JP2000051190A - Medical x-ray device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give natural feeling in moving work and improve the operability of a bed, or the like, by setting an operation input of the rigidity of a bed, a support mechanism, or an X-ray image detector to a value selected by an operation input rigidity selecting means and operating the bed, the support mechanism, or the X-ray image detector by the set operation input. SOLUTION: An operation input rigidity setter 15 is equipped in the front step of a force-position convertor (bed) 11 to convert an operation input instruction value to a position quantity onto a conventional control system. An operation input value is set by the operation input rigidity setter 15 so that the moving speed characteristics of the bed 11 become same as a case when the inertial force exists, and an operation feeling parameter of the operation input rigidity setter 15 is enabled to be selected by an operation input rigidity selector 16. The operation input rigidity setter 15 is equippe with, for instance, a means to give the outputted wave form a constant delay to an inputted waveform so as to give characteristics same as a case when inertial force exists. A method to generate a constant waveform delay by inserting a low pass filter into the means is considered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an X-ray diagnostic apparatus and an X-ray diagnostic apparatus.
The present invention relates to a medical X-ray apparatus such as an X-ray CT apparatus, and in particular, for positioning a diseased part of a subject or the like, a bed or X-ray tube apparatus on which the subject lies, and a support for supporting an X-ray image detector. The present invention relates to a medical X-ray apparatus having an operation means suitable for controlling movement of a mechanism or an X-ray image detector.

[0002]

2. Description of the Related Art Conventionally, a bed or an X-ray tube apparatus on which a subject of an X-ray diagnostic apparatus or an X-ray CT apparatus is placed, and a support mechanism for supporting an X-ray image detector or a moving operation of an X-ray image detector. For example, a patient bed of an X-ray CT apparatus will be described as an example.
The device performs the examination with the patient lying on the bed.

At the time of this inspection, it is necessary to control the position by which the bed is brought closer to an X-ray CT scanner equipped with an X-ray tube, an X-ray detector, etc. by driving a motor for controlling the movement of the bed by remote control. It was a device. However, in recent years IVR
As (interventional radiology) has become popular, the number of procedures for simultaneously performing treatment and examination by combining the X-ray CT apparatus and a circulatory organ X-ray examination apparatus capable of performing an angiography examination has increased. . In this system, the bed on which the subject lies is the same for X-ray CT and for angiography, in order to perform the entire procedure from examination to treatment without moving the subject. It is desirable to do.

[0004] For this reason, there has been an increasing demand for a bed on which a subject is to be laid while having both a function as a bed for X-ray CT and a function as a bed for angio examination.

That is, there has been a demand for a bed for X-ray CT which has a high speed and good positioning accuracy, and a bed for angiography inspection capable of freely floating in the front-rear direction and the left-right direction. FIG. 7 shows an example in which such a system is used to perform everything from examination to treatment. In this figure, a subject 50 is aligned with a scanner 51 of an X-ray CT apparatus, an examination is performed, and a diseased part of the subject is specified. (FIG. 7 (a))

Next, the couch 52 is moved while the subject 50 is placed thereon, and the X-ray tube 60 and the image intensifier I.I. I. 61 (here, the supporter of this combination is referred to as a C-arm supporter), insert a catheter into a blood vessel, and perform treatment while confirming the position of the catheter with this angiography apparatus. . (FIG. 7 (b))

[0007] At the time of examination and treatment of the foot-side part of the subject 50, such as the blood vessels of the lower limb, at the time of treatment, the bed 52 is moved to the head side to radiate the diseased part from the C-arm support. To the isocenter. (FIG. 7 (c))

At this time, a method of performing positioning by moving the C-arm supporter can be considered. However, since the C-arm supporter is large, not only the moving means becomes large, but also high-precision positioning is required. It is not suitable for this system. In this manner, the bed 52 is moved back and forth,
The diseased part is moved by moving it in the left-right direction (the X and Y directions in FIG. 7 (c)), and the procedure from inspection to treatment is performed.

Therefore, during such angio examination or treatment, the bed 52 can be freely operated manually in the front, rear, left and right directions. However, since the bed mechanism is large, the load is heavy and a large operation force is required. I do.

[0010] That is, the above bed control device uses the X-ray C
Since the control device is a position control device that satisfies the positioning control required for the T inspection, it is not possible to perform a delicate operation of manually moving the IVR required for the operation. Further, in a device for manually operating the couch, since the weight of the patient is applied, the operation force of the operator is large, and the couch is excessively moved by the influence of the inertia force when moved. It wasn't.

[0011] Therefore, during such angio examination or treatment, the bed can be freely operated manually back and forth, left and right, but the bed mechanism is large, so the load is heavy and a large operation force is required. In addition, the conventional bed control device has been a position control device that satisfies the high-speed positioning control required for the X-ray CT examination, so that it is not possible to perform the delicate operation of moving the hand required for the operation of the IVR. Furthermore, since the weight of the subject is added to the load of the bed, the operating force of the operator is large, and the bed is excessively moved due to the effect of the inertia force when moved. Absent. Therefore, in order to move the bed manually and lightly and freely with an operation force that also considers the weight of the subject, a method of detecting the operation force and controlling the operation force by feedback is disclosed in Japanese Patent Application Laid-Open No. Hei 8-280668. Is disclosed.

FIG. 8 shows a control system for controlling a vertical operation force of a bed disclosed in Japanese Patent Application Laid-Open No. 8-280668. A frame surrounded by a dotted line in FIG. 8 indicates a generally used position control system.

In the position control system, position detection means 13 such as an encoder (not shown) connected to the bed is used to detect a position signal 6 indicating a current position obtained by integrating an output pulse of the encoder, and a force detection of an operation input. A position deviation is obtained by subtracting the current position and the position obtained by adding the target position 4 to the position obtained by converting the operation input detected by the force detector by the force-position converter I1. The arithmetic unit 3, an amplifier 5 for amplifying the output of the arithmetic unit 3, an arithmetic unit 8 for obtaining a speed deviation between the output and a bed moving speed signal 10 described later, and driven by the output of the arithmetic unit 8 The bed driving motor 9, a bed 11 as a load that is moved by the rotation of the motor, an integrator 14 that integrates the speed of the bed 11 with time, and the speed information of the movement of the bed are detected and the calculation is performed. Table 8 Constituted by the speed detector 12 for negative feedback.

With the above configuration, in the ordinary position control, the current position is negatively fed back (position feedback) to the computing unit 3 in order to operate the bed to move to the given target position 4 so that the target position is obtained. 4, that is, the position deviation. Then, when there is a positional deviation, a rotational driving force of the motor is generated by the above configuration.

Therefore, the bed 11 continues to move until there is no positional deviation due to the position feedback. When the couch reaches the target position, the positional deviation disappears and the rotational driving force of the motor disappears, so that the couch stops at the target position. Here, the operating force of the operator pressing the bed is expressed in a form to be added to the rotational driving force of the motor that moves the bed, as shown in FIG.

However, in this state, the operating force is merely a disturbance to the bed and the target position does not change. Therefore, the operating force is canceled by the position feedback. Does not move.
Therefore, the force detector 7 is attached to the bed, and the operating force of the operator pressing the bed is detected.

Then, the detected operation force is converted into a position amount by the force-position converter I1, and is added to the target position. In this case, the magnitude of the position amount to be converted is determined in proportion to the magnitude of the input operating force. Thus, when the operation force is generated, the target position changes, and the rotational feedback of the motor is generated by the position feedback, and the bed moves. When the operation force input direction is made to coincide with the increase / decrease direction of the target position, the bed can be moved in accordance with the operation force input direction.

The rotational driving force (hereinafter referred to as an assist force) of the motor which is generated in response to the operation force is determined by the characteristic of the force-position converter I1. A large assist force is generated, and the operator can move the bed with a small operation force.

That is, the relationship between the operating force command value and the moving speed of the bed is such that when a large operating force is input, the moving amount of the bed increases in proportion to the input, and is converted to a target position farther from the current position, and becomes smaller. When the operation force is input, the movement amount becomes small and is converted to a target position close to the current position.

The position of the bed is controlled so as to reach these target positions. Since the target position farther from the current position has a larger position control deviation from the current position, the speed control deviation for driving the motor is smaller. The bed becomes larger and the bed moves faster. Conversely, the closer the target position is to the current position, the smaller the amount of positional deviation from the current position is. Therefore, the amount of speed control deviation for driving the motor becomes smaller, and the moving speed of the bed becomes slower. As described above, when a large operating force is input, the moving speed of the bed increases, and when a small operating force is input, the moving speed decreases.

[0021]

Here, it is assumed that an operation input command value having a step waveform as shown in FIG. 9A is input to the bed control device. Since the operation input command value is converted into a position amount by the above-described proportional relationship, the position deviation amount has the same step waveform as the operation input waveform as shown in FIG. Also, since the speed deviation amount is the same,
The moving speed of the bed also has a step waveform.

However, in the case of manually operating an ordinary familiar object, an inertial force naturally exists in the object according to its mass. Due to the action of the inertial force, the moving speed of the step waveform as in the case of the bed is not obtained.
For example, when the object is stationary, the inertial force is a force to keep the object stationary, while the inertial force is a force to keep the object stationary.
As shown in (c), the waveform rises as if a delay occurred. Further, due to the delayed portion of the rising edge of the waveform, an operation sensation occurs in which the object does not move yet and the reaction force of the applied force is felt in the palm of the hand, even though the operator continues to apply the force. However, in the bed, the bed control device compensates for the inertial force of the bed, and there is little delay in rising of the waveform. Such a difference is cited as a cause of unnatural operation of the bed, and the bed control method has not solved the problem.

That is, according to the above-described conventional method, it is effective to reduce the operation force of the operator and reduce the burden on the operator. However, the operation force of the operator and the moving speed waveform of the bed caused by this are effective. Since this relationship is fixed so that the delay in the rise of is minimized, it is not possible to obtain an operation sensation that satisfies all of the surgical procedure, the diseased site, and the operator.

[0024] This is usually when moving a familiar object.
The inertial force according to the mass of the object naturally exists, and the operation by our hands is more or less small, and the operation is performed while feeling the inertial force of the moving object with the hand. However, in the case of the bed, the inertia force is large due to its large mass, which causes a burden on the operation. Therefore, the inertia force is compensated by the bed control device, thereby reducing the operation force of the operator. As a result, the operation feeling becomes difficult to feel the inertial force. Therefore, there were some disadvantages shown below.

(1) Since the inertia force is compensated for by the bed control device, a natural operation feeling of handling a light object cannot be obtained even though the operation force is close to that of moving a light object. (2) Depending on the individual differences in the operation feeling of the operator and the operation method,
There are inconveniences such as excessively applying force because the inertia force is not felt much, and excessive positioning of the bed due to excessive travel. (3) In the case of doctors and technicians who usually have many opportunities to operate the couch, they naturally become accustomed to the operation of the couch, but nurses who do not operate the couch unless necessary in an emergency or an external doctor or An unspecified number of medical personnel, such as technicians, need to be accustomed to operating the bed, and it is inconvenient to operate the bed at any time.

As described above, in the conventional couch control device, the inertia force is large due to the large mass of the couch and the subject, and the operation burden is compensated. If the inertial force is completely compensated for, it is not always easy to handle, because the operation feeling is different from the case of operating a familiar object by hand.

Accordingly, an object of the present invention is to provide a bed or an X-ray tube apparatus on which a subject of an X-ray diagnostic apparatus or an X-ray CT apparatus is placed and a support mechanism for supporting an X-ray image detector or an X-ray image detection apparatus. A bed or X-ray tube device on which an unspecified number of persons who are involved in medical treatment give a natural feeling to the operation of moving the device, and easily support the subject, and a support mechanism or X-ray for supporting the X-ray image detector An object of the present invention is to provide a medical X-ray apparatus capable of handling an image detector and the like and improving operability of the bed and the like.

[0028]

An object of the present invention is to provide a bed on which a subject is laid, a support mechanism for supporting an X-ray tube apparatus and an X-ray image detector which are opposed to each other with the bed placed therebetween, Operation input detection means for detecting each operation input of the bed or the support mechanism or the X-ray image detector, and position detection means for detecting the position of the bed or the support mechanism or the X-ray image detector, The operation input detected by the operation input detection unit is converted into a position amount, and the amount of the position detected by the position detection unit matches the position amount obtained by adding the target position amount to the converted position amount. As described above, in the medical X-ray apparatus provided with the operating force control means for controlling the operating force of the bed, the supporting mechanism, or the X-ray image detector, the operating force control means includes the bed, the supporting mechanism, or the X-ray image detector. Is the operational sensation parameter of An operation input rigidity setting unit for setting the rigidity of the operation input, and an operation input rigidity selecting unit for arbitrarily selecting the rigidity of the operation input, the operation input rigidity of the bed or the support mechanism or the X-ray image detector. Is set to the value selected by the operation input rigidity selection means by the operation input rigidity setting means, and the bed, the support mechanism, or the X-ray image detector is operated by the operation input of the set rigidity.

Further, the operation input rigidity setting means is provided with means for automatically adjusting the rigidity of the operation input in accordance with the operation of the bed, the support mechanism, or the X-ray image detector. With this configuration, for example, in the case of the bed operation, the operation hardness, which represents the operation feeling of the bed operation,
The rigidity of the so-called operating force, such as softness, weight, and lightness,
Since it can be arbitrarily selected according to the surgeon's preference, the purpose of diagnosis and treatment, etc., the operability of the bed is further improved.

Further, the operation input rigidity setting means is provided with a means for automatically adjusting the rigidity of the operating force in accordance with the operation of the bed, so that the rigidity of the operating force is optimized according to the moving operation of the bed. Is automatically set to the value
The bed can be operated with a more natural operation feeling.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings, taking an example in which the present invention is applied to a bed operation. FIG.
FIG. 7 shows a control system for controlling the operation force of the bed according to the present invention.

This control system is provided with an operation input rigidity setting device 15 in front of a force-position converter I1 for converting an operation input command value into a position amount in the conventional control system of FIG. The operation input stiffness setting unit 15 can set an operation input value such that the parameter has the same characteristics as the case where there is inertia force, and the operation input stiffness setting unit 15 can select the operation sensation parameter with the operation input stiffness selection unit 16. Except for the operation input stiffness setting unit 15 and the operation input stiffness selector 16, the configuration is the same as that of FIG.

FIGS. 2, 3 and 4 show an operation input rigidity setting device 1.
5 shows the configuration and characteristics thereof.
In the operation input stiffness setting device 15, for example, in order to have the same characteristics as in the case where there is an inertial force, for example,
Means are provided for giving a constant delay to the output waveform.

As a means for this, a method of generating a constant waveform delay by inserting a low-pass filter can be considered. However, in order to make it possible to finely set the operational feeling, control based on compliance described later is used. Here, the compliance indicates the hardness when the surface of the object is pressed, and is expressed by a model as shown in FIG.

FIG. 2 shows an object P, a spring, and a damper. The mass of the object P is M [kg], and the elastic coefficient of the spring is K.
[N / m], and the viscosity coefficient of the damper is D [Ns / m]. When a force F [N] is applied to the object P, the object P is pushed in the direction of the applied force, and a displacement d [m] of the stationary position is generated. The displacement d is determined by a combination of the values of M, K, and D, and the temporal amplitude characteristic of the displacement d is also determined by the combination.

Here, the compliance value is represented by equation (1).

(Equation 1) From equation (1), the greater the displacement d caused by the applied force F, the smaller the compliance value, and it can be compared to a touch of pressing a soft object. The compliance value is determined by a combination of the values of M, K, and D. By adjusting the value, it is possible to change the operation feeling of the bed.

FIG. 3 shows that the step input force F
The waveform of the displacement d when the values of M, K, and D are changed is shown.
The relationship between the values of M, K, and D and the operational feeling will be described. As shown in FIG. 3A, when K is increased, the displacement d generated when the object P is pushed is small, and when K is decreased, the displacement d is increased. Here, the amount of dent generated when the surface of the object is pressed is referred to as the displacement d, and when K is compared with the operational feeling, when K is increased, the operational feeling of pressing a hard object is obtained. The operation feels like pressing. Next, when D is changed, as shown in FIG. 3B, the displacement d finally reached is the same, but the convergence time t required to reach the displacement d is different. Assuming that the movement of the object is slower as t is longer and faster as t is shorter, increasing D increases the feeling of operation and decreasing D decreases the feeling of operation.

As for the remaining M, as shown in FIG. 3 (c), the finally settled displacement d is the same. However, when M is increased, the rise of the waveform is delayed and vibration occurs. Rises quickly and no vibration is seen. From this, M is related to the frequency at which the waveform converges and the behavior of the object, and when M is increased, the operation feel is restless. As described above, by adjusting the compliance value by changing the values of M, K, and D, it is possible to finely set the operation feeling.

Next, the above-described model based on compliance can be realized by the configuration shown in FIG. A frame surrounded by a dotted line indicates the operation input rigidity setting device 15 and is configured by a microcomputer, thereby enabling simplification of a circuit, complicated calculation, and signal processing.

As shown in FIG. 4, the operation input command value is input as the force F. Next, a feedback value of a reaction force fk by a spring described later and a damping force fd by a damper are added to the force F by the adder 17. Then, the divider 1
The acceleration a of the object P is calculated by dividing the mass M by 8. Then, the next stage of the integrator 19 integrates the acceleration a with time to calculate the velocity v.

Since the damper is a mechanical system responding to a change in the speed of the object P, the speed v is multiplied by the viscosity coefficient D by the multiplier 20 to calculate the damping force fd by the damper. Feedback to On the other hand, the displacement d of the object M is obtained by integrating the speed v with the integrator 21 over time. Finally, since the spring is a mechanical system responding to a change in the position of the object P, the calculated displacement d is multiplied by the value of the elastic coefficient K by the multiplier 22,
The reaction force fk by the spring is calculated and fed back to the adder 17. Next, in the operation input stiffness setting device 15 having the above-described configuration, the displacement d when the operation input command value of the step waveform is input is shown in FIG. Show.

In this figure, when the two are compared, when the operation input stiffness setting device 15 is used, a delay occurs in the rise of the waveform, and the delayed portion is similar to the inertia force to the operator. Can give a feel. Further, the rising characteristic is a delay of the control based on the compliance. By adjusting M, D, and K, the operation feeling can be changed.

For example, in the case where importance is placed on the safety of the bed operation and the feel of an operation heavier than the current state is given, the value of the viscosity coefficient D may be increased. On the other hand, when the moving distance of the bed is long and a light operation feeling is required, the value of the elastic coefficient K may be reduced. Thus, by changing the values of the parameters M, D, and K and adjusting the compliance value,
Various operating feelings can be set.

As described above, various operational feelings can be set by changing the values of the M, D, and K parameters.
The operation feeling that the operator feels comfortable is different. In addition, the person who operates the bed is not only a doctor, but also a technician who assists the doctor,
There are cases such as nurses, and an unspecified number of people often operate the bed.

For example, when a person who is not accustomed to the operation of the bed operates the bed, the operation feeling of the bed is softer and softer, so that the operation becomes easier to use and easier to handle. On the other hand, for people who frequently operate the couch, it is more responsive and stiff to operate the couch more accurately and faithfully according to the operation amount of the operator. Excellent. Next, even if the operator is the same, if the operative procedure or diseased part is different, the required operation feeling of the bed may be different. For example, it is easier to handle the positioning of the distal end of the catheter by giving importance to the safety of the operation and giving it a feel of a duller and heavier operation than in the current situation in order to perform a fine operation. When the amount of operation of the bed is large, such as when the catheter is moved all at once, the operation becomes lighter with a lighter operation feeling.

As described above, it is possible to set various operation feelings by changing the values of the parameters of M, D, and K. However, if the parameters of M, D, and K are fixed,
It is not possible to obtain an operation sensation that satisfies all of a surgical procedure, a disease site, and an operator. Therefore, as shown in FIG. 1, the values of the parameters of M, D, and K of the operation input stiffness setting device 15 can be changed each time according to a surgical procedure, a diseased site, or an operator. An operation input rigidity selector 16 is provided. The operation input stiffness selector 16 includes means for outputting the values of M, D, and K parameters to the outside as electric signals in accordance with the operation feeling selected by the operator.
It is connected to the operation input stiffness setting device 15 to change the values of M, D, and K parameters.

FIG. 6A shows a specific example of the operation input rigidity selector 16. FIG. 6A shows an apparatus using a generally used trackball, which is an input device using a ball. The sphere is semi-fixed to the input device, and the sphere can be freely rotated back and forth and left and right by manual operation.

The spherical surface has a marker indicating the rotation angle and position of the sphere. In addition, the rotation of the sphere is divided into two axes of the front-back direction and the left-right direction, and the position of the marker is indicated by the position of the two-axis rotation angle. Also, in conjunction with the rotation of the sphere, an electric signal such as a voltage or a pulse indicating the rotation angle of the marker is output to the outside. For example, when the marker is moved in the front-rear direction, the rotation angle of the sphere in the front-rear direction changes, and the change is converted as an electric signal such as a voltage or a pulse and input to the operation input rigidity setting device 15. And
The operation input stiffness setting device 1 is linked with the increase or decrease of the electric signal.
The value of the viscosity coefficient D of 5 increases or decreases. Here, FIG.
As shown in (2), D is increased as the marker position is closer to +90 degrees in the forward direction, and D is decreased as the position of the marker is closer to -90 degrees in the backward direction. Further, the movement of the marker in the left-right direction is similarly converted into an electric signal and input to the operation input rigidity setting device 15. Then, the value of the elastic coefficient K increases / decreases in conjunction with the increase / decrease of the electric signal. Similarly to D, K is increased as the position of the marker is closer to +90 degrees in the right direction, and is decreased as the position of the marker is closer to -90 degrees in the left direction.

When the marker is set at the center position, standard K and D values are set in advance. In addition, the value of M is fixed here. For example, when a person who is not accustomed to operating the couch operates, the operation feeling of the couch is heavy and soft, so that the operation is easy to use and easy to handle. In such a case, it is necessary to increase the D value or decrease the K value. In some cases, it is also effective to add and adjust both of them.

In this case, in the operation input stiffness selector 16, as shown in FIG. 6B, in order to make the operation feel heavy, the marker may be moved in the forward direction (+90 degrees).
Then, the D value of the operation input stiffness setting device 15 increases in conjunction with the increase in the rotation angle in the front-back direction, and the operation feeling becomes heavy. Similarly, to soften the operation feeling, the marker may be moved to the left (-90 degrees). Then, the K value of the operation input stiffness setting device 15 decreases in conjunction with the decrease in the rotation angle in the left-right direction, and the operation feeling becomes soft. Also, it is possible to make the marker soft and light, and if the marker is moved diagonally as shown in FIG. 6 (c), the rotation angle in the front-back and left-right directions changes. 15 K value and D value are changed,
The feel of operation is soft and light. Further, if the rotation angle is adjusted, the softness and lightness can be further adjusted. On the other hand, in the case of a person who frequently operates the couch, the operation feeling of the couch is more sensitive and harder, so that the couch can be accurately and faithfully moved according to the operation amount of the operator. In such a case, it is necessary to reduce the D value or increase the K value.

In some cases, it is also effective to add and adjust both of them. In this case, in the operation input stiffness selector 16, in order to make the operation feeling sensitive, the marker is moved backward (-90 degrees), or
By moving to the right (+90 degrees), a hard and sensitive operation feeling can be obtained. In addition, if the marker is moved backward (-90 degrees) and rightward (+90 degrees), the marker moves obliquely, and both the K value and the D value change, so that the operation feeling is sensitive and hard.

Next, even if the operator is the same, if the operative procedure or the diseased part is different, the required operation feeling of the bed may be different. For example, it is easier to handle the positioning of the distal end of the catheter with a heavier operation feeling than the current state, with an emphasis on the safety of the operation in order to perform a fine operation.

In this case, by moving the marker in the forward direction (+90 degrees), the D value of the operation input stiffness setting device 15 increases, and the operation feeling can be increased. When the amount of operation of the bed is large, such as when the catheter is moved all at once, the operation becomes lighter with a lighter operation feeling. Even in this case, by moving the marker in the backward direction (-90 degrees), the D value of the operation input rigidity setting device 15 becomes small, and the operation feeling can be reduced.

In the above embodiment, as shown in FIG. 9 (c), by using a generally known compliance control, a constant delay is given to the moving speed waveform, so that a natural operation can be performed. As in the case of the operation, an operation for feeling the inertial force can be realized. Further, the constant delay can be adjusted by a control parameter in the compliance control, and the operator can adjust the operation sensation by arbitrarily setting the value according to the operation sensation desired by each operator. can do. The values of the control parameters are fixed irrespective of the operation status of the table after being set by each operator. Therefore, it is possible to further improve the following points to make the operation feeling more natural. it can.

(1) If the control parameters are fixed irrespective of the operation of the table, acceleration is not as good as in the case of a natural operation, and the whole operation lacks lightness of operation. Is concerned. (2) Also, the combination of control parameter values considering safety when the table speed is high is different from the combination of control parameter values considering comfort of operation when the table speed is low, and the control parameters are fixed. If they do, safety and comfort cannot be achieved at the same time, making optimization difficult.

As described above, if the control parameters are fixed irrespective of the table operation, there is room for improvement in the operation feeling that satisfies all of them.

By giving a certain delay to the operation force command value by the above compliance control, an operation that feels the inertial force can be realized. However, when compared with the movement when a natural object is pushed, the same operation is performed. Not a movement. In general, a motion when a natural object is pressed is an acceleration motion of F = M × a. Here, assuming that there is constant friction,
Assuming that there is a force input shown in FIG. 9A, the movement of the natural object increases as shown in FIG. 10A until the operation input becomes zero, and then gradually decelerates due to friction. And the waveform stops.

On the other hand, in the above-described compliance control, since all the forces applied to the object P having a certain mass are not converted into velocity, as shown in FIG. Unlike the above, the speed does not increase until the operation input becomes zero, and the rising of the waveform is slow.

That is, in the compliance control, all the forces applied to an object having a certain mass are not converted into acceleration, so that the acceleration is worse than that of a natural object. The reason why the acceleration is reduced is that the force for pushing the object is reduced by the reaction force of the spring and the damping force of the damper generated when the object having a certain mass is pushed. Therefore, in order to convert all the force applied to the object into acceleration, K and D can be made zero and the reaction force of the spring and the damping force of the damper can be eliminated. However, for operational safety reasons, FIG.
It is not very desirable that the speed continues to increase as shown in FIG.

Therefore, when the speed of the table is low, the K value is set to zero to improve the acceleration of the operation, and when the speed of the table is high, a constant K value is given so that the speed does not increase beyond a certain speed. It is necessary to limit the increase in speed and to make the control parameters variable in accordance with the operation of the table.

Therefore, in the above compliance control, the value is fixed to a constant value regardless of the operation of the table.
The control parameters of the compliance control are adjusted as shown in FIG. That is, the operability can be further improved by using the variable compliance control. As an example of the variable compliance control, an example in which the value of the elastic coefficient K is adjusted based on the moving speed of the table will be described.

FIGS. 10 and 11 are diagrams for explaining the difference between the case where the control parameter of the compliance control is fixed and the case where the control parameter is variable. In the case where the control parameters are made variable, M and D are set to constant values regardless of the table speed, and K is made variable. About that K, FIG.
As shown in (a), it changes in proportion to the table moving speed. When the table moving speed is zero, K is also set to zero.

In the above control parameters, FIG.
FIGS. 10B and 10C show moving speed waveforms when the operation input shown in FIG. 10 (b) and 10 (c), comparing the waveforms when K is fixed and when it is variable, when K is variable, the rise of the waveform is faster and the acceleration at the start of operation is higher. Is improved. Further, the rise of the waveform coincides with the rise of the acceleration motion, and it is more natural when K is variable. In addition, in the acceleration motion, as long as the operation input continues, the speed increases, but when K is made variable, the K increases in proportion to the speed. Eventually, the speed settles to the same value as when K is fixed, and the speed is limited without continuing to increase as in the acceleration motion. The finally settling speed is determined by the relationship between K and the operation input. The larger the maximum value of K, the lower the speed. Therefore, when importance is placed on the safety of the speed rather than the acceleration of the operation, setting the maximum value of K to a large value limits the speed and enables safe operation. In the above-described example, K is made variable in proportion to the table speed.
As shown in FIG. 1B, it is also an effective method to use a non-linear function such as a sine function and an exponential function.

FIGS. 12 and 13 show waveforms of the moving speed when the section where K = 0 is made longer than the speed of the table. As shown in FIGS. 12A and 12B, K
As the section of = 0 is the longest (speed 0−V2), the section of the same acceleration as the acceleration motion is longer, and the natural operation is continued. Therefore, if a natural operation feeling is desired over a wide speed range, the section of K = 0 may be lengthened.
Next, FIG. 13B shows the moving speed when the size of the operation input is changed as shown in FIG. 13A in the case where the section of K = 0 is the longest (speed 0−V2). 3 shows the waveforms of FIG. As shown in FIG. 13B, the speed increases to the upper limit (Vmax) for any operation input. Although this is a feature of acceleration motion, it cannot be realized when the conventional control parameters are fixed.By making the control parameters variable, a high speed can be obtained even with a small operation input. , Operation becomes lighter. In this way, by varying the control parameters, the compliance control motion can be approximated to a natural acceleration motion. Further, in the example described above, K is made variable, but it is also possible to apply M and D similarly. In addition, the value of K is adjusted in proportion to the table speed. However, it is also effective to adjust the control parameters using the acceleration of the table, the magnitude of the operation input, and the like.

Next, the above-described compliance control with variable control parameters, that is, variable compliance control, can be realized by the configuration shown in FIG. Also,
A frame surrounded by a dotted line indicates the operation input stiffness automatic adjuster 15 ', and by performing the operation with a microcomputer, simplification of a circuit, complicated calculation, and signal processing are enabled. Here, following the above-described example, the configuration will be described by taking as an example a case where M and D are fixed and K is adjusted in proportion to the table speed. As shown in FIG. 14, the operation input command value is substituted as the operation input F. next,
A feedback value of a reaction force fK by a spring and a damping force fd by a damper, which will be described later, is added to the operation input F by the adder 17. Then, the divider 18 divides by the value of the mass coefficient M to calculate the acceleration a of the object having the mass M. Then, the next stage of the integrator 19 integrates the acceleration a with time to calculate the velocity v. Since the damper is a mechanical system that responds to a change in the velocity of the object having the mass M, the multiplier 20 multiplies the velocity v by the viscosity coefficient D to calculate the damping force fd by the damper. give feedback. On the other hand, the displacement d of the object having the mass M can be obtained by time-integrating the velocity v by the integrator 21. Finally, since the spring is a mechanical system responding to a change in the position of the object having the mass M, the displacement d
Then, the multiplier 22 multiplies the value of the elastic coefficient K adjusted according to the speed of a table described later to calculate the reaction force fK by the spring and feeds it back to the adder 17.

Next, a configuration for adjusting K according to the speed of the table will be described with reference to FIG. As an input indicating a table operation, the position-speed converter 31 calculates the table speed using the calculated displacement d. Alternatively, the actual moving speed of the table can be obtained by speed detecting means such as an encoder provided on the table, and this can be input (not shown).
Next, the calculated table speed is used as the zero hold unit 29 in the next stage.
, A process for setting the moving speed to zero is performed according to the zero hold value output device 30. As shown in FIG. 15D, when the input speed is lower than the zero hold value + v and higher than the zero hold value -v, the output of the output unit is set to zero. The zero hold value output unit 30 is for inputting and setting the zero hold value v of the zero hold unit 29.
As shown in (c), the operator can arbitrarily set the value using a variable resistor. FIG. 12A shows the zero hold unit 29 and the zero hold value output unit 30.
As described above, the section of the speed where K = 0 can be set, and the acceleration of the operation can be adjusted. next,
The speed output from the zero hold unit 29 is input to a plurality of gain calculators 26, 27, and 28 at the next stage. For example, as shown in FIG. 16 (b), the gain calculator 26 outputs a gain from 0 to 1 according to the input speed. When the speed of the table is zero, the gain outputs zero. The gain increases in proportion to the increase, and becomes 1 when the speed is the maximum speed Vmax. The output characteristics of the gain include those shown in FIGS. 16C and 16D in addition to the above.
A non-linear function such as a trigonometric function or an exponential function may be used. Note that these gain calculators 26, 27, 28
It is selected by the selector 25 shown in the next stage. This selector 2
Regarding No. 5, as shown in FIG. 16A, the operator can arbitrarily select the gain characteristic by switching the switch. On the other hand, the maximum elastic modulus value output device 2
In step 4, as shown in FIG. 15B, the maximum value of the elastic coefficient K of the compliance control is set and input. Further, as shown in FIG. 15A, the operator can arbitrarily set the value using a variable resistor. Thereby, as shown in FIG. 10, the maximum speed of the table is determined by the relationship between K and the operation input, and is limited by the maximum value of K, so that the speed safety can be adjusted. As described above, the multiplier 23 multiplies the output gain of the gain calculator by the maximum value of the maximum elastic modulus,
The value of K used in the compliance control is determined. The value of K changes according to the output gain value of the gain calculator. Further, as described above, since the gain takes a value in the range of 0 to 1, the value of K varies from 0 to the value set and input by the maximum elastic modulus output device according to the gain. In addition, since the value of the gain changes following the table speed, when the table speed changes, the K value of the compliance control also changes following the change in the gain. Therefore, for changes in table speed,
Automatic adjustment can be performed so that the K value takes an optimum value.

With the above configuration, variable compliance control can be realized, and according to the operation of the table,
Since the operation input rigidity can be automatically adjusted so as to be the most optimal, a natural operation feeling can be obtained. Next, an operation example using such variable compliance control will be described.

Here, following the above-described example, a case where M and D are fixed and K is adjusted in proportion to the table speed will be described as an example. Note that the section where K = 0 is set to 0−V1. When the table is stopped,
The K value is 0 because the gain output of the gain calculator in FIG. 14 is 0. Therefore, as described above, when K is 0, all of the pressed force is converted into acceleration, and there is no loss of force. Therefore, when the table starts to be pushed, the bed efficiently accelerates and moves lightly. When the bed is continuously pressed with a constant force, the speed of the bed increases. Here, the section where K = 0 can be set by the zero hold value output unit shown in FIG. 15C, and since it is set to V1, K = 0 until the bed speed reaches V1. Is maintained. In other words, until the speed of the couch reaches V1, all the pressing force becomes an acceleration motion that is converted into an acceleration, so that a natural and light state continues. Further, when the bed continues to be pushed and the speed of the bed exceeds V1,
An output speed other than zero is generated from the zero hold unit shown in FIG. 15C, and the gain of the gain calculator is not zero. Therefore, the state of K = 0 is lost, the value of K is generated according to the speed, and a reaction force by the spring is generated. Then, due to the reaction force, the pushing force is reduced, so that the acceleration of the bed is reduced, and the increase in the speed starts to slow down.

Thereafter, when the push is further continued, the value of K increases with an increase in the speed, and the pushing force is greatly reduced. Therefore, the acceleration of the bed is further reduced, and the increase in the speed is greatly reduced. Finally, at the time when the pressing force and the reaction force of the spring are equally balanced, the table speed keeps a constant value, and the speed does not further increase even if the pressing is continued. This speed can be adjusted by setting the maximum value of K in the maximum elastic modulus value output device shown in FIGS.

