JP2007125241A - Bed for medical image diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical image diagnostic apparatus provided with a bed by which a subject can be easily evacuated manually. <P>SOLUTION: The bed for moving the subject 3 to an imaging space of an imaging device 1 has: a top plate 2a for loading the subject; a driving mechanism 4 for driving the top plate 2a; and an auxiliary mechanism 8 for manually moving the top plate in a direction evacuating from the imaging space. The auxiliary mechanism 8 is provided with: a release part for releasing connection between the top plate 2a and the driving mechanism 4; and a biasing part which imparts auxiliary force in a direction evacuating the top plate. Thus, in the case of evacuating, force to be imparted manually can be reduced by the amount of the auxiliary force of the auxiliary mechanism without being affected by the driving mechanism, and the top plate 2a can be pulled out easily. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a medical image diagnostic apparatus bed, and more particularly to a bed provided with a mechanism for retracting a subject in an emergency.

  As medical image diagnostic apparatuses, there are various apparatuses such as a CT apparatus and a magnetic resonance imaging (hereinafter referred to as MRI) apparatus. In these apparatuses, the subject is placed on the top plate of the bed, and the imaging part of the subject is moved to the imaging range of the apparatus to perform imaging. The top plate is normally moved by a top plate driving mechanism. After the top plate is moved to the imageable range, the position is held by a position holding mechanism that uses frictional force. On the other hand, in an emergency, it is necessary to retract the subject from the imaging range, but conventionally, the top plate on which the subject is placed is separated from the drive mechanism and the position holding mechanism, and the top plate is manually moved.

For example, in Patent Document 1, by operating an operation handle attached to the top plate, the auxiliary wheel descends from the bottom surface of the top plate and lifts the top plate from the bed body, thereby releasing the contact with the drive mechanism. A configuration in which the top plate can be manually pulled out is disclosed.
Japanese Patent Laid-Open No. 6-14919

  In recent years, in medical diagnostic imaging apparatuses, a configuration that can image the whole body of a subject without rearranging the subject is becoming mainstream, the top plate has a long moving stroke, and the top plate is drawn into the gantry to the end. There is an increase in the number of configurations. For this reason, at the time of emergency evacuation, the operator needs to grasp the handle at the end of the top plate with an unnatural posture that causes the upper body to enter the gantry, and the whole body of the subject comes out of the gantry from the posture. It is necessary to move the top plate to a long stroke. The labor required for the evacuation work is increasing from the viewpoint of both the required force and the amount of movement. In addition, since the medical diagnostic imaging apparatus cannot adopt a known metal mechanism having a small dynamic friction resistance such as a metal bearing or a high-performance tire due to the imaging mechanism, it is difficult to reduce the dynamic friction resistance itself. Moreover, since it is assumed that electric power cannot be used in an emergency, the assist by electric power cannot be used.

  The top plate retracting mechanism described in Patent Document 1 is configured to lower the auxiliary wheel from the bottom surface of the top plate and lift the top plate from the bed body, but in reality, the subject is placed on the top plate, The auxiliary wheel must be lowered against the body weight, and a wedge must be inserted between the top plate and the support part of the auxiliary wheel to fix the auxiliary wheel. I don't think so.

  An object of the present invention is to provide a medical image diagnostic apparatus provided with a bed that can easily perform an operation of manually retracting a subject.

  In order to achieve the above object, a medical image diagnostic apparatus of the present invention includes an imaging device that images a subject and a bed that moves the subject to the imaging space of the imaging device, and the bed mounts the subject. A top plate, a drive mechanism for driving the top plate, and an auxiliary mechanism for manually moving the top plate in a direction to retract from the imaging space. The auxiliary mechanism includes a release unit that releases the connection between the top plate and the drive mechanism, and a biasing unit that applies an auxiliary force in a direction in which the top plate is retracted. As a result, during retraction, the force that is manually applied by the amount of the auxiliary force of the auxiliary mechanism is reduced without being affected by the drive mechanism.

  The drive mechanism can be configured to have a holding portion that holds the position of the top plate by a frictional force. In the case of this configuration, the effect that the manual release can be easily achieved by the release part releasing the connection is remarkable.

