Abstract:
An imaging capsule activating system includes a capsule containing a radiation source and an arrangement with the radiation source mounted thereon. The arrangement is configured to selectively allow emission of radiation from the radiation source. A blocking arrangement is configured to selectively block emission of radian from the radiation source. In a rest position, the emission of radiation from the arrangement is blocked. A movement arrangement configured to move the blocking arrangement relative to the arrangement. A controller operates the radiation source and the blocking arrangement. An activation coil is electrically coupled with the controller and has an initial configuration without current flow. An external activating coil receives the imaging capsule and is operable to inductively induce current flow in the activation coil within the capsule.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/802,377, having a filing date of 15 Mar. 2013, which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to imaging capsules and, more specifically, to activation of imaging capsules with alternating current. 
       BACKGROUND 
       [0003]    One method for examining the gastrointestinal tract for the existence of polyps and other clinically relevant features that may indicate regarding the potential of cancer is performed by swallowing an imaging capsule that will travel through the tract and view the patient&#39;s situation. In a typical case the trip can take between 24-48 hours, after which the imaging capsule exits in the patient&#39;s feces. Typically the patient swallows a contrast agent to enhance the imaging ability of the imaging capsule. Then the patient swallows the imaging capsule to examine the gastrointestinal tract while flowing through the contrast agent. The imaging capsule typically includes a radiation source, for example including a radioisotope that emits X-rays or Gamma rays. The radiation is typically collimated to allow it to be controllably directed toward a specific area during the imaging process. In an exemplary case the imaging capsule is designed to measure Compton back-scattering and transmits the measurements (e.g. count rate) to an external analysis device, for example a computer or other dedicated instruments. 
         [0004]    In a typical implementation a radio-opaque contrast agent is used so that a position with a polyp will have less contrast agent and will measure a larger back-scattering count. Alternatively, other methods may be used to image the gastrointestinal tract. 
         [0005]    U.S. patent application Ser. No. 7,787,926 to Kimchy, the disclosure of which is incorporated herein by reference, describes details related to the manufacture and use of such an imaging capsule. 
         [0006]    Use of an imaging capsule requires a power source to be connected to the capsule electronics to supply power to the electronics for operation. If the capsule is stored prior to use with the capsule electronics in an active condition, the electronics may draw power from the batteries and/or experience current leakage. If the power source were to fail, the imaging capsule can malfunction in various ways. For example, if the capsule includes an actuatable shutter for blocking radiation when such radiation is not desired, radiation may be emitted without constraint causing potential harm to the patient. 
         [0007]    If the imaging capsule is equipped with an internal switch for activating the capsule electronics, such activation may require access to an interior of the capsule. Such a breach of the capsule could leave the capsule in an unsealed, vulnerable condition for use by a patient. 
         [0008]    It may thus be desirable to provide an activation apparatus and method that allow the capsule electronics to be connected to the batteries and remain with no power and no current leakage in a sealed shell while the capsule is in storage and enable activation of the electronics without breaching the capsule shell, thus leaving it sealed. 
       SUMMARY OF THE INVENTION 
       [0009]    This disclosure concerns the description of activation mechanisms for activating the electronic circuits of an imaging capsule. The capsule is designed to be swallowed by the patient and travels through the Gastro Intestinal tract. An example of such a concealment mechanism is described in U.S. patent application Ser. No. 10/596,065, filed on May 26, 2006, now U.S. Pat. No. 7,787,926, titled Intra Lumen Imaging Capsule, and PCT Publication No. WO 2012/035528, titled Fail-safe Radiation Concealment Mechanism, the disclosures of which are incorporated herein by reference. 
         [0010]    The concealment mechanism is designed with shutters that are normally closed, effectively stopping the emitted radiation from the radiation source within the capsule to exit the capsule, thus reducing the exposure of the patient to ionizing radiation. 
         [0011]    When the radiation is emitted and the collimator is moving and scanning, detectors (13) in  FIGS. 1-4  detect X-ray Fluorescence and Compton scattering photons which are used for 3D imaging within the colon as described in U.S. Pat. No. 7,787,926. 
         [0012]    The described mechanisms open the shutters only when the capsule requires these photons (or beta electrons) for imaging the internal lumen of the gastro intestinal tract. 
         [0013]    According to various aspects of the disclosure, an imaging capsule activating system includes a capsule containing a radiation source, and an arrangement with the radiation source mounted thereon. The arrangement is configured to selectively allow emission of radiation from the radiation source. A blocking arrangement is configured to selectively block emission of radian from the radiation source. In a rest position, the emission of radiation from the arrangement is blocked. A movement arrangement configured to move the blocking arrangement relative to the arrangement. A controller operates the radiation source and the blocking arrangement. An activation coil is electrically coupled with the controller and has an initial configuration without current flow. An external activating coil receives the imaging capsule and is operable to inductively induce current flow in the activation coil within the capsule. 
         [0014]    In accordance with the disclosure, a method of activating an imaging capsule includes providing a capsule similar to that described above, disposing the imaging capsule in an open external activating coil, and operating the external activating coil to inductively induce current flow in the activation coil with the capsule. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present disclosure will be understood and better appreciated from the following detailed description taken in conjunction with the drawings. Identical structures, elements or parts, which appear in more than one figure, are generally labeled with the same or similar number in all the figures in which they appear, wherein: 
           [0016]      FIG. 1A  is a schematic illustration of an exemplary screening system in accordance with various aspects of the disclosure; 
           [0017]      FIG. 1B  is a schematic illustration of an exemplary external data-recording unit of the system of  FIG. 1A  in accordance with various aspects of the disclosure; 
           [0018]      FIG. 2  is an illustration of an exemplary fail-safe imaging capsule according to various aspects of the disclosure; 
           [0019]      FIG. 3  is an illustration of a capsule with an external activating coil according to various aspects of the disclosure; 
           [0020]      FIG. 4  is an illustration of a capsule being activated by an external activating coil according to various aspects of the disclosure; and 
           [0021]      FIG. 5  is a schematic illustration of an electronic activating circuit in the capsule according to various aspects of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, corresponding or similar reference numbers will be used, when possible, throughout the drawings to refer to the same or corresponding parts. 
         [0023]    Reference is made to  FIG. 1A , which is a schematic illustration of a screening system  141 , in accordance with various aspects of the disclosure. The system  141  typically comprises an ingestible capsule  150  and an external data-recording unit  152 . For some applications, the data-recording unit  152  ( FIG. 1B ) may be worn on the waist of a subject  154  (as shown in  FIG. 1A ) or elsewhere on the subject&#39;s body, such as the wrist (configuration not shown), etc. Alternatively, for some applications, the capsule  150  may comprise an internal data-recording unit, and the external data-recording unit  152  may not be provided. In these applications, the data recorded by the capsule  150  is retrieved after the capsule has been expelled from the body. 
         [0024]    During a typical screening procedure using system  141 , an oral contrast agent  170  is administered to subject  154 . Contrast agent  170  is typically adapted to pass through a gastrointestinal (GI) tract  172  and be expelled with the feces, substantially without being absorbed into the blood stream. The contrast agent material may be similar to compounds used routinely for the study of the GI with X-rays, such as Barium sulfate liquid concentrate, iodine-based compounds, or other such materials. For some applications, additional appropriate contrast agents include Tantalum, Gadolinium, Thorium, Bismuth, and compounds of these materials. After the contrast agent is administered (e.g., several hours after the contrast agent is administered), subject  154  swallows capsule  150 . 
         [0025]    Capsule  150  travels through GI tract  172 , emitting gamma and/or X-ray radiation. Beginning at a certain point in time, capsule  150  records the Compton scattered gamma and/or X-ray photons that strike one or more radiation detectors  162  ( FIG. 2 ). The count rate information received from each of the radiation detectors is typically stored together with a time stamp for that measurement. Within a time period typically of less than one second (e.g., several tens to several hundred milliseconds), it is assumed that the capsule and the surrounding colon wall and the contrast agent are in quasi-steady state. Taking small enough time intervals and integrating the counts over the small intervals allows for this quasi-steady-state assumption. The data may be stored in the capsule and sent by the capsule to the external recording unit from time to time, or after data-gathering has been completed. 
         [0026]    Reference is now made to  FIG. 1B , which is a schematic illustration of the external data-recording unit  152 , in accordance with an exemplary embodiment of the present disclosure. The data-recording unit  152  may comprise a receiver/memory unit  155 , a support electronics/battery unit  156 , an antenna  157 , and/or user controls  158 . In some aspects, the unit  152  may also include a strap  159 , such as a belt or wrist/arm strap, for coupling the unit to the subject  154 . 
         [0027]    Reference is now made to  FIG. 2 , which is a schematic illustration of a perspective view of an exemplary failsafe imaging capsule  100 , according to various aspects of the disclosure. Various embodiments of failsafe imaging capsules are illustrated and described in U.S. patent application Ser. No. 13/821,999 (U.S. Patent Application Publication No. 2013/0172740), filed Mar. 11, 2013, U.S. patent application Ser. No. 13/895,345 (U.S. Patent Application Publication No. 2014/0037069), filed May 15, 2013, and U.S. Provisional Patent Application No. 61/___,___, filed on ______, entitled “LINEAR FAIL SAFE RADIATION CONCEALMENT MECHANISM” by Yoav Kimchy, all of which are incorporated herein by reference. 
         [0028]    In an exemplary embodiment of the invention, a patient first swallows a contrast agent which mixes with the content of their gastrointestinal tract to increase the accuracy of the measurements. Then the patient swallows imaging capsule  100  to examine the gastrointestinal tract as imaging capsule  100  proceeds through the gastrointestinal tract. In an exemplary embodiment of the invention, imaging capsule  100  is designed to automatically block radiation from being emitted from it until receiving instructions to release radiation and image its surroundings. In an exemplary embodiment of the invention, no power is required to prevent blocking emission of radiation. Thus, if imaging capsule  100  lacks power the radiation will be blocked. 
         [0029]    In an exemplary embodiment of the invention, imaging capsule  100  includes an encasement  105  for holding and protecting the elements of the device from acids and other liquids or gases along its path of motion. Optionally, the encasement should be able to withstand external pressures for at least 50-100 hours to allow for imaging capsule  100  to traverse the gastrointestinal tract and exit while still intact. Inside encasement  105 , imaging device  100  includes a power source  180  (e.g. one or more batteries), a motor  185 , a radiation source  110 , a detector  195 , a transceiver  135 , and a controller  199 . The controller  199  may be programmed with instructions for operating all the capsule functions, including operation of the transceiver  135 . In an exemplary embodiment of the invention, radiation source  110  is located on a rotatable disk  145  and provides radiation that is blocked by a filling material  130  that forms the disk (e.g. made of lead or tungsten or other dense materials). Optionally, the radiation is only free to travel in a few specific directions through collimators  120 . 
         [0030]    In an exemplary embodiment of the invention, power source  180  provides power to motor  185 , motor  185  is configured to rotate disk  145  around a rotation axis  125  with radiation source  110  and collimators  120  mounted on disk  145 . In some embodiments, the collimator may be non-rotating, and the motor may be configured to move an arrangement linearly to block/unblock beams emitted from the radiation source and/or non-rotating collimator. 
         [0031]    Optionally, one or more directed radiation beams are emitted from collimators  120  controllably scanning the surroundings through imaging capsule  100 . Optionally, detector  195  detects backscattered particles resulting from the directed radiation beam. In an exemplary embodiment of the invention, detector  195  counts the detected particles and provides the information to transceiver  135  for transmission to an external device (e.g. a computer) for processing and optionally constructing a visual representation of the information. In some embodiments of the invention, transceiver  135  uses radio frequency (RF) transmissions to receive instructions from an external device and to provide information to the external device. Optionally, the external device may instruct imaging capsule  100  to start scanning, to stop scanning, and/or to scan in a specific motion pattern or at specific times. 
         [0032]    It should be appreciated that the radiation source  110  may be adapted to emit gamma rays, X-rays, and/or beta electrons (i.e., radiation having energy of at least 10 keV). For some applications, the radiation source  110  may comprise a radioisotope or a miniature radiation generator. In some aspects of the disclosure, radiation source  110  may comprise a miniature X-ray generator, such as those described in one or more of the following references: U.S. Pat. Nos. 6,134,300 and 6,353,658 to Trebes et al.; Haga, A. et al., “A miniature x-ray tube,” Applied Physics Letters 84(12):2208-2210 (2004); and Gutman, G. et al., “A novel needle-based miniature x-ray generating system,” Phys Med Biol 49:4677-4688 (2004). Such a miniature X-ray generator or X-ray tube may be used for radiation source  110  instead of a radioisotope to illuminate the colon contents with X-ray photons. Turning such a generator on and off as needed typically reduces exposure of the subject to radiation. In addition, the energy range can be better controlled and the flux may be higher for the on periods without increasing subject total exposure. It should be appreciated that the capsule  100  may include more than one radiation source  110 . According to various aspects, the capsule  100  may comprise one or more gamma and/or X-ray radiation sources and/or sources of beta electrons, such as T1201, Xe133, Hg197, Yb169, Ga67, Tc99,Tc99m, In111, I131 or Pd100. 
         [0033]    Referring now to  FIG. 3 , according to various aspects, a capsule activation system  302  includes the capsule  100  and an external activating coil  3 . The capsule  100  may contain an activation coil  2  within the capsule  100 . For purposed of clarity, the capsule  100  is shown in  FIG. 3  with its other components removed. The external activating coil  3  may be electrically coupled with an alternating current source  4  via a switch  5 . The switch  5  can be operable to provide electric current from the alternating current source  4  to the external activating coil  3  when desired. The external activating coil  3  is an open coil configured to receive the capsule  100 . 
         [0034]      FIG. 4  illustrates activation of the activation coil  2  within the capsule  100 . As shown, the capsule  100  is placed in the open external activating coil  3 . The switch  5  is closed such that current is permitted to flow from the alternating current source  4  through the external coil  3 . The flow of current through the external coil  3  inductively induces current flow through the activation coil  2  within the capsule  100 . 
         [0035]    Referring now to  FIG. 5 , the current induced inside the capsule  100  via the external activating coil  3  is rectified and drives a load switch  6 , such as, for example, switch TPS22913 from Texas Instruments. The load switch  6 , in turn, drives current to the capsule controller  199 . The controller  199  includes an embedded switch which, in turn, latches the port connected to the load switch  6  to keep the load switch  6  in on state even after the capsule  100  is removed from the external activating coil  3 . 
         [0036]    Once the load switch  6  is on and the controller  199  is on, the embedded switch in the capsule controller  199  activates all the capsule functions, including operation of the RF transceiver  135 , which can then be used to send and receive messages and instructions to and from the capsule  100 . 
         [0037]    From the foregoing, it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications or variations may be made without deviating from the spirit or scope of inventive features claimed herein. Other embodiments will be apparent to those skilled in the art from consideration of the specification and figures and practice of the arrangements disclosed herein. It is intended that the specification and disclosed examples be considered as exemplary only, with a true inventive scope and spirit being indicated by the following claims and their equivalents.