Abstract:
A system provides a multi-axis translation and orientation capability for optical imaging. The system includes an optical imaging apparatus providing a signal representing a digitized image, and a mechanical frame. The frame includes a first set of articulations capable of independently translating the optical imaging apparatus in multiple linear directions. The system also includes a second set of articulations formed as joints providing at least three independent degrees of rotation of the optical imaging apparatus. The system also provides an opening configured to permit the frame to be postured about a patient such that an isocenter corresponds to a region of interest of the patient, and includes an illumination source attached to the frame and configured to direct illumination towards the isocenter. The system also comprises a camera system co-located with the illumination source and having a focal plane at the isocenter.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    This disclosure relates generally to imaging technology, and in particular to a system and method for positioning imaging equipment relative to an isocenter or locus associated with a region of interest. 
       BACKGROUND 
       [0002]    Many medical diagnostic, surgical and interventional procedures rely on imaging tools to provide information descriptive of status of visually perceived representations of portions or organs of a patient. In part as a result of increasing sophistication of medical tools in general, and imaging apparatus in particular, more types of imaging devices are being adapted for application in the context of surgical procedures. 
         [0003]    In many instances, medical tools capable of rendering images of organs or tissues have found great utility and have been adapted to facilitate types of surgery. These find application in many situations, and are very useful in situations where the surgeon cannot directly see the operating site, or when the features of interest are not amenable to direct visual inspection, or to enable comparison of a present image with other image data, among other instances. These applications have resulted in development of a broad variety of tools, including x-ray, CT and fluoroscopic visualizing aids, and many different types of optical imaging devices. 
         [0004]    In turn, such applications frequently benefit when the imaging tool is mobile or portable, easily positioned to achieve a desired position and to hold the desired position, may be readily adjusted about an isocenter or patient-centric locus, may include capability for machine-driven positioning, provides a stable platform, and presents numerous other aspects somewhat unique to the operating room environment. These include need to be compliant with safety and regulatory requirements for medical imaging equipment, and to satisfy sterility requirements within the operating room, such as control of air borne particulates, compatibility with draping, and constraints relating to fluid containment and cleaning. 
         [0005]    Accordingly, the resultant support systems for such visualization equipment include significant mechanical considerations in order to facilitate the required degrees of freedom in articulation and transportation. A suitable footprint and acceptable mobility, each adapted to the operating room environment, are important aspects. There may be need to provide capability for self-contained propulsion, and for onboard control and visualization aspects, together with suitable electrical power and signal sharing capabilities. Use of a modular ‘drop-in’ shielded electronics cabinet allows exchange or modification of control and/or signal processing apparatus. Other environmental apparatus, such as chillers, may be needed and may be directed to the imaging apparatus itself. Design, manufacture, operation and maintenance are all capable of some degree of benefit when similar requirements may be addressed using similarly-developed and operated equipment, to some extent. 
         [0006]    In many imaging applications, pixelated detectors are increasingly employed to realize electronic digital representations of image data. In turn, digital techniques provide great imaging flexibility, such as, for example, overlay or direct comparison, on the fly, of various aspects and views from various times. For example, pre-surgery images can be available, in real time, in the operating room scenario, for comparison to images reflective of the present status of the same tissues. Many other types of special-purpose enhancements are now also possible. In some instances, imaging aids, such as contrast-enhancing agents, are introduced into the subject or patient to aid in increasing available data content from the imaging technique or techniques being employed. 
         [0007]    Increasing sophistication of these imaging and visualization apparatus also result in significant cost, not only develop these devices, but also to acquire them, to train operators in using them, and service technicians to maintain them, and in educating physicians to be familiar with their capabilities and benefits. As a result, a significant investment is involved with respect to each such tool. 
         [0008]    The advent of digital imaging technologies resulted in a large number of new medical applications and usages for imaging tools. Digital images are made up of pixels, and these images are generally visualized by assigning each pixel a numerical value corresponding to a color or a shade of gray, and then displaying that assigned representation in the corresponding position for that pixel on a graphical display. A digital image can be adjusted by varying the numerical values of each pixel, for example by forming each pixel as a weighted combination of images formed at different times, or formed from illumination from different spectral components or by combining images including light-emitting, shadowgraphic, and reflected image data. The raw image data is manipulated by software using algorithms and mathematical computations to optimize the image. These types of images, alone or in combination with other data, provide useful tools for improving medical procedures. 
         [0009]    For the reasons stated above, and for other reasons discussed below, which will become apparent to those skilled in the art upon reading and understanding the present disclosure, there are needs in the art to provide more highly automated image computation engines and protocols for application and usage of such capabilities, in order to streamline gathering of information in support of increasingly stringent and exacting performance and economic standards in settings such as medical imaging. 
       BRIEF DESCRIPTION 
       [0010]    The above-mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and studying the following disclosure. 
         [0011]    In one aspect, a system provides a multi-axis translation and orientation capability for optical imaging. The system includes an optical imaging apparatus providing a signal representing a digitized image and a frame. The frame includes a first set of articulations capable of independently translating the optical imaging apparatus in multiple linear directions. The system also includes a second set of articulations formed as joints providing at least three independent degrees of rotation of the optical imaging apparatus. The system also provides an opening configured to permit the frame to be postured about a patient such that an isocenter corresponds to a region of interest of the patient, and an illumination source attached to the frame and configured to direct illumination towards the isocenter. The system also comprises an image detection apparatus co-located with the illumination source and having a focal plane at the isocenter. The image detection apparatus provides the signal, and the signal includes electronic information representing a pixelated optical image of the region of interest. 
