Patent Publication Number: US-2007118012-A1

Title: Method of assembling an in-vivo imaging device

Description:
PRIOR APPLICATION DATA  
      The present application claims benefit from prior US Provisional Application Ser. No. 60/738,972, entitled, “IN-VIVO IMAGING DEVICE AND OPTICAL SYSTEM THEREOF”, filed on Nov. 23, 2005, incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to a method of assembling an in-vivo imaging device for capsule endoscopy.  
     BACKGROUND OF THE INVENTION  
      Such in-vivo sensing devices, may be in the form of swallowable or ingestible capsules which may move through a body lumen. The in-vivo sensing device may include, for example, an imaging system for obtaining images from inside the body lumen, such as the gastrointestinal (GI) tract as it moves through it. The imaging system may include, for example, an illumination unit, such as a set of light emitting diodes (LEDs), or other suitable light sources, an imaging sensor and an optical system, which focuses the images onto the imaging sensor. A transmitter and antenna may be included for transmitting the images signals to an external data recorder. A power source, such as one or more batteries, may also be included for powering the various electrical and electronic components. Typically, the imaging system, transmitter, antenna, batteries and other components are assembled in the in-vivo sensing device&#39;s housing in a compact and secure manner, which takes into account the cooperation between the electrical and electronic components and the required optical properties of the in-vivo sensing device.  
     SUMMARY OF THE INVENTION  
      In accordance with the present invention, there is provided a method for assembling an in-vivo imaging device comprising the steps of: 
          (i) providing two optical heads and a circuit board having two rigid portions connected by a flexible portion;     (ii) attaching the optical heads to the rigid portions;     (iii) providing a first sleeve having two opposing open ends;     (iv) folding the circuit board so that the optical heads are positioned over the open ends;     (v) placing domes over the optical heads; and     (vi) bringing the domes into abutment with the first sleeve so that the first sleeve and the domes form a closed housing enclosing the circuit board and the optical heads.        

      In accordance with some embodiments, the comprises the further steps of: 
          (a) placing at least one battery in a second sleeve having two opposing open ends; and     (b) placing the second sleeve in the first sleeve.        

      In accordance with some embodiments, the step of placing at least one battery in a second sleeve is performed prior to the step folding the circuit board.  
      In accordance with some embodiments, at least one battery is placed in the first sleeve.  
      In accordance with some embodiments, the first sleeve is placed between the two optical heads with the flexible portion passing between the two opposing open ends prior to folding the circuit board; and at least one battery is placed in the first sleeve after positioning one of the optical heads over one of the open ends.  
      In accordance with some embodiments, the domes are joined to the first sleeve by a process chosen from the following group: gluing, fraction fitting, press fitting, snap fitting, laser welding, laser melting, spin welding, and ultra sonic welding.  
      In accordance with some embodiments, there is provided a method for assembling an in-vivo imaging device comprising: 
          (i) attaching optical heads to a circuit board;     (ii) folding the circuit board so that the optical heads are positioned over the open ends of a connecting sleeve;     (iii) placing domes over the optical heads; and     (vi) bringing the domes into abutment with the first sleeve so that the connecting sleeve and the domes form a closed housing enclosing the circuit board and the optical heads.       

    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings in which:  
       FIG. 1  schematically illustrates an in vivo imaging system and device according to some embodiments of the present invention;  
       FIG. 2  schematically illustrates a perspective view of an in vivo imaging device according to some embodiments of the present invention in a body lumen;  
       FIG. 3  schematically illustrates a longitudinal cross section of an in vivo imaging device according to some embodiments of the present invention;  
       FIGS. 4A and 4B  schematically illustrate a top view and a bottom view, respectively. of a circuit board, in accordance with an embodiment of the present invention;  
       FIG. 5A  schematically illustrates a connecting sleeve, according to some embodiments of the present invention;  
       FIG. 5B  schematically illustrates a side view, of a battery contact, in accordance with some embodiments of the present invention;  
       FIG. 6A  is a schematic flow-chart of a method of assembling an in vivo imaging device, in accordance with some embodiments of the invention;  
       FIGS. 6B-6F  schematically illustrate a method of assembling an in vivo imaging device, in accordance with some embodiments of the invention;  
       FIG. 6G  is a schematic flow-chart of a method of assembling an in vivo imaging device, in accordance with some embodiments of the invention;  
       FIG. 7A  is a schematic flow-chart of another method of assembling an in vivo imaging device, in accordance with some embodiments of the present invention;  
       FIG. 7B  schematically illustrates a method of assembling an in vivo imaging device, in accordance with some embodiments of the present invention; and  
       FIG. 7C  schematically illustrates a perspective view of the in vivo imaging device shown in  FIG. 7B  in an assembled state.  
