and  256 , may be functionally associated with electronic components (such as processors, amplifiers, discrete components), which may be mounted on one or more printed circuit boards (PCBs) and/or connected to one or more electrical wires. According to some embodiments, the PCBs may be foldable such as to allow compact accommodation of the cameras within tip component  210 . 
     Referring again to  FIGS.  2 A and  2 B , tip component  210  includes a front windows arrangement  232 , a first side-windows arrangement  234 , and a second side-windows arrangement  236 . Front windows arrangement  232  may include a central window  232   a,  and three windows  232   b,    232   c,  and  232   d  surrounding central window  232   a.  Front camera  242  may be positioned behind (i.e. proximally to) central window  232   a  (and is, thus, hidden from view in  FIGS.  2 A and  2 B ). The three illumination modules of front illumination unit  252  may be positioned behind windows  232   b,    232   c,  and  232   d,  respectively (and are, thus, not visible in  FIGS.  2 A and  2 B ). According to some embodiments, each of the three illumination modules may include a plurality of LEDs, for example, two, three, or four LEDs which may be arranged in an array. According to some embodiments, the LEDs may emit light at the same wavelength. According to some alternative embodiments, different LEDs may emit light at different wavelengths, respectively. According to some embodiments, the windows may differ from one another in shape and/or in size. In particular, according to some embodiments, central window  232   a  may differ in shape and/or size from windows  232   b,    232   c,  and  232   d.    
     Front surface  222  includes a front holes arrangement  201  (i.e. a front arrangement of holes; shown in  FIG.  11 A ). Each of the holes has set therein a respective window element (e.g. a windowpane) pertaining to front windows arrangement  232 . Indicated are a central window element  282   a,  and window elements  282   b,    282   c,  and  282   d,  pertaining to central window  232   a,  and windows  232   b,    232   c,  and  232   d,  respectively. Each hole-window element pair constitutes a window (from one of the window arrangements). For example, a central front hole  201   a  (from front holes arrangement  201 ) and central window element  282   a  constitute central window  232   a.  Each of the window elements of front windows arrangement  232  is set within a corresponding hole from the front holes arrangement. For example, window element  282   a  is set within central front hole  201   a.  More specifically, each of the holes is shaped and dimensioned to have affixed therein (for example, by soldering) a corresponding window element, essentially as elaborated on below in the description of  FIGS.  4 A- 4 C . 
     First side-windows arrangement  234  may include a central window  234   a  and two windows  234   b  and  234   c  respectively positioned on opposite sides of central window  234   a.  First side-camera  244  may be positioned behind central window  234   a.  The two illumination modules of first side-illumination unit  254  may be positioned behind windows  234   b  and  234   c,  respectively (and are, thus, not visible in  FIG.  2 A ). Each of the two illumination modules may include a plurality of light emitting diodes (LEDs, e.g. which may be arranged in an array). According to some embodiments, the windows may differ from one another in shape and/or in size. In particular, according to some embodiments, central window  234   a  may differ in shape and/or size from windows  234   b  and  234   c.    
     First side-surface  224  includes a first side-holes arrangement  203  (shown in  FIG.  11 B ). Each of the holes has set therein a respective window element pertaining to first side-windows arrangement  234 . Indicated are a central window element  284   a,  and window elements  284   b  and  284   c,  pertaining to central window  234   a,  and windows  234   b  and  234   c,  respectively. More specifically, each of the holes is shaped and dimensioned to have affixed therein (for example, by soldering) a corresponding window element from first side-windows arrangement  234 . 
     Second side-windows arrangement  236  may include a central window  236   a  and two windows  236   b  and  236   c  respectively positioned on opposite sides of central window  236   a.  Second side-camera  246  may be positioned behind central window  236   a  (and is, thus, hidden from view in  FIG.  2 B ). The two illumination modules of second side-illumination unit  256  may be positioned behind windows  236   b  and  236   c,  respectively (and are, thus, not visible in  FIG.  2 B ). Each of the two illumination modules may include a plurality of LEDs (e.g. arranged in an array). According to some embodiments, the windows may differ from one another in shape and/or in size. In particular, according to some embodiments, central window  236   a  may differ in shape and/or size from windows  236   b  and  236   c.    
     Second side-surface  226  includes a second side-holes arrangement  205  (shown in  FIG.  11 C ). Each of the holes has set therein a respective window element pertaining to second side-windows arrangement  236 . Indicated are a central window element  286   a,  and window elements  286   b  and  286   c,  pertaining to central window  236   a,  and windows  236   b  and  236   c,  respectively. More specifically, each of the holes is shaped and dimensioned to have affixed therein (for example, by soldering) a corresponding window element from second side-windows arrangement  236 . 
