Patent Description:
In performing various procedures, such as surgical procedures on a human patient, an imaging system may be used to image the patient. For example a fluoroscopic system may be used to emit x-rays from a source that is detected or received by a detector. Based upon the detection by the detector, images are generated of the patient. Certain systems are adapted for use during a procedure, such as the ARCADIAS ® Avantic ® Multi-Purpose C-Arm Imaging System sold by Siemens Medical Solutions USA, Inc. having a place of business in Malvern, PA, USA.

Generally, a C-Arm imaging system includes a source generally opposed to a detector on a "C" shaped or curved arm that is fixed. The arm extends along an arc where the source is near one end of the arm and the detector at the other end of the arm. The C-Arm may be moved relative to the patient to acquire images at different relative positions, such as an anterior to posterior and medial to lateral image perspectives. The arm, however, of the C-Arm, is generally a fixed arc dimension such that ends of the arm are fixed relative to one another based upon the geometry of the arm.

Documents <CIT> and <CIT> relate to imaging systems having a "C"-shaped and an "O"-shaped configuration.

The invention is defined by independent claims <NUM> and <NUM>.

According to various embodiments, an imaging system is provided that includes a source and a detector. The source may emit a radiation, such as x-ray radiation, that can be detected by the detector. An image may be generated based upon the amount of radiation reaching the detector. The amount of radiation may be attenuated by a portion of a subject in the path of the x-rays. The x-ray source and detector may be moved relative to a subject being imaged according to a changeable or transformable rotor that can assist in acquiring various types of image data.

A transformable imaging system can be used to efficiently acquire two dimensional image data based upon a single or limited number of subject exposures or three-dimensional (3D) volumetric image data based upon a plurality of exposures. For example, in a first configuration, an imaging system may have a "C" shaped arm that is less than annular and may acquire image data less than <NUM> degrees around the patient. These images may be best viewed or displayed as two dimensional images of a subject or may be used to generate 3D images of the subject. In a second configuration the imaging system may have an "O" shape or an annular shape and acquire image data substantially around, such as <NUM> degrees around, a subject based upon moving a detector and/or source through a path that is around or at a plurality of position relative to a subject. The annular or <NUM> degree acquisition of image data may allow for crisper or clearer 3D images for display.

According to various embodiments a system may include a configurable housing and/or rotor in and/or on which a detector and source may move. The detector and source may be operated in at least two manners based upon at least two configurations of the imaging system. Therefore a single system may be operable in two configurations to allow for versatility and flexibility of a single system.

The following description is merely exemplary in nature. The present teachings are directed toward an imaging and a navigation system that is able to track an instrument and display it on a display. It is understood, however, that the systems disclosed herein may be applied to non-surgical applications for imaging, tracking, navigation, etc. during various repair or maintenance procedures on machinery, devices, etc..

<FIG> shows an operating theatre (or inside of an operating room) <NUM> and a user <NUM> (e.g., a physician) performing a procedure on a subject (e.g., a patient) <NUM> positioned on a table or surface <NUM>. In performing the procedure, the user <NUM> may use an imaging system <NUM> to acquire image data of the patient <NUM>. The image data acquired of the patient <NUM> can include two-dimensional (2D) such as in a C-arm mode or three-dimensional (3D) images such as in a computer tomography (CT) mode. Models, such as surface renderings or volumetric models, may be generated using the acquired image data. The model can be a three-dimensional (3D) volumetric model generated based on the acquired image data using various techniques, including algebraic iterative techniques. The image data (designated <NUM>) can be displayed on a display device <NUM>, and additionally, may be displayed on a display device 32a associated with an imaging computing system <NUM>. The displayed image data <NUM> may include 2D images, 3D images, and/or a time changing 3D (also referred to as 4D) images. The displayed image data <NUM> may also include acquired image data, generated image data, and/or a combination of the acquired and generated image data.

Image data acquired of a patient <NUM> may be acquired as 2D projections. The 2D projections may then be used to reconstruct 3D volumetric image data of the patient <NUM>, such as when a selected number of differing perspective images are acquired of the patient <NUM>. Also, theoretical or forward 2D projections may be generated from the 3D volumetric image data. Accordingly, image data may be used to provide 2D projections and/or 3D volumetric models.

The display device <NUM> may be part of a computing system <NUM>. The computing system <NUM> may include a memory system <NUM> including one or a variety of computer-readable media. The computer-readable media may be any available media that is accessed by the computing system <NUM> and may include both volatile and non-volatile media, and removable and non-removable media. By way of example, the computer-readable media may include computer storage media and communication media. Storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store computer-readable instructions, software, data structures, program modules, and other data and which can be accessed by the computing system <NUM>. The computer-readable media may be accessed directly or through a network such as the Internet.

In one example, the computing system <NUM> can include an input device <NUM>, such as a keyboard, and one or more processors <NUM> (the one or more processors may include multiple-processing core processors, microprocessors, etc.) that may be incorporated with the computing system <NUM>. The input device <NUM> may include any suitable device to enable a user to interface with the computing system <NUM>, such as a touchpad, touch pen, touch screen, keyboard, mouse, joystick, trackball, wireless mouse, audible control or a combination thereof. Furthermore, while the computing system <NUM> is described and illustrated herein as comprising the input device <NUM> discrete from the display device <NUM>, the computing system <NUM> may include a touchpad or tablet computing device and may be integrated within or be part of the imaging computing system <NUM>. A connection may be provided between the computing system <NUM> and the display device <NUM> for data communication to allow driving the display device <NUM> to illustrate the image data <NUM>. Further, a communication line <NUM> may be provided between the imaging computer system <NUM> and the computer system <NUM>.

The imaging system <NUM> will be described in further detail herein, but may include certain portions included in an O-Arm® imaging system. The O-Arm® imaging system can include the O-Arm® imaging system sold by Medtronic, Inc. having a place of business in Colorado, USA. The imaging system may further include, in various embodiments, certain and selected portions of the imaging systems described in <CIT>, <CIT>, <CIT>, and <CIT> and/or <CIT>;<CIT>;<CIT>; and <CIT>.

In various embodiments, the imaging system <NUM> may include a mobile cart <NUM>, the imaging computing system <NUM> and a gantry <NUM>. The gantry <NUM> may include a member or fixed dimension element. The fixed dimension member <NUM> may have a height 34x at an upper surface or edge 34y' (such as a highest point on the fixed dimension member <NUM>) that is a selected height above a surface 34y that supports the imaging system <NUM>. The height may be about <NUM> feet (about <NUM> meters) to about <NUM> feet (about <NUM> meters), may be five feet (about <NUM> meters) or less, or may be selected such that a user that is five feet six inches (about <NUM> meters) tall may easily see over the fixed dimension member <NUM>. The imaging system further include an x-ray source <NUM>, a collimator (not shown), one or both of a multi-row detector <NUM> and a flat panel detector <NUM>, and a rotor <NUM>. With reference to <FIG>, the mobile cart <NUM> may be moved from one operating theater or room to another and the gantry <NUM> may be moved relative to the mobile cart <NUM>, as discussed further herein. This allows the imaging system <NUM> to be mobile and used for various procedures without requiring a capital expenditure or space dedicated to a fixed imaging system. Although the gantry <NUM> is shown as being mobile, the gantry <NUM> may not be connected to the mobile cart <NUM> and may be in a fixed position.

The gantry <NUM> may define an isocenter <NUM> of the imaging system <NUM>. In this regard, a centerline C1 through the gantry <NUM> may pass through the isocenter or center of the imaging system <NUM>. Generally, the patient <NUM> can be positioned along the centerline C1 of the gantry <NUM>, such that a longitudinal axis <NUM> of the patient <NUM> is aligned with the isocenter of the imaging system <NUM>.

The imaging computing system <NUM> may control the movement, positioning and adjustment of the multi-row detector <NUM>, the flat panel detector <NUM> and the rotor <NUM> independently to enable image data acquisition via an image processing module <NUM> of the processor <NUM>. The processed images may be displayed on the display device <NUM>. The imaging system <NUM> may be precisely controlled by the imaging computing system <NUM> to move the source <NUM>, collimator, the multi-row detector <NUM> and the flat panel detector <NUM> relative to the patient <NUM> to generate precise image data of the patient <NUM>. It is understood, however, that the source <NUM>, and the detectors <NUM>, <NUM> may be fixed at selected positons relative to the rotor <NUM>.

In addition, the imaging system <NUM> may be connected or in connection with the processor <NUM> via the connection <NUM> which includes a wired or wireless connection or physical media transfer from the imaging system <NUM> to the processor <NUM>. Thus, image data collected with the imaging system <NUM> may also be transferred from the imaging computing system <NUM> to the computing system <NUM> for navigation, display, reconstruction, etc..

The imaging system <NUM> may also be used during an non-navigated or navigated procedure. In a navigated procedure, a localizer may be used to determine location of tracked members and portions. The tracked members and portions may include the patient <NUM>, the imaging system <NUM>, the user <NUM>, tracked instruments (e.g. drills, awls, probes), etc. The localizer may be one or both of an optical localizer <NUM> or an electromagnetic localizer <NUM>. The localizer may further include an ultrasound localizer, a radar localizer, etc. The localizer may be used to generate a field or receive or send a signal within a navigation domain relative to the patient <NUM>. If desired, the components associated with performing a navigated procedure (e.g. the localizer) may be integrated with the imaging system <NUM>. The navigated space or navigational domain relative to the patient <NUM> may be registered to the image data <NUM> to allow registration of a navigation space defined within the navigational domain and an image space defined by the image data <NUM>. A patient tracker (or a dynamic reference frame) <NUM> may be connected to the patient <NUM> to allow for a dynamic registration and maintenance of the registration of the patient <NUM> to the image data <NUM>. It is understood, however, that imaging systems are not required to be used with a navigation or tracking system. Imaging systems, including those disclosed herein, may be used for imaging and evaluation of image data with navigation.

One or more instruments may be tracked within the navigational domain, including relative to the patient <NUM>. Instruments may include an instrument <NUM> that may then be tracked relative to the patient <NUM> to allow for a navigated procedure. The instrument <NUM> may include respective optical tracking devices <NUM> (including active or passive tracking devices, including those discussed herein) and/or an electromagnetic tracking device <NUM> (shown in phantom) to allow for tracking of the instrument <NUM> with either or both of the optical localizer <NUM> or the electromagnetic localizer <NUM>. The instrument <NUM> may include a communication line 72a with a navigation interface device (NID) <NUM>. The NID <NUM> may communicate with the electromagnetic localizer <NUM> and/or the optical localizer <NUM> directly or via the processor <NUM> via communication lines 60a and 62a respectively. The NID <NUM> may communicate with the processor <NUM> via a communication line <NUM>. The imaging system <NUM> may also communicate with the NID <NUM> via a communication line <NUM>. The connections or communication lines can be wire based as shown or the corresponding devices may communicate wirelessly with each other.

The localizer <NUM> and/or <NUM> along with the selected tracking devices may be part of a tracking system that tracks the instrument <NUM> relative to the patient <NUM> to allow for illustration of the tracked location of the instrument <NUM> relative to the image data <NUM> for performing a procedure. The tracking system alone or in combination with a navigation system is configured to illustrate a tracked location (including a tracked 3D position (i.e. x,y,z coordinates) and one or more degrees of freedom of orientation (i.e. yaw, pitch, and roll)) relative to the image data <NUM> on the display <NUM>. Various tracking and navigation systems include the StealthStation® surgical navigation system sold by Medtronic, Inc. and those disclosed in <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>. As is generally understood, the processor <NUM> may execute selected instructions to illustrate a representation (e.g. an icon) of the tracked portion relative to the image data <NUM>.

The instrument <NUM> may be interventional instruments and/or implants. Implants may include a ventricular or vascular stent, a spinal implant, neurological stent or the like. The instrument <NUM> may be an interventional instrument such as a deep brain or neurological stimulator, an ablation device, or other appropriate instrument. Tracking the instrument <NUM> allow for viewing the location of the instrument <NUM> relative to the patient <NUM> with use of the registered image data <NUM> and without direct viewing of the instrument <NUM> within the patient <NUM>. For example, the instrument <NUM> may be graphically illustrated as an icon, as discussed further herein, superimposed on the image data <NUM>.

