Electrical impedance tomography experiment device for lung

Abstract

The invention discloses an electrical impedance tomography experiment device for lungs, which adopts a respiration simulator to inflate and exhaust the lungs of a model, so that the lungs can operate like living lungs, the authenticity of the model is greatly restored, and a relatively real environment can be provided for testing. Meanwhile, parameters such as respiratory rate, exhaled air volume, inspired air volume, exhaled air pressure change and inspired air pressure change of a real person can be adopted to be converted into signals for controlling the respiration simulator, so that the environment of the lung can be further truly restored. According to the model, the bayonet socket, the insertion hole and the locking block are quickly inserted and assembled, so that on one hand, the lung can be prevented from floating and being exposed out of the liquid level during use to affect the test; on the other hand, disassembly and assembly and air supply connection of the model can be quickly realized, so that great convenience is brought to use. The electrode unit is used for fixing the electrode, so that the replacement of the electrode can be greatly facilitated, and meanwhile, the replaced electrode is ensured not to be dislocated.

Description

Technical Field

[0001] The invention relates to an electrical impedance tomography testing technology, in particular to an electrical impedance tomography experimental device for lungs. Background Art

[0002] Electrical Impedance Tomography (EIT) is a new type of medical functional imaging technology. Its principle is to apply a weak current to the electrodes on the surface of the human body, measure the voltage value on other electrodes, and reconstruct the internal impedance value or the change value of the impedance based on the relationship between voltage and current. EIT is an ideal non-destructive medical imaging technology with attractive application prospects. However, the technology is not yet mature and the imaging accuracy is low, so further research is still needed.

[0003] In the Chinese invention patent application with publication number CN114699062A, an electrical impedance tomography model, experimental device and method are disclosed, which uses a lung model immersed in saline, and then detects the electric field through an electrode group to obtain the corresponding lung model image. The above patent technology can only perform static tests, and cannot be tested when the lung model is in a normal breathing state, so it is impossible to fully and effectively test the corresponding bioelectrical impedance tomography technology.

[0004] Based on current research, human experiments are rarely used because the safety and accuracy of such equipment are not very high and the technology is not mature enough. But eventually this technology will be applied to living bodies, so it is necessary to restore the living body environment as much as possible during the research and testing process, which can increase the success rate of subsequent technologies used in living body tests. However, there is no such technology at present. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide an electrical impedance tomography experimental device for the lungs, which can simulate the movements and environment of living lungs to more realistically restore the state of living lungs, thereby providing a basis for subsequent living experiments.

[0006] To achieve the above-mentioned purpose, the present invention provides an electrical impedance tomography experimental device for lungs, comprising a frame, an experimental barrel, and a model, wherein the model comprises lungs, bronchi, a total trachea, and a socket, wherein two lungs are respectively mounted and fixed on fixed bronchi, the bronchi and the socket are mounted and fixed on the total trachea, the interior of the total trachea is a hollow total trachea hole, the bronchi are connected to the total trachea hole, and the bronchi are connected to the pipeline inside the lungs; The experimental barrel is installed on the rack, the interior of the experimental barrel is a hollow experimental cavity, the bottom of the experimental cavity and the rack are fixed with a mounting seat, the mounting seat is assembled with the model so that the model is fixed in the experimental cavity, and during the experiment, the experimental cavity is filled with a conductive liquid with a conductive function, and the conductive liquid immerses the model; An electrode is also directly or indirectly installed on the experimental barrel, and one end of the electrode is immersed in the conductive liquid; an air supply hole is provided on the mounting seat, and the air supply hole is connected to the breathing simulator, and the breathing simulator is used to input air flow into the air supply hole or extract air flow to drive the lungs to expand and contract.

[0007] As a further improvement of the present invention, the breathing simulator comprises a piston cylinder, a piston cover, a piston, and a piston rod. The interior of the piston cylinder is a hollow piston, the piston is sealed and slidably installed in the piston cavity, the piston cover is installed at the open end of the piston cylinder located in the piston cavity, one end of the piston rod is assembled with the piston, and the other end passes through the piston cover and can be axially slidably assembled with the piston; One end of the piston rod passing through the piston cover is assembled with the electric cylinder shaft of the electric cylinder, and the electric cylinder is installed on the frame; the air supply hole is communicated with the piston cavity.

[0008] As a further improvement of the present invention, the air supply hole is sealed and fixed to one end of the air inlet pipe, the air inlet pipe is connected to the piston chamber through a connecting pipe, a gas flow meter is connected in series on the connecting pipe, and is connected to the detection interface of the barometer, the gas flow meter is used to detect the amount of air passing through and the volume of the passing gas can be calculated in combination with the duration, and the barometer is used to detect the air pressure and air pressure changes of the passing airflow.

[0009] As a further improvement of the present invention, the mounting seat is further provided with a switch hole, a plug hole, a lock groove, a notch groove, and a ring groove, the two ends of the lock groove are respectively connected with the notch groove and the plug hole, the ring groove is arranged on the outer wall of the mounting seat, and the detection hole is connected with the notch groove and passes through the mounting seat; The lock groove is engaged with the lock block and slidably assembled, and a lock block pin is installed on the lock block; one end of the lock block enters the plug hole and is pressed against the plug socket, and the other end is pressed against or assembled with the inner side of the elastic ring; the elastic ring is installed in the ring groove and the elastic ring is elastic, which exerts an elastic force on the lock block to prevent it from moving away from the plug hole; The lock block pin is in close contact with or in contact with the switch inclined surface, the switch inclined surface is arranged on the switch block, the switch block is installed on one end of the switch rod, the other end of the switch rod passes through the switch hole and is assembled with the switch ring, the switch ring can be axially slidably sleeved outside the intake pipe; the switch rod and the switch hole can be axially slidable and sealed. The switch block is engaged and slidably installed in the notch. When the switch rod moves downward, it can drive the switch block to move downward. The switch inclined surface squeezes the locking block pin to drive the locking block to squeeze the elastic ring and move away from the plug-in hole.

