Abstract:
A method of examining internal body portions of patients. The method includes providing an imaging capsule including an image capturing unit, mounting the imaging capsule on a first elongate tube suitable for insertion into a body cavity, in a manner which prevents release of the imaging capsule from the first elongate tube within a body cavity, inserting the first elongate tube with the capsule mounted thereon into a patient, retracting the first elongate tube from the patient, separating the imaging capsule from the first elongate tube, disposing of the first elongate tube, mounting the imaging capsule on a second elongate tube and inserting the second elongate tube with the imaging capsule mounted thereon into a patient.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 119(e) of U.S. provisional application 60/773,932, filed Feb. 16, 2006 and of U.S. provisional application 60/806,162, filed Jun. 29, 2006, the disclosures of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to endoscopes and particularly to endoscopes having disposable parts. 
       BACKGROUND OF THE INVENTION 
       [0003]    Endoscopes are used to view internal tissue of humans, and for many other tasks. Endoscopes are used to acquire high quality images, and allow access to body tissue for taking biopsy samples, delivery of therapeutic means and/or introduction of fluids. It is desired to allow easy maintenance and sterilization of endoscopes. 
         [0004]    U.S. Pat. No. 4,895,138 to Yabe, the disclosure of which is incorporated herein by reference, describes an endoscope having an imaging unit at its distal end, which is designed to be replaceable by a technician for ease of maintenance. 
         [0005]    U.S. patent publication 2004/0082883 to Kohno, the disclosure of which is incorporated herein by reference, describes an ultrasound endoscope having a separable head-top to facilitate maintenance. 
         [0006]    Instead of using an elongate probe, it has been suggested to use a small video capsule which acquires images within the patient and passes the images to a control station outside the patient. U.S. Pat. No. 5,604,531 to Iddan et al., the disclosure of which is incorporated herein by reference, describes a stand alone video capsule for swallowing by a patient. U.S. Pat. No. 6,632,171 to Iddan et al., the disclosure of which is incorporated herein by reference, describes a clamp for insertion of the capsule into the patient, for example when swallowing is not an option. The stand alone video capsules are limited, however, in collecting biopsy samples and in navigation. 
         [0007]    U.S. patent publication 2001/0051766 to Gazdzinski and U.S. Pat. No. 5,653,677 to Okada, the disclosures of both of which are incorporated herein by reference, describe endoscopes having detachable video capsules. 
         [0008]    U.S. Pat. No. 6,916,286 to Kazakevich, the disclosure of which is incorporated herein by reference, describes an endoscope having a video unit rotatably mounted on the distal end of the endoscope. 
         [0009]    These endoscopes are complex and may be difficult to sterilize. 
         [0010]    As sterilization of endoscopes is relatively difficult, disposable sheaths which cover an endoscope are used to isolate the endoscope from the patient tissue, so as to avoid time-consuming cleaning and disinfection processes. In some cases it is desired to have one or more channels run along the endoscope. These channels may be used, for example, to pass tools and fluids (e.g., water, drugs, air) to body tissue and/or to remove fluids from the body (e.g., using suction). As the sheath should completely isolate the endoscope from the human tissue, such channels are generally attached to the sheath, and do not extend within the endoscope. This, however, enlarges the cross-section of the sheath-covered endoscope being inserted into the patient. Such a larger diameter may make the insertion of the endoscope more difficult or may prevent the insertion altogether. In addition, the loading of the endoscope into the sheath is a complex task, especially since it should be done in a sterile environment, or, at a minimum, a contaminant-free environment. 
         [0011]    U.S. Pat. No. 5,892,630 to Broome, the disclosure of which is incorporated herein by reference, describes a disposable endoscope, which has a non-disposable optical portion at its proximal end. While this endoscope may solve the problem of sterilization, it may not provide an image of sufficient quality. 
       SUMMARY OF THE INVENTION 
       [0012]    An aspect of some embodiments of the present invention relates to an endoscope formed of a disposable elongate probe and a non-disposable video capsule (referred to also as an imaging capsule) mounted along its length, possibly at its distal end. Optionally, the disposable elongate probe defines a compartment for receiving the video capsule in a manner which isolates the video capsule from body tissue. Alternatively or additionally, the video capsule has smooth and/or crevice-free outer surfaces and/or has other properties which allow easy reprocessing, e.g., disinfecting, cleaning and/or sterilizing. 
         [0013]    The use of a disposable insertion tube of an elongate probe with a non-disposable video capsule allows using a mainly disposable endoscope, with a high quality and/or expensive imaging unit and possibly an expensive proximal articulation handle. Since the video unit is reusable, it can be of higher quality than the disposable units of the prior art. 
         [0014]    The video capsule is optionally designed to allow fast mounting on the disposable elongate probe, for example by fitting into a respective compartment in the probe. Possibly, the video capsule is adapted to be mounted without use of tools, bonding material (e.g., glue, epoxy) and/or without use of screws. In some embodiments of the invention, the video capsule is designed to be mounted within less than half a minute or even less than ten seconds. 
         [0015]    In some embodiments of the invention, the video capsule is mounted at a distal end of the probe, within less than 5 centimeters or even less than two centimeters from its distal tip. Alternatively, the capsule is mounted along the length of the probe, optionally within the distal half or distal third of its length. 
