Patent Description:
It would be desirable to make these imaging devices mobile, so that they can move to various locations within a hospital or other health services environment. This is difficult due to the size, weight and overall number of components required for making an operable imaging system. Furthermore, these systems typically require a power system that can provide high-voltages (e.g., <NUM> kV) to components that rotate within the system around an imaging bore. Conventional imaging systems generally utilize a dedicated high-voltage power source and a complex power delivery mechanism, such as a slip-ring or a high-voltage cable system, to deliver the required power to the rotating imaging components. While these power systems may work fine for conventional fixed imaging systems, they are not ideal for mobile systems, which are ideally much more compact and lightweight than conventional systems. Furthermore, when transporting a mobile system outside of the traditional radiology environments, it is typically not possible to obtain the power required to perform imaging procedures from standard power outlets.

<CIT> describes a drive system for a mobile imaging device that includes a main drive geared into a drive wheel for propelling the imaging system, including a base and one or more imaging components, across a surface, a scan drive that moves the drive mechanism and the one or more imaging components relative to the base to provide an imaging scan, and a suspension drive that extends the drive wheel relative to a bottom surface of the base when the imaging system is in transport mode and retracts the drive wheel relative to the bottom surface of the base when the imaging system is in an imaging mode.

<CIT> describes a mobile medical imaging device that allows for multiple support structures, such as a tabletop or seat, to be attached, and in which the imaging gantry is indexed to the patient by translating up and down the patient axis, where the imaging gantry may translate, rotate and/or tilt with respect to the support base and may also rotate in-line with the support base to facilitate easy transport or storage of the device.

An imaging system according to claim <NUM> includes a first portion comprising a base having a length dimension, a second portion that rotates with respect to the first portion and translates relative to the first portion along the length dimension of the base, and a locking mechanism that prevents the first portion when at a first translational position along the length dimension from translating relative to the second portion by rotation of the second portion to a first angular position relative to the first portion causing engagement, wherein the locking mechanism permits the second portion to translate relative to the base when the second portion is not rotated to the first angular position.

Further exemplary embodiments include an imaging system that includes a first portion of the system, a second portion of the system, wherein the second portion rotates with respect to the first portion, and a locking mechanism having a first lock portion on the first portion of the system and a second lock portion on the second portion of the system, and wherein the first lock portion engages with the second lock portion to prevent the second portion of the system from rotating with respect to the first portion of the system when the second portion of the system is rotated to one or more pre-determined angles relative to the first portion of the system.

Further exemplary embodiments include a system that includes a first portion of the system, a second portion of the system having a housing, wherein the second portion of the system rotates with respect to the first portion of the system, and at least one cable that provides an electrical connection between the first and second portions of the system, wherein the at least one cable is fixed at a first position on the first portion of the system and is fixed at a second position on the second portion of the cable, and the rotation of the second portion of the system relative to the first portion of the system in a first direction causes the at one cable to be fed into a service loop located in the housing of the second portion of the system, and the rotation of the second portion of the system relative to the first portion of the system in a second direction opposite the first direction causes the at least one cable to be fed out of the service loop in the housing of the second portion of the system.

Further exemplary embodiments include an imaging system that includes a gantry having at least one imaging component, and a gimbal that supports the gantry such that the gantry may tilt with respect to the gimbal in tilt direction, wherein the gimbal has an outer surface facing the gantry that is convexly curved or angled in the gantry tilt direction.

Further exemplary embodiments include a control system and a related method for controlling an imaging device, wherein the control system includes a holster mounted to the imaging device, a user interface device removably mounted in the holster and operably connected to a control unit of the imaging device, the user interface device comprising a display configured to display system information and at least one user input component for controlling operation of the imaging device.

Further exemplary embodiments include a method of operating an imaging system that includes translating a second portion of the imaging system relative to a first portion of the imaging system, rotating the second portion to a first angular position with respect to the second portion, and engaging a locking mechanism to prevent the first portion from translating relative to the second portion when the second portion is in the first angular position.

Further exemplary embodiments include a method of operating an imaging system that includes rotating a second portion of the imaging system with respect to a first portion of the imaging system, and engaging a locking mechanism that prevents the second portion from rotating with respect to the first portion by rotating the second portion to a pre-determined angular position relative to the first potion.

Further exemplary embodiments include a method of operating a system having a second portion that rotates with respect to a first portion and at least one cable that provides an electrical connection between the first and second portions of the system, the method including rotating the second portion of the system in a first direction relative to the first portion to feed the at least one cable into a service loop located in a housing of the second portion, and rotating the second portion of the system in a second direction, opposite the first direction, relative to the first portion to feed the at least one cable out of the service loop in the housing of the second portion of the system.

Other features and advantages of the present invention will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings of which:.

This application is related to <CIT>, now <CIT>, <CIT>, and <CIT>. The entire contents of all of these applications are hereby incorporated by reference for all purposes.

Referring to <FIG>, a mobile imaging system <NUM> according to one embodiment of the invention includes a mobile base <NUM>, a gimbal <NUM>, a gantry <NUM>, and a pedestal <NUM>. The system <NUM> includes image collection components, such as a rotatable x-ray source and detector array or stationary magnetic resonance imaging components, that are housed within the gantry <NUM>. The system <NUM> is configured to collect imaging data, such as, for example x-ray computed tomography (CT) or magnetic resonance imaging (MRI) data, from an object located within the bore of the gantry <NUM>, in any manner known in the medical imaging field. The pedestal <NUM> is adapted to support a tabletop support <NUM> that can be attached to the pedestal <NUM> in a cantilevered manner and extend out into the bore of the gantry <NUM> to support a patient or other object being imaged.

The gantry <NUM> and gimbal <NUM> are illustrated in <FIG>. The gimbal <NUM> is a generally C-shaped support that is mounted to the top surface of base <NUM> and includes a pair of arms <NUM>, <NUM> extending up from the base. The arms <NUM>, <NUM> are connected to opposite sides of gantry <NUM> so that the gantry is suspended above base <NUM> and gimbal <NUM>. In one embodiment, the gimbal <NUM> and gantry <NUM> can rotate together about a first axis (a) relative to the base <NUM>, and the gantry <NUM> can tilt about a second axis (a') relative to the gimbal <NUM> and base <NUM>.

In certain embodiments, the gimbal <NUM> and gantry <NUM> can translate with respect to the base <NUM> to provide an imaging scan. The gimbal <NUM> can include bearing surfaces that travel on rails <NUM>, as shown in <FIG>, to provide the translation motion of the gimbal <NUM> and gantry <NUM>. A scan drive mechanism can drive the translation of the gantry and gimbal relative to the base, and a main drive mechanism can drive the entire system in a transport mode. In the embodiment of <FIG>, both of these functions are combined in a drive system <NUM> that is located beneath the gimbal <NUM>.

In certain embodiments, the base <NUM> of the system can be omitted, and the gimbal <NUM> can sit directly on the ground to support the gantry <NUM>. In other embodiments, the gimbal can be omitted, and the gantry <NUM> is a stand-alone gantry that sits on the ground.

<FIG> is an exploded view of the gimbal <NUM>, illustrating how the gimbal <NUM> may be connected to the gantry <NUM> in various embodiments. As shown in <FIG> , the gimbal <NUM> may be assembled from multiple pieces. Upper portions <NUM>, <NUM> of the gimbal <NUM> may be securely fastened to opposing sides of the gantry <NUM>. The upper portions <NUM>, <NUM>, which may have a shape similar to "earmuffs," may include a bearing apparatus that enables the "tilt" motion of the gantry <NUM> relative to the gimbal <NUM>. The upper portions <NUM>, <NUM> may also be fastened to the respective arms <NUM>, <NUM> of the gimbal <NUM>. For ease of assembly, it may be preferable to fasten the upper portions <NUM>, <NUM> to the gantry <NUM> before connecting the entire gantry/upper portion assembly to the respective arms <NUM>, <NUM> of the gimbal <NUM>. Also shown in <FIG> is a cover <NUM> that may be placed over an access opening in one or both arms <NUM>, <NUM> of the gimbal <NUM>. An additional cover <NUM> may be provided over the base of the gimbal <NUM>, and may be removed to access a bearing and/or drive system positioned within or beneath the base of the gimbal <NUM>. The access opening(s) of the gimbal <NUM> may be sealed by gasket(s) to isolate the interior of the gimbal <NUM> from the outside environment and facilitate airflow cooling of the system, such as described in <CIT>.

<FIG> is a cross-sectional view of the gantry <NUM> and gimbal <NUM> that illustrates a number of components of the imaging system <NUM>, which in this embodiment comprises an X-ray CT imaging system, including an x-ray source <NUM>, high-voltage generator <NUM>, x-ray detector <NUM>, battery system <NUM>, computer <NUM>, rotor drive mechanism <NUM>, docking system <NUM> and charging system <NUM>. A number of these components, including the x-ray source <NUM>, high-voltage generator <NUM>, x-ray detector <NUM>, battery system <NUM>, computer <NUM> and rotor drive mechanism <NUM>, are mounted on a rotor <NUM>, as is illustrated in the exploded view of <FIG>. The rotor <NUM> and the components mounted thereto, rotate within a housing defined by an outer shell <NUM> of the gantry <NUM>.

The system <NUM> thus has a rotating portion <NUM>, which includes the rotor <NUM> and the various components mounted to the rotor that rotate within the gantry <NUM> during an imaging scan, and a non-rotating portion <NUM>, that generally includes the other components of the system, including the base <NUM>, gimbal <NUM>, and the outer shell <NUM> of the gantry <NUM>. The charging system <NUM> is located on the non-rotating portion <NUM> of the system. The docking system <NUM> provides intermittent connection between the rotating and non-rotating portions <NUM>, <NUM> for transfer of power and/or data between the two portions.

During an imaging scan, the rotor <NUM> rotates within the interior of the gantry, while the imaging components such as the x-ray source <NUM> and x-ray detector <NUM> obtain imaging data for an object positioned within the bore of the gantry, as is known, for example, in conventional X-ray CT scanners. The rotor drive mechanism <NUM> drives the rotation of the rotor <NUM> around the interior of the gantry <NUM>. The rotor drive mechanism <NUM> may be controlled by a system controller that controls the rotation and precise angular position of the rotor <NUM> with respect to the gantry <NUM>, preferably using position feedback data, such as from a position encoder device.

Various embodiments of the imaging system <NUM> may be relatively compact, which may be desirable, for example, in a mobile imaging system. One way in which the system <NUM> may be made compact is in the design of the gantry <NUM> and its interface with the rotating portion <NUM> (e.g., the rotor <NUM> and the various components mounted to the rotor <NUM>). In embodiments, the outer shell <NUM> of the gantry <NUM> may comprise both a protective outer covering for the rotating portion <NUM> and a mounting surface for a bearing that enables the rotating portion <NUM> to rotate <NUM>° within the outer shell <NUM> of the gantry <NUM>.

<FIG> is an exploded view of a gantry <NUM> according to one embodiment that illustrates the outer shell <NUM>, the rotor <NUM> and a bearing assembly <NUM>. <FIG> illustrates the assembled gantry <NUM>. As is shown in <FIG>, the outer shell <NUM> of the gantry <NUM> may be a generally O-shaped covering of a structural material that may at least substantially fully enclose the rotating portion <NUM>, including the rotor <NUM> and any components mounted to the rotor, over one or more sides of the rotating portion <NUM>. The outer shell <NUM> of the gantry <NUM> may be conceptually considered an "exoskeleton," that both supports the rotating portion <NUM> of the system <NUM>, preferably in three dimensions, and also provides a protective barrier between the rotating portion <NUM> and the external environment. In embodiments, the outer shell <NUM> of the gantry <NUM> may support at least about <NUM>%, such as more than <NUM>%, and preferably more than about <NUM>%, such as more than <NUM>%, and even more preferably <NUM>% of the weight of the rotating portion <NUM> of the imaging system <NUM>. In embodiments, the outer shell <NUM> itself may be supported by one or more other components, such as a gimbal <NUM>, base <NUM> and/or drive mechanism <NUM>, as shown in <FIG>, for example. In other embodiments, the outer shell <NUM> may be supported directly on the ground, for example, or via other means, such as raised on a pedestal, table, cart or other support, or suspended or cantilevered from a wall, ceiling or other support structure. In certain embodiments, an outer shell <NUM> of the gantry <NUM> that comprises both a protective outer covering for the rotating portion <NUM> and a mounting surface for a bearing for rotation of the rotating portion <NUM> may provide the gantry <NUM> with various degrees-of-freedom, such as the "tilt" motion about axis (a') and/or rotation about axis (a) as shown in <FIG>, as well as translation motion for imaging applications and/or transport of the gantry <NUM>.

The outer shell <NUM> may be fabricated from a sufficiently rigid and strong structural material, which may include, for example, metal, composite material, high-strength plastic, carbon fiber and combinations of such materials. In preferred embodiments, the outer shell <NUM> may be comprised of a metal, such as aluminum. The outer shell <NUM> may be machined or otherwise fabricated to relatively tight tolerances. The outer shell <NUM> may be formed as a one piece, unitary component. In other embodiments, the outer shell <NUM> may be comprised of multiple components and/or materials that may be joined using any suitable technique to provide the shell <NUM>.

The outer shell <NUM> may have an outer circumferential surface <NUM> that may extend around the periphery of the rotating portion <NUM> of the system <NUM> to substantially fully enclose the rotating portion <NUM> around its outer circumference. As used herein, "substantially fully enclose" means that the circumferential surface <NUM> encloses at least about <NUM>%, such as at least about <NUM>% (e.g., <NUM>% or more), and preferably at least about <NUM>%, such as at least about <NUM>% (e.g., between <NUM>% and <NUM>%) of the rotating portion <NUM> around its outer circumference. As shown in <FIG>, for example, the outer shell <NUM> may substantially fully enclose the rotating portion while also including one or more openings, such as opening <NUM> (where the gantry <NUM> is secured to the gimbal <NUM>) and access opening <NUM>.

The outer shell <NUM> may also include at least one side wall <NUM> that may extend from the outer circumferential surface <NUM> to a bore <NUM> of the gantry <NUM> and may substantially fully enclose the rotating portion <NUM> around one side of the rotating portion. In embodiments, the outer shell <NUM> may include two side walls, one on each side (e.g., front and rear) of the gantry <NUM>, and the two side walls may substantially fully enclose the rotating portion <NUM> around two sides of the rotating portion. In the embodiment shown in <FIG> the outer shell <NUM> includes a side wall <NUM> on a first side (e.g., the front side) of the gantry <NUM>. As shown in <FIG>, an opposite (e.g., rear) side wall <NUM> of the gantry <NUM> may be formed by the combination of the outer shell <NUM>, bearing assembly <NUM>, and/or the rear surface of the rotor <NUM>. The side wall <NUM> may substantially fully enclose the various components mounted to the rotor <NUM> around a side of these components. The outer circumferential wall <NUM> and the side walls <NUM> and <NUM> may define a cavity <NUM>, as shown in <FIG>, and the various components mounted to the rotor <NUM> may rotate within the cavity <NUM>. A protective outer covering may be provided over the rear side wall <NUM> and/or over the interior circumference of the gantry <NUM> (e.g., around the outer circumference of the bore <NUM>) to provide an additional barrier between the rotating portion <NUM> and the external environment. The protective covering may be comprised of a thin, lightweight material, such as plastic.

As will be discussed in further detail below, the drive mechanism for the rotating portion <NUM> of the imaging system may utilize a belt drive on the rotor <NUM>, where the belt for the drive is mounted to a fixed railing <NUM>, as is shown in <FIG>. In various embodiments, a railing <NUM> or similar fixed structure for the rotor drive <NUM> may be located on the internal surface of side wall <NUM>.

