Simulation device for EIT system performance evaluation and method for evaluating EIT system performance

Abstract

The invention provides a simulation device for EIT system performance evaluation and a method for evaluating EIT system performance, and relates to the field of biomedical measurement. The simulation device comprises a substrate, a resistor network is arranged on the substrate, and the resistor network is divided into a plurality of resistor areas; the plurality of first variable resistors are respectively arranged in the plurality of resistance areas; the plurality of second variable resistors are respectively arranged in the plurality of resistance areas; and the controller is used for controlling the resistance values of the first variable resistor and the second variable resistor to respectively change according to the first set working frequency and the second set working frequency. The simulation device provided by the invention can better simulate the impedance distribution change caused by pulmonary respiration and pulmonary blood perfusion in the chest of the human body, so that the simulation device can be used for performing multifunctional accurate evaluation on the imaging performance of the EIT system in a motif experiment of the EIT system.

Description

Technical Field

[0001] The present application relates to the field of biomedical measurement, and in particular to a simulation device for evaluating EIT system performance and a method for evaluating EIT system performance. Background Art

[0002] Electrical Impedance Tomography (EIT) is an emerging medical imaging technology developed in recent years. It reconstructs an image that reflects the internal structure of an object by measuring the distribution of its electrical properties (e.g., conductivity distribution, permittivity distribution, etc.). Currently, EIT systems have begun to be used in clinical practice.

[0003] In the process of developing an EIT system, it is generally necessary to verify the performance of the EIT system through experiments to evaluate whether the performance of the EIT system meets the requirements. In the process of experimenting with the EIT system, a simulation device that can simulate the impedance distribution of the corresponding part of the human body (for example, the chest cavity) needs to be used as the test object of the EIT system, so that the EIT system can be simulated and tested to detect the signal-to-noise ratio and accuracy of the EIT system imaging. However, the electrical characteristic distribution of the simulation device used in the current EIT system experiment is always different from the real electrical characteristic distribution of the corresponding part of the human body, and it is difficult to simulate the changes in the electrical characteristic distribution of the corresponding part of the human body during physiological activities (for example, lung breathing, lung blood perfusion, etc.), which will affect the accuracy of the signal-to-noise ratio and accuracy of the EIT system imaging. At the same time, since the simulation device used in the current EIT system experiment does not take into account problems such as local lung function loss (for example, one-quarter lung function loss, two-quarter lung function loss, etc.), the performance of the EIT system for imaging problems such as local lung function loss cannot be evaluated.

[0004] Therefore, it is hoped to provide a simulation device for evaluating the performance of the EIT system, whose electrical characteristic distribution can be closer to the actual electrical characteristic distribution of the corresponding parts of the human body, and can better simulate the changes in the electrical characteristic distribution of the corresponding parts of the human body during physiological activities (for example, lung breathing, lung blood perfusion, etc.), and at the same time can simulate problems such as local lung function loss, thereby facilitating improving the accuracy of evaluating the performance of the EIT system through the simulation device and realizing the performance evaluation of the EIT system in imaging problems such as local lung function loss. Summary of the invention

[0005] One of the embodiments of the present application provides a simulation device for evaluating the performance of an EIT system, comprising: a substrate, on which a resistor network is arranged, the resistor network is divided into a plurality of resistor areas, and the impedance distribution of the plurality of resistor areas is used to simulate the impedance distribution of different areas of the chest cavity; a plurality of first variable resistors, the plurality of first variable resistors are respectively arranged in the plurality of resistor areas; a plurality of second variable resistors, the plurality of second variable resistors are respectively arranged in the plurality of resistor areas; a controller, the controller is communicatively connected with the plurality of first variable resistors and the plurality of second variable resistors, and is used to control the resistance value of the first variable resistor to change according to a first set working frequency to simulate the impedance distribution change of the chest cavity area corresponding to the resistance area thereof caused by breathing, and is used to control the resistance value of the second variable resistor to change according to a second set working frequency to simulate the impedance distribution change of the chest cavity area corresponding to the resistance area thereof caused by pulmonary blood perfusion.

[0006] In some embodiments, a third variable resistor is further included, and the third variable resistor is arranged in at least one of the resistance areas. The controller is communicated with the third variable resistor and is used to control the resistance value of the third variable resistor to change according to a third set operating frequency to simulate the impedance distribution change in the chest caused by heart beating.

[0007] In some embodiments, the resistor network is divided into a first resistor region and a second resistor region, and the impedance distributions of the first resistor region and the second resistor region are used to simulate the impedance distributions of the left lung region and the right lung region of the thorax, respectively.

[0008] In some embodiments, the resistor network is divided into four quadrant resistor regions, and the impedance distributions of the four quadrant resistor regions are used to simulate the impedance distributions of the left anterior lung region, the right anterior lung region, the right posterior lung region, and the left posterior lung region of the thoracic cavity, respectively.

[0009] In some embodiments, the first set operating frequency is 0.15 Hz~0.5 Hz.

[0010] In some embodiments, the second set operating frequency is 0.6 Hz to 3 Hz.

[0011] In some embodiments, the third set operating frequency is the same as the second set operating frequency.

[0012] In some embodiments, the resistor network includes at least two wire coils and multiple fixed resistors, wherein the at least two wire coils are arranged on the substrate from the inside to the outside around the center of the substrate, a contact is arranged at the center of the substrate, and a number of contacts are evenly arranged on the wire coils, and the multiple fixed resistors are respectively arranged between two adjacent contacts.

[0013] In some embodiments, at least some of the contacts on the outermost conductor coil are provided with lead-out ports, and the lead-out ports are used to electrically connect to electrodes on the electrode belt of the EIT system.

[0014] One of the embodiments of the present application provides a method for evaluating the performance of an EIT system, using the simulation device described in any of the above embodiments, and the method includes: connecting the EIT system to the simulation device and setting the working state of the simulation device; obtaining an electrical impedance image of the simulation device in the current working state through the EIT system; and evaluating the performance of the EIT system based on the electrical impedance image.

