JPH0456270B2 - - Google Patents

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a ring-type ECT device.

(b) Prior art A ring-type ECT device uses a computer to process data obtained by arranging a large number of radiation detectors in a ring shape around a subject to detect radiation emitted from within the subject's body. This method reconstructs an image of the distribution of radioactive substances within the body of a subject as a tomographic image, but depending on the radionuclide used, or especially in the case of whole body detection, the detection site may vary, such as the head or various parts of the body. Accordingly,
Collimator needs to be replaced. However, because the collimator is made of radiation-shielding materials such as lead, it is extremely heavy, weighing over 100 kilograms.
Replacement work is not only not easy but also dangerous.

(C) Purpose This invention provides a ring-type collimator that allows several types of collimators to be replaced safely, reliably, and easily.
The purpose is to provide an ECT device.

(D) Configuration In the ring type ECT device according to the present invention, in addition to the gantry containing a large number of detectors arranged in a ring shape, a cart can be freely connected to the gantry, and the cart can be connected to the gantry. , so that it can be moved to a position away from the gantry when the connection with the gantry is released. The cart is provided with a plurality of support arms that respectively support a plurality of collimators prepared according to the detection site of the subject and the type of radionuclide, and the gantry can be connected to the support arms. Provide a connecting arm. One of the support arm and the connecting arm is provided with a projectable shaft, and the other is provided with a hole for receiving this shaft. Further, a locking mechanism is provided which locks the shaft when the supporting arm and the connecting arm are brought into contact with their end surfaces and the shaft protrudes from one side and enters the hole of the other. and the connecting arm are connected such that their end surfaces are abutted against each other and the collimator can be delivered. When connected in this way, the collimator is transferred from the support arm of the truck to the connection arm of the gantry or vice versa, and the collimator attached to the gantry can be replaced. After the exchange is complete, this connection is released and the truck is moved away from the gantry.

(E) Embodiment In FIG. 1, the gantry 1 includes a large number of radiation detectors (see radiation detector 12 in FIG. 3) arranged in a ring shape around a tunnel 11 provided in the center of the gantry 1. , these detectors can be tilted, rotated,
It has a built-in mechanism that provides movements such as extortion. The bed 2 moves the subject 3 up and down and back and forth, and inserts the subject 3 into the tunnel 11 of the gantry 1. The truck 4 is placed on a rail 41 that reaches up to the gantry 1, and various collimators 5 are supported by a plurality of support arms 6 attached to a rotatable column 42, respectively. The gantry 1 is provided with a connecting arm 7 for connecting to the supporting arm 6 of the cart 4 that is brought close.

More specifically, as shown in FIG. 2 and FIG. I am now able to move away. A hole 44 is provided in the floor, and when the carriage 4 is in the backward position with respect to the gantry 1, a pin 45 of the carriage 4 is inserted.
enters this hole 44 to fix the carriage 4 in this position. A disk 46 is attached to the rotatable column 42 so that the disk 46 rotates together with the column 42. A groove 47 is provided in the disc 46 corresponding to the direction of the support arm 6, and the direction of the support arm 6 is determined by fitting the pin 45 into this groove 47. The support arm 6 supports the collimator 5 so that the center of the collimator 5 is at the same height as the center of the ring of the radiation detector 12 of the gantry 1. The connecting arm 7 of the gantry 1 is connected to this support arm 6.
It is located at a position corresponding to Note that FIG. 3 shows a state in which one collimator 5 is attached to the gantry 1, that is, a state in which the collimator 5 is arranged inside the ring of the radiation detector 12 and concentrically with this ring.

As shown in FIGS. 4 and 5, the support arm 6 has rails 61 on its lower surface and both side surfaces, and the support arm 6 penetrates through the through hole 51 of the collimator 5, and has a rail 61 on the inner surface of the through hole 51. The provided wheels 52 sandwich the rails 61 so that the collimator 5 can move along the support arm 6. A stopper 63 is provided at the tip of the support arm 6 to prevent the collimator 5 from coming off. Similarly, the connecting arm 7 is provided with a rail and a stopper 73.

The supporting arm 6 and the connecting arm 7 are provided with a mechanism for connecting them to each other. That is, as shown in FIG.
1, and this shaft 8 is constantly pulled in the direction of recess into the connecting arm 7 by a tension spring 81. This axis 8
A knob 82 is fixed to the knob 8.
2 protrudes outward from a long groove 72 provided in the connecting arm 7, and the engagement between this knob 82 and the long groove 72 prevents the shaft 8 from rotating and limits the amount of sliding in the length direction of the shaft 8. be done. A permanent magnet 83 is attached to the rear end of the shaft 8, and a magnetically sensitive switch 84 fixed inside the connecting arm 7 detects whether the shaft 8 is in the retracted position or the extended position. ing. A retainer 74 for holding a stopper 73 is attached to the upper surface of the connecting arm 7. The stopper 73 has a lock pin 7 at its lower end.
5, and is biased by a compression spring 76 in the direction in which the stopper 73 pops out. In addition, the support arm 6
A hole 62 for receiving the shaft 8 is formed at the tip thereof, and a stopper 63 held by a retainer 64, having a lock pin 65, and biased in the projecting direction by a compression spring 66 is provided on the top surface of the hole 62. It is provided. The shaft 8 has lock pins 65, 75.
Lock holes 86 and 87 are formed for entering the
The lock holes 86, 87 are enlarged internally as shown in FIG. 7, so that if the lock pins 65, 75 are inserted and then rotated, they will not come off.

Next, the operation of selecting an arbitrary collimator 5 and mounting it on the gantry 1 will be described. First, at a position where the cart 4 is moved away from the gantry 1, the pin 45 is lowered, removed from the groove 47, and inserted into the hole 44, and the column 42 is rotated to set the collimator 5 according to the detection site of the subject 3 and the type of radionuclide. choose. After selecting, pin 45
Raise it and fit it into the groove 47 to lock the support column 42 from rotating. Next, the cart 4 is moved to the gantry 1 side, and the supporting arm 6 and the connecting arm 7 are butted against each other. For safety reasons, unless the cart 4 is moving away from the gantry 1 and the pin 45 is in the position where it enters the hole 44, the pin 45 will hit the floor and will not be lowered even if you try to lower it. groove 47
It is designed so that it does not come off and the support column 42 cannot rotate. When the ends of the support arm 6 and the connecting arm 7 are brought into contact with each other, operate the knob 82 to protrude the shaft 8, and insert the end of the shaft 8 into the hole 6 of the support arm 6.
2, push in the stopper 63 to retract it, insert the lock pin 65 into the lock hole 86, and then rotate the stopper 63 to lock it. Similarly, the stopper 73 is operated to lock the lock pin 75 into the lock hole 87. In this way, the supporting arm 6 and the connecting arm 7 are connected with their axes aligned, and at this time the stoppers 63, 73 are retracted. The collimator 5 can therefore be moved from the supporting arm 6 to the connecting arm 7. Since the magnetically sensitive switch 84 detects that the shaft 8 is in the protruding and connected state, all drive systems in the gantry 1 can be turned off to ensure safe and smooth installation of the collimator 5. In addition, the signal obtained from the magnetically sensitive switch 84 can be used to light up an indicator light or operate a buzzer to alert the operator and other people that the collimator is being attached. After the collimator 5 is moved and fixed in the gantry 1 as shown in FIG. 3, the stoppers 63 and 73 are turned, respectively. Then, the engagement between the lock pins 65, 75 and the lock holes 86, 87 is released, and
As the stoppers 63 and 73 protrude, the shaft 8 retracts, and the support arm 6 and the connecting arm 7 are disconnected.
Thereafter, the carriage 4 is moved and fixed by inserting the pin 45 into the hole 44 at a position away from the gantry 1. On the contrary, collimator 5 is connected to gantry 1.
The same is true when transferring from to trolley 4.

In the above embodiment, the connection state is confirmed by detecting the protrusion or retraction of the shaft 8 using a combination of the permanent magnet 83 and the magnetically sensitive switch 84, but other switches such as a micro switch may also be used. It is also possible to employ a different detection mechanism.

In addition, in the above example, the rail 41 extends toward the gantry 1 and the truck 4 only moves toward or away from the gantry 1, but the rail 41
By changing the configuration of the collimator 1, two or more carts 4 can be selectively used, and more collimators can be stored and replaced. Furthermore, in addition to the collimator, a radiation source storage container and a jig for position adjustment of the detector can also be stored and replaced.

(F) Effect According to the present invention, the collimator, which is a heavy object, is selected while being attached to the truck, and the collimator is replaced after the truck is connected to the gantry, so that handling of the heavy collimator is easy. Moreover, the replacement work can be performed safely and reliably.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram of an embodiment of the present invention;
Fig. 2 is a plan view of the same embodiment, Fig. 3 is a side view of the same embodiment, Fig. 4 is a partially enlarged side view of part A in Fig. 1, and Fig. 5 is viewed from the left of Fig. 4. FIG. 6 is a partially enlarged vertical sectional view of the connecting portion between the support arm and the connecting arm, and FIG. 7 is a partially enlarged perspective view showing the locking pin and the locking hole. 1... Gantry, 2... Bed, 3... Subject, 4... Dolly, 5... Collimator, 6... Support arm, 7... Connection arm.

Claims (1)

[Claims] 1. A gantry containing a large number of detectors arranged in a ring shape, and a truck that can be freely connected to the gantry and can be moved to a position away from the gantry when the connection is released, and the truck is , the gantry has a plurality of support arms each supporting a plurality of collimators prepared according to the detection site of the subject and the type of radionuclide, the gantry has a connecting arm connectable to the support arm, A projectable shaft provided on one of the supporting arm and the connecting arm, a hole provided in the other for receiving the shaft, and the end surfaces of the supporting arm and the connecting arm are brought into contact with each other so that the shaft is placed on one side. A locking mechanism is provided, which locks this shaft when the collimator protrudes further and enters the other hole, thereby connecting the support arm and the connecting arm in a state where their end surfaces are brought into contact with each other and the collimator can be delivered. A ring-type ECT device that is characterized by: