Pulmonary edema monitoring system and method

Abstract

The invention relates to the technical field of medical monitoring, and provides a pulmonary edema monitoring system and method. The system comprises an electrode band, and the electrode band is at least provided with a first electrode array and a second electrode array; wherein the first electrode array surrounds the thoracic cavity of a target object so as to collect EIT data of the thoracic cavity of the target object; the second electrode array is symmetrically arranged on the thoracic cavity of the target object to collect BIS data of the thoracic cavity of the target object; the synchronous control module is connected with the first electrode array and the second electrode array and used for synchronously controlling the first electrode array to collect real-time EIT data of the thoracic cavity of the target object and controlling the second electrode array to collect real-time BIS data of the thoracic cavity of the target object; the generation module is connected with the synchronous control module and used for generating pulmonary edema monitoring information of the target object in real time based on the real-time EIT data and the real-time BIS data of the thoracic cavity of the target object, and pulmonary edema can be accurately monitored in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of medical monitoring, and in particular, to a pulmonary edema monitoring system and method. Background Art

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Pulmonary edema refers to a pathological state in which excessive fluid accumulates in the pulmonary interstitium and alveoli. It is a common complication of various cardiopulmonary diseases and kidney diseases. For example, patients with heart failure, acute respiratory distress syndrome (ARDS), and renal failure often suffer from pulmonary edema. Clinically, the examination of pulmonary edema generally uses traditional imaging methods such as chest X-ray, CT, and ultrasound. However, traditional imaging often has limitations such as radiation, complex operation, high requirements for patient cooperation (especially for critically ill patients or those in the ICU), and it is difficult to achieve dynamic, continuous, real-time, and accurate bedside monitoring. This makes it impossible for doctors to dynamically adjust the intervention of pulmonary edema according to the changes of pulmonary edema, which may cause the risk of the patient's pulmonary edema becoming more severe or not being intervened in a timely and effective manner. Summary of the Invention

[0004] To solve the technical problems existing in the above background art, the present invention provides a pulmonary edema monitoring system and method. The present invention combines two bioimpedance measurement techniques, Electrical Impedance Tomography (EIT) and Biological Impedance Spectroscopy (BIS), to monitor pulmonary edema, which can achieve dynamic, continuous, real-time, and accurate bedside monitoring of the patient's pulmonary edema, is beneficial to optimizing the treatment of pulmonary edema and improving the prognosis of the patient, and has the advantages of simple operation, no radiation, non-invasiveness, and low requirements for patient cooperation.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The first aspect of the present invention provides a pulmonary edema monitoring system.

[0007] A pulmonary edema monitoring system includes:

[0008] An electrode belt, on which at least a first electrode array and a second electrode array are provided; wherein, the first electrode array is wound around the chest of the target object to collect EIT data of the chest of the target object; the second electrode array is symmetrically arranged on the chest of the target object to collect BIS data of the chest of the target object;

[0009] A synchronization control module, connected to the first electrode array and the second electrode array, is used to synchronously control the first electrode array to collect real-time EIT data of the chest cavity of the target object, and control the second electrode array to collect real-time BIS data of the chest cavity of the target object;

[0010] A generation module, connected to the synchronization control module, is used to generate pulmonary edema monitoring information of the target object in real time based on the real-time EIT data and real-time BIS data of the chest cavity of the target object.

[0011] Further, the generation module includes a parameter extraction unit, which is used to extract pulmonary edema-related parameters from the real-time BIS data in real time. The pulmonary edema-related parameters include at least one of extracellular water ratio, total thoracic impedance value, impedance phase angle, and Cole-Cole model fitting parameters.

[0012] Further, the generation module further includes a determination unit, a processing unit, and a reconstruction unit,

[0013] The determination unit is used to obtain a real-time bioimpedance spectrum according to the real-time BIS data, determine the impedance value corresponding to a specific frequency in the real-time bioimpedance spectrum; and obtain a real-time background conductivity distribution according to the impedance value;

[0014] The processing unit is used to calculate a real-time sensitivity matrix according to the real-time background conductivity distribution;

[0015] The reconstruction unit is used to reconstruct an EIT image of the chest cavity of the target object by using a dynamic differential imaging algorithm according to the real-time sensitivity matrix and the real-time EIT data.

[0016] Further, the electrode band further includes a flexible baseband. The first electrode array includes N first electrodes arranged at equal intervals on the flexible baseband along the extension direction of the flexible baseband; the second electrode array includes M second electrodes arranged on both sides of the flexible baseband and symmetrically arranged with respect to the first electrode array, and the second electrodes are connected to the flexible baseband through wires; where N>M.

[0017] Further, the electrode band further includes a flexible baseband. The first electrode array includes N first electrodes arranged at equal intervals on the flexible baseband along the extension direction of the flexible baseband; the second electrode array includes M second electrodes arranged alternately between the first electrodes along the extension direction of the flexible baseband; where N>M.

[0018] Further, the second electrodes are symmetrically arranged on the front chest and the back of the chest cavity of the target object.

[0019] Further, the synchronization control module includes a signal generator and a time-division multiplexing switch,

[0020] The signal generator is used to generate excitation signals that are alternately applied to the first electrode array and the second electrode array;

[0021] The time-division multiplexing switch is used to switch the working states of the first electrode array and the second electrode array according to a preset working timing.

[0022] Further, the preset working timing includes:

[0023] Activating the first electrode array to collect EIT data in a first time window;

[0024] Switching to the second electrode array to collect BIS data in a second time window.

[0025] Further, the pulmonary edema monitoring information of the target object includes: pulmonary edema-related parameters and an EIT image of the chest cavity of the target object, and the EIT image includes a ventilation distribution image and a perfusion distribution image.

[0026] The second aspect of the present invention provides a method for monitoring pulmonary edema.

[0027] A method for monitoring pulmonary edema, applied to the pulmonary edema monitoring system described in the first aspect, includes:

[0028] Wearing the flexible baseband on the chest cavity of the target object;

[0029] Through the synchronous control module, generating excitation signals that are alternately applied to the first electrode array and the second electrode array, so that the first electrode array collects EIT data and the second electrode array collects BIS data;

[0030] According to the real-time BIS data, obtaining a real-time bioimpedance spectrum, determining the impedance value corresponding to a specific frequency in the real-time bioimpedance spectrum; according to the impedance value, obtaining a real-time background conductivity distribution; according to the real-time background conductivity distribution, calculating a real-time sensitivity matrix; according to the real-time sensitivity matrix and the real-time EIT data, using a dynamic differential imaging algorithm to reconstruct an EIT image of the chest cavity of the target object.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] The present invention provides an edema monitoring system and method, which monitors pulmonary edema by combining two bioimpedance measurement techniques, electrical impedance tomography (EIT) and bioelectrical impedance spectroscopy (BIS). It not only has the advantages of convenient operation, low requirement for patient cooperation, no radiation, and non-invasiveness, but also can achieve dynamic, continuous, real-time, and accurate bedside monitoring, facilitating doctors to accurately and dynamically give early warnings, conduct treatment, and evaluate the curative effect according to the changes in pulmonary edema, which is conducive to timely and effective intervention in patients' pulmonary edema and is of great help in optimizing the treatment of pulmonary edema and improving the prognosis of patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation to the invention.

[0034] Figure 1 is a schematic structural diagram of the pulmonary edema monitoring system shown in the embodiments of the present invention;

[0035] Figure 2 is a schematic structural diagram of an electrode strip shown in the embodiments of the present invention;

[0036] Figure 3 is a schematic structural diagram of another electrode strip shown in the embodiments of the present invention;

[0037] Figure 4 is a schematic structural diagram of the synchronization control module shown in the embodiments of the present invention;

[0038] Figure 5 is a schematic structural diagram of the generation module shown in the embodiments of the present invention;

[0039] Wherein, 100, pulmonary edema monitoring system; 10, electrode strip; 110, first electrode array; 111, first electrode; 120, second electrode array; 121, second electrode; 130, flexible baseband; 20, synchronization control module; 21, signal generator; 22, time-division multiplexing switch; 30, generation module; 31, parameter extraction unit; 32, determination unit; 33, processing unit; 34, reconstruction unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0042] It should be understood that the "system", "device", "unit" and / or "module" used herein is a method for distinguishing different components, elements, parts, sections or assemblies at different levels. However, if other words can achieve the same purpose, the said words can be replaced by other expressions.

[0043] As shown in this specification and the claims, unless the context clearly indicates otherwise, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

[0044] When terms such as "first", "second", "third", etc. are used in the description of various features in the specification of the present invention, these terms are only used to distinguish these features and should not be construed as indicating or implying the relevance, relative importance or implicitly indicating the number of the indicated features.

[0045] In clinical practice, doctors generally use imaging methods to examine pulmonary edema. However, traditional imaging methods such as X-ray imaging, computed tomography, enhanced computed tomography, etc. often require going to a specific location for examination, with complex operations, high requirements for patient cooperation, and being radioactive or invasive. Especially for patients in the ICU, the risk of going out for examination is extremely high, which limits the use of these examinations. Although ultrasound is not radioactive or invasive, it still has requirements for the patient's body position, and at present, it is difficult to achieve dynamic, continuous, real-time and accurate bedside monitoring of pulmonary edema by ultrasound. The above limitations make it impossible for current doctors to accurately and dynamically monitor the changes of pulmonary edema in real time through these methods, unable to timely treat the patients and evaluate the curative effect, and it is easy to cause delays in the patient's condition.

[0046] To this end, an embodiment of the present invention provides a pulmonary edema monitoring system, including: an electrode belt, on which there are at least a first electrode array and a second electrode array. The first electrode array is configured to be arranged around the chest cavity of the target object to collect EIT data of the chest cavity of the target object, and the second electrode array is configured to be symmetrically arranged on the chest cavity of the target object to collect BIS data of the chest cavity of the target object; a synchronization control module, communicatively connected to the first electrode array and the second electrode array, and the synchronization control module is configured to: synchronously control the first electrode array and the second electrode array to collect real-time EIT data and real-time BIS data respectively; a generation module, and the generation module is configured to: generate real-time pulmonary edema monitoring information of the target object based on the real-time EIT data and real-time BIS data of the chest cavity of the target object. The pulmonary edema monitoring system provided in this embodiment monitors pulmonary edema by combining two bioimpedance measurement techniques, electrical impedance tomography and bioelectrical impedance spectroscopy. It not only has the advantages of convenient operation, low requirement for patient cooperation, no radiation, and non-invasiveness, but also can achieve dynamic, continuous, real-time, and accurate bedside monitoring, facilitating doctors to accurately and dynamically give early warnings, provide treatment, and evaluate the curative effect according to the changes in pulmonary edema, which is conducive to timely and effective intervention in the pulmonary edema of patients and is of great help in optimizing the treatment of pulmonary edema and improving the prognosis of patients.

[0047] Figure 1 It is a schematic structural diagram of a pulmonary edema monitoring system according to some embodiments of the present invention. Figure 2 、 Figure 3 It is a schematic structural diagram of an electrode belt according to an embodiment of the present invention.

[0048] As Figure 1 shown, the pulmonary edema monitoring system 100 provided in an embodiment of the present invention may include an electrode belt 10, a synchronization control module 20, and a generation module 30.

[0049] The electrode belt 10 will be described in detail below.

[0050] The electrode belt 10 has at least a first electrode array 110 and a second electrode array 120. The first electrode array can be arranged around the chest cavity of the target object to collect real-time EIT data of the chest cavity of the target object, and the second electrode array can be symmetrically arranged on the chest cavity of the target object to collect real-time BIS data of the chest cavity of the target object.

[0051] In some embodiments, the EIT data of the target object's chest cavity may refer to the EIT measurement voltage obtained by applying an alternating current through the first electrode 111 serving as the excitation electrode in the first electrode array 110 and measuring the potential difference between other electrodes in the first electrode array 110 on the target object's chest cavity that serve as acquisition electrodes; the BIS data of the target object's chest cavity may refer to the bioimpedance spectrum obtained by applying a multi-frequency alternating current through the second electrode array 120 and measuring the impedance values of the chest cavity or lungs at different frequencies by means of frequency sweeping.

[0052] In some embodiments, as Figure 2 shown, the electrode strip 10 may include a flexible baseband 130, the first electrode array 110 may include 16 first electrodes 111, and the 16 first electrodes 111 may be arranged at equal intervals along the extension direction of the flexible baseband on the flexible baseband 130.

[0053] In some embodiments, the second electrode array 120 may include 4 second electrodes 121, and the 4 second electrodes 121 may be symmetrically distributed in pairs on both sides of the flexible baseband 130 with respect to the first electrode array 110 and connected to the flexible baseband through wires. With such an arrangement, by wearing the electrode strip 10 around the target object's chest cavity, the first electrode array 110 can be wrapped and attached around the circumference of the target object's chest cavity, and the second electrode array 120 can be symmetrically attached to the target object's chest cavity.

[0054] In some embodiments, the length of the flexible baseband 130 may be 20 cm to 150 cm. In some embodiments, the material of the flexible baseband may be medical silicone rubber.

[0055] In some embodiments, the interval between two adjacent first electrodes 111 may be 15 mm to 90 mm.

[0056] In some embodiments, when the electrode strip 10 is worn around the target object's chest cavity, the 16 first electrodes 111 may be located at the 4th to 6th intercostal levels of the target object's chest cavity, so that the first electrode array 110 can more accurately collect the EIT data of the target object's chest cavity.

[0057] In some embodiments, when the electrode strip 10 is worn around the target object's chest cavity, two of the 4 second electrodes 121 may be respectively located at the second intercostal space of the left and right midclavicular lines of the target object's chest cavity, and the other two second electrodes 121 may be respectively located at the 8th intercostal space of the left and right anterior axillary lines of the target object's chest cavity. Thus, the second electrode array 120 can more accurately collect the BIS data of the target object's chest cavity.

[0058] In some embodiments, the distance between the connection positions of the two second electrodes 121 connected above the flexible baseband 130 on the flexible baseband 130 can be set according to the distance between the midclavicular lines on both sides of a normal adult. The distance between the connection positions of the two second electrodes 121 connected below the flexible baseband 130 on the flexible baseband 130 can be set according to the distance between the anterior axillary lines on both sides of a normal adult. The distance from the two second electrodes 121 connected above the flexible baseband 130 to the flexible baseband 130 can be set according to the distance from the 2nd intercostal space to the 4th to 6th intercostal spaces of a normal adult. The distance from the second electrode 121 connected below the flexible baseband 130 to the flexible baseband 120 can be set according to the distance from the 8th intercostal space to the 4th to 6th intercostal spaces of a normal adult.

[0059] In some embodiments, as Figure 3 shown, the 4 second electrodes 121 can be arranged to interleave with the 16 first electrodes 111 on the flexible baseband 130. In some embodiments, the first and last of the 4 second electrodes 121 can be arranged to interleave behind the 2nd first electrode 111 and the 14th first electrode 111 respectively, and there can be 4 first electrodes 111 spaced between the middle two of the 4 second electrodes 121.

[0060] In some embodiments, the 4 second electrodes 121 can be symmetrically arranged on the front and back of the chest cavity, that is, two of the 4 second electrodes 121 can be located on the front chest of the target object, and the other two second electrodes 121 can be located on the back of the target object, being symmetric with the two second electrodes 121 on the front chest.

[0061] The synchronous control module 20 will be described in detail below.

[0062] The synchronous control module 20 can be communicatively connected to the first electrode array 110 and the second electrode array 120, and is used to synchronously control the first electrode array 110 and the second electrode array 120 to respectively collect the real-time EIT data and real-time BIS data of the chest cavity of the target object, so as to realize the real-time synchronous collection of the EIT data and BIS data of the chest cavity of the target object. By synchronously collecting the real-time EIT data and real-time BIS data of the chest cavity of the target object, the time homology and signal integrity of the real-time EIT data and real-time BIS data can be ensured, and the physiological state at the same time point can be reflected, avoiding errors caused by acquisition differences, thereby improving the accuracy of subsequent pulmonary edema monitoring and the reliability of clinical decision-making. Among them, the real-time EIT data of the chest cavity of the target object can include the real-time EIT measurement voltage of the chest cavity of the target object, and the real-time BIS data of the chest cavity of the target object can include the real-time bioimpedance spectrum of the chest cavity or lungs of the target object.

[0063] Figure 4 It is a schematic structural diagram of the synchronization control module shown in an embodiment of the present invention.

[0064] In some embodiments, in order to synchronously control the first electrode array 110 and the second electrode array 120 to respectively collect real-time EIT data and real-time BIS data of the chest cavity of the target object, as Figure 4 shown, the synchronization control module 20 may include a signal generator 21 and a time-division multiplexing switch 22.

[0065] The signal generator 21 can be used to generate excitation signals alternately applied to the first electrode array and the second electrode array.

[0066] In some embodiments, the excitation signal applied by the signal generator 21 to the first electrode array may be a sinusoidal alternating current of 50 kHz.

[0067] In some embodiments, the excitation signal applied by the signal generator 21 to the second electrode array may be a swept-frequency signal of 1 kHz to 1 MHz.

[0068] The time-division multiplexing switch 22 can be used to switch the working states of the first electrode array 110 and the second electrode array 120 according to a preset working procedure.

[0069] In some embodiments, the preset working timing may include: activating the first electrode array 110 to collect real-time EIT data in the first time window, and switching to the second electrode array 120 to collect real-time BIS data in the second time window. Among them, the working timing of the time-division multiplexing switch 22 can be synchronized by a quartz crystal oscillator, and the clock jitter is less than 1 μs.

[0070] In some such embodiments, the first time window may be 0 to 50 ms, and the second time window may be 50 ms to 110 ms. As an example description, the time-division multiplexing switch 22 can activate the first electrode array 110 between 0 - 50 ms to collect real-time EIT data at a specific frequency (for example, 50 kHz), and can activate the second electrode array 120 between 50 ms - 110 ms to perform a sweep from 1 kHz to 1 MHz and collect real-time BIS data.

[0071] Next, the generation module 30 will be described in detail. The generation module 30 is connected to the synchronization control module 20, and the generation module 30 can be used to generate real-time pulmonary edema monitoring information of the target object based on the real-time EIT data and real-time BIS data of the chest cavity of the target object.

[0072] <[ Figure 5 It is a schematic structural diagram of the generation module shown in an embodiment of the present invention;

[0073] In some embodiments, the pulmonary edema monitoring information of the target object may include pulmonary edema-related parameters extracted from the real-time BIS data of the target object. Further, as Figure 5 shown, the generating module 30 may include a parameter extraction unit 31, and the parameter extraction unit 31 may be configured to extract pulmonary edema-related parameters from the real-time BIS data in real time.

[0074] In some embodiments, the pulmonary edema-related parameters may include at least one of the extracellular water ratio, the total thoracic impedance value, the impedance phase angle, and the Cole-Cole model fitting parameters. Among them, the extracellular water ratio refers to the ratio of extracellular water to total body water (ECW%). When pulmonary edema occurs, the extracellular fluid (interstitial and alveolar fluid) increases significantly, and the ECW% increases abnormally; the total thoracic impedance value refers to the overall thoracic impedance value at a specific frequency (for example, 50 kHz). Pulmonary edema will cause enhanced tissue conductivity (decreased impedance). Therefore, the total thoracic impedance value is negatively correlated with the severity of pulmonary edema; the impedance phase angle refers to the phase difference between the current and voltage during BIS acquisition, which can reflect the integrity of the cell membrane and tissue electrical properties. When pulmonary edema occurs, the cell membrane function is damaged (such as inflammation causing changes in membrane permeability), and the impedance phase angle usually decreases; the Cole-Cole model fitting parameters may include the extracellular resistance and intracellular resistance separated by fitting the BIS spectrum curve through the Cole-Cole model. When pulmonary edema occurs, the extracellular resistance decreases (the extracellular fluid increases), and the intracellular resistance may decrease due to cell edema or rupture; the Cole-Cole model fitting parameters may also include the frequency at which the imaginary part of the impedance reaches an extreme value in the Cole-Cole curve, which reflects the cell membrane capacitance characteristics. When pulmonary edema occurs, the increase in extracellular fluid may cause the characteristic frequency to shift to a lower frequency; the Cole-Cole model fitting parameters may also include the cell membrane capacitance value calculated by the Cole-Cole model, that is, the membrane capacitance, which is related to the integrity of the cell membrane. When pulmonary edema occurs, it may cause changes in the cell membrane structure, resulting in abnormal membrane capacitance.

[0075] By generating the pulmonary edema monitoring information of the target object in real time, and the pulmonary edema monitoring information includes the above-mentioned pulmonary edema-related parameters, the above-mentioned pulmonary edema-related parameters can not only be used to distinguish whether there is pleural effusion, pulmonary edema, normal lung tissue or lung consolidation in the chest cavity of the target object, but also help clinicians clarify the real-time situation of pulmonary edema through real-time monitoring of the above-mentioned pulmonary edema-related parameters, which is helpful for the judgment, early warning, treatment, prognosis, etc. of the severity of pulmonary edema.

[0076] In some embodiments, the pulmonary edema monitoring information of the target object may further include the EIT image of the chest cavity of the target object, that is, the impedance distribution image of the chest cavity of the target object obtained by electrical impedance tomography technology, which is also the impedance distribution image reconstructed based on the EIT data collected by the first electrode array 110.

[0077] Further, the generating module 30 may include a determining unit 32, a processing unit 33, and a reconstructing unit.

[0078] During the progression of pulmonary edema, in addition to the effects of inhalation and exhalation and blood inflow and outflow, the conductivity in the chest cavity of the target object is also affected by the exudate in the alveoli, and the exudate increases the conductivity of the lungs, resulting in a significant decrease in the impedance of the overall chest cavity. After effective intervention on the target object and improvement of the pulmonary edema situation, the situation is reversed. As the fluid decreases and the lung conductivity decreases, the impedance of the overall chest cavity will increase compared with that before the intervention. In this case, the change range of the conductivity in the lungs exceeds the effective interval of the linear assumption of the sensitivity matrix (Jacobian matrix), and the error of the existing dynamic EIT reconstruction algorithm using linearized solution increases significantly, resulting in artifacts and unable to truly reflect the ventilation change and perfusion change. The determining unit 32 of the generating module 30 according to the present invention can be used to determine the real-time background conductivity distribution based on the real-time BIS data. Specifically, the real-time BIS data may include the real-time bioimpedance spectrum, and the real-time bioimpedance spectrum may include the impedance corresponding to different frequencies. Therefore, the impedance value corresponding to a specific frequency (for example, the frequency of the excitation current applied to collect the EIT data) can be determined from the real-time bioimpedance spectrum, and then the real-time background conductivity distribution can be updated according to the impedance value. Specifically, the average conductivity of the overall chest cavity is calculated based on the impedance value at a specific frequency obtained from the BIS, the chest circumference of the target object, and the effective measurement height of the BIS (when the second electrode array is in the same plane, the effective measurement height is about 10 cm; when the second electrode is attached to the 2nd and 8th ribs of an adult, the effective measurement height is about 20 - 25 cm); the conductivity in the lung area in the chest cavity changes, while the conductivity of the fat, muscle, and bone in the chest cavity remains unchanged; therefore, the real-time background conductivity distribution is updated according to the change of the average conductivity. For example, in the field of EIT, assuming that the initial background conductivity distribution is uniform, the average conductivity of the chest cavity at a specific frequency obtained from the initial BIS data is 0.2 S / m; when the average conductivity of the overall chest cavity becomes 0.5 S / m, since the change is caused by the change in the conductivity of the lungs, the dynamic background conductivity distribution is no longer uniform; the conductivity of the lung area is calculated using volume weighting (the lungs account for 35% of the volume of the chest cavity), then the area outside the lungs remains 0.2 S / m, while the lung area is 1.06 S / m, thus obtaining the real-time background conductivity distribution.

[0079] The processing unit 33 can be used to calculate a real-time sensitivity matrix (Jacobian matrix) based on the real-time background conductivity distribution. In some embodiments, the elements of the real-time sensitivity matrix J can be calculated by the following formula:

[0080]

[0081] where J ji is the element of the real-time sensitivity matrix J, and J ij can represent the linear influence of the conductivity change of the j-th unit (pixel or grid cell) on the i-th voltage measurement; σ is the real-time background conductivity distribution; Ω j is the geometric region of the j-th unit in the finite element mesh; and respectively represent the electric potential gradients under the i-th current injection pattern and the j-th current injection pattern, and can be obtained by solving the Laplace equation using the finite element method.

[0082] It can be understood that when collecting real-time EIT data through the first electrode array 110, every two first electrodes 111 in the first electrode array 110 (for example, adjacent or opposite first electrodes) will take turns as the excitation electrode pair to inject current for voltage measurement. The i-th voltage measurement is the voltage measurement when the i-th pair of first electrodes 111 serves as the excitation electrode pair to inject current. The i-th current injection pattern is the current injection when the i-th pair of first electrodes 11 serves as the excitation electrode pair, and the j-th current injection pattern is the current injection when the j-th pair of first electrodes 111 serves as the excitation electrode pair.

[0083] After calculating all the elements J ij of the real-time sensitivity matrix J one by one, they can be arranged according to the rules to construct the corresponding real-time sensitivity matrix J. Among them, the number of rows of the real-time sensitivity matrix J corresponds to the total number of EIT acquisition channels (or EIT measurement voltages). For example, if the first electrode array 110 includes 16 first electrodes and the adjacent excitation and adjacent acquisition method is used, the total number of EIT acquisition channels is 208 (16×13), that is, the number of rows of the real-time sensitivity matrix J is 208; the number of columns of the real-time sensitivity matrix J corresponds to the total number of units in the finite element mesh. For example, if the finite element mesh is divided into 1000 units, the number of columns of the real-time sensitivity matrix J is 1000.

[0084] The reconstruction unit 34 can be used to reconstruct the EIT image of the chest cavity of the target object in real time based on the real-time sensitivity matrix and the real-time EIT data. Among them, the real-time EIT data can include the EIT measurement voltage obtained by applying current to the chest cavity of the target object in real time through the first electrode array 110.

[0085] Furthermore, the reconstruction unit 34 can reconstruct the EIT image through a dynamic differential imaging algorithm. The mathematical model of the dynamic differential imaging algorithm can be ΔV = J×Δσ, where ΔV is the voltage difference between the EIT measurement voltage corresponding to the reference frame and the EIT measurement voltage corresponding to the current frame, J is the real-time sensitivity matrix (Jacobian matrix), and Δσ is the conductivity change of the current frame relative to the reference frame. By obtaining Δσ and mapping Δσ into a dynamic image, the real-time EIT image of the chest cavity of the target object can be obtained.

[0086] In the embodiment of the present invention, the sensitivity matrix of the dynamic differential imaging algorithm used in the EIT image reconstruction process is calculated by obtaining the real-time background conductivity distribution of the chest cavity of the target object from the real-time BIS data. Compared with calculating the sensitivity matrix based on the assumed background conductivity in the traditional dynamic imaging algorithm, the real-time sensitivity matrix calculated based on the real-time background conductivity distribution can more accurately reflect the physical relationship between the EIT measurement voltage and the internal conductivity change, reduce the model error of the dynamic differential imaging algorithm, reduce imaging artifacts, and can significantly improve the accuracy of EIT image reconstruction, reflecting the real ventilation and perfusion conditions.

[0087] In some embodiments, the pulmonary edema monitoring information of the target object further includes the EIT image of the chest cavity of the target object, and the EIT image includes a ventilation distribution image and a perfusion distribution image. The ventilation distribution image can provide the area of abnormal ventilation in the lungs of the target object, and this area may be due to alveolar collapse caused by pulmonary edema. When the area of abnormal ventilation gradually increases, it indicates that the pulmonary edema condition of the target object deteriorates; on the contrary, when the area of abnormal ventilation remains unchanged or gradually decreases, it indicates that the pulmonary edema condition of the target object is under control. The perfusion distribution image can provide the area of abnormal perfusion in the lungs of the target object, and this area includes a decrease in perfusion due to edema and / or a compensatory increase in perfusion in some areas. When the area of abnormal perfusion gradually increases, it indicates that the pulmonary edema condition of the target object deteriorates; on the contrary, when the area of abnormal perfusion remains unchanged or gradually decreases, it indicates that the pulmonary edema condition of the target object is under control.

[0088] In some embodiments, the pulmonary edema monitoring information of the target object includes the EIT image of the chest cavity of the target object and the pulmonary edema-related parameters extracted from the real-time BIS data in real time. The combination of the two can help doctors timely and accurately grasp the pulmonary edema condition of the target object, and can provide more pathophysiological information for the diagnosis and treatment of pulmonary edema by clinicians, thus facilitating timely and accurate early warning, treatment, and prognosis, etc.

[0089] It should be noted that the above description of the pulmonary edema monitoring system 100 and its modules is only for convenience of description and does not limit this specification within the scope of the examples given. It can be understood that for those skilled in the art, after understanding the principle of the system, they may, without departing from this principle, make any combination of the various modules, or form a subsystem and connect it to other modules. In some embodiments, Figure 1 the synchronization control module and the generation module disclosed in [reference] can be different modules in a system, or a single module can implement the functions of the above two or more modules. For example, each module can share a storage module, or each module can have its own storage module respectively. Such variations are all within the protection scope of this specification.

[0090] The beneficial effects that the embodiments of the present invention may bring include but are not limited to: (1) The pulmonary edema monitoring system provided in this embodiment monitors pulmonary edema by combining two bioimpedance measurement techniques, electrical impedance tomography (EIT) and bioelectrical impedance spectroscopy (BIS). It not only has the advantages of convenient operation, low requirement for patient cooperation, no radiation, and non-invasiveness, but also can achieve dynamic, continuous, real-time, and accurate bedside monitoring, facilitating doctors to accurately and dynamically give early warnings, conduct treatments, and evaluate treatment effects according to the changes in pulmonary edema, which is helpful for timely and effective intervention in patients' pulmonary edema and is of great assistance in optimizing the treatment of pulmonary edema and improving the prognosis of patients; (2) During the EIT image reconstruction process in the embodiments of the present invention, the sensitivity matrix in the dynamic differential imaging algorithm is calculated by using the real-time background conductivity distribution of the target object's chest cavity obtained from the real-time BIS data, which can more accurately reflect the physical relationship between the EIT measured voltage and the internal conductivity change, reduce the model error of the dynamic differential imaging algorithm, thereby reducing imaging artifacts, making the imaging of conductivity changes closer to the real physiological state, significantly improving the accuracy of EIT image reconstruction, and reflecting the real pulmonary ventilation and pulmonary perfusion conditions.

[0091] In another embodiment of the present invention, a method for monitoring pulmonary edema, which is applied to the above-mentioned pulmonary edema monitoring system, includes:

[0092] Wear the flexible baseband on the chest cavity of the target object;

[0093] Through the synchronization control module, generate an excitation signal that is alternately applied to the first electrode array and the second electrode array, so that the first electrode array collects EIT data and the second electrode array collects BIS data;

[0094] According to real-time BIS data, obtain a real-time bioimpedance spectrum, and determine the impedance value corresponding to a specific frequency in the real-time bioimpedance spectrum; according to the impedance value, obtain a real-time background conductivity distribution; according to the real-time background conductivity distribution, calculate a real-time sensitivity matrix; according to the real-time sensitivity matrix and real-time EIT data, adopt a dynamic differential imaging algorithm to reconstruct an EIT image of the chest cavity of the target object.

[0095] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pulmonary edema monitoring system, characterized in that, Comprising: An electrode belt, on which at least a first electrode array and a second electrode array are provided; wherein, the first electrode array is wound around the chest cavity of a target object to collect EIT data of the chest cavity of the target object; the second electrode array is symmetrically arranged on the chest cavity of the target object to collect BIS data of the chest cavity of the target object; A synchronous control module, connected to the first electrode array and the second electrode array, for synchronously controlling the first electrode array to collect real-time EIT data of the chest cavity of the target object, and controlling the second electrode array to collect real-time BIS data of the chest cavity of the target object; A generation module, connected to the synchronous control module, for generating pulmonary edema monitoring information of the target object in real time based on the real-time EIT data and real-time BIS data of the chest cavity of the target object.

2. The pulmonary edema monitoring system according to claim 1, wherein The generation module includes a parameter extraction unit for extracting pulmonary edema-related parameters from the real-time BIS data in real time, and the pulmonary edema-related parameters include at least one of extracellular water ratio, total thoracic impedance value, impedance phase angle, and Cole-Cole model fitting parameters.

3. The pulmonary edema monitoring system according to claim 1, characterized in that, The generation module further includes a determination unit, a processing unit, and a reconstruction unit. The determination unit is configured to obtain a real-time bioimpedance spectrum according to the real-time BIS data, and determine the impedance value corresponding to a specific frequency in the real-time bioimpedance spectrum; According to the impedance value, obtain a real-time background conductivity distribution; The processing unit is configured to calculate a real-time sensitivity matrix according to the real-time background conductivity distribution; The reconstruction unit is configured to reconstruct an EIT image of the chest cavity of the target object by using a dynamic differential imaging algorithm according to the real-time sensitivity matrix and the real-time EIT data.

4. The pulmonary edema monitoring system according to claim 1, wherein The electrode belt further includes a flexible baseband, and the first electrode array includes N first electrodes arranged at equal intervals along the extension direction of the flexible baseband; The second electrode array includes M second electrodes arranged on both sides of the flexible baseband and symmetrically arranged with respect to the first electrode array, and the second electrodes are connected to the flexible baseband through wires; wherein, N>M.

5. The pulmonary edema monitoring system according to claim 1, wherein The electrode belt further includes a flexible baseband, and the first electrode array includes N first electrodes arranged at equal intervals along the extension direction of the flexible baseband; The second electrode array includes M second electrodes arranged alternately between the first electrodes along the extension direction of the flexible baseband; wherein, N>M.

6. The pulmonary edema monitoring system according to claim 4 or 5, characterized in that, The second electrodes are symmetrically arranged on the front chest and back of the chest cavity of the target object.

7. The pulmonary edema monitoring system according to claim 1, wherein The synchronous control module includes a signal generator and a time-division multiplexing switch. The signal generator is configured to generate an excitation signal alternately applied to the first electrode array and the second electrode array; The time-division multiplexing switch is configured to switch the working states of the first electrode array and the second electrode array according to a preset working timing.

8. The pulmonary edema monitoring system according to claim 7, wherein, The preset working timing includes: Activating the first electrode array to collect EIT data in a first time window; Switching to the second electrode array to collect BIS data in a second time window.

9. The pulmonary edema monitoring system according to claim 1, wherein The pulmonary edema monitoring information of the target object includes: parameters related to pulmonary edema and EIT images of the chest cavity of the target object, and the EIT images include ventilation distribution images and perfusion distribution images.

10. A method for monitoring pulmonary edema, characterized in that, Applied to the pulmonary edema monitoring system according to any one of claims 1-9, comprising: Wearing the flexible baseband on the chest cavity of the target object; Through the synchronization control module, generating an excitation signal alternately applied to the first electrode array and the second electrode array, so that the first electrode array collects EIT data and the second electrode array collects BIS data; According to the real-time BIS data, obtain the real-time bioimpedance spectrum, determine the impedance value corresponding to a specific frequency in the real-time bioimpedance spectrum; according to the impedance value, obtain the real-time background conductivity distribution; according to the real-time background conductivity distribution, calculate the real-time sensitivity matrix; according to the real-time sensitivity matrix and the real-time EIT data, adopt the dynamic differential imaging algorithm to reconstruct the EIT image of the chest cavity of the target object.

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