Abstract:
Provided is a system for advancing an article along a path. The system may include a head member, a dispatching member, and an eversion sleeve. Also provided is a method for assembling a system for advancing an article along a path.

Description:
TECHNICAL FIELD 
       [0001]    This presently disclosed subject matter relates to the field of systems and methods for advancing an article along a path. 
       BACKGROUND 
       [0002]    The principle of an eversion sleeve to be used in conjunction with a catheter is known for many years in the field of medical devices. Such sleeves are used for enabling an access to different body cavities such as the colon system or the urethral system, and navigating within respective biological lumens. Below are a number of prior art examples in which a device having an eversion sleeve is used. 
         [0003]    U.S. Pat. No. 4,493,711 discloses a catheter having an inverted-evertable non-elastic tube with a diameter throughout equal to or greater than the catheter body, an axially aligned end opening at the distal end, and a multifold configuration of the distal end to maintain end-sealing during inversion and eversion. 
         [0004]    US 2003/208223 discloses an apparatus incorporating an elongate hollow element for being positioned along a body cavity of a patient. The hollow element has a leading region and a trailing region and is arranged for being progressively everted along the hollow element from the leading region to thereby be increasingly extended for progressively lining the body cavity as the trailing region follows along. 
         [0005]    U.S. Pat. No. 4,043,345 discloses a catheter including a flexible hose attached to one end of a rigid tube through which fluid pressure may be applied to invert said hose from an invaginated position within said tube to an exserted position extending outwardly of said tube having formed at the distal of said hose a valve which remains closed when the hose is in the invaginated position and which opens with the hose in its exserted position. 
       SUMMARY OF THE PRESENTLY DISCLOSED SUBJECT MATTER 
       [0006]    According to one aspect of the presently disclosed subject matter, there is provided a system for advancing an article along a path, comprising: 
         [0007]    a head member; 
         [0008]    a dispatching member; and 
         [0009]    an eversion sleeve configured with an outside portion having a sleeve end configured to be fixed to the dispatching member, an everting portion configured for slidingly articulating to the head member and an inside portion configured to extend from the everting portion towards the dispatching member; 
         [0010]    said inside portion and said outside portion are configured to form a space therebetween for receiving a propelling fluid for exerting force on the everting portion, thereby gradually advancing a segment of the inside portion towards the head member causing it to slidingly displace with respect to the head member and gradually advancing a respective segment of the everting portion into the outside portion, thereby everting said eversion sleeve inside out and advancing the head member along the path; 
         [0011]    wherein said head member is configured with an internal portion for retaining the everting portion and facilitating the everting portion to slide with respect to the head member. 
         [0012]    According to a further aspect of the presently disclosed subject matter, there is provided a device for advancing an article along a path, comprising: 
         [0013]    a head member; 
         [0014]    a dispatching member; 
         [0015]    an eversion sleeve configured with an outside portion having a sleeve end fixed to the dispatching member, an everting portion slidingly articulated to the head member and an inside portion extending from the everting portion towards the dispatching member; and 
         [0016]    a space formed between said inside portion and said outside portion for receiving a propelling fluid for exerting force on the everting portion, thereby gradually advancing a segment of the inside portion towards the head member causing it to slidingly displace with respect to the head member and gradually advancing a respective segment of the everting portion into the outside portion, thereby everting said eversion sleeve inside out and advancing the head member along the path; 
         [0017]    wherein said head member is configured with an internal portion for retaining the everting portion and facilitating the everting portion to slide with respect to the head member. 
         [0018]    The term ‘article’ as used herein in the specification and claims, denotes the head member with or without an electric or mechanical unit mounted thereto, a video camera, a stills camera, an imaging system, sensing system, a treatment system, a working tool, a communication system, a treatment equipment, etc. 
         [0019]    The term ‘path’ as used herein in the specification and claims, denotes a canal, a channel, a cavity, a tunnel, an underpass, a lumenway, a tube, a lumen, a conduit, etc. 
         [0020]    The term ‘fluid’ as used herein in the specification and claims, denotes a gaseous fluid, such as air, helium, etc. or a liquid fluid such as water, oil, etc. 
         [0021]    The eversion sleeve of the presently disclosed subject matter is made of a resilient and/or flexible material that allows advancing the eversion sleeve with the head member mounted thereto along a curved path with the ability to curve and bend the eversion sleeve during the advancement when contacting the walls of the path, thereby following the path. During advancement of the eversion sleeve, it will follow a path of least resistance, so when a bend occurs, the eversion sleeve will follow it. 
         [0022]    The eversion process involves deployment of the eversion sleeve by turning it inside out. This allows advancing the eversion sleeve and its head member with a substantially low friction within the internal surface of the path that can be rough and can include various obstacles therealong, thereby allowing easy and reliable self-propulsion of the head member along the path. Eventually, the eversion process is such that the outside portion of the sleeve remains substantially stationary with respect to the walls of the path, and the main element that may be subject to friction with the path is the head member. 
         [0023]    Any one or more of the following features, designs and configurations can be incorporated in the system and the device of presently disclosed subject matter, independently or in combination thereof: 
         [0024]    The head member can be made of a substantially rigid material that preserves its shape also when the force exerted by the propelling fluid on the everting portion is reduced or terminated (i.e., the pressure of the propelling fluid within the space drops). This can allow the head member and/or the entire device to perform its designated function at any location along the path also when there is a pressure drop of propelling fluid. 
         [0025]    The everting portion can be configured with an external surface engaging the internal portion of the head member, and an internal surface on which the force of the propelling fluid is to be exerted. 
         [0026]    The internal portion of the head member can be configured with at least one narrow portion having a first cross-sectional diameter D 1  taken perpendicularly to its length and at least one wide portion having a second cross-sectional diameter D 2  taken perpendicularly to its length, which is greater than D 1 . The at least one narrow portion is configured to engage the external surface of the everting portion and prevent axial displacement of the head member with respect to the everting portion, while allowing the everting portion to slidingly displace with respect to the internal portion. 
         [0027]    The narrow portion can be formed as a circumferential groove formed in the head member. 
         [0028]    The at least one narrow portion can be disposed closer to the outside portion than the at least one wide portion. 
         [0029]    The at least one narrow portion can be disposed between two of said wide portions. 
         [0030]    The head member can further comprise a retaining member configured for engaging the internal surface of the everting portion and applying an outwardly pressing force thereon, thereby retaining the everting portion in proximity to the internal portion while allowing the everting portion for slidingly displacing with respect to the internal portion. 
         [0031]    The retaining member can be located in close proximity to the wide portion of the internal portion. The retaining member can have an exterior face having a shape which is mimicking the shape of the wide portion. 
         [0032]    The retaining member can have a central opening for allowing the inside portion to pass therethrough. 
         [0033]    The retaining member can have a torus shape. 
         [0034]    The head member can further be configured with a frontal portion with a rounded profile. The rounded profile can be a sphere-like profile. 
         [0035]    The dispatching member can have an annular shape and can be configured with a perimetric rim for sealingly circumferentially fixing to the sleeve end, a nozzle for allowing the internal portion to pass therethorugh, and an inlet for interfacing with a pumping mechanism configured for introducing the propelling fluid into the space. 
         [0036]    The dispatching member can be configured with a nozzle disposed at its center. 
         [0037]    The system and the device can comprise a pumping mechanism for introducing the propelling fluid into the space, thereby generating a positive pressure therein and exerting the force on the everting portion. 
         [0038]    The eversion sleeve can be made of one of the following materials: silk, nylon, rubber, deformable plastic material. 
         [0039]    The eversion sleeve can be made of a fluid-tight material. 
         [0040]    The space can be sealed from the surrounding. 
         [0041]    The interior of the internal portion can define an elongate lumen allowing electrically or mechanically communicating therethrough between an exterior of the device at the surrounding of the dispatching member and the head member and its surrounding. The elongate lumen can allow introducing therethrough objects (e.g., endoscopes, measuring instruments, sensors, working tools), cables (e.g., electric cables, Bowden cables, fibers), or tubes. 
         [0042]    The head member can be mounted to an operational unit including one or more of the following: a video camera, a stills camera, an imaging system, sensing system, a treatment system, a working tool, and a communication system. 
         [0043]    The head member and the operational unit can be integrated into a single unit. 
         [0044]    The head member can be mounted to a steering mechanism having a body member connected to a front end of the head member. The steering mechanism is configured for directing the head member during its advancing an article along the path. 
         [0045]    The steering mechanism can comprise at least one pair of wheels and at least one controlling mechanism configured for controlling the direction of said pair of wheels. 
         [0046]    The controlling mechanism can include at least one Bowden cable extending along the elongate lumen and a tensioning mechanism mounted to the at least one Bowden cable for controlling the direction of said pair of wheels. 
         [0047]    The steering mechanism can comprise two pairs of wheels disposed consecutively with respect to each other and with respect to the head member. The frontal pair of the two pairs of wheels can be controllable by the controlling mechanism. 
         [0048]    The steering mechanism can allow the head member to perform sharp turns along the path at an angle of about  90 ° or more than  90 ° . 
         [0049]    Extraction of the propelling fluid from the space can reduce the force on the everting portion, thereby allowing gradually pulling back a segment of the inside portion towards the dispatching member and advancing a respective segment of the outside portion towards the head member, thereby drawing the head member backwardly along the path. 
         [0050]    The system and the device can further comprise a reel on which the internal portion is wound around, for feeding the eversion sleeve via the dispatching member during supply of the propelling fluid into the space. 
         [0051]    According to a further aspect of the presently disclosed subject matter, there is provided a method for assembling a system for advancing an article along a path, the system comprising: a head member having an internal portion, a dispatching member having a nozzle, and an eversion sleeve, the method comprising: 
         [0052]    (i) introducing a part of said eversion sleeve via said nozzle; 
         [0053]    (ii) everting the eversion sleeve inside out, thereby forming an outside portion having a sleeve end, an everting portion and an inside portion extending from the everting portion towards the dispatching member; and 
         [0054]    (iii) mounting said everting portion to said internal portion so as to retain the everting portion and facilitate it to slide with respect to the head member; and 
         [0055]    (iv) sealingly fixing said sleeve end to said dispatching member, thereby forming a space therebetween for receiving a propelling fluid for exerting force on the everting portion. 
         [0056]    The method for assembling can further include a step of introducing said part of said eversion sleeve via a retaining member, which is performed between steps (i) and (ii), and a step of locating the retaining member at an internal surface of the everting portion for applying an outwardly pressing force thereon, which is performed between steps (iii) and (iv). 
         [0057]    The step (iv) can further include a step of locating the retaining member within a wide portion of the head member. 
         [0058]    According to a further aspect of the presently disclosed subject matter, there is provided a method for using a device for advancing an article along a path, comprising: 
         [0059]    (i) providing the device, comprising: a head member; a dispatching member; an eversion sleeve configured with an outside portion having a sleeve end fixed to the dispatching member, an everting portion slidingly articulated to the head member and an inside portion extending from the everting portion towards the dispatching member; and a space formed between said inside portion and said outside portion; said head member being configured with an internal portion for retaining the everting portion and facilitating the everting portion to slide with respect to the head member. 
         [0060]    (ii) locating said device at a particular location at the path with the head member facing towards an advancement direction along the path; and 
         [0061]    (iii) introducing a propelling fluid into the space for exerting force on the everting portion, thereby gradually advancing a segment of the inside portion towards the head member causing it to slidingly displace with respect to the head member and gradually advancing a respective segment of the everting portion into the outside portion, thereby everting said eversion sleeve inside out and advancing the head member along the advancement direction. 
         [0062]    The method can further comprise steps of: providing the device with a steering mechanism having a body member connected to a front end of the head member; and operating the steering mechanism for directing the advancement direction of the head member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0063]    In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which: 
           [0064]      FIG. 1A  is an exploded prospective view of a device according to one example of the presently disclosed subject matter, constituting a system for advancing an article along a path; 
           [0065]      FIG. 1B  is a rear perspective view of the device of  FIG. 1A , in its initial state; 
           [0066]      FIG. 1C  is a cross-sectional view taken along line A-A of a portion Al of the device of  FIG. 1B ; 
           [0067]      FIG. 1D  is a cross-sectional view taken along line B-B of the device of  FIG. 1B ; 
           [0068]      FIG. 2A  is a rear perspective view of the device of  FIG. 1B , in its elongated state; 
           [0069]      FIG. 2B  is a cross-sectional view taken along line C-C of the device of  FIG. 2A ; 
           [0070]      FIG. 3  is a top view of the device of  FIG. 1B , in its elongated state along a path; 
           [0071]      FIG. 4  is a rear perspective view of the device of  FIG. 2A , configured with a steering mechanism mounted to its head member; 
           [0072]      FIG. 5A  is a top view of the device of  FIG. 4 , in its elongated state with particularly advancing an article along a path having a right-angled turn; and 
           [0073]      FIG. 5B  is the device of  FIG. 5A  with further advancing an article along the path at the right-angled turn. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0074]    Attention is first directed to  FIGS. 1A to 1D  in which a system  1 ′ ( FIG. 1A ) and a device  1  ( FIGS. 1B to 1D ) for advancing an article along a path are shown, in accordance with one example of the presently disclosed subject matter. The device  1  constitutes an assembled form of the system  1 ′, and therefore, although explanations below are made with respect to the device  1 , they are also relevant for the system  1 ′. 
