JP5902332B1 - Respiratory synchronization system - Google Patents

Abstract

When a user of a respiratory synchronization system detects an abnormal state of a subject's breathing motion, the supply of a gate signal is stopped quickly and reliably without any error by a simple operation. In a respiratory synchronization system, a gate cutoff switch includes a series circuit of an LED and a normally open switch section. A power line 58 and a ground line 60 are connected to the series circuit 76, and a gate cutoff signal line 62 is connected to a connection point 70 between the LED 66 and the switch unit 68. When the switch unit 68 is pressed, a gate cutoff signal is output to the sensor port 12 via the gate cutoff signal line 62, and the supply of the gate signal to the external device 20 is stopped. [Selection] Figure 10

Description

  The present invention relates to a respiratory synchronization system that causes an external device to perform radiotherapy or image capturing on a subject in synchronization with the breathing motion of the subject.

  Conventionally, the respiratory motion of a subject is detected by a respiratory sensor, a gate signal is generated based on the respiratory signal corresponding to the respiratory motion detected by the respiratory sensor, and the gate signal is supplied to an external device, thereby performing the respiratory motion. There is known a respiratory synchronization system that causes an external device to perform radiotherapy or image capturing on a synchronized subject (see, for example, Patent Documents 1 and 2).

  In a respiratory synchronization system to which the techniques of Patent Documents 1 and 2 are applied, a respiratory sensor and an external device are connected to a sensor port, and the sensor port is connected to a personal computer (PC). The respiration signal output from the respiration sensor is transmitted from the sensor port to the PC. The PC creates a gate signal for controlling an external device based on the respiratory signal. The created gate signal is transmitted from the PC to the external device via the sensor port. Therefore, an external device such as a radiotherapy apparatus or an image diagnostic apparatus irradiates the subject with radiation according to the received gate signal or executes image capturing to perform radiotherapy or image on the subject synchronized with the breathing motion. Shooting is possible.

JP 2004-8370 A JP 2004-105359 A

  When performing radiotherapy or imaging on a subject, the user of the respiratory synchronization system detects that the subject's breathing motion is abnormal from the appearance of the subject or the temporal change in the respiratory signal. For example, the user operates the input operation unit such as a keyboard or mouse of the PC to instruct the PC to stop supplying the gate signal to the external device, thereby stopping the supply of the gate signal, and the radiation treatment by the external device. Alternatively, image capturing is stopped.

  On the other hand, when the breathing motion of the subject is restored from the abnormal state to the normal state, the user who has recognized the restoration operates the input operation unit to instruct the PC to resume the supply of the gate signal. Thereby, it is possible to resume radiation therapy or image capturing on the subject.

  However, when stopping the supply of the gate signal from the input operation unit of the PC, for example, a series of operations such as clicking the mouse cursor after moving the cursor to a specific position is required. It was difficult to do without error.

  The present invention has been made in consideration of such problems, and when the user of the respiratory synchronization system detects an abnormal state of the respiratory motion of the subject, the supply of the gate signal can be stopped quickly with a simple operation. It is another object of the present invention to provide a respiratory synchronization system that can reliably perform without error.

  The present invention relates to a respiration sensor that detects a breathing motion of a subject, a sensor port that is connected to an external device that performs radiotherapy or imaging on the subject, and a personal computer that is connected to the sensor port ( PC).

  The respiratory synchronization system creates a gate signal based on a respiratory signal corresponding to the respiratory action detected by the respiratory sensor, and supplies the gate signal to the external device, thereby synchronizing the radiation synchronized with the respiratory action. Treatment or imaging is performed.

  The respiratory synchronization system is configured as follows in order to achieve the above object.

  That is, the respiratory synchronization system further includes a gate cutoff switch that cuts off the supply of the gate signal. The gate cut-off switch includes a light emitting element and a normally open type switch unit connected in series to the light emitting element. Two power supply lines are connected to both ends of the series circuit of the light emitting element and the switch unit, and a signal line is connected to a connection point between the light emitting element and the switch unit.

  Here, when power is supplied to the series circuit via the two power supply lines, the gate cut-off switch is connected to the light emitting element while the switch unit is pushed and is in a conductive state. And a gate cutoff signal corresponding to the potential at the connection point is output to the sensor port via the signal line. Thereby, the sensor port stops the supply of the gate signal to the external device based on the input of the gate cutoff signal.

  Thus, in the present invention, when the user detects that the respiratory action of the subject is in an abnormal state during the execution of the radiotherapy or the image capturing on the subject, the user By pushing the part, the gate cutoff signal is output from the gate cutoff switch to the sensor port. Since the sensor port stops the supply of the gate signal to the external device based on the gate cutoff signal, the radiotherapy or the imaging is stopped.

  Therefore, according to the present invention, when the breathing motion of the subject is in an abnormal state, the user simply stops the supply of the gate signal by pressing the switch unit, thereby the radiotherapy or the Image capture is stopped. As a result, in the present invention, the supply of the gate signal is stopped as compared with a method of performing a series of operations such as, for example, clicking after moving the cursor to a specific position with the mouse from the input operation unit of the PC. A simple operation can be carried out quickly and reliably.

  Moreover, in the present invention, the following effects can be obtained by configuring the respiratory synchronization system as described above.

  That is, the light emitting element and the switch unit are connected in series in the gate cutoff switch, and the two power supply lines and the signal line are connected to the series circuit. Therefore, before the user operates the respiratory synchronization system, confirming in advance that the gate cutoff switch functions normally by pressing the switch unit and confirming whether the light emitting element is lit or not. Is possible. As a result, even if the user presses the switch unit during the radiotherapy or the image capturing, the gate cut-off switch is not functioning because it is broken (the gate signal is not broken even if the gate cut-off switch is operated). Can be avoided.

  In the present invention, the sensor port may be configured such that the gate of the switch is returned to an open state after stopping the supply of the gate signal to the external device due to the input of the gate cutoff signal. You may further have a mode setting part which sets the operation mode of the said gate cutoff switch at the time of the input of the interruption | blocking signal being stopped, and restarting supply of the said gate signal.

  In this case, in the present invention, the gate signal is a pulse signal that is repeatedly generated in synchronization with the breathing motion of the subject. For this reason, the mode setting unit may be configured to perform the first mode in which the supply of the gate signal is immediately resumed when the input of the gate cutoff signal is stopped, or from the rising edge of the next pulse signal when the input of the gate cutoff signal is stopped. What is necessary is just to set to either of the 2nd modes which restart supply of a signal.

  Accordingly, the supply of the gate signal to the external device can be resumed at an accurate timing according to the type of the external device in synchronization with the breathing motion of the subject.

  That is, when the external device is a radiotherapy apparatus, radiation is applied during the supply period of the gate signal, so that the restraint time of the subject for the radiotherapy is shortened as much as possible. Depending on the mode, the supply of the gate signal may be resumed immediately after the input of the gate cutoff signal is stopped.

  On the other hand, when the external device is an image diagnostic apparatus such as CT or MRI, the second mode is used to input the gate cutoff signal in order to perform image capturing in synchronization with the rising of the gate signal supply. After stopping, the supply of the gate signal may be resumed after waiting for the next pulse signal to rise. When the supply of the gate signal is resumed without being synchronized with the respiratory signal, the image quality of the acquired diagnostic image is deteriorated, but the supply of the gate signal is resumed after waiting for the next pulse signal to rise. It is possible to obtain a higher-quality diagnostic image that is taken in synchronization with the respiratory signal.

  According to the present invention, when the breathing motion of the subject is in an abnormal state, the supply of the gate signal is stopped only by the user pressing the switch unit, thereby stopping the radiotherapy or image capturing. As a result, compared with a method of performing a series of operations such as clicking the mouse after the cursor is moved to a specific position from the input operation unit of the PC, in the present invention, the supply of the gate signal is simplified. Can be carried out quickly and reliably without errors.

It is a block diagram of the respiratory synchronization system of a comparative example. It is a timing chart which shows operation | movement of the comparative example of FIG. FIG. 2 is a sequence diagram illustrating a time lapse of information communication between an external device, a sensor port, and a PC in the comparative example of FIG. 1. It is a block diagram of the respiration synchronization system concerning this embodiment. FIG. 5 is a sequence diagram illustrating the time lapse of information communication between an external device, a sensor port, and a PC in the embodiment of FIG. 4. 6A to 6C are flowcharts showing processing of the gate signal processing unit in the sensor port when a gate output instruction, a gate creation start instruction, and a gate creation stop instruction are received, respectively. It is the flowchart which illustrated the process of the gate signal process part in a sensor port at the time of creating a gate signal. FIG. 8 is a flowchart illustrating details of the process of Step S64 of FIG. 7 (second gate signal generation process). FIG. It is a timing chart for demonstrating one function of a gate signal processing part. It is a partial circuit block diagram of the respiration synchronization system of FIG. 3 is a timing chart illustrating an operation when a gate is shut off in the present embodiment. It is the flowchart which illustrated the gate interruption | blocking process of the gate signal processing part in a sensor port.

  A preferred embodiment of a respiratory synchronization system according to the present invention will be described below in detail with reference to the accompanying drawings.

[1. Configuration of Comparative Example]
Prior to the description of the respiratory synchronization system 10 (see FIG. 4) according to the present embodiment, the configuration of a conventional respiratory synchronization system 30 (comparative example) will be described with reference to FIG.

  As shown in FIG. 1, the respiratory synchronization system 30 of the comparative example includes a sensor port 12 and a personal computer (PC) 14. Between the sensor port 12 and the PC 14, it is possible to bidirectionally transmit and receive signals or information by packet communication at predetermined intervals (for example, every 25 ms) via the relay box 16.

