CN101982204B

CN101982204B - System and method for providing a breathing gas

Info

Publication number: CN101982204B
Application number: CN2010105225272A
Authority: CN
Inventors: M·莫里斯; G·W·弗洛利德; N·J·卡兰
Original assignee: Invacare Corp
Current assignee: Invacare Corp
Priority date: 2004-06-18
Filing date: 2005-06-20
Publication date: 2012-09-05
Anticipated expiration: 2025-06-20
Also published as: CN101014380A; AU2005265201B2; CN101982204A; CN101014380B; EP1784237A1; CA2571164C; CA2571164A1; JP2008503272A; WO2006009939A2; AU2005265201A1

Abstract

Systems and methods for providing a breathing gas are provided. In one embodiment, the method includes sensing a sensed parameter associated with delivery of the breathing gas; changing a control parameter associated with a flow/pressure control element in response to a difference between the sensed parameter and a first predetermined sensed parameter value during a first portion of a breathing cycle; determining a transition from the first portion to a second portion of the breathing cycle based at least in part on the changing control parameter; changing the control parameter to cause a first change in the sensed parameter during the second portion of the breathing cycle based at least in part on the determined transition; and changing the control parameter to cause a second change in the sensed parameter during a third portion of the breathing cycle based at least in part on the first predetermined sensed parameter value.

Description

Be used to provide the system and method for breathing gas

The application is to be that June 20, application number in 2005 are 200580028591.2 and denomination of invention dividing an application for the application for a patent for invention of " being used to provide the system and method for breathing gas " applying date.

The application requires to enjoy the U.S. Provisional Patent Application serial number No.60/580 that submitted on June 18th, 2004,845 priority.

Technical field

The present invention relates to basically and carries breathing gas to the patient respiratory road, and relates in particular to patient's breathing cycle and carry breathing gas in phase.

Background technology

Obstructive sleep apnea be by upper respiratory tract of flaccid muscles to upper respiratory tract degree depleted or that block by these identical muscle gradually and the respiratory tract disordered breathing that causes.Known obstructive sleep apnea can be treated through the nasal meatus that air pressurized is applied to the patient.This of forced air is applied in patient's the upper respiratory tract and formed gas clamping plate (pneumaticsplint), stops upper respiratory tract depleted or block thus.

In the treatment of obstructive sleep apnea, have multiple known CPAP therapy, comprise for example other CPAP of single-stage and the other CPAP of twin-stage.The other CPAP of single-stage comprises and uses single curative or medical specified CPAP rank consistently.That is, in the whole breathing cycle, single treatment positive air pressure is transported to the patient.Though this therapy is successful in the treatment obstructive sleep apnea, owing in exhalation process, just be transported to the positive air pressure rank in the patient respiratory road, some patients experience discomfort when exhaling.

In response to this discomfort, developed the other CPAP therapy of twin-stage.The other CPAP of twin-stage is included in the higher treatment CPAP of intake period conveying and between expiration, carries lower treatment CPAP.This higher treatment CPAP rank is known usually to be air-breathing positive airway pressure or " IPAP ".This lower treatment CPAP rank is known usually to be exhale positive airway pressure or " EPAP ".Because EPAP is lower than IPAP, compare with the other CPAP therapy of single-stage, the patient needs the less power of expense to exhale between expiration and therefore experiences less discomfort.

Yet the exploitation of the other CPAP of twin-stage has significantly increased the complexity of CPAP equipment, because these equipment must accurately determine when the air-breathing and expiration of patient, and coordinates its IPAP and EPAP rank suitably.A kind of method be confirm just to be transported to the patient air instant and mean flow rate and then relatively both to confirm that the patient is air-breathing or in expiration.If instant flow velocity thinks that greater than mean flow rate the patient is air-breathing.If instant flow velocity, thinks that the patient is exhaling less than mean flow rate.

Though in treatment obstructive sleep apnea and other with breathing relevant disease disorderly such as the neuromuscular of chronic obstructive pulmonary disease and influence breathing muscle and tissue; CPAP is success, and also being starved of provides the addition method of delivering therapeutic breathing gas to the patient.

Summary of the invention

On the one hand, a kind of method that breathing gas is provided is provided.In one embodiment; This method comprises: a) the sensing sensor parameter relevant with the conveying of breathing gas; B) change the control parameter relevant in response to the difference between the sensor parameter during the first of current breathing cycle and the first predetermined sensor parameter value with the flow/pressure control element; C) confirm to be converted to second portion according to changing the control parameter at least in part from the first of current breathing cycle; D) at least in part according to fixed transformation; Change first of the sensor parameter of control parameter during and change, and e with the second portion that causes the current breathing cycle) at least in part according to the first predetermined sensor parameter value, change second of the sensor parameter of control parameter during and change with the third part that causes the current breathing cycle.

Description of drawings

In being included in description and constitute in its a part of accompanying drawing, show embodiments of the invention, it is with top general description of the present invention that provides and detailed description given below, as the example the principles of the invention.

Fig. 1 is the functional block diagram that an embodiment of the system that is used to carry breathing gas is shown.

Fig. 2 is the flow chart that the embodiment of the control treatment that is used for this system is shown.

Fig. 3 illustrates the valve gear positions in time of an embodiment who is used for this system and the figure of cover pressure.

Fig. 4 illustrates the valve gear positions in time of another embodiment that is used for this system and the figure of cover pressure.

Fig. 5 illustrates the valve gear positions in time of the another embodiment that is used for this system and the figure of cover pressure.

Fig. 6 is another embodiment that is used to carry the breathing gas system.

Fig. 7 A-7C illustrates another embodiment of the control treatment that is used for this system.