Further, the imaging system <NUM> may include a tracking device, such as an optical tracking device <NUM> or an electromagnetic tracking device <NUM> to be tracked with a respective optical localizer <NUM> or the electromagnetic localizer <NUM>. The tracking devices <NUM>, <NUM> may be associated directly with the source <NUM>, multi-row detector <NUM>, flat panel detector <NUM>, rotor <NUM>, the gantry <NUM>, or other appropriate part of the imaging system <NUM> to determine the location of the source <NUM>, multi-row detector <NUM>, flat panel detector <NUM>, rotor <NUM> and/or gantry <NUM> relative to a selected reference frame. As illustrated, the tracking devices <NUM>, <NUM> may be positioned on the exterior of the housing of the gantry <NUM>. Accordingly, portions of the imaging system <NUM> may be tracked relative to the patient <NUM> to allow for initial registration, automatic registration, or continued registration of the patient <NUM> relative to the image data <NUM>. The known position of the rotor <NUM> relative to the gantry <NUM>, on which the tracking devise are placed, may be used to determine the position of the rotor <NUM> and the include detectors <NUM>, <NUM> and source <NUM>. Alternatively, or in addition thereto, the tracking devices may be placed directly on the rotor <NUM> and/or the source <NUM> and detector <NUM>, <NUM>.

As discussed above, the user <NUM> can perform a procedure on the patient <NUM>. The user <NUM> may position the instrument <NUM> relative to, such as within, the patient <NUM>. For example, the instrument <NUM> can include an awl, tap, a probe, a screwdriver, an instrument to hold or position one or more screws, a rod, or the light. The instrument <NUM> may be tracked, as discussed above, and the location determined relative to the patient <NUM> and/or the imaging system <NUM>.

An operative or operating portion (which may be a detachable portion) of the instrument <NUM> may be positioned subdermally and transdermally. In various embodiments, the portion of the instrument <NUM> positioned subdermally are positioned through a small incision or stab wound formed on or in the patient <NUM>. Therefore, direct viewing, such as with visual viewing directly by the user <NUM> may be substantially hindered and/or impossible due to the overlayment of soft tissue including dermis, muscle, and the like. Therefore, the tracking and navigation systems, as discussed above, can be used to display representations of the instrument <NUM> relative to the image data <NUM> on display <NUM>.

With continuing reference to <FIG>, the operating theater can include the imaging system <NUM> that includes a transformable portion that may change configuration based upon a selected instruction. The transformable or multiple configurable imaging system <NUM> may include the rotor <NUM> having at least a fixed length portion or segment <NUM> in a "C" shape configuration, as illustrated in <FIG> or the rotor portion in an "O" shape configuration rotor <NUM>', as illustrated in <FIG>. The imaging system <NUM> when in the "C" shaped configuration may not enclose a circle and includes an opening <NUM> that is a side opening or laterally from an outside of the rotor <NUM>. When the imaging system is in the "C" shape configuration rotor <NUM> it may operate as a C-arm. The opening <NUM> allows access to the patient <NUM> from the user <NUM> even when the imaging system <NUM> is near the patient <NUM>. A complete circle (as illustrated in <FIG>) does not allow side access to the patient <NUM> through the "O" shape configuration rotor <NUM>'.

The moveable rotor <NUM> may move relative to the gantry <NUM>, as discussed herein. The gantry <NUM> may have a fixed configuration and the rotor <NUM> moves relative to the gantry <NUM> due to coupling of a rotor drive system <NUM>, as discussed further herein, to allow for movement of the rotor <NUM> relative to the gantry <NUM>. The drive system <NUM> can be operated by the computer system <NUM>, as also discussed further herein.

Turning reference to <FIG> the imaging system <NUM> can be transformed or configured to include the "O" shaped configuration rotor <NUM>'. The "O" shaped configuration rotor <NUM>' does not include the side opening <NUM>, but includes a substantially annular configuration. When the imaging system <NUM> is in the "O" shaped configuration rotor <NUM>' it may be operated as a CT mode or as the O-Arm® imaging system. The rotor drive <NUM> may still be operated to move the "O" shaped configuration rotor <NUM>' relative to the gantry <NUM>, but the "O" shaped configuration rotor <NUM>' may move in at least a <NUM>° circle around the subject <NUM> that may be placed within the "O" shaped configuration rotor <NUM>'. The subject <NUM> may be placed within the annular portion of the "O" shaped configuration rotor <NUM>' by first having the "C" shaped configuration rotor <NUM>, as illustrated in <FIG>, moved relative to the patient <NUM> and then changing or transforming the imaging system <NUM> to the "O" shaped configuration rotor <NUM>', as illustrated in <FIG>, as discussed further herein.

Returning reference to <FIG>, the imagining system <NUM> in the "C" shaped configuration rotor <NUM> may operate as a conventional C-arm, including those discussed above. With additional reference to <FIG>, the imaging system <NUM> in the "C" shaped configuration rotor <NUM> can generally move at least <NUM>° around an isocenter <NUM> using the rotor drive <NUM>. The source <NUM> is positioned substantially opposed to the detector or plurality of detectors <NUM>, <NUM>. The source <NUM> may be positioned away from a base <NUM> of the cart or a floor.

The "C" shaped configuration rotor <NUM> may be rotated generally in the direction of arrow <NUM> along a distance or arc length <NUM> relative to an end of the gantry <NUM>. It is understood that the arc length <NUM> can be any appropriate arc length, and is illustrated in <FIG> as exemplary indicating a possible position or movement of the "C" shaped configuration rotor <NUM>. The "C" shaped configuration rotor <NUM> may then continue to move generally in the direction of arrow <NUM> including an arc length distance <NUM> relative to an end of the gantry <NUM>. The "C" shaped configuration rotor <NUM> may be held on the gantry <NUM> with an appropriate amount, such as a maintaining or connecting leg portion <NUM> that may extend between a first terminal end <NUM> and a stop point <NUM>. It is understood that the holding portion <NUM> can be based on various considerations such as the rigidity or mass of the overhang length <NUM>, weight of the "C" shaped configuration rotor <NUM>, strength or rigidity of the gantry <NUM>, and other considerations. Further, it is understood, that the arc length <NUM> may be selected based upon the position of the drive <NUM> and other mechanical and connections to allow for movement of the "C" shaped configuration rotor <NUM>.

With specific reference to <FIG>, the "C" shaped configuration rotor <NUM> may also rotate in a substantially opposite direction, such as in the direction of arrow <NUM>, from that illustrated in <FIG>. In moving in the direction of arrow <NUM>, the first terminal end <NUM> extends away from the gantry <NUM>. The first terminal end <NUM> may also be moved an arc length <NUM>' that may be substantially equal in length to arc length <NUM>. Further an overhang or connecting length <NUM>' may be the distance between a minimal overhang or contact point <NUM>' and a second terminal end <NUM> of the "C" shaped configuration rotor <NUM>.

Accordingly, it is understood that the "C" shaped configuration rotor <NUM> may move relative to the gantry <NUM> of the imaging system <NUM> a selected or maximum amount of movement. Generally the movement may be about <NUM>°, such that allowing the detector <NUM>, <NUM> to move at least <NUM>° around the isocenter <NUM> at which the patient <NUM> may be positioned. In other words, the movement of the detector <NUM>, <NUM> may be limited to about <NUM>° of total movement around the isocenter <NUM>. It is further understood, however, that the detector <NUM>, <NUM> may move less than or greater than <NUM> °, including about <NUM>° to about <NUM>° around the isocenter <NUM>.

With continuing reference to <FIG> and <FIG>, the imagining system <NUM> in the "C" shaped configuration rotor <NUM> that includes the open space <NUM>, can be operated in a manner substantially similar to a generally known C-arm. In the "C" shaped configuration rotor <NUM>, generally fluoroscopic images or two dimensional (2D) images may be acquired of the patient <NUM>. The two dimensional or fluoroscopic images may be used to efficiently acquire image data the patient <NUM> during an operative procedure, as illustrated in <FIG>. The "C" shaped configuration rotor <NUM> including the opening <NUM> may also allow for an efficient movement of the imaging system <NUM> relative to the subject <NUM>.

Further, the opening <NUM> may allow easy access to the patient <NUM> during imaging to allow the user <NUM> to perform a procedure with the imaging system <NUM> positioned relative to the patient <NUM>, such as in a position to acquire intra-operative images of the patient <NUM>. Thus, the opening <NUM> may assist the user <NUM> in performing a procedure on the patient <NUM> by allowing the user <NUM> to acquire intra-operative images data for viewing on the display <NUM>. The image data <NUM> can be used to update the user <NUM> regarding the procedure, including confirmation of a procedure, positioning of an implant, or other portions thereof.

According to various embodiments, the user <NUM> may access the patient <NUM> while the patient is at the isocenter <NUM> of the imaging system <NUM> through the side opening <NUM>. Thus, the user <NUM> may image the patient <NUM> during the procedure to assist in the procedure, such as implant placement. The imaging system <NUM>, therefore, need not be removed during a procedure. Also, as discussed herein, the imaging system <NUM> may be transformed into the "O" shaped configuration rotor <NUM>' to acquire additional image data, such as image data for a 3D image of the patient <NUM>. The single imaging system may provide the user <NUM> with different types of image data at different times without requiring separate imaging systems.

In addition to rotating generally along a path defined by the gantry <NUM>, the "C" shaped configuration rotor <NUM> may move or pivot around an axis <NUM> that may extend generally perpendicular to the long axis <NUM> (as illustrated in <FIG>) of the base <NUM> or the axis <NUM> of the patient <NUM>. Further, the long axis <NUM> may be generally parallel to the floor or support surface on which the imaging system <NUM> is placed. The central axis <NUM> may allow for a swivel or rotation around the patient <NUM> generally in the direction of arrow <NUM>. Alternatively, or in addition possible motions of the imaging system are also illustrated in <FIG> as discussed herein.

The movement around the axis <NUM> in the direction of arrow <NUM> may be allowed by a spindle or axle <NUM> that extends from the base <NUM> and is driven by a gantry drive <NUM> via a coupling <NUM>. Thus, the gantry may rotate around the axle <NUM> allowing the "C" shaped configuration rotor <NUM> to also rotate. Further, the gantry <NUM> may also be moved with a connection <NUM>, similar to the gantry movement systems discussed above and including in the O-arm ® imaging system. The gantry drive <NUM> may then be coupled to the connection <NUM>. The gantry drive <NUM> may be similar to the rotor drive <NUM>, discussed above, and further herein, or any appropriate drive including worm gear, a hydraulic system, a pneumatic system, an electrical motor, a serpentine belt drive, or other appropriate drive or connection system.

It is understood, as illustrated in <FIG>, that the connection <NUM> may be eliminated or moved to allow for the rotation in the direction of arrow <NUM>. The connection <NUM> may allow for other movements, as discussed herein, but may restrict a rotation around the axis <NUM>. Thus, the axle <NUM> may interconnect the gantry <NUM> and the base <NUM> to allow for rotation of the gantry <NUM> around the axis <NUM>. The drive <NUM>, therefore, may be moved relative to the base <NUM> and be connected (e.g. with a belt) to the gantry <NUM> and/or rotator <NUM> for movement of the rotor <NUM>.

Alternatively, or in addition to the axle <NUM>, the "C" shaped configuration rotor <NUM> may rotate relative to the gantry <NUM> by interconnection with an axle <NUM> that extends from the gantry <NUM> and engages the moveable rotor <NUM>, such as via a recess track or other appropriate connection. Therefore the gantry <NUM> may be fixed relative to the base <NUM> while the rotor <NUM> rotates relative to the gantry <NUM>. The amount of rotation generally in direction of arrow <NUM> may be selected or limited to a configuration of the imaging system <NUM>. The rotation, however, may include about <NUM>° rotation around the axis <NUM>.

Further, the gantry may also move in selected movements relative to the cart <NUM>, including the base <NUM>. As discussed herein, the gantry may move independent of the "C" shaped configuration rotor <NUM> via the axle <NUM> or the connection <NUM>. The movements may allow for iso-sway, linear translation, etc. of the gantry to further move the "C" shaped configuration rotor <NUM>.

Returning reference to <FIG> and additional reference to <FIG>, the imaging system <NUM> may be transformed or reconfigured to include the "O" shaped configuration rotor <NUM>', is illustrated in <FIG> and <FIG>. The imaging system <NUM> including the "C" shaped configuration rotor <NUM>, as illustrated in <FIG>. As discussed herein, one or more moveable segments may move to change the "C" shaped rotor <NUM> to the "O" shaped rotor <NUM>'. Various exemplary embodiments of the moveable segments are discussed herein.

The "C" shaped configuration rotor <NUM> when changing to the "O" shaped configuration rotor <NUM>' can include intermediate shapes, such as one or two intermediate shapes, as generally illustrated in <FIG>. For example the "C" shaped configuration rotor <NUM> may include a first moveable segment <NUM> and a second moveable segment <NUM>. The first and second moveable segments <NUM>, <NUM> can extend from the respective terminal ends <NUM> and <NUM> of the "C" shaped configuration rotor <NUM>. The moveable segments <NUM>, <NUM> may be held or stored within the "C" shaped configuration rotor <NUM> when the "C" shaped configuration rotor <NUM> is in the "C" shaped configuration, as illustrated in <FIG>, and extends when a command is provided to move the moveable segments <NUM>, <NUM> to form the "O" shaped configuration rotor <NUM>'.

A drive <NUM> and/or a drive <NUM> may be provided to move the moveable segments <NUM>, <NUM>. The first and second moveable segments <NUM>, <NUM> can extend from the respective terminal ends <NUM> and <NUM> of the "C" shaped configuration rotor <NUM> generally in the direction of arrows <NUM>' and <NUM>', respectively, as illustrated in <FIG>. The moveable segments <NUM>, <NUM> may also move generally radially outward or away from the isocenter <NUM> in the directions of arrows <NUM>" and <NUM>". The first moveable segment <NUM> includes an outer edge with teeth <NUM> and the second moveable segment includes a second outer edge with teeth <NUM>. The movement of the moveable segments <NUM>, <NUM> allows for the outer edges to be aligned with the outer edge of the fixed length segment <NUM>.

Further, as illustrated in <FIG>, a third moveable segment <NUM> can extend from the first moveable segment <NUM> and a fourth moveable segment <NUM> can extend from the second moveable segment <NUM> by being driven by the drives <NUM>, and/or <NUM> as described above. The third moveable segment may also move in an arc along arrow <NUM>' and radially in the direction of arrow <NUM>". Further, the fourth moveable segment <NUM> may move in an arc along arrow <NUM>' and radially in the direction of arrow <NUM>", similar to the movements described above. These movements allow respective outer edges with teeth <NUM> and <NUM> to be aligned with the outer edge of the fixed length segment <NUM>. The third and fourth moveable segments <NUM>,<NUM> can then meet or join at a joint region <NUM>, as illustrated in <FIG>.

Each of the moveable segments <NUM>, <NUM>, <NUM>, <NUM> can be held or stored within the "C" shaped configuration rotor <NUM> and extend therefrom upon a command by a user, such as the user <NUM>, to reconfigure the imaging system <NUM> into the "O" shaped configuration rotor <NUM>'. The movements of the segments <NUM>, <NUM>, <NUM>, <NUM> can be in the appropriate manner, including those discussed further herein.

As illustrated in <FIG> and <FIG>, the "O" shaped configuration rotor <NUM>' can extend annularly, generally about <NUM> degrees, around the isocenter <NUM> at which the patient <NUM> may also be placed. The patient <NUM> may be placed on the table <NUM> to be imaged with the "O" shaped configuration rotor <NUM>' by moving the imaging system <NUM> near or adjacent to the table <NUM> with the patient <NUM> placed when the imaging system is in the "C" shaped configuration rotor <NUM>. After moving the imaging system to have the patient <NUM> at a selected relative location, e.g. at the isocenter <NUM>, the command can be entered (e.g. with the input <NUM> or directly to the imaging computer <NUM>) to reconfigure the imaging system <NUM> to the "O" shaped configuration rotor <NUM>'. The "O" shaped configuration rotor <NUM>' can then rotate around the patient <NUM>, including around the long axis <NUM> of the patient <NUM>. The long axis <NUM> (as illustrated in <FIG>) of the patient <NUM> may generally be placed such that it intersects the isocenter <NUM> of the imaging system <NUM>. The rotation of the "O" shaped configuration rotor <NUM>' can be generally in the direction of arrow <NUM> around the long axis <NUM> and the isocenter <NUM>.

It is understood, however, that the "O" shaped configuration rotor <NUM>', as illustrated in <FIG> and <FIG>, may also move relative to the isocenter <NUM> in other movements. For example the gantry <NUM> may be moved relative to the isocenter <NUM> linearly along the long axis <NUM>, such as generally in the direction of arrow 198a. The gantry <NUM> also may be moved generally perpendicular to the long axis <NUM> generally in direction of arrow 198b. Still further, the gantry <NUM> may also be moved angularly relative to the long axis generally in the direction of arrow 198c, all is illustrated in <FIG>. The movements of the gantry <NUM> may be with the gantry drive <NUM>, discussed above, and due to the connections of the axle <NUM> or the connection <NUM>.

When the imaging system <NUM> has been reconfigured to the "O" shaped configuration rotor <NUM>' the source <NUM> and the detectors <NUM>, <NUM> can move generally in a path relative to the patient <NUM>. The path may be at least <NUM>° around the patient to acquire image data substantially in an entire circle <NUM>° round the patient <NUM>. The path of the detector <NUM>, <NUM>, however, need not be circular and may be spiral, less than a circle, or travel over a portion of path previously completed to acquire image data. The path may be defined by movements of the rotor <NUM> and/or the gantry <NUM>. In acquiring the image data around the patient <NUM>, such as <NUM>°, a volumetric reconstruction can be made of the patient <NUM> using the image data acquired around the patient. The image data acquired and the reconstruction thereof can be known according to various techniques including those disclosed in <CIT>, <CIT>, <CIT>, and <CIT>. For example, the image data can be acquired at the plurality of the angles relative to the patient <NUM> to identify or determine the geometry of the structures being in imaged. Nevertheless, when the imaging system <NUM> is in the "O" shaped configuration rotor <NUM>' the patient <NUM> can be imaged substantially completely angularly around the patient <NUM>.

Accordingly, as illustrated above, the imaging system <NUM> may be configurable between the "C" shaped configuration rotor <NUM>, as illustrated in <FIG>, and the "O" shaped configuration rotor <NUM>', as illustrated in <FIG>. This can allow the imaging system <NUM> to acquire image data according to different techniques while allowing the user <NUM> to access the patient <NUM> during an operative procedure. As discussed above, when in the "C" shaped configuration rotor <NUM> the user <NUM> may have substantially free access to the patient <NUM> through the opening <NUM>, as illustrated in <FIG>. However, if it is desired or selected to acquire image data for a more complete volumetric reconstruction, the imaging system <NUM> can be reconfigured to include the "O" shaped configuration rotor <NUM>' as illustrated in <FIG> and <FIG>.

With continued reference to <FIG>, the drive <NUM> of the imaging system <NUM> is coupled between the fixed length segment <NUM> of the rotor <NUM> and the moveable segments <NUM>, <NUM>, <NUM>, <NUM>. The drive <NUM> can operably move the segments <NUM>, <NUM>, <NUM>, <NUM> to reconfigure the imaging system between the "C" shaped configuration rotor <NUM> and the "O" shaped configuration rotor <NUM>'. The drive <NUM> can be provided in various configurations or types including an electric motor, a hydraulic motor, a pulley and cable system driven by a selected motor, a pneumatic system, a belt drive system including a belt driven by the drive <NUM>, or the like including linkages to the segments <NUM>, <NUM>, <NUM>, <NUM>. As discussed further herein the drive <NUM> can interconnect to the segments, such as the first segment <NUM>, to move the first segment <NUM> relative to the fixed length segment or portion <NUM>.

As also discussed further herein the first segment <NUM> can be moved to a position within an internal wall <NUM>, as illustrated in <FIG>, of the fixed length portion <NUM>. It is further understood that various linkages, including rigid, flexible, and multi member linkages, may connect the fixed length segment <NUM> and the moveable segments <NUM>, <NUM>, <NUM>, <NUM> to move the segments <NUM> -<NUM> relative to fixed length segment <NUM>. Further an additional drive, including the drive <NUM> may be provided to engage a selected number of segments, including the second and fourth segments <NUM>,<NUM> to move those segments relative to the fixed length segment <NUM> while the first drive <NUM> moves only the first and the third segments <NUM>, <NUM>. Further, it is understood that any appropriate number of the moveable segments may be provided, including less than the four or more than the four moveable segments <NUM>, <NUM>, <NUM>, <NUM>. Also, any selected number of the moveable segments may be provided to extend from only one end of the fixed length segment <NUM>.

With continued reference to <FIG>, the imaging system <NUM> includes the gantry <NUM> positioned or moveable relative to the cart <NUM>. The cart <NUM> can include the portions as described above, including the computer <NUM> and the monitor 32a. The gantry <NUM> may have mounted thereon the drive <NUM> that can include various portions to engage the rotor <NUM>, <NUM>' to move the rotor <NUM>, <NUM>' relative to the gantry <NUM> and relative to the cart <NUM>. According to various embodiments, the fixed length segment <NUM> may include an engageable portion, such as a tooth edge or a track <NUM> that can be engaged by a driver portion <NUM>, which may include a belt or wheel. The driver portion <NUM> may include at least one tooth (not illustrated) to engage the tooth <NUM> of the track portion of the fixed length segment <NUM>.

The movement of a motor of the drive <NUM>, which may be driven by a motor, including an electric motor, a hydraulic motor, or other appropriate motor, can move the drive portion <NUM> to move the fixed length segment <NUM> as illustrated in <FIG>. Accordingly the source <NUM> and the detector <NUM>, <NUM> can be moved relative to the patient <NUM> that is positioned within an opening of the fixed length segment <NUM>. X-rays may be emitted from the emitter <NUM> and detected on the detector <NUM>, <NUM> for generation of image data <NUM>. The gantry <NUM> can also move relative to the cart <NUM>, using the gantry drive <NUM>, as discussed above, which may be an electrical drive system, a hydraulic drive system, or the like to move the gantry <NUM> relative to the patient <NUM>. The gantry <NUM>, therefore, may move relative to the cart <NUM> and the patient <NUM>. As the fixed length segment <NUM> is connected to the gantry <NUM> the fixed length segment <NUM> may also move in these directions relative to the patient <NUM> and the cart <NUM> with the gantry <NUM>.

With continued reference to <FIG>, the segments <NUM>, <NUM>, <NUM>, and <NUM> can extend from the fixed length segment <NUM> to form "O" shaped configuration rotor <NUM>'. The moveable segments <NUM>, <NUM>, <NUM>, and <NUM> include the external surfaces <NUM>,<NUM>, <NUM> and <NUM>, respectively, that can be moved to be coextensive or extend from the tooth track <NUM> on the fixed length segment <NUM>. As discussed above, the moveable segments may move in both arcuate or curved paths and linear paths (e.g. radially from center of the arc) to form a continuous track for the "O" shaped configuration rotor <NUM>'. Accordingly when the segments <NUM>, <NUM>, <NUM>, and <NUM> are extended from the fixed length segment <NUM> the tooth track <NUM> of the fixed length segment <NUM> can continue to substantially continuously and smoothly <NUM>° in the "O" shaped configuration rotor <NUM>' by connection with the exterior surfaces <NUM>,<NUM>, <NUM> and 187of the segments <NUM>, <NUM>, <NUM>, and <NUM>. Therefore, the "O" shaped configuration rotor <NUM>' can be driven by the drive <NUM> at least <NUM>° around the patient <NUM> to acquire images of the patient <NUM>.