  The urging unit is configured to always apply auxiliary force, and the drive mechanism is configured to drive the top plate against the auxiliary force when moving the top plate in the direction of inserting the imaging plate into the imaging space. be able to. By adopting a configuration in which an auxiliary force is always applied in this way, a mechanical structure such as a spring that does not use electric power can be used as an auxiliary mechanism, so that manual retraction is possible even during a power failure. For example, the urging portion can be configured to have a constant load spring that applies a certain auxiliary force regardless of the position of the top plate.

  The release unit may be configured to include an electric clutch that is connected in an energized state and released in an energized stop state, and a switch that stops energization of the electric clutch. As a result, it is possible to release the drive mechanism by operating the switch in an emergency and without any operation in the event of a power failure.

  The auxiliary mechanism may include a rope having one end connected to the top plate, and apply auxiliary force to the top plate via the rope. Since one end of the rope moves as the top plate is driven by the drive mechanism, the top plate movement amount can be detected by providing the rope with detection means for detecting the movement amount.

  According to the present invention, it is possible to reduce the operating force when manually retracting a subject in an emergency. Therefore, it is possible to realize a medical image diagnostic apparatus including a bed that can easily perform an operation of manually retracting a subject.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the medical image diagnostic apparatus according to the first embodiment will be described. As shown in FIG. 1, this medical image diagnostic apparatus includes a bed 20 on which a subject 3 is arranged and an imaging device for imaging the subject. Here, a case where the imaging apparatus is an MRI apparatus will be described as an example, but the imaging apparatus is not limited to an MRI apparatus, and may be another imaging apparatus such as a CT apparatus. An MRI apparatus includes a static magnetic field generation system that generates a static magnetic field in an imaging space, a gradient magnetic field generation system that applies a gradient magnetic field pulse to a subject disposed in the imaging space, and a high-frequency magnetic field that applies a high-frequency magnetic field pulse to the subject A transmission system, a high-frequency magnetic field reception system that receives a nuclear magnetic resonance signal generated by the subject, an arithmetic control unit that performs image reconstruction processing of the obtained data, and the like, and controls each unit according to instructions from the arithmetic control unit. A sequencer for executing the imaging sequence and an operation unit 23 are provided. A static magnetic field generation system, a gradient magnetic field generation system gradient magnetic field coil, and a high-frequency magnetic field transmission system transmission coil are arranged inside the gantry 1 of FIG. Other components such as a power supply for the gradient magnetic field generation system and the high-frequency magnetic field generation system, and a sequencer are disposed in the housing 24 outside the gantry 1.

  The gantry 1 has a cylindrical shape and is arranged with the central axis horizontal. An imaging space is formed in the central space 25 of the gantry 1 by a static magnetic field generation system or the like. The subject 3 is inserted into the imaging space by the bed 20.

  As shown in FIG. 1, the bed 20 includes a top plate 2a and a bed body 2e. The top plate 2 a includes a plurality of wheels 2 b on the lower surface, and can travel on the upper surface of the bed main body 2 e and the lower wall surface of the internal space 25 of the gantry 1. The bed body 2e includes a timing belt 2d and a top plate driving mechanism 4 that drives the timing belt 2d. The top plate 2a is connected to the timing belt 2d in the bed 20 by a connecting metal fitting 2c. The timing belt 2d drives the top plate 2a in the longitudinal direction. A handle 22 is provided at the end of the top plate 2a. On the side surface of the bed body 2e, a retraction switch 21 is provided at a position where the operator can operate. In an emergency, when the operator operates the retraction switch 21, it is possible to grasp the handle and pull out the top plate 2a from the gantry 1.

  The structure of the top plate drive mechanism 4 will be described with reference to FIG. The top plate drive mechanism 4 includes a pulley 4a around which a timing belt 2d is wound, an electric clutch 4b that is disposed on the side of the pulley 4a and connected to a rotating shaft of the pulley 4a, and an electric clutch via gears 4c and 4d. A motor 4e with a brake connected to the rotating shaft 4b and a manual retraction assist mechanism 5 disposed on the other side of the pulley 4a and connected to the rotating shaft. That is, the timing belt 2d to which the top plate 2a is connected is connected to the motor 4e with a brake through the pulley 4a, the clutch 4b, and the gears 4c and 4d. The brake-equipped motor 4e is operated by a control signal from an arithmetic control unit or a sequencer according to an instruction received by the operation unit 23 of the MRI apparatus, and drives and moves the timing belt 2d. Thereby, the motor 4e with a brake moves the top plate 2a to a desired position and holds the position by the brake.

  The electric clutch 4b is configured to be in a connected state when energized and in a released state when energization is stopped. Here, an excitation type electric clutch is used. The retraction switch 21 is connected to the power supply line of the electric clutch 4b. When the retraction switch 21 is pressed, energization to the electric clutch 4b is stopped and the electric clutch 4b is released. The electric clutch 4b is also released when the power supply is stopped due to a power failure or the like. Therefore, in the normal stationary state, the top plate 2a is held in position by the brake of the motor 4e with brake, but when the connection with the motor 4e with brake is released by the electric clutch 4b, the top plate 2a is manually operated. It is possible to evacuate.

  On the other hand, the manual retraction assist mechanism 5 always urges the pulley 4a in a direction in which the top plate 2a is retracted, that is, in a direction in which the top plate 2a is pulled out from the gantry 1. The structure of the manual retraction assist mechanism 5 will be described with reference to FIGS. The manual retraction assist mechanism 5 includes a drum 5a connected to the rotation shaft of the pulley 4a, a drum 5b disposed to face the drum 5a, and a constant load spring 5c. The constant load spring 5c has one end fixed to the drum 5a and the other end fixed to the drum 5b, and is wound respectively. The length of the constant load spring 5 c is longer than the stroke length until the top plate 2 a is completely pulled out from the gantry 1. As a result, the constant load spring 5c can always urge the pulley 4a in a direction to pull out the top plate 2a with a constant load regardless of the position of the top plate 2a. 6b.

Next, the operation of the medical image diagnostic apparatus according to the first embodiment will be described.
The operator mounts the subject 3 on the top plate 2 a of the bed 20 and operates the operation unit 23 to operate the motor 4 e with a brake of the top plate drive mechanism 4 to enter the imaging space 25 in the gantry 1. Insert the top plate 2a. Thereafter, a desired imaging sequence is executed by the MRI apparatus to image the subject.

  FIG. 4 is an explanatory diagram showing the relationship of forces acting on the top plate 2a when the top plate driving mechanism 4 moves the top plate 2a. When driving the top plate 2a, the weight of the top plate 2a, the weight of the subject 3 placed on the top plate 2a, and the friction of the wheel 2b are opposite to the direction in which the top drive mechanism 4 is driven. A friction reaction force 6a is generated in the direction. This friction reaction force 6a is different from the movement direction when the top plate drive mechanism 4 moves the top plate 2a in the direction of inserting the top plate 2a into the gantry 1 or when it moves out of the gantry 1. Occurs in the opposite direction. On the other hand, the manual retraction assisting force 6b for urging the pulley 4a by the manual retraction assist mechanism 5 always acts in the direction of moving the top panel 2a from the gantry 1 to the outside regardless of the movement direction of the top panel 2a.

  Therefore, when the top plate driving mechanism 4 moves the top plate 2a toward the inside of the gantry 1, the top plate is opposed to the combined force of the friction reaction force 6a and the manual retraction assist force 6b of the manual retraction assist mechanism 5. Move 2a. As the motor 4e with a brake of the top plate drive mechanism 4, a motor having a driving force 6c sufficiently larger than the friction reaction force 6a and the manual retreat assist force 6b is provided. After the top plate 2a is moved into the gantry 1, the position is held by the braking force of the motor 4e with brake. When the top plate driving mechanism 4 moves the top plate 2a from the inside of the gantry 1 to the outside, the top plate 2a is driven while being urged by the manual retraction assist force 6b against the friction reaction force 6a.

  When an emergency situation or a power failure occurs with the top plate 2a inserted in the gantry 1, the operator grasps and pulls the handle 22 of the top plate 2a and manually retracts it from the gantry 1. In the event of an emergency, the operator depresses the retract switch 21 on the side surface of the bed body 2e and releases the clutch 4b of the top plate drive mechanism 4, thereby disconnecting the pulley 4a from the brake-equipped motor 4e. In the case of a power failure, it is not necessary for the operator to operate, and energization of the clutch 4b is stopped and the release state is established.

  FIG. 5 is a diagram illustrating a relationship between forces acting on the top plate 2a when the top plate 2a is manually retracted. When the top plate 2a is manually retracted from the gantry 1, a friction reaction force 7a is generated as in the case where the top plate 2a is driven by the top plate driving mechanism 4, but the manual retraction assist mechanism 5 is provided with the top plate 2a. Since the manual retraction assisting force 6b is the same as the direction in which the operator pulls the top plate 2a by hand, the force 7b required for the operator is reduced by the manual retraction assisting force 6b.

  The manual retraction assisting force 6b is set to be smaller than the friction reaction force 7a in a state where the subject 3 is not placed on the top 2a. Therefore, the position of the top plate 2a is maintained even when the connection between the top plate 2a and the top plate drive mechanism 4 is released by the clutch 4b. The auxiliary force 6b can be set by adjusting the spring force of the constant load spring 5c.

  As described above, in the present embodiment, the manual retraction assist mechanism 5 always urges the top plate 2a in the direction of pulling out the top plate 2a without using electric power, and the motor 4e is opposed to the auxiliary force 6b in the normal state. Since the plate 2a is moved into the gantry 1, during manual retraction, the force 7b for manually pulling the top plate by the amount of the auxiliary force 6b is reduced, and the top plate 2a can be easily pulled out of the gantry 1 with a small force. be able to. Therefore, the burden on the operator can be reduced. Further, since the motor 4e needs to move the top plate 2a against the auxiliary force 6b, the load is slightly increased. However, since an electric motor having a sufficiently large driving force can be easily prepared, the movement of the top plate 2a There is no risk of affecting accuracy.

  Further, since the auxiliary force 6b is generated by a mechanical structure called the constant load spring 5c, the auxiliary force 6b can be retracted not only when the switch 21 is operated in an emergency but also during a power failure.

  In the present embodiment, the brake motor 4e of the top panel drive mechanism 4 is configured to operate under the control of the operation unit 23 of the MRI apparatus. However, an operation unit different from the operation unit 23 may be provided. Is possible.

Next, a medical image diagnostic apparatus according to a second embodiment will be described with reference to FIGS.
The medical image diagnostic apparatus according to the second embodiment is different from the first embodiment in that a manual retraction assist mechanism 8 for the bed 20 is provided separately from the top plate drive mechanism 4. The rest of the configuration of the bed 20 and the configuration of the MRI apparatus are the same as those in the first embodiment, and a description thereof will be omitted.

  The top plate drive mechanism 4 has the same configuration as that in FIG. 2, but the manual retraction assist mechanism 4 in FIG. 2 is not provided. In the second embodiment, as shown in FIG. 6, a manual retraction assist mechanism 8 is provided inside the bed main body 2 e separately from the top plate drive mechanism 4.

  As shown in FIG. 7, the manual retraction assist mechanism 8 includes a rope 8d, a drum 8a, drums 8i and 8b, and a constant load spring 8c. One end of the rope 8d is fixed to the top plate 2a by the top plate connecting portion 8e, and the other end is fixed to the drum 8a and wound. The drum 8i is connected to the drum 8a and a rotation shaft. The drum 8b is disposed to face the drum 8i. The constant load spring 8c has one end fixed to the drum 8i and the other end fixed to the drum 8b, and is wound respectively. The length of the constant load spring 8c is longer than the stroke length until the top plate 2a is completely pulled out from the gantry 1 to the outside. Moreover, the length of the rope 8d is also longer than the stroke length of the top plate 2a. As a result, the constant load spring 5c can pull the rope 8d in the direction in which the top plate 2a is pulled out with a constant load regardless of the position of the top plate 2a, and becomes an auxiliary force when the top plate 2a is manually retracted. . Therefore, the same effect as the first embodiment can be obtained.

