Abstract:
According to exemplary embodiments of the present disclosure, apparatus, device and method can be provided which can provide imaging of biological tissues, e.g., luminal organs in vivo, using optical techniques in an automatic or semiautomatic manner. The exemplary apparatus, device and method can utilize a tethered capsule catheter with a mechanism for manual, semi-automatic or automatic traversing in the luminal organ with a controlled velocity and/or image quality. The exemplary apparatus can include feedback information about tension applied to the catheter during its movement that can be used to adjust velocity and assure patient comfort and safety for example during passing through natural sphincters and/or narrowing of the luminal organs and preventing from breaking of the catheter. The exemplary apparatus can also adjust velocity in order to provide good quality of acquired images, for example to engaged peristalsis and provide contact with the tissue. In one exemplary embodiment of the present disclosure, the exemplary mechanism for a controlled advancement of the catheter can be positioned outside of the patient&#39;s mouth, and can include a position sensor providing information about the position of the capsule in respect to the luminal organ for orientation of the acquired data.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    The present application relates to and claims priority from U.S. Provisional Patent Application Ser. No. 61/934,298 filed Jan. 31, 2014, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates to catheters, and more specifically to exemplary embodiments of apparatus, systems and methods which facilitate manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device. 
       BACKGROUND INFORMATION 
       [0003]    Catheters have been utilized in the past to obtain information regarding tissue sample within and/or externally from a body structure. A number of catheters have been produced, including capsule catheters, including those which are tethered. However, controlled motion of such capsule catheters may not have been easily effectuated. 
         [0004]    Accordingly, there may be a need to address and/or overcome at least some of the above-described issues and/or deficiencies. 
       SUMMARY OF EXEMPLARY EMBODIMENT(S) 
       [0005]    Exemplary embodiments of apparatus, systems and methods according to the present disclosure can be provided to facilitate manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device. 
         [0006]    In one exemplary embodiment, apparatus, device and method can be provided which can facilitate imaging of biological tissues, e.g., luminal organs in vivo, using optical techniques in an automatic, semiautomatic and/or manual manner. The exemplary apparatus, device and method can utilize a tethered capsule catheter with a mechanism for manual, semi-automatic or automatic traversing in the luminal organ with a controlled velocity and/or image quality. The exemplary apparatus can include feedback information about tension applied to the catheter during its movement that can be used to adjust velocity and assure patient comfort and safety for example during passing through natural sphincters and/or narrowing of the luminal organs and preventing from breaking of the catheter. The exemplary apparatus can also adjust velocity in order to provide good quality of acquired images, for example to engaged peristalsis and provide contact with the tissue. In one exemplary embodiment of the present disclosure, the exemplary mechanism for a controlled advancement of the catheter can be positioned outside of the patient&#39;s mouth, and can include a position sensor providing information about the position of the capsule in respect to the luminal organ for orientation of the acquired data. 
         [0007]    To that end, exemplary apparatus and method for determining a force on at least one section thereof within at least one anatomical structure can be provided. For example, using a catheter first arrangement, it is possible to obtain image data regarding (i) at least one first portion of the anatomical structure(s) and/or (ii) at least one second portion of the first arrangement, when the first arrangement is inserted within the anatomical structure(s). Further, using, e.g., a force measurement second arrangement, it is possible to determine the force on the section(s) of the apparatus using the image data. According to a further exemplary embodiment of the present disclosure, the image data can include information that can be a difference information between a surface of the first portion and a surface of the second portion. In addition or alternatively, the image data can include information solely regarding the second portion. 
         [0008]    In another exemplary embodiment of the present disclosure, a position control arrangement can be utilized to provide an adjustable control of the position of the first arrangement using the determined force. The position control arrangement can include a plurality of rollers. The control of the first arrangement can be performed via a control of an operator based on the determined force, and/or automatically using a computer based on the determined force. 