The emitter <NUM> and the detectors <NUM>, <NUM> can remain substantially relative to the fixed length segment <NUM> while the "O" shaped configuration rotor <NUM>' rotates around the patient <NUM> to acquire the image data of the patient <NUM>. In other words, the emitter <NUM> and the detector <NUM>, <NUM> need not move relative to the fixed length segment <NUM> to achieve rotation or movement around the patient <NUM>. Further, any or all of the emitter <NUM> and the detector <NUM>, <NUM> may be placed between sidewalls of the fixed length segment <NUM>, as illustrated in <FIG>. Thus, when rotating the O" shaped configuration rotor <NUM>' the patient is not substantially exposed to the emitter <NUM> and the detector <NUM>, <NUM>. A top wall may also be provided to further protect or shield the patient from the emitter <NUM> and the detector <NUM>, <NUM>.

The movement of the gantry <NUM>, including either the fixed length segment <NUM> and the "C" shaped configuration rotor <NUM> or the "O" shaped configuration rotor <NUM>', can be operated by a drive signal from the computer <NUM> to the drive <NUM>. The drive signal can include a distance and speed of movement signal for gantry <NUM> and the rotor <NUM>, <NUM>' relative to the patient <NUM>. Thus, the drive signal from the computer <NUM> can include movements generally along the arrows 198a, 198b, and 198c. The computer <NUM> can provide a drive signal to move the fixed gantry <NUM> and/or the rotation of the gantry <NUM>, <NUM>' to move the detector <NUM>, <NUM> and/or emitter <NUM> relative to the patient <NUM>. Possible drive scans can be provided by user <NUM> or other operators as disclosed in U. Patent application <CIT> <CIT>, <CIT>, and <CIT>.

With additional reference to <FIG>, the rotor <NUM> including segments <NUM> and <NUM> are illustrated in cross section from <FIG>. The fixed length segment <NUM> can include the first exterior wall <NUM> and a second exterior wall <NUM>. The two exterior walls <NUM>, <NUM> can be interconnected by a bottom or exterior wall <NUM> or a plurality of reinforcing struts or members. The drive track including the teeth <NUM> can be formed into at least one edge of the outer wall <NUM> or formed on one of the exterior walls <NUM>, <NUM>. The detectors <NUM>, <NUM> may also be substantially confined or placed within a volume defined between the sidewalls <NUM>, <NUM>. The emitter <NUM> may also be similarly positioned opposed to the detectors <NUM>, <NUM>. An inner cover or inner annular wall <NUM> may also be provided to complete a volume within the fixed length segment <NUM> to cover the emitter <NUM> and the detector <NUM>, <NUM>.

The segments <NUM> and <NUM> can be drawn into or between the two wall members <NUM>, <NUM>, as illustrated in <FIG>. The segments <NUM> and <NUM> need not have a bottom panel that is coextensive with the bottom panel <NUM> of the fixed length segment <NUM>, but can be separate wall members, including a first wall member 182a and a second wall member 182b and the fourth segment <NUM> can include a first wall member 186a and a second wall member 186b. It is understood, however, that connecting members 182c and 186c can optionally interconnect the respective wall members 182a, 182b and 186a and 186b.

Regardless of the specific configuration of the moveable segments <NUM>, <NUM>, the segment drive <NUM> and/or <NUM> can include a linkage <NUM> coupled to the second segment <NUM> and a second linkage <NUM> coupled to the fourth segment <NUM>. The linkages <NUM>, <NUM> can include hydraulic linkages, cables, fixed bar linkages, articulated bar linkages, or other appropriate linkages. According to an appropriate configuration the drive <NUM> and/or <NUM> can operate the linkages <NUM>, <NUM> to move the second segment <NUM> and the fourth segment <NUM> relative to the fixed length segment <NUM> to move the segments <NUM>, <NUM> between the "C" shaped configuration rotor <NUM> the "O" shaped configuration rotor <NUM>'. Appropriate clearances can be provided between the segments <NUM>, <NUM> and the fixed length segment <NUM> and the detectors <NUM>, <NUM> of the imaging system <NUM>. The segments <NUM>, <NUM> can move on selected rails or track within the fixed length segment <NUM> to change between the "C" shaped configuration rotor <NUM> the "O" shaped configuration rotor <NUM>'.

A lock device may also be provided to lock any of the moveable segments <NUM>, <NUM>, <NUM>, and <NUM> relative to one another and/or the fixed length segment <NUM>. The lock device may include a moveable pin or member that moves to engage at least two of the moveable segments <NUM>, <NUM>, <NUM>, <NUM> and/or the fixed length segment <NUM>. The lock device may also include locking or fixing the selected drives <NUM>, <NUM>, and/or <NUM>. The lock device, however, holds the various segments in the selected configurations.

Accordingly, the imaging system <NUM> that may include the rotor <NUM>, <NUM>' may have the fixed length segment <NUM> and the movable segments <NUM>, <NUM>, <NUM>, <NUM>. The moveable segments <NUM>, <NUM>, <NUM>, <NUM> can be moved relative to the fixed length segment <NUM> of to change the form of the imaging system between the C" shaped configuration rotor <NUM> the "O" shaped configuration rotor <NUM>'. It is further understood that the first segment and the third segment <NUM>, <NUM> can also move relative to the fixed length segment <NUM> of the gantry <NUM> in a manner similar to that illustrated and described as relative to the second and fourth segments <NUM>, <NUM>. The computer <NUM> may also be used to operate movement of the segments <NUM>, <NUM>, <NUM>, <NUM> to reconfigure the transformable imaging system <NUM> from the "C" shaped configuration rotor <NUM> the "O" shaped configuration rotor <NUM>', and vice versa. Also, the moveable segments may be provided in any appropriate number.

As illustrated in <FIG>, in various embodiments, the moveable segments <NUM>, <NUM>, <NUM>, <NUM> may move from two ends of the fixed length portion <NUM>. In the illustrated embodiment, opposing segments such as <NUM> and <NUM> move towards one another to complete the "O" shaped rotor <NUM>'. It is understood, however, that various embodiments may differ from the specific example illustrated, but may incorporate portions of the specific embodiment illustrated in <FIG>.

In various embodiments, moveable segments, such as all of the moveable segments may extend from only one end (also referred to as a "top" or a "bottom") of the fixed length rotor segment <NUM>. For example, rather than the moveable segments <NUM> and <NUM> moving towards one another, all of the moveable segments may collapse to one end of the fixed length segment <NUM> to form the "C" shaped rotor <NUM>, such as near a bottom near the spindle <NUM>, and then move out and towards a top of the fixed length segment <NUM>. Upon reaching the top the moveable segments would then form the "O" shaped rotor <NUM>'. The moveable segments may be stacked vertically relative to one another prior to moving to change the shape of the rotor. Further, the segments may telescope out to change the shape of the rotor.

In various embodiments, the number of moveable segments may be any appropriate selected number. For example, one, two, three, five, or more moveable segments may be provided. The arc length of each moveable segment may be selected, therefore, to configure the gantry from the "C" shaped rotor <NUM> to the "O" shaped rotor <NUM>'. Thus, two moveable segments may include one moveable segment that moves from the bottom and another that moves from the top of fixed length portion <NUM> to meet to form the "O" shaped rotor <NUM>'. Further, a single moveable segment may move from one end of the fixed length portion <NUM> to contact the other end to form the "O" shaped rotor <NUM>'.

In various embodiments, as illustrated in <FIG>, the imaging system <NUM> may include a two portion moveable segment, having a first portion <NUM> and a second portion <NUM>. The first portion <NUM> may extend from a first end <NUM> of the fixed length segment <NUM>. The second portion <NUM> may extend from a second end <NUM> of the fixed length segment <NUM>. Each portion <NUM>, <NUM> moves in the direction of the respective arrows <NUM>' and <NUM>' towards the opposing ends <NUM>, <NUM> of the fixed length segment <NUM>. It is understood, however, that both of the portions <NUM>, <NUM> may move in the same direction from one of the ends <NUM> or <NUM> towards the other <NUM> or <NUM> rather than the two portions <NUM>, <NUM> moving from opposing ends of the fixed segment <NUM>. The movement of the first and second portions <NUM>, <NUM> may operate in a manner similar to movement of the moveable segments discussed above. Further, movement of the first and second portions <NUM>, <NUM> causes the "C "shaped rotor <NUM> to be transformed to the "O" shaped rotor <NUM>'.

Each of the first and second portions <NUM>, <NUM> includes an arc length great enough to complete the "O" shaped rotor <NUM>'. Each of the first and second portions <NUM>, <NUM>, however, only forms one side or surface of the "O" shaped rotor <NUM>'. For orientation only, for example, the first portion <NUM> forms the left side and the second portion <NUM> forms the right side. In other words, each of the portions <NUM>, <NUM> are near or adjacent to one of the exterior sidewalls <NUM>, <NUM> of the fixed length segment <NUM>.

Each of the first and second portions <NUM>, <NUM> may include track portions to complete the track for movement of the source <NUM> and the detector(s) <NUM>, <NUM> or the track to move the "O" shaped rotor <NUM>' relative to the gantry <NUM>. In various embodiments, the fixed length segment <NUM> may form about <NUM> degrees of a circle and each of the first and second portions <NUM>, <NUM> may each form about <NUM> degrees of a circle. Thus, movement of the first and second portions <NUM>, <NUM> may form the "O" shaped rotor <NUM>'. It is also understood that each of the portions <NUM>, <NUM> may be formed of multiple members to form the first and second portions <NUM>, <NUM>.

In various embodiments, including those discussed above, the imaging system <NUM> can be provided as specifically illustrated, including in <FIG> and <FIG>, or may be altered or replaced with various features including those discussed further herein. With initial reference to <FIG>, an imaging system <NUM> is illustrated. The imaging system <NUM> can included portions and features that are substantially identical to the imaging system <NUM> discussed above. For example, the imaging system <NUM> can include the cart <NUM>, the imaging computer <NUM>, the base <NUM>, the connection or arm <NUM>, and at least one drive motor or mechanism <NUM>. The imaging system <NUM> may also be augmented to include portions of the imaging system <NUM>, as discussed above, as understood by one skilled in the art. Nevertheless, the imaging system <NUM> can include certain features as discussed further herein.

The imaging system <NUM> may include a gantry <NUM> that has an unchanging gantry portion or segment 334a. The unchanging portion 334a may also be referred to as a static or non-adjustable portion. In various embodiments, the static portion 334a has a fixed dimension (e.g. an arc length) and other segments may move relative to the static segment 334a. For example, the unchanging gantry portion 334a can form or define an arc that has a center, such as an isocenter of an imaging system, which is less than <NUM>°. The unchanging portion 334a forms at least a part of an arc between a first end 334a' and a second end 334a". Further, the unchanging portion 334a may have a height 334x at an upper most or highest point 334y' of the unchanging portion 334a above a surface 334y, such as a floor on which the imaging system <NUM> is placed, that is about five feet (about <NUM> meters) or less, including about five feet six inches (about <NUM> meters) in height. It is understood by one skilled in the art that the height of the unchanging portion 334a may be selected for various purposes, such as to allow a user of a selected height to see over the unchanging portion 334a.

According to various embodiments therefore, the imaging system may define a maximum dimension that is less than a selected amount. For example, the unchanging gantry portion 334a may further include a height or upper dimension that may be no higher or shorter than eye or sight line level of an average person that may move the imaging system <NUM>. This may assist in ease of movement of the imaging system and viewing relative to the imaging system <NUM>, especially when an operator moves the cart <NUM> of the imaging system <NUM>. The gantry <NUM>, having the unchanging gantry portion 334a, therefore, allows for a smaller dimension extending from a portion of the cart <NUM> opposite or away from the monitor 32a, where an operator may be positioned when moving the cart <NUM>. Thus, the imaging system <NUM> allows for a selected clearance and efficient mobility.