  Further, the rope 8d has a pair of pulleys 8h, a pulley 8g, and a rotary encoder 8f disposed between the top plate connecting portion 8e and the drum 8a. The pulley 8g is rotated by the movement of the rope 8d, and the rotary encoder 8f detects the rotation amount. Therefore, the amount of movement of the top board 2a can be detected by taking the amount of rotation of the rotary encoder 8f into the calculation control unit of the MRI apparatus or a calculation unit separately received and converting the amount of rotation into a distance. Note that the amount of movement of the top plate 2a is used when the top plate 2a is moved normally by the top plate drive mechanism 4, not during manual retraction.

  As described above, according to the configuration of the second embodiment, as in the configuration of the first embodiment, not only the auxiliary force at the time of manual retraction is obtained, but also the manual retraction assist mechanism 8 has a top plate. A movement amount detection function can be added.

It is explanatory drawing which shows the structure of the medical image diagnostic apparatus of 1st Embodiment. In the medical image diagnostic apparatus of FIG. 1, it is explanatory drawing which shows schematic structure of the top-plate drive mechanism 4 of the bed. FIG. 2 is an explanatory diagram showing a schematic configuration of a manual retraction assist mechanism 8 of the bed 20 in the medical image diagnostic apparatus of FIG. 1. It is explanatory drawing which shows operation | movement of the top-plate drive mechanism 4 by 1st Embodiment. It is explanatory drawing which shows the operation | movement at the time of manual retraction of the top plate 2a by 1st Embodiment. It is explanatory drawing which shows the structure of the medical image diagnostic apparatus of 2nd Embodiment. It is explanatory drawing which shows schematic structure of the manual evacuation assistance mechanism 8 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gantry, 2a ... Top plate, 2b ... Wheel, 2c ... Connection metal fitting, 2d ... Timing belt, 2e ... Bed main body, 4 ... Top plate drive mechanism, 4a ... Pulley, 4b ... Electric clutch, 4c, 4d ... Gear, 4e ... Motor with brake, 5 ... Manual retraction assist mechanism, 5a, 5b ... Drum, 6a ... Friction reaction force, 6b ... Manual retraction assist force, 6c ... Driving force, 8 ... Manual retraction assist mechanism, 8a, 8b ... Drum, 8c ... Constant load spring, 8d ... Rope, 8e ... Top plate connection part, 8f ... Rotary encoder, 8g ... Pulley, 8h ... Pulley, 8i ... Drum, 20 ... Bed, 21 ... Retraction switch, 22 ... Handle, 23 ... Operation Part, 24 ... housing | casing, 25 ... imaging space.

Claims (6)

A medical image diagnostic apparatus comprising: an imaging device that images a subject; and a bed that moves the subject to the imaging space of the imaging device,
The bed includes a top plate on which a subject is mounted, a drive mechanism for driving the top plate, and an auxiliary mechanism for manually moving the top plate in a direction of retreating from the imaging space,
The auxiliary mechanism includes a release unit that releases the connection between the top plate and the drive mechanism, and a biasing unit that applies auxiliary force in the direction in which the top plate is retracted. apparatus.   The medical image diagnostic apparatus according to claim 1, wherein the drive mechanism includes a holding unit that holds a position of the top plate by a frictional force.   3. The medical image diagnostic apparatus according to claim 1, wherein the biasing unit is configured to always apply the auxiliary force, and the driving mechanism moves in a direction in which the top plate is inserted into the imaging space. In the case of performing the medical image diagnosis apparatus, the top plate is driven against the auxiliary force.   The medical image diagnostic apparatus according to claim 3, wherein the urging unit includes a constant-load spring that applies the constant auxiliary force regardless of the position of the top plate.   5. The medical image diagnostic apparatus according to claim 1, wherein the release unit is connected in an energized state and is released in an energized stop state, and stops energization of the electric clutch. A medical image diagnostic apparatus comprising a switch. The medical image diagnostic apparatus according to claim 1, wherein the auxiliary mechanism has a rope having one end connected to the top plate, and the auxiliary force is applied to the top plate via the rope. The one end of the rope moves as the top plate is driven by the drive mechanism,
The medical image diagnosis apparatus according to claim 1, wherein the rope is provided with detection means for detecting a movement amount of the rope.

Images