[0015] In some embodiments, the working state of the simulation device includes: the resistance values ​​of all variable resistors in the simulation device change according to the corresponding set working frequency.

[0016] In some embodiments, the working state of the simulation device also includes: the resistance value of the first variable resistor and / or the second variable resistor in at least one resistance area in the simulation device remains unchanged, and the resistance values ​​of the remaining variable resistors in the simulation device still change according to the corresponding set working frequency.

[0017] In some embodiments, the resistor network is divided into a first resistor region and a second resistor region, and the impedance distributions of the first resistor region and the second resistor region are respectively used to simulate the impedance distributions of the left lung region and the right lung region of the chest cavity, and the working state of the simulation device includes: the resistance values ​​of all variable resistors in the simulation device change according to the corresponding set operating frequency, and the resistance change of the first variable resistor in the first resistor region has a phase difference with the resistance change of the first variable resistor in the second resistor region.

[0018] The simulation device provided in the embodiment of the present application can simulate the impedance distribution change caused by lung breathing and pulmonary blood perfusion in the human chest cavity through the resistance change of the first variable resistor and the second variable resistor in each resistance area, so as to accurately evaluate the imaging performance of the EIT system through the phantom experiment of the EIT system, such as the signal-to-noise ratio, accuracy, stability and other indicators. At the same time, by controlling (for example, turning off) the first variable resistor and the second variable resistor in one or more resistance areas, the simulation device can simulate the local lung function loss, the left and right lung breathing delay and other conditions, so that the performance of the EIT system can be multifunctionally evaluated through the phantom experiment of the EIT system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0020] Figure 1 It is a schematic diagram of the structure of a simulation device according to some embodiments of the present application.

[0021] Figure 2 It is a schematic diagram of the structure of a simulation device according to other embodiments of the present application.

[0022] Figure 3 It is a schematic diagram of the principle of a resistor network according to some embodiments of the present application.

[0023] Figure 4 It is a schematic diagram of an impedance model according to some embodiments of the present application.

[0024] Figure 5 The present invention is a flowchart of a method for evaluating an EIT system according to some embodiments of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. On the contrary, the present application covers any substitutions, modifications, equivalent methods and schemes made on the essence and scope of the present application as defined by the claims. Further, in order to enable the public to have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. For those skilled in the art, the present application can be fully understood without the description of these details.

[0026] As a new medical imaging technology, Electrical Impedance Tomography (EIT) technology has been increasingly studied in the treatment of lung diseases. It is a functional imaging technology that does not produce radiation effects on human cells, is non-invasive, and can be used for real-time online monitoring.

[0027] During the development of the EIT system, it is necessary to conduct a phantom experiment on the EIT system to evaluate the performance of the EIT system, that is, to use a simulation device that can simulate the corresponding part of the human body (for example, the chest cavity) as the test object of the EIT system. In practical applications, taking the human chest cavity as an example, a resistor network can be set on a circuit board according to the impedance distribution of the human chest cavity as a simulation device for the EIT system phantom experiment. Although the impedance distribution of the resistor network of the simulation device can be relatively close to the real impedance distribution of the chest cavity, it cannot simulate the impedance distribution change of the human chest cavity during physiological activities (for example, lung breathing, lung blood perfusion, etc.), which has an impact on the evaluation of the imaging performance of the EIT system (for example, signal-to-noise ratio, accuracy, stability, etc.). At the same time, for the situation of local lung function loss in the chest cavity, the general simulation device cannot simulate it, which makes it impossible to evaluate the performance of the EIT system in imaging the situation of local lung function loss when performing chest imaging by using the simulation device as a test object. In other words, it is impossible to verify whether the EIT system can accurately detect the situation of lung function loss.

[0028] An embodiment of the present application provides a simulation device for evaluating the performance of an EIT system, comprising: a substrate, on which a resistor network is arranged, the resistor network is divided into a plurality of resistor areas, and the impedance distribution of the plurality of resistor areas is used to simulate the impedance distribution of different areas of the chest cavity; a plurality of first variable resistors, the plurality of first variable resistors are respectively arranged in the plurality of resistor areas; a plurality of second variable resistors, the plurality of second variable resistors are respectively arranged in the plurality of resistor areas; a controller, the controller is communicatively connected with the plurality of first variable resistors and the plurality of second variable resistors, and is used to control the resistance value of the first variable resistor to change according to a first set operating frequency to simulate the impedance distribution change of the chest cavity area corresponding to the resistance area thereof caused by breathing, and is used to control the resistance value of the second variable resistor to change according to a second set operating frequency to simulate the impedance distribution change of the chest cavity area corresponding to the resistance area thereof caused by pulmonary blood perfusion. The simulation device provided in the embodiment of the present application can simulate the impedance distribution changes caused by lung breathing and lung blood perfusion in the human chest cavity through the resistance changes of the first variable resistor and the second variable resistor in each resistance area, so as to accurately evaluate the imaging performance of the EIT system through the phantom experiment of the EIT system, such as the signal-to-noise ratio, accuracy, stability and other indicators. At the same time, by controlling (for example, turning off) the first variable resistor and the second variable resistor in one or more resistance areas, the simulation device can simulate the situation of local lung function loss, so that the imaging performance of the EIT system for the situation of local lung function loss can be accurately evaluated through the phantom experiment of the EIT system. It can be understood that the lung function in the embodiment of the present application can refer to the physiological activities occurring in the lungs. Therefore, in the embodiment of the present application, the lung function can mainly include breathing, lung blood perfusion, etc.

[0029] The simulation device provided in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0030] Figure 1 It is a schematic diagram of the structure of a simulation device according to some embodiments of the present application. Figure 2 It is a schematic diagram of the structure of a simulation device according to other embodiments of the present application.

[0031] Combination Figure 1 and Figure 2 As shown, the simulation device 100 may include a substrate 110 , a resistor network 120 , a plurality of first variable resistors 130 , a plurality of second variable resistors 140 , and a controller (not shown in the figure).