[0010] As a further improvement of the present invention, a roller is also installed on the switch ring, and the roller card is inserted into the roller groove and slidably assembled therewith, the roller groove is arranged on the switch frame, one end of the switch frame is hinged to the shaft block through the switch frame shaft, the middle part of the switch shaft is assembled and fixed to the mounting block through an elastic member, the mounting block and the shaft block are both installed on the frame, the elastic member is elastic and applies an elastic force to the switch frame to prevent it from rotating away from the mounting seat.

[0011] As a further improvement of the present invention, one end of the air supply hole away from the air inlet pipe is sealed and fixed to one end of the plug-in tube, the plug-in tube is inserted into the main air pipe hole and a plurality of penetrating air holes are provided at the connection point between the plug-in tube and the main air pipe hole near the bronchus, the inner diameter of the main air pipe hole and the corresponding part of the air holes is larger than the outer diameter of the plug-in tube; the end of the plug-in tube without the air holes is sealed with the main air pipe hole.

[0012] As a further improvement of the present invention, the mounting seat is further provided with a detection hole, which is a blind hole and one end of which passes through the mounting seat; A sliding seat is axially slidably mounted on the intake pipe, and a sliding seat spring is mounted on the portion of the intake pipe outside the intake pipe and between the sliding seat and the end face of the plug-in hole, and the sliding seat spring is used to apply an elastic force to the sliding seat to hinder its movement toward the end face of the plug-in hole; the sliding seat is engaged and slidably mounted in the plug-in hole; a magnet is mounted on the sliding seat, and a reed switch is mounted at the position of the detection hole corresponding to the magnet, the reed switch is fixed on one end of the detection rod, and the other end of the detection rod passes through the detection hole, and the signal of the reed switch is introduced into the industrial computer.

[0013] As a further improvement of the present invention, a protective shell is fixed on the frame and outside the experimental barrel, one side of the protective shell is open and closed by a door panel, one side of the door panel is hinged to the protective shell by a hinge, and the other side is assembled with the protective shell by a door lock; an X-ray source is installed on the inner side of the door panel, and a detector is installed on the side of the protective shell located at the experimental barrel away from the X-ray source; the X-ray source is responsible for emitting X-ray beams, which will penetrate the experimental barrel and the model, and the detector is responsible for receiving the penetrated X-rays and converting them into electrical signals, which are then transmitted to a computer for processing to construct an internal structure image of the model.

[0014] As a further improvement of the present invention, a barrel cover is also installed on the top of the experimental barrel, and the electrodes are evenly installed along the inner side of the barrel cover; a barrel cover groove is provided on the inner side of the barrel cover, and the barrel cover groove is plugged into the top edge of the experimental barrel to realize rapid positioning and installation of the barrel cover and the experimental barrel; a probe rack is also installed on the experimental barrel, and a probe of an ultrasonic liquid level meter is installed on the probe rack, and the probe is used to emit ultrasonic waves to the liquid surface in the experimental barrel to detect the liquid level height, so that the industrial computer can calculate the volume through the liquid level height.

[0015] As a further improvement of the present invention, an electrode unit is installed on the inner side of the barrel cover, and the electrode is installed in the corresponding electrode unit. The electrode includes a positioning sleeve and an electrode part. The positioning sleeve is made of insulating material. The electrode part is connected to the imaging device by a wire and the electrode part is immersed in a conductive liquid. The electrode unit includes a fixed seat and a movable seat fixed on the inner side of the barrel cover. One side of the fixed seat is hinged to one side of the movable seat through a rotating shaft. A buckle groove is provided on the other side of the fixed seat. A buckle plate is provided on the other side of the movable seat. A buckle protrusion is provided on the buckle plate. The buckle plate is elastic and the buckle protrusion is snapped into the buckle groove to complete the assembly of the fixed seat and the movable seat. The fixed seat and the movable seat are respectively provided with a first half hole and a second half hole, the first half hole and the second half hole are respectively clamped and assembled with the positioning sleeve, and limiting rings are respectively provided at both ends of the positioning sleeve passing through the first half hole and the second half hole, and the limiting rings are tightly attached to the end faces of the fixed seat and the movable seat.

[0016] As a further improvement of the present invention, the lung includes four independent lobes, each lobe is equipped with a conductor, the conductor is conductive and one end of the conductor passes through the corresponding lobe and the other end enters the corresponding lobe; Each lung lobe is connected to the corresponding bronchus, and the four bronchi are connected to one end of the first shunt tube, one end of the second shunt tube, one end of the third shunt tube, and one end of the fourth shunt tube, respectively. The other ends of the first shunt tube, the other ends of the second shunt tube, the other ends of the third shunt tube, and the other ends of the fourth shunt tube are connected to the outlet of the first reversing valve, the outlet of the second reversing valve, the outlet of the third reversing valve, and the outlet of the fourth reversing valve, respectively. The first inlet of the first reversing valve, the first inlet of the second reversing valve, the first inlet of the third reversing valve, The first inlet of the fourth reversing valve is respectively connected to the liquid supply pipe, the second inlet of the first reversing valve, the second inlet of the second reversing valve, the second inlet of the third reversing valve, and the second inlet of the fourth reversing valve are respectively connected to the gas supply pipe, and the first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve are respectively used to control their outlets to selectively connect to the first inlet and the second inlet; the first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve are all reversing valves, and the first shunt pipe, the second shunt pipe, the third shunt pipe, and the fourth shunt pipe are also shunt pipes; The liquid supply system includes a liquid supply pump and a return pump. The inlet of the liquid supply pump is connected to the conductive liquid, and the outlet is connected to the inlet of the hydraulic meter and the inlet of the liquid flow meter. The outlet of the liquid flow meter is connected to the liquid supply pipe. The outlet of the liquid supply pump is also connected to the inlet of the return pump. The outlet of the return pump is connected to a device for storing the conductive liquid. The air supply system comprises a breathing simulator, the air port of the breathing simulator is connected with the inlet of the barometer and the inlet of the gas flow meter, and the outlet of the gas flow meter is connected with the air supply pipe.

[0017] The beneficial effects of the present invention are: The present invention uses a breathing simulator to inflate and exhaust the lungs of the model, so that the lungs can operate like living lungs, which greatly restores the authenticity of the model and can provide a relatively real environment for testing. At the same time, the present invention can use parameters such as real people's breathing frequency, expiratory volume, inspiratory volume, expiratory pressure change, inspiratory pressure change, etc. to convert them into signals for controlling the breathing simulator, so that the environment of the lungs can be further restored. The model of the present invention uses a socket and a socket hole, and a lock block for quick plug-in assembly. On the one hand, it can prevent the lungs from floating up and exposing the liquid surface when in use, affecting the test; on the other hand, it can quickly realize the disassembly and assembly of the model and the air supply connection, thereby greatly facilitating use. The present invention also uses an electrode unit to fix the electrode, which can greatly facilitate the replacement of the electrode and ensure that the replaced electrode is not misplaced. The present invention also uses CT to scan the two-dimensional image of the lung and the liquid level change to infer the three-dimensional image of the lung, so as to obtain a comparison benchmark with the electrical impedance tomography image to determine whether the test technology meets the expected requirements; the gap between the detection and the existing high-precision test technology is convenient for subsequent improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1-Figure 2 is a structural schematic diagram of embodiment 1; Figure 3 It is a cross-sectional view of the central plane where the axis of the main gas pipe 930 is located; Figure 4 It is a cross-sectional view at another center plane where the axis of the main gas pipe 930 is located; Figure 5 yes Figure 4 Enlarged view of F1 in the middle; Figure 6-Figure 7 It is a schematic diagram of the structure after removing part of the frame 100, opening the top plate 140 and the door plate 120; Figure 8-Figure 9 is a schematic diagram of the structure after a portion of the rack 100 is removed; Figure 10-12 It is a schematic diagram of the structure of the experimental barrel 160, the barrel cover 170, and the switch frame 610; Figure 13-Figure 14 It is a schematic diagram of the structure of the electrode unit 180 and the electrode 280; Fig.15 is a schematic diagram of the structure of the electrode unit 180; Fig.16 It is a schematic diagram of the structure of the model, the mounting base 410, and the switch frame 610; Fig.17 It is a schematic diagram of the structure of the model (part), the mounting base 410, and the switch frame 610; Fig.18 It is a schematic diagram of the structure of the model (part), the mounting base 410, and the switch ring 530; Fig.19 is a schematic diagram of the structure of the mounting seat 410; Figure 20-21 It is a schematic diagram of the structure of the model, the mounting cover 420, the switch rod 440, and the air intake pipe 330; Fig. 22 It is a schematic diagram of the structure of the switch block 490, the lock block 460, the plug socket 940, and the slide seat 510; Fig.23 is a schematic block diagram of Embodiment 2; Fig.24 is a schematic block diagram of a liquid supply system in Embodiment 2; Fig.25 is a schematic block diagram of the gas supply system in Embodiment 2; Figure 26-Figure 27 It is a schematic diagram of the structure of the plug-in tube 430 and the shunt tube 950 in the second embodiment. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Embodiment 1

[0020] See also Figure 1-Figure 10 The electrical impedance tomography experimental device of this embodiment includes a frame 100, a door panel 120, a protective shell 130, a top cover 140, an experimental barrel 160, a barrel cover 170, and a model. The model includes a lung 910, a bronchus 920, a main trachea 930, and a socket 940. The two lungs 910 are respectively installed and fixed on the fixed bronchus 920, and the bronchus 920 and the socket 940 are installed and fixed on the main trachea 930. The main trachea 930 has a hollow main trachea hole 931 inside. The bronchus 920 is connected to the main trachea hole 931, and the bronchus 920 is connected to the pipeline inside the lung. When in use, the main trachea hole 931 is inflated or evacuated to drive the two lungs to expand and contract, thereby simulating the movement of the living lung.

[0021] The frame 100 is provided with a protective shell 130 and an experimental barrel 160, the interior of the experimental barrel 160 is a hollow experimental chamber 161, a mounting seat 410 is fixedly mounted on the bottom of the experimental chamber 161 and the frame 100, and the mounting seat 410 is assembled with the model so that the model is fixedly mounted in the experimental chamber 161. During the experiment, the experimental chamber 161 is filled with a conductive liquid having a conductive function, and the conductive liquid immerses the model. In this embodiment, the conductive liquid is physiological saline, which is used to simulate skin resistance.

[0022] An electrode 280 is also directly or indirectly mounted on the test barrel 160 , one end of the electrode 280 is immersed in the conductive liquid, and the other end is connected to a test device for conducting an experiment.

[0023] The mounting seat 410 is provided with an air supply hole 411 , which is in communication with the breathing simulator 230 . The breathing simulator 230 is used to input airflow into the air supply hole 411 or extract airflow to drive the lungs 910 to expand or contract.

[0024] The breathing simulator 230 includes a piston cylinder 231, a piston cover 232, a piston 233, and a piston rod 234. The interior of the piston cylinder 231 is a hollow piston chamber 2311. The piston 233 is sealed and slidably installed in the piston chamber 2311. The piston cover 232 is installed at the open end of the piston cylinder 231 located in the piston chamber 2311. One end of the piston rod 234 is assembled with the piston 233, and the other end passes through the piston cover 232 and can be axially slidably assembled with it.

[0025] One end of the piston rod 234 passing through the piston cover 232 is assembled with the cylinder shaft of the electric cylinder 220, and the electric cylinder 220 is installed on the frame 100. The electric cylinder 220 is a servo electric cylinder, which can accurately control the extension length and extension speed of its electric cylinder shaft, thereby controlling the displacement amount and displacement speed of the piston.

[0026] The air supply hole 411 is connected to the piston chamber 2311, so that the air supply hole 411 can be inflated or exhausted when the piston 233 moves. Considering the loss of air leakage during operation, a pressure compensation valve can be connected to the air supply hole 411 or the piston chamber 2311, and once the air pressure in the air supply hole 411 or the piston chamber 2311 is low, air is actively sucked in for replenishment.

[0027] Since the size of the piston cavity is fixed, the amount of inflation and exhaust that can be generated by the displacement of the piston is fixed. When in use, the inflation and exhaust can be controlled by the displacement of the piston; at the same time, the speed of inflation and exhaust can be controlled by controlling the movement speed of the piston, that is, simulating the speed of inhalation and exhalation; the frequency of the piston reciprocating inflation and exhaust can be used to simulate the breathing frequency. Specifically, the breathing frequency, exhaled volume and inhaled volume can be monitored by external equipment such as a respiratory monitor, a spirometer and the like, and then the corresponding data can be input into the industrial computer 210 to convert into parameters for the electric cylinder 220 to drive the breathing simulator 230 to work.

[0028] In some embodiments, the air supply hole 411 is sealed and fixed to one end of the air inlet pipe 330, and the air inlet pipe 330 is connected to the piston chamber 2311 through the connecting pipe 320. The connecting pipe 320 is connected in series with a gas flow meter 260 and is connected to the detection interface of the barometer 240. The gas flow meter 260 is used to detect the amount of air passing through and the volume of the gas passing through can be calculated in combination with the duration, and the barometer is used to detect the air pressure and pressure changes of the air flow. When in use, the air flow volume calculated by the gas flow meter 260 is compared with the preset inhalation volume (volume) and exhalation volume (volume) to determine whether the preset requirements are met. The barometer 240 detects the exhalation pressure, inhalation pressure, and breathing frequency of the simulated breathing by detecting the detected air pressure and pressure changes. This design is to simulate the breathing of living bodies more accurately. At the same time, a large amount of data is required for verification during the research process, and bringing the tester into the laboratory for one-by-one testing will obviously cause high costs and safety hazards. Therefore, it is entirely possible to use equipment to collect the exhaled volume, inhaled volume, respiratory rate, changes in exhaled air pressure, and inhaled air pressure of the experimental subjects, and then input them into the device. This is not only low-cost, but also can restore the breathing state of the living body as much as possible, so as to improve the accuracy of the experiment and the reliability of the technology.

[0029] See also Figure 1-Figure 11 , Figure 16-Figure 22 The mounting seat 410 is also provided with a switch hole 412, a detection hole 413, a plug hole 414, a lock groove 415, a missing groove 416, and a ring groove 417. The two ends of the lock groove 415 are respectively connected with the missing groove 416 and the plug hole 414. The ring groove 417 is arranged on the outer wall of the mounting seat 410. The detection hole 413 is connected with the missing groove 417 and passes through the mounting seat 410. The detection hole 413 is a blind hole and one end passes through the mounting seat 410.

[0030] The locking groove 415 is engaged with the locking block 460 and slidably assembled. The locking block 460 is equipped with a locking block pin 461. One end of the locking block 460 enters the plug hole 414 and is pressed against the plug seat 940, and the other end is pressed against or assembled with the inner side of the elastic ring 470. The elastic ring 470 is installed in the ring groove 417 and the elastic ring 470 is elastic. It exerts an elastic force on the locking block 460 to prevent it from moving away from the plug hole 414, so that the locking block remains Figure 5 state.

[0031] The lock block pin 461 is in close contact with or in contact with the switch inclined surface 491, and the switch inclined surface 491 is provided on the switch block 490, and the switch block 490 is mounted on one end of the switch rod 440, and the other end of the switch rod 440 passes through the switch hole 413 and is assembled with the switch ring 530, and the switch ring 530 is axially slidable and sleeved outside the intake pipe 330. The switch rod 440 and the switch hole 413 are axially slidable and sealed.

[0032] The switch block 490 is engaged and slidably installed in the notch 416 . When the switch rod 440 moves downward, it can drive the switch block 490 to move downward. The switch inclined surface 491 squeezes the locking block pin 461 to drive the locking block 460 to squeeze the elastic ring 470 and move away from the plug hole 414 .

[0033] The mounting seat 410 is also provided with a mounting cover 420, and a through hole 421 is provided at a position corresponding to the plug-in hole 414. The mounting cover 420 is also provided with a guide block 422 that engages with and slides with the guide groove 492. The guide groove 492 is provided on the switch block 490 to guide the switch block 490 to slide in the notch 416.

[0034] The switch ring 530 is also provided with a roller 531, which is inserted into and slidably assembled with the roller groove 611. The roller groove 611 is provided on the switch frame 610. One end of the switch frame 610 is hinged to the shaft block 101 through the switch frame shaft 630. The middle part of the switch shaft 610 is assembled and fixed to the mounting block 102 through an elastic member 620. The mounting block 102 and the shaft block 101 are both mounted on the frame 100. The elastic member 620 is elastic and exerts an elastic force on the switch frame 610 to prevent it from rotating away from the mounting seat 410, so as to keep the switch frame in the initial state. Fig.17 state.

[0035] In some embodiments, the locking block 460 is provided with a locking block inclined surface 462, and the socket 940 is provided with a socket inclined surface 941, and the socket inclined surface 941 can be fitted with the locking block inclined surface 462, thereby squeezing the locking block 460 until the socket 940 passes through the locking block 460, and then the locking block 460 is reset under the elastic force of the elastic ring 470 to be clamped on the upper end surface of the socket 940 ( Figure 5 shall prevail).