         [0009]    The determined force can include a pressure on the section of the first arrangement. It is possible to use a computer which can be specifically programmed and/or modified to effectuate a control of a position of the first arrangement, where the first arrangement can includes a capsule and a tether which can be connected to the capsule. The control of the tether by the computer can be controlled using the determined force. The second arrangement can determine the force by analyzing a strain on or of the tether. According to still another exemplary embodiment of the present disclosure, the first arrangement can include a capsule and a fiber which is connected to the capsule. The second arrangement can be used to determine the force by analyzing a strain on or of the fiber. 
         [0010]    In addition or alternatively, the image data can be obtained using an interferometric configuration. The second arrangement can utilize the interformetric configuration to determine a strain on the second portion so as to determine the force. A position sensor arrangement can be connected to the first arrangement and configured to provide further data indicative of a position of the first arrangement within the anatomical structure(s). A position control arrangement can be provided that is configured to provide an adjustable control of the first arrangement using the determined force and the further data. The second arrangement can include a computer which can be configured to reconstruct at least one image of the first portion based on the further data. The position sensor arrangement can includes an array of position sensors. The first arrangement can include a capsule and a tether which is connected to the capsule, and the sensors can be connected along a length of the tether at predetermined locations. The position control arrangement can be or include a pullback arrangement which can be configured to provide a pullback of the position of the first arrangement using the determined force. 
         [0011]    These and other objects, features and advantages of the present disclosure will become apparent upon reading the following detailed description of embodiments of the disclosure, and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Further objects, features and advantages of the present disclosure will become apparent from the following detailed description taken in conjunction with the accompanying drawings showing illustrative embodiment of the present disclosure, in which: 
           [0013]      FIG. 1  is a diagram of an imaging system according to an exemplary embodiment of the present disclosure, which can include a tethered capsule catheter with an automatic pullback mechanism and position sensor; 
           [0014]      FIG. 2  is a set of illustrations for exemplary data from a human esophagus acquired with tethered capsule and imaged with an optical frequency domain system according to an exemplary embodiment of the present disclosure showing change(s) in the acquired data when the external tension on the capsule is applied by a lower esophageal sphincter; 
           [0015]      FIG. 3  is a set of illustrations for exemplary data from a human esophagus acquired with tethered capsule and imaged with the optical frequency domain system according to an exemplary embodiment of the present disclosure showing influence of the tissue contact on the quality of images; 
           [0016]      FIG. 4A  is a flow diagram of an exemplary method with a feedback loop for the device velocity based on tension and image quality according to an exemplary embodiment of the present disclosure; 
           [0017]      FIG. 5A  is a cross-sectional illustration of a human esophagus for providing a calibration of the system according to an exemplary embodiment of the present disclosure; 
           [0018]      FIG. 5B  is a cross-sectional illustration of exemplary data from a human esophagus acquired with the tethered capsule arrangement according to an exemplary embodiment of the present disclosure, and imaged with the exemplary optical frequency domain system according to an exemplary embodiment of the present disclosure provide when both a capsule contour and a surface contour are within the tolerance of the tension and contact, respectively; 
           [0019]      FIG. 5C  is a cross-sectional illustration of exemplary data from the human esophagus acquired with the exemplary tethered capsule arrangement according to an exemplary embodiment of the present disclosure, and imaged with the optical frequency domain system according to an exemplary embodiment of the present disclosure when the capsule contour is larger than tension tolerance, whereas the surface contour is within the contact tolerance; 
           [0020]      FIG. 5D  is a cross-sectional illustration of exemplary data from the human esophagus acquired with the exemplary tethered capsule arrangement, and imaged with the exemplary optical frequency domain system a cross-sectional illustration when the capsule contour is smaller than the tension tolerance, whereas more than 50% of the surface contour is outside of the contact tolerance; 
           [0021]      FIG. 6A  is a diagram of the imaging system according to another exemplary embodiment of the present disclosure, which can include the tethered capsule catheter with a pullback or push forward effectuated by rollers; 
           [0022]      FIG. 6B  is a diagram of the imaging system according to still another exemplary embodiment of the present disclosure, which can include the tethered capsule catheter with the pullback or the push forward effectuated by a threaded arrangement; and 
           [0023]      FIGS. 7A and 7B  are diagrams of different exemplary configurations of the imaging system according to still a further exemplary embodiment of the present disclosure, which can include the tethered capsule catheter and including a position information arrangement. 
