CN112370622B

CN112370622B - Equivalent air suction instrument

Info

Publication number: CN112370622B
Application number: CN202011068387.6A
Authority: CN
Inventors: 何建行; 王洪奎; 李春景
Original assignee: Individual
Current assignee: Weihai Hongyuan Medical Technology Co.,Ltd.
Priority date: 2020-10-08
Filing date: 2020-10-08
Publication date: 2023-04-28
Anticipated expiration: 2040-10-08
Also published as: WO2022073339A1; CN112370622A

Abstract

The invention provides an equivalent inspiration meter which comprises an oxygen source, a throttle valve, a valve group, a flexible air bag, a rigid container, an inflator pump, a mask assembly and a system controller. The flexible air bag is arranged in the rigid container, high-pressure oxygen output by the oxygen source can be recorded into the flexible air bag to be inflated at a fixed speed through the throttle valve and the electromagnetic valve, and the system controller can accurately charge a certain amount of oxygen into the flexible air bag by controlling the inflation time; the inflator is capable of providing a pressure within the rigid container that is greater than one atmosphere. The mask assembly includes a mask body and a mask synchronizing switch. The equivalent inhalation device can enable the patient to inhale equivalent gas before CT scanning, thereby reducing or eliminating respiratory errors, and has important significance for interventional therapy or puncture biopsy by CT guidance.

Description

Equivalent air suction instrument

Technical Field

The invention relates to an auxiliary device for a medical image acquisition process, and belongs to the technical field of medical image systems.

Background

CT intervention is a mature and effective percutaneous puncture nonvascular interventional technique, comprises CT guided percutaneous puncture biopsy and interventional treatment, and can be used for various parts of the whole body, including brain, chest, abdomen, musculoskeletal systems and the like.

CT has higher density resolution and spatial resolution, and can clearly show the size, shape and position of lesions and the adjacent relation between lesions and surrounding tissues and organs. The method has the advantages of accurate positioning of the lesions, clear knowledge of the conditions of soft tissues in and around the lesions, avoidance of important tissue structures or lesion necrosis areas, accurate determination of needle insertion points, angles and depths, and accurate realization of puncture targets by adjustment at any time under scanning monitoring. In contrast, ultrasound guided penetration has limitations, in the case of lung and bone biopsy, due to the high attenuation coefficient of the lung, acoustic impedance exists at the air-soft tissue, air-liquid plane and bone interface, so that the ultrasound energy is attenuated, CT is better, and for body type obesity, the focus is located in the deep skin, and CT guided penetration evaluates the target area better.

Typically, a patient will take a breath hold and hold before a CT scan is performed by the physician. If the inhalation amount of each time is different, the viscera position of the patient is changed, so that the obtained CT sheets are different, which is a troublesome matter for interventional therapy and puncture biopsy. Accordingly, there is a need in the art to provide a device that allows the patient to inhale an equal amount of air into the lungs before each CT scan, thereby reducing or eliminating respiratory errors, which is significant for interventional procedures and needle biopsies conducted with CT guidance.

Disclosure of Invention

The invention aims to provide an equivalent aspirator so as to eliminate puncture errors caused by respiration when interventional therapy or puncture biopsy is performed under CT guidance.

The technical scheme of the invention is as follows.

The first aspect of the invention provides an equivalent aspirator comprising: an oxygen source, a throttle valve, a valve set, a flexible bladder, a rigid container, an inflator pump, a mask assembly, and a system controller; it is characterized in that the method comprises the steps of,

the rigid container has a first opening and a second opening; the flexible bladder is mounted within the rigid container and has an inlet mounted to the first opening, thereby forming a first space within the flexible bladder having a first opening and a second space within the rigid container having a second opening;

the first space is connected to the oxygen source and the mask assembly through a first opening, the valve set, the throttle valve; the second space is connected with the inflator pump through a second opening and the valve group.