[0032] The substrate 110 may be a circuit board, wherein the surface of the substrate 110 may correspond to the imaging plane of the EIT system. In some embodiments, since the imaging plane of the EIT system is a cross section of the human chest toward the sole of the foot, the surface of the substrate 110 may correspond to the cross section of the human chest toward the sole of the foot.

[0033] The resistor network 120 is arranged on the substrate 110. The resistor network 120 may be composed of a plurality of resistors connected in series and in parallel. The impedance distribution of the resistor network 120 may be used to simulate the impedance distribution in the human chest cavity (when no physiological activity occurs). Further, the resistor network 120 may be divided into a plurality of resistor regions (for example, Figure 1 The first resistance region 120A, the second resistance region 120B, or Figure 2 The impedance distribution of several resistor regions is used to simulate the impedance distribution of different areas of the chest cavity, that is, each resistor region can correspond to a certain area in the chest cavity. More descriptions of the resistor network can be found elsewhere in this manual, so we will not describe them in detail here.

[0034] In some embodiments, Figure 1 As shown, the resistor network 120 can be divided into a first resistor region 120A and a second resistor region 120B, and the impedance distributions of the first resistor region 120A and the second resistor region 120B can be used to simulate the impedance distributions of the left lung region and the right lung region of the thorax, respectively, wherein the dotted line L used to divide the first resistor region 120A and the second resistor region 120 can correspond to the sagittal axis passing through the thorax in human anatomy. In some embodiments, as Figure 2 As shown, the resistor network 120 can be divided into four quadrant resistor regions, namely, a first quadrant resistor region 121, a second quadrant resistor region 122, a third quadrant resistor region 123 and a fourth quadrant resistor region 124. Figure 2 The surface of the substrate 110 shown in the figure corresponds to the cross section of the human chest cavity toward the sole of the foot. Therefore, the impedance distribution of the four-quadrant resistor area can be used to simulate the impedance distribution of the left front lung area, the right front lung area, the right back lung area and the left back lung area of ​​the chest cavity, respectively. The mutually orthogonal dotted lines X and Y used to divide the four-quadrant area can correspond to the coronal axis and sagittal axis passing through the chest cavity in human anatomy. It should be noted that the resistor network 120 is divided into Figure 1 The first resistance region 120A and the second resistance region 120B are shown as being divided into Figure 2 The four-quadrant regions shown are only examples and are not intended to be limiting. Using other division methods to divide the resistor network 120 into multiple resistor regions should also be within the protection scope of the present application.

[0035] Several first variable resistors 130 may be respectively arranged in several resistance regions, that is, one first variable resistor 130 is arranged in each resistance region. For example, Figure 1 A first variable resistor 130 is disposed in each of the first resistance region 120A and the second resistance region 120B, or Figure 2 The first variable resistors 130 are respectively arranged in the four quadrant resistance regions.

[0036] Several second variable resistors 140 may be respectively arranged in several resistance regions, that is, one second variable resistor 140 is arranged in each resistance region. For example, Figure 1 A second variable resistor 140 is disposed in each of the first resistance region 120A and the second resistance region 120B, or Figure 2 Second variable resistors 140 are respectively arranged in the four quadrant resistance regions.

[0037] It can be understood that the first variable resistor 130 and the second variable resistor 140 can refer to resistors whose resistance values ​​can be adjusted. Further, the controller can be connected to the plurality of first variable resistors 130 and the plurality of second variable resistors 140 for communication, and is used to control the resistance value of the first variable resistor 130 to change according to the first set working frequency to simulate the impedance distribution change caused by breathing in the chest area corresponding to the resistance area where the first variable resistor 130 is located, and is used to control the resistance value of the second variable resistor 140 to change according to the second set working frequency to simulate the impedance distribution change caused by pulmonary blood perfusion in the chest area corresponding to the resistance area where the second variable resistor 140 is located. By controlling the resistance values ​​of the plurality of first variable resistors 130 and the plurality of second variable resistors 140 to change according to the corresponding set working frequency, the controller can enable the simulation device 100 to better simulate the impedance distribution change when the human chest cavity undergoes physiological activities (breathing and pulmonary blood perfusion), so that the performance of the EIT system can be better evaluated by using the simulation device 100 as a test object of the EIT system phantom experiment. It should be noted that, since the electrical impedance image acquired through the EIT system is a dynamic image, the impedance distribution change of the simulation device 100 can be reflected in the electrical impedance image of the simulation device 100 acquired through the EIT system.

[0038] In some embodiments, since the resistance value of the first variable resistor 130 in each resistance area changes according to the corresponding first set operating frequency, it can simulate the impedance distribution change caused by breathing in the corresponding chest area, and the resistance value of the second variable resistor 140 in each resistance area changes according to the corresponding second set operating frequency, it can simulate the impedance distribution change caused by pulmonary blood perfusion in the corresponding chest area, and lung function may mainly include breathing and pulmonary blood perfusion. Therefore, by controlling the variable resistors (the first variable resistor 130 and / or the second variable resistor 140) in at least one resistance area in the resistance network 120 through the controller, the simulation device 100 can simulate the situation of local lung function loss.

[0039] As an example, Figure 1 As shown, the controller controls the resistance of the first variable resistor 130 and the second variable resistor 140 in the first resistance area 120A and the second resistance area 120B to change according to the first set working frequency and the second set working frequency respectively, so that the impedance distribution of the first resistance area 120A and the second resistance area 120B can change, wherein the impedance distribution change of the first resistance area 120A and the second resistance area 120B caused by the resistance change of the first variable resistor 130 can simulate the impedance distribution change of the left lung area and the right lung area caused by breathing, and the impedance distribution change of the first resistance area 120A and the second resistance area 120B caused by the resistance change of the second variable resistor 140 can respectively simulate the impedance distribution change of the left lung area and the right lung area caused by pulmonary blood perfusion.

[0040] In some embodiments, by controlling the first variable resistor 130 and / or the second variable resistor 140 in one of the first resistance area 120A and the second resistance area 120B to stop working (i.e., the resistance value of the first variable resistor 130 and / or the second variable resistor 140 does not change) or the resistance value of the first variable resistor 130 and / or the second variable resistor 140 changes according to a non-set working frequency, and the variable resistor in the other resistance area works normally, the situation of the lack of lung function (breathing and / or pulmonary blood perfusion) in the left lung area or the right lung area can be simulated, so that the simulation device 100 can be used as a test subject of the EIT system phantom experiment to evaluate the EIT system's effect on the lack of local lung function (lung function (respiration) in the left lung area or the right lung area). The performance of imaging the situation of lack of pulmonary function in the left lung region (lack of respiration and / or pulmonary blood perfusion), or the ability of the EIT system to detect the lack of local pulmonary function, for example, when the first variable resistor 130 and the second variable resistor 140 of the first resistance area 120A are set to stop working, and the first variable resistor 140 and the second variable resistor 140 in the second resistance area 120B work normally, the electrical impedance image of the simulation device 100 is obtained through the EIT system at this time. If the electrical impedance image can accurately show that the impedance distribution of the first resistance area 120A has not changed, it means that the EIT system has good performance in imaging the lack of pulmonary function in the left lung region, can meet the needs of imaging the lack of pulmonary function in the left lung region, and has the ability to detect the lack of pulmonary function in the left lung region. It can be understood that the normal operation of the variable resistor means that the resistance value of the variable resistor changes according to the corresponding set working frequency.

[0041] As another exemplary illustration, Figure 2As shown, the controller controls the resistance values ​​of the first variable resistor 130 and the second variable resistor 140 in the four-quadrant resistance area to change according to the first set operating frequency and the second set operating frequency respectively, so that the impedance distribution of the four-quadrant resistance area can change, wherein the impedance distribution change caused by the resistance change of the first variable resistor 130 in the four-quadrant resistance area can simulate the impedance distribution change caused by breathing in the left front lung area, the right front lung area, the right back lung area and the left back lung area, and the impedance distribution change caused by the resistance change of the second variable resistor 140 in the four-quadrant resistance area can respectively simulate the impedance distribution change caused by pulmonary blood perfusion in the left front lung area, the right front lung area, the right back lung area and the left back lung area. In some embodiments, by controlling the first variable resistor 130 and / or the second variable resistor 140 in one or more quadrant resistance regions of the four-quadrant resistance region to stop working (i.e., the resistance value of the first variable resistor 130 and / or the second variable resistor 140 does not change) or the resistance value of the first variable resistor 130 and / or the second variable resistor 140 changes according to a non-set working frequency, and the variable resistors in the remaining quadrant resistance regions work normally, it is possible to simulate the lack of lung function (breathing and / or pulmonary blood perfusion) in one or more of the left front lung region, the right front lung region, the right rear lung region, and the left rear lung region, so that the simulation device 100 can be used as a test subject for an EIT system phantom experiment to evaluate the effect of the EIT system on the local lung. The performance of imaging of functional loss, or the ability of the EIT system to detect local lung function loss, can be detected. For example, when the first variable resistor 130 and the second variable resistor 140 in the first quadrant resistance area 121 are set to stop working, while the first variable resistor 140 and the second variable resistor 140 in the remaining quadrant resistance areas work normally, the electrical impedance image of the simulation device 100 is obtained through the EIT system. If the electrical impedance image can accurately show that the impedance distribution of the first quadrant resistance area 121 has not changed, it means that the EIT system has good performance in imaging lung function loss in the left front lung area, can meet the needs of imaging lung function loss in the left front lung area, and has the ability to detect lung function loss in the left front lung area.

[0042] In some embodiments, when the resistor network 120 includes multiple resistor areas, the controller controls the resistance of the first variable resistor 130 in two resistor areas among the multiple resistor areas to change according to the first set operating frequency (i.e., normal operation), and the resistance change of the first variable resistor 130 in the two resistor areas has a phase difference, which can simulate the respiratory delay between the two chest areas corresponding to the two resistor areas, so that the simulation device 100 can be used as a test object for the EIT system phantom experiment to evaluate the imaging performance of the EIT system in the case of delayed breathing in the two chest areas corresponding to the two resistor areas, or in other words, it can detect the ability of the EIT system to detect respiratory delay in the two chest areas corresponding to the two resistor areas. For example, the electrical impedance image of the simulation device 100 is obtained through the EIT system. If the electrical impedance image can accurately show that the impedance distribution change of the two resistance areas has a delay and meets the corresponding set phase difference, then it means that the EIT system has good performance in respiratory delay imaging of the two chest areas corresponding to the two resistance areas, can meet the imaging requirements of the respiratory delay of the two chest areas corresponding to the two resistance areas, and has the ability to detect the respiratory delay of the two chest areas corresponding to the two resistance areas.

[0043] As an example, Figure 1As shown, by controlling the resistance value of the first variable resistor 130 in the first resistance region 120A to change according to the first set operating frequency (i.e., normal operation), the resistance value of the first variable resistor 130 in the second resistance region 120B to change according to the second set operating frequency, and making the resistance value change of the first variable resistor 130 in the first resistance region 120A and the resistance value change of the first variable resistor 130 in the second resistance region 120B have a phase difference, the remaining variable resistors in the resistance network 120 (i.e., the second variable resistor 140) work normally. Since the normal operation of the first variable resistor 130 can simulate the impedance distribution change caused by breathing, the resistance value change of the first variable resistor 130 in the first resistance region 120A and the resistance value change of the first variable resistor 130 in the second resistance region 120B are different. The phase difference of the resistance change of the resistor 130 can simulate the respiratory delay between the left lung area and the right lung area, so that the simulation device 100 can be used as a test object for the EIT system phantom experiment to evaluate the imaging performance of the EIT system for the situation with delayed breathing of the left and right lungs, or it can detect the ability of the EIT system to detect the respiratory delay of the left and right lungs. For example, the electrical impedance image of the simulation device 100 is obtained through the EIT system. If the electrical impedance image can accurately show that the impedance distribution change of the first resistor area 120A and the impedance distribution change of the second resistor area 120B have a delay and meet the corresponding set phase difference, it means that the EIT system has good performance in delayed imaging of left and right lung breathing, can meet the imaging requirements of left and right lung breathing delay, and has the ability to detect left and right lung breathing delay.

[0044] As another exemplary illustration, Figure 2 As shown, by controlling the resistance values ​​of the variable resistors in the four-quadrant resistance areas to change according to the corresponding set operating frequencies, and at the same time controlling the resistance value changes of the first variable resistors 130 in two of the quadrant resistance areas to have a phase difference, the respiratory delay of the chest areas corresponding to the two quadrant resistance areas (for example, the left front lung area and the right front lung area, the left front lung area and the right back lung area, the left front lung area and the left back lung area, the right front lung area and the right back lung area, the right front lung area and the left back lung area, or the right back lung area and the left back lung area) can be simulated, so that the simulation device 100 can be used as a test object for the EIT system phantom experiment to evaluate the imaging performance of the EIT system for the situation where the respiratory delay of the chest area corresponding to any two quadrant resistance areas is delayed, or in other words, the ability of the EIT system to detect the respiratory delay of the chest area corresponding to any two quadrant resistance areas can be detected.

[0045] Since the human heart beat will affect the impedance distribution change of the human chest cavity, in order to make the simulation device 100 more realistically simulate the impedance distribution change of the human chest cavity, in some embodiments, Figure 1 and Figure 2As shown, the simulation device 100 may further include a third variable resistor 150. The third variable resistor 150 may be arranged in at least one resistance region, and the controller may be in communication connection with the third variable resistor 150, and is used to control the resistance value of the third variable resistor 150 to change according to the third set working frequency to simulate the impedance distribution change of the chest cavity caused by the heart beat. In some embodiments, in order to make the resistance value change of the third variable resistor 150 better simulate the impedance distribution change of the chest cavity caused by the heart beat, the position of the third variable resistor 150 in the resistor network 120 may be set corresponding to the position of the heart in the chest cavity. For example, in Figure 1 In the embodiment, the third variable resistor 150 may be disposed in the first resistance region 120A. Figure 2 In the embodiment, the third variable resistor 150 can be disposed in the first quadrant resistor region 121. In some embodiments, the position of the third variable resistor 150 in the resistor network 120 can also be disposed at any position in the resistor network 120. For example, the third variable resistor 150 can be disposed at the second resistor region 120B or at the junction of the first resistor region 120A and the second resistor region 120B. For another example, the third variable resistor 150 can be disposed in any one quadrant resistor region of the four quadrant resistor regions or at the junction of any two quadrant resistor regions.

[0046] In some embodiments, the variable resistors in the embodiments of the present application (including the first variable resistor 130, the second variable resistor 140, and the third variable resistor 150) can change in a sinusoidal wave or a sinusoidal half-wave under the control of the controller, so that the resistance change of the variable resistor can better simulate the change in impedance distribution when the corresponding physiological activities (including breathing, pulmonary blood perfusion, and heart beats) occur in the corresponding chest area, so that the simulation device 100 can better simulate the change in impedance distribution when physiological activities occur in the human chest. In some embodiments, the variable resistors in the embodiments of the present application can have the same or different resistance change ranges. In some embodiments, the first variable resistor (or the second variable resistor) located in different resistance areas can have the same or different resistance change ranges.

[0047] In some embodiments, in order to further enable the first variable resistor 130 to better simulate the impedance distribution changes caused by breathing in the corresponding chest area, the first set operating frequency can be set according to the breathing frequency of a normal adult, and therefore, the first set operating frequency can be 0.15Hz~0.5Hz. In some embodiments, in order to further enable the second variable resistor 140 to better simulate the impedance distribution changes caused by pulmonary blood perfusion in the corresponding chest area, the second set operating frequency can be set according to the pulmonary blood perfusion frequency of a normal adult, and therefore, the second set operating frequency can be 0.6Hz~3Hz. In some embodiments, in order to further enable the third variable resistor 150 to better simulate the impedance distribution changes caused by heart beats in the human chest, the third set operating frequency can be set according to the heart beat frequency of a normal adult. Since the human heart beat frequency and the pulmonary blood perfusion frequency are the same, the second set operating frequency is the same as the third set operating frequency.

[0048] The resistor network in the embodiment of the present application will be described in detail below.

[0049] Figure 3 It is a schematic diagram of the principle of a resistor network according to some embodiments of the present application.

[0050] In some embodiments, Figure 3 As shown, the resistor network 120 may include at least two conductive coils 125 and a plurality of fixed resistors 126, wherein the at least two conductive coils 125 are arranged on the substrate 110 from the inside to the outside around the center of the substrate 110, and a contact point (at Figure 3 Indicated by black dots in the figure), a plurality of contacts are evenly arranged on the conductor coil 125 (in Figure 3 (represented by black dots in the figure), multiple fixed resistors 126 are respectively arranged between two adjacent contacts, that is, the two ends of each fixed resistor 126 are respectively connected to two adjacent contacts. Among them, the fixed resistor can refer to a resistor whose resistance value remains unchanged or whose change is negligible. It can be understood that the two adjacent contacts can include the contact at the center of the substrate 110 and any one of the contacts on the innermost conductor coil 120, two adjacent contacts on the same conductor coil 120, and two adjacent contacts on two adjacent conductor coils 120, wherein the contact can refer to a welding point or other forms of connection points arranged on the substrate 110 or the conductor coil 120.

[0051] In some embodiments, the first variable resistor 130 or the second variable resistor 140 can be arranged between two contacts in the same resistance region and connected in parallel with the fixed resistor 126 located between the two contacts. The two contacts between which the first variable resistor 130 or the second variable resistor 140 is arranged can be two adjacent contacts or two contacts separated by at least one contact, that is, in the same resistance region, the fixed resistor connected in parallel with the first variable resistor 130 or the second variable resistor 140 can be one or more. In some embodiments, the third variable resistor 150 can be arranged between two contacts in the same resistance region or in different resistance regions and connected in parallel with the fixed resistor 126 located between the two contacts.

[0052] In some embodiments, the contour shape of the wire coil 125 may be a regular or irregular shape such as a circle or a rectangle. In some embodiments, in order to enable the simulation device 100 to better simulate the impedance distribution of the human chest cavity, the contour shape of the wire coil 125 may match the contour shape of the human chest cavity, that is, the contour shape of the wire coil 125 may be the same as the contour shape of the human chest cavity.

[0053] In order to enable the simulation device 100 to better simulate the impedance distribution of the human chest cavity, in some embodiments, the fixed resistors 126 located on the same wire coil 125 have the same resistance value, the fixed resistors located in the innermost wire coil 125 have the same resistance value, and the fixed resistors located between two adjacent wire coils 125 have the same resistance value. In some embodiments, in order to further enable the simulation device 100 to better simulate the impedance distribution of the human chest cavity, except for the fixed resistor located on the outermost conductor coil 125 having the smallest resistance, the resistance values ​​of other fixed resistors increase from the inside to the outside according to their positions. For example, the substrate 110 is provided with a first conductor coil, a second conductor coil, ..., an (n-1)th conductor coil, and an nth conductor coil from the inside to the outside around the center of the substrate 110. The resistance value of the fixed resistor in the first conductor coil, the resistance value of the fixed resistor between the first conductor coil and the second conductor coil, the resistance value of the fixed resistor on the second conductor coil, ..., the resistance value of the fixed resistor on the (n-1)th conductor coil, and the resistance value of the fixed resistor between the (n-1)th conductor coil increase in sequence, wherein the resistance value of the fixed resistor on the nth conductor coil is smaller than the resistance value of the fixed resistor in the first conductor coil.

[0054] In some embodiments, the number of the conductive coils 125 of the resistor network 120 may be 2, 3, 4, 5, 6, 7, etc. As an example, see Figure 3 As shown, the resistor network 120 includes seven conductive coils 125 arranged from the inside to the outside around the center of the substrate 110.

[0055] In some embodiments, the number of contacts on each wire coil 125 may be the same or different. In some embodiments, the number of contacts on each wire coil 125 may increase from the inside to the outside. In some embodiments, the number of contacts on each wire coil 125 may be set according to actual conditions. Further, the number of contacts on each wire coil 125 may be set according to the actual resistivity distribution of the human chest cavity. As an example, Figure 3 As shown, seven conductive coils 125 are provided on the substrate 110 , and the numbers of contact points on the seven conductive coils 125 are 4, 8, 16, 16, 16, 32, and 32 respectively from the inside to the outside.

[0056] It should be noted that Figure 3 The structure of the resistor network shown is only an example of the present application and is not intended to be limiting. When a resistor network with other structures is used to replace it, it should also be within the scope of protection of the present application.

[0057] In some embodiments, at least some of the contacts on the outermost conductor coil are provided with lead-out ports, which can be used to electrically connect the electrodes 200 on the electrode belt of the EIT system to enable the EIT system to measure the simulation device 100 .

[0058] Figure 4 It is a schematic diagram of an impedance model according to some embodiments of the present application.

[0059] In some embodiments, in combination Figure 3 and Figure 4 As shown, the simulation device 100 further includes an impedance model 160 electrically connected to the lead-out port. Figure 4 As shown, the impedance model 160 may include an output port 161, a connection port 162, a first resistor 163 and a parallel branch; wherein the output port 161 is connected to the lead-out port, the first resistor 163 and the parallel branch are arranged in series between the output port 161 and the connection port 162, and the parallel branch is formed by connecting the second resistor 164 and the capacitor 165 in parallel. By arranging the impedance model 160 between the lead-out port and the electrode, the resistance value provided by the impedance model 160 can simulate the contact impedance between the electrode and the human skin, so that the simulation device 100 can better simulate the actual impedance distribution when the human chest cavity contacts the electrode belt of the EIT system, and thus it is more conducive to improving the accuracy of the performance evaluation of the EIT system when the simulation device 100 is used as a test object for a phantom experiment.

[0060] Figure 5 The present invention is a flowchart of a method for evaluating an EIT system according to some embodiments of the present application.

[0061] like Figure 5As shown, the embodiment of the present application further provides a method 500 for evaluating an EIT system. The method 500 uses the simulation device 100 provided in the embodiment of the present application, that is, the method 500 uses the simulation device 100 as a test object of the EIT system phantom experiment to achieve performance evaluation of the EIT system. Further, the method 500 may include the following steps:

[0062] Step S510 , connecting the EIT system to the simulation device 100 , and setting the working state of the simulation device 100 .

[0063] In step S510, Figure 3 As shown, the electrodes on the electrode belt of the EIT system can be electrically connected to the lead-out port in the simulation device 100. In some embodiments, the working state of the simulation device 100 may include the working state of each variable resistor (the first variable resistor 130, the second variable resistor 140 or the third variable resistor 150) in the resistance network 120. In some embodiments, the working state of the variable resistor may include whether its resistance value changes according to the corresponding set working frequency.

[0064] Step S520: acquiring an electrical impedance image of the simulation device in the current working state through the EIT system.

[0065] In step S520, after setting the working state of the simulation device 100, the EIT system is started to collect the electrical impedance image of the simulation device 100 in the current working state. The electrical impedance image of the simulation device 100 in different working states will also be different.

[0066] Step S530 : evaluating the performance of the EIT system based on the electrical impedance image.

[0067] In step S530 , based on the electrical impedance images of the simulation device 100 in different states, the performance of the EIT system to be evaluated is also different.

[0068] In some embodiments, the working state of the simulation device 100 may include: all variable resistors in the simulation device 100 (including the first variable resistor 130, the second variable resistor 140, and if there is a third variable resistor 150, the third variable resistor 150 is also included) change according to the corresponding set working frequency (i.e., normal operation). Based on the electrical impedance image of the simulation device 100 in this working state, the basic imaging performance of the EIT system can be evaluated, including indicators such as signal-to-noise ratio, accuracy, and stability, that is, to verify whether the EIT system can accurately collect electrical impedance images of the human chest during physiological activities. As an exemplary illustration, if the impedance distribution change in the electrical impedance image of the simulation device 100 in this working state collected by the EIT system is consistent with the impedance distribution change caused by the simulation device 100 caused by the normal operation of all variable resistors in the simulation device 100, it means that the basic imaging performance of the EIT system is good and can accurately collect electrical impedance images of the human chest during physiological activities.

[0069] In some embodiments, the working state of the simulation device 100 may include: the resistance value of the first variable resistor 130 and / or the second variable resistor 140 in at least one resistance region of the simulation device 100 remains unchanged (not working) or the resistance value does not change according to the corresponding set working frequency (abnormal working), and the resistance values ​​of the remaining variable resistors in the simulation device 100 still change according to the corresponding set working frequency (normal working). Since the simulation device 100 in this working state can simulate the situation of partial lung function loss, the electrical impedance image of the simulation device 100 in this working state can evaluate the imaging performance of the EIT system for partial lung function loss. As an exemplary illustration, in the electrical impedance image of the simulation device 100 in this working state acquired by the EIT system, if the resistance area where the first variable resistor 130 and / or the second variable resistor 140 is not working or working abnormally does not undergo impedance distribution change or abnormal impedance distribution change (i.e., different from the impedance distribution change caused by the normal operation of the first variable resistor 130 and / or the second variable resistor 140 in the resistance area) is accurately displayed, it means that the EIT system has good imaging performance for local lung function loss, and can accurately acquire the electrical impedance image when the local lung function of the human chest is lost, and accurately detect the area where the human chest lung function is lost. In some embodiments, if in the electrical impedance image, the resistance area where the first variable resistor 130 is not working or working abnormally does not undergo impedance distribution change or abnormal impedance distribution change is accurately displayed, it means that the EIT system has good imaging performance for local lung respiratory function loss, and can accurately acquire the electrical impedance image when the local lung respiratory function of the human chest is lost, and accurately detect the area where the human chest lung respiratory function is lost. In some embodiments, if in the electrical impedance image, the resistance area where the second variable resistor 140 is not working or working abnormally does not change in impedance distribution or the impedance distribution change abnormality is accurately displayed, it means that the EIT system has good imaging performance for local pulmonary blood perfusion function loss, can accurately collect electrical impedance images when local pulmonary blood perfusion function loss occurs in the human chest cavity, and accurately detect the area where the human chest cavity pulmonary blood perfusion function loss occurs. In some embodiments, if in the electrical impedance image, the resistance area where the first variable resistor 130 and the second variable resistor 140 are not working or working abnormally does not change in impedance distribution or the impedance distribution change abnormality is accurately displayed, it means that the EIT system has good imaging performance for local respiratory and pulmonary blood perfusion function loss, can accurately collect electrical impedance images when local respiratory and pulmonary blood perfusion function loss occurs in the human chest cavity, and accurately detect the area where the human chest cavity respiratory and pulmonary blood perfusion function loss occurs.

[0070] In some embodiments, in combination Figure 1As shown, the resistor network 120 is divided into a first resistor region 120A and a second resistor region 120B, and the impedance distributions of the first resistor region 120A and the second resistor region 120B are used to simulate the impedance distributions of the left lung region and the right lung region of the chest cavity, respectively. The working state of the simulation device 100 may include: the resistance values ​​of all variable resistors in the simulation device 100 change according to the corresponding set working frequency, and the resistance change of the first variable resistor 130 in the first resistor region 120A and the resistance change of the first variable resistor 130 in the second resistor region 120B have a phase difference. Since the simulation device 100 in this working state can simulate the situation where the left and right lungs of the human chest cavity have a delayed breathing, the electrical impedance image of the simulation device 100 in this working state can evaluate the imaging performance of the EIT system for the delayed breathing of the left and right lungs, so as to detect whether the EIT system can accurately collect the electrical impedance image of the left and right lungs of the human chest cavity with delayed breathing and accurately detect the breathing delay between the left and right lungs of the human body. As an exemplary illustration, in the electrical impedance image of the simulation device 100 in this working state acquired by the EIT system, if the phase difference between the impedance distribution change of the first resistance area 120A and the impedance distribution change of the second resistance area 120B is consistent with the phase difference between the resistance change of the first variable resistor 130 in the first resistance area 120A and the resistance change of the first variable resistor 130 in the second resistance area 120B, then it means that the EIT system has good imaging performance with delayed breathing of the left and right lungs, can accurately acquire the electrical impedance image with delayed breathing of the left and right lungs of the human chest cavity, and accurately detect the breathing delay between the left and right lungs.

[0071] In some embodiments, in combination Figure 2As shown, the resistor network 120 can be divided into four quadrant resistor areas, namely the first quadrant resistor area 121, the second quadrant resistor area 122, the third quadrant resistor area 123 and the fourth quadrant resistor area 124. The impedance distribution of the four quadrant resistor areas can be used to simulate the impedance distribution of the left front lung area, the right front lung area, the right rear lung area and the left rear lung area of ​​the chest cavity, respectively. The working state of the simulation device 100 may include: the resistance values ​​of all variable resistors in the simulation device 100 change according to the corresponding set operating frequency, and the resistance value changes of the first variable resistor 130 in the two quadrant resistor areas have a phase difference. Since the simulation device 100 in this working state can simulate the situation where there is a breathing delay in two chest regions among the left anterior lung region, the right anterior lung region, the right posterior lung region and the left posterior lung region, the electrical impedance image of the simulation device 100 in this working state can evaluate the imaging performance of the EIT system for the breathing delay in any two chest regions among the left anterior lung region, the right anterior lung region, the right posterior lung region and the left posterior lung region, so as to detect whether the EIT system can accurately acquire the electrical impedance image with breathing delay in any two chest regions among the left anterior lung region, the right anterior lung region, the right posterior lung region and the left posterior lung region, and accurately detect the breathing delay between any two chest regions among the left anterior lung region, the right anterior lung region, the right posterior lung region and the left posterior lung region. As an exemplary explanation, in the electrical impedance image of the simulation device 100 in this working state acquired by the EIT system, if the phase difference between the impedance distribution changes in the two quadrant resistance areas is consistent with the phase difference between the resistance changes of the first variable resistor in the two quadrant resistance areas, then it means that the EIT system has good imaging performance for breathing delay in any two chest regions among the left front lung region, the right front lung region, the right back lung region and the left back lung region, and can accurately acquire electrical impedance images with breathing delay in any two chest regions among the left front lung region, the right front lung region, the right back lung region and the left back lung region, and accurately detect the breathing delay between any two chest regions among the left front lung region, the right front lung region, the right back lung region and the left back lung region.

[0072] The beneficial effects that may be brought about by the embodiments of the present application include but are not limited to: (1) The simulation device provided in the embodiments of the present application can better simulate the impedance distribution of the corresponding part of the human body (chest cavity), which is beneficial to improving the accuracy of the EIT system in evaluating its performance through a phantom experiment; (2) The simulation device provided in the embodiments of the present application controls the change in the resistance of the variable resistor through a controller to control the change in the impedance distribution of the simulation device, which can better simulate the change in the impedance distribution of the corresponding part of the human body when physiological activities occur, thereby further improving the accuracy of the EIT system in evaluating its performance through a phantom experiment; (3) The simulation device provided in the embodiments of the present application can be used to evaluate the performance of the EIT system in imaging local lung function loss in the human chest cavity, delayed breathing of the left and right lungs, and other conditions.

[0073] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0074] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this application. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0075] It should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a rotating connection or a sliding connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood in combination with specific circumstances.

[0076] In addition, when terms such as "first", "second", and "third" are used in the specification of this application to describe various features, these terms are only used to distinguish these features and cannot be understood as indicating or implying the relationship between the features, the relative importance, or implicitly indicating the number of features indicated.

[0077] At the same time, the present application uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0078] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0079] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A simulation device for EIT system performance evaluation, characterized in that: include: A substrate, on which a resistor network is arranged, wherein the resistor network is divided into a plurality of resistor regions, and impedance distributions of the plurality of resistor regions are used to simulate impedance distributions of different regions of the chest cavity; a plurality of first variable resistors, wherein the plurality of first variable resistors are respectively arranged in the plurality of resistance regions; a plurality of second variable resistors, wherein the plurality of second variable resistors are respectively arranged in the plurality of resistance regions; A controller, the controller is communicatively connected with the plurality of first variable resistors and the plurality of second variable resistors, and is used to control the resistance value of the first variable resistors to change according to a first set operating frequency to simulate the impedance distribution change caused by breathing in the chest area corresponding to the resistance area where the first variable resistors are located, and is used to control the resistance value of the second variable resistors to change according to a second set operating frequency to simulate the impedance distribution change caused by pulmonary blood perfusion in the chest area corresponding to the resistance area where the second variable resistors are located.

2. The simulation device according to claim 1, characterized in that It also includes a third variable resistor, which is arranged in at least one of the resistance areas. The controller is communicated with the third variable resistor and is used to control the resistance value of the third variable resistor to change according to a third set operating frequency to simulate the impedance distribution change in the chest caused by heart beating.

3. The simulation device according to claim 1 or 2, characterized in that: The resistor network is divided into a first resistor region and a second resistor region, and the impedance distributions of the first resistor region and the second resistor region are used to simulate the impedance distributions of the left lung region and the right lung region of the thoracic cavity, respectively.

4. The simulation device according to claim 1 or 2, characterized in that: The resistor network is divided into four quadrant resistor regions, and the impedance distributions of the four quadrant resistor regions are used to simulate the impedance distributions of the left front lung region, the right front lung region, the right rear lung region and the left rear lung region of the thoracic cavity, respectively.

5. The simulation device according to claim 1 or 2, characterized in that: The first set operating frequency is 0.15Hz~0.5Hz.

6. The simulation device according to claim 1 or 2, characterized in that: The second set operating frequency is 0.6 Hz to 3 Hz.

7. The simulation device according to claim 2, characterized in that The third set operating frequency is the same as the second set operating frequency.

8. The simulation device according to claim 1 or 2, characterized in that: The resistor network includes at least two conductive coils and a plurality of fixed resistors, wherein the at least two conductive coils are arranged on the substrate from the inside to the outside around the center of the substrate, a contact is arranged at the center of the substrate, and a plurality of contacts are evenly arranged on the conductive coils, and the plurality of fixed resistors are respectively arranged between two adjacent contacts.

9. The simulation device according to claim 8, characterized in that At least some of the contacts on the outermost conductor coil are provided with lead-out ports, which are used to electrically connect to electrodes on the electrode belt of the EIT system.

10. A method for evaluating the performance of an EIT system, using the simulation device according to any one of claims 1 to 9, characterized in that: The method comprises: Connecting the EIT system to the simulation device and setting the working state of the simulation device; Acquire an electrical impedance image of the simulation device in a current working state through an EIT system; The performance of the EIT system is evaluated based on the electrical impedance image.

11. The method according to claim 10, characterized in that The working state of the simulation device includes: the resistance values ​​of all variable resistors in the simulation device change according to the corresponding set working frequency.

12. The method according to claim 10, characterized in that The working state of the simulation device also includes: The resistance value of the first variable resistor and / or the second variable resistor in at least one resistance region in the simulation device remains unchanged, and the resistance values ​​of the remaining variable resistors in the simulation device still change according to the corresponding set operating frequency.

13. The method according to claim 10, characterized in that The resistor network is divided into a first resistor region and a second resistor region, and the impedance distributions of the first resistor region and the second resistor region are used to simulate the impedance distributions of the left lung region and the right lung region of the thoracic cavity, respectively. The working state of the simulation device includes: The resistance values ​​of all variable resistors in the simulation device change according to the corresponding set operating frequency, and the resistance value change of the first variable resistor in the first resistance area has a phase difference with the resistance value change of the first variable resistor in the second resistance area.

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