The gantry <NUM> can include one or more outer wall segments, such as four outer wall segments <NUM>, <NUM>, <NUM>, and <NUM> (see <FIG> and <FIG>) that form a cross-section with a volume inside of the wall segments <NUM>, <NUM>, <NUM>, and <NUM>. The cross-section may be a selected geometry. For example, as illustrated, the cross-section may include a rectangular cross-section.

The gantry <NUM>, therefore, can define a space within the wall segments in which a portion can move, such as the emitter <NUM> and detectors such as the detectors <NUM> and <NUM>. The cross-sectional area of the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can also house movable portions that allow the gantry <NUM> to change shape from the portion formed by the unchanging portion 334a to other shapes, including those discussed further herein and illustrated in <FIG>. As discussed further herein, the segments included or positioned within the volume defined by the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can be moved relative to the non-changing portion 334a of the gantry <NUM> to change a shape of the gantry <NUM> and/or an operation of the imaging system <NUM>.

Further, positioned within the cross-sectional area defined by the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can be a rotor <NUM>. The rotor <NUM> can be similar to the rotor <NUM>, as discussed above. For example, the source <NUM> and the detectors <NUM>-<NUM> may be mounted to the rotor <NUM>. The rotor <NUM> can move within the gantry <NUM> to allow for imaging of a subject, such as the patient <NUM>.

It is understood, in various embodiments, the rotor <NUM> may be positioned or provided to be immobile for various operational reasons. For example, with reference to <FIG>, the imaging system <NUM> can be provided in a stowed or transportation configuration. In a transportation configuration, the gantry <NUM> is formed or has terminal extents or perimeters defined only by the non-changing portion 334a. The rotor <NUM> can be positioned within the non-changing gantry portion 334a. The rotor <NUM> may be formed of collapsible portions to allow the rotor <NUM> to be collapsed to fit within the non-changing gantry portion 334a. The rotor <NUM>, as discussed above, may also include the source <NUM> and the detectors <NUM>-<NUM> associated therewith. Thus, the source <NUM> and the detectors <NUM>-<NUM> may be retracted or positioned within the non-changing gantry portion 334a. In the collapsed or transportation configuration, as specifically illustrated in <FIG>, the imaging system <NUM> can be efficiently moved and stored in a facility, such as a hospital. The small configuration or collapsed configuration may also allow for greater access to the patient <NUM> by the user <NUM>.

With reference to <FIG>, the gantry <NUM> may be operated to change its configuration. The configuration of the imaging system <NUM>, therefore, can be changed to allow operation of the imaging system <NUM> in various operational manners. In various embodiments, as discussed herein, one or more pieces of the gantry may move, one of more pieces of the rotor <NUM> may move, or combinations thereof to change the configuration of the imaging system <NUM>. The configuration may be changed for difference purposes, such as operation of the imaging system in different and selectable manners and/or movement and storage of the imaging system <NUM>.

Transformation or changing the configuration of the gantry is illustrated in <FIG>. Discussion herein includes reference to <FIG> in addition to a specific segmental change as illustrated in <FIG>. As illustrated in <FIG>, a first movable portion <NUM> and a second movable portion <NUM> can extend (e.g. telescope) from the non-changing portion 334a of the gantry <NUM>, is illustrated in <FIG>. In particular, the first and second movable portions <NUM>-<NUM> can extend from within the volume formed by the exterior wall segments <NUM>-<NUM>. As discussed further herein, the first movable portions <NUM>, <NUM> can each include an external wall portion, such as a wall section <NUM>, <NUM>, <NUM>, and <NUM>. Each of the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can form an internal volume, as also discussed further herein. Further, the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can form an external taper or have an angle relative to a longitudinal axis or a central axis formed through the internal volume of the movable portions <NUM>-<NUM>.

The angle of the walls or surface of the wall segments <NUM>, <NUM>, <NUM>, and <NUM> of the segments <NUM>-<NUM> can cause the segments to engage the non-changing portion 334a. The external walls <NUM>, <NUM>, <NUM>, and <NUM> engage internal surfaces of the wall segments <NUM>-<NUM> to assist in engaging or holding the first movable portions <NUM>-<NUM> relative to the non-changing gantry portion 334a. The engagement may occur as the movable portions <NUM> and <NUM> move out from the non-changing gantry portion 334a. In moving out, the taper of the external walls <NUM>, <NUM>, <NUM>, and <NUM> move closer to and then engage the internal surfaces of the walls of the non-changing gantry portion 334a, as illustrated in Figs. 11B and <FIG>. When engaged, the movable portions <NUM> and <NUM> may be at least partially supported and fixed by the engagement. As discussed herein, further movable portions may be similarly held.

With continuing reference to <FIG> and additional reference to <FIG>, a third movable portion <NUM> and a fourth movable portion <NUM> can move relative to the first and second movable portions <NUM>-<NUM>, respectively. Again, each of the third and fourth movable portions <NUM>, <NUM> include wall segments, such as wall segments <NUM>, <NUM>, <NUM>, and <NUM>. Again, the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can taper or form an angle relative to an internal surface of the respective wall segments <NUM>-<NUM> of the first movable portions <NUM>-<NUM>. The taper or angle can assist in engaging or holding respective third and fourth movable portions <NUM>-<NUM> relative to the first and second movable portions <NUM>-<NUM>.

Turning reference to <FIG>, a fifth movable portion <NUM> and a sixth movable portion <NUM> can move relative to the third and fourth movable portions <NUM>, <NUM>, respectively. Again, each of the fifth and sixth movable portions <NUM>, <NUM> can include external wall segments, such as external wall segments <NUM>, <NUM>, <NUM>, and <NUM>. Each of the wall segments <NUM>, <NUM>, <NUM>, and <NUM> can engage or contact an internal surface of wall segments <NUM>, <NUM>, <NUM>, and <NUM> in the extended configuration, as discussed above. Each respective movable portion can move relative to and engage or assist in holding the next extending movable portions.

Finally, with reference to <FIG>, a seventh movable portion <NUM> and an eighth movable portion <NUM> can extend from the respective fifth and sixth movable portions <NUM>, <NUM>. Again, the seventh and eighth movable portions <NUM>-<NUM> can include external wall segments, such as four wall segments <NUM>, <NUM>, <NUM>, and <NUM>. The wall segments <NUM>, <NUM>, <NUM>, and <NUM> can again include an external taper or angle relative to an internal surface of the wall segments <NUM>, <NUM>, <NUM>, and <NUM> to assist in engaging or holding the seventh and eighth movable portions <NUM>, <NUM> relative to the fifth and sixth movable portions <NUM>, <NUM> in a manner similar to that discussed above.

Illustrated in <FIG> and discussed above is an example of various embodiments wherein the moveable portions extend from both ends 334a', 334a"of the non-changing gantry portion 334a. It is understood, however, that in various embodiments that all of the moveable segments may extend from only one of the ends 334a' or 334a". In various further embodiments, an unequal number of the moveable segments may move from either one of the ends 334a' or 334a" (for example five segments extend from the end 334a' and three segments extend from the end 334a"). Regardless, the gantry <NUM> may be transformed or reconfigured to various shapes including a "C" shape and an "O" shape for operation and/or transport of the imaging system <NUM>.

It is further understood that the imaging system <NUM> by including the plurality of moveable segments may allow the imaging system <NUM> to achieve various shapes between a fully open "C" shape and the "O" shape. For example, the "C" shape may be provided to have an arc length only equal to the unchanging portion 334a. The "C" shape may then be changed to have an arc length of less than one moveable segment in addition to the unchanging portion 334a. Additional length may be added in small portions without completing the "O" shape and up to the "O" shape. Thus, the multiple moveable segments allow for a large range of user selectability of size for the gantry, including any arc length between the fully open "C" shape (with the moveable segments retracted completely) to the "O" shape.

With reference to <FIG> and <FIG>, the non-changing gantry portion 334a and the respective movable gantry portions <NUM>, <NUM>, <NUM>, and <NUM> are illustrated. It is understood that the movable portions <NUM>, <NUM>, <NUM>, and <NUM> may include a similar geometry and configuration and are therefore not repeated, but are understood to include features as discussed further herein. As discussed above, the non-changing gantry portion 334a includes the wall segments <NUM>-<NUM>, and each wall segment <NUM>-<NUM> can include internal surfaces thereof that engage external surfaces of the wall segments <NUM>-<NUM> of the first movable portion <NUM>. Further, the third movable portion <NUM> includes the external wall segments <NUM>-<NUM> that can include a geometry and configuration to engage internal surfaces of the wall segments <NUM>-<NUM>. The fifth movable portion <NUM> includes the wall segments <NUM>-<NUM> that may have external surfaces to engage internal surfaces of the wall segment <NUM>-<NUM> of the third movable portion <NUM>. Finally, the seventh movable portion <NUM> includes the external wall segments <NUM>-<NUM> that may have surfaces to engage internal surfaces of the wall segments <NUM>-<NUM> of the fifth movable portion <NUM>.

The various wall segments and surfaces allow the movable portions <NUM>, <NUM>, <NUM>, <NUM> to move a selected amount relative to each other and the non-changing gantry portion 334a. Further, the various wall segments and surfaces may allow the movable portions <NUM>, <NUM>, <NUM>, <NUM> to move to selected positions and be held or fixed relative to each other and the non-changing portion 334a. For example, as each of the movable portions <NUM>, <NUM>, <NUM>, <NUM> are moved relative to the non-moving portion 334a, the wall segments allow the respective movable portions <NUM>, <NUM>, <NUM>, <NUM> to move and engage in a fixed selected position relative to the non-changing portion 334a and/or the other movable portions. This allows the various configurations of the imaging system <NUM> to be achieved. Specific configurations of the internal wall surfaces and external wall surfaces can be selected to achieve various rigidities and may be based on material selection of the gantry <NUM>, therefore, exemplary embodiments are discussed herein for illustration purposes only.

With continuing reference to <FIG>, the gantry <NUM> including the non-changing portion 334a and the various movable portions <NUM>, <NUM>, <NUM>, <NUM>, are illustrated in extended and semi-extended configurations. The movable portions move relative to the non-changing portion 334a to allow the gantry <NUM> to change shape from the shape illustrated in <FIG> to a substantially "O"-shape or annular shape as illustrated in <FIG>. The various movable portions <NUM>, <NUM>, <NUM>, <NUM> can be moved relative to the non-changing portion 334a according to various mechanisms, including linkages, individually mounted servo motors, and the like.

For instance, a linkage system can be interconnected with a single motor, such as the motor <NUM>, to sequentially move and selectively move each of the movable portions <NUM>, <NUM>, <NUM>, <NUM> relative to the non-changing portion 334a. Alternatively, or in addition to the linkage, a servo motor or selected motor can be interconnected with each of the movable portions <NUM>, <NUM>, <NUM>, <NUM> that can be individually operated to move the selected movable portion relative to another of the movable portions <NUM>, <NUM>, <NUM>, <NUM> and/or the non-changing portion 334a. Either or both of these systems may drive wheels <NUM>. The wheels <NUM> may also only provide a guide or bearing for the movement of the movable portions <NUM>, <NUM>, <NUM>, <NUM>. In this manner, the gantry <NUM> can be changed between selected configurations from the fully opened or collapsed configuration illustrated in <FIG> to a closed or annular configuration as illustrated in <FIG>.

With additional reference to <FIG>, an end of the non-changing portion 334a and two movable portions <NUM> and <NUM> are illustrated. The movable portions can include a shape or geometry mentioned above and illustrated in greater detail here. A first terminal end of the first movable portion <NUM> includes a first terminal end <NUM> that includes at least one dimension, such as an external width dimension <NUM>. The external dimension <NUM> may be greater than an internal terminal end dimension <NUM> at a second terminal end <NUM> of the non-changing portion 334a. In this way, as the movable portion <NUM> moves out of the non-changing gantry portion 334a, the wall segments <NUM>-<NUM> can engage, such as interferingly engage the internal surface of the non-changing gantry portion 334a. A third terminal end <NUM> of the first movable portion <NUM> may include an external dimension <NUM> that is less than the external dimension <NUM> of the non-changing portion. In this way, the first movable portion <NUM> tapers from the first terminal end <NUM> to the third terminal end <NUM>.