         [0012]    In another aspect, a camera support includes a rigid member, and an illumination source rotatably mounted on the rigid member. A camera system is mounted on the rigid member with the illumination source and is coupled thereto. The camera system is responsive to illumination associated with the illumination source and has a focal plane. A group of guides are coupled to the rigid member, the guides having mutually orthogonal axes of motion. At least one of the guides includes a computer-controllable motor drive for lifting the rigid member. A group of joints each contribute a degree of freedom of rotation to the rigid member. A basal member is coupled to the rigid member via the group of guides and the group joints, and the rigid member is thus cantilevered. The group of guides and the group of joints cooperate to adjust a position of the camera system to cause the focal plane to coincide with a region of interest, and to facilitate motion of the camera system while maintaining the focal plane in coincidence with the region of interest. 
         [0013]    In a further aspect, a mobile optical imaging system includes an arcuate supporting member and an optical imaging apparatus coupled to one end of the arcuate supporting member. The optical imaging apparatus includes an illumination source and a camera system. The camera system provides a digital signal representing an image. A first counterweight is coupled to an end of the arcuate supporting member distal from the one end such that the first counterweight is opposed to the optical imaging apparatus. A basal member provides a second counterweight for cantilevering the arcuate support member. The basal member also includes a self-contained power supply and has motorized propulsion capabilities. The arcuate member is slidably coupled to the basal member to permit rotation of the optical imaging apparatus and the first counterweight about an isocenter coincident with a focal plane of the optical imaging assembly. A data conditioning module is provided that is capable of processing the digital signal to provide a modified signal representing a desired image type. A display is coupled to the data conditioning module. The display is configured to provide an optical image based on the modified signal. 
         [0014]    Systems, processes, and computer-readable media of varying scope are described herein. In addition to the aspects and advantages described in this summary, further aspects and advantages will become apparent by reference to the drawings and by reading the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a block diagram of an overview of a system configured to improve the display of images from an imaging apparatus. 
           [0016]      FIGS. 2 through 4  illustrate simplified examples of support systems capable of utility in the system of  FIG. 1 . 
           [0017]      FIGS. 5 and 6  are simplified block diagrams illustrating a number of degrees of freedom of motion associated with the support systems of  FIGS. 2 through 4 . 
           [0018]      FIG. 7  is a simplified block diagram of an optical assembly capable of utility in the system of  FIG. 1 , which may be supported via apparatus, such as exemplified by the preceding FIGs. 
           [0019]      FIG. 8  is a simplified block diagram of an optical assembly embodiment capable of utility in the system of  FIG. 1 . 
           [0020]      FIG. 9  illustrates an example of a general computation resource useful in the context of the environment of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which are shown, by way of illustration, specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized, and that logical, mechanical, electrical and other changes may be made, without departing from the scope of the embodiments. 
         [0022]    The term “optical imaging system” as used herein may include one or more cameras or camera systems, with computers, electronics, software and an optional illumination system. The term “illumination system” as used herein refers to a source of photons that may be provided by incandescent, LED, or laser based apparatus whose light output may be spectrally controlled by interference, holographic, and absorptive, or tunable filters, whose intensity may be time-varying and modified by the electronics and/or computer controls. The terms “camera” and “camera system” as used herein refer to a collection of one or more detectors configured with interference, holographic, absorptive, dichroic, or tunable filters; mirrors; and lenses that capture images which may be under the control of the computer and/or electronics that may be optionally synchronized to an illumination system. 
         [0023]    The term “optical Imaging” as used herein refers to an imaging modality that may include imaging based on illumination in the visible light spectrum, and/or which may comprise image information derived from illumination in the ultraviolet, visible and infrared light spectral regions, for enhancing intra-operative visualization and characterization of tissues through their endogenous optical properties, or bioluminescence or chemiluminesence (i.e., not necessarily involving any explicit external light source), and/or with various contrast/fluorescent agents or thermography. This is an arena which is currently the subject of many research projects being conducted at various institutions and corporations, often in cooperation with clinical partners. 
         [0024]    As used herein, the term “arcuate” refers to a shape that may comprise a portion or all of an ellipse or circle. As used herein, the term “illumination” is defined to refer to photons which do not necessarily correspond to light visible to humans. Ranges of parameter values described herein are understood to include all subranges falling therewithin. The following detailed description is, therefore, not to be taken in a limiting sense. 
         [0025]    The detailed description is divided into five sections. In the first section, a system level overview is provided. In the second section, examples of mobile optical imaging system configurations are described. In the third section, an optical imaging system useful in the context of the preceding sections is discussed. The fourth section discloses hardware and an operating environment, in conjunction with which embodiments may be practiced. The fifth section provides a conclusion which reviews aspects of the subject matter described in the preceding four segments of the detailed description. A technical effect of the systems and processes described herein includes provision of optical images in situ in operating room environments and finding application in medical technologies. 
       I. System Overview 
       [0026]      FIG. 1  is a simplified diagram of an overview of an imaging system  100  that is configured to improve display of images from one or more imaging tools. The imaging system  100  includes a mount aspect  102  that may comprise a gantry, C-arm or other adjustable, as well as stable, support  103 . Examples of some components, which are often typically included in a basal member in mobile imaging systems, not all of which may be needed in some applications, such as various electronic systems, propulsion capabilities, controllers, power supply elements, displays and other portions that need not be directly incorporated into the support  103 , are collectively grouped within dot-dashed outline  104 . 
         [0027]    An camera system  105 , which may include optical imaging capabilities, provides illumination  106  via an optional illumination source  107 , and may be attached to the support  103 , or may be separate from the support  103 , or may be absent, depending on the imaging task being addressed. The illumination source  107 , when employed, is configured to provide a relatively even distribution of illumination  106 , that is, to illuminate a field of view or a region, at a specified distance, or over a range of distances, from the illumination source  107 . The illumination  106  may comprise full-spectrum illumination, bandwidth-controlled illumination, infrared illumination, ultraviolet illumination and/or other imaging illumination. 