         [0075]    The device  1  comprises a head member  10 , a retaining member  30 , a dispatching member  50 , an eversion sleeve  60 , and a pumping mechanism in the form of a pump  90 . The device  1  can optionally comprise an operational unit  100  which can be mounted to the head member  10  when needed. 
         [0076]    As shown in  FIG. 1A , the eversion sleeve  60  is an elongate sleeve wound about a take-up reel  70 . The eversion sleeve  60  is shown in  FIG. 1A  with its front end turned inside out, thereby forming three main portions: an inside portion  62 , an everting portion  64  and an outside portion  66  which is turned at an angle of 180° with respect to the non-everted inside portion  62 . As shown in  FIG. 1C , the everting portion  64  is defined as a portion of the eversion sleeve  60  which extends between imaginary circles M and N of the sleeve. It should be indicated that the location of the everting portion  64 , and respectively the length of the inside portion  62  and the outside portion  66  is dynamic, and depends on the extent of eversion of the eversion sleeve  60 , as described below. 
         [0077]    The eversion sleeve  60  is made of a fluid-tight material, for example, nylon. When being put under pressure, the eversion sleeve  60  is resilient and flexible, thereby allowing advancement of the head member  10  along a curved path, as explained below with reference to  FIG. 3 . Although the everting portion  64  of  FIG. 1A  is shown in its non-deformed state, when the device  1  is assembled, and particularly, when the head member  10  and the retaining member  30  are mounted to the everting portion, the shape of the everting portion is changed in accordance with the structure of the head member  10  and the retaining member  30  (as shown in  FIG. 1C ). 
         [0078]    As explained below in a detailed manner, in operation of the device  1 , introduction of a propelling fluid into the interior of the device  1  causes the eversion sleeve  60  to be continuously everted while increasing the length of the outside portion  66  and decreasing the length of the inside portion  62 . This eversion is followed by sliding displacement of the head member  10  with respect to the eversion sleeve  60 , which results in movement of the head member  10  along an elongation X-axis extending along the length of the device  1 . 
         [0079]    The dispatching member  50  includes an annular housing  54  with an opening  55  for sealingly receiving a closure  52  therein. The housing  54  is configured with a perimetric rim  56 . As shown in  FIGS. 1B and 1C , a sleeve end  67  of the outside portion  66  is sealingly fixed to the perimetric rim  56 . The closure  52  has a nozzle  53  disposed at its center for allowing the inside portion  62  to pass therethorugh. The housing  54  further has an inlet  57  for interfacing with the pump  90  for fluidly communicating therebetween. The inside portion  62  is extending from the everting portion  64  towards the dispatching member  50 , and from there to the take-up reel  70 .The everting portion  64  is configured with an external surface  72  (shown in  FIG. 1A ) and an internal surface  74  (shown in  FIG. 1C ). The external surface  72  is engaging an internal portion  12  of the head member  10 . The head member  10  is structured so as to retain the everting portion  64  in proximity thereto, while allowing and facilitating it to slide with respect to the internal portion  12 . In particular, as shown in  FIG. 1C , the internal portion  12  is configured with a narrow portion  13  having a first cross-sectional diameter Dl taken perpendicularly to its length along the X-axis. The narrow portion  13  is a circumferential groove formed in the head member  10 . The internal portion  12  is further configured with a wide portion  14  having a second cross-sectional diameter D 2  taken perpendicularly to its length along the X-axis. D 2  is greater than Dl. The narrow portion  13  is retaining the eversion sleeve by engaging the external surface  72  and preventing displacement of the head member  10  with respect to the everting portion  64  along the X-axis, while allowing the eversion sleeve  60  to slidingly displace with respect to the internal portion  12 . 