         [0016]    The video capsule may be self contained with all the elements required for operation, such as a battery, transceiver, antenna and/or LEDs, or one or more of the elements may be located within the disposable elongate probe. Accordingly, in some embodiments of the invention, electrical wires connecting to the video capsule, for example to provide power or confer image data, do not extend along the length of the elongate probe. Furthermore, the elongate probe possibly does not have optical fibers running along its length. 
         [0017]    Optionally, the video capsule is powered by a battery located within the video capsule. Alternatively or additionally, the video capsule is powered by an external power source using wireless energy coupling. Further alternatively or additionally, a battery is located along the length of the probe or in the handle of the probe and is connected through wires and/or a coupling port to the video capsule. 
         [0018]    There is therefore provided in accordance with an exemplary embodiment of the invention, a method of examining internal body portions of patients, comprising providing an imaging capsule including an image capturing unit, mounting the imaging capsule on a distal end of a first elongate tube suitable for insertion into a body cavity, in a manner which prevents release of the imaging capsule from the first elongate tube within a body cavity, inserting the first elongate tube with the capsule mounted thereon into a patient, retracting the first elongate tube from the patient, separating the imaging capsule from the first elongate tube, disposing of the first elongate tube, mounting the imaging capsule on a second elongate tube; and inserting the second elongate tube with the imaging capsule mounted thereon into a patient. 
         [0019]    Optionally, the first elongate tube has a length of at least 50 centimeters. Optionally, inserting the first elongate tube into a body cavity comprises inserting into the intestine of a patient. Optionally, mounting the imaging capsule on the distal end comprises mounting in a manner such that the imaging capsule is stationary relative to the distal end of the first elongate tube. Optionally, mounting the imaging capsule on the distal end comprises mounting such that the imaging capsule is isolated from the environment outside the tube. 
         [0020]    Optionally, mounting the imaging capsule on the distal end comprises mounting in a compartment in the elongate tube. Optionally, mounting the imaging capsule on the distal end comprises mounting in a compartment in the elongate tube, such that the imaging capsule fills most of the compartment. Optionally, the compartment comprises a recess which receives only part of the imaging capsule. Optionally, mounting the imaging capsule on the distal end comprises mounting such that a distal end of the imaging capsule is less than 30 millimeters behind a distal tip of the elongate tube. Possibly, the method includes recharging a battery of the imaging capsule between insertions of the first and second elongate tubes into patients. 
         [0021]    Possibly, the method includes cleaning the imaging capsule between insertions of the first and second elongate tubes into patients. Optionally, the imaging capsule is not sterilized between insertions of the first and second elongate tubes into patients. Possibly, the method includes repeating the mounting and inserting for at least five different insertions into one or more patients. Possibly, the method includes repeating the mounting and inserting at least three times in a single day. 
         [0022]    Optionally, mounting the imaging capsule comprises mounting such that the imaging capsule forms electrical contact with an electrical port within the elongate tube. Optionally, mounting the imaging capsule comprises mounting so as to form a contact between a power supply outside of the imaging capsule and a unit within the imaging capsule utilizing power of the power supply. Optionally, mounting the imaging capsule comprises mounting such that a transmitter within the imaging capsule forms a contact with an antenna in the elongate tube. 
         [0023]    Optionally, mounting the imaging capsule comprises mounting such that the imaging capsule forms electrical contact with wires leading along the elongate tube to a proximal end thereof. Optionally, mounting the imaging capsule on the distal end comprises mounting within the distal 20% of the length of the elongate tube. Optionally, the elongate tube comprises at least one working channel adapted to allow passage of fluid or surgical tools into the patient. Optionally, disposing of the elongate tube comprises disposing of the tube together with a handle used for deflecting the elongate tube. Possibly, the method includes using a same handle for deflecting the first and second elongate tubes. Optionally, the elongate tube is rigid or semi-rigid. 
         [0024]    Optionally, mounting the imaging capsule comprises mounting without at least one of screws and bonding material. Optionally, mounting the imaging capsule comprises mounting without use of screws. Optionally, mounting the imaging capsule comprises mounting without use of a bonding material. 
         [0025]    There is further provided in accordance with an exemplary embodiment of the invention, an endoscope, comprising an optical imaging capsule including an optical image capturing unit; and an elongate tube, having a distal end adapted for insertion into a body cavity, and adapted to receive the imaging capsule at a position in its distal half in a manner which prevents detachment of the capsule from the elongate tube while a distal end of the elongate tube is in a body cavity, but allows release of the capsule from the elongate tube, when the tube is not in the body cavity, wherein the elongate tube does not have power wires extending from a proximal point of the insertion tube to the position for receiving the imaging capsule, which operably connect to the imaging capsule. Optionally, the optical imaging capsule includes a battery. Optionally, the optical imaging capsule includes a port adapted to connect to a respective port in the elongate tube. Optionally, the elongate tube defines a compartment adapted to receive the capsule, such that a distal wall of the elongate tube separates the capsule from tissue distal to the elongate tube. Optionally, the elongate tube defines a compartment adapted to receive the capsule, such that the elongate tube entirely surrounds the capsule. 
         [0026]    Optionally, the elongate tube does not have electrical wires extending from a proximal point of the insertion tube to the position for receiving the imaging capsule. 
