WO2023185116A1 - 射频发射线圈的损耗模型确定方法、装置、设备及介质 - Google Patents
射频发射线圈的损耗模型确定方法、装置、设备及介质 Download PDFInfo
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- Embodiments of the present application relate to the field of medical equipment, for example, to a method, device, equipment and medium for determining a loss model of a radio frequency transmitting coil.
- the radiofrequency excitation pulse used to excite proton precession contains two major components: electric field and magnetic field.
- the electric field will cause power deposition to cause tissue heat generation.
- the specific absorption rate (Specific Absorption Rate) is used internationally.
- Absorption Rate (SAR) is used as an indicator of magnetic resonance safety to evaluate it. Severe electric field energy concentration is extremely harmful to the human body. If this is not predicted in advance and monitored in real time, especially when the body temperature regulation of the exposed subject is impaired, it can easily cause damage to local tissue of the human body and cause secondary damage. Since the SAR value cannot be measured in vivo, during the actual magnetic resonance examination, electromagnetic numerical simulation is generally used to simulate and predict the real scanning situation to ensure that the SAR level meets international safety restrictions before scanning to better ensure patient safety.
- SAR the radio frequency energy absorbed by the imaging object per unit mass in unit time, and the measurement unit is W/kg.
- the physical meaning of SAR is the power dissipated per kilogram of human body mass within a specific volume V, which can be expressed by the following formula:
- ⁇ is the conductivity distribution of the tissue
- ⁇ is the density distribution of the tissue
- V represents the volume range of the calculated SAR
- E is the electric field distribution corresponding to the scanning layer.
- the numerical simulation is generally used to calculate and simulate the real scanning situation.
- the numerical calculation simulation includes a complex and realistic representation of the radio frequency transmitting coil and human anatomy to obtain the required slices.
- the electric field data E is used to calculate the SAR value according to formula (1) to achieve prediction of radio frequency energy deposition. If the simulation results exceed the threshold specified by the relevant standards, the imaging scan will not be performed. If the simulation results meet the relevant standards, the imaging scan will be performed.
- Embodiments of the present application provide a method, device, equipment and medium for determining the loss model of a radio frequency transmitting coil.
- embodiments of the present application provide a method for determining a loss model of a radio frequency transmitting coil.
- the method includes:
- embodiments of the present application also provide a loss model determination device, which includes:
- the actual measurement module is configured to obtain the first index data of at least two evaluation indicators of the scattering parameters of each transmission channel of at least one transmission channel of the magnetic resonance system radio frequency transmission coil in the actual measurement environment;
- the loss simulation model building module is set to connect equivalent resistances in parallel or series to each circuit component of the virtual radio frequency transmitting coil to establish a loss simulation model
- the parameter adjustment module is configured to adjust the equivalent resistance and matching capacitance of each emission channel in the loss simulation model, so that the adjusted scattering parameters of each emission channel in the loss simulation model are the first of at least two evaluation indicators.
- the error between the second index data and the corresponding first index data is within a corresponding threshold range to obtain the loss model of the radio frequency transmitting coil.
- Figure 1 is a flow chart of a method for determining the loss model of a radio frequency transmitting coil provided in Embodiment 1 of the present application;
- Figure 2 is a schematic diagram comparing the measured scattering parameter curve and the simulated scattering parameter curve provided in Embodiment 1 of the present application;
- Figure 3 is a structural block diagram of a device for determining a loss model of a radio frequency transmitting coil provided in Embodiment 2 of the present application;
- Figure 4 is a structural block diagram of an electronic device provided in Embodiment 3 of the present application.
- the electromagnetic field numerical simulation in related technologies at least fails to accurately simulate the energy loss distribution of the radio frequency transmitting coil.
- Figure 1 is a flow chart of a method for determining a loss model of a radio frequency transmitting coil provided by an embodiment of the present application.
- This embodiment can improve the accuracy of radio frequency transmitting coil simulation by simulating the loss of the radio frequency transmitting coil.
- This method can be executed by the device for determining the loss model of the radio frequency transmitting coil provided in the embodiment of the present application.
- the device can be implemented in the form of software and/or hardware, and configured and applied in the processor of the electronic device. The method includes the following.
- the actual measured environment is the actual working environment of the radio frequency transmitting coil.
- Scattering parameters are used to describe the energy transfer between each transmit channel of the radio frequency transmit coil, including reflection, crosstalk and loss.
- At least two evaluation indicators of the scattering parameters include bandwidth, input impedance, etc.
- This embodiment takes 3dB bandwidth and input impedance as an example for explanation.
- the sources of loss of the radio frequency transmitting coil include transmission line loss, loss of the coil itself, dielectric loss and radiation, etc.
- the quality factor (Q factor) is usually used to analyze the energy conversion efficiency of the coil.
- the Q value can be defined as the ratio of stored energy to consumed energy in the resonant circuit, as shown in the following equation (2), or it can also be expressed as the size of the resonant frequency f 0 relative to the 3dB bandwidth, as shown in the following equation (3).
- W stored is the stored energy
- W loss is the consumed energy
- BW 3dB is the 3dB bandwidth.
- the Q value can, to a certain extent, make the electromagnetic simulation calculation of the radio frequency transmitting coil more consistent with the energy loss in actual work, reduce simulation errors in loss, and thereby improve the accuracy of SAR prediction. sex.
- part of the loss difference between simulation and actual measurement can be quantitatively analyzed by comparing the 3dB bandwidth of the scattering parameters.
- the resistor serves as an energy-consuming component and converts electrical energy into heat energy; while the ideal lossless capacitor and inductor serve as energy storage components and only exchange energy without consuming energy.
- the resonant frequency of the radio frequency transmitting coil will be stable at the center frequency point f 0 , as shown in equation (4), which will cause the inductor L and capacitor C in the circuit to remain approximately unchanged, and the Energy storage remains unchanged. Therefore, the difference between the simulated Q value of the RF transmitting coil and the actual Q value of the RF transmitting coil can be compensated by adjusting the resistance R of the equivalent resistance of the loss device.
- the input impedance Z in of the input end of each transmission channel is calculated according to equation (5), where Z 0 is the characteristic impedance of each transmission channel, and S ii is the scattering when the i-th transmission channel resonates. parameter.
- the difference in impedance matching is compensated by changing the matching capacitance of each transmit channel of the RF transmit coil.
- an appropriate number of network analyzers are used to measure the actual scattering parameters of each emission channel within a preset time period to obtain the S 11 curve, S 22 curve...S ii curve.
- the baseline where the maximum value is located is the position of 0dB.
- first parameter data of the support layer inside the radio frequency transmitting coil in the magnetic resonance system in the actual measurement environment is obtained.
- the first parametric data includes dimensions and electrical parameters of the support layer.
- second parameter data of the shielding layer outside the radio frequency transmitting coil in the magnetic resonance system in the actual measurement environment is obtained, and the second parameter data includes the size and electrical parameters of the shielding layer.
- the virtual radio frequency transmitting coil is the radio frequency transmitting coil in the simulation software.
- the equivalent resistance includes but is not limited to the loss resistance of electronic components such as capacitors and inductors, and also includes the common equivalent resistance of the support layer, shielding layer, coil conductor, diode, antenna radiation loss, etc.
- an equivalent resistance is set and an initial value is set for each ideal component, for example, an equivalent resistance is connected in series or parallel to each capacitor, and/or an equivalent resistance is connected in series or parallel to each inductor.
- the initial value of equivalent resistance can be determined based on empirical values, such as 0.2 ⁇ .
- a support layer is built inside the virtual radio frequency transmitting coil according to the first parameter data, and the support layer is closely attached to the inner wall of the virtual radio frequency transmitting coil to provide each circuit component of the virtual radio frequency transmitting coil. Connect an equivalent resistor in parallel or in series to establish a loss simulation model. It can be understood that the support layer built inside the virtual radio frequency transmitting coil is the same as the first parameter data of the support layer obtained in the actual measurement.
- a shielding layer is built on the outside of the virtual radio frequency transmitting coil according to the second parameter data, and the shielding layer is closely attached to the outside of the virtual radio frequency transmitting coil.
- Each circuit component of the virtual radio frequency transmitting coil is Connect an equivalent resistor in parallel or in series to establish a loss simulation model.
- the shielding layer built outside the virtual radio frequency transmitting coil is the same as the second parameter data of the shielding layer obtained in the actual measurement.
- the second parameters include dimensions and electrical parameters, where the dimensions include thickness and the electrical parameters include dielectric constant, magnetic permeability and electrical conductivity.
- This embodiment quantitatively fits the actual measurement results by adjusting the resistance of the equivalent resistance of the components of each emission channel and the capacitance of the matching capacitor of each emission channel.
- This embodiment improves at least the problem that the radio frequency transmitting coil model cannot accurately simulate the load loss of the radio frequency transmitting coil.
- the simulation is started when all parameter settings are ensured to be correct, and the second 3dB bandwidth data of each transmission channel obtained in the current loss simulation model and the first 3dB bandwidth data of each transmission channel obtained in the actual measurement environment are determined.
- the equivalent resistance is reduced.
- the equivalent resistance is raised.
- the current resistance value of the equivalent resistor is used as the target resistance value; determine the second input impedance data of each transmit channel obtained in the current loss simulation model and the actual measurement environment The second error between the acquired first input impedance data of each transmit channel, when the second error is detected to be greater than the upper limit of the second threshold range, the capacitance of the matching capacitor is increased, and when the second error is detected to be less than the upper limit of the second threshold range, the capacitance of the matching capacitor is increased. When the lower limit of the second threshold range is reached, the capacitance of the matching capacitor is reduced. When the second error is detected to be within the second threshold range, the current capacitance of the matching capacitor is used as the target capacitance.
- the scattering parameter curve of each emission channel is derived, and the scattering parameter curve of each emission channel is translated left and right to make the resonant frequency of each emission channel consistent with the actual one.
- the same start and end frequencies are used to intercept the 10 MHz range.
- the scattering parameters (see Figure 2, the solid line is the measured scattering parameter curve, the dotted line is the simulated scattering parameter curve), and determine the second 3dB bandwidth data corresponding to the current simulation model, and the second 3dB bandwidth data and the first 3dB The first error between bandwidth data. If the first error is greater than 0.05, reduce the resistance of the equivalent resistor by 0.1 ⁇ .
- the first error is less than -0.05, increase the resistance of the equivalent resistor by 0.1 ⁇ , and re-execute the simulation after adjusting the resistance. Operate, and determine the second 3dB bandwidth data of each transmission channel, and the first error between the second 3dB bandwidth data of each transmission channel and the corresponding first 3dB bandwidth data, if the first error is between -0.05 and 0.05 , then the current resistance value of the equivalent resistor is used as the target resistance value of the loss model; if the first error is greater than 0.05, or less than 0.05, continue to adjust the resistance value of the equivalent resistor, and re-execute the simulation operation after the resistance value is adjusted.
- Table 1 shows the measured values and simulated values of the 3dB bandwidth data of each transmit channel of the radio frequency transmitting coil. It can be seen from the table that the error between the simulated values and the measured values in the 3dB bandwidth dimension is less than or equal to 4.86%.
- Table 1 Measured and simulated values of 3dB bandwidth data for each transmit channel of the radio frequency transmit coil
- the adjustment range of the resistance value is set smaller and smaller.
- the second resistance adjustment range can be 0.05 ohm.
- the input scattering parameter curve of each transmitting channel is derived, and the input scattering parameter curve of each transmitting channel is translated left and right to make the resonant frequency of each transmitting channel consistent with the actual one.
- 10 MHz is intercepted at the same start and end frequencies.
- the scattering parameters within the range are determined, and the second input impedance data corresponding to the current simulation model and the second error between the second input impedance data and the first input impedance data are determined. If the second error is greater than 0.01, increase the capacitance of the matching capacitor by 0.1 unit.
- the second error is less than -0.01, reduce the capacitance of the matching capacitor by 0.1 unit, and re-execute the simulation after the capacitance is adjusted. Operate, and determine the second input impedance data of each transmission channel, and the second error between the second input impedance data of each transmission channel and the corresponding first input impedance data, if the second error is between -0.01 and 0.01 , then the current capacitance of the matching capacitor is used as the target capacitance of the capacitor in the loss model; if the second error is greater than 0.01, or less than -0.01, continue to adjust the capacitance of the matching capacitor, and re-execute the simulation after the capacitance adjustment operate, and determine the second input impedance data of each transmitting channel until the second error between the second input impedance data of each transmitting channel and the corresponding first input impedance data is between -0.01 and 0.01, at which time the second The capacitance corresponding to the error is the target capacitance of the matching capacitor in the loss model.
- Table 2 shows the measured values and simulated values of the input impedance of each transmit channel of the RF transmit coil. From this table, it can be seen that the simulated values and measured values of each transmit channel corresponding to the loss model are different in the dimension of input impedance. The error is less than or equal to 0.17%.
- Table 2 Actual measured values and simulated values of the input impedance data of each transmit channel of the radio frequency transmit coil
- the adjustment range of the capacitance is set smaller and smaller.
- the adjustment range of the subsequent capacitance is half of the adjustment range of the previous capacitance.
- each transmit channel of the radio frequency transmit coil is configured with a matching capacitor of target capacitance, and the load resistance of each transmit channel when working is the target resistance value.
- the loss model can be used to predict the SAR value.
- the scanning parameters of the magnetic resonance system when using the current scanning strategy for magnetic resonance imaging such as forward power, backward power, and the bioelectromagnetic simulation model of the scanned object are obtained, and the bioelectromagnetic simulation model and the scanning The parameters are imported into the loss model, and then electromagnetic simulation is started to obtain the SAR distribution in the scanning area, and based on the SAR distribution, it is determined whether the global SAR value and local SAR value of the scanning object meet international standards. If so, the scanning strategy can be used Carry out imaging scanning on the scanned object. If not, you need to adjust the scanning strategy, such as adjusting the emission model, scanning location, etc., and then perform simulation prediction again until the determined global SAR value and local SAR value meet international standards.
- the loss model determination method obtains the first index data of at least two evaluation indicators of the scattering parameters of each transmission channel of the radio frequency transmission coil of the magnetic resonance system in the actual measurement environment; for each circuit element of the virtual radio frequency transmission coil The device is connected in parallel or in series with an equivalent resistor to establish a loss simulation model; adjust the equivalent resistance and matching capacitance of each transmit channel in the loss simulation model so that at least two of the scattering parameters of each transmit channel in the adjusted loss simulation model are The error between the second index data of each evaluation index and the corresponding first index data is within a corresponding threshold range to obtain a loss model of the radio frequency transmitting coil.
- the scattering parameter data can refer to the curve in Figure 2.
- the curve in Figure 2 is the scattering parameter data of each of the eight channels.
- Figure 3 is a structural block diagram of a device for determining a loss model of a radio frequency transmitting coil according to an embodiment of the present application.
- the device is used to execute the method for determining the loss model of the radio frequency transmitting coil provided in any of the above embodiments.
- the device can be implemented as software or hardware.
- the device includes:
- the actual measurement module 11 is configured to obtain at least two first index data of preset evaluation indicators for each transmission channel of the radio frequency transmission coil of the magnetic resonance system in the actual measurement environment;
- the loss simulation model building module 12 is configured to connect an equivalent resistor in parallel or in series to each circuit component of the virtual radio frequency transmitting coil to establish a loss simulation model;
- the parameter adjustment module 13 is configured to adjust the equivalent resistance and matching capacitance of each transmission channel in the loss simulation model, so that the second index data of the preset evaluation index of each transmission channel in the adjusted loss simulation model is consistent with the corresponding third
- the error between the index data is within the corresponding threshold range to obtain the loss model of the radio frequency transmitting coil.
- At least two evaluation indicators of scattering parameters include bandwidth and input impedance.
- the actual measurement module is configured to obtain the scattering parameter data of each transmission channel of the magnetic resonance system radio frequency transmission coil collected in the actual measurement environment; determine the first bandwidth data and the third bandwidth data of each transmission channel based on the scattering parameter data of each transmission channel.
- One input impedance data is configured to obtain the scattering parameter data of each transmission channel of the magnetic resonance system radio frequency transmission coil collected in the actual measurement environment; determine the first bandwidth data and the third bandwidth data of each transmission channel based on the scattering parameter data of each transmission channel.
- the actual measurement module is also configured to obtain the first parameter data of the shielding layer inside the radio frequency transmitting coil in the actual measurement environment;
- the loss simulation model building module is configured to build a support layer inside the virtual radio frequency transmitting coil according to the first parameter data, and connect an equivalent resistor in parallel or series to each circuit component of the virtual radio frequency transmitting coil to establish a loss simulation model.
- the actual measurement module is further configured to obtain the second parameter data of the shielding layer outside the radio frequency transmitting coil in the actual measurement environment;
- the loss simulation model building module is configured to build a shielding layer outside the virtual radio frequency transmitting coil according to the second parameter data, and connect an equivalent resistor in parallel or in series to each circuit component of the virtual radio frequency transmitting coil to establish a loss simulation model.
- the circuit component is a capacitor or an inductor, and an equivalent resistance is connected in series or in parallel to the component.
- the parameter adjustment module is configured as:
- the device for determining the loss model of the radio frequency transmission coil obtains the first index data of at least two evaluation indicators of the scattering parameters of each transmission channel of the radio frequency transmission coil of the magnetic resonance system in the actual measurement environment through the actual measurement module; through loss simulation
- the model building module connects an equivalent resistance in parallel or series to each circuit component of the virtual radio frequency transmitting coil to establish a loss simulation model; the parameter adjustment module adjusts the equivalent resistance and matching capacitance of each transmit channel in the loss simulation model to achieve
- the error between the second index data of at least two evaluation indexes of the scattering parameters of each transmission channel in the adjusted loss simulation model and the corresponding first index data is within the corresponding threshold range to obtain the loss of the radio frequency transmission coil Model.
- the device for determining the loss model of the radio frequency transmitting coil provided by the embodiments of the present application can execute the method for determining the loss model of the radio frequency transmitting coil provided by any embodiment of the present application, and has the corresponding functional modules and beneficial effects of the execution method.
- Figure 4 is a structural block diagram of an electronic device provided by an embodiment of the present application.
- the device includes a processor 201, a memory 202 (also called a storage device), an input device 203 and an output device 204; the processing in the device
- the number of processors 201 can be one or more.
- one processor 201 is taken as an example; the processor 201, memory 202, input device 203 and output device 204 in the device can be connected through a bus or other means.
- Figure 4 Take the example of connecting via a bus.
- the memory 202 can be used to store software programs, computer-executable programs and modules, such as program instructions/modules corresponding to the method for determining the loss model of the radio frequency transmitting coil in the embodiment of the present application (for example, the actual measurement module 11. Loss simulation model establishment module 12 and parameter adjustment module 13).
- the processor 201 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 202, that is, implementing the above-mentioned method for determining the loss model of the radio frequency transmitting coil.
- the memory 202 may mainly include a stored program area and a stored data area, where the stored program area may store an operating system and an application program required for at least one function; the stored data area may store data created based on the use of the terminal, etc.
- the memory 202 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage device.
- memory 202 may further include memory located remotely relative to processor 201, and these remote memories may be connected to the device through a network. Examples of the above-mentioned networks include but are not limited to the Internet, intranets, local area networks, mobile communication networks and combinations thereof.
- the input device 203 may be used to receive input numeric or character information and generate key signal inputs related to user settings and functional control of the device.
- the output device 204 may include a display device such as a display screen, for example, a display screen of a user terminal.
- Embodiments of the present application also provide a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform a method for determining a loss model of a radio frequency transmitting coil.
- the method includes:
- the error between the index data is within the corresponding threshold range to obtain the loss model of the radio frequency transmitting coil.
- the embodiments of the present application provide a storage medium containing computer-executable instructions.
- the computer-executable instructions are not limited to the method operations described above, and can also perform the determination of the loss model of the radio frequency transmitting coil provided by any embodiment of the present application. Related operations in the method.
- the present application can be implemented with the help of software and necessary general hardware, or can also be implemented by hardware.
- the embodiments of the present application can be embodied in the form of software products in essence or those that contribute to related technologies.
- the computer software products can be stored in computer-readable storage media, such as computer floppy disks, Read-Only Memory (ROM), Random Access Memory (RAM), FLASH, hard disk or optical disk, etc., including a number of instructions to make a computer device (which can be a personal Computer, server, or network device, etc.) executes the method for determining the loss model of the radio frequency transmitting coil described in various embodiments of this application.
- the storage medium may be a non-transitory storage medium.
- the various units and modules included are only divided according to functional logic, but are not limited to the above divisions, as long as the corresponding functions can be realized. Yes; in addition, the specific names of each functional unit are only for the convenience of distinguishing each other and are not used to limit the protection scope of the present application.
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Abstract
本申请实施例公开了一种射频发射线圈的损耗模型确定方法、装置、设备及介质，该方法包括：获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据；为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型；调整损耗仿真模型中所述每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
Description
本申请要求在2022年03月28日提交中国专利局、申请号为202210308684.6的中国专利申请的优先权，以上申请的全部内容通过引用结合在本申请中。
本申请实施例涉及医疗设备领域，例如涉及一种射频发射线圈的损耗模型确定方法、装置、设备及介质。
在磁共振成像(Magnetic Resonance Imaging，MRI)中，用于激发质子进动的射频激励脉冲包含电场和磁场两大成分，其中电场会导致功率沉积引起组织产热，国际上使用特定吸收率(Specific Absorption Rate，SAR)作为磁共振安全性指标对其评估。严重的电场能量集中对人体伤害极大，若不对此加以提前预测和实时监控，特别是在暴露对象的体温调节受损的情况下，极易引起人体局部组织损伤，造成二次伤害。由于SAR值无法在体测量，在实际磁共振检查过程中，一般通过电磁数值仿真的方法来模拟预测真实的扫描情况，在扫描前确保SAR水平满足国际安全限制，更好地保证患者安全。
为了将磁共振环境中射频暴露引发的过度热应激风险降到最低，国际电工委员会(The International Electrotechnical Commission，简称IEC)和美国食品和药品管理局(The United States Food and Drug Administration，简称FDA)的国际公认安全标准设定了对人体对象安全扫描的SAR限制。SAR的定义是单位质量成像体在单位时间内所吸收的射频能量，计量单位为W/kg。在人体成像中，SAR的物理含义是在特定的体积V内每公斤的人体质量中耗散的功率，可用以下公式表示：
其中，σ为组织的电导率分布，ρ为组织的密度分布，V表示计算SAR的体积范围，E为扫描层面对应的电场分布。
在实际磁共振检查过程中，一般通过数值仿真的方法来计算模拟真实的扫描情况，为准确起见，数值计算模拟包括对于射频发射线圈和人体解剖结构复杂而真实的表示，得到所需片层的电场数据E，从而根据公式(1)计算出SAR值，实现射频能量沉积预测。如果仿真结果超过相关标准规定的阈值，则不执行成像 扫描，如果符合相关标准规定，则执行成像扫描。
发明内容
本申请实施例提供了一种射频发射线圈的损耗模型确定方法、装置、设备及介质。
第一方面，本申请实施例提供了一种射频发射线圈的损耗模型确定方法，该方法包括：
获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据；
为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型；
调整损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
第二方面，本申请实施例还提供了一种损耗模型确定装置，该装置包括：
实测模块，设置为获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据；
损耗仿真模型建立模块，设置为为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗的仿真模型；
参数调整模块，设置为调整损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
为了说明本申请实施例，下面将对实施例描述中所需要使用的附图做一简单地介绍。下面描述中的附图是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本申请实施例一提供的射频发射线圈的损耗模型确定方法的流程图；
图2是本申请实施例一提供的实测散射参数曲线与仿真散射参数曲线的对比示意图；
图3是本申请实施例二提供的射频发射线圈的损耗模型确定装置的结构框图；
图4是本申请实施例三提供的电子设备的结构框图。
通过分析可发现，相关技术中的电磁场数值仿真至少存在无法准确模拟射频发射线圈能量损耗分配的状况。
以下将参照本申请实施例中的附图，通过实施方式描述本申请。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
实施例一
图1是本申请实施例提供的射频发射线圈的损耗模型确定方法的流程图。本实施例可以通过模拟射频发射线圈的损耗提高射频发射线圈仿真的准确度的情况。该方法可以由本申请实施例提供的射频发射线圈的损耗模型确定装置来执行，该装置可以采用软件和/或硬件的方式实现，并配置在电子设备的处理器中应用。该方法包括如下。
S101、获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据。
其中，实测环境为射频发射线圈的实际工作环境。
散射参数(Scattering parameters，S参数)用于描述射频发射线圈各发射通道之间的能量传递，包括反射、串扰和损耗等。
其中，散射参数的至少两个评价指标包括带宽、输入阻抗等，本实施例以3dB带宽和输入阻抗为例进行说明。
在磁共振系统中，射频发射线圈的损耗来源包括传输线损耗、线圈本身的损耗、介质损耗和辐射等，通常使用品质因子(Quality factor，Q因子)分析线圈的能量转换效率。Q值可以定义为谐振电路中存储能量与消耗能量的比值，如下式(2)所示，也可表示为谐振频率f
0相对于3dB带宽的大小，如下式(3)所示。
其中，W
stored为存储能量，W
loss为消耗能量，BW
3dB为3dB带宽。
从能量传输的角度来说，拟合Q值在一定程度上能够使射频发射线圈的电 磁仿真计算与实际工作中的能量损耗程度更加吻合，减少仿真在损耗方面的误差，从而提高SAR预测的准确性。而且根据Q值定义，在中心频率稳定的情况下，通过比较散射参数的3dB带宽可以定量分析仿真与实测的一部分损耗差异。
在串联/并联谐振RLC电路中，电阻作为耗能元件，把电能转化为热能；而理想无损耗的电容和电感作为储能元件，只进行能量交换，而不消耗能量。载入不同负载时，射频发射线圈的谐振频率将稳定在中心频点f
0处，如式(4)所示，这将导致电路中的电感L和电容C近似不变，射频发射线圈中的储能不变。因此仿真得到的射频发射线圈的Q值与射频发射线圈的实际Q值之间的差异可以通过调整损耗器件的等效电阻的阻值R来进行补偿。
在一个实施例中，为了保证仿真精度，根据式(5)计算各发射通道输入端的输入阻抗Z
in，其中，Z
0为各发射通道的特性阻抗，S
ii为第i发射通道谐振时的散射参数。通过改变射频发射线圈的各个发射通道的匹配电容量弥补阻抗匹配差异。
在一个实施例中，使用适量网络分析仪测量预设时间段内各个发射通道的实际散射参数，以得到S
11曲线、S
22曲线……S
ii曲线。确定射频发射线圈的谐振频率以设置中心频点，频带范围为10MHz。确定各个S
ii曲线的最大值，该最大值所在基线即为0dB所在位置，将该基线向下平移3dB，平移后的基线与S
ii曲线的两个交点分别记为f
H和f
L，则3dB带宽为BW
3dB＝f
H-f
L。将S
ii曲线在谐振频率上的对应的幅度值输入至式(5)中，以得到各个发射通道的输入阻抗数据，并将该各个发射通道的输入阻抗数据作为损耗仿真的目标。
由于实际射频发射线圈中的支撑层和屏蔽层是整个射频系统中介质损耗的大部分来源。为此，在一个实施例中，获取实测环境中磁共振系统中射频发射线圈内侧的支撑层的第一参数数据。该第一参数数据包括支撑层的尺寸和电气参数。在另一实施例中，获取实测环境中磁共振系统中射频发射线圈外侧的屏蔽层的第二参数数据，该第二参数数据包括屏蔽层的尺寸和电气参数。
S102、为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型。
其中，虚拟射频发射线圈为仿真软件中的射频发射线圈。
其中，等效电阻包括但不限于电容、电感等电子元器件的损耗电阻，还包括 支撑层、屏蔽层、线圈导体、二极管、天线辐射损耗等部分的共同等效电阻。
在一个实施例中，为每个理想元器件设置等效电阻并设置初始值，比如，为每个电容串联或并联一个等效电阻，和/或，为每个电感串联或并联一个等效电阻。等效电阻的初始值可以根据经验值来确定，比如0.2Ω。
在一个实施例中，根据第一参数数据在虚拟射频发射线圈的内侧搭建支撑层，且使该支撑层与该虚拟射频发射线圈的内壁紧密贴合，为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型。可以理解的是，在虚拟射频发射线圈的内侧搭建的支撑层与实测中获取的支撑层的第一参数数据相同。示例性的，第一参数包括尺寸和电气参数，其中，尺寸包括厚度，电气参数包括介电常数、磁导率和电导率，在虚拟射频发射线圈内侧搭建的支撑层与实测中的支撑层的厚度均为5-6mm，介电常数均为ε＝4.8，磁导率均为μ＝1，电导率均为σ＝0.004。
在一个实施例中，根据第二参数数据在虚拟射频发射线圈的外侧搭建屏蔽层，且使该屏蔽层与该虚拟射频发射线圈的外侧紧密贴合，为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型。可以理解的是，在虚拟射频发射线圈的外侧搭建的屏蔽层与实测中获取的屏蔽层的第二参数数据相同。示例性的，第二参数包括尺寸和电气参数，其中尺寸包括厚度，电气参数包括介电常数、磁导率和电导率。
S103、调整损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到射频发射线圈的损耗模型。
本实施例通过调整各个发射通道的元器件的等效电阻的阻值以及各个发射通道的匹配电容的电容量，定量拟合实测结果。
本实施例改善了射频发射线圈模型至少存在的无法准确模拟射频发射线圈负载损耗的情况。
本实施例中，在保证各种参数设置均正确时启动仿真，确定当前损耗仿真模型中获取的各个发射通道的第二3dB带宽数据与实测环境下获取的各个发射通道的第一3dB带宽数据之间的第一误差，在检测到第一误差大于第一阈值范围的上限值时降低等效电阻阻值，在检测到第一误差小于第一阈值范围的下限值时升高等效电阻阻值，在检测到第一误差在第一阈值范围内时，将等效电阻的当前阻值作为目标阻值；确定当前损耗仿真模型中获取的各个发射通道的第二输 入阻抗数据与实测环境中获取的各个发射通道的第一输入阻抗数据之间的第二误差，在检测到第二误差大于第二阈值范围的上限值时增大匹配电容的电容量，在检测到第二误差小于第二阈值范围的下限值时降低匹配电容的电容量，在检测到第二误差在第二阈值范围内，将匹配电容的当前电容量作为目标电容量。
在一个实施例中，仿真结束后，导出各个发射通道的散射参数曲线，左右平移各个发射通道的散射参数曲线以使各个发射通道的谐振频率与实际一致，同时以同样的起止频率截取10MHz范围内的散射参数(参见图2，实线为实测散射参数曲线，虚线为仿真得到的散射参数曲线)，并确定当前仿真模型对应的第二3dB带宽数据，以及该第二3dB带宽数据与第一3dB带宽数据之间的第一误差。如果该第一误差大于0.05，则将等效电阻的阻值减少0.1Ω，如果该第一误差小于-0.05，则将等效电阻的阻值增加0.1Ω，并在阻值调整后重新执行仿真操作，并确定各个发射通道的第二3dB带宽数据，以及各发射通道的第二3dB带宽数据与对应第一3dB带宽数据之间的第一误差，如果该第一误差在-0.05到0.05之间，则将等效电阻的当前阻值作为损耗模型的目标阻值；如果该第一误差大于0.05，或小于0.05，则继续调整等效电阻的阻值，并在阻值调整后重新执行仿真操作，以及确定各个发射通道的第二3dB带宽数据，直至各个发射通道的第二3dB带宽数据与对应第一3dB带宽数据之间的第一误差在-0.05到0.05之间，此时该第一误差对应的阻值即为损耗模型的目标阻值。表1示出了射频发射线圈的各个发射通道的3dB带宽数据的实测值和仿真值，从该表可以看出，仿真值与实测值在3dB带宽这一维度上的误差小于或等于4.86％。
表1射频发射线圈的各个发射通道的3dB带宽数据的实测值与仿真值
可以理解的是，在等效阻值调整时，阻值的调整幅度被设置的越来越小。示例性的，如果第一次的阻值调整幅度为0.1欧姆，则第二次的阻值调整幅度可选为0.05欧姆。
在一个实施例中，仿真结束后，导出各个发射通道的输入散射参数曲线，左右平移各个发射通道的输入散射参数曲线以使各个发射通道的谐振频率与实际 一致，同时以同样的起止频率截取10MHz范围内的散射参数，并确定当前仿真模型对应的第二输入阻抗数据，以及该第二输入阻抗数据与第一输入阻抗数据之间的第二误差。如果该第二误差大于0.01，则将匹配电容的电容量增加0.1个单位，如果该第二误差小于-0.01，则将匹配电容的电容量降低0.1个单位，并在电容量调整后重新执行仿真操作，并确定各个发射通道的第二输入阻抗数据，以及各发射通道的第二输入阻抗数据与对应第一输入阻抗数据之间的第二误差，如果该第二误差在-0.01到0.01之间，则将匹配电容的当前电容量作为损耗模型中电容的目标电容量；如果该第二误差大于0.01，或小于-0.01，则继续调整匹配电容的电容量，并在电容量调整后重新执行仿真操作，以及确定各个发射通道的第二输入阻抗数据，直至各个发射通道的第二输入阻抗数据与对应第一输入阻抗数据之间的第二误差在-0.01到0.01之间，此时该第二误差对应的电容量即为损耗模型中匹配电容的目标电容量。表2示出了射频发射线圈的各个发射通道的输入阻抗的实测值和仿真值，从该表可以看出，损耗模型对应的各个发射通道的仿真值与实测值在输入阻抗这一维度上的误差小于或等于0.17％。
表2射频发射线圈的各个发射通道的输入阻抗数据的实测值和仿真值
可以理解的是，在调整匹配电容时，电容量的调整幅度被设置的越来越小。示例性的，后一次电容量的调整幅度为前一次电容量调整幅度的一半。
可以理解的是，当第一误差在第一阈值范围内，第二误差在第二阈值范围内时，认为损耗模型仿真得到的损耗与射频发射线圈的实际损耗一致，因此损耗模型可用于SAR预测。在损耗模型中，射频发射线圈各个发射通道配置有目标电容量的匹配电容，且各个发射通道工作时的负载电阻为目标阻值。
可以理解的是，损耗模型确定之后，即可使用该损耗模型进行SAR值的预测。在一个实施例中，获取磁共振系统在使用当前扫描策略进行磁共振成像时的扫描参数，比如前向功率、后向功率，以及扫描对象的生物电磁仿真模型，将该生物电磁仿真模型和扫描参数导入损耗模型中，然后开启电磁仿真，以得到扫描区域内的SAR分布，以及根据该SAR分布确定扫描对象的全局SAR值和局部 SAR值是否满足国际通用标准，若是，则可采用该扫描策略对扫描对象进行成像扫描，若否，则需要调整扫描策略，比如调整发射模型、扫描部位等，然后重新进行仿真预测，直至确定的全局SAR值和局部SAR值满足国际通用标准。
本申请实施例提供的损耗模型确定方法，获取实测环境中磁共振系统射频发射线圈的各个发射通道的散射参数的至少两个评价指标的第一指标数据；为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型；调整损耗仿真模型中各个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的各个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到射频发射线圈的损耗模型。利用射频发射线圈中谐振电路的参数特性，多方面等效射频发射线圈的损耗来源，从能量损耗角度提高电磁仿真的计算精度，使磁共振系统载入成像对象时的能量沉积预测更加准确，为协议实施保留更多的安全余量。
在一实施例中，对于每个发射通道的散射参数数据，散射参数数据可参考图2中的曲线，图2中的曲线即为8个通道各自的散射参数数据。
接着，可以根据上文公式BW
3dB＝f
H-f
L计算带宽，根据公式5计算输入阻抗。
实施例二
图3是本申请实施例的射频发射线圈的损耗模型确定装置的结构框图。该装置用于执行上述任意实施例所提供的射频发射线圈的损耗模型确定方法，该装置可选为软件或硬件实现。该装置包括：
实测模块11，设置为获取实测环境中磁共振系统射频发射线圈的各个发射通道的预设评价指标的至少两个第一指标数据；
损耗仿真模型建立模块12，设置为为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型；
参数调整模块13，设置为调整损耗仿真模型中各个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的各个发射通道的预设评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到射频发射线圈的损耗模型。
在一实施例中，散射参数的至少两个评价指标包括带宽和输入阻抗。
在一实施例中，实测模块设置为获取实测环境中采集的磁共振系统射频发射线圈的各个发射通道的散射参数数据；根据各个发射通道的散射参数数据确定各个发射通道的第一带宽数据和第一输入阻抗数据。
在一实施例中，实测模块还设置为获取实测环境中射频发射线圈内侧的屏 蔽层的第一参数数据；
损耗仿真模型建立模块设置为根据第一参数数据在虚拟射频发射线圈的内侧搭建支撑层，为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型。
在一实施例中，实测模块还设置为获取实测环境中射频发射线圈外侧的屏蔽层的第二参数数据；
损耗仿真模型建立模块设置为根据第二参数数据在虚拟射频发射线圈的外侧搭建屏蔽层，为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型。
在一实施例中，电路元器件为电容或电感，为元件串联或并联一个等效电阻。
在一实施例中，参数调整模块设置为：
确定当前损耗仿真模型中获取的各个发射通道的第二带宽数据与实测环境下获取的各个发射通道的第一带宽数据之间的第一误差，在检测到第一误差大于第一阈值范围的上限值时降低等效电阻的阻值，在检测到第一误差小于所述第一阈值范围的下限值时升高等效电阻的阻值，在检测到第一误差在第一阈值范围内时，将等效电阻的当前阻值作为目标阻值；
确定当前损耗仿真模型中获取的各个发射通道的第二输入阻抗数据与实测环境中获取的各个发射通道的第一输入阻抗数据之间的第二误差，在检测到第二误差大于第二阈值范围的上限值时增大匹配电容的电容量，在检测到第二误差小于第二阈值范围的下限值时降低匹配电容的电容量，在检测到第二误差在第二阈值范围内时，将匹配电容的当前电容量作为目标电容量。
本申请实施例提供的射频发射线圈的损耗模型确定装置，通过实测模块获取实测环境中磁共振系统射频发射线圈的各个发射通道的散射参数的至少两个评价指标的第一指标数据；通过损耗仿真模型建立模块为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型；通过参数调整模块调整损耗仿真模型中各个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的各个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到射频发射线圈的损耗模型。利用射频发射线圈中谐振电路的参数特性，多方面等效射频发射线圈的损耗来源，从能量损耗角度提高电磁仿真的计算精度，使磁共振系统载入成像对象时的能量沉积预测更加准确，为协议实施保留更多的安全余量。
本申请实施例所提供的射频发射线圈的损耗模型确定装置可执行本申请任 意实施例所提供的射频发射线圈的损耗模型确定方法，具备执行方法相应的功能模块和有益效果。
实施例三
图4为本申请实施例提供的电子设备的结构框图，如图4所示，该设备包括处理器201、存储器202(也可称为存储装置)、输入装置203以及输出装置204；设备中处理器201的数量可以是一个或多个，图4中以一个处理器201为例；设备中的处理器201、存储器202、输入装置203以及输出装置204可以通过总线或其他方式连接，图4中以通过总线连接为例。
存储器202作为一种计算机可读存储介质，可用于存储软件程序、计算机可执行程序以及模块，如本申请实施例中的射频发射线圈的损耗模型确定方法对应的程序指令/模块(例如，实测模块11、损耗仿真模型建立模块12以及参数调整模块13)。处理器201通过运行存储在存储器202中的软件程序、指令以及模块，从而执行设备的各种功能应用以及数据处理，即实现上述的射频发射线圈的损耗模型确定方法。
存储器202可主要包括存储程序区和存储数据区，其中，存储程序区可存储操作系统、至少一个功能所需的应用程序；存储数据区可存储根据终端的使用所创建的数据等。此外，存储器202可以包括高速随机存取存储器，还可以包括非易失性存储器，例如至少一个磁盘存储器件、闪存器件、或其他非易失性固态存储器件。在一些实例中，存储器202可进一步包括相对于处理器201远程设置的存储器，这些远程存储器可以通过网络连接至设备。上述网络的实例包括但不限于互联网、企业内部网、局域网、移动通信网及其组合。
输入装置203可用于接收输入的数字或字符信息，以及产生与设备的用户设置以及功能控制有关的键信号输入。
输出装置204可包括显示屏等显示设备，例如，用户终端的显示屏。
实施例四
本申请实施例还提供了一种包含计算机可执行指令的存储介质，所述计算机可执行指令在由计算机处理器执行时用于执行一种射频发射线圈的损耗模型确定方法，该方法包括：
获取实测环境中磁共振系统射频发射线圈的各个发射通道的散射参数的至少两个评价指标的第一指标数据；
为虚拟射频发射线圈的每个电路元器件并联或串联一等效电阻，以建立损耗仿真模型；
调整损耗仿真模型中各个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述各个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
本申请实施例所提供的一种包含计算机可执行指令的存储介质，其计算机可执行指令不限于如上所述的方法操作，还可以执行本申请任意实施例所提供的射频发射线圈的损耗模型确定方法中的相关操作。
通过以上关于实施方式的描述，所属领域的技术人员可以清楚地了解到，本申请可借助软件及必需的通用硬件来实现，也可以通过硬件实现。基于这样的理解，本申请的实施例本质上或者说对相关技术做出贡献的部分可以以软件产品的形式体现出来，该计算机软件产品可以存储在计算机可读存储介质中，如计算机的软盘、只读存储器(Read-Only Memory，简称ROM)、随机存取存储器(Random Access Memory，简称RAM)、闪存(FLASH)、硬盘或光盘等，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述的射频发射线圈的损耗模型确定方法。
存储介质可以是非暂态(non-transitory)存储介质。
值得注意的是，上述射频发射线圈的损耗模型确定装置的实施例中，所包括的各个单元和模块只是按照功能逻辑进行划分的，但并不局限于上述的划分，只要能够实现相应的功能即可；另外，各功能单元的具体名称也只是为了便于相互区分，并不用于限制本申请的保护范围。
注意，上述仅为本申请的一些实施例。本领域技术人员会理解，本申请不限于这里所述的特定实施例，对本领域技术人员来说能够进行各种变化、重新调整和替代而不会脱离本申请的保护范围。因此，虽然通过以上实施例对本申请进行了说明，但是本申请不仅仅限于以上实施例，在不脱离本发明构思的情况下，还可以包括更多其他等效实施例，而本申请的范围由所附的权利要求范围决定。
Claims (10)
- 一种射频发射线圈的损耗模型确定方法，包括：获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据；为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型；调整所述损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
- 根据权利要求1所述的方法，其中，所述散射参数的至少两个评价指标包括带宽和输入阻抗。
- 根据权利要求2所述的方法，其中，所述获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据，包括：获取实测环境中采集的磁共振系统射频发射线圈的每个发射通道的散射参数数据；根据每个发射通道的散射参数数据确定每个发射通道的第一带宽数据和第一输入阻抗数据。
- 根据权利要求1所述的方法，所述方法还包括：获取实测环境中所述射频发射线圈内侧的支撑层的第一参数数据；所述为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型，包括：根据所述第一参数数据在虚拟射频发射线圈的内侧搭建支撑层，为所述虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型。
- 根据权利要求4所述的方法，所述方法还包括：获取实测环境中所述射频发射线圈外侧的屏蔽层的第二参数数据；所述为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型，包括：根据所述第二参数数据在虚拟射频发射线圈的外侧搭建屏蔽层，为所述虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型。
- 根据权利要求1所述的方法，其中，所述虚拟射频发射线圈的电路元器件为电容或电感中的至少一个；为所述电容串联或并联等效电阻；为所述电感串联或并联等效电阻。
- 根据权利要求1-6任一所述的方法，其中，所述调整所述损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，包括：确定当前损耗仿真模型中获取的每个发射通道的第二带宽数据与实测环境下获取的每个发射通道的第一带宽数据之间的第一误差，响应于检测到所述第一误差大于第一阈值范围的上限值，降低所述等效电阻的阻值，响应于检测到所述第一误差小于所述第一阈值范围的下限值，升高所述等效电阻的阻值，响应于检测到所述第一误差在所述第一阈值范围内，将所述等效电阻的当前阻值作为目标阻值；确定所述当前损耗仿真模型中获取的每个发射通道的第二输入阻抗数据与实测环境中获取的每个发射通道的第一输入阻抗数据之间的第二误差，响应于检测到所述第二误差大于第二阈值范围的上限值，增大匹配电容的电容量，响应于检测到所述第二误差小于所述第二阈值范围的下限值，降低所述匹配电容的电容量，响应于检测到所述第二误差在所述第二阈值范围内，将所述匹配电容的当前电容量作为目标电容量。
- 一种射频发射线圈的损耗模型确定装置，包括：实测模块，设置为获取实测环境中磁共振系统射频发射线圈的至少一个发射通道中的每个发射通道的散射参数的至少两个评价指标的第一指标数据；损耗仿真模型建立模块，设置为为虚拟射频发射线圈的每个电路元器件并联或串联等效电阻，以建立损耗仿真模型；参数调整模块，设置为调整损耗仿真模型中每个发射通道的等效电阻和匹配电容，以使调整后的损耗仿真模型中的所述每个发射通道的散射参数的至少两个评价指标的第二指标数据与对应的第一指标数据之间的误差在相应的阈值范围内，以得到所述射频发射线圈的损耗模型。
- 一种电子设备，所述电子设备包括：一个或多个处理器；存储装置，设置为存储一个或多个程序；当所述一个或多个程序被所述一个或多个处理器执行，使得所述一个或多个处理器实现如权利要求1-7中任一所述的射频发射线圈的损耗模型确定方法。
- 一种包含计算机可执行指令的存储介质，所述计算机可执行指令在由计算机处理器执行时用于执行如权利要求1-7中任一所述的射频发射线圈的损耗模型确定方法。
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