The bearing assembly <NUM> according to one embodiment is shown in <FIG> and <FIG>. In this embodiment, the bearing assembly <NUM> includes a first race <NUM> that may be securely fastened to the outer shell <NUM> of the gantry <NUM>, and a second race <NUM> that may be securely fastened to the rotor <NUM>. A bearing element <NUM> (<FIG>) is provided between the first race <NUM> and the second race <NUM>, and is configured to allow the second race <NUM> (along with the rotor <NUM> to which it is attached) to rotate concentrically within the first race <NUM>, preferably with minimal friction, thereby enabling the rotor <NUM> to rotate with respect to the outer shell <NUM> of the gantry <NUM>. In the exemplary embodiment of <FIG>, the bearing assembly <NUM> may abut against a lip <NUM> in the rotor, and a plurality of fastening members <NUM> (such as bolts) may be provided through the lip <NUM> and into the second race <NUM> around the periphery of the rotor <NUM> to securely fasten the rotor <NUM> to the bearing assembly <NUM>. The bearing assembly <NUM> may also be provided at least partially within the outer circumferential wall <NUM> of the outer shell <NUM> and against a lip <NUM> in the outer shell <NUM> of the gantry <NUM>. A plurality of fastening members (similar to fastening members <NUM>) may be provided through the lip <NUM> and into the first race <NUM> around the periphery of the outer shell <NUM> to securely fasten the outer shell <NUM> to the bearing assembly <NUM>. A small gap <NUM> may be provided between lip <NUM> and lip <NUM>. In some embodiments, all or a portion of the bearing assembly <NUM> may be integrally formed as a part of the outer shell <NUM> or of the rotor <NUM>, or of both. For example, the first race <NUM> may be formed as an integral surface of the outer shell <NUM> and/or the second race <NUM> may be formed as an integral surface of the rotor <NUM>. In various embodiments, the entire bearing assembly for enabling the rotation of the rotating portion <NUM> with respect to the non-rotating portion <NUM> of the imaging system <NUM> may be located within the generally O-shaped gantry <NUM>.

The outer diameter of the gantry <NUM> can be relatively small, which may facilitate the portability of the system <NUM>. In a preferred embodiment, the outer diameter (OD in <FIG>) of the gantry <NUM> is less than <NUM> (<NUM> inches), such as between <NUM> and <NUM> (<NUM> and <NUM> inches), and in one embodiment is <NUM> (<NUM> inches). The outer circumferential wall <NUM> of the outer shell <NUM> may be relatively thin to minimize the OD dimension of the gantry <NUM>. In addition, the interior diameter of the gantry <NUM>, or equivalently the bore <NUM> diameter (ID in <FIG> ), can be sufficiently large to allow for the widest variety of imaging applications, including enabling different patient support tables to fit inside the bore, and to maximize access to a subject located inside the bore. In one embodiment, the bore diameter of the gantry <NUM> is greater than <NUM> (<NUM> inches), such as between <NUM> and <NUM> (<NUM> and <NUM> inches), and in some embodiments can be between <NUM> and <NUM> (<NUM> and <NUM> inches). In one exemplary embodiment, the bore has a diameter of <NUM> (<NUM> inches). As shown in <FIG>, the gantry <NUM> generally has a narrow profile, which may facilitate portability of the system <NUM>. In one embodiment, the width of the gantry <NUM> (W) is less than <NUM> (<NUM> inches), and can be <NUM> (<NUM> inches) or less.

A number of features of the various embodiments may facilitate the compact size of the imaging gantry <NUM>. For example, as previously discussed the outer shell <NUM> of the gantry <NUM> may be a relatively thin yet rigid exoskeleton structure that provides a protective outer covering for the rotating components while simultaneously supporting the rotating components in multiple dimensions as they rotate relative to the outer shell <NUM>. Various additional features are illustrated in <FIG>, which illustrates the rotating portion <NUM> of the imaging system <NUM> according to one embodiment. The various components, such as x-ray source <NUM>, detector <NUM>, high-voltage generator <NUM>, heat exchanger <NUM>, computer <NUM>, battery system <NUM>, docking system <NUM> and rotor driver <NUM>, may be mounted to rotor <NUM> and configured to fit and rotate within the internal cavity <NUM> of the gantry <NUM> shown in <FIG>. As shown in <FIG> and <FIG>, for example, this may include providing the drive mechanism <NUM> within the interior cavity <NUM> of the gantry <NUM>, which may aid in minimizing the outer diameter and width dimensions of the gantry <NUM> while also enabling a relatively large bore diameter. Various other components may be configured to facilitate a compact gantry design. For example, as shown in <FIG>, the high-voltage generator <NUM>, which may be one of the larger components of the rotating portion <NUM>, may have at least one surface <NUM>, <NUM> that is angled or curved to substantially correspond with the curvature of the gantry <NUM> and/or bore <NUM>. Another example of a high-voltage generator <NUM> with an angled or curved outer surface is shown in <FIG>. Similarly, the battery system <NUM> may be housed in a chassis having at least one surface <NUM>, <NUM> that is angled or curved to substantially correspond with the curvature of the gantry <NUM> and/or bore <NUM>. In this way, the outer diameter of the gantry may be minimized while also maintaining a relatively large bore diameter.

The imaging system <NUM> generally operates in a conventional manner to obtain images of an object located in the bore of the gantry. For example, in the case of an x-ray CT scan, the rotor <NUM> rotates within the housing of the gantry <NUM> while the imaging components, including the x-ray source and x-ray detector, obtain image data at a variety of scan angles. Generally, the system obtains image data over relatively short intervals, with a typical scan lasting less than a minute, or sometimes just a few seconds. During these short intervals, however, a number of components, such as the x-ray source tube and the high-voltage generator, require a large amount of power, including, in some embodiments, up to <NUM> kW of power.

In one embodiment, the power for the rotating portion <NUM> of the system <NUM> is provided by a battery system <NUM> that is located on the rotating portion <NUM> of the system <NUM>. An advantage of the battery-based power supply is that the conventional schemes for delivering power to the imaging components, such as complicated and expensive slip-ring systems and bulky cable systems, can be avoided.

As shown in <FIG> and <FIG>, the battery system <NUM> is mounted to and rotates with the rotor <NUM>. The battery system <NUM> includes a plurality of electrochemical cells. The cells can be incorporated into one or more battery packs. In one embodiment, for example, the battery system <NUM> includes seven battery packs <NUM>, with sixty-four cells per pack <NUM>, for a total of <NUM> cells. The battery system <NUM> is preferably rechargeable, and is recharged by the charging system <NUM> when the rotor <NUM> is not rotating. In one embodiment, the battery system <NUM> consists of lithium iron phosphate (LiFePO<NUM>) cells, though it will be understood that other suitable types of batteries can be utilized.

The battery system <NUM> provides power to various components of the imaging system <NUM>. In particular, since the battery system <NUM> is located on the rotating portion <NUM> of the imaging system <NUM>, the battery system <NUM> can provide power to any component on the rotating portion <NUM>, even as these components are rotating with respect to the non-rotating portion <NUM> of the imaging system <NUM>. Specifically, the battery system <NUM> is configured to provide the high voltages and peak power required by the generator <NUM> and x-ray tube <NUM> to perform an x-ray imaging scan. For example, a battery system may output ~360V or more, which may be stepped up to 120kV at a high-voltage generator (which may also be located on the rotating portion <NUM>) to perform an imaging scan. In addition, the battery system <NUM> can provide power to operate other components, such as an on-board computer <NUM>, the detector array <NUM>, and the drive mechanism <NUM> for rotating the rotor <NUM> within the gantry <NUM>.

Each of the battery packs <NUM> includes an associated control circuit <NUM>, which can be provided on a circuit board. In certain embodiments, the control circuits <NUM> can communicate with one another and/or with a main battery controller that is also located on the rotating portion <NUM> of the imaging system <NUM>.

The battery pack control circuit(s) <NUM> are configured to monitor and/or alter the state of charge of each of the electrochemical cells <NUM> in the battery pack <NUM>. An example of a battery pack control circuit <NUM> is shown in <FIG>. In this embodiment, the control circuit <NUM> connects across each individual cell <NUM>. The control circuit <NUM> monitors the voltage of the cell <NUM>, and generates signals from the analog-to-digital converter <NUM> that indicate the charge-state of the cell. These signals are provided to the main battery controller <NUM>, which monitors the charge-state of all the cells in the battery system. The controller <NUM> may comprise a processor having an associated memory that may execute instructions (e.g. software) stored in the memory. The main battery controller <NUM> can send control signals to the respective control circuits <NUM> to alter the state of charge of each electrochemical cell <NUM>. In the embodiment of <FIG>, the main battery controller <NUM> alters the charge-state of the cell <NUM> by switching on transistor <NUM>, which connects the cell <NUM> across load resistor <NUM>. The cell <NUM> can then be partially drained in a controlled manner. The battery controller <NUM> can continue to monitor the charge state of the cell <NUM> and switch off the transistor <NUM> when the cell <NUM> reaches a pre-determined charge state. In one embodiment, whenever the cell <NUM> is in danger of overcharging, the load resistor is switched in until the battery is at a safe charge state. In certain embodiments, if an overcharge condition is actually reached in one or more cells, the charging system can be switched off while the load resistor continues to drain the cell. Other cell charging and balancing schemes can also be employed.

