Lung electrical impedance tomography physical model and use method thereof

Abstract

The invention belongs to the technical field of biological electromagnetic measurement and imaging, and discloses a lung electrical impedance imaging physical model and a using method thereof.The lung electrical impedance imaging physical model comprises an elastic conductive simulated thorax, the elastic conductive simulated thorax is provided with a top cover and a bottom cover, and the top cover is connected with a simulated airway; the simulated airway comprises a first bronchial duct, a second bronchial duct and a third bronchial duct, the first bronchial duct penetrates through the top cover and is in sealed connection with the top cover, the second bronchial duct and the third bronchial duct are located in the elastic conductive simulated thorax, and the upper ends of the second bronchial duct and the third bronchial duct are both communicated with the lower end of the first bronchial duct; the lower ends of the second bronchial canal and the third bronchial canal are connected with simulated lungs, and conductive layers are arranged on the surfaces of the simulated lungs. The lung ventilation impedance change process can be simulated, and EIT equipment of different manufacturers can be compatible.

Description

Technical Field

[0001] The present invention belongs to the technical field of bioelectromagnetic measurement and imaging, and in particular relates to a physical model of lung electrical impedance imaging and a method for using the same. Background Art

[0002] Electrical impedance tomography (EIT) technology enables noninvasive, dynamic, and continuous monitoring of impedance changes within the human body associated with physiological and pathological states. This technology has been clinically validated in the field of localized lung ventilation imaging, providing an innovative approach for the precise diagnosis and treatment assessment of respiratory diseases. During the exhibition, promotion, installation, commissioning, and operational demonstrations of EIT equipment, physical models are often required for device performance testing. Currently, mainstream test models include resistor networks (calibration plates) and water tank models, but both have significant limitations: they cannot visually replicate the dynamic impedance changes during lung ventilation, and their fixed electrode position, size, and number make them incompatible with EIT equipment from different manufacturers. Therefore, a physical model and supporting method for lung EIT imaging that can intuitively simulate the changes in lung ventilation impedance while also being simple, low-cost, and highly versatile is urgently needed. Summary of the Invention

[0003] To address the problems in the prior art, the present invention aims to provide a physical model for pulmonary electrical impedance tomography (EIT) and its use method. The present invention can simulate the change process of pulmonary ventilation impedance and is compatible with EIT equipment from different manufacturers.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows: A physical model for lung electrical impedance imaging includes an elastic conductive simulated thorax, which is provided with a top cover and a bottom cover. A simulated airway is connected to the top cover. The simulated airway includes a first bronchus, a second bronchus, and a third bronchus. The first bronchus passes through the top cover and is sealed to the top cover. The second and third bronchus are located inside the elastic conductive simulated thorax. The upper ends of the second and third bronchus are both connected to the lower end of the first bronchus. The lower ends of the second and third bronchus are both connected to simulated lungs. The surface of the simulated lungs is provided with a conductive layer.

[0005] Preferably, the elastic conductive simulated thorax is a hollow cylindrical structure.

[0006] Preferably, EIT electrode installation sites for installing EIT electrodes are evenly provided on the periphery of the elastic conductive simulated thorax.

[0007] Preferably, the elastic conductive simulated thorax is made of conductive rubber.

[0008] Preferably, the top cover has a threaded bottle mouth and a bottle cap connected to the threaded bottle mouth through a threaded structure, wherein the threaded bottle mouth is connected to the inner cavity of the elastic conductive simulated thorax, and the first bronchial duct passes through the bottle cap and is sealed to the bottle cap.

[0009] Preferably, the top cover is transparent.

[0010] Preferably, the simulated lung adopts an ellipsoidal elastic airbag, and a conductive layer is provided on the surface of the ellipsoidal elastic airbag.

[0011] Preferably, the simulated lung is detachably connected to the second bronchus and the third bronchus.

[0012] Preferably, the types of the simulated lung include normal lung simulated lung, local ventilation abnormality simulated lung, pneumothorax simulated lung and compliance abnormality simulated lung; Among them, the simulated lung with local ventilation abnormality is obtained by gluing together some areas of the simulated lung with normal lung; For the pneumothorax simulated lung, it is obtained by setting holes in the normal lung simulated lung; For the abnormal compliance simulated lung, a simulated lung with a thickness different from that of the normal lung simulated lung is used.

[0013] The present invention also provides a method for using the above-mentioned pulmonary electrical impedance imaging physical model, comprising the following steps: Injecting a conductive liquid into the inner cavity of the elastic conductive simulated thorax, wherein the liquid level of the conductive liquid is above the top of the simulated lung, and a preset distance is left between the liquid surface of the conductive liquid and the lower surface of the top cover; Injecting air into the first bronchus from one end of the first bronchus that is outside the elastic conductive simulated chest to expand the simulated lung, and controlling the change in the simulated lung volume by adjusting the injection pressure; On the outer wall of the elastic conductive simulated thorax, EIT electrodes of the EIT device are evenly arranged along the circumference of the elastic conductive simulated thorax. The EIT electrodes are within the height range of the simulated lung, and the EIT device is used for monitoring and imaging.

[0014] The present invention has the following beneficial effects: The present invention uses an elastic conductive simulated thorax to simulate the human thorax, and uses a simulated airway and a simulated lung to simulate the breathing process of the human lung. Since the surface of the elastic conductive simulated thorax and the simulated lung is provided with a conductive layer, when in use, a conductive liquid is injected into the elastic conductive simulated thorax so that the simulated lung (5) is immersed in the conductive liquid. In this way, the human chest environment can be simulated, and the electrical impedance changes caused by lung ventilation during the human breathing process can be dynamically simulated, thereby enabling the use of EIT equipment to monitor and image the physical model of the lung electrical impedance imaging of the present invention. In addition, since the elastic conductive simulated thorax is conductive, the EIT electrodes of the EIT equipment can be evenly placed on the outside of the elastic conductive simulated thorax, so that EIT equipment from different manufacturers can be well compatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the three-dimensional structure of the physical model of lung electrical impedance imaging in an embodiment of the present invention; Figure 2 Different types of simulated lungs in the embodiments of the present invention; Figure 3 This is a schematic diagram of the entirety of the elastic conductive simulated thorax, top cover, bottom cover, and simulated airway after they are connected in an embodiment of the present invention.

[0016] In the figure, 1-simulated airway, 2-bottle cap, 3-threaded bottle mouth, 4-top cover, 5-simulated lung, 6-elastic conductive simulated thorax, 7-EIT electrode installation site, 8-bottom cover, 9-normal lung simulated lung, 10-local ventilation abnormality simulated lung, 11-pneumothorax simulated lung, 12-compliance abnormality simulated lung. DETAILED DESCRIPTION

[0017] The present invention will be described below with reference to the accompanying drawings and embodiments. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0018] See also Figure 1 and Figure 3 The lung electrical impedance imaging physical model of this embodiment includes an elastic conductive simulated thorax 6, which is provided with a top cover 4 and a bottom cover 8. The top cover 4 is connected to a simulated airway 1, and the simulated airway 1 includes a first bronchus, a second bronchus, and a third bronchus. The first bronchus passes through the top cover 4 and is sealed with the top cover 4. The second bronchus and the third bronchus are located inside the elastic conductive simulated thorax 6. The upper ends of the second bronchus and the third bronchus are both connected to the lower end of the first bronchus. The lower ends of the second bronchus and the third bronchus are both connected to a simulated lung 5, and the surface of the simulated lung 5 is provided with a conductive layer.

[0019] The method for using the pulmonary electrical impedance imaging physical model in the above embodiment of the present invention includes the following steps: A conductive liquid is injected into the inner cavity of the elastic conductive simulated thorax 6. The liquid level of the conductive liquid is above the top of the simulated lung 5, and a preset distance is left between the liquid surface of the conductive liquid and the lower surface of the top cover 4. This distance ensures that the simulated lung 5 can be smoothly inflated later and can exert an elastic reaction on the simulated lung 5. The principle is that the cavity between the top of the conductive liquid and the lower surface of the top cover 4 will accommodate an air layer of a certain thickness. When the simulated lung 5 is inflated, the liquid level of the conductive liquid will rise due to the expansion of the simulated lung 5. At this time, the air layer will be compressed by the pressure of the conductive liquid. When the simulated lung 5 is deflated, the simulated lung 5 will be deflated smoothly due to the pressure of the conductive liquid and the rebound effect of the air layer. Through this principle, the human respiratory process is effectively simulated. Then, air is injected into the first bronchial tube from one end of the first bronchial tube, which is located outside the elastic conductive simulated thorax 6, to expand the simulated lung 5. The volume change of the simulated lung 5 is controlled by adjusting the injection pressure. In addition, by injecting air and inhaling air at a preset frequency, the simulated lung 5 can be controlled to simulate the breathing process of the human lung. On the outer wall of the elastic conductive simulated thorax 6 , EIT electrodes of the EIT device are evenly arranged along the circumference of the elastic conductive simulated thorax 6 . The EIT electrodes are within the height range of the simulated lung 5 , and the EIT device is used for monitoring and imaging.

[0020] As a typical embodiment of the present invention, in this example, the elastic conductive simulated thorax 6 is a hollow cylindrical structure used to simulate the actual human thorax. The bottom cover 8 is fixedly connected (e.g., bonded) to the bottom of the elastic conductive simulated thorax 6 and seals the lower end of the elastic conductive simulated thorax 6. To ensure stability after the entire device is placed, the bottom cover 8 can also be fixed to a fixed bracket. In addition, the top cover 4 covers the upper end of the elastic conductive simulated thorax 6 and can seal the upper end of the elastic conductive simulated thorax 6. The top cover 4 can be fixedly connected (e.g., bonded) to the upper end of the elastic conductive simulated thorax 6, or it can be removably sealed (e.g., provided with a sealing strip on the lower surface of the top cover 4 for sealing with the upper end of the elastic conductive simulated thorax 6, and the top cover 4 and the elastic conductive simulated thorax 6 are connected by a quick clamp). This removable connection between the top cover 4 and the elastic conductive simulated thorax 6 facilitates replacement of the simulated lung 5 and the injection and removal of conductive liquid. Furthermore, a removable sealing connection between the simulated airway 1 and the top cover 4 can also be used to facilitate replacement of the simulated lung 5 and the injection and removal of conductive liquid.

[0021] As a preferred embodiment of the present invention, in this embodiment, the elastic conductive simulated thorax 6 is evenly provided with EIT electrode mounting sites 7 for mounting EIT electrodes. The provision of EIT electrode mounting sites 7 facilitates the positioning and mounting of EIT electrodes, thereby facilitating accurate test results.

[0022] As a preferred embodiment of the present invention, in this embodiment, the elastic conductive simulated thorax 6 can be made of conductive rubber. The conductive rubber has good elasticity and can better simulate the human thorax. At the same time, it also has conductivity and can meet the signal acquisition requirements of the EIT equipment.

[0023] As a preferred embodiment of the present invention, this embodiment can bond the top cover 4 to the elastic conductive simulated thorax 6, and set the simulated airway 1 and the top cover 4 to be in a detachable sealed connection. Specifically, the top cover 4 can be designed to have an upwardly protruding threaded bottle mouth 3 on its top surface and a bottle cap 2 connected to the threaded bottle mouth 3 via a threaded structure, wherein the threaded bottle mouth 3 is connected to the inner cavity of the elastic conductive simulated thorax 6, and the first bronchial tube passes through the bottle cap 2 and is sealed with the bottle cap 2. In the above structure, the bottle cap 2 is connected to the entire simulated airway 1 as an integral structure, and the bottle cap 2 and the threaded bottle mouth 3 can be easily disassembled and assembled, which also facilitates the installation and replacement of the simulated lung 5.

[0024] As a preferred embodiment of the present invention, in this embodiment, the top cover 4 is transparent, which makes it easy to observe the inner cavity of the elastic conductive simulated thorax 6 during the experiment, and is beneficial to the observation of the liquid level when the conductive liquid is injected and the inflation process of the simulated lung 5.

[0025] As a preferred embodiment of the present invention, in this embodiment, the simulated lung 5 uses an ellipsoidal elastic airbag with a conductive layer on its surface. This structure is simple and practical, and helps reduce equipment costs.

[0026] As a preferred embodiment of the present invention, in this embodiment, the simulated lung 5 is detachably connected to the second bronchus and the third bronchus, and the detachable connection method can be: 1. tying the mouth of the ellipsoidal elastic airbag with a rubber band; 2. setting the mouth of the ellipsoidal elastic airbag to the mouth structure of a balloon, and providing outer flanges at the ends of the second bronchus and the third bronchus, the outer edge diameter of the outer flange being larger than the diameter of the mouth of the ellipsoidal elastic airbag, and directly tightly fitting the mouth of the ellipsoidal elastic airbag to the ends of the second bronchus and the third bronchus when in use, and using the outer flanges at the ends of the second bronchus and the third bronchus to limit and fix the ellipsoidal elastic airbag.

[0027] As a preferred embodiment of the present invention, see Figure 2 In this embodiment, the types of simulated lungs 5 ​​include normal lung simulated lung 9, local ventilation abnormality simulated lung 10, pneumothorax simulated lung 11 and compliance abnormality simulated lung 12; The simulated lung 10 with local ventilation abnormality is obtained by gluing together a portion of the upper area of ​​the simulated lung 9 with normal lung; The pneumothorax simulated lung 11 is obtained by setting holes in the normal lung simulated lung 9; The abnormally compliant simulated lung 12 uses a simulated lung of a different thickness from the normal lung simulated lung 9. It can also be understood that the abnormally compliant simulated lung 12 can be understood as a plurality of simulated lungs 5 ​​of the same specifications but different thicknesses. One of the simulated lungs 5 ​​of thickness is defined as the normal lung simulated lung 9, and the simulated lungs 5 ​​of other thicknesses are the abnormally compliant simulated lungs 12.

[0028] Example The physical model of pulmonary electrical impedance imaging in this embodiment includes the following core parts: 1.1 Simulated Thoracic Cage Module It includes a simulated thorax 6, which is made of conductive rubber into a hollow cylinder in the shape of the thorax to simulate the shape and conductive properties of the human chest cavity. The surface of the simulated thorax 6 is evenly marked with several EIT electrode installation sites 7 on the circumference of the simulated thorax 6. The EIT electrode installation sites 7 are used to assist in the installation of EIT electrodes and are compatible with various types of EIT electrode sheets or electrode belts. The top of the simulated thorax 6 is equipped with a transparent plastic cover (i.e., the upper cover 4), which fits tightly with the hollow cylinder. The center of the transparent plastic cover has an upward-convex threaded bottle mouth 3, and the threaded bottle mouth 3 is threadedly connected to the bottle cap 2. The overall structure of the threaded bottle mouth 3 and the bottle cap 2 can be connected to the simulated airway module. The bottom of the simulated thorax 6 is fixedly sealed with a bottom cover 8. The bottom of the bottom cover 8 is equipped with a plastic bracket for easy support and fixation.

[0029] 1.2 Simulated airway module It includes a simulated airway 1, constructed of a flexible tube. From top to bottom, it divides from a single channel (i.e., the primary bronchus) into two branches (i.e., the secondary and tertiary bronchus), forming an inverted "Y" shape. The distal ends (i.e., lower ends) of these branches (i.e., the secondary and tertiary bronchus) can be connected to a simulated lung 5. The upper portion of the primary bronchus of simulated airway 1 penetrates the bottle cap 2 and is securely and sealed to its center. The top of the primary bronchus of simulated airway 1 is an air inlet, which can be connected to a ventilator or air pump.

[0030] 1.3 Simulated Lung Module It includes a simulated lung 5 placed within a simulated thorax 6. The simulated lung 5 is constructed from an ellipsoidal elastic airbag coated with a conductive material (e.g., conductive silver paint). Airbags are classified into two types: those that simulate normal lungs (e.g., normal lung simulated lung 9) and those that simulate diseased lungs. Disease-simulating airbags come in a variety of styles, allowing them to simulate a variety of lung diseases. For example, gluing parts of the airbag together can simulate lungs with localized ventilation abnormalities (referred to as localized ventilation abnormality simulated lung 10); adding small holes to the airbag can simulate pneumothorax (referred to as pneumothorax simulated lung 11); and using airbags of varying thickness can simulate varying lung compliance (e.g., abnormal compliance simulated lung 12).

[0031] 2. Usage Step 1: Assemble the physical model for lung electrical impedance tomography in this embodiment. First, inject an appropriate amount of conductive liquid (such as saline) into the simulated thorax 6. The liquid level should be above the EIT electrode mounting site 7 and not lower than the top of the simulated lung 5. Then, connect the simulated lung 5 to the simulated airway 1. Finally, connect the bottle cap 2 to the threaded bottle neck 3. When the simulated lung 5 needs to be replaced, the bottle cap 2 can be separated from the threaded bottle neck 3 and the simulated lung 5 can be removed for replacement.

[0032] Step 2: Connect the simulated airway 1 to the ventilator or air pump, and adjust the air pressure to control the changes in the simulated lung sac volume (the simulated tidal volume is adjustable from 0 to 1000 ml).

[0033] Step 3: Connect the electrical impedance device for imaging. Fix the EIT electrodes at the electrode points of the physical model, turn on the EIT device, set the relevant parameters, and then start monitoring and imaging.

[0034] This paper designs a dynamic ventilation system consisting of a conductive rubber thorax, airway, and simulated lung. This system can intuitively simulate the temporal changes in human ventilation impedance, outperforming existing physical models such as static resistor networks and water tanks. The model is simple to assemble, has low material costs, and utilizes a non-fixed electrode layout to accommodate the testing needs of various EIT equipment models. Furthermore, conductive lung sacs are designed based on the characteristics of lung ventilation diseases, more closely resembling the ventilation response of lung tissue under both normal and pathological conditions.

[0035] Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A physical model of pulmonary electrical impedance tomography, characterized in that: The invention comprises an elastic conductive simulated thorax (6), wherein the elastic conductive simulated thorax (6) is provided with a top cover (4) and a bottom cover (8), wherein the top cover (4) is connected to a simulated airway (1), wherein the simulated airway (1) comprises a first bronchus, a second bronchus and a third bronchus, wherein the first bronchus passes through the top cover (4) and is sealed with the top cover (4), wherein the second bronchus and the third bronchus are located inside the elastic conductive simulated thorax (6), wherein the upper ends of the second bronchus and the third bronchus are both connected to the lower end of the first bronchus, and the lower ends of the second bronchus and the third bronchus are both connected to a simulated lung (5), wherein the surface of the simulated lung (5) is provided with a conductive layer.

2. A physical model of lung electrical impedance tomography according to claim 1, characterized in that: The elastic conductive simulated thorax (6) is a hollow cylindrical structure.

3. A physical model of lung electrical impedance tomography according to claim 1, characterized in that: The outer periphery of the elastic conductive simulated thorax (6) is evenly provided with EIT electrode mounting sites (7) for mounting EIT electrodes.

4. A physical model of lung electrical impedance tomography according to claim 1, characterized in that: The elastic conductive simulated thorax (6) is made of conductive rubber.

5. A physical model of lung electrical impedance tomography according to claim 1, characterized in that: The top cover (4) comprises a threaded bottle mouth (3) and a bottle cap (2) connected to the threaded bottle mouth (3) via a threaded structure, wherein the threaded bottle mouth (3) is in communication with the inner cavity of the elastic conductive simulated thorax (6), and the first bronchial tube passes through the bottle cap (2) and is sealed to the bottle cap (2).

6. A physical model for lung electrical impedance tomography according to claim 1, characterized in that: The top cover (4) is transparent.

7. A physical model for lung electrical impedance tomography according to claim 1, characterized in that: The simulated lung (5) adopts an ellipsoidal elastic airbag, and a conductive layer is provided on the surface of the ellipsoidal elastic airbag.

8. A physical model of lung electrical impedance tomography according to claim 1, characterized in that: The simulated lung (5) is detachably connected to the second bronchus and the third bronchus.

9. A physical model for lung electrical impedance tomography according to claim 1, characterized in that: The types of the simulated lung (5) include a normal lung simulated lung (9), a local ventilation abnormality simulated lung (10), a pneumothorax simulated lung (11) and a compliance abnormality simulated lung (12); Among them, the local ventilation abnormality simulated lung (10) is obtained by gluing the upper part of the normal lung simulated lung (9); For the pneumothorax simulated lung (11), it is obtained by setting holes in the normal lung simulated lung (9); The abnormal compliance simulated lung (12) uses a simulated lung having a thickness different from that of the normal lung simulated lung (9).

10. The method for using the pulmonary electrical impedance imaging physical model according to any one of claims 1 to 9, characterized in that: The steps include: Injecting a conductive liquid into the inner cavity of the elastic conductive simulated thorax (6), wherein the liquid level of the conductive liquid is located above the top of the simulated lung (5), and a preset distance is left between the liquid surface of the conductive liquid and the lower surface of the top cover (4); Injecting air into the first bronchus from one end of the first bronchus that is outside the elastic conductive simulated thorax (6) to expand the simulated lung (5), and controlling the volume change of the simulated lung (5) by adjusting the injection pressure; On the outer wall of the elastic conductive simulated thorax (6), EIT electrodes of the EIT device are evenly arranged along the circumference of the elastic conductive simulated thorax (6). The EIT electrodes are within the height range of the simulated lung (5), and the EIT device is used for monitoring and imaging.

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