Fig. 8 A-8C shows the lung flow in time, valve gear positions, controlled pressure and the pressure sensor that are used for system embodiment shown in Fig. 6.

Fig. 9 is the another embodiment that is used to carry the breathing gas system.

The specific embodiment

Before various embodiment were discussed, the definition of looking back some exemplary term of using in the whole open text was suitable.The odd number of all terms and plural form fall into definition separately:

" logic " in this use includes, without being limited to hardware, firmware, software and/or the combination of each, with execution function or action, and/or causes another functions of components or action.For example, according to required application or demand, logic can comprise the microprocessor of software control, such as discrete logic or other programmed logic equipment of application-specific IC (ASIC).Logic can also embed as software fully.

" software " in this use includes, without being limited to one or more computer-readables and/or executable instruction, its cause computer or other electronic equipment with required mode carry out function, action or/behavior.Instruction can embed with various forms, such as program, algorithm, piece or comprise each application or from the program of the code of dynamic link library.Software can be also implemented with various forms, such as stand-alone program, funcall, JAVA service small routine (Servlet), applet, be stored in the executable instruction of instruction, part operation system or other type in the memorizer.The form that persons of ordinary skill in the art will recognize that software is the demand according to the environment of for example required demands of applications, its operation and/or designer/programmer etc.

" breathing state " in this use comprises any state or combinations of states, and wherein gas is introduced lung and/or from lung, discharged.For example, first breathing state can be with that air is introduced lung be relevant, and second breathing state can with from lung, discharge air relevant.In addition, breathing state can have one or more sub-states.For example, air-breathing beginning can be a kind of breathing state, and air-breathing end can be another kind of breathing state, has the scope that defines one or more other breathing states therebetween.Similar, the beginning of expiration and end, and scope therebetween also can be by one or more breathing state definition.

System and method described here is particularly suited for assisting general breathing patient's breathing, though they can also be applied to other respiratory therapy, comprises for example acute and the home care ventilation.With reference now to Fig. 1,, shows the block diagram 100 of an embodiment of system shown.System comprises controller 102, the hair-dryer 106 with control logic 104, the variable position lift valve 108 with two-way stepper motor and pressure transducer 112.Flow channel 110 provides from valve 102 to patient interface 114 path for breathable gas.Patient interface 114 can be any nose cup, face shield, intubate or similar devices.Pressure transducer 112 sensings are such as the breathing gas parameter of pressure in the flow channel 110, and it is relevant with the pressure in the patient interface 114 and indicate this pressure.Controller 102 is preferably based on processor, and can comprise various input/output circuitries, comprises that modulus (A/D) input and digital-to-analogue (D/A) export.Controller 102 sends to valve 108 with valve gear positions data 116, pressure data 118 is sent it back controller 102 reads being used to control its position and pick off 112.

The valve gear positions is preferably by stepper motor description definition and can comprise and be less than 1 shelves or the gear positions of whole shelves.Usually, the scope of valve gear positions can be from any negative to any positive number.A preferred valve gear positions scope comprises 0 to 100, and wherein gear positions 0 is relevant with the valve position of complete closed, and gear 100 is relevant with the valve position of opening fully.Therefore, be blower speed and the valve constitution that provides, each valve gear positions can be confirmed as and change with approximate pressure and to equate (for example, valve gear positions equal the 0.2cm water column pressure variation).

Though with reference to the flow/pressure control element of variable position valve 108 forms with the sensor element of pressure transducer 112 forms, described the embodiment of Fig. 1, flow/pressure control and sensor element can comprise the equipment of other type.For example, the flow/pressure control element can be the variable-ratio hair-dryer, with the variable-ratio hair-dryer of linear valve or solenoid valve combination, with the variable-ratio hair-dryer of the variable position valve combination of stepper motor control, with the variable-ratio hair-dryer of the variable position valve combination of linear valve or solenoid valve or stepper motor control or any other appropriate combination of these parts.Sensor element can comprise flow transducer, temperature sensor, infrared light emission/pick off, motor current sensor or separately or with the motor speed sensor of pressure transducer combination.The data that produce from these pick offs feed back to controller 102 and are used for handling.

With reference now to Fig. 2,, will be with reference to the wherein operation of illustrated flow chart description system.In the flow chart hereinafter, rectangular element is represented processing block and is showed software instruction or the instruction group.The tetragon element is represented data I/O processing block, and representative relates to the input of data or reads the perhaps output of data or the software instruction or the instruction group of transmission.This illustrate and this flow chart of describing do not represent the grammer of any special programming language.On the contrary, flow chart shows those skilled in the art and can be used to make circuit or produce the function information of software with the processing of executive system.It should be noted that such as many routine program elements of the use of circulation and the initialization of variable and temporary variable not shown.

In piece 200, controller 102 is opened valve 108 and hair-dryer 106 is set for produce the speed of predetermined pressure in its output.Via the pressure in the memorizer that is stored in controller 102-speed question blank, this predetermined pressure is set to the normal pressure that medical treatment is given for the patient basically and adds the for example additonal pressure of 5cm water column.Though described the additonal pressure of 5cm water column, also can select not comprise other pressure of additonal pressure.The normal pressure of medical treatment regulation normally is higher than the pressure of ambient pressure.For example, the scope of predetermined pressure can be from 4 to 20cm water columns.In case hair-dryer 106 is provided with so that the pressure of this setting to be provided, it changes during the valid function of equipment hardly.Instead, controller 102 uses the gear positions of valve 108 to regulate output pressure to control both through closed loop and open loop.Closed loop control is the function of pressure sensor, and open loop control is the function of time.Jointly, the operation of these control loops guidance system in patient's the whole breathing cycle.Should also be noted that closed loop and open loop control can also be based on such as gas temperature and/or (for example, the CO of the gas in the patient interface in instant and mean flow rate, the patient interface ₂) other parameter of composition.