      It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.  
      It is noted that some embodiments of the present invention may be directed to an autonomous, typically ingestible in-vivo device. Other embodiments need not be ingestible. Devices or systems according to embodiments of the present invention may be similar to embodiments described in International Application WO 01/65995 and/or in U.S. Pat. No. 5,604,531, each of which are assigned to the common assignee of the present invention and each of which are hereby fully incorporated by reference. Furthermore, a receiving and/or display system suitable for use with embodiments of the present invention may also be similar to embodiments described in WO 01/65995 and/or in U.S. Pat. No. 5,604,531. Devices and systems as described herein may have other configurations and other sets of components.  
      Reference is made to  FIG. 1 , which shows a schematic diagram of an embodiment of an in-vivo imaging device  40  and an external receiver  90  and transmitter/receiver  31  in accordance with an embodiment of the invention. In one embodiment, the system may include a device  40  having an imager  36  and/or  36 ′ (such as for example a CMOS, a CCD, etc.), an optical system which may include lens holder  32  and/or  32 ′, lenses and other optical elements and illumination sources  34  such as one or more LEDs (Light Emitting Diode), and/or OLEDs (Organic LED) or other suitable illumination sources. According to one embodiment the imager, optical system and light source are positioned behind a viewing window  30 . Viewing window  30  may be a transparent elongated dome. The device may include a power source such as silver oxide batteries, lithium batteries, other suitable electrochemical cells having a high energy density, or the like. Other power sources may be used. For example, instead of internal power source or in addition to it, an external power source may be used to transmit power to device  40 . In some embodiments, an additional sensor may be included in the device, for example, pH, temperature, pressure or other physiological parameter sensors. Other components or sensors may also be included. A processor may be included in the device which may be for example capable of processing signals that are received by device  40  into for example command or control signals that may control, activate, deactivate or otherwise alter an operative state of components that may be included in device  40 . The transceiver  31  may be a transmitter or a receiver or both that may be capable of receiving wireless signals and transmitting wireless signals; in some embodiments only transmission (for example, transmission of image data from imagers  36  and/or  36 ′) may occur. Transceiver  31  may also have other functions. In some embodiments, transceiver  31  and the processor may be or may be included in a single integrated circuit. Device  40  may include antenna that may be operably attached to transceiver  31 . In some embodiments, the antenna may be used for, or in the performance of, both the receipt and transmission of wireless signals by transceiver  31 . In other embodiments there may be more than one antenna. In some embodiments, device  40  may transmit but not receive signals. An additional sensor or other components need not necessarily be included.  
      According to one embodiment of the present invention, device  40  may include two optical units. Each optical unit may include, for example, the transparent elongated dome  30  behind which are situated illumination sources  34 , lens holders  32 ,  32 ′ and imager  36 ,  36 ′. According to some embodiments of the present invention, device  40  is capable of simultaneously obtaining images of the body lumen, for example, the GI tract, from two ends of the device. For example, according to one embodiment of the present invention, device  40  may be a cylindrical capsule having a front end and a rear end, which is capable of passing the entire GI tract. The front and rear ends may define a longitudinal direction and a longitudinal axis of the device  40 . The lens holders  32 ,  32 ′ and imagers  36 ,  36 ′ may be located along the longitudinal axis. The imagers  36 ,  36 ′ may be perpendicular to the longitudinal axis. The system in a cylindrical capsule can image the GI tract in the front and in the rear of the capsule. The images may be transmitted simultaneously or serially and may be displayed separately or as a single combined image.  
      When used herein, terms like top, bottom, front, rear, over, above, etc., are considered relative terms descriptive of, for example, when the imaging device  40  is in a specific orientation relative to the viewer or the relative position of components of the device.  
      According to some embodiments of the present invention, the device  40  may include one or more light blockers such as light blockers  33  and  33 ′ which may include a suitable structure to reduce backscatter. In some embodiments, the light blocker may be formed and/or shaped such that it blocks stray light from reaching and/or flooding the imagers, such as imager  36  and imager  36 ′.  
      According to some embodiments the optical system in the device  40  may enable a wide field of view  37 .  
      External to device  40  may be the receiver  90  and possibly a transmitter. Receiver  90  and a possible transmitter (typically including or associated with an antenna or antenna array) may be housed or included in the same housing or unit, or may be housed in one or more separate units. For example, a transmitter and receiver may be housed in a portable unit that may be carried or worn by a patient and/or may be integrated into a transceiver.  
      Receiver  90  may be connected to and/or in electrical communication with a processor  92  which may process, for example, data signals such as, for example, sensory or image data signals that are received from device  40  and/or control data received from device  40 . In some embodiments, receiver  90  may be operably connected to a monitor/display  93  and/or a storage system  91  that may display and/or store the image or other sensory data collected and transmitted by device  40 . Processor  92  may analyze data received by receiver  90  and may be in communication with storage system  91 , transferring image data (which may be stored and transferred as for example frame data) or other data to and from storage system  91 . Processor  92  may also provide the analyzed data to display  93  where a user may view the images. Display  93  may present or display the data such as, for example, image frame data or video data of, for example, the gastrointestinal (GI) tract or other body lumen. In one embodiment, processor  92  may be configured for real time processing and/or for post processing to be performed. Other monitoring and receiving systems may be used.  
      A transmitter may typically be connected to and/or in electrical communication with processor  92 . Processor  92  may function, at least partially as a controller and/or include, for example, a controller to process, for example, control commands to device  40  via the transmitter. In other embodiments of the present invention, signals other than control commands may be processed by processor  92  with, for example, the controller and transmitted via the transmitter. In yet other embodiments, the controller and processor may be separate units that may be in electrical communication with each other. In some embodiments of the present invention, control commands generated, for example, by the controller may be based on data received by the receiver  90  and processed by processor  92 . In other embodiments, control commands generated, by the controller may be based on, user input data, for example, a patient or external operator may for example, initiate the transmission of a wireless signal and/or command from, for example, the transmitter to transceiver  31 . In yet other embodiments, control commands may be based on both user input data and data receiver and/or processed by processor  92 .  
      In some embodiments, transceiver  31  may be a half duplex transceiver where the transceiver  31  alternates from transmitting to receiving, e.g. via time division multiple access (TDMA). Typically, the transmission rate to the external receiver  90  may be significantly higher than the transmission rate from external transmitter to the transceiver  31 . For example, device  40  may transmit, e.g. image frame data to external receiver  90  at a rate of 1-10 Mbits/s, e.g. 2.7 Mbits/s, while the external transmitter may transmit control commands to the transceiver  31  that may be at rate of 10-30 Kbits/sec.  
       FIG. 2  is a schematic illustration of in-vivo imaging device  40  in accordance with some embodiments of the present invention. According to one embodiment of the present invention, device  40  may be partially or entirely transparent. For example, device  40  may include areas, such as a front and rear transparent optical domes  230  and  230 ′, which may allow components inside device  40  to have an un-obstructed field-of-view of the environment external to device  40 . Other shaped transparent areas may be used. The front and rear transparent optical domes  230  and  230 ′ may define a longitudinal direction and a longitudinal axis of the device  40 .  
      According to one embodiment of the present invention, each of the transparent domes  230  and  230 ′ may, respectively, include viewing windows  240  and  240 ′. According to some embodiments of the present invention the viewing windows  240  and  240 ′ may for example be transparent to the light emitted by illumination sources  234  that is reflected back off of, for example, an endo-luminal wall to device  40 . According to some embodiments of the present invention, the transparent domes  230  and  230 ′ may be configured such that an appropriate field of view and/or field of illumination of the body lumen walls may be achieved with a reduced risk of stray light or backscatter from illumination sources  234  onto imagers  236  and  236 ′. The imagers  236 ,  236 ′ may be located along the longitudinal axis and may be perpendicular thereto. According to some embodiments of the present invention the two viewing windows  240  and  240 ′ may be configured such that a field of view  241  in the range of between 80-150 degrees is enabled; other suitable fields of view may be used. According to one embodiment of the present invention the effective focal distance (also referred to as the effective focal length), of the device  40  may typically be between 0 to 40 mm; however, other suitable distances may be used.  
      In one embodiment, as device  40  traverses body lumen  270 , device  40  may capture images substantially simultaneously of one or more areas of body lumen  270 , such as locations  271  and  273 . According to some embodiments of the present invention illumination sources  234  may illuminate locations  271  and  273  of body lumen  270 . The light from illuminated locations  271  and  273  may be reflected, focused and/or transferred using the optical system which may include lens holders  232  and  232 ′, and received by imagers  236  and  236 ′, which may thereby capture an image of locations  271  and  273 . The lens holders  232 ,  232 ′ may be located along the longitudinal axis.  
