Abstract:
The present invention is directed to a two-dimensional scanning arrangement for a laser vein-illumination device that includes a base and a frame connected to the base using at least one flexible hinge. The hinge allows the frame to move angularly with respect to the base in a first direction. The invention further includes a means for exciting angular oscillations of the frame at or near said frame&#39;s resonant frequency. An elastic torsional element having a proximal end rigidly attached to said frame and a distal end rigidly attached to a mirror is also included. The torsional element allows the mirror to move angularly with respect to the frame in a second direction, generally perpendicular to the first direction. There may also be a means for exciting the angular oscillations of the mirror. 
     The invention also includes a device for optically inspecting confined spaces having one or more small access orifices. The device includes at least one laser light source and a scanning means which scans one or more laser beam in a two-dimensional pattern over an inspection area. Also present is at least one light detector, sensitive to the light of the laser beam(s) being reflected from the inspection area. There is also a connecting member being thin and long enough to reach the inspection area through the access orifice.

Description:
This application is a continuation in part of application Ser. No. 11/478,322, filed on Jun. 29, 2006, U.S. patent application Ser. No. 11/700,729, filed Jan. 31, 2007, and U.S. patent application Ser. No. 11/807,359, filed May 25, 2007. This application is also a continuation in part of U.S. patent application Ser. No. 12/215,713, filed Jun. 27, 2008, U.S. patent application Ser. No. 11/823,862, filed Jun. 28, 2007, and U.S. application Ser. No. 12/804,506, filed Jul. 22, 2010. This application claims priority on U.S. Application Ser. No. 61/279,980, filed Oct. 28, 2009. All the foregoing disclosures are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to the field of vein illumination on a patient. The invention is also direct to an apparatus for performing an endoscopy in medical procedures 
     BACKGROUND OF THE INVENTION 
     Vein illumination devices are known in the art. The vein illumination devices can have various mounting arrangements, including but not limited to mounting on a needle, on a head piece, on a tourniquet, on the back of the hand, and on a goose neck stand, etc. Various such devices are shown in our prior patent applications including of application Ser. No. 11/478,322, filed on Jun. 29, 2006, U.S. patent application Ser. No. 11/700,729 filed Jan. 31, 2007 and U.S. patent application Ser. No. 11/807,359 filed May 25, 2007, U.S. patent application Ser. No. 12/215,713 filed Jun. 27, 2008 and U.S. patent application Ser. No. 11/823,862 filed Jun. 28, 2007 and U.S. application Ser. No. 12/804,506 filed Jul. 22, 2010. 
     SUMMARY OF THE INVENTION 
     In one embodiment, the present invention is directed to a two-dimensional scanning arrangement for a laser vein-illumination device. The device includes a base and a frame connected to the base using at least one flexible hinge. The hinge allows the frame to move angularly with respect to the base in at least a first direction. The invention further includes a means for exciting angular oscillations of the frame at or near said frame&#39;s resonant frequency. An elastic torsional element having a proximal end rigidly attached to said frame and a distal end rigidly attached to a mirror is also included. The torsional element allows the mirror to move angularly with respect to the frame in a second direction, generally perpendicular to the first direction. There may also be a means for exciting the angular oscillations of the mirror. 
     The present invention also includes an imaging system. In one embodiment the device is for optically inspecting confined spaces having one or more small access orifices. The device includes at least one laser light source and a scanning means which scans one or more laser beam in a two-dimensional pattern over an inspection area. Also present is at least one light detector, sensitive to the light of the laser beam(s) being reflected from the inspection area. There is also a connecting member being thin and long enough to reach the inspection area through the access orifice. The device of the present invention has a variety of uses including but not limited to use as an endoscope in certain medical procedures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows each of the embodiments of  FIGS. 1A to 3E  in a single compilation demonstrating the general relationship between them. 
         FIG. 1A  shows the removable head portion of the device of the present invention. 
         FIG. 2  shows how the head piece and body can be separated. 
         FIG. 3A  shows the head piece mounted on a syringe. 
         FIG. 3B  shows a head piece with a mechanical connector arranged to receive the head portion of the device. 
         FIG. 3C  shows a tourniquet piece with a mechanical connector arranged to receive the head portion of the device. 
         FIG. 3D  shows the back of the hand adaptor with a mechanical connector arranged to receive the head portion. 
         FIG. 3E  shows a flexible arm with a mechanical connector arranged to receive the head portion of the device. 
         FIGS. 4A and 4B  show an arrangement for moving a scanning mirror along a first axis. 
         FIG. 5  shows the elements of  FIGS. 4A  and B mounted on a frame. 
         FIG. 6  shows a bottom perspective view of the device of  FIG. 5 . 
         FIG. 7  shows a top rear perspective view of the device of  FIG. 5 . 
         FIG. 8  shows a center perspective view of the device of  FIG. 5 . 
         FIG. 9  shows a top view of the device of  FIG. 5 . 
         FIG. 10  shows a side view of the device of  FIG. 5 . 
         FIG. 11  shows a side view of the opposite side of the device of  FIG. 5 . 
         FIG. 12  shows a bottom view of the device of  FIG. 5 . 
         FIG. 12A  shows a top view of the frame of the endoscope. 
         FIG. 12B  shows a graph of the feedback voltage in the drive and feedback state. 
         FIG. 12C  shows a graph of the feedback voltage in the drive and feedback state where the drive and the feedback state are shorter than in  FIG. 12B   
         FIG. 12D  shows a graph of the feedback voltage that is induced in the coil by the magnet. 
         FIG. 12E  shows the distance between the coil and magnet that changes over time. 
         FIG. 12F  shows the feedback voltage as a function of the distance between the coil and the magnet. 
         FIG. 13  shows an example of the endoscopic device of the present invention. 
         FIG. 14  shows an embodiment where one or more of the elements of the laser camera are moved from the distal end of the endoscope. 
         FIG. 15  shows a scanning arrangement where the lens linearly oscillates in a direction perpendicular to the laser beam. 
         FIG. 16  shows an alternative embodiment of a scanning arrangement. 
         FIG. 17  shows the piezo elements in more detail. 
         FIG. 18  shows an alternative embodiment of the piezo elements. 
         FIG. 19  shows the use of permanent magnets on the fiber. 
         FIG. 20  shows an arrangement for limiting the Field of View of the light detector. 
         FIG. 21  shows the light rays emanating from the scanning arrangement. 
         FIG. 22  shows an arrangement where a laser of variable wavelength is used. 
         FIG. 23  shows an arrangement where the laser beam is split into several sub beams. 
         FIG. 24  shows a prior art rigid endoscope. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As seen in  FIGS. 1-3  there is a laser based scanning device that includes a body  10  with a removable headpiece  11 . The body and the head piece may be connected together by any suitable means. Preferably, there is an electrical connection between the body  10  and the headpiece. One or the other or both of the body and/or the headpiece may have a source of electrical power such as a battery. 
       FIGS. 1 ,  2  and  3 A- 3 E show a modular design system wherein the device has a removable head portion that can be held (mounted) in a plurality of ways.  FIG. 1  shows each of the  FIGS. 1A-3E  in a single compilation showing a relationship between them. 
       FIG. 2  shows a head portion on the right hand side of the drawing and a body portion of the left hand side. The head portion is a vein illumination device as previously described, including a small rechargeable battery for operating the unit for a short period of time. The body portion contains a larger battery, which is capable of charging the small battery when the two pieces are mated. 
       FIG. 1A  shows the body portion and the head portion mated together and utilized in a handheld mode. While in this mated configuration, the unit can be placed in a charger (not shown) for charging the battery in the body portion and the smaller battery in the head portion. Alternatively, the charger can charge just the battery in the body portion, which in turn charges the smaller battery in the head portion. Still further, the charger can be arranged to receive just the body portion, and/or just the head portion, without them being mated, and charge their respective batteries. 
       FIG. 2  shows the head portion removed from the body portion. The mating provides electrical connections (for providing charging power from the body to the head) as well as mechanical connection between the two. When the head is removed it continues to run off its small battery and functions as a vein illumination device. The head can now be mounted on a plurality of types of devices ( FIGS. 03A-03E ), provided each device has a mechanical connector adapted to receive the mechanical connector of the head. Further, each of the plurality of types of devices could also contain a battery or power source which connects through the electrical connector and powers the head or charges the small battery in the head. 
       FIG. 3A  shows the head mounted on a syringe. The syringe has a mechanical connector arranged to receive the head. Alternative to a syringe, any device that is used for access to a vein can be arranged with a mechanical connector to receive the head. For example, but not limited to, a vacutainer, iv kit, butterfly, hypodermic, etc. 
       FIG. 3B  shows a head piece with a mechanical connector arranged to receive the head portion of the device. The head piece is shown as a band, however, any device mounted to the head or body can be arranged with a mechanical connector for receiving the head piece of the device. For example, but not limited to, a hat, helmet, miners hat, fireman&#39;s hat, surgeon&#39;s hat, eye glasses, etc. 
       FIG. 3C  shows a tourniquet piece with a mechanical connector arranged to receive the head portion of the device. The tourniquet can be a manual type or can be a pump driven device. 
       FIG. 3D  shows a back of the hand adaptor with a mechanical connector arranged to receive the head portion of the device. The back of the hand adaptor can be a strap that attaches around the hand, or alternatively, can be a glove or other connection device. Further, the adaptor can attach to the fingers, such as, for example, a connection configured as brass knuckles, or a ring, or a ring that covers more than one finger. 
       FIG. 3E  shows a flexible arm with a mechanical connector arranged to receive the head portion of the device. The flexible arm can be configured to mount in a variety of ways, such as, but not limited to, clamping, having a weighted base, fasteners, connected to rolling wheels, etc. 
     In  FIGS. 4A ,  4 B and  5 , an arrangement for moving a scanning mirror along two perpendicular axes is described.  FIGS. 4A and 4B  show the mechanics for moving the mirror  20  along a first axis. A glass fiber  21  with a small diameter, for example diameter in the range of about 0.05 mm to about 0.5 mm may be used. In one embodiment the diameter may be about 0.21 mm. The fiber extends from a base or holder  22  to a mirror  20 . The length of the fiber is preferably from about 5 mm to about 50 mm. The mirror can vary in size as well. In this embodiment, the length of the fiber is about 11 mm and the dimension of the mirror is about 0.9 mm by 9 mm. It will be appreciated by those skilled in the art that other lengths or dimensions can be used. The mirror is secured onto the fiber  21  by for example glue or other suitable connecting material. A piezo-electric element  26  is then secured with one end attached to the fiber  21  and the other end floating. Glue, for example, may be used to secure the piezo-electric element to the fiber. Alternatively, the piezo-electric element  26  can be attached to a common base to which the fiber  21  is attached as well, and vibrations are still passed to the fiber  21 . When the piezo-electric element  26  is excited with the electrical signal of the frequency equal to the frequency of the torsional resonance of the fiber-mirror system, which in this embodiment happens to be 18.5 kHz, it vibrates and induces the corresponding angular displacements to the attached fiber at the same rate of 18.5 kHz. Other fiber mirror systems may have a different torsional resonance frequency. Due to the high quality factor of the fiber-mirror system, the angular displacement of the mirror is many times greater than that of the opposite end of the fiber and in this embodiment reaches approximately ±7 degrees. The torsion node of the fiber may be higher than fundamental, meaning that at least one torsional node, i.e. a cross-section of the fiber which remains still during oscillations, is formed. Such nodes allow for generally higher oscillation frequency at the expense of generally lower oscillation amplitude. 
     It has been found that the amplitude of mirror rotation is dependent on the thickness and length of the fiber, the size and weight of the mirror, and the frequency and intensity at which the piezo-electric element shakes the fiber  21 . 
       FIG. 5  shows the elements of  FIG. 4A  mounted in a frame  30 . In this embodiment, the piezo-electric element  26  is mounted to the frame which in turn holds the end of the fiber  21  opposite to the mirror (acts as the base from  FIG. 4A ). The frame  30  connects by four rectangular brass hinges  24  to a base  23 . Preferably, both ends of the hinges are soldered to the frame and to the base, so the frame can move angularly with respect to the base. In one embodiment the base  23  may have vein scanning device similar to the vein scanning device shown in copending U.S. application Ser. No. 12/804.506 filed Jul. 22, 2010. 
     Besides soldering other connection methods may be employed as well, such connection methods preferably allowing for both mechanical rigidity and electrical conductivity. In addition to providing mechanical support for the frame and acting as springs in a resonant system, the hinges may also serve as electrical conductors for drive and feedback signals. A magnet  25  is also attached to the frame  30 . The geometry of the brass hinges are selected so that the resonant frequency of moving the frame  30  (and the attached mirror elements from  FIG. 4A ) is approximately equal to the desired frequency of the motion of the mirror  20  about the second axis perpendicular to the first axis. An electric coil (not shown) is used for creating the variable magnetic field around the magnet  25 . In response, the magnet  25  generates the torque which in turn causes the frame to rotate about the second axis. For optimal efficiency, the coil should be placed as close as possible to the magnet, however, minimal mechanical clearance sufficient for the magnet to move without mechanical interference should be observed. It is particularly advantageous if the second axis passes through the center of the mirror  20 , as in this case the center of the mirror experiences very little or no translational motion which facilitates aligning the mirror with the incoming laser beam. It has been found that there is little or no crosstalk between two axes of mirror oscillations in this arrangement. 
     It may also be beneficial to attach another permanent magnet  40  to the fiber  21 , so the coil  41  may be used to drive the oscillation of the mirror  20  in the first direction (around the axis of the fiber), as illustrated by  FIG. 12A . Likewise, these coil and magnet should be as close as possible to each other with only a necessary clearance left between them. The same magnet-coil pair can be used to collect positional feedback from the mirror. Furthermore, the coil may be switched between drive state and feedback state in time, as illustrated on  FIG. 12B . As the magnet attached to a fiber or a frame engages in oscillations, the feedback voltage  51  is induced in the coil. During feedback state, no external voltage is applied to the coil, so the feedback voltage  51  may be amplified, digitized or otherwise processed by electronic control circuits (not shown). During drive state, the external voltage  50  is applied to the coil, thus providing power for sustained mechanical oscillations. Alternatively, the drive and feedback states may be shorter, occupying only a portion of an oscillation cycle as shown on  FIG. 12C . Variable and non-periodic switching between drive and feedback states are possible as well. 
     Additionally, since in the process of oscillation in the second direction (frame  30  oscillation) the distance between magnet  40  and coil  41  changes, the amplitude of the feedback signal from mirror oscillation will be changing depending on the position of the frame, thus enabling frame positional feedback collection from the same magnet-coil pair.  FIG. 12D  shows, as a function of time, a comparatively large feedback voltage  60  induced in the coil while the magnet is in its closest position to the coil, and a comparatively small feedback voltage  61  induced in the coil while the magnet is in its furthest position from the coil,  FIG. 12E  shows the distance  62  between the coil and the magnet, changing due to frame oscillations. Finally,  FIG. 12F  shows the resulting feedback voltage  63 . Largest amplitude of this voltage corresponds to the closest proximity between the coil  41  and the magnet  40   FIGS. 6-12  show various views of the device of  FIG. 5 . 
     A laser camera  42  can be used at the end of an endoscope to form a laser-based endoscopic imager. These applications include but are not limited to U.S. patent application Ser. No. 12/215,713, filed Jun. 27, 2008, U.S. patent application Ser. No. 11/807,064 filed May 25, 2007 and U.S. patent application Ser. No. 11/807,359 filed May 25, 2007 the disclosures of which are incorporated herein by reference. Generally, unlike a conventional CCD (Charge-Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) camera, which uses defused illumination and a large array of light-sensitive detectors, a laser camera uses a scanning laser beam as an illumination source and a single detector, which receives the laser light reflected from the surface of interest. In one possible arrangement, illustrated by  FIG. 13 , the main elements of a laser camera, such as a laser light source  100 , a scanning arrangement  101  and a light detector  102  are all located at a distal end  103   a  of a thin connecting member  103 , which serves to bring the endoscope to a close proximity with the area to be inspected. The laser beam  107  is formed into a raster by the scanning arrangement  101  and directed toward the inspection area  109  through an optical window  110 . The reflected light  108  reaches the light detector  102 , carrying the information about the inspected area. 
     Connecting member  103  may be flexible, as well as rigid. As typical for endoscopy applications, said inspected area is usually situated in a confined space with only a small access orifice available, hence maintaining the minimal thickness of the endoscope is essential. Such confine spaces include the inner cavities of human body, other biological objects, as well as manufactured objects, such as pipelines or engine cylinders. Referring further to  FIG. 13 , the proximal end  103   b  of the connecting member does not go into confined spaces and hence does not need to be miniaturized. The proximal end carries the control block  105 , responsible for power supplies, signal processing, user interface and other auxiliary functions, and an LCD screen  106  or other means of visually presenting the optical information gathered from the inspected area to the eyes of the User. In this embodiment, said optical information is delivered from the distal end of the endoscope electronically, through cable bundle  104 , which runs the length of the endoscope. In other arrangements, said cable bundle may also include optical fibers or any combination of electronic and optical signal delivery means. 
     For the purpose of keeping the endoscope as thin as possible, it may be advantageous to move some or all of the elements of the laser camera from the distal end of the endoscope to its proximal end. An arrangement which exemplifies this idea is presented on  FIG. 14 . Here, the laser light source  100  and a light detector  102  are at the proximal end. Optical fibers  120  are delivering laser light to the scanner  101 , which is still at the distal end. The reflected light  108 , carrying the information about inspected area, is also delivered to the light detector through optical fibers. Additional optical elements  121 , such as lenses, might be needed to efficiently couple the light into and out of the optical fibers. 
     Typically, the scanning arrangement  101  would include two angularly-oscillating mirrors or one bi-axial mirror. However, other scanning methods may be used as well. One of them is illustrated on  FIG. 15 , where the laser beam  107  is directed towards a lens  131 , which linearly oscillates in the direction perpendicular to the laser beam. Assuming that the laser beam is collimated or nearly collimated, the lens would focus the beam into a focal plane  132 , while scanning the focused spot along the direction of its own oscillations. 
     Another possible scanning arrangement is depicted on  FIG. 16 . A fiber  1  connects to a mirror  2  which is mounted at an angle (in this example 45 degrees) to the center lengthwise axis of the fiber  1 . The mirror is mounted so that the center of mass of the mirror is not along the center lengthwise axis of the fiber  1 . It should be noted that this fiber  1  is used as a mechanical structure and is not carrying any of the laser light. Four piezo-electric elements  10  are positioned in a rectangle around the base of the fiber  1 . The piezo-electric elements  10  are affixed to the fiber  1  at the end closer to the mirror  2 . The other end of the piezo-electric elements are affixed to the tubing of the endoscope (not shown). Two opposing piezo elements are driven at a high frequency (1 khz to 30 Khz) to cause the fiber to vibrate, which in turn results in the mirror rotating approximately about the center lengthwise axis of the fiber  1  in the manner previously described with reference to  FIGS. 4A and 4B . The other two opposing piezo elements are driven at a lower frequency (60 hz-1000 hz) and cause the fiber  1  and therefore the attached mirror  2  to move about a second axis. 
     Still referring to  FIG. 16 , a laser light  11  is carried through a fiber cable in the endoscope (not shown) and is then reflected off a bounce mirror  12  (in this example 45 degrees) onto the moving mirror  2  which projects a raster pattern out the tip of the endoscope. 
       FIG. 17  shows in greater detail the four piezo elements  10  surrounding the fiber  1 . (Where is this Figure) Opposing piezo-electric element  10   b  are driven at the higher frequency but at opposite phase to cause the rotation of the mirror. Opposing piezo-electric elements  10   a  are driven at the lower frequency, but out of phase, to cause the fiber to sway in the opposite direction. 
     Feedback is often required in imaging systems to provide knowledge of the position of the rastering laser beam. In the systems of  FIGS. 4A ,  4 B,  16  and  17 , additional feedback piezo elements can be attached to the fiber. Movement of the fiber will move the feedback piezo-electric elements and by measuring the voltage across them provides indication of the fiber&#39;s position. 
     In addition to being used as a mechanical structure, a fiber can also be used to carry light and thus conduct optical signals, providing that it is made from a suitable optical material, such as glass or transparent plastic. In this case, if the end of a fiber is excited into oscillation, said fiber may serve as a scanning arrangement. It should be noted that both the laser beam, the light reflected from the inspection area, or both can be carried by optical fibers. It is also possible to have the laser beam and the light reflected from the inspection area to move through the same optical fiber in opposite directions. 
     In one possible arrangement, the piezo-electric elements  210  can be attached to fiber  201  transversely, as depicted on  FIG. 18 . A piezo-electric element&#39;s alternative expansions and contractions induce oscillations of the distal end of the fiber. If the excitation frequency is close to the principal resonant frequency of the fiber, the amplitude of the fiber oscillations can be sufficient to raster over the inspected area. 
     Alternatively, the oscillations can be excited by a permanent magnet  211 , which is attached to the fiber and is subjected to variable magnetic field generated by the coil  212 , as depicted on  FIG. 19 . 
     Generally, the light detector of the laser camera is exposed to the light reflected from the whole of the inspected area covered by the rastering laser beam. However, in some cases it might be advantageous to limit the Field of View (FOV) of the light detector to a smaller area  215 , which does not cover the whole of the inspected area  216 , as illustrated by  FIG. 20 . In this case, to insure that the light reflected from the inspected area can always reach the light detector, the FOV of the detector needs to move synchronously with the laser beam. This might be accomplished by directing the reflected light through a separate scanning arrangement, which is synchronized with the scanning arrangement for the laser light. Alternatively, the same scanning arrangement may be used for both rastering laser beam and reflected light.  FIG. 20  further illustrates this principle, as two optical fibers  201 , one carrying the laser beam  107  and the other the reflected light  108 , are mechanically joined together and made to oscillate together due to excitation provided by the piezo-electric element  210 . Respectively, the detector FOV(Field of View)  215  moves together with the scanned laser beam  107   a  and always overlaps it. 
     Further miniaturization of an endoscope can be achieved if the scanning arrangement is moved to the proximal end of the endoscope as well, so no mechanical or electrical elements is left at the distal end and light is the only media travelling through the connecting member. It is worth noting, that all-optical image transmission through an optical fiber has been eluding scientists and engineers for decades. While conceptual ideas exists, a practical solution is yet to be developed. Consequently, the flexible endoscopes (more about rigid endoscopes below) today use either a bundle of optical fibers, each responsible for a single pixel of the image, which increases the thickness of the endoscope and limit the image resolution, or use a camera at the distal end of the endoscope. 
     The principle problem complicating the image transmission through an optical fiber is a variable number of bounces from the boundary of the fiber each ray can go through, depending on its angle of incidence. Respectively, the rays emanating from the same point may not end up in the same point or in the same order on the opposite end of the fiber, thus scrambling the transmitted image. However, for a laser camera this problem is manageable, as illustrated by  FIG. 21 . While the rays  222  to  224 , emanating from the scanning arrangement  101 , reach the end of the fiber  225  in chaotic order, each of those rays would still illuminate a distinct point on the inspected area (not shown). The light reflected from each of those points can still be detected and recorded, and the order in which the rays are reaching the inspected area, while chaotic, is repeatable from scan to scan, so the record of the reflected light can be restored into a meaningful image of the inspected area. 
     Other methods of endoscopic all-optical image collection can be enabled as well with the laser camera.  FIG. 22  depicts an arrangement where the laser  100  of variable wavelength is used, and its wavelength is changed continuously. A grating  231  at the distal end of the fiber  230  translates wavelength change into a change of the angle at which the beam propagates, thus scanning the inspected area. In this arrangement, the fiber  230  can be a single-mode fiber. 
     Another arrangement is shown on  FIG. 23 , where the laser beam  107  is split into several sub-beams. Each of those sub-beams is directed through a controllable delay element  241  and then on into one of the optical fibers  240 , which may also be single-mode fibers. Assuming that each subsequent delay element  241  increases the delay into a respective fiber by an equal interval Δt, the resultant output beam emanating from the distal end of the fibers will be deflected by an angle α, α≈c*Δt/d, where c is the speed of light and d is the distance between adjacent fibers. 
     An important class of endoscopes are rigid endoscopes depicted on  FIG. 24  (Prior Art, from http://www.vet.uga.edu/mis/img/equipment/exotics/image003.jpg). In those, the image is optically relayed from the distal to the proximal end through a system of lenses, usually, so-called Hopkins Rod Lenses. The laser camera, positioned entirely at the proximal end can be used in this class of endoscopes as well, instead of a conventional imaging camera or an optical eye piece. Additionally, the laser camera can be used without any relay lenses, assuming that the connecting piece of the endoscope is tubular and possesses a smooth reflective inner surface. In this case, the laser light can travel through it in a way similar to traveling through optical fiber, as illustrated on  FIG. 21  and discussed above. 
     In a previous disclosure, laser imaging systems were described which are multispectral. Such multispectral techniques can be applied to the endoscope described herein. Further, in previous disclosures we described a closed loop laser imaging system which is capable of capturing images with very high dynamic range. Such techniques can be applied to the endoscope described herein. Finally, trans-illumination has been previously described and can be applied to the endoscope described herein. 
     While the term endoscope has been used herein, it is understood that the approaches described herein can be applied to any type of instrument wherein a laser fiber is used for connecting imaging capture electronics over a distance to a remote location, such as, remote material inspections, other medical procedures, etc.