         [0027]    There is further provided in accordance with an exemplary embodiment of the invention, an endoscope, comprising an optical imaging capsule including an optical image capturing unit; and an elongate tube, having a distal end adapted for insertion into a body cavity, and adapted to receive the imaging capsule at a position in its distal half in a manner which prevents detachment of the capsule from the elongate tube while a distal end of the elongate tube is in a body cavity, without requiring at least one of screws and bonding material, but allows release of the capsule from the elongate tube, when the tube is not in the body cavity. 
         [0028]    Optionally, the elongate tube is adapted to receive the imaging capsule in a manner which prevents detachment without use of screws. 
         [0029]    Optionally, the elongate tube is adapted to receive the imaging capsule in a manner which prevents detachment without use of bonding material. 
         [0030]    Optionally, the elongate tube is adapted to removably receive the imaging capsule at its distal end in a manner which prevents movement of the capsule relative to the elongate tube while a distal end of the elongate tube is in a body cavity. 
         [0031]    Optionally, the elongate tube does not include wires which are adapted to operably connect the imaging capsule to a power source at a proximal end of the tube. 
         [0032]    Optionally, the elongate tube defines a recess adapted to receive the capsule, such that the capsule occupies at least 90% of the volume of the recess. 
         [0033]    Optionally, the capsule can be mounted onto the elongate tube within less than 15 seconds. Optionally, the elongate tube is adapted to receive the capsule in a manner which allows removal of the capsule and use in a different elongate tube in a different patient, without sterilization of the capsule. Optionally, the imaging capsule is adapted to be mounted on the elongate tube without use of tools. Optionally, the elongate tube comprises a recess adapted to partially receive the imaging capsule. Optionally, the elongate tube comprises a recess adapted to receive the entire imaging capsule. 
         [0034]    There is further provided in accordance with an exemplary embodiment of the invention, an endoscope, comprising an imaging capsule including, an optical image capturing unit and at least one of a LED, a battery and a wireless transmission unit adapted to operate in conjunction with the image capturing unit and an elongate tube adapted for insertion into a body cavity, and adapted to removably receive the imaging capsule at its distal end in a manner which prevents movement of the capsule relative to the elongate tube while a distal end of the elongate tube is in a body cavity. Optionally, the imaging capsule is connected to the elongate tube without any screws. Optionally, the imaging capsule does not have parts that extend proximally beyond the distal half of the elongate tube. Optionally, the imaging capsule comprises at least one LED arranged to illuminate an area imaged by the image capturing unit. 
         [0035]    Optionally, the imaging capsule comprises at least one battery arranged to power the image capturing unit. Optionally, the imaging capsule comprises at least one wireless transmission unit. Optionally, the imaging capsule has a shape of a section of a cylinder. 
         [0036]    Optionally, the imaging capsule does not include means for self navigation within a patient. Optionally, the imaging capsule has at least one external surface which is not adapted for contact with internal body tissue. Optionally, the endoscope does not include an optical fiber running along its length. Optionally, the elongate tube defines a recess at its distal end, covering less than the entire cross section of the distal end, adapted to removably receive the imaging capsule in a manner which prevents release of the capsule from the elongate tube while a distal end of the elongate tube is in a body cavity. 
         [0037]    There is further provided in accordance with an exemplary embodiment of the invention, a disposable elongate probe for invasive medical procedures, comprising an elongate tube adapted for insertion into a body cavity, a proximal handle, at least one working channel extending along the elongate tube, at least one steering control allowing manipulation of a direction of the elongate tube from the proximal handle and at least one compartment at a distal portion of the elongate tube, adapted to receive an imaging capsule in a manner which prevents its release while the elongate tube is within a patient, but allows mounting of the capsule in the compartment without use of at least one of screws, tools and a bonding material. 
         [0038]    There is further provided in accordance with an exemplary embodiment of the invention, an imaging capsule for use with a disposable elongate probe, comprising a housing having at least one outer surface not suitable for movement within a body cavity while contacting body tissue, an optical image capturing unit within the housing and at least one electrical unit adapted to operate in conjunction with the image capturing unit. 
         [0039]    Optionally, the imaging capsule includes a port adapted for electrical contact with a respective port in the elongate probe. Optionally, the imaging capsule includes a wireless transmitter adapted to transmit images acquired by the image capturing unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    Exemplary non-limiting embodiments of the invention will be described with reference to the following description of the embodiments, in conjunction with the figures. Identical structures, elements or parts which appear in more than one figure are preferably labeled with a same or similar number in all the figures in which they appear, and in which: 
           [0041]      FIG. 1  is a schematic illustration of an endoscope system, in accordance with an exemplary embodiment of the present invention; 
           [0042]      FIG. 2A  is an enlarged view of a distal end of an insertion tube of the endoscope of  FIG. 1 , in accordance with an exemplary embodiment of the invention; 
           [0043]      FIG. 2B  is an enlarged view of a distal end of the insertion tube of  FIG. 2A , in which a video capsule is outside a respective compartment in the distal end, in accordance with an exemplary embodiment of the invention; 
           [0044]      FIG. 3  is a sectional view of a video capsule, in accordance with an exemplary embodiment of the invention; 
           [0045]      FIG. 4A  is a sectional view of a video capsule, in accordance with another exemplary embodiment of the invention; 
           [0046]      FIG. 4B  is a sectional view of a video capsule, in accordance with still another exemplary embodiment of the invention; 
           [0047]      FIG. 5  is a schematic illustration of an endoscope partially within an intestine, in accordance with an exemplary embodiment of the invention; and 
           [0048]      FIGS. 6 and 7  are schematic illustrations of an endoscope partially within an intestine with a stiff outer sleeve thereon, in accordance with an exemplary embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0049]      FIG. 1  is a schematic illustration of an endoscope system  100 , in accordance with an exemplary embodiment of the present invention. System  100  optionally includes a disposable elongate insertion tube  102  having a handle  104  carrying manipulation controls  106 , an optionally adjustable distal end  109  and a control station  110 , for example including a portable computer. 