      Reference is made to  FIG. 3 , which shows a schematic representation of a longitudinal cross-section of a device  300  according to embodiments of the present invention. The device  300  may include two optical domes  302  and  302 ′. According to one embodiment of the present invention each optical dome  302  and  302 ′ may be an integral part of two elongated ends of a capsule, such as a transparent front end  304  and a transparent rear end  304 ′. According to one embodiment of the present invention the front and rear ends  304  and  304 ′ may be attached to a connecting sleeve, for example an opaque sleeve  305  having two opposing open ends. According to some embodiments of the present invention behind the transparent ends  304  and  304 ′ may be, respectively, situated for example illumination sources  342 , lens holder  344  and  344 ′, imagers  319  and  319 ′ a transmitter/receiver such as an ASIC  320  and a switch  321  such as a MEMS switch or a reed switch RI-80 SMD. The lens holders  344 ,  344 ′ contain various optical components (not shown), such as optical lenses, for focusing light on the imagers  319 ,  319 ′. Each lens holder  344 ,  344 ′ along with its associated optical components is referred to herein as an optical head. The device  300  may further include one or more power sources  345 , such as E370 or E399 or GP370 batteries, which may provide power to the entirety of electrical elements of the device, and an antenna  317  for transmitting and/or receiving, for example, image signals from the imagers  342  and  342 ′. According to some embodiments of the present invention, device  300  is capable of simultaneously obtaining images of the body lumen, for example, the GI tract, from two ends of the device. For example, according to one embodiment of the present invention device  300  may be a floatable capsule having a front end and a rear end, which is capable of passing the entire GI tract.  
      According to one embodiment of the present invention the device  300  may include two battery contacts, such as battery contact  330  which may be located at the sides of the batteries  345 , and battery contact  340  which may be located beneath the batteries  345 .  
      According to one embodiment of the present invention, the various components of the device  300  may be disposed on a circuit board  350  including rigid and flexible portions; preferably the components are arranged in a stacked vertical fashion. For example, rigid portion  351  of the circuit board  350  may hold an imager  319 , an antenna  342  a lens holder  344  and a light blocker  333 , while rigid portion  361  may hold a lens holder  344 ′, an imager  319 ′ and a light blocker  333 ′. According to one embodiment of the present invention, the other side of the rigid portion  351  may include, for example, a transmitter/receiver  320  and a switch  321 , while the other side of rigid portion  361  may hold a battery contact  340  for battery or power source(s)  345 . According to one embodiment of the present invention, rigid portions  351  and  361  of the circuit board  320  may include, for example, an illumination source, such as one or more LEDs  342  or other illumination sources. According to some embodiments of the present invention, each rigid portion of the circuit board may be connected to another rigid portion of the circuit board by a flexible connector portion  322  of the circuit board  350 . According to one embodiment of the present invention, each rigid portion of the circuit board may include two rigid sections; sandwiched between the rigid sections is a flexible connector portion of the circuit board for connecting the rigid boards. In alternate embodiments, other arrangements of components may be placed on a circuit board having rigid portions connected by flexible portions.  
      Arrangements of components as described above may be included in other capsule shaped devices., for example, a device having only one transparent dome and one imager for imaging from only one end of the device.  
      According to one embodiment components may be arranged in an in vivo autonomous imaging device on an array of chips using flip chip bonding.  
      In alternate embodiments, a circuit board having rigid portions and flexible portions may be used to arrange and hold components in other in vivo sensing devices, such as a swallowable capsule measuring pH, temperature or pressure, or in a swallowable imaging capsule having components other than those described above. Such circuit boards may be similar to embodiments described in U.S. application No. 10/879,054 entitled IN VIVO DEVICE WITH FLEXIBLE CIRCUIT BOARD AND METHOD FOR ASSEMBLY THEREOF, and U.S. application No. 60/298,387 entitled IN VIVO SENSING DEVICE WITH A CIRCUIT BOARD HAVING RIGID SECTIONS AND FLEXIBLE SECTIONS, each incorporated by reference herein in their entirety.  
      According to some embodiments of the present invention, one or more components of device  300 , for example the lens holders  344  and  344 ′, the imagers  319  and  319 ′, the transmitter  320  and the switch  321  may be packaged and may be further attached and/or interconnected for example, to the circuit board  350  using three dimensions (3D) chip scale packaging techniques. For example, according to one embodiment of the present invention, the lens bolder  344 , the imager  319 , the transmitter  320  and the circuit board  320  may be interconnected to one another by using, for example a bonding layer such as a Solder Bumps layer.  
