CN1024114C - Microcomputerized controller of respirator - Google Patents

Abstract

The present invention relates to a microcomputer controller for a respirator, which comprises an inspiratory flow sensor, an inspiratory valve, a pressure sensor, an expiratory flow sensor, an expiratory valve, a PEEP valve, a display alarm board, a front panel and a microcomputer control board. The microcomputer controller can form a ring-closed automatic control system for controlling flow and pressure in a breath loop of a patient and having various breath functions and monitor functions, and the control to the high-pressure air in a driving loop of the respirator is relatively independent from the control of the low-pressure air in the loop of the patient. In the present invention, the tasks of three sub-systems of timing, loop control and monitor in the control system are finished by a unitary hardware loop matched with different software program functional modules. The microcomputer controller has the advantages of small size, simple structure, low cost, multiple functions, convenient clinical use, high safety and reliability and convenient maintenance.

Description

Microcomputerized controller of respirator

The invention belongs to the control device of medium being imported the intravital a kind of medical apparatus and instruments of people, particularly a kind of microcomputerized controller of pneumatic respirator.

Respirator in the world is varied, and the bird respirator of the U.S. is typically arranged, but this respirator is operated and adjusted also inconvenience, at present seldom use owing to can not be applicable to the critical patient; The respirator that the electric electricing breathing machine of the seventies, US and European have many respirators and Chinese Shaoxing salable instrucment and meter plant to produce all belongs to this series products, though this class ventilator-structure is fairly simple, precision is not high; Micro-processor controlled breathing equipment has appearred after nineteen eighty-three in the world, for example U.S. Pat 4,637,385, US4,726,366, British patent GB2101895 etc., but the servo control mechanism difference of the controlled device-air-channel system of these respirators is very big, the control scheme that realizes is also different, and complex structure, cost height; Pneumatic, complicated electric controlled multi-functional respirator salable on the our times, Siemens's 900 serial respirators for example, have independently high drive compressor and complicated control system, air-channel system and control system respectively have a combined case, wherein air-channel system is fairly simple, control system is but quite complicated, control system volume and cost are the twice of air-channel system, control system is divided timing, control loop, three subsystems of monitoring again, adopt many analog devices to realize, complex structure, cost height, be difficult for extended function.

The objective of the invention is for a kind of microcomputerized controller of pneumatic respirator is provided, it makes the control system structure of respirator simple more, cost is low, volume is little, function is many, use respirator operation automation, the ratio of performance to price of this microcomputerized controller higher, be convenient to extended function, mobile flexible, easy to use, be fit to user's request more.

The objective of the invention is to realize: inspiratory flow sensor with following scheme, the expiratory gas flow pick off, pressure transducer, inlet valve, outlet valve, the PEEP valve all is installed in the breathing air-channel system of respirator, these senser elements and servo valve are used metal tube in gas circuit, silicone rubber spare is connected with plastic tube, inspiratory flow sensor is inserted in the middle of the air-breathing road, inlet valve is connected with mechanical driving device with motor, pressure transducer is connected on the air-breathing road by plastic tube, the expiratory gas flow pick off, outlet valve, the PEEP valve is installed in the middle of the expiration road successively, outlet valve is connected with mechanical driving device with the electromagnetic controller that drives outlet valve, and display alarm board is fixed on the front panel; Computer control board and inspiratory flow sensor, motor, pressure transducer, the expiratory gas flow pick off, electromagnetic controller, preamplifier, display alarm board, electrically connecting between front panel adjusted knob and display device and the on and off switch adopts flat cable to link, formation can realize the flow of the patient breathing circuit of seven kinds of respiratory functions and control function, the closed loop automatic control system of pressure, so just made the microcomputerized controller of pneumatic respirator, and the control of the low-pressure gas of the control of the gases at high pressure in the driving loop of respirator and patient breathing circuit is relatively independent; Computer control board can be finished the task of timing, control loop and three subsystems of monitoring, the used computer control board of microcomputerized controller can adopt 8 or 16 bit CPU chip or single-chip microcomputers, in save as the 24K byte, seven parallel interfaces, eight A/D input interfaces, a D/A output interface; Inlet valve adopts stepper motor driven shears valve, the shears valve that outlet valve adopts electromagnetic controller to drive; Inspiratory flow sensor, pressure transducer and expiratory gas flow pick off adopt high-precision sensor, adjusting knob on the front panel is shared for seven respiratory functions, general respirator dedicated capacity and pressure bound warning adjusting knob have been cancelled, its function multiply by up and down coefficient of variation by computer control board according to capacity or pressure set points to be determined automatically, microcomputerized controller can attach together with the air-channel system of respirator in same combination box, combination box can be placed on respectively on the levels that has the arbor wheel framework with air compressor, and assembling becomes an incorporate integral body.

The present invention with unified hardware circuit, be equipped with the task of timing that different software program functional devices realized control system, control loop, three subsystems of monitoring, microcomputer digitizer integrated level height in addition, hardware circuit greatly reduces, therefore volume greatly reduces, thereby the microcomputerized controller of respirator and the air-channel system of respirator can be attached together in same casing, simple in structure, with low cost, and make technical specifications such as the function of respirator and precision all be listed as world's first; Respirator has improved the precision of respirator, thereby has reduced the influence of critical patient's lung compliance and air flue change in resistance owing to adopted this microcomputerized controller; Cancelled the special-purpose warning bound of general respirator setting knob on the panel, causing reports to the police thinks that machine is out of order by mistake in case owing to mistake is set, when the upper pressure limit warning takes place when, can make machine close inlet valve automatically, drive outlet valve, in order to avoid overvoltage impairing the lung, to clinical very easy to use, safe and reliable, be convenient to safeguard.

The invention will be further described below with reference to accompanying drawing:

Fig. 1 is the microcomputerized controller principle schematic of respirator

Fig. 2 is the microcomputerized controller structural plan sketch map of respirator

Fig. 3 is the front-panel structure sketch map

Fig. 4 is the hardware block diagram of computer control board

Fig. 5 is the software function block diagram of computer control board

In Fig. 1,1 is that inspiratory flow sensor, 2 is that air-breathing road, 3 is that inlet valve, 4 is that pressure transducer, 5 is that expiratory gas flow pick off, 6 is that expiration road, 7 is that outlet valve, 8 is that PEEP valve, 9 is that motor, 10 is that electromagnetic controller, 11 is that preamplifier, 12 is that computer control board, 13 is that display alarm board, 14 is a front panel

In Fig. 2,21 be the air-channel system of microcomputerized controller and respirator combination box, 22 for empty oxygen mixer, 23 for measuring equipment for oxygen concentration ard, 24 for the demand check valve, 25 for biofilter, 26 for reservoir bag, 27 for relief valve, 28 for regulated power supply

In Fig. 3,30 are the digital demonstration of setting value, and 31 is frequency, moisture and alarm indicator, 32 is alarm lamp, 33 are the digital demonstration of actual measurement parameter, 34 is that three measured values show the selection key switch, and 35 for triggering pressure knob, and 36 is the airway pressure knob, 37 is the minute ventilation knob, 38 is empty oxygen mixer adjusting knob, and 39 are the oxygen concentration demonstration, and 301 is airway pressure gauge, 302 is that seven respiratory functions are selected key switch, 303 is quiet two minutes buttons, and 304 is reset key, and 305 is on and off switch, 306 is the breath holding time knob, 307 is the inspiratory duration knob, and 308 is the respiratory frequency knob, and 309 is that three setting values show the selection key switch

In Fig. 4,40 is CPU, and 41 is control logic, and 42 is EPROM, and 43 is RAM, and 44 is the D/A interface, and 45 is the A/D interface, and 46 is display latch and driver, and 47 are buffering and latch, and 48 is special-purpose LPT and valve driver, and 49 is intervalometer

In Fig. 5,50 are initialization, and 51 are sampling and storage, and 52 are the respiratory function conversion, and 53 is control module, and 54 are timing, and 55 for calculating and handling, and 56 for showing, 57 for reporting to the police, and 58 are self check

With reference to Fig. 1, Fig. 2 and Fig. 3, inspiratory flow sensor 1, expiratory gas flow pick off 5, pressure transducer 4, inlet valve 3, outlet valve 7 and PEEP valve 8 all are installed in the patient respiration air-channel system of respirator, these senser elements and servo valve are used metal tube in breathing gas circuit, silicon is connected with plastic tube as glue spare, inspiratory flow sensor 1 is inserted in the middle of the air-breathing road 2, inlet valve 3 is connected with motor 9 usefulness mechanical driving devices, pressure transducer 4 is connected on the air-breathing road 2 by plastic tube, expiratory gas flow pick off 5, outlet valve 7, PEEP valve 8 is installed in the middle of the expiration road 6 successively, outlet valve 7 is connected with the electromagnetic controller 10 usefulness mechanical driving devices that drive outlet valve 7, the upper fixed display alarm board 13(of pro-panel 14 installs the digital demonstration 30 of setting value on display alarm board 13, respiratory frequency, tidal volume and alarm show 31, alarm indicator 32, the actual measurement parameter code shows 33); Seven respiratory function also is housed on the pro-panel 14 selects key switch 302(IPPV, SIGH, SIMV((f)/2), SIMV((f)/4), MMV, CPAP, PSV), select interlocking key switch (setting value demonstration selection key switch 309 for two three, measured value shows selects key switch 34), six knob (respiratory frequency knobs 308 that respiration parameter is set, inspiratory duration knob 307, breath holding time knob 306, minute ventilation knob 37, airway pressure knob 36, trigger pressure knob 35), empty oxygen mixer adjusting knob 38, oxygen concentration shows 39, airway pressure gauge 301, quiet 2 minutes buttons 303, reset key 304 and on and off switch 305; Adjusting knob on the front panel 14 is shared for seven respiratory functions, general respirator dedicated capacity and pressure bound warning adjusting knob have been cancelled, holding under the control state, the capacity limit can multiply by coefficient of variation up and down according to the capacity setting value, automatically determine that by computer control board 12 the pressure limit is regulated then and replaced with airway pressure adjusting knob 36; Under voltage-controlled state, the pressure limit can multiply by coefficient of variation by pressure set points, is determined automatically by computer control board 12, and the capacity limit is regulated then and replaced with minute ventilation adjusting knob 37; Inspiratory flow sensor 1, pressure transducer 4 and expiratory gas flow pick off 5 adopt high-precision sensor; The shears valve that inlet valve 3 adopts motor 9 to drive is controlled the size that subtended angle left and closed by inlet valve 3 by the variation of stepper 9 travel directions, step number, thus the size of control ventilation; The shears valve that outlet valve 7 adopts electromagnetic controller 10 to drive is controlled opening or closing of outlet valve 7 by electromagnetic controller 10 there is electric power or not, exhales with control; The computer control board 12 that microcomputerized controller adopted can adopt 8 or 16 s' cpu chip or single-chip microcomputer, as: Z80,8085,8088,8051 or 8098 microsystems that constitute, in save as the above byte of 16K, seven above parallel interfaces, 8 to 16 A/D input interfaces, a D/A output interface; The breathing analog quantity parameter of A/D input interface input comprises actual measurement ventilation parameter (pressure, flow), set ventilation parameter (per minute ventilation, airway pressure, pressure is sent out at the angle), set timing parameters (respiratory frequency, inspiratory duration, breath holding time), digital output interface output inspiratory flow resets, motor four phase switches and electromagnetic controller switching signal, computer control board 12 can be finished regularly, the task of control loop and three subsystems of monitoring, computer control board 12 and inspiratory flow sensor 1, motor 9, pressure transducer 4, expiratory gas flow pick off 5, electromagnetic controller 10, preamplifier 11, display alarm board 13, electrically connecting between adjusting knob on the front panel 14 and display device and the on and off switch can adopt flat cable to link, formation can realize that IPPV is interrupted formal the breathing, SIGH sighs, SIMV((f)/2) be interrupted forced breathing synchronously, SIMV((f)/4) be interrupted forced breathing synchronously, MMV forces the per minute ventilation, the CPAP continuous positive pressure breathing, PSV pressure is supported the flow of the patient breathing circuit of seven kinds of respiratory functions and control function, the pressure closed loop automatic control system, like this, just made the microcomputerized controller of respirator; And make the low-pressure gas control of the control of gases at high pressure in gas-powered loop of respirator and patient breathing circuit relatively independent, the air-channel system of microcomputerized controller and respirator can attach together in same combination box 21, combination box 21 can be placed on respectively on the levels that has the arbor wheel framework with air compressor, and assembling becomes an incorporate integral body.

It is to select the selector switch signal of key switch 302 generations to input to computer control board 12 through the digital interface of computer control board 12 by the respiratory function on the front panel 14 that this microcomputerized controller respiratory function is selected, and corresponding respiratory function program is carried out in 12 inputs of instruction computer control board; The realization of respiratory function is will be set value through the A/D interface by respiration parameter setting adjusting knob on the front panel 14 to input to computer control board 12; Pressure transducer 4, inspiratory flow sensing 1 and expiratory gas flow pick off 5 measured actual measurement parameters also input to computer control board 12 through the A/D input interface, utilize computer control board 12 to calculate, survey the comparison of parameter and setup parameter, the correction and the Digital Signal Processing such as compensation, filtering of inspiratory flow sensor 1 and motor 9 curves, by digital interface output corresponding control signal, the subtended angle of control inlet valve 3 and outlet valve 7, thus the closed loop of adjusting respiratory flow, realization capacity or pressure is in real time controlled automatically; For simplify the hardware and software of microcomputerized controller as far as possible, breathing pattern is divided into mechanical ventilation (holding control or voltage-controlled), autonomous respiration (CPAP or PSV) and mixing ventilation (SIMV, MMV) three kinds of fundamental types, adopt the software and hardware of multiplexing mechanical ventilation or autonomous respiration for mixing ventilation as far as possible, after carrying out some special processing, promptly change the processing of corresponding machinery or autonomous respiration mode over to; Under the controlled mechanical ventilation state, computer control board 12 is according to the breathing time parameter control inlet valve of setting 3 and the switch time of outlet valve 7; Under spontaneous breathing state, computer control board 12 is according to observed pressure and trigger relatively opening inlet valve 3 and closing outlet valve 7 of pressure, according to relatively the closing inlet valve 3 and open outlet valve 7 of the flux lower limit (PSV pattern) of observed pressure and the authorized pressure upper limit (CPAP pattern) or measured discharge and regulation, thus the control breathing time; Under the Aided Machine aeration status, air-breathing startup is identical with autonomous respiration, air-breathing stop then identical with the control mechanical respiration.The demonstration of respiration parameter is by computer control board 12 respiration parameter of measuring in the respiratory function implementation procedure to be exported to charactron through the display driver circuit of display alarm board 13 to show, for saving charactron, with clinical parameter commonly used, show with special-purpose charactron as respiratory frequency and tidal volume, other then shows selector switch by front panel 14, input to computer control board 12 through digital interface, select relevant parameter to show it.It is with the flow and pressure measured value and the comparison of warning upper lower limit value that record in the respiratory function implementation procedure by computer control board 12 that alarm signal is handled; If transfinite, then export corresponding alarm signal, can export by display interface, distinguish different alarm with one digit number sign indicating number pipe demonstration different digital, also can be by general digital interface output, by display lamp demonstration separately.The cost of this microcomputerized controller has only been used with 1/4th of shelves product, uses through hospital clinical, and is very convenient, and can also resist the electromagnetic interference of radioknife.

Claims (8)

1, a kind of inspiratory flow sensor [1] that comprises, inlet valve [3], drive the motor [9] of inlet valve [3], pressure transducer [4], expiratory gas flow pick off [5], outlet valve [7], drive the electromagnetic controller [10] of outlet valve [7], PEEP valve [8], preamplifier [11], display alarm board [13], the microcomputerized controller of the respirator of front panel [14], it is characterized in that described controller also comprises can finish regularly, the computer control board [12] of control loop and three subsystem tasks of monitoring, formation can realize the flow of the patient breathing circuit of seven kinds of respiratory functions and control function, the closed loop automatic control system of pressure, and the control of the low-pressure gas of the control of the gases at high pressure in the driving loop of respirator and patient breathing circuit is relatively independent; The senser element of experiencing flow and pressure of this microcomputerized controller and control are air-breathing, the servo valve of expiratory gas flow all is installed in the breathing air-channel system of respirator, senser element and servo valve are used metal tube in gas circuit, silicone rubber spare is connected with plastic tube, inspiratory flow sensor [1] is inserted in the middle of the air-breathing road [2], inlet valve [3] is connected with mechanical driving device with motor [9], pressure transducer [4] is connected on the air-breathing road [2] by plastic tube, expiratory gas flow pick off [5], outlet valve [7], PEEP valve [8] is contained in the middle of the expiration road [6] successively, outlet valve [7] is connected with mechanical driving device with the electromagnetic controller [10] that drives outlet valve [7], display alarm board [13] is fixed on the front panel [14], computer control board [12] and inspiratory flow sensor [1], motor [9], pressure transducer [4], expiratory gas flow pick off [5], electromagnetic controller [10], preamplifier [11], display alarm board [13], electrically connecting between the adjusting knob on the front panel [14] and display device and the on and off switch can adopt flat cable to link.

2, microcomputerized controller as claimed in claim 1, it is characterized in that the computer control board (12) that microcomputerized controller adopts can adopt 8 or 16 bit CPU chip or single-chip microcomputers, in save as the above byte of 16K, seven above parallel interfaces, 8 to 16 A/D input interfaces, a D/A output interface.

3, microcomputerized controller as claimed in claim 1, the air-channel system that it is characterized in that described microcomputerized controller and expiration machine can attach together in same combination box (21), combination box (21) can be placed on respectively on the levels that has the arbor wheel framework with air compressor, and assembling becomes an incorporate integral body.

4, microcomputerized controller as claimed in claim 1, it is characterized in that being equipped with on the described front panel (14) for seven adjustment joint knobs that respiratory function is shared, cancelled the special-purpose bound warning of general respirator adjusting knob, its function multiply by up and down coefficient of variation by computer control board (12) according to capacity or pressure set points to be determined automatically.

5, microcomputerized controller as claimed in claim 1, it is characterized in that it is to select the selector switch signal of key switch generation to input to computer control board (12) through the digital interface of computer control board (12) by the respiratory function on the front panel (14) that respiratory function is selected, corresponding respiratory function program is carried out in instruction computer control board (12) input; The realization of respiratory function is will be set value through the A/D input interface by the last respiration parameter setting of front panel (14) adjusting knob to input to computer control board (12); Pressure transducer (4), the measured actual measurement parameter of inspiratory flow sensor (1) and expiratory gas flow pick off (5) also inputs to computer control board (12) through the A/D input interface of computer control board (12), calculate through computer control board (12), the comparison of actual measurement parameter and setup parameter, the correction and the compensation of the curve of inspiratory flow sensor (1) and motor (9), Digital Signal Processing such as filtering, D/A output digital interface output corresponding control signal by computer control board (12), the subtended angle of control inlet valve (3) and outlet valve (7), thereby adjust respiratory flow in real time, the closed loop of realization capacity or pressure is controlled automatically, under the controlled mechanical ventilation state, computer control board (12) is according to the respiration parameter control inlet valve of setting (3) and the switch time of outlet valve (7), under spontaneous breathing state, computer control board (12) is according to the switch time of observed pressure or flow parameter control inlet valve (3) and outlet valve (7), under the Aided Machine aeration status, air-breathing startup is identical with autonomous respiration, air-breathing stop then identical with mechanical control breathing.

6, as claim 1 or 5 described microcomputerized controllers, it is characterized in that this microcomputerized controller is divided into mechanical ventilation (holding control or voltage-controlled) to breathing pattern, autonomous respiration (CPAP or PSV) and mixing ventilation (SIMV, MMV) three fundamental types, the software and hardware that mixes multiplexing mechanical ventilation of ventilation or autonomous respiration promptly changes corresponding machinery or autonomous respiration mode over to after carrying out some special handlings.

7, as claim 1 or 5 described microcomputerized controllers, the demonstration that it is characterized in that respiration parameter is by computer control board (12) respiration parameter of measuring in the respiratory function implementation procedure to be exported to charactron through the display driver circuit of display alarm board (13) to show, other then passes through the demonstration selector switch of front panel (14), input to computer control board (12) through A/D input digit interface, select relevant parameter to show it.

8, as claim 1 and 5 described microcomputerized controllers, it is characterized in that it is with the flow and pressure measured value and the comparison of warning upper lower limit value that record in the respiratory function implementation procedure by computer control board (12) that alarm signal is handled, if transfinite, then export corresponding alarm signal, can export by display interface, distinguish different alarm with one digit number sign indicating number pipe demonstration different digital, also can be by general digital interface output, by display lamp demonstration separately.

Images