At piece 202, for subsequent treatment reads and store pressure.At piece 204, average valve gear positions is determined and keeps or upgrade.In step 206, controller 102 determines whether that pressure sensor descends.This preferably realizes through current pressure sensor is compared with last pressure sensor.If current pressure sensor is less, pressure descends and to take place and flow process advances to piece 208 so.At piece 208, controller 102 increases the valve gear positions and descends with compensatory pressure.Increase the valve gear positions and have increase from the flow of the breathing gas of valve output conveying and the effect of pressure.Gear positions crossover ground changes up to the error or the difference that minimize between the pressure sensor.During this stage of operation, controller 102 tries hard in flow channel 112, keep constant pressure to exhale up to sensing the patient.

At piece 210, the difference between the instant and average valve position is integrated in time and is stored in the memorizer.The summation of six this integrations is through determining whether the beginning (piece 212 and 214) of this summation greater than air-breathing threshold value, and is used to confirm the beginning of inhalation breath state.If summation is greater than threshold value, the beginning of inhalation breath state has taken place and intervalometer begins to measure the inhalation breath state at piece 216.This measurement continues up to having been found that peak value valve gear positions in piece 218.Confirm peak value valve gear positions through last valve gear positions being compared with current valve gear positions and will bigger gear positions being stored in the memorizer as peak value valve gear positions.(for example, 80ms), controller 102 hypothesis peak value valve gear positions in this expiratory phase takes place so, and the breathing state measure of time that in piece 220, stops suction if peak value valve gear positions is in remaining unchanged of certain hour cycle.Peak value valve gear positions is a threshold value that indication inhalation breath state closes to an end.

At piece 222, controller 102 tests are to determine whether that through reading pressure signal the pressure increase takes place.If the pressure increase takes place after having been found that peak value valve gear positions, the inhalation breath state is approaching end so.Piece 224 reduce flow that valve positions provide with reduction with pressure so that the constant pressure in the maintenance air flow passage.This handles again through crossover and realizes, handle through this crossover, current pressure sensor and formerly the error between the pressure sensor be minimized.Piece 226 tests are to pass through relatively two variable V AR ₁And VAR ₂And determine whether that the inhalation breath state finishes.These variablees are as giving a definition:

VAR ₁=(instant gear positions)-(average gear positions)

VAR ₂=[(peak value gear positions)-(average gear positions)] * threshold value

Variable " threshold value " is 85% or 0.85 a percent value for example, but can also select other percent value.If VAR ₁＜VAR ₂, so the inhalation breath state finished and the expiration breathing state or just prepared the beginning.

Piece 228 reduces the valve gear positions according to the unloading function of exhaling, and said expiration unloading function reduces the pressure of carrying in time, thus the pressure of during the pressure of initial delivery during the expiration breathing state is less than the inhalation breath state, carrying.Pressure descends up to predetermined minimum pressure is provided, and it can comprise ambient pressure.This lower pressure keeps an expiratory duration cycle in piece 230, promptly for example is 2.5 times of suction condition time cycle of recording.Can also select be different from 2.5 multiple after this finishes time cycle, read pressure signal and the valve gear positions increases according to the pressure-loaded function at piece 232.This pressure-loaded function reads current pressure and in time output pressure is turned back to the normal pressure of medical treatment regulation, and wherein system seeks the beginning of inhalation breath state again.

By this way, during the expiratory phase of breathing cycle, provide normal pressure, and during the expiration phase of breathing cycle, provide lower pressure lower pressure to be exhaled to allow the patient with assisting patients in air-breathing.This system carries with respect to the continuously positive airway pressure of other types comfort level to a certain degree is provided, because for any appreciable time cycle, the patient need not exhale facing to the uniform pressure that intake period is used.

With reference now to Fig. 3,, shows diagram valve gear positions curve 300 and the figure of output pressure curve 302 as time function.Article two, curve overlapping with more clearly illustrate between pressure and the valve gear positions synchronously.Curve referring now to Fig. 3 is looked back operating instruction.

Before state 0, system is in the closed loop control and via the pressure of positive its output place of sensing of its pressure transducer.Because before state 0, exist very little pressure to change, this system keeps constant valve gear positions, this has caused constant output pressure (normal pressure of preferably, medical treatment regulation).This usually occurs in the latter stage that the patient exhales, and the very little pressure that wherein in system, exists the patient to cause changes.

When the patient begins when air-breathing, sense pressure by pressure transducer 112 and descend.This pressure descends and causes system further to open valve 108 with the air-breathing pressure decline that causes of compensation patient with the gear mode.In this intake period, system attempts keeping output pressure to equal the normal pressure of medical treatment regulation basically.Each gear positions of valve equals known approximate pressure and changes (for example, 0.2cm water column).The pressure of pressure sensor and setting (promptly; The normal pressure of medical treatment regulation) difference between has produced error amount; System attempts through suitably adjusting the valve gear positions to minimize this error amount, and the said valve gear positions of suitably adjusting has suitably been adjusted the pressure of carrying.

When the valve gear positions increases, the time cycle that state 0 takes place and triggering is confirmed, its guiding state 1.During this confirmed the time cycle, the difference between instant valve gear positions and the average gear positions was along with 6 intervals are integrated.For clarity sake, Fig. 3 only shows 3 intervals.Air-breathing and air-breathing timer begins if the summation of these 6 integrations, is supposed the patient so greater than threshold value, and it measures inspiratory duration.

