JPH0447671Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is used in the field of auxiliary equipment or safety equipment for medical diagnostic equipment.

The present invention relates to a gamma camera safety switch.

(b) Prior Art FIG. 2 is a schematic block diagram of a conventional example. 1
0 is a γ camera detector, and 32 is a stand controller. 20' is a normally open switch (N, O), which is equivalent to the one attached to the front of the collimator 14.

In this case, the γ camera detector 10 and the collimator 1
Even if detector 4 and detector 4 are not completely attached,
0 moves, which is dangerous, and even if contact occurs in that state, the switch may not operate.

(c) Purpose The purpose of this invention is to create a gamma camera safety switch that allows the detector to be moved only when the gamma camera detector and collimator are completely attached, and that operates the switch after confirming the condition. The goal is to provide the following.

(D) Configuration The purpose of the above is when the switch circuit, which has a switch terminal that closes when a foreign object touches the front side of the collimator and a resistor in parallel with this, and the gamma camera detector and collimator are completely installed. and a switch detection circuit configured to supply power to the switch circuit, and the switch detection circuit is provided with a series circuit of two parallel comparators and a logic circuit,
This is achieved in such a way that the gamma camera detector is only movable when the gamma camera detector and collimator are fully mounted.

(E) Embodiment A preferred embodiment of the present invention will be described based on FIG. 1 of the drawings.

A shows the attachment end of the γ camera detector 10 and the collimator 14, and b shows the contact part of the switch electrode between the detector 10 and the collimator 14 by an enlarged part. On the other hand, 20 is collimator 1
This is a switch circuit attached to the front surface of the switch terminal 4, and consists of a switch terminal 16 and a resistor 18 in parallel with the switch terminal 16. In this way, when the collimator 14 is floating, that is, when the collimator 14 is incompletely attached, the situation is the same as when the switch circuit 20 is not connected, and the detector 10 does not move.

As shown in the figure, the switch detection circuit c or the detection circuit 30 includes two parallel comparators 22a,
22b and a logic circuit 24 (NOR) in series. As a result, when the input impedance is infinite, nothing is connected to the switch circuit 20, and when the input impedance is large, the switch circuit 2
It is detected that the switch 16 connected to the switch 16 is not operating, and that the switch 16 is operating when the input impedance is 0. Here, as shown by the illustrated arrow, a control signal is sent to the stand controller 32 so that the detector 10 can be moved only in the case of contact b.

In other words, using the comparators 22a and 22b, the pulled-up output of the collimator 14 is
Compare the state of 0V, intermediate voltage, and power supply voltage with the reference voltage in the circuit, and when it is 0V and power supply voltage,
The output of either collimator 22 is turned on,
Turn off the control signal and stop the stand from moving.

In order to temporarily move the stand for maintenance reasons when the collimator 14 is removed, an override switch 28 is attached and a circuit for turning on the control signal is added to the output side of the detection circuit. 26 is a gate circuit.

(f) Effects The present invention has the effect of confirming that the safety switch is completely installed and that the collimator is also completely installed.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figure 2 is a circuit diagram showing one embodiment of the present invention.
The figure is a schematic diagram of a conventional example. 10 is a γ camera detector, 14 is a collimator, 2
0 is a collimator side switch circuit, 22 is a comparator, 24 is a logic circuit, 26 is a gate circuit, 28
30 is an override switch, 30 is a switch detection circuit, 32 is a stand controller, and b is a contact point between the switch circuit and the switch detection circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A switch terminal that closes when a foreign object touches the front side of the collimator, a switch circuit that has a resistor in parallel with the switch terminal, a gamma camera detector, and a collimator that are completely installed. It consists of a switch detection circuit that supplies power to the switch circuit at certain times, and the switch detection circuit has a series circuit of two parallel comparators and a logic circuit, and the gamma camera detector and collimator are completely installed. A gamma camera safety switch characterized in that the gamma camera detector is movable only when. (2) characterized in that an override switch for temporarily movable the γ camera detector is connected to the output side of the switch detection circuit;
A gamma camera safety switch according to claim 1 of the utility model registration claim.