Neutron dose measurement method and device

Abstract

One aspect of the present invention provides a method for measuring a neutron dose. The method includes the steps of: determining a unit to be corrected corresponding to a dose monitoring system; determining a first correction factor based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system; and determining a real-time dose of neutrons to a patient by correcting the dose monitoring system based on the first correction factor. The present application determines the real-time dose of neutrons to a patient by determining the first correction factor and correcting the sensitivity of the dose monitoring system, thereby avoiding measurement errors due to sensitivity reduction or position change of the dose monitoring system and improving the accuracy and reliability of the measurement result. Another aspect of the present invention provides a device for measuring a neutron dose corresponding to the method.

Description

[Technical Field]

[0001] This application relates to the technical field of neutron dosimetry, and in particular to a method and apparatus for measuring neutron dose. [Background technology]

[0002] The dose monitoring system, as the two eyes of Boron Neutron Capture Therapy (BNCT), plays a very important role in the entire process of tumor treatment, being able to evaluate the neutron dose irradiated to the patient and stop the irradiation when the neutron dose reaches a predetermined value.

[0003] However, although conventional dose monitoring systems can measure the real-time neutron dose to a patient, the sensitivity of the dose monitoring system decreases after a certain period of measurement, resulting in errors in the measurement results, making it impossible to accurately control the irradiation time based on a predetermined value of the neutron dose. Summary of the Invention [Problem to be solved by the invention]

[0004] In order to solve the above technical problems, the present application has been proposed. The embodiments of the present application provide a method and apparatus for measuring neutron dose. [Means for solving the problem]

[0005] In a first aspect, a method for measuring neutron dose according to one embodiment of the present application includes the steps of determining a unit to be corrected corresponding to a dose monitoring system, determining a first correction coefficient based on the number of radiations emitted by a non-metallic unit to be activated after being activated by neutrons, the non-metallic unit including a non-metallic member and a first detection unit that detects the number of radiations emitted after being activated by neutrons, and the unit to be corrected corresponding to the dose monitoring system, and determining a real-time dose of neutrons to a patient by correcting the dose monitoring system based on the first correction coefficient.

[0006] According to the first aspect, in some embodiments of the first aspect, the method further includes the steps of setting a unit to be corrected as a counting rate to be corrected, determining a first neutron reaction rate based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons, and determining a first correction coefficient based on the counting rate to be corrected and the first neutron reaction rate.

[0007] According to the first aspect, in some embodiments of the first aspect, the method further includes a step of determining a non-metallic average count rate for the activation period corresponding to the non-metallic unit to be activated based on the count rate to be corrected, and a step of determining a first correction factor based on the first neutron reaction rate and the non-metallic average count rate.

[0008] According to the first aspect, in some embodiments of the first aspect, the method further includes a step of determining a second correction coefficient based on the number of radiations emitted by a non-metallic unit to be activated, which includes a metal member and a second detection unit that detects the number of radiations emitted by the metal member after being activated by neutrons, and the number of radiations emitted by a unit to be corrected corresponding to the dose monitoring system or a metal unit to be activated after being activated by neutrons, and a step of correcting the corrected dose monitoring system by correcting the first correction coefficient based on the second correction coefficient.

[0009] According to the first aspect, in some embodiments of the first aspect, the method further includes a step of determining a second neutron reaction rate based on the number of radiations emitted by the metal unit to be activated after being activated by neutrons, a step of determining a metal average count rate for the activation period corresponding to the metal unit to be activated based on the count rate to be corrected, and a step of determining a second correction factor based on the first neutron reaction rate and the metal average count rate or the second neutron reaction rate.

[0010] According to the first aspect, in some embodiments of the first aspect, the step of correcting the corrected dose monitoring system by correcting the first correction factor based on the second correction factor further includes the steps of determining difference information between the first correction factor and the second correction factor, and if it is determined based on the difference information that the first correction factor satisfies a predetermined difference threshold condition, determining a correction value corresponding to the dose monitoring system based on the first correction factor, and determining a real-time dose of neutrons to the patient based on the correction value corresponding to the dose monitoring system, a dose conversion factor, and an irradiation time corresponding to the patient.

[0011] According to the first aspect, in some embodiments of the first aspect, the dose conversion coefficient includes a boron dose conversion coefficient, and the step of determining a real-time dose of neutrons to the patient based on a correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the exposure time corresponding to the patient includes a step of determining a real-time dose rate correction value for cancer cells corresponding to the dose monitoring system based on the correction value corresponding to the dose monitoring system and the boron dose conversion coefficient, and a step of determining a real-time dose of neutrons to cancer cells of the patient based on the real-time dose rate correction value for the cancer cells and the exposure time.

[0012] According to the first aspect, in some embodiments of the first aspect, the dose conversion coefficient includes a non-cancerous cell dose conversion coefficient, and the step of determining the real-time dose of neutrons to the patient based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the previously irradiated time corresponding to the patient includes the steps of determining a real-time dose rate correction value to the non-cancerous cells corresponding to the dose monitoring system based on the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient, and determining the real-time dose of neutrons to the non-cancerous cells of the patient based on the real-time dose rate correction value of the non-cancerous cells and the previously irradiated time.

[0013] According to the first aspect, in some embodiments of the first aspect, the material of the non-metallic unit to be activated includes at least one of phosphorus, sulfur, silicon, and bromine.

[0014] In a second aspect, a neutron dose measuring device according to one embodiment of the present application includes a first determination module, a second determination module, and a third determination module, wherein the first determination module determines a unit to be corrected corresponding to a dose monitoring system, the second determination module determines a first correction coefficient based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system, the non-metallic unit to be activated includes a non-metallic member and a first detection unit that detects the number of radiations emitted by the non-metallic member after being activated by neutrons, and the third determination module determines a real-time dose of neutrons to a patient by correcting the dose monitoring system based on the first correction coefficient.

