JPH0212574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control device for a movable body that improves safety.

One of the diagnostic devices is an X-ray fluoroscopic imaging device. This X-ray fluoroscopic imaging device is equipped with, for example, an X-ray television camera for fluoroscopy, an image intensifier for optical image conversion, and a spot shot device. is converted into an optical image, which is captured by an X-ray television camera and displayed as an image on a CRT (cathode ray tube) display device.

The bed top can be raised and lowered, and for example, a desired image can be obtained by raising and lowering the bed top while viewing the examination target area of a subject to which a contrast medium has been administered using the CRT display device. When obtained, a spot shot device is activated to take a photograph of the image.

An example of such a diagnostic X-ray fluoroscopic imaging device is shown in FIG. In the figure, 1 is a support base for supporting the entire device, 2 is a bed supported and held by this support base 1 so that it can be raised and lowered, and 3 is this bed 2.
A top plate for placing a subject is provided on the top plate so as to be movable in the longitudinal direction thereof, and 3a is a step board provided at one end of the top plate 3. 4 is an X-ray tube, and this X-ray tube 4 is supported by a support arm 5 provided on the side of the bed 2 so as to face the top plate 3.

Inside the bed 2, an imaging system such as an image intensifier, an X-ray television camera, and a spot shot device is provided opposite the X-ray tube 4, and these imaging systems are linked to the movement of the support arm 5. The X-ray tube 4 is always opposed to the X-ray tube 4.

This type of device can be used by placing your feet on the footboard 3a and
The subject is placed supine, the bed 2 is raised and lowered, and X-ray fluoroscopy and photography are performed.

The top plate 3 is movable in the directions indicated by arrows A-A' and B-B' in the figure, so that a desired region can be positioned within the X-ray irradiation field. Further, the entire apparatus including the bed 2 can be raised and lowered in the direction of the arrow C-C'. Top plate 3 A
In a standard device, the amount of movement in the -A' direction is 1000 mm to 1500 mm, and the tilting angle range of the bed 2 is about 105° to 180°.

By the way, in order to be able to arbitrarily select the diagnosis site, it is better to have a large movement amount of the top plate 3, and in order to arbitrarily position a contrast medium such as barium within the diagnosis site, it is better to have a large tilting angle range. good.

On the other hand, since the height of the top plate when the tilting angle is horizontal is a little less than 900 mm, when the top plate 3 is moved in the A-A' direction and the tilting operation is performed, the top plate 3 will appear as shown in Figure 2.
There may be interference between the floor surface FR or the top plate 3 and the ceiling.

In order to avoid this interference, the position of the top plate 3 and the bed 2
The tilting angle of the top plate 3 is usually detected by some kind of detector, and a malfunction prevention function is usually provided to prevent the above-mentioned interference from occurring due to the movement or tilting of the top plate 3.

Let us now consider the case of a conventional photo sensor, which is often used as such a detector.

Generally, a plate-shaped dog 6 is provided near one longitudinal side of the top plate 3 along the longitudinal direction of the top plate 3, as shown in FIG. The light emitting element and the light receiving element of the photo sensor 7 are made to face each other, and then the photo sensor 7 is fixed to the frame of the top plate 3.

In a detector having such a configuration, by moving the top plate 3, the dog 6 moves together with the top plate 3, and thereby the dog 6 blocks the optical path of the photo sensor 7 which is in a fixed position. By detecting this and using the detection output as a detection signal for reaching the movement limit of the top 3, the movement of the top 3 in the A-A' direction is stopped.

However, in this case, if the photo sensor 7 fails, the top plate 3 may move out of control, resulting in an accident. The failure of the photo sensor 7 is thought to include destruction of the light emitting element and destruction of the light receiving element. If the light emitting element is destroyed, it will cause a light emission failure, and if the light receiving element is destroyed, no detection output will be obtained, and especially when a photo transistor is used as the light receiving element, the leakage current will increase due to the destruction. Also, failure may be caused by disconnection of the lead wire of the photo sensor. Furthermore, not only optical detection using a photo sensor but also detection using a limit switch or the like may result in failure of detection.

The present invention has been made in view of the above circumstances, and it divides the movable area of a movable part such as a top plate into at least two in the moving direction of the movable body, and separates each of these divided movable areas. The configuration includes separate detectors for each detection area, and a circuit that generates an alarm output when the detection contents of these detectors match, and the position of the movable part is detected by the two detectors. The above drawback is solved by stopping the drive of the movable part or warning of danger when the detected contents are the same, and the movable part is moved beyond the limit of movement due to a failure of the detector. It is an object of the present invention to provide a drive control device for a movable body that prevents such problems from occurring.

4 to 8 regarding one embodiment of the present invention.
This will be explained with reference to the figures.

FIG. 4 is a perspective view showing the configuration of the detector portion of the present device, and 41 and 42 in the figure are L-shaped dogs.
Of the dogs 41 and 42, the former moves from Pa to Pb out of the entire movable area of the movable part indicated by Pa to Pc.
The latter is provided along the moving direction of the movable part over the section from Pb to Pc, and the latter is similarly provided at a position where its movement locus does not overlap with that of the former. 43,
A photo sensor 44 detects the dogs 41 and 42, a photo sensor 43 detects the dog 41, and a photo sensor 44 detects the dog 42. Also photo sensors 43, 44
are both fixedly disposed at the same detection position, and the dogs 41 and 42 are attached to the movable part in correspondence with the movable area of the movable part based on this detection position.

Therefore, if the movable part is in the movable area,
A dog is located on one of the photo sensors,
The optical path of the photo sensor is blocked. photo
When the optical path is not blocked, the output of the sensors 43 and 44 is, for example, logic "1"("H" level),
When shut off, logic is “0” (“L” level))
shall be.

Therefore, if the arrangement shown in FIG. 4 is adopted, when the output of the photo sensor 43 is "1", the output of the photo sensor 44 is "0", and when the output of the photo sensor 43 is "0", the output of the photo sensor 44 is "0". 44 becomes an output "1".

In other words, the photo sensors 43 and 44 will never be in the same output state, and if they are in the same output state, it is likely that the movable part has moved out of the movable range or that the photo sensor or the like has malfunctioned. become. In particular, failure of the photo sensor is not limited to only one case, but can be detected even when both of the photo sensors fail simultaneously due to excessive noise voltage or the like. That is, if the photo sensors 43 and 44 fail at the same time, it is presumed that they are in the same failure mode, so the outputs of the photo sensors 43 and 44 may both be "1", or may both be "0". Either of these is the case, and therefore it is determined that there is a failure.

A circuit for making the determination according to FIG. 5 is shown. In the figure, 43 and 44 are the photo sensors, LED is a light emitting diode as a light emitting element thereof, and PTR is a photo transistor as a light receiving element. Here, the photo sensor 44 is a sensor for detecting the head side movement limit of the vertical movement of the top plate, and the photo sensor 43 is used for backing up the photo sensor 44. Reference numeral 51 indicates a top plate head side movement switch for driving and moving the top plate toward the head side of the subject; 52 indicates the photo sensors 43 and 44;
input the photo transistor PTR output of
53 is an inverter that inverts the output of the exclusive OR gate 52, and 54 operates with the output of the inverter 53 as a base input.
An NPN type transistor 55 is a light emitting diode (LED) connected to the collector side of the transistor 54 for indicating a photo sensor failure.
This light emitting diode 55 has its anode side connected to a DC power supply of +15V via a resistor. Further, the emitter side of the transistor 54 is grounded, and when the transistor 54 is turned on, the light emitting diode 55 is lit, and the transistor 54 is turned on.
4 is turned off, the light emitting diode 55 is turned off. 56 is the exclusive or gate 52
A first AND gate 57 takes the logical product of the output of the photo sensor 44 and the output of the photo sensor 44, and a second AND gate 57 takes the logical product of the output of the AND gate 56 and the output of the top plate head side moving switch 51. 58 is a drive circuit that is operated by the output of the second AND gate 57 to generate a drive control output for the top plate; 59 is a drive circuit that is operated by the output of this drive circuit 58 to drive the top plate in the vertical direction. This is a motor for driving the top plate up and down. Note that the photo transistor 4
The anode side of the 3 and 44 light emitting diodes LEDs is connected to the DC power supply +15V via a pull-up resistor.
The photo transistor PTR has its collector side connected to a DC power supply +15V, and its emitter side grounded via a resistor.

Next, the operation of this apparatus having the above configuration will be explained.

Here, the photo sensor 43 is set so that the output becomes logic "0" when the top moves, for example, in the head side direction from the center of the bed within a distance _L1 , The photo sensor 44 is set so that the output becomes logic "0" when the top moves within a distance range _L2 in the foot direction from the center of the bed. When 51 is turned on, its output is set to logic "1". However, L ₁ and L ₂ are appropriate distance ranges that do not interfere with the ceiling or floor when the top plate is raised or lowered.

The operation will be explained under the above preconditions. First, the top plate should move toward the side of the head with the center of the bed as a reference.
Let us consider a case where the top plate head side moving switch 51 is turned on at a distance of L ₃ (0<L ₃ <L ₁ ). When both the photo sensors 43 and 44 are operating normally, the output of the photo sensor 43 is "0" and the output of the photo sensor 44 is "1". Since the inputs of the gate 52 are "0" and "1", its output is "1". Therefore, since the output of the inverter 53 that inverts the output of the exclusive OR gate 52 becomes "0", the transistor 5
4 is off, and the light emitting diode 55 does not light up. Furthermore, since the output of the exclusive OR gate 52 is "1" and the output of the photo sensor 44 is "1", the inputs of the first AND gate 56 are both "1", so the output is "1". The second AND gate 57, which receives this output and the output of the top plate head side moving switch 51, has both inputs as "1" and output as "1". Therefore, the drive circuit 58 for moving the top plate toward the head becomes active, and the top up/down drive motor 59 operates to move the top plate toward the head of the subject.

Next, when the top plate is at the L ₃ position, turn on the top plate head side movement switch 51 to move the top plate until the top plate reaches the L ₄ position (L ₃ < L ₄ < L ₁ ). Sometimes, for some reason, the photo transistor PTR of the photo sensor 43 is destroyed and the photo transistor
Let us consider the case where conduction occurs between the collector emitter of the PTR.

The relationship between the signals of each output is shown in a time chart as shown in FIG. 6, where t ₁ is the time when the top plate head side moving switch 51 is turned on, and t ₂ is the time when the photo sensor 43 fails. Incidentally, when the output of the inverter 53 is "1", the light emitting diode 55 lights up,
Further, when the output of the second AND gate 57 is "1", it indicates that the top plate is moving toward the head.

That is, initially the output of the photo sensor 43 is "0" (FIG. 6a) and the output of the photo sensor 44 is "1" (FIG. 6b), so the output of the exclusive OR gate 52 is as shown in FIG. "1" as shown in d
The output of the first AND gate 56 is "1" as shown in FIG. 6e, and the output of the inverter 53 is "0" as shown in FIG. 6f. The transistor 54 that is connected is off, and the light emitting diode 54 is in an extinguished state. In addition, the second top plate head side moving switch 5
Since the output of the AND gate 57 is "0" (FIG. 6c), the output of the AND gate 57 is "0", so the drive circuit 58
is inactive and the top plate is in a stopped state.

When the top plate head side moving switch 51 is turned on at time _t1 as shown in FIG. The output "1" and the output of this top plate head side moving switch 51 are input. Then, as shown in FIG. 6g, the second AND gate 57
The output becomes "1", so that the drive circuit 58 becomes active and the top vertical drive motor 59 is driven. As a result, the top plate begins to move toward the side of the head.

At time _t2 , when the photo sensor 43 has traveled a distance of _L4 , the photo sensor 43 fails and its photo transistor
When the emitter and collector of the PTR become conductive, the output of the photo sensor 43 becomes "1".
On the other hand, since the position is _L4 , the photo sensor 44
The output of is "1", and therefore, the output of the exclusive OR gate 52 which takes the exclusive OR of both becomes "0" as shown in FIG. 6d.

Therefore, the output of the inverter 53 which receives this as its input becomes "1" as shown in FIG. This indicates a failure. On the other hand, the output of the exclusive OR gate 52 and the photo sensor 4
The output of the first AND gate 56 that receives the output of 4 becomes "0" because the output of the exclusive OR gate 52 changes to "0", and thereby the output of the second AND gate 57 becomes "0". "become. Therefore, the drive circuit 58 stops operating, and the top vertical drive motor 59 also stops, so that the top is no longer driven.

In this manner, even if the top plate head side movement switch 51 is in the ON state, the movement of the top plate can be stopped at the time when the photo sensor 43 fails, and the light emitting diode 55 can be turned on for display.

The above operation is exclusive or gate 52
Since the input of 1 is aimed at the outputs of the photo sensors 43 and 44, the same result will occur even if the other photo sensor has a similar failure.

It can be seen from FIG. 6 that even if the top plate head side movement switch 51 is in the ON state, the movement of the top plate stops when the photo sensor fails.

Next, when the top plate is at the _L3 position, turn on the top plate head side movement switch 51 to move the top plate, and when the top plate reaches the _L4 position, the photo sensor 43
Let us assume that the light emitting diode LED in the phototransistor PTR is destroyed, causing a failure in emitting light, and that the collector and emitter of the phototransistor PTR are always in a non-conducting state.

In this case, the output of the photo sensor 43 is "0"
, and it is "0" even when it is normal, so the output state does not change even at the time of failure, as shown in Figure 7a, and therefore the top plate is still moving even after passing this failure position _L4 . It turns out.

However, if the top plate even slightly exceeds the limit point _L1 , the non-faulty photo sensor 4
4 changes from "1" to "0" as shown in FIG. 7b, the output of the exclusive OR gate 52 and the first and second AND gates 56, 57 as shown in FIG. 7d, e, and g. Since the outputs of all change to "0", the top plate stops.

In other words, the top plate is L ₁ toward the head and L ₂ toward the feet from the reference point.
It will not run out of control beyond the set allowable movement range.

Also, as the output of the exclusive OR gate 52 changes to "0", the inverter 53
The output is also " ₁ " at the L1 position as shown in Figure 7f.
As a result, the transistor 54 is turned on and the light emitting diode 55 lights up, indicating a failure. In addition, in FIG. 7, the time when the top plate head side movement switch 51 is turned on is _t1 , and the position of the top plate at that time is _L3 ,
The time when the photo sensor 43 fails is _t2 , the position of the top plate at that time is _L4 , and the time when the top plate reaches position _L1 is _t3 , and the outputs of each element are shown. In addition, the light emitting diode LED of the photo sensor 44
Even in the case where a light emission failure occurs, the exclusive OR gate 52 performs the same operation as described above.

A summary of the failure details and combinations of failures in the photo sensors 43 and 44 and the output relationship of each element at that time is as shown in FIG.

Therefore, with this device, a failure in the movable part position detection system can be quickly detected and stopped, so that such a failure can prevent the top plate from moving out of control and coming into contact with the ceiling or floor, damaging the device or the room, or injuring the patient. Accidents such as injury can be prevented.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope of the gist thereof. For example, a micro switch, a reed switch, etc. may be used as a position detector. In addition, the top board can be moved in different directions, such as the head side, the left and right sides of the feet, etc., and by combining it with a logic circuit and a logic circuit, the top board can be controlled. In addition to detecting the position, this device can also be applied to detecting the compression force of the compression tube used in X-ray fluoroscopic imaging.Furthermore, in the above embodiment, the movable areas are divided and each However, the entire movable area may be monitored simultaneously using different detectors.

In this way, the present invention divides the movable region of the movable body into at least two parts in the direction of movement of the nuclear movable body, and includes a detector that detects when the movable body is located in one of the regions, and a detector that detects when the movable body is located in one of the regions. A detector is provided to detect when the movable body is in the area, and a circuit that generates an alarm output when the output contents of both detectors match and the circuit for controlling the drive of the movable body is active, The area within the permissible movement range of the moving body is monitored by two detectors each targeting a different detection target area, and the output contents of the two detectors are always different in the case of normal conditions. At the same time, in the event that the detector fails, an alarm output is generated at least by utilizing the fact that the contents of the detector match immediately after exceeding the permissible movement range;
Since it is possible to stop the drive and display an alarm,
Driving a movable body with excellent safety features, such as preventing the occurrence of accidents such as the movable body exceeding its movement limit and running out of control even in the unlikely event that the detector malfunctions. A control device can be provided.

[Brief explanation of drawings]

Figure 1 is a perspective view showing an example of a diagnostic X-ray fluoroscopic imaging device, Figure 2 is a diagram showing interference with the floor due to the top plate position and tilting angle, and Figure 3 is a diagram showing the top plate and installation. FIG. 4 is a perspective view showing the relationship between the dog and the photo sensor in the apparatus of the present invention; FIG.
The figure is a circuit configuration diagram of the device of the present invention, and FIGS. 6 and 7 are time charts for explaining the operation of the device.
FIG. 8 is a diagram for explaining the output relationship of each element according to the situation of each photo sensor of this apparatus. 2...Bed, 3...Top plate, 41, 42...Dog, 43, 44...Photo sensor, 51...Top plate head side drive switch, 52...Exclusive or gate, 53...Inverter, 54 ...transistor, 55, LED...light emitting diode, 5
6, 57...AND gate, 58...Drive circuit,
PTR...Photo transistor.

Claims (1)

[Scope of Claims] 1. Driving a movable body having a function of detecting whether or not the movable body is within a movable region using a detector and preventing the movable body from being driven and moved outside of the region. In the control device, the movable region is divided into at least two in the moving direction of the movable body, and a detector is provided for each of these divided movable regions as a detection region, and each of these detection 1. A drive control device for a movable body, comprising a circuit that generates an alarm output when the detected contents of the device match.