DE102005031808A1 - Equipment for pressure control with respirators has control unit and sensor, which evaluates situation of, inhaled and exhaled phases and pressure drop is created with inhaled phase before beginning of exhaled phase - Google Patents

Abstract

The equipment (1) has a control unit (2) and a sensor, which is connected with a gas supply and is adjustable at two different pressure levels. The control unit evaluates the situation of inhaled and exhaled phases and a pressure drop is created with the inhaled phase before the beginning of exhaled phase.

Description

The The invention relates to a method for pressure control in ventilators, in in dependence of at least one metrologically detected ventilation parameters the pressure on at least two different pressure levels adjustable is.

The Invention relates to this In addition, a device for pressure control in ventilators, the a control unit and at least one sensor for a Has ventilation parameters and those with a breathing gas supply coupled, which is adjustable to at least two different pressure levels is.

A Application in medical devices is related with breathing air supplies, which are part of a CPAP therapy (Continious-Positive-Airway-Pressure) be used. Likewise, applications in so-called bilevel, APAP and home ventilation possible. Likewise, such Respiratory air supplies used in the hospital during intensive care ventilation. To avoid dehydration of the respiratory tract it proves in particular for longer periods of ventilation as appropriate, a Humidification of the air to be carried out. Such humidification the breath can also be realized in other applications.

It can but also various applications outside the field of medical technology respectively. For example, with respirators for divers or firefighters the problem occur that used hoses bend the ventilators or compressed become. The same problem can also be found in the industrial sector activities the use of respirators to protect the person concerned before the action of environmental gases and in which the persons concerned through the activities envisaged hands not free to act on the respirators used to be able to. Finally are Also, applications in the field of ventilators conceivable by astronauts or pilots are used.

The hitherto known methods and devices are not yet in enough for that suitable, one possible to provide extensive ease of use, in particular despite of the respirator prescribed ventilation pressure the transition of inspiration phases and expiratory phases as possible largely approximates a normal breathing process. As annoying is especially felt by a user of the ventilator, if at the beginning of the expiratory phase a relatively high ventilation pressure present, which counteracts an exhalation.

task It is therefore an object of the present invention to provide a method of the invention mentioned type to improve such that an increased ease of use achieved becomes.

These Task is inventively characterized solved, that the Pressure during an inspiratory phase is reduced before a start of the expiratory phase becomes.

Further Object of the present invention is to provide a device of initially mentioned type for achieving an improved user comfort to construct.

These Task is inventively characterized solved, that the Control unit the timing of inspiration phases and expiratory phases evaluates and a pressure drop within the inspiratory phase pretend before the beginning of the expiratory phase.

By the pressure reduction already before one end of the inspiratory process becomes a diminished expiratory pressure provided and nevertheless ensured by the reduced residual pressure, that one Internal pressure support the flow paths for the breathing gas is present. It is thereby a high functionality at the same time pleasant conditions of use.

One perceived as particularly pleasant pressure curve is achieved by that the Pressure reduction after exceeding a flow maximum performed becomes.

A Another control variant is that the pressure drop after a specifiable flow reduction is performed.

A Reliable pressure reduction at the beginning of the expiratory phase can be achieved by the fact that the pressure drop with a Minimum time interval to an already detected or based the waveform of one related to the flow Parameters predicted phase change is performed.

A secured pressure reduction can be achieved that the pressure drop with a maximum time to an already detected or based on the waveform of a the flow-related parameter predicted phase change is performed.

A further increase in user comfort can be achieved by that the Pressure reduction is continued after a phase change.

to execution an optimization of the pressure control is proposed that the pressure drop is performed according to a predetermined lowering profile.

A particularly simple embodiment is that the Pressure reduction according to a substantially linear ramp carried out becomes.

Also wear it to a simple device control in that the Pressure reduction essentially passively by idling the conveyor carried out becomes.

One greater Optimierungsge space is provided by the fact that the pressure drop is actively performed using at least one control.

A Another variant is that the pressure drop in a first lowering phase is active and then carried out passively.

Furthermore is also thought that the Pressure reduction in a first reduction phase passive and then active carried out becomes.

a Collapse of the flow paths can be prevented by the fact that after the implementation of Pressure reduction of the pressure for a predeterminable range on a substantially constant lower pressure level is maintained.

Also proves to be advantageous for preventing obstructions the existence Pressure increase is given before one end of the expiratory phase.

One optimal time for the end of the pressure reduction is defined by the pressure increase in dependence from an evaluation of the flow profile and / or the course of a performed with the flow related signal.

A Further optimization of the operation can take place in that the pressure increase is performed according to a predetermined increase profile.

Also in terms of pressure increase, it contributes to a simple device control in that the pressure increase is carried out essentially linearly.

One typical field of application is opened by a higher first Pressure level is set to a pressure level of about 10 mbar.

to Achieving a pleasant user comfort proves itself in usually considered sufficient second lower pressure level at a pressure level of about 7 to 8 mbar is given.

The