     The windows (i.e. the windows of window arrangements  232 ,  234 , and  236 ) protect the cameras (i.e. cameras  242 ,  244 , and  246 ) and the illumination units (i.e. illumination units  252 ,  254 , and  256 ) from body fluids and debris during an endoscopy procedure. Further, shaft distal section  206  (and, in particular, tip component  210 ) may be fluidly sealed such as to prevent air/gas from entering therein during an endoscopy procedure and when undergoing cleaning. Air penetration may lead to the formation of a condensate on the lenses of the cameras and the inner surfaces of the windows, and thereby blur video and images obtained by the cameras. Moisture may lead to corrosion of the electrical components within shaft distal section  206 , which may result in malfunctioning of the cameras and the illumination units. In order to prevent air penetration, an inert gas, such as nitrogen, may be pumped into shaft distal section  206 , prior to the sealing thereof. The illumination modules (on the illumination units), which may include light sources, such as LEDs, are configured to illuminate the field-of-view of the cameras. 
     According to some embodiments, each window element (windowpane) in each of the window arrangements (i.e. window arrangements  232 ,  234 , and  236 ) may be made of, or include, sapphire glass (synthetic sapphire). According to some embodiments, front surface  222  and each of side-surfaces  224 , and  226  may be made of, or include, stainless steel. According to some embodiments, rims of the holes (of the holes arrangements) are made of, or include, stainless steel. According to some such embodiments, each of the window elements may be bonded to the rim of the hole wherein the window element is set, using solder material configured to strongly and permanently bond sapphire glass to stainless steel. According to some embodiments, the solder material is, or includes, a noble metal, such as, for example, gold, silver, and/or platinum, thereby helping to ensure the integrity of the bond over time. More specifically, each hole may be slightly larger than the corresponding window element, such that, when the window element is positioned within the hole, with the respective center points thereof coinciding, a gap is present between the window element and the rim of the hole. The gap is sufficiently wide to accommodate the solder material which bonds the window element to the rim (i.e. the solder material affixes the window element within the hole). In particular, the solder material and each hole-window element pair are configured such that the solder material fluidly seals the gap between the hole and the window element and remains intact under steam sterilization (e.g. autoclave sterilization). 
     According to some embodiments, wherein the window elements are made of sapphire glass and the side-surfaces are made of stainless steel, the thickness of the sapphire glass window elements is selected to be sufficiently thick to (i) maintain integrity during the soldering of the window elements to the holes, and (ii) not be deformed or fractured due to mechanical stresses which the stainless steel side-surfaces may exert on the window elements (e.g. due to thermal expansion or contraction). 
     According to some embodiments, first side-windows arrangement  234  may be set within a first side-niche  274  (indicated in  FIG.  2 C ) within first side-surface  224 . First side-niche  274  may form a shallow indentation on first side-surface  224 . Similarly, according to some embodiments, second side-windows arrangement  236  may be set within a second side-niche  276  (indicated in  FIG.  2 C ) within second side-surface  226 . Second side-niche  276  may form a shallow indentation on second side-surface  226 . Each of side-niches  274  and  276  may form a flat depression on the respective side-surface, thereby allowing to affix within holes in the depression flat windows elements, which may be easier to produce than concave window elements and may potentially be more durable. Thus, according to some embodiments, side-niches  274  and  276  form a flat depressions, and each of window elements  284   a,    284   b,  and  284   c  and windows  286   a,    286   b,  and  286   c  is flat. 
       FIG.  3    provides a schematic, exploded view of a shaft distal section  306  of a shaft  302  of an endoscope  300 , which is a specific embodiment of endoscope  200 . In particular, shaft distal section  306  is a specific embodiment of shaft distal section  206  and includes a tip component  310  which is a specific embodiment of tip component  210 . According to some embodiments, and as depicted in  FIG.  3   , tip component  310  is formed of three parts: a tip first part  311 , a tip second part  313 , and a tip third part  315 . The three parts may be soldered, welded (e.g. laser welded), and/or glued onto one another, such as to fluidly seal tip component  310  and shaft distal section  306 . Also indicated are a shaft body  308  (of shaft  302 ), which is a specific embodiment of shaft body  208 , a front windows arrangement  332 , which is a specific embodiment of front windows arrangement  232 , and a first side-windows arrangement  334 , which is a specific embodiment of first side-windows arrangement  234 . 
     Referring also to  FIGS.  4 A- 4 C ,  FIG.  4 A  provides a schematic, exploded view of tip first part  311 , according to some embodiments.  FIG.  4 B  provides a schematic, exploded view of tip second part  313 , according to some embodiments.  FIG.  4 C  provides a schematic, exploded view of tip third part  315 , according to some embodiments. 
     According to some embodiments, tip first part  311  includes a circumferential frame  331 , a front surface  322 , front windows arrangement  332 , a front camera  342 , a front illumination unit  352 , and a first PCB  321 . Front illumination unit  352  may include three front illumination modules: a front illumination module  352   a,  a front illumination module  352   b,  and a front illumination module  352   c.  Front windows arrangement  332  includes window elements  382  and a front holes arrangement  301 . Indicated are window elements  382   a,    382   b,    382   c,  and  382   d —of front windows arrangement  332 —which correspond to front holes  301   a,    301   b,    301   c,  and  301   d,  respectively. Front surface  322 , front camera  342 , and front illumination unit  352  are specific embodiments of front surface  222 , front camera  242 , and front illumination unit  252 , respectively. Circumferential frame  331  distally terminates in front surface  322 . According to some embodiments, circumferential frame  331  may be characterized by a round or oval transverse cross-section. 
     According to some embodiments, tip second part  313  includes a cover section  333 , a first side-niche  374 , first side-windows arrangement  334 , a first side-camera  344 , a first side-illumination unit  354 , and a second PCB  323 . First side-illumination unit  354  may include two side-illumination modules: a side-illumination module  354   a  and a side-illumination module  354   b . First side-windows arrangement  334  includes window elements  384  and a first side-holes arrangement  303 . Indicated are window elements  384   a,    384   b,  and  384   c —of first side-windows arrangement  334 —which correspond to first side-holes  303   a,    303   b,  and  303   c,  respectively. First side-niche  374 , first side-camera  344 , and first side-illumination unit  354  are specific embodiments of first side-niche  274 , first side-camera  244 , and first side-illumination unit  254 , respectively. The first side-windows arrangement is included in cover section  333 , as elaborated on below. 
     According to some embodiments, tip third part  315  includes a hull  335 , a second side-niche  376 , a second side-windows arrangement  336 , a second side-camera  346 , a second side-illumination unit  356 , and a third PCB  325 . Second side-illumination unit  356  may include two side-illumination modules: a side-illumination module  356   a  and a side-illumination module  356   b.  Second side-windows arrangement  336  includes window elements  386  and a second side-holes arrangement  305 . Indicated are window elements  386   a,    386   b,  and  386   c  corresponding to second side-holes  305   a,    305   b,  and  305   c,  respectively. Window elements  386   a,    386   b,  and  386   c  form part of second side-windows arrangement  336 , which is a specific embodiment of second side-windows arrangement  236 . Second side-niche  376 , second side-camera  346 , and second side-illumination unit  356  are specific embodiments of second side-niche  276 , second side-camera  246 , and second side-illumination unit  256 , respectively. 
     Hull  335  is dimensioned such as to accommodate (at least) cameras  242 ,  244 , and,  246 , illumination units  252 ,  254 , and  256 , and PCBs  321 ,  323 , and  325 . More specifically, hull  335  is hollow, being open on a hull distal end  337  (i.e. a distal end of hull  335 ) and on a hull proximal end  339 . Circumferential frame  331  is configured to be fitted on hull distal end  337  (thereby mounting tip first part  311  on tip third part  315 ). Hull  335  further includes a side-opening  341  whereon cover section  333  is configured to be fitted (thereby mounting tip second part  313  on tip third part  315 ). Also indicated is a rim  343  of side-opening  341 . Finally, hull proximal end  339  is configured to be fitted on a shaft body distal end  312  (i.e. the distal end of shaft body  308 ), thereby attaching tip component  310  to shaft body  308 . 
     First PCB  321  may have front camera  342  mounted thereon, as well as electronic components related to the operation of front camera  342  and front illumination unit  352 , such as electronic switches and/or amplifiers configured, for example, to switch on/off front camera  342  and to set an (illumination) intensity of front illumination unit  352 . Second PCB  323  may have first side-camera  344  mounted thereon, as well as electronic components related to the operation of first side-camera  344  and first side-illumination unit  354 . Third PCB  325  may have second side-camera  346  mounted thereon, as well as electronic components related to the operation of second side-camera  346  and second side-illumination unit  356 . 
     According to some embodiments, one or more of PCBs  321 ,  323 , and  325  may be foldable. For example, according to some embodiments and as depicted in  FIGS.  4 A and  4 C , respectively, first PCB  321  and third PCB  325  are foldable. 
