Abstract:
A docking station for one or more x-ray detectors is disclosed and designed to secure an x-ray detector when not in use to limit exposure of an x-ray detector to drops, jars, and other potentially damaging incidents. The docking station may be equipped to regulate the temperature of a stored x-ray detector. Thermal regulation can be achieved passively or actively using convection, conduction, radiation, and other thermal transference principles. The docking station may also include an electronic interface that communicates with a stored x-ray detector such that thermal regulation may be achieved dynamically and responsively. The docking station may be free-standing or wall-mounted. The docking station may be remote from or integrated with an x-ray scanner. The docking station may also be equipped to charge/re-charge batteries of a stored x-ray detector.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates generally to diagnostic imaging and, more particularly, to a docking station that regulates the temperature of a stored detector.  
         [0002]     X-ray imaging is a non-invasive technique to capture images of medical patients for clinical diagnosis as well as inspect the contents of sealed containers, such as luggage, packages, and other parcels. To capture these images, an x-ray source irradiates a scan subject with a fan beam of x-rays. The x-rays are then attenuated as they pass through the scan subject. The degree of attenuation varies across the scan subject as a result of variances in the internal composition of the subject. The attenuated energy impinges upon an x-ray detector designed to convert the attenuating energy to a form usable in image reconstruction. A control system reads out electrical charge stored in the x-ray detector and generates a corresponding image. For a conventional, screen film detector, the image is developed on a film and displayed using a backlight.  
         [0003]     Increasingly, flat panel, digital x-ray detectors are being used to acquire data for image reconstruction. Flat panel detectors are generally constructed as having a scintillator, which is used to convert x-rays to visible light that can be detected by a photosensitive layer. The photosensitive layer includes an array of photosensitive or detection elements that each store electrical charge in proportion to the light that is individually detected. Generally, each detection element has a light sensitive region and a region comprised of electronics to control the storage and output of electrical charge. The light sensitive region is typically composed of a photoconductor, and electrons are released in the photoconductor when exposed to visible light. During this exposure, charge is collected in each detector element and is stored in a capacitor situated in the electronics region. After exposure, the charge in each detector element is read out using logic controlled electronics.  
         [0004]     Each detector element is conventionally controlled using a transistor-based switch. In this regard, the source of the transistor is connected to the capacitor, the drain of the transistor is connected to a readout line, and the gate of the transistor is connected to a scan control interface disposed on the electronics in the detector. When negative voltage is applied to the gate, the switch is driven to an OFF state, i.e. no conduction between the source and drain. On the other hand, when a positive voltage is applied to the gate, the switch is turned ON resulting in connection of the source to the drain. Each detector element of the detector array is constructed with a respective transistor and is controlled in a manner consistent with that described below.  
         [0005]     Specifically, during exposure to x-rays, negative voltage is applied to all gate lines resulting in all the transistor switches being driven to or placed in an OFF state. As a result, any charge accumulated during exposure is stored in each detector element capacitor. During read out, positive voltage is sequentially applied to each gate line, one gate at a time. In this regard, only one detector element is read out at a time. A multiplexer may also be used to support read out of the detector elements in a raster fashion. An advantage of sequentially reading out each detector element individually is that the charge from one detector element does not pass through any other detector elements. The output of each detector element is then input to a digitizer that digitizes the acquired signals for subsequent image reconstruction on a per pixel basis. Each pixel of the reconstructed image corresponds to a single detector element of the detector array.  
         [0006]     As described above, indirect detection, digital x-ray detectors utilize a layer of scintillating material, such as Cesium iodide (Csl), to convert incident radiation to visible light that is detected by light sensitive regions of individual detector elements of a detector array. Generally, the transistor controlled detector elements are supported on a thin substrate of glass. The substrate, which supports the detector elements as well as the scintillator layer, is supported by a panel support. The panel support is not only designed to support the detector components, but also isolates the electronics that control the detector from the image detecting components. The electronics are supported by the panel support and enclosed by the back cover.  
         [0007]     As described above, x-ray detectors have a multitude of electronic components. These electronic components are increasingly requiring more power to carry out the complex processes required for operation of the x-ray detector, e.g. data acquisition and data readout. These increased power requirements can expose the x-ray detector to increased thermal loads thereby resulting in “hot spots” on an external surface of the x-ray detector. As such, when a hot spot occurs, the x-ray detector must be removed from service and allowed to cool.  
         [0008]     One proposed solution is to incorporate a fan in the x-ray detector that is designed to exhaust heated air to a cooler ambient. While such a solution may work in principle, as a medical device, an x-ray detector must remain sealed such that disinfectant and other sterilizing products can be applied without damaging the internal detector components. As such, designing the x-ray detector to have an exhaust port that would allow the ingress of cleaning agents is not practicable. Additionally, such an exhaust port would allow the ingress of dust and other fine particle debris that may interfere with operation of the x-ray detector.  
         [0009]     Other proposed solutions include radiation and free convection; however, both are inadequate in responsively regulating the temperature of an x-ray detector. Since an x-ray detector has relatively little surface area, radiation losses are low and not rapid. Similarly, free convection does not remove a sufficient amount of heat to maintain the x-ray detector at a required temperature in a responsive manner. That is, x-ray detectors are iteratively placed in an in-use state and a non-use state. If a hot spot develops while the x-ray detector is in-use, the x-ray detector must be removed from use and allowed to cool. Free convection is capable of removing the heat but the time required to do so can be lengthy, resulting in considerable down-time of the x-ray detector. This can be problematic for high use facilities such as emergency rooms, triage centers, and the like where turnaround time can be critical to diagnosing a patient. The same criticality can be found in non-medical environments such as baggage screening at airports, postage facilities, etc.  
         [0010]     Also, these proposed solutions are solely concerned with dissipating heat from an x-ray detector, not maintaining the temperature of the x-ray detector within a prescribed temperature range. It is well-recognized that the components of an x-ray detector operate more efficiently when the temperature of the components are maintained within a given range. Accordingly, there is a need to dynamically monitor the temperature of an x-ray detector when not in use and actively regulate the temperature of the detector to be within a given range. As such, when the x-ray detector is placed in use after a period of non-use, the time customarily required to heat-up to an optimal temperature is avoided thereby further reducing the down-time of the x-ray detector.  
         [0011]     Therefore, it would be desirable to design an apparatus that stores an x-ray detector during x-ray detector non-use and regulates the temperature of a stored x-ray detector to enhance operability of the x-ray detector when the x-ray detector is removed from storage and placed in use.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0012]     The present invention is directed to an x-ray detector docking station with thermal regulation of stored x-ray detectors that overcomes the aforementioned drawbacks.  
         [0013]     A docking station for one or more x-ray detectors is disclosed and designed to secure an x-ray detector when not in use to limit exposure of an x-ray detector to drops, jars, and other potentially damaging incidents. Additionally, the docking station is equipped to regulate the temperature of a stored x-ray detector. Thermal regulation can be achieved passively or actively using convection, conduction, radiation, and other thermal transference principles. The docking station includes an electronic interface that communicates with a stored x-ray detector such that thermal regulation may be achieved dynamically and responsively. The docking station may be free-standing or wall-mounted. The docking station may be remote from or integrated with an x-ray scanner. The docking station may also be portable.  
         [0014]     Therefore, according to one aspect, the present invention includes an x-ray detector storage device having a storage bin sized to store at least one x-ray detector. The storage device also has a temperature regulator configured to adjust a temperature of a stored x-ray detector to a desired temperature. In another aspect, the temperature regulator may adjust the temperature of a stored x-ray detector so as to take into account the surrounding relative humidity, such that condensation does not occur on the x-ray detector or the docking station components.  
         [0015]     In accordance with another aspect, an x-ray detector storage apparatus is presented and includes a receptacle sized to receive an x-ray detector during non-use of the x-ray detector. The apparatus also has a temperature control interface connected to the receptacle and configured to provide feedback as to a temperature of an x-ray detector when the x-ray detector is disposed within the receptacle. A thermal exchange system is configured to regulate the temperature of an x-ray detector when the x-ray detector is disposed within the receptacle. The apparatus further includes a controller operationally connected to receive the feedback and control the thermal exchange system to reduce a difference between the temperature of an x-ray detector disposed in the receptacle and a desired temperature.  
         [0016]     According to yet another aspect, the present invention includes an x-ray detector docking station having a storage bin sized to receive one or more flat panel x-ray detectors and an interface configured to receive temperature data from a flat panel x-ray detector disposed in the storage bin. The docking station further includes means for regulating a temperature of the flat panel x-ray detector based on temperature data received from the interface.  
         [0017]     Various other features and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.  
         [0019]     In the drawings:  
         [0020]      FIG. 1  is a pictorial view of an exemplary mobile x-ray imaging system.  
         [0021]      FIG. 2  is a schematic block diagram of the exemplary x-ray imaging system shown in  FIG. 1 .  
         [0022]      FIG. 3  is a perspective view of a portable, solid-state, flat panel, digital x-ray detector incorporating the present invention.  
         [0023]      FIG. 4  is an exploded view of the x-ray detector shown in  FIG. 3 .  
         [0024]      FIG. 5  is a perspective view of a portable, solid-state, flat panel, digital x-ray detector according to another embodiment of the present invention.  
         [0025]      FIG. 6  is a perspective view of a portable, solid-state, flat panel, digital x-ray detector according to yet another embodiment of the present invention.  
         [0026]      FIG. 7  is perspective view of an x-ray detector docking station according to the present invention.  
         [0027]      FIG. 8  is a top view of the x-ray detector docking station illustrated in  FIG. 7 .  