Preferably, the valve group comprises a first valve, a second valve, a third valve and a fourth valve;

the first opening is connected with the first end of a three-way pipe; the second end of the three-way pipe is connected with the oxygen source through the first valve and the throttle valve; the second end of the tee pipe is connected with the mask assembly through the second valve;

the second opening is connected with the first end of a four-way pipe; the second end of the four-way pipe is connected with the external environment through the third valve; the third end of the four-way pipe is connected with an inflator pump through the fourth valve; the fourth end of the four-way pipe is connected with a first pressure gauge.

Preferably, the system controller is capable of controlling each valve of the valve train such that the valve train is in one of the following states

First state: the first valve and the third valve are opened, and the second valve and the fourth valve are closed; at the moment, oxygen of the oxygen source is filled into the first space, and air in the second space is discharged;

second state: the first valve and the third valve are closed, the second valve is closed, and the fourth valve is opened; the inflator pump inflates the second space at the moment;

third state: the first valve and the third valve are closed, the second valve is opened, and the fourth valve is closed; at this time, the first space outputs oxygen outwards.

Preferably, the pressure gauge further comprises a self-calibration device, wherein the self-calibration device comprises a rigid self-calibration bottle and a second pressure gauge; the input port of the self-calibrating bottle is connected with the second valve and is also provided with an opening connected with the second pressure gauge.

Preferably, the mask assembly includes a mask body and a mask synchronizing switch;

the mask body has a contour suitable for forming airtight fit with the face of a user, and a gas inlet;

the mask synchronous switch comprises a coaxial inner tube, a coaxial outer tube and a switch driver; corresponding macropores are formed in the coaxial inner tube and the coaxial outer tube respectively, a vent tube is further arranged on the coaxial outer tube, and the coaxial inner tube and the coaxial outer tube are connected with the second valve through the vent tube.

Preferably, the outer diameter of the coaxial inner tube is substantially equal to the inner diameter of the coaxial outer tube, one ends of the two tubes are open ends and are communicated with the gas inlet of the mask body, and the other ends of the two tubes are provided with a switch driver and are sealed from the outside.

Preferably, the system controller is capable of controlling the switch driver to rotate the inner coaxial tube relative to the outer coaxial tube so as to cause the mask assembly to be in one of:

state 1: the large holes of the coaxial inner tube are aligned with the large holes of the coaxial outer tube; at this time, external air can enter the mask body through the coaxial outer tube and the coaxial inner tube;

state 2: the large hole of the coaxial inner tube is aligned with the small vent pipe of the coaxial outer tube; the oxygen output by the first space can enter the mask body through the second valve;

state 3: the perforation of the coaxial inner tube is aligned with the wall of the non-opening tube of the coaxial outer tube; the mask body is now isolated from the outside.

Preferably, the first valve, the second valve, the third valve and the fourth valve are all normally closed electromagnetic valves.

The second aspect of the present invention provides a method for calibrating an equivalent aspirator according to the above technical solution, the method comprising the following steps:

step 101, controlling the valve group to be in the first state, and using the oxygen source to charge air into the flexible air bag at a certain speed through the throttle valve, and charging a certain amount of oxygen into the flexible air bag by controlling the charging time;

step 102, controlling the valve group to be in the second state, and inflating the second space by using the inflator pump to enable the pressure in the rigid container to be greater than one atmosphere;

step 103, connecting the output end of the second valve to the input port of the self-calibration container;

step 104, controlling the valve group to be in the third state; and recording a reading of a second pressure gauge on the self-calibration device;

step 105, repeating steps 101-104 a plurality of times, if the readings of the second pressure gauge each time differ by less than 8%, then it is demonstrated that an equivalent inflation can be accomplished to the first space within the flexible bladder.

A third aspect of the present invention provides a method for assisting in performing CT image acquisition using an equivalent aspirator according to one of the above aspects, the method comprising the steps of:

step 201, installing the mask body on the face of a patient, and controlling the mask assembly to be in a state 1, a state 2 and a state 1 in sequence, so as to enable the patient to inhale, exhale and re-inhale correspondingly;

step 202, switching the mask assembly to a state 3, performing CT scanning, and switching the mask assembly to a state 2 after obtaining a picture so as to allow the patient to breathe freely;

step 203, determining a point of interest according to the need;

step 204, moving the CT bed to enable the fault of the interest point to be located in a CT scanning plane;

step 205, controlling the mask assembly to be in a state 1, a state 2 and a state 1 in sequence, and accordingly enabling the patient to inhale, exhale and re-inhale;

at step 206, a CT single-layer scan is performed.

Through the technical scheme, the invention can achieve the following technical effects.

(1) The volume of gas filled into the flexible air bag can be accurately controlled;

(2) Can allow the patient to exhale the air in the lung as much as possible before inhaling;

(3) The oxygen filled in the flexible air bag can be fully sucked into the lung of a patient during inspiration, and the air quantity sucked by the patient during CT scanning is equal each time because the air quantity of the oxygen filled into the flexible air bag is equal each time, so that the error caused by breathing is avoided.

Drawings

FIG. 1 is a schematic diagram of a CT real-time positioning precision puncture system according to the present invention;

FIG. 2 is a schematic diagram of a robot configuration of the CT real-time positioning precision puncture system of FIG. 1;

FIG. 3 is a schematic view of a robot hand structure of the robot of FIG. 2;

FIG. 4 is a schematic view of the trocar gripper structure of the robot of FIG. 2;

FIG. 5 is a schematic view of an equivalent aspirator of the robot of FIG. 1;

figure 6 is a schematic view of a mask assembly of the equivalent aspirator of figure 5.

The meaning of the individual reference numerals in the figures is as follows:

10-CT scanning equipment, 20-puncture robot, 30-system control box, 40-equivalent aspirator and 50-computer;

the device comprises a large-aperture bearing, a first connecting piece 22-a mechanical arm 23-a mechanical arm 24-a mechanical arm 25-a puncture angle controller 26-a box-type sliding block 27-an inner sleeve driver 28-a second connecting piece, a C1-upper machine box, a C2-lower machine box, a T1-outer sleeve, a T2-inner sleeve, a U-cantilever structural member, a M1-first motor, a L1-first lead screw, a B1-first nut, a G1-outer gear and a G2-inner rack;

241-puncture depth controller, 242-puncture driver, 243-depth control slider, 244-pressure plate, 245-trocar holder, 246-first bearing, 247-first linear slide, 248-second bearing, 249-second linear slide, M2-second motor, L2-second screw, B2-second nut, M3-third motor, L3-third screw, B3-third nut;

401-flexible air bag, 402-rigid container, 403-throttle valve, 404-medical oxygen bottle, 405-inflator, 406-first pressure gauge, 407-second pressure gauge, 408-self-calibration bottle, 409-mask body, 410-coaxial outer tube, 411-coaxial inner tube, 412-switch driver, 413-small vent tube, 414-large hole, 415-system controller, K1-first valve, K2-second valve, K3-third valve, K4-fourth valve, K5-fifth valve, P1-tee, P2-tee.

Detailed Description

The term "CT" as used herein means CT (Computed Tomography), i.e., computed tomography, which refers to an image examination technique that uses precisely collimated X-rays, gamma rays, ultrasound, etc., together with extremely sensitive detectors, to scan one by one cross-sections around a part of the body. The rays used can be classified differently according to the type: x-ray CT (X-CT), gamma-ray CT (gamma-CT), and the like.

The terms "proximal" and "distal" as used herein refer to the positional relationship with respect to the CT machine, i.e., the end proximal to the CT machine and the end distal to the CT machine.

As shown in fig. 1, a CT real-time positioning accurate puncture system according to the present invention includes: a CT scanning device 10, a puncture robot 20, a control system 30, an equivalent aspirator 40 and a computer 50.

As shown in fig. 2, the puncture robot 20 of the CT real-time positioning precision puncture system in fig. 1 includes: the machine box, the mechanical arm 23, the mechanical arm 24 and the puncture angle controller 25.

The penetration robot 20 is adapted to be positioned directly behind the CT scanning apparatus 10. The chassis comprises an upper chassis C1 and a lower chassis C2. The system control box is mounted on the lower casing C2 of the puncture robot 20.

The middle part of the upper chassis C1 is provided with a basically cylindrical machine manhole, and a large-aperture bearing 21 is arranged at the near end of the machine manhole. When the puncture robot 20 is placed right behind the CT scanning apparatus 10, the center axis of the machine manhole coincides with the center axis of the scanning hole of the CT scanning apparatus 10. The large bore bearing 21 includes an outer sleeve T1 and an inner sleeve T2. The outer sleeve T1 is mounted on the upper chassis C1. A first connecting piece 22 is arranged at the upper proximal end inside the inner sleeve T2, and a box-type sliding block 26 is fixed at the lower end of the first connecting piece 22. The mechanical arm 23 is connected to the first connecting member 22 through the box-type slider 26.

The distal end of the mechanical arm 23 is disposed in the machine manhole, is parallel to the central axis of the machine manhole, and can move in a circular arc shape near the outer circumference of the machine manhole above the inside of the hole of the CT scanning apparatus 10 with the rotation of the inner sleeve T2 of the large-aperture bearing 21.

The robot 24 is disposed at a proximal end of the mechanical arm 23, and is configured to perform a puncturing operation.

The puncture angle controller 25 is disposed at a distal end of the mechanical arm 23, and is configured to control an angle of the puncture operation of the robot 24.

In a preferred embodiment, the distal end of the first connector 22 is fitted with a cantilever structure U parallel to the axis of the large bore bearing 22. The distal end of the cantilever structure U is provided with a first motor M1 and a first lead screw L1 parallel to the cantilever structure. In a preferred embodiment, the cantilever structure U is a U-channel. The shaft of the first motor M1 is connected with a first screw rod L1. The first nut B1 on the first screw L1 is fixed to the housing of the puncture angle driver 25. The first motor M1 is capable of driving the first nut B1 to move on the first lead screw L1, thereby driving the penetration angle driver 25, the mechanical arm 23 and the robot arm 24 to move longitudinally in the CT scanning apparatus bore, thereby positioning the trocar holder 245 on the robot arm 24 in or out of the X-ray scanning plane of the CT scanning apparatus.

In a preferred embodiment, a circular arc-shaped rack G2 is disposed under the inner portion of the inner sleeve T2. The upper chassis C1 further includes an inner sleeve driver 27, where the inner sleeve driver 27 includes a gear G1 engaged with the circular rack G2, so as to drive the inner sleeve T2 to rotate. Those skilled in the art will appreciate that the curved rack G2 may be an inner rack or an outer rack as desired.

In a preferred embodiment, to eliminate breathing errors, an equivalent aspirator 40 is also mounted within the robot. The equivalent inspiratory apparatus 40 is capable of delivering an equivalent amount of oxygen each time the patient inhales. The patient inhales an equal amount of oxygen before each CT scan, thus substantially eliminating breathing errors and allowing the patient to breathe freely.

The system control box 30 is connected to the computer 50 via an interface (e.g., RS 232). The penetration robot 20 can automatically aim the penetration trocar at the target point accurately as long as it receives the penetration point and the target point determined by the doctor, and can automatically, real-time and accurately penetrate the target point set in the patient. In a preferred embodiment, the computer 50 is configured on a dedicated console, positioned adjacent to the control device of the CT scanning device, for coordinated operation.

As shown in fig. 3, the robot hand 24 of the CT real-time positioning precision puncture robot according to the present invention includes: a penetration depth controller 241, a penetration driver 242, and a trocar holder 245. The robot arm 24 is mounted at the proximal end of the robot arm 23 at a substantially right angle to the robot arm 23.

In a preferred embodiment, the penetration depth controller 241 includes a second motor M2, a second screw L2, a second nut B2, a first linear slide 247, and a depth control slider 243. The second motor M2 is fixed at the proximal end of the mechanical arm 23, a rotating shaft of the second motor M2 is connected with the second screw rod L2, a second nut B2 on the second screw rod L2 is connected with a depth control slider 243 of the first linear sliding rail 247, the depth control slider 243 is connected with the puncture driver 242, and the second motor M2 can drive the puncture driver 25 to move up and down. In an alternative embodiment, the rotation shaft of the second motor M2 is set in a horizontal direction, the second screw L2 is set in a vertical direction, the rotation shaft of the second motor M2 is connected with a first bevel gear, the upper end of the second screw L2 is connected with a second bevel gear, and the first bevel gear can be meshed with the second bevel gear and the axes of the first and second bevel gears are mutually perpendicular.

In a preferred embodiment, the puncture driver 242 includes a third motor M3, a third screw L3, a third nut B3, and a pressing plate 244. The rotating shaft of the third motor M3 is connected with the third screw L3, and a third nut B3 on the third screw L3 is connected with the pressing plate 244. In a more preferred embodiment, the pressure plate 244 is "7" shaped, and a trocar is disengaged from the robot 24 each time the pressure plate 244 is depressed to the lowermost end.

As shown in fig. 4, the trocar holder 245 of the CT real-time positioning precision puncture robot according to the present invention includes a connection plate a, a first strip-shaped plate b, and a second strip-shaped plate c. The first and second strip plates b and c are parallel to each other and perpendicular to the arm 6, and the upper ends thereof are connected to the connection plate a, triangular grooves are formed on opposite sides between the first and second strip plates, respectively, and the trocars are disposed in trocar guide holes formed by the two triangular grooves.

In addition, the trocar holder 245 can also be used to hold a marking device prior to performing a lancing operation, thereby marking the site to be lanced to confirm that the set lancing position is in agreement with the actual condition. In a preferred embodiment, the marking device may be a marker pen suitable for use in a medical environment.

In a preferred embodiment, a U-shaped wing is provided on the face of the second nut B2 facing the first linear rail 247, and the U-shaped wing is connected to the depth control slider 243 and the puncture driver 242.

As shown in fig. 5, the equivalent aspirator 40 of the CT real-time positioning precision puncture robot according to the present invention includes: flexible bladder 401, rigid container 402, throttle valve 403, medical oxygen cylinder 404, inflator 405, valve set, mask assembly, and system controller 415.

The rigid container 402 has a first opening and a second opening; the flexible bladder 401 is mounted within the rigid container 402 and its inlet is mounted to the first opening, thereby forming a first space with a first opening within the flexible bladder 401 and a second space with a second opening within the rigid container 402.

The first space is connected to the medical oxygen cylinder and the mask assembly through a first opening, the valve set, the throttle valve 403. The second space is connected to the inflator 405 through a second opening, the valve train.

In a preferred embodiment, the valve group comprises a first valve K1, a second valve K2, a third valve K3 and a fourth valve K4.

In a preferred embodiment, the first valve K1, the second valve K2, the third valve K3, and the fourth valve K4 are all normally closed solenoid valves.

The first opening is connected with a first end of a three-way pipe P1; the second end of the tee pipe P1 is connected with the medical oxygen bottle 404 through the first valve and the throttle valve 403. The second end of the tee P1 is connected to the mask assembly via the second valve K2.

In a preferred embodiment, a fifth valve K5 is also provided between the second valve K2 and the mask assembly to shut off oxygen output to the mask assembly in situations such as a self-calibration process.

The second opening is connected with the first end of one four-way pipe P2; the second end of the four-way pipe P2 is connected with the external environment through the third valve; the third end of the four-way pipe P2 is connected with an inflator pump through the fourth valve; the fourth end of the four-way pipe P2 is connected with a first pressure gauge.

In a preferred embodiment, the system controller 415 is capable of controlling each valve of the valve train such that the valve train is in one of the following states.

First state: the first valve K1 and the third valve K3 are opened, and the second valve K2 and the fourth valve K4 are closed. At this time, the oxygen in the medical oxygen bottle 404 is filled into the first space, the air in the second space is discharged, and the external pressure is maintained in both the first space and the second space.

Second state: the first valve K1 and the third valve K3 are closed, the second valve K2 is closed, and the fourth valve K4 is opened. At this time, the inflator pump inflates the second space, and the pressure in the second space gradually increases.

Third state: the first valve K1 and the third valve K3 are closed, the second valve K2 is opened, and the fourth valve K4 is closed. At this time, the first space outputs oxygen outwards, and the pressures in the first space and the second space gradually decrease.

In a preferred embodiment, the equivalent aspirator 40 further comprises a self-calibration device comprising a rigid self-calibration bottle 406 and a second pressure gauge 407. The input port of the self-calibrating bottle 406 is connected to the second valve K2 and also has an opening to the second pressure gauge.

As shown in fig. 6, the mask assembly includes a mask body 409 and a face-synchronized switch.

The mask body 409 has a profile adapted to form an airtight fit with the face of the user, and a gas inlet.

The mask synchronizing switch includes a coaxial outer tube 410, a coaxial inner tube 411, and a switch driver 412. The coaxial inner tube 411 and the coaxial outer tube 410 are respectively provided with corresponding large holes 414. The coaxial outer tube 410 is further provided with a vent tube 413, and is connected to the second valve K2 through the vent tube 413.

The coaxial inner tube 411 has an outer diameter substantially equal to an inner diameter of the coaxial outer tube 410, and has one end which is an open end and communicates with the gas inlet of the mask body 409, and the other end of which is provided with a switch driver 412 and is sealed from the outside.

The system controller 415 can control the switch driver 412 to rotate the inner coaxial tube 411 relative to the outer coaxial tube 410, thereby placing the mask assembly in one of the following states.

State 1: the large aperture of the inner coaxial tube 411 is aligned with the small vent tube 413 of the outer coaxial tube 410; the oxygen output from the first space can now enter the mask body 409 through the second valve K2.

State 2: the large holes of the inner coaxial tube 411 are aligned with the large holes of the outer coaxial tube 410; at this time, the outside air can enter the mask body through the coaxial outer tube and the coaxial inner tube.

State 3: the large holes of the coaxial inner tube 411 are aligned with the non-open tube wall of the coaxial outer tube 410; the mask body 409 is now isolated from the outside.

The following describes a method of calibrating an equivalent aspirator according to the above embodiment, which is as follows.

Step 101, controlling the valve group to be in the first state, slowly inflating the flexible air bag 401 through the throttle valve 403 by using the medical oxygen bottle at a certain speed, and controlling the amount of oxygen inflated into the flexible air bag by controlling the inflation time.

Step 102, controlling the valve set to be in the second state, and inflating the second space with the inflator 405 to cause the pressure in the rigid container 402 to be greater than one atmosphere.

Step 103, connecting the output of the second valve K2 to the input of the self-calibrating bottle 408.

Step 104, controlling the valve group to be in the third state; and records the reading of the second pressure gauge 407 on the self-calibration device.

Step 105, repeating steps 101-104 a plurality of times, if the readings of the second pressure gauge 407 each time differ by less than 8%, then it is demonstrated that an equivalent inflation can be accomplished to the first space within the flexible bladder. In a more preferred embodiment, the readings of the second pressure gauge 407 differ by within 5% each time.

A method for assisting in performing CT image acquisition using the equivalent aspirator according to one of the above embodiments is described below, the steps of the method being as follows:

step 201, the mask body is mounted on the face of the patient, and the mask assembly is controlled to be in a state 1, a state 2 and a state 1 in sequence, so that the patient can inhale, exhale and re-inhale correspondingly.

Step 202, the mask assembly is switched to state 3, CT scan is performed, and after a picture is taken, the mask assembly is switched to state 2 to allow the patient to breathe freely.

And step 203, determining the point of interest according to the requirement.

At step 204, the CT couch is moved such that the point of interest slice is located in the CT scan plane.

Step 205, controlling the mask assembly to be in state 1, state 2, and state 1 in sequence, and accordingly, allowing the patient to inhale-exhale-re-inhale.

At step 206, a CT single-layer scan is performed.

Those skilled in the art will appreciate that when the mask assembly is in state 1, a certain amount of oxygen needs to be output to the mask assembly, and accordingly, a certain amount of oxygen needs to be inflated into flexible bladder 401 before switching to state 1. The control sequence of the valve set during the specific oxygen delivery process is the same as the calibration method process of the equivalent aspirator and is not repeated here.

The following describes a method for performing medical image acquisition and puncture using the CT real-time positioning precision puncture robot according to the above embodiment, which is as follows.

Step 301, installing the mask body on the face of the patient, and controlling the mask assembly to be in a state 1, a state 2 and a state 1 in sequence, so as to enable the patient to inhale, exhale and re-inhale correspondingly.

Step 302, the mask assembly is switched to state 3, CT scan is performed, and after a picture is taken, the mask assembly is switched to state 2 to allow the patient to breathe freely.

Step 303, determining the puncture point and the target point on the tomographic image with the largest (or larger) tumor tomographic image area.

At step 304, the CT couch is moved such that the patient puncture site slice is located in the CT scan plane.

Step 305, controlling the mask assembly to be in state 1, state 2, and state 1 in sequence, and accordingly, allowing the patient to inhale-exhale-re-inhale.

Step 306, the mask assembly is switched to a state 3 to perform CT single-layer scanning, at this time, a doctor can see the aiming puncture point and the target point of the sleeve on a CT computer screen, and send out a puncture command to complete accurate puncture.

While the invention has been described and illustrated in detail in the foregoing description with reference to specific embodiments thereof, it should be noted that various equivalent changes and modifications could be made to the above described embodiments without departing from the spirit of the invention as defined by the description and drawings.

Claims

1. An equivalent aspirator, comprising: an oxygen source, a throttle valve, a valve set, a flexible bladder, a rigid container, an inflator pump, a mask assembly, and a system controller; the method is characterized in that:

the first space is connected to the oxygen source and the mask assembly through a first opening, the valve set, the throttle valve; the second space is connected with the inflator pump through a second opening and the valve group;

the valve group comprises a first valve, a second valve, a third valve and a fourth valve;

the second opening is connected with the first end of a four-way pipe; the second end of the four-way pipe is connected with the external environment through the third valve; the third end of the four-way pipe is connected with an inflator pump through the fourth valve; the fourth end of the four-way pipe is connected with a first pressure gauge;

the system controller is capable of controlling each valve of the valve train such that the valve train is in one of the following states

third state: the first valve and the third valve are closed, the second valve is opened, and the fourth valve is closed; outputting oxygen outwards from the first space at the moment;

the mask assembly includes a mask body and a mask synchronizing switch;

2. The equivalent aspirator according to claim 1, further comprising a self-calibration device comprising a rigid self-calibration bottle and a second pressure gauge; the input port of the self-calibrating bottle is connected with the second valve and is also provided with an opening connected with the second pressure gauge.

3. An equivalent aspirator according to claim 1, characterized in that the outer diameter of the coaxial inner tube is substantially equal to the inner diameter of the coaxial outer tube, one ends of both tubes are open ends and communicate with the gas inlet of the mask body, and the other ends of both tubes are mounted with a switch driver and sealed from the outside.

4. An equivalent aspirator according to claim 3, wherein said system controller is capable of controlling said switch driver to rotate said inner coaxial tube relative to said outer coaxial tube to thereby place said mask assembly in one of the following conditions

State 1: the large hole of the coaxial inner tube is aligned with the vent pipe of the coaxial outer tube; the oxygen output by the first space can enter the mask body through the second valve;

state 2: the large holes of the coaxial inner tube are aligned with the large holes of the coaxial outer tube; at this time, external air can enter the mask body through the coaxial outer tube and the coaxial inner tube;

state 3: the large holes of the coaxial inner tube are aligned with the wall of the non-opening tube of the coaxial outer tube; the mask body is now isolated from the outside.

5. The inhalation apparatus according to one of claims 1 to 4, wherein the first, second, third and fourth valves are all normally closed solenoid valves.

6. A method of calibrating an equivalent aspirator according to claim 2, characterized by the steps of:

step 103, connecting the output end of the second valve to the input port of the self-calibrating bottle;

step 105, repeating steps 1-4 a plurality of times, if the readings of the second pressure gauge each time differ by less than 8%, then it is demonstrated that an equivalent inflation can be accomplished to the first space within the flexible bladder.

7. A method for assisting in performing CT image acquisition using an equivalent aspirator according to any one of claims 1-4, characterized in that the method comprises the steps of:

step 203, determining a point of interest according to the need;

at step 206, a CT single-layer scan is performed.