  A respiratory sensor 18 and an external device 20 are connected to the sensor port 12. The external device 20 is a radiotherapy apparatus that performs radiation therapy by irradiating an affected area of a subject such as a patient (not shown), or CT (Computed Tomography), MRI (MRI) that captures a predetermined image including the affected area of the subject. This is a diagnostic imaging apparatus such as Magnetic Resonance Imaging. On the other hand, a respiration sensor 18 including a pressure sensor such as a load cell or a laser sensor detects a respiration operation of the subject and outputs the detection result to the sensor port 12 as a respiration signal.

  As illustrated in FIG. 2, the respiratory signal is a waveform signal having a substantially sine wave shape with a period T (for example, T = 5 s), and the upper waveform of the half cycle corresponds to inspiration, and the lower waveform of the half cycle. Corresponds to exhalation. In addition, since the respiration sensor 18 and the external device 20 are disclosed in Patent Documents 1 and 2, detailed description thereof is omitted in this specification.

  Returning to FIG. 1, the sensor port 12 implements various functions of the sensor port 12 by reading and executing firmware stored in advance in the storage unit 22. That is, the sensor port 12 includes a gate signal processing unit 24 and a transfer data generation unit 28 in addition to the storage unit 22. In addition, the sensor port 12 executes the firmware at a processing cycle (for example, 2.5 ms) faster than the processing cycle of the PC 14 or the communication cycle of packet communication between the sensor port 12 and the PC 14 (25 ms). Various processes can be executed.

  The gate signal processing unit 24 supplies a gate signal (first gate signal) created in the PC 14 to the external device 20 in accordance with a predetermined instruction received from the PC 14 via the relay box 16.

  Here, the gate signal is a control signal supplied to the external device 20 in order to cause the external device 20 to execute radiation irradiation or image capturing on the subject in synchronization with the breathing motion of the subject. That is, as illustrated in FIG. 2, when a gate output upper limit value (threshold, change condition) and a gate output lower limit value are set for the respiratory signal, between the gate output upper limit value and the gate output lower limit value. When a breathing signal is input to the gate signal, the gate signal is turned on. On the other hand, when there is no respiratory signal between the gate output upper limit value and the gate output lower limit value, the gate signal is turned off.

  Specifically, the gate signal switches from the off state to the on state when the value of the respiratory signal decreases with time in the half cycle on the inhalation side and falls to the gate output upper limit value at time t1. Thereafter, if the value of the respiratory signal increases with time in the half cycle on the expiration side and rises to the gate output upper limit value at time t2, the gate signal is switched from the on state to the off state.

  The gate output upper limit value and the gate output lower limit value can be specified as desired values by, for example, the user operating the input operation unit 36 (see FIG. 1) of the PC 14.

  Further, since the respiratory signal is a signal having a substantially sinusoidal waveform with a period T, the PC 14 creates a pulse signal that is turned on at the expiration side for each period T. For this reason, FIG. 2 illustrates a case where the next pulse signal is generated at a time point t3 after a period T from the time point t1 after the pulse signal is generated in the time period t1 to t2. Therefore, if the value of the respiratory signal changes in the same way with time in each cycle T, the PC 14 can repeatedly create a gate signal at the same timing for each cycle T.

  As described above, since the PC 14 repeatedly generates a pulse signal as a gate signal every period T, the gate signal processing unit 24 outputs the gate signal generated by the PC 14 to the external device 20, so that the breathing operation of the subject is performed. The external device 20 can execute radiation irradiation or image capturing on the subject at the same timing every cycle T.

  In response to a predetermined instruction transmitted from the PC 14 via the relay box 16, the transfer data generation unit 28 generates predetermined data including transfer signals and the supply status of the gate signal to the external device 20 as transfer data. The generated transfer data is transmitted to the PC 14 via the relay box 16 by packet communication every communication cycle. In this case, the transfer data generation unit 28 starts generation and transmission of transfer data by receiving a data transfer start instruction from the PC 14, and on the other hand, by receiving a data transfer stop instruction from the PC 14, Stop sending.

  On the other hand, in FIG. 1, the PC 14 implements various functions of the PC 14 by reading and executing an application (software) stored in advance in the storage unit 34. That is, in addition to the storage unit 34, the PC 14 includes an input operation unit 36, a display unit 38, an initialization instruction unit 40, a data transfer instruction unit 42, a gate signal creation unit (first gate signal creation unit) 46, and a respiratory abnormality determination unit. 48. In this case, since the PC 14 is equipped with an OS, the processing speed is lower than that of the sensor port 12, but complicated processing can be executed by executing an application.

  Specifically, the input operation unit 36 is a keyboard or a mouse operated by a user of the respiratory synchronization system 30, and the display unit 38 is a display device such as a display on which various types of information are displayed for the user. .

  The initialization instruction unit 40 causes the sensor port 12 to execute initialization processing by transmitting an initialization instruction that instructs execution of initialization processing to the sensor port 12 via the relay box 16. The data transfer instruction unit 42 transmits a data transfer start instruction for instructing start of transmission of transfer data and a data transfer stop instruction for instructing stop of transmission of transfer data to the sensor port 12 via the relay box 16.

  The gate signal creation unit 46 creates a first gate signal based on the respiratory signal included in the transfer data received by the PC 14, and uses the created first gate signal as a gate output instruction via the relay box 16 to the sensor port 12. Send to.

  The respiratory abnormality determination unit 48 determines whether or not the subject's respiratory motion is in an abnormal state based on the temporal change of the respiratory signal included in the received transfer data.

  In this case, if the respiratory abnormality determination unit 48 determines that the respiratory action is in an abnormal state, the respiratory abnormality determination unit 48 notifies the gate signal creation unit 46 of the determination result. The gate signal creation unit 46 stops creating the first gate signal based on the notified determination result.

  On the other hand, if the respiratory abnormality determination unit 48 determines that the breathing motion has been restored from the abnormal state to the normal state, the respiratory abnormality determination unit 48 notifies the gate signal creation unit 46 of the determination result. The gate signal creation unit 46 resumes creating the first gate signal based on the notified determination result.

[2. Operation of comparative example and its problems]
The respiratory synchronization system 30 of the comparative example is configured as described above. Next, the operation of the comparative example and its problems will be described with reference to FIGS.

  Conventionally, as one of the important indexes indicating the performance of the respiratory synchronization system 30, there is a gate delay time Td. The gate delay time Td is defined as the processing time required for the respiratory synchronization system 30 from when the breathing motion of the subject changes until the gate signal corresponding to the change in the breathing motion is output. In FIG. 2, the waveform of an ideal gate signal is shown by a solid line, and the case where the gate delay time Td is generated is shown by a one-dot chain line. In FIG. 2, the times t1 to t4, t2 to t5, and t3 to t6 are illustrated as the gate delay time Td.

  Therefore, if the gate delay time Td is large, an error occurs when the external device 20 performs radiation irradiation or image capturing (hereinafter also referred to as respiratory synchronization irradiation) synchronized with the breathing operation. Specifically, in the case of radiotherapy, it becomes an error in the radiation irradiation position. In the case of image shooting, an error occurs in shooting timing, which leads to deterioration in image quality. For example, if the subject's breathing rate is 12 times per minute, T = 5 s. Therefore, if Td = 100 ms, a time error of 2% with respect to the period T occurs. Therefore, in order to accurately perform radiation irradiation or image capturing in synchronization with the respiration operation, it is necessary to shorten the gate delay time Td to a level that can be ignored with respect to the period T.

  In the respiratory synchronization system 30 of the comparative example, the process of creating the gate signal from the respiratory signal is performed by software of the PC 14. There are a plurality of gate modes (operation modes at the time of gate signal creation) in creating a gate signal, and there are a plurality of setting parameters to be referred to for each gate mode. Therefore, since the conditions for creating the gate signal are complicated, such complicated processing is performed by the software of the PC 14.

  For example, if an abnormal state of a respiratory signal due to coughing, sneezing, hiccups, etc. is detected during radiation therapy, the radiation of radiation is interrupted by temporarily turning off the gate signal to ensure patient safety. There is a need to. In this case, in order to detect an abnormal state of the respiratory signal, a larger and more complicated process such as waveform prediction of the respiratory signal is required. Therefore, in the comparative example, the above processing is realized by software of the PC 14 having a high-performance CPU (Central Processing Unit) and a large-capacity memory. Therefore, it has not been considered to execute the above complicated processing by a method other than the execution of the software of the PC 14.

  However, the software of the PC 14 is executed as an application on the OS. Therefore, it is difficult to always guarantee high-speed real-time response. In addition, when a specific task in the OS occupies the CPU, there is a possibility that the execution of the application may be hindered for a short time. Further, regarding the time required for supplying the gate signal to the external device 20, in addition to the processing time of the application, the time for transferring the respiratory signal from the sensor port 12 to the PC 14 via the relay box 16, and the generation result of the gate signal ( ) To the sensor port 12 from the PC 14 must be taken into consideration. Therefore, in the respiratory synchronization system 30, the gate delay time Td from the input of the respiratory signal from the respiratory sensor 18 to the sensor port 12 to the output of the gate signal from the sensor port 12 to the external device 20 can be significantly reduced. It was difficult.

  Here, in the respiratory synchronization system 30 of the comparative example, the packet communication between the PC 14 and the sensor port 12 and the supply of the gate signal to the external device 20 include between the external device 20, the sensor port 12 and the PC 14. Transmission / reception of signals or information will be described with reference to the sequence diagram of FIG.

  When the application stored in the storage unit 34 is read and activated in the PC 14, the following various processes are executed in the PC 14. On the other hand, when the firmware stored in the storage unit 22 is read and activated in the sensor port 12, the following various processes are realized in the sensor port 12.

  First, in step S <b> 1, the initialization instruction unit 40 transmits an initialization instruction packet to the sensor port 12. The sensor port 12 initializes the hardware and firmware states in the sensor port 12 according to the initialization setting information included in the received packet.

  Note that the gate signal supplied from the sensor port 12 to the external device 20 is initialized to an off state indicating radiation irradiation or image capturing stop.