[0015] According to the second aspect, in some embodiments of the second aspect, the second determination module sets the unit to be corrected as the count rate to be corrected, determines a first neutron reaction rate based on the number of corrected radiations emitted by the non-metallic unit to be activated after being activated by neutrons, and determines a first correction coefficient based on the count rate to be corrected and the first neutron reaction rate.

[0016] Furthermore, the second determination module determines a non-metallic average counting rate for the activation period corresponding to the non-metallic unit to be activated based on the counting rate to be corrected, and determines a first correction factor based on the first neutron reaction rate and the non-metallic average counting rate.

[0017] According to the second aspect, in some embodiments of the second aspect, the device further includes a fourth determination module and a fifth determination module, wherein the fourth determination module determines a second correction coefficient based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and the number of radiations emitted by the unit to be corrected corresponding to the dose monitoring system or the metallic unit to be activated after being activated by neutrons, wherein the metallic unit to be activated includes a metallic member and a second detection unit that detects the number of radiations emitted by the metallic member after being activated by neutrons, and the fifth determination module corrects the corrected dose monitoring system by correcting the first correction coefficient based on the second correction coefficient.

[0018] Furthermore, the second determination module determines a second neutron reaction rate based on the number of radiations emitted by the metal unit to be activated after being activated by neutrons, determines a metal average counting rate for the activation period corresponding to the metal unit to be activated based on the counting rate to be corrected, and determines a second correction coefficient based on the first neutron reaction rate and the metal average counting rate or the second neutron reaction rate.

[0019] According to the second aspect, in some embodiments of the second aspect, the fifth determination module further determines difference information between the first correction coefficient and the second correction coefficient, and if it determines that the first correction coefficient satisfies a predetermined difference threshold condition based on the difference information, determines a correction value corresponding to the dose monitoring system based on the first correction coefficient, and determines a real-time dose of neutrons to the patient based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the irradiation time corresponding to the patient.

[0020] In a third aspect, a computer-readable storage medium according to an embodiment of the present application includes a computer program for executing any one of the above methods for measuring neutron dose.

[0021] In a fourth aspect, an electronic device according to an embodiment of the present application includes a processor that executes any one of the above neutron dose measurement methods, and a memory that stores instructions executable by the processor. [Effects of the Invention]

[0022] The neutron dose measurement method, neutron dose measurement device, computer-readable storage medium, and electronic device according to the embodiments of the present application determine a unit to be corrected corresponding to a dose monitoring system, and then determine a first correction coefficient for correcting the sensitivity of the dose monitoring system based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system, thereby determining the real-time dose of neutrons to a patient, avoiding measurement errors due to reduced sensitivity or position changes of the dose monitoring system, and improving the accuracy and reliability of the measurement results. [Brief explanation of the drawings]

[0023] The above and other objects, features, and advantages of the present application will become more apparent from a more detailed description of the embodiments of the present application, taken in conjunction with the accompanying drawings, which provide a further understanding of the embodiments of the present application, constitute a part of the specification, and explain the present application together with the embodiments of the present application, but do not limit the present application. In the drawings, like reference numerals generally represent like parts or steps.

[0024] [Figure 1] 1 is a flowchart of a method for measuring neutron dose according to one exemplary embodiment of the present application. [Figure 2] 1 is a flowchart of a method for measuring neutron dose according to another exemplary embodiment of the present application; [Figure 3] 10 is a flowchart of a method for measuring neutron dose according to yet another exemplary embodiment of the present application. [Figure 4] 10 is a flowchart of a method for measuring neutron dose according to yet another exemplary embodiment of the present application. [Figure 5] 1 is a flowchart for determining a real-time dose of neutrons to a patient based on a correction value corresponding to a dose monitoring system, a dose conversion coefficient, and an exposure time corresponding to the patient, according to an exemplary embodiment of the present application. [Figure 6]10 is a flowchart for determining a real-time dose of neutrons to a patient based on a correction value corresponding to a dose monitoring system, a dose conversion coefficient, and an exposure time corresponding to the patient, according to another exemplary embodiment of the present application. [Figure 7] 10 is a flowchart of a method for measuring neutron dose according to yet another exemplary embodiment of the present application. [Figure 8] 1 is a schematic diagram of a neutron dose measurement device according to an exemplary embodiment of the present application; [Figure 9] 1 is a schematic configuration diagram of an electronic device according to an exemplary embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, the technical means in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and are not all of the embodiments, and all other embodiments that can be obtained by those skilled in the art based on the embodiments of the present application without any creative work are all within the scope of protection of the present application.

[0026] Boron neutron capture therapy destroys cancer cells through nuclear reactions within tumor cells. The principle of this therapy is as follows: First, a patient is injected with a special boron-containing compound. This compound has a strong affinity for cancer cells, quickly concentrating within the cancer cells after entering the body and with minimal distribution in other tissues. This boron-containing compound is non-toxic and harmless to humans, and has no therapeutic effect on cancer. The cancer cells are then irradiated with neutron beams. While this radiation does not significantly damage the body, the neutrons react with the boron that has entered the cancer cells, resulting in the release of highly lethal radiation. This radiation has a short range, only the length of a single cancer cell. Therefore, it kills only the cancer cells and spares surrounding tissue. This technique, which selectively kills complex cancer cells without damaging normal tissue, is called boron neutron capture therapy.

[0027] Dose monitoring systems, as the two eyes of boron neutron capture therapy, play a crucial role throughout the entire tumor treatment process, assessing the neutron dose irradiated to the patient and terminating irradiation when the neutron dose reaches a predetermined value. In conventional technology, the most accurate method for measuring neutron dose is neutron activation analysis. However, this method requires removal and measurement after neutron irradiation, which is very time-consuming and does not provide immediate results, making it impossible to determine the real-time neutron dose to the patient. Prompt activation analysis can determine the real-time neutron dose to the patient, but the complex background radiation field results in certain measurement errors and problems such as beam disturbance. Furthermore, this method requires additional hardware equipment, which is costly and requires high maintenance costs.

[0028] On the other hand, active detectors, such as BF3 detectors, can measure neutron doses in real time. However, the BF3 content in BF3 detectors gradually decreases after a certain period of neutron irradiation, resulting in a decrease in the detector's sensitivity. Therefore, a BF3 detector that has been used for a certain period of time will inevitably respond differently to the same neutron intensity compared to an unused BF3 detector, resulting in measurement errors. Therefore, to ensure the dose monitoring system operates correctly, the BF3 detector's sensitivity must be calibrated periodically.

[0029] 1 is a flowchart of a method for measuring neutron dose according to an exemplary embodiment of the present application. As shown in FIG. 1, the method for measuring neutron dose according to the embodiment of the present application includes the following steps S10 to S30.

[0030] In step S10, a unit to be corrected corresponding to the dose monitoring system is determined.

[0031] In one embodiment of the present application, the units to be corrected are counting rate (unit: n / s), neutron flux (unit: N / cm 2), neutron dose (unit: Gy), etc. The counting rate can be determined based on the real-time counting of the counter.

[0032] In step S20, a first correction coefficient is determined based on the number of radiations emitted by a non-metallic unit to be activated, which includes a non-metallic member and a first detection unit that detects the number of radiations emitted by the non-metallic member after being activated by neutrons, and the unit to be corrected corresponding to the dose monitoring system.

[0033] In one embodiment of the present application, the non-metallic unit to be activated is a phosphorus sheet ( 31 The first detector may be a counter that detects the amount of radiation emitted after the non-metallic member is activated by neutrons. For example, the non-metallic unit to be activated may be placed in the air at the exit of the neutron beam or in a phantom. When irradiated with neutrons for a certain period of time, 31 P is reacted with neutrons 31 After stopping the neutron irradiation, a counter is used to count the 1266 keV radiation emitted by the non-metallic units to be activated after being activated by neutrons, and a first correction coefficient is determined based on the number of radiation and the units to be corrected, and the first correction coefficient corrects the units to be corrected to correct the sensitivity of the dose monitoring system.

[0034] In step S30, the real-time dose of neutrons to the patient is determined by correcting the dose monitoring system based on the first correction factor.

[0035] In practical application, first, the unit to be corrected corresponding to the dose monitoring system is determined, then a first correction coefficient is determined based on the number of radiations emitted after the non-metallic unit to be activated is activated by neutrons and the unit to be corrected, and finally, the dose monitoring system is corrected based on the first correction coefficient to determine the real-time dose of neutrons to the patient.

[0036] A neutron dose measurement method according to an embodiment of the present application determines a unit to be corrected corresponding to a dose monitoring system, and then determines a first correction coefficient for correcting the sensitivity of the dose monitoring system based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system, thereby determining the real-time dose of neutrons to a patient, avoiding measurement errors due to reduced sensitivity or position changes of the dose monitoring system, and improving the accuracy and reliability of the measurement results.

[0037] Fig. 2 is a flowchart of a method for measuring neutron dose according to another exemplary embodiment of the present application. The embodiment shown in Fig. 1 of the present application is expanded to the embodiment shown in Fig. 2 of the present application, and the following description will focus on the differences between the embodiment shown in Fig. 2 and the embodiment shown in Fig. 1, and will omit a description of the same points.

[0038] As shown in FIG. 2, in the method for measuring neutron dose according to the embodiment of the present application, the step of setting the unit to be corrected as the count rate to be corrected includes the following steps S31 to S32.

[0039] In step S31, the first neutron reaction rate is determined based on the number of corrected radiations emitted after the non-metallic unit to be activated is activated by neutrons.

[0040] In one embodiment of the present application, the first neutron reaction rate RR1 is determined by the following equation (1):

number

[0041] In the above equation (1), λ is the decay constant, C is the number of radiations measured within the counting time (net count), N1 is the number of target nuclei of the irradiated non-metallic unit of the activation object, ε is the detection efficiency of the activation detector for the corrected radiation, Y is the corrected radiation branching ratio of the corrected radiation, f1 is the self-absorption correction coefficient of the corrected radiation, G is the flux fluctuation correction coefficient, and t irr is the neutron irradiation time, and t cis the cooling time (i.e., the time from the end of neutron irradiation to the start of counting radiation), and t m is the measurement time of the radiation number.

[0042] In step S32, a first correction factor is determined based on the counting rate and the first neutron reaction rate to be corrected.

[0043] For example, after determining the counting rate and the first neutron reaction rate to be corrected, the counting rate and the first neutron reaction rate to be corrected can be calculated to obtain the first correction coefficient.

[0044] In one embodiment of the present application, first, the average non-metallic count rate for the activation period corresponding to the non-metallic unit to be activated is determined based on the count rate to be corrected, and then the first correction factor is determined based on the first neutron reaction rate and the average non-metallic count rate.

[0045] Specifically, the non-metallic average counting rate

number

number

[0046] In the above formula (2), B t is the counting rate to be corrected, and T1 is the activation period corresponding to the non-metallic unit to be activated. The first correction coefficient k1 is determined by the above formula (1) and the following formula (3).

number

[0047] The neutron dose measuring method according to the embodiment of the present application improves the accuracy of the correction result by determining the first correction coefficient based on the first neutron reaction rate and the non-metallic average counting rate.

[0048] In one embodiment of the present application, a second correction coefficient is determined based on the number of radiation rays emitted by a non-metallic unit to be activated after being activated by neutrons, and the number of radiation rays emitted by a unit to be corrected corresponding to the dose monitoring system or a metallic unit to be activated after being activated by neutrons, the metallic unit to be activated includes a metallic member and a second detection unit that detects the number of radiation rays emitted by the metallic member after being activated by neutrons, and the corrected dose monitoring system is corrected by correcting the first correction coefficient based on the second correction coefficient.

[0049] Specifically, the second correction coefficient may be determined based on the number of radiation rays emitted by the non-metallic unit to be activated after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system, or may be determined based on the number of radiation rays emitted by the non-metallic unit to be activated after being activated by neutrons and the number of radiation rays emitted by the metallic unit to be activated after being activated by neutrons. The present application does not particularly limit this.

[0050] In one embodiment of the present application, the metal unit to be activated may be gold foil. For example, the metal unit to be activated may be placed in air at the exit of the neutron beam or in a phantom. When irradiated with neutrons for a certain period of time, the metal unit to be activated undergoes an activation reaction with the neutrons. After the neutron irradiation is stopped, a counter is used to count the correction radiation emitted by the metal unit to be activated after being activated by the neutrons. A second correction factor is determined based on the number of radiations emitted by the non-metal unit to be activated after being activated by the neutrons and the number of radiations emitted by the metal unit to be activated after being activated by the neutrons. The second correction factor determines whether the correction method for the metal activation method or the non-metal activation method is accurate.

[0051] Fig. 3 is a flowchart of a method for measuring neutron dose according to another exemplary embodiment of the present application. The embodiment shown in Fig. 1 of the present application is expanded to the embodiment shown in Fig. 3 of the present application, and the following description will focus on the differences between the embodiment shown in Fig. 3 and the embodiment shown in Fig. 1, and will omit a description of the same points.

[0052] As shown in FIG. 3, the neutron dose measuring method according to the embodiment of the present application includes the following steps S21 to S23.

[0053] In step S21, the second neutron reaction rate is determined based on the number of radiations emitted after the metal unit to be activated is activated by neutrons.

[0054] In one embodiment of the present application, the second neutron reaction rate RR2 is determined by the following equation (4):

number

[0055] In the above equation (4), λ is the decay constant, C is the number of radiations measured within the counting time (net count), N2 is the number of target nuclei of the irradiated metal unit of the activation target, ε is the detection efficiency of the activation detector for the corrected radiation, Y is the corrected radiation branching ratio of the corrected radiation, f1 is the self-absorption correction coefficient of the corrected radiation, G is the flux fluctuation correction coefficient, and t irr is the neutron irradiation time, and t c is the cooling time (i.e., the time from the end of neutron irradiation to the start of counting radiation), and t m is the measurement time of the radiation number.

[0056] In step S22, the average metal count rate for the activation period corresponding to the metal unit to be activated is determined based on the count rate to be corrected.

[0057] In one embodiment of the present application, the metal average count rate

number

number

[0058] In the above formula (5), B t is the counting rate to be corrected, and T2 is the activation period corresponding to the metal unit to be activated.

[0059] In step S23, a second correction factor is determined based on the first neutron reaction rate and the metal average counting rate or the second neutron reaction rate.

[0060] In one embodiment of the present application, the second correction coefficient k2 is determined by the following equation (6).

number

[0061] In another embodiment of the present application, the second correction factor may be determined based on the ratio of the first neutron reaction rate to the second neutron reaction rate.

[0062] In addition, the embodiment of the present application helps to improve the accuracy of the correction result by determining the second correction coefficient based on the first neutron reaction rate and the metal average counting rate or the second neutron reaction rate.

[0063] Fig. 4 is a flowchart of a method for measuring neutron dose according to another exemplary embodiment of the present application. The embodiment shown in Fig. 1 of the present application is expanded to the embodiment shown in Fig. 4 of the present application, and the following description will focus on the differences between the embodiment shown in Fig. 4 and the embodiment shown in Fig. 1, and will omit a description of the same points.

[0064] As shown in FIG. 4, in the neutron dose measurement method according to the embodiment of the present application, the step of correcting the corrected dose monitoring system by correcting the first correction factor based on the second correction factor includes the following steps S41, S43, and S44.

[0065] In step S41, difference information between the first correction coefficient and the second correction coefficient is determined.

[0066] In one embodiment of the present application, the difference information may be the difference between the first correction coefficient and the second correction coefficient.

[0067] In step S43, if it is determined that the first correction coefficient satisfies the predetermined difference threshold condition based on the difference information, a correction value corresponding to the dose monitoring system is determined based on the first correction coefficient.

[0068] In one embodiment of the present application, the predetermined difference threshold condition may be 5% or 10% of the first correction factor, and the specific value of the predetermined difference threshold condition may be set according to actual circumstances, and this embodiment does not further limit it. If the difference between the first correction factor and the second correction factor is less than or equal to the predetermined difference threshold condition, it is determined that the first correction factor satisfies the predetermined difference threshold condition, and a correction value corresponding to the dose monitoring system is determined based on the product of the first correction factor and the count rate to be corrected, i.e., according to the following formula (7):

number

[0069] In the above formula (7), B r is the correction value corresponding to the dose monitoring system.

[0070] In step S44, a real-time neutron dose to the patient is determined based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the irradiation time corresponding to the patient.

[0071] In one embodiment of the present application, a real-time dose of neutrons to a patient is determined based on a product of a correction value corresponding to a dose monitoring system, a dose conversion coefficient, and an exposure time corresponding to the patient.

[0072] The neutron dose measurement method according to the embodiment of the present application verifies whether the difference information between the first correction coefficient and the second correction coefficient satisfies a predetermined difference threshold condition, and if so, obtains a correction value corresponding to the dose monitoring system based on the first correction coefficient, thereby improving the accuracy and reliability of the correction result of the first correction coefficient.

[0073] 5 is a flowchart for determining a real-time neutron dose to a patient based on a correction value corresponding to a dose monitoring system, a dose conversion coefficient, and an exposure time corresponding to the patient, according to one exemplary embodiment of the present application. The embodiment shown in FIG. 4 of the present application is expanded to the embodiment shown in FIG. 5 of the present application, and the following description will focus on the differences between the embodiment shown in FIG. 5 and the embodiment shown in FIG. 4, and will omit a description of the same points.

[0074] As shown in FIG. 5, in the neutron dose measurement method according to the embodiment of the present application, the step of determining the real-time neutron dose to the patient based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the irradiation time corresponding to the patient includes the following steps S441 to S442.

[0075] Specifically, the dose conversion coefficients include a boron dose conversion coefficient.

[0076] In step S441, a real-time dose rate correction value for cancer cells corresponding to the dose monitoring system is determined based on the correction value corresponding to the dose monitoring system and the boron dose conversion coefficient.

[0077] In one embodiment of the present application, a real-time dose rate correction value for cancer cells corresponding to the dose monitoring system is determined based on the product of the correction value corresponding to the dose monitoring system and the boron dose conversion coefficient, i.e., by the following equation (8):

number

[0078] In the above formula (8), D t1is the real-time dose rate correction value for cancer cells (unit: Gy / s), and σ is the thermal neutron reaction cross section (unit: cm 2 ), f2 is the neutron attenuation correction factor by the activation detector, and K is the boron dose conversion factor (unit: Gy × cm) of the boron concentration when the flux becomes 1 ppm. 2 / ppm), N is the actual boron concentration (units: ppm), and CBE is the combined biological effectiveness coefficient.

[0079] In step S442, a real-time dose of neutrons to the cancer cells of the patient is determined based on the real-time dose rate correction value of the cancer cells and the irradiation time.

[0080] In one embodiment of the present application, the real-time neutron dose to the cancer cells of a patient is determined based on the integration of the real-time dose rate correction value of the cancer cells over the irradiation period, that is, by the following equation (9).

number

[0081] In the above formula (9), D acm1 is the cumulative dose of neutrons during the irradiation period of the patient's cancer cells (i.e., the real-time dose of neutrons), and T is the irradiation time of the patient.

[0082] The neutron dose measurement method according to the embodiment of the present application obtains the real-time dose of neutrons to the cancer cells of a patient, accurately evaluates the neutron dose irradiated to the cancer cells of the patient, and stops the irradiation in a timely manner when the neutron dose reaches a predetermined value.

[0083] 6 is a flowchart for determining a real-time neutron dose to a patient based on a correction value, a dose conversion coefficient, and an irradiation time corresponding to the patient, corresponding to a dose monitoring system according to another exemplary embodiment of the present application. The embodiment shown in FIG. 5 of the present application is expanded to the embodiment shown in FIG. 6 of the present application, and the following description will focus on the differences between the embodiment shown in FIG. 6 and the embodiment shown in FIG. 5, and will omit a description of the same points.

[0084] As shown in FIG. 6, in the neutron dose measurement method according to the embodiment of the present application, the step of determining the real-time neutron dose to the patient based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the irradiation time corresponding to the patient includes the following steps S443 to S444.

[0085] Specifically, the dose conversion coefficients include non-cancer cell dose conversion coefficients.

[0086] In step S443, a real-time dose rate correction value for non-cancerous cells corresponding to the dose monitoring system is determined based on the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient.

[0087] In one embodiment of the present application, a real-time dose rate correction value for non-cancerous cells corresponding to the dose monitoring system is determined based on the product of the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient, i.e., by the following equation (10).

number

[0088] In the above formula (10), D t2 is the real-time dose rate correction value for non-cancerous cells (unit: Gy / s), and σ is the thermal neutron reaction cross section (unit: cm 2 ), f2 is the neutron attenuation correction factor by the activation detector, and K t is the non-cancer cell dose conversion factor, and RBE is the relative biological effectiveness factor.

[0089] In step S444, a real-time dose of neutrons to the non-cancerous cells of the patient is determined based on the real-time dose rate correction value of the non-cancerous cells and the irradiation time.

[0090] In one embodiment of the present application, the real-time neutron dose to the non-cancerous cells of a patient is determined based on the integration of the real-time dose rate correction value of the non-cancerous cells over the irradiation period, that is, by the following equation (11).

number

[0091] In the above formula (11), D acm2 is the cumulative dose of neutrons during the irradiation period of the patient's non-cancerous cells (i.e., the real-time dose of neutrons), and T is the irradiation time of the patient.

[0092] In the actual application process, first, a real-time dose rate correction value for non-cancerous cells corresponding to the dose monitoring system is determined based on the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient, and then the real-time neutron dose to the patient's non-cancerous cells is determined based on the real-time dose rate correction value for non-cancerous cells and the irradiation time.

[0093] The neutron dose measurement method according to the embodiment of the present application can obtain the real-time dose of neutrons to the non-cancerous cells of a patient, accurately evaluate the neutron dose irradiated to the non-cancerous cells of the patient, and provide more reference data for tumor treatment.

[0094] Fig. 7 is a flowchart of a method for measuring neutron dose according to another exemplary embodiment of the present application. The embodiment shown in Fig. 4 of the present application is expanded to the embodiment shown in Fig. 7 of the present application, and the following description will focus on the differences between the embodiment shown in Fig. 7 and the embodiment shown in Fig. 4, and will omit a description of the same points.

[0095] As shown in FIG. 7, in the neutron dose measurement method according to the embodiment of the present application, when it is determined that the first correction coefficient satisfies a predetermined difference threshold condition based on the difference information, the method further includes the following steps S42 to S44 before the step of determining a correction value corresponding to the dose monitoring system based on the first correction coefficient and the counting rate to be corrected.

[0096] In step S42, it is determined whether the first correction coefficient satisfies a predetermined difference threshold condition based on the difference information between the first correction coefficient and the second correction coefficient.

[0097] In one embodiment of the present application, if the difference between the second correction coefficient 8 and the first correction coefficient 11 is equal to or less than the predetermined difference threshold condition, it is determined that the second correction coefficient 8 satisfies the predetermined difference threshold condition, and steps S43 and S44 are executed. If the difference between the second correction coefficient 8 and the first correction coefficient 11 is greater than the predetermined difference threshold condition, it is determined that the second correction coefficient 8 does not satisfy the predetermined difference threshold condition, and the second correction coefficient 8 is again obtained by activation with neutrons from the metal unit 4 to be activated, and the first correction coefficient 11 is again obtained by activation with neutrons from the non-metal unit 9 to be activated, until the second correction coefficient 8 satisfies the predetermined difference threshold condition.

[0098] For example, if the predetermined difference threshold condition is 10% and the difference between the second correction coefficient 8 and the first correction coefficient 11 is 7%, the difference between the second correction coefficient 8 and the first correction coefficient 11 is smaller than the predetermined difference threshold condition, and it is determined that the second correction coefficient 8 satisfies the predetermined difference threshold condition. Conversely, if the difference between the second correction coefficient 8 and the first correction coefficient 11 is 13%, the difference between the second correction coefficient 8 and the first correction coefficient 11 is larger than the predetermined difference threshold condition, and it is determined that the second correction coefficient 8 does not satisfy the predetermined difference threshold condition.

[0099] As shown in FIG. 7, the BF3 detector 1 is placed in a beam shaping assembly (BSA) and is irradiated with neutrons. The boron element in the BF3 detector 1 undergoes a nuclear reaction with the neutrons, resulting in 10 B(N,A) 7 Li is generated and A and 7 The Li charged particles are collected by a high-voltage electrode driven by a voltage, generating an induced electric pulse signal. The pulse signal is transmitted to a signal processing circuit 2 via a coaxial cable, which performs pulse amplification, filtering, and shaping on the pulse signal. The processed pulse signal is transmitted to a counter 3 for pulse counting to obtain the count rate (i.e., the count rate to be corrected), and the intensity of the neutron beam can be measured in real time based on the count rate.

[0100] However, after undergoing a nuclear reaction with a certain flux of neutrons, the content of boron in the BF3 detector 1 gradually decreases, reducing the sensitivity of the BF3 detector 1. Therefore, to ensure that the dose monitoring system operates correctly, the sensitivity of the BF3 detector needs to be corrected at regular intervals.

[0101] The specific steps of the correction operation are as follows:

[0102] For example, the non-metallic unit 9 to be activated may be placed in the air at the exit of the neutron beam or in a phantom, and when irradiated with neutrons for a certain period of time, the non-metallic unit 9 to be activated undergoes an activation reaction with the neutrons. After the neutron irradiation is stopped, the activated non-metallic unit is placed in front of the activation detector 5 of the measurement device, and the signal processing circuit 6 performs a preprocessing operation on the correction radiation emitted by the non-metallic unit 9 to be activated after being activated by neutrons, shaping the correction radiation to remove noise, and then counting the correction radiation using the counter 3 to obtain a first neutron reaction rate 10. A first correction coefficient 11 is determined based on the first neutron reaction rate 10.

[0103] Furthermore, the metal unit 4 to be activated may be placed in the air at the exit of the neutron beam or in a phantom, and when irradiated with neutrons for a certain period of time, the metal unit 4 to be activated undergoes an activation reaction with the neutrons. After the neutron irradiation is stopped, the activated non-metallic unit is placed in front of the activation detector 5 of the measurement device, and a signal processing circuit 6 performs preprocessing on the correction radiation emitted by the metal unit 4 to be activated after being activated by neutrons, shaping the correction radiation and removing noise. The correction radiation is then counted using a counter 3 to obtain a second neutron reaction rate 7, and a second correction coefficient 8 is determined based on the second neutron reaction rate 7.

[0104] The material of the non-metallic unit to be activated includes at least one of phosphorus, sulfur, silicon, and bromine, the corrective radiation emitted by the metallic unit to be activated and the non-metallic unit to be activated after activation includes gamma rays and / or electron radiation, and the activation detector includes at least one of high-purity germanium, a semiconductor detector, a scintillator, and an ionization chamber detector.

[0105] 8 is a schematic diagram of a neutron dose measurement device according to an exemplary embodiment of the present application. As shown in FIG. 8, the neutron dose measurement device according to the embodiment of the present application includes a first determination module 100, a second determination module 200, and a third determination module 300; The first determination module 100 determines a unit to be corrected corresponding to the dose monitoring system; the second determination module 200 determines a first correction coefficient based on the number of radiations emitted by the non-metallic unit to be activated after being activated by neutrons and a correction target unit corresponding to the dose monitoring system, the non-metallic unit to be activated including a non-metallic member and a first detection unit that detects the number of radiations emitted by the non-metallic member after being activated by neutrons; The third determination module 300 determines the real-time dose of neutrons to the patient by correcting the dose monitoring system based on the first correction factor.

[0106] In one embodiment of the present application, the second determination module 200 further sets the unit to be corrected as the count rate to be corrected, determines a first neutron reaction rate based on the number of corrected radiations emitted by the non-metallic unit to be activated after being activated by neutrons, and determines a first correction coefficient based on the count rate to be corrected and the first neutron reaction rate.

[0107] In one embodiment of the present application, the second determination module 200 further determines a non-metallic average count rate for the activation period corresponding to the non-metallic unit to be activated based on the count rate to be corrected, and determines a first correction factor based on the first neutron reaction rate and the non-metallic average count rate.

[0108] In one embodiment of the present application, the neutron dose measurement device further includes a fourth determination module and a fifth determination module, wherein the fourth determination module determines a second correction coefficient based on the number of radiations emitted by a non-metallic unit to be activated after being activated by neutrons and the number of radiations emitted by a unit to be corrected or a metallic unit to be activated corresponding to the dose monitoring system after being activated by neutrons, wherein the metallic unit to be activated includes a metallic member and a second detection unit that detects the number of radiations emitted by the metallic member after being activated by neutrons. The fifth determination module corrects the corrected dose monitoring system by correcting the first correction coefficient based on the second correction coefficient.

[0109] In one embodiment of the present application, the second determination module 200 further determines a second neutron reaction rate based on the number of radiations emitted by the metal unit to be activated after being activated by neutrons, determines a metal average count rate for the activation period corresponding to the metal unit to be activated based on the count rate to be corrected, and determines a second correction coefficient based on the first neutron reaction rate and the metal average count rate or the second neutron reaction rate.

[0110] In one embodiment of the present application, the fifth determination module further determines difference information between the first correction coefficient and the second correction coefficient, and if it determines that the first correction coefficient satisfies a predetermined difference threshold condition based on the difference information, determines a correction value corresponding to the dose monitoring system based on the first correction coefficient, and determines a real-time dose of neutrons to the patient based on the correction value corresponding to the dose monitoring system, the dose conversion coefficient, and the irradiation time corresponding to the patient.

[0111] In one embodiment of the present application, the fifth determination module further determines a real-time dose rate correction value for the cancer cells corresponding to the dose monitoring system based on the correction value corresponding to the dose monitoring system and a boron dose conversion coefficient, and determines a real-time dose of neutrons to the patient's cancer cells based on the real-time dose rate correction value for the cancer cells and the irradiation time.

[0112] In one embodiment of the present application, the fifth determination module further determines a real-time dose rate correction value for non-cancerous cells corresponding to the dose monitoring system based on the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient, and determines a real-time dose of neutrons to the patient's non-cancerous cells based on the real-time dose rate correction value for the non-cancerous cells and the irradiation time.

[0113] The operation and functions of the first determination module 100, the second determination module 200, and the third determination module 300 in the neutron dose measuring device shown in Figure 8 can be referred to in the neutron dose measuring method shown in Figures 1 to 7 above, and to avoid duplication, the explanation will be omitted here.

[0114] An electronic device according to an embodiment of the present application will be described below with reference to Fig. 9. Fig. 9 is a schematic diagram of an electronic device according to an exemplary embodiment of the present application.

[0115] As shown in FIG. 9, the electronic device 50 includes one or more processors 501 and a memory 502.

[0116] The processor 501 may be a central processing unit (CPU) or other type of processing unit having data processing and / or instruction execution capabilities, and may control other components in the electronic device 50 to perform desired functions.

[0117] The memory 502 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, or flash memory. One or more computer program instructions may be stored in the computer-readable storage medium, and the processor 501 may execute the program instructions to implement the neutron dose measurement method and / or other desired functions of each embodiment of the present application. The computer-readable storage medium may store various contents, such as a count rate to be corrected, a first correction factor, a second correction factor, and a real-time neutron dose.

[0118] In one example, electronic device 50 may further include input devices 503 and output devices 504, these components being interconnected by a bus system and / or other type of connection mechanism (not shown).

[0119] The input device 503 may include, for example, a keyboard, a mouse, and the like.

[0120] The output device 504 can output various information to the outside, including the count rate to be corrected, the first correction coefficient, the second correction coefficient, the real-time neutron dose, etc. The output device 504 may include, for example, a display, a speaker, a printer, a communication network, and a remote output device connected thereto.

[0121] Of course, for simplicity, Fig. 9 shows only some of the components of the electronic device 50 that are relevant to the present application, and omits components such as buses, input / output interfaces, etc. Besides, the electronic device 50 may further include any other appropriate components depending on a particular application.

[0122] In addition to the above methods and apparatus, embodiments of the present application may also be a computer program product including computer program instructions that, when executed by a processor, cause the processor to perform the steps of the neutron dose measurement method according to each embodiment of the present application described above in this specification.

[0123] The computer program product may be written in any combination of one or more programming languages ​​to create program code for carrying out the operations of embodiments of the present application, including object-oriented programming languages ​​such as Java, C++, etc., as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may run entirely on the user's computing device, partially on the user's device, as a separate software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0124] Furthermore, an embodiment of the present application may be a computer-readable storage medium having stored thereon computer program instructions, which, when executed by a processor, cause the processor to perform the steps in the neutron dose measurement method according to each embodiment of the present application, as described above in this specification.

[0125] The computer-readable storage medium may be any combination of one or more computer-readable media. The computer-readable medium may be a readable signal medium or a readable storage medium. The computer-readable storage medium may include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include an electrical connection having one or more conductors, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0126] Although the basic principles of the present application have been described above in combination with specific embodiments, it should be noted that the benefits, advantages, effects, etc. mentioned in the present application are merely examples and are not limiting, and it is not necessarily believed that each embodiment of the present application has these benefits, advantages, effects, etc. Furthermore, the specific details of the above disclosure are merely for the purpose of illustration and ease of understanding and are not limiting, and the above details do not limit the application to be realized using the above specific details.

[0127] Block diagrams of devices, apparatus, instruments, and systems herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner depicted in the block diagrams. As one of ordinary skill in the art will recognize, these devices, apparatus, instruments, and systems may be connected, arranged, or configured in any manner. For example, words such as "comprise," "contain," and "have" are open-ended terms and can be used interchangeably with "including but not limited to." As used herein, the terms "or" and "and" refer to and can be used interchangeably with the term "and / or," unless the context clearly dictates otherwise. As used herein, the term "for example" refers to and can be used interchangeably with the phrase "for example, but not limited to."

[0128] In the devices, apparatuses, and methods of the present application, each component or step can be disassembled and / or recombined, and such disassembly and / or recombination should be considered as equivalent means of the present application.

[0129] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the present application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0130] The above description has been provided for purposes of illustration and description, and is not intended to limit the present application to the form disclosed herein. While several examples and embodiments have been described above, those skilled in the art will recognize several variations, modifications, variations, additions, and subcombinations thereof.

Claims

1. determining a unit to be corrected corresponding to the dose monitoring system; determining a first correction coefficient based on the number of radiations emitted by a non-metallic unit to be activated after being activated by neutrons, the non-metallic unit including a non-metallic member and a first detection unit that detects the number of radiations emitted by the non-metallic member after being activated by neutrons, and a unit to be corrected corresponding to the dose monitoring system; and determining a real-time dose of neutrons to a patient by correcting the dose monitoring system based on the first correction factor, a second correction factor based on: (i) the number of radiation rays emitted by the non-metallic unit to be activated after being activated by neutrons and a unit to be corrected corresponding to the dose monitoring system; (ii) the number of radiation rays emitted by the non-metallic unit to be activated after being activated by neutrons and the number of radiation rays emitted by a metallic unit to be activated after being activated by neutrons, the metallic unit including a metallic member and a second detection unit that detects the number of radiation rays emitted by the metallic member after being activated by neutrons; or (iii) the unit to be corrected corresponding to the dose monitoring system and the number of radiation rays emitted by the metallic unit to be activated after being activated by neutrons; and a step of correcting the corrected dose monitoring system by correcting the first correction factor based on the second correction factor.

2. setting the unit to be corrected as a count rate to be corrected; determining a first neutron reaction rate based on the number of radiations emitted by the non-metallic units to be activated after being activated by neutrons; 2. The method for measuring neutron dose according to claim 1, further comprising the step of determining a first correction factor based on the count rate to be corrected and the first neutron reaction rate.

3. determining an average non-metallic count rate for an activation period corresponding to the non-metallic unit to be activated based on the count rate to be corrected; 3. The method for measuring neutron dose according to claim 2, further comprising determining the first correction factor based on the first neutron reaction rate and the non-metallic average count rate.

4. determining a second neutron reaction rate based on the number of radiations emitted by the metal units to be activated after being activated by neutrons; determining an average metal count rate for an activation period corresponding to the metal unit to be activated based on the count rate to be corrected; 3. The method for measuring neutron dose according to claim 2, further comprising the step of: (i) determining the second correction factor based on the first neutron reaction rate and the metal average counting rate; (ii) determining the second correction factor based on the first neutron reaction rate and the second neutron reaction rate; or (iii) determining the second correction factor based on the metal average counting rate and the second neutron reaction rate.

5. The step of correcting the dose monitoring system after correction by correcting the first correction factor based on the second correction factor includes: determining difference information between the first correction coefficient and the second correction coefficient; determining a correction value corresponding to the dose monitoring system based on the first correction coefficient when it is determined based on the difference information that the first correction coefficient satisfies a predetermined difference threshold condition; and determining a real-time dose of neutrons to the patient based on a correction value corresponding to the dose monitoring system, a dose conversion coefficient, and an irradiation time corresponding to the patient.

6. the dose conversion coefficients include a boron dose conversion coefficient, and the step of determining a real-time dose of neutrons to the patient based on a correction value corresponding to the dose monitoring system, the dose conversion coefficient, and an irradiation time corresponding to the patient includes: determining a real-time dose rate correction value for cancer cells corresponding to the dose monitoring system based on the correction value and the boron dose conversion coefficient; and determining a real-time dose of neutrons to the cancer cells of the patient based on the real-time dose rate correction value of the cancer cells and the irradiation time.

7. the dose conversion coefficients include non-cancer cell dose conversion coefficients, and the step of determining a real-time dose of neutrons to the patient based on a correction value corresponding to the dose monitoring system, the dose conversion coefficients, and an irradiation time corresponding to the patient includes: determining a real-time dose rate correction value for non-cancerous cells corresponding to the dose monitoring system based on the correction value corresponding to the dose monitoring system and the non-cancerous cell dose conversion coefficient; and determining a real-time dose of neutrons to non-cancerous cells of the patient based on the real-time dose rate correction value of the non-cancerous cells and the irradiation time.

8. 2. The method for measuring neutron dose according to claim 1, wherein the material of the non-metallic unit to be activated contains at least one of phosphorus, sulfur, silicon, and bromine.

9. a first determination module, a second determination module, and a third determination module; The first determination module determines a unit to be corrected corresponding to the dose monitoring system; the second determination module determines a first correction coefficient based on the number of radiations emitted by a non-metallic unit to be activated after being activated by neutrons and a unit to be corrected corresponding to the dose monitoring system, the non-metallic unit to be activated including a non-metallic member and a first detection unit that detects the number of radiations emitted by the non-metallic member after being activated by neutrons; the third determination module determines a real-time dose of neutrons to a patient by correcting the dose monitoring system based on the first correction factor; a fourth determination module and a fifth determination module, wherein the fourth determination module determines a second correction coefficient (i) based on the number of radiation rays emitted by the non-metallic unit of the activation target after being activated by neutrons and the unit to be corrected corresponding to the dose monitoring system, (ii) based on the number of radiation rays emitted by the non-metallic unit of the activation target after being activated by neutrons and the number of radiation rays emitted by the metallic unit of the activation target after being activated by neutrons, or (iii) based on the unit to be corrected corresponding to the dose monitoring system and the number of radiation rays emitted by the metallic unit of the activation target after being activated by neutrons, wherein the metallic unit of the activation target includes a metallic member and a second detection unit that detects the number of radiation rays emitted by the metallic member after being activated by neutrons, and the fifth determination module corrects the corrected dose monitoring system by modifying the first correction coefficient based on the second correction coefficient.

10. 10. The neutron dose measuring device of claim 9, wherein the second determination module sets the unit to be corrected as a counting rate to be corrected, determines a first neutron reaction rate based on the number of correction radiations emitted by the non-metallic unit to be activated after being activated by neutrons, and determines the first correction coefficient based on the counting rate to be corrected and the first neutron reaction rate.

11. 11. The neutron dose measuring device according to claim 10, wherein the second determination module further determines a non-metallic average count rate for an activation period corresponding to the non-metallic unit to be activated based on the count rate to be corrected, and determines the first correction coefficient based on the first neutron reaction rate and the non-metallic average count rate.

12. The neutron dose measuring device of claim 10, wherein the fourth determination module determines a second neutron reaction rate based on the number of radiations emitted by the metal unit to be activated after being activated by neutrons, determines a metal average counting rate for the activation period corresponding to the metal unit to be activated based on the counting rate to be corrected, and determines the second correction coefficient (i) based on the first neutron reaction rate and the metal average counting rate, (ii) based on the first neutron reaction rate and the second neutron reaction rate, or (iii) based on the metal average counting rate and the second neutron reaction rate.

13. 10. The neutron dose measuring device according to claim 9, wherein the fifth determination module further determines difference information between the first correction coefficient and the second correction coefficient, and when it determines that the first correction coefficient satisfies a predetermined difference threshold condition based on the difference information, determines a correction value corresponding to the dose monitoring system based on the first correction coefficient, and determines a real-time dose of the neutrons to a patient based on the correction value corresponding to the dose monitoring system, a dose conversion coefficient, and an irradiation time corresponding to a patient.

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