       FIG.  5    provides a schematic cross-sectional view of tip second part  313 , according to some embodiments. A first side-lens assembly  364  and a first side-image sensor  366  of first side-camera  344  are also indicated. First side-lens assembly  364  and first side-image sensor  366  are integrated within tip second part  313 . Window elements  384  are shown positioned within first side-niche  374 . 
       FIG.  6 A  provides a schematic, perspective view of a hull  635  of a tip component  610 , according to some embodiments.  FIG.  6 B  provides a side-view of hull  635 , according to some embodiments. Tip component  610  is a specific embodiment of tip component  310 . Hull  635  is a specific embodiment of hull  335  of tip third part  315  of endoscope  300 . In both of  FIGS.  6 A and  6 B , an inner surface  649  of hull  635 , and a niche inner surface  677 , are visible. Niche inner surface  677  is included in inner surface  649 . Niche inner surface  677  constitutes the inner surface of the wall of the indentation defined by a second side-niche (not visible in  FIGS.  6 A and  6 B ), which is a specific embodiment of second side-niche  376 . The second side-niche includes a (second) side-holes arrangement  605 , which is a specific embodiment of second side-holes arrangement  305 . According to some embodiments, and as depicted in  FIGS.  6 A and  6 B , niche inner surface  677  may be flat. Also indicated are a hull distal end  637 , a hull proximal end  639 , a side-opening  641 , and a rim  643  of side opening  641 . 
     Side-holes arrangement  605  includes a central side-hole  605   a  and two side-holes  605   b  and  605   c  respectively positioned distally and proximally to central side-hole  605   a.  According to some embodiments, niche inner surface  677  includes corner surface-niches  651   b  (not all of which are marked), each of which forms a respective depression extending from a rim  655   b  of side-hole  605   b.  Corner surface-niches  651   b  are configured to accommodate corners of an illumination module, which is characterized by a height and/or width greater than the diameter of side-hole  605   b.  In particular, each of corner surface-niches  651   b  may constitute a respective region of reduced thickness of the wall of the indentation, defined by the second side-niche, as compared to the rest of the wall. Similarly, according to some embodiments, niche inner surface  677  includes corner surface-niches  651   c  (not all of which are marked) forming respective depressions extending from a rim  655   c  of side-hole  605   c.  Corner surface-niches  651   c  are configured to accommodate corners of an illumination module, which may be characterized by a height and/or width greater than the diameter of side-hole  605   c.  In particular, each of corner surface-niches  651   c  may constitute a respective region of reduced thickness of the wall of the indentation, defined by the second side-niche, as compared to the rest of the wall. 
     As used herein, according to some embodiments, the terms “corner niche” and “corner surface-niche” may be used interchangeably. 
       FIG.  7    provides a schematic cross-sectional view of a portion of a tip component  710 , according to some embodiments. Tip component  710  is a specific embodiment of tip component  210 . According to some embodiments, tip component  710  is a specific embodiment of tip component  310 . According to some embodiments, tip component  710  is a specific embodiment of tip component  610 . The cross-section is taken such as to bisect a window  736   b  of a (second) side-holes arrangement, which is a specific embodiment of window  236   b  (and according to some embodiments, a specific embodiment of the distalmost window from second side-windows arrangement  336  of tip component  310 ). Window  736   b  includes a side-hole  705   b  and a window element  786   b  soldered thereto. According to some embodiments, side-hole  705   b  and window element  786   b  are a specific embodiments of side-hole  305   b  and window element  386   b,  respectively. 
     Indicated is a gap g between a window element  786   b  and a rim of side-hole  705   b.  Also indicated is a width w of the gap g. When window element  786   b  is affixed within side-hole  705   b,  the gap g is filled with solder material, which bonds window element  786   b  (more precisely, the rim thereof) to a rim of side-hole  705   b.  According to some embodiments, the width w of the gap g may measure between about 0.02 millimeters and about 0.1 millimeters. As a non-limiting example, according to some embodiments, the width w of the gap g may measure about 50 micrometers. According to some embodiments, a thickness q of window element  786   b  may measure between about 0.2 millimeters and about 1 millimeter. As a non-limiting example, according to some embodiments, the thickness q of window element  786   b  may measure about 0.6 millimeters. 