         [0080]    According to other examples, the head member may be configured with more than one narrow portion and/or with more than one wide portion. The narrow and the wide portions may be positioned at different combinations with respect to each other. 
         [0081]    In addition to the structure of the head member  10 , the retaining member  30  is also used for retaining the head member  10  to the eversion sleeve  60 . 
         [0082]    The retaining member  30  is a hollow resilient member having a torus shape, the exterior surface of which is mimicking the shape of surface of the wide portion  14 . 
         [0083]    The retaining of the head member  10  to the eversion sleeve  60  is performed by positioning the retaining member  30  at the wide portion  14  from the side of the internal surface  74 , so that the everting portion  64  is disposed between the retaining member  30  and the head member  10 . In this position, the retaining member  30  applies an outwardly pressing force on the internal surface  74 , thereby retaining the everting portion  64  in proximity to the internal portion  12  while allowing the everting portion  64  to slidingly displace with respect to the internal portion  12 . 
         [0084]    As best seen in  FIG. 1C , a fluid-tight sealable space  80  is formed within the device  1  between the inside portion  62  and the outside portion  66 . The space  80  is in fluid communication with the pump  90  via a hose  92  which is connected to the inlet  57 . The space  80  is sealed from the surrounding of the device  1  and is configured for receiving a propelling pressurized fluid in the form of air from the pump  90 . The pump  90  can be manually or electrically operated. 
         [0085]    Reference is now made to  FIGS. 2A and 2B  in order to explain how introduction of air into the space  80  increases the length of the outside portion  66  while it remains stationary, thereby advancing the head member  10  along the X-axis by rolling the head member  10  with a sliding motion with respect to the eversion sleeve  60 . 
         [0086]    As a result of introduction of a predetermined amount of air into the space  80 , a pressure gradient is generated within the space  80  with respect to the surrounding of the device  1 . Due to a limited resilience of the eversion sleeve  60  in the radial direction, the pressure of the air within the space  80  generates a force F (shown in  FIG. 1C ) which is directed generally along the X-axis. The force F is exerted on the everting portion  64  straightly and via the retaining member  30 . Exertion of the force F applies a pulling force on the inside portion  62  in the direction of the X-axis, gradually advancing a segment of the inside portion  62  towards the head member  10  with respective rotation of the take-up reel  70 . This segment has a length L (shown in  FIG. 1C ). As a result of the pulling force applied thereon, the segment of the inside portion  62  slides between the head member  10  and the retaining member  30 , gradually advancing a segment of the everting portion  64  into the outside portion  66 . This results in increasing the length of the outside portion  66  by a length of L/2 and advancing the head member in the X-axis direction to a distance of L/2. In other words, the exertion of the force F causes eversion of a segment of the eversion sleeve  60  having the length L, which results in advancement of the head member  10  along a distance of L/2 (as shown in  FIG. 2A ). Therefore, during introduction of air into the space  80 , the speed of advancement of the inside portion  62  is twice than the speed of advancement of the head member  10 . 
         [0087]    The head member  10  is made of a rigid material that preserves its shape also when the pressure of air within the space  80  drops, for example, when the head member  10  was advanced to a particular location along the path, and the pump  90  was disconnected from the device  1 . This ability of the head member  10  to preserve its shape allows it to perform its designated function (e.g., measuring, sensing, optically inspecting, etc.) at any location along the path also when there is a pressure drop within the space  80 . 
         [0088]    The head member  10  is configured with a frontal portion having a rounded profile, and with an attachment member  15  disposed at its frontal edge. The attachment member  15  can be used for mounting different members to the head member  10  for different needs. According to the example of  FIGS. 1A-1D and 2A-2B , the attachment member  15  can be optionally connected to the operational unit  100 . The operational unit  100  includes a camera  105  at its frontal end (shown in  FIGS. 1C and 2B ). According to the example of  FIGS. 4 and 5A-5B , the attachment member  15  can be used for mounting a steering mechanism thereto. 
