CN111921048B

CN111921048B - Device and method for external calibration of breathing machine

Info

Publication number: CN111921048B
Application number: CN202010767176.5A
Authority: CN
Inventors: 周平; 刘国先; 杨勇; 傅洪波
Original assignee: Jinan University
Current assignee: Jinan University
Priority date: 2020-08-03
Filing date: 2020-08-03
Publication date: 2022-06-14
Anticipated expiration: 2040-08-03
Also published as: CN111921048A

Abstract

The invention discloses a device for externally calibrating a breathing machine, which comprises a cylinder structure, a support frame, a marker post, a center rod and a host; the cylinder structure comprises a cylinder body, an air inlet pipe and a partition plate, wherein the cylinder body is in a cylinder shape with one open end, the air inlet pipe is arranged on the wall surface opposite to the open end, and the partition plate is movably arranged in the cylinder body; the supporting frame is fixed at the opening end of the cylinder body; one end of the marker post is fixed on the clapboard, and the other end of the marker post can be movably connected on the supporting frame; a plurality of light blocking pieces are arranged on the marker post at intervals, an optical coupling sensor is arranged at the joint of the supporting frame and the marker post, and the light blocking pieces can penetrate through the optical coupling sensor; one end of the central rod is fixed at the center of the partition plate, and the other end of the central rod penetrates through the center of the support frame; a pressure sensor is arranged at the joint of the central rod and the partition plate, and a spring is arranged on the central rod; the cylinder structure is arranged on the host machine; the host is internally provided with a memory; the memory is electrically connected with the optical coupling sensor and the pressure sensor. The invention relates to the technical field of medical instruments.

Description

Device and method for external calibration of breathing machine

Technical Field

The invention relates to the technical field of medical instruments, in particular to a device and a method for externally calibrating a breathing machine.

Background

Various medical severe breathing machines are important medical instruments for rescuing and maintaining the life of patients in hospitals. All kinds of medical severe breathing machines at present can carry out inside self-checking and calibration to the inside various sensors of instrument before using, like flow sensor, pressure sensor etc. just can allow the supplementary function of ventilating that the doctor used the breathing machine to the instrument after the calibration detects, just can connect dedicated breathing machine pipeline and treat patient or maintain the function of ventilating of breathing.

However, if the sensor of the breathing machine is out of order and drifts, and the detection program in the breathing machine is out of order or has problems, and the sensor in the breathing machine is not detected out of order or drifts, the breathing machine passes all the self-checking programs, and the doctor can use the breathing machine as normal. However, since the sensor of the ventilator is in an abnormal condition, the set flow or pressure parameters during the treatment or respiratory maintenance of the patient will not meet the actual conditions, because the special conditions of the critical patient are very sensitive to the parameters of the ventilator, and the patient is easily injured or the treatment effect is not good under the condition of wrong parameter setting of the ventilator, which causes serious medical accidents.

Therefore, it is necessary for each clinical department using the ventilator to periodically compare and calibrate the parameters of various sensors of the ventilator using the instrument device, and it can avoid the risk and injury to the patient caused by the abnormal condition that the sensor inside the ventilator fails and the ventilator does not detect the abnormal condition. Such external calibration devices are currently lacking.

Disclosure of Invention

The aim of the present invention is to overcome the drawbacks and drawbacks of the prior art and to provide a device for external calibration of ventilators which allows external calibration of the sensors of the ventilator, ensuring that the parameters of the ventilator can be matched to the actual values during the treatment of the patient.

It is another object of the present invention to provide a method of externally calibrating a ventilator.

The purpose of the invention can be realized by the following technical scheme: a device for external calibration of a respirator comprises a cylinder structure, a support frame, a marker post, a center rod and a host;

the cylinder structure comprises a cylinder body, an air inlet pipe and a partition plate, wherein the cylinder body is in a cylinder shape with one open end, the air inlet pipe is arranged on the wall surface opposite to the open end, and the partition plate is movably arranged in the cylinder body;

the support frame is fixed at the opening end of the barrel body; one end of the marker rod is fixed on the partition plate, and the other end of the marker rod is movably connected to the support frame; a plurality of light blocking sheets are arranged on the marker post at intervals, an optical coupling sensor is arranged at the joint of the support frame and the marker post, and the light blocking sheets can penetrate through the optical coupling sensor;

one end of the central rod is fixed at the center of the partition plate, and the other end of the central rod penetrates through the center of the support frame; a pressure sensor is arranged at the joint of the central rod and the partition plate, a spring is arranged on the central rod, one end of the spring is connected with the pressure sensor, and the other end of the spring is fixed on the central rod;

the cylinder structure is arranged on the host machine; the host is internally provided with a memory; the memory is electrically connected with the optical coupling sensor and the pressure sensor.

Furthermore, the central rod comprises a spring section and a threaded section, the spring section comprises a pressure sensor, a fixed plate and a spring arranged between the pressure sensor and the fixed plate, the pressure sensor is fixed in the center of the partition plate, and the fixed plate is arranged between the spring section and the threaded section and is in threaded connection with the threaded section; the thread section is provided with threads, and the end part is provided with a pressure adjusting knob. The pressure adjusting knob can adjust the position of the fixing plate on the threaded section, so that the spring is compressed or stretched, and the value of the pressure sensor is changed.

Furthermore, a flow sensor is arranged on the air inlet pipe and electrically connected with the memory. The flow sensor is used for measuring the instantaneous flow rate of the gas flowing into the cylinder.

Furthermore, a pressure sensor is arranged on the air inlet pipe and electrically connected with the memory. The pressure sensor is used for measuring the pressure of the gas flowing into the cylinder.

Furthermore, the marking rod is provided with scale marks. The moving distance of the marker post can be obtained by reading the change of the scale mark.

Furthermore, a display screen and a function button are further arranged on the host. The display screen is used for displaying each parameter value of calibration, and the function button is convenient to carry out various function operations on the calibration device.

Furthermore, lubricating oil is filled or a ball bearing is installed at the movable connection positions of the marking rod, the central rod and the support frame. The sliding friction force of the marking rod, the center rod and the support frame can be reduced.

The other purpose of the invention can be realized by the following technical scheme: a method of externally calibrating a ventilator, comprising the steps of:

starting an external calibration device, and performing zero calibration and airflow parameter calibration on a pressure sensor and a pressure sensor of the external calibration device;

connecting a breathing pipeline of a breathing machine to an air inlet pipe of a cylindrical structure, starting a simulated lung operation mode of the breathing machine, and setting operation parameters of the breathing machine according to requirements;

the gas flow rate, the pressure and the volume parameters of the operation of the breathing machine are transmitted into a memory in the host through the optical coupling sensor, the pressure sensor, the flow sensor and the pressure sensor, the operation parameters of the breathing machine detected by the external calibration device are compared with the operation parameters set by the breathing machine, and whether the operation parameters of the breathing machine exceed the error range or not is judged.

Further, the pressure adjusting knob is adjusted to enable the pressure of the pressure sensor to be zero, the numerical value of the pressure sensor is adjusted to be zero, and zero calibration of the pressure sensor and the pressure sensor is completed.

Further, the pressure adjusting knob is adjusted to enable the partition board to extrude gas in the cylinder body, the gas pressure in the cylinder body is changed, the gas pressure required by the lung simulating mode of the respirator is achieved, and gas pressure parameter calibration is completed.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the external calibration device provided by the invention can measure each parameter of gas entering the cylinder, compares the parameter with the gas parameter output by the respirator, and judges the accuracy of each parameter of the respirator, whether the ventilation function is normal or not and whether the ventilation function can be normally used or not according to the comparison result.

2. The external calibration device has simple structure, can ensure that each parameter of the instrument is accurate, and has high reliability.

Drawings

FIG. 1 is a schematic diagram of an external calibration device according to an embodiment of the present invention;

FIG. 2 is a left side view of FIG. 1;

fig. 3 is a schematic structural view of the open end of the cylinder in the embodiment of the invention.

Wherein: 11: barrel, 12: an intake pipe, 13: a separator, 2: support frame, 3: marker post, 31: light barrier, 32: scale line, 4: center rod, 41: spring section, 42: thread segment, 43: fixing plate, 44: pressure adjusting knob, 5: opto-coupler sensor, 6: pressure sensor, 7: flow sensor, 8: pressure sensor, 9: host, 91: display screen, 92: function buttons.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

As shown in fig. 1 and 2, an apparatus for calibrating the exterior of a ventilator includes a cylindrical structure, a support frame 2, a marker post 3, a center post 4, an optical coupling sensor 5, a pressure sensor 6, a flow sensor 7, a pressure sensor 8, and a host 9.

The cylindrical structure includes a cylindrical body 11, an intake pipe 12, and a partition plate 13. The cylinder 11 is in a cylindrical shape with one open end, an air inlet pipe 12 is arranged on the wall surface opposite to the open end, and a partition plate 13 is movably arranged inside the cylinder 11. The calibration device uses a cylinder structure as an artificial lung to simulate human lung organs, a breathing pipeline of a breathing machine is connected to an air inlet pipe 12, and after the breathing machine is started, air enters a cylinder body 11 through the air inlet pipe 12, so that a partition plate 13 is pushed to move. The air inlet pipe 12 is provided with a flow sensor 7 and a pressure sensor 8. The flow sensor 7 is an ultrasonic flow sensor for measuring the instantaneous flow rate of the gas flowing into the cylinder 11. The pressure sensor 8 is used to measure the pressure of the gas flowing into the cylinder 11. The cylinder structure is arranged on the host machine 9, a memory is arranged in the host machine 9, the memory is electrically connected with the flow sensor, the optical coupling sensor, the pressure sensor and the pressure sensor, and data measured by all the sensors can be stored in the memory. Still be equipped with display screen 91 and function button 92 on the host computer shell, display screen 91 is used for showing each parameter numerical value of calibration, and function button 92 conveniently carries out various function operations to calibrating device.

The support frame 2 is fixed at the opening end of the cylinder body 11. The support frame 2 is cross-shaped, and a round hole is arranged in the middle of the cross shape. A semi-circular ring type supporting seat is embedded in one vertical plate of the cross-shaped supporting frame and used for supporting the marker post. One end of the sign rod 3 is fixed on the clapboard, and the other end passes through the semicircular annular supporting seat. A plurality of light blocking sheets 31 are arranged on the marker post 3 at intervals, an optical coupler sensor 5 is arranged at the joint of the support frame 2 and the marker post 3, namely the position of the semicircular annular support seat, and the light blocking sheets 31 can pass through the optical coupler sensor 5. With the movement of the partition 13, the marking rod 3 will move toward the opening of the cylinder, and the light blocking sheet 31 will pass through the light coupling sensor 5 successively. When the light blocking sheet 31 passes through the optical coupling sensor 5, a pulse signal is triggered, and since the distance of each light blocking sheet 31 is a certain value, the pulse signal is counted, and the moving distance of the marking rod 3 can be calculated. Meanwhile, the marking rod 3 is also provided with scale marks 32, and the moving distance of the marking rod 3 can be obtained by reading the number of the scale marks. Lubricating oil can be filled or a ball bearing can be installed at the joint of the marking rod and the supporting frame, so that the sliding friction force of the marking rod and the supporting frame reaches a very small range, and the calculation of the gas pressure in the cylinder is not influenced. Meanwhile, the calibration device of the invention can take the error caused by the friction force into account and correct the error through a relevant program.

One end of the central rod 4 is fixed at the center of the partition plate 13, and the other end of the central rod passes through the round hole of the support frame 2. The central rod 4 comprises a spring section 41 and a threaded section 42, the spring section 41 comprising a pressure sensor 6, a fixing plate 43 and a spring mounted between the pressure sensor 6 and the fixing plate 43. Pressure sensor 6 is fixed in the baffle center, and when 11 inside gas increase of barrel led to the baffle to the motion of barrel opening direction, the baffle will compress the spring, makes the spring take place deformation, and the pressure that the spring received will transmit pressure sensor 6 at the spring end, and the pressure value that pressure sensor 6 measured is the pressure of the internal gas of barrel. The fixing plate 43 is installed between the spring section and the threaded section and is in threaded connection with the threaded section 42. The threaded section 42 is threaded and the end is provided with a pressure adjustment knob 44. The position of the fixing plate 43 in the threaded section 42 can be changed by rotating the pressure adjusting knob 44, so that the spring is extended or compressed, and the purpose of adjusting the initial pressure value of the pressure sensor 6 is achieved. The joint of the central rod 4 and the support frame can also be filled with lubricating oil or provided with a ball bearing.

Before calibrating the respirator, the calibrating device of the invention firstly ensures that each parameter of the instrument is accurate, otherwise, the calibrating device has no meaning for calibrating other instruments.

First, the accuracy of the gas volume is guaranteed. The gas volume in the cylinder corresponds to the tidal volume of the ventilator, and the accuracy of the gas volume in the cylinder ensures the accuracy of the tidal volume of the ventilator. Since the cylinder body corresponds to a metering cylinder in which the gas volume is proportional to the moving position of the diaphragm, the increased gas volume inside the cylinder body can be measured by measuring the moving distance of the diaphragm. In this embodiment, the moving distance of the spacer is measured by an optical coupler sensor provided on the index rod. When the marker post moves along with the partition board, the light blocking sheet induces pulse signals in the optical coupling sensor, and the number of the pulse signals is in direct proportion to the linear distance of the marker post in movement, namely the movement distance of the partition board. In addition, the marker post is provided with scale marks, and the moving distance of the marker post can be read through the scale marks, so that whether the volume change of the gas in the cylinder conforms to the actual situation or not is judged, and the measuring accuracy of the gas volume is ensured.

Secondly, the accuracy of the gas pressure is ensured. The pressure sensors and the pressure sensors can be pre-stored with initial data of the two sensors under different spring pressures and different gas pressures during self-calibration, the self-calibration method comprises the steps of placing the partition plate 13 at a specific calibration position, sealing the air inlet pipe 12, adjusting the pressure knob 44 to enable the left partition plate 13 to generate pressure on the gas in the cylinder 11, sensing corresponding electrical parameter values on the gas pressure sensor 7 and the pressure sensor 6 at the bottom of the central rod due to the change of the gas pressure, and comparing the values with the self-calibrated values at the last time to know whether the sensors generate errors or drift. And comparing the detected data with the last data before each calibration use to determine the effectiveness and accuracy of the current sensor so as to better judge whether the sensor drifts in the use process. The accuracy of the parameters can be obtained by comparing the measured values of the two sensors after range conversion.

And thirdly, the accuracy of the gas flow is ensured. Ultrasonic flow sensing utilizes the principle that ultrasonic waves encounter a moving medium to generate frequency conversion to measure the flow of the entering gas. When the calibration device is used for self-testing, gas enters the cylinder, the flow sensor measures the flow of the inflowing gas, the optical coupler sensor records the moving distance (d) and the moving time (t) of the partition plate, the moving distance of the partition plate represents the increased volume of the gas in the cylinder (the volume is V, V is sdt, and s is the sectional area of the cylinder), and the ratio of the increased volume of the gas to the moving time of the partition plate is the flow Q (Q is V/t) of the gas in the cylinder, so that self-comparison calibration can be carried out on the flow sensor through the displacement parameters recorded in the calibration device.

The invention relates to a method for externally calibrating a respirator, which comprises the following steps:

(1) and starting an external calibration device, and performing zero calibration and airflow parameter calibration on the pressure sensor and the pressure sensor of the external calibration device. And adjusting the pressure adjusting knob to a proper position to enable the pressure of the pressure sensor to be zero, adjusting the numerical value of the pressure sensor to be zero, and completing zero calibration of the pressure sensor and the pressure sensor. When the breathing machine gas pressure parameter is required to be calibrated, the pressure adjusting knob can be adjusted as required, and due to the screwing action of the threads inside the knob, the knob can extrude the spring when being rotationally adjusted, so that the pressure is generated on the partition plate, the gas pressure inside the cylinder can be changed, and the gas pressure required by the simulated lung required to be tested by the breathing machine is achieved.

(2) Before the calibrating device calibrates the respirator, the instrument firstly runs a self-detection program, extracts the original data of each sensor needing self-detection, compares the data with the data obtained by self-detection, and determines that the operating condition of each sensor is normal.

(3) After the self-checking is completed, the breathing pipeline of the breathing machine is connected to the air inlet pipe of the cylinder structure, the simulated lung operation mode of the breathing machine is started, and the operation parameters of the breathing machine, such as the tidal volume, the airway pressure and the airway flow, are set as required. When the respirator starts to operate, displayed parameters are tidal volume and airway pressure value, airway flow can be displayed on a screen of the respirator, and when parameter calibration is carried out, a pressure adjusting knob can be adjusted as required, so that the pressure of the gas in the cylinder can better simulate the pressure of the lung of a human body. The parameters of the gas generated by the operation of the respirator are also recorded in the memory of the calibration device through the transmission effect of the cylinder structure, and are displayed on the screen of the host computer, and can be compared with the parameters of the respirator, and if the error exceeds the range, the sensor of the respirator can be adjusted or replaced according to the requirement.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A device for externally calibrating a respirator is characterized by comprising a cylinder structure, a support frame, a marker post, a center rod and a host;

2. The apparatus of claim 1, wherein the center rod comprises a spring section and a threaded section, the spring section comprises a pressure sensor, a fixing plate and a spring installed between the pressure sensor and the fixing plate, the pressure sensor is fixed at the center of the partition plate, and the fixing plate is installed between the spring section and the threaded section and is in threaded connection with the threaded section; the thread section is provided with threads, and the end part of the thread section is provided with a pressure adjusting knob.

3. The apparatus of claim 1, wherein a flow sensor is disposed on the inlet conduit, the flow sensor being electrically connected to the memory.

4. The apparatus of claim 1, wherein a pressure sensor is disposed on the inlet conduit, the pressure sensor being electrically connected to the memory.

5. The apparatus according to claim 1, wherein the marker post is provided with graduations.

6. The apparatus of claim 1, wherein the main body further comprises a display and a function button.

7. The device of claim 1, wherein the moveable connection of the marker post, the center post and the support frame is lubricated or provided with a ball bearing.