Abstract: A vehicle may include a flutter resistant caster. The vehicle may include a frame, a drive wheel coupled to the frame, a caster housing coupled to the frame, a caster, a locking element, a first bearing, and a biasing element. The caster housing may include an opening. The caster may include a caster wheel and a caster stem extending through the opening in the caster housing. The caster stem may be configured to rotate relative to the caster housing. The locking element may be coupled to the caster stem. The first bearing may be coupled to the caster stem. The biasing element may be coupled to the caster stem. The biasing element may be configured to exert a force on the first bearing.

Abstract: A telescopic lifting unit with a first segment, a second segment, and a third segment. The first and second segments may be displaced relative to one another, and the second and third segments may be displaced relative to one another. The first and second segments may be moved relative to one another by a motor unit, and the second and third segments may be moved relative to one another by a cable hoist.

Abstract: The present disclosure relates to systems and methods for positioning an X-ray scanner. The systems may perform the methods to obtain an origin related to an X-ray scanner; determine a coordinate system based on the origin; determine coordinates of a second location of the X-ray scanner based on the origin and the coordinate system; obtain coordinates of a first location based on the origin and the coordinate system; and determine, based on the origin and the coordinates of the second location, positioning information of the X-ray scanner configured to cause the X-ray scanner to be positioned at the first location from the second location of the X-ray scanner.

Abstract: An imaging device for obtaining long-film images of an anatomical element of a patient or of another object includes a wheeled base comprising an elongate track; a trolley comprising a base portion slidably connected to the elongate track and an upper portion rotatably connected to the base portion, the trolley slidable along the elongate track a distance of at least 40 cm; a C-shaped arm defining a semi-circle about a C-shaped arm axis, the C-shaped arm rotatably supported by the upper portion of the trolley; a source fixedly secured to the C-shaped arm; and a detector fixedly secured to the C-shaped arm opposite the source.

Abstract: Provided is a laser projection apparatus, a control method thereof, and a laser guidance system including the laser projection apparatus. The laser projection apparatus for projecting planned operation information of an insertion location and an insertion angle on a C-arm image photographed using a C-arm fluoroscopy device directly onto an affected part includes a line laser module configured to generate a line laser and to form a plane by rotating around an origin, a matching unit configured to calculate a coordinate representing the insertion location in a C-arm coordinate system based on C-arm fluoroscopy, calculate an insertional vector according to the coordinate representing the insertion location and the insertion angle, and calculate a vector perpendicular to the plane formed by the line laser in the C-arm coordinate system according to the insertional vector, and a control unit configured to control the line laser module based on the vector perpendicular to the plane.

Abstract: Hybrid detection systems and methods for C-arm interventional x-ray systems are provided. The hybrid detection system can have a changeable x-ray detection system that is coupled to an integrated within a C-arm x-ray imaging system. The changeable x-ray detector system can include an energy-integrating x-ray detector, and a photon-counting x-ray detector. The C-arm x-ray imaging system using only one detector at a time to acquire x-ray imaging data.

Abstract: Methods and systems are provided for collapsing a column of a mobile imaging system. In one example, a method may include collapsing a column coupled to a mobile imaging system in response to user interaction, while concomitantly driving the mobile imaging system.

Abstract: A computed tomographic (CT) system includes a gantry having a rotating part including a light source, a light source drive control circuit, a rechargeable battery, and a rotating part interface. The gantry includes a detector, a detector control and signal processing circuit, and an image memory. The rotating part may rotate around a central axis. The CT system includes a gantry table on which the gantry is mounted and which includes a host interface. The CT system includes a motor that may cause the gantry to move within a gantry moving range, and a control unit that may process and display image data obtained from the gantry. The rotating part interface may face the host interface, such that the rotating part and host interfaces are configured to be electrically connected with each other, based on the gantry being at a predetermined position within the gantry moving range.

Abstract: An imaging system is disclosed. The imaging system is operable to acquire and/or generate image data at positions relative to a subject. The imaging system includes a drive system configured to move the imaging system.

Abstract: A mobile radiography system includes a wheeled transport frame and a vertical column mounted on the transport frame. A telescoping arm is attached to the vertical column and to an x-ray tube head. The telescoping arm includes a first section, a second section movable within the first section, and a third section movable within the second section. The first section and the second section each include a drag assembly configured to provide a drag force on the linearly movable section therewithin. The drag assemblies each include a friction material pressed against the linearly movable section to provide a constant drag force on the linearly movable section while it moves. A permanent pressure source presses the friction material against the linearly movable section.

Abstract: A mobile radiographic imaging system includes a mobile radiographic imaging apparatus and a radiographic imaging cassette. The radiographic imaging apparatus includes a displacement mechanism that electrically displaces a radiation emission unit and a displacement mechanism controller that controls the operation of the displacement mechanism. The radiographic imaging cassette includes a remote operation unit that is provided in a housing to remotely operate the displacement mechanism and an operation instruction transmission unit that transmits an operation instruction for operating the displacement mechanism to the displacement mechanism controller in a case where the remote operation unit is operated.

Abstract: A filter system is for the local attenuation of X-radiation. In an embodiment, the filter system includes a filter device, arranged in a beam path of an X-ray apparatus and including a channel arrangement, the channel arrangement including a multiplicity of channel sections extending in parallel on a plane; a supply device to provide a 2-phase fluid flow containing drops of an absorber liquid, to absorb X-radiation and a carrier liquid transparent to X-radiation; and a sorting section, including an input connected to the supply device, a first output connected to the channel arrangement, a second output, and a deflection device to direct individual drops of the absorber liquid to the first output or the second output.

Abstract: A robotic surgery system including an imaging system having a source element and a detector element, and a coupling member coupling the source element to the detector element. The system further includes an instrument support structure extending from the coupling member, and a surgical instrument coupled to the moveable support structure.

Abstract: A mobile radiography system includes a wheeled transport frame and a telescoping vertical column mounted on the transport frame. The vertical column includes a stationary base section and a vertically movable upper section coupled to the base section. A cap is positioned in a nest at the top of the movable upper section whereby a counterweight in the movable upper section displaces the cap when the counterweight is extended through the nest and replaces the cap in the nest when the counterweight is retracted into the movable upper section. A padded section of the nest and the counterweight prevents impact noise when the cap contacts the nest or the counterweight. Magnets are used to hold the cap and the nest together in alignment when they are adjacent.

Abstract: A scanning object carrier (1), which is provided for installation on a scanner rocker (2) of a scanning device (3) for scanning at least one, in particular dental, object (20), wherein the scanning object carrier (1) includes a base body (4) and at least one fastening device (5) for fastening the base body (4) to the scanner rocker (2) and at least one object fixing device (6) for fixing the object (20) to the scanning object carrier (1), wherein the object fixing device (6) is mounted in a pivotable manner on the base body (4) relative to the base body (4), and wherein the object fixing device (6) is mounted in a pivotable manner on the base body (4) between two end positions (7, 8) by freely following gravity.

Abstract: Methods and systems are provided for controlling movement of a mobile imaging system. In one example, a mobile imaging system includes a mobile drive system, an imaging assembly coupled to the mobile drive system, and a driving interface configured to move the imaging assembly relative to the mobile drive system both axially and radially in response to user manipulation, and further configured to generate signals in response to the axial movement of the imaging assembly, the mobile drive system configured to move in response to the signals.

Abstract: A system and method for performing a navigation procedure including a surgical tool, an imaging device, and a computing device. The surgical tool is navigated to a target tissue located in a target area to perform a surgical procedure on the target tissue. The imaging device acquires image data of the target area while the surgical tool is being navigated to the target tissue by automatically traversing back and forth along a path relative to the target area and acquiring image data of the target area while traversing the path. The computing device receives the image data acquired by the imaging device and displays the image data such that the surgical tool can be navigated to the target tissue while simultaneously visualizing a position of the surgical tool relative to the target tissue from multiple perspectives relative to the target area.

Abstract: The present disclosure relates to an X-ray imaging apparatus. The X-ray imaging apparatus includes a first column connected to a main body, a second column connected to the first column and provided to be movable relative to the first column, an arm connected to the second column and slidably provided along the second column, and a weight compensator provided to compensate for the weight of the second column and the arm, wherein the weight compensator, the second column and the arm are connected by a wire, and the second column is provided with an elastic member connected to the arm and providing an elastic force such that the arm is moved by a uniform force regardless of the position of the second column.

Abstract: An articulated arm to suspend an X-ray head from a support section in a radiographic imaging apparatus comprising two pairs of linkages separated and joined to an intermediate linkage wherein the proximal end of the first pair of linkages is connected to the support section and the distal end of the second pair of linkages is connected to the X-ray head, and further wherein the linkages in the first pair of linkages are parallel and rotatable about the connection to the support section, the linkages in the second pair of linkages are parallel and rotatable about the intermediate linkage, and whereby a rotational orientation of a mounting for the X-ray head about an axis which is parallel to the axes about which the first pair of linkages are rotatable remains constant when the first pair of linkages is rotated relative to the support section and/or the second pair of linkages is rotated relative to the intermediate linkage.

Abstract: Supporting devices for small and portable X-ray devices are described. In particular, this application describes supporting devices for portable X-ray devices containing a movable base unit with multiple legs with different lengths and heights configured so that the legs have a nestable configuration, an adjustable member extending from the mobile base unit so the adjustable member has an adjustable height, an extension arm connected to the adjustable member so the extension arm collapses toward and extends away from the adjustable member, and a connecting member connecting the extension arm with a portable x-ray device so the connecting member can rotate up to 360 degrees in the x, y, or z direction. The connecting member can also connect the extension arm with a portable x-ray device so the portable x-ray device is removable from the connecting member and capable of being operated independently by hand. Other embodiments are described.

Abstract: A crane includes a carrier, a superstructure mounted on the carrier and including a boom, a cable extending from the boom, a lifting appliance coupled to the cable, and an optical detection system. The optical detection system includes an image capture device configured to capture an image, and an optical detection computer configured to detect one or more objects in the captured image, the one or more objects selected from: the lifting appliance, the cable, a load coupled to the lifting appliance, an object remote from the crane and a marker. The computer is also configured to analyze the one or more detected objects and determine a condition of a crane component based on the analysis of the one or more detected objects. Methods of determining the condition of the crane component and controlling crane operation are also included.

Abstract: A chassis has a structure in which a front structure and a rear structure are linked by an upper floor and a lower floor. The front structure is linked to a front wheel via a coupling member, a front wheel support member and a shaft. The front structure has a cylindrical support member. In addition, the rear structure is linked to a rear wheel via a shaft. A reinforcing member, which links the front structure and the rear structure in the central part of a space for accommodating a battery, is installed inside the space for accommodating the battery. The front end of the reinforcing member is linked to the cylindrical support member in the front structure. The upper surface of the reinforcing member is fixed to the upper floor and the lower surface of the reinforcing member is fixed to the lower floor.

Abstract: A radiation-irradiation device includes a leg unit, a radiation source unit, an arm unit, a body unit, and a raising/lowering mechanism. The arm unit includes a first arm connected to the radiation source unit, a second arm, a first rotational moving portion that connects the first arm to the second arm so as to allow the first arm and second arm to be rotationally movable relative to each other, and a second rotational moving portion that connects the second arm to the raising/lowering mechanism so as to allow the second arm to be rotationally movable relative to the raising/lowering mechanism. The rotation of the second arm from an initial rotational movement position is regulated by the body unit in a case in which the arm unit is positioned at a position other than a first position where the arm unit is raised or lowered by the raising/lowering mechanism.

Abstract: An arrangement includes a stationary part of a gantry of a computed tomography scanner and a first rotating part of the gantry of the computed tomography scanner. The first rotating part and the stationary part are connectable to one another via a bearing assembly such that the first rotating part is arranged in a bearing position relative to the stationary part and is mounted via the bearing assembly such that it is rotatable about a system axis. The first rotating part and the stationary part are connectable to one another via a holding apparatus such that the first rotating part is arranged in a holding position relative to the stationary part independently of the bearing assembly. In both the bearing position and the holding position, a central opening of the first rotating part and a central opening of the stationary part are arranged about the system axis.

Abstract: Disclosed herein is a mobile x-ray imaging apparatus having an improved structure to reinforce security of an x-ray detector. A mobile x-ray imaging apparatus includes an x-ray source configured to generate and radiate x-rays, one or more x-ray detectors provided to detect the x-rays radiated from the x-ray source, a storage unit having one or more slots in which the one or more x-ray detectors are stored, and one or more locking units installed in the storage unit to limit withdrawal of the one or more x-ray detectors stored in the one or more slots, wherein the one or more locking units may include a pressing member provided to be pressable and one or more rotating members configured to directly receive a pressing force of the pressing member and provided to rotate and protrude toward an inside of the one or more slots.

Abstract: A radiographic imaging apparatus comprises: a leg unit that is capable of traveling on an apparatus-placement surface by a wheel unit; a body unit that is held on the leg unit; an arm unit that is connected to the body unit and is capable of protruding upward from the body unit; and a radiation source that is mounted on the arm unit, wherein the arm unit includes a body-side part that is capable of extending and retracting in a direction of the protruding of the arm unit and is connected to the body unit, and a radiation source-side part on which the radiation source is mounted, the radiation source-side part is connected to a distal end side of the body-side part so as to be revolvable in a direction where an angle between the radiation source-side part and the body-side part changes, and revolution regulating unit.

Abstract: A mobile medical imaging robot is disclosed. The robot comprises a medical imaging device, and a vehicle configured to carry the medical imaging device. The vehicle is motorized so as to move on a surface, such the floor of an examination room. The robot further comprises a cable designed to link said vehicle to a wall of a room, such as a medical examination room. In at least one non-limiting embodiment, motorized robot movements along the surface are controlled manually by a user.

Abstract: A medical imaging apparatus has a data acquisition scanner having a patient receiving zone at least partially enclosed by the scanner, and at least one acquisition unit equipped with a camera to acquire positional data. The at least one acquisition unit has a first imaging optics system and at least one second imaging optics system that differs from the first imaging optics system with regard to at least one optical property or attribute that affects the acquisition of the positional data.

Abstract: A radiography apparatus is provided in which delays in imaging do not occur due to the influence of preliminary preparation of a radiation detector. The FPD 4 receives a signal from an X-ray tube control unit 6 and then completes preliminary preparation for the detection of radiation during accelerated movement of an X-ray tube 3 or the FPD 4. That is, the accelerated movement of the X-ray tube 3 or the FPD 4 and the preliminary preparation for the detection of radiation are carried out simultaneously. This enables imaging to be started immediately after the start of constant speed movement of the X-ray tube 3 or the FPD 4 without having to wait for constant speed movement thereof to start preliminary preparation of the FPD 4 as in conventional apparatuses. As a result, delays in imaging do not affect the radiation image.

Abstract: A mobile scanner includes a base, an articulating boom assembly, a scanning assembly, and a boom-power system. The articulating boom assembly includes a proximal vertical boom section pivotably secured to the base; a distal vertical boom section; and an intermediate horizontal boom section disposed between the proximal vertical boom section and the proximal vertical boom section. The articulating boom assembly forms a general inverted U-shape when in a deployed position, so as to present an opening therethrough for the passing of an object to be scanned. The scanning assembly is disposed at least in part on the distal vertical boom section for scanning the object in the opening. The boom-power system is configured to place the articulating boom assembly into the deployed position. The articulating boom assembly is configured to remain in the deployed position without the boom-power system keeping the articulating boom assembly in the deployed position.

Abstract: A radiation imaging control device has a display control function to output, to a display unit, information indicating display content to be displayed on the display unit in order to cause the display unit to display imaging conditions for radiation imaging and a radiation image obtained by radiation imaging under at least one of the imaging conditions. The control device determines the presence or absence of abnormality concerning radiation imaging, and causes, in the case where the presence of abnormality is determined, a storage unit to store the information indicating display content that is output to the display unit by the display control function at a timing based on the abnormality.

Abstract: The present application relates to a container inspection system, comprising a radiation source (31), a radiation detection apparatus and a quay crane for hoisting a container onto an automated guided vehicle, said radiation source (31) and said radiation detection apparatus being provided on said quay crane, for performing a scanning inspection on said container loaded on said vehicle. The present application, which does not need a special allocation of approach of the radiation source and the radiation detection apparatus, conveniently effectuates scanning inspection of a container, and improving the inspection efficiency.

Abstract: A method and device for controlling a linear accelerator as well as a linear accelerating system are provided according to examples of the present disclosure. In an example, a first component of the linear accelerator is controlled to move according to a motion instruction; when it is detected that the first component reaches a first position, the first component is controlled to pause moving, and a second component of the linear accelerator is controlled to move in a preset direction; when it is detected that the second component reaches a second position, the second component is controlled to stop moving, and the first component is controlled to continue to move according to the motion instruction.

Abstract: An x-ray imaging device can include an x-ray detector and an optical-blocking filter. The x-ray detector has an entrance-window surface for receiving x-rays, at least one side surface, and a back surface facing in an opposite direction from the entrance-window surface. The optical-blocking filter is deposited on and fully covers at least the entrance-window surface and the side surface of the x-ray detector, wherein the optical-blocking filter blocks visible, ultraviolet, and near-infrared light.

Abstract: The present disclosure provides a system and method for inspecting an aircraft. An X-ray/Gamma ray radiation source and a detector are located at above and below a fuselage of an aircraft, respectively. The X-ray/Gamma ray radiation source emits a beam of radiation[ ], wherein the X-ray/Gamma ray radiation[ ] passes through the aircraft to be inspected. The detector receives and converts the beam of X-ray/Gamma ray radiation[ ] that has passed through the aircraft to an output signal, and the system generates a vertical transmission image in real time.

Abstract: An inspection device 1 includes an inspection table 2 on which an inspection target T which is a set of a plurality of solid drugs O is placed, a vibration unit 3 that vibrates the inspection table 2, an imaging unit 4 that acquires an image of the inspection target T, which is placed on the inspection table 2, in a first direction along the inspection table 2, and a control unit 5 that determines whether the solid drugs O in the inspection target T overlap each other, based on inspection target information including appearance information of each of the drugs forming the inspection target T and the image of the inspection target T in the first direction, and operates the vibration unit 3 in a case in which it is determined that the solid drugs O overlap each other.

Abstract: A vehicle-mounted inspection system comprises: a chassis; a rotation mechanism disposed on the chassis; a first ray emission device connected to the rotation mechanism and configured to emit a ray; a first detection device connected to the rotation mechanism and configured to receive the ray emitted by the first ray emission device; and a second ray emission device connected to the rotation mechanism and configured to emit a ray. The rotation mechanism is configured to rotate the first ray emission device, the first detection device and the second ray emission device substantially around an upright axis between a retracted position and an operating position.

Abstract: Disclosed herein is a mobile fluoroscopic imaging system, and methods of use. A table top imaging system can include a support, an x-ray source carried by the support, an x-ray detector carried by the support and positionable at a distance from the source; a primary x-ray propagation axis extending between the source and the detector. The distance between the source and the detector can be adjustable along the axis, and the axis can be angularly adjustable throughout an angular range.

Abstract: An imaging system including a scanner and a transport mechanism mounted to the base of the scanner, wherein the transport mechanism includes a gross movement mechanism for transporting the scanner relatively quickly across room distances and a fine movement mechanism for moving the scanner precisely, relative to the object being scanned, during scanning.

Abstract: A medical device, such as a mobile C-arm, is positioned and/or aligned via a touch-sensitive control panel of a tablet. The touch-sensitive control panel provides access to one or more function units, for example, for initiating control signals for a positioning and/or an alignment of the medical device, or a second function unit for specifying a direction of movement for a mobile medical unit, or a third function unit for specifying a motion speed for the mobile medical device.

Abstract: An improved configuration of a mobile-type radiographic image pickup device reliably stops on a flat path without play. More specifically, the prevent invention stops reliably on an inclined path. Where a carriage accelerates regardless of that fact that a deceleration control unit has begun to restrict the movement of the carriage, a brake control unit causes a brake device to operate. According to the present invention, if the carriage accelerates regardless of the fact that a deceleration control unit has begun to restrict the movement of the carriage, the brake device is promptly operated, and prevents concern regardless of the application of an instruction to stop the carriage which is travelling on an incline, and prevents the carriage from running for a long period to time.

Abstract: An X-ray diagnostic system is provided that is capable of fitting the vertical position of the X-ray tube to each mode of photography without being affected by the height of the ceiling. The X-rays irradiated from the X-ray tube and transmitted through the subject are detected, and photographed images are captured based on the detected X-rays; the system comprises a supporting member, an arm member, and a height adjuster; the supporting member is provided on the ceiling of a room, formed in a pillar shape, and configured in such a way that the entire length is vertically extended and shortened. The arm member has a base end section connected to the lower end portion of the supporting member and a tip section on which the X-ray tube is mounted. The height adjuster adjusts the vertical position of the X-ray tube by moving the tip section of the arm member relative to the supporting member.

Abstract: A boom has an x-ray head attached to one end thereof and the x-ray head has an x-ray source disposed therein. In a docked position of the boom, the x-ray source is disabled. In a deployed position, the x-ray source is enabled. A handle attached to the x-ray head is movable into at least two different positions. A first one of the positions disables the x-ray source while a second one of the positions enables the x-ray source. The handle extends a preselected distance from the x-ray source such that the handle maintains at least the preselected distance between the x-ray source and a subject to be exposed thereby.

Abstract: An inclined PET device is provided in which the cut plane of a detector ring upon which a plurality of PET detectors are disposed is inclined so that it does not intersect perpendicularly with the long axis of a bed that carries a subject to be examined and in which an open space that passes through the bed in a direction perpendicular to the long axis thereof is formed, in order to enable access to the subject to be examined. The PET detectors are disposed and stacked in a direction parallel to the long axis of the bed. Thereby, the number of PET detectors is reduced and device cost is reduced, while the detector ring as well as the device can be miniaturized. At the same time, the open space that passes through the bed in a direction perpendicular to the long axis can be preserved.

Abstract: Device comprising: a chassis (1) which supports the entire assembly, a telescopic column (2) which comprises a lower fixed portion (5) rotating with respect to a vertical axis, and at least one upper mobile portion (6), a telescopic arm (3) that moves along the vertical column and that supports an x-ray emitter (4) at its end, wherein the telescopic arm-head assembly can be moved from the lower position of the mobile column in its retracted position to the upper position of the mobile column in its extended position, and also in that all the movements of the column are manual and have a mechanical balancing mechanism which comprises a first mechanism consisting of a spring, a block and tackle, and a variable radius pulley all housed in the fixed portion of the column, and a second balancing mechanism consisting of a recovery pulley and a two-radii pulley which balances the weight between the input of the cable and that of the telescopic arm and head assembly.

Abstract: Methods and computing systems for determining a committed information rate for a plurality of cell sites are described. Data associated with throughput of combined voice and data traffic communicated between a core network and the plurality of cellular sites is received. An oversubscription ratio for the committed information rate is determined based on a predetermined service outage threshold and a plurality of peak throughput values of the combined voice and data traffic over a plurality of time periods. An oversubscribed committed information rate for the plurality of cellular sites is determined based on the oversubscription ratio.

Abstract: Disclosed is an X-ray imaging apparatus, which includes a plurality of X-ray generation modules configured to emit X-rays to a subject, the X-ray generation modules being configured to move independently of one another, an X-ray detector configured to detect a plurality of X-rays emitted from the plurality of X-ray generation modules and which have passed through the subject, and an image processor configured to acquire a plurality of X-ray images from the plurality of detected X-rays.

Abstract: A mobile X-ray imaging apparatus includes: a mobile cart having a casing as an exterior member; an X-ray generation unit that can be stored in the casing; a handle portion arranged on an upper portion of the casing; and a movable portion having the handle portion and configured to be alternately stored in and pulled out from the casing, wherein an upper portion of the movable portion is pulled out in an inclined state from the mobile cart through a drawing-out operation performed on the handle portion by the operator.

Abstract: A mobile medical imaging device that allows for multiple support structures, such as a tabletop or a seat, to be attached, and in which the imaging gantry is indexed to the patient by translating up and down the patient axis. In one embodiment, the imaging gantry can translate, rotate and/or tilt with respect to a support base, enabling imaging in multiple orientations, and can also rotate in-line with the support base to facilitate easy transport and/or storage of the device. The imaging device can be used in, for example, x-ray computed tomography (CT) and/or magnetic resonance imaging (MRI) applications.

Abstract: A movable X-ray generation apparatus includes an X-ray tube configured to perform irradiation with X-rays, an arm configured to support the X-ray tube, a cart unit configured to support and move the arm, and a monitor mounted on the upper portion of the cart unit. The movable X-ray generation apparatus includes a first member configured to support the monitor to be pivotable about a first rotation axis, and a second member configured to support the first member to be pivotable about a second rotation axis different from the first rotation axis with respect to the cart unit. At least one of the first rotation axis and the second rotation axis provides a rotation axis parallel to the display surface of the monitor and perpendicular to a moving surface on which the cart unit moves.