When peak value valve gear positions has reached state 2, this inspiratory duration is measured and is stopped.Peak value valve gear positions through will be formerly valve gear positions and the comparison of current valve gear positions and will bigger gear positions be stored in the memorizer and confirm peak value valve gear positions as peak value valve gear positions.(for example, 80ms) do not change, system postulation takes place for this expiratory phase peak value valve gear positions so if peak value valve gear positions keeps the certain hour cycle.

After state 2, system looks is exhaled and is triggered.This realizes that through comparing two variablees two variablees are all based on the valve gear positions.This equality has been defined as VAR in the above ₁And VAR ₂If VAR ₁≤VAR ₂, trigger existence and system so and move to state 3.

At state 3, the closed variable position valve 108 of system is so that provide lower pressure in its output.Through reducing the valve gear positions to for example position 0 (that is, closure) or other certain positions, valve 108 can be fast and linear closed (the definite slope that for example, has the 3ms/ gear).During the pith of exhaling, system provides than employed pressure that will be lower of intake period now.It is easier that this makes that the patient exhales.

From state 3 to state 4, system is from the open loop control, and do not change the valve gear positions according to pressure or any other parameter.During this confirmed the time cycle, valve remained on its gear positions.As stated, the time cycle can be 2.5 times of the inspiratory duration (that is 2 the time from state 1 to state) formerly confirmed.This is the discharge degree part of system's operation.

At state 4, the expiratory duration cycle stops and system progressively applies pressure to its output reaches the medical treatment regulation again up to pressure normal pressure.System reloads pressure in its output now.This pressure through sense conditions 4 realizes that it causes mainly due to the patient exhales, and changes the valve gear positions fast to meet this pressure.Therefore this expiration phase begins with a pressure that depends on patient's breath pressure.From state 4 to state 5, system progressively changes the valve gear positions with linear mode (for example, having definite slope of 40ms/ gear), progressively opens valve reaches higher medical treatment regulation again up to output pressure normal pressure thus.It is air-breathing that system has been ready to next patient now, wherein repeats this processing.

Fig. 4 shows the embodiment of the invention that relates to the control that triggers based on exhaling.In this, except inspiration trigger is not provided, this control is similar to above-mentioned.Especially, the breathing cycle measure of time is as the function of peak value valve gear positions.Time between two peak value valve gear positions (state 2) is measuring of time breathing cycle.The expiration of state 3 triggers, from the unloading part of state 3 to 4 with described identical with as above with reference to figure 3 from the loading section of state 4 to 5.Unloading part (state 3 to 4) and loading section (state 4 to 5) are defined the conduct percentage ratio of time breathing cycle of breathing cycle formerly.These percentage range can be very wide, makes that unloading and loading section are from about 50% to 85% of time breathing cycle together but be chosen usually.The advantage of this embodiment is its less processing that needs controller 102.

Illustrated among Fig. 5 is one embodiment of the present of invention, and it uses instant and average valve gear positions with breathing state that detects the patient and the pressure of carrying according to the state coordination that has detected.In this embodiment, system is from closed loop control mode, wherein its pressure sensor and based on this its output of pressure adjustment always.More particularly,,, increase to promote, confirmed average valve gear positions to the air-breathing pressure of carrying and valve gear positions reduce to be reduced to the pressure that expiration is carried through the valve gear positions according to the pressure that feeds back to controller 102 along with patient respiratory.Through instant valve gear positions and average valve gear positions are compared, can detect patient's breathing state.If instant valve gear positions is on average valve gear positions, the patient is just air-breathing.If instant valve gear positions is under average valve gear positions, the patient exhales.In order to reduce too early or unsettled triggering, average valve gear positions can be offset to actual value that is higher than air-breathing detection and the actual value that is lower than its detection of exhaling.

In Fig. 5, the instant valve gear positions of Reference numeral 502 indications is passed through average valve gear positions with positive slope.This indication patient descends with the air-breathing pressure that causes of compensation patient because valve is increasing its gear positions just air-breathing.The instant valve gear positions of Reference numeral 504 indications is passed through average valve gear positions with negative slope.This indication patient exhales, because valve is reducing the pressure rising that its gear positions is exhaled and caused with the compensation patient.According to this detection, can Application of I PAP rank in intake period, and between expiration, can use the EPAP rank.The next air-breathing detection of Reference numeral 506 indications.

Shown in Fig. 6 is the another embodiment of the present invention of system's 600 forms.Except variable position valve 108 was in the vent position about flow channel 110, system 600 was similar with system 100 (Fig. 1).And controller 102 comprises control logic 602.In this, the breathing gas of hair-dryer 106 outputs advances to patient interface 114 in flow channel 110.Variable position valve 108 is placed to it can shift the breathing gas from flow channel 110 and patient interface 114.The gear positions of valve 108 receives logic 602 controls.Though described the embodiment of Fig. 6 with reference to the sensor element of the flow/pressure control element of variable position valve 108 forms and pressure transducer 112 forms, flow/pressure control element and sensor element can comprise the equipment of other types.For example, the flow/pressure control element can be the variable-ratio hair-dryer, with the variable-ratio hair-dryer of linear valve or solenoid valve combination, with the variable-ratio hair-dryer of the variable position valve combination of stepper motor control, with the variable-ratio hair-dryer of the variable position valve combination of linear valve or solenoid valve and stepper motor control or any other appropriate combination of these parts.Sensor element can comprise flow transducer, temperature sensor, infrared light emission/pick off, motor current sensor or separately or with the motor speed sensor of pressure transducer combination.The data that produce from these pick offs feed back to controller 102 and are used for handling.

Fig. 7 A-C shows the flow chart of the embodiment that relates to control logic 602.In piece 700, controller 102 draught excluders 108 and hair-dryer 106 is set for produce the speed of predetermined pressure in its output.Via the pressure in the memorizer that is stored in controller 102-speed question blank, this predetermined pressure is generally the normal pressure that the patient is set to the medical treatment regulation, adds the additonal pressure composition.The additonal pressure composition can be percentage ratio or some other values that pressure is set.The additonal pressure composition is provided, thereby, can carrying the medical normal pressure of stipulating under the situation mostly if not a plurality of schemes of all needs of patients.The normal pressure of medical treatment regulation normally is higher than the pressure of ambient pressure.For example, the scope of the pressure of regulation can be from 4 to 20cm water columns.In case hair-dryer 106 is configured to provide required pressure, it does not change during the valid function of equipment hardly.Instead, controller 102 uses the gear positions of valve 108 to regulate output pressure.

At piece 702, read and store pressure.At piece 704, logic is confirmed intermediate value valve gear positions, breathing rate (Fig. 7 C) and upper and lower breathing rate threshold value.In one embodiment, intermediate value valve gear positions and upper and lower breathing rate threshold value can be confirmed as follows:

Intermediate value valve gear=(current * 0.0003)+(formerly * 0.9997)

Breathing rate upper threshold value=intermediate value+(intermediate value * 0.1)

Breathing rate lower threshold value=intermediate value-(intermediate value * 0.1)

Wherein " current " represented current valve gear positions, and " formerly " represented intermediate value valve gear positions formerly, and " intermediate value " expression intermediate value valve gear positions.Logic can initially circulate to confirm above-mentioned value through several breathing states.

In case confirm upper and lower breathing rate threshold value, keep watch on the valve gear positions and be used for confirming of breathing rate.With reference to figure 7C, confirm the slope of valve gear change at piece 742.This can realize through in time current and one or more gear positions of valve formerly being compared.If the slope of valve gear positions is for negative in piece 744, then logic advances to piece 746.Otherwise logic loops is got back to

piece

742 or 704 to continue processing up to next valve gear change.At piece 746, logic testing has been reduced to breathing rate (BR) threshold value (referring to Fig. 8 B) down to determine whether the valve gear positions.If logic advances to piece 748, wherein its test is to determine whether that the valve gear positions has been reduced to down breathing rate (BR) threshold value (referring to Fig. 8 B) down.If logic advances to piece 750, wherein be the current breathing record end time and be that next breathes recording start time.According to the start and end time of each breathing, can calculate and store breathing rate (for example, frequency of respiration/minute) to be used for follow-up use.

Back, through the pressure that is provided with is compared with the pressure that is read by pressure transducer 112, produce pressure error at piece 706 with reference to figure 7A.In piece 708, pressure error is used to produce valve gear error, and it can be according to following formula:

V _error＝(P _error*P)+(D _error*D)+(S _error*S)

" V wherein _Error" be valve gear error, " P _Error" be pressure error, " D _Error" be current and the pressure error difference between formerly pressure error is calculated, " S _Error" be the summation of pressure error, and " P ", " D ", " S " are constants." V _Error" equality General Definition proportional integral difference quotient (hereafter PID) servo controller.Usually, experience studied systematic function after, the constant of selected " P ", " D ", " S ".In addition, can also be these constant theory of selection values.This PID SERVO CONTROL is effective basically in whole logical operation, although also can accept operation intermittently in during the part of patient respiratory state.As will describe, patient's respiratory characteristic to the given situation of the effect of systematic function under, logic utilizes the pressure setting of the various PID of being used for controllers to produce suitable pressure output.

Piece 710 tests are to determine whether that valve gear error is more than or equal to zero.If logic advances to piece 712, wherein the valve gear positions increases one or more gears so that attempt reducing error.Otherwise logic advances to piece 714, and wherein the valve gear positions reduces one or more gears to attempt and the minimizing error.Should be noted that valve gear positions that logic adopts can equal maybe can be not equal to a gear of the stepper motor of said control valve motion.For example, valve gear can equal half gear motion of the stepper motor of valve.

After

step

712 or 714, logic is advanced to piece 716, wherein keeps watch on the valve gear to peak value valve gear positions.In one embodiment, the following definite air-breathing threshold value of logical foundation:

Air-breathing threshold value=[(peak value-intermediate value) * 0.5]+intermediate value

Wherein " peak value " is the peak value valve gear positions from one or more breathing cycles formerly, and " intermediate value " is intermediate value valve gear positions, and 0.5 is the typical proportion factor.Can use other scale factor value in other embodiments.After current valve gear positions surpassed air-breathing threshold value, logic began to confirm peak value valve gear positions.Through comparing and select bigger value to confirm peak value valve gear positions with valve gear positions formerly current valve gear positions.

At piece 718, the following definite unloading threshold value of logical foundation:

Unloading threshold value=[(peak value-intermediate value) * T]+intermediate value

Wherein " peak value " is the peak value valve gear positions from one or more breathing cycles formerly, and " intermediate value " is intermediate value valve gear positions, and " T " is the percentage ratio unloading trigger value of from question blank, confirming according to the per minute frequency of respiration of confirming.Shown in the example table 1 below of per minute frequency of respiration:

Table 1

In form 1, that each " per minute frequency of respiration " value has is relative, corresponding " T (% unloading) " value of value " X ", " Y ", " Z " form, and it is generally equal to or less than 1.For any " per minute frequency of respiration " value that provides, being somebody's turn to do " T (% unloading) " value can be identical or different, and how soon definite unloading cycle begins with respect to intermediate value valve gear positions.For example, near 1 " T (% unloading) " value will promote the unloading threshold value far above intermediate value valve gear positions, so more promptly make with respect to the valve gear positions and to trigger the pressure minimizing." T (% the unloading) " value of approaching zero (0) will reduce the unloading threshold value makes it near intermediate value valve gear positions, so cause laterly that with respect to the valve gear positions triggering pressure reduces.Usually, " per minute frequency of respiration " value is big more, and " T (% unloading) " value is big more.Should also be noted that one or more " per minute frequency of respiration " value can have relative identical or different " T (% unloading) " value.