     It is to be understood that the above description of the affixing of window element  786   b  within side-hole  705   b,  and, in particular, the geometry and dimensions of the window element and the side-hole, may apply not only for the rest of side-holes for the side-illumination modules (side-holes—not shown in  FIG.  7   —which are specific embodiments of side-holes  305   c,  and side-holes  303   b  and  303   c ), but also for the front holes for the front illumination modules (front holes—not shown in  FIG.  7   —which are specific embodiments of front holes  301   b,    301   c,  and  301   d ). Further, according to some embodiments, the above description also applies for the holes for the cameras (front holes and side-holes—not shown in  FIG.  7   —which are specific embodiments of front hole  301   a,  and side-holes  303   a  and  305   a ). 
     As depicted in  FIG.  7   , side-hole  705   b  may include a support ledge  765   b  configured to support (sustain) window element  786   b  within side-hole  705   b  prior to the soldering of window element  786   b  onto the rim of side-hole  705   b.  According to some embodiments, support ledge  765   b  may extend along the full length of the rim of side-hole  705   b  and centrally project therefrom (i.e. project towards the center of the circle defined by side-hole  705   b ). According to some alternative embodiments, support ledge  765   b  may be segmented. That is, support ledge  765   b  may include at least two separate segments, with each of the segments projecting centrally from the rim of side-hole  705   b.  Each of the rest of the side-holes for the side-illumination modules may include essentially identical or similar support ledges. Further, according to some embodiments, each of the front holes for the front illumination modules may include essentially identical or similar support ledges. According to some embodiments, each of the holes for the cameras may include a support ledge with full circumferential support (i.e. the support ledge is not segmented), thereby preventing “parasitic” light from reaching the respective image sensor. 
     According to some embodiments, segmented support ledges may allow for further compactification of the arrangement of the camera and the illumination modules within the tip component, More specifically, since the “missing segments” of the support ledge do not block light emitted by the respective illumination module, these “missing segments” therefore allow for increased illumination by the illumination module, and therefore allow using a smaller illumination module to achieve a desired illumination level. 
       FIG.  8    provides a schematic side-view of a portion of a tip component  810 , according to some embodiments. Tip component  810  is a specific embodiment of tip component  210 . According to some embodiments, tip component  810  is a specific embodiment of tip component  310 . According to some embodiments, tip component  810  is a specific embodiment of tip component  610 . According to some embodiments, tip component  810  is a specific embodiment of tip component  710 . 
     Depicted are a (central) side-hole  805   a  for a side-camera (not shown) and a side-hole  805   c  for a side-illumination module  856   c,  according to some embodiments. Side-hole  805   a  includes a support ledge  865   a  projecting centrally (towards the center of the circle defined by side-hole  805   a ) from a rim  855   a  of side-hole  805   a.  Support ledge  865   a  may constitute a circular flange extending centrally along the full circumference of side-hole  805   a.  Similarly, side-hole  805   c  includes a support ledge  865   c  projecting centrally (towards the center of the circle defined by side-hole  805   c ) from a rim  855   c  of side-hole  805   c.  Support ledge  865   c  may constitute a circular flange extending along the full circumference of side-hole  805   c.  As a non-limiting example, in  FIG.  8    side-illumination module  856   b  is depicted as including two LEDs. 
     Each of the remaining holes for the cameras (both side and front) and the illumination modules (both side and front) may include essentially identical or similar support ledges to support ledge  865   a  and support ledge  865   c,  respectively. 
       FIG.  9    provides a schematic perspective side-view of a portion  971  of a hull  935  of a tip component  910 , according to some embodiments. Tip component  910  is a specific embodiment of tip component  210 . According to some embodiments, tip component  910  is a specific embodiment of tip component  310 . According to some embodiments, tip component  910  is a specific embodiment of tip component  610 . According to some embodiments, tip component  910  is a specific embodiment of tip component  710 . 
     Depicted are a central side-hole  905   a  for a side-camera (not shown) and a side-hole  905   b  for a side-illumination module  956   a  of a second side-illumination unit  956 , according to some embodiments. Second side-illumination unit  956  is a specific embodiment of second side-illumination unit  256 . Side-hole  905   a  includes a support ledge  965   a  projecting centrally (towards the center of the circle defined by side-hole  905   a ) from a rim  955   a  of side-hole  905   a.  Support ledge  965   a  may constitute a circular flange extending centrally along the full circumference of side-hole  905   a,  essentially as described above with respect to side-hole  805   a  of tip component  810 . Side-hole  905   b  includes a support ledge  965   b  projecting centrally (towards the center of the circle defined by side-hole  905   b ) from a rim  955   b  of side-hole  905   b.  Support ledge  965   b  may include two opposite-facing, or substantially opposite-facing, segments: a segment  965   b   1  and a second segment  965   b   2 . As a non-limiting example, in  FIG.  9    side-illumination module  956   a  is depicted as including three LEDs. 
     According to some embodiments, support ledge  965   b  may extend along less than two thirds of the circumference of the respective rim. For example, each of first segment  965   b   1  and second segment  965   b   2  may extend along less than 33% of the circumference of a rim  955   b  of side-hole  905   b.  According to some embodiments, support ledge  965   b  may extend along less than half of the circumference of the respective rim. For example, each of first segment  965   b   1  and second segment  965   b   2  may extend along less than 25% of the circumference of rim  955   b  of side-hole  905   b.    
     Each of the remaining holes for the cameras may include essentially identical or similar support ledges to support ledge  965   a.  Each of the remaining holes for the illumination modules (both side and front) may include essentially identical or similar support ledges to support ledge  965   b,  respectively. 
       FIG.  10    provides a schematic, perspective, semi-transparent view of a hull  1035  of a tip third part  1015  (not all parts of which are shown) of a tip component  1010  (not all parts of which are shown). Tip component  1010  is a specific embodiment of tip component  910 . Tip third part  1015  includes a second side-illumination unit  1056  installed thereon, according to some embodiments. Second side-illumination unit  1056  is a specific embodiment of second side-illumination unit  956 . 
     Depicted is a second side-holes arrangement  1005 , according to some embodiments. Side-holes arrangement  1005  includes a central side-hole  1005   a  for a second side-camera (not shown) centrally positioned between two side-holes  1005   b  and  1005   c  for side-illumination modules  1056   a  and  1056   b  (of side-illumination unit  1056 ), respectively. Side-hole  1005   b  is positioned distally to central side-hole  1005   a  while side-hole  1005   c  is positioned proximally to central side-hole  1005   a.  That is, side-hole  1005   b  is positioned more closely to a hull distal end  1037  of hull  1035  than each of side-holes  1005   a  and  1005   c,  and side-hole  1005   c  is positioned more closely to a hull proximal end  1039  of hull  1035  than each of side-holes  1005   a  and  1005   b.  Each of side-holes  1005   b  and  1005   c  may include a segmented support ledge: segmented support ledges  1065   b  and  1065   c,  respectively. 
     More specifically, and as shown in  FIG.  10   , support ledge  1065   b  may include two opposite-facing, or substantially opposite-facing, segments: a (distal) first segment (not visible in  FIG.  10   ) and a (proximal) second segment  1065   b   2 . Similarly, support ledge  1065   c  may include two opposite-facing, or substantially opposite facing, segments: a (distal) first segment (not visible in  FIG.  10   ) and a (proximal) second segment  1065   c   2 . According to some embodiments, each of the support ledges may extend along less than two thirds of the circumference of the respective rim. For example, each of the first segment of support ledge  1065   c  and second segment  1065   c   2  may extend along less than 33% of the circumference of a rim  1055   c  of side-hole  1005   c.  According to some embodiments, each of the support ledges may extend along less than half of the circumference of the respective rim. For example, each of the first segment of support ledge  1065   c  and second segment  1065   c   2  may extend along less than 25% of the circumference of rim  1055   c  of side-hole  1005   c.  Each of the remaining holes for the illumination modules (both side and front) may include essentially identical or similar support ledges to support ledges  1065   b  and  1065   c.    
       FIG.  11 A  schematically depicts a front holes arrangement  201  on front surface  222 , according to some embodiments. Front holes arrangement  201  includes a central front hole  201   a  and, according to some embodiments, three surrounding front holes  201   b,    201   c,  and  201   d.  Front holes  201   b,    201   c,  and  201   d  may be symmetrically disposed around front hole  201   a.  Indicated is a diameter D of front surface  222  (which according to some embodiments equals the diameter of a tip component  210 ), a characteristic scale d F  of front hole  201   a  and a characteristic scale d′ F  of front holes  201   b,    201   c,  and  201   d.  In embodiments wherein the front holes are round, the characteristic scales d F  and d′ F  correspond to the respective diameters of front hole  201   a  and front holes  201   b,    201   c,  and  201   d,  respectively. Also indicated is a spacing y F  between a rim of front hole  201   a  and rims of front holes  201   b,    201   c,  and  201   d,  a distance v F  between the centers of front holes  201   a  and  201   b  (which may equal the distance between the centers of front holes  201   a  and the centers of front holes  201   c  and  201   d ), and a distance t between the rims of the surrounding front holes  201   b,    201   c,  and  201   d  and the rim of front surface  222 . 
     According to some embodiments, a relation between the diameter D, the characteristic scale d F , and the spacing y F  may be related by y F ≈(D−3·d F )/4. Here, the symbol ≈ is used to indicate that the left-hand side of an equation is about equal to the right-hand side of the equation. More generally, the magnitude of y F  may be given by (a·D−b·d F )/c, wherein a equals about 1, b equals about 3, and c equals about 4. According to some embodiments, a magnitude of the distance t may be about equal to the magnitude of the spacing y F . According to some embodiments, the spacing y F  and/or the distance t may be as small as about 0.05 millimeters. 
       FIG.  11 B  schematically depicts first side-holes arrangement  203  set within first side-niche  274 , according to some embodiments. First side-holes arrangement  203  includes a central first side-hole  203   a  and, according to some embodiments, a pair of first side-holes  203   b  and  203   c  respectively positioned distally and proximally to first side-hole  203   a.  That is, side-hole  203   b  is positioned more closely to front surface  222  than each of first side-holes  203   a  and  203   c,  and first side-hole  203   c  is positioned more closely to shaft body  208  than each of first side-holes  203   a  and  203   b.  Indicated is a characteristic scale d S  of first side-hole  203   a  and a characteristic scale d′ S  of first side-holes  203   b  and  203   c.  In embodiments wherein the first side-holes are round, the characteristic scales d S  and d′ S  correspond to the respective diameters of first side-hole  203   a  and first side-holes  203   b  and  203   c,  respectively. Also indicated is a spacing y S  between a rim of first side-hole  203   a  and rims of first side-holes  203   b  and  203   c,  and a distance vs between the centers of first side-holes  203   b  and  203   c.    
       FIG.  11 C  schematically depicts second side-holes arrangement  205  set within second side-niche  276 , according to some embodiments. Second side-holes arrangement  205  includes a central second side-hole  205   a  and, according to some embodiments, a pair of second side-holes  205   b  and  205   c  respectively positioned distally and proximally to second side-hole  205   a.  That is, side-hole  205   b  is positioned more closely to front surface  222  than each of first side-holes  205   a  and  205   c,  and first side-hole  205   c  is positioned more closely to shaft body  208  than each of first side-holes  205   a  and  205   b.  Indicated is a characteristic scale d″ S  of second side-hole  205   a  and a characteristic scale d′″ S  of second side-holes  205   b  and  205   c.  In embodiments wherein the second side-holes are round, the characteristic scales d″ S  and d′″ S  correspond to the respective diameters of second side-hole  205   a  and second side-holes  205   b  and  205   c,  respectively. Also indicated is a spacing y′ S  between a rim of second side-hole  205   a  and rims of second side-holes  205   b  and  205   c,  and a distance v′ S  between the centers of second side-holes  205   b  and  205   c.    
     According to some embodiments, the characteristic scale d″ S  may be equal to, or at least comparable to, the characteristic scale d S , the characteristic scale d′″ S  may be equal to, or at least comparable to, the characteristic scale d′ S , and the spacing y′ S  may be equal to, or at least comparable to, the spacing y S . 
     As a non-limiting example, according to some embodiments, each of front holes  201  and side-holes  203  and  205  is round, 3.2 mm≤d F ≤4.9 mm, each of d′ F , d S , and d″ S  is comparable to d F , d′ S  and d′″ S  each range from d F  to about 1.3·d F , 10 mm≤D≤15 mm, y F  may be equal to about 0.05 millimeters, y S  and y′ S  may each range from about 0.5 millimeters to about 1.25 millimeters, and t may be comparable to y F . 
     As another non-limiting example, according to some embodiments, each of front holes  201  and side-holes  203  and  205  is round, 0.1 mm≤d F ≤0.4 mm, each of d′ F , d S , and d″ S  is comparable to d F , d′ S  and d′″ S  each range from about d F  to about 1.3·d F , 2 mm≤D≤6 mm, y F  may be equal to about 0.05 millimeters, y S  and y′ S  may each range from about 0.5 millimeters to about 1.25 millimeters, and t may be comparable to y F . 
     As yet another non-limiting example, according to some embodiments, each of front holes  201  and side-holes  203  and  205  is round, d F  is equal to about 3.4 millimeters, each of d′ F , d S , and d″ S  is comparable to d F , d′ S  and d′″ S  are each equal to about 4.5 millimeters, v F  is equal to about 3.7 millimeters, v S  and v′ S  each equal about 10.4 millimeters, y F  may be equal to about 0.3 millimeters, y S  and y′ S  may each range from about 0.5 millimeters to about 1.25 millimeters, and t may be comparable to y F . 