       
    
    
       [0024]    Throughout the drawings, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components, or portions of the illustrated embodiments. Moreover, while the present disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments and is not limited by the particular embodiments illustrated in the figures and provided in amended claims. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0025]      FIG. 1  shows a block diagram of an optical imaging capsule catheter system/apparatus according to an exemplary embodiment of the present disclosure. This exemplary apparatus can include, e.g., a microstructural imaging system  110  and an optical imaging catheter including a tether  100 , a capsule  120  and an automatic pullback mechanism  140  (which can also effectuate a push forward) mounted outside of an imaged organ or structure  180 . Exemplary The microstructural imaging system  110  can utilize at least one of the following modalities and/or configurations optical frequency domain imaging, optical coherence tomography, spectral domain OCT, confocal microscopy, spectrally-encoded confocal microscopy, two photon microscope, second harmonic microscopy, third harmonic microscope, CARS, stimulated Raman microscopy, etc. For example, such exemplary imaging system  110  can detect an electro-magnetic radiation (e.g., remitted light) from any object or tissue surrounding the capsule  120  to acquire and/or determine information regarding microstructures on or in the object or tissue. The pullback mechanism  140  can be mounted on the tether, handheld, mounted to a headset/mouthguard/chinrest, or attached to the imaging system  110 . Information regarding the pullback (or the push forward) velocity can complement and/or be used with information about the orientation of the capsule  120  in the esophagus by adding a position sensing mechanism inside of the base of the capsule  160  and/or its tip  170 . Such exemplary mechanism can be also mounted behind the proximal end of the capsule  150  and/or outside  180  of a human subject. The exemplary mechanism can be based on marks on the tether, mechanical surface contact with a roller/encoder, speckle correlation or image correlation using acquired optical images or images from additional camera, by adding accelerometer and/or gyroscope based sensor, pressure sensor, temperature sensor, magnetic sensors, pH sensor etc. The exemplary mechanism can include a functional segmentation of the tether, proximal to the tether relaying additional physiological or localization measurements. The exemplary mechanism may include modules within or attached to the distal tip of the capsule to take measurements distal to the capsule. 
         [0026]    When moving from manual operation of the exemplary catheter to the automatic mode the main challenge is to maintain patient comfort during pulling the capsule up the esophagus and passing lower and upper sphincter. It is important to adjust the capsule velocity whenever the patient feels discomfort, e.g. when the esophagus strongly collapses on the capsule preventing it from moving, which will apply tension to the catheter.  FIG. 2  shows a set of illustrations providing exemplary results from imaging human esophagus using a tethered capsule catheter with the optical frequency domain imaging systems according to an exemplary embodiment of the present disclosure. In such exemplary case, the capsule  160  was pulled using the tether from the stomach  230 , through lower esophageal sphincter  240  and 20 cm, up the esophagus  250 . While the capsule  160  was moving up the esophagus, a side-viewing optics enclosed inside of the capsule was rotated providing exemplary circumferential cross-sectional images  202 ,  204 ,  206  of the tissue surrounding the capsule. After a collection of the images from the full capsule pullback, a longitudinal cross sectional image  200  through the whole dataset can be obtained. Each horizontal line in the image  200 , e.g., starting from the center and moving to the sides shows cross-section through an inner capsule wall  210 , an outer capsule wall  220  and the tissue  260 . The circumferential image  202  can correspond to a start point of data collection in the stomach  230 . 
         [0027]    When the capsule  160  is being pulled up it passes lower esophageal sphincter  240  where the sphincter muscles apply external pressure on the capsule  160  preventing its motion up the esophagus  250 . This exemplary pressure can cause the whole catheter to stretch for a distance of less than few millimeters, which can be visible on the circumferential  204  and longitudinal  200  images as artificial increase of capsule diameter  215 . The inner diameter  210  of the capsule imaged by an exemplary interferometric technique can be viewed as artificially extended with the amount of tension, due to a stretching and elongating of the fiber in the catheter in respect to the reference arm. This can be quantified by real-time processing of the image*=s (e.g., based on segmentation) of the inner  210  and/or outer  220  wall of the capsule  280 , and comparing it to the calibrated diameter without any tension  290 . Additionally the maximum tension tolerance  295  can be established for safety during the procedure. This information can be used as, e.g., an immediate feedback to the automatic pullback (or push forward) mechanism or capsule operator performing procedure to slow down while passing the sphincters or any other narrower areas of any lumen. Configuration can improve a comfort of the patient, and protect the catheter from breaking, due to excessive force and stretching. Such information about the tension  280  can be acquired during the procedure and used for assessment of the tension force from passage resistance, which in case of lower esophageal sphincter for example could be used for monitoring and diagnosing of gastro esophageal reflux disease. 
         [0028]    It can be important for the automatic pullback (or an automatic push forward) to obtain good quality data from the whole imaged organ or part(s) thereof.  FIG. 3  shows another longitudinal cross sectional image  300  obtained in a human subject. In this exemplary case shown in  FIG. 3  the capsule  160  was pulled using the tether from the stomach  330 , through a lower esophageal sphincter  340  and about 20 cm up the esophagus  350 . During the length of the pull-back the tissue position in respect to t the capsule  160  was changing. Each horizontal line in the image  300 , starting from the center and moving to the sides shows cross-section through an inner capsule wall  310 , an outer capsule wall  320  and the tissue  360 . The tissue surface  380  can be delineated (e.g. using segmentation) to emphasize the tissue contact profile changes over the whole dataset. If the exemplary technology used for tissue imaging has limited imaging range, for example because of the optical or data acquisition performance, a tissue profile tolerance  390  can be established, which can be in the fixed distance  395  from the inner capsule wall  310  and the outer capsule wall  320 . Frame  302  shows an example of a severe loss of a contact where more than 50% of the tissue&#39;s surface profile is outside the tissue contact tolerance ring  390 , which means that the image quality can be compromised and some information about the tissue will be missing. Frame  304  on the other hand represents good contact with the tissue where almost 100% of the tissue&#39;s surface profile is inside a tissue contact tolerance ring  390 , providing best quality and comprehensive image. A moderate contact frame  306  can indicate the situation in which more than 50% of the tissue&#39;s surface profile is inside the tissue contact tolerance ring  390 , providing reasonably comprehensive image. In some cases of imaging of luminal organs in GI tract, the contact between the capsule  160  and the tissue can be provided using a natural peristalsis by having a subject to dry swallow or sip water. 
         [0029]    Based on the real-time processing of the acquired data and the calibration of the imaging range of the system according to an exemplary embodiment of the present disclosure, an automatic feedback (or push forward) can be provided to the automatic pullback (or push forward) mechanism or the operator may stop when the contact with the tissue is not sufficient. The exemplary mechanism can be further optimized for the percentage of the tissue in contact and number of consecutive frames without contact before the warning sound signal. Further, a display on the screen or automatic change of velocity can be generated. This exemplary information about loss of contact and response of the organ to swallowing  380  can be acquired during the exemplary procedure, and used for an assessment of the peristalsis and dynamics of the gastrointestinal tract, similar to exemplary results obtained from motility measurements. 