         [0050]    Endoscope system  100  may be used for substantially any endoscopic procedure and the details (e.g., size, shape, elements included) of insertion tube  102 , handle  104  and the other parts of system  100  are selected according to its task. In the following description an exemplary endoscope for examination of the intestine, is described. 
       Insertion Tube 
       [0051]    Insertion tube  102  optionally includes an articulation mechanism, for example including cables, which allows deflection control of distal end  109  thereof, from handle  104 . In some embodiments of the invention, the articulation mechanism allows four-way deflection of distal end  109 . Alternatively, the articulation mechanism allows deflection in fewer directions or in more directions (e.g., in 8 directions), possibly in all directions. In a exemplary embodiment of the invention, the deflection mechanism is in accordance with any of the embodiments and/or combinations of details in U.S. Pat. No. 5,667,476 to Frassica et al., U.S. Pat. No. 6,740,030 to Martone et al. and/or U.S. Pat. No. 5,704,898 to Kokish, the disclosures of all of these patents are incorporated herein by reference. 
         [0052]    Insertion tube  102  optionally has an outer diameter greater than 2 millimeters or even greater than 5 millimeters, depending on the tasks and/or anatomy for which it is planned. Possibly, insertion tube  102  has a diameter of less than 14 millimeters, less than 10 millimeters or even less than 7 millimeters. In an exemplary embodiment of the invention, insertion tube  102  has an outer diameter of about 9 mm. Insertion tube  102  may have substantially any length, according to the task for which endoscope system  100  is designed, for example a length greater than 20 centimeters or even greater than 50 centimeters. Generally, for use in the intestine a length of at least 1.5 meters or even 2 meters, is used. 
         [0053]    Insertion tube  102  may be rigid, semi-rigid with a flexible bending section or flexible. Optionally, if flexible, the insertion tube is sufficiently flexible to allow it to make at least a 90° bend or 150° bend with a radius of less than 20 mm, or even less than 10 mm, for example so that it can negotiate the turns of the intestine. Optionally, in one or more directions, insertion tube  102  can be manipulated to form a 180° bend or even at least a 270° bend over a distance of less than 30 millimeters. Possibly, insertion tube  102  allows different extents of bending in different directions. In an exemplary embodiment of the invention, insertion tube  102  is deflectable over 180° in the up-down direction and over 160° in the left-right direction. 
       Capsule Compartment 
       [0054]      FIGS. 2A and 2B  show an enlarged view of distal end  109  of insertion tube  102 , in accordance with an exemplary embodiment of the invention. A compartment  108  adapted to receive a video capsule  120  is defined at a distal end  109  of insertion tube  102 . In  FIG. 2A  video capsule  120  is shown within compartment  108 , with its upper wall and its cover  112  (described below) transparent so that its contents may be viewed. In  FIG. 2B , video capsule  120  is shown with its upper wall opaque. The upper wall of video capsule  120  as well as its bottom wall, its other walls and the parts of insertion tube  102  may be transparent or opaque, as desired. 
         [0055]    Compartment  108  and video capsule  120  are optionally sized and shaped so that video capsule  120  entirely fits into the compartment. A cover  112  optionally fits above video capsule  120  within compartment  108  and separates the video capsule from body tissue of the patient. In some embodiments, cover  112  forms a hermetic seal eliminating the need to disinfect or sterilize video capsule  120 . In some embodiments of the invention, a rubber or other elastomeric lining is placed within compartment  108  in a manner which prevents body fluids from entering the compartment. Possibly, as illustrated in  FIG. 2B , cover  112  includes a notch  142  and tube  102  has a respective slot  140 , which together lock the compartment  108  in a manner which prevents opening within the patient. Alternatively or additionally, any other locking mechanism is used to keep compartment  108  closed while tube  102  is in a patient. In some embodiments of the invention, opening of compartment  108  to remove capsule  120  requires, under normal conditions, breaking at least a portion of tube  102  so that it cannot be reused in another patient. 
         [0056]    In other embodiments of the invention, instead of compartment  108 , a recess which only partially receives video capsule  120 , is used. For example, the recess may be at the distal tip of the elongate tube  102 . The recess optionally receives at least 10%, at least 20% or even at least 30% of the video capsule. It is noted, however, that the recess may receive less than 80% or even less than 50% of the video capsule. 
         [0057]    In some embodiments of the invention, compartment  108  or any other recess is sized and/or shaped to receive capsule  120 , such that when video capsule  120  is in the compartment it occupies most of the volume of the recess. Possibly, video capsule  120  occupies at least 70%, 80% or even at least 90% of the volume of the recess. In some embodiments of the invention, video capsule  120  occupies substantially the entire volume of the recess. Optionally, the recess is separated from the interior of insertion tube  102 , such that openings leading to compartment  108  or other recess cannot be used to access elements of disposable insertion tube  102 , such as elements of an articulation mechanism. 
         [0058]    Video capsule  120  optionally tightly fits into compartment  108 , so that it does not move, rotate or exit the compartment without human intervention and/or does not move within or exit compartment  108  while the distal end  109  of the insertion tube  102  is in the patient. Optionally, video capsule  120  has a non-symmetric shape, which prevents rotation within compartment  108  and/or incorrect placement by a physician. In an exemplary embodiment of the invention, video capsule  120  has a shape of a section of a cylinder, for example having a D shaped cross section. It is noted that since in some embodiments of the invention video capsule  120  does not come in contact with internal body tissue, video capsule  120  may have sharp or rough surfaces or any other surfaces which are not suitable for contacting internal human tissue. Furthermore, video capsule  120  optionally does not include means for self navigation within a patient. 
         [0059]    As mentioned above, in some embodiments of the invention cover  112  prevents capsule  120  from exiting the compartment. Alternatively or additionally, any other method of securing video capsule  120  within compartment  108 , is used, such as a magnet, one or more detents or undercuts with respective notches, an adhesive and/or a quarter turn fastener. In some embodiments of the invention, capsule  120  includes a threading on one of its sides and is screwed into a respective threading in the compartment. In some embodiments of the invention, in accordance with this alternative, cover  112  is absent, allowing faster insertion and removal of capsule  120 . 
         [0060]    Possibly, before inserting capsule  120  into compartment  108  it is covered by a disposable cover, which is disposed after use, thus simplifying the cleaning process between uses of capsule  120 , or even eliminating the need to clean or disinfect capsule  120  between uses. 
       Further Details of Insertion Tube 
       [0061]    A front window  123  optionally allows a clear view from video capsule  120  to tissue distal from insertion tube  102 . Window  123  is possibly formed of an optically clear plastic, such as acrylic or polycarbonate with a thickness of, for example, between 0.01-1.0 millimeters. In some embodiments of the invention, front window  123  has an arrangement for cleaning the window from outside, as described in U.S. provisional patent application 60/763,267, filed Jan. 30, 2006, and titled “Controllable Colonscope” and/or in PCT application PCT/IL2007/000116, filed Jan. 30, 2007, the disclosures of which are incorporated herein by reference. 
         [0062]    One or more channels optionally extend along insertion tube  102 , from its distal end to handle  104 . In an exemplary embodiment of the invention, insertion tube  102  includes a working channel  152 , an air channel  154  and a water channel  156 . It is noted, however, that the insertion tube may include channels for other purposes, may include fewer channels, no channels at all, or may include more than three or even more than five channels. 
         [0063]    Compartment  108  optionally occupies less than the entire cross-section of elongate tube  102 , optionally less than 70% of the area of the cross-section or even less than half the area of the cross-section. Thus, part of the cross-section remains unobstructed for passage of the working channels. 
         [0064]    As mentioned above, compartment  108  is located, in some embodiments of the invention, close to the distal end  109  of elongate tube  102 , for example within less than 4 centimeters, 2 centimeter or even less than 1 centimeter from the distal end of the elongate tube. Alternatively, compartment  108  may be located along the elongate tube, remote from the distal end, separated by at least 5 or even 8 centimeters from the distal end  109 . In some embodiments of the invention, in accordance with this alternative, compartment  108  is located in the distal half or distal third of the length of elongate tube  102 . In accordance with this alternative, camera  124  is oriented radially outward to acquire images along side insertion tube  102 . 
       Video Capsule 
       [0065]      FIG. 3  is a sectional view of video capsule  120  along an axis corresponding to the length of insertion tube  102 , in accordance with an exemplary embodiment of the invention. Video capsule  120  includes one or more optic lenses  122 , one or more cameras  124  (e.g., a CCD or CMOS) or other image capturing devices, an optional antenna  126 , an optional wireless transmitter  128  and an optional battery  132 . A timing and/or control unit  148  optionally controls the operation of camera  124 . 
         [0066]    In some embodiments of the invention, video capsule  120  includes one or more LEDs, for example two LEDs  136  ( FIG. 2B ), which illuminate the area imaged by camera  124 . In some embodiments of the invention, video capsule  120  includes at least four LEDs, at least six LEDs or even at least 10 LEDs. In some embodiments of the invention, one or more of the LEDs have corresponding lenses (not shown) which direct their light. In an exemplary embodiment of the invention, the lenses of LEDs  136  direct their light to a common point to which camera  124  is directed. Alternatively, the lenses of LEDs  136  direct the light of the LEDs in different directions so as to light a large area, in front, side and/or back directions. Possibly, the operation of LEDs  136  is controlled by control unit  148 . 
         [0067]    Possibly, a front panel  138  of video capsule  120  is transparent, allowing light from LEDs  136  to pass freely toward body tissue and return to camera  124 . Alternatively, front panel  138  may be partially opaque, with separate transparent windows for LEDs  136  and camera  124 , to prevent glare. Alternatively or additionally, window  123  of insertion tube  102  is replaced by an opaque wall which has within it a plurality of separate windows corresponding to respective elements (camera, LEDs) in capsule  120 . 
       Battery 
       [0068]    Battery  132  is optionally a rechargeable battery, which is recharged between uses of video capsule  120 . In some embodiments of the invention, a physician may have two or more video capsules  120  which are used intermittently, one being reprocessed and/or having its battery recharged while the other is in use. Alternatively or additionally, the battery is easily removed from video capsule  120  for recharging. Alternatively or additionally to using rechargeable batteries, non-rechargeable batteries may be used. The batteries are optionally replaced after one or more medical procedures. 
         [0069]    In some embodiments of the invention, the power of video capsule  120  is based solely on battery  132  and power wires do not extend along or within insertion tube  102 . Alternatively or additionally, wires extending along insertion tube  102  connect a port  130  to a power source (not shown) at the proximal end of the insertion tube, for example through handle  104  and/or to a battery in handle  104 . Video capsule  120  optionally includes a port  134  which connects to port  130  on tube  102  when video capsule  120  is placed in compartment  108 . When video capsule  120  is inserted into compartment  108  contact is formed between ports  130  and  134  and power is supplied to video capsule  120 . The power supplied through ports  130  and  134  may be in addition to battery  132 , for example to charge the battery  132 , or instead of the battery. 
         [0070]    In other embodiments of the invention, insertion tube  102  or handle  104  carries within it a disposable battery (or batteries) connected to port  130 . 
       Antenna 
       [0071]    As mentioned above, in some embodiments of the invention, video capsule  120  includes an antenna  126  and transmitter  128  which are used to wirelessly transmit the acquired images from camera  124  to a control station  110  ( FIG. 1 ). In some embodiments of the invention, video capsule  120  additionally includes a receiver, or transmitter  128  comprises a transceiver, such that control commands may be transmitted from control station  110  to video capsule  120 , for example for adjusting the zoom of the camera, the rate of acquiring images and/or the resolution of the camera. Other operation parameters of video capsule  120 , which may be controlled wirelessly include which LEDs  136  are operative and the direction to which camera  124  is aimed. 
         [0072]    Alternatively or additionally to the antenna being within capsule  120 , an antenna is included in a portion of tube  102  adjacent compartment  108 , with an electrical connection to transmitter  128  (or a transceiver) in the video capsule  120 , for example through ports  130  and  134 . Further alternatively or additionally, acquired images are passed over wires extending along tube  102  to its proximal end. In some embodiments of the invention, the acquired images are transmitted in a modulated form (e.g., AM or FM) over the same wire used for providing power to capsule  120 . 
         [0073]    Further alternatively or additionally, video capsule  120  comprises a large memory  170  in which the acquired images are stored. For example, in some embodiments of the invention, transmitter  128  conveys low quality images to control station  110 , while high quality images are stored in the memory and are viewed after the endoscope is removed from the patient. In other embodiments of the invention, transmitter  128  conveys high quality images and the images in the large memory (in those embodiments in which a large memory is included) serve as backups in case there are transmission problems. The backup can allow, for example, reducing the redundancy added to the signals for transmission. In some embodiments of the invention, a user can determine whether high quality or low quality images are transmitted. 
       Size and Rigidity 
       [0074]    Video capsule  120  optionally has a length of less than 5 centimeters, less than 3 centimeters or even less than one centimeter, so as to minimize its effect on the flexibility of elongate tube  102 , in those embodiments in which video capsule  120  is rigid. In some embodiments of the invention, video capsule  120  has a length of less than 10%, less than 5% or even less than 2% of the length of elongate tube  102 . In an exemplary embodiment of the invention, elongate tube  102  is longer than a meter or even longer than a meter and a half, and the capsule has a length of less than 0.8% of the length of the elongate tube. 
         [0075]    In some embodiments of the invention, video capsule  120  is rigid. Alternatively, the casing of capsule  120  and optionally some of its components, for example battery  132 , are at least partially flexible, in order to allow the tip of insertion tube  102  high flexibility when capsule  120  is within it. Further alternatively or additionally, video capsule  120  is formed of a plurality of relatively rigid units connected through more flexible connectors. 
         [0076]      FIG. 4A  is a sectional view of video capsule  188 , in accordance with another exemplary embodiment of the invention. Video capsule  188  is formed of a video unit  190  and a power unit  192 , which are connected to each other through a flexible connector  194 . As shown, antenna  126  and battery  132  are located in power unit  192  and are connected to video unit  190  by wires  196  passing through flexible connector  194 . It is noted, however, that any other distribution of the elements of the video capsule between units may be used. While video unit  190  is shown as being formed from two units, it may include more than two, more than three or even more than four units. Optionally, flexible connector  194  has a cross-section area of less than 50% or even less than 20% of the cross section areas of the units  190  and  192 . 