         [0028]      FIG. 9  is a cross-sectional view of the x-ray detector docking station of  FIG. 8  taken along lines  9 - 9  thereof and illustrating one embodiment of regulating the temperature of a stored x-ray detector in accordance with the present invention.  
         [0029]      FIG. 10  is a cross-sectional view similar to the view of  FIG. 9  illustration another embodiment of regulating the temperature of a stored x-ray detector in accordance with another aspect of the present invention.  
         [0030]      FIG. 11  is a top view of an x-ray detector docking station according to a further embodiment of the present invention.  
         [0031]      FIG. 12  is a cross-sectional view of the x-ray detector docking station of  FIG. 11  taken along lines  12 - 12  thereof.  
         [0032]      FIG. 13  is a cross-sectional view of an x-ray detector docking station in accordance with another embodiment of the present invention.  
         [0033]      FIG. 14  is a schematic block diagram of a thermal regulating docking station in accordance with one aspect of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]     The present invention will be described with respect to a flat panel, solid-state, indirect detection, and portable digital x-ray detector for use with a mobile x-ray imaging system. However, the present invention is equivalently applicable with other types of x-ray detectors including direct detection digital detectors. Additionally, the present invention may be used with stationary or fixed room x-ray imaging systems. Further, the present application makes reference to an imaging “subject” as well as an imaging “object”. These terms are not mutually exclusive and, as such, use of the terms is interchangeable and is not intended to limit the scope of the appending claims.  
         [0035]     Referring now to  FIG. 1 , an exemplary mobile x-ray imaging system  10  applicable with a portable x-ray detector incorporating the present invention is shown. An x-ray source  12  is mounted or otherwise secured to an end of horizontal arm  20 . Arm  20  allows the x-ray source  12  to be variably positioned above a subject in such a manner so as to optimize irradiation of a particular area of interest. The x-ray source  12  is typically mounted through a gimbal type arrangement (not shown) in column  14 . In this regard, the x-ray source may be rotated vertically from a rest or park position on the mobile x-ray unit base  16  to the appropriate position above the subject in order to take an x-ray exposure of the subject. The rotational movement of column  14  is typically limited to a value of 360 degrees or less to prevent entanglement of high voltage cables  18  used to provide electrical power to the x-ray source  12 . Cables  18  may be connected to a utility line source (not shown) or a battery (not shown) in the base  16  to energize the x-ray source  12  as well as other electronic components of the system  10 . One skilled in the art will appreciate that system  10  may be equipped or connectable to a display unit (not shown) for the display of images captured from the imaging subject. As will be described more fully below, the mobile system may include a retractable storage bin  21  for storage of an x-ray detector within base  16 . The storage bay may also be constructed to regulate the temperature of the stored x-ray detector using passive as well as active thermal control techniques. While only a single stored x-ray detector is shown, it is contemplated that the storage bin may be sized to hold multiple x-ray detectors. Additionally, it is preferred that the storage bin snuggly receive each x-ray detector to limit movement, vibration, stresses, and the like on the stored x-ray detector when the x-ray scanner is being transported. In this regard, the storage bin may include foam or other deformable material to receive an x-ray detector in a tightly fashion as well dampen any force that may otherwise be placed on a stored detector when the x-ray scanner is jarred.  
         [0036]     Referring now to  FIG. 2 , a schematic of x-ray imaging system  10  is illustrated. As referenced above, system  10  includes x-ray source  12  designed to project a fan bean of irradiation  22  from focal spot  24  along axis  26  toward an object to be imaged  28 . One skilled in the art will appreciate that medical patients as well as luggage, packages, and the like may be non-invasively inspected using the exemplary x-ray imaging system  10 . A flat panel digital detector  30  detects x-rays passing through and attenuated by object  28 . A collimator assembly  32 , schematically shown in  FIG. 2  as comprising collimator blades, may be used to collimate the x-ray fan beam  22  to control the scope of irradiation.  
         [0037]     A host or scanner interface  34  includes a communication interface  36 , a keyboard  38  or other data entry device, a CPU  40 , memory  42 , and a display unit  44 , such a computer monitor, to display reconstructed images of the object. A bus  46  connects the keyboard  38 , CPU  40 , memory  42 , and display unit  44  to the communication interface  36 . The CPU may include a microprocessor, digital signal processor, microcontroller, as well as other devices designed to carry out logic and processing operations. Signals corresponding to an x-ray image are read out from flat panel detector  30  via readout electronics  46 . While not shown, it is contemplated that the host interface  34  may be connected to a centralized facility via the Internet or communications link for monitoring and maintenance.  
         [0038]     Additionally, the readout electronics may read out signals from the flat panel detector across a tethered connection between the detector and the imaging system. It is also contemplated that read out may be achieved across a wireless communication between the detector and imaging system. In this regard, one skilled in the art will appreciate that the imaging system and detector may be equipped with transceivers, antennas, and other operational circuitry to support the wireless transmission of data.  
         [0039]     Referring now to  FIG. 3 , a perspective view illustrates a portable, flat panel x-ray detector  30  incorporating the present invention. Detector  30  is preferably an indirect detection, solid-state, digital detector that determines x-ray attenuation through an imaging subject from the emission of light by a scintillator that emits light upon the incidence of x-rays. The detector  30  includes a cover  48  formed of lightweight, durable composite material. A handle  50  is incorporated into the cover to support the portability of the detector. As shown, the detector  30  may be constructed without a fixed tether. In this regard, the detector may be connected to a tether (not shown), which is connected to the readout electronics when in use. When not in use, the detector may be easily detached from tether and stored remotely from the imaging system. The top of the cover includes a template  52  that visually defines the surface dimensions of the scintillator layer in the detector. Template  52  is designed to visually assist a user in positioning of the detector for data acquisition.  
         [0040]     While the present invention is particularly applicable with indirect detection digital detectors, the present invention may also be implemented with direct detection digital detectors. Direct detection digital detectors utilize a layer of amorphous selenium or similar material photoconductor coupled to a thin film transistor array. X-ray interaction in the selenium layer releases electrons (or electron holes), which are used to form signal directly. An electrode is often used to create an electric field across the selenium layer to minimize the lateral spread of electrons, preserving spatial resolution. In addition to selenium, mercuric iodide, cadmium telluride, and lead iodide may be used.  
         [0041]     Referring now to  FIG. 4 , an exploded view schematically illustrates the internal composition of detector  30 . Detector  30  includes a top cover  54  that along with base cover  56  provides a shell or enclosure for its internal components. Both covers  54 ,  56  are preferably formed of a composite material, such as carbon graphite, and impact-absorbing material, such as viscoelastic foam, so as to house and protect the detector components from fracture when exposed to a load or dropped. As will be described in greater detail below, covers  54  and  56  may be constructed with bumpers, foam inserts, layers of impact absorbing material, and the like to inhibit fracturing of the detector components when dropped or exposed to a load. When assembled, the top cover  54  is constructed in such a manner that the detector may be placed on a floor and support a standing subject. In this regard, the top cover panel  54  is designed to minimally deflect when subjected to a load.  
         [0042]     Top cover  54  and base cover  56  collectively form handle  50  when assembled. The handle supports portability of the detector. Additionally, the detector is constructed to be quickly detached from a tether (not shown) that is used to connect the detector to the scanner during data acquisition and readout. As such, detector  30  may be transported to and from multiple scan stations remote from one another. This is particularly advantageous for emergency rooms and other triage facilities. Further, the portability and detachability of the detector further enhances the mobility of a mobile x-ray imaging system, such as that shown in  FIG. 1 .  
         [0043]     Detector  30  further includes a scintillator layer  58  designed to convert incident x-rays or gamma rays to visible light. Scintillator layer  58 , which may be fabricated from Csl or other scintillating material, is designed to emit light proportional to the number and energy of the x-rays received. As such, light emissions will be higher in those regions of the scintillator layer  58  where either more x-rays were received or the energy level of the received x-rays was higher. Since the composition of the subject will attenuate the x-rays projected by the x-ray tube, the energy level of the x-rays impinging upon the scintillator layer will not be uniform across the scintillator layer. This variation in light emission will be used to capture contrast in the reconstructed image.  
         [0044]     The light emitted by the scintillator layer  58  is detected by detector elements of a detector element array  60 . Each detector element  62  corresponds to a picture element or pixel in the reconstructed image. Each detector element  62  includes a light sensitive or photoconductive region  64  and an electronics region  66 . During exposure to x-rays, electrons are released in the light sensitive region  64  in proportion to the light detected in the region  64 . The electronics region  66  includes a capacitor (not shown) that stores the electrical charge accumulated by the light sensitive region. After exposure, a thin-film-transistor (not shown) in the electronics region  66  is biased so as to connect the capacitor to readout electronics. Generally, a multiplexer (not shown) is used to control read out of the discrete detector elements in a sequential, raster fashion. In this regard, the output of each detector element is sequentially input to a digitizer for digitization for subsequent image reconstruction.  
         [0045]     The thin-film-transistors of the detector elements  62  are supported by a glass substrate  68 . Lead lines (not shown) etched in substrate  68  are used for routing of the electrical output of the detector elements as well as applying the biasing voltages to the thin-film-transistors. The glass substrate is generally very thin and fragile. In this regard, as referenced above, the top cover and base cover  54  and  56  are designed with impact absorbing material to help prevent fracturing of the glass substrate. Additionally, as the detector  30  may be used to support a relatively large load during imaging, e.g. imaging of the feet of an average sized adult male, the top cover panel  54  is further designed to reduce the stress on the detector to further prevent fracturing of the glass substrate and other detector components.  
         [0046]     The glass substrate  68  is supported by a detector panel support  70 . Panel support  70  is not only designed to support substrate  68 , but is also used to separate the x-ray conversion and light detection components from the electronics  72 . Panel support  70  is constructed to include radiation absorbing material in addition to structurally supporting material. Incorporating radiation absorbing material within the panel support reduces or eliminates the detection of backscattered x-rays. That is, the radiation absorbing material absorbs x-rays passing through the scintillator layer, detector element array, and glass substrate, as well as x-rays that deflect off the back cover of the detector. In this regard, the electronics  72  are not imaged.  
         [0047]     Electronics  72 , in one embodiment, have an L-shape and is disposed to support the processing and logic control electronics of the detector. The electronics preferably includes LEDs for monitoring operation and diagnostics of the detector. The motherboard may also include temperature sensors for providing feedback as to the temperature of the detector as well as the temperature of the subject. The electronics may also support an accelerometer designed to detect acceleration of the detector and store data accordingly. In this regard, the accelerometer may be used to record the date and time when the detector experienced dramatic increases in acceleration, i.e. when dropped. The electronics may also include various storage devices including flash storage. In a wireless implementation, the motherboard may include an antenna and transceiver for wirelessly transmitting data to the x-ray scanner. Additionally, the electronics may include a battery or other DC power source for powering the detector electronics. The electronics are supported by base cover panel  56 .  
         [0048]     As described above, the x-ray detector is designed to withstand relatively high-energy impacts, stresses, and strains such that the relatively sensitive components, i.e. scintillator layer, detector element array, glass substrate, and motherboard, are not damaged when the detector is dropped or stepped upon. In this regard, in one embodiment, the x-ray detector  30  includes two layers of impact-absorbing material  74 ,  76 . One layer  74  is sealed against or otherwise placed in proximity to the undersurface of top cover panel  54  so as to be sandwiched between the top cover panel and scintillator layer  58 . The other layer  76  is sealed or otherwise placed in proximity to the top surface of base panel  56  so as to be sandwiched between motherboard  72  and base panel  56 . While two impact-absorbing layers  74 ,  76  are shown, it is contemplated that the detector may include only a single layer which is preferably sealed against the undersurface of top cover panel  54  or multiple layers interstitially disposed between the detector components. In this regard, the impact-absorbing material is designed not to attenuate radiation and, as such, does not interfere with data acquisition.  
         [0049]     The impact-absorbing material is preferably a viscoelastic material that is designed to absorb the shock and vibrations placed on the detector when dropped but also deflect the force placed on the detector when stepped upon or otherwise subjected to a load, e.g. a standing patient for a foot/feet scan. In this regard, the impact absorbing material will deform when subjected to a load, but also recover its shape when the load is removed. As such, the impact-absorbing material has a memory.  
         [0050]     The viscoelastic material, which may be foam or other plastic, is designed to deflect and absorb stresses and strains on the detector. As such, when the detector is stepped upon or dropped, the internal components of the detector, e.g. scintillator layer, detector element array, glass substrate, and motherboard, do not fracture or are otherwise damaged. One skilled in the art will appreciate that the thickness, density and composition of the impact-absorbing material may be variably selected to define the limits by which the detector may be subjected to a load or dropped without damage to the detector components. Preferably, however, the detector should have sufficient impact absorbing material such that the damage does not result when the detector is dropped a distance of 20 cm. and/or subjected to a point-load of 370 lbs.  
         [0051]     Further, it is contemplated that layers  74  and  76  can have similar or dissimilar thicknesses, and be composed of similar or dissimilar impact absorbing material(s). For example, layer  74  may be designed to be more absorbent and deflective than layer  76 . In this regard, layer  74  may be thicker than layer  76  or formed from material with improved absorption and deflective characteristics. Additionally, layer  74  may be formed of foam having pronounced viscoelastic properties whereas layer  76  is formed of a polycarbonate, PVC, or other material with less pronounced viscoelastic characteristics.  
         [0052]     Referring now to  FIG. 5 , it is contemplated that the x-ray detector  30  may be constructed to have impact-absorbing inserts  78  placed in cavities positioned internally about the perimeter of the x-ray detector cover  48 . The inserts may be positioned internally about the entire perimeter of the detector cover or, as illustrated in  FIG. 5 , positioned at identified impact zones  80 . For example, inserts  78  may be positioned at each corner of the detector  30 . Accordingly, when dropped, the detector is more likely to impact a floor or other surface at a corner. It is recognized that the detector may be constructed that its weight distribution increases the likelihood that that detector will impact the floor or other surface at a corner when dropped. By incorporating impact-absorbing material at the corners of the cover  48 , the shock and resulting vibrations of the drop incident may be absorbed by the insert  78  and prevented from transferring to the internal components of the detector. It is recognized that the entirety of the shock may not be absorbed or otherwise deflected, but a sufficient percentage of the shock is absorbed such that any shock or vibration experienced by the internal components is of a magnitude insufficient to cause damage to the internal components. Additionally, by incorporating the inserts internally within the detector, the overall size and weight of the detector is negligibly increased, if any.  
         [0053]     It is contemplated that the inserts  78  may be used in conjunction with a layer of impact-absorbing material positioned between the top cover and base panels and the internal components of the detector, such as that shown and described with respect to  FIG. 4 . In this regard, the layers of impact-absorbing material may be fabricated from materials with better deflective properties than impact absorption properties. On the other hand, the inserts  78  may be fabricated from materials having better impact absorption properties than deflective properties. As a result of this construction, the detector is able to handle greater point loads and greater impacts than that achieved with inserts or layers of impact absorbing material alone.  
         [0054]     It is also contemplated that “bumpers” of impact-absorbing material may be secured, sealed, or otherwise connected to the external perimeter of the x-ray detector cover. This embodiment is illustrated in  FIG. 6 . As shown, bumpers  82  of impact absorbing material may be sealed against one or more corners of the detector cover  48 . As the corners are identified as impact zones, the bumpers are shown at each corner. It is recognized that other impact zones may be identified around the perimeter of the cover  48  and, as such, receive a bumper. In this regard, it is contemplated that a continuous bumper may be sealed against the entire perimeter of the cover  48 . In contrast to the embodiments described with respect to  FIGS. 4 and 5 , the bumpers  82  shown in  FIG. 6  may increase the size of the detector. On the other hand, it is contemplated that the corners of the cover  48  may be replaced with bumpers  82  so as to not increase the size of the detector.  
         [0055]     For instance, the cover  48  may be molded in such a manner that impact-absorbing material is used at the corners rather than the composite material used throughout the remainder of the cover. Or, cover  48  may be initially constructed without corners whereupon properly shaped wedges of impact-absorbing material may be glued or otherwise sealed to the cover so as to fill in the voids defined at the corners. Further, similar to the embodiment illustrated in  FIG. 5 , the detector of  FIG. 6  may be constructed to include impact-absorbing material at selected impact zones as well as layers of impact-absorbing material such as that shown in  FIG. 4 .  
         [0056]     Referring now to  FIG. 7 , a docking station  84  for an x-ray detector is shown. The docking station  84  illustrated is sized to store multiple x-ray detectors  30 ; however, it is contemplated that the docking station may be designed to hold a single x-ray detector. Docking station  84  may be free-standing and, as such, include legs  86  or mounted on a wall or other structure (not shown) in a customary manner. The docking station is a dual purpose apparatus as it designed to store x-ray detectors while they are not in use, and includes a thermal exchanger and control to regulate the temperature of the stored x-ray detectors. As will be described, it is contemplated that thermal regulation of stored x-ray detectors may be achieved in accordance with the principles of radiation, conduction, convection, or a combination thereof.  
         [0057]     Referring now to  FIG. 8 , a top view of docking station  84  illustrates alignment and storage of x-ray detectors  30  therein. In one embodiment, docking station  84  includes a plurality of ribs  88  that extend from the base  92  of the docking station  84  to define a plurality of receptacles  90 , each sized to receive a single x-ray detector  30 . The ribs  88  are preferably formed of a viscoelastic material or foam that directs placement of an x-ray detector  30  when being inserted into a receptacle  90  for storage without causing damage of the exterior to the x-ray detector  30 . As will be described in greater detail below, the docking station includes a controller that interfaces with each x-ray detector. As such, each x-ray detector includes a pinned or socket connector that mates with a counterpart connector in the base of the docking station. To ease user connection of an x-ray detector to the docking station interface connector, ribs  84  are designed to define a channel that when the x-ray detector is placed therein, a connection between the x-ray detector and docking station is achieved relatively effortlessly and in a manner that can be repeated with each placement of an x-ray detector in the docking station.  
         [0058]     As illustrated in  FIG. 8 , the base  92  of the docking station  84  includes a plurality of bores  94  that permit the ingress of cooling or heating fluid, such as ambient air, into the docking station. Referring now to  FIG. 9 , bores  94  extend through the base  92  of the docking station  84  and, as such, define a plurality of thermal exchange paths  96 . Exchange paths  96  are designed to allow ambient air to pass through the base  92  and upwardly along the exterior of the stored x-ray detectors  30 . As air passes about the x-ray detectors  30 , heat is removed from therefrom and the x-ray detectors are brought to a desired temperature. It is also contemplated that cooling or heating elements (not shown) may be placed in the thermal exchange paths  96  to manipulate the temperature of the air passing therethrough to accelerate the thermal regulation of the x-ray detectors. Additionally, the docking station  84  may be mounted to a wall in a conventional manner such that the x-ray detectors  30  are stored parallel to the floor. As a result, natural air flow through paths  96  may be increased to effectuate accelerated heating and/or cooling of the x-ray detectors  30 .  
         [0059]     Still referring to  FIG. 9 , as described above, each x-ray detector  30  includes a connector  98  that interfaces with a socket or mating connector  100  secured to the base  92  of the docking station  84 . When connected, the docking station  84  can smartly regulate the temperature of an x-ray detector or provide an indication that an x-ray detector has not reached a desired temperature. That is, each x-ray detector  30  may be equipped with a sensor (not shown) that monitors surface as well as internal temperatures. The sensor can then provide feedback to a controller (not shown) in the docking station  84 . The docking station controller may then continue to receive feedback from the sensor while the x-ray detector is being thermally regulated. From the feedback, the docking station may ascertain if the x-ray detector has reached a desired temperature and illuminate LEDs (not shown) accordingly. The LEDs may be on the x-ray detector or on the docking station itself. As such, when the x-ray detector has been cooled or heated to a given temperature, or within a desired temperature range, an LED may be illuminated signaling to a user that the x-ray detector is ready to be placed into use. Conversely, if the temperature of the x-ray detector is outside the desired temperature range, an LED may be illuminate signaling such to a user.  
         [0060]     The present invention also contemplates the use of a forced air convection to regulate the temperature of stored x-ray detectors. Referring now to  FIG. 10 , docking  84  may be equipped with a fan assembly  102  designed to draw air from the ambient  104  through opening  106 . It is preferred that fan assembly  102  be a variable speed fan. In this regard, feedback received from the thermal sensors in the stored x-ray detectors may be processed by a controller in the docking station and used to control the speed of fan  102 . While a single fan  102  is shown to force air collectively through paths  96 , it is contemplated that each x-ray detector receptacle  90  may be equipped with a fan. Additionally, it is contemplated that each receptacle may be equipped to include a heating and/or cooling element in paths  96  to expedite the thermal exchange process. Further, docking station  84  is shown without a cover; however, it is contemplated that a cover may be used to seal the x-ray detector within the docking station. In this regard, drawn air may be circulated throughout the docking station. As such, heat from one x-ray detector may be used to heat a cooled x-ray detector, and vice-versa, to achieve temperature equilibrium across the bank of x-ray detectors.  
         [0061]     Referring now to  FIG. 11 , a top view of docking station in accordance with alternate embodiment of the present invention is shown. In this embodiment, docking station  84  includes ribs  88  and thermoelectric devices  108 . The thermoelectric devices  108  may include a Peltier device that be caused to cool as well as a heat an x-ray detector  30 . Devices  108  include heat sinks that are in contact with the stored detectors to dissipate heat therefrom. It is contemplated that a single thermoelectric device  108  may be used for each x-ray detector  30  or, as illustrated, a pair of thermoelectric devices  108  for each x-ray detector  30 . The thermoelectric modules  108  are also configured to define the boundaries of the storage receptacle to which a detector is to be placed when stored.  
         [0062]     A cross-sectional view of  FIG. 11  taken along lines  12 - 12  is shown in  FIG. 12  illustrating a height contemplated for each thermoelectric module  108  relative to a stored x-ray detector  30 . Preferably, each module  108  is sized to cover at least the template  52  ( FIG. 3 ) on each x-ray detector  30 . Similar to the embodiments described above, docking station  84  includes a connector  100  connectable to a mate  98  of each stored x-ray detector to facilitate the communication of temperature data from the x-ray detector to a docking station controller. In this regard, the thermoelectric devices may be dynamically controlled to achieve the desired thermal regulation of each x-ray detector. As is well known, operation of Peltier devices is controlled by the direction of current applied thereto. As such, the docking station controller may selectively bias each thermoelectric device to achieve either a cooling or a heating of a corresponding x-ray detector  30 .  
         [0063]     Yet another contemplated embodiment is illustrated in  FIG. 13 . The present invention contemplates the use of thermal exchange fluid that may be circulated by a heater/cooler assembly  110 . In this regard, docking station  84  includes a number of fluid paths  112  for circulating fluid, such as liquid coolant, about the stored x-ray detectors  30 . One skilled in the art will appreciate that assembly  110  includes a motor and pump assembly to effectuate circulation of fluid from reservoir  114  through paths  112 . In this embodiment, it is preferred that coolant be caused to circulate throughout the entire docking station. In this regard, heat from a “hot” x-ray detector may be used to heat the coolant passing thereabout and this heat may then be transferred to a “cold” x-ray detector or deposited in reservoir to assist in maintaining a relatively constant reservoir temperature. It also contemplated that assembly  110  may include a chiller or heater for cooling or heating the thermal exchange fluid directly. Operation of the assembly  110  may be controlled from feedback data received from temperature sensors in the stored x-ray detectors via interfaces  98 - 100 .  
         [0064]     Referring now to  FIG. 14 , a block diagram schematically illustrates operation of the docking stations described above. Docking station  84  includes a controller  116  that is configured to receive feedback  118  from temperature sensors  120  of each stored x-ray detector  30  of detector bank  122 . From the feedback received from each detector  30 , controller illuminates an LED  124  of an LED bank  126  for each stored x-ray detector  30 . The LED bank  126  may be disposed on the x-ray detector  30  or on the docking station itself. In one contemplated embodiment, the controller illuminates a “green” LED if the x-ray detector is within a desired range, a “yellow” LED if the x-ray detector is outside the desired range but within a usable range, and “red” LED if the x-ray detector has a temperature that can significantly impact the operability of the detector or exceeds a maximum allowable temperature for usage. One skilled in the art will appreciate that other indicators and indication methods may be used. Additionally, the docking station may include a humidity sensor  127  that monitors the relative humidity of the ambient and provides feedback  129  to the controller  116 .  
         [0065]     From feedback  118 ,  129 , controller  116  regulates operation of thermal exchange system  128 . For instance, for a docking station incorporating a fan, the speed of the fan may be adjusted. For a docking station having thermoelectric devices, the bias applied to each thermoelectric device may be adjusted. For a docking station designed to circulate coolant, coolant flow may be adjusted. For a docking station having a compressor for passing compressed air around the stored detector, the controller may adjust operation of the compressor based on the temperature of the stored x-ray detector. In short, controller  116  regulates the thermal exchange system such that the temperature of the stored x-ray detector is quickly brought to within a desired temperature range, i.e., reduces the difference between a measured x-ray detector temperature and a desired temperature. Further, the controller is programmed to compare the temperature of the stored x-ray detector to the desired temperature and, from the comparison, determine a rate of temperature adjustment needed to bring the temperature of the stored x-ray detector to the desired temperature without placing thermal stress on internal components of the stored x-ray detector. Moreover, it is preferred that controller  116  regulate the thermal exchange system  128  such that the relative humidity is taken into account so that condensation on the stored x-ray detectors and docking station components is prevented. In this regard, the “down-time” of a cooling x-ray detector or the “warm-up time” of a cold x-ray detector is reduced. Decreasing down-time and warm-up time effectively increases the operability of an x-ray detector which leads to increased patient throughput and reduced x-ray detector supply needs.  
         [0066]     It is contemplated that docking station  84  may be a free standing device, wall mounted, or incorporated into an x-ray scanner. In this regard, a fixed or stationary as well as a mobile x-ray scanner may have a dedicated docking station for storage as well as thermal regulation of an x-ray detector. It is also contemplated that the docking station may be a mobile apparatus and, as such, incorporates wheeled legs. Additionally, the docking station may include a battery to power its electronic components when connection to a utility power source is not feasible. Moreover, the docking stations described above were shown with respect to similarly sized x-ray detectors; however, it is contemplated that the docking station may be designed to store and thermally regulate various sized x-ray detectors. Additionally, as described above, the docking stations are designed to communicate with a stored x-ray detector. It is contemplated that that the same connector used to connect the x-ray detector to the x-ray scanner may be used to interface with the docking station. This connection may be across a serial or a parallel connection, for example, USB, IEEE 1394, and Ethernet. It is also contemplated that temperature data may be communicated from an x-ray detector to the docking station across a wireless connection. In this regard, the docking station may include antennas, receivers, and other operational circuitry to support the wireless transference and processing of data.  
         [0067]     Additionally, the docking station may be configured to charge or recharge batteries or energy storage devices of a stored detector using one of a number of techniques, such as direct electrical contact or induction. In this regard, the receptacle for an x-ray detector may have spring-loaded contacts or some other method of continuous electrical connection to the x-ray detector, such that an electrical connection could be made for charging. Induction may be also used to avoid exposed leads. While induction may add heat to a stored x-ray detector, the environmental controls of the docking station described herein would be capable of maintaining the temperature of a stored x-ray detector within prescribed limits, notwithstanding the additional heat from induction charging. Charging of a battery in an x-ray detector may also be achieved via the interface described above connecting an x-ray detector to the docking station.  
         [0068]     Therefore, the present invention includes an x-ray detector storage device having a storage bin sized to store at least one x-ray detector. The storage device also has a temperature regulator configured to adjust a temperature of a stored x-ray detector to a desired temperature.  
         [0069]     An x-ray detector storage apparatus is presented and includes a receptacle sized to receive an x-ray detector during non-use of the x-ray detector. The apparatus also has a temperature control interface connected to the receptacle and configured to provide feedback as to a temperature of an x-ray detector when the x-ray detector is disposed within the receptacle. A thermal exchange system is configured to regulate the temperature of an x-ray detector when the x-ray detector is disposed within the receptacle. The apparatus further includes a controller operationally connected to receive the feedback and control the thermal exchange system to reduce a difference between the temperature of an x-ray detector disposed in the receptacle and a desired temperature.  
         [0070]     The present invention includes an x-ray detector docking station having a storage bin sized to receive one or more flat panel x-ray detectors and an interface configured to receive temperature data from a flat panel x-ray detector disposed in the storage bin. The docking station further includes means for regulating a temperature of the flat panel x-ray detector based on temperature data received from the interface.  
         [0071]     The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.