         [0030]      FIG. 4  shows a method according to an exemplary embodiment of the present disclosure for utilizing the exemplary system for controlled pullback velocity based on the tension and tissue contact feedback. After calibration (block  405 ) of the exemplary system outside of the patient, the tension tolerance  400  and contact tolerance  410  can be established. After the capsule  160  is swallowed by the patient, the imaging procedure can begin, and the capsule  160  is traversing in the GI tract either using automatic system, or operator control with automated measurement. In both cases, the capsule  160  can travel with some velocity V (block  430 ). The tissue images can be acquired (block  417 ) and processed in real time (block  419 ) to provide a capsule wall contour  420  and a tissue surface contour  430 , which can be compared with tension tolerance  400  and contact tolerance  410 , respectively (block  419 ). If any of the signals is out of the tolerance, the feedback is provided to decrease the velocity or completely stop the capsule (blocks  450 ,  455 ). The loop can be performed multiple times, and when the tolerance is regained the pullback can be continued (block  460 ). The exemplary system can be optimized for a number of the iterations of the feedback loop before the automatic system switches to manual mode for example. 
         [0031]      FIG. 5A  shows a cross-section of a human esophagus for providing certain parameters for a calibration of the system according to an exemplary embodiment of the present disclosure. One of the possible ways can be to release the tension from the catheter before the procedure and image the capsule without any tissue surrounding it. The image can be processed to extract initial, no-tension capsule diameter  550 , based on that dimension establish the tension tolerance  500  and the tether length, which position at the image should be fixed for the whole study. Using initial capsule diameter  550  and imaging system specification, like imaging range  540  the contact tolerance  510  can be calculated. 
         [0032]      FIGS. 5B-5D  show respective cross-sections of exemplary data from the human esophagus acquired with the exemplary tethered capsule arrangement according to an exemplary embodiment of the present disclosure, and imaged with the optical frequency domain system according to an exemplary embodiment of the present disclosure. For example, as shown in  FIG. 5B , both feedback signals are provided within their tolerance, and the velocity of the capsule can be maintained. As shown in  FIG. 5C , the contact with the tissue can be perfect (e.g., 100% of the tissue surface contour  530  inside of the contact tolerance), although the capsule wall contour  520  is outside the tension tolerance  500  and the capsule should be stopped for safety and comfort reasons. Because the contact tolerance contour  510  is, e.g., always in fixed distance from the capsule wall contour  520 , it is in different position than provided in the illustrations of  FIGS. 5B and 5C . The reversed situation is illustrated in  FIG. 5D , where there is no tension at the tether but there is less than 50% contact with the tissue, and the capsule should be stopped to regain contact and provide best quality of acquired data. 
         [0033]    According to another exemplary embodiment of the present disclosure, feedback from catheter tension, tissue contact and capsule velocity can be used for optimal automatic volumetric imaging. For example, the exemplary automatic pullback (or push forward) configuration can utilize a translation stage in one exemplary embodiment of the present disclosure to pull and/or push the tether with controlled velocity. Such exemplary configuration can utilize a motor attached to the reel to coil the tether. In another exemplary embodiment shown in  FIG. 6A , the mechanisms can comprise one or more roller(s)  610 ,  615  which can include one or more driven wheels and/or one or more free rolling guide wheels. Either or both of the driven or rolling guide wheels may be fitted with and/or include an encoder. Wheel assemblies may be replaced for easy disinfection and reuse. Encoders may reside behind sealed optically translucent or magnetically conductive barriers to ease and/or simplify disinfection for reuse. The rolling guide wheel(s) of the roller(s)  610 ,  615  can also be used in manual mode for further, position/velocity sensing, and further controlled motion or in an automatic mode for a computer-controlled motion. The exemplary mechanism can have several modes of operation controlled by the operator, e.g. free motion, controlled speed  1 ,  2 ,  3 , etc., positional hold. According to still another exemplary of the present disclosure, an exemplary mechanism  650  shown at  FIG. 6B  may utilize and/or include a threaded tether with a rotating threaded collar  660 . For example, such threaded collar would rotate within in a handheld or system mounted stage to advance the capsule  120 . 
         [0034]    In addition to tension and tissue contact feedback (or push forward), it can be beneficial for both the human operator in the manual mode and the automatic pullback (or push forward) mechanism in an automatic mode to have information regarding the velocity of the capsule to provide an appropriate coverage of the organ or part(s) thereof. In one exemplary embodiment (see  FIG. 7A ), information about the velocity can be provided by an exemplary position sensing system  720 , which can comprise of and or be configured to implement a number of features and/or components (e.g., a sensor array, etc.) that can be directly or indirectly fixed to the tether  100 . In one example, the position sensing system  720  that is fixed to the tether  100  at about 50 mm or farther from the capsule  120  can have various shapes with beveled edges to prevent from scratching the tissue. In addition, or as an alternative, the component(s) of the position sensing system  720  can fully surround the tether  100  or be provided on one side of the tether  100 . 
         [0035]    In another exemplary embodiment (shown in  FIG. 7B ), exemplary component(s) of the position sensing system  720  can be located or situated in a flexible region  750  of the tether  100 , e.g., closer than about 50 mm to the capsule  120 . In this exemplary embodiment, the component(s) of the position sensing system  620  should facilitate a flexure of the flexible region  750  proximal to the capsule  120 , should have a diameter that is (e.g.,) at most the diameter of a centering element of the capsule  120 , and a length thereof should be (e.g.,) at most the rigid length of the flexible element  750 . In one exemplary embodiment, the position sensing system  720  and/or the flexible region  750  can comprise an array of sensors (e.g., pressure, temperature, pH, location sensors, etc.) or other optical, electronic and/or mechanical subsystem. 
         [0036]    Electrical and/or optical signals can be delivered to the exemplary component(s) of the position sensing system  720  wirelessly or with wires inside or outside of the tether  100 . The wires can be coiled along the length of the tether  100  to maintain its flexibility and bendability. The wires can also or alternatively be delivered in an additional lumen being a part of the tether  100  or being attached to it on the outside. Information from the position sensor can be collected by the imaging system  110  and/or used in post-processing for correct reconstruction of the imaging data. This exemplary information can be also utilized for real-time feedback to the catheter operator in manual mode and/or to the automatic pullback (or push forward) mechanism in the automatic mode for pull-back (or push forward) velocity adjustment to provide full coverage of the imaged organ. 
         [0037]    The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Indeed, the arrangements, systems and methods according to the exemplary embodiments of the present disclosure can be used with and/or implement any OCT system, OFDI system, SD-OCT system or other imaging systems, and for example with those described in International Patent Application PCT/US2004/029148, filed Sep. 8, 2004 which published as International Patent Publication No. WO 2005/047813 on May 26, 2005, U.S. patent application Ser. No. 11/266,779, filed Nov. 2, 2005 which published as U.S. Patent Publication No. 2006/0093276 on May 4, 2006, and U.S. patent application Ser. No. 10/501,276, filed Jul. 9, 2004 which published as U.S. Patent Publication No. 2005/0018201 on Jan. 27, 2005, and U.S. Patent Publication No. 2002/0122246, published on May 9, 2002, the disclosures of which are incorporated by reference herein in their entireties. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures which, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. In addition, all publications and references referred to above can be incorporated herein by reference in their entireties. It should be understood that the exemplary procedures described herein can be stored on any computer accessible medium, including a hard drive, RAM, ROM, removable disks, CD-ROM, memory sticks, etc., and executed by a processing arrangement and/or computing arrangement which can be and/or include a hardware processors, microprocessor, mini, macro, mainframe, etc., including a plurality and/or combination thereof. In addition, certain terms used in the present disclosure, including the specification, drawings and claims thereof, can be used synonymously in certain instances, including, but not limited to, e.g., data and information. It should be understood that, while these words, and/or other words that can be synonymous to one another, can be used synonymously herein, that there can be instances when such words can be intended to not be used synonymously. Further, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it can be explicitly being incorporated herein in its entirety. All publications referenced above can be incorporated herein by reference in their entireties.