  In step S <b> 3, the data transfer instruction unit 42 of the PC 14 transmits a data transfer start instruction packet to the sensor port 12. In step S4, the transfer data generation unit 28 of the sensor port 12 receives the data transfer start instruction and starts a data transfer operation to the PC 14. That is, the transfer data generation unit 28 performs processing such as digitization, noise reduction, and respiratory phase detection on the respiratory signal from the respiratory sensor 18, and then the respiratory signal data, the respiratory phase data, and the respiratory sensor 18. Transfer data including various information such as status and sensor port 12 status is generated, and the generated transfer data packet is transmitted to the PC 14 via the relay box 16.

  In this case, the transfer data generation unit 28 transmits transfer data packets to the PC 14 at regular time intervals (for example, 25 ms) until receiving a data transfer stop instruction packet from the PC 14 (step S5). In FIG. 3, the broken line arrow indicates that the transmission process in step S <b> 5 is performed at regular time intervals in order to distinguish it from transmission / reception of other signals or information.

  Each time the PC 14 receives a packet of transfer data, the PC 14 stores the various types of information included in the transfer data in the storage unit 34. In step S6, the gate signal creation unit 46 creates a gate signal value according to a preset gate signal output condition based on the received various pieces of information. Various information such as the value of the gate signal, the respiratory waveform, the respiratory phase, the state of the respiratory sensor 18 and the state of the sensor port 12 are displayed on the screen of the display unit 38.

  The gate signal creation unit 46 transmits a packet of a gate output instruction including the value of the created gate signal to the sensor port 12. Upon receiving the gate output instruction packet, the gate signal processing unit 24 outputs a gate signal indicating the value to the external device 20 in step S7. Thereby, the external device 20 can start irradiation of the radiation to the subject in accordance with the supplied gate signal in step S8.

  In step S5, since the transfer data is transmitted from the sensor port 12 to the PC 14 at regular time intervals, the gate signal creation unit 46 executes the process of step S6 every time the transfer data is received, and creates a gate signal value. Then, a gate output instruction is transmitted to the sensor port 12 at regular time intervals. Accordingly, the sensor port 12 can output the gate signal created by the PC 14 to the external device 20 at a certain time interval and instruct radiation irradiation.

  By the way, every time the transfer data is received by the PC 14, the respiratory abnormality determination unit 48 of the PC 14 determines whether or not the respiratory signal included in the transfer data deviates from the preset normal range, that is, the respiratory signal. It is determined whether or not an abnormal state has occurred in the breathing motion of the subject.

  If it is determined in step S9 that the breathing motion is in an abnormal state, the respiratory abnormality determination unit 48 notifies the gate signal creation unit 46 of the determination result. In step S <b> 10, the gate signal generation unit 46 temporarily stops the generation of the gate signal based on the notification from the respiratory abnormality determination unit 48. That is, the gate signal creation unit 46 shifts the value of the pulse signal constituting the gate signal from the on state to the off state, and transmits a packet of the gate output instruction (off) including the result to the sensor port 12.

  In step S <b> 11, the gate signal processing unit 24 outputs a gate signal indicating an off state to the external device 20 when receiving a gate output instruction (off) packet. Thereby, the external device 20 stops the irradiation of the radiation to the subject in accordance with the supplied gate signal in step S12.

  Thereafter, in step S13, if it is determined that the subject's breathing motion has been restored to the normal state based on the breathing signal included in the transfer data received by the PC 14, the breathing abnormality determination unit 48 gates the determination result. The signal creation unit 46 is notified. Thereby, in step S14, the gate signal creation unit 46 creates the gate signal based on various information such as the respiratory signal data included in the transfer data received next based on the notification from the respiratory abnormality determination unit 48. Then, the packet of the gate output instruction (ON) including the value of the created gate signal is transmitted to the sensor port 12.

  In step S <b> 15, the gate signal processing unit 24 outputs a gate signal indicating the value to the external device 20 when receiving a gate output instruction packet, as in step S <b> 7. As a result, in step S <b> 16, the external device 20 can restart radiation irradiation on the subject according to the supplied gate signal.

  Thereafter, when the user operates the input operation unit 36 to instruct the end of radiation irradiation, in step S17, the gate signal generation unit 46 ends the generation of the gate signal and changes the gate signal from the on state to the off state. Transition. Then, the gate signal creation unit 46 transmits a packet of a gate output instruction (OFF) to the sensor port 12.

  In step S18, when receiving the gate output instruction (off) packet, the gate signal processing unit 24 outputs a gate signal indicating the off state to the external device 20 as in step S11. Thereby, in step S19, the external device 20 ends the radiation irradiation on the subject according to the supplied gate signal.

  Finally, in step S <b> 20, the data transfer instruction unit 42 transmits a data transfer stop instruction packet to the sensor port 12. In step S <b> 21, the transfer data generation unit 28 receives the data transfer stop instruction and stops the data transfer operation for the PC 14.

  As described above, in the respiratory synchronization system 30 of the comparative example, the gate signal is created by the software on the PC 14. Therefore, a gate signal can be created based on complicated gate signal output conditions including the occurrence of an abnormal state of breathing motion.

  However, as described above, since it is executed as an application on the OS, the time required for supplying the gate signal to the external device 20 is the communication time of the packet between the sensor port 12 and the PC 14 in addition to the processing time of the application. It is also necessary to consider. Therefore, it is difficult to further shorten the gate delay time Td from the current value (for example, several tens of ms). In addition, because the gate signal creation depends on software, a problem occurs in the software gate signal creation process, etc., and the gate signal should be in the off state. If so, the subject is erroneously irradiated with radiation, and the subject is inadvertently irradiated with radiation.

[3. Configuration of this embodiment]
Next, the configuration of the respiratory synchronization system 10 according to the present embodiment will be described with reference to FIG. In the description of the respiratory synchronization system 10, the same components as those of the comparative example of the respiratory synchronization system 30 (see FIG. 1) will be described using the same reference numerals, and detailed description thereof will be omitted.

  Compared with the respiratory synchronization system 30 of the comparative example, in the respiratory synchronization system 10 according to the present embodiment, a gate cutoff switch 50 connected to the sensor port 12 via the relay box 16 is provided on the PC 14 side. In the respiratory synchronization system 10, the sensor port 12 has a plurality of new functions in the power supply unit 52 and the gate signal processing unit 24 (see FIG. 1) in addition to the storage unit 22 and the transfer data generation unit 28. And a gate signal processor 54 provided. Further, in the respiratory synchronization system 10, the PC 14 further includes a gate signal creation instruction unit 44.

  In the respiratory synchronization system 10 according to the present embodiment configured as described above, the gate signal processing unit 54 reads and activates the firmware stored in the storage unit 22 in addition to the gate signal supply function to the external device 20. Thus, further functions can be realized.

  Specifically, the gate signal processing unit 54 starts creating a predetermined gate signal (second gate signal) based on the respiratory signal in accordance with a predetermined instruction received from the PC 14 via the relay box 16, or the gate Stop signal creation. That is, when the gate signal processing unit 54 receives a gate creation start instruction for instructing the start of gate signal creation, the gate signal processing unit 54 starts creation of the gate signal, and receives a gate creation stop instruction for instructing stoppage of gate signal creation. It functions as a second gate signal creation unit that stops creating a gate signal.

  Therefore, upon receiving the gate creation start instruction, the gate signal processing unit 54 sets the gate output upper limit value and the gate output lower limit value with reference to the gate creation start instruction, and then synchronizes with the respiratory signal (breathing action). The second gate signal is repeatedly generated at the same timing for each period T.

  Further, the gate signal processing unit 54 functions as a gate signal output unit that supplies either the generated second gate signal or the first gate signal generated in the PC 14 to the external device 20. To do. Specifically, if the second gate signal is being created during the time period from when the gate creation start instruction is received until the gate creation stop instruction is received, the gate signal processing unit 54 externally creates the created second gate signal. Output to the device 20. On the other hand, if the second gate signal is not being created, the gate signal processing unit 54 outputs the first gate signal created by the PC 14 to the external device 20.

  Further, the gate signal processing unit 54 monitors the duration of the ON state of the second gate signal when the first gate signal is OFF during the generation of the second gate signal, and the duration is set to a predetermined threshold time. When it arrives, it functions as a gate signal monitoring unit that shifts the gate signal output to the external device 20 to the OFF state.

  In the present embodiment, both the sensor port 12 and the PC 14 respectively create gate signals. Therefore, in order to shorten the gate delay time Td as much as possible and supply the gate signal to the external device 20 in real time, the gate signal processing unit 54 of the sensor port 12 creates the second gate signal and outputs it to the external device 20. do it.

  However, when a second gate signal that is different from the first gate signal created by the PC 14 operated by the user is created and supplied to the external device 20, the subject is inadvertently irradiated with radiation or an image. There is a risk of shooting. In order to prevent this, the gate signal processing unit 54 is safe when the second gate signal is in the on state even though the first gate signal is in the off state, and this state continues for the threshold time or longer. From the viewpoint, the gate signal output to the external device 20 is switched to the off state. Thereby, the supply of the gate signal from the gate signal processing unit 54 to the external device 20 is forcibly stopped, and the respiratory synchronization irradiation can be stopped.

  Further, the gate signal processing unit 54 centers the gate output upper limit value when the value of the respiratory signal falls to the gate output upper limit value on the inhalation side of FIG. 2 and the second gate signal changes from the off state to the on state. Respiration signal monitoring for prohibiting the transition from the on state to the off state, which is the next state change of the second gate signal, during the period in which the respiration signal fluctuates within the hysteresis width wh (see FIG. 9). It functions as a part.

