A channel consistency evaluation method and system for EIT system

Abstract

The present application provides a channel consistency evaluation method and system for an EIT system, which relates to the field of electrical impedance imaging, and the method includes: obtaining the measured voltage of each channel of the EIT system, wherein the channel includes an excitation electrode pair and a measurement electrode pair; classifying the channels, and determining the reference voltage corresponding to the category based on the measured voltages of all channels under the same category; calculating the consistency index of the channel based on the measured voltage of the channel and the reference voltage corresponding to the category of the channel; evaluating the consistency of the channel based on the consistency index of the channel, and if the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirements. The present application provides a channel consistency evaluation method and system for an EIT system, which is not limited by the measurement method of the EIT system, and can be applied to the channel consistency evaluation of EIT systems using various measurement methods.

Description

Technical Field

[0001] The present application relates to the field of electrical impedance imaging, and in particular to a channel consistency evaluation method and system for an EIT system. Background Art

[0002] Electrical impedance tomography (EIT) is an emerging medical imaging technology. Its basic principle is that different tissues in the body have different electrical impedances under different physiological and pathological conditions. Various methods are used to apply a small safe driving current / voltage to the body through electrodes attached to the surface of the body. By measuring the response information of the driving current or voltage in the body, the image of the electrical impedance distribution or its changes inside the body is reconstructed.

[0003] In the EIT system, multiple channels are required to obtain multiple measurement response information for electrical impedance image reconstruction. Among them, the consistency of the channels of the EIT system is a key indicator to measure the balance and stability of the hardware circuit of the EIT system, and to a certain extent, it can also reflect the acquisition accuracy of its channels and the degree of error in the subsequent signal processing. Therefore, it is of great significance to evaluate the consistency of the channels of the EIT system. However, since there are multiple measurement methods (electrode excitation modes) in the EIT system, the adjacent electrode excitation mode is more widely used, which also leads to the fact that the method for evaluating the consistency of the channels of the EIT system is generally only applicable to the EIT system using the adjacent electrode excitation mode. For the EIT system using other measurement methods (for example, the relative electrode excitation mode or other customized electrode excitation modes, etc.), there is currently no good consistency evaluation method that can accurately evaluate its consistency.

[0004] Therefore, it is desired to provide a method for evaluating the consistency of channels of an EIT system, which can be applicable to EIT systems using various measurement methods and ensure that the consistency evaluation has high accuracy. Summary of the invention

[0005] One of the embodiments of the present application provides a channel consistency evaluation method of an EIT system, including:

[0006] The method comprises the following steps: obtaining a measurement voltage of each channel of the EIT system, wherein the channel includes an excitation electrode pair and a measurement electrode pair; classifying the channels, and determining a reference voltage corresponding to the category based on the measurement voltages of all channels under the same category; calculating a consistency index of the channel based on the measurement voltage of the channel and the reference voltage corresponding to the category of the channel; and evaluating the consistency of the channel based on the consistency index of the channel. If the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirement.

[0007] In some embodiments, the method further includes: determining an overall consistency index of the EIT system based on the consistency indexes of each channel of the EIT system; evaluating the overall consistency of the EIT system based on the overall consistency index of the EIT system, and if the overall consistency index is not less than a second evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0008] In some embodiments, the method further includes: determining the number of channels in the EIT system whose consistency does not meet the requirements; evaluating the overall consistency of the EIT system based on the number of channels in the EIT system whose consistency does not meet the requirements, if the number of channels in the EIT system whose consistency does not meet the requirements is less than a third evaluation threshold, then the overall consistency of the EIT system meets the requirements.

[0009] In some embodiments, the reference voltage corresponding to the category is an average value of measured voltages of all channels under the category.

[0010] In some embodiments, the calculation formula of the channel consistency index is: Wherein, C is the consistency index of the channel, V is the measured voltage of the channel, The reference voltage corresponding to the channel category.

[0011] In some embodiments, the measurement mode of the EIT system is a relative electrode excitation mode, and obtaining the measurement voltage of each channel of the EIT system includes: selecting two relative electrodes on the electrode strip of the EIT system as excitation electrode pairs in turn, inputting an excitation current into the excitation electrode pair each time an excitation electrode pair is selected, and then selecting two adjacent electrodes on the electrode strip other than the excitation electrode pair as measurement electrode pairs in turn to measure the voltage, so as to obtain the measurement voltage of each channel; wherein the number of the excitation electrode pairs is N, each excitation electrode pair corresponds to (N-4) measurement electrode pairs respectively constituting channels therewith, N is the number of electrodes on the electrode strip, and N is an even number not less than 6.

[0012] In some embodiments, the measurement mode of the EIT system is an adjacent electrode excitation mode, and obtaining the measurement voltage of each channel of the EIT system includes: selecting two adjacent electrodes on the electrode strip of the EIT system as excitation electrode pairs in turn, inputting an excitation current into the excitation electrode pair each time an excitation electrode pair is selected, and then selecting two adjacent electrodes on the electrode strip other than the excitation electrode pair as measurement electrode pairs in turn to measure the voltage, so as to obtain the measurement voltage of each channel; wherein the number of the excitation electrode pairs is N, each excitation electrode pair corresponds to (N-3) measurement electrode pairs respectively constituting channels therewith, N is the number of electrodes on the electrode strip, and N is an even number not less than 4.

[0013] In some embodiments, the classifying the channels comprises: classifying the channels based on the number of electrodes with the smallest interval between the measurement electrode pairs and the stimulation electrode pairs in the channels.

[0014] One of the embodiments of the present application provides a channel consistency evaluation system for an EIT system, the system comprising: an acquisition module, the acquisition module being used to acquire the measurement voltage of each channel of the EIT system; a determination module, the determination module being used to classify the channels and determine a reference voltage corresponding to the category based on the measurement voltages of all channels under the same category, wherein the number of electrodes with the minimum interval between the measurement electrode pairs and the excitation electrode pairs in all channels under the same category is the same; a calculation module, the calculation module being used to calculate a consistency index of the channel based on the measurement voltage of the channel and the reference voltage corresponding to the category of the channel; and an evaluation module, the evaluation module being used to evaluate the consistency of the channel based on the consistency index of the channel, and if the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirements.

[0015] In some embodiments, the system also includes an overall consistency evaluation module, which is used to determine the overall consistency index of the EIT system based on the consistency indexes of each channel of the EIT system, and evaluate the overall consistency of the EIT system based on the overall consistency index of the EIT system. If the overall consistency index is not less than a second evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0016] In some embodiments, the system also includes an overall consistency evaluation module, which is used to determine the number of channels in the EIT system whose consistency does not meet the requirements, and evaluate the overall consistency of the EIT system based on the number of channels in the EIT system whose consistency does not meet the requirements. If the number of channels in the EIT system whose consistency does not meet the requirements is less than a third evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0017] The channel consistency evaluation method and system of the EIT system provided in the embodiment of the present application determines the reference voltage corresponding to the channel category, and then calculates its consistency index according to its measured voltage and the reference voltage to use it as the basis for channel consistency evaluation. It is not limited by the measurement method of the EIT system, and can be applied to the channel consistency evaluation of the EIT system using various measurement methods, and has high evaluation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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:

[0019] Figure 1 is an exemplary flow chart of a channel consistency evaluation method of an EIT system according to some embodiments of the present application;

[0020] Figure 2 It is a schematic diagram of the distribution of multiple electrodes of the EIT system on the measurement object;

[0021] Figure 3 4 is a block diagram of a channel consistency evaluation system of an EIT system according to some embodiments of the present application. DETAILED DESCRIPTION

[0022] 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.

[0023] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0024] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0025] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0026] Electrical Impedance Tomography (EIT) is an emerging medical imaging technology used to obtain the distribution image of the electrical impedance or impedance change of biological organs (such as the brain, chest cavity, etc.). When the EIT system is working, the electrode belt is placed on the surface of the biological body so that the multiple electrodes on the electrode belt are in contact with the biological surface, and an excitation current / voltage is applied to the biological body through the electrodes, and then the response voltage / current of the excitation current / voltage in the biological body is measured through other electrodes to reconstruct the image of the electrical impedance distribution or its change inside the biological body. Among them, during the working process of the EIT system, multiple electrodes can constitute multiple channels, each channel can collect data and perform corresponding data processing on it. Specifically, each channel includes an excitation electrode pair and a measurement electrode pair. When the excitation current / voltage is applied through the excitation electrode pair, the response voltage / current measured by the measurement electrode pair is the data collected by the corresponding channel.

[0027] In the EIT system, each channel can correspond to an analog-to-digital conversion (ADC) circuit, and the consistency of the channels of the EIT system can be used to measure the stability and balance of the corresponding hardware circuits (e.g., ADC circuits), thereby reflecting the stability and balance of the entire EIT system. The consistency of the channel can refer to the consistency between the data collected by the channel and the characteristics of the channel. The better the consistency of the channel, the better the stability and balance of the corresponding hardware circuit, the higher the accuracy of the collected data, and the smaller the error in data processing. Therefore, in practice, it is of great significance to evaluate the consistency of the EIT system channels. For example, by evaluating the consistency of the EIT system channels, it is convenient to propose improvements to the hardware circuits of the EIT system, or to verify whether the consistency of the EIT system channels meets the factory requirements.

[0028] When the EIT system is working, different measurement modes (e.g., adjacent electrode excitation mode, relative electrode excitation mode, etc.) can be selected. In different electrode excitation modes, the relative positions between the two electrodes in the excitation electrode pair in the channel of the EIT system and the relative positions between the two electrodes in the measurement electrode pair are different. For example, in the adjacent electrode excitation mode, the excitation electrode pair in the channel is two adjacent electrodes on the electrode belt, and the measurement electrode pair is the other two adjacent electrodes on the electrode belt; while in the relative electrode excitation mode, the excitation electrode pair in the channel is two opposite electrodes on the electrode belt, and the measurement electrode pair is the other two adjacent electrodes on the electrode belt.

[0029] In some embodiments, when the EIT system adopts the adjacent electrode excitation mode, the reciprocity principle can be used to evaluate the consistency of the EIT system channel. Specifically, when evaluating the consistency of a certain channel, the consistency of the channel can be evaluated by determining the difference between the measured current / voltage of the channel and the measured current / voltage of the channel that is reciprocal to the channel. The smaller the difference between the measured current / voltage of the channel and the measured current / voltage of the channel that is reciprocal to the channel, the better the consistency. The channel that is reciprocal to the channel can be regarded as a channel obtained by exchanging the excitation electrode pair and the measurement electrode pair in the channel, that is, the excitation electrode pair and the measurement electrode pair in the channel that is reciprocal to the channel are the measurement electrode pair and the excitation electrode pair in the channel, respectively.

[0030] However, the method of using the reciprocity principle to evaluate the consistency of the EIT system channels is not applicable to the consistency evaluation of the channels of the EIT system that adopts other measurement methods other than the adjacent electrode excitation mode. Taking the relative excitation electrode mode as an example, in a certain channel of the EIT system, since the relative position between the two electrodes in the excitation electrode pair is different from the relative position between the two electrodes in the measurement electrode pair, the channel obtained by swapping the excitation electrode pair and the measurement electrode pair in the channel cannot be used as a channel reciprocal with the channel, so the reciprocity principle cannot be used to evaluate the consistency of the EIT system channels. It can be seen that for EIT systems that adopt other measurement methods other than the adjacent electrode excitation mode, the methods for evaluating the consistency of their acquisition channels are very limited.

[0031] The embodiment of the present application provides a channel consistency evaluation method for an EIT system, the method comprising: obtaining the measured voltage of each channel of the EIT system, the channel comprising an excitation electrode pair and a measurement electrode pair; classifying multiple channels, and determining a reference voltage corresponding to a category based on the measured voltages of all channels under the same category; calculating a consistency index of the channel based on the measured voltage of the channel and the reference voltage corresponding to the category of the channel; evaluating the consistency of the channel based on the consistency index of the channel, if the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirements. The channel consistency evaluation method for an EIT system provided by the embodiment of the present application can be applied to the channel consistency evaluation of an EIT system using various measurement methods, and has high accuracy.

[0032] The channel consistency evaluation method of the EIT system provided in the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0033] Figure 1 It is an exemplary flow chart of a channel consistency evaluation method of an EIT system according to some embodiments of the present application.

[0034] like Figure 1 As shown, the channel consistency evaluation method 100 of the EIT system provided in the embodiment of the present application may include the following steps:

[0035] Step S110, obtaining the measured voltage of each channel of the EIT system.

[0036] When the EIT system performs electrical impedance imaging, the EIT system collects data through multiple channels to obtain multiple independent data and then reconstructs the image to obtain an electrical impedance image. Further, the EIT system includes multiple electrodes, and each channel may include an excitation electrode pair and a measurement electrode pair. In some embodiments, when a channel performs data acquisition, an excitation current is applied to the measurement object through the excitation electrode pair of the channel, and then the voltage of the measurement electrode pair of the channel is measured to obtain the measurement voltage of the channel, and the measurement voltage of the channel is the data collected by the channel.

[0037] In some embodiments, when the number of electrodes included in the EIT system is certain, the measurement method adopted by the EIT system is different, and the determination of each channel of the EIT system will also be different, thereby making the process of obtaining each acquisition channel of the EIT system also different.

[0038] The following will take the EIT system containing 16 electrodes as an example. Figure 2 The process of acquiring each acquisition channel of the EIT system is exemplified.

[0039] Figure 2It is a schematic diagram of the distribution of multiple electrodes of the EIT system on the measurement object.

[0040] It can be understood that the multiple electrodes of the EIT system are arranged on corresponding electrode belts, and the electrode belts are worn around the measurement object, so the multiple electrodes of the EIT system can appear on the measurement object as follows: Figure 2 In addition, it should be noted that Figure 2 The number of electrodes shown as 16 is only an example and is not intended to limit the number of electrodes of the EIT system. Different EIT systems may have different numbers of electrodes. For example, the number of electrodes included in the EIT system may range from 4 to 128.

[0041] like Figure 2 As shown, the EIT system may include 16 electrodes, namely electrode 1, electrode 2, electrode 3, . . . , electrode 14, electrode 15 and electrode 16.

[0042] In some embodiments, the measurement mode of the EIT system may be a relative electrode excitation mode. When the measurement mode of the EIT system adopts the relative electrode excitation mode, two electrodes in the excitation electrode pair in the channel of the EIT system are two opposite electrodes, and the measurement electrode pair is two adjacent electrodes except the excitation electrode pair.

[0043] Furthermore, when obtaining the measured voltage of each channel of the EIT system, two electrodes on the electrodes of the EIT system may be selected in sequence as excitation electrode pairs, wherein the number of excitation electrode pairs is N, where N is the number of electrodes on the electrode belt, and N is an even number not less than 6.

[0044] As an example, Figure 2 As shown, electrode 1 and electrode 9, electrode 2 and electrode 10, electrode 3 and electrode 11, electrode 4 and electrode 12, electrode 5 and electrode 13, electrode 6 and electrode 14, electrode 7 and electrode 15, electrode 8 and electrode 16, electrode 9 and electrode 1, electrode 10 and electrode 2, electrode 11 and electrode 3, electrode 12 and electrode 4, electrode 13 and electrode 5, electrode 14 and electrode 6, electrode 15 and electrode 7, electrode 16 and electrode 8 can be selected in sequence as excitation electrode pairs, for a total of 16 electrode excitation pairs.

[0045] When each excitation electrode pair is selected, an excitation current is input to the excitation electrode pair, and then two adjacent electrodes other than the excitation electrode pair are selected in turn as measurement electrode pairs for voltage measurement to obtain the measurement voltage of each channel. Wherein, each excitation electrode pair corresponds to (N-4) measurement electrode pairs respectively constituting channels (ab, cd) with it, wherein a and b respectively represent the two electrodes constituting the excitation electrode pair in the channel (ab, cd), and c and d respectively represent the two electrodes constituting the measurement electrode pair in the channel (ab, cd).

[0046] As an example, Figure 2 As shown, when electrode 1 and electrode 9 are selected as the excitation electrode pair, the excitation current can be continuously input to electrode 1 and electrode 9, and then electrode 2 and electrode 3, electrode 3 and electrode 4, electrode 4 and electrode 5, electrode 5 and electrode 6, electrode 6 and electrode 7, electrode 7 and electrode 8, electrode 10 and electrode 11, electrode 11 and electrode 12, electrode 12 and electrode 13, electrode 13 and electrode 14, electrode 14 and electrode 15 and electrode 16 are selected in sequence as the measurement electrode pair for voltage measurement. The measured voltages of channel (1-9, 2-3), channel (1-9, 3-4), channel (1-9, 4-5), channel (1-9, 5-6), channel (1-9, 6-7), channel (1-9, 7-8), channel (1-9, 10-11), channel (1-9, 11-12), channel (1-9, 12-13), channel (1-9, 13-14), channel (1-9, 14-15), and channel (1-9, 15-16) are obtained respectively.

[0047] It can be concluded that when the EIT system includes N electrodes and the measurement method of the EIT system adopts the relative electrode excitation mode, the EIT system can have N excitation electrode pairs. Since each selected excitation electrode pair can be applied with an excitation current to obtain the measurement voltage of (N-4) channels, the EIT system has a total of (N 2 -4N) channels. Furthermore, when the measurement method of the EIT system adopts the relative electrode excitation mode, a total of EIT system (N 2 -4N) channels. For example, when the EIT system includes 16 electrodes, a total of 192 channels of the EIT system can be measured. The voltage measured by the measuring electrode pair is the measured voltage of the channel formed by the measuring electrode pair and the currently selected excitation electrode pair.

[0048] In some embodiments, the measurement mode of the EIT system may be an adjacent electrode excitation mode. When the measurement mode of the EIT system adopts the adjacent electrode excitation mode, two electrodes in an excitation electrode pair in a channel of the EIT system are adjacent electrodes, and a measurement electrode pair is two adjacent electrodes other than the excitation electrode pair.

[0049] Furthermore, when obtaining the measured voltage of each channel of the EIT system, two adjacent electrodes on the electrodes of the EIT system may be selected in sequence as the excitation electrode pair. The number of the excitation electrode pairs is N, where N is the number of electrodes on the electrode belt, and N is an even number not less than 4. As an example, Figure 2 As shown, electrode 1 and electrode 2, electrode 2 and electrode 3, electrode 3 and electrode 4, electrode 4 and electrode 5, electrode 5 and electrode 6, electrode 6 and electrode 7, electrode 7 and electrode 8, electrode 8 and electrode 9, electrode 9 and electrode 10, electrode 10 and electrode 11, electrode 11 and electrode 12, electrode 12 and electrode 13, electrode 13 and electrode 14, electrode 14 and electrode 15, electrode 15 and electrode 16, electrode 16 and electrode 1 can be selected in sequence as excitation electrode pairs, for a total of 16 electrode excitation pairs.

[0050] When each excitation electrode pair is selected, an excitation current is input to the excitation electrode pair, and then two adjacent electrodes other than the excitation electrode pair are selected in turn as measurement electrode pairs for voltage measurement to obtain the measurement voltage of each channel. Wherein, each excitation electrode pair corresponds to (N-4) measurement electrode pairs respectively constituting channels (ab, cd) with it, wherein a and b respectively represent the two electrodes constituting the excitation electrode pair in the channel (ab, cd), and c and d respectively represent the two electrodes constituting the measurement electrode pair in the channel (ab, cd).

[0051] As an example, Figure 2As shown, when electrode 1 and electrode 2 are selected as the excitation electrode pair, the excitation current can be continuously input to electrode 1 and electrode 2, and then electrode 3 and electrode 4, electrode 4 and electrode 5, electrode 5 and electrode 6, electrode 6 and electrode 7, electrode 7 and electrode 8, electrode 8 and electrode 9, electrode 9 and electrode 10, electrode 10 and electrode 11, electrode 11 and electrode 12, electrode 12 and electrode 13, electrode 13 and electrode 14, electrode 14 and electrode 15 and electrode 16 are selected in turn as the measurement electrode pair to measure the voltage, so as to obtain the channel (1 -2, 2-3), channel (1-2, 2-3), channel (1-2, 3-4), channel (1-2, 4-5), channel (1-2, 5-6), channel (1-2, 6-7), channel (1-2, 7-8), channel (1-2, 8-9), channel (1-2, 9-10), channel (1-2, 10-11), channel (1-2, 11-12), channel (1-2, 12-13), channel (1-2, 13-14), channel (1-2, 14-15), channel (1-2, 15-16).

[0052] It can be concluded that when the EIT system includes N electrodes and the measurement method of the EIT system adopts the adjacent electrode excitation mode, the EIT system can have N excitation electrode pairs. Since each selected excitation electrode pair can apply the excitation current to obtain the measurement voltage of (N-3) channels, the EIT system has a total of (N 2 -3N) channels. Furthermore, when the measurement method of the EIT system adopts the adjacent electrode excitation mode, a total of EIT system (N 2 -3N) channels. For example, when the EIT system includes 16 electrodes, a total of 208 channels of the EIT system can be measured. The voltage measured by the measuring electrode pair is the measured voltage of the channel formed by the measuring electrode pair and the currently selected excitation electrode pair.

[0053] In some embodiments, when two adjacent electrodes other than the excitation electrode pair are selected in turn as the measurement electrode pair for voltage measurement, the potential of each electrode other than the excitation electrode pair can be measured, and then the potential difference between the two adjacent electrodes can be calculated in turn. The potential difference is the voltage value obtained by measuring the excitation electrode pair, which is also the measurement voltage of the corresponding channel.

[0054] It should be noted that the measurement method of the EIT system can also use other electrode excitation modes besides the above-mentioned relative electrode excitation mode and adjacent electrode excitation mode. For example, two electrodes with an interval of 1, 2, 3 electrodes, etc. among multiple electrodes can be selected as an excitation electrode pair, and / or two electrodes with an interval of 0, 1, 2, 3 electrodes, etc. among multiple electrodes can be selected as a measurement electrode pair. Regarding how to obtain the measurement voltage of each channel of the EIT system in other measurement modes, please refer to the above-mentioned description of obtaining the measurement voltage of each channel of the EIT system in the relative electrode excitation mode and the relative electrode excitation mode, which will not be repeated here.

[0055] Step S120 , classifying the channels, and determining a reference voltage corresponding to the category based on the measured voltages of all channels in the same category.

[0056] Since the multiple electrodes of the EIT system are distributed in a ring shape during measurement, the channels with the same relative position of the measuring electrode pair and the excitation electrode pair can be equivalent, that is, the measurement voltage of the channel with the same relative position of the measuring electrode pair and the excitation electrode pair is theoretically the same. Among them, the relative position of the measuring electrode pair and the excitation electrode pair in the channel can be represented by the number of electrodes with the minimum interval between the measuring electrode pair and the excitation electrode pair in the channel. Therefore, in some embodiments, the channels are classified based on the number of electrodes with the minimum interval between the measuring electrode pair and the excitation electrode pair in the channel. Among them, the channels under the same category are equivalent under ideal conditions, that is, the collected measurement voltages are the same, but because there will inevitably be consistency problems in the channels in practice, the actual measurement voltages of the channels under the same category will be different. Therefore, when evaluating the consistency of the channels, it is necessary to determine the reference voltage corresponding to the category based on the measurement voltages of all channels under the same category. In some embodiments, the reference voltage corresponding to the category is the average value of the measurement voltages of all channels under the category.

[0057] In some embodiments, the number of categories of EIT system channels is not only related to the number of electrodes included, but also related to the measurement method of the EIT system.

[0058] In some embodiments, when the measurement mode of the EIT system is the relative electrode excitation mode, the number of categories m of the EIT system channels can be determined by the following formula:

[0059] in, N is the number of electrodes included in the EIT system.

[0060] Taking the EIT system containing 16 electrodes as an example, the 192 channels of the EIT system can be divided into 3 categories.

[0061] The channels with a minimum spacing of 0 electrodes between the measuring electrode pair and the excitation electrode pair belong to the first category. For example, channels (1-9, 2-3), channels (1-9, 7-8), channels (1-9, 10-11), channels (1-9, 15-16), channels (2-10, 3-4), channels (2-10, 8-9), channels (2-10, 11-12), channels (2-10, 16-1), etc. are all in the first category. There are 64 channels in the first category. The average value of the measured voltages of the 64 channels in the first category is the reference voltage corresponding to the first category.

[0062] The channels with a minimum interval of 1 electrode between the measuring electrode pair and the excitation electrode pair belong to the second category, for example, channels (1-9, 3-4), channels (1-9, 6-7), channels (1-9, 11-12), channels (1-9, 14-15), channels (2-10, 4-5), channels (2-10, 7-8), channels (2-10, 12-13), channels (2-10, 15-16), etc. are all in the second category. There are 64 channels in the second category, and the average value of the measured voltages of the 64 channels in the second category is the reference voltage corresponding to the second category.

[0063] The channels with two electrodes with the minimum interval between the measuring electrode pair and the excitation electrode pair belong to the third category, for example, channel (1-9, 4-5), channel (1-9, 5-6), channel (1-9, 12-13), channel (1-9, 13-14), channel (2-10, 5-6), channel (2-10, 6-7), channel (2-10, 13-14), channel (2-10, 14-15), etc. are all in the third category. There are 64 channels in the third category, and the average value of the measured voltages of the 64 channels in the third category is the reference voltage corresponding to the third category.

[0064] In some embodiments, when the measurement mode of the EIT system is the adjacent electrode excitation mode, the number of categories of the EIT system channels can be determined by the following formula:

[0065] Where N is the number of electrodes included in the EIT system.

[0066] Taking the EIT system containing 16 electrodes as an example, the 208 channels of the EIT system can be divided into 7 categories. The channels with the minimum interval between the measuring electrode pair and the excitation electrode pair being 0 belong to the first category, for example, channels (1-2, 3-4), channels (1-2, 15-16), channels (2-3, 4-5), channels (2-3, 16-1), channels (3-4, 5-6), channels (3-4, 1-2) and the like are all in the first category. There are a total of 32 channels in the first category, and the average value of the measured voltages of the 32 channels in the first category is the reference voltage corresponding to the first category.

[0067] The channels with one electrode having the minimum interval between the measuring electrode pair and the excitation electrode pair belong to the second category, for example, channels (1-2, 4-5), channels (1-2, 14-15), channels (2-3, 5-6), channels (2-3, 15-16), channels (3-4, 6-7), channels (3-4, 16-1) and the like are all in the second category. There are 32 channels in the second category in total, and the average value of the measured voltages of the 32 channels in the second category is the reference voltage corresponding to the second category.

[0068] The channels with two electrodes with the minimum interval between the measuring electrode pair and the excitation electrode pair belong to the third category, for example, channels (1-2, 5-6), channels (1-2, 13-14), channels (2-3, 6-7), channels (2-3, 14-15), channels (3-4, 7-8), channels (3-4, 15-16) and the like are all in the third category. There are 32 channels in total in the third category, and the average value of the measured voltages of the 32 channels in the third category is the reference voltage corresponding to the third category.

[0069] The channels in which the minimum interval between the measuring electrode pair and the excitation electrode pair is 3 belong to the fourth category. There are a total of 32 channels under the fourth category. For example, channels (1-2, 6-7), channels (1-2, 12-13), channels (2-3, 7-8), channels (2-3, 13-14), channels (3-4, 8-9), channels (3-4, 14-15) and other channels are all in the fourth category; the average value of the measured voltages of the 32 channels under the fourth category is the reference voltage corresponding to the fourth category.

[0070] The channels in which the minimum interval between the measuring electrode pair and the excitation electrode pair is 4 belong to the fifth category. There are a total of 32 channels under the fifth category. For example, channels (1-2, 7-8), channels (1-2, 11-12), channels (2-3, 8-9), channels (2-3, 12-13), channels (3-4, 9-10), channels (3-4, 13-14), etc. are all in the fifth category. The average value of the measured voltages of the 32 channels under the fifth category is the reference voltage corresponding to the fifth category.

[0071] The channels in which the minimum interval between the measuring electrode pair and the excitation electrode pair is 4 belong to the sixth category. There are a total of 32 channels under the sixth category. For example, channels (1-2, 8-9), channels (1-2, 10-11), channels (2-3, 9-10), channels (2-3, 11-12), channels (3-4, 10-11), channels (3-4, 12-13), etc. are all in the sixth category. The average value of the measured voltages of the 32 channels under the sixth category is the reference voltage corresponding to the sixth category.

[0072] The channels in which the minimum interval between the measuring electrode pair and the excitation electrode pair is 5 belong to the sixth category. There are a total of 32 channels under the sixth category. For example, channels (1-2, 8-9), channels (1-2, 10-11), channels (2-3, 9-10), channels (2-3, 11-12), channels (3-4, 10-11), channels (3-4, 12-13), etc. are all in the sixth category. The average value of the measured voltages of the 32 channels under the sixth category is the reference voltage corresponding to the sixth category.

[0073] The channel with 6 electrodes with the minimum interval between the measuring electrode pair and the excitation electrode pair belongs to the seventh category. There are a total of 16 channels under the seventh category. For example, channels (1-2, 9-10), channels (2-3, 10-11), channels (3-4, 11-12), etc. are all in the seventh category; the average value of the measured voltages of the 16 channels under the seventh category is the reference voltage corresponding to the seventh category.

[0074] It should be noted that when the EIT system adopts measurement methods other than the adjacent electrode excitation mode and the relative electrode excitation mode, the channels of the EIT system can also be classified based on the number of electrodes with the minimum interval between the measuring electrode pairs and the excitation electrode pairs in the channel. The specific classification method can be referred to the above content on the classification of EIT system channels under the adjacent electrode excitation mode and the relative electrode excitation mode, which will not be repeated here.

[0075] Step S130 , calculating a consistency index of the channel based on the measured voltage of the channel and a reference voltage corresponding to the category of the channel.

[0076] In step S130 , the consistency index of the channel may be determined based on the following formula.

[0077]

[0078] Where C is the consistency index of the channel, V is the measured voltage of the channel, The reference voltage corresponding to the channel category.

[0079] As an example, when the EIT system includes 16 electrodes and the measurement mode of the EIT system is the relative electrode excitation mode, the measurement voltage of channels (1-9, 2-3) is V (1923) , the reference voltage corresponding to the category (first category) of channel (1-9, 2-3) is Then the consistency index of channel (1-9, 2-3) is

[0080] Through step 130, the consistency index of each channel of the EIT system can be obtained.

[0081] Step S140: evaluating the consistency of the channel based on the consistency index of the channel.

[0082] In step S140, the greater the consistency index of the channel, the better the consistency of the channel. Further, if the consistency index of the channel is not less than the first evaluation threshold, the consistency of the channel meets the requirements. Among them, the channel whose consistency meets the requirements indicates that the balance and stability of the hardware circuit corresponding to the channel, the accuracy of the collected data, the error degree of data processing, etc. can meet the requirements of the EIT system for electrical impedance imaging, and can meet the factory inspection standards. When the consistency index of the channel is less than the first evaluation threshold, this indicates that the balance and stability of the hardware circuit corresponding to the channel, the accuracy of the collected data, and the error degree of data processing do not meet the factory standards, and the hardware circuit corresponding to the channel needs to be improved to improve the consistency of the channel.

[0083] In some embodiments, even if a small number of channels in the EIT system do not meet the consistency requirements, the imaging quality of the EIT system will not be affected, and the EIT system can pass the factory inspection. Therefore, in some embodiments, the channel consistency evaluation method 100 of the EIT system provided in the embodiment of the present application may also include evaluating the overall consistency of the EIT system, and verifying whether the EIT system can meet the factory standards by evaluating the overall consistency of the EIT system.

[0084] In some embodiments, when evaluating the overall consistency of the EIT system, the overall consistency index of the EIT system can be determined based on the consistency indexes of each channel of the EIT system, and then the overall consistency of the EIT system is evaluated based on the overall consistency index of the EIT system. If the overall consistency index is not less than the second evaluation threshold, the overall consistency of the EIT system meets the requirements. In some embodiments, the overall consistency index of the EIT system can be the average value of the consistency indexes of each channel.

[0085] In some embodiments, when evaluating the overall consistency of the EIT system, the number of channels in the EIT system whose consistency does not meet the requirements is determined, and then the overall consistency of the EIT system is evaluated based on the number of channels in the EIT system whose consistency does not meet the requirements. If the number of channels in the EIT system whose consistency does not meet the requirements is not less than a third evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0086] Figure 3 4 is a block diagram of a channel consistency evaluation system of an EIT system according to some embodiments of the present application.

[0087] like Figure 3 As shown, the embodiment of the present application also provides a channel consistency evaluation system 300 of an EIT system, and the channel consistency evaluation system 300 may include an acquisition module 310, a determination module 320, a calculation module 330, and an evaluation module 340. Among them, the acquisition module 310 can be used to obtain the measurement voltage of each channel of the EIT system; the determination module 320 can be used to classify the channels, and determine the reference voltage corresponding to the category based on the measurement voltage of all channels under the same category, wherein the number of electrodes with the minimum interval between the measurement electrode pair and the excitation electrode pair in all channels under the same category is the same; the calculation module 330 can be used to calculate the consistency index of the channel based on the measurement voltage of the channel and the reference voltage corresponding to the category of the channel; the evaluation module 340 can be used to evaluate the consistency of the channel based on the consistency index of the channel, and if the consistency index of the channel is not less than the first evaluation threshold, the consistency of the channel meets the requirements.

[0088] In some embodiments, the channel consistency evaluation system 300 may further include an overall consistency evaluation module, which is used to determine the overall consistency index of the EIT system based on the consistency index of each channel of the EIT system, and evaluate the overall consistency of the EIT system based on the overall consistency index of the EIT system. If the overall consistency index is not less than the second evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0089] In some embodiments, the channel consistency evaluation system 300 also includes an overall consistency evaluation module, which is used to determine the number of channels in the EIT system whose consistency does not meet the requirements, and evaluate the overall consistency of the EIT system based on the number of channels in the EIT system whose consistency does not meet the requirements. If the number of channels in the EIT system whose consistency does not meet the requirements is less than a third evaluation threshold, the overall consistency of the EIT system meets the requirements.

[0090] It should be noted that the above description of the channel consistency evaluation system 300 and its modules is only for convenience of description and does not limit the present specification to the scope of the embodiments. It is understandable that, after understanding the principle of the system, those skilled in the art may arbitrarily combine the modules or form a subsystem to connect with other modules without deviating from the principle. In some embodiments, Figure 3 The determination module and calculation module disclosed in the specification may be different modules in a system, or one module may realize the functions of two or more modules. For example, each module may share a storage module, or each module may have its own storage module. Such variations are within the scope of protection of this specification.

[0091] The beneficial effects that may be brought about by the embodiments of the present application include but are not limited to: (1) The use of the channel consistency evaluation method and system of the EIT system provided in the embodiments of the present application is not limited by the measurement method of the EIT system, and can be applicable to the channel consistency evaluation of the EIT system using various measurement methods; (2) The channel consistency evaluation method and system of the EIT system provided in the embodiments of the present application determine the reference voltage corresponding to the channel category, and then calculate its consistency index based on its measured voltage and the reference voltage to use this as the basis for channel consistency evaluation, which has high evaluation accuracy.

[0092] 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.

[0093] 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.

[0094] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the embodiments of the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the embodiments of the present invention may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0095] The embodiments of the present application are described with reference to flowcharts and / or block diagrams of methods, terminal devices (systems) or computer program products provided according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable terminal device. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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 channel consistency evaluation method for an EIT system, characterized in that: include: Obtaining a measurement voltage of each channel of the EIT system, wherein the channel includes an excitation electrode pair and a measurement electrode pair; Classifying the channels and determining a reference voltage corresponding to the category based on measured voltages of all channels under the same category; calculating a consistency index of the channel based on a measured voltage of the channel and a reference voltage corresponding to a category of the channel; The consistency of the channel is evaluated based on the consistency index of the channel. If the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirement.

2. The method according to claim 1, characterized in that Also includes: Determining an overall consistency index of the EIT system based on consistency indexes of individual channels of the EIT system; The overall consistency of the EIT system is evaluated based on the overall consistency index of the EIT system. If the overall consistency index is not less than a second evaluation threshold, the overall consistency of the EIT system meets the requirement.

3. The method according to claim 1, characterized in that Also includes: Determining the number of channels in the EIT system whose consistency does not meet the requirement; The overall consistency of the EIT system is evaluated based on the number of channels whose consistency does not meet the requirement in the EIT system. If the number of channels whose consistency does not meet the requirement in the EIT system is less than a third evaluation threshold, the overall consistency of the EIT system meets the requirement.

4. The method according to claim 1, characterized in that: The reference voltage corresponding to the category is an average value of the measured voltages of all channels under the category.

5. The method according to claim 1, characterized in that The calculation formula of the consistency index of the channel is: Wherein, C is the consistency index of the channel, V is the measured voltage of the channel, The reference voltage corresponding to the channel category.

6. The method according to claim 1, characterized in that The measurement mode of the EIT system is a relative electrode excitation mode, and obtaining the measurement voltage of each channel of the EIT system includes: Two opposite electrodes on the electrode strip of the EIT system are selected in sequence as excitation electrode pairs. Each time an excitation electrode pair is selected, an excitation current is input into the excitation electrode pair. Then, two adjacent electrodes other than the excitation electrode pair on the electrode strip are selected in sequence as measurement electrode pairs for voltage measurement to obtain the measurement voltage of each channel. The number of the excitation electrode pairs is N, and each excitation electrode pair corresponds to (N-4) measurement electrode pairs that respectively constitute channels with it. N is the number of electrodes on the electrode strip, and N is an even number not less than 6.

7. The method according to claim 1, characterized in that The measurement mode of the EIT system is an adjacent electrode excitation mode, and obtaining the measurement voltage of each channel of the EIT system includes: Two adjacent electrodes on the electrode strip of the EIT system are selected in sequence as excitation electrode pairs. Each time an excitation electrode pair is selected, an excitation current is input into the excitation electrode pair. Then, two adjacent electrodes other than the excitation electrode pair on the electrode strip are selected in sequence as measurement electrode pairs for voltage measurement to obtain the measurement voltage of each channel. The number of the excitation electrode pairs is N, and each excitation electrode pair corresponds to (N-3) measurement electrode pairs that respectively constitute channels with it. N is the number of electrodes on the electrode strip, and N is an even number not less than 4.

8. The method according to claim 6 or 7, characterized in that: The categorizing of the channels comprises: Channels are categorized based on the number of electrodes with the smallest spacing between measurement electrode pairs and excitation electrode pairs in the channel.

9. A channel consistency evaluation system for an EIT system, characterized in that: The system comprises: An acquisition module, the acquisition module is used to acquire the measured voltage of each channel of the EIT system; A determination module, the determination module is used to classify the channels and determine a reference voltage corresponding to the category based on the measured voltages of all channels under the same category, wherein the number of electrodes with the minimum interval between the measuring electrode pairs and the excitation electrode pairs in all channels under the same category is the same; a calculation module, the calculation module being used to calculate a consistency index of the channel based on a measured voltage of the channel and a reference voltage corresponding to a category of the channel; An evaluation module is used to evaluate the consistency of the channel based on the consistency index of the channel. If the consistency index of the channel is not less than a first evaluation threshold, the consistency of the channel meets the requirement.

10. The system according to claim 9, characterized in that The system also includes an overall consistency evaluation module, which is used to determine the overall consistency index of the EIT system based on the consistency indexes of each channel of the EIT system, and evaluate the overall consistency of the EIT system based on the overall consistency index of the EIT system. If the overall consistency index is not less than a second evaluation threshold, the overall consistency of the EIT system meets the requirements.

11. The system according to claim 9, characterized in that The system also includes an overall consistency evaluation module, which is used to determine the number of channels in the EIT system whose consistency does not meet the requirements, and evaluate the overall consistency of the EIT system based on the number of channels in the EIT system whose consistency does not meet the requirements. If the number of channels in the EIT system whose consistency does not meet the requirements is less than a third evaluation threshold, the overall consistency of the EIT system meets the requirements.

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