At piece 720, logic testing has been reduced to the unloading threshold value down to determine whether the valve gear positions.If not, logic loops turns back to piece 702 to continue effective PID SERVO CONTROL of valve gear positions.If logic advances to piece 722.At piece 722, logic confirms that unloading pressure reduces control waveform and relevant pressure setting with pressure.Equally, be provided with the minimizing timer.In one embodiment, unloading pressure is confirmed as follows:

Unloading pressure=P _Set-[P _Set* ((Δ V*V _ScaleThe * of)/K) S]

" P wherein _Set" be the normal pressure of medical treatment regulation, " Δ V " is the variation by the valve gear positions of (peak value-intermediate value) definition, " V _Scale" be from the value of table 2 (infra) selection and based on P _Set, " K " is constant (for example, in the scope of 2000-4000, for example 3000), and " S " be among the scope 1-3 constant but can be less than 1 or greater than 3.If because some operating condition, logic only needs to keep simply the pressure of regulation, " S " thus constant can be set to the pressure that 0 unloading pressure equals to stipulate." V _Scale" value can based on the regulation pressure (P _Set), for example, as shown in table 2.

Table 2

P _set	V _scale
		0	0
1	0
		2	0
3	0
		4	0.28
5	0.28
		6	0.25
7	0.25
		8	0.25
9	0.23
		10	0.23
11	0.22
		12	0.22
13	0.18
		14	0.15
15	0.15
		16	0.14
17	0.14
		18	0.12
19	0.12

20

0.12

At form 2, P _SetThe scope from 0 to 20 of value, and the scope of the positive pressure value of expression medical treatment regulation.Each P _SetValue has relative corresponding V _ScaleValue (" A ", " B ", " C " etc.), it can be confirmed by the theoretical modeling of formerly experience or system.For example, if system 600 is configured to be operated in the relative broad range of patient interface 114, so every type patient interface 114 can be at setting pressure P _SetCause the Light Difference of the performance of system 600 down.Therefore, the technical staff can be chosen in and understand various patient interfaces to confirming V after the influence of systematic function _ScaleValue.Usually, as shown in table 2, " V _Scale" scope of value can from 0 to 0.28, but other embodiment can exceed this scope.And, can adopt some safety measure to exceed some rank not allow unloading pressure to descend.For example, if pressure P _SetBe the 4cm water column, logic cannot allow any discharge degree so, because the pressure of this setting has been the normal pressure of low-down medical treatment regulation.Yet as a rule, unloading pressure confirms to have produced the value less than the normal pressure of medical treatment regulation.

In addition, in piece 722, logic is confirmed for example 195 pressure settings, and it has defined control waveform for the pressure setting reduces to unloading pressure setting.These pressure are provided with by effective PID SERVO CONTROL and use.In one embodiment, 195 pressure settings reduce timer (for example 780ms) acquisition by pressure.In one embodiment, can be for the control waveform of unloading cycle by the slope to lower part and retaining part definition.The slope can comprise 10 pressure settings to the lower part, and it sequentially reduces to the unloading pressure setting with the pressure setting from the setting of treatment pressure in the 40ms that for example is made up of for example 10 4ms increments.Retaining part is through the 740ms that for example is made up of for example 185 4ms cycles and keep pressure and be arranged on the unloading pressure setting.Should be noted that the value that can select other values and describe only means shows one embodiment of the present of invention.Shall also be noted that during the slope and/or retaining part of unloading cycle pressure sensor can be used in to be confirmed or the adjustment control waveform again.

In piece 724, adjustment valve gear positions is to attempt making pressure sensor follow the pressure setting of fixed control waveform, and wherein this control waveform is to be used for the pressure setting is reduced to the unloading pressure setting.In other words, piece 724 uses the logic identical with piece 706-714, because effectively the PID SERVO CONTROL is used to proofread and correct the valve gear positions, and the pressure of control waveform is provided for required pressure setting.For example, each pressure is provided with definition and " pressure is set ", and it is compared with pressure sensor to produce pressure error, and said pressure error is used by effective PID SERVO CONTROL.

In piece 726, logic testing is to determine whether that pressure reduces timer and (for example, 780ms) stops.If logic advances to piece 732.If not, logic advances to piece 728, and wherein it determines whether to reach the unloading pressure setting in the control waveform.Stop if pressure reduces timer, logic advances to piece 732, and wherein it prepares pressure is re-loaded to the normal pressure of medical treatment regulation.If in piece 728, also do not reach the unloading pressure setting, logic loops turns back to piece 724 and proceeds the effective PID SERVO CONTROL to the valve gear positions according to the pressure setting of control waveform.If in piece 728, reached the unloading pressure setting, logic advances to piece 730, and wherein in whole effective PID SERVO CONTROL of valve gear positions, the unloading pressure setting is held, and reduces timer up to pressure and stops.

After pressure minimizing timer has stopped, logic execution block 732, wherein it confirms that pressure increases control waveform and relevant pressure setting.Equally, be provided with pressure and increase timer.In one embodiment, logic is confirmed for example 100 pressure settings, and it has defined control waveform for the normal pressure (treatment pressure) that pressure is increased to the medical treatment regulation.This waveform is based on the pressure setting and the medical normal pressure of stipulating when reducing the timer termination.In one embodiment, pressure increase timer can be set to 400ms.In one embodiment, the control waveform that is used for loading cycle can be defined to top by the slope.The slope can comprise 100 pressure settings to top, and it sequentially is increased to the setting of treatment pressure with the pressure setting from the unloading pressure setting in the 400ms that for example is made up of for example 100 4ms increments.In another embodiment, the control waveform that is used for loading cycle can be defined to top and retaining part by the slope with the mode similar with the control waveform of describing in the above that is used for unloading cycle.Again, should be noted that can select other values and described value only to mean illustrates one embodiment of the present of invention.Should also be noted that pressure sensor can be used in again definite or the slope of adjustment loading cycle and/or the control waveform during the retaining part.