  Further, the gate signal processing unit 54 focuses on the gate output upper limit when the value of the respiratory signal rises to the gate output upper limit on the expiration side in FIG. 2 and the second gate signal changes from the on state to the off state. During the period in which the respiratory signal fluctuates within the hysteresis width wh, the transition from the off state to the on state, which is the next state change of the second gate signal, is prohibited.

  Returning to FIG. 4, the gate signal creation instruction unit 44 of the PC 14 sends a gate creation start instruction and a gate creation stop instruction to the sensor port 12 via the relay box 16 due to the operation of the input operation unit 36 by the user. Send to. In this case, if the respiratory abnormality determination unit 48 determines that the respiratory action of the subject is in an abnormal state based on the temporal change of the respiratory signal included in the transfer data received from the sensor port 12, the determination result is the gate signal. The creation instruction unit 44 is also notified. Thereby, the gate signal creation instruction unit 44 notifies the sensor port 12 of the gate creation stop instruction via the relay box 16 based on the notified determination result even when the gate signal processing unit 54 creates the second gate signal. . As a result, the gate signal processing unit 54 stops the generation of the second gate signal based on the received gate generation stop instruction.

  On the other hand, if the respiratory abnormality determination unit 48 determines that the breathing motion has been restored from the abnormal state to the normal state, the respiratory abnormality determination unit 48 also notifies the gate signal creation instruction unit 44 of the determination result. The gate signal creation instruction unit 44 notifies the sensor port 12 of a gate creation start instruction via the relay box 16 based on the notified determination result even when the gate signal processing unit 54 stops the creation of the second gate signal. Thereby, the gate signal processing unit 54 resumes the creation of the second gate signal based on the received gate creation start instruction.

  The gate cutoff switch 50 and the functions in the sensor port 12 and the PC 14 related to the gate cutoff switch 50 will be described later.

  The respiratory synchronization system 10 according to the present embodiment is configured as described above. Next, characteristic functions of the respiratory synchronization system 10 (first embodiment, second embodiment) will be described.

[4. Function of First Embodiment]
In the first embodiment, the above-described item 2. This is a characteristic function of the respiratory synchronization system 10 for solving the problem of the comparative example described in the above.

  That is, a first object of the first embodiment is to provide the respiratory synchronization system 10 in which the gate delay time Td is shortened. Moreover, 1st Embodiment sets it as the 2nd objective to provide the respiration synchronization system 10 which improved the reliability and safety | security of the gate signal. Furthermore, a first object of the first embodiment is to provide a respiratory synchronization system 10 that is not easily affected by noise included in the respiratory signal.

  In order to achieve the first and second objects, in the first embodiment, the software in the PC 14 (the component that functions by the software) executes the process of creating the first gate signal based on the respiratory signal, while the sensor port 12 The second gate signal generation process based on the respiratory signal is also executed in parallel with the firmware (the component that functions by) of the first firmware. That is, in the respiratory synchronization system 10, the second gate signal created by the firmware is normally output to the external device 20, while the first gate signal is output to the external device 20 when the second gate signal is not being created. To do.

  As described above, the second gate signal created by the firmware of the sensor port 12 is normally output to the external device 20. Accordingly, the second gate signal having a short gate delay time Td that does not include the communication time between the sensor port 12 and the PC 14 and the software processing time of the PC 14 can be output to the external device 20.

  In the first embodiment, when the second gate signal is in the on state and the time period in which the first gate signal is in the off state continues for a certain time, the gate signal supplied to the external device 20 is in the off state. To. As described above, the second gate signal created by the firmware and the first gate signal created by the software are collated, and if the ON state of the second gate signal and the OFF state of the first gate signal continue for a certain time or more, it is safe. The off-state gate signal is output to the external device 20. Accordingly, it is possible to avoid the risky on-state gate signal from being continuously output due to a malfunction in the generation process of the gate signal, and to output a highly reliable and safe gate signal to the external device 20. it can.

  Furthermore, in the first embodiment, when it is detected that the breathing motion of the subject according to the breathing signal is in an abnormal state, the first gate signal and the second gate signal generation process are stopped, The second gate signal is turned off to wait for restoration to the normal state. When the normal state is restored, the creation processing of the first gate signal and the second gate signal is resumed. As described above, advanced processing such as detection of an abnormal state of the respiratory signal and recovery processing after the occurrence of the abnormal state is performed by controlling the software of the PC 14, thereby realizing a high functional level similar to the conventional one. Can do.

  Furthermore, in order to achieve the third object, in the first embodiment, when the firmware creates the second gate signal from the respiration signal based on the creation condition of the gate signal, the condition for changing the state of the second gate signal When detecting (a condition for changing from an on state to an off state or from an off state to an on state), the state of the second gate signal is changed, and the respiration signal does not vary more than a certain value from the value at that time. The next state change of the second gate signal is suppressed. In this way, by providing hysteresis characteristics to the level determination process of the respiration signal, if the amplitude of noise included in the respiration signal is less than a certain value (hysteresis width), the second gate signal is again transmitted within a short period. It is possible to prevent a changing phenomenon (flapping at the time of change). Compared to software, the firmware can create the second gate signal by high-speed processing, but is more susceptible to noise included in the respiratory signal. Therefore, by taking such noise countermeasures, a more reliable second gate signal can be created and supplied to the external device 20.

[5. Operation of First Embodiment]
Next, specific operations for realizing the first embodiment will be described with reference to FIGS. Here, the same operations as those in the respiratory synchronization system 30 of the comparative example described in FIGS. 1 to 3 are denoted by the same step numbers, and detailed description thereof is omitted.

  In the respiratory synchronization system 10, the sensor port 12 further includes a gate signal processing unit 54, and the PC 14 further includes a gate signal creation instruction unit 44, and other components also perform predetermined operations in accordance with the operations of these components. Is different from the breath synchronization system 30 of the comparative example. The operation of these components is realized by executing firmware on the sensor port 12 and executing an application on the PC 14. Further, as shown in the sequence diagram of FIG. 5, also in the respiratory synchronization system 10, steps S <b> 1 to S <b> 5 are first executed as in the case of FIG. 3.

  When the user operates the input operation unit 36 of the PC 14 to instruct the start of respiratory synchronization irradiation in step S31 after the execution of step S5 is started at regular intervals, a gate signal generation instruction is issued. The unit 44 transmits, to the sensor port 12, a gate creation start instruction packet instructing the start of creation of the second gate signal. The packet for instructing the start of gate creation includes a gate mode indicating various conditions for creating the second gate signal and various parameter information.

  Accordingly, in step S32, the gate signal processing unit 54 starts generating the second gate signal based on the respiratory signal in accordance with the received gate generation start instruction. In step S <b> 33, when the created second gate signal is turned on, the gate signal processing unit 54 outputs the second gate signal to the external device 20. As a result, the external device 20 starts irradiating the subject with radiation in accordance with the input second gate signal in step S8. Note that the generation process of the second gate signal is normally continuously performed until a packet of a gate generation stop instruction is received from the PC 14.

  Thereafter, the gate signal creation unit 46 of the PC 14 executes the process of step S <b> 6, and transmits a gate output instruction (ON) packet to the sensor port 12. In the sensor port 12, output processing of the second gate signal from the gate signal processing unit 54 to the external device 20 is started. Therefore, even if the sensor port 12 receives the gate output instruction (ON), the gate signal processing unit 54 continues to output the second gate signal to the external device 20.

  When the output of the second gate signal to the external device 20 is started in step S33, the transfer data generation unit 28 outputs the gate output to the external device 20 by the gate signal processing unit 54 in the subsequent processing of step S5. The value of the signal is included in the transfer data and transmitted to the PC 14.

  Next, when the respiratory abnormality determination unit 48 determines that the respiratory action is in an abnormal state by executing step S9, the determination result is notified to the gate signal generation instruction unit 44 and the gate signal generation unit 46. Thereby, in step S <b> 34, the gate signal creation instruction unit 44 creates a gate creation stop instruction packet for instructing the stop of the creation of the second gate signal, and transmits the packet to the sensor port 12. In step S35, when the gate signal processing unit 54 of the sensor port 12 receives the gate creation stop instruction, the gate signal processing unit 54 stops the creation of the second gate signal.

  In step S10, the gate signal creation unit 46 of the PC 14 receives the determination result of the respiratory abnormality determination unit 48, stops the creation of the first gate signal, and indicates that the first gate signal is turned off. A gate output instruction (off) packet is created and transmitted to the sensor port 12. As a result, in step S36, the gate signal processing unit 54 turns off the gate signal supplied to the external device 20, and stops the irradiation of radiation by the external device 20 (step S12).

  Thereafter, in step S13, when the respiratory abnormality determination unit 48 determines that the breathing motion has been restored to the normal state, the determination result is notified to the gate signal generation instruction unit 44 and the gate signal generation unit 46. Thereby, in step S <b> 37, the gate signal creation instruction unit 44 creates a gate creation start instruction packet for instructing the start of creation (resumption of creation) of the second gate signal, and transmits the packet to the sensor port 12. In step S38, when receiving the gate creation start instruction, the gate signal processing unit 54 of the sensor port 12 resumes the creation of the second gate signal. As a result, in step S39, the gate signal processing unit 54 resumes the output of the second gate signal and resumes radiation irradiation by the external device 20 (step S16).

  Further, the gate signal creation unit 46 of the PC 14 resumes the creation of the first gate signal in step S <b> 14, and transmits a gate output instruction (ON) packet including the value of the created first gate signal to the sensor port 12.

  Thereafter, in the next step S40, when the generated second gate signal is turned off, the gate signal processing unit 54 shifts the second gate signal from the on state to the off state, and converts the off-state second gate signal to the off state. Output to the external device 20. Thereby, in step S19, the external device 20 stops the irradiation of the radiation to the subject according to the supplied second gate signal.

  On the other hand, also in the PC 14, in step S <b> 17, the gate signal creation unit 46 shifts the first gate signal from the on state to the off state, and transmits a packet of a gate output instruction (off) to the sensor port 12.

