Abstract:
The present invention relates to probe apparatuses and component combinations thereof that are used to recognize possibly abnormal living tissue using a detected early increase in microvascular blood supply and corresponding applications. In one embodiment there is disclosed an apparatus that emits broadband light obtained from a light source onto microvasculature of tissue disposed within a human body and receives interacted light that is obtained from interaction of the broadband light with the microvasculature for transmission to a receiver. Different further embodiments include combinations of optical fibers, polarizers and lenses that assist in the selection of a predetermined depth profile of interacted light. In another embodiment, a kit apparatus is described that has various probe tips and/or light transmission elements that provide for various combinations of predetermined depth profiles of interacted light. In a further embodiment, a method of making a spectral data probe for depth range detection selectivity for detection of blood within microvasculature of tissue is described.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/143,407 filed Jan. 8, 2009 entitled “Probe Apparatus for Recognizing Abnormal Tissue”, the entire contents of which is incorporated by reference herein. 
         [0002]    This application is related to co-pending U.S. patent application Ser. No. 11/604,653 filed Nov. 27, 2006, entitled “Method of Recognizing Abnormal Tissue Using the Detection of Early Increase in Microvascular Blood Content”, the disclosure of which is incorporated in its entirety by reference, which application claims priority to U.S. Application No. 60/801,947 entitled “Guide-To-Colonoscopy By Optical Detection Of Colonic Micro-Circulation And Applications Of Same”, which was filed on May 19, 2006, the contents of which are expressly incorporated by reference herein. 
         [0003]    This application is also related to co-pending U.S. patent application Ser. No. 11/604,659 filed Nov. 27, 2006 and entitled “Apparatus For Recognizing Abnormal Tissue Using The Detection Of Early Increase In Microvascular Blood Content,” the contents of which are expressly incorporated by reference herein. 
         [0004]    This application is also related to co-pending U.S. patent application Ser. No. 11/261,452 entitled “Multi-Dimensional Elastic Light Scattering”, filed Oct. 27, 2005, the contents of which are expressly incorporated herein by reference. 
         [0005]    Some references, which may include patents, patent applications and various publications, are cited and discussed in the description of this invention. The citation and/or discussion of such references is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the invention described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference. 
     
    
     FIELD OF THE INVENTIONS 
       [0006]    The present invention relates generally to light scattering and absorption, and in particular to probe apparatuses and component combinations thereof that are used to screen for possibly abnormal living tissue 
       BACKGROUND 
       [0007]    Optical probes are known that detect optical signals. Simple optical probes will transmit broadband or a laser light to a target with one optical fiber, and receive the light such as light that is elastically scattered from a specimen, fluorescent light, Raman scattered light, etc., with another optical fiber. The received backscattered light can be channeled to a receiver, such as a CCD array, and the spectrum of the signal is recorded therein. 
         [0008]    While such probes work sufficiently for their intended purposes, new observations in terms of the type of measurements that are required for diagnostic purposes have required further enhancements and improvements. 
       SUMMARY 
       [0009]    The present inventions relates generally to light scattering and absorption, and in particular to probe apparatuses and component combinations thereof that are used to recognize possibly abnormal living tissue. 
         [0010]    In one aspect, the embodiments described herein are directed toward an apparatus that emits broadband light obtained from a light source onto microvasculature of tissue, particularly in a mucosal tissue layer disposed within a human body, and receives interacted light that is obtained from interaction of the broadband light with the microvasculature for transmission to a receiver. 
         [0011]    In another aspect, the embodiments described herein are directed toward a apparatus that emits broadband light obtained from a light source onto tissue disposed within a human body, particularly in a mucosal tissue layer disposed within a human body, and receives interacted light that is obtained from interaction of the broadband light with the microarchitecture tissue for transmission to a receiver. 
         [0012]    In a particular aspect, a disposable, finger mounted optical probe is described. 
         [0013]    In a further embodiment, an optical probe that contains a disposable tip with a retractable integral probe is disclosed. 