An opening, such as a cross-sectional opening defined by the wall segments <NUM>-<NUM> of the non-changing gantry portion 334a include the internal dimension <NUM> that is greater than the dimension <NUM> of the third terminal end <NUM>, but it less than the external dimension <NUM> of the first terminal end <NUM>. Accordingly, as the second movable portion <NUM> moves out of the non-changing gantry portion 334a, a physical interference occurs between the movable portion <NUM> and the non-changing gantry portion 334a. This physical interference, along with any other selected locking mechanisms, such as a pin and wedge and the like, hold the movable portion <NUM> relative to the non-changing gantry portion 334a in a selected shape or configuration.

It is understood that the other movable portions can also include a similar configuration relative to the portions to which they move. For example, the third movable portions may include a fourth terminal end <NUM> that has an external dimension <NUM> that is greater than an internal dimension <NUM> of the third terminal end <NUM>. Thus, the third movable portion <NUM> may move and physically engage the second movable portion <NUM>.

Thus, a terminal end may include an external cross-sectional area, such as defined at least in part by the dimensions noted above, that is greater than an internal cross-sectional area at a second terminal end. The greater cross-sectional area being smaller than an opening through which the movable portion moves. Thus, a physical interference and connection can be formed between the various moving portions to form the gantry <NUM> in a selected shape that may be changed between the substantially open shape illustrated in <FIG> and the O shape illustrated in <FIG>.

Returning reference specifically to <FIG> and <FIG>, as discussed above, the emitter <NUM> and selected detectors <NUM>, <NUM> can be positioned on the rotor <NUM> to rotate within the gantry <NUM>. The rotor <NUM> may move on a track, such as a track formed by one or more track members. The track members can include a first or first pair of track members <NUM> movably connected by a linkage or pair of linkages <NUM> to the fourth wall portion <NUM> of the non-changing gantry portion 334a. The first rail or track member <NUM> can extend the entire arcuate dimension of the non-changing portion 334a of the gantry <NUM>. The track members <NUM> allow for the rotor <NUM> to engage relative to the gantry <NUM> and allow movement of the rotor <NUM> relative to the gantry <NUM>.

The track can also include rail members, as discussed further herein, that are interconnected with the various movable portions <NUM>-<NUM>. For example, one or a pair or second number of track members <NUM> can be movably connected with the first movable portion <NUM> by one or more linkages <NUM>. A third track member or members <NUM> can be movably interconnected with the third movable portion <NUM> by one or more linkages <NUM>. Fourth track member or members <NUM> may be movably interconnected with the fifth movable portion <NUM> with movable linkages of <NUM>. Also, fifth track member or members <NUM> can be interconnected with the seventh movable portion <NUM> with linkages <NUM>. The linkages <NUM> may not need to be movable relative to the movable portion <NUM>. The track members <NUM> may be fixably connected to the seventh movable portion <NUM> as the diameter formed by the fifth track members <NUM> relative to the seventh movable portion <NUM> may define the circumference of the completed track for movement of the rotor <NUM>. It is understood, however, that the fifth track members <NUM> may be also movably mounted relative to the seventh movable portion <NUM>. Moreover, it is understood that the opposing movable portions <NUM>-<NUM> may also include track members similar to the counterpart track members <NUM>-<NUM>, discussed above, but are not repeated here for clarity of the current discussion.

According to various embodiments, as the movable portions, for example, the first movable portion <NUM>, moves from the non-changing gantry portion 334a, the first track member <NUM> can be moved either alone or in combination with the second track portion <NUM> to form a complete track extending from the non-changing gantry portion 334a. Similarly, as each of the other movable portions <NUM>, <NUM>, <NUM> move, the various track portions can move to align the track members to form a track for the rotor <NUM> to ride along.

To assist in providing clearance for the track members to move relative to each other and the various movable portions <NUM>-<NUM>, the top walls or a portion of the top wall may include one or more grooves <NUM> to allow at least an end portion of the respective track members to move through the respective top walls of the movable portions <NUM>-<NUM>. Thus, the track members may move from a collapsed or retracted position, as illustrated in <FIG>, into aligned positions with the respective track members. It is further understood that the track members can move any appropriate amount and the amount illustrated in the drawings is simply for the current discussion and illustration.

Further, when the movable portions are held within the other respective movable portions and/or the non-changing gantry portion 334a, the track members <NUM>-<NUM> can be retracted or withdrawn into space between respective wall segments of the gantry portions. As illustrated in <FIG>, the track member <NUM> is between the wall segment <NUM> of the non-changing gantry portion 334a and the top wall segment <NUM> of the second movable portion <NUM>. Similarly, the other track members can be retracted into a space provided between each of the respective gantry portions, as exemplarily illustrated in <FIG>. The track members may be moved into the track forming position as illustrated in <FIG>.

The track portions, including the tracked portions <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, can be moved from the retracted position to the extended position to form the track for movement of the rotor <NUM> using various mechanisms such as individual servo motors for each of the tracked portions, connected linkages to a drive (e.g. the drive <NUM>), or other appropriate movement mechanisms. For example, individual servo motors or linkages can be included in each of the movable portions <NUM>-<NUM> to move the track members to be deployed position once the movable portion is in a selected position, such as deployed to an operating position. Further, the movement of the track members can be provided to move gradually such that as the movable portion is moving to the deployed or operating position, the track member can also be moving simultaneously. In this way, the track member can reach the deployed position and the movable portion can reach the deployed position substantially simultaneously.

An imaging system for acquiring images of a patient, including those discussed above is disclosed according to various embodiments. Alternatively, or in addition to the specific examples illustrated and discussed above, an imaging system <NUM>, according to various embodiments, is illustrated with initial reference to <FIG>. The imaging system <NUM> can include portions that are similar to the portions discussed above and will not be described in detail here. For example, the imaging system <NUM> may include the cart <NUM> which may be movable, such as being pushed by an operator manually or powered with a motor, via wheels <NUM> or other appropriate mobility devices. The imaging system <NUM> may further include a display device (e.g. a monitor) 32a which may be used to monitor operation of the imaging system <NUM> and/or view images acquired with the imaging system <NUM>. The imaging system <NUM> may further include the imaging computer <NUM> which may process images on the imaging system <NUM> and/or transmit image data to other processing systems. Further, the motor <NUM> can be used to move various portions of the imaging system <NUM>, such as with a control input (e.g. a stick) <NUM>. Portions of the imaging system <NUM> that may be moved include a rotor <NUM>.

In various embodiments, the imaging system <NUM> may be an x-ray or fluoroscopy imaging system. In these embodiments, the imaging system <NUM> will include a source, which is operable to emit x-rays, and one or more detectors such as the first detector <NUM> and the second detector <NUM>. As initially illustrated in <FIG>, the source <NUM> and the detectors <NUM>, <NUM> can be positioned at a selected location relative to the rotor <NUM>. The source <NUM> may move with and/or independently of the detectors <NUM>, <NUM>. Further, each of the detectors may move independently of each other and/or the source <NUM>.

The rotor <NUM> can be moved relative to the cart <NUM>, such as with a connection or arm <NUM> to a base portion of the cart <NUM>, as discussed above. The motor <NUM> may be incorporated into the connection <NUM> and may connect or engage the rotor <NUM>, with one or more teeth <NUM> formed or provided on an exterior surface of the rotor <NUM>. The rotor <NUM> can include a fixed or unchanging segment <NUM> on which the teeth <NUM> are formed. The unchanging fixed rotor portion <NUM> can extend along an arc from a first end <NUM> to a second end <NUM>. For the unchanging portion <NUM>, the length of the arc is not changeable by a user, as discussed above. Although the entire rotor <NUM> may be reshaped, according to various embodiments (e.g. telescoping segments), the unchanging portion or segment <NUM> does not have a length, i.e. arc length, which is changeable.

It is understood, however, that the rotor <NUM> need not move relative to the cart <NUM>. As discussed herein, the source <NUM> and the detectors <NUM>, <NUM> may move relative the cart <NUM> and to each other. Thus, the rotor <NUM> need not move relative to the cart to alter a position of the source <NUM> relative to one or more of the detectors <NUM>, <NUM>. As discussed herein, the rotor <NUM> may include a moveable portion that may allow the imaging system to form a fully annular track system. Thus, the imaging system <NUM> need not have a moveable rotor and only the source <NUM> and the detectors <NUM>, <NUM> may move. It is understood, however, that both the rotor <NUM> and the source <NUM> and detectors <NUM>, <NUM> may move and all may move independent of the others.

The patient <NUM> may be positioned near the isocenter <NUM> of the rotor <NUM>, in a manner similar to that discussed above to the other imaging exemplary embodiments. The patient <NUM> can then be imaged with the imaging system <NUM>, in a manner as generally understood by one skilled in the art, by emitting x-rays from the source <NUM> to be detected by selected one or more of the detectors <NUM>, <NUM>. The imaging system <NUM> may hold the source <NUM> and the detectors <NUM>, <NUM> relative to one another during the imaging.

The rotor <NUM> may be interconnected with the connection <NUM> directly and/or through linkages. The rotor <NUM> also may engage the motor <NUM>. For example, a track or engaging portion can movably couple the rotor <NUM>, such as the unchanging rotor portion <NUM> directly to the connection <NUM>. It is understood, however, a gantry <NUM> (illustrated in phantom), may also be provided to extend from the connection <NUM>. The gantry <NUM> may be similar to the gantry <NUM>, discussed above, and may support the rotor <NUM> during movement. It is understood, however, that the gantry <NUM> is not required for operation of the imaging system <NUM>.

The imaging system <NUM> can be operated in a manner to collect image data of the patient <NUM> in a manner similar to that discussed above. The rotor <NUM>, however, can be manipulated to be configured between a generally "C"-shaped configuration, as illustrated in <FIG>, and an "O"-shaped configuration as illustrated in <FIG>. A moveable segment <NUM> of the rotor <NUM> may move relative to the unchanging segment <NUM>, as discussed herein, to change the shape of the rotor <NUM>.

The rotor <NUM> can house or contain the source <NUM> and the detectors <NUM>, <NUM>. Again, it is understood, that only a single detector may be provided or more than two detectors may be provided. Nevertheless, both the source <NUM> and the detectors <NUM>, <NUM> can move within and relative to the rotor <NUM>, including the non-changing portion or fixed segment <NUM>. Further, as discussed above, the rotor <NUM> may also move relative with the cart <NUM> independently of the movement of the source <NUM> and the detectors <NUM>, <NUM>.

According to various embodiments, a track including a rail member <NUM> may be positioned within the non-changing segment <NUM>. Each of the source <NUM> and the detectors <NUM>, <NUM> can then be moved along the rail <NUM> to selected positions to acquire image data of the patient <NUM>. As illustrated in <FIG>, the source <NUM> may be positioned near the detectors <NUM>, <NUM>, such as near the arm <NUM>. As illustrated in <FIG>, the source <NUM> can also be positioned substantially opposite the detectors <NUM>, <NUM> to acquire an image of the patient <NUM>. The source <NUM> can move from the position as illustrated in <FIG> to the position as illustrated in <FIG> and the detectors <NUM>, <NUM> can also move from the position as illustrated in <FIG> to the position as illustrated in <FIG>. When positions are substantially opposite one another, the imaging system <NUM> can acquire image data of the patient <NUM> in a selected manner, such as collecting x-ray projections through the patient <NUM>.

It is understood that the non-changing segment <NUM> can be moved relative to the connection <NUM> to acquire image data at difference projections (i.e. angles of the detectors <NUM>, <NUM>) relative to the patient <NUM>. For example, the non-changing portion of the rotor <NUM> can generally move in the direction of arrow <NUM>, as illustrated in <FIG>, to a position about <NUM>° from the position as illustrated in <FIG>. It is further understood that the non-changing portion <NUM> can generally move in the direction of arrow <NUM> to a position that is substantially <NUM>° from that illustrated in <FIG> or <NUM>° in an opposite direction relative to that illustrated in <FIG>. Nevertheless, image data can be acquired of the patient <NUM> during movement of the non-changing rotor portion <NUM> or at selected discrete positions as the rotor moves in the direction of arrows <NUM>, <NUM>. For example, an anterior-to-posterior and medial-to-lateral image can be acquired of the patient <NUM> to acquire two projections to the patient <NUM>. Alternatively, or in addition thereto, a plurality of projections can be acquired through the patient <NUM> as the non-changing portion <NUM> moves relative to the patient <NUM>.

In the "C"-shaped configuration, the imaging system <NUM> may acquire one or more two-dimensional (2D) images. The 2D images are acquired as image data that may be then transformed to three-dimensional (3D) images. The 2D or 3D images may be viewed by the user, such as a surgeon, for assisting in selected procedures. The images may be registered to a patient space, as is understood in the art, for performing a navigated surgical or other selected procedure. Further, the images may be used for determining or viewing selected portions of the patient anatomy.

In various embodiments, the imaging system, as discussed herein, may also be changed to an "O: shaped configuration. In the "O"-shaped configuration the imaging system <NUM> may acquire images similar to those in other generally known CT-imaging systems. The images may be used to generated 3D images of the patient <NUM>. Further, the "O"-shaped configuration may be used to acquired images at any selected perspective relative to the patient <NUM>. Thus, the imaging system <NUM> may be provided to provide a changeable or alterable imaging system between a "C"-shaped imagine configuration to an "O"-shaped configuration.

Further, the imaging system <NUM>, according to various embodiments including various embodiments as discussed above, may be provided as a compact imaging system. In particular, the imaging system <NUM> may be configured to the "C"-shaped configuration for mobility and storage purposes. In various embodiments, the rotor <NUM> may have a height 710x at a selected highest or upper most point <NUM>0y' of the rotors <NUM> above a floor or surface 710y that supports the imaging system <NUM>, similar in dimensions as discussed above. For example, the height may be about five feet. Thus, the imaging system need not be maintained in the "O"-shaped configuration at all times. This allows the imaging system <NUM> to acquire images in a CT-imaging system manner (e.g. with a full <NUM> degree spin around the patient <NUM>) or in a C-arm configuration with the single imaging system <NUM>.

While the rotor <NUM> may move, as discussed above, the source and detectors <NUM>, <NUM>, <NUM> can also be moved with appropriate movement mechanisms. For example, individual motors (36a, 38a, and 40a), such as servomotors, can be connected to the source <NUM> and the detectors <NUM>, <NUM>, respectively. Instructions may be sent to the servomotors 36a, 38a, and 40a and to cause them to activate and move by instructions from the imaging computer <NUM> and/or based on input from a user. Also, the source <NUM> and the detectors <NUM>, <NUM> can be moved by connections, such as belt connections with the motor <NUM>. The movement of the source <NUM> and the detectors <NUM>, <NUM> can be powered according to various systems, including those generally known in the art. The operation protocol for moving the source <NUM> and the detectors <NUM>, <NUM> will be discussed in further detail herein.

In addition to and alternatively to moving the non-changing segment <NUM> as illustrated from <FIG> or vice versa, as discussed above, the movable segment <NUM>, as illustrated in <FIG>, can be moved from either end <NUM>, <NUM> of the non-changing segment <NUM>. As illustrated in <FIG>, the movable segment <NUM> can move to exit from the end <NUM> generally in the direction of arrow <NUM>. The movable segment <NUM> can define an internal volume similar to an internal volume defined by the non-changing segment <NUM> to allow movement of the source <NUM> and the detectors <NUM>, <NUM> therein.

The movable segment <NUM> extends from a first end <NUM> to a second end <NUM> generally along an arc length. The movable segment <NUM> can further include an exterior tooth portion <NUM> similar to the tooth portion <NUM> of the non-changing segment <NUM>. The movable segment <NUM> can continue moving to any appropriate configuration relative to the non-changing segment <NUM> such as until a complete circle or total "O" configuration is achieved, such as an "O"-shape, as illustrated in <FIG>.

The movable portion <NUM> can be used to form the "O"-shaped configuration of the imaging system <NUM>, including the rotor <NUM>, as illustrated in <FIG>. As discussed above, the "O"-shaped configuration may allow the source <NUM> and the detectors <NUM>, <NUM> to move generally in a <NUM>° motion around the patient <NUM>. When the rotor <NUM> is in the "O"-shape, the isocenter <NUM> may not change from when the rotor is in the "C"-shaped configuration. Thus, the isocenter <NUM> may be constant for the imaging system <NUM>. The patient <NUM> may be positioned at or near the isocenter <NUM>, including a selected portion of the patient of which image data is selected to be acquired.

The movable portion <NUM> can have a portion of the rail <NUM> formed therein such that when the movable segment <NUM> completes the "O"-shaped configuration, the source <NUM> and the detectors <NUM>, <NUM> can traverse <NUM>° around the isocenter <NUM> on the rail <NUM>. Further, the tooth surface <NUM> can be moved into alignment with the tooth surface <NUM> so that the rotor <NUM> may also move relative to the patient <NUM>. It is understood, however, that the rotor <NUM> need not move in a <NUM>° movement as the source <NUM> and detectors <NUM>, <NUM> can move <NUM>° within the rotor <NUM> once the movable segment <NUM> is moved to connect the first end <NUM> and the second end <NUM> to allow movement of the source <NUM> and the detectors <NUM>, <NUM> within the "O"-shape of the rotor <NUM>, as illustrated in <FIG>.

Further, as discussed above, the rotor <NUM> can be moved relative to the cart <NUM> via the connection <NUM>. For example, the connection <NUM> can be moved up and down generally in the direction of double-headed arrow <NUM> and back and forth as illustrated by a double-headed arrow <NUM>. Further, the connection <NUM> can move the rotor <NUM> in a sway movement such as illustrated by the double-headed arrow <NUM> around an axis, such as an axis <NUM>.

Therefore, the imaging system <NUM> can include the rotor <NUM> that can be change from a "C"-shape, as illustrated in <FIG> to an "O"-shaped configuration as illustrated in <FIG>. Further, the imaging system <NUM> can include the rotor <NUM> that achieves the configuration between the "C"-shape and the "O"-shape, as illustrated in <FIG>. It is further understood that the movable segments <NUM> can extend from either of the ends <NUM> or <NUM>. Therefore, the movable segment <NUM> may extend from the end <NUM> and move towards the end <NUM> generally in the direction opposite of the arrow <NUM>.

The changeability of the imaging system <NUM> from the "C"-shaped configuration to the "O"-shaped configuration also allows the single imaging system <NUM> (and according to various embodiments as discussed above) to operate in various manners without moving the patient <NUM>. For example, the imaging system <NUM> may be operated as a "C"-arm to acquire selected 2D images while allowing great access to the patient <NUM>. The imaging system <NUM> may also acquire CT type images using data acquired during a <NUM> spin around the patient. The different images may be acquired of the patient without moving the patient <NUM>. This may allow the single imaging system <NUM> to operate in various manners during a single procedure, such as an operative procedure, without requiring movement of the patient <NUM> or altering a position of the patient <NUM> during the procedure.

The imaging system <NUM> including the source <NUM> and detectors <NUM>, <NUM> can be operated according to various schemes to ensure or assist in ensuring that the source <NUM> is positioned opposite a selected one of the detectors <NUM>, <NUM>. As discussed above, the source <NUM> may move independently of the detectors <NUM>, <NUM> relative to the rotor <NUM>. Therefore, operation of the source <NUM> relative to the detectors <NUM>, <NUM> may be necessary to ensure that the source <NUM> is opposite the detectors <NUM>, <NUM> for imaging. Further, it is understood, that the imaging system <NUM> may include only a single one of the detectors <NUM>, <NUM>. For the following discussion the detector <NUM> would be specifically included for clarity. It is understood, however, that the control schemes discussed herein can be used to operate the imaging system <NUM> including a plurality of the detectors <NUM>, <NUM>.

With initial reference of <FIG> a command (referred to as a co-command) scheme is illustrated in a flowchart <NUM> where various portions referred to therein may include either or both hardware components specifically designed for the disclosed purpose, include firmware software for performing a disclosed purpose, or a general purpose processor that is executing software for a disclosed purpose. As discussed above, a user may operate the imaging system <NUM> from the cart <NUM> or other appropriate processor communicating and/or connected with the imaging system <NUM>. For example, the user may operate the imaging system processor <NUM> via input, such as the pointer <NUM> (as illustrated in <FIG>) or a keyboard that is interconnected with the cart <NUM>. The user can input a command that directs the imaging system processor <NUM> to operate and/or move various portions of the imaging system <NUM>, including the source <NUM> and the detector <NUM>. As illustrated in the flowchart <NUM>, a command may be provided in a command block 802a and a command block 802b. The two command blocks 802a, 802b operate the control scheme in the flowchart <NUM> as a co-command control scheme. The command blocks 802a and 802b may include instructions based on the input by the user from the controller <NUM> and produce signals based thereon.

The command from the command block 802a may be sent as a signal 804a to a source axis <NUM>. The command from the command block 802b may be the an offset signal from the signal 804a and can be sent as signal 804b. The offset signal 804b may be offset, as discussed further herein, from the signal 804a. The signal 804a may also be sent or diverted from the signal line 804a to a summing junction <NUM>. The summing junction may both sum and subtract signals, as is generally known by one skilled in the arts. The offset signal 804b can be transmitted by the combiner block <NUM>.

The offset can be any appropriate offset, such as about <NUM>° to about <NUM>°, including exactly <NUM>°. As discussed above, the source <NUM> may generally be positioned substantially opposite or <NUM>° from the detector <NUM> to acquire images of the patient <NUM>. When the source <NUM> is substantially <NUM>° from the detector <NUM>, image data (and images based thereon) may be acquired as x-rays pass through the patient <NUM> on a substantially straight line from the source <NUM> to the detector <NUM>. The signal from the command block 802b, therefore, can be provided <NUM>° offset or separate from command block 802a and the signal 804a sent to the source axis <NUM> as the offset transmitted signal <NUM>.

The offset signal <NUM> can then be sent to the detector axis <NUM>. The source axis <NUM>, as illustrated in the flowchart <NUM>, can include both control mechanisms (e.g. PID controllers) and plant mechanisms (e.g. servomotor 36a) that are included with or within the source <NUM> to move the source <NUM>. Further, the detector axis <NUM> can also refer to control mechanisms (e.g. PID controllers) and plant mechanisms (e.g. servomotor 36a) with or within the detector <NUM>.

The signal 804a may reach the source axis <NUM> and be received by a source controller <NUM>. The source controller <NUM> may include a controller summing junction <NUM> that initially receives the signal 804a and a controller <NUM>. The summing junction may both sum and subtract signals, as is generally known in the controller arts. The controller <NUM> may be any appropriate controller (such as a proportional integral derivative controller (PID)). The controller <NUM> may transmit the signal 804a from the command input 802a and to a plant mechanism <NUM> through, optionally, an amplifier <NUM>. The plant mechanism <NUM> may include the servomotor 36a that is used to move or drive the source <NUM> to a selected position. The signal 804a from the command module 802a can be provided to the plant mechanism <NUM> to move or power the servomotor 36a, acting as the plant mechanism <NUM>, to position the source <NUM> at a selected location.

A signal from the plant mechanism <NUM> can then be transmitted to an encoder <NUM> to sense a position of the source <NUM>. A signal of the sensed position from the encoder <NUM> can be provided back to the summing junction <NUM> to assist in controlling the position of the source <NUM> and/or a speed of travel of the source <NUM>. The encoder <NUM> may, however, generate a signal separate from the plant mechanism <NUM> to determine an absolute position, relative position, or amount of movement of the source <NUM> over a period (e.g. since last movement or since start of movement). Therefore, the source <NUM> can be moved in a first direction based upon the signal 804a from the command module 802a.

