Notification system, control method for notification system, and notification program

Abstract

To urge an operator to correct an initially set injection protocol, when a heart rate of a subject is fluctuated higher than a specified value.SOLUTION: A notification system 120 includes: a heart rate acquisition part 11 for acquiring a baseline heart rate and a measured heart rate of a subject obtained through measurement; a determination part 12 for determining whether or not the measured heart rate is fluctuated higher than a specified value to the baseline heart rate, by comparing the baseline heart rate with the measured heart rate; and a notification part 10 for performing notification, when it is determined that the measured heart rate is fluctuated higher than the specified value.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a notification system that performs notification when the heart rate fluctuates, etc.

Background Art

[0002] Patent Document 1 discloses a configuration in which the initial volume of a contrast agent is decreased if the patient's heart rate is below or equal to a predetermined threshold level, and the initial volume of the contrast agent is increased if the patient's heart rate is above the predetermined threshold level. Also, Patent Document 1 discloses a configuration in which the initial volume of a contrast agent is decreased if the patient's heart rate is below a predetermined threshold level, and the initial volume of the contrast agent is increased if the patient's heart rate is above or equal to the predetermined threshold level.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The heart rate of a subject, which is the object to be imaged, may fluctuate due to fear or tension towards the examination, etc. Also, the heart rate fluctuates when arrhythmia such as tachycardia or bradycardia occurs in the subject. And due to the fluctuation of the heart rate, the timing at which the contrast agent reaches the tissue to be imaged is shifted, so the timing at which the target pixel value is reached in the tissue to be imaged is also shifted. Therefore, when the heart rate fluctuates greatly, it is necessary to adjust the imaging timing, which increases the workload of the operator.

Means for Solving the Problems

[0005] To solve the above problems, as an example of the present invention, a notification system includes a heart rate acquisition unit that acquires a reference heart rate and a measured heart rate of a subject obtained by measurement, a determination unit that compares the reference heart rate and the measured heart rate and determines whether the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate, and a notification unit that performs notification when it is determined that the measured heart rate has changed by the predetermined value or more.

[0006] Further, as another example of the present invention, a control method is a control method of a notification system including a computer. The computer acquires a reference heart rate and a measured heart rate of a subject obtained by measurement, compares the reference heart rate and the measured heart rate, determines whether the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate, and performs notification when it is determined that the measured heart rate has changed by the predetermined value or more.

[0007] Further, as another example of the present invention, a notification program causes a computer to function as a heart rate acquisition unit that acquires a reference heart rate and a measured heart rate of a subject obtained by measurement, a determination unit that compares the reference heart rate and the measured heart rate and determines whether the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate, and a notification unit that performs notification when it is determined that the measured heart rate has changed by the predetermined value or more.

[0008] Thereby, when the heart rate of the subject changes by a predetermined value or more, it is possible to prompt the operator to correct the initially set injection protocol.

[0009] Further features of the present invention will become apparent from the following description of exemplary embodiments illustrated with reference to the accompanying drawings.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0011] Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments are arbitrary and can be changed according to the configuration of the apparatus to which the present invention is applied or various conditions. Also, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below.

[0012] Unless otherwise specified, the term "contrast agent" includes both the contrast agent alone and a chemical solution containing the contrast agent and other solvents and additives. Also, hereinafter, unless otherwise specified, the term "pixel value" includes the CT value at the imaging site to be contrasted, the sum or average value of the CT values of the pixels included in the region of interest (ROI), or the SD value (standard deviation value) of the region of interest. Furthermore, the pixel value includes a value obtained by subtracting the value at the imaging site that is not contrasted from these values (for example, the CT value of the imaging site in simple CT). The region of interest is preset or the operator can select the region of interest.

[0013] [First Embodiment] With reference to FIG. 1 which is a schematic diagram, the injection system 120 and the imaging system 130 will be described. At least one of the injection system 120 and the imaging system 130 has a prediction unit S (FIG. 2) that predicts the change over time of the pixel value in the tissue of the subject and also functions as a simulator. Also, at least one of the injection system 120 and the imaging system 130 functions as a notification system described later.

[0014] As shown in FIG. 1, the injection system 120 includes an injection head 20 which is an example of an injection device that injects a contrast agent according to a set injection protocol. The injection system 120 also includes a touch panel 26 which is an example of a display unit. The injection head 20 injects a chemical solution filled in a syringe, for example, physiological saline and various contrast agents, into a subject. The injection system 120 further includes a stand 22 that holds the injection head 20 and a console 23 that is wired or wirelessly connected to the injection head 20.

[0015] The console 23 functions as a control device for controlling the injection head 20. The console 23 includes a touch panel 26 that functions as a display unit and an input unit, and can communicate with the injection head 20 and the imaging device 30 wiredly or wirelessly. This touch panel 26 can display an injection protocol, an input state of the device, a setting state, an injection result, and various information. Also, an operator can input chemical solution information, an injection protocol, tissue information, subject information, a target value, etc. through the touch panel 26. As an example, the target value is a target pixel value desired when imaging an imaging site and a target maintenance time such as a maintenance time for maintaining the target pixel value. Alternatively, the injection system 120 may include a display as a display unit and a numeric keypad or a keyboard as an input device instead of the touch panel 26.

[0016] Furthermore, instead of the console 23, the injection system 120 may have a control device connected to the injection head 20 and a display unit (for example, a tablet terminal or a touch panel display) separate from the control device to which the injection situation of the chemical solution is displayed. In this case, the control device includes a control unit 25 (FIG. 2) of the injection head 20. Also, the injection head 20 and the control device of the injection head 20 can be integrally configured with the stand 22. Further, instead of the stand 22, a ceiling suspension member can be provided, and the injection head 20 can be suspended from the ceiling through the ceiling suspension member.

[0017] The injection head 20 may have a remote control device (e.g., a hand switch or a foot switch) for remotely operating the injection head 20. This remote control device can remotely operate the injection head 20 to start or stop the injection. Further, the injection head 20 may have a power source or a battery. This power source or battery can be provided either in the injection head 20 or in the control device of the injection head 20, or can be provided separately from these.

[0018] Also, the injection head 20 includes a syringe holding part on which a syringe filled with a chemical solution is mounted, and a drive mechanism (not shown) for pushing out the chemical solution in the syringe according to an injection protocol. Further, the injection head 20 has an operation part 28 for inputting the operation of the drive mechanism. The operation part 28 is provided with, for example, a forward button of the drive mechanism, a backward button of the drive mechanism, an injection start button, and an air check confirmation button, etc. Further, the injection head 20 may be provided with a head display on which injection conditions, injection status, input status of the device, setting status, and various injection results are displayed. For example, the head display is installed on the side of the injection head 20 or built into the injection head 20. Further, the head display may be a touch panel type display operable by an operator. In this case, the operator can input various information from the screen displayed on the head display. Further, a device (e.g., a tablet terminal) capable of remotely operating the injection head 20 may be provided inside and outside the hospital.

[0019] When the contrast agent is injected, accessories such as an extension tube are connected to the tip of the syringe mounted on the injection head 20. Then, when the injection preparation is completed, the operator presses the confirmation button of the operation part 28. Alternatively, the operator may touch-operate the confirmation button displayed on the touch panel 26. Thereby, the injection head 20 waits in a state where injection can be started. When the injection is started, the contrast agent pushed out from the syringe is injected into the subject's body through the extension tube.

[0020] In addition, the syringe holding part of the injection head 20 can be equipped with a prefilled syringe having a data carrier such as an RFID chip, an IC tag, or a barcode, and various syringes. Therefore, the injection head 20 is provided with a reading part for reading the data carrier attached to the syringe. The data carrier stores chemical solution information regarding the chemical solution. Furthermore, the injection head 20 may have three or more syringe holding parts, or may have only one syringe holding part.

[0021] The injection head 20 can receive information from a server (external storage device) not shown in the figure, and can also transmit information to the server. Also, the imaging device 30 of the imaging system 130 can receive information from the server and can also transmit information to the server. The server is, for example, a RIS (Radiology Information System), a PACS (Picture Archiving and Communication System), or a HIS (Hospital Information System).

[0022] The server may store an examination order in advance. The examination order includes subject information regarding the subject and examination information regarding the examination content. Also, the server can store information regarding the imaging result such as the data of the image transmitted from the imaging device 30 and information regarding the injection result transmitted from the injection head 20. In addition, an external imaging system or an image creation workstation can be used to operate the injection head 20 and the imaging device 30.