         [0014]    Different further embodiments of both the disposable, finger mounted optical probe and the optical probe that contains the disposable tip with the retractable integral probe are described which include various combinations of optical fibers, polarizers and lenses that assist in the selection of a predetermined depth profile of interacted light for a variety of different wavelength ranges of light, and for different applications. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    These and other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures, wherein: 
           [0016]      FIGS. 1 and 2  illustrate a housing of a disposable, finger mounted optical probe according to one embodiment. 
           [0017]      FIG. 3  illustrates a disposable tip and re-usable trunk usable in one embodiment of the disposable, finger mounted optical probe. 
           [0018]      FIGS. 4(   a )-( b ) illustrate another embodiment of the disposable, finger mounted optical probe containing a pre-loaded optical assembly. 
           [0019]      FIGS. 5   a - 5   c  are illustrations of the method of use of the disposable, finger mounted optical probe. 
           [0020]      FIGS. 6A , B( 1 )-( 2 ) and C show usage of an embodiment of an optical probe that contains a permanent housing and disposable tip with retractable integral optical fibers. 
           [0021]      FIG. 7  illustrates a partial illustration of a particular embodiment of an optical probe that contains a permanent housing and a disposable tip assembly with a retractable integral optical fiber assembly. 
           [0022]      FIG. 8  illustrates a partial illustration of another particular embodiment of an optical probe that contains a permanent housing and disposable tip assembly with a retractable integral optical fiber assembly. 
           [0023]      FIG. 9  illustrates a particular embodiment of a disposable tip that includes a protective sheath that is used with the optical probe that contains a permanent housing and disposable tip assembly with a retractable integral optical fiber assembly. 
           [0024]      FIG. 10  illustrates a partial illustration of a further particular embodiment of an optical probe that contains a permanent housing and disposable tip assembly with a retractable integral optical fiber assembly and an integral CCD module. 
           [0025]      FIG. 11  illustrates a particular optical probe assembly configuration used for EIBS. 
           [0026]      FIG. 12  illustrates another particular optical probe assembly configuration used for EIBS. 
           [0027]      FIG. 13  illustrates a further particular optical probe assembly configuration used for EIBS. 
           [0028]      FIG. 14  illustrates in cross section an embodiment of optical fibers and polarizer usable in the optical probe assembly configurations illustrated in any of  FIGS. 11 ,  12 , and  13 . 
           [0029]      FIG. 15  illustrates in cross section a further embodiment of optical fibers and polarizer usable in the optical probe assembly configurations illustrated in any of  FIGS. 11 ,  12 , and  13 . 
           [0030]      FIG. 16  illustrates a particular optical probe assembly configuration used for LEBS. 
           [0031]      FIG. 17  illustrates another particular optical probe assembly configuration used for LEBS. 
           [0032]      FIG. 18  illustrates a further particular optical probe assembly configuration used for LEBS. 
           [0033]      FIG. 19  illustrates a further particular optical probe assembly configuration used for LEBS. 
           [0034]      FIG. 20  illustrates a further particular optical probe assembly configuration used for LEBS. 
           [0035]      FIGS. 21(   a ) and ( b ) illustrate in cross section an embodiment of optical fibers usable in the optical probe assembly configurations illustrated in any of  FIGS. 16-20 . 
           [0036]      FIG. 22  illustrates in cross section a further embodiment of optical fibers usable in the optical probe assembly configurations illustrated in any of  FIGS. 16-20 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    The present inventions are more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Various embodiments are now described in detail. Referring to the drawings, like numbers indicate like components throughout the views. As used in the description herein, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Moreover, titles or subtitles may be used in the specification for the convenience of a reader, which shall have no influence on the scope of the present invention. Additionally, some terms used in this specification are more specifically defined below. 
         [0038]    The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention, For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same thing can be said in more than one way. Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, not is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification. 
         [0039]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control. 
         [0040]    As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated. 