In certain embodiments, the battery system includes processing circuitry that is configured to implement a control scheme to cause the electrochemical cells to have substantially the same charge state. This control scheme can be implemented by a main battery controller <NUM>, for example, or can be implemented by the plurality of battery pack control circuits <NUM> in communication with each another. In one exemplary embodiment of the control scheme for the battery system, a load resistor is switched in for each cell when the cell either exceeds the desired charge voltage or when the cell exceeds the average cell voltage by a pre-determined threshold. The charging system is disabled if any cell exceeds the maximum charging voltage.

<FIG> schematically illustrates the battery system <NUM>, charging system <NUM> and docking system <NUM> according to one embodiment. The charging system <NUM> provides electrical power to the battery system <NUM> in order to charge the rechargeable electrochemical cells. In a preferred embodiment, the charging system <NUM> is located on the non-rotating portion <NUM> of the imaging system <NUM>. For example, the charging system <NUM> can be located on the gimbal <NUM>, the outer shell <NUM> of the gantry <NUM>, the base <NUM> or the pedestal <NUM> (see, e.g., <FIG>). In a preferred embodiment, the charging system <NUM> is located on the gimbal <NUM>. <FIG>, <FIG> illustrate one embodiment of a charging system <NUM> that is located on the gimbal <NUM>. The charging system <NUM> is electrically coupled to the battery system <NUM> at least during the times when the rotating portion <NUM> of the imaging system <NUM> is stationary relative to the non-rotating portion <NUM>, such as in between imaging scans. The charging system <NUM> need not be, and in preferred embodiments is not, electrically coupled to the rotating portion <NUM> during an imaging scan. In one embodiment, the docking system <NUM> couples the charging system <NUM> to the battery system <NUM> when the rotating portion <NUM> is in a stationary or "park" mode, as is described in greater detail below.

The charging system <NUM> is configured to receive input power from an external power source, such as a standard wall power outlet. The charging system <NUM> can include circuitry that conditions the input power to render it suitable for recharging the battery packs <NUM> on the rotor <NUM>. The charging system <NUM> can also include control circuitry that communicates with the battery pack control circuit(s) and controls the operation of the charging system.

In one embodiment, the charging system <NUM> is configured to automatically begin charging of the battery system <NUM> when the charging system <NUM> is electrically coupled to the battery system <NUM>. During the charging operation, the battery pack control circuits <NUM> and/or the main battery controller <NUM> monitor the state of charge of the individual cells <NUM>, and can instruct the charging system <NUM> to terminate charging when a pre-determined charge-state is reached. For example, charging can terminate when one or more of the electrochemical cells <NUM> reach a full state of charge.

The docking system <NUM> is configured to selectively couple and de-couple the rotating <NUM> and non-rotating <NUM> portions of the imaging system <NUM>. As schematically illustrated in <FIG>, a first portion 36a of the docking system <NUM> is located on the rotating portion <NUM> of the system, preferably on the rotor <NUM>, and includes a mating surface that faces towards the outer circumference of the gantry <NUM>. A second portion 36b of the docking system <NUM> is located on the non-rotating portion <NUM> of the system, such as on the gimbal <NUM>, and includes a mating surface that faces into the interior housing of the gantry. When the system is in "park" mode, the rotor <NUM> automatically rotates to a position where the first 36a and second 36b portions of the docking system <NUM> are aligned and facing one another. Mating features (e.g., pin(s) and socket(s)) on one or both of the first 36a and second 36b portions of the docking system are actuated to physically connect the two portions 36a, 36b. During an imaging scan, the two portions 36a, 36b disengage from each other, and the first portion 36a rotates with the rotor <NUM> inside the interior housing of the gantry <NUM>.

The docking system <NUM> includes at least one electrical connection for providing power to components on the rotating portion <NUM>, including the rechargeable battery system <NUM>. When the docking system <NUM> is disengaged, such as during an imaging scan, power for the components of the rotating portion <NUM> comes from the battery system <NUM>. Components on the non-rotating portion <NUM> of the imaging system <NUM> can remain powered by an external power source, such as grid power.

In one embodiment, the docking system <NUM> further includes at least one electrical connection for data transfer between the rotating and non-rotating portions of the imaging system <NUM>. The rotating portion <NUM> of the imaging system <NUM> obtains imaging data at the detector array <NUM>, and this data may be transferred off the rotating portion <NUM> via the docking system <NUM> for processing and/or display. In one embodiment, the rotating portion <NUM> of the imaging system <NUM> includes a computer <NUM> having a memory and processor. The image data obtained at the detector <NUM> may be sent to the computer <NUM> for temporary storage and optional processing while the rotating portion <NUM> is rotating. Following an image scan, the rotating and non-rotating portions of the system are connected by the docking system <NUM>, and the data from the on-board computer <NUM> may be downloaded off the rotating portion <NUM> for further processing and/or display.

An embodiment of a docking system <NUM> is shown in <FIG>. The first portion 36a of the docking system <NUM> includes a pair of moveable rods <NUM> that reciprocate between a first, disengaged position (<FIG>) and a second, engaged position (<FIG>). The first portion 36a is shown in <FIG>. An electrical connector 53a is secured between the rods <NUM> and moves with the movement of the rods. An actuator, which in this embodiment includes a motor <NUM> and lead screw <NUM>, drives the movement of the rods <NUM> and connector 53a. The second portion 36b of the docking system <NUM> is illustrated in <FIG>, which shows a pair of slots <NUM> and an electrical connector 53b that is configured to mate with the connector 53a on the first portion 36a. During engagement of the docking system <NUM>, the rods <NUM> from the first portion 36a move into engagement with the corresponding slots <NUM> in the second portion 36b of the docking system. This engagement prevents the rotating portion <NUM> from moving relative to the non-rotating portion <NUM> while the docking system is engaged. The rods <NUM> and slots <NUM> also ensure that the respective electrical connectors 53a, 53b on the first and second portions 36a, 36b are properly aligned as the actuator mechanism <NUM>, <NUM> moves the connectors 53a, 53b into mating engagement. When the docking system <NUM> is engaged (<FIG>), the connectors 53a, 53b carry electrical power to charge the battery system, and also enable data and control signals to pass between the rotating and non-rotating portions of the system.

<FIG> illustrate the location of the docking system <NUM> within the imaging system <NUM>. As seen most clearly in <FIG>, the first portion 36b is mounted to and rotates with the rotor <NUM>. Between scans, the rotor <NUM> rotates to the "park" position of <FIG>, and the docking system <NUM> is engaged. The second portion 36b of the docking system <NUM> is located on the gimbal <NUM>, as shown in <FIG>. In a preferred embodiment, the second portion 36b is mounted to the bearing on the gimbal that allows the gantry to tilt with respect to the gimbal, such that the second portion 36b rotates with the tilting motion of the gantry, which allows the docking system to dock and undock while the gantry is tilted.

In one embodiment of a docking sequence, the control circuitry on the rotor <NUM> causes the rotor drive mechanism <NUM> to rotate the rotor to the "park" position, preliminary to docking. Then, the control circuitry causes the actuator mechanism <NUM>, <NUM> to drive the rods <NUM> (fast) to the point where the tapered end portions of the rods <NUM> (see, e.g., <FIG>) engage with "rollers" that define the slots <NUM> on the second portion 36b of the docking mechanism. Then, the control parameters of the rotor drive mechanism are relaxed such that it can be back driven. The mating electrical contacts are then prepared to engage such that they are protected from damage during docking, as is discussed further below. Next, the rods <NUM> are driven (slow) to the "docked" position whereby the tapered portion of the rods pushes the rotor into alignment through contacting the rollers on the mating dock. The control circuitry then reads a loopback signal on the dock to determine proper engagement, and once proper engagement is determined, the electrical connections (e.g., power and data connections) between the rotating <NUM> and non-rotating <NUM> portions of the system are engaged. Rotor drive control parameters are then restored, and the position is assigned within the control software.

<FIG> is a schematic illustration of the system power circuitry during a docking procedure, according to one embodiment. The system is shown in a docked configuration, with the components on the non-rotating portion <NUM>, including charger <NUM> and one or more device(s) <NUM>, which branch off a main power bus <NUM>, electrically connected to the components on the rotating portion <NUM>, including battery <NUM> and one or more device(s) <NUM>, via docking system <NUM>. To un-dock the system, the electrical connection between the rotating <NUM> and non-rotating <NUM> components must be broken. However, at the voltages and currents used by the system, as the respective contacts physically separate, the electricity will continue to flow briefly across the gap, forming a spark. This spark tarnishes and erodes the contacts over time, and in some cases can weld the contacts together.

There is a similar problem when the system re-docks. If the voltages on each side of the docking system are significantly different, large currents may flow through the dock as the two sides of the power system equalize. These currents can overheat the contacts.

In one embodiment, both of these problems are solved by designing and operating the system so that the voltage on the non-rotating <NUM> (charger) side is higher than the voltage on the rotating <NUM> (battery) side whenever the dock is being mated or unmated. That guarantees that current can only flow in one direction through the dock. Then, before the mating or unmating procedure is performed, a switch <NUM>, which can be a solid-state relay (SSR), is opened to prevent current flow in that direction (i.e. from the non-rotating to the rotating side). The docking system <NUM> can then be safely docked or undocked.

An inrush current limiting circuit <NUM>, which can comprise an NTC resistor, for example, is provided in series with the relay <NUM> to protect components, including the relay(s) and the docking system <NUM>, against damage from current inrush during a docking procedure when the relay <NUM> is turned on.

Note that when the system is docked, power is always free to flow from the batteries <NUM> to components on the non-rotating side <NUM> of the system via diode <NUM> and docking system <NUM>. However, the rotating portion <NUM> cannot receive power from the non-rotating portion unless the relay <NUM> is switched on. The relay <NUM> can also be used to halt charging of the batteries in an over-charge or other emergency situation.

In practice, this configuration means that the system generally cannot be undocked while it is not plugged into the wall (i.e., the entire system is being run off the batteries) or when the main/transport drive for the system is active because this component can draw more power than the charger can source. However, neither of these cases is particularly restrictive within normal use of the system.

The systems can include additional safety/failsafe features, such as relays <NUM>, <NUM> to protect the various device component(s) <NUM>, <NUM> on both the non-rotating and rotating sides <NUM>, <NUM> of the system. For example, in the case where the non-rotating portion <NUM> loses power during a scan (i.e. with the system un-docked), the system can be configured so that all the relays <NUM> on the non-rotating portion <NUM> automatically turn off, so that the non-rotating portion <NUM> is essentially electrically inert when, after the scan, the rotating portion <NUM> re-docks. Similar relays <NUM> can be provided on the rotating portion <NUM>, for example, to selectively turn off components <NUM>.

In certain embodiments, data transfer between the rotating <NUM> and non-rotating <NUM> portions of the imaging system <NUM> can be accomplished using a slip ring system. With the slip ring system, continuous electrical contact is maintained between the stationary and rotating parts of the imaging system <NUM>. In one embodiment, a conductive ring is positioned on the outer circumference of the rotating portion <NUM> and electrical contacts, such as conductive brush(es), are located on the non-rotating portion <NUM> and maintain continuous contact with the rotating portion <NUM> during imaging. During an imaging scan, data is transferred from the rotating to the non-rotating portions via the slip ring in real-time. Power to the rotating portion <NUM> can be provided through the docking system <NUM> to the rechargeable battery system <NUM>, as described above. The slip ring system can therefore be optimized for high-speed data transfer. The slip ring system in this embodiment need not be designed for high-voltage, high-power operation, which can help minimize the complexity and expense of the slip ring system. In an alternative embodiment, a cable system can be used for data transfer between the rotating and non-rotating portions. As with the slip ring embodiment, the cable system need not be designed for high-voltage, high-power operation, since primary power to the rotating portion is provided by the rechargeable battery system.

In another alternative embodiment, the rotating portion <NUM> can include a wireless transmitter for transmitting the data off of the rotating portion <NUM> via a wireless communication link. In this embodiment, the image data need not be transferred over the docking system <NUM> or a slip-ring or cable system.

The docking system <NUM> may also be used to transmit control signals between the rotating and non-rotating portions of the imaging system <NUM>. The control signals can include, for example, signals from a main system controller <NUM> (<FIG>), located on the non-rotating portion <NUM> to components on the rotating portion <NUM>, such as the x-ray source and detector, battery system and on-board computer, as well as signals from the rotating portion to the non-rotating portion, such as signals from the battery system <NUM> to the charging system <NUM> with respect to the charge state of the electrochemical cells. It will be understood that these signals can also be sent over a slip ring or cable system or by a wireless link, as described above.

As previously discussed, an advantage of the battery-based power supply of the invention is that the conventional schemes for delivering power to the imaging components, such as complicated and expensive slip-ring systems and bulky cable systems, can be avoided. In one embodiment, during an imaging scan the imaging system <NUM> is essentially severed in two, with two independent sub-systems (i.e., the rotating and non-rotating portions) operating independently of one another. This is different from conventional imaging systems, in which the rotating components remain physically coupled to the non-rotating portion of the system, via a cable or slip-ring or the like.

In one embodiment, as shown in <FIG>, the present invention includes a non-contact signaling apparatus <NUM> located at discrete positions on the rotating and non-rotating portions of the imaging system. The signaling apparatus <NUM> allows for minimal communication between the rotating and non-rotating portions of the imaging system. In one aspect, the signaling apparatus <NUM> functions as a safety mechanism. For example, during an imaging scan, the signaling apparatus <NUM> on the non-rotating portion <NUM> communicates a signal to the rotating portion <NUM>, instructing the rotating portion <NUM> to continue the scan. This periodic signaling from the non-rotating portion to the rotating portion enables the scan to continue. However, if for any reason the scan needs to be terminated (such as due to a loss of power or because of a patient or clinician safety issue), the signaling apparatus <NUM> ceases communication of these "enable scan" signals. This lack of a signal causes the rotating component to immediately terminate the scan, without having to wait for the rotating portion to fully complete the scan and return to the docking position.

The signaling apparatus <NUM> can also be used to provide a signal from the rotating to the non-rotating portions to continue the scan. For example, if there is a malfunction on the rotating portion of the system (e.g., the x-ray generator fails to produce radiation, the rotor fails to rotate properly, etc.), it does not make sense for the non-rotating components to continue with the scan. In this embodiment, the scan is automatically terminated when the rotating portion stops sending signals to the non-rotating portion via the signaling apparatus <NUM>.

In some embodiments, the signaling apparatus <NUM> may be used to transmit synchronization information from the rotating portion <NUM> to the non-rotating portion <NUM> of the imaging system. For example, a signaling apparatus <NUM> on the rotating portion <NUM> may communicate a signal to the non-rotating portion <NUM> to assist in coordinating various functions between the two portions. In one example, the signaling apparatus <NUM> may be used to coordinate a z-axis translation of the gantry <NUM> relative to the patient with the rotational motion of the rotor <NUM>. Since the two halves of the imaging system become physically disconnected during a scan, this allows for the two halves to coordinate when they are going to start a scan sequence. A typical sequence is for the docking system to disconnect, the rotor to start accelerating, and then a signal is sent from the rotating portion to the non-rotating portion via the signaling apparatus <NUM> to trigger the start of the z-axis translation.

The non-contact signaling apparatus <NUM> may use, for example, optical or magnetic signals. One embodiment of the signaling apparatus <NUM> is schematically illustrated in <FIG>. In this embodiment, the non-contact signaling apparatus <NUM> employs optical signaling, and includes light-emitting diodes (LEDs) <NUM> and photodetectors <NUM> at discrete positions on the rotating <NUM> and non-rotating <NUM> portions of the imaging system. Two sets of signaling devices, each set consisting of an LED <NUM> and a photo-detector <NUM>, are located on the non-rotating portion <NUM> of the imaging system <NUM>, such as on the gantry <NUM> or the gimbal <NUM>. Two additional sets of signaling devices, each also consisting of an LED <NUM> and photo-detector <NUM>, are located on the rotating portion <NUM> of the imaging system <NUM>, and in particular, on the rotor <NUM>. The two sets of signaling devices on the non-rotating portion <NUM> are on opposite sides of the gantry <NUM>; i.e., separated by <NUM> degrees. The two sets on the rotating portion <NUM> are separated by <NUM> degrees. In this way, the rotating <NUM> and non-rotating <NUM> portions of the imaging system <NUM> may exchange signals with one another at every <NUM> degrees of rotation of the rotating portion <NUM>.

According to another aspect, the imaging system <NUM> includes a rotor drive mechanism <NUM>, as shown in <FIG>, <FIG> and <FIG>, which drives the rotation of the rotating portion <NUM> relative to the non-rotating portion <NUM>. One embodiment of the rotor drive mechanism <NUM> is illustrated in <FIG>. In this embodiment, the rotor <NUM> is driven by an internal belt drive. The belt <NUM> extends around the outer circumference of a circular railing <NUM>. The railing <NUM> (which can be seen in the exploded view of <FIG> and in <FIG>) is mounted to an interior wall of the outer shell <NUM> of the gantry <NUM>. The drive mechanism <NUM> includes a motor <NUM>, gear <NUM> and rollers <NUM>, and is mounted to the rotor <NUM>. The belt <NUM> is looped through the drive mechanism <NUM>, running between each of the rollers <NUM> and the railing <NUM>, and over the gear <NUM>, as is most clearly illustrated in <FIG> and <FIG>. (When viewed from the side, the path of the belt <NUM> through the drive mechanism <NUM> somewhat resembles the Greek letter omega, Ω). The gear <NUM> is driven by the motor <NUM>. As the gear <NUM> rotates, it meshes with the belt <NUM>, which is held against the railing <NUM> by the rollers <NUM>. The rotation of the gear <NUM> causes the drive mechanism <NUM> to "ride" along the length of the belt <NUM>, thus driving the rotation of the rotor <NUM>, which is attached to the drive mechanism <NUM>, around the circumference of the gantry <NUM>.

As shown, for example, in <FIG> and <FIG>, the drive mechanism <NUM> is mounted to the rotor <NUM> beneath the detector array <NUM>, and opposite the x-ray source tube <NUM>. This can be advantageous, since the motorized components of the drive mechanism <NUM> can result in EM interference with the tube that can affect the position of the x-ray focal spot. By placing the drive mechanism on the opposite side of the rotor <NUM> from the x-ray source <NUM>, the possibility of EM interference is minimized.

As discussed above, embodiments may include a mobile imaging system, such as system <NUM> shown in <FIG>, in which the gantry <NUM> and an optional gimbal <NUM> may translate with respect to the base <NUM> to provide an imaging scan (i.e., in an imaging mode), and the entire system, including the base <NUM>, gantry <NUM> and gimbal <NUM> may be driven in a transport mode. In the embodiment of <FIG>, a drive system <NUM> located within an open region of the base <NUM> and beneath the gimbal <NUM> and gantry <NUM> may provide both the translation motion of the gantry <NUM>/gimbal <NUM> in an imaging mode and the translation of the entire system <NUM> in a transport mode.

Various embodiments include a mechanism that prevents one or more components of the system <NUM> that translate relative to the base <NUM> in a scan mode (such as the gantry <NUM>, gimbal <NUM> and drive mechanism <NUM>, collectively referred to as "translating components") from translating relative to the base <NUM> when the system <NUM> is in transport mode. In one embodiment, the one or more translating components may be locked to a "transport" position to prevent the translating components from moving relative to the base <NUM>, such as by translating up and down the rails <NUM> in the z-axis direction. The transport position may be located anywhere along the length of the base, such as towards the middle of the base for balance/ease of transport. <FIG> illustrates a mechanism <NUM> for locking the translating components <NUM> in a transport position <NUM>. In various embodiments, the translating components <NUM> (e.g., drive mechanism <NUM>, gimbal <NUM> and gantry <NUM>) translate relative to the base <NUM> during a scan mode, and at least a portion of the translating components <NUM> (e.g., gimbal <NUM> and gantry <NUM>) rotate relative to the base <NUM> to a second rotational position in a transport mode, and a latching mechanism <NUM> is operable when the translating components <NUM> are in the second rotational position to prohibit translation of the translating components <NUM> relative to the base <NUM>.

The latching mechanism <NUM> may automatically engage when the translating components <NUM> are in the second rotational position, and are translated to a transport position <NUM> with respect to the base <NUM>. The latching mechanism <NUM> may not be engaged when the translating components <NUM> are translated to the transport position <NUM> but are not in the second rotational position. In one example, the latching mechanism <NUM> engages when the translating components <NUM> (e.g., gimbal <NUM> and gantry <NUM>) are rotated "in line" with the base <NUM> and are located at, or are translated to, a discrete transport position <NUM> along the length of the base <NUM>. In embodiments, the latching mechanism <NUM> may be configured such that engagement of the latch is not triggered while the system is in a scan mode (e.g., with the gimbal <NUM> rotated out of the "in line" position, such as where the gimbal <NUM> and gantry <NUM> are rotated generally perpendicular to the length of the base <NUM>, or ±<NUM>° from an "in line" position, as shown in <FIG>).

One implementation is shown in <FIG>. The latching mechanism <NUM> may include a spring-loaded slider <NUM> in a guide <NUM> that is connected to the gimbal <NUM>. (In this embodiment, the block <NUM> next to the slider <NUM> attaches the gimbal <NUM> to the drive mechanism <NUM>. For clarity, the gimbal <NUM> is not shown in <FIG>). On one end of the slider is a bearing/roller <NUM>. This rides on a bearing surface <NUM> in the gimbal <NUM>, as illustrated by dashed-dotted line in <FIG>, which is a bottom view of the system <NUM>, looking up to the base <NUM>, the drive mechanism <NUM> and the lower portion of the gimbal <NUM> (indicated schematically by the dashed-dotted line). The spring-loaded slider <NUM> is biased towards the bearing surface <NUM> of the gimbal <NUM> in this embodiment.

Attached to the second end of the slider <NUM> is a latch <NUM> (z-latch), as shown in the enlarged view of <FIG>. A strike plate <NUM> having a slot <NUM> for the latch <NUM> is on the base <NUM>, at the "transport" position <NUM>. During imaging, the gimbal <NUM> is rotated out of the "in line" configuration (see, e.g. <FIG>), and the gimbal <NUM> may translate up and down the base <NUM>, and the z-latch <NUM> passes the strike plate <NUM> without engaging the slot <NUM>. When the gimbal <NUM> is rotated to an in-line position, then the bearing/roller <NUM> is spring-biased into a detent/slot <NUM> on the bearing surface <NUM> of the gimbal <NUM>, which moves the z-latch <NUM> closer to the interior side wall of the base <NUM>. Thus, when the gimbal <NUM> is located at or translates to a position such that the z-latch <NUM> is adjacent to the strike plate <NUM>, the z-latch <NUM> is pushed into the slot <NUM> of the strike plate <NUM>, locking the position of the translating components <NUM> (e.g., the gimbal <NUM>, the gantry <NUM> and the drive mechanism <NUM>) with respect to the base <NUM>. When the gimbal <NUM> is rotated out-of-line again, the bearing/roller <NUM> rolls out of the detent <NUM> and along the bearing surface <NUM> of the gimbal <NUM>, which pushes the z-latch <NUM> away from the strike plate <NUM> and the translating components <NUM> can again translate relative to the base <NUM>.

In embodiments, control software of the imaging system <NUM> may be configured to drive the translating components <NUM> to the "transport" position <NUM> so that the z-latch <NUM> engages the strike plate <NUM> whenever the system <NUM> enters transport mode.

Other latching mechanisms to prevent translation of the translating components <NUM> relative to the base <NUM> during transport mode are possible, and could utilize a servo-motor, magnetic latch, etc..

In embodiments, the rotation of the gimbal <NUM> and gantry <NUM> relative to the base <NUM>/drive mechanism <NUM> may be performed using a motorized system, with an encoder on the bearing that enables the gimbal <NUM> and gantry <NUM> to rotate to a selected angular position relative to base <NUM>. In embodiments, the gimbal <NUM> and gantry <NUM> may be rotated to any arbitrary angle relative to the base <NUM>. In other embodiments, the rotation of the gimbal <NUM> and gantry <NUM> may be performed manually.

