Lung rehabilitation real-time evaluation system based on EIT parameters

Abstract

The invention relates to a lung rehabilitation real-time evaluation system based on EIT parameters, and the system comprises a phrenic nerve-abdominal muscle electrical stimulation module which is used for carrying out the electrical stimulation of phrenic nerves and abdominal muscles of a patient; the electrical impedance tomography equipment is used for monitoring the electrical impedance change of the lung of the patient in real time; the data processing module is used for receiving lung electrical impedance data monitored by the electrical impedance tomography equipment and calculating parameters; the curative effect evaluation module is used for evaluating the lung rehabilitation curative effect according to the calculated parameters; the aging evaluation module is used for evaluating the short-term curative effect and duration of phrenic nerve-abdominal muscle combined electrical stimulation by using EIT parameters; and the early warning module is used for performing early warning according to a set threshold range and a parameter change trend, and performing information feedback on the curative effect module and the aging module according to an early warning level and a real-time state of the patient. The medicine has the advantages that the lung ventilation function of a patient can be effectively improved in the aspect of lung rehabilitation curative effect; in the aspect of lung rehabilitation timeliness, real-time and quantitative evaluation of timeliness characteristics provides a powerful objective tool for accurate implementation and effect evaluation of passive lung rehabilitation.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a real-time assessment system for lung rehabilitation based on electrical impedance tomography (EIT) parameters. Background Technology

[0002] Stroke is an acute cerebrovascular disease caused by the sudden rupture or blockage of blood vessels in the brain, leading to brain tissue damage. Post-stroke, respiratory dysfunction is common, resulting in high rates of pulmonary infection and mortality. Previous studies have shown that active interventions such as respiratory muscle training and manual breathing exercises can effectively improve respiratory function and reduce the incidence of pulmonary complications. However, patients with impaired consciousness or severe respiratory failure have significantly limited ability to actively participate in respiratory training. Therefore, how to implement safe and effective passive pulmonary rehabilitation and establish an objective efficacy evaluation system has become an urgent problem to be solved in the field of respiratory rehabilitation. Currently, clinical evaluation of pulmonary rehabilitation effects mainly relies on patients' subjective symptom descriptions and indirect physiological indicators (such as shortness of breath index and pulmonary function tests), lacking assessment methods that can reflect respiratory function status in real time, dynamically, and objectively. This affects the precision and individualization of pulmonary rehabilitation treatment and restricts the innovation and development of respiratory rehabilitation techniques.

[0003] Electrical impedance tomography (EIT) is a novel, non-invasive, real-time, and dynamic medical imaging technique. It reconstructs an image of the body's internal electrical impedance distribution by applying a weak electric current to the body surface and measuring the voltage changes between electrodes. Since the electrical impedance of lung tissue changes with respiratory movements, EIT can reflect lung ventilation and perfusion in real time and dynamically, providing a completely new means of monitoring lung function.

[0004] However, EIT technology still faces some problems in clinical application. It cannot assess the timeliness and efficacy of lung function, nor can it dynamically capture timeliness characteristics and analyze their trajectory to provide a reference for clinical treatment plans.

[0005] In summary, there is an urgent need for an assessment system that can evaluate the timeliness and efficacy of lung function, dynamically capture its timeliness characteristics, and analyze its trajectory to provide a reference for clinical treatment plans. However, no such real-time lung rehabilitation assessment system based on EIT parameters has been reported to date. Summary of the Invention

[0006] The purpose of this invention is to provide a real-time assessment system for pulmonary rehabilitation based on EIT parameters, which evaluates the immediate therapeutic effect and time-dependent characteristics of pulmonary ventilation function, and dynamically captures and analyzes the time-dependent characteristics and trajectory.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A real-time assessment system for pulmonary rehabilitation based on EIT parameters, the system comprising:

[0009] The phrenic nerve-abdominal muscle electrical stimulation module is used to electrically stimulate the patient's phrenic nerve and abdominal muscles. The phrenic nerve-abdominal muscle electrical stimulation module includes a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module. The phrenic nerve electrical stimulation module works during the inspiratory phase and issues an inspiratory command to perform inspiratory electrical stimulation. The abdominal muscle electrical stimulation module works during the expiratory phase and issues an expiratory command to perform expiratory electrical stimulation. The combination of inspiratory and expiratory electrical stimulation forms a single respiratory cycle electrical stimulation.

[0010] Electrical impedance tomography equipment is used to monitor changes in the lung electrical impedance of patients in real time;

[0011] The data processing module is used to receive lung electrical impedance data monitored by the electrical impedance tomography device and calculate the following EIT parameters: including the region of interest (ROI) ventilation percentage (ROI%), global inhomogeneity index (GI), center of ventilation (CoV), end-expiratory lung impedance difference (ΔEELI), tidal impedance variation (TIV), and ventilation-perfusion matching index (LPB / HPB index, LHI).

[0012] The efficacy evaluation module is used to evaluate the efficacy of pulmonary rehabilitation based on the calculated parameters. The efficacy evaluation module is equipped with an efficacy comparison unit, which is preset with a threshold range for the change value of the EIT parameter. When the parameter value falls within this range, the efficacy parameter is selected.

[0013] The efficacy assessment module evaluates the short-term efficacy and duration of combined phrenic nerve-abdominal muscle electrical stimulation using EIT parameters at the time points before and after electrical stimulation treatment, and at 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, and 50 min after treatment.

[0014] The early warning module issues warnings based on a set threshold range and parameter change trend. When the parameter exceeds the threshold range or exhibits an abnormal change trend, it issues an early warning signal.

[0015] The early warning module also includes a feedback mechanism, which, after issuing an early warning signal, provides feedback to the efficacy module and the timeliness module based on the early warning level and the patient's real-time status.

[0016] As a preferred technical solution, the efficacy assessment module specifically evaluates the efficacy of pulmonary rehabilitation by combining EIT evaluation parameters and clinical scoring parameters.

[0017] As a preferred technical solution, the output end of the efficacy evaluation module is also equipped with an efficacy data analysis module. The efficacy data analysis module analyzes EIT parameters and clinical score parameters before treatment and at the 2-week treatment time point. After analysis, the efficacy data analysis module shows that the ROI% and COV in the gravity-dependent area both increased significantly, while the GI index decreased significantly.

[0018] As a preferred technical solution, the output end of the timeliness assessment module is also equipped with a timeliness data analysis module. The timeliness data analysis module dynamically captures timeliness and accurately depicts the change trajectory of gravity-dependent region ROI% and CoV parameters every minute within 50 minutes after stimulation. After stimulation ends, the change trajectory shows that gravity-dependent region ROI% and CoV achieve significant improvement, reaching a peak, and then gradually weakens, weakening to the pre-treatment level 50 minutes after the end of treatment.

[0019] As a preferred technical solution, the stimulation parameters of the phrenic nerve electrical stimulation module during inspiratory phase electrical stimulation and the abdominal muscle electrical stimulation module during expiratory phase electrical stimulation are as follows: stimulation frequency 30-50Hz, single stimulation duration 1-2 seconds, pulse width 300μs, stimulation intensity gradually increased from the minimum intensity 0mA to the level tolerated by the patient or until the patient's muscle contraction can be felt, and each treatment lasts 15 minutes.

[0020] As a preferred technical solution, the phrenic nerve-abdominal muscle electrical stimulation module includes a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module, which provides synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, causing the diaphragm and abdominal muscles to contract regularly.

[0021] As a preferred technical solution, the parameters of the electrical impedance tomography device are taken as the average of 5 respiratory cycles, and the cycle with a relatively stable baseline is selected among the 5 respiratory cycles.

[0022] As a preferred technical solution, the phrenic nerve-abdominal muscle electrical stimulation module is equipped with 6 pairs of external electrodes to provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles.

[0023] The advantages of this invention are:

[0024] 1. This invention provides a real-time assessment system for pulmonary rehabilitation based on EIT parameters. In terms of pulmonary rehabilitation efficacy, it can effectively improve patients' pulmonary ventilation function. Regarding the timeliness of pulmonary rehabilitation, the real-time and quantitative assessment of timeliness characteristics provides a powerful objective tool for the precise implementation and effectiveness evaluation of passive pulmonary rehabilitation. Combined phrenic nerve-abdominal muscle electrical stimulation with EIT guidance holds promise as a powerful measure to improve the pulmonary rehabilitation outcomes of stroke patients with respiratory dysfunction.

[0025] 2. For the first time, electrical impedance tomography (EIT) was used to dynamically evaluate the immediate effects and time-dependent characteristics of combined phrenic nerve-abdominal muscle electrical stimulation (EIT) on pulmonary ventilation in patients. Key findings include: Electrical stimulation significantly improved the ROI% in the gravity-dependent area and optimized CoV, with this effect lasting approximately 50 minutes. This result not only validates the immediate improvement in pulmonary ventilation in the target population but also, for the first time, finely characterizes its unique short-term time-dependent pattern. Furthermore, EIT successfully achieved real-time, non-invasive, and quantitative monitoring of the dynamic evolution of therapeutic effects, fully demonstrating its practical value in evaluating the efficacy of passive pulmonary rehabilitation.

[0026] 3. The revealed time-to-effect characteristic of "peak effect after stimulation, lasting approximately 50 minutes" has significant clinical implications. Immediately after stimulation, a significant increase in ROI% and CoV in the gravity-dependent area was observed, indicating that phrenic-abdominal muscle electrical stimulation can rapidly induce coordinated contraction of the diaphragm and abdominal muscles. Enhanced diaphragmatic contraction directly increases overall ventilation and may promote alveolar re-expansion in the dorsal gravity-dependent area (reflected in an increased ROI%), while synchronous contraction of the abdominal muscles, by increasing intra-abdominal pressure, not only assists exhalation and promotes gas exchange but may also optimize the distribution of ventilation in the ventral-dorsal region (reflected in increased CoV levels and a shift of ventilation towards the dorsal-dependent area). This rapid onset of action is particularly important for stroke patients with respiratory dysfunction requiring immediate improvement in ventilation. The effect lasting approximately 50 minutes suggests that a single 15-minute stimulation can produce a therapeutic effect lasting nearly one hour, providing a direct basis for determining treatment intervals (e.g., once per hour), helping to optimize clinical treatment protocols and maximize rehabilitation benefits.

[0027] 4. Successfully applied EIT to the efficacy evaluation of phrenic-abdominal muscle electrical stimulation, highlighting its unique advantages: Dynamic capture of timeliness: EIT's high temporal resolution allows us to accurately depict the minute-by-minute changes in key parameters such as gravity-dependent region ROI% and CoV within 50 minutes after stimulation, which is impossible with traditional pulmonary function tests (such as pulmonary ventilation) or blood gas analysis. The clearly displayed "time to peak" and "duration of effect" in the results directly stem from EIT's continuous monitoring capabilities.

[0028] 5. Non-invasive bedside quantitative regional ventilation: EIT requires no active patient cooperation, has no radiation risk, and can be performed at the bedside, perfectly meeting the assessment needs of patients with respiratory dysfunction after stroke. The gravity-dependent area ROI% (quantitative improvement in gravity-dependent area ventilation) and CoV (quantitative shift in ventilation distribution center) indicators it provides objectively reflect the optimizing effect of phrenic-abdominal muscle electrical stimulation on regional ventilation distribution, which is difficult to reflect in overall lung function parameters.

[0029] 6. Unveiling the underlying physiological mechanism: The increase in the ROI% of the gravity-dependent area and the dorsal shift of CoV suggest that phrenic-abdominal muscle electrical stimulation may effectively promote ventilation in the dorsal gravity-dependent area, which is prone to collapse and hypoventilation in supine patients. Although the GI index (reflecting ventilation spatial heterogeneity) and ΔEELI (reflecting end-expiratory lung volume) did not show significant changes in this study, there were significant differences at specific time points, revealing that spatial heterogeneity changed to varying degrees within 50 minutes after stimulation, although this stimulation did not cause significant changes. Multiparameter analysis of EIT still provides a valuable perspective for understanding the mechanism of action of combined stimulation (such as improving ventilation / perfusion matching and reducing intrapulmonary shunting).

[0030] 7. It is equipped with an early warning module and a feedback mechanism. The early warning module can issue early warning signals in a timely manner based on the set thresholds and parameter change trends, reminding medical staff to pay attention to changes in the patient's lung function, detect potential risks in advance, help adjust the treatment plan in a timely manner, and reduce the risk of the patient's condition deteriorating. Attached Figure Description

[0031] Appendix Figure 1 This is a structural block diagram of a real-time lung rehabilitation assessment system based on EIT parameters according to the present invention.

[0032] Appendix Figure 2 This is a research and experimental technical roadmap for a real-time lung rehabilitation assessment system based on EIT parameters according to the present invention.

[0033] Appendix Figure 3 This is a diagram showing the distribution of lung ventilation levels and quadrants in the EIT (Extracorporeal Intake) system.

[0034] Appendix Figure 4 This is a distribution diagram of ΔEELI.

[0035] Appendix Figure 5 This is a graph of EIT evaluation parameters.

[0036] Appendix Figure 6 These are images showing the effects of lung rehabilitation before and after treatment.

[0037] Appendix Figure 7 This is an intentional representation of the time-dependent trajectory of the ROI% of the gravity-dependent region after electrical stimulation.

[0038] Appendix Figure 8 This is an intentional representation of the time-dependent trajectory of CoV in the ventilation center after electrical stimulation. Detailed Implementation

[0039] The present invention will now be further described with reference to the embodiments and the accompanying drawings.

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0042] In the description of the embodiments of the present invention, it should be noted that the terms "lower edge," "upper edge," "one end," "the other end," "front and back," "left and right," "lateral," and "longitudinal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances. Additionally, in this embodiment... Figure 4 , Figure 5 as well as Figure 6 The text content mentioned in the figure is system-provided text content and is unrelated to the technical solution of this invention. There is no need to understand the text content in the figure.

[0043] Please refer to Figure 1 , Figure 1 This is a structural block diagram of a real-time pulmonary rehabilitation assessment system based on EIT parameters according to the present invention. The real-time assessment system for pulmonary rehabilitation based on EIT parameters includes:

[0044] The phrenic nerve-abdominal muscle electrical stimulation module is used to electrically stimulate the patient's phrenic nerve and abdominal muscles. Six pairs of external electrodes provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, causing regular contractions of these muscles. During treatment, the patient lies supine. The phrenic nerve stimulation electrode and reference electrode are placed on the lower third of the outer edge of the sternocleidomastoid muscle on both sides of the neck and on the surface of the pectoralis major muscle, respectively. The rectus abdominis muscle stimulation electrode and reference electrode are placed on the abdominal muscle in the middle of the lower edge of the ribs and on the abdominal muscle at the upper edge of the pubic symphysis, respectively. The external oblique muscle stimulation electrode and reference electrode are placed at the intersection of the outer edges of the rectus abdominis muscle and the umbilicus level, and at the intersection of the midaxillary lines and the umbilicus level, respectively.

[0045] Electrical impedance tomography (EIT) is used to monitor changes in pulmonary electrical impedance in patients in real time. The effect of this design is to non-invasively quantify regional ventilation status. EIT requires no active patient cooperation, has no radiation risk, and can be performed at the bedside, perfectly meeting the assessment needs of patients with respiratory dysfunction after stroke. The gravity-dependent area of ​​origin (ROI%) and CoV (quantitative ventilation center shift) indicators it provides objectively reflect the optimizing effect of phrenic-abdominal muscle electrical stimulation on regional ventilation distribution, which is difficult to reflect in overall pulmonary function parameters.

[0046] The data processing module receives pulmonary electrical impedance data monitored by the EIT device and calculates the following parameters: gravity-dependent region of interest (ROI%), GI index, CoV, and ΔEELI. The EIT pulmonary ventilation impedance tomographic images are artificially divided into four parallel regions, or custom regions of interest (ROIs), according to a hierarchical distribution from ventral to dorsal. These ROIs are categorized as ROI1, ROI2, ROI3, and ROI4. This study primarily observes the percentage of the total area occupied by the sum of gravity-dependent regions ROI3 and ROI4, used to observe changes in pulmonary ventilation in the gravity-dependent region before and after electrical stimulation. The GI index is the dispersion of tidal impedance changes at each pixel calculated by EIT, reflecting the spatial heterogeneity of regional pulmonary ventilation. The GI index is highly correlated with the degree of alveolar opening. A smaller GI index indicates more uniform overall pulmonary ventilation. CoV refers to the ventilation center calculated based on the weighted average of the changes in tidal resistance of each pixel in spatial location. It aims to quantify the changes in ventilation distribution in the vertical direction along the ventral and dorsal sides. A value less than 50% indicates preferential distribution of ventilation towards the ventral region, while a larger ratio indicates a greater proportion of preferential distribution towards the dorsal region. ΔEELI is the difference in end-expiratory impedance between two respiratory cycles, primarily reflecting changes in end-expiratory lung volume. Since changes in end-expiratory lung volume and ΔEELI increase linearly, monitoring pre- and post-ΔEELI can measure changes in end-expiratory lung volume between two time points.

[0047] The efficacy assessment module is used to evaluate the efficacy of pulmonary rehabilitation based on the calculated parameters. This module includes an efficacy comparison unit. The comparison unit has a preset threshold range for the change values ​​of the EIT parameters. When a parameter value falls within this range, the efficacy parameter is selected. For example, if the efficacy change value of the gravity-dependent area ROI% is greater than 6.25±0.63, then the gravity-dependent area ROI% is selected as a significant efficacy parameter. More specifically, if the patient's gravity-dependent area ROI% value is 39.73±10.63 after 0 weeks of electrical stimulation and 49.46±10.39 after 2 weeks, the efficacy comparison unit automatically matches the patient's gravity-dependent area change value to 9.73±0.24. This change value is greater than the threshold of 6.25±0.63, and the efficacy assessment module selects the gravity-dependent area ROI% as an efficacy parameter. Other parameters are judged using the same threshold method, which will not be repeated here. The effect of this design is to enable the quantification of reference indicators for pulmonary rehabilitation efficacy, namely, indicators such as ROI% in gravity-dependent areas (quantifying the improvement in ventilation in gravity-dependent areas) and CoV (quantifying the shift of the ventilation distribution center).

[0048] The time-efficacy assessment module records the short-term efficacy and duration of combined phrenic nerve-abdominal muscle electrical stimulation (EIT) at 5 minutes before and 0, 5, 10, 15, 20, 30, 40, and 50 minutes after treatment, using EIT parameters (gravity-dependent area ROI%, GI index, CoV, and ΔEELI distribution map). The advantage of this design is that the high temporal resolution of the time-efficacy assessment module allows us to accurately depict the minute-by-minute changes in key parameters such as gravity-dependent area ROI% and CoV within 50 minutes after stimulation, which is impossible with traditional pulmonary function tests (such as spirometry) or blood gas analysis. The clearly displayed "time to peak" and "duration of effect" in the results directly stem from the continuous monitoring capability of EIT.

[0049] The efficacy assessment module specifically assesses the efficacy of pulmonary rehabilitation by combining EIT evaluation parameters and clinical scoring parameters before phrenic nerve-abdominal muscle electrical stimulation treatment.

[0050] The efficacy assessment module also includes an efficacy data analysis module at its output. This module analyzes EIT parameters and clinical scoring parameters before treatment and at two weeks post-treatment, revealing a significant increase in ROI% and COV in the gravity-dependent area, and a significant decrease in the GI index. The design reveals a potential physiological mechanism: the increase in ROI% in the gravity-dependent area and the dorsal shift of CoV suggest that phrenic-abdominal muscle electrical stimulation may effectively promote ventilation in the dorsal gravity-dependent area, which is prone to collapse and hypoventilation in supine patients. While the GI index (reflecting ventilation homogeneity) and ΔEELI (reflecting end-expiratory lung volume) did not show significant changes in this study, significant differences were observed at specific time points, revealing varying degrees of change in spatial heterogeneity within 50 minutes after stimulation, although this stimulation did not cause significant changes initially. Multi-parameter analysis of EIT still provides a valuable perspective for understanding the mechanisms of action of combined stimulation (such as improving ventilation / perfusion matching and reducing intrapulmonary shunting).

[0051] The output of the time-effect assessment module is also equipped with a time-effect data analysis module. The time-effect data analysis module records the short-term efficacy and duration of the combined phrenic nerve-abdominal muscle electrical stimulation 5 minutes before and after the treatment (0 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min) using EIT parameters (ROI% of gravity-dependent area, GI index, CoV, ΔEELI distribution map). It concludes that the electrical stimulation can effectively promote ventilation in the dorsal gravity-dependent area.

[0052] The timeliness data analysis module dynamically captures the timeliness of data, accurately depicting the minute-by-minute changes in key parameters such as ROI% and CoV in the gravity-dependent area within 50 minutes after stimulation. After stimulation, the changes show a significant improvement in ROI% and CoV in the gravity-dependent area (the criteria for significant improvement are: when ROI% and CoV in the ventilation distribution center reach their peak values ​​after stimulation, the changes exceed 3%-5%, and the changes from the peak values ​​to the pre-treatment levels also exceed 3%-5%; for example, a significant improvement is defined as an increase of more than 3 percentage points in ROI% within 5 minutes after stimulation and a decrease of no more than 5 percentage points within 40 minutes after stimulation; a significant improvement is also defined as an increase of more than 3 percentage points in CoV within 5 minutes after stimulation and a decrease of no more than 5 percentage points within 40 minutes after stimulation). This effect peaks at the end of stimulation and then gradually weakens, returning to pre-stimulation levels in approximately 50 minutes. The effect of this design is that a significant increase in ROI% and CoV in the gravity-dependent area is observed immediately after stimulation, indicating that phrenic-abdominal muscle electrical stimulation can rapidly induce coordinated contraction of the diaphragm and abdominal muscles. Enhanced diaphragmatic contraction directly increases overall ventilation and may promote alveolar recruitment in the dorsal gravity-dependent area (reflected in an increased ROI%). Synchronous abdominal muscle contraction, by increasing intra-abdominal pressure, not only assists exhalation and promotes gas exchange but may also optimize ventilation distribution in the ventrodorsolateral region (reflected in elevated CoV levels and a shift of ventilation towards the dorsal region). This rapid onset of action is particularly important for stroke patients with respiratory dysfunction requiring immediate improvement in ventilation. The effect lasting approximately 50 minutes suggests that a single 15-minute stimulation can produce a therapeutic effect lasting nearly one hour, providing a direct basis for determining treatment intervals (e.g., once per hour), helping to optimize clinical treatment protocols and maximize rehabilitation benefits.

[0053] The early warning module issues warnings based on a set threshold range and parameter change trends. When a parameter exceeds the threshold range or exhibits an abnormal change trend, an early warning signal is issued. Specifically, the early warning module sets thresholds and parameter change trends. Data from the efficacy evaluation data analysis module and the timeliness evaluation data analysis module are compared with these thresholds and parameter change trends to determine whether to issue an early warning signal. The effect of this design is that the early warning module can promptly issue warning signals based on set thresholds and parameter change trends, reminding medical staff to pay attention to changes in the patient's lung function, detect potential risks early, help adjust treatment plans in a timely manner, and reduce the risk of the patient's condition worsening.

[0054] The early warning module also includes a feedback mechanism, which provides corresponding feedback suggestions to medical staff based on the early warning level and the patient's real-time status after an early warning signal is issued. These feedback suggestions include, but are not limited to:

[0055] 1. In the efficacy assessment module, re-acquire the EIT parameters and clinical score parameters;

[0056] 2. In the time-effect assessment module, the timing is readjusted before and at the end of electrical stimulation treatment, and the EIT parameters are used to evaluate the short-term efficacy and duration of combined phrenic nerve-abdominal muscle electrical stimulation.

[0057] The technical effect of the above solution is that, upon the occurrence of an early warning, targeted feedback suggestions are generated based on the warning signal and the patient's real-time status. These feedback suggestions are specific and practical, guiding medical staff to take timely measures.

[0058] The stimulation parameters for the phrenic nerve electrical stimulation module during inspiratory phase and the abdominal muscle electrical stimulation module during expiratory phase are as follows: stimulation frequency 30-50Hz, single stimulation duration 1-2 seconds, pulse width 300μs, and stimulation intensity gradually increased from the minimum intensity of 0mA until the patient's tolerance is reached or muscle contraction can be felt. Each treatment lasts 15 minutes. The advantages of this design are: these stimulation parameters have been validated through numerous clinical trials, and the electrical stimulation effect is best under these parameters; secondly, the use of inspiratory and expiratory electrical stimulation achieves synergistic stimulation, providing a synergistic compensatory effect (while existing technologies only provide single-phase stimulation and lack synergistic compensatory effects); and thirdly, the design is based on the patient's respiratory cycle, minimizing interference caused by the patient's breathing.

[0059] The phrenic-abdominal muscle electrical stimulation module comprises a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module, providing synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, resulting in rhythmic contractions of both. The design demonstrated a synergistic effect from the combined stimulation, with rapid and significant improvement in dorsal ventilation (increased ROI% and CoV in the gravity-dependent area), supporting the potential synergistic effect of phrenic-abdominal muscle electrical stimulation. Phrenic nerve electrical stimulation alone primarily enhances inspiratory and overall ventilation, with limited effect on optimizing expiratory and ventrodorsolateral ventilation distribution; abdominal muscle electrical stimulation alone mainly affects expiratory and airway clearance. The simultaneous improvement in gravity-dependent ventilation and optimized dorsal ventilation distribution observed in this study suggest that the temporal coordination of diaphragmatic inspiratory contraction and abdominal expiratory contraction is crucial. This coordination mimics physiological respiratory pump activity, more effectively mobilizing the ventilation potential of the gravity-dependent area.

[0060] In addition, the phrenic nerve-abdominal muscle electrical stimulation module includes a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module. The phrenic nerve electrical stimulation module works during the inspiratory phase, stimulating the phrenic nerve to cause regular contraction of the diaphragm, thereby enhancing the patient's inspiratory capacity. The abdominal muscle electrical stimulation module works during the expiratory phase, stimulating the abdominal muscles and enhancing the patient's expiratory capacity. Each phrenic nerve-abdominal muscle electrical stimulation treatment lasts for 15 minutes, and a single respiratory cycle of electrical stimulation includes both inspiratory and expiratory phases. During the inspiratory phase, the phrenic nerve electrical stimulation module stimulates the phrenic nerve, causing regular contraction of the diaphragm. Simultaneously, the module issues an "inhale" command, and the patient performs voluntary inhalation. The stimulation frequency is 30-50 Hz, the duration of a single stimulation is 1-2 seconds, the pulse width is 300 μs, and the stimulation intensity gradually increases from the minimum intensity of 0 mA until the patient's tolerance is reached or muscle contraction is palpable. This stimulates the phrenic nerve, causing regular diaphragm contraction and enhancing the patient's inspiratory capacity. During the expiratory phase, the abdominal muscle electrical stimulation module stimulates the abdominal muscles, causing regular contraction. Simultaneously, the module issues an "exhale" command, and the patient performs voluntary exhalation. The stimulation frequency is 30-50 Hz, the duration of a single stimulation is 1-2 seconds, the pulse width is 300 μs, and the stimulation intensity gradually increases from the minimum intensity of 0 mA until the patient's tolerance is reached or muscle contraction is palpable. This stimulates the abdominal muscles and enhances the patient's expiratory capacity.

[0061] The EIT parameters of the electrical impedance tomography (EIT) device were taken as the average of five respiratory cycles, with the cycle showing a relatively stable baseline selected. The EIT device is equipped with EIT electrode straps, the position of which significantly affects the electrical impedance imaging. The EIT electrode straps are typically installed in the 4th-5th intercostal space, but this position can be adjusted upwards when the diaphragm is elevated. The intercostal plane and patient position are noted for each EIT monitoring session, such as the nipple plane or 2 cm above or below the nipple, with the head of the bed elevated 30 degrees. For multiple dynamic measurements of a single patient, the electrode strap positions are marked on the body surface to ensure assessment is performed at the same plane.

[0062] The phrenic nerve-abdominal muscle electrical stimulation module is equipped with 6 pairs of external electrodes to provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles.

[0063] It should be noted that:

[0064] This study confirms that combined phrenic-abdominal muscle electrical stimulation can rapidly (onset immediately after treatment) and effectively (lasting approximately 50 minutes) improve regional pulmonary ventilation in stroke patients with respiratory dysfunction, particularly optimizing ventilation in gravity-dependent areas and ventricular-dorsal ventilation distribution. Electrical impedance tomography (EIT), as a non-invasive, bedside, and dynamic monitoring technique, successfully enabled real-time, quantitative assessment of the time-dependent characteristics of this therapeutic effect, providing a powerful objective tool for the precise implementation and efficacy evaluation of passive pulmonary rehabilitation. Phrenic-abdominal muscle electrical stimulation combined with EIT guidance holds promise as a novel strategy for improving pulmonary rehabilitation outcomes in stroke patients with respiratory dysfunction.

[0065] To verify the efficacy and timeliness of the real-time lung rehabilitation assessment system of this invention, the applicant conducted relevant clinical experiments. Please refer to... Figure 2 , Figure 2 This is a research and experimental technical roadmap for a real-time lung rehabilitation assessment system based on EIT parameters according to the present invention.

[0066] Experimental Example 1: Evaluation of Therapeutic Effect

[0067] Eighteen stroke patients admitted to the Department of Rehabilitation Medicine, First Affiliated Hospital of Chongqing Medical University, between September and December 2024, and meeting the inclusion and exclusion criteria were selected as the study subjects in chronological order of admission. Inclusion criteria: ① Age 18–80 years; ② Meets the diagnostic criteria for stroke in the "Chinese Guidelines for the Diagnosis and Treatment of Cerebral Hemorrhage 2019" and the "Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018", and confirmed as stroke by cranial CT or MRI; ③ All were first-time stroke patients with stable vital signs and Glasgow Coma Scale (GCS) scores ≥9; ④ Unable to perform active breathing training, or able to perform active breathing training but with maximum inspiratory pressure <30% of predicted value; ⑤ Informed consent from the patient or their family. Exclusion criteria: ① Pneumothorax; ② Active pulmonary tuberculosis; ③ Wearing a pacemaker or other electrical stimulation modules; ④ Malignant tumor; ⑤ Primary lung disease; ⑥ Severe heart, liver, or kidney disease; ⑦ Severe cognitive impairment or mental disorder preventing cooperation; ⑧ Unhealed wounds after thoracic or abdominal surgery; ⑨ Requires ventilator support; ⑩ Pregnant or lactating women; Electrode pad allergy; Participants were assigned to other studies outside of this study. They were randomly assigned to a control group (6 cases) and an experimental group (12 cases) using a computer-generated random number table (see Table 1). The control group received routine pulmonary rehabilitation treatment; the experimental group received routine pulmonary rehabilitation treatment plus phrenic nerve-abdominal muscle electrical stimulation. Specific protocols are as follows:

[0068] (1) Treatment methods

[0069] ① Control group: routine pulmonary rehabilitation and other functional training.

[0070] A. Routine pulmonary rehabilitation training

[0071] a. Airway clearance therapy: mainly using techniques such as vibration and tapping. Each session lasts 10 minutes, once a day, 5 days a week, for 2 weeks.

[0072] b. Postural drainage: Referring to chest X-ray, monitor the effect of pulmonary secretion clearance by blood oxygenation. Position the affected lung in a high position with the opening of its draining bronchus facing downward. This will encourage sputum to be coughed up by gravity through the trachea, thus aiding in sputum drainage. Each session lasts 10 minutes, once a day, 5 days a week, for 2 weeks.

[0073] B. Other functional training: including early posture management, joint mobility, etc.

[0074] ②Experimental group: In addition to the treatment of the control group, phrenic nerve-abdominal muscle electrical stimulation was added.

[0075] A. Instruments:

[0076] Phrenic nerve-abdominal muscle electrical stimulation uses six pairs of external electrodes to provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, causing the diaphragm and abdominal muscles to contract rhythmically.

[0077] B. Operating Procedures:

[0078] During treatment, the patient lies down. The diaphragm stimulation electrode and reference electrode are placed on the lower 1 / 3 of the outer edge of the sternocleidomastoid muscle on both sides of the patient's neck and on the surface of the pectoralis major muscle, respectively. The rectus abdominis stimulation electrode and reference electrode are placed on the abdominal muscle in the middle of the lower edge of the ribs and on the abdominal muscle at the upper edge of the pubic symphysis, respectively. The external oblique muscle stimulation electrode and reference electrode are placed at the intersection of the outer edges of the rectus abdominis muscle and the horizontal line at the level of the umbilicus on both sides and at the intersection of the midaxillary line and the horizontal line at the level of the umbilicus on both sides, respectively.

[0079] C. Treatment prescription:

[0080] As a preferred method: stimulation frequency of 40Hz, single stimulation duration of 2 seconds, pulse width of 300μs, stimulation intensity gradually increased from the minimum intensity of 0mA until the patient's tolerance is reached or muscle contraction can be felt, each treatment lasting 15 minutes. Once a day, 7 days a week, for 2 weeks.

[0081] (2) Evaluation of Results

[0082] The two groups were compared and analyzed before and 2 weeks after phrenic nerve-abdominal muscle electrical stimulation (PHS) treatment. The parameters of EIT, SCSS, coagulation, antibiotic use, lung CT, blood oxygen saturation, CPIS, presence of deep vein thrombosis in the lower extremities, and pulmonary infection rate were compared and analyzed. The occurrence of adverse events was also analyzed to explore the efficacy and safety of phrenic nerve-abdominal muscle electrical stimulation in pulmonary rehabilitation of tracheotomy patients.

[0083] Key indicators: EIT parameters (Gravity-dependent region ROI%, GI index, CoV, ΔEELI distribution map).

[0084] Secondary indicators: SCSS, blood oxygen saturation, CPIS and pulmonary infection rate.

[0085] Safety indicators: Whether any adverse events occurred during the process.

[0086] ①EIT Evaluation

[0087] EIT evaluation parameters included gravity-dependent region of interest (ROI%), GI index, CoV, and ΔEELI. EIT evaluations at each time point were performed in both groups prior to combined phrenic nerve-abdominal muscle electrical stimulation.

[0088] A. ROI and ROI% in the gravity-dependent region

[0089] EIT lung ventilation impedance tomography images are divided into regions according to the "layered distribution from ventral to dorsal" and the "four-quadrant distribution with the image center as the origin." The EIT lung ventilation images are artificially divided into four parallel regions or quadrants, i.e., customized regions of interest (ROIs). That is, the lung ventilation images can be divided into ROI1, ROI2, ROI3, and ROI4 (see...). Figure 3 Each ROI's coverage area is displayed by a corresponding regional impedance waveform. This waveform shows the sum of impedance changes within a specific ROI and allows for comparison of impedance changes across different lung regions, presenting the regional ventilation distribution of the lungs. For a selected ROI, ROI% = (selected region impedance change / global impedance change) × 100% (i.e., ROI = regional ventilation volume / total ventilation volume × 100%). Therefore, within a customized region of interest, ROI1% + ROI2% + ROI3% + ROI4% = 100%.

[0090] In clinical practice, ROI1-ROI2 are generally considered to be non-gravity-dependent areas, while ROI3-ROI4 are considered gravity-dependent areas (i.e., ROI% of gravity-dependent areas = ROI3% + ROI4%). When a patient's body position changes, it can lead to changes in ventilation in the gravity-dependent areas of the lungs, thereby affecting the overall and local ventilation distribution of the lungs.

[0091] B. GI Index

[0092] The GI index is the dispersion of tidal impedance changes at each pixel, calculated using EIT, and is used to reflect the spatial heterogeneity of regional lung ventilation. The GI index is highly correlated with the degree of alveolar opening in a given area. The smaller the GI index, the more uniform the overall ventilation within the lungs.

[0093] C, CoV

[0094] CoV refers to the ventilation center calculated based on the weighted average of the changes in tidal resistance of each pixel in spatial location. It aims to quantify the changes in ventilation distribution in the vertical direction of the ventral and dorsal sides. A value less than 50% means that ventilation is preferentially distributed towards the ventral region, and an increase in the ratio indicates that the proportion of ventilation preferentially distributed towards the dorsal region is increasing.

[0095] D、ΔEELI

[0096] ΔEELI is the difference in end-expiratory impedance between two points in the respiratory cycle, primarily reflecting changes in end-expiratory lung volume. Since the change in end-expiratory lung volume increases linearly with ΔEELI, the change in end-expiratory lung volume between two points can be measured by monitoring ΔEELI before and after the expiration. To illustrate regional variations, the ΔEELI value of each pixel is represented by different color levels. When ΔEELI > 0, it is represented by blue; when ΔEELI < 0, it is represented by orange; and the portion where ΔEELI = 0 is represented by black. The brighter the color, the larger the absolute value of the relative rate of change of ΔEELI. Figure 4 ).

[0097] The EIT evaluation parameters are taken as the average of 5 respiratory cycles (e.g., Figure 5 To exclude interfering waves, we selected cycles with relatively stable baselines within 5 respiratory cycles; cycles showing significant elevation or depression were excluded. Furthermore, the position of the EIT electrode straps significantly affects electrical impedance imaging. The EIT electrode straps are typically placed in the 4th-5th intercostal space, but this position can be appropriately raised when the diaphragm is elevated. The intercostal plane and patient position are noted for each EIT monitoring session, such as the nipple plane or 2 cm above or below the nipple, with the head of the bed elevated 30 degrees. For multiple dynamic measurements of a single patient, the electrode strap positions are marked on the body surface to ensure assessment at the same plane.

[0098] ②SCSS scoring

[0099] SCSS is a method where assessors observe the intensity of a patient's cough and convert the results into a score for evaluation. Patients are instructed to cough as many times as possible. Assessments are conducted before and 2 weeks after diaphragmatic-abdominal muscle electrical stimulation (DES) treatment in both groups. Cough intensity is assessed on a scale of 0 to 5, from weak to strong. 0-2 points are weak, and 3-5 points are strong.

[0100] ③ Coagulation function

[0101] The coagulation status of patients was observed by D-dimer testing, and the results were assessed at two time points before and two weeks after diaphragmatic-abdominal muscle electrical stimulation treatment in both groups.

[0102] ④ Lung CT

[0103] Assessments were conducted before and 2 weeks after diaphragmatic-abdominal muscle electrical stimulation treatment in both groups.

[0104] ⑤ Blood oxygen saturation

[0105] Assessments were conducted before and 2 weeks after diaphragmatic-abdominal muscle electrical stimulation treatment in both groups.

[0106] ⑥CPIS score

[0107] The Clinical Pulmonary Infection Score (CPIS) is a scoring system that integrates clinical, imaging, and microbiological criteria to assess the severity of infection and predict whether antibiotic use should be adjusted or discontinued. Assessments were conducted in both groups before and 2 weeks after diaphragmatic-abdominal muscle electrical stimulation (DES) treatment.

[0108] ⑦ Lung infection rate

[0109] Lung infection rate = (Number of people with lung infections / Total number of people) × 100%.

[0110] (3) Comprehensive data analysis

[0111] The two groups were compared and analyzed before treatment and at 2 weeks post-treatment, comparing EIT parameters, coagulation, lung CT, SCSS, antibiotic use, blood oxygen saturation, CPIS, presence of lower extremity deep vein thrombosis, and pulmonary infection rate to explore the efficacy of phrenic nerve-abdominal muscle electrical stimulation (EELI) in pulmonary rehabilitation of stroke patients. It was expected that the experimental group would show a significant increase in ROI% and COV in the gravity-dependent region, a significant decrease in GI, and that the ΔEELI distribution map would effectively reflect changes in end-expiratory lung volume. The experimental group showed better clinical scores (SCSS, CPIS, etc.) than the control group.

[0112] Table 1 General Information

[0113]

[0114] Table 2 Changes in EIT data at weeks 0 and 2 of treatment.

[0115]

[0116] Note: Gravity-dependent region ROI%: Percentage of gravity-dependent region; GI index: Ventilation heterogeneity index, reflecting regional ventilation distribution; COV: Ventilation center, reflecting dorsal ventilation; ΔEELI: End-expiratory lung impedance difference, measuring the change in end-expiratory lung volume between two time points; Compared with pre-treatment levels in the same group a P < 0.05.

[0117] Results: 1. There were no significant differences in baseline data such as age, height, weight, and EIT parameters between the two groups before treatment. Two weeks after treatment: ① Both groups showed significantly higher ROI% and COV in the gravity-dependent area than before treatment (P < 0.05), while other EIT parameters (GI index, ΔEELI) showed no significant differences; ② The experimental group had higher ROI% and COV in the gravity-dependent area than the control group, which was directly observed in the images from the electrical impedance tomography (EIT) device, demonstrating its therapeutic effect (see...). Figure 6 1. However, the difference was not statistically significant (P>0.05); 2. The efficacy parameters can be screened by the changes in EIT parameters before and after patient stimulation. For example, when the efficacy change value of the gravity-dependent area ROI% is greater than 6.25±0.63, the gravity-dependent area ROI% is selected as a significant efficacy parameter. In this embodiment, the value of the gravity-dependent area ROI% of the patient at 0 weeks of electrical stimulation is 39.73±10.63; the value of the gravity-dependent area ROI% of the patient at 2 weeks of electrical stimulation is 49.46±10.39. The efficacy comparison unit automatically matches the patient's gravity-dependent area change value as 9.73±0.24. This change value is greater than the threshold of 6.25±0.63, so the efficacy assessment module selects the gravity-dependent area ROI% as an efficacy parameter.

[0118] Conclusion: Phrenic nerve-abdominal muscle electrical stimulation for 2 weeks has a potential impact on local ventilation distribution in the gravity-dependent area of ​​stroke patients.

[0119] The effect of electrical stimulation on clinical scores (see Table 3)

[0120] Table 3. Data changes in clinical scores due to electrical stimulation.

[0121]

[0122] Note: GCS score: Disorders of consciousness score; S5Q score: Standardized 5-question score; SCSS score: Semi-quantitative cough score; CPIS score: Severity of lung infection score.

[0123] Results: There were no significant differences in GCS, S5Q, SCSS, and CPIS scores (P > 0.05).

[0124] Experiment Example 2: Evaluation of Timeliness

[0125] 2.1 General Information

[0126] Thirty-five stroke patients admitted to the Department of Rehabilitation Medicine of the First Affiliated Hospital of Chongqing Medical University between January 2025 and July 2025 were selected in chronological order of admission.

[0127] Inclusion criteria: ① Age 18–80 years; ② Meets the diagnostic criteria for stroke as outlined in the "Chinese Guidelines for the Diagnosis and Treatment of Cerebral Hemorrhage 2019" and the "Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018," and is confirmed by cranial CT or MRI; ③ First-time onset of stroke, stable vital signs, Glasgow Coma Scale (GCS) score ≥9; ④ Unable to perform active breathing training, or able to perform active breathing training but with a maximum inspiratory pressure <30% of the predicted value; ⑤ Informed consent from the patient or their family.

[0128] Exclusion criteria: ① Pneumothorax; ② Active pulmonary tuberculosis; ③ Wearing a pacemaker or other electrical stimulation modules; ④ Malignant tumor; ⑤ Primary lung disease; ⑥ Severe heart, liver, or kidney disease; ⑦ Severe cognitive impairment or mental disorder preventing cooperation; ⑧ Unhealed wounds after thoracic or abdominal surgery; ⑨ Requires ventilator support; ⑩ Pregnant or lactating women; Electrode pad allergy; Participate in other studies besides this one.

[0129] 2.2 Methods

[0130] Phrenic nerve-abdominal muscle electrical stimulation uses six pairs of external electrodes to provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, causing the diaphragm and abdominal muscles to contract rhythmically.

[0131] During treatment, the patient lies down. The diaphragm stimulation electrode and reference electrode are placed on the lower 1 / 3 of the outer edge of the sternocleidomastoid muscle on both sides of the patient's neck and on the surface of the pectoralis major muscle, respectively. The rectus abdominis stimulation electrode and reference electrode are placed on the abdominal muscle in the middle of the lower edge of the ribs and on the abdominal muscle at the upper edge of the pubic symphysis, respectively. The external oblique muscle stimulation electrode and reference electrode are placed at the intersection of the outer edges of the rectus abdominis muscle and the horizontal line at the level of the umbilicus on both sides and at the intersection of the midaxillary line and the horizontal line at the level of the umbilicus on both sides, respectively.

[0132] The phrenic nerve-abdominal muscle electrical stimulation module includes a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module. The phrenic nerve electrical stimulation module operates during the inspiratory phase, stimulating the phrenic nerve to induce regular contractions of the diaphragm, thereby enhancing the patient's inspiratory capacity. The abdominal muscle electrical stimulation module operates during the expiratory phase, stimulating the abdominal muscles and enhancing the patient's expiratory capacity. Each phrenic nerve-abdominal muscle electrical stimulation treatment lasts for 15 minutes, and a single respiratory cycle includes both inspiratory and expiratory electrical stimulation. During the inspiratory phase, the phrenic nerve electrical stimulation module stimulates the phrenic nerve, causing regular contraction of the diaphragm. Simultaneously, the module issues an "inhale" command, and the patient performs voluntary inhalation. The stimulation frequency is 30-50 Hz, the duration of a single stimulation is 1-2 seconds, the pulse width is 300 μs, and the stimulation intensity gradually increases from the minimum intensity of 0 mA until the patient's tolerance is reached or muscle contraction is palpable. This stimulates the phrenic nerve, causing regular diaphragm contraction and enhancing the patient's inspiratory capacity. During the expiratory phase, the abdominal muscle electrical stimulation module stimulates the abdominal muscles, causing regular contraction. Simultaneously, the module issues an "exhale" command, and the patient performs voluntary exhalation. The stimulation frequency is 30-50 Hz, the duration of a single stimulation is 1-2 seconds, the pulse width is 300 μs, and the stimulation intensity gradually increases from the minimum intensity of 0 mA until the patient's tolerance is reached or muscle contraction is palpable. This stimulates the abdominal muscles and enhances the patient's expiratory capacity.

[0133] 2.3 Evaluation

[0134] The EIT parameters were taken as the average of five respiratory cycles. To exclude interfering waves, cycles with relatively stable baselines were selected; cycles showing significant elevation or depression were excluded. Furthermore, the position of the EIT electrode straps significantly affects impedance imaging. The EIT electrode straps are typically placed in the 4th-5th intercostal space, but this position can be appropriately raised when the diaphragm is elevated. The intercostal plane and patient position were noted for each EIT monitoring session, such as the nipple plane or 2 cm above or below the nipple, with the head of the bed elevated 30 degrees.

[0135] 2.3.1 ROI% in the Gravity-Dependent Region

[0136] The pulmonary ventilation impedance tomography (ERT) images were artificially divided into four parallel regions, or custom regions of interest (ROIs), based on a "layered distribution from ventral to dorsal." These ROIs are categorized as ROI1, ROI2, ROI3, and ROI4. This study primarily observes the percentage of the total area occupied by the sum of gravity-dependent regions ROI3 and ROI4, to assess changes in pulmonary ventilation in these regions before and after electrical stimulation.

[0137] 2.3.2 GI Index

[0138] The GI index is the dispersion of tidal impedance changes at each pixel, calculated using EIT, and is used to reflect the spatial heterogeneity of regional lung ventilation. The GI index is highly correlated with the degree of alveolar opening in a given area. The smaller the GI index, the more uniform the overall ventilation within the lungs.

[0139] 2.3.3 Ventilation Center CoV

[0140] CoV refers to the ventilation center calculated based on the weighted average of the changes in tidal resistance of each pixel in spatial location. It aims to quantify the changes in ventilation distribution in the vertical direction of the ventral and dorsal sides. A value less than 50% means that ventilation is preferentially distributed towards the ventral region, and an increase in the ratio indicates that the proportion of ventilation preferentially distributed towards the dorsal region is increasing.

[0141] 2.3.4 Changes in end-expiratory lung impedance ΔEELI

[0142] ΔEELI is the difference in end-expiratory impedance between two points in the respiratory cycle, primarily reflecting changes in end-expiratory lung volume. Since changes in end-expiratory lung volume and ΔEELI increase linearly, monitoring ΔEELI before and after expiration can be used to measure changes in end-expiratory lung volume between two points.

[0143] 2.4 Evaluation Time Points

[0144] Before treatment (T0), at the end of treatment (T1), 5 min after treatment (T2), 10 min after treatment (T3), 15 min after treatment (T4), 20 min after treatment (T5), 25 min after treatment (T6), 30 min after treatment (T7), 40 min after treatment (T8), 50 min after treatment (T9).

[0145] 2.5 Statistical Analysis

[0146] SPSS 25.0 software was used. The measurement data conformed to a normal distribution. Represented. Count data are expressed using x. 2 Tests were performed. One-way repeated measures ANOVA was used to compare all time points before and after treatment, with P < 0.05 considered statistically significant. Simple effects analysis was used to compare each parameter at different time points.

[0147] 3. Results

[0148] One-way repeated measures ANOVA showed that: (1) Time had a significant main effect on the ROI% of the gravity-dependent region (F = 7.003, P < 0.001). At T0, the ROI% of the gravity-dependent region was lower than that of T1-T5 (P < 0.05), at T1, the ROI% of the gravity-dependent region was higher than that of T2 and T4-T9 (P < 0.05), at T2, the ROI% of the gravity-dependent region was higher than that of T8 and T9 (P < 0.05), at T3, the ROI% of the gravity-dependent region was higher than that of T4-T9 (P < 0.05), and at T5, the ROI% of the gravity-dependent region was higher than that of T9 (P < 0.05); (2) Time had a significant main effect on COV (F = 5.722, P < 0.001). At T0, COV was lower than T1-T5 (P<0.05), at T1, COV was higher than T4-T9 (P<0.05), at T2, COV was higher than T9 (P<0.05), and at T3, COV was higher than T7-T9 (P<0.05); (3) The main effect of time on the GI index was not significant (F=1.849, P=0.097), but the differences in GI index at multiple time points between T1 and T9 were statistically significant. At T0, GI was higher than at T7 (P<0.05); at T1, GI was higher than at T7 (P<0.05); at T2, GI was higher than at T3 and T7 (P<0.05); at T4, GI was higher than at T5 (P<0.05); at T5, GI was lower than at T9 (P<0.05); at T7, GI was lower than at T8 and T9 (P<0.05); (4) The main effect of time on △EELI was not significant (F=0.208, P=0.871), and there were no statistically significant differences between time points (all P>0.05).

[0149] Table 4. Changes in EIT data at different time points

[0150]

[0151] Note: T0: before treatment, T1: after treatment, T2: 5 minutes after treatment, T3: 10 minutes after treatment, T4: 15 minutes after treatment, T5: 20 minutes after treatment, T6: 25 minutes after treatment, T7: 30 minutes after treatment, T8: 40 minutes after treatment, T9: 50 minutes after treatment.

[0152] Compared to T0, a P < 0.05; compared with T1, b P is less than 0.05; compared with T2, c P < 0.05; compared with T3, d P < 0.05; compared with T4, e P < 0.05; compared with T5, f P < 0.05; compared with T6, gP < 0.05; compared with T7, h P < 0.05; compared with T8, iP < 0.05; compared with T9, jP < 0.05;

[0153] At time T0, "-" represents the pre-treatment level of ΔEELI. The values ​​for T1-T9 are the differences between the end-tidal lung impedance value at that time and the pre-treatment level.

[0154] Reference Figure 7 and Figure 8 EIT monitoring revealed that phrenic-abdominal muscle electrical stimulation had a significant time-dependent effect on the ventilation distribution in the gravity-dependent area (the criteria for significant improvement were: a change of more than 3%-5% in the ROI% and CoV in the ventilation distribution center when they reached their peak after stimulation, and a change of more than 3%-5% in the value as they gradually decreased from the peak to the pre-treatment level; for example, a significant improvement was considered to be a change trajectory in the ROI% of the gravity-dependent area that increased by more than 3 percentage points within 5 minutes after stimulation and decreased by no more than 5 percentage points within 40 minutes after stimulation; a significant improvement was also considered to be a change trajectory in the CoV that increased by more than 3 percentage points within 5 minutes after stimulation and decreased by no more than 5 percentage points within 40 minutes after stimulation). The baseline value before treatment was (45.32±8.15), which showed a continuous upward trend during stimulation, reaching a peak of (49.71±8.72%) at the end of treatment. It then showed a gradual decline, recovering to (45.52±8.31) 50 minutes after treatment (P<0.05). Changes in CoV values ​​revealed a significant spatial redistribution of ventilation distribution: pre-treatment (48.96±4.75) shifted dorsally to (51.08±5.33) at the end of treatment (P<0.05). This shift corresponds to an increase in the ROI% of the gravity-dependent zone, confirming that electrical stimulation can promote a shift of ventilation toward the dorsal gravity-dependent zone.

[0155] 5. Conclusion

[0156] Phrenic-abdominal muscle electrical stimulation (PES) can rapidly (onset immediately after treatment) and effectively (lasting approximately 50 minutes) improve regional pulmonary ventilation in stroke patients, particularly optimizing ventilation distribution in gravity-dependent areas. Electrical impedance tomography (EIT), a non-invasive, bedside, and dynamic monitoring technique, has successfully enabled real-time, quantitative assessment of the time-dependent characteristics of this treatment, providing a powerful objective tool for the precise implementation and effectiveness evaluation of passive pulmonary rehabilitation. Combined PES with EIT guidance, phrenic-abdominal muscle electrical stimulation holds promise as a powerful measure to improve pulmonary rehabilitation outcomes in stroke patients with respiratory dysfunction.

[0157] The present invention provides a real-time assessment system for pulmonary rehabilitation based on EIT parameters. Its main function is to assess pulmonary function in terms of timeliness and to provide auxiliary assessment of the efficacy of pulmonary function. The combination of the two can assess the efficacy in real time and dynamically, providing an objective evaluation method for passive pulmonary rehabilitation. It has broad application prospects in clinical promotion and research on potential mechanisms.

[0158] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the principle of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A real-time assessment system for pulmonary rehabilitation based on EIT parameters, characterized in that, The aforementioned real-time rehabilitation efficacy assessment system includes: The phrenic nerve-abdominal muscle electrical stimulation module is used to electrically stimulate the patient's phrenic nerve and abdominal muscles. The phrenic nerve-abdominal muscle electrical stimulation module includes a phrenic nerve electrical stimulation module and an abdominal muscle electrical stimulation module. The phrenic nerve electrical stimulation module works during the inspiratory phase and issues an inspiratory command to perform inspiratory electrical stimulation. The abdominal muscle electrical stimulation module works during the expiratory phase and issues an expiratory command to perform expiratory electrical stimulation. The combination of inspiratory and expiratory electrical stimulation forms a single respiratory cycle electrical stimulation. Electrical impedance tomography equipment is used to monitor changes in the lung electrical impedance of patients in real time; The data processing module is used to receive lung electrical impedance data monitored by the electrical impedance tomography device and calculate the following parameters: gravity-dependent region ROI%, overall heterogeneity index GI, ventilation center CoV, end-expiratory lung impedance difference ΔEELI, tidal impedance change TIV, and ventilation-perfusion matching index LHI. The efficacy evaluation module is used to evaluate the efficacy of pulmonary rehabilitation based on the calculated parameters. The efficacy evaluation module is equipped with an efficacy comparison unit, which is preset with a threshold range for the change value of the EIT parameter. When the parameter value falls within this range, the efficacy parameter is selected. The efficacy assessment module evaluates the short-term efficacy and duration of combined phrenic nerve-abdominal muscle electrical stimulation using EIT parameters at the time points before and after electrical stimulation treatment, and at 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, and 50 min after treatment. The early warning module issues warnings based on a set threshold range and parameter change trend. When the parameter exceeds the threshold range or exhibits an abnormal change trend, it issues an early warning signal. The early warning module also includes a feedback mechanism, which, after issuing an early warning signal, provides feedback to the efficacy module and the timeliness module based on the early warning level and the patient's real-time status.

2. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The efficacy assessment module specifically evaluates the efficacy of pulmonary rehabilitation by combining EIT evaluation parameters and clinical scoring parameters.

3. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The output of the efficacy assessment module is also equipped with an efficacy data analysis module. The efficacy data analysis module analyzes EIT parameters and clinical score parameters before treatment and at the 2-week treatment time point. After analysis, the efficacy data analysis module shows that the ROI% in the gravity-dependent area and COV in the ventilation center both increased significantly, and the overall heterogeneity index (GI) decreased significantly.

4. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The output of the timeliness assessment module is also equipped with a timeliness data analysis module. The timeliness data analysis module dynamically captures timeliness and accurately depicts the change trajectory of gravity-dependent ROI% and ventilation center CoV parameters every minute within 50 minutes after stimulation. After stimulation, the change trajectory shows that the gravity-dependent ROI% and ventilation distribution center CoV have achieved significant improvement and reached a peak. Thereafter, the effect gradually weakens and weakens to the pre-treatment level 50 minutes after the end of treatment.

5. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The stimulation parameters for the phrenic nerve electrical stimulation module during inspiratory phase and the abdominal muscle electrical stimulation module during expiratory phase are as follows: stimulation frequency 30-50Hz, single stimulation duration 1-2 seconds, pulse width 300µs, stimulation intensity gradually increased from minimum intensity 0mA to the level tolerated by the patient or until the patient's muscle contraction can be felt, and each treatment lasts 15 minutes.

6. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The phrenic nerve-abdominal muscle electrical stimulation module provides synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles, causing the diaphragm and abdominal muscles to contract rhythmically.

7. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The parameters of the electrical impedance tomography (EIT) device are taken as the average of 5 respiratory cycles. Among the 5 respiratory cycles, the cycle with a relatively stable baseline is selected.

8. The real-time assessment system for pulmonary rehabilitation according to claim 1, characterized in that, The phrenic nerve-abdominal muscle electrical stimulation module is equipped with 6 pairs of external electrodes to provide synergistic feedback electrical stimulation to the phrenic nerve and abdominal muscles.

Images