[0036] In some embodiments, one end of the air supply hole 411 away from the air inlet pipe 330 is sealed and fixedly assembled with one end of the plug-in tube 430, the plug-in tube 430 is inserted into the main air pipe hole 931 and a plurality of penetrating air holes 431 are provided at the connection between the plug-in tube 430 and the main air pipe hole 931 near the bronchus 920, the inner diameter of the main air pipe hole 931 and the corresponding part of the air hole 431 is larger than the outer diameter of the plug-in tube 430, so that the air flow can be introduced into the bronchus 920; the end of the plug-in tube 430 without the air hole 431 is sealed with the main air pipe hole 931, and this design is mainly to improve the stability of the assembly of the model and the mounting base.

[0037] Preferably, a slide seat 510 is axially slidably mounted on the air inlet pipe 330, and a slide seat spring 480 is mounted on the portion of the air inlet pipe 330 between the slide seat 510 and the end surface of the plug hole 414. The slide seat spring 480 is used to apply elastic force to the slide seat 510 to prevent it from moving toward the end surface of the plug hole 414; the slide seat 510 is engaged and slidably mounted in the plug hole 414. The two ends of the slide seat spring 480 are preferably assembled and fixed with the slide seat 510 and the end surface of the plug hole 414, which is mainly to prevent the slide seat 510 from sliding out of the air inlet pipe 330.

[0038] Preferably, a magnet 520 is installed on the slide 510, and a reed switch 202 is installed at the position corresponding to the detection hole 413 and the magnet 520. The reed switch 202 is fixed on one end of the detection rod 450, and the other end of the detection rod 450 passes through the detection hole 413, and the signal of the reed switch 202 is introduced into the industrial computer. Figure 5 When the socket 940 is not inserted into the socket hole 414 or not inserted in place, the slide spring 480 drives the slide 510 to move toward the installation cover 420. At this time, the magnet is misaligned with the reed switch, so the reed switch remains disconnected.

[0039] See also Figure 4 When the model needs to be installed, the switch frame 610 is rotated downward to drive the switch ring 530 to move downward. The switch ring 530 drives the switch block 490 to move downward through the switch rod 440, so that the switch slope 491 squeezes the switch pin to drive the lock block 480 to move away from the socket hole 414 until it does not prevent the socket 940 from being inserted. Then the main tube hole 931 is sleeved on the outside of the plug-in tube 430, and the plug-in socket 940 passes through the through hole 421 and enters the plug-in hole 414, and then the slide 520 is pushed to squeeze the slide spring 480 and move down until the magnet is directly opposite to the reed switch. The reed switch closes and sends a signal to the industrial computer. The industrial computer prompts the operator in a pre-set manner, and then the operator releases the switch frame 610. The elastic member 620 drives the switch frame 610, the switch ring 530, and the switch block 490 to reset through elastic force, and the elastic ring 470 drives the locking block 480 to reset, so that the slide 520 pushes the plug-in socket 940 upward until it is pressed tightly against the locking block 480 to complete the installation.

[0040] When testing is required, the operation of the electric cylinder 220 can be controlled according to the program to control the inflation and deflation of the lung 910, and the electric field is detected by the electrode to obtain the image of the lung 910. The specific breathing frequency, breathing pressure change, exhalation speed, inhalation speed, etc. can be controlled by controlling the operation state of the electric cylinder 220.

[0041] In some embodiments, a CT scanning function is also added, specifically, a protective shell 130 is fixed on the frame 100 and outside the experimental barrel 160, one side of the protective shell 130 is open and closed by a door panel 120, one side of the door panel 120 is hinged to the protective shell 130 by a hinge, and the other side is assembled with the protective shell 130 by a door lock. When in use, the door lock can be opened to open the door panel 120 with the hinge as the center. A plug-in frame 150 is installed on the top of the protective shell 130, and a frame groove 151 is provided on the plug-in frame 150. The frame groove 151 is engaged with the top plate edge 141 of the top plate 140, so that the top plate 140 closes the top opening of the protective shell 130. The design of the door panel 120 and the top plate 140 is mainly to facilitate the placement of the model.

[0042] An X-ray source 271 is installed inside the door panel 120, and a detector 272 is installed on the side of the protective shell 130 located at the experimental barrel 160 away from the X-ray source 271; the X-ray source 271 is responsible for emitting X-ray beams, which will penetrate the experimental barrel and the model, and the detector 272 is responsible for receiving the X-rays after penetration and converting them into electrical signals, which are then transmitted to the computer for processing to construct an image of the internal structure of the model. This is mainly to verify the accuracy of the imaging image detected by the electrode 280.

[0043] In some embodiments, a barrel cover 170 is also installed on the top of the experimental barrel 160, and the electrodes 280 are evenly installed along the inner side of the barrel cover 170; a barrel cover groove 171 is provided on the inner side of the barrel cover 170, and the barrel cover groove 171 is plugged with the top edge of the experimental barrel 160 to achieve rapid positioning and installation of the barrel cover 170 and the experimental barrel. Compared with the method of fixing the electrode on the edge of the experimental barrel 160 by transmission, this design has the advantages of low interference with model placement and easy installation and use.

[0044] Preferably, a probe rack 172 is also installed on the experimental barrel 170, and a probe 201 of an ultrasonic liquid level meter is installed on the probe rack 172. The probe 201 is used to emit ultrasonic waves to the liquid surface in the experimental barrel to detect the liquid level, and the volume can be calculated by the liquid level because the inner cross-sectional area of ​​the experimental barrel is fixed.

[0045] When in use, the lung 910 will contract and relax, causing the volume inside the experimental barrel to change. By detecting the change in the liquid level, the change in volume can be calculated, thereby providing a reference for determining the three-dimensional state of the lung, so as to verify the accuracy of the electrode detection imaging. In actual use, the functional relationship between the volume change of the lung 910 and the change in the liquid level in the experimental barrel, as well as the three-dimensional state of the lung at this time, can be tested in advance, and then the volume change of the lung 910 can be quickly determined using the functional relationship. The three-dimensional state of the lung can be obtained by 3D laser scanning. After a large amount of data collection, the liquid level change can naturally be associated with the lung volume and state change and the corresponding relationship function can be obtained, so as to directly calculate the stereogram of the corresponding state in subsequent experiments. This design is mainly to combine the two-dimensional plane image of the CT scan of the lung 910 with the calculated stereogram and the electrical impedance tomography image to compare, in order to test the reliability and accuracy of the technology. The two-dimensional plane image is mainly used when it is used, and the stereogram is only used when there is a clear difference between the two-dimensional plane image and the electrical impedance tomography image.

[0046] See also Figure 11-Figure 15 Preferably, since the electrode 280 needs to be replaced frequently during use, and the installation position of the electrode 280 is required to be strict during the experiment, the present embodiment installs an electrode unit 180 on the inner side of the barrel cover 170, and the electrode 280 is installed in the corresponding electrode unit 180, so that the electrode can be quickly replaced.

[0047] The electrode 280 includes a positioning sleeve 281 and an electrode part 282. The positioning sleeve 281 is made of insulating material. The electrode part 282 is connected to the imaging device by a wire and is immersed in a conductive liquid. The electrode unit 180 includes a fixed seat 181 and a movable seat 182 fixed to the inner side of the barrel cover 170. One side of the fixed seat 181 is hinged to one side of the movable seat 182 through a rotating shaft 184. A buckle groove 1811 is provided on the other side of the fixed seat 181. A buckle plate 183 is provided on the other side of the movable seat 182. A buckle protrusion 1831 is provided on the buckle plate 183. The buckle plate 183 is elastic and the buckle protrusion 1831 is inserted into the buckle groove 1811 to complete the assembly of the fixed seat 181 and the movable seat 182.

[0048] The fixed seat 181 and the movable seat 182 are respectively provided with a first half hole 1812 and a second half hole 1821, the first half hole 1812 and the second half hole 1821 are respectively clamped and assembled with the positioning sleeve 281, and the two ends of the positioning sleeve 281 passing through the first half hole 1812 and the second half hole 1821 are respectively provided with a limiting ring 2811, and the limiting ring 2811 is tightly attached to the end surface of the fixed seat 181 and the movable seat 182, so as to realize the axial positioning of the positioning sleeve 281 relative to the first half hole 1812 and the second half hole 1821. When the electrode 280 needs to be replaced, it is only necessary to directly open the movable seat 182, take out the electrode 280 and replace it.

[0049] In some embodiments, a water tank 110 is also installed on the frame 100, and the inner side and bottom of the experimental barrel 160 are connected to the water tank 110 through a drain pipe 310. A water valve 250 is connected in series to the drain pipe 310. When in use, the drain pipe is controlled by the water valve to discharge the conductive liquid in the experimental barrel 160 or to store the conductive liquid in the experimental barrel after closing the water valve 250. Embodiment 2

[0050] See also Fig.23 In order to further simulate the real situation of the lungs, this embodiment separates each lobe of the lung (left lung and right lung), and a conductor is installed on each lobe. The conductor is conductive and one end of the conductor passes through the corresponding lobe and the other end enters the corresponding lobe. This design is mainly to enable the conductive liquid in the experimental cavity to be conductively connected with the conductive liquid in the lobe when the inside of the lobe is filled with conductive liquid, thereby facilitating imaging. Theoretically, the shape of the conductor is not limited, as long as the conductive connection between the inside and outside of the lobe is achieved. In some embodiments, needle-shaped metals, cylindrical metals, etc. can be selected.

[0051] Each lung lobe is connected to the corresponding bronchus, and the four bronchi are connected to one end of the first shunt tube, one end of the second shunt tube, one end of the third shunt tube, and one end of the fourth shunt tube, respectively. The other ends of the first shunt tube, the other ends of the second shunt tube, the other ends of the third shunt tube, and the other ends of the fourth shunt tube are connected to the outlet of the first reversing valve, the outlet of the second reversing valve, the outlet of the third reversing valve, and the outlet of the fourth reversing valve, respectively. The first inlet of the first reversing valve, the first inlet of the second reversing valve, the first inlet of the third reversing valve, and the first inlet of the fourth reversing valve are connected to the liquid supply pipe, respectively. The second inlet of the first reversing valve, the second inlet of the second reversing valve, the second inlet of the third reversing valve, and the second inlet of the fourth reversing valve are connected to the air supply pipe, respectively. The first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve are used to control their outlets to select one of the first inlet and the second inlet to be connected. The first reversing valve, the second reversing valve, the third reversing valve and the fourth reversing valve are all reversing valves, which are named for the convenience of expression. Similarly, the first shunt pipe, the second shunt pipe, the third shunt pipe and the fourth shunt pipe are also shunt pipes, which are named for the convenience of expression.

[0052] See also Fig.24 The liquid supply system includes a liquid supply pump and a return pump. The inlet of the liquid supply pump is connected to the conductive liquid, and the outlet is connected to the inlet of the hydraulic meter and the inlet of the liquid flow meter. The outlet of the liquid flow meter is connected to the liquid supply pipe. The outlet of the liquid supply pump is also connected to the inlet of the return pump. The outlet of the return pump is connected to the device for storing the conductive liquid. When it is necessary to supply water to the lung lobe, the outlet of the corresponding reversing valve is connected to the second inlet, the water supply pump is started to pump the conductive liquid into the liquid supply pipe and the return pump is not started. The liquid flow meter measures the flow rate to convert the volume, and the hydraulic meter detects the liquid supply hydraulic pressure until the corresponding requirements are met. When it is necessary to pump out the water in the lung lobe, the return pump is started and the liquid supply pump is not started, thereby generating a suction force on the liquid supply pipe to pump the water in the corresponding lung lobe into the device for storing the conductive liquid, and the hydraulic meter and the liquid flow meter detect the hydraulic pressure and flow rate respectively, thereby measuring the liquid pressure, flow rate and volume during extraction.

[0053] See also Fig.25 The air supply system includes a breathing simulator, the air port of the breathing simulator is connected to the inlet of the barometer and the inlet of the gas flow meter, and the outlet of the gas flow meter is connected to the air supply pipe. When it is necessary to supply or exhaust air to the corresponding lung lobe, the outlet of the corresponding reversing valve is connected to the first inlet, and the breathing simulator is started to inflate and inhale the corresponding lung lobe to simulate the breathing state. The barometer and the gas flow meter detect the air flow pressure and gas flow respectively, and the volume can be calculated by the gas flow and time.

[0054] See also Figure 26-Figure 27 The plug-in pipe 430 of this embodiment may be different from that of the first embodiment, and the specific design may be as follows: Four plug-in channels 432 are provided on the plug-in tube 430 , each plug-in channel 432 is respectively connected to the outlet of the corresponding reversing valve, and each shunt tube 950 is respectively inserted into the corresponding plug-in channel 432 to be connected to the outlet of the corresponding reversing valve.

[0055] This design is mainly for ease of use and simple structure. Figure 26-Figure 27 The structure is different from the structure of the plug-in tube 430 in the first embodiment, and can be understood as providing another structure without constituting any restrictive interpretation. Figure 26-Figure 27 The structures shown are only for convenience of presentation and are not specific structural diagrams or structural drawings of the corresponding structures.

[0056] Preferably, the four shunt tubes 950 can be integrated into one plug, and the plug can be directly plugged into the plug tube 430 to achieve quick plugging and connection between the shunt tube 950 and the corresponding plug channel 432 .

[0057] When air is supplied to the lung lobes, the current inside and outside the lung lobes is disconnected, which is similar to a normal living lung. When conductive fluid is supplied to the lung lobes, the conductive fluid inside and outside the lung lobes conducts electricity through the conductor, thereby achieving electrical impedance imaging in this state.

[0058] This embodiment can supply air and exhaust air, supply conductive fluid and exhaust conductive fluid to the four lobes respectively, thereby enabling multiple tests, which greatly facilitates subsequent research and technical improvements.

Claims

1. An electrical impedance tomography experimental device for lungs, characterized by: It includes a rack, an experimental barrel, and a model. The model includes lungs, bronchi, a total trachea, and a socket. Two lungs are respectively installed and fixed on fixed bronchi. The bronchi and the socket are installed and fixed on the total trachea. The total trachea has a hollow total trachea hole inside. The bronchi are connected to the total trachea hole, and the bronchi are connected to the pipe inside the lungs. The experimental barrel is installed on the rack, the interior of the experimental barrel is a hollow experimental cavity, the bottom of the experimental cavity and the rack are fixed with a mounting seat, the mounting seat is assembled with the model so that the model is fixed in the experimental cavity, and during the experiment, the experimental cavity is filled with a conductive liquid with a conductive function, and the conductive liquid immerses the model; An electrode is also directly or indirectly installed on the experimental barrel, and one end of the electrode is immersed in the conductive liquid; an air supply hole is provided on the mounting seat, and the air supply hole is connected to the breathing simulator, and the breathing simulator is used to input air flow into the air supply hole or extract air flow to drive the lungs to expand and contract.

2. The electrical impedance tomography experimental device according to claim 1, characterized in that: The breathing simulator comprises a piston cylinder, a piston cover, a piston, and a piston rod. The piston cylinder contains a hollow piston, which is sealed and slidably mounted in the piston cavity. The piston cover is mounted at the open end of the piston cylinder located in the piston cavity. One end of the piston rod is assembled with the piston, and the other end passes through the piston cover and is axially slidably assembled with the piston. One end of the piston rod passing through the piston cover is assembled with the cylinder shaft of the electric cylinder, and the electric cylinder is installed on the frame; the air supply hole is connected with the piston cavity; The air supply hole is sealed and fixed to one end of the air inlet pipe, the air inlet pipe is connected to the piston cavity through a connecting pipe, a gas flow meter is connected in series on the connecting pipe, and the connecting pipe is connected to the detection interface of the barometer, the gas flow meter is used to detect the amount of air passing through and the volume of the passing gas can be calculated based on the duration, and the barometer is used to detect the air pressure and pressure changes of the passing air flow.

3. The electrical impedance tomography experimental device according to claim 1, characterized in that: The mounting seat is also provided with a switch hole, a plug hole, a lock slot, a notch slot, and a ring slot. The two ends of the lock slot are respectively connected with the notch slot and the plug hole. The ring slot is arranged on the outer wall of the mounting seat. The detection hole is connected with the notch slot and passes through the mounting seat. The lock groove is engaged with the lock block and slidably assembled, and a lock block pin is installed on the lock block; one end of the lock block enters the plug hole and is pressed against the plug socket, and the other end is pressed against or assembled with the inner side of the elastic ring; the elastic ring is installed in the ring groove and the elastic ring is elastic, which exerts an elastic force on the lock block to prevent it from moving away from the plug hole; The lock block pin is in close contact with or in contact with the switch inclined surface, the switch inclined surface is arranged on the switch block, the switch block is installed on one end of the switch rod, the other end of the switch rod passes through the switch hole and is assembled with the switch ring, the switch ring can be axially slidably sleeved outside the intake pipe; the switch rod and the switch hole can be axially slidable and sealed. The switch block is engaged and slidably installed in the notch. When the switch rod moves downward, it can drive the switch block to move downward. The switch inclined surface squeezes the locking block pin to drive the locking block to squeeze the elastic ring and move away from the plug-in hole.

4. The electrical impedance tomography experimental device according to claim 3, characterized in that: A roller is also installed on the switch ring, and the roller card is inserted into the roller groove and slidably assembled with it. The roller groove is set on the switch frame. One end of the switch frame is hinged with the shaft block through the switch frame shaft. The middle part of the switch shaft is assembled and fixed with the mounting block through an elastic member. The mounting block and the shaft block are both installed on the frame. The elastic member is elastic and applies an elastic force to the switch frame to prevent it from rotating away from the mounting seat.

5. The electrical impedance tomography experimental device as claimed in claim 3, characterized in that: One end of the air supply hole away from the air inlet pipe is sealed and fixedly assembled with one end of the plug-in tube. The plug-in tube is inserted into the main air pipe hole and a number of penetrating air holes are provided at the connection point between the plug-in tube and the main air pipe hole near the bronchus. The inner diameter of the main air pipe hole and the corresponding part of the air hole is larger than the outer diameter of the plug-in tube. The end of the plug-in tube without the air hole is sealed with the main air pipe hole.

6. The electrical impedance tomography experimental device according to claim 3, characterized in that: The mounting seat is also provided with a detection hole, which is a blind hole and one end of which passes through the mounting seat; A sliding seat is axially slidably mounted on the intake pipe, and a sliding seat spring is mounted on the portion of the intake pipe outside the intake pipe and between the sliding seat and the end face of the plug-in hole, and the sliding seat spring is used to apply an elastic force to the sliding seat to hinder its movement toward the end face of the plug-in hole; the sliding seat is engaged and slidably mounted in the plug-in hole; a magnet is mounted on the sliding seat, and a reed switch is mounted at the position of the detection hole corresponding to the magnet, the reed switch is fixed on one end of the detection rod, and the other end of the detection rod passes through the detection hole, and the signal of the reed switch is introduced into the industrial computer.

7. The electrical impedance tomography experimental device according to any one of claims 1 to 6, characterized in that: A protective shell is fixed on the rack and outside the experimental barrel, one side of the protective shell is open and closed by a door panel, one side of the door panel is hinged to the protective shell by a hinge, and the other side is assembled with the protective shell by a door lock; an X-ray source is installed on the inner side of the door panel, and a detector is installed on the side of the protective shell located at the experimental barrel away from the X-ray source; the X-ray source is responsible for emitting X-ray beams, which will penetrate the experimental barrel and the model, and the detector is responsible for receiving the penetrated X-rays and converting them into electrical signals, which are then transmitted to a computer for processing to construct an internal structure image of the model.

8. The electrical impedance tomography experimental device according to any one of claims 1 to 6, characterized in that: A barrel cover is also installed on the top of the barrel, and the electrodes are evenly installed along the inner side of the barrel cover; a barrel cover groove is provided on the inner side of the barrel cover, and the barrel cover groove is plugged into the top edge of the experimental barrel to realize rapid positioning and installation of the barrel cover and the experimental barrel; a probe rack is also installed on the experimental barrel, and a probe of an ultrasonic liquid level meter is installed on the probe rack, and the probe is used to emit ultrasonic waves to the liquid surface in the experimental barrel to detect the liquid level, so that the industrial computer can calculate the volume through the liquid level.

9. The electrical impedance tomography experimental device according to claim 8, characterized in that: An electrode unit is installed on the inner side of the barrel cover, and the electrode is installed in the corresponding electrode unit. The electrode includes a positioning sleeve and an electrode part. The positioning sleeve is made of insulating material. The electrode part is connected to the imaging device by a wire and the electrode part is immersed in a conductive liquid. The electrode unit includes a fixed seat and a movable seat fixed on the inner side of the barrel cover. One side of the fixed seat is hinged to one side of the movable seat through a rotating shaft. A buckle groove is provided on the other side of the fixed seat. A buckle plate is provided on the other side of the movable seat. A buckle protrusion is provided on the buckle plate. The buckle plate is elastic and the buckle protrusion is snapped into the buckle groove to complete the assembly of the fixed seat and the movable seat. The fixed seat and the movable seat are respectively provided with a first half hole and a second half hole, the first half hole and the second half hole are respectively clamped and assembled with the positioning sleeve, and limiting rings are respectively provided at both ends of the positioning sleeve passing through the first half hole and the second half hole, and the limiting rings are tightly attached to the end faces of the fixed seat and the movable seat.

10. The electrical impedance tomography experimental device according to claim 1, characterized in that: The lung includes four independent lobes, each lobe is equipped with a conductor, the conductor is conductive and one end of the conductor passes through the corresponding lobe and the other end enters the corresponding lobe; Each lung lobe is connected to the corresponding bronchus, and the four bronchi are connected to one end of the first shunt tube, one end of the second shunt tube, one end of the third shunt tube, and one end of the fourth shunt tube, respectively. The other ends of the first shunt tube, the other ends of the second shunt tube, the other ends of the third shunt tube, and the other ends of the fourth shunt tube are connected to the outlet of the first reversing valve, the outlet of the second reversing valve, the outlet of the third reversing valve, and the outlet of the fourth reversing valve, respectively. The first inlet of the first reversing valve, the first inlet of the second reversing valve, the first inlet of the third reversing valve, The first inlet of the fourth reversing valve is respectively connected to the liquid supply pipe, the second inlet of the first reversing valve, the second inlet of the second reversing valve, the second inlet of the third reversing valve, and the second inlet of the fourth reversing valve are respectively connected to the gas supply pipe, and the first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve are respectively used to control their outlets to selectively connect to the first inlet and the second inlet; the first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve are all reversing valves, and the first shunt pipe, the second shunt pipe, the third shunt pipe, and the fourth shunt pipe are also shunt pipes; The liquid supply system includes a liquid supply pump and a return pump. The inlet of the liquid supply pump is connected to the conductive liquid, and the outlet is connected to the inlet of the hydraulic meter and the inlet of the liquid flow meter. The outlet of the liquid flow meter is connected to the liquid supply pipe. The outlet of the liquid supply pump is also connected to the inlet of the return pump. The outlet of the return pump is connected to a device for storing the conductive liquid. The air supply system comprises a breathing simulator, the air port of the breathing simulator is connected with the inlet of the barometer and the inlet of the gas flow meter, and the outlet of the gas flow meter is connected with the air supply pipe.

Images