Abstract:
An imaging system for imaging an object, comprising a scanner; and a transport mechanism mounted to the base of the scanner, wherein the transport mechanism comprises a crawl drive for crawling along the floor supporting the imaging system so as to index the scanner relative to an object during scanning of the object.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS 
       [0001]    This patent application claims benefit of: 
         [0002]    (i) pending prior U.S. Provisional Patent Application Ser. No. 60/670,164, filed Apr. 11, 2005 by Andrew P. Tybinkowski et al. for ANATOMICAL IMAGING SYSTEM WITH CENTIPEDE DRIVE (Attorney&#39;s Docket No. NLOGICA-1 PROV); and 
         [0003]    (ii) pending prior U.S. Provisional Patent Application Ser. No. 60/593,001, filed Jul. 30, 2004 by Bernard Gordon et al. for ANATOMICAL SCANNING SYSTEM (Attorney&#39;s Docket No. NLOGICA-14 PROV). 
         [0004]    The two above-identified patent applications are hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0005]    This invention relates to anatomical imaging systems in general, and more particularly to anatomical imaging systems of the sort utilizing Computerized Tomography (CT) systems and the like. 
       BACKGROUND OF THE INVENTION 
       [0006]    Strokes are the third leading cause of death in the United States (causing approximately 17,000 deaths per year) and the number one cause of long-term disability (affecting nearly 5 million people). Strokes result from abrupt damage to the brain or spinal cord caused by an abnormality of the blood supply. 
         [0007]    Strokes typically occur in one of two forms: (i) hemorrhagic which occurs with the rupture of a blood vessel; and (ii) ischemic, which occurs with the obstruction of a blood vessel. 
         [0008]    Rapid diagnosis is a key component of stroke management. This is because treatments for ischemic strokes may be contra-indicated for treatment of hemorrhagic strokes and, furthermore, the effectiveness of a particular treatment can be time-sensitive. In particular, the only approved therapy for acute ischemic strokes, i.e., the administration of tPA to eliminate clots, is contra-indicated for hemorrhagic strokes. Furthermore, tPA is most effective if it is administered within 3 hours of the onset of an ischemic stroke. However, current diagnosis times (i.e., the time needed to identify that the patient is suffering from a stroke and to identify the hemorrhagic or ischemic nature of the stroke) frequently exceeds this 3 hour window. As a result, only a fraction, of ischemic stroke victims are properly treated with tPA. 
         [0009]    Imaging is generally necessary to: (i) distinguish strokes from other conditions; (ii) distinguish between the different types of strokes (i.e,, hemorrhagic or ischemic); and (ii) determine suitable treatments. Computerized Tomography (CT) has emerged as the key imaging modality in the diagnosis of strokes. CT scans, including Non-Enhanced CT, CT angiography and CT perfusion, provide the necessary and sufficient information for diagnosing and treating strokes. 
         [0010]    Unfortunately, however, the “round-trip” time between the emergency room (where the patient is typically first received) and the radiology department (where the CT machine is typically located) can frequently take up to several hours, even in the best hospitals. As a result, the time spent in transporting the patient from the emergency room to the CT machine and back again can consume critical time which can compromise treatment of the patient. 
         [0011]    Thus, there is a need for a new and improved CT machine which is particularly well suited for use in stroke applications. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention comprises a new and improved anatomical imaging system which addresses the foregoing problems. More particularly, the present invention comprises a small, mobile CT machine that can be moved to the patient so that the patient can be scanned at their current location, thus dramatically reducing diagnostic times. The mobile CT machine can be located in the emergency room, is easy to transport directly to the patient&#39;s bedside, and provides image quality favorably comparable to traditional, fixed-location CT machines which require patient transport. 
         [0013]    In essence, the new CT machine eliminates traditional transportation delays by allowing patients to be scanned in the emergency room, while remaining on their gurney. 
         [0014]    More particularly, with a conventional CT machine, the CT machine is fixed in place, typically in the radiology department. The patient is moved to the CT machine, placed on a precision-advancement patient platform and then, with the scanning apparatus remaining stationary, the patient is advanced into the scanning zone of the CT machine using the precision-advancement patient platform. In contrast, with new CT machine of the present invention, the patient remains in the emergency room on their gurney, the GT machine is moved to the patient and then, while the patient remains stationary, the CT machine is precision-advanced relative to the patient so that the scanning zone of the CT machine moves relative to the patient. Thus, the new CT machine of the present invention can he wheeled into position in an emergency room and the patient scanned while remaining on their gurney, without ever having to move the patient from the emergency room to the radiology department, and then off the gurney and onto the moving platform of a traditional, fixed-location CT machine. 
         [0015]    As a consequence of this novel approach to CT scanning, the new CT machine requires a precision-advancement mechanism for moving the entire CT machine relative to the patient during the scanning process. 
         [0016]    To this end, the present invention provides a novel centipede belt drive which provides high precision movement of the CT machine relative to the patient during scanning. In particular, the centipede belt drive is designed to provide substantially the same degree of precision when moving the CT machine about the patient as conventional CT machines provide when moving the precision-advancement patient platform relative to the fixed scanning zone of the conventional CT machine. 
         [0017]    Preferably the novel CT machine comprises two transport mechanisms: one for moving the CT machine relatively quickly across room distances prior to scanning, and one for moving the CT machine precisely relative to the patient during scanning. 
         [0018]    In one preferred form of the invention, there is provided an anatomical imaging system comprising: 
         [0019]    a CT machine; and 
         [0020]    a transport mechanism mounted to the base of the CT machine, wherein the transport mechanism, comprises a fine movement mechanism for moving the CT machine precisely, relative to the patient, during scanning. 
         [0021]    In another preferred form of the invention, there is provided an anatomical imaging system comprising: 
         [0022]    a CT machine; and 
         [0023]    a transport mechanism mounted to the base of the CT machine, wherein the transport mechanism comprises: 
         [0024]    a gross movement mechanism for transporting the CT machine relatively quickly across room distances; and 
         [0025]    a fine movement mechanism for moving the CT machine precisely, relative to the patient, during scanning. 
         [0026]    In another preferred form of the invention, there is provided an imaging system, comprising: 
         [0027]    a scanner; and 
         [0028]    a transport mechanism mounted to the base of the scanner, wherein the transport mechanism comprises:
       a gross movement mechanism for transporting the scanner relatively quickly across room distances; and   a fine movement mechanism for moving the scanner precisely, relative to the object being scanned, during scanning.       
 
         [0031]    In another preferred form of the invention, there is provided a method for scanning a patient comprising: 
         [0032]    providing an anatomical imaging system, the system comprising;
       a CT machine; and   a transport mechanism mounted to the base of the CT machine, wherein the transport mechanism comprises:
           a gross movement mechanism for transporting the CT machine relatively quickly across room distances; and   a fine movement mechanism for moving the CT machine precisely, relative to the patient, during scanning;   
               
 
         [0037]    transporting the CT machine to the patient across room distances, using the gross movement mechanism; and 
         [0038]    scanning the patient while moving the CT machine precisely, relative to the patient, with the fine movement mechanism. 
         [0039]    In another preferred form of the invention, there is provided a method for scanning a patient, comprising: 
         [0040]    moving a CT machine across room, distances to the patient; and 
         [0041]    scanning the patient while moving the CT machine precisely relative to the patient during scanning. 
         [0042]    In another preferred form of the invention, there is provided a method for scanning an object, comprising: 
         [0043]    moving a scanner across room distances to the the object; and 
         [0044]    scanning the object while moving the scanner precisely relative to the object during scanning, 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0045]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
           [0046]      FIGS. 1-6  are a series of views showing the exterior of a novel CT machine formed in accordance with the present invention; 
           [0047]      FIG. 7  is a bottom view of the CT machine showing its novel transport mechanism; 
           [0048]      FIGS. 8-10  show the CT machine&#39;s gross movement mechanism and fine movement mechanism secured to the frame of the CT machine; 
           [0049]      FIGS. 11-14  show details of the construction of the CT machine&#39;s gross movement mechanism; and 
           [0050]      FIGS. 15-25  show details of the construction of the CT machine&#39;s fine movement mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     CT Machine  5   
       [0051]    Looking first at  FIGS. 1-6 , there is shown a novel CT machine  5  formed in accordance with the present invention. CT machine  5  generally comprises a base  10  which supports a torus  15 . Torus  15  defines a center opening  20 . Base  10  and torus  15  together comprise the CT scanning apparatus which is used to scan the patient anatomy positioned in center opening  20 . Such scanning apparatus typically comprises a rotating X-ray source and X-ray detector, and various electronic hardware and software for controlling the apparatus and processing the acquired data so as to generate the CT scans. Such scanning apparatus may foe of the sort well known in the art. 
         [0052]    CT machine  5  also comprises the novel transport mechanism  100  which will hereinafter be discussed. 
       Transport Mechanism  100   
       [0053]    As noted above, CT machine  5  is intended to be moved to the patient, and then scan the patient while the patient remains stationary on their gurney. 
