Abstract:
An autonomous device that may include for example a camera, a transmitter for transmitting a signal from the camera and a storage compartment for retaining a substance in the device. A method of delivering a medicament to a patient including imaging a gastro intestinal tract with an autonomous device, identifying a target location in such tract, and releasing a medicament from the device at the target location.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. patent application Ser. No 09/807,892, filed on Jun. 6, 2001, now U.S. Pat. No. 6,950,690,which is a national phase application of International Application PCT/LL99/00554 filed Oct. 21, 1999, which in turn takes benefit from Israeli Patent Application 126727 filed on Oct. 22, 1998, all of which are incorporated by reference herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method for identifying a target location in the gastrointestinal tract and for direct delivery of a device to the identified location 
     BACKGROUND OF THE INVENTION 
     In the gastrointestinal tract, the stomach is connected, through the small intestine, a long tube that folds many times to fit inside the abdomen, to the large intestine. There are numerous pathologies of the gastrointestinal tract, such as lesions causing chronic gastrointestinal tract blood loss, which occurs in about 2% of US adults, malignancies, most of which give a poor prognosis, and bowel obstructions; simple, closed-loop, strangulated and incarcerated. Some of these pathologies, such as small intestinal tumors, are difficult to diagnose. Diagnostic methods of the small intestine are usually symptom related or invasive, such as barium enemas or surgery. New methods of diagnosis can lead to an earlier diagnosis and improved prognosis. 
     U.S. Pat. No. 5,604,531 describes an in viva video camera system which can image the gastrointestinal tract. Reference is now made to  FIG. 1 , which is a block diagram illustration of a prior art in vivo video camera system for imaging the gastrointestinal tract The in vivo video camera system typically comprises a swallowable capsule  10  for viewing inside the digestive system and for transmitting video data, a reception system  12  typically located outside a patient and a data processor  14  for processing the video data. The data processor  14  typically operates two monitors, a position monitor  16  on which the current location of the capsule  10  within the digestive system is displayed and an image monitor  18  on which the image currently viewed by the capsule  10  is displayed. 
     The reception system  12  can either be portable, in which case, the data it receives is temporarily stored in a storage unit  19 , prior to its processing in data processor  14 , or it can be stationary and close to the data processor  14 . 
     Reference is now made to  FIGS. 2 and 3  which are a schematic illustration of calculations performed by a prior art data processor for processing the video data obtained by the above in vivo video camera system.  FIG. 2  is a front view illustration of the patient  22  with an antenna array  30  wrapped around him. On it, four antennas  34   a - 34   d  are noted. Antennas  34   a  and  34   b  are located in a column at one side of the patient  22  and antennas  34   c  and  34   d  are located in a column at the other side of the patient  22 . 
     Since the strength of a signal received by any given antenna depends on its distance from and angle to the transmitter, the ratio of the signal strengths between any two antennas, which have the transmitter between them, is constant along a curve which intersects the location of the transmitter. Thus, antennas  34   a  and  34   b  define curve  30   a  and antennas  34   c  and  34   d  define curve  30   b.    
     The intersection of curves  30   a  and  30   b  is the location of the transmitter which is the location of the capsule  10 . The curves  30   a  and  30   b  are typically determined In a calibration step for a predefined number of constant values. 
     The designation of antennas  34   a - 34   d  depends on and is determined from the width L 1  of the patient  22 , which value is typically provided to data processor  14  (of  FIG. 1 ) Alternatively, there can be a plurality of antenna arrays  30 , one for each of a pre-defined number of widths L 1 . The antennas  34   a - 34   d  are then constant for each antenna array  30 . 
     The location of the capsule  10 , thus generated, is typically denoted by a two-dimensional vector P, having a length P and an angle □, from the center point O of an X-Y coordinate system. 
     The cross-sectional location (within an X-Z plane) of the capsule  10  can also be determined using a similar calculation to that illustrated in  FIG. 2 . A cross-section of the patient  22  is illustrated in  FIG. 3 . For this determination, four antennas  34   e - 34   h , which are opposite in a cross-sectional manner, are utilized. 
     Once again, the ratio of the signal strengths between two antennas, which have the transmitter between them, is constant along a curve which intersects the location of the transmitter. Thus, antennas  34   e  and  34   h  define curve  30   c  and antennas  34   f  and  34   g  define curve  30   d.    
     The location of the capsule  10  thus generated is typically denoted by a two-dimensional vector Q having a length Q and an angle □, from the center point O). 
     The two vectors P and Q are combined to determine the three-dimensional location of the capsule  10 . The location can be displayed two- or three-dimensionally on position monitor  16  (of  FIG. 1 ), typically, though not necessarily, as an overlay to a drawing of the digestive tract. 
     There exist methods for the delivery of medicament to a selected site in the gastrointestinal tract, such as the use of time delivery capsules made of material that dissolves in a particular environment and/or within a particular time period, within the gastrointestinal tract. In these methods, the delivery of medicament is dependent on the predictability of the particular environment to which the capsule is directed. 
     Controllable apparatuses for delivery of medicaments are described in U.S. Pat. Nos. 5,558,640 and 4,239,040 While using these apparatuses or capsules the delivery of medicament may be obstructed, such as by folds in the intestine. 
     These methods can not be relied upon for localized release of a medicament. 
     U.S. Pat. No. 5,279,607 describes a method of obtaining directional data from the passage of an ingestible radio signal transmitting capsule. This data is subsequently compared to directional data from a capsule carrying medicament passing through the alimentary canal, for remotely triggering the release of medicament at a calculated geometric location along the gastrointestinal tract. A location selected in this method, cannot be aligned with sites of interest, such as pathologies, since no diagnostic information, such as information relating to the pathology, can be obtained in this method. Furthermore, due to the constant peristaltic movement of the alimentary canal, the geometric location of a site is not the same in a first and second pass, so that this one parameter is only partially sufficient for selection of a site. 
     There exist no medicament delivering systems which combine diagnostic and therapeutic processes. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method for delivering a utility device to a target location in the gastrointestinal tract. The method combines identification of a target in the gastrointestinal tract and delivery of a utility device to the identified target location. The method of the present invention comprises the steps of: 
     a) generating a map of the gastrointestinal tract, employing a sensing and utility device for a first pass, or, optionally, a plurality of passes through the gastrointestinal tract; and 
     b) delivering the sensing and utility device to a target location identified on the map, using the sensing and utility device in a second pass or, optionally, a plurality of passes, through the gastrointestinal tract. The sensing and utility device used in the second pass, may be the same or different than the device used in the first pass. 
     The term “sensing and utility device”, in the present invention, refers to a device which is swallowable or placeable (such as described in IL patent application number 122716, assigned to the common assignees of the present invention and which is hereby incorporated by reference), and is capable of sensing selected parameters of the gastrointestinal tract. The device also comprises means for performing a job in the gastrointestinal tract. It is controllable and is capable of being monitored and of generating a map of the gastrointestinal tract. 
     The sensing and utility device may comprise, for example, any one or any combination of a video camera, which generates an image of the gastrointestinal tract, or sensing means, such as temperature, pressure or pH sensors or means for sensing the presence of blood, microorganisms, parasites or pathological indications or any objects alien to the gastrointestinal tract. 
     Means for performing a job may be any means suitable for researching, diagnosing or treating pathologies in the gastrointestinal tract, for example, fluid or cell sampling means, marker releasing means or medicament releasing means. 
     A map of the gastrointestinal tract may be generated by inserting the sensing and utility device into the gastrointestinal tract, monitoring the progress of the device through the gastrointestinal tract and optionally displaying the locations, two or three dimensionally, on a position monitor. 
     Monitoring the device is by periodically or repeatedly locating the device, preferably, as described in U.S. Pat. No. 5,604,531 assigned to the common assignees of the present invention. U.S. Pat. No. 5,604,531 is hereby incorporated by reference. 
     Delivering the sensing and utility device to a target location identified on the map comprises the steps of inserting the sensing and utility device into the gastrointestinal tract, in a second pass, receiving data from the device, either visual, from a video camera, or from the output of other sensing means, performing signal analysis of the data generated in the first pass and the data received from said sensing and utility device in the second pass; and controlling, such as by IR or telephony, the sensing and utility device according to the signal analysis. 
     The method of the present invention may be used for research, diagnostic or therapeutic purposes in the gastrointestinal tract. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: 
         FIG. 1  is a block diagram illustration of a prior art in vivo video camera system for imaging the gastrointestinal tract; 
         FIGS. 2 and 3  are schematic illustrations of calculations performed by a prior art data processor for processing the video data obtained by the in vivo video camera system for imaging the gastrointestinal tract, utilizing an antenna array, wherein  FIG. 3  is a top view illustration of the antenna array and  FIG. 2  is a cross-sectional illustration of the antenna array. 
         FIG. 4  is an illustration of a sensing and utility device according to a preferred embodiment of the invention; 
         FIG. 5A  is an illustration of a storage compartment, according to a preferred embodiment of the invention, in a recoiled position of the bi stable spring; 
         FIG. 5B  is an illustration of a storage compartment, according to a preferred embodiment of the invention, in an extended position of the bi stable spring; 
         FIG. 5C  is an enlargement of the storgae compartment tip, according to a preferred embodiment of the invention; 
         FIG. 6  is an illustration of a sensing and utility device operable according to a preferred embodiment of the invention; and 
         FIG. 7  is an illustration of a generated and displayed map in the method according to a preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The method of the present invention combines diagnostic and therapeutic processes. For example, the method combines identifying and localizing a pathology in the gastrointestinal tract with administrating treatment to the location of the pathology, by non invasive means. This combination is provided by employing a sensing and utility device which is inserted into the gastrointestinal tract, either by swallowing it or by placing it in the gastrointestinal tract. The above mentioned IL patent application 122716 describes a device for the placement of an autonomous capsule in the gastrointestinal tract, which bypasses the need for swallowing the capsule by the patent. 
     Reference is now made to  FIG. 4  which is an illustration of a sensing and utility device according to a preferred embodiment of the invention. The sensing and utility capsule shaped device, generally referenced  40 , typically comprises a light source  42 , a viewing window  44 , through which the light illuminates the inner portions of the digestive system, a camera system  46 , such as a charge-coupled device (CCD) or CMOS camera, which detects the images, an optical system  48  (typically comprising a mirror  47  and a focusing lens  47 ′) which focuses the images onto the CCD or CMOS camera system  46 , a transmitter  41 , which transmits the video signal of the CCD or CMOS camera system  46 , a power source  43 , such as a battery, which provides power to the entirety of electrical elements of the capsule and a storage compartment  45 , for the controllable discharge of medicaments or markers or for the controllable collection of fluid or cell samples from the environment, such as in a biopsy procedure. 
     The sensing and utility device can additionally include any known sensor element  49  such as temperature, pressure or pH sensors or means for sensing the presence of blood, microorganisms, parasites or pathological indications or any objects alien to the gastrointestinal tract. 
     Reference is now made to  FIGS. 5A ,  5 B and  5 C which are illustrations of a storage compartment, according to a preferred embodiment of the invention 
     Storage compartment  55  is located preferably at an end of the sensing and utility device, generally referenced  50 . The storage compartment is defined by an inflexible barrier  59  and the device shell. The storage compartment contains a pouch  56  made of flexible material which is encased by the device outer shell  52  and by a firm diaphragm  54  having an elasticity which will allow it to accommodate to a capsule shape. Diaphragm  54  is horizontally movable between the inflexible barrier  59  and the device tip. At the device tip there is an area  58 , in the outer shell of the device, which is permeable and which allows passage of substances from or into the pouch  56 . Permeability may be conferred, for instance by the area  58  being porous or sieve like. The pouch  56  is designed to retain substances such as releasable medicaments or markers or such as fluid or cell samples from the gastrointestinal tract environment. The pouch  56  bulk is determined by a bi stable spring  53 , preferably made of a memory shape metal such as TiNi. The spring  53  is attached, at one end to the solid barrier  59 , and at its other end, to the diaphragm  54 . The spring  53  may be made to extend (as shown in  FIG. 5B ) or recoil (as shown in  FIG. 5A ) by providing different temperatures, as known in the art (the means for providing different temperatures, such as conducting wires, are not shown). Thus, the pouch  56  bulk may be reversably increased or decreased. 
       FIG. 5A  illustrates a piercing pin  57  which is attached to the pouch wall and which protrudes into the pouch  56  inner space, in the direction of the opposing pouch wall  56 ′. For releasing a substance from pouch  56  into the gastroinestinal tract environment, spring  53  is made to extend, causing diaphragm  54  to move towards the device end, thrusting the piercing pin  57  into the opposing pouch wall  56 ′, rupturing it. A substance contained in the pouch  56  will be released into a space  51  provided between the opposing pouch wall  56 ′ and the outer shell permeable area  58 . The released substance may then pass through the openings in the permeable area  58  into the gastrointestinal tract. 
       FIG. 5B  illustrates a pouch  56  meant for collecting a sample from the gastrointestinal tract. In this embodiment the bi stable spring  53  is lodged in opposing pouch wall  56 ′. The spring  53  is made to recoil, pulling with it diaphragm  54  and piercing pin  57 , such that piercing pin  57  is dislodged from the opposing pouch wall  56 ′, rupturing it and leaving an opening in the pouch, through which substances from the environment are drawn into the pouch  56 . The opening in the pouch is sealed after the sample is drawn in from the environment, ensuring a fixed volume and sterility of the collected sample. 
     Pin  57  may be a hollow cylinder through which substances may pass to or from the gastrointestinal tract. 
       FIG. 5C  is an enlargement of the device end, through which substances are drawn into, or released from, the pouch. As can be seen in this figure, space  51  is provided, ensuring that the pin  57 , either before being dislodged from wall  56 ′ for collecting substances, or when piercing wall  56 ′ for release of substances, doesn&#39;t protrude further than the device shell  52  and injure the patient&#39;s insides. 
     Reference is now made to  FIGS. 6 and 7 .  FIG. 6  is an illustration of a sensing and utility device operable according to a preferred embodiment of the invention, and  FIG. 7  is an illustration of a map of the gastrointestinal tract generated in the method, according to a preferred embodiment of the invention. 
     Capsule  60  moves through the gastrointestinal tract  62  in a first pass to generate, by visual means, a map of the gastrointestinal tract and to identify, by visual means or other sensor means, a location of interest in the gastrointestinal tract. In its second pass, capsule  60  moves through the gastrointestinal tract and is controlled to perform a job at the identified location. 
     Recognition of the location, identified in the first pass, is done, in analyzing unit  65 , by analysis of the map generated in the first pass and bringing into conformity parameters, visual or others, obtained in the first pass and in the second pass. This may be acheived by any of the well known techniques of image matching by correlation, as done in image analysis, or any other suitable signal analysis techniques. 
     As the capsule  60  moves through the digestive system (gastrointestinal tract)  62 , in its first pass, it views the walls of the digestive system in the method described in  FIGS. 2 and 3  and in U.S. Pat. No. 5,604,531, and transmits the resultant images to a reception system  64  typically located outside a patient. The reception system  64  receives a multiplicity of versions of the images, each version received by a different antenna (described in  FIGS. 2 and 3 ) and either stores the received signals in the storage unit  68  or provides the received signals, directly, by IR or telephony, to the data processor  66 . The data processor  66  typically operates two monitors, a position monitor  63 , on which the current location of the capsule  60  within the digestive system is recorded, and, optionally, displayed and an image monitor  61 , on which the image currently viewed by the capsule  60  is displayed. 
     The reception system  64  can either be portable, in which case, the data it receives is temporarily stored in a storage unit  68  prior to its processing in data processor  66 , or it can be stationary and close to the data processor  66 . 
     The capsule  60  location can be displayed two- or three-dimensionally on position monitor  63 , typically, though not necessarily, as an overlay to a drawing of the digestive tract. The progress of capsule  60  is monitored by repeated or periodic localization of the capsule, and can be displayed on position monitor  63 . 
     A forward filming device can be distinguished from a backwards filming device by the flow direction of the image information relating to the direction of the device motion enables more precise localization of the storage compartment end of the device. Furthermore, analysis of the optical flow enables to calculate the device velocity in the gastrointestinal tract. 
     The repeated localizations generate a map of the route taken by the capsule in the gastrointestinal tract  62 . The generated map  70  is shown in  FIG. 7 . For maximum accuracy, images displayed on image monitor  61  are compared with the generated map  70  displayed on position monitor  63  to identify the location of a pathology  72 , though, a location may be identified by analysis of parameters other than visual (such as pH, temp, etc.), which were sensed during the first pass in the gastrointestinal tract. 
     Upon identifying the location of a pathology  72  on the gastrointestinal tract map  70 , either visually or by analysis of other sensor means input, capsule  60  is inserted into the gastrointestinal tract for a second pass. As capsule  60  moves through the digestive system  62 , in its second pass, it is monitored as above. When arriving at the location of the pathology  72 , or at any other point on map  70 , determined as the point for advantageously releasing medicament for the treatment of the pathology, the capsule  60  is controlled to release the medicament from the medicament storage compartment of the capsule ( 45  in  FIG. 4 ). The release of the medicament may be autonomous, automatically controlled by analyzing unit  65  or remotely controlled by an external operator. 
     It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather the scope of the invention is defined by the claims which follow: