JPH0526548Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a scintillation camera.

[Prior art] A radioisotope administered into a patient's body
A scintillation camera is known that inspects the human body by observing how it is distributed and accumulated in internal organs as an image.

Conventionally, when using such a scintillation camera, one has to select a collimator according to the purpose of the inspection from among various collimators that differ in the energy level of the radiation to be detected, the sensitivity, or the resolution of the image. It was attached to the front of the scintillation camera body using screws.

The type of the attached collimator is recorded from the keyboard of the device that controls the camera and performs image processing.

[Problems to be Solved by the Invention] However, in this case, there have been cases where the collimator has been used without being securely tightened with screws when installing it. The collimator weighs several tens of kilograms, and if it falls, there is a risk of death or injury to patients or technicians. Therefore, there was a problem that it was dangerous to use the collimator with the collimator incompletely attached.

Furthermore, since the type of collimator installed is manually recorded by a technician or the like, there is a possibility that the setting may be incorrect, in which case there is a problem in that the correct image cannot be determined.

In view of the above problems, it is an object of the present invention to provide a scintillation camera that eliminates the danger caused by incomplete attachment of a collimator and that can always obtain correct images.

[Means for Solving the Problems] To this end, the present invention provides elements with different impedances for each type and electrode contacts connected to the elements on the collimator side, while the camera body An electrode contact is attached to the side, which contacts the electrode contact on the collimator side when the collimator is attached, and the impedance of the element is measured through the electrode contact, and the type of the collimator is determined based on the measured impedance. This is what I did.

[Operation] The type of collimator can be determined by measuring the impedance of the element, so the type can be automatically input without error, so images can always be recorded correctly. In addition, when the collimator is incompletely attached, the electrode contacts on the camera body side become open, and incomplete attachment can be determined by measuring the impedance described above, so it is possible to use the scintillation camera with the collimator incompletely attached. Danger can be prevented.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a side view of a scintillation camera according to an embodiment of the present invention, and FIG. 2 is a bottom view thereof. In these figures, a rectangular flat collimator 2 is fixed below a scintillation camera body 1 formed in a box shape with bolts 3a to 3d. Various types of collimators 2 are available with different levels of radiation energy to be detected, sensitivities, and image resolutions, and the collimator 2 is attached to the scintillation camera body 1 as shown in the figure, depending on the purpose of the inspection. Ru.

A rectangular safety switch plate 5 is further fixed below the collimator 2 with screws 4a to 4d.

As shown in FIG. 3a, this safety switch board 5 consists of two conductive and flexible transparent boards 5a,
5b are formed sandwiching disc-shaped insulators 5c to 5f.

A lead wire 5g is connected to one end of the plate 5a, and a lead wire 5h is connected to the opposite end of the plate 5b. The surface of the safety switch plate 5 is covered with a film-like cover 5i, as shown in FIG.

The two plates 5a and 5b are usually spaced apart from each other by a certain distance, as shown in FIG. However, when pressure is applied to the surfaces, the two come into contact and become electrically conductive, as shown in Figure c. This forms a switch circuit S that closes when an object comes into contact with the surface. The lead wires 5g and 5h, which serve as terminals of the switch circuit S, are connected to screws 4a and 4b, respectively.

In addition, at the end of the safety switch plate 5, there is a
A resistor R ₁ is arranged as shown in FIG. One end of the resistor _R1 is connected to the plate 5a, and the other end is connected to the lead wire 5h.

A safety switch plate 5 as described above is fixed to each of the various collimators 2. The resistance value of the resistor _R1 provided on the safety switch plate 5 differs depending on the type of collimator 2.

FIG. 4 shows a cross-sectional view of the area around the screw 4a, and a Teflon material 6 having a tubular shape with one end closed is fixed to the collimator 2 so as to penetrate therethrough. The screw 4a is made of a metal material and meshes with a screw hole drilled in one end surface of the Teflon material 6,
Its tip is in contact with one end of a spring 7 disposed inside the Teflon material 6 tube.

A disk-shaped lid 8 made of a metal material such as copper is fixed to the other end surface of the Teflon material 6. The central portion of the lid 8 on the scintillation camera body 1 side is raised to form an electrode contact 8a. The scintillation camera body 1 also includes an electrode contact 9 that is made of a metal material such as copper and contacts the electrode contact 8a.
is buried and fixed.

The area around the screw 4c is also configured in the same manner as above.

On the other hand, on the scintillation camera body 1 side,
As shown in FIG. 5, the electrode contact 9 corresponding to the screw 4a is grounded, and the electrode contact 9 corresponding to the screw 4b
is connected to a DC voltage +V via a resistor _R2 . Further, an analog-to-digital conversion circuit 10 for measuring the voltage between the two electrode contacts 9 is provided.

Further, a collimator type determination circuit 11 is disposed outside the scintillation camera body 1 to determine the type of the collimator 2 based on the voltage converted into a digital signal, and its output is sent to an image processing device and a control device (not shown). has been entered.

When using the scintillation camera of this embodiment with the above configuration, the collimator 2 is selected depending on the purpose of inspection. Since a safety switch plate 5 is attached to each collimator 2, the collimator 2 is attached to the scintillation camera body 1 with bolts 3a while the safety switch plate 5 is attached.
Fixed by ~3d.

As a result, the electrode contact 8a on the collimator 2 side
and the electrode contact 9 on the side of the scintillation camera body 1, and as shown in FIG. 5, the resistance _R1 of the safety switch plate 5 and the switch circuit S are
Alternatively, it is connected to two electrode contacts 9 on the scintillation camera body 1 side via the spring 7, the lid 8, and the electrode contact 8a.

The switch circuit S is normally open. Therefore, the analog-to-digital conversion circuit 10 receives the DC voltage + divided by the resistor _R1 and the resistor _R2 .
V is applied.

As mentioned above, _R1 of the safety switch plate 5 differs depending on the type of safety switch plate 5, so
The analog-to-digital conversion circuit 10 receives different voltages depending on the type of safety switch board 5, converts the voltages into digital signals, and outputs the digital signals.

The voltage value detected for each type of collimator 2 is determined in advance, and each voltage value and a certain allowable deviation value for determination are set in the collimator type determination circuit 11.

The collimator type determination circuit 11 determines the type of the collimator 2 by determining within which set voltage deviation the voltage input from the analog-to-digital conversion circuit 10 lies. For example, as shown in FIG. 6, when the detected voltage v is within the range of v ₁ to _{v 2} , the collimator is used for low energy, when it is within the range of v 2 to v 3, it is used as the collimator for medium energy, and when the detected voltage v is within the range of v ₂ to v ₃ , it is used as the collimator for _medium energy. If it is within the range of ~v ₄ , it is determined that it is a high energy collimator. In this way, resistance
R ₂ and the analog-to-digital conversion circuit 10 are resistors R ₁
A resistance value discriminating circuit is configured to determine the difference in the resistance values of the resistors based on the detected voltage v.

On the other hand, when the collimator 2 is not attached to the scintillation camera body 1, the electrode contacts 9 are open. Further, when the collimator 2 is attached, if the bolts 3a to 3d are not sufficiently tightened, the electrode contacts 8a and 9 will be separated and not in contact with each other. In these cases, the detected voltage v becomes the power supply voltage +v. Therefore, the detection voltage v is the above v ₄
In the above case, the collimator type determination circuit 11
It is determined that the collimator is not attached.

Further, when an object comes into contact with the surface of the safety switch plate 5, the switch circuit S is closed. In this case, the detection voltage v becomes 0V. Therefore, when the detected voltage v is less than or equal to the detected voltage _v1 , it is determined that there is a contact with an object.

Such determination result information of the collimator type determination circuit 11 is input to an image processing device and a control device (not shown). The image processing device executes predetermined image processing according to input collimator type information. Furthermore, when contact with an object is detected during control of moving the scintillation camera body 1, the control device immediately stops the control.

As described above, in this embodiment, the safety switch board 5 is provided with a resistor _R1 having a different resistance value depending on its type in parallel with the switch circuit S, and the collimator 2 is connected to the resistor _R1 . The scintillation camera body 1 is provided with an electrode contact 9 that contacts the electrode contact 8a. Then, the resistance value of the resistor R ₁ is measured based on the detected voltage v when current is applied between the two electrode contacts 9, and from the measurement results, the type of collimator, the mounting state of the collimator, and the contact of an object to the safety switch plate 5 are determined. We are trying to detect this.

As a result, the type of collimator 2 installed is
Since the information is automatically input to the image processing apparatus without manual input, there is no possibility of erroneous input, and a correct image can always be obtained.

In addition, if the collimator 2 is not installed completely,
Since the electrode contact 9 is in an open state and incomplete attachment is determined based on the detected voltage v, an alarm can be displayed from the control device or the like at this time. This prevents the danger of the scintillation camera body 1 being used with the collimator incompletely attached and causing the collimator 2 to fall.

In addition, in the above embodiment, the resistor _R1 was arranged in parallel with the switch circuit S of the safety switch board 5, but
Of course, the resistor _R1 may be arranged on the safety switch plate 5 or the collimator 2 independently of the switch circuit S, and the electrode contact may also be provided separately. Also,
It goes without saying that the same configuration can be achieved by using components with different impedances such as capacitors and coils in place of the resistor _R1 .

[Effects of the invention] As described above, according to the invention, elements with different impedances for each type and electrode contacts connected to the elements are disposed on the collimator side, while on the scintillation camera body side. The collimator is equipped with an electrode contact that comes into contact with the electrode contact on the collimator side when the collimator is attached, and the impedance of the element is determined through the electrode contact, and the type of the collimator is determined based on the determined impedance. Therefore, the type of collimator can be entered automatically without having to enter it into the image processing device manually, eliminating input errors and ensuring that correct images are always obtained. If the collimator is incomplete, the electrode contacts on the camera side will be open, and incomplete attachment of the collimator can be detected, thereby preventing the danger of using a scintillation camera with the collimator incompletely attached. It becomes like this.

[Brief explanation of drawings]

Figure 1 is a side view of a scintillation camera according to an embodiment of the present invention, Figure 2 is its bottom view, and Figure 3 is a side view of a scintillation camera according to an embodiment of the present invention.
Figures a to d are structural diagrams of the safety switch board, and Figure 4 is a cross-sectional view of the area around the screws that serve as the terminals of the safety switch board.
FIG. 5 is a conceptual diagram showing the circuit configuration with the collimator attached, and FIG. 6 is an explanatory diagram showing the type of collimator and other determinations based on the detected voltage. 1...Scintillation camera body, 2...Collimator, 3a to 3d...Bolts, 4a to 4d...
...Screw, 5...Safety switch plate, 5a, 5b...
Plate, 5c to 5f...Insulator, 5g, 5h...Lead wire, 6...Teflon material, 7...Spring, 8
... Lid body, 8a ... Electrode contact, 9 ... Electrode contact,
10...Analog-to-digital conversion circuit, 11...Collimator type determination circuit, _R1 ...Resistor.

Claims (1)

[Claims for Utility Model Registration] (1) In a scintillation camera that is used with various collimators attached to the front of the camera body, the collimator side has elements with different impedances for each type, and While arranging the connected collimator side electrode contact,
The camera body side includes a body side electrode contact that comes into contact with the collimator side electrode contact when the collimator is attached, an impedance measuring means that measures the impedance of the element via the body side electrode contact, and the measured impedance. 1. A scintillation camera, comprising: determination means for determining the type of collimator. (2) In claim 1 of the utility model registration claim, the collimator is equipped with a switch plate equipped with a switch circuit that closes when an object comes into contact with the front surface of the collimator, and the element is connected in parallel with the switch circuit. A scintillation camera, characterized in that the scintillation camera is connected to the switch board and arranged on the switch board.