CN114190914B - Electrical impedance imaging method and computer readable storage medium - Google Patents
Electrical impedance imaging method and computer readable storage medium Download PDFInfo
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Abstract
The invention provides an electrical impedance imaging method, which comprises the following steps: acquiring an image transformation matrix and an initial coefficient matrix; calculating the product of the image transformation matrix and the initial coefficient matrix as a target coefficient matrix; acquiring a plurality of continuous signal amplitude vectors, wherein each signal amplitude vector comprises sub-signal amplitudes between the rest two electrodes when two electrodes in all the electrodes are sequentially used as excitation electrode pairs; calculating a standard amplitude vector according to the plurality of signal amplitude vectors; calculating a target amplitude vector according to the signal amplitude vector and the standard amplitude vector; calculating the product of the target amplitude vector and the target coefficient matrix as an equipotential impedance value vector; and generating an electrical impedance image according to the allele impedance value vector. In addition, the invention also provides a computer readable storage medium. According to the technical scheme, the image can be subjected to noise reduction, sharpening and other processing under the condition of not additionally consuming operation resources, and the operation amount of image processing is greatly reduced.
Description
Technical Field
The present invention relates to the field of electrical impedance imaging technology, and in particular, to an electrical impedance imaging method and a computer-readable storage medium.
Background
Electrical Impedance Tomography (EIT) is a technique for imaging using Electrical Impedance characteristics of organs and tissues of the human body. The electrical impedance tomography uses the resistivity distribution in the human body as a target to reconstruct a tissue image in the human body. When a lesion occurs in an organ or tissue of a human body, the impedance of the lesion occurring portion is different from the impedance of a lesion not occurring portion, and thus a lesion of the organ or tissue of the human body can be diagnosed by measuring the impedance. In the process of electrical impedance tomography, a certain number of electrodes are fixed on a human body, and data for generating an image are acquired by exciting two electrodes in turn and measuring the potential difference between the other electrodes.
After the reconstruction of the impedance distribution image is realized, certain post-processing is often required to ensure the quality of the image. Generally speaking, these post-processes also occupy certain computing resources, and reduce the operation efficiency of the device. Therefore, it is an urgent problem to solve how to perform some processing such as noise reduction and sharpening on an image without consuming extra computing resources.
Disclosure of Invention
The invention provides an electrical impedance imaging method and a computer readable storage medium, which can greatly reduce the operation amount of image processing.
In a first aspect, an embodiment of the present invention provides an electrical impedance imaging method, including:
acquiring an image transformation matrix and an initial coefficient matrix;
calculating a product of the image transformation matrix and the initial coefficient matrix as a target coefficient matrix;
acquiring a plurality of continuous signal amplitude vectors, wherein each signal amplitude vector comprises sub-signal amplitudes between the rest two electrodes when two electrodes in all the electrodes are sequentially used as excitation electrode pairs;
calculating a standard amplitude vector according to the signal amplitude vectors;
calculating a target amplitude vector according to the signal amplitude vector and the standard amplitude vector;
calculating the product of the target amplitude vector and the target coefficient matrix as an equipotential impedance value vector; and
and generating an electrical impedance image according to the equipotential impedance value vector.
In a second aspect, embodiments of the invention provide a computer readable storage medium for storing program instructions executable by a processor to implement an electrical impedance imaging method as described above.
According to the electrical impedance imaging method and the computer-readable storage medium, the sub-signal amplitude obtained by each measurement forms a corresponding signal amplitude vector, a standard amplitude vector is calculated according to the signal amplitude vector, and an equipotential impedance value vector is calculated according to the signal amplitude vector, the standard amplitude vector and a target coefficient matrix, so that an electrical impedance image is generated. The process of generating the electrical impedance image is matrixed, and the calculation flow is simplified. Before calculating the equipotential impedance value vector, an image transformation matrix for carrying out image processing on the electrical impedance image is constructed, the image transformation matrix is multiplied by an initial coefficient matrix for weighting the signal amplitude vector, so that a target coefficient matrix is obtained, and the equipotential impedance value vector which is subjected to image processing can be obtained by directly multiplying the target amplitude vector by the target coefficient matrix. Equivalently, the partial image post-processing process is integrated into the process of generating the electrical impedance image, the image processing is not required to be carried out on the electrical impedance image generated each time, the operation amount of the image processing is greatly reduced, and the image processing method can carry out noise reduction, sharpening and other processing on the image under the condition of not additionally consuming operation resources.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a flowchart of an electrical impedance imaging method according to an embodiment of the present invention.