       Other Details of Capsule 
       [0077]    In some embodiments of the invention, video capsule  120  is activated by a control signal transmitted from control station  110 . Alternatively or additionally, video capsule  120  has a switch which is manually activated by a physician when it is inserted into compartment  108 . Further alternatively or additionally, video capsule  120  is operated by a switch which is automatically activated by a respective actuator on an inner wall of compartment  108 . Further alternatively or additionally, any other activation method known in the art may be used. 
         [0078]      FIG. 4B  is a sectional view of video capsule  120 , in accordance with still another exemplary embodiment of the invention. The embodiment of  FIG. 4B  illustrates a capsule  120  which does not carry a battery, but rather receives power through ports  134  using any of the methods discussed above. In some embodiments of the invention, the optics of camera  124  include a prism  172  and/or other optic element which provides for a wide field of view, possibly greater than 120°, greater than 150° or possibly even greater than 180°. The walls of capsule  120  at least in a section  176  and the corresponding walls of insertion tube  102  are optionally transparent around most or all the circumference of the capsule, in order to allow for acquiring images from the large field of view. 
         [0079]    The above discussed details (e.g., shape, size, composition, elements) of video capsule  120  may be varied using any of the methods known in the art, such as using any of the embodiments and/or alternatives described in any of above mentioned U.S. Pat. Nos. 5,604,531, 6,632,171, 5,653,677 and 6,916,286 and/or U.S. patent publication 2001/0051766. 
       Usage 
       [0080]    In preparation for a medical procedure, an insertion tube  102  is optionally removed from its sterile package and a video capsule is inserted into its compartment  108 . After the medical procedure is completed, video capsule  120  is removed from compartment  108  and insertion tube  102 , with or without handle  104 , is discarded. Video capsule  120  is optionally reprocessed and prepared for a next medical procedure. A single video capsule may be limited to a specific number of uses, e.g., up to 50, up to 30 or even only up to 10, or may have an unlimited use as long as it works. Possibly, a single video capsule is used with at least five, at least ten or even more disposable elongate tubes. A single video capsule is possibly inserted into at least three, at least five or even at least eight insertion tubes  102  during a single day. The insertion of video capsule  120  into compartment  108  is optionally performed in a physicians clinic, less than an hour, less than half an hour, or even less than 10 minutes before the endoscopic procedure. 
         [0081]    Alternatively or additionally, video capsule  120  may be limited to an amount of transmitted data or a number of times battery  132  is recharged. In some embodiments of the invention, transmitter  128  and/or a controller (e.g.,  148 ) of video capsule  120  are configured to stop operating when a predetermined condition is fulfilled. 
         [0082]    The reprocessing optionally includes disinfecting, cleaning and/or sterilizing video capsule  120 . The level of cleaning and disinfecting may depend on the extent to which the interior of compartment  108  is isolated from its exterior. Alternatively or additionally, the extent of disinfecting may depend on the body organ into which tube  102  is inserted. 
         [0083]    During the medical procedure, insertion tube  102  is inserted into the patient in accordance with the specific procedure and the anatomy. In some embodiments of the invention, at least 10 centimeters, 15 centimeters or even at least 20 or 30 centimeters of insertion tube  102  are inserted into the patient. 
         [0084]    In some embodiments of the invention, the reprocessing includes replacing battery  132  or recharging the battery. Possibly, the reprocessing includes checking that capsule  120  is operative before its use. Optionally, a dedicated testing apparatus is used to test the module. The testing apparatus optionally includes a display unit which displays images to camera  124  and possibly a switch which causes capsule  120  to operate. 
         [0085]    In some embodiments of the invention, video capsule  120  includes flat outer surfaces and/or is hermitically closed, in a manner which allows simple sterilization and/or disinfection. 
         [0086]    Video capsule  120  and compartment  108  are optionally designed to allow fast insertion of the video capsule into the compartment and/or fast removal from the compartment. In some embodiments of the invention, the insertion and the removal each requires less than a minute, less than half a minute or even less than 10 seconds. Optionally, the insertion and/or removal of video capsule  120  from compartment  108  do not require use of tools and/or do not involve screwing or unscrewing of screws. Alternatively, a custom tool, designed specifically for manipulating video capsule  120  and/or handling compartment  108 , e.g., a tool designed specifically for inserting video capsule  120  into compartment  108 , is used. In other embodiments of the invention, one or more tools are required for inserting and/or removing video capsule  120 . Possibly, the insertion and removal can be performed by an untrained person and do not require a technician. In some embodiments of the invention, the insertion and/or removal of video capsule  120  from compartment  108  do not require use of a bonding material (e.g., epoxy) or any other material, which is required to change its state, for example to harden from a liquid or semi-liquid state to a more solid state. 
         [0000]    Insertion into Colon 
         [0087]      FIG. 5  is a schematic illustration of insertion tube  102  introduced into a colon  200 , in accordance with an exemplary embodiment of the invention. An outer sleeve  182 , having a controllable stiffness, is optionally mounted over a distal portion of insertion tube  102 . In some embodiments of the invention, a control knob  184  is used to control the stiffness of sleeve  182  and control a locking state between outer sleeve  182  and insertion tube  102 . Optionally, outer sleeve  182  covers more than 25% or even more than 33% of the length of insertion tube  102 . Alternatively or additionally, outer sleeve  182  has a length of less than 100 centimeters, less than 80 centimeters or even less than 70 cm. In an exemplary embodiment of the invention, outer sleeve has a length of about 65 cm. 
         [0088]    Outer sleeve  182  optionally has an outer diameter greater than the outer diameter of insertion tube  102  by no more than 5 millimeters or even no more than 3 millimeters. Optionally, outer sleeve  182  has an outer diameter smaller than 16 millimeters, for example about 12 millimeters. 
         [0089]    Initially, control knob  184  is set to lock outer sleeve  182  to insertion tube  102 , while outer sleeve  182  has a relatively low rigidity, although optionally greater than the rigidity of insertion tube  102 . In this state, insertion tube  102  with outer sleeve  182  on it, is inserted into colon  200 . At any time, for example when nearly all (e.g., over 90%) of outer sleeve  182  is within the colon, control knob  184  may be turned, so as to gradually stiffen outer sleeve  182  and thus straighten insertion tube  102  and the portions of colon  200  in which outer sleeve  182  is located.  FIG. 6  shows an intermediate stiffness state of outer sleeve  182 . The stiffness is optionally further increased until outer sleeve  182  is completely straight, as shown in  FIG. 7 . The locking of insertion tube  102  to outer sleeve  182  is then optionally released and insertion tube  102  is pushed further into the colon. 
         [0090]    The stiffness of outer sleeve  182  is optionally controlled using any method known in the art, such as according to any of the embodiments of U.S. Pat. No. 4,601,283 to Chikama, U.S. Pat. No. 4,893,613 to Hake, Japanese patent publication 6,237,886, U.S. Pat. No. 6,585,641 to Jordfald and/or U.S. Pat. No. 6,761,685 to Adams et al., the disclosures of all of which patents are incorporated herein by reference. 
         [0091]    The use of outer sleeve  182  reduces the chances and/or number of occurrences of insertion tube  102  folding over itself within the colon and/or enhances the control and eases the manipulation required by the user during the introduction of the insertion tube into the body. The straightening of the colon makes the access of insertion tube  102  therein simpler, as is known in the art. 
         [0092]    Alternatively to an outer sleeve with a controllable stiffness, a relatively stiff sleeve is inserted over insertion tube  102 , after it is inserted into the colon in order to straighten the colon and add to the stiffness of the insertion tube. 
         [0093]    It is noted, that although the above description relates to insertion into the colon, system  100  may be used in other body cavities, for example in accessing the stomach through the esophagus and/or accessing the small intestine through the stomach and/or esophagus. It is noted that all details, dimensions and descriptions appearing on the figures are brought by way of non-limiting example and many other embodiments with different sizes and details are included in the scope of embodiments of the present invention. For example, a bronchoscope in accordance with an embodiment of the present invention may have a diameter of between about 4-5 millimeters, while an ear, nose, throat (ENT) endoscope may have a diameter of 3-4 millimeter. 
         [0094]    Other apparatus designs may be used instead of those discussed above, for example any of the details in U.S. provisional application 60/763,267, filed Jan. 30, 2006, and titled “Controllable Colonscope”, mentioned above. Although the above description relates mainly to the intestines, the embodiments of the present invention are not limited to any specific body organ and may be used for any body part, including the spine, thoraces, joint (e.g., knee) and bronchial. Depending on the specific body organ and/or task to be performed, the size, shape, structure (e.g., rigid, semi-rigid, flexible) and/or number or layout of working channels of insertion tube  102  is selected. Similarly, the size of capsule  120  and the apparatus it carries within may vary for different body organs and/or tasks. 
         [0095]    While capsule  120  may be designed for only a single type of insertion tube, in some embodiments of the invention capsule  120  may be designed to operate with a plurality of different types of insertion tubes, for example differing in size (e.g., diameter), cross-sectional shape, number of channels and/or in the intended body organ for which they are designed. Similarly, a single type of insertion tube may be used, in some embodiments of the invention, with a plurality of different types of invention capsules, differing, for example, in the type of camera and/or optics (e.g., wide field, zoom) they employ. 
         [0096]    It will be appreciated that the above-described methods may be varied in many ways, including, changing materials, sizes and shapes. For example, rather than camera  124  having a forward view, camera  124  may have a sideways view. Alternatively or additionally, video capsule  120  may include more than one camera, possibly more than three cameras, viewing different directions and/or operating with different light wavelengths. Alternatively or additionally, rather than including the camera lens  122  in capsule  120 , the lens may be included in disposable insertion tube  102 . This alternative may be used to make capsule  120  smaller. 
         [0097]    It should also be appreciated that the above described description of methods and apparatus are to be interpreted as including apparatus for carrying out the methods, and methods of using the apparatus. 
         [0098]    The present invention has been described using non-limiting detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features and/or steps described with respect to one embodiment may be used with other embodiments and that not all embodiments of the invention have all of the features and/or steps shown in a particular figure or described with respect to one of the embodiments. Variations of embodiments described will occur to persons of the art. Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the claims, “including but not necessarily limited to”. 
         [0099]    It is noted that some of the above described embodiments may describe the best mode contemplated by the inventors and therefore may include structure, acts or details of structures and acts that may not be essential to the invention and which are described as examples. Structure and acts described herein are replaceable by equivalents which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the invention is limited only by the elements and limitations as used in the claims.