         [0054]    To this end, in one preferred form of the invention, and looking now at  FIG. 7 , CT machine  5  preferably comprises a transport mechanism  100  which comprises two different mechanisms for moving CT machine  5 : (i) a gross movement mechanism  105  for transporting CT machine  5  quickly across significant distances (e.g., across a room to the patient); and (ii) a fins movement mechanism  110  for moving CT machine  5  precisely across small distances (e.g., relative to the patient during scanning). As will hereinafter foe discussed, fine movement mechanism  110  preferably comprises the aforementioned centipede belt drive for precisely moving the CT machine relative to the patient during scanning. 
         [0055]    As seen in  FIGS. 3-10 , gross movement mechanism  105  and fine movement mechanism  110  are both secured to the frame  115  of base  10  so that they can, alternatively, support CT machine  5 , 
       Gross Movement Mechanism  105   
       [0056]    Gross movement mechanism  105  is used to transport CT machine  5  quickly across significant distances (e.g., across a room to the patient). More particularly, and looking now at  FIGS. 8-14 , gross movement mechanism  105  preferably comprises two identical, spaced-apart caster units  117  which cooperate to form the gross movement mechanism  105 . 
         [0057]    Each caster unit  117  comprises a chassis  120  having a pair of casters  125  rotatably mounted thereto. Chassis  120  is movably mounted to a support block  130 , and support block  130  is in turn secured to frame  115 , More particularly, chassis  120  is movably mounted to support block  130  by means of a pair of slide rods  135  and support block  130  are slidably received in slide housings  140  which are secured to support block  130 . An actuator (hydraulic or otherwise)  145 , which is mounted to support block  130 , has its actuator rod  150  engaging chassis  120 . As noted above, support block  130  is secured to frame  115  of CT machine  5 . 
         [0058]    As a result of this construction, when it is desired to move CT machine  5  about on gross movement mechanism  105 , gross movement mechanism  105  is operated as follows. The two caster units  117  are operated in a coordinated fashion so that their actuators (hydraulic or otherwise)  145  extend their actuator rods  150  so as to cause chassis  120  to project downward from support blocks  130 , whereby to cause the casters  125  to engage the floor and support CT machine  5  on the casters  125 . CT machine  5  can then be maneuvered about a room on the casters  125 . When it is desired to use the CT machine  5  for scanning, the gross movement mechanism  105  is operated as follows. The two caster units  11  are operated in a coordinated fashion so that their actuators (hydraulic or otherwise)  145  retract their actuator rods  150  so as to cause chassis  120  to return towards support blocks  130 , whereby to seat fine movement mechanism  110  of CT machine  5  securely on the floor. 
         [0059]    In one configuration, gross movement mechanism  105  comprises two identical caster units  117 , with one caster unit  117  located on each side of the patient. Alternatively, more than two caster units  11  may be provided (e.g., three or four), and they may be distributed about base  10  of CT machine  5  in any desired configuration. 
       Fine Movement Mechanism  110   
       [0060]    Fine movement mechanism  110  is used to move CT machine  5  precisely relative to the patient during scanning. More particularly, and looking now at  FIGS. 7 and 9 , fine movement mechanism  110  preferably comprises two identical, spaced-apart centipede belt drive units  153  which cooperate to form the fine movement mechanism  110 . 
         [0061]    Looking next at  FIGS. 15-25 , each centipede belt drive unit  153  comprises a chassis  155  which is secured to frame  115 . Chassis  155  preferably comprises two halves ( FIG. 18 ) which are secured together to form a single housing with an interior space. Chassis  155  has a belt  160  drivably mounted thereto. More particularly, chassis  155  comprises a pair of drive gears (sometimes referred to as a timing pulley)  165  which are rotatably mounted to chassis  155 . Drive gears  165  comprise teeth  170  which engage counterpart ribs (not shown) formed on the interior of belt  160 , such that when drive gears  165  are rotated, their rotational motion is transferred to belt  160 . Preferably teeth  170  have an arched configuration, so as to provide a uniform engagement between adjacent teeth and the drive belt, thereby allowing precision transfer of motion between the drive gear and the drive belt. One or more motors  175  are secured to chassis  155 . Preferably motors  175  are located inside the centipede belt drive unit to save space. A transmission belt  1 . 80  connects the drive shaft of motor  175  to at least one of the drive gears  165 , whereby the one or more motors  175  can be used to turn belt  160  and thereby drive the unit. 
         [0062]    A suspension unit  185 , such as the one shown in  FIGS. 18-25 , or another suspension unit of the sort well known in the belt drive art, is preferably secured to chassis  155  within the interior of belt  160  so as to distribute the load of CT machine  5  across a plurality of rollers and onto the belt  160 . In one preferred construction, suspension unit  18   5  comprises ( FIGS. 21-25 ) a pair of roller assemblies  190  balanced with a pair of rockers  195  which are mounted on an axle  200  and balanced, with four springs  205 . Additional suspension rollers (e.g., rollers  210  in  FIGS. 18-20 ) may also be provided if desired. 
         [0063]    As a result of this construction, when it is desired to move CT machine  5  on fine movement mechanism  110 , CT machine  5  is lowered onto fine movement mechanism  105  (i.e., by retracting the casters  125  of gross movement mechanism  105 ), and then fine movement mechanism  110  is operated as follows. The two centipede belt drive units  153  are operated in a coordinated fashion so that their motors  175  rotate drive gears  165 , whereby to turn belts  160  and thereby precisely advance CT machine  5  (e.g., relative to a patient). 
         [0064]    The centipede belt drive unit  153  is designed to move the CT machine relative to the patient in one of two motions; (1) indexed movement using discrete steps for slice scanning; and (2) smooth movement using substantially continuous motion for helical scanning. The centipede belt drive unit  153  achieves this through the use of the aforementioned floor-engaging drive belts  160  which provide the necessary precision movement and repeatability 
         [0065]    The centipede belt drive system is preferably configured to allow multi-directional patient scanning, i.e., scanning in both forward and backward directions. 
         [0066]    In a preferred embodiment of the invention, two independent centipede belt drive units  153  are used, one on each side of the patient. The two centipede belt drive units are driven in a coordinated fashion so as to effect the precise movement desired. In this respect it should be appreciated that, due to the use of two independent belt drives, differences in components or external conditions (e.g., floor tilt) may create a yawing effect. This is resolved by driving each belt separately at an appropriate rate, 
         [0067]    A feedback system is preferably used to ensure that each centipede belt drive unit  153  is moving at the desired speed. An encoder device (e.g., an optical encoder or a rotary potentiometer or other device) may be used to determine the rate of drive gear movement so as to regulate belt movement. In this respect it should be appreciated that, in view of the very small movements associated with CT scanning, hysteresis problems may arise with the drive belts  160 . The encoder device may also be used to identify and compensate for any such hysteresis. 
         [0068]    In one configuration, the fine movement mechanism  105  comprises two identical centipede belt drive units  153 , with the two identical drives straddling the patient. Alternatively, the CT machine could be provided with wheels on each side of the patient, and a single centipede belt drive unit  153  could be provided to move the wheeled assembly during scanning movement. 
       Use 
       [0069]    In accordance with the present invention, transport mechanism  100  can be used to move CT machine  5  as follows. Initially, CT machine  5  is raised on its gross movement mechanism  105  by causing actuators (hydraulic or otherwise)  145  to extend their actuator rods  150 , whereby to cause casters  125  to engage the floor and support CT machine  5  on the casters  125 . CT machine  5  can then be maneuvered about a room on its casters  125 , i.e., so that a patient lying on a gurney may foe positioned within the center opening  20  of CT machine  5  without moving the patient off the gurney. Thereafter, gross movement mechanism  105  is operated so that the caster units  11  retract their actuator rods  150  so as to cause chassis  120  to return towards their support blocks  130 , whereby to permit the drive belts  160  of fine movement mechanism  110  to engage the floor. Thereafter, when scanning is commenced, motors  175  are used to precisely advance belt  160 , and hence CT machine  5 , relative to the patient during scanning. 
         [0070]    Thus, in one preferred form of the invention, the fine movement mechanism  110  operates only during the scanning process. More particularly, prior to scanning, the CT machine is moved to the patient on gross movement mechanism  105 ; thereafter, the fine movement mechanism  105  engages the floor and operates during scanning to move the CT machine relative to the patient during the scanning process. Alternatively, where fine movement mechanism  110  is capable of reasonably rapid rates of speed, gross movement mechanism  105  may be omitted entirely and only fine movement mechanism  110  provided. 
       Application to Other Types of Scanning Systems 
       [0071]    It should be appreciated that the present invention is not limited to use in medical applications or, indeed, to use with CT machines. Thus, for example, the present invention may be used in connection with CT machines used for non-medical applications, e.g., with CT machines used to scan inanimate objects. Furthermore, the present invention may be used with non-CT-type scanning systems. In essence, the present invention has application to any scanning device which requires that the scanning apparatus be precisely moved relative to the scanned object. Thus, for example, the present invention may foe used in conjunction with other types of scanners. 
       Modifications 
       [0072]    It will be appreciated that still further embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure. It is to be understood that the present invention is by no means limited to the particular constructions herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the invention.