In piece 734, adjustment valve gear positions is to attempt making pressure sensor follow the pressure setting of fixed control waveform, and wherein this control waveform is the normal pressure setting that is used for the pressure setting is increased to the medical treatment regulation.In other words, piece 734 uses the logic identical with piece 706-714 and 724, because effectively the PID SERVO CONTROL is used to proofread and correct the valve gear positions, and the pressure of control waveform is provided for required pressure setting.

In piece 736, logic testing is to determine whether that pressure increases timer and (for example, 400ms) stops.If logic advances to piece 700, wherein pressure is set to the normal pressure of medical treatment regulation.If not, logic advances to piece 738, and wherein it determines whether to reach the positive airway pressure setting (for example, treatment pressure setting) of the medical treatment regulation in the control waveform.If in piece 738, also do not reach the normal pressure setting of medical treatment regulation, logic loops turns back to piece 734 and proceeds the effective PID SERVO CONTROL to the valve gear positions according to the pressure setting of control waveform.If in piece 738, reached treatment pressure, logic advances to piece 740, and wherein in whole effective PID SERVO CONTROL of valve gear positions, the normal pressure setting of medical treatment regulation is held, and increases timer up to pressure and stops.Stop in case pressure increases timer, logic loops turns back to piece 700 and repeats this processing for next breathing cycle.

With reference now to Fig. 8 A-8C,, shows the lung flow in time, valve gear positions, controlled pressure and the pressure sensor that are used for Fig. 6 illustrated embodiment.Fig. 8 A illustrates entering lung in time and the flow of the breathing gas that from lung, comes out.Fig. 8 B illustrates valve gear positions in time, and intermediate value valve gear, last or following breathing rate (BR) threshold value, air-breathing threshold value and unloading threshold value.The use of these values and threshold value has been described with reference to the logic of figure 7A-7C.Fig. 8 C illustrates the controlled pressure waveform, and it is by the pressure of confirming pressure setting and system's sensing.In intake period, the PID servo controller is attempted to keep pressure is set, and it is the normal pressure that is used for patient's medical treatment regulation.Because patient demand, this causes that the valve gear positions changes, and it is increased to peak value valve gear positions and then reduces.During this stage, the peak value gear positions is kept watch on, and calculates intermediate value valve gear positions.In the time of under the valve gear positions drops to the unloading threshold value, unloading pressure reduces control waveform along with pressure and is used for reducing pressure and the related pressure setting that drops to unloading pressure is determined together by effective PID SERVO CONTROL.Pressure reduces timer and also begins.If because the patient respiratory characteristic, pressure sensor reaches unloading pressure before reducing the timer termination, then keep unloading pressure and stop up to reducing timer by effective PID servo controller.Stop in case reduce timer, no matter whether reach unloading pressure, the pressure sensor when all stopping according to the minimizing timer confirms that with the normal pressure of medical treatment regulation pressure increases control waveform and relevant pressure setting.Increase control waveform during increasing the time cycle, to get back to set treatment pressure to the pressure increase by effective PID servo controller working pressure.Because the effectively effect of PID servo controller and patient respiratory characteristic, before increasing the timer termination, pressure can be increased to required treatment rank.

Illustrated among Fig. 9 is further embodiment of this invention of system's 700 forms.System 700 is similar in appearance to system 600 (Fig. 6).Fig. 9 shows environment input 702 and filter 704, and it is provided to ambient air the input that links to each other with hair-dryer 106.Environment input 702 lies in the system of formerly describing and corresponding hair-dryer operation of Fig. 1 and 6 with filter 204.System 700 also comprises non-ambient input 704, and it receives the breathing gas that is shifted from flow channel 110 by variable position valve 108.This layout is different among Fig. 6, wherein shift breathing gas by variable position valve 108, but the gas that must will not shift is led the blowback blower fan.Otherwise system 700 operates with the modes of describing with reference to figure 6,7A-C and 8A-C in the above identical with system 600.And selection, variation and the replacement described about system 600 are suitable for system 700 equally, except they are not transferred to breathing gas in the non-ambient input 704.In other embodiments, can between filter 704 and hair-dryer 106, one or more additional filters be provided.

Though show the present invention through the explanation embodiment, though and quite detailed description embodiment, the intention of description be not restriction or by any way the scope of the restriction claim of enclosing to this details.To be easy to find other advantages and modification to those skilled in the art.For example, the valve gear positions can change according to nonlinear function, and this nonlinear function is as the replacement of linear function, additional or make up with linear function.Replacement or additional parameter that can the sensing flowing gas comprise the flow velocity through use traffic sensor adjustment valve gear positions.More particularly, can also use the variation of mobile direction and/or flow velocity (for example, instant and average).Therefore, its wideer aspect, the present invention is not limited to specific detail, exemplary device and the illustrative example that illustrates and describe.Therefore, under the situation of the spirit of the basic inventive concept that does not break away from the applicant and scope, can break away from these details.

Claims

1. device that is used to provide breathing gas comprises:

The flow/pressure control element is suitable for the control breathing transfer of gas;

Pick off, the sensor parameter that sensing is relevant with the conveying of breathing gas; And

Controller; With flow/pressure control element and sensor communication; This controller during in response to the suction condition of breathing cycle sensor parameter and the difference between the first predetermined sensor parameter value and change the control parameter relevant with the flow/pressure control element; Confirm transformation according to the control parameter at least in part, during the unloading part of expiration state, change the control parameter at least in part according to fixed transformation and change to cause first of sensor parameter from the suction condition of breathing cycle to the expiration state; And during the loading section of expiration state, change the control parameter to cause second variation of sensor parameter according to the first predetermined sensor parameter value at least in part.

2. according to the device of claim 1, wherein, sensor parameter is breathing gas pressure, breathing gas flow, breathing gas temperature or breathing gas composition.

3. according to the device of claim 1 or 2, wherein, the flow/pressure control element comprises the variable position valve, and the control parameter is the valve gear positions.

4. according to the device of claim 3, wherein, during suction condition, controller is confirmed valve gear error and is changed the control parameter to minimize valve gear error according to the sensor parameter and the first predetermined sensor parameter value at least in part.

5. device according to claim 1 and 2; Wherein, The flow/pressure control element comprises the variable position valve; The control parameter is the valve gear positions, and in order to confirm the transformation of the unloading part from suction condition to the expiration state, controller is confirmed the unloading threshold value and confirmed that whether the valve gear positions of variable position valve in change procedure be less than the unloading threshold value.

6. according to the device of claim 5; Wherein, in order to confirm the unloading threshold value, controller is confirmed breathing rate; Confirm intermediate value valve gear positions; For one or more breathing cycles are formerly confirmed peak value valve gear positions, the predetermined percentage unloading factor that identification is relevant with the breathing rate of confirming, and calculate the unloading threshold value according to fixed intermediate value valve gear positions at least in part.

7. according to the device of claim 1 or 2; Wherein, During the unloading part of expiration state, controller is confirmed the second predetermined sensor parameter value, and the timing time that reduces timer is set to predetermined discharge time; Predetermined sensor parameter value sequence is partly confirmed in the unloading that is the expiration state according to the first and second predetermined sensor parameter values at least in part, and basis should change the control parameter up to reducing the timer termination by predetermined sensor parameter value sequence at least in part.

8. according to the device of claim 7, wherein, the flow/pressure control element comprises the variable position valve; The control parameter is the valve gear positions, the pressure that the first predetermined sensor parameter value is a regulation, and the second predetermined sensor parameter value is a unloading pressure; And in order to confirm the second predetermined sensor parameter value, controller is confirmed peak value valve gear positions; Confirm intermediate value valve gear positions; Through deducting intermediate value valve gear positions from peak value valve gear positions to obtain first intermediate object program, multiply by first intermediate object program to obtain second intermediate object program with first constant, multiply by second intermediate object program with the pressure of stipulating; Calculating pressure skew thus, and through from the pressure of regulation, deducting pressure calculations of offset unloading pressure.

9. device according to claim 1 and 2; Wherein, During the loading section of expiration state; The loading section that the timing time that controller confirms the second predetermined sensor parameter value, will increase timer is set to the predetermined load time, be the expiration state according to the first and second predetermined sensor parameter values is at least in part confirmed predetermined sensor parameter value sequence, and at least in part according to changing the control parameter up to increasing the timer termination by predetermined sensor parameter value sequence.

10. device according to claim 3 wherein, is confirmed that transformation from the suction condition of breathing cycle to the expiration state comprises and is confirmed average valve gear positions.

11. device according to claim 3 wherein, is confirmed that transformation from the suction condition of breathing cycle to the expiration state comprises and is confirmed instant valve gear positions.

12. device according to claim 3 wherein, is confirmed that transformation from the suction condition of breathing cycle to the expiration state comprises and is confirmed peak value valve gear positions.

13. device according to claim 1 and 2 wherein, confirms that transformation from the suction condition of breathing cycle to the expiration state is at least in part according to predetermined percentage threshold.

14. device according to claim 1 and 2, wherein, the flow/pressure control element comprises variable speed blower, and the control parameter is a blower speed.

15. device according to claim 14; Wherein, Controller is suitable for the speed of regulating hair-dryer in response to the difference between the sensor parameter during the suction condition of breathing cycle and the first predetermined sensor parameter value; Be reduced in the blower speed during the unloading part of expiration state according to the unloading function of exhaling at least in part, and be increased in the blower speed during the loading section of expiration state according to the expiration loading function at least in part.

16. device according to claim 14; Wherein, During the unloading part of expiration state; Predetermined sensor parameter value sequence is partly confirmed in the unloading that the timing time that controller confirms the second predetermined sensor parameter value, will reduce timer is set to predetermined discharge time, be the expiration state according to the first and second predetermined sensor parameter values at least in part, and at least in part according to changing the control parameter up to reducing the timer termination by predetermined sensor parameter value sequence.

17. device according to claim 1 and 2, wherein, said controller comprises:

The control logic that is used to execute instruction; And

Memorizer with a plurality of executable instructions, wherein said executable instruction comprises:

First instruction set of the sensor parameter that sensing is relevant with the conveying of breathing gas;

Change second instruction set of the control parameter relevant with the flow/pressure control element in response to the difference between the sensor parameter during the suction condition of breathing cycle and the first predetermined sensor parameter value;

Confirm the 3rd instruction set according to the control parameter at least in part from the suction condition of breathing cycle to the transformation of expiration state;

During the unloading part of expiration state, change four instruction set of control parameter at least in part to cause that first of sensor parameter changes according to fixed transformation.

18. device according to claim 17; Wherein, said executable instruction further comprises according to loading function and before detecting the beginning of suction condition next time and during the loading section of expiration state, changes five instruction set of control parameter with second variation that causes sensor parameter according to the first predetermined sensor parameter value at least in part.

19. device according to claim 18, wherein, said loading function is linear function.