       FIG.  12    provides a schematic, longitudinal, cross-sectional view of a first side-section of tip component  210 , according to some embodiments. The first side-section includes first side-surface  224 . The cross-section is taken along the same line as in  FIG.  2 C . First side-niche  274  is depicted. According to some embodiments, the optical axis O 1  of first side-lens assembly  264  (not shown in  FIG.  12   ) may be slightly tilted relative to the positive y-axis. In such embodiments, window element  284   a  may be slightly offset (tilted) with respect to the x-axis. (Each of window elements  284   b  and  284   c  may be parallel to the x-axis.) An angle δ indicates the offset angle of window element  284   a  relative to the x-axis. 
     According to some embodiments, δ is smaller than about 5 degrees. According to some embodiments, δ is smaller than about 3 degrees. According to some embodiments, δ is smaller than about 2 degrees. Each option corresponds to different embodiments. 
     Also indicated is a depth k of first side-niche  274 . According to some embodiments, the depth k may be between about 0.01 millimeters and about 1 millimeter, between about 0.05 millimeters and about 1 millimeter, or between about 0.1 millimeters and about 1 millimeter. Each possibility corresponds to separate embodiments. 
     It will be understood that the scope of the disclosure also covers shafts for semi-rigid endoscopes. As used herein, according to some embodiments, a “semi-rigid endoscope” may refer to an endoscope including a semi-rigid shaft. The semi-rigid shaft may include a rigid elongated member, a distal tip portion, and a maneuvering portion mounted between, and mechanically coupling, the elongated member and the distal tip portion, as described in PCT application publication No. WO2016181404 to A. Levy, which is incorporated herein by reference in its entirety. The semi-rigid shaft includes at least two cameras: a front camera and one or more side-cameras. The front camera is positioned on the distal tip portion. Each of the one or more side cameras may be positioned on the distal tip portion, the maneuvering portion, or the elongated member. The semi-rigid shaft further includes one or more illumination components configured to illuminate the FOV provided by the at least two cameras. The maneuvering portion is configured to bend, rotate, and/or angulate the distal tip portion, and thereby controllably change the combined FOV provided by the at least two cameras. 
     Thus, according to an aspect of some embodiments, not depicted in the figures, there is provided a semi-rigid endoscope. The semi-rigid endoscope may be similar to endoscope  100 , but differs therefrom in including a semi-rigid shaft, as described in the preceding paragraph, instead of a rigid shaft. In particular, the cameras and illumination units of the semi-rigid endoscope may be similar to the cameras and illumination units of endoscope  100 , or specific embodiments thereof, i.e. endoscopes  200  and  300 , and endoscopes including tip components  610 ,  710 ,  810 ,  910 , and  1010 . Relative positions of the cameras and the illumination units may be similar, for example, to those of cameras  242 ,  244 , and  246 , and illumination units  252 ,  254 , and  256 , of endoscope  200 . Window elements of the tip component may be affixed within holes on a housing of the tip component, essentially as described above with respect to endoscope  200  and endoscopes including tip component  710 . In particular, the window elements may be made of, or include, sapphire glass while the solder material may include a noble metal, such as gold or platinum. 
     As used herein, according to some embodiments, the term “housing”, employed in reference to a tip component of an endoscope, refers to the tip component without windows (e.g. with the windows yet to be fitted on and affixed to the housing). 
     As used herein, according to some embodiments, the terms “circuit board” and “printed circuit board” are interchangeable. 
     As used herein, according to some embodiments, an element/component may be said to be made of a given material, when consisting of, or consisting essentially of, a composition including in weight at least 50%, 70%, 80%, or 90% of the given material. Each option corresponds to different embodiments. 
     It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the disclosure. No feature described in the context of an embodiment is to be considered an essential feature of that embodiment, unless explicitly specified as such. 
     Although stages of methods according to some embodiments may be described in a specific sequence, methods of the disclosure may include some or all of the described stages carried out in a different order. A method of the disclosure may include a few of the stages described or all of the stages described. No particular stage in a disclosed method is to be considered an essential stage of that method, unless explicitly specified as such. 
     Although the disclosure is described in conjunction with specific embodiments thereof, it is evident that numerous alternatives, modifications and variations that are apparent to those skilled in the art may exist. Accordingly, the disclosure embraces all such alternatives, modifications and variations that fall within the scope of the appended claims. It is to be understood that the disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth herein. Other embodiments may be practiced, and an embodiment may be carried out in various ways. 
     The phraseology and terminology employed herein are for descriptive purpose and should not be regarded as limiting. Citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the disclosure. Section headings are used herein to ease understanding of the specification and should not be construed as necessarily limiting.