       FIGS. 4A and 4B  schematically illustrate a top view and a bottom view, respectively, of a circuit board  400  in accordance with some embodiments of the invention. In some embodiments, circuit board  400  may be an example of circuit board  350  of  FIG. 3 . In some embodiments, circuit board  400  may be used in conjunction with device  40  of  FIG. 1 , or with other suitable devices and systems for in vivo sensing or in vivo imaging, for example, in a capsule having only one transparent dome and one imager for imaging from only one end of the capsule.  
      According to some embodiments of the present invention, circuit board  400  may include, for example, one or more rigid portions and one or more flexible portions. For example, circuit board  400  may include rigid portions  451  and  461 , which may be interconnected using flexible portion  422 . Although two rigid portions and one flexible portion are shown, embodiments of the present invention are not limited in this regard, and may include other numbers, orders or combinations of rigid portions and/or flexible portions.  
      In some embodiments, rigid portion  451  and/or rigid portion  461  may include, for example, one or more illumination sources  442  such as LEDs and/or OLEDs, and optionally one or more resistors  431  and capacitors  432  to regulate or control the power provided to illumination sources  442 . Although two rigid portions  451  and  461  having illumination sources  442  are shown, embodiments of the invention are not limited in this regard; for example, in one embodiment, circuit board  400  may include rigid portion  451  and may not include rigid portion  561 .  
      In some embodiments, rigid portion  451  may include a first imager  419  an antenna  417  a transmitter/receiver such as an ASIC  420 , a switch  421  and one or more battery contact pads  443  for connecting the electrical components of the in-vivo device  300  to the battery  345 .  
      In some embodiments, rigid portion  461  may include a battery holder  440 , e.g., a spring able to hold a battery, such as battery  345 , or other power source in place.  
      According to some embodiments the present invention, rigid portion  461  may optionally include a second imager  419 ′. Although two imagers  419  and  419 ′ are shown, embodiments of the invention are not limited in this regard; for example, in one embodiment, circuit board  400  may include one imager, or another suitable number of imagers.  
      According to some embodiments of the present invention, the one or more flexible portions of circuit board  400  may allow bending, folding, twisting or positioning of circuit board  400  into certain shapes. For example, circuit board  400  may have a “C” shape as shown in  FIG. 3  or other suitable shapes.  
      Reference is now made to  FIG. 5A  which schematically illustrates a connecting sleeve  500  according to some embodiments of the present invention. In some embodiments, connecting sleeve  500  may be used in conjunction with device  40  of  FIG. 1 , or with other suitable devices and systems for in vivo sensing or in vivo imaging.  
      According to one embodiment of the present invention the connecting sleeve  500  may include for example three battery contacts  551 . According to one embodiment of the present invention the battery connects  551  may be placed, for example in the inside section of the connecting sleeve  500 . The battery contacts  551  may be reed shaped and may be inserted, for example on three protrusions  552  from the sleeve inner wall. According to one embodiment of the present invention, the three protrusions  552  may be integral to the connecting sleeve  500  inner wall.  
       FIG. 5B  schematically illustrates a side view, of a battery contact, for example the battery contact  551 , in accordance with some embodiments of the present invention. According to one embodiment of the present invention one edge of the battery contact  551 , for example edge  560 , may have a shape of, for example, a plate, and may include a connection point  561  which may be used as a connection point between the battery  250  and the battery contact  551 . According to one embodiment of the present invention, the other edge of the battery contact, for example edge  570  may be shaped for example as a boomerang, and may include a connection point (e.g.  571 ) between the battery contact  551  and the battery contact pads  443  (shown in  FIG. 4B ).  
      A battery contact such as described above may be used in other in vivo imaging device, such as in a capsule having only one transparent dome and one imager for imaging from only one end of the capsule. The battery contact  551  is only one illustrative example of a battery contact that may be used with the present invention. Other types of battery contacts may also be used with the present invention.  
       FIG. 6A  is a schematic flow-chart of a method of assembling an in vivo imaging device, such as device  300  of  FIG. 3 , in accordance with some embodiments of the invention. As indicated at box  600 , the method may optionally include folding an electric circuit board, such as a rigid-flex circuit board  602 , and attaching or connecting the electric circuit board  602  to an optical unit, for example a front elongated transparent optical unit  604 , as shown in  FIG. 6B .  