In various embodiments, a latching mechanism (i.e., rotation latch) may maintain rotating components (e.g., the gimbal <NUM> and gantry <NUM>) at a particular rotational position relative to non-rotating components (e.g., the base <NUM> and drive mechanism <NUM>) of the system <NUM>. The rotation latch may be manually controlled or servo-controlled, for example. In one embodiment, the rotation latch is cable actuated. The rotation latch may snap into place (engage) when the rotating components (e.g., gimbal <NUM> and gantry <NUM>) are rotated to particular angle relative to the non-rotating components (e.g., base <NUM> and drive mechanism <NUM>), and the latch may be released (disengaged) via a release mechanism. In one embodiment, the release mechanism may be located on an arm of the gimbal <NUM> and is linked to a lever that releases latch (e.g., via a cable).

An embodiment of a rotation latch <NUM> is shown in <FIG>. In this embodiment, the latch <NUM> includes a spring-loaded latch arm <NUM> connected to a fixed latch portion <NUM> by a pivot bearing <NUM>, as shown in <FIG>. The latch <NUM> may be mounted to a first portion of the system that rotates (e.g., upper portion of the gimbal <NUM> and gantry <NUM>, collectively the "rotating components") with respect to a second portion of the system (e.g., the base <NUM>, the drive mechanism <NUM> and a lower portion of the gimbal <NUM> mounted to the drive mechanism <NUM>, collectively the "non-rotating portion" <NUM>). Alternatively, the latch may be located on the rotating portion of the system and engages with a latch receiver (receptacle) on the non-rotating portion of the system.

<FIG> shows a side view of a gimbal <NUM> and a bottom view of the gimbal <NUM> viewed along line A-A. As shown in <FIG>, a circular member <NUM> is located on non-rotating portion <NUM> (e.g., the lower portion of the gimbal <NUM> or the drive mechanism <NUM>) and contains latch receivers <NUM> which are precisely located at pre-determined angular positions. Other configurations may be utilized. In this embodiment, the latch receivers <NUM> (receptacles) are at three locations, corresponding to "in line" position of the gimbal <NUM> (e.g., for transport), and +/- <NUM> degrees (i.e., scanning positions). The larch arm <NUM> may be spring biased against the outer circumference of the circular member <NUM>, and the nose <NUM> of the latch <NUM> may glide over the outer circumference of the circular member <NUM> (such as via bushings <NUM> shown in <FIG>) as the rotating components (e.g., upper portion of gimbal <NUM> and the gantry <NUM>) rotate with respect to the non-rotating portion <NUM> of the system. When the latch nose <NUM> reaches a latch receiver <NUM>, the latch nose <NUM> is pushed into the receiver <NUM>, locking the rotational position of the rotating components relative to the non-rotating portion <NUM> of the system. The latch receivers <NUM> may be located at any arbitrary angular position around the circumference of the circular member <NUM>. The latch <NUM> may be adjusted using adjustment screws to ensure that the rotating components are at the precise desired rotational angle relative to the non-rotating portion <NUM> when the latch engages. For example, for an imaging scan, it may be important that the gimbal <NUM> and gantry <NUM> are precisely perpendicular to the long axis of the base <NUM> (e.g., the patient axis). The latch <NUM> may be released via a cable <NUM> that is attached to the latch arm <NUM> and may extend through the interior of the gantry <NUM> (e.g., up through an arm <NUM> of the gantry <NUM>) to a release mechanism (not visible in <FIG>). When the latch <NUM> is released, the rotating components may rotate with respect to the non-rotating portion <NUM> of the system.

In embodiments, the latch nose <NUM> and receivers <NUM> may have mating tapered faces to provide zero backlash. The two faces 2117a, 2117b of the tapered latch nose <NUM> may be at different angles, as shown in <FIG>. For each latch nose face 2117a, the line of force to the latch pivot <NUM> may be perpendicular to the latch nose face 2117a. The normal force of the nose may be inside the latch ring circle <NUM> (defined by the circular member <NUM> shown in <FIG>) so the latch <NUM> will not "cam out" under load. This, the latch <NUM> may hit exactly the right spot every time to maintain proper angle and alignment of the system, and the latch nose <NUM> will not "cam out" of the receiver slot <NUM>, resulting in high reliability.

Embodiments may include a system having a cable management system. In embodiments, a first plurality of cables may extend between the sides of the gimbal <NUM>, and a second purality of cables may extend between the gimbal <NUM> and the base <NUM>/drive mechanism <NUM>. It may be challenging to manage the second plurality cables, particularly as the gimbal <NUM> rotates with respect to the base <NUM> and drive mechanism <NUM>. A cable management system <NUM> according to one embodiment is shown in <FIG> and <FIG>. In various embodiments, a first plurality of cables may extend across the gimbal <NUM> and rotate with the gimbal <NUM> with respect to the base <NUM>. A second plurality of cables may enter the gimbal via an opening that rotates and extend into a service loop that extends into an arm of the gimbal, and may rotate with the gimbal with respect to the base. Rotation of the gimbal in a first direction causes the cable to be pulled up into the gimbal arm, and rotation in a second direction may cause the cables to extend out of the loop. The first plurality of cables may be secured within the gimbal so as to avoid interference with the second group as the gimbal rotates.

<FIG> is a top partial view of a gimbal <NUM> with the covers <NUM>, <NUM> (see <FIG>) removed. The gimbal <NUM> may include a lower portion <NUM> that may be fixed to the drive mechanism (e.g., fixed carriage) and may comprise part of the non-rotating portion of the system, as described above. An upper portion <NUM> of the gimbal <NUM> may rotate with respect to the non-rotating portion of the system, such as via a bearing system between the upper <NUM> and lower <NUM> portions of the gimbal <NUM>. The gantry <NUM> and imaging components may be attached to the upper portion <NUM> of the gimbal <NUM> as described above. One or more cables <NUM> connecting the non-rotating portion of the system to the rotating portion of the system (e.g., providing power and/or data between the portions) may be fed up from the drive mechanism <NUM> and/or base <NUM> through an opening in the gimbal <NUM> and may be fed up through a chute <NUM> (see <FIG>) into the interior of an arm <NUM> of the gimbal <NUM>. The one or more cables <NUM> may form a service loop <NUM> within the arm <NUM> of the gantry <NUM>, as shown in <FIG>. One end <NUM> of the loop <NUM> may be fixed to the upper (i.e., rotating) portion <NUM> of the gantry <NUM> (see <FIG>), and the opposite end of the loop may be free to feed in and out through the chute <NUM> as the upper portion <NUM> rotates. The arm <NUM> may include a generally flat interior surface <NUM> to allow the service loop <NUM> to slide up and down within the gimbal arm <NUM> as the cable(s) <NUM> are fed into and out from the loop <NUM>.

<FIG> are bottom views of the gimbal <NUM> that schematically illustrate the one or more cables <NUM> being fed into and out of the service loop in the gimbal arm <NUM> as the upper portion <NUM> of the gimbal <NUM> rotates relative to the lower portion <NUM>. In <FIG>, the gimbal <NUM> may be in an "in-line" position relative to the base <NUM> (e.g., a transport position). The one or more cables <NUM> may be fixed to the lower (i.e., non-rotating) portion <NUM> of the gimbal <NUM> at a position <NUM> that is proximate to the opening or chute <NUM> that feeds the cables <NUM> up into the service loop in the gimbal arm <NUM>. In <FIG>, the upper portion <NUM> of the gimbal <NUM> is rotated <NUM>° from the "in-line" position of <FIG>, and may be oriented perpendicular to the base <NUM> (e.g., a scan position), such as shown in <FIG>. The rotation of the upper portion <NUM> relative to the lower portion <NUM> causes the one or more cables <NUM> to be fed out from the service loop as shown in <FIG>. Rotating the upper portion <NUM> in the opposite direction (e.g., back to the position of <FIG>) causes the one or more cables <NUM> to be fed back up through the opening/chute <NUM> into the service loop. <FIG> shows the gimbal <NUM> rotated <NUM>° relative to the position of <FIG> (i.e., back to an "in-line" configuration with the positions of the arms <NUM>, <NUM> switched relative to <FIG>). In this position, the cables <NUM> may be substantially completely fed out from the service loop.

The one or more cables <NUM> may be located within a channel <NUM> formed in the gimbal <NUM> as the cable(s) <NUM> are fed out from the service loop. As shown in <FIG>, for example, the channel <NUM> extends proximate to the outer circumference of the lower (i.e., non-rotating) portion <NUM> of the gimbal <NUM> along one side of the gimbal <NUM>. By confining the cables <NUM> in channels <NUM>, they may be prevented from interfering with other components within the gimbal, such as separate cables running between the arms <NUM>, <NUM> of the gimbal. Multiple channels <NUM> may be provided (e.g., at different radial positions on the lower non-rotating portion <NUM> of the gimbal). Each channel <NUM> may contain a bundle of cables, which may be vertically stacked and enclosed in a protective covering, for example. Channels <NUM> located closer to the outer circumference of the gimbal <NUM> may require a larger service loop <NUM> in the gimbal arm <NUM> because the cables must travel a greater distance as the gimbal rotates.

<FIG> are top views of the gimbal <NUM> schematically illustrating the cable management system <NUM> according to one embodiment. In this view, a second group <NUM> of one or more cables is shown extending between the respective arms <NUM>, <NUM> of the gimbal <NUM>. The second cable group <NUM> may extend proximate to the outer circumference of the base of the gimbal <NUM> on the opposite side as the first group of one or more cables <NUM> (i.e., on the opposite side of the gimbal rotation axis), so that the two cable groups do not interfere with each other. <FIG> shows the gimbal <NUM> at <NUM>° rotation relative to the base (corresponding to the "in-line" position of <FIG>), <FIG> shows the gimbal at a <NUM>° rotation (corresponding to the scaning position of <FIG>), and <FIG> shows the gimbal at a <NUM>° rotation (corresponding to the "in-line" position of <FIG>). <FIG> also illustrate the service loop <NUM> increasing or decreasing in size depending on the rotational position of the gimbal <NUM>.

Alternatively or in addition to the cables <NUM> described above, in some embodiments at least a portion of the power and/or data may be passed between the rotating portion (gimbal, gantry, etc.) and the non-rotating portion (e.g., base, drive mechanism) of the system via a slip ring.

<FIG> illustrate a gimbal <NUM> having a spherically shaped outer surface <NUM> that faces the gantry <NUM> according to an embodiment. As described above, the gantry <NUM> may be attached to the gimbal <NUM> at two pivot points and may tilt with respect to the gimbal <NUM>. During this tilt motion, the gantry <NUM> swings through an arc over the outer surface of the gimbal <NUM> facing the gantry <NUM>. The gantry <NUM> may have relatively sharp corners which may interfere with the gantry <NUM> swinging over the surface of the gimbal <NUM> and may require the gantry <NUM> to be raised away from the surface of the gimbal <NUM> and thus higher from the ground to provide the necessary clearance. This may produce mechanical instability and increase the size of the system.

In one embodiment, the surface <NUM> of the gimbal <NUM> which faces the gantry has a generally concave contour (e.g., curved, angled or both) along the direction through which the gantry <NUM> swings during tilt motion. In embodiments, the surface <NUM> of the gimbal <NUM> may be substantially spherical, as illustrated schematically by the imaginary sphere <NUM> contacting the surface <NUM> of the gimbal <NUM> in <FIG>. The sphere <NUM> may be considered an extension of the surface <NUM> of the gimbal <NUM> that faces the gantry <NUM> (as shown, for instance, in <FIG>). As shown in the side view of <FIG>, the surface <NUM> of the gimbal <NUM> may have a circular cross-section with a radius, SR, in a direction transverse to the tilt direction of the gantry <NUM> (i.e., into and out of the page in <FIG>). The surface <NUM> of the gimbal <NUM> may be generally concentric with the outer diameter of the O-shaped gantry ring <NUM> that is supported by the gimbal <NUM>. In addition, the surface <NUM> of the gimbal <NUM> may also have a circular cross-section along the tilt direction of the gantry (i.e., in the direction of arrows <NUM> in <FIG> ), as is shown in the side view of <FIG>. The radius of the circular-cross section of <FIG> may be the same radius (i.e., SR) as in <FIG>. Thus, the surface <NUM> facing the gantry <NUM> may define a portion of a sphere <NUM> as shown in <FIG>. This configuration may allow the gantry <NUM> to be mounted lower on the system, such that the gantry <NUM> may nest within the gimbal <NUM> with an extremely small clearance between the gimbal <NUM> and gantry <NUM>, while still permitting the gantry <NUM> to freely tilt with respect to the gimbal <NUM>. The configuration of <FIG> may also provide added structural support for the gimbal <NUM>.

In embodiments, a mobile imaging system <NUM> such as described above may have a user interface (UI) device <NUM>, such as a touchscreen controller/display (e.g., <NUM>,<NUM>-<NUM>,<NUM> (<NUM>-<NUM> inch) screen, such as a <NUM>,<NUM> (<NUM> inch) screen), that may be removably mounted in a holster <NUM> that is attached to the system <NUM> (e.g., on the gimbal <NUM>, the gantry <NUM>, or any other part of the system <NUM> that is easily accessible by a user), as shown in <FIG>. The UI device <NUM> may be used to control the system <NUM>, and may receive and display feedback from the system. A cable <NUM> may be attached to and/or plug into one of several ports on system to connect the user interface device <NUM> to the system <NUM>. The cable <NUM> may be retractable into the system (e.g., within the gimbal <NUM>) or may be located external to the system. The length of the cable <NUM> may be <NUM>-<NUM> feet, such as <NUM>-<NUM> feet (e.g., <NUM> feet). For example, the UI device <NUM> may be plugged into ports on either side of gimbal <NUM>. This may enable a user holding the UI device <NUM> to move around to any side of the system <NUM>, step behind a lead barrier during x-ray imaging, etc., while operating the system <NUM> through a wired fashion, as may be required by applicable regulations. The UI device <NUM> may also use a wireless interface with the system <NUM> where regulations allow.

<FIG> show, respectively, perspective (<FIG>), front (<FIG>) and side (<FIG>) views of an embodiment user interface device <NUM> mounted in a holster <NUM>. The holster <NUM> may be located in any location on the system <NUM>. In one preferred embodiment, the holster <NUM> may be mounted to or integrally formed in a distal or "earmuff" portion <NUM>, <NUM> of the gimbal <NUM>, as described above in connection with <FIG>. The holster <NUM> may have features <NUM>, such as grooves in the sides of the holster <NUM>, that may be gripped by a user to facilitate steering of the system <NUM> when the system is driven in transport mode. The holster <NUM> may include one or more control inputs <NUM> (e.g., buttons, switches, etc.) for the system <NUM>. Additional control inputs (e.g., hard keys <NUM>) may be provided on the user interface device <NUM>. The user interface device <NUM> may be a handheld device (e.g., a pendant device, a tablet device, etc.) that may be removed by sliding the device <NUM> up and out of the holster <NUM>. The display <NUM> may display system information and menu options that may enable a user to control the operation of the system. The user interface device <NUM> may be operably connected to a control system of the device, such as the computer <NUM> in the gantry <NUM> shown in <FIG>, and/or one or more additional control units that may be located elsewhere on the device, such as in the gimbal <NUM>, base <NUM>, drive mechanism <NUM>, etc. The user interface device <NUM> may be used to control the operation of the system when it is both within the holster <NUM> and removed from the holster <NUM>.

The foregoing method descriptions are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. Words such as "thereafter," "then," "next," etc. are not necessarily intended to limit the order of the steps; these words may be used to guide the reader through the description of the methods.

Claim 1:
An imaging system (<NUM>), comprising:
a first portion (<NUM>) comprising a base (<NUM>) having a length dimension;
a second portion (<NUM>) rotatable with respect to the first portion (<NUM>) and translatable relative to the first portion (<NUM>) along the length dimension of the base (<NUM>); and
a locking mechanism (<NUM>) that is adapted to prevent the first portion (<NUM>) when at a first translational position (<NUM>) along the length dimension from translating relative to the second portion (<NUM>) by rotation of the second portion (<NUM>) to a first angular position relative to the first portion (<NUM>) causing engagement; and
wherein the locking mechanism (<NUM>) permits the second portion (<NUM>) to translate relative to the base (<NUM>) when the second portion (<NUM>) is not rotated to the first angular position.