         [0089]    An interior of the internal portion  62  defines an elongate lumen  63  (shown in  FIGS. 1C, 1D and 2B ) allowing electrically or mechanically communicating therethrough between an exterior of the device at the surrounding of the dispatching member and the head member  10  and its surrounding. The lumen  63  can allow introducing therethrough into the location of the head member along the path different objects (e.g., endoscopes, measuring instruments, sensors, working tools), cables (e.g., electric cables, Bowden cables, fibers), or elongate elements. According to the present example, the lumen  63  can be used for passing therethorugh electric cables to the camera  105  for communicating with the camera  105  and providing power supply thereto. 
         [0090]    Reference is now made to  FIG. 3  in which the device  1  is shown within a curved path  200 . As mentioned above, the eversion sleeve  60  is made of a resilient and/or flexible material that allows advancing the outside portion  66  of the eversion sleeve  60  with the head member  10  mounted thereto along the curved structures. For example, when the head member  10  is advanced along the path  200 , and reaches the wall of the path  200  at a turning point  202 , further advancement of the head member  10  will cause the outside portion  66  to bend, thereby following the shape and the structure of the path  200 . 
         [0091]    The eversion process described above, which involves deployment of the eversion sleeve  60  by turning it inside out, allows advancing the head member  10  with a minimal friction along the path  200 , since the outside portion  66  does not need to slide within the path  200  during the advancement of the head member  10 . Therefore, the degree of the pressure of air that needs to be supplied into the space  80  for the advancement of the head member  10  along the path  200  is also reasonable. 
         [0092]    It should be indicated that the head member  10  can also be advanced backwardly within path  200 , for example, after finishing its intended operation. This can be done by reducing the pressure within the space  80 , thereby allowing gradually pulling the inside portion  62  in the opposite direction, resulting in decrease of the length of the outside portion  62  and respective backward movement of the head member  10 . 
         [0093]    Although the eversion sleeve  60  has a finite length, its length can be manually or automatically increased by sealingly connecting thereto an additional eversion sleeve by known in the art techniques (e.g., heat welding). This can allow advancing the head member  10  along a path which is extremely long, even more than it was known to the operator prior to the introduction of the head member into the path. 
         [0094]    Reference is now made to  FIGS. 4 and 5A-5B , in which the device  1  includes a steering mechanism  150  mounted to the head member  10 . The steering mechanism  150  is configured for directing the head member  10  during its advancing an article along the path. 
         [0095]    The steering mechanism  150  includes a first body member  152  and a second body member  154  pivotally connected therebetween. The first body member  152  is pivotally connected to the attachment member  15 . The first body member  152  has a first pair of wheels  153  disposed at both its sides, and the second body member  154  has a second pair of wheels  155  disposed at both its sides. The wheels  153  and  155  are configured to be rotated by themselves upon advancement of the head member  10  along the path. 
         [0096]    The steering mechanism  150  further includes a controlling mechanism (not shown) configured for controlling the direction of the pair of wheels. In particular, the controlling mechanism is configured for changing the direction of the first and the second body members  152  and  154  with respect to the X-axis and with respect to each other. The controlling mechanism is configured with two Bowden cables  162  and  164  (shown in  FIG. 4 ), each connected to its respective body members  152  and  154 . The Bowden cables extend within the lumen  63 , along the entire length of the inside portion  62 . The controlling mechanism further includes a tensioning mechanism mounted to the Bowden cables  162  and  164  for controlling the tension of these cables, and thereby changing the direction of the first and the second body members  152  and  154  with respect to the X-axis. 
         [0097]    In  FIGS. 5A-5B  there is shown a path  300  having a sharp right-angled turn. As shown in  FIG. 5B , in order to allow the head member  10  to turn left and not to be stuck at an injunction of the path, the second body member  154  is rotated by respective tensioning of the Bowden cable  164 . This rotation allows the head member  10  to turn left and thereby continue its advancing an article along the path  300 . 
         [0098]    According to another example, when the structure of the path is unknown to the operator of the device  1 , the steering mechanism can be used in conjunction with a video camera mounted to the head member or to the steering mechanism. The video camera can provide a real time picture of the region in front of the head member, and the steering mechanism can be used by the user for navigating the head member to a preferred direction.