As described above, K of the compliance control
Is automatically adjusted according to the speed of the table,
Since the operation input rigidity is automatically adjusted so as to be the most optimal, a natural operation feeling can be obtained. If a lighter state of the acceleration movement that operates in the same manner as the movement of the normal object is further required, turn the volume of the variable resistor shown in FIG. By widening the section of the speed in which the state of 0 is maintained, the natural and light state is maintained for a long time.

On the other hand, when importance is placed on safety so that the speed does not increase too much, the resistance of the variable resistor shown in FIG. 15A is turned to a value lower than the standard value to increase the maximum value of K. By setting, the speed can be suppressed.
As described above, since the operation feeling that the operator is most comfortable to operate is set by the operation input stiffness automatic adjuster, the control parameters are automatically set. The bed can be operated in a state where the operation feeling is most suitable.

The case where the present invention is applied to the bed of the X-ray diagnostic apparatus has been described above. However, other than the bed, an X-ray tube apparatus, a support mechanism for supporting the X-ray image detector, an X-ray image detector, or the like. It goes without saying that the present invention can be applied to not only the moving operation but also the operation of a bed other than the X-ray diagnostic apparatus, for example, a bed such as a magnetic resonance imaging apparatus or an apparatus requiring a moving operation other than the bed.

[0073]

As described above, according to the present invention, the operation input stiffness, which is most easily operated by the operator, is set to the value selected by the operation input stiffness selector by the operation input stiffness setting device. The bed can be operated with an operation feeling suitable for the user's preference and operation method. Further, by providing a means for automatically adjusting the parameter for determining the rigidity of the operation force in accordance with the table operation, a more natural operation feeling can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a control system of a control device in which the present invention is applied to a bed.

FIG. 2 is a diagram illustrating a control model based on compliance.

FIG. 3 is a relationship diagram between time and displacement when a compliance control model constant changes.

FIG. 4 is a diagram showing a configuration of a control system of the operation input rigidity setting device of the present invention.

FIG. 5 is a diagram showing the relationship between time and displacement when the operation input rigidity setting device of the present invention is used.

FIG. 6 is a diagram showing a specific example of an operation input rigidity selector according to the present invention.

FIG. 7 is a diagram showing an example of a system in which a circulatory organ X-ray inspection apparatus and an X-ray CT apparatus are combined.

FIG. 8 is a configuration diagram of a control system of a conventional control device.

FIG. 9 is a diagram illustrating a difference between control in which inertia force is compensated and control in consideration of inertia force.

FIG. 10 is a diagram showing a difference between a case where the elastic coefficient of compliance control is fixed and a case where the elastic coefficient is variable.

FIG. 11 is a diagram illustrating a relationship between a table moving speed and an elastic coefficient in compliance control.

FIG. 12 is a diagram showing a difference in a moving speed waveform of a table in which a section where an elastic coefficient of compliance control is zero is used as a parameter.

FIG. 13 is a diagram illustrating a difference in a moving speed waveform of the table when the operation input is different in the variable compliance control.

FIG. 14 is a diagram showing a configuration of a control system of the operation input stiffness automatic adjuster of the present invention.

FIG. 15 is a diagram showing specific examples of elements of the operation input stiffness automatic adjuster of the present invention and their characteristics.

FIG. 16 is a diagram showing a gain calculator and its characteristics of the automatic operation input stiffness adjuster of the present invention.

[Explanation of symbols]

 Reference Signs List 1 force-position converter I 4 force-position converter II 7 force detector 12 speed detection 13 position detection 15 operation input stiffness setting device 15 'operation input stiffness automatic adjuster 16 operation input stiffness selector 50 subject 52 patient Sleeper (patient table)

Claims (2)

[Claims] 1. A bed on which a subject is laid, a support mechanism for supporting an X-ray tube apparatus and an X-ray image detector arranged opposite to each other with the bed therebetween, and the bed or the support mechanism or X-ray An operation input detection unit that detects each operation input of the image detector; and a position detection unit that detects each position of the bed or the support mechanism or the X-ray image detector. Convert the operation input to the position amount,
The operating force of the bed or the support mechanism or the X-ray image detector is controlled so that the amount of the position detected by the position detecting means matches the amount of the position obtained by adding the amount of the target position to the amount of the converted position. Input X-ray apparatus, comprising: an operation input rigidity setting unit configured to set an operation input rigidity, which is an operation feeling parameter of the bed, the support mechanism, or the X-ray image detector, in the operation force control unit. And operation input rigidity selection means for arbitrarily selecting the operation input rigidity, wherein the operation input rigidity of the bed or the support mechanism or the X-ray image detector is set to a value selected by the operation input rigidity selection means. A medical X-ray apparatus, which is set by the operation input rigidity setting means, and operates the bed, the support mechanism, or the X-ray image detector with the operation input having the set rigidity. 2. The operation input stiffness setting means includes means for automatically adjusting the stiffness of the operation input in accordance with the operation of the bed, the support mechanism, or the X-ray image detector. 4. The medical X-ray apparatus according to claim 1.