         [0028]    The illumination  106  and/or light from the region of interest gives rise to illumination  106 ′, which returns to the camera system  105 . One or more imaging devices or cameras  108 , such as charge-coupled device-based, pixelated imaging apparatus configured to provide digital electronic signals representative of an image, may be postured to focus within a region that may be illuminated via the illumination source  107 . In other words, the illumination source  107  is configured to provide a locus of evenly distributed light  106  over a spatial region that is coincident with a focal plane or field of view of the camera  108 . In some applications, multiple cameras  108 , for example providing different optical characteristics, may be contemporaneously employed. When stability and other mechanical support requirements warrant such, a counterweight  110  is coupled such that it is opposed to the camera  108 . 
         [0029]    The system  100  is configured to operate in conjunction with, or to include, a test subject support  111 . In one embodiment, components of the system  100 , and a test subject  112 , are maintained in a defined geometric relationship to one another by the gantry, c-arm or other appropriate support  103 . A distance between the camera system  105  and the patient  112  may be varied, depending on the type of examination sought, and the angle of the illumination  106  respective to the test subject  112  can be adjusted with respect to the body to be imaged  112 , responsive to the nature of imaging desired. For example, a region of interest  116  may be postured to coincide with the focal plane of the camera system  105 . 
         [0030]    The gantry  102  or C-arm  103  and the test subject support or table  110  cooperatively engage to enable relative motion of the test subject  112  longitudinally, that is, along an axis extending into and out of the plane of  FIG. 1 . For example, when the system  100  is configured as a mobile or wheeled unit, the gantry, support or c-arm maybe be translated along an axis parallel to, for example, a long axis of the test subject support  111 . 
         [0031]    The system  100  also optionally includes a control module  120 . The control module  120  may include a motor controller  122  configured to move the test subject support  111  and thus the test subject  112  relative to the illumination source  107  and/or support  103 , and may also control motors in the gantry  102 , C-arm or other support  103  or other device, and/or operate to position/move the camera system  105  relative to the test subject  112  and/or the rigid support  103 . 
         [0032]    The control module  120  may also include a drive controller  124  configured to control electrical drive parameters, for example affecting optical aspects and/or motion, delivered to the camera system  105 . 
         [0033]    In one embodiment, a chiller  128  supplies coolant to the camera system  105 . The chiller  128  may be contained in a basal member comprising a mobile, self-propelled, internally powered, wheeled unit that also forms a base for cantilevering the support  103  and camera system  105  relative to the test subject support  110 . 
         [0034]    One or more computers  130  are connected to the control module  120  via a bus  132  configured for receiving data descriptive of operating conditions and configurations and for supplying appropriate control signals. Buses  134  and  134 ′ act to transfer data and control signals, for example with respect to an image processing module  135 , via interconnections such as  134 ′,  134 ″ that are configured for exchange of signals and data to and/or from the computer  130  as well as other elements of the system  100  and/or external computation or communications resources. 
         [0035]    The system  100  also includes a bus  136 , a bus  138  and an operator console  140 . The operator console  140  is coupled to the system  100  through the bus  134 . The operator console  140  includes one or more displays  142  and a user input interface  144 . The user input interface  144  may include a keyboard, touchscreen, mouse or other tactile input device, and/or capability for voice commands and/or other input devices. The one or more displays  142  provide video, symbolic and/or audio or other information relative to operation of system  100 , displaying user-selectable options and images descriptive of the test subject  112 , and may display a user interface for facilitating user selection among various modes of operation and other system settings. The one or more displays  142  may be attached to the system  100 , or may include display capability remote from the system  100 . 
         [0036]    The image processing module  135  facilitates automation of accurate measurement and assessment, and is capable of forming multiple, coordinated images for display, for example via the displays  142 . The image processing module  135  may comprise a separate and distinct module, which may include application-specific integrated circuitry, or may comprise one or more processors coupled with suitable computer-readable program modules, or may comprise a portion of the computer  130  or other computation device. 
         [0037]    The system  100  also includes data communications, storage and memory devices  150 , coupled via the bus  136  to the computer  130  through suitable interfaces. The data communications, storage and memory devices  150  may include interface capabilities  152  for data exchange. The interface capabilities  152  may include RF, ultrasonic, infrared, fiber optic, cable and/or other data transmission/reception facilities, and may be broad-band, high data rate links for rapidly coupling larger amounts of data, such as still or moving images or volumetric data, between one or more computers or facilities. The data communications, storage and memory devices  150  may include mass data storage capabilities  154  and one or more removable data storage device ports  156 . The one or more removable data storage device ports  156  are adapted to detachably couple to portable data memories  158 , which may include optical, magnetic and/or semiconductor memories and may have read and/or write capabilities, and which may be volatile or non-volatile devices or may include a combination of the preceding capabilities. 
         [0038]    For example, medical image data or data related to medical images may be transferred, stored or read, using conventional protocols via the various data communications, storage and memory devices  150 . The Digital Imaging and Communications in Medicine or DICOM® protocol is one example of a conventional and widely-adopted data format which thus promotes sharing and transmission of digital medical image data, however, it will be appreciated that other data compression, decompression, transmission and interpretation protocols may be usefully employed. 
         [0039]    The system  100  further includes an image data acquisition and conditioning module  160  having data inputs coupled to the camera system  105  and is also coupled by the bus  138  to the one or more computers  130 . The data acquisition and conditioning module  160  includes circuitry for capturing digital data from the camera system  105  to be supplied to the one or more computers  130  for ultimate display via at least one of the displays  142  and for potential storage in the mass storage device  154  and/or data exchange with remote facilities (not shown in  FIG. 1 ). The acquired image data may be conditioned in the data acquisition and conditioning module  160 , the image processing module  135 , the one or more computers  130 , or a combination thereof. 
         [0040]    The system  100  also includes a power supply  170 , coupled via interconnections represented as a power supply bus  172 , shown in dashed outline, to other system elements, and a power supply controller  174 . The full range of interconnection of the power supply  170  to other elements of the system  100  is not shown in  FIG. 1 , in order to promote simplicity of illustration and ease of understanding. 
         [0041]    In some embodiments, the system  100  is configured to be a mobile system equipped and includes portable power supply capabilities  170 , such as a gang of batteries. In other words, the system  100  may comprise a wheeled unit and may be electromotively powered in self-contained fashion, lending physical agility to the ensemble of attributes offered by the system  100 . The batteries, in turn, may provide a counterweight, facilitating cantilevering of the articulated mounting and positioning bracket  103  employed to support the camera system  105 . 
         [0042]    In some settings, such as in an emergency room, articulation of a mobility function may be limited to motion of a system  100  that is generally dedicated to application within that setting, suite or environment. In other settings, such mobility may include scheduled sequential visits to areas such as a cardiac unit, an ICU and other loci, where such imaging capability provides critical assistance, such as when the test subject  112  is not postured in a fashion consistent with movement of the test subject  112  and yet aperiodic variations in work load are not favorable to cost-effective deployment of a system  100  incapable of ready, self-propelled, operator-guided, “at need” physical translation of location. In one embodiment, electrically-powered motors coupled to a drive train effectuate operator-directed motion of the system  100 . 
         [0043]    Self-portable systems  100  employing a C-arm  103 , rather than a gantry  102 , also provide motion capabilities relative to the test subject  112  and promote maintaining some known spatial relationships between the camera system  105  and the test subject  112  while changing other spatial relationships therebetween. For example, a known distance between a region of interest may be maintained while engaging in an angular adjustment. 
         [0044]    As part of initiating data collection, and then in the subsequent process of analyzing image data from the system  100 , a clinician will need to interact with the system  100  in order to select an image type or mode, and to specify data manipulation and display aspects. Conversion of data from the camera  108  to diagnostically-useful image data includes specification of settings appropriate to the desired type of image and to aspects specific to the individual patient  112 . 
         [0045]    It is possible that the image processing may be executed on the same physical system that controls the illumination source  107  and other elements of the system  100  that collect the image data, and this may be desirable, for example, in the operating room. However, another manner in which this technique may be employed includes transfers, through physical or electronic media, of the image data from the system  100  to a remote computing device where the technique may be applied on the transferred data. This latter situation may apply with respect to diagnostic procedures, for example, where time is not of the essence, or to settings involving consultation with an expert who is not physically present, for comparison of “before and after” data and other types of considerations. 
         [0046]    Features finding utility in one or more applications for optical imaging systems  100  include ease of transportation between areas, and suitable protection for the camera system  105  to avoid misalignment or damage which might occur during translation of the system  100  from one area of deployment to another. Capability for ready positioning of the camera system  105 , coupled with physical stability when in position, also are useful aspects. For example, at least with some types of camera systems  105 , it is helpful, in some applications, to be able to position the imaging device or camera  108  within a narrow focal range of the regions of interest, which may comprise patient tissue. In some applications, a range of about eighteen inches (forty-five centimeters) is useful. 
         [0047]    In some applications, the support  103  needs to be able to position the camera system  105 , weighing approximately 50 to 70 pounds (circa twenty to thirty kilograms). In some applications, the support  103  needs to be able to position the camera system  105 , weighing about five to thirty pounds (two to twelve kilograms). The support  103  desirably includes capabilities for a broad range of motion, manual or motorized or both, ranging from three degrees of freedom of motion, to six or more degrees of freedom, as is described below in more detail with reference to  FIGS. 6 and 7 . 
         [0048]    In at least one embodiment, the C-arm or other support  103  is movable in several directions along multiple image acquisition paths, including, for example, an orbital direction, a longitudinal direction, a lateral direction, a transverse direction, a pivotal direction and a “wig-wag” direction. In at least one embodiment, the illumination source  107  and camera  108  are movably positioned on the support  103 . Thus, the support  103 , along with the illumination source  107  and camera  108 , may be moved and positioned about the positioning device  111  on, or in which, the patient or object being imaged  112  has been situated. 
         [0049]    The displays or monitor/monitors  142  are usefully capable of accurately displaying high quality images and desirably are well positioned for surgeon visibility. Such displays  142  may include one or more of conventional flat-panel displays, projection-type displays, holographic displays or head-mounted displays. 
         [0050]    In one embodiment, digital data representing images from the camera system  105  include DICOM-compatibility to promote interoperability, for example to enable data and image exchange in order to facilitate consultation between physicians, and for archiving image related data in a standardized, broadly-used format. Some types of illumination sources  107  and/or cameras  108  may require cooling, internally contained within mobile examples of such camera system  105  and equipped in conformance with avoiding spread of dust and other contaminants in a sterile environment. Motorized positioning of the camera  108  operable via remote control, such as tactile input devices or voice-actuated commands, may be desirable, for example, to enable a physician to position the camera  108  from the tableside. 
         [0051]    There are many different ways possible for achieving articulated visual image apparatus other benefits of the subject matter disclosed herein. The apparatus of  FIGS. 2 through 7 , described below in more detail with reference to Section II, provide but a few examples for addressing these various needs. 
       II. Exemplary Mobile Support Systems and Articulation 
       [0052]      FIGS. 2 through 5  illustrate simplified examples of support systems capable of utility in the system  100  of  FIG. 1 , while  FIGS. 6 and 7  are simplified block diagrams illustrating a number of degrees of freedom of motion associated with the support systems of  FIGS. 2 through 5 . These support systems, and the optical imaging apparatus supported thereby, may find particular application in situations involving hospital operating rooms and emergency care areas, and in other medical arenas. 
         [0053]    In general, imaging apparatus support systems are used in at least two different ways. In one mode of usage, the imaging device may be employed to render views all having a common patient-centric or isocentric aspect. In others, such as colonoscopic procedures, the field of view and the region being imaged need to be moved from one location to another, and one depth to another, in imaging the areas of interest. As a result, in some systems, either type of motion is enabled by the selection of suitable adjustments. 