  In the next step S41, when the user operates the input operation unit 36 of the PC 14 to instruct the end of the respiration synchronization irradiation, the gate signal generation instruction unit 44 generates a packet of a gate generation stop instruction and generates a sensor port 12. Send to. In step S42, when receiving the gate creation stop instruction, the gate signal processing unit 54 of the sensor port 12 stops the creation of the second gate signal. Although the second gate signal is already in the off state, the second gate signal in the on state is erroneously output from the gate signal processing unit 54 to the external device 20 by stopping the generation of the second gate signal. Can be prevented.

  Finally, the data transfer instruction unit 42 performs the process of step S20 and transmits a data transfer stop instruction packet to the sensor port 12, and the transfer data generation unit 28 performs the process of step S21 and issues a data transfer stop instruction. The data transfer operation to the PC 14 is stopped.

  Next, details of a part of processing in the sensor port 12 in the sequence diagram of FIG. 5 will be described with reference to FIGS. 6A to 6C.

  FIG. 6A is a flowchart illustrating the processing of the gate signal processing unit 54 (see FIG. 4) when receiving a gate output instruction packet from the PC 14. In this case, when the parameter included in the packet is a gate output instruction (ON) in which the first gate signal is on (step S51: YES), the gate signal processing unit 54 determines whether the first gate signal is in the first gate in step S52. Set the signal value to 1 (on state). On the other hand, when the parameter included in the packet is a gate output instruction (OFF) for turning off the first gate signal (step S51: NO), the gate signal processing unit 54 determines that the first gate signal in step S53. Is reset to 0 (off state). By such processing, the gate signal processing unit 54 can supply the first gate signal to the external device 20 instead of the second gate signal when the generation of the second gate signal is stopped. It becomes.

  FIG. 6B is a flowchart illustrating the processing of the gate signal processing unit 54 when a gate creation start instruction packet is received from the PC 14 in steps S32 and S38 of FIG. In this case, when receiving the packet, the gate signal processing unit 54 receives the second packet in the gate signal processing unit 54 based on the creation conditions (gate output upper limit value, gate output lower limit value, etc.) included in the packet in step S54. Initialize the gate signal creation conditions. In the next step S55, the gate signal processing unit 54 sets a second gate signal creation flag indicating that the second gate signal is being created to 1. As a result, the gate signal processing unit 54 is ready to generate the second gate signal, and each unit in the sensor port 12 can recognize that the second gate signal is being generated.

  FIG. 6C is a flowchart illustrating the processing of the gate signal processing unit 54 when a gate creation stop instruction packet is received from the PC 14 in steps S35 and S42 of FIG. In this case, when receiving the packet, the gate signal processing unit 54 resets the second gate signal generation flag to 0 in step S56. As a result, the gate signal processing unit 54 can stop the generation of the second gate signal and can make each part in the sensor port 12 recognize the stop of the generation of the second gate signal.

  The transmission / reception of signals or information among the external device 20, the sensor port 12, and the PC 14 in the first embodiment of the respiratory synchronization system 10 is as described above. Next, the gate signal creation processing in the sensor port 12 will be described more specifically with reference to FIGS. Here, the operation of the gate signal processing unit 54 will be mainly described.

  FIG. 7 is a flowchart for explaining the processing operation of the gate signal processing unit 54. The operations shown in FIG. 7 include a case where the second gate signal is generated and output to the external device 20, a case where the first gate signal is output to the external device 20 instead of the second gate signal, and a gate in the off state. There are cases where a signal is forcibly output. Accordingly, FIG. 7 corresponds to the processes of steps S2, S32, S33, S35, S36, S38, S39, S40, and S42 in FIG.

  Specifically, the gate signal generation process in the gate signal processing unit 54 is a process performed at the head part of the gate signal process, and is always executed at regular intervals (for example, 2.5 ms) in the form of timer interruption. The

  That is, in step S61, the gate signal processing unit 54 determines whether or not the second gate signal generation flag is 1. Since the second gate signal creation flag is 0 in the initial state such as step S2 (step S61: NO), the gate signal processing unit 54 supplies the first gate signal to the external device 20 in the next step S62. Set as a power gate signal. Thereby, the gate signal processing unit 54 supplies the first gate signal to the external device 20 according to the set content.

  Further, the gate signal processing unit 54 has a timer (not shown). In step S63, the value of the timer is reset to 0, and the current process is terminated.

  Thereafter, when the sensor port 12 receives the packet for instructing the start of gate creation in step S32 or the like, the gate signal processing unit 54 has set the second gate signal creation flag to 1 (step S61: YES). In S64, the second gate signal is created. Accordingly, since the second gate signal generation flag is 1 and the generation process of the second gate signal is being performed, the gate signal processing unit 54 supplies the second gate signal to the external device 20 in step S65. Set as the gate signal to be used.

  In the next step S66, the gate signal processing unit 54 determines whether or not the second gate signal is 1 (on state) and the first gate signal is 0 (off state). If the second gate signal is 0 or the first gate signal is 1 (step S66: NO), the gate signal processing unit 54 performs the process of step S63 to reset the timer to 0, and this time Terminate the process.

  On the other hand, when the second gate signal is 1 and the first gate signal is 0 in step S66 (step S66: YES), the gate signal processing unit 54 determines that the timer value is less than 200 (step S67: YES), in step S68, the timer value is incremented by 1, and the current process is terminated.

  If the timer value reaches 200 in step S67 as a result of repeatedly performing the process of FIG. 7 (step S67: NO), the gate signal processing unit 54 determines the gate signal to be supplied to the external device 20 in step S69. Is turned off to end the current process.

  When the first gate signal is 0 and the second gate signal is 1 (step S66: YES), the PC 14 issues an instruction to turn off the first gate signal. Nevertheless, it means that the second gate signal is on. In this case, if the supply of the second gate signal from the sensor port 12 to the external device 20 is continued, the subject may be inadvertently irradiated with radiation.

  Therefore, the gate signal processing unit 54 has a timer for monitoring that the abnormal state of the gate signal continues, in which the second gate signal is 1 and the first gate signal is 0. Accordingly, when the process shown in FIG. 7 is executed every 2.5 ms, the timer value is incremented by 1, and the timer value reaches 200, that is, 500 ms (= 2.5 ms × 200 from the start of timer timing). After that, the gate signal processing unit 54 turns off the output of the gate signal from the sensor port 12 to the external device 20 until the abnormal state of the gate signal is resolved thereafter.

  Next, the processing in step S64 in FIG. 7 will be described in more detail with reference to the flowchart in FIG. 8 and the timing chart in FIG.

  In step S71, the gate signal processing unit 54 determines whether or not the gate change inhibition flag is 0.

  Here, the gate change inhibition flag will be described with reference to FIG. When the respiratory signal changes in a substantially sine wave shape with the passage of time (see FIG. 2), the gate signal processing unit 54 turns off the second gate signal when the value of the respiratory signal decreases to the gate output upper limit value at time t1. Transition from state to on state. In this case, the gate signal processing unit 54 maintains the second gate signal in the ON state from the time point t1 to the time point t2, and then when the value of the respiratory signal increases to the gate output upper limit value at the time point t2, Transition from the on state to the off state.

  By the way, as shown in FIG. 9, when noise is included in the respiratory signal, for example, when the respiratory signal is turned on at time t1 and the value of the respiratory signal rises to the gate output upper limit value at time t7 immediately after time t1. The gate signal processing unit 54 shifts the second gate signal from the on state to the off state. Then, when the value of the respiratory signal decreases to the gate output upper limit value at time t8 after time Tc1 has elapsed from time t7, the state is shifted to the ON state.

  In other words, the second gate signal is ideally turned on from the time t1 to the time t2 during the period T. However, if the noise shown by the solid line is superimposed on the ideal respiratory signal waveform shown by the alternate long and short dash line in FIG. 9, a flutter (chattering) occurs when the state of the second gate signal changes at time t1.

  This may also occur when the state of the second gate signal changes at time t2. In this case, when the value of the respiratory signal falls to the gate output upper limit value at time t9 immediately after time t2, the gate signal processing unit 54 shifts the second gate signal from the off state to the on state, and time Tc2 has elapsed from time t9. When the value of the respiratory signal rises to the gate output upper limit at a later time t10, the state is shifted to the off state.

  Therefore, in the respiratory synchronization system 10, the gate signal processing unit 54 of the sensor port 12 sets a hysteresis width of wh up and down around the gate output upper limit value around the time points t1 and t2. After the time point t1, when the respiratory signal moves up and down within the hysteresis width wh, the gate signal processing unit 54 maintains the ON state of the second gate signal and shifts to the OFF state that is the next state change. Ban. In addition, when the respiratory signal moves up and down within the hysteresis width wh after the time point t2, the gate signal processing unit 54 maintains the second gate signal in the off state, and shifts to the on state, which is the next state change. Ban. As a result, the occurrence of fluttering when the state of the second gate signal changes due to noise superimposed on the respiratory signal is suppressed.

  Returning to FIG. 8, the gate change inhibition flag in step S71 is set to 1 when the state of the second gate signal changes, and is 1 while the respiratory signal remains within the hysteresis width wh. It is a flag that takes Therefore, the gate change inhibition flag has a role of inhibiting the next state change of the second gate signal during the period within the hysteresis width wh. Note that the gate change suppression flag is 0 at times other than this period.

  Here, the hysteresis width wh needs to be larger than the amplitude of noise superimposed on the respiratory signal. Therefore, the hysteresis width wh may be set to a predetermined value (for example, 2% of the variable range of the respiration signal) or may be specified by a parameter of a packet of a gate signal creation start instruction from the PC 14.

  Therefore, in the initial state such as step S2 in FIG. 5, since the sensor port 12 has not received the packet for starting the gate creation, the gate change inhibition flag is 0 in FIG. 8 (step S71: YES), and The 2-gate signal is also 0 (step S72: YES).

  Next, the gate signal processing unit 54 checks whether or not the current respiratory signal value falls within the gate creation condition, that is, between the gate output upper limit value and the gate output lower limit value (step S73). If the value of the respiration signal is between the gate output upper limit value and the gate output lower limit value (step S73: YES), the gate signal processing unit 54 sets the second gate signal to 1 in step S74, and the next step In step S75, the gate change suppression flag is set to 1, and the process in step S64 is completed.

  On the other hand, if there is no respiratory signal value between the gate output upper limit value and the gate output lower limit value (step S73: NO), the gate signal processing unit 54 immediately ends the process of step S64.

  Next, when the gate change inhibition flag is 1 in step S71, that is, immediately after the state of the second gate signal is changed (step S71: NO), in the next step S76, the gate signal processing unit 54 It is checked whether or not the value of the current respiratory signal is within the hysteresis width wh. If the value of the respiration signal is within the hysteresis width wh (step S76: YES), the gate signal processing unit 54 immediately ends the process of step S64. That is, the state of the second gate signal once turned on or off at time t1 or time t2 is maintained, and the next state change of the second gate signal within the hysteresis width wh due to noise is prevented. To do.

  On the other hand, if the value of the respiratory signal deviates from the hysteresis width wh (step S76: NO), in the next step S77, the gate signal processing unit 54 has to generate a state change of the second gate signal due to noise. Judgment is made, the gate change inhibition flag is reset to 0, and the process of step S64 is terminated.

  In this way, the gate change suppression flag is set to 1 when the value of the second gate signal changes, and the second gate signal is continued until the respiratory signal leaves the hysteresis width wh centered on the gate output upper limit value. It has a role to suppress state changes. Thereby, when the state of the second gate signal changes, it is possible to prevent the occurrence of a phenomenon in which the second gate signal changes again in a short period (fluctuation at the time of state change) due to noise included in the respiratory signal.

  Next, when the gate change suppression flag is 0 (step S71: YES) and the second gate signal is 1 (step S72: NO), in step S78, the gate signal processing unit 54 determines the current respiratory signal value. Is in between the gate output upper limit value and the gate output lower limit value.

  When the value of the respiration signal is not between the gate output upper limit value and the gate output lower limit value (step S78: NO), in the next step S79, the gate signal processing unit 54 resets the second gate signal to 0. To do. In the next step S80, the gate signal processing unit 54 sets the gate change inhibition flag to 1, and ends the current process in step S64.

  On the other hand, if the value of the respiratory signal is between the gate output upper limit value and the gate output lower limit value (step S78: YES), the gate signal processing unit 54 immediately ends the process of step S64.

[6. Effect of First Embodiment]
As described above, in the first embodiment, the gate signal processing unit 54 provided in the sensor port 12 connected to the external device 20 creates the second gate signal and outputs it to the external device 20. Thereby, the gate delay time Td of the gate signal output to the external device 20 can be easily and reliably shortened. As a result, a gate signal can be supplied to the external device 20 in real time, and the external device 20 can be operated in synchronization with breathing with higher accuracy.

  That is, in the first embodiment, the process of creating the gate signal from the respiratory signal is performed in parallel with the firmware of the sensor port 12 in addition to the conventional software of the PC 14. Therefore, normally, the second gate signal created by the firmware is output to the external device 20. As a result, normally, the second gate signal created by the firmware is output to the external device 20, so that the communication delay time between the sensor port 12 and the PC 14 and the processing time of the software are not included. A short gate signal can be output to the external device 20.

  If the second gate signal is not being created, the gate signal processing unit 54 supplies the first gate signal to the external device 20 in order to operate the external device 20 reliably.

  Further, the gate signal creation instruction unit 44 notifies the sensor port 12 of a gate creation start instruction for instructing the start of creation of the second gate signal and a gate creation stop instruction for instructing to stop the creation of the second gate signal. The gate signal processing unit 54 can reliably generate the second gate signal after receiving the gate generation start instruction until receiving the gate generation stop instruction.

  Further, the gate signal processing unit 54 of the sensor port 12 monitors the duration of the ON state of the second gate signal when the first gate signal is OFF during the generation of the second gate signal, When the threshold time (500 ms in the first embodiment) is reached, the second gate signal is shifted to the off state. When the second gate signal created by the firmware is on and the first gate signal created by the software is off, and this state continues for a certain period of time, the gate signal is turned off and the external device 20 is turned off. Output to. Thereby, it is possible to supply a gate signal with high safety and reliability.

  That is, if the second gate signal in the ON state is continuously generated on the sensor port 12 side even though the first gate signal in the OFF state is generated on the PC 14 side, it is supplied to the external device 20. By forcibly shifting the gate signal to the OFF state, it is possible to prevent unnecessary gate signals from being supplied to the external device 20 and inadvertently performing radiation therapy or image capturing on the subject.

  In this way, the second gate signal created by the firmware is compared with the first gate signal created by the software, and if the second gate signal on state and the first gate signal off state continue for a certain time or longer, By outputting a safe-side off-state gate signal to the device 20, it is possible to prevent the danger-side on-state gate signal from being continuously output due to a malfunction in the gate signal creation process in the firmware or software. In addition, a highly reliable and safe gate signal can be output to the external device 20.

  The PC 14 also includes a respiratory abnormality determination unit 48 that determines whether or not the respiratory action is in an abnormal state based on the respiratory signal. Thereby, the gate signal creation instruction unit 44 transmits a gate creation stop instruction to the sensor port 12 when the breathing abnormality determination unit 48 determines that the breathing operation is in an abnormal state, while the breathing operation is started from the abnormal state. When the respiratory abnormality determination unit 48 determines that the normal state has been restored, a gate creation start instruction can be transmitted to the sensor port 12. Even in this case, it is possible to supply a gate signal with high safety and reliability.

  That is, when the software detects an abnormal state of the respiratory signal, the second gate signal creation process by the firmware is stopped, the second gate signal is turned off, the recovery from the abnormal state is waited, and the firmware is restored when the normal state is restored. The second gate signal creation process is resumed. Therefore, advanced processing such as detection of an abnormal state of the respiratory signal and recovery processing from the abnormal state is performed by software control, and in the first embodiment, a high processing level similar to the conventional one is realized. Can do.

  The gate creation start instruction includes the designated gate output upper limit value and gate output lower limit value as conditions for changing the state of the second gate signal. When the gate signal processing unit 54 of the sensor port 12 creates the second gate signal based on this change condition, after the state of the second gate signal changes, a predetermined hysteresis centered on the gate output upper limit value is obtained. When the respiratory signal varies within the range of the width wh, the next state change of the second gate signal is prohibited.

  That is, when the firmware detects the condition for changing the state of the second gate signal when the firmware generates the second gate signal from the respiration signal based on the generation condition of the second gate signal, the state of the second gate signal is changed. While changing, the next state change of the second gate signal is suppressed as long as the respiration signal does not change from the value at that time by the hysteresis width wh or more.

  Thus, while the respiratory signal fluctuates within the hysteresis width after the second gate signal changes, the next state change of the second gate signal is prohibited, thereby causing noise included in the respiratory signal. Thus, it is possible to prevent the occurrence of a phenomenon in which the state of the second gate signal changes again in a short period after the state change of the second gate signal (fluctuation at the time of state change).

[7. Configuration of Second Embodiment]
Next, a second embodiment of the respiratory synchronization system 10 according to the present embodiment will be described with reference to FIGS.

  In the second embodiment, as shown in FIG. 4, a gate cutoff switch 50 is provided on the PC 14 side, and a power supply unit 52 and a gate signal processing unit 54 are provided on the sensor port 12. In the second embodiment, the gate signal output from the gate signal processing unit 54 to the external device 20 is forcibly stopped due to the user's operation of the gate cutoff switch 50. The second embodiment will be described in detail below.

  As described in the first embodiment, the gate signal processing unit 54 creates a gate signal to be supplied to the external device 20 according to the flowchart of FIG. Therefore, in the following description of the second embodiment, “gate signal” refers to a signal supplied from the gate signal processing unit 54 to the external device 20.

  As shown in FIG. 10, three wires are provided between the sensor port 12 and the gate cutoff switch 50. Of these, two are a power supply line 58 and a ground line 60 as power supply lines, and the remaining one is a gate cutoff signal line 62. In the power supply unit 52, a resistor 64 having a resistance value R1 is connected to a power line 58.

  In the gate cutoff switch 50, a light emitting diode (LED) 66 as a light emitting element and a normally open type switch unit 68 are connected in series. In this case, a power line 58 is connected to the anode side of the LED 66. A gate cutoff signal line 62 is connected to a connection point 70 between the cathode side of the LED 66 and the switch unit 68. The end of the switch unit 68 opposite to the connection point 70 is grounded to the earth 72 of the sensor port 12 via the ground line 60. In the sensor port 12, a resistor 74 having a resistance value R2 (R1 << R2) is connected between the gate cutoff signal line 62 and the ground line 60. The LED 66 and the switch unit 68 constitute a series circuit 76.

  In this case, when power is supplied from the power supply unit 52 to the gate cutoff switch 50 via the resistor 64, the power supply line 58, and the ground line 60 (for example, + 5V power supply), the switch unit 68 is pressed. If not, since the resistance value R2 of the resistor 74 is large, only a slight forward current flows through the LED 66, and the LED 66 remains off. In this state, since the voltage drop of the resistor 64 and the LED 66 is small, the gate cutoff signal line 62 becomes a high level voltage close to + 5V.

  On the other hand, since the resistor 74 is short-circuited by the switch unit 68 while the switch unit 68 is pushed and is in a conductive state, a large forward current flows through the LED 66 and the LED 66 is lit. In this case, the gate cutoff switch 50 outputs a signal corresponding to the potential at the connection point 70 to the sensor port 12 via the gate cutoff signal line 62 as a gate cutoff signal. In addition, when the switch part 68 will be in a conduction | electrical_connection state, since the earth | ground 72 and the connection point 70 become the substantially same electric potential, a gate interruption | blocking signal turns into a low level signal near 0V.

  The gate signal processing unit 54 stops outputting the gate signal to the external device 20 when the switch unit 68 is pressed and a low-level gate cutoff signal is input. On the other hand, when the switch unit 68 is opened and the low-level gate cutoff signal is not input, the gate signal processing unit 54 resumes the output of the gate signal to the external device 20.

  The gate signal processing unit 54 stops the output of the gate signal to the external device 20 due to the input of the gate cutoff signal, and then the gate cutoff signal is input due to the switch unit 68 returning to the open state. When stopping and restarting the output of the gate signal, it functions as a mode setting unit for setting the operation mode of the gate cutoff switch 50 for the sensor port 12. Specifically, as shown in FIG. 11, the gate signal is a pulse signal that is repeatedly generated every predetermined period T. Therefore, the gate signal processing unit 54 outputs the gate signal when the input of the gate cutoff signal is stopped. Is set to the first mode (therapeutic mode) that immediately restarts, or is set to the second mode (diagnostic mode) that resumes the output of the gate signal from the rise of the next pulse signal when the input of the gate cutoff signal stops .

  FIG. 11 illustrates a case where the switch unit 68 is pressed for the time Tg from time t11 to time t12. In this case, in the first mode, the output of the gate signal is resumed immediately after the time Tg from the time point t12.

  On the other hand, in the second mode, the output of the gate signal is not resumed at time t12, the second pulse signal is turned off at time t13, and the third pulse is reached at time t14 after the elapse of time Ts from time t11. At the timing when the signal is turned on, the output of the gate signal to the external device 20 is resumed. Thereby, the gate signal always rises at a timing synchronized with the respiratory signal.

  The treatment mode refers to a gate signal supply mode in the case where the external device 20 is a radiotherapy apparatus and performs radiotherapy for irradiating a subject with radiation. The diagnostic mode is a gate signal supply mode in the case where an image is taken on a subject when the external device 20 is an image diagnostic apparatus.

  Also in the second embodiment, packets of transfer data are transmitted from the sensor port 12 to the PC 14 at regular intervals. Therefore, when a gate cutoff signal is input from the gate cutoff switch 50 to the sensor port 12, the gate signal processing unit 54 sets the first mode or the second mode, and the external device depends on the operation mode set by the gate signal processing unit 54. When the output of the gate signal to 20 is stopped or restarted, the transfer data generation unit 28 can include information indicating these situations in the transfer data and transmit it to the PC 14. Accordingly, when the PC 14 receives the transfer data, the display unit 38 can also display information on the operation state of the gate cutoff switch 50 on the screen.

[8. Characteristic functions of the second embodiment]
Next, characteristic functions of the second embodiment will be described.

  First, in the second embodiment, the gate cutoff switch 50 is connected to the external device 20 when an abnormality such as a sudden change in the respiratory state occurs in the subject during the execution of radiation therapy or image capturing on the subject. The output gate signal immediately shifts to the OFF state, and functions as an operating means for stopping radiation irradiation or image capturing.

  Therefore, the gate cutoff switch 50 is hardly operated normally. However, since it is an important safety measure to stop radiation exposure and image capture when the subject is abnormal, it will not break down during actual use and will not fail to perform its original function. There is a need to. Therefore, in the second embodiment, a single failure of any one of the components constituting the gate cutoff switch 50 or the like, that is, only one component fails, and the other components appear to be normal. When a malfunction occurs, the influence of the malfunction on the subject is avoided and the situation where the operation of the gate cutoff switch 50 does not work is avoided.

  That is, in the second embodiment, the user presses the switch unit 68 to turn on the LED 66 in a state where power is supplied from the power supply unit 52 to the gate cutoff switch 50 prior to radiation irradiation or image capturing, and It is confirmed in advance that the LED 66 is turned off by releasing the hand from the switch unit 68. As a result of this prior confirmation, a failure phenomenon that appears when a single failure of each component constituting the gate cutoff switch 50 and the like occurs will be described below.

  (1) If a short circuit failure or an open failure of the LED 66 has occurred, the LED 66 will not light even if the switch unit 68 is pressed during prior confirmation. Accordingly, it is possible to detect a short circuit failure or an open failure of the LED 66 by the prior confirmation.

  (2) When a short circuit failure of the switch unit 68 occurs, the resistor 74 is in a short circuit state, so that the LED 66 is always lit even if the switch unit 68 is not pressed. Therefore, it is possible to detect a short circuit failure of the switch unit 68 by prior confirmation.

  (3) When an open failure of the switch unit 68 occurs, the LED 66 is not lit even if the switch unit 68 is pressed. Therefore, it is possible to detect an open failure of the switch unit 68 by prior confirmation.

  (4) The resistor 64 functions as a current limiting resistor that suppresses the current flowing through the power supply line 58. Therefore, when a short circuit failure of the resistor 64 has occurred, an excessive current flows through the power supply line 58 at the time of prior confirmation. Therefore, it is possible to detect in advance a short circuit failure of the resistor 64 by detecting an excessive current with a current sensor or the like (not shown). Note that the detection result of the current sensor may be included in the transfer data and transmitted from the sensor port 12 to the PC 14 to notify the user.

  (5) If an open failure of the resistor 64 has occurred, the LED 66 will not light up even if the switch unit 68 is pressed during prior confirmation. Therefore, it is possible to detect an open failure of the resistor 64 by prior confirmation.

  (6) When a short circuit failure of the resistor 74 has occurred, the state is the same as when the switch unit 68 is pressed during normal operation. Therefore, the LED 66 is always lit even if the switch unit 68 is not pressed. Therefore, it is possible to detect a short circuit failure of the resistor 74 by prior confirmation.

  (7) When the open circuit failure of the resistor 74 has occurred, the resistance value R2 is in a very large value. At the time of prior confirmation, when the switch unit 68 is pressed, the LED 66 is lit, and the switch unit 68 When the hand is released, the LED 66 is turned off. This state is not affected by a failure in the operation of the gate cutoff switch 50 and operates normally.

  (8) When the disconnection of the power supply line 58 has occurred, the LED 66 is not lit even if the switch unit 68 is pressed during prior confirmation. Therefore, it is possible to detect a disconnection failure of the power supply line 58 by prior confirmation.

  (9) When the disconnection of the gate cutoff signal line 62 has occurred, the gate cutoff signal line 62 continues to be output from the gate cutoff switch 50 because the potential of the gate cutoff signal line 62 is always low. In this case, it becomes a failure failure to the safe side. As for the result of the failure, the operation state of the gate cut-off switch 50 is included in the transfer data and notified from the sensor port 12 to the PC 14, and the display unit 38 of the PC 14 displays (notifies) the information on the operation state. Thus, the user can detect the operation state in advance.

  (10) When the ground line 60 is disconnected or the power supply line 58 and the gate cutoff signal line 62 are short-circuited, the LED 66 is not lit even when the switch unit 68 is pressed at the time of prior confirmation. Therefore, it is possible to detect a disconnection of the ground line 60 or a short circuit between the power supply line 58 and the gate cutoff signal line 62 by prior confirmation.

  (11) When a short circuit occurs between the ground line 60 and the gate cutoff signal line 62, the LED 66 is always lit even if the switch unit 68 is not pressed. Therefore, it is possible to detect a short circuit between the ground line 60 and the gate cutoff signal line 62 by prior confirmation.

  (12) When a short circuit occurs between the power supply line 58 and the ground line 60, the LED 66 is not lit even if the switch unit 68 is pressed during prior confirmation. Therefore, it is possible to detect a short circuit between the power supply line 58 and the ground line 60 by prior confirmation.

  As described above, all failures other than (7) and (9) can be detected by prior confirmation. That is, the failure (7) does not affect the operation of the gate cutoff switch 50. Further, in the case of the failure (9), since the gate cutoff operation is always performed, it becomes a safety-side failure that the gate signal is not output to the external device 20.

  As a result, it is possible to avoid the occurrence of a failure in which the gate cutoff switch 50 does not work during radiation irradiation or image capturing. As for the failure (9), as described above, the sensor port 12 notifies the PC 14 of the state of the gate cutoff signal, and the state of the gate cutoff switch 50 is displayed on the screen of the display unit 38 by software. If notified to the person, it becomes possible to detect in advance.

  By the way, when the external device 20 is a radiotherapy apparatus, the radiotherapy apparatus irradiates radiation when the gate signal is on, and stops radiation when the gate signal is off. On the other hand, when the external device 20 is an image diagnostic apparatus such as CT or MRI, imaging is performed at the rising edge of the gate signal (when the state changes from the off state to the on state).

  Therefore, when the gate cutoff switch 50 is operated, the sensor port 12 immediately turns off the gate signal. Then, regarding the method of restarting the output of the gate signal after the operation of the gate cut-off switch 50 is released, the sensor port 12 has a first mode (treatment mode) and a second mode (diagnosis) according to the requirements of the external device 20. Mode) and two operation modes. Accordingly, the sensor port 12 resumes the output of the gate signal by operating in any one of the operation modes. This operation mode may be instructed to the sensor port 12 by the software as part of the initialization instruction for the sensor port 12 (see step S1 in FIG. 3 and FIG. 5) based on information set in the software of the PC 14 in advance.

  As shown in FIG. 11, when the user presses down the gate cutoff switch 50 for a time Tg from time t11 to time t12, in the first mode, the gate signal is turned off only during the period when the gate cutoff switch 50 is operated. When the operation of the gate cutoff switch 50 is released, the output of the gate signal is immediately resumed. Thereby, in the first mode, the gate signal is output from time t12. As a result, in the case of radiotherapy, the treatment time can be shortened.

  On the other hand, in the second mode, in addition to the period (time Tg) in which the gate cutoff switch 50 is operated, the gate signal is turned off until the falling edge of the pulse signal after the operation is released (time point t13). Then, the gate output is restarted from the rise of the next pulse signal (time t14). That is, the output of the gate signal is prohibited during time Ts from time t11 to time t14.

  Accordingly, in the case of image diagnosis such as CT and MRI, when the operation of the gate cutoff switch 50 is released, imaging is resumed in synchronization with the breathing operation of the subject from the rise of the next pulse signal. Thereby, it is possible to prevent the diagnostic image from being disturbed by the operation of the gate cutoff switch 50.

[9. Operation of Second Embodiment]
Next, the operation of the second embodiment will be described with reference to FIG. FIG. 12 illustrates the gate blocking process in the gate signal processing unit 54 of the sensor port 12.

  The gate cut-off process is a process performed at the final part of the gate signal process, that is, a stage in which the gate signal is output from the sensor port 12 to the external device 20, and is in the form of a timer interrupt in a certain cycle (for example, 2.5 ms). Always executed every time.

  In the sensor port 12, in the initial state, the value of the gate signal created by the flowchart of FIG. 7 is 0 (step S81: NO), so the gate signal processing unit 54 performs the second mode (diagnostic mode) in step S82. ), The gate cutoff flag indicating that the gate cutoff operation is being executed is reset to zero. Thereafter, in step S83, the value of the gate signal output from the gate signal processing unit 54 to the external device 20 is set to 0 (off state), and the current process ends.

  Next, when the supply of the first gate signal from the PC 14 to the sensor port 12 is started or the generation of the second gate signal is started by the gate signal processing unit 54, the gate signal becomes 1 (ON state). (Step S81: YES). Therefore, in step S84, the gate signal processing unit 54 checks the value of the gate cutoff signal input from the gate cutoff switch 50.

  In this case, if the gate cut-off signal is a high level signal, the switch unit 68 is not pushed (step S84: NO), so in the next step S85, the gate signal processing unit 54 sets the gate cut-off flag. It is determined whether or not it is zero. In the initial state, since the gate cutoff flag is 0 (step S85: YES), the gate signal processing unit 54 sets the value of the gate signal to be output to the external device 20 to 1 in step S83, and this process Exit. That is, the gate signal processing unit 54 supplies the gate signal in the on state to the external device 20.

  Next, when the switch section 68 of the gate cutoff switch 50 is pressed and the gate cutoff signal becomes a low level signal (step S84: YES), in the next step S86, if it is the second mode (diagnostic mode) (step (S86: YES), the gate signal processing unit 54 sets the gate cutoff flag to 1 in step S87, and sets the value of the gate signal output to the external device 20 to 0 in the next step S88. Thereby, the gate signal processing unit 54 outputs the gate signal in the off state to the external device 20 in step S83.

  The gate cutoff flag is a control flag for storing in the storage unit 22 that the gate cutoff operation has been started in the second mode. In this case, once the gate cutoff flag is set (step S85: NO), even if the gate cutoff switch 50 is released and the gate cutoff signal returns to the high level signal, the gate signal is changed to 0 in step S88. The gate signal in the off state is output to the external device 20. Accordingly, in the second mode, the gate cutoff operation is continued until the gate signal created by the flowchart of FIG. 7 becomes 0 and the gate cutoff flag is reset to 0.

  On the other hand, in the first mode (therapeutic mode) (step S86: NO), since the gate cutoff flag is not set, the gate cutoff switch 50 of the gate cutoff switch 50 is pushed and the gate cutoff is limited only when the gate cutoff signal is zero. Will perform the action.

[10. Effect of Second Embodiment]
Conventionally, when performing radiotherapy or imaging on a subject, the user detects that the subject's breathing motion is abnormal based on the appearance of the subject or temporal changes in the respiratory signal. For example, the person operates the input operation unit 36 of the PC 14 to instruct the PC 14 to stop the supply of the gate signal, thereby stopping the supply of the gate signal to the external device 20, and performing radiation therapy or imaging by the external device 20. Had stopped.

  On the other hand, when the breathing motion of the subject is restored from the abnormal state to the normal state, the user who has recognized the restoration operates the input operation unit 36 to instruct the PC 14 to resume the supply of the gate signal, The supply of the gate signal to the external device 20 is resumed, and the radiotherapy or image capturing for the subject is resumed.

  However, when stopping the supply of the gate signal from the input operation unit 36 of the PC 14, for example, a series of operations such as clicking the cursor after moving the cursor to a specific position is required. And it was difficult to perform without error.

  Therefore, in the second embodiment, as described above, when the user detects that the breathing motion of the subject is in an abnormal state during the execution of radiotherapy or image capturing on the subject, the user switches the switch. By pushing the part 68, a gate cutoff signal is output from the gate cutoff switch 50 to the sensor port 12. Since the sensor port 12 stops the supply of the gate signal to the external device 20 based on the gate cutoff signal, the radiotherapy or the imaging is stopped.

  Therefore, according to the second embodiment, when the breathing motion of the subject is in an abnormal state, the supply of the gate signal is stopped only by the user pressing the switch unit 68, thereby enabling radiotherapy or imaging. Stopped. As a result, in the second embodiment, the supply of the gate signal is stopped as compared with a method in which the input operation unit 36 of the PC 14 performs a series of operations such as clicking the cursor after moving the cursor to a specific position with the mouse. Can be performed quickly and reliably without errors by a simple operation.

  Moreover, in the second embodiment, the following effects can be obtained by configuring the respiratory synchronization system 10 as described above.

  That is, the LED 66 and the switch unit 68 are connected in series in the gate cutoff switch 50, and the power supply line 58, the ground line 60, and the gate cutoff signal line 62 are connected to the series circuit 76. Therefore, before the user operates the respiratory synchronization system 10, it is possible to confirm in advance that the gate cutoff switch 50 functions normally by pressing the switch unit 68 and confirming whether the LED 66 is lit. Become. As a result, even if the user presses the switch unit 68 during radiotherapy or image capturing, the gate cut-off switch 50 has failed and does not function (even if the gate cut-off switch 50 is operated, the gate signal cannot be cut off due to the failure). Can be avoided.

  In the second embodiment, the gate signal processing unit 54 performs the first mode in which the supply of the gate signal to the external device 20 is immediately resumed when the input of the gate cutoff signal is stopped, or the next when the input of the gate cutoff signal is stopped. Is set to one of the second modes in which the supply of the gate signal to the external device 20 is restarted from the rise of the pulse signal.

  Accordingly, the supply of the gate signal to the external device 20 can be resumed at an accurate timing according to the type of the external device 20 in synchronization with the breathing motion of the subject.

  That is, when the external device 20 is a radiotherapy apparatus, radiation is applied during the gate signal supply period, so that the subject's restraint time for radiotherapy is shortened as much as possible. The supply of the gate signal may be resumed immediately after the input of the cutoff signal is stopped.

  On the other hand, when the external device 20 is an image diagnostic apparatus such as CT or MRI, in order to perform image capturing in synchronization with the rising of the supply of the gate signal, after the input of the gate cutoff signal is stopped in the second mode, The supply of the gate signal may be resumed after waiting for the next pulse signal to rise. If the supply of the gate signal is resumed without synchronizing with the respiratory signal, the image quality of the acquired diagnostic image is degraded.However, the supply of the gate signal is resumed after waiting for the next pulse signal to rise. It is possible to acquire a higher-quality diagnostic image that is photographed synchronously.

  Note that the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Respiration synchronization system 12 ... Sensor port 14 ... PC 18 ... Respiration sensor 20 ... External apparatus 44 ... Gate signal creation instruction | indication part 48 ... Respiration abnormality determination part 50 ... Gate interruption | blocking switch 52 ... Power supply part 54 ... Gate signal processing part 58 ... Power supply line 60 ... Ground line 62 ... Gate cut-off signal line 66 ... LED
68 ... Switch unit 70 ... Connection point 76 ... Series circuit

Claims (2)

A respiratory sensor for detecting a respiratory motion of the subject, a sensor port connected to an external device for performing radiotherapy or image capturing on the subject, and a personal computer connected to the sensor port,
A gate signal is created based on a breathing signal corresponding to the breathing motion detected by the breathing sensor, and the gate signal is supplied to the external device, so that the radiotherapy or the image capturing synchronized with the breathing motion is performed. In the respiratory synchronization system to be performed,
A gate cut-off switch for cutting off the supply of the gate signal;
The gate cut-off switch includes a light emitting element and a normally open switch unit connected in series to the light emitting element,
Two power supply lines are connected to both ends of the series circuit of the light emitting element and the switch unit, and a signal line is connected to a connection point between the light emitting element and the switch unit,
When power is supplied to the series circuit via the two power supply lines, the gate cut-off switch turns on the light emitting element while the switch unit is pushed and is in a conductive state. A gate cutoff signal corresponding to the potential of the connection point is output to the sensor port via the signal line,
The respiratory synchronization system according to claim 1, wherein the sensor port stops the supply of the gate signal to the external device based on the input of the gate cutoff signal. The respiratory synchronization system of claim 1, wherein
After the sensor port stops supplying the gate signal to the external device due to the input of the gate cutoff signal, the input of the gate cutoff signal stops due to the switch unit returning to the open state. And a mode setting unit for setting an operation mode of the gate cutoff switch when resuming the supply of the gate signal,
The gate signal is a pulse signal that is repeatedly generated in synchronization with the breathing motion of the subject,
The mode setting unit may be a first mode in which the supply of the gate signal is immediately resumed when the input of the gate cutoff signal is stopped, or when the input of the gate cutoff signal is stopped, A respiratory synchronization system, wherein the system is set to one of the second modes in which supply is resumed.

Images