[0023] The injection system 120 further includes a measuring device 29 that measures the heart rate of the subject. As an example, the measuring device 29 is wired or wirelessly connected to the console 23. Alternatively, the measuring device 29 may be connected to the injection head 20. In this case, the heart rate measured by the measuring device 29 is transmitted by the injection head 20 to the console 23. The measuring device 29 is, for example, a pulse oximeter. The pulse oximeter has a probe unit that clamps a part of the subject's body (for example, a fingertip or an earlobe).

[0024] Alternatively, the measuring device 29 may be a cardiac output meter or an electrocardiograph that acquires the electrocardiogram information of the patient. Thereby, a more accurate heart rate can be obtained and the determination accuracy can be improved. Further, the measuring device 29 may be a pulse oximeter that attaches a piezoelectric element (for example, a piezo element) to a part of the subject's body to acquire the heart rate. The piezoelectric element directly detects the vibration of the blood vessel wall of the blood vessel of the subject. Note that the measuring device 29 may transmit the measured heart rate outside the injection system 120. For example, the measuring device 29 may transmit the measured heart rate to the imaging system 130.

[0025] The imaging system 130 includes a medical imaging device 30 that is wired or wirelessly connected to the injection head 20 and images the subject. Examples of the imaging device 30 include various medical imaging devices such as an MRI (Magnetic Resonance Imaging) device, a CT (Computed Tomography) device, an angiography device, a PET (Positron Emission Tomography) device, a SPECT (Single Photon Emission Computed Tomography) device, a CT angiography device, an MR angiography device, an ultrasonic diagnostic device, and a blood vessel imaging device. Hereinafter, an example in which the imaging system 130 includes a CT device will be described.

[0026] The imaging device 30 includes an imaging unit 31 that images a subject according to an imaging plan, and a control device 32 that controls the entire imaging device 30. The imaging plan includes, for example, an imaging site, an effective tube voltage, a model name, a manufacturer name, an imaging time, a tube voltage, an imaging range, a rotation speed, a helical pitch, an exposure time, a dose, and an imaging method. Then, the control device 32 controls the imaging unit 31 to image the subject according to the imaging plan. Further, the control device 32 may also function as a simulator that predicts the change over time of pixel values. In addition, the control device 32 can communicate with an external storage device such as a server, the imaging unit 31, and the injection head 20 by wire or wirelessly.

[0027] The imaging unit 31 includes a couch, an X-ray source that irradiates the subject with X-rays, and an X-ray detector that detects the X-rays transmitted through the subject. In addition, the imaging unit 31 irradiates the subject with X-rays and images a fluoroscopic image of the subject by back-projecting the inside of the subject based on the X-rays transmitted through the subject.

[0028] The imaging device 30 has a display 33. The display 33 is connected to the control device 32. In addition, the display 33 displays the input state, setting state, imaging result, and various information of the device. Alternatively, the control device 32 and the display 33 can also be integrally configured. Further, the imaging device 30 has an interface 34 such as a keyboard that functions as an input unit. The operator can input chemical solution information, injection protocol, tissue information, subject information, target values, etc. from the interface 34 into the imaging device 30.

[0029] [Notification System] At least one of the injection system 120 and the imaging system 130 also functions as a notification system. Hereinafter, with reference to FIG. 2, an example in which the injection system 120 functions as a notification system will be described.

[0030] The console 23 of the injection system 120 includes a control unit 25 as a computer composed of a CPU or the like, and a storage unit 24 that stores a notification program PG1. The control unit 25 controls each part of the console 23 according to the program stored in the storage unit 24. Further, the control unit 25 has a prediction unit S, a notification unit 10, a heart rate acquisition unit 11, a determination unit 12, a protocol generation unit 13, a protocol acquisition unit 14, a chemical solution information acquisition unit 15, a subject information acquisition unit 16, a target value acquisition unit 17, a tissue information acquisition unit 18, and a display control unit 19. And the console 23 also functions as a simulator (perfusion simulator) that predicts the temporal change of pixel values in the tissue of the subject.

[0031] The control unit 25 executes various processes corresponding to the notification program PG1 implemented in the storage unit 24, whereby each part is logically realized as various functions. Alternatively, at least a part of these functional units may be provided externally. For example, the control unit 25 may acquire the heart rate of the subject from the heart rate acquisition unit 11 of an external device. In this case, the console 23 functions as a notification system in cooperation with the external device. When the prediction unit S is provided outside the console 23, the control unit 25 receives the simulation result from the external prediction unit S.

[0032] The storage unit 24 is a computer-readable non-transitory recording medium. And the storage unit 24 has a RAM (Random Access Memory) as a system work memory for the control unit 25 to operate, a ROM (Read Only Memory) for storing programs or system software, an HDD (Hard Disk Drive), or an SDD (Solid State Drive). Further, the storage unit 24 stores a notification program PG1 that performs notification when it is determined that the measured heart rate has changed to a predetermined value or more.

[0033] The notification program PG1 causes the control unit 25 to function as a prediction unit S, a notification unit 10, a heart rate acquisition unit 11, a determination unit 12, a protocol generation unit 13, a protocol acquisition unit 14, a chemical solution information acquisition unit 15, a subject information acquisition unit 16, a target value acquisition unit 17, a tissue information acquisition unit 18, and a display control unit 19. Further, the notification program PG1 also functions as a simulation program that causes the control unit 25 to predict the temporal change of pixel values in the tissue of the subject. Alternatively, the control unit 25 can also control various processes according to the notification program PG1 stored in a portable recording medium such as a CD (Compact Disc) and a DVD (Digital Versatile Disc), a CF (Compact Flash) card, or an external storage medium such as a server connected to the Internet or a LAN.

[0034] When the determination unit 12 determines that the measured heart rate has changed to a predetermined value or more, the notification unit 10 of the control unit 25 performs notification. As an example, when the protocol generation unit 13 generates a modified injection protocol, the notification unit 10 displays the modified injection protocol on the touch panel 26. Thereby, the notification unit 10 notifies the operator that the heart rate has changed. However, the notification unit 10 may notify the change before the injection protocol is modified. As an example of the notification before modification, the notification unit 10 displays at least one of an image and a character string indicating the change (for example, the character string "has changed") on the touch panel 26. Alternatively, the notification unit 10 emits a sound or voice indicating the change from a speaker, or emits light indicating the change from the touch panel 26 or a light emitting unit. The light emitting unit can be provided on the console 23 or the injection head 20. Further, the notification unit 10 may notify that it is necessary to change the imaging timing due to the change in the heart rate (for example, advancing the timing by 1 second or delaying the timing by 1 second).

[0035] Further, the notification unit 10 may read the correction injection protocol from the storage unit 24 and display the injection speed and injection volume for each chemical solution as the correction injection protocol on the touch panel 26. Further, the notification unit 10 may display the injection speed and injection volume numerically, or may display them in a form such as an image or a graph. Note that the notification unit 10 may display the injection speed and injection volume on the touch panel 26 simultaneously, or may display them separately.

[0036] The heart rate acquisition unit 11 of the control unit 25 acquires a reference heart rate used for the determination by the determination unit 12 and a measured heart rate of the subject obtained by measurement. As an example, the reference heart rate is the standard heart rate (beats per minute) of a human at rest and is stored in the storage unit 24. Further, the reference heart rate may be the heart rate of the subject measured at rest. Then, the heart rate acquisition unit 11 acquires the reference heart rate from the storage unit 24. Alternatively, the heart rate acquisition unit 11 may acquire the reference heart rate from an external storage device such as a server.

[0037] Further, the heart rate acquisition unit 11 acquires the measured heart rate of the subject from the measuring device 29. As an example, the measured heart rate is measured at an arbitrary timing until the start of injection. Alternatively, the measured heart rate may be the average value of the heart rates measured from the completion of the air check or injection preparation to the start of injection. The air check is a process of confirming that there are no air bubbles inside the syringe and tube of the injection system 120. As an example, the air check is completed by operating the air check button displayed on the touch panel 26 or the air check button of the injection head 20. When the heart rate acquisition unit 11 detects the operation, it starts acquiring the measured heart rate of the subject from the measuring device 29. Further, the injection preparation is completed by operating the preparation completion button displayed on the touch panel 26 or the preparation completion button of the injection head 20. Note that the heart rate acquisition unit 11 may continue to acquire the measured heart rate even after the start of injection.

[0038] The determination unit 12 of the control unit 25 acquires the reference heart rate and the measured heart rate from the heart rate acquisition unit 11 and compares the two. Then, the determination unit 12 determines whether or not the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate. As an example, the predetermined value is a value corresponding to 10 bpm or 10 to 20% of the reference heart rate. For example, when the reference heart rate is 70 bpm, if the measured heart rate reaches 60 bpm or 80 bpm, the determination unit 12 determines that the change is by a predetermined value or more.

[0039] The protocol generation unit 13 of the control unit 25 generates an initial injection protocol based on the chemical solution information of the chemical solution, the subject information of the subject, etc., and stores it in the storage unit 24. Further, the protocol generation unit 13 may generate the initial injection protocol in consideration of the target value, the inspection information, etc. in addition to the subject information, etc. Also, when the determination unit 12 determines that the measured heart rate has changed by a predetermined value or more, the protocol generation unit 13 corrects the initial injection protocol of the chemical solution to generate a corrected injection protocol. Then, the protocol generation unit 13 stores the generated corrected injection protocol in the storage unit 24. The initial injection protocol and the corrected injection protocol include, as an example, the injection time and injection speed of each chemical solution. Further, the initial injection protocol and the corrected injection protocol may include information such as the presence or absence of post-pushing injection of the contrast agent with physiological saline, the increase or decrease of the injection speed, the presence or absence of cross-injection, the presence or absence of link speed setting, and the volume of the injection tube.

[0040] Also, the initial injection protocol and the corrected injection protocol may include information such as the presence or absence of post-pushing injection of the contrast agent with physiological saline, the increase or decrease of the injection speed, the presence or absence of cross-injection, the presence or absence of link speed setting, and the volume of the injection tube. Cross-injection is an injection method in which, until a set time has elapsed from the start of injection, the contrast agent is injected at a speed higher than the injection speed of physiological saline, and then the contrast agent is injected so that the injection speed gradually decreases, and at the same time, physiological saline is injected so that the injection speed gradually increases. Also, link speed setting is a setting in which the injection speeds of the contrast agent and physiological saline are linked so that they become the same.

[0041] The protocol generation unit 13 may obtain the initial timing at which the predicted pixel value reaches the target pixel value from the initial simulation result by the prediction unit S. In this case, the protocol generation unit 13 generates a modified injection protocol so that the predicted pixel value reaches the target pixel value at a timing within a predetermined range from the initial timing. For example, when the protocol generation unit 13 determines that the predicted pixel value reaches the target pixel value at a timing within a predetermined range from the initial timing in the modified simulation result by the prediction unit S, the injection protocol used for creating the modified simulation result is generated as the modified injection protocol. Here, the initial timing includes the first timing at which the predicted pixel value first reaches the target pixel value and the second timing at which the predicted pixel value that has decreased after the first timing reaches the target pixel value again.

[0042] Specifically, with reference to FIGS. 3 and 4, generation of the modified injection protocol will be described. FIG. 3 is a time-contrast effect curve (hereinafter also referred to as TEC) showing the initial simulation result when a chemical solution is injected according to the initial injection protocol. FIG. 4 is a time-contrast effect curve showing the modified simulation result when a chemical solution is injected according to the modified injection protocol. In the initial injection protocol of FIG. 3, the injection rate is 4.0 mL / sec and the injection volume is 60 mL. And as subject information, height 165 cm, weight 60 kg, male gender, and age 30 years are used, and the imaging site is the ascending aorta. Also, curve A1 is the TEC when the heart rate is 70 bpm, curve B1 is the TEC when the heart rate is 60 bpm, and curve C1 is the TEC when the heart rate is 80 bpm. Alternatively, the initial simulation result may be a table showing the predicted pixel value for each elapsed time from the start of injection.

[0043] Also, in curve A1, the first timing T1 when the predicted pixel value first reaches the target pixel value of 400 HU is when approximately 17 seconds have elapsed since the start of injection. Also, the second timing T2 when the predicted pixel value that decreases from the peak value reaches the target pixel value of 400 HU after the first timing T1 is when approximately 24.5 seconds have elapsed since the start of injection. And in curve A1, the peak timing when the predicted pixel value reaches the peak value is when approximately 21.5 seconds have elapsed since the start of injection. As shown in FIG. 3, in the initial simulation results, when the heart rate of the subject fluctuates, each of the first timing and the second timing changes. Specifically, in curve B1 when the heart rate is 60 bpm, the first timing is when approximately 16.5 seconds have elapsed since the start of injection, and the second timing is when approximately 26.5 seconds have elapsed since the start of injection. Also, in curve C1 when the heart rate is 80 bpm, the first timing is when approximately 18.5 seconds have elapsed since the start of injection, and the second timing is when approximately 23 seconds have elapsed since the start of injection.

[0044] In imaging, any timing within the range from the first timing to the second timing is set as the imaging timing. As an example, the timing at the center of the range is set as the imaging timing. Therefore, if the first timing or the second timing changes, the imaging timing needs to be corrected, increasing the workload of the operator. Also, if the imaging timing is not corrected, there is a possibility that imaging will be performed at a timing when the desired target pixel value cannot be obtained.

[0045] Therefore, the protocol generation unit 13 acquires the initial timing at which the predicted pixel value reaches the target pixel value from the initial simulation result, and generates a modified injection protocol so that the predicted pixel value reaches the target pixel value at a timing within a predetermined range from the initial timing. As an example, the predetermined range is 1 second before and after each of the first timing and the second timing, more preferably 0.5 second. Note that the predetermined range for the first timing and the predetermined range for the second timing may be different. For example, the predetermined range for the first timing may be 0.5 second before the first timing and 1 second after the first timing, and the predetermined range for the second timing may be 0.5 second before the second timing and 1 second after the second timing.

[0046] Accordingly, if the modified injection protocol is set, it is not necessary to correct the imaging timing even if the heart rate fluctuates. Specifically, in FIG. 4, in curve B2 when the heart rate is 60 bpm and curve C2 when the heart rate is 80 bpm, each of the first timing and the second timing substantially coincides with the first timing T1 and the second timing T2 in curve A1 when the heart rate is 70 bpm. Note that the modified injection protocol when the heart rate is 80 bpm has an injection speed of 4.3 mL / sec and an injection amount of 66 mL. Also, the modified injection protocol when the heart rate is 60 bpm has an injection speed of 4.1 mL / sec and an injection amount of 52 mL.

[0047] Alternatively, the peak timing at which the predicted pixel value reaches the peak value may be set as the imaging timing. In this case, the protocol generation unit 13 acquires the peak timing at which the predicted pixel value reaches the peak value from the initial simulation result. Then, the protocol generation unit 13 generates a modified injection protocol so that the predicted pixel value reaches the peak value at a timing within a predetermined range from the peak timing. For example, when the protocol generation unit 13 determines that the predicted pixel value reaches the peak value at a timing within a predetermined range from the peak timing of the initial simulation result in the modified simulation result by the prediction unit S, the injection protocol used for creating the modified simulation result is generated as the modified injection protocol. As an example, the predetermined range is 0.5 seconds before and after the peak timing. Further, the protocol generation unit 13 may generate a modified injection protocol so that the peak value of the predicted pixel value is within a predetermined range from the peak value of the initial simulation result. As an example, the predetermined range is a range of 50 HU above and below the peak value, or a range of plus or minus 10% with respect to the peak value.

[0048] Furthermore, the protocol generation unit 13 may acquire a predetermined timing and generate a modified injection protocol so that the predicted pixel value reaches the peak value at a timing within a predetermined range from the acquired timing. For example, when the protocol generation unit 13 determines that the predicted pixel value reaches the peak value at a timing within a predetermined range from the predetermined timing in the modified simulation result by the prediction unit S, the injection protocol used for creating the modified simulation result is generated as the modified injection protocol. As an example, the protocol generation unit 13 acquires the imaging timing input by the operator via the touch panel 26 or the imaging timing included in the imaging plan as the predetermined timing. Alternatively, the protocol generation unit 13 may acquire the imaging timing as the predetermined timing from the storage unit 24 or an external storage device such as a server. As an example, the predetermined range is 0.5 seconds before and after the peak timing.

[0049] Note that the protocol generation unit 13 may generate the initial injection protocol by reading from the storage unit 24 the initial injection protocol created corresponding to standard subject information (e.g., body weight). Alternatively, if a medical staff member has previously created the initial injection protocol, the protocol generation unit 13 may generate the initial injection protocol by reading the said initial injection protocol. Further, the protocol generation unit 13 may generate a plurality of modified injection protocols.

[0050] The protocol acquisition unit 14 of the control unit 25 acquires the initial injection protocol generated by the protocol generation unit 13 from the storage unit 24. Further, the protocol acquisition unit 14 may acquire the initial injection protocol input by the operator via the touch panel 26. Alternatively, the protocol acquisition unit 14 may acquire the injection protocol from the storage unit 24, an external storage device, or the injection head 20. For example, the protocol acquisition unit 14 may acquire from the storage unit 24 or an external storage device such as a server the initial injection protocol previously created by a medical staff member.

[0051] The chemical solution information acquisition unit 15 of the control unit 25 acquires chemical solution information of chemical solutions (e.g., contrast agent and physiological saline). Further, the chemical solution information acquisition unit 15 can acquire the chemical solution information input by the operator via the touch panel 26. The chemical solution information includes, for example, iodine amount, viscosity, osmotic pressure ratio, contrast agent amount, physiological saline amount, product ID, product name, chemical classification, contained components, concentration, expiration date, syringe volume, syringe pressure resistance, cylinder inner diameter, piston stroke, and lot number, etc. Alternatively, the chemical solution information acquisition unit 15 may acquire the chemical solution information from the storage unit 24, an external storage device, or the injection head 20. Further, the chemical solution information acquisition unit 15 may acquire the chemical solution information from a reading unit built into the injection head 20. The said reading unit reads the chemical solution information from a data carrier attached to the syringe mounted on the injection head 20.

[0052] The subject information acquisition unit 16 of the control unit 25 acquires subject information of a subject. The subject information includes, for example, hemoglobin amount, body weight, height, body surface area, cardiac function, reference heart rate, stroke volume, cardiac output, estimated glomerular filtration rate (eGFR), creatinine value, age, gender, fat-free body weight, body mass index, circulating blood volume, subject number (subject ID), history of the subject's diseases and side effects, subject name, date of birth, blood volume, and blood flow velocity, etc.

[0053] Also, as an example, the subject information acquisition unit 16 acquires subject information input by an operator via the touch panel 26. Further, the subject information acquisition unit 16 may acquire subject information from the storage unit 24 or an external storage device. Examples of such an external storage device include RIS, PACS, HIS, an imaging system, and an image creation workstation. Further, the subject information acquisition unit 16 may acquire subject information from the imaging device 30 or the injection head 20 shown in FIG. 1.

[0054] The target value acquisition unit 17 of the control unit 25 acquires a target pixel value as an example of a target value. Further, the target value acquisition unit 17 may acquire a target maintenance time for maintaining the target pixel value. For example, the target value acquisition unit 17 acquires a target pixel value or a target maintenance time input by an operator via the touch panel 26. Alternatively, the target value acquisition unit 17 may acquire a pre-stored target value from the storage unit 24, an external storage device, or the injection head 20. For example, the target value acquisition unit 17 may acquire a TEC indicating the imaging result at the previous imaging or a target pixel value or a target maintenance time in the initial simulation result at the previous imaging.

[0055] The tissue information acquisition unit 18 of the control unit 25 acquires the tissue information of the subject. The tissue information includes, for example, the number of compartments in the tissue (e.g., the number of divided compartments of blood vessels and organs), the volume of the tissue (e.g., the volume of the blood vessel lumen), the volume of capillaries, the volume of the extracellular fluid compartment, the blood flow rate per unit tissue (e.g., blood flow velocity), the leakage rate of the contrast agent in the tissue (e.g., capillary permeability surface area), the washback rate of the contrast agent in the tissue (e.g., capillary permeability surface area), and the pixel value inherent to the tissue, etc.

[0056] Further, the tissue information acquisition unit 18 may acquire the tissue information input by the operator via the touch panel 26 or the interface 34. Tissues include the heart (e.g., the right ventricle and the left ventricle), blood vessels, kidneys, ureters, other organs, and muscles. For example, when the tissue information acquisition unit 18 acquires the pixel value inherent to the tissue, the prediction unit S predicts the degree of enhancement by the contrast agent based on the pixel value inherent to each tissue. Also, the tissue information acquisition unit 18 may acquire the tissue information from the storage unit 24, an external storage device, or the injection head 20.

[0057] The display control unit 19 of the control unit 25 causes the display unit to display a selection screen for the modified injection protocol. For example, on the selection screen, the display control unit 19 displays a button for allowing the operator to select whether to set the modified injection protocol.

[0058] The control unit 25 may further include an inspection information acquisition unit (not shown) that acquires inspection information. For example, the inspection information acquisition unit acquires, as inspection information, site information that identifies the inspection site. The operator can input the inspection information from the touch panel 26 or the interface 34. This inspection information includes, as an example, site information that identifies the inspection site to be imaged, a pressure limit, the iodine amount per unit time per body weight (or also referred to as the iodine amount used), tube voltage (kV), inspection number (inspection ID), inspection date and time, chemical solution type, chemical solution name, and characteristics of the imaging device 30, etc. The site information is information that can identify the site (range) selected as the imaging target. For example, the site information includes the inspection site name, the name of the imaging method, and the distance from the injection site of the chemical solution to the inspection site.

[0059] The prediction unit S of the control unit 25 simulates the temporal change of the predicted pixel values in the subject's tissue. Specifically, the prediction unit S creates an initial simulation result based on the initial injection protocol, the contrast agent information, the subject information, and the reference heart rate. Further, the prediction unit S creates a corrected simulation result based on the corrected injection protocol, the contrast agent information, the subject information, and the measured heart rate. The tissue of the subject to be simulated is the site selected by the operator as the imaging site. As an example, the prediction unit S creates a TEC indicating the temporal change of the predicted pixel values as the initial simulation result or the corrected simulation result. Further, the prediction unit S may obtain the pixel values of each compartment obtained by dividing the subject's tissue into a plurality of parts at each time, and store them in the storage unit 24 as a simulation result in association with each tissue. Further, the prediction unit S may calculate from the simulation result a predicted maintenance time during which a predetermined pixel value, for example, a target pixel value, is maintained.

[0060] As an example, the prediction unit S receives the body weight or fat-free body weight as the subject information from the subject information acquisition unit 16. Further, the protocol generation unit 13 generates an initial injection protocol and delivers it to the prediction unit S. For example, the protocol generation unit 13 calculates the injection time and injection rate of the contrast agent and physiological saline as the initial injection protocol based on the examination site, the body weight of the subject, and the iodine amount of the contrast agent. Then, the prediction unit S simulates the temporal change of the pixel values in the subject's tissue in each of a plurality of compartments obtained by dividing the subject's tissue along the blood flow direction based on the initial injection protocol. This simulation is executed based on the subject information, the injection protocol, and the tissue information. Thereby, the prediction unit S creates a TEC indicating the temporal change of the predicted pixel values at the examination site as the initial simulation result.

[0061] Furthermore, the prediction unit S receives from the subject information acquisition unit 16, as the subject information, the hemoglobin amount (g / dL), body weight (kg), height (cm), cardiac function (%), reference heart rate (bpm), body surface area (m 2) may receive the cardiac output (L / min) and eGFR. Thereby, the prediction unit S can perform a more accurate high-precision simulation based on more information. Alternatively, the prediction unit S may calculate at least one of the body surface area, the cardiac output, and the estimated glomerular filtration volume. For example, the body surface area can be calculated by the Fujimoto formula, the Du Bois formula, or the Shintani formula based on the body weight and height. Also, the cardiac output can be calculated based on the body surface area, the cardiac function, and the reference heart rate. Further, eGFR can be calculated based on the creatinine value, age, and gender.

[0062] When the prediction unit S is provided externally, the injection system 120 includes a subject information acquisition unit 16, a chemical solution information acquisition unit 15, and a target value acquisition unit 17, and the external prediction unit S can receive necessary information from each of these units. Then, the injection system 120 acquires the simulation result from the external prediction unit S. That is, each unit of the injection system 120 and the external prediction unit S cooperate to function as a simulator. Note that the prediction unit S may perform a more accurate simulation by further considering the information included in the imaging plan.

[0063] [Prediction of Temporal Change in Pixel Value] Hereinafter, an example of the simulation by the prediction unit S will be described. Each tissue of the subject is divided into a plurality of compartments along the blood flow direction according to the number of divided compartments of the tissue acquired from the tissue information acquisition unit 18. The prediction unit S divides the volume of the tissue including the compartment to be predicted, the capillary volume of the tissue, and the extracellular fluid cavity volume of the tissue by the number of divided compartments, and predicts the temporal change in the pixel value for each compartment.

[0064] The tissues of the subject include the right ventricle, aorta, vein, artery, brain (or head), upper limb, myocardium (e.g., myocardium dominated by the right coronary artery, myocardium dominated by the anterior descending branch, myocardium dominated by the circumflex branch), lung, liver, stomach, spleen, pancreas, intestinal tract, kidney, ureter, lower limb, left ventricle, ascending aorta, descending aorta, and abdominal aorta. And the contrast agent injected from the upper limb vein moves to each organ through the right ventricle, lung, left ventricle, aorta (e.g., ascending aorta, descending aorta), and then reaches the right ventricle through the vein. And the contrast agent injected into the body is excreted outside the body through the kidney and ureter.