         [0054]    The support systems of  FIGS. 2 through 5  illustrate examples employing modified mobile C-arm gantries as the imaging apparatus gantries, however, it will be appreciated that other types of support systems may be usefully employed, to provide one or more useful aspects such as mobility, appropriate degrees of freedom of motion and other properties, as described herein, without departing from the spirit and scope of the disclosed subject matter. 
         [0055]      FIG. 2  illustrates an exemplary mobile imaging system  200 . The mobile imaging system  200  includes an exemplary assembly of salient imaging components  202  providing a multi-axis profiling imaging capability that includes a rigid support  203 , which is also adjustable, as is described in more detail below. 
         [0056]    The support  203  of  FIG. 2  is illustrated as comprising a rigid, arcuate member. A basal member or component support frame  204  that, in the example of  FIG. 1 , provides a pedestal for cantilevering the imaging components  202  and rigid support  203 , and includes provisions, such as a modular ‘drop-in’ shielded electronics cabinet, for accommodating numerous infrastructural components, for example, such as are above described in conjunction with the dot-dashed outline  104  of  FIG. 1 . 
         [0057]    An imaging apparatus  205 , analogous to the camera system  105  of  FIG. 1 , is attached to the rigid support  203 , which is illustrated as comprising a conventional c-arm support. The optical imaging apparatus  205  includes an illumination source  207  and one or more imaging devices, such as a camera  208 . 
         [0058]    A counterweight  210 , if needed, may be provided, for example at an end of the c-arm  203  distal from, or other position associated with other forms or support and suitably positions relative to, the optical imaging assembly  205 . As a result, balance and maneuverability of the resulting system  200  can similar to that of conventional mobile x-ray C-arm positioning devices, facilitating operator training by maintaining configuration and application similarities. 
         [0059]    More specifically, in usage, an isocentric design postures a region of interest or tissue of interest at a desired focal length, while adjustments are made to effect changing an angle of the line-of-sight of the optical imaging apparatus  205 . Conventional gas spring assists, which may reduce the weight requirement of the counterweight  210 , maintain ease of manual positioning through at least a portion of those ranges of positions that are most important and most clinically beneficial, while allowing for locked positioning after adjustment. 
         [0060]    A test subject support or operating table  211  is illustrated in dashed outline below the imaging apparatus  205 . The test subject support  211  is illustrated in conjunction with a test subject  212 , represented by a dotted elliptical outline. 
         [0061]    An adjustable multi-axial mount  213 , such as a gimbal or motorized, computer-regulated and/or operator controllable articulation, couples the imaging system  205  to the rigid support  203 . A bumper  214  may be coupled to the imaging apparatus  205  to provide a measure of protection from physical shock, as will be discussed below in more detail. 
         [0062]    The test subject  212  is postured to place a portion of the test subject  212  comprising a region of interest  216  in coincidence with a focal plane of the camera  208 , via adjustment of the rigid support  203 , the basal member  204 , the test subject support  212  and/or the adjustable mount  213 . 
         [0063]    As a portion of the basal member  204 , the mobile imaging system  200  may optionally include control module  220 . Forward mobility for the system  200  may be effectuated by powered wheels  223 , and casters  223 ′ may provide directional maneuverability. In some embodiments, a chiller  228  provides chilled coolant via conduits  229 . The conduits  229  are routed, in part, through a channel in the rigid support  203 . 
         [0064]    Electrical power for computer-controlled or operator-directed motors for driving a propulsion system (not illustrated) may be supplied via a self-contained power supply  270 . In some embodiments, the power supply may comprise conventional lead-acid batteries positioned to counterbalance and cantilever the rigid support  203 . As a result, the system  200  is able to provide functionality and/or mobility, even during a power outage. 
         [0065]    Various degrees of translational and rotational freedom of motion are described with reference to an exemplary Cartesian coordinate system.  FIG. 2  depicts x-axis  282 , y-axis  283  and z-axis  284 , collectively defining an origin, which is adjustable to be coincident with the region of interest  216 . The origin also is coincident with a focal plane of camera  208  of the imaging apparatus  205 . In this example, the focal plane is in the x-y plane. 
         [0066]    User-directed control of motors for propelling the imaging system  200 , and/or for actuating a motorized lift  285  for adjusting elevation of the imaging components  202 , among other purposes, may be realized, for example via a tableside and/or other user input controls (not shown in  FIG. 2 ) in data communication with, but physically separate or separable from, the rigid support  203  and/or the support frame  204 . Control access points may also be included via the ‘dog house’ control module  220 . 
         [0067]    Hand-, foot-, and/or voice-operable input-output media (e.g., input media  144 ,  FIG. 1 ) may provide controls for magnification modification, such as zoom in or out capabilities, for the camera  208 , can trigger or manually over-ride automatic focus aspects, and may be used to select among functions such as snap or still image preparation, cine or movie-like displays, recall of image data from electronic or electronically-compatible image storage elements (e.g., memory devices  150  and/or data interface  152  of  FIG. 1 ) for purposes of review, or to realize side-by-side comparison of different views, for suitably-weighted overlay of multiple imaging modes, such as fluorescence images overlaid with reflected illumination images, or for other comparisons, or for permitting multiple image data types to be contemporaneously engaged, or for changing the display  142  to modify or select color, black and white, functional optical, merge and controls for changing the relative weight of imaged components in forming composite images. 
         [0068]    The motorized lift column  285  provides controlled z-axis  284  motion capabilities, and a cross-arm and brake assembly  286  provides controlled y-axis  283  motion. An articulated cross-arm rotation joint  292  and lock  292 ′ allows ‘propeller’ rotation (also known as ‘flip-flop’ motion) of the rigid support  203 , to put it into a desired position, and then locked. A rear-capture sliding joint  294  mechanically couples the basal member to the rigid support  203 . The sliding joint  294  together with a mechanical lock  294 ′ facilitates orbital rotation (rotation about the y-axis  283 , that is, in the x-z plane) of the rigid support  203  and maintaining a desired position. 
         [0069]      FIG. 3  depicts an exemplary mobile imaging system  300 , in a different posture than that shown in  FIG. 2 . The rigid support  303  of  FIG. 3  has been orbitally rotated (as indicated by direction arrows  387  and dashed circular outline  387 ′) by an angle θ. As a result, an imaging axis  384 ′ is tilted, relative to the z axis  384 , isocentrically, that is, such that intersection of the focal plane of the imaging assembly  305  with the region of interest  316  is maintainable. 
         [0070]    Additionally, the optical imaging assembly  305  of  FIG. 3  is mounted such that the bumper  314  directly coupled the rigid support  303  and the rigid support protect the optical imaging assembly  305  from physical shock. 
         [0071]      FIG. 4  illustrates another exemplary mobile imaging system  400 . The system  400  incorporates a motorized lift column  485  for providing linear motion along the z axis  484 , however, in contrast to the systems  200  and  300  of  FIGS. 2 and 3 , the cross-arm  486  couples to a conventional L-arm  490  via a cross arm lockable rotary joint  492 . 
         [0072]    The cross arm rotation and lock joint  492  permits so-called “propeller” type rotation of the rigid support  403 . A rear capture channel  494  and associated lock provide orbital rotation capability, i.e., as shown by direction arrows  487 , via another articulation  495  that is coupled to the L-arm  490 . It will be appreciated that orientation, such as isocentric rotation, is possible via other types of mounting and articulation apparatus and shapes for the support systems. For example, such systems may be designed to allow rotation within a predetermined subset of, or throughout, the 360 degrees of possible orientations. 
         [0073]      FIG. 5  is a simplified block diagram showing a front view (i.e., looking to the left or down the x-axis  482  depicted in  FIG. 4 ) of a mobile imaging system  500 , illustrating several modes of articulation. The system  500  of  FIG. 5  includes representations of the rigid support  503 , the basal member  504  (in dashed outline), the imaging apparatus  505 , the counterweight  510  and the patient support table  511  (in dashed outline). A y-axis  583  direction arrow and a z-axis direction arrow  584  facilitate relating the geometry of  FIG. 5  to that of other FIGs. 
         [0074]    A bidirectional arrowed arc  587  indicates a ‘propeller’ type motion, corresponding, for example, to adjustment as described with reference to slidable coupling  292  of  FIG. 2 , or rotation about the cross-arm rotary joint  492  of  FIG. 4 . The propeller motion may be isocentric. 
         [0075]    In other words, when the initial alignment of the imaging system  500  is such that the region of interest (such as region  416 ) coincides with a center about which the rotation or propeller motion occurs, the region of interest is separated from the imaging apparatus  505  by a constant distance, which is chosen such that the focal plane of the imaging apparatus  505  intersects the region of interest. Consequently, rotation of the rigid support  503  via propeller motion need not necessarily require other positional adjustments or optical adjustments to maintain image integrity. 
         [0076]    A bidirectional arrowed arc  588  indicates a different type of angular adjustment of the imaging apparatus  505  relative to the rigid support  503 . The arc  588  may correspond to adjustment of the imaging  505  apparatus via the gimbal-type arrangement mentioned with respect to  FIGS. 2 and 3 . This form of articulation does not tend to be isocentric, and thus may be coordinated with adjustments in order to maintain focus or to continue to image the region of interest. 
         [0077]      FIG. 6  is a simplified block diagram showing a top plan view (i.e., looking to the down the z-axis  484  depicted in  FIG. 4 ) of a mobile imaging system  600 , illustrating several modes of articulation. The rendering of  FIG. 6  includes representations of the rigid support  603 , the basal member  604  (in dashed outline), the imaging apparatus  605  and the patient support table  611  (in dashed outline). An x-axis direction arrow  682  and a y-axis  683  direction arrow facilitate relating the geometry of  FIG. 6  to that of other FIGs. 
         [0078]    A bidirectional arrowed arc  688 ′ indicates a rotation of the optical imaging assembly  605  about a center  688 ″, for example, based on articulation of a joint such as the gimbal  313  of  FIG. 3 . However, in practice, this type of image rotation is easily accomplished without need for physical motion, for example, via the image processing engine  135  of  FIG. 1 . A bidirectional arrowed arc  689  indicates a ‘wig-wag’ type of articulation. The effect of this type of adjustment is to sweep the focus of the imaging system  605  along an arc  689 ′, represented by a dashed arc in  FIG. 6 . This type of motion typically has very limited range of rotation for the rigid support about a center  689 ″. 
         [0079]    Usage of a platform, such as briefly described with reference to  FIGS. 2 through 6 , for deployment of imaging apparatus, provides benefits. Both types of systems may use similar optical displays, such as dual flat-panel monitors capable of providing high quality color or black-and-white images, and readily mountable to provide position adjustability, for example via an articulating arm assembly. As a result, parts inventories, maintenance, and operator training aspects provide a degree of synergism, resulting in reduced overhead. 
         [0080]    The disclosed examples can provide mass and positioning flexibility aspects similar to those of conventional mobile x-ray systems. The ‘footprint’ and mobility aspects for such systems are ‘tried and true’ in the operating room context, and are compatible with the optical system requirements. The following section briefly describes some exemplary optical imaging assembly considerations. 
       III. Optical Imaging Assembly 
       [0081]    In the previous section, tools developed in furtherance of functionality with respect to mobile imaging apparatus were disclosed and described. In this section, an optical imaging assembly, and description of capabilities of the imaging assembly, are provided with reference to a block diagram.  FIG. 7  is a simplified block diagram of an optical system  700  capable of utility in the system  100  of  FIG. 1 , and which may be supported via apparatus such as exemplified by  FIGS. 2 through 6 . 
         [0082]    The imaging assembly  705  includes an suitable light beam  706  via an illumination source  707 , and also includes a camera  708 . The camera  708  has a focal plane  714 , and is focused to be able to accurately image features within a region  715 . In some embodiments, the illumination source  707  provides a light beam  706  having intensity and spectral characteristics selected for a particular type of imaging task. 
         [0083]    The illumination source  707  and camera system  708  are selected to be able to provide images based on illumination  706 ′ leaving the region of interest, which may have wavelength characteristics corresponding to a selected band of optical frequencies falling within a range extending from the infrared, that is, a wavelength of up to one point three microns, to the ultraviolet. In some instances, the excitation illumination  706  may be chosen to have a wavelength which excites fluorescence, based on the endogenous properties of the tissues being imaged, or based on specific compounds introduced into the patient. 
         [0084]      FIG. 8  is a simplified block diagram of an embodiment  800  of an optical assembly  805  capable of utility in the system of  FIG. 1 . The optical assembly  805  of the embodiment  800  includes a transparent cooling plate  805  and a cold light source  807 , such as an LED light source, mounted in front of the transparent cooling plate  805 . A lens and focusing assembly  810 , which may be motor-driven and controllable via the computer  130  and/or the user input media  144  of  FIG. 1 , is configured on a side of the cooling plate  805  opposite an opening extending through the light source  807 . A first dichroic beam splitter/filter  812  is positioned in an optical path at an output of the lens assembly  810 , and a second dichroic beam splitter/filter  813  is positions in the optical path at one output of the first dichroic beam splitter/filter  812 . 
         [0085]    Mirrors (which may be formed as prisms or in other conventional ways)  814 ,  815 ,  816  and  817  are each positioned in respective portions of the optical paths resulting from the first  812  and second  813  beam splitters. An optical color video camera  820  is positioned to capture the portion of the incident light reflected by the first mirror  814 . A near infrared camera  822  is positioned to capture the portion of the incident light reflected by the second mirror  815 . A third near infrared camera  824  is positioned to capture light reflected by the third and fourth mirrors  816 ,  817 , after amplification by an optical image intensifier  826 . 
         [0086]    In one embodiment, the optical video camera  820  is a conventional CCD-type camera, such as a model IMC-80F camera manufactured by Imi Tech of Seoul, Korea and distributed by Graftek Imaging of Austin, Tex. 
         [0087]    In one embodiment, the near infrared cameras  822  and  824  are monochrome cameras, such as a C4742-80-12AG camera, manufactured by Hamamatsu Photonics K.K. having facilities throughout Japan and also distributed by Graftek Imaging. Filters such as may be incorporated with the dichroic beam splitter  813 , or at an input to each camera  822 ,  824 , or both, may, for example, direct 700 nanometer light to the camera  824  and 800 nanometer light to the camera  826 . 
         [0088]    Fluorinert® coolant, or other fluid coolant that is relatively transparent to the illumination for the images formed from the cameras  820 ,  822  and  824  is circulated through the cooling plate  805 . This provides chilling, if needed, for the cameras  822 / 824 , and thermally isolates the camera system from the light source  807 . 
       IV. Hardware and Operating Environment 
       [0089]      FIG. 9  illustrates an example of a general computer environment  900  that includes a computation resource  902  capable of implementing the processes described herein. It will be appreciated that other devices may alternatively used that include more components, or fewer components, than those illustrated in  FIG. 9 . 
         [0090]    The illustrated operating environment  900  is only one example of a suitable operating environment, and the example described with reference to  FIG. 9  is not intended to suggest any limitation as to the scope of use or functionality of the embodiments of this disclosure. Other well-known computing systems, environments, and/or configurations may be suitable for implementation and/or application of the subject matter disclosed herein. 
         [0091]    The computation resource  902  includes one or more processors or processing units  904 , a system memory  906 , and a bus  908  that couples various system components including the system memory  906  to processor(s)  904  and other elements in the environment  900 . The bus  908  represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port and a processor or local bus using any of a variety of bus architectures, and may be compatible with SCSI (small computer system interconnect), or other conventional bus architectures and protocols. 
         [0092]    The system memory  906  includes nonvolatile read-only memory (ROM)  910  and random access memory (RAM)  912 , which may or may not include volatile memory elements. A basic input/output system (BIOS)  914 , containing the elementary routines that help to transfer information between elements within computation resource  902  and with external items, typically invoked into operating memory during start-up, is stored in ROM  910 . 
         [0093]    The computation resource  902  further may include a non-volatile read/write memory  916 , represented in  FIG. 9  as a hard disk drive, coupled to bus  908  via a data media interface  917  (e.g., a SCSI, ATA, or other type of interface); a magnetic disk drive (not shown) for reading from, and/or writing to, a removable magnetic disk  920  and an optical disk drive (not shown) for reading from, and/or writing to, a removable optical disk  926  such as a CD, DVD, or other optical media. 
         [0094]    The non-volatile read/write memory  916  and associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computation resource  902 . Although the exemplary environment  900  is described herein as employing a non-volatile read/write memory  916 , a removable magnetic disk  920  and a removable optical disk  926 , it will be appreciated by those skilled in the art that other types of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, FLASH memory cards, random access memories (RAMs), read only memories (ROM), and the like, may also be used in the exemplary operating environment. 
         [0095]    A number of program modules may be stored via the non-volatile read/write memory  916 , magnetic disk  920 , optical disk  926 , ROM  910 , or RAM  912 , including an operating system  930 , one or more application programs  932 , other program modules  934  and program data  936 . Examples of computer operating systems conventionally employed for some types of three-dimensional and/or two-dimensional medical image data include the NUCLEUS® operating system, the LINUX® operating system, and others, for example, providing capability for supporting application programs  932  using, for example, code modules written in the C++® computer programming language. 
         [0096]    A user may enter commands and information into computation resource  902  through input devices such as input media  938  (e.g., keyboard/keypad, tactile input or pointing device, mouse, foot-operated switching apparatus, joystick, touchscreen or touchpad, microphone, antenna etc.). Such input devices  938  are coupled to the processing unit  904  through a conventional input/output interface  942  that is, in turn, coupled to the system bus. A monitor  950  or other type of display device is also coupled to the system bus  908  via an interface, such as a video adapter  952 . 
         [0097]    The computation resource  902  may include capability for operating in a networked environment (as illustrated in  FIG. 1 , for example) using logical connections to one or more remote computers, such as a remote computer  960 . The remote computer  960  may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computation resource  902 . In a networked environment, program modules depicted relative to the computation resource  902 , or portions thereof, may be stored in a remote memory storage device such as may be associated with the remote computer  960 . By way of example, remote application programs  962  reside on a memory device of the remote computer  960 . The logical connections represented in  FIG. 9  may include interface capabilities, e.g., such as interface capabilities  152  ( FIG. 1 ) a storage area network (SAN, not illustrated in  FIG. 9 ), local area network (LAN)  972  and/or a wide area network (WAN)  974 , but may also include other networks. 
         [0098]    Such networking environments are commonplace in modern computer systems, and in association with intranets and the Internet. In certain embodiments, the computation resource  902  executes an Internet Web browser program (which may optionally be integrated into the operating system  930 ), such as the “Internet Explorer®” Web browser manufactured and distributed by the Microsoft Corporation of Redmond, Wash. 
         [0099]    When used in a LAN-coupled environment, the computation resource  902  communicates with or through the local area network  972  via a network interface or adapter  976 . When used in a WAN-coupled environment, the computation resource  902  typically includes interfaces, such as a modem  978 , or other apparatus, for establishing communications with or through the WAN  974 , such as the Internet. The modem  978 , which may be internal or external, is coupled to the system bus  908  via a serial port interface. 
         [0100]    In a networked environment, program modules depicted relative to the computation resource  902 , or portions thereof, may be stored in remote memory apparatus. It will be appreciated that the network connections shown are exemplary, and other means of establishing a communications link between various computer systems and elements may be used. 
         [0101]    A user of a computer may operate in a networked environment  100  using logical connections to one or more remote computers, such as a remote computer  960 , which may be a personal computer, a server, a router, a network PC, a peer device or other common network node. Typically, a remote computer  960  includes many or all of the elements described above relative to the computer  900  of  FIG. 9 . 
         [0102]    The computation resource  902  typically includes at least some form of computer-readable media. Computer-readable media may be any available media that can be accessed by the computation resource  902 . By way of example, and not limitation, computer-readable media may comprise computer storage media and communication media. 
         [0103]    Computer storage media include volatile and nonvolatile, removable and non-removable media, implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules or other data. The term “computer storage media” includes, but is not limited to, RAM, ROM, EEPROM, FLASH memory or other memory technology, CD, DVD, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other media which can be used to store computer-intelligible information and which can be accessed by the computation resource  902 . 
         [0104]    Communication media typically embodies computer-readable instructions, data structures, program modules or other data, represented via, and determinable from, a modulated data signal, such as a carrier wave or other transport mechanism, and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal in a fashion amenable to computer interpretation. 
         [0105]    By way of example, and not limitation, communication media include wired media, such as wired network or direct-wired connections, and wireless media, such as acoustic, RF, infrared and other wireless media. The scope of the term computer-readable media includes combinations of any of the above. 
         [0106]    The computer  902  may function as one or more of the control segments of module  120  ( FIG. 1 ), the computer  130 , the operator console  140  and/or the data acquisition and conditioning module  160 . 
       V. Conclusion 
       [0107]    The disclosed examples combine a number of useful features and present advantages in modern hospital settings. These examples leverage prior capabilities associated with mobile x-ray imaging tools, including mechanical and electrical reliability under a wide range of potentially-applicable circumstances. Additionally, compatibility with existing tools and modes for image data representation, and conventional image data storage and exchange standards facilitate interoperability with existing modules developed for those purposes, as well as promoting compatibility with newer approaches, such as integrated surgical navigation. The disclosed capabilities also benefit from compatibility with existing systems, and thus coordinate with other operator training, reducing probability of error, such as may occur in time-critical scenarios. 
         [0108]    These examples additionally employ tools for remote, table-side positioning, in fashions often familiar to many physicians from prior experience with other mobile medical imaging tools, such as mobile fluoroscopic tools employed in contexts including cardiac surgery. Combining surgical navigation sensors with motorized, operator-directed imaging tool motion enhances a gamut of opportunities for automated positioning solutions. Maintaining broad compatibility with requirements for ancillary elements needed in the surgical environment, such as cart draping accessories and c-arm or other gantry or support mechanism draping, reduces the breadth of inventory items needed for infrastructural elements, presenting cost and supply management benefits, and aiding in appropriate deployment of those types of items in usage. 
         [0109]    Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any adaptations or variations. For example, although described in procedural terms, one of ordinary skill in the art will appreciate that implementations can be made in a procedural design environment or any other design environment that provides the required relationships. 
         [0110]    In particular, one of skill in the art will readily appreciate that the names or labels of the processes and apparatus are not intended to limit embodiments. Furthermore, additional processes and apparatus can be added to the components, functions can be rearranged among the components, and new components to correspond to future enhancements and physical devices used in embodiments can be introduced without departing from the scope of embodiments. One of skill in the art will readily recognize that embodiments are applicable to future communication devices, different file systems, and new data types. The terminology used in this disclosure is meant to include all object-oriented, database and communication environments and alternate technologies which provide the same functionality as described herein.