JP5341055B2 - Gantry mobile CT scanner - Google Patents

Description

  The present invention relates to a gantry moving CT (Computed Tomography) scanner (scanner) in which a gantry moves toward a stationary subject and irradiates the subject with radiation.

  In general, a CT scanner has a configuration in which a gantry that emits radiation is fixed and a subject moves to the gantry.

  When such a CT scanner is used to detect the position of the affected part of the subject and perform radiotherapy or surgery based on the position information, the gantry is stationary, so the radiation is moved by moving the subject side. It is necessary to perform treatment and surgery, and there is a problem that position reproducibility is difficult.

  Therefore, a gantry moving CT scanner in which the subject is stationary and the gantry moves is proposed.

  However, since a gantry moving CT scanner needs to drive a heavy gantry with good responsiveness, a servo motor is used as a drive source.

  However, since a gantry moving CT scanner needs to drive a heavy gantry with good responsiveness, a servo motor is used as a drive source.

  Furthermore, in order to reduce the moment of inertia of the drive source and obtain a large torque, the structure is driven via a speed reducer with a large reduction ratio.

  In the case of a CT scanner having such a configuration, when a power failure occurs during diagnosis, it is necessary to retract the gantry from the subject and lower the subject from the bed.

  However, the rotational resistance of the servo motor itself is amplified by the speed reducer, resulting in a state where a brake is applied, and there is a problem that the gantry cannot be easily moved manually.

  In order to solve this, it is conceivable that a clutch is provided in the drive system and the gantry can be moved by disengaging the clutch.

  However, when a clutch is used, the configuration becomes complicated, and when a meshing clutch is used as the clutch, there is a problem that the position accuracy is reduced due to backlash when the clutch is turned on and off.

  The present invention has been made in view of the above problems, and a first object thereof is to provide a gantry moving CT scanner that can easily move the gantry at the time of a power failure.

  A second problem is to provide a gantry moving CT scanner that can easily move the gantry in the event of a power failure with a simple configuration.

  The invention according to claim 1, which solves the above-mentioned problem, is a gantry moving CT scanner in which a gantry moves toward a stationary subject and irradiates the subject with radiation, and a speed reducer is provided on the gantry. A drive wheel that is driven through, a freely rotatable auxiliary wheel provided in the vicinity of the drive wheel, and a drive wheel lifting mechanism that lifts the drive wheel from the floor and makes the auxiliary wheel contact the floor A gantry moving CT scanner characterized by being provided.

  Since the drive wheels are driven via a speed reducer, if a power failure occurs while the gantry is moving, the rotational resistance of the drive source itself such as the motor is amplified by the speed reducer and the brakes are applied. Stop.

  The gantry can be easily moved by operating the driving wheel lifting mechanism, lifting the driving wheel from the floor, and bringing the auxiliary wheel that can freely rotate into contact with the floor.

  Since the drive wheels are only lifted, the positional accuracy does not decrease.

  According to a second aspect of the present invention, the driving wheel lifting mechanism according to the first aspect is provided with an arm member that is rotatably provided on the axle side of the driving wheel and a distal end side of the arm member. Auxiliary wheel, a screw rod provided on the base side so as to be rotatable in a state in which axial movement is prohibited, and a nut member provided on the arm member that is prevented from rotating and is screwed with the screw rod. A gantry moving CT scanner characterized by comprising:

  When the screw rod is rotated, the nut screwed to the screw rod is prevented from rotating. Therefore, the nut and the arm member provided with the nut move along the screw rod, and the arm member moves to the drive wheel. Rotating about the axle, the auxiliary wheel provided on the distal end side of the arm member comes into contact with the floor, and the driving wheel on the proximal end side of the arm member is lifted from the floor.

  The gantry can be easily moved by lifting the drive wheel from the floor with a simple mechanism comprising a screw rod and a nut member and bringing the auxiliary wheel that can freely rotate into contact with the floor.

According to a third aspect of the present invention, the drive wheel lifting mechanism according to the first aspect is provided with an arm member having an intermediate portion rotatably provided on an axle of the drive wheel, and one of the arm members on a rotating end side. An auxiliary wheel provided, a first link having one end rotatably attached to the other end of the arm member, and one end rotatably attached to an intermediate portion of the first link; When the other end portion is rotatably attached to the base side and the driving wheel is in contact with the floor, the one end portion side of the first link has a substantially “<” shape and is toggled. One end of the first link is rotatably attached to the other end side of the first link from the connection between the second link forming the joint mechanism and the second link of the first link.・ The first in the direction to crush the "<" shape of the joint mechanism If you rotate the link, which is the first link and the gantry mobile CT scanner, characterized in that comprising a third link abutting on said second link.

  Since the axle of the drive wheel is provided in the middle of the arm member, the auxiliary wheel is provided on one end side, and the one end of the first link is provided on the other end side, the toggle joint mechanism When the first link is rotated in the direction of crushing the “<” shape, the arm member is lifted around the axle of the drive wheel, the drive wheel is lifted from the floor, and the auxiliary wheel contacts the floor.

  At this time, due to the weight of the gantry, a force acts on the first link and the second link in the direction of creating the “<” shape of the toggle joint mechanism, but the third link is the first link and the second link. Since it abuts against the second link, that state is maintained.

  The gantry can be easily moved by lifting the drive wheel from the floor with a simple toggle joint mechanism comprising the first to third links and bringing the auxiliary wheel capable of free rotation into contact with the floor.

  As described above, according to the present invention, it is possible to realize a gantry moving CT scanner that can easily move a gantry at the time of a power failure.

It is a section lineblock diagram of a gantry movement type CT scanner of an example of an embodiment. It is the cross-sectional block diagram seen from the left side surface of FIG. It is an enlarged view of the drive wheel lifting mechanism of FIG. FIG. 4 is a left side view of FIG. 3. It is a principal part block diagram explaining the other example of a driving wheel lifting mechanism. It is a figure explaining the operation | movement of FIG. It is a figure explaining the operation | movement of FIG.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(overall structure)
First, an overall configuration of a gantry moving CT scanner according to an embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional configuration diagram of a gantry moving CT scanner according to an embodiment, and FIG. 2 is a cross-sectional configuration diagram viewed from the left side of FIG.

  In FIG. 1, a subject 1 is placed on a bed 3 fixed on a floor F.

  A rail 5 is provided on the floor F, and the gantry 7 moves on the rail 5.

  In the gantry 7, a sub-base 13 provided on the base 11 so as to be tiltable in the front-rear direction with respect to the base 11 is provided. A fixed casing (casing) 15 is provided on the sub-base 13, and a rotating casing 17 is rotatably provided with respect to the fixed casing 15.

  In FIG. 2, reference numeral 19 denotes a motor that is provided on the sub-base 13 and that rotationally drives the rotary casing 17 via a belt 21.

  The rotating casing 17 includes a tube 23 that is a radiation source that emits radiation to the subject 1 placed in the rotating casing 17, and a detector that detects the radiation that has passed through the subject 1. 25. A collimator 27 is provided near the tube 23 and adjusts the radiation direction of the radiation of the tube 23.

  When the rotating casing 17 is rotated by the motor 19, the tube 23 and the detector 25 rotate around the subject 1, and the transmitted radiation transmitted through the subject 1 is detected by the detector 25. Such detection of transmitted radiation is called a scan, and a tomographic image of the subject 1 is reconstructed based on a plurality of views obtained by this scan.

  Returning to FIG. 1, the base 11 is driven by a driven wheel 31 that rolls on the rail 5 and a motor 32, and is driven by a speed reducer (see FIG. 2) 34 having a large reduction ratio. And a drive wheel 35 that rolls.

  An auxiliary wheel 37 that can freely rotate is provided in the vicinity of the drive wheel 33. In the present embodiment, the auxiliary wheel 37 is disposed so as to be positioned with a slight gap from the rail 5 in a normal state.

  When the drive wheel lifting mechanism 50 is operated, the drive wheel 33 is lifted from the rail 5 (floor F).

(Drive wheel lifting mechanism)
The drive wheel lifting mechanism 50 will be described with reference to FIGS. 3 and 4. 3 is an enlarged view of the drive wheel lifting mechanism of FIG. 1, and FIG. 4 is a left side view of FIG.

  In FIG. 3, the base 11 is provided with two first sub-bases 55 and 55 'for supporting the drive wheels 33 using bolts 53 (see FIG. 4 for the first sub-base 55'). ).

  Further, second sub-bases 59 and 59 'are attached to the upper portions of the first sub-bases 55 and 55' using bolts 57 (see FIG. 4 for the second sub-base 59 ').

  The shaft 61 of the drive wheel 33 is provided with base end portions of arm members 63 and 63 'for rotation (see FIG. 4 for the arm member 63'). An auxiliary wheel 37 is provided at the lower part of the arm members 63, 63 'on the rotating end side so as to be freely rotatable.

  In FIG. 4, a screw rod 71 is disposed between the second sub-bases 59 and 59 'in the vertical direction. The screw rod 71 is roughly divided into an upper small diameter portion 73, a large diameter portion 75, and a lower small diameter portion 77 from the top.

  The upper small-diameter portion 73 is formed with a bolt head portion 73a formed in the shape of a bolt head portion and a first male screw portion 73b formed with a male screw.

  The lower small-diameter portion 77 is formed with a second male screw portion 77a in which a male screw is formed.

  A screw rod support member 81 having a hole 81a through which the upper small diameter portion 73 of the screw rod 71 is inserted is provided between the second sub-bases 59 and 59 '. Protrusions 81b and 81c that fit into holes 59a and 59a 'formed in the sub-bases 59 and 59' are formed and fixed between the second sub-bases 59 and 59 '.

  Furthermore, a bearing nut (bearing-nut) 83 is screwed into the first male thread portion 73b of the upper small diameter portion 73 of the screw rod 71, and the bearing nut 83, the large diameter portion 75 of the screw rod 71, and the upper small diameter portion. When the screw rod support member 81 is sandwiched between the step portion 71a and the portion 73, the screw rod 71 is rotatably held in a state where movement in the axial direction is prohibited.

  Between the arm members 63 and 63 ′, a nut member 85 in which a female screw portion 85 a into which the second male screw portion 77 a of the screw rod 71 is screwed is disposed.

  The nut member 85 is formed with convex portions 85b and 85c that fit into holes 63a and 63a 'formed in the arm members 63 and 63', and is fixed in a state in which the rotation is prevented between the arm members 63 and 63 '. Has been.

  A disk-shaped stopper 87 is attached to the lower end face of the screw rod 71 using a screw 89.

  Further, in the arm member 63, 91 and 91 ′ are bearings that rotatably support the axle 37a of the auxiliary wheel 37.

  Next, the operation of the above configuration will be described.

  If a power failure occurs while making a diagnosis while moving the gantry 7, the drive wheels 33 are driven via the speed reducer 34 having a large reduction ratio, so the gantry 7 stops immediately.

  Here, when the gantry 7 is retracted from the subject 1 and the subject 1 needs to be lowered from the bed 3, the bolt head 73 a is rotated with a wrench and the screw rod 71 is rotated.

  When the screw rod 71 whose axial movement is prohibited is rotated, the nut member 85 screwed into the second male threaded portion 77a of the screw rod 71 is prevented from rotating. The arm members 63 and 63 'provided with the member 85 move along the screw rod 71, and the arm members 63 and 63' rotate around the axle 61 of the drive wheel 33 (in the direction of arrow I in FIG. 3). The auxiliary wheel 37 provided on the distal end side of the arm members 63, 63 ′ contacts the rail 5, and the drive wheel 33 on the proximal end side of the arm members 63, 63 ′ is lifted from the rail 5.

  According to the above configuration, the drive wheel 33 is lifted from the rail 5 and the auxiliary wheel 37 abuts on the rail 5, so that the gantry 7 can be easily moved.

  Further, the gantry 7 can be easily moved by a simple mechanism including the screw rod 71 and the nut member 85.

  Furthermore, since the drive wheel 33 is only lifted, the positional accuracy is not lowered.

  The present invention is not limited to the above embodiment. In the above embodiment, the auxiliary wheel 37 is disposed so as to be positioned with a slight gap from the rail 5 in a normal state. However, the auxiliary wheel 37 may be in contact with the rail 5 to be able to roll.

  In the above embodiment, the gantry 7 is immediately stopped by the braking force of the reducer 34 having a large reduction ratio at the time of a power failure. However, if a brake is provided to stop the rotation of the motor shaft after a power failure, Furthermore, safety is improved.

  Furthermore, in the above embodiment, a mechanism using a screw rod and a nut is used as the drive wheel lifting mechanism. However, for example, a toggle joint mechanism as shown in FIG. 5 may be used. Note that the state of FIG. 5 is a state in which the driving wheel contacts the floor F and the driving wheel is driven to move the gantry.

  In the figure, an intermediate portion of an arm member 111 is rotatably provided on an axle 103 of the drive wheel 101.

  On one rotation end side of the arm member 111, an auxiliary wheel 121 is provided so as to be positioned through a slight gap with the rail 5 in a normal state.

  One end of the first link 131 is rotatably attached to the other rotation end of the arm member 111 using a pin 133. The first link 131 is bent upward at two locations A and B in the middle portion.

  One end portion of the second link 141 is rotatably attached to the intermediate portion (A) of the first link 131 using a pin 143. The other end of the second link 141 is attached to the base using a pin 145.

  When the driving wheel 101 is in contact with the floor, the one end side of the first link 131 and the second link 141 form a substantially “<” shape to form a toggle joint mechanism. Has been.

  Further, a third link is provided on the other end side of the first link 131 from the connection portion of the first link 131 with the second link 141, that is, on the intermediate portion (B) of the first link 131. One end of 151 is rotatably attached using a pin 153. The intermediate portion of the third link 151 is bent at two locations C and D, and the first contact surface 155 that can contact the second link 141 and the corner portion can contact the second link 141. A bent corner portion 157 and a second contact surface 159 that can contact the first link 131 are formed.

  In the state shown in FIG. 5, when the other rotation end side of the first link 131 is pushed in the F direction and the first link 131 is rotated in the direction of crushing the “<” shape of the toggle joint mechanism, The arm member 111 rotates in the direction of arrow II around the axle 103 of the drive wheel 101, and the auxiliary wheel 121 abuts on the rail 5. After the auxiliary wheel 121 comes into contact with the rail 5, as shown in FIG. 6, the arm member 111 rotates in the direction of arrow II around the axle 123 of the auxiliary wheel 121, and the driving wheel 101 is lifted from the rail 5, The gantry can be easily moved.

  As shown in FIG. 6, when one end portion side of the first link 131 and the second link 141 are substantially linear, the first contact surface 155 of the third link 151 is the second link. 141, the second contact surface 159 of the third link 151 contacts the first link 131, and the state is maintained.

To release this state, the third link 151 is pushed in the direction of arrow G in FIG. Then, the third link 151 rotates with the bent corner portion 157 contacting the second link 141 as a fulcrum, and one of the first links 131 with respect to the first link 131 and the second link 141. This acts so as to crush the state in which the end portion side and the second link 141 are substantially linear. Furthermore, the state where the first contact surface 155 of the third link 151 contacts the second link 141 and the state where the second contact surface 159 of the third link 151 contacts the first link 131 are present. 7 is released, and the arm member 111 is moved along the arrow II around the axle 123 of the auxiliary wheel 121 as shown in FIG.
The wheel rotates in the direction I, and the driving wheel 101 comes into contact with the rail 5, and after the driving wheel 101 comes into contact, the wheel rotates around the axle 103 of the driving wheel 101 and returns to the original state.

5 Rail 7 Gantry 33 Drive Wheel 37 Auxiliary Wheel 50 Drive Wheel Lifting Mechanism

Claims (2)

A gantry moving type CT scanner comprising a gantry that moves on a rail toward a stationary subject and irradiates the subject with radiation, and a moving means for moving the gantry,
The moving means is
In the space between the gantry and the floor facing it, the gantry is provided on the gantry,
Driving wheels driven via a speed reducer provided at a position corresponding to the rail;
An auxiliary wheel provided in a position corresponding to the rail in the vicinity of the drive wheel and capable of freely rotating;
An arm member having both an axle of the driving wheel and an axle of the auxiliary wheel is provided, and the auxiliary wheel is brought into contact with the rail by rotating the arm member so that the driving wheel is lifted from the rail. Drive wheel lifting mechanism to move to
Equipped with a,
The drive wheel lifting mechanism is
An arm member provided on the axle of the drive wheel so that the base end side is rotatably provided, and the axle of the auxiliary wheel is provided rotatably on the tip side;
A screw rod that is rotatably provided with axial movement prohibited,
A nut member which is provided on the arm member and is prevented from rotating, and to which the screw rod is screwed;
A screw rod support member fixed to the gantry and rotatably supporting the screw rod in a state where axial movement is prohibited;
With
The auxiliary wheel abuts on the rail and the drive wheel is lifted from the rail by the movement of the nut member and the arm member along the screw rod by rotating the screw rod. Gantry mobile CT scanner. A gantry moving type CT scanner comprising a gantry that moves on a rail toward a stationary subject and irradiates the subject with radiation, and a moving means for moving the gantry,
The moving means is
In the space between the gantry and the floor facing it, the gantry is provided on the gantry,
Driving wheels driven via a speed reducer provided at a position corresponding to the rail;
An auxiliary wheel provided in a position corresponding to the rail in the vicinity of the drive wheel and capable of freely rotating;
An arm member having both an axle of the driving wheel and an axle of the auxiliary wheel is provided, and the auxiliary wheel is brought into contact with the rail by rotating the arm member so that the driving wheel is lifted from the rail. Drive wheel lifting mechanism to move to
Equipped with a,
The drive wheel lifting mechanism is
An arm member in which an intermediate portion is rotatably provided on an axle of the driving wheel, and an axle of the auxiliary wheel is provided on one rotating end side;
A first link having one end rotatably attached to the other end of the arm member;
In a state where one end portion is rotatably attached to the intermediate portion of the first link, the other end portion is rotatably attached to the gantry, and the driving wheel is in contact with the floor, the first link A second link that forms a toggle joint with a substantially "<" shape on one end side of the
One end portion of the first link is rotatably attached to the other end portion side of the first link from the connection portion of the first link with the second link, and the “<” shape of the toggle joint is crushed. A third link that contacts the first link and the second link when the first link is rotated in a direction;
Gantry mobile CT scanner according to claim <br/> comprise a.

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