[0065] To obtain the change in pixel value in each tissue (e.g., blood vessel and organ) as a function of time, the prediction unit S uses, for example, a differential equation such as the following Equation 1. Here, the concentration of the contrast agent flowing into the compartment is C1, the concentration of the contrast agent flowing out of the compartment is C2, the volume of the compartment is V, and the blood flow volume (blood flow velocity) per unit tissue in the compartment is Q.

[0066]

Equation

[0067] Furthermore, to obtain the change in pixel value in tissues other than the right ventricle, left ventricle, and blood vessels, the prediction unit S considers the leakage rate when the contrast agent permeates from the capillary to the extracellular fluid cavity and the re-leakage rate when the contrast agent permeates from the extracellular fluid cavity to the capillary. Therefore, the prediction unit S uses, for example, differential equations such as the following Equation 2 and Equation 3. Here, the volume of the extracellular fluid cavity is Vec, the concentration of the contrast agent in the extracellular fluid cavity is Cec, the volume of the capillary is Viv, the concentration of the contrast agent in the capillary is Civ, the leakage rate is PS1, and the re-leakage rate is PS2.

[0068]

Equation

[0069]

Equation

[0070] The prediction unit S obtains, as a function of time, the elapsed time since the start of injection and the change in the pixel value (i.e., the contrast agent concentration) by solving the above differential equation. Further, the prediction unit S may calculate the amount of contrast agent discharged based on a predetermined discharge rate, and perform a simulation by subtracting the amount of discharge from the contrast agent in the capillaries of the kidney. Thereby, a simulation is performed such that a part of the contrast agent that has reached the kidney is subtracted from the total amount of contrast agent in the whole body (i.e., in the plasma). By simulating the discharge of the contrast agent, the total amount of contrast agent in the whole body decreases over time, so that a more accurate simulation can be performed.

[0071] When the simulation is completed, the prediction unit S sequentially stores the simulation results in the storage unit 24. This simulation result includes a TEC indicating the change over time of the pixel value at the inspection site, and may also include information on the pixel value for each time associated with the tissue. Alternatively, the prediction unit S may perform a simulation using a known pharmacokinetic model such as the method described in Japanese Patent No. 3553968.

[0072] [Generation of Modified Injection Protocol] When the operator mounts the syringe after turning on the power of the injection head 20, the reading unit of the injection head 20 reads the chemical solution information (e.g., product ID) and sends it to the control unit 25. Then, the chemical solution information acquisition unit 15 of the control unit 25 acquires the chemical solution information read by the reading unit and temporarily stores it in the storage unit 24 as the chemical solution information. Further, the display control unit 19 of the control unit 25 causes the touch panel 26 to display the product name, iodine content, etc. based on the manufacturer name and product ID. Alternatively, the chemical solution information acquisition unit 15 may acquire the product name input by the operator on the touch panel 26 as the chemical solution information.

[0073] In parallel, the display control unit 19 causes the touch panel 26 to display a selection screen for the imaging site. As an example, the display control unit 19 causes an image imitating a human figure to be displayed on the touch panel 26 in order to allow the operator to select a major classification of the imaging site such as the chest and abdomen. The operator touches the touch panel 26 to select the major classification of the imaging site. Then, the display control unit 19 causes a list of intermediate classifications of the imaging site such as the left ventricle and ascending aorta to be displayed on the touch panel 26 in order to allow the operator to select the intermediate classification of the imaging site. The operator touches the touch panel 26 to select the intermediate classification of the imaging site. As a result, the tissue information acquisition unit 18 acquires information identifying the imaging site (for example, the ascending aorta) and causes the selected imaging site to be stored in the storage unit 24.

[0074] Based on the selected imaging site, the target value acquisition unit 17 reads out from the storage unit 24 the ROI, the target pixel value of the ROI, and the target maintenance time that are stored in correspondence with the imaging sites that can be selected in advance. As an example, the target pixel value is 400 HU and the target maintenance time is 10 sec. Alternatively, at least one of the ROI, the target pixel value of the ROI, and the target maintenance time may be input by the operator from the touch panel 26.

[0075] Subsequently, the display control unit 19 causes an input field for subject information as physical conditions and the like to be displayed on the touch panel 26. Then, the operator inputs, as subject information, for example, the weight of the subject to the touch panel 26. Then, the subject information acquisition unit 16 acquires the weight of the subject and stores it in the storage unit 24. At this time, the display control unit 19 may display the weight of the subject on the touch panel 26. In parallel, the heart rate acquisition unit 11 acquires the reference heart rate input by the operator and stores it in the storage unit 24. Further, the subject information acquisition unit 16 may acquire the height, gender, and age as subject information input by the operator. Alternatively, the subject information acquisition unit 16 may acquire subject information from an external server or a measuring instrument (not shown) such as a cardiac output meter and a weighing scale. Similarly, the heart rate acquisition unit 11 may acquire the reference heart rate from an external server or the measuring device 29. Note that the subject information acquisition unit 16 may acquire the subject information stored in advance from the storage unit 24.

[0076] The prediction unit S calculates the circulating blood volume BV using the input subject information and stores it in the storage unit 24 as the cardiac output. As an example, the prediction unit S calculates the circulating blood volume BV by multiplying the body weight by a coefficient. For example, the coefficient is a value of 0.07 or more and 0.08 or less, and preferably 0.07. Alternatively, the prediction unit S may acquire a predetermined value (for example, 5 L in the case of an adult) stored in advance from the storage unit 24 as the circulating blood volume BV.

[0077] Alternatively, the prediction unit S may calculate the circulating blood volume BV of a male using the following formula 4, or may calculate the circulating blood volume BV of a female using the following formula 5. Here, T is the height (m) and W is the weight (kg).

[0078]

Number

[0079]

Number

[0080] Furthermore, the prediction unit S calculates the cardiac output based on the reference heart rate (for example, the heart rate per minute). For example, the prediction unit S reads out the stroke volume stored in advance (for example, the standard stroke volume of 70 mL) and calculates the cardiac output by multiplying the stroke volume by the reference heart rate. Alternatively, the prediction unit S may acquire the stroke volume from the measuring device 29. As an example, the reference heart rate is a measured value obtained by measuring the heart rate of the subject at rest, or a standard human heart rate (for example, 60 bpm to 70 bpm).

[0081] Alternatively, the prediction unit S may calculate the cardiac output by dividing the weight of the subject by 13. Further, the prediction unit S may calculate the cardiac output by multiplying the body surface area by a cardiac coefficient (for example, 2800). As an example, the prediction unit S calculates the body surface area using a method such as the Fujimoto method, the DuBois method, or the Shintani method. Note that the prediction unit S may calculate the stroke volume. For example, the prediction unit S calculates the stroke volume by dividing the cardiac output by the reference heart rate. The prediction unit S performs the above-described calculation processes and the like at an arbitrary timing before the execution of the simulation. As an example, the prediction unit S executes each process and the like at the timing when the protocol acquisition unit 14 acquires the initial injection protocol.

[0082] In addition, the chemical solution information acquisition unit 15 acquires chemical solution information (for example, iodine content mgI / mL) input by the operator. Alternatively, the chemical solution information acquisition unit 15 may acquire chemical solution information read by the reading unit of the injection head 20 from an IC tag or the like of the syringe. Further, the target value acquisition unit 17 acquires a pre-stored target value from the storage unit 24. Note that the order of acquisition of the subject information, the chemical solution information, and the target value is arbitrary, and acquisition of at least two types of information may be performed simultaneously. Then, at the timing when the operator inputs the subject information, the protocol acquisition unit 14 generates the initial injection protocol and stores it in the storage unit 24. Note that the protocol acquisition unit 14 may further refer to the tube voltage input by the operator to generate the initial injection protocol. Alternatively, the protocol acquisition unit 14 may acquire the initial injection protocol input by the operator, or may acquire a pre-stored initial injection protocol from the storage unit 24 or an external server or the like.

[0083] As shown in FIG. 5, when the protocol acquisition unit 14 acquires the initial injection protocol generated by the protocol generation unit 13, the prediction unit S executes a simulation to create an initial simulation result (S501). That is, the prediction unit S performs a simulation based on the initial injection protocol, the chemical solution information, the subject information, and the reference heart rate, and creates an initial simulation result. In addition to these pieces of information, the prediction unit S may perform a simulation with reference to the tissue information and the examination information. Then, the prediction unit S stores the initial simulation result including the first timing T1 and the second timing T2 (FIG. 3) at which the target pixel value is reached in the storage unit 24. Here, the display control unit 19 may display the initial simulation result on the touch panel 26 so as to indicate the first timing T1 and the second timing T2 to the operator. Usually, the operator determines the imaging timing based on the standard heart rate or the heart rate of the subject at rest. Therefore, it is desirable that the reference heart rate is the standard heart rate or the heart rate of the subject at rest.

[0084] In parallel with the simulation, the heart rate acquisition unit 11 acquires the heart rate of the subject measured by the measuring device 29 as the measured heart rate (S502). As a specific example, the measuring device 29 measures the heart rate per second and multiplies the measured heart rate by 60, and delivers the resulting value as the measured heart rate (bpm) to the heart rate acquisition unit 11. The measuring device 29 may always measure the heart rate, or may measure the heart rate at an arbitrary timing, for example, at the completion of the air check. Further, the heart rate acquisition unit 11 may acquire the heart rate from the completion of the air check to the start of injection, and use the average heart rate per minute during the measurement time (for example, the moving average of the heart rate) as the measured heart rate. Also, the measurement by the measuring device 29 and the acquisition of the heart rate by the heart rate acquisition unit 11 may be performed before or after the creation of the initial simulation result.

[0085] Then, the determination unit 12 compares the measured heart rate with the reference heart rate to determine whether the heart rate has changed by a predetermined value (for example, 10 bpm or a value corresponding to 20% of the reference heart rate) or more (S503). Note that the upper predetermined value that is the upper threshold for the reference heart rate and the lower predetermined value that is the lower threshold may be different. For example, the upper threshold may be 10 bpm and the lower threshold may be 20 bpm. Further, without setting the lower threshold, when the measured heart rate is less than the reference heart rate, the determination unit 12 may determine that there is no change in the heart rate. This is because when the heart rate changes by a predetermined value or more, the timing at which the predicted pixel value reaches the peak value shifts by about 1 second, but when the measured heart rate is less than the reference heart rate, the maintenance time of the target pixel value does not become shorter.

[0086] When the determination unit 12 determines that the heart rate has not changed by a predetermined value or more (NO in S503), the chemical solution will be injected according to the initial injection protocol. Therefore, the display control unit 19 displays the injection start button on the touch panel 26. Then, when the operator touches the start button, the injection starts (S510) and the process ends. Alternatively, the operator may press the start button of the injection head 20.

[0087] On the other hand, when the determination unit 12 determines that the heart rate has changed by a predetermined value or more (YES in S503), the protocol generation unit 13 modifies the initial injection protocol to generate a modified injection protocol (S504). Specifically, the protocol generation unit 13 optimizes the modified injection protocol so that the first timing and the second timing in the simulation result using the measured heart rate after the change and the modified injection protocol are substantially the same as the first timing and the second timing in the initial simulation result. As an example, the allowable deviation for each timing is ±0.5 seconds. Within this range, even if the maximum deviation occurs, the variation in the predicted maintenance time is 1 second or less.

[0088] For example, when the amount of change in the heart rate reaches the upper threshold, the protocol generation unit 13 modifies the initial injection protocol so as to increase the injection amount by a predetermined amount. Further, when the amount of change in the heart rate reaches the lower threshold, the protocol generation unit 13 modifies the initial injection protocol so as to decrease the injection amount by a predetermined amount. Here, in order to increase or decrease the injection amount, the protocol generation unit 13 increases or decreases at least one of the injection speed or the injection time by a predetermined amount (for example, 0.1 mL / sec or 0.1 sec).

[0089] Note that since there is also an injection protocol or the like that changes the injection speed during injection, the injection speed may be at least temporarily decreased when the amount of change reaches the upper threshold, and the injection speed may be at least temporarily increased when the amount of change reaches the lower threshold. Then, the prediction unit S calculates the cardiac output by multiplying the calculated stroke volume by the measured heart rate after the change. Further, the prediction unit S executes a simulation using the corrected injection protocol obtained by the protocol generation unit 13 and the measured heart rate after the change. Then, the prediction unit S creates a TEC as a corrected simulation result (S505).

[0090] The correction by the protocol generation unit 13 and the simulation by the prediction unit S are repeated until the deviation between the first timing and the second timing in the corrected simulation result and the first timing and the second timing in the initial simulation result falls within a predetermined range. When it is determined that the deviation falls within the allowable range, the protocol generation unit 13 causes the storage unit 24 to store the injection protocol used when creating the simulation result as a corrected injection protocol proposed by the notification unit 10 to the operator (S506). Note that when the allowable deviation at each timing does not fall within the allowable range, the notification unit 10 may notify the operator to that effect. In this case, the operator injects the chemical solution using the initial injection protocol or manually corrects the initial injection protocol.

[0091] Alternatively, the protocol generation unit 13 may modify the initial injection protocol by reading out a modified injection protocol stored in advance from the storage unit 24. For example, the storage unit 24 stores in advance a modified injection protocol corresponding to a heart rate increased by a predetermined value (e.g., 10 bpm) with respect to the reference heart rate and a modified injection protocol corresponding to a heart rate decreased by a predetermined value with respect to the reference heart rate. When the heart rate increases, the protocol generation unit 13 reads out the modified injection protocol corresponding to the increased heart rate. When the heart rate decreases, the protocol generation unit 13 reads out the modified injection protocol corresponding to the decreased heart rate.

[0092] When the modified injection protocol is generated, the notification unit 10 displays the modified injection protocol on the touch panel 26 (S507) and notifies the operator that a change has occurred. Further, the notification unit 10 may notify by displaying the TEC as the modified simulation result on the touch panel 26. At this time, the notification unit 10 may display that the imaging timing needs to be changed together with the TEC. Further, the notification unit 10 may simultaneously display the TEC as the initial simulation result and the TEC as the modified simulation result. In this case, the notification unit 10 may display both TECs superimposed or may display both TECs side by side. Furthermore, the notification unit 10 may display the modified injection protocol on the touch panel 26. Also, simultaneously with or before or after the notification by the notification unit 10, the display control unit 19 may display a selection screen on which a selection button for the modified injection protocol or a selection button for whether modification is possible is displayed on the touch panel 26.

[0093] The operator who has recognized the notification by the notification unit 10 may interrupt the start of the injection until the amount of change in the heart rate falls below a predetermined value. In this case, when the amount of change in the heart rate falls below a predetermined value and the determination unit 12 determines that there is no change in the heart rate, the display control unit 19 causes the start button for injection to be displayed on the touch panel 26. Alternatively, until the determination unit 12 determines that there is no change in the heart rate, the control unit 25 may restrict or ignore the operation of the start button for injection. Further, when the amount of change in the heart rate falls below a predetermined value and the determination unit 12 determines that there is no change in the heart rate, the notification unit 10 may notify the operator to that effect.

[0094] In parallel with the notification by the notification unit 10, or before and after the notification, the display control unit 19 causes a change button from the initial injection protocol to the modified injection protocol to be displayed on the touch panel 26. When the operator touches and operates the change button to select a change in the injection protocol (YES in S508), the modified injection protocol is set instead of the initial injection protocol (S509). Thereafter, the display control unit 19 causes the start button for injection to be displayed on the touch panel 26. Then, when the operator touches and operates the start button, the injection starts (S510) and the process ends. On the other hand, when the operator does not select a change in the injection protocol (NO in S508), the chemical solution is injected according to the initial injection protocol. Therefore, the display control unit 19 causes the start button for injection to be displayed on the touch panel 26. Then, when the operator touches and operates the start button, the injection starts (S510) and the process ends.

[0095] In addition, the notification unit 10 may display a string indicating that the heart rate has changed and that the injection protocol can be selected for modification on the touch panel 26. In this case, the notification unit 10 may display the modified injection protocol according to the touch operation by the operator. Further, without the operator's confirmation, the protocol generation unit 13 may automatically set the modified injection protocol instead of the initial injection protocol. In this case, the injection system 120 injects the chemical solution according to the automatically set modified injection protocol. Also, the notification unit 10 may display a string indicating that the heart rate has changed and that the injection protocol has been modified on the touch panel 26. Furthermore, the notification unit 10 may display at least one of the initial simulation result and the modified simulation result simultaneously with the modified injection protocol. The notification unit 10 may display a plurality of simulation results in a superimposed manner or side by side.

[0096] Note that the display control unit 19 may display the change button before creating the modified injection protocol. When the operator touches the change button, the protocol generation unit 13 executes the modified injection protocol, and the prediction unit S executes the simulation. Also in this case, the notification unit 10 may display the generated modified injection protocol, and the display control unit 19 may display a button for confirming the change of the injection protocol. Alternatively, the protocol generation unit 13 may automatically set the modified injection protocol instead of the initial injection protocol without the operator's confirmation.

[0097] According to the invention according to the first embodiment described above, when the heart rate of the subject fluctuates above a predetermined value, it is possible to prompt the operator to modify the initially set initial injection protocol. Then, when the operator selects the change from the initial injection protocol to the modified injection protocol, it is possible to change to an injection protocol that does not require a change in the imaging timing. As a result, even when the heart rate fluctuates greatly, it is not necessary to adjust the imaging timing and imaging conditions, and an increase in the work load of the operator can be suppressed.

[0098] Also, even if the subject's heart rate fluctuates immediately before imaging, the injection protocol can be adjusted during the preparation for injection using the simulation results by the prediction unit S. Therefore, a corrected injection protocol in which the target pixel value and fluctuations during target maintenance are suppressed can be proposed to the operator. As a result, there is no need to adjust the imaging timing and no need to change the shooting plan, so an increase in the operator's workload can be suppressed.

[0099] [Second Embodiment] The second embodiment will be described with reference to FIGS. 6 and 7. The second embodiment is different from the first embodiment in that the monitoring of the subject's heart rate continues during injection. In the description of the second embodiment, differences from the first embodiment will be described, and the same reference numerals will be assigned to the components that have already been described, and the description thereof will be omitted. Unless otherwise specified, components with the same reference numerals exhibit substantially the same operations and functions, and their effects are also substantially the same.

[0100] The heart rate acquisition unit 11 of the second embodiment acquires the measured heart rate from the measuring device 29 even after the start of injection. Then, the determination unit 12 determines the fluctuation of the heart rate with the measured heart rate at the time of generating the corrected injection protocol as the reference heart rate. Further, when it is determined that the heart rate has fluctuated, the notification unit 10 notifies the operator of the fluctuation. As an example, the prediction unit S executes re-simulation based on the corrected injection protocol or the initial injection protocol (hereinafter also referred to as the set injection protocol) set to be used during injection and the measured heart rate measured during injection. Then, the notification unit 10 causes an image or a character string indicating the peak timing at which the predicted pixel value reaches the peak value to be displayed on the touch panel 26. As a result, the display position of the peak timing changes according to the fluctuation of the heart rate. Therefore, by visually recognizing the change in the display position, the operator can recognize the fluctuation of the heart rate. Alternatively, the notification unit 10 may cause an image or a character string indicating the imaging timing according to the fluctuation of the heart rate to be displayed on the touch panel 26.

[0101] When the prediction unit S executes resimulation, the protocol generation unit 13 may modify the original injection protocol to regenerate a modified injection protocol. In this case, the notification unit 10 can display the modified injection protocol on the touch panel 26 to notify the operator of the change. Also, the display control unit 19 displays a change button to confirm with the operator whether there is a change in the injection protocol. Alternatively, the protocol generation unit 13 may automatically replace a part of the original injection protocol with the modified injection protocol. In this case, the injection protocol is dynamically modified before or during injection according to the change in the heart rate. For example, the injection protocol is dynamically modified so that the injection volume increases or decreases by increasing or decreasing the injection time or the injection speed.

[0102] Also, the notification unit 10 may display on the touch panel 26 at least one of the first timing when the predicted pixel value first reaches the target pixel value, the second timing when the predicted pixel value reaches the target pixel value after the first timing, and the peak timing when the predicted pixel value reaches the peak value. Further, when it is determined that the measured heart rate has changed by a predetermined value or more, the notification unit 10 may change the display mode of the at least one timing.

[0103] As an example, the display control unit 19 creates a timing display screen 170 as shown in FIG. 6 and displays it on the touch panel 26. Then, the notification unit 10 synthesizes indicators FS1 and FS2 indicating the imaging timing corresponding to the peak timing along the elapsed time bar T indicating the elapsed time based on the set injection protocol and displays them on the touch panel 26. The horizontal axis of the timing display screen 170 indicates the elapsed time (sec) with the injection start timing of the chemical solution as a reference (zero). In the example of FIG. 6, the elapsed time bar T indicating the elapsed time and the protocol display column P indicating the injection protocol are included in the timing display screen 170.

[0104] In the protocol display column P shown in FIG. 6, in the first phase of injecting the contrast agent, it is shown that the injection rate is 5.0 mL / sec and the injection volume is 47 mL. Also, in the second phase of injecting the contrast agent, it is shown that the injection rate is 3.5 mL / sec and the injection volume is 20 mL. Further, in the third phase of injecting the physiological saline, it is shown that the injection rate is 2.5 mL / sec and the injection volume is 20 mL. And when 25.0 seconds have elapsed since the start of the injection, the initial imaging timing is indicated by the indicator FS1. As an example, the imaging timing indicated by the indicator FS1 is the peak timing in the corrected simulation result or the initial simulation result. By means of the indicator FS1, the notification unit 10 causes the peak timing to be displayed on the touch panel 26.

[0105] The timing display screen 170 changes according to the progress of the elapsed time. Specifically, in the timing display screen 170, the elapsed time bar T changes so as to become longer according to the progress of the elapsed time. For example, FIG. 6 shows a state in which the elapsed time bar T, which was initially displayed as zero, has changed until 26 seconds have elapsed since the start of the injection. Further, when the determination unit 12 determines that the heart rate has fluctuated, the notification unit 10 changes the display mode of the peak timing. Specifically, the notification unit 10 changes the timing display screen 170 so that the peak timing after the fluctuation is indicated by the indicator FS2. In the example of FIG. 6, the indicator FS2 indicates the peak timing after the fluctuation at the point when 27.0 seconds have elapsed since the start of the injection. That is, the notification unit 10 moves the indicator FS1 to the display position of the indicator FS2.

[0106] As an example, the notification unit 10 obtains the peak timing with reference to the result of the resimulation created by the prediction unit S. Then, the indicator FS1 is moved so that the indicator FS2 is displayed at the peak timing. For example, when the peak timing is advanced, the notification unit 10 moves the indicator FS1 at a timing when the elapsed time from the start of injection is short (for example, when 24 seconds have elapsed). When the notification unit 10 can obtain the imaging timing from the imaging system 130 or the like, the imaging timing and the peak timing do not have to match. In this case, the notification unit 10 moves the indicator FS1 so as to match the amount of variation of the peak timing. For example, when the peak timing varies by 1 second, the notification unit 10 moves the indicator FS1 indicating the imaging timing by a distance corresponding to 1 second. The shapes of the indicators FS1 and FS2 may be an inverted triangle, a circle, an ellipse, an upward triangle, a rectangle, a polygon, or a star.

[0107] Furthermore, the notification unit 10 may notify the operator that the imaging timing is approaching. As an example, the notification unit 10 changes the display mode of the indicators FS1 and FS2 as the imaging timing approaches to notify the imaging timing. For example, the notification unit 10 notifies the imaging timing by shortening the blinking interval of the indicators FS1 and FS2 as the imaging timing approaches. Alternatively, as the imaging timing approaches, the notification unit 10 changes the color, size, shape, or brightness of the indicators FS1 and FS2 to notify the imaging timing. Alternatively, the notification unit 10 may cause a speaker (not shown) to emit sound and notify the imaging timing by shortening or lengthening the interval at which the sound is emitted as the imaging timing approaches, or by increasing or decreasing the frequency. Alternatively, the notification unit 10 may cause a light emitting unit (not shown) to emit light and notify the imaging timing by shortening or lengthening the interval at which the light is emitted as the imaging timing approaches, or by emitting the light brighter or darker.

[0108] Furthermore, the notification unit 10 may display a countdown timer 171 as a timer for notifying the imaging timing. Note that the countdown timer 171 in FIG. 6 displays numbers. However, the notification unit 10 may notify the imaging timing by changing the position of the hands of the timer image in the shape of an analog clock or the display mode of the timer. As an example, the notification unit 10 may notify the imaging timing by gradually changing a fan-shaped countdown timer 171 into a circular shape as the imaging timing approaches. Furthermore, the notification unit 10 may notify the imaging timing by gradually shortening the length of a substantially rectangular countdown timer 171 as the imaging timing approaches.

[0109] When the injection system 120 and the imaging system 130 are interlocked, the notification unit 10 may change the display modes of the indicators FS1 and FS2 as compared with the case where they are not interlocked, to notify the interlock. For example, during the interlock in which the injection system 120 and the imaging system 130 transmit and receive information (for example, injection start timing or imaging timing) to and from each other, the notification unit 10 may change the colors of the indicators FS1 and FS2 from green before the interlock to red. As an example, when the injection system 120 and the imaging system 130 are interlocked, when the imaging timing is reached after the start of injection, imaging is automatically performed. In the case of a CT apparatus, X-ray exposure is also automatically performed.

[0110] As shown in FIG. 7, the notification unit 10 may notify the operator of the imaging possible time range 173. In the example of FIG. 7, the display control unit 19 creates a pressure display screen 172 and displays it on the touch panel 26. In this case, the display control unit 19 displays a horizontal axis indicating the elapsed time based on the set injection protocol and a vertical axis indicating the injection pressure in the pressure display column R. Then, the notification unit 10 synthesizes an indicator FS1 indicating the imaging timing in the pressure display column R and displays it on the touch panel 26. Alternatively, the display control unit 19 may display a vertical axis indicating the injection rate, or may display a vertical axis indicating the injection rate and a vertical axis indicating the injection pressure.

[0111] As an example, the time range 173 is a range from the first timing when the predicted pixel value first reaches the target pixel value to the second timing when the predicted pixel value reaches the target pixel value after the first timing. Based on this time range 173, the notification unit 10 causes the touch panel 26 to display the first timing and the second timing. As an example, the notification unit 10 causes the touch panel 26 to display a line indicating the time range 173, an image of a rectangle, etc., along the horizontal axis of the pressure display screen 172. Alternatively, the notification unit 10 may display a number indicating the length of time from the first timing to the second timing (i.e., the predicted maintenance time). Further, the notification unit 10 may display numbers indicating each of the first timing and the second timing (i.e., the elapsed time since the start of injection).

[0112] Furthermore, when the determination unit 12 determines that the heart rate has fluctuated, the notification unit 10 may change the display mode of the time range 173. As an example, the notification unit 10 changes the position or length of a line or an image indicating the time range 173 after the fluctuation. Note that the notification unit 10 may simultaneously display the time range 173 and the indicators FS1 and FS2 indicating the imaging timing. Further, when the heart rate has fluctuated, the notification unit 10 may change the display modes of the time range 173 and the indicator FS1 as described above.

[0113] In addition, the notification unit 10 may notify the operator that imaging has been performed within the imaging possible time range. As an example, the notification unit 10 acquires information on the execution timing at which imaging has been performed from the imaging system 130 or an external detection device. Then, the notification unit 10 determines whether imaging has been performed within the imaging possible time range, and if imaging has been performed within the time range, changes the display modes of the indicators FS1 and FS2. For example, the notification unit 10 changes the colors of the indicators FS1 and FS2. As an example, the detection device is an X-ray detection device that detects X-rays during imaging, an analysis device that detects an image of a subject or the like during imaging and detects the execution timing of imaging from the image analysis result, or an audio detection device that detects audio during imaging.

[0114] Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Inventions modified within the scope not contrary to the present invention, and inventions equivalent to the present invention are also included in the present invention. Further, each of the embodiments and each of the modified forms can be appropriately combined within the scope not contrary to the present invention.

[0115] For example, when generating a correction injection protocol, the protocol generation unit 13 may acquire the first timing (for example, the elapsed time from the start of injection) input by the operator, add the target maintenance time to the first timing, and calculate the second timing. Alternatively, the protocol generation unit 13 may acquire the first timing and the second timing input by the operator. Further, the protocol generation unit 13 may acquire the first timing and the second timing from the TEC indicating the past imaging results stored in the storage unit 24 or an external server. Also in these cases, the protocol generation unit 13 generates a correction injection protocol such that the predicted pixel value reaches the target pixel value at a timing within a predetermined range from each acquired timing.

[0116] Note that the imaging timing is not limited to once. For example, when the hepatic artery and the portal vein are selected as the imaging target sites, there are two imaging timings. Further, the peak timing is not limited to once. For example, a simulation using an injection protocol in which the pixel value that has dropped from the first peak value rises again and reaches the second peak value may be executed. In this case, imaging may be performed at the second peak timing, and the first timing and the second timing are set corresponding to each imaging timing. Further, when imaging a plurality of imaging sites simultaneously, etc., imaging may be performed only at the second peak timing. However, the imaging timing does not have to coincide with the first or second peak timing, and imaging may be performed at any timing after the target pixel value has been reached.

[0117] Also, the imaging timing may be a time range having a predetermined width. As an example, a time range required for imaging, for example, a time range of about 1 sec to 10 sec may be set as the imaging timing. This time range can be set, for example, as a range including the times before and after with the peak timing at the center. Further, the notification system can also be provided in the imaging system 130. In this case, the control unit 25 is provided in the control device 32, and the display 33 functions as a display unit. Furthermore, the measuring device 29 may be provided outside the injection system 120. In this case, the console 23 functions as a notification system in cooperation with the measuring device 29 provided outside. In addition, the initial injection protocol, the modified injection protocol, the change history of the heart rate, the initial simulation result, and the modified simulation result may be stored in the storage unit 24. Further, these pieces of information may be stored in a server (external storage device) not shown.

Explanation of Signs

[0118] 10: Notification unit, 11: Heart rate acquisition unit, 12: Determination unit, 13: Protocol generation unit, 14: Protocol acquisition unit, 15: Chemical solution information acquisition unit, 16: Subject information acquisition unit, 17: Target value acquisition unit, 26: Display unit, 120: Notification system, PG1: Notification program, S: Prediction unit

Claims

1. A heart rate acquisition unit that acquires a reference heart rate and a measured heart rate of a subject obtained by measurement; A determination unit that compares the reference heart rate and the measured heart rate to determine whether the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate; An alert unit that alerts when it is determined that the measured heart rate has changed by the predetermined value or more; An alert system comprising a protocol generation unit that, when it is determined that the measured heart rate has changed by the predetermined value or more, corrects an initial injection protocol of a chemical solution to generate a corrected injection protocol.

2. The alert system according to claim 1, wherein the alert unit performs the alert by causing the corrected injection protocol to be displayed on a display unit.

3. A protocol acquisition unit that acquires the initial injection protocol; A chemical solution information acquisition unit that acquires chemical solution information of the chemical solution; A subject information acquisition unit that acquires subject information of the subject; A target value acquisition unit that acquires a target pixel value; The alert system according to claim 2, further comprising a prediction unit that simulates a temporal change in a predicted pixel value in the tissue of the subject.

4. The prediction unit creates an initial simulation result based on the initial injection protocol, the chemical solution information, the subject information, and the reference heart rate, and creates a corrected simulation result based on the corrected injection protocol, the chemical solution information, the subject information, and the measured heart rate. The alert system according to claim 3.

5. The protocol generation unit acquires an initial timing at which the predicted pixel value reaches the target pixel value from the initial simulation result, and generates the corrected injection protocol so that the predicted pixel value reaches the target pixel value at a timing within a predetermined range from the initial timing. The alert system according to claim 4.

6. The initial timing includes a first timing at which the predicted pixel value first reaches the target pixel value and a second timing at which the predicted pixel value reaches the target pixel value after the first timing. The alert system according to claim 5.

7. The protocol generation unit acquires the peak timing at which the predicted pixel value reaches the peak value from the initial simulation result, and generates the correction injection protocol so that the predicted pixel value reaches the peak value at a timing within a predetermined range from the peak timing. The notification system according to claim 4.

8. The prediction unit creates a corrected simulation result based on the correction injection protocol, the chemical solution information, the subject information, and the measured heart rate. The protocol generation unit acquires a predetermined timing, and generates the correction injection protocol so that the predicted pixel value reaches the peak value at a timing within a predetermined range from the predetermined timing. The notification system according to claim 3.

9. A heart rate acquisition unit that acquires a reference heart rate and a measured heart rate of a subject obtained by measurement. A determination unit that compares the reference heart rate and the measured heart rate, and determines whether or not the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate. A notification unit that performs notification when it is determined that the measured heart rate has changed by the predetermined value or more. A target value acquisition unit that acquires a target pixel value. A prediction unit that simulates the temporal change of the predicted pixel value in the tissue of the subject. The notification unit causes the display unit to display at least one of the first timing at which the predicted pixel value first reaches the target pixel value, the second timing at which the predicted pixel value reaches the target pixel value after the first timing, and the peak timing at which the predicted pixel value reaches the peak value. A notification system that changes the display mode of the at least one timing when it is determined that the measured heart rate has changed by the predetermined value or more.

10. A control method for a notification system including a computer, wherein the computer acquires a reference heart rate and a measured heart rate of a subject obtained by measurement. compares the reference heart rate and the measured heart rate, and determines whether or not the measured heart rate has changed by a predetermined value or more with respect to the reference heart rate. When it is determined that the measured heart rate has changed by the predetermined value or more, a control method of correcting the initial injection protocol of the chemical solution to generate a correction injection protocol and performing notification.

11. A computer A heart rate acquisition unit that acquires a reference heart rate and a measured heart rate of a subject obtained by measurement. A determination unit that compares the reference heart rate and the measured heart rate to determine whether the measured heart rate has fluctuated by a predetermined value or more with respect to the reference heart rate; An alert unit that alerts when it is determined that the measured heart rate has fluctuated by the predetermined value or more; An alert program that functions as a protocol generation unit that modifies the initial injection protocol of the chemical solution to generate a modified injection protocol when it is determined that the measured heart rate has fluctuated by the predetermined value or more.

Images