The detector axis <NUM> can include components similar to the source axis <NUM>, including a detector controller <NUM>. The detector controller <NUM> may include a detector summing junction <NUM> that receives the offset signal <NUM> from the combiner <NUM>. The offset signal, being offset by <NUM>°, can operate to move the detector to a position or in a direction opposite the movement of the source <NUM>. Further, as the offset signal is <NUM>° of that of the source <NUM>, the detector <NUM> may generally be moved substantially opposite the source on the rotor <NUM>.

Accordingly, the signal can pass from the summing junction <NUM> to a detector controller852 (which may be any appropriate controller, such as a PID controller) and then be provided, optionally, through an amplifier <NUM> to a plant mechanism <NUM>. As discussed above, the plant mechanism <NUM> may be the servomotor 38a, as discussed above, provided with the detector <NUM>. Therefore, the offset signal <NUM> can be used to operate the plant mechanism <NUM> to move the detector <NUM> substantially opposite the source <NUM>.

The detector axis <NUM> may further include a detector encoder <NUM>, similar to the source encoder <NUM>. A signal from the plant mechanism <NUM> can then be transmitted to the detector encoder <NUM> to sense a position of the detector <NUM>. A signal of the sensed position from the detector encoder <NUM> can be provided back to the summing junction <NUM> to assist in controlling the position of the detector <NUM> and/or a speed of travel of the detector <NUM>. The detector encoder <NUM> may, however, generate a signal separate from the plant mechanism <NUM> to determine an absolute position, relative position, or amount of movement of the source <NUM> over a period (e.g. since last movement or since start of movement).

Further, output signals from the source axis <NUM> can include an output signal <NUM> to the command module 802a. In a similar manner, an output signal <NUM> from the detector axis <NUM> can be provided to the command module 802b. The signals provided to the command modules 802a, 802b can be used to confirm positioning of the source <NUM> and the detector <NUM> at the selected positions in the rotor <NUM>.

Accordingly, the control mechanism or scheme <NUM>, illustrates how the source axis <NUM> (which includes the source <NUM>) and the detector axis <NUM> (which includes the detector <NUM>) receive selected signals and use the signals to control movement of the respective source <NUM> and detector <NUM>. The control scheme <NUM>, therefore, illustrates how the source <NUM> can be moved substantially to a position opposite of the detector <NUM>. In this manner, the source <NUM> can be moved to any selected relative to the patient on the rotor <NUM>, but also be substantially opposite the detector <NUM> based upon an input from the user.

The flowchart <NUM> illustrates at least one control or co-command scheme for controlling the movements of the source <NUM> relative to and with movement of the detector <NUM>. According to various embodiments, <FIG> illustrates an alternative or second control scheme as a master-slave scheme illustrated in the flowchart <NUM>. In the master/slave control scheme, various components and controllers may be substantially similar as in the co-command scheme according to the flowchart <NUM>, but may be operated in a different manner, as discussed herein. As discussed above in relation to the co-command scheme <NUM>, the command modules 802a, 802b may provide signals, as discussed herein, to the source axis <NUM> and the detector axis <NUM>. As discussed above, the respective axes <NUM>, <NUM> may include controllers and plant mechanisms to control and move the respective source <NUM> and detector <NUM>.

A signal <NUM> is sent from the command block <NUM> to the source axis <NUM>. The source axis <NUM> can include the same components as illustrated in the command scheme <NUM> and will not be described in detail, but mentioned briefly. Initially, the signal can be received within the source controller <NUM> including the summing junction <NUM> and then transmitted to the controller <NUM> (which may be a PID controller as discussed above). The signal may then be, optionally, amplified in the amplifier <NUM> and used to drive the plant or power mechanism <NUM>. An encoder may receive a signal form the plant <NUM> and/or sense a position of the source <NUM> and return a signal to the summing junction <NUM> in the source controller <NUM>.

The master/slave control scheme <NUM> may differ from the co-command control scheme <NUM> in that the detector axis <NUM> may receive a signal from the source axis <NUM>, including a signal <NUM> from the encoder <NUM>, rather than responding directly to a signal <NUM> from the command module 802b. The signal <NUM> from the command module 802b may include an offset, such as the offset discussed above. As discussed above, the offset may be about <NUM>° to about <NUM>°, including exactly <NUM>°, to produce the offset signal <NUM>.

The signal <NUM> from the source axis <NUM> may go to the summing junction <NUM> that also receives the signal <NUM> from the command module 802b. From the summing junction <NUM> the offset signal <NUM> may then be transmitted to the detector axis <NUM>. Thus, the detector axis <NUM> receives the signal <NUM> from the source axis <NUM> prior to any action, therefore the detector axis is a slave to the source axis <NUM>. It is understood, however, that the source axis 810o may be a slave to the detector axis <NUM>.

The offset signal <NUM> is initially received within the detector controller <NUM> including the summing junction <NUM> and transmitted to the controller <NUM> (which may be a PID controller, as discussed above). The signal may then be, optionally, amplified in the amplifier <NUM> and transmitted to the plant/motor <NUM>. An encoder <NUM> may also be used to determine a position signal of the detector <NUM>, as discussed above. An output signal <NUM>, optionally, can then be provided to the command module 802b to determine whether the final position based upon input of the use of the source <NUM> and the detector <NUM> has been reached.

In the master/slave command scheme <NUM>, the signal to the detector axis <NUM> is based, at least in part, upon the output signal <NUM> from the source axis <NUM>. Therefore, the detector <NUM> only moves based upon movement, as encoded in the signal <NUM>, output from the source axis <NUM>. This can allow the slower component, for example the source <NUM>, to dictate movement of the faster moving component, for example the detector <NUM>. This may ensure that the two components can reach a selected position at a selected time in synchronization. It is understood, however, that the source may not be the faster moving component; this is simply provided for the current discussion.

Further, it is understood that the offset signal <NUM> may not be a <NUM>° offset. For example, the signal <NUM> may be a -<NUM>° signal and the offset signal and the offset signal <NUM> may be a +<NUM>° signal. As the detector <NUM> moves based upon an output signal from the source axis <NUM>, the detector <NUM> would still be <NUM>° separated from the source <NUM>.

An average and difference command scheme <NUM> is illustrated in <FIG>. The command scheme <NUM> is a further alternative to controlling movement of the source <NUM> and the detector <NUM> relative to one another within the imaging system <NUM>. The control scheme <NUM> may include various components similar to that discussed above, that are not discussed in further detail here, but only briefly listed here. The control scheme <NUM>, nevertheless, may include a first control module <NUM> that may be includes or provided in the imaging processor <NUM> or other appropriate processor. The first control module <NUM> can include various components as discussed herein, which may be embodied in the processor <NUM> or other appropriate processor. The first control module <NUM> may include firmware included with a processor or include programmable software that is executed by a general processor. Further, the first control module <NUM> may be a separate component that is interconnected with the imager <NUM> that may receive an input from the user for positioning the source <NUM> and the detector <NUM>. The input from the user may be provided with or from the command modules 802a, 802b, as discussed above.

The first control module <NUM> in controlling the position of the source <NUM> and the detector <NUM> can receive an input from the user regarding a selected position from the command modules 802a, 802b. The first control module <NUM> can receive an input regarding an average speed of the system as input <NUM> which goes to an initial summing junction <NUM> then to a first controller <NUM> (such as a PID controller). An output signal from the controller <NUM> may be an output signal <NUM> that is transmitted to a second summing junction <NUM> and to the source axis <NUM>. The source axis 810may include various components, including those components discussed above in the source axis <NUM>. The various components will not be further discussed here, however, the source axis 810may include the controller and the plant mechanism for moving the source <NUM> and the encoder or a sensor for sensing movement of the source <NUM>.

The signal <NUM> may further be transmitted to a third summing junction <NUM> and transmitted to the detector axis <NUM>. Again, the detector axis 820can include components as discussed above in the detector axis <NUM>, and are not reiterated here. For example, the detector axis 820may include the controller, to the plant mechanism to move the detector <NUM>, and the encoder to determine or sense a position of the detector <NUM>.

The first control module <NUM> can further receive a difference signal <NUM> from the command module 802b that may include the offset of the detector <NUM> relative to the source <NUM>. The difference signal <NUM> may be transmitted to a fourth summing junction <NUM> and to a second controller <NUM> (which may be a PID controller). An output signal <NUM> from the controller <NUM> may be transmitted to the third summing junction <NUM> and to the second summing junction <NUM>. The signal from the two summing junctions <NUM>, <NUM> can then be provided, respectively, to the detector axis <NUM> and the source axis <NUM>. Therefore, each of the detector axis <NUM> and the source axis 810may receive signals regarding both the average speed and difference in speed of the two axes <NUM>, <NUM>.

The source axis <NUM> can then output a source axis signal <NUM> and the detector axis <NUM> can output a detector axis signal <NUM> to a signal conditioning module <NUM>. The signal conditioning module <NUM> may also include firmware executed by a selected processor or programmable software executed by a selected processor. In the signal conditioning module <NUM>, a summation of the source axis output signal <NUM> and the detector axis output signal <NUM> may be made in a fifth summing junction <NUM> and a summation signal <NUM> is then divided in half in a computation or average module <NUM> and an average signal <NUM> may be output from the computation module <NUM>. The signal conditioning module <NUM> further includes a summing junction <NUM> which may output a difference signal <NUM> as a difference between the source axis output signal <NUM> and the detector axis output signal <NUM>. Both the averaging signal <NUM> and the difference signal <NUM> can be input to the first control module <NUM> to control the position of the detector <NUM> and the source <NUM> to provide feedback regarding an instant position and/or speed of the source <NUM> and detector <NUM>.

As discussed above, the imaging system <NUM> includes the source <NUM> and the detector <NUM> (and/or the detector <NUM>) that may move relative to one another within the rotor <NUM>. As the source <NUM> and the detector <NUM> may move relative to one another, various control schemes, including those discussed above and illustrated in the control schemes <NUM>, <NUM>, and <NUM>, may be used to control position of the source <NUM> and the detector <NUM> relative to one another. The control scheme allows the source <NUM> and the detector <NUM> to be selectively movable relative to one another without being positioned on a rigid connection system. As the source <NUM> and the detector <NUM> are able to move relative to one another, selected perspectives of the patient <NUM> may be acquired which may vary beyond those allowed if the source <NUM> and the detector <NUM> are rigidly positioned relative to one another on a fixed mechanism, such as an arcuate structure. Therefore, the control schemes allow the control of the position of the source <NUM> relative to the detector <NUM> for imaging of the patient <NUM>. Further, the control schemes can ensure that at selected times the source <NUM> is substantially opposed to the detector <NUM> for acquiring images of the subject <NUM>. It is further understood, however, that a non-human patient may be imaged with the imaging system <NUM>.

Claim 1:
A system transformable to image a subject in at least two configurations, comprising:
a gantry member (<NUM>) extending from a first gantry terminal end (<NUM>) to a second gantry terminal end (<NUM>);
a rotor (<NUM>) having:
a fixed length segment (<NUM>) having a "C" shape with a first terminal end and a second terminal end and a first sidewall having a first external edge opposed to a second sidewall having a second external edge, wherein a volume is at least partially formed between the first sidewall and the second sidewall;
a source (<NUM>) connected at a first positon within the volume;
a detector (<NUM>) connected at a second position on the fixed length segment within the volume and substantially opposed to the source (<NUM>);
one or more moveable segments, including a first moveable segment (<NUM>) extending from a first segment end to a second segment end;
the system further comprising:
a rotor drive (<NUM>) operably connected to the gantry member (<NUM>) and the rotor (<NUM>) to move the rotor (<NUM>) relative to the gantry member (<NUM>);
wherein the source (<NUM>) and the detector (<NUM>) move with the rotor (<NUM>) relative to the gantry member (<NUM>) when the rotor drive (<NUM>) drives the rotor (<NUM>) relative to the gantry member (<NUM>); characterized in the rotor further comprising a segment drive (<NUM>) coupled between the fixed length segment and the one or more moveable segments, wherein the segment drive is configured to move the one or more moveable segments relative to the fixed length segment both in a curved path and in a linear path radially from the center of the fixed length segment between an open configuration substantially in the "C" shape and a closed configuration in an "O" shape.