      As indicated at box  610 , the method may optionally include attaching or connecting a connecting sleeve, such as, according to one embodiment, a nontransparent connecting sleeve  606  to the front elongated transparent optical unit  604  as shown in  FIG. 6C .  
      As indicated at box  620 , according to one embodiment of the present invention, the method may optionally include attaching or connecting the electric circuit board to the sleeve  606  as shown in  FIG. 6D . For example, a flexible portion  612  of the electric circuit board  602  may be located in a groove (not seen) of the connecting sleeve  606 .  
      As indicated at box  630 , the method may optionally include inserting one or more batteries, such as batteries  642  into the connecting sleeve  606 , as shown in  FIG. 6E .  
      As indicated at box  640 , according to one embodiment of the present invention, the method may optionally include, folding the circuit board  602  and attaching a rear optical unit to the connecting sleeve  606 . For example, according to one embodiment of the present invention, as shown  FIG. 6F , a transparent optical rear unit  605  may be attached or connected to the connecting sleeve  606 .  
      The method of assembling an in vivo imaging device, such as device  300  of  FIG. 3 , as described above with respect to  FIG. 6A , may be carried out in any desired order and is not restricted to the order of the steps as shown in  FIG. 6A .  
       FIG. 6G  is a schematic flow-chart of another method of assembling an in vivo imaging device, such as device  300  of  FIG. 3 , in accordance with some embodiments of the invention. As indicated in box  650 , the method may optionally include the step of providing two optical heads (as mentioned above, an optical head is referred to herein as lens holder  344 ,  344 ′ along with its associated optical components). As indicated in box  652 , the method may optionally include the step of attaching the optical heads to the circuit board rigid portions  602 . As indicated in box  654 , the method may optionally include the step of providing the connecting sleeve  606 . The connecting sleeve  606  is generally cylindrical in form, having two opposing open ends. As indicated in box  656 , the method may optionally include the step of folding the circuit board so that the optical heads are positioned over the open ends. As indicated in box  658 , the method may optionally include the step of placing domes  302 ,  302 ′ (or, equivalently, elongated ends  304 ,  304 ′ of the device  300 ) over the optical heads. As indicated in box  660 , the method may optionally include the step of bringing the domes  302 ,  302 ′ (or, equivalently, elongated ends  304 ,  304 ′ of the device  300 ) into abutment with the connecting sleeve  606  so that the connecting sleeve  606  and the domes  302 ,  302 ′ form a closed housing. The closed housing defines the boundary surface of the in-vivo device  300 .  
      In accordance with some embodiments, the method may comprise the optional step of placing at least one battery  345  in a holding sleeve (not shown) prior to being placed in the connecting sleeve  606 . The holding sleeve may aid in holding a number of batteries together as a single battery pack. The holding sleeve may have two opposing open ends. In accordance with some embodiments step of placing at least one battery  345  in the holding sleeve is performed prior to the step of folding the circuit board so that the optical heads are positioned over the open ends.  
      In accordance with some embodiments, the method may comprise the optional step of placing the at least one battery  345  in placing at least one battery in the connecting sleeve  606 .  
      In accordance with some embodiments, the method may comprise placing the connecting sleeve  606  between the two optical heads with the flexible portion  612  passing between the two opposing open ends prior to the step of folding the circuit board; and the at least one battery is placed in the connecting sleeve  606  after positioning one of the optical heads over one of the open ends of the connecting sleeve  606 .  
       FIG. 7A  is a schematic flow-chart of another method of assembling an in vivo imaging device, such as device  300  of  FIG. 3 , in accordance with some embodiments of the invention. As indicated at box  700 , the method may optionally include folding an electric circuit board. For example folding a rigid-flex circuit board around a battery.  
      As indicated at box  710 , according to one embodiment of the present invention, the method may optionally include inserting the rigid-flex circuit board and the battery to a connecting sleeve for example to a nontransparent connecting sleeve.  
      As indicated at box  720 , the method may optionally include connecting two optical units to the connecting sleeve  606 , for example connecting two transparent elongated front and rear optical units  604  and  605 , to the nontransparent connecting sleeve  606  as shown in  FIGS. 7B and 7C .  
      According to some embodiment of the present invention, the in vivo imaging device components, such as the front and rear transparent optical units  604  and  605  and the connecting sleeve  606  may be joined together by using one or more of the following methods: fraction fitting, press fitting, snap fitting, laser welding, laser melting, spin welding, and ultra sonic welding.  
      While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.