FIG. 2 is a first sub-flowchart of an electrical impedance imaging method according to an embodiment of the present invention.
FIG. 3 is a second sub-flowchart of an electrical impedance imaging method according to an embodiment of the present invention.
FIG. 4 is a third sub-flowchart of an electrical impedance imaging method according to an embodiment of the present invention.
FIG. 5 is a fourth sub-flowchart of an electrical impedance imaging method according to an embodiment of the present invention
Fig. 6 is a schematic diagram of an electrical impedance imaging apparatus provided by an embodiment of the invention.
Fig. 7 is a schematic view of the electrode belt of fig. 1.
Fig. 8 is a schematic diagram of the iso-site image depicted in fig. 1.
Fig. 9 is a schematic diagram of the image transformation matrix shown in fig. 2.
Fig. 10 is a schematic diagram of the initial coefficient matrix shown in fig. 3.
Fig. 11 is a schematic internal structure diagram of a terminal according to an embodiment of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the above-described drawings (if any) are used for distinguishing between similar items and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances, in other words that the embodiments described are to be practiced in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and any other variation thereof, may also include other things, such as processes, methods, systems, articles, or apparatus that comprise a list of steps or elements is not necessarily limited to only those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such processes, methods, articles, or apparatus.
It should be noted that the description relating to "first", "second", etc. in the present invention is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
Please refer to fig. 6 in combination, which is a schematic diagram of an electrical impedance imaging apparatus according to an embodiment of the present invention. The electrical impedance imaging apparatus 20 comprises a body 21 and an electrode belt 22. When the object to be tested is tested, the object to be tested needs to surround the chest and fix the electrode belt 22, two electrodes 220 of all the electrodes 220 arranged on the electrode belt 22 apply high-frequency alternating signals emitted according to a certain rule, and the signals are measured between the other two electrodes 220.
Please refer to fig. 1 in combination, which is a flowchart of an electrical impedance imaging method according to an embodiment of the present invention. The electrical impedance imaging method is applied to an electrical impedance imaging device 20 for generating an electrical impedance image about the body of a measured object from signals measured by electrode strips 22. The electrical impedance imaging method provided by the embodiment reconstructs electrical impedance distribution of the measured object to form an electrical impedance image according to the measured signal based on the equipotential line back projection algorithm. The electrical impedance imaging method specifically comprises the following steps.
And step S102, constructing an image transformation matrix and an initial coefficient matrix. In this embodiment, both the image transformation matrix and the initial coefficient matrix are constant matrices. The image transformation matrix is used for carrying out enhancement processing on the electrical impedance image. Wherein the enhancement processing includes, but is not limited to, noise reduction, sharpening, and the like. The specific process of constructing the image transformation matrix and the initial coefficient matrix will be described in detail below.
Step S104, the product of the image transformation matrix and the initial coefficient matrix is calculated as a target coefficient matrix. Since the image transformation matrix and the initial coefficient matrix are both constant matrices, the product of the image transformation matrix and the initial coefficient matrix can be used as a target coefficient matrix and applied to the subsequent calculation process. It will be appreciated that the target coefficient matrix is also a constant matrix.
Step S106, a plurality of continuous signal amplitude vectors are obtained. In this embodiment, each signal amplitude vector includes sub-signal amplitudes between two remaining electrodes of all the electrodes sequentially serving as pairs of excitation electrodes. Taking the electrode belt 22 shown in fig. 7 as an example, the electrode belt 22 includes 16 electrodes, and the 16 electrodes are numbered 1-16. When the electrode belt 22 is wound into a closed pattern for signal measurement, two adjacent electrodes are sequentially selected as an excitation electrode pair, and the sub-signal amplitudes between the other two adjacent electrodes are sequentially measured. For example, selecting electrode 1 and electrode 2 as an excitation electrode pair, and measuring the sub-signal amplitudes between electrode 3 and electrode 4, between electrode 4 and electrode 5, between electrode 5 and electrode 6, and so on until electrode 15 and electrode 16 in turn; and selecting the electrode 2 and the electrode 3 as an excitation electrode pair, and sequentially measuring the amplitude of the sub-signal between the two corresponding electrodes until all two adjacent electrodes in the electrode band 22 are used as the excitation electrode pair. When all two adjacent electrodes in the electrode belt 22 are used as excitation electrode pairs, and the sub-signal amplitudes are measured between the other two adjacent electrodes, one measurement is completed, and all the sub-signal amplitudes obtained by one measurement form a signal amplitude vector. Wherein all sub-signal amplitudes in the signal amplitude vector are arranged according to the order of measurement. It will be appreciated that when the electrode strip 22 comprises n electrodes, a signal magnitude vector comprises n x (n-3) sub-signal magnitudes. It will be appreciated that several signal magnitude vectors in succession are ordered according to time of measurement.
And step S108, calculating a standard amplitude vector according to the signal amplitude vectors. Wherein the standard magnitude vector is used to calculate the dynamic variation of the signal magnitude vector. The specific process of calculating the standard magnitude vector from the plurality of signal magnitude vectors will be described in detail below.
Step S110, a target magnitude vector is calculated according to the signal magnitude vector and the standard magnitude vector. Wherein the target magnitude vector represents a difference between the signal magnitude vector and the norm magnitude vector. The specific process of calculating the target magnitude vector from the signal magnitude vector and the standard magnitude vector will be described in detail below.
Step S112, calculating the product of the target amplitude vector and the target coefficient matrix as the equipotential impedance value vector. In this embodiment, the vector of equipotential impedance values includes the impedance value for each equipotential point in the image of the equipotential point. Wherein, the equal-position image is a pre-constructed image. Specifically, the iso-site image can be constructed using a Finite Element Method (FEM). The area of the object to be measured around the electrode belt 22 is taken as a circle, a plurality of concentric circles are divided in the circle according to a certain rule, a plurality of nodes are arranged on each concentric circle as equipotential points, and a plurality of units with triangular shapes are formed by connecting the equipotential points on each concentric circle to form an equipotential point image (as shown in fig. 8). The number of the concentric circles and the number of the equal-position points on each concentric circle may be set according to actual situations, and are not limited herein.
And step S114, generating an electrical impedance image according to the allelic point impedance value vector. Rendering the equivalent point image according to the equivalent point impedance value vector to obtain an electrical impedance image. It is understood that the equipotential points in the equipotential point image correspond to pixels in the electrical impedance image.
In the above embodiment, the sub-signal amplitudes obtained by each measurement form a corresponding signal amplitude vector, a standard amplitude vector is calculated according to the signal amplitude vector, and an equipotential impedance value vector is calculated according to the signal amplitude vector, the standard amplitude vector and the target coefficient matrix, so as to generate the electrical impedance image. The process of generating the electrical impedance image is matrixed, and the calculation flow is simplified. In the prior art, after an initial electrical impedance image is generated according to a signal amplitude, the target electrical impedance image with good quality can be obtained only by performing certain image processing on the initial electrical impedance image. However, the image processing of the initial electrical impedance image occupies certain computing resources, and reduces the operation efficiency of the electrical impedance imaging device. Therefore, before calculating the equipotential impedance value vector, an image transformation matrix for carrying out image processing on the electrical impedance image is constructed, the image transformation matrix is multiplied by an initial coefficient matrix for weighting the signal amplitude vector, so that a target coefficient matrix is obtained, and the equipotential impedance value vector which is subjected to image processing can be obtained by directly multiplying the target amplitude vector by the target coefficient matrix. Equivalently, the partial image post-processing process is integrated into the process of generating the electrical impedance image, the image processing is not required to be carried out on the electrical impedance image generated each time, the operation amount of the image processing is greatly reduced, and the image processing method can carry out noise reduction, sharpening and other processing on the image under the condition of not additionally consuming operation resources. The calculation process is optimized, the calculation is rapid, the time required by electrical impedance imaging is shortened, and the overall efficiency of the electrical impedance imaging equipment is improved.
Please refer to fig. 2 in combination, which is a first sub-flowchart of an electrical impedance imaging method according to an embodiment of the present invention. The step S102 of constructing the image transformation matrix specifically includes the following steps.
Step S202, constructing an equal-locus image. Wherein the allelic image includes a plurality of allelic points. In this embodiment, the iso-site image may be constructed using a Finite Element Method (FEM). The area of the object to be measured around the electrode belt 22 is taken as a circle, a plurality of concentric circles are divided in the circle according to a certain rule, a plurality of nodes are arranged on each concentric circle as equipotential points, and a plurality of units with triangular shapes are formed by connecting the equipotential points on each concentric circle to form an equipotential point image (as shown in fig. 8). And in the constructed equal-locus image, all the equal loci are numbered according to a certain rule. The number of the concentric circles and the number of the equal-position points on each concentric circle may be set according to actual situations, and are not limited herein.
Step S204, the elements of each row and each column in the image transformation matrix are arranged in a one-to-one correspondence with the equipotential points. And the sequence of each row element and the sequence of each column element in the image transformation matrix are consistent with the sequence of the allele numbers. For example, the allelic image includes three allelic positions: the equal position points A, the equal position points B and the equal position points C, the rows in the image transformation matrix are in one-to-one correspondence with the equal position points A, the equal position points B and the equal position points C in sequence, the columns in the image transformation matrix correspond to the allelic point a, the allelic point B, and the allelic point C one by one in sequence (as shown in fig. 9).
In step S206, elements in the image transformation matrix are generated according to the image processing method. In the present embodiment, the elements in the image transformation matrix are generated accordingly, depending on the type of image processing to be performed on the finally generated electrical impedance image. It will be appreciated that the elements of the image transformation matrix corresponding to different types of image processing are different.
In the above embodiment, the number of elements in the image transformation matrix is constructed according to the number of medium sites in the equipotential image, and then the corresponding elements in the image transformation matrix are generated according to the image processing method, so as to generate the image transformation matrix capable of performing image processing on the electrical impedance image. The setting of the elements in the image transformation matrix can be adjusted according to actual conditions, and flexibility is improved. It is understood that any image processing procedure that is only related to the number of the equipotential points in the equipotential image and is not related to the impedance values of the equipotential points can be advanced to the electrical impedance image generation procedure without any influence on the amount of computation in the electrical impedance image generation procedure.
Please refer to fig. 3 in combination, which is a second sub-flowchart of the electrical impedance imaging method according to the embodiment of the present invention. The step S102 of constructing the initial coefficient matrix specifically includes the following steps.
Step S302, constructing an equipotential line image. The equipotential line image comprises a plurality of equipotential lines, and an equipotential region is formed between every two equipotential lines. And constructing an equipotential line image according to an equipotential line back projection algorithm, wherein the size and the shape of the equipotential line image are consistent with those of the equipotential point image. Specifically, two adjacent electrodes are sequentially selected as an excitation electrode pair, sub-signal amplitudes between the other two adjacent electrodes are sequentially measured, each sub-signal amplitude is back-projected to an equipotential line image to form a plurality of equipotential lines, and an area between the two adjacent equipotential lines is an equipotential area. It will be appreciated that the number of equipotential regions in the equipotential line image is the same as the number of sub-signal amplitudes in each signal amplitude. In the constructed equipotential line image, all the equipotential regions are numbered according to a certain rule. For example, when electrode 1 and electrode 2 are selected as an excitation electrode pair, sub-signal amplitudes between electrode 3 and electrode 4, between electrode 4 and electrode 5, between electrode 5 and electrode 6, and so on until electrode 15 and electrode 16 are measured in sequence, each sub-signal amplitude is back-projected into an equipotential line image to form a plurality of equipotential lines, and an area between two adjacent equipotential lines is an equipotential area (as shown in fig. 7).
Step S304, the elements of each column in the initial coefficient matrix are set in one-to-one correspondence with the equipotential points. Wherein, the order of each column element in the initial coefficient matrix is consistent with the order of the allele numbers.
Step S306, the elements of each row in the initial coefficient matrix are set in one-to-one correspondence with the allelic regions. Wherein the order of each row element in the initial coefficient matrix is consistent with the order of the allelic region.
Step S308, elements in the initial coefficient matrix are generated according to the equipotential point images and the equipotential line images. In the present embodiment, it is determined whether the equipotential points are located within the equipotential region based on the equipotential point image and the equipotential line image. When the equipotential points are located in the equipotential regions, the elements in the initial coefficient matrix corresponding to the equipotential points and the equipotential regions are 1; when the equipotential point is not located within the equipotential region, the element in the initial coefficient matrix corresponding to the equipotential point and the equipotential region is 0. When the number of electrodes in the electrode belt 22 is constant, the elements in the initial coefficient matrix are fixed. Thus, the initial coefficient matrix is a constant matrix. For example, the allelic image includes three allelic positions: the equipotential line images comprise an equipotential point A, an equipotential point B and an equipotential point C, and the equipotential line images comprise two equipotential areas: and the rows in the initial coefficient matrix are sequentially in one-to-one correspondence with the allelic regions a, B and C. If the equal locus a and the equal locus B are located in the equal allele region a and the equal locus C is located in the equal allele region B, the initial coefficient matrix is shown in fig. 10.
Please refer to fig. 4 in combination, which is a third sub-flowchart of the electrical impedance imaging method according to an embodiment of the present invention. Step S108 specifically includes the following steps.
Step S402, respectively calculating the electrode impedance value corresponding to each signal amplitude vector according to the current value and the signal amplitude vector. In this embodiment, the sum of all the sub-signal amplitudes in each signal amplitude vector is calculated, and the quotient of the sub-signal amplitude sum and the current value is calculated as the electrode impedance value. The amplitude and frequency of the high-frequency current input from the excitation electrode pair each time are constant, but the amplitude and frequency of the current may be set according to actual conditions, and are not limited herein. Therefore, the current value can be regarded as a constant value. The electrode impedance value is a numerical value and is used for representing the overall impedance in one measurement.
Step S404, dividing a plurality of signal amplitude vectors into a plurality of groups according to a preset rule. Wherein the plurality of sets of signal magnitude vectors are arranged in accordance with the acquired temporal order. In this embodiment, the signal amplitude vectors in each set of signal amplitude vectors are continuous, and the plurality of sets of signal amplitude vectors are sorted according to the continuity of the signal amplitude vectors, i.e., the time sequence. The specific process of dividing the signal amplitude vectors into multiple groups according to the preset rule will be described in detail below.
In step S406, the minimum electrode impedance value is selected from the electrode impedance values corresponding to each set of signal amplitude vectors as a standard impedance value. It will be appreciated that each set of signal magnitude vectors corresponds to a standard impedance value.
Step S408, using the signal amplitude vector corresponding to the standard impedance value as a standard amplitude vector. It will be appreciated that each set of signal magnitude vectors corresponds to a standard magnitude vector.
Step S110 specifically includes: and respectively calculating corresponding target amplitude vectors according to each signal amplitude vector in each group of signal amplitude vectors and the standard amplitude vector corresponding to the previous group of signal amplitude vectors. That is, each signal magnitude vector in each set of signal magnitude vectors is calculated with the standard magnitude vector corresponding to the previous set of signal magnitude vectors. In this embodiment, the target magnitude vector is calculated according to a formula. Specifically, the formula is: Δ V = logV m -logV std . Where Δ V represents a target magnitude vector, V m Representing a signal magnitude vector, V, in a current set of signal magnitude vectors std And representing the standard amplitude vector corresponding to the last group of signal amplitude vectors. It will be appreciated that each signal magnitude vector corresponds to a target magnitude vector, and that each measurement of a signal magnitude vector will produce an electrical impedance image. Wherein each signal amplitude vector in the first set of signal amplitude vectors is calculated corresponding to a predetermined standard amplitude vectorThe target magnitude vector of (1).
In the above embodiment, the signal amplitude vectors are divided into a plurality of groups, the standard amplitude vector is selected according to the electrode impedance value corresponding to each group, and the target amplitude vector is calculated according to the signal amplitude vector of each group and the standard amplitude vector of the previous group. In the process of obtaining the signal amplitude vector, different standard amplitude vectors are dynamically formed, so that the reliability of the target amplitude vector is improved. In addition, if the signal amplitude vector acquired by the human body at the end of expiration is used as the standard amplitude vector, the formed target amplitude vector can be used for offsetting the measurement error caused by the difference of the electrical impedance imaging equipment and the accessories thereof to the maximum extent, and simultaneously, the individual difference between different tested objects can be kept as much as possible and formed into an electrical impedance image. Meanwhile, when the lung exhales, the air in the lung is gradually reduced, and the corresponding electrode impedance value is also gradually reduced. Therefore, when the electrode impedance value is minimum, the corresponding signal amplitude vector can be judged as the end-expiratory measurement.
Please refer to fig. 5 in combination, which is a fourth sub-flowchart of the electrical impedance imaging method according to the embodiment of the present invention. Step S404 specifically includes the following steps.
Step S502, a minimum value among the electrode impedance values is calculated. It will be appreciated that since the signal magnitude vector is continuous, the corresponding electrode impedance values are also continuous. In this embodiment, the first derivative of the electrode impedance value is calculated based on the calculated continuous electrode impedance values, and the minimum value of the electrode impedance value is obtained based on the first derivative of the electrode impedance value. Specifically, the first derivative of the present electrode impedance value is the difference between the present electrode impedance value and the previous electrode impedance value. And if the first derivative of the last electrode impedance value is less than 0 and the first derivative of the current electrode impedance value is greater than 0, the current electrode impedance value is a minimum value.
Step S504, sequentially dividing the minimum values of the preset number into the same group according to the time sequence. It is understood that the preset number of minima are divided into the same group in chronological order of the calculation of the electrode impedance values. Wherein the preset number is 15-20. In some possible embodiments, the predetermined number may be 6-12.
Step S506, all signal amplitude vectors between the signal amplitude vectors corresponding to the last minimum value in the two adjacent groups of minimum values are divided into the same group. In this embodiment, the signal amplitude vector corresponding to the last minimum value in the current set of minimum values and the signal amplitude vector corresponding to the next set of minimum values are the same set. The number of signal amplitude vectors in each set of signal amplitude vectors is not necessarily the same.
It can be understood that, in the actual measurement process, when a signal amplitude vector is obtained for the first time, the electrode impedance value is calculated according to the signal amplitude vector, and a target amplitude vector is calculated according to the signal amplitude vector and a preset standard amplitude vector; when the signal amplitude vector is obtained for the second time, calculating an electrode impedance value according to the signal amplitude vector, calculating a first derivative of the electrode impedance value according to the current electrode impedance value and the last electrode impedance value, and calculating a target amplitude vector according to the signal amplitude vector and a preset labeled amplitude vector; and by analogy, whether the electrode impedance value is a minimum value or not is judged according to the first-order derivative of the electrode impedance value, when the electrode impedance value is the minimum value, the minimum value is stored, and until the stored minimum value reaches a preset number, the signal amplitude vector corresponding to the minimum value in the preset number of the minimum values is marked as a standard amplitude vector. It is understood that the signal magnitude vectors acquired before the minimum reaches the preset number are of the same group. Then, the next acquired signal amplitude vector and the current acquired standard amplitude vector calculate a target amplitude vector, and the obtained minimum value is stored again, and the standard amplitude vector is marked again according to the new minimum value.
In some possible embodiments, the signal magnitude vectors may be divided into multiple groups according to a preset time. And when the time for continuously acquiring the signal amplitude vectors reaches the preset time, dividing the corresponding signal amplitude vectors in the corresponding preset time into the same group. Wherein the preset time is 10-20 seconds.
In the above embodiment, the signal amplitude vector is divided according to the minimum value of the electrode impedance value. It will be appreciated that as the lung exhales, the air in the lung gradually decreases, and the corresponding electrode impedance value also gradually decreases. Therefore, the signal amplitude vector corresponding to the minimum value can be regarded as the end-expiratory measurement, and the breathing cycle of the measured object can be judged according to the minimum value. And dividing the signal amplitude vectors into a plurality of groups according to the breathing cycle, namely dividing the signal amplitude vectors into a plurality of groups according to the dynamic breathing process.
Please refer to fig. 11, which is a schematic diagram of an internal structure of a terminal according to an embodiment of the present invention. The terminal 10 includes a computer-readable storage medium 11, a processor 12, and a bus 13. The computer-readable storage medium 11 includes at least one type of readable storage medium, which includes a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory, etc.), a magnetic memory, a magnetic disk, an optical disk, and the like. The computer readable storage medium 11 may in some embodiments be an internal storage unit of the terminal 10, such as a hard disk of the terminal 10. The computer readable storage medium 11 may also be, in other embodiments, an external storage device of the terminal 10, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the terminal 10. Further, the computer-readable storage medium 11 may also include both an internal storage unit of the terminal 10 and an external storage device. The computer-readable storage medium 11 may be used not only to store application software and various types of data installed in the terminal 10 but also to temporarily store data that has been output or will be output.
The bus 13 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 11, but this is not intended to represent only one bus or type of bus.
Further, the terminal 10 may also include a display assembly 14. The display component 14 may be a Light Emitting Diode (LED) display, a liquid crystal display, a touch-sensitive liquid crystal display, an Organic Light-Emitting Diode (OLED) touch panel, or the like. The display component 14 may also be referred to as a display device or display unit, as appropriate, for displaying information processed in the terminal 10 and for displaying a visual user interface, among other things.
Further, the terminal 10 may also include a communication component 15. The communication component 15 may optionally include a wired communication component and/or a wireless communication component, such as a WI-FI communication component, a bluetooth communication component, etc., typically used to establish a communication connection between the terminal 10 and other intelligent control devices.
The processor 12 may be, in some embodiments, a Central Processing Unit (CPU), controller, microcontroller, microprocessor or other data Processing chip for executing program codes stored in the computer-readable storage medium 11 or Processing data. In particular, the processor 12 executes a processing program to control the terminal 10 to implement an electrical impedance imaging method.
While fig. 11 shows only the terminal 10 with components 11-15 for implementing an electrical impedance imaging method, it will be understood by those skilled in the art that the structure shown in fig. 11 does not constitute a limitation of the terminal 10, and that the terminal 10 may include fewer or more components than shown, or some components may be combined, or a different arrangement of components.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, insofar as these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is intended to include these modifications and variations.
The above-mentioned embodiments are only examples of the present invention, which should not be construed as limiting the scope of the present invention, and therefore, the present invention is not limited by the claims.
Claims (10)
1. An electrical impedance imaging method, characterized in that it comprises:
constructing an image transformation matrix and an initial coefficient matrix;
calculating a product of the image transformation matrix and the initial coefficient matrix as a target coefficient matrix;
acquiring a plurality of continuous signal amplitude vectors, wherein each signal amplitude vector comprises sub-signal amplitudes between the rest two electrodes when two electrodes in all the electrodes are sequentially used as excitation electrode pairs;
calculating a standard amplitude vector according to the signal amplitude vectors;
calculating a target magnitude vector according to the signal magnitude vector and the standard magnitude vector;
calculating the product of the target amplitude vector and the target coefficient matrix as an equipotential impedance value vector; and
and generating an electrical impedance image according to the equipotential impedance value vector.
2. Electrical impedance imaging method according to claim 1, wherein calculating a norm magnitude vector from the plurality of signal magnitude vectors comprises in particular:
respectively calculating an electrode impedance value corresponding to each signal amplitude vector according to the current value and the signal amplitude vector;
dividing the plurality of signal amplitude vectors into a plurality of groups according to a preset rule, wherein the plurality of groups of signal amplitude vectors are arranged according to the acquired time sequence;
selecting the minimum electrode impedance value from the electrode impedance values corresponding to each group of signal amplitude vectors as a standard impedance value; and
and taking the signal amplitude vector corresponding to the standard impedance value as the standard amplitude vector.
3. Electrical impedance imaging method according to claim 2, wherein calculating a target magnitude vector from the signal magnitude vector and the norm magnitude vector comprises in particular:
and respectively calculating corresponding target amplitude vectors according to each signal amplitude vector in each group of signal amplitude vectors and the standard amplitude vector corresponding to the previous group of signal amplitude vectors.
4. Electrical impedance imaging method according to claim 1, characterized in that constructing an image transformation matrix comprises in particular:
constructing an isosite image, wherein the isosite image comprises a plurality of isosites;
setting elements of each row and elements of each column in the image transformation matrix in one-to-one correspondence with the equipotential points; and
generating elements in the image transformation matrix according to an image processing method.
5. The electrical impedance imaging method of claim 4, wherein constructing the initial coefficient matrix specifically comprises:
constructing an equipotential line image, wherein the equipotential line image comprises a plurality of equipotential lines, and an equipotential area is formed between every two equipotential lines;
setting elements of each column in the initial coefficient matrix in one-to-one correspondence with the equipotential points;
setting elements of each row in the initial coefficient matrix in one-to-one correspondence with the allelic regions; and
and generating elements in the initial coefficient matrix according to the equipotential point image and the equipotential line image.
6. The electrical impedance imaging method of claim 5, wherein generating elements of the initial coefficient matrix from the equipotential point image and the equipotential line image specifically comprises:
judging whether the equipotential points are located in the equipotential area or not according to the equipotential point image and the equipotential line image;
when the equipotential point is located in the equipotential region, an element in the initial coefficient matrix corresponding to the equipotential point and the equipotential region is 1; and
when the equipotential point is not located within the equipotential region, an element in the initial coefficient matrix corresponding to the equipotential point and the equipotential region is 0.
7. An electrical impedance imaging method according to claim 2, wherein dividing the plurality of signal magnitude vectors into groups according to a predetermined rule comprises:
calculating a minimum value of the electrode impedance values;
dividing the minimum values of the preset number into the same group in sequence according to the time sequence; and
and dividing all signal amplitude vectors between the signal amplitude vectors corresponding to the last minimum value in the two adjacent groups of minimum values into the same group.
8. The electrical impedance imaging method of claim 7, wherein calculating the minima in the electrode impedance values comprises in particular:
calculating a first derivative of the electrode impedance value; and
and acquiring the minimum value of the electrode impedance value according to the first derivative of the electrode impedance value.
9. An electrical impedance imaging method according to claim 2, wherein calculating the electrode impedance value corresponding to each signal magnitude vector based on the current value and the signal magnitude vector comprises:
calculating the sum of all sub-signal amplitudes in each signal amplitude vector; and
and calculating the quotient of the sum of the sub-signal amplitudes and the current value as the electrode impedance value.
10. A computer readable storage medium for storing program instructions executable by a processor to implement an electrical impedance imaging method as claimed in any one of claims 1 to 9.
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