         [0041]    The present invention, in one aspect, relates to a probe apparatus that is used for optically screening a target for tumors or lesions. Various targets and corresponding optical probe types are disclosed, as well as various different probe housing designs are disclosed, and combination of them can be used interchangeably. Certain of the optical probe designs are for use in detecting what is referred to as “Early Increase in microvascular Blood Supply” (EIBS) that exists in tissues that are close to, but are not themselves, the lesion or tumor. Other of the LEBS (Low-coherence Enhanced Backscattering) optical probe designs are for use in detecting backscattered light that results from the interaction of low-coherent light with abnormal scattering structures in the microarchitecture of the tissue that exist in tissues that are close to, but are not themselves, the lesion or tumor. Both of these optical probe types, which have been described in applications previously filed and which are, as a result, known. As will be described herein, whether detection is made using the techniques associated with EIBS or LEBS probes and microarchitecture of the tissue, the probes as described herein, while normally made for usage with one of these techniques, will have aspects that are common between them. 
         [0042]    One difference between a probe that detects EIBS and an LEBS probe that detects tissue microarchitecture is that with an probe that detects EIBS, data from a plurality of depths can be obtained in one measurement by looking at co-pol and cross-pol and co-pol minus cross-pol received signals, whereas for an LEBS probe, only one depth is obtained for a specific configuration. 
         [0043]    A particular application described herein is for detection of such lesions in colonic mucosa in early colorectal cancer (“CRC”), but other applications such as pancreatic cancer screening are described as well. 
         [0044]    The target is a sample related to a living subject, particularly a human being. The sample is a part of the living subject, such that the sample is a biological sample, wherein the biological sample may have tissue developing a cancerous disease. 
         [0045]    The neoplastic disease is a process that leads to a tumor or lesion, wherein the tumor or lesion is an abnormal living tissue (either premalignant or cancerous), which for the probes described herein is typically a colon cancer, an adenomatous polyp of the colon, or other cancers. 
         [0046]    The measuring step is performed in vivo using the probes described herein and may further comprise the step of acquiring an image of the target. The image, obtained at the time of detection, can be used to later analyze the extent of the tumor, as well as its location. 
         [0047]    In the various embodiments, the probe projects a beam of light to a target that has tissues and/or blood circulation associated therewith, depending upon the target type. Light scattered from the target is then measured, and target information is obtained from the measured scattered light. The obtained target information can be information for the targets as described in the patent applications incorporated by reference above, as well as the data related to blood vessel size and oxygenated hemoglobin as described in U.S. patent application Ser. No. 12/350,955 filed Jan. 8, 2009 entitled “Method Of Screening For Cancer Using Parameters Obtained By The Detection Of Early Increase In Microvascular Blood Content” filed on this same day, bearing Attorney Docket Number 042652-0376943. 
         [0048]    The beam of light projected is obtained from a light source that may comprise an incoherent light source (such as a xenon lamp, light emitting diode, etc). 
         [0049]    In all of the embodiments described herein, there is at least one first type fiber comprises an illumination fiber, wherein the illumination fiber is optically coupled to the light source. 
         [0050]    There is also at least one second type fiber formed with one or more collection fibers, wherein the one or more collection fibers are optically coupled to a detector, such as an imaging spectrograph and a CCD at the distal end portion, which imaging spectrograph is used to obtain an image of the target and obtain detected data therefrom. 
         [0051]    The following further details of the preferred embodiments that will further describe the invention. Without intent to limit the scope of the invention, exemplary instruments, apparatus, methods and their related results according to the embodiments of the present invention are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the invention. Moreover, certain theories are proposed and disclosed herein; however, in no way they, whether they are right or wrong, should limit the scope of the invention so long as the invention is practiced according to the invention without regard for any particular theory or scheme of action. 
         [0052]    The optical probes described herein can be used in-vivo to take optical measurements of tissue, such as just inside the rectum to assess a patient&#39;s risk of colon cancer. If rectal, the rectally inserted probe for analysis of rectal mucosa provides a means of assessing a patient&#39;s risk of developing colon cancer without the need for colonoscopy or colon purging. 
         [0053]    In order to facilitate the acquisition of such a measurement, the probes described herein are necessarily introduced into a patient&#39;s colorectal vault via an insertion device such as a colonoscope, an upper GI therapeutic scope (a device which is generally known), a disposable, finger mounted device, or an optical probe that contains a permanent housing and disposable tip with retractable integral optical fibers, the latter of which are further described herein. 
         [0054]    For clinical evaluation of a colon, the probe is inserted into the rectum to establish contact with the colorectal mucosal wall, perform optical measurements as needed, and is then removed. The probes described further herein provide an insertion device for guiding the probe on a pathway through the rectum to reach the colo-rectal mucosal wall, while shielding the probe tip from possible blockage caused by loose stool that the probe may encounter. While contacting the colorectal mucosal wall, the insertion device then allows the optical portion of probe to extend some distance out of the tip of the insertion device and perform optical measurements as needed. 
         [0055]    The optical probes with insertion devices as described further herein contain components that are partially or entirely disposable, since for health reasons certain components are not readily used in multiple different patients. 
         [0056]      FIGS. 1-3  illustrate a housing  110  of a disposable, finger mounted optical probe  100  according to one embodiment, which is a semi-flexible component that includes a finger loop  116  worn over the physicians finger. As shown in  FIG. 3 , incorporated within the housing  110  is a complete optical probe  120 , including a re-usable trunk  140  and disposable tip  130 , described further herein, which are connected together by some type of engagement mechanism, such as threads on both the tip assembly  130  and the trunk assembly  140 . This finger mounted optical probe  100  is inserted into the patient&#39;s rectum mounted on the finger of the physician, allowing for passage of the optical probe  120  to the mucosal wall for measurement acquisition while shielding from potential loose stool both the optical probe, and particularly the optical components of the optical probe  120  that are disposed within the disposable tip  130 . 
         [0057]    The housing  110  of the disposable, finger mounted optical probe  100  is sufficiently lubricious to provide for easy passage of optical fibers through internal lumen  112 , and on its outer surface for non-lubricated device insertion into a patient&#39;s rectum. The housing may be made of liquid injection molded silicone rubber or similar material. Further, a parylene-N coating may be added to some or all surfaces of the housing  110  to increase overall lubricity for ease of feeding of probe through inner lumen, and insertion into the patient. 
         [0058]    The outer front surface of the housing  110  preferably includes a perforated membrane  114  that shields the probe tips from loose stool that may be encountered within the patient, through which the probe tip can pass through just prior to acquisition of optical measurement on the mucosal wall, as described herein, though such a perforated membrane  114  is not necessarily needed. 
         [0059]    Further, the disposable, finger mounted optical probe  100  will preferably either have: 1) a pre-formed geometry/curvature such that it can be guided to the proper location in the colo-rectal mucosal anatomy, 2) sufficient flexibility such that the physician can bend and/or manipulate it to the same area for optical measurement, or 3) some combination of both aforementioned attributes. If preformed, the probe  100  preferably has flexibility such that it could be inserted in a straight fashion, and shape memory such that it would retake its original shape once fully inserted into patient&#39;s colorectal vault. 
         [0060]    The probe  100  as illustrated in  FIG. 1-3  allows for pass through of a fully assembled optical probe. This embodiment require the disposable tip  130  to be attached to the reusable trunk  140  prior to insertion. The disposable tip  130  is clean or sterile when initially used prior to insertion, and also includes attached thereto a hygienic sheath  150  that acts as a hygienic shield to cover the reusable trunk  140 , which need not be sterile or sterilized when used. The hygienic sheath  150  may be made of a sterile thin polyethylene film or similar material. 
         [0061]      FIGS. 4(   a )-( b ) illustrate another embodiment of the disposable, finger mounted optical probe  100 A containing a pre-loaded optical assembly. In this embodiment, the housing  110  and the lumen  112  therein provides for pre-loading of an optical assembly  160 , such that the re-usable trunk (as described with reference to  FIG. 3)  will connect to the optical assembly  160  (essentially the same as the disposable tip  130 ) within the lumen  112 , and the entire assembly, once connected, can then continue to be positioned by moving through the lumen  112 , and eventually out through any perforated membrane  114 . As shown in  FIG. 4(   b ), the optical assembly, in one embodiment, may include a lens mount  162 , a rolling diaphragm  164  that provides fixturing of the optical assembly and a hygienic seal This hygienic seal can be simply a narrowing of the lumen such that the lens mount  162  fits tightly around the optical assembly to prevent fluid from flowing backward but is not so tight as to prevent the optical assembly from sliding forward and back, and a lens  166 , though other components, such as polarizers and spacers, can also be used within optical assembly  160 . 
         [0062]    In the embodiment of  FIG. 4 , the hygienic sheath is preferably attached to the disposable housing  110  at the entry end  118  of the housing, though the sheath is not shown in the Figure, though it could also be attached within the lumen  112  and be part of the optical assembly  160  to address the possibility of cross-contamination. This sheath would extend back to cover all non-disposable surfaces of the probe assembly which may be manipulated by the physician. The finger-mounted insertion device  100 A is preferably entirely disposable, and intended for single-use. An advancement assist ring  116  may be permanently attached to the optical probe to facilitate single handed probe insertion. 
         [0063]    Measurement acquisition may be initiated by a foot pedal connected to an instrumentation unit, a button built into the reusable portion of the probe assembly, or some other mechanism. If blind measurement acquisition and/or insertion is not deemed acceptable, a forward viewing CCD or CMOS camera module may be designed into the device, with camera residing in the reusable probe trunk, and window built into the disposable insertion device, as shown in  FIG. 10 . 
         [0064]      FIGS. 5   a - 5   c  are illustrations of the method of use of the disposable, finger mounted optical probe  100 . In use, the probe assembly  120 , formed of the re-usable trunk  140  and the disposable tip  130 , is inserted into the housing  110  as shown, and an advancement assist ring  180 , permanently attached to the re-usable trunk  140 , will attach to the end  118  of the housing  110 . As shown in  FIGS. 5A and 5B , the sheath  150  is pulled back so that it extends sufficiently below the sterile gloved hand of the physician to provide a sterile environment for the patient. As shown in  FIG. 5C , the disposable tip  130  of the probe assembly  120  is pushed through the perforated membrane  114  at the time the measurement is taken. 
         [0065]    FIGS.  6 A( 1 )-( 2 ), B and C show usage of an embodiment of an optical probe  200  that contains a permanent housing  210  and a disposable tip assembly  220  with retractable integral optical fiber assembly  220  (essentially the same as the optical assembly  120  that is formed of the disposable tip  130  and the re-usable trunk  140  as described in the  FIG. 3  embodiment above), as well as an overall view of this embodiment. In all of the embodiments there exist the permanent housing  210 , which preferably includes thereon a trigger activation button  212 , a grip  214  for holding in the physician hand, and a roller wheel  216  or similar element integrated into the housing  210  to facilitate single-handed probe advancement, as shown in  FIG. 6A . FIGS.  6 B 1  and  6 B 2  show at a high level both the connection of the disposable tip assembly  230  to the re-usable trunk assembly  240 , as well as the unwrapping of the protective sheath  250  over the exterior of the housing  210 . It is noted that in  FIG. 6A  the sheath  250  is only shown unrolled on the insertion portion  260 , but preferably the sheath  250  will extend below the entire housing  210 .  FIG. 6C  provides close up views of the disposable tip assembly  230 , and shows both a CCD forward viewing window  270  for a CCD array disposed therebehind (not shown here, though components illustrated in  FIG. 10  can work herein), as well as the perforated membrane  280  through which the disposable tip  220  assembly will be moved when the measurement is taken. In use, the insertion portion  260  is inserted into the patient&#39;s rectum, with the grip  214  of the housing  210  held by the physician, allowing for internal optical assembly to be positioned on the mucosal wall while shielded from potential loose stool. This allows for advancement of the internal optical probe assembly, including the lens as described hereinafter, out of the protective cap associated with the disposable tip assembly  220 , and onto the patient&#39;s colo-mucosal wall for measurement acquisition. 
         [0066]    In a preferred implementation, the housing  210  a two-piece, rigid injection molded handle comprised of ABS (Acrylonitrile butadiene styrene) or similar material. Further, an overmolded soft-touch material such as Pebax or Hytrel may comprise the insertion portion  260 . The disposable tip assembly  230  in this configuration may be comprised of a similar soft-touch material overmolded soft-touch material such as Pebax or Hytrel. The hygienic sheath  250  attached to the lens mount  238  within disposable tip assembly  230  may be made of a thin polyethylene film or similar material. 
         [0067]    It is noted that it may be that a sheath  250  isn&#39;t used, and the insertion portion  260  is sterilized after each use. In such a use, the insertion portion  260  is preferably lubricious enough on its outer surfaces for non-lubricated device insertion into a patient&#39;s rectum. 
         [0068]    Further, this probe  200  also preferably has 1) a pre-formed geometry/curvature such that it locates the internal optical assembly, and particularly the optical tip, onto proper location in the colo-rectal mucosal anatomy, and 2) sufficient flexibility such that the physician could bend and/or manipulate the device to the same area for optical measurement. The probe  200  is sufficiently flexible such that it can be inserted in a straight fashion, and has shape memory such that it retakes its original shape once fully inserted into patient&#39;s colorectal vault. 
         [0069]      FIG. 7  illustrates a partial illustration of a particular embodiment of an optical probe  200 A, with only the optical components shown, not the sheath  250  and lower part of the housing  210 . The shown semi-flexible insertion portion  260  contains therein the retractable integral optical fiber assembly  220 , formed of the disposable tip assembly  230  and the trunk assembly  240 . As shown the trunk assembly  240  will contain an outer sheath  248 , which preferably includes at the distal end a protrusion ring  242 , which abuts a similar protrusion ring  262  associated with the insertion portion of the housing  210 . Also associated with the re-usable trunk assembly  240  is a springing engaging mechanism  244  for the optical components of the disposable tip assembly  230  to connect in an aligned manner, as well as, in certain configurations, other optical components  246 , such as a polarizer or protective cover. Other engagement mechanism, such as threads on both the tip assembly  230  and the trunk assembly  240  can be used. 
         [0070]    The disposable tip assembly  230  contains a protective cap  231  that has an alignment element  233  and perforated membrane  236 , described further herein, that maintains the lens mount  238  in place prior to connection to the optical fiber trunk assembly  240 . As shown in  FIG. 9 , the disposable tip assembly also preferably has attached thereto the sheath  250   
         [0071]    The lens mount  238  will contain a lens  232 , such as a GRIN lens, a ball lens, an achromatic doublet lens, etc can be used, disposed therein or as part of a one-piece assembly, as well as an alignment member  234  that engages with the alignment element  233 . The alignment member  234  in one embodiment is a channel into which a protrusion that is the alignment element  233  fits. Once the disposable tip assembly  230 , and specifically the lens mount  238 , is connected to the trunk assembly  240 , and the engaging mechanism  244 , the entire optical assembly  220  is moved through the rectum to the measurement point. At that time, the optical fiber assembly  220  can be slightly rotated and moved forward, so that the lens mount  238 , via the alignment member  234 , is guided by the alignment element  233 , so that the lens  232  can protrude through the perforated membrane  236 . 
         [0072]      FIG. 8  illustrates a partial illustration of a particular embodiment of an optical probe  200 B, with only the optical components shown, not the sheath  250  and lower part of the housing  210 . In this embodiment, as shown the disposable tip assembly  230  does not contain a front face to the protective cover  231  or a perforated member, and as such the lens  232 , mounted in the lens mount  238 , is exposed. Otherwise, the elements shown in  FIG. 8  are the same as those described previously with respect to  FIG. 7 . Since the lens  232  is pre-exposed, the probe  200 B does not required advancement of retractable integral optical fiber assembly  220  to break through any protective cap membrane. Thus, once inserted and put into contact with the patient&#39;s colo-mucosal wall, the probe  200 B is immediately ready for measurement acquisition. 
         [0073]    If blind insertion is not deemed acceptable, a forward viewing CCD camera may be designed into the device, with camera residing in the tip of reusable portion of the wand, and window built into the disposable wand tip, as shown in  FIG. 10 . As shown, the disposable tip assembly  230  is modified by including the glass viewing cover  237  as part of the protective cap  231 , and the probe  200  further includes a CCD or CMOS module, as will as an image return wiring  292  as needed. Depending on the configuration, the CCD or CMOS module may include battery power, may be powered via wires for the power, and/or the power and/or image signals may be transmitted wirelessly using various conventional data and short range power transmission schemes. 
         [0074]    Different penetration depths are implemented with these probes in a variety of ways. Different fibers and/or disposable tips can be used (in some instances with different probes, in other instances all within the same probe) in order to achieve the desired results. For probes that detect EIBS in particular, the choice of the spacing between the fiber termination and lens (e.g. nominally  1  focal length but could be more or less) and selection of the lens type and focal length adjustment depth can be used to achieve different penetration depth. For LEBS probes that detect tissue microarchitecture, the selection of the lens and the distance from the termination of the fibers to the lens or the length of the glass spacer determine the special coherence length of light, which will vary the penetration depth. 
         [0075]    In use, depending upon the target and the application, each probe may take multiple measurements, and the detected data from each measurement stored for subsequent usage. Typically a number of different measurement locations, such as 3-6, but not typically greater than 10 will be made. Depending on the probe or the manner in which the probe is used, various different penetration depths may then be sensed at each measurement location. 
         [0076]      FIG. 11  illustrates a particular optical probe assembly configuration used for EIBS.  FIG. 12  illustrates another particular optical probe assembly configuration used for EIBS. It is noted that the lens mount and polarizer mount may be combined to form a single component.  FIG. 13  illustrates a further particular optical probe assembly configuration used for EIBS. It is noted that the lens mount and polarizer mount may be combined to form a single component. In each of  FIGS. 11 ,  12  and  13 , the components are identified, and they together show that various combinations of components can be used: certain embodiments may or may not have polarizers, spacers and different numbers of optical fibers can also be used. In this regard, reference is made to the previously filed U.S. patent application Ser. No. 11/604,659 filed Nov. 27, 2006 and entitled “Apparatus For Recognizing Abnormal Tissue Using The Detection Of Early Increase In Microvascular Blood Content.” 
         [0077]      FIG. 14  illustrates in cross section an embodiment of optical fibers and polarizer usable in the optical probe assembly configurations illustrated in any of  FIGS. 11 ,  12 , and  13 . 
         [0078]      FIG. 15  illustrates in cross section a further embodiment of optical fibers and polarizer usable in the optical probe assembly configurations illustrated in any of  FIGS. 11 ,  12 , and  13 , and shows a decentering or making the fibers slightly asymmetric with respect to the probe center to minimize reflections. This could be used on any probe designs that detect EIBS described herein. 
         [0079]      FIG. 16  illustrates a particular optical probe assembly configuration used for LEBS.  FIG. 17  illustrates another particular optical probe assembly configuration used for LEBS.  FIG. 18  illustrates a further particular optical probe assembly configuration used for LEBS.  FIG. 19  illustrates a further particular optical probe assembly configuration used for LEBS.  FIG. 20  illustrates a further particular optical probe assembly configuration used for LEBS. In both of the  FIG. 19  and  FIG. 20  probe designs, no lens is used but the solid glass spacer ( FIG. 20 ) or air gap with coverglass ( FIG. 19 ) between the fiber terminations and the tissue selects a specific (and predetermined) spatial coherence length that corresponds to a desired depth. This lensless concept that uses a fix-distance spacer (air or glass) can be used to establish a spatial coherence length. In the other embodiments, the components are identified, and they together show that various combinations of components can be used: certain embodiments may or may not have polarizers, spacers and different numbers of optical fibers can also be used. 
         [0080]      FIGS. 21(   a ) and ( b ) illustrate in cross section an embodiment of optical fibers usable in the optical probe assembly configurations illustrated in any of  FIGS. 16-20 . 
         [0081]      FIG. 22  illustrates in cross section a further embodiment of optical fibers usable in the optical probe assembly configurations illustrated in any of  FIGS. 16-20 .  FIG. 22  shows a decentering or making the fibers slightly asymmetric with respect to the probe center to minimize reflections. This could be used on any LEBS probe designs described herein. This gives a potential advantage in that internal reflections off surfaces (e.g. the lens/tissue interface, air/lens interface, etc) will be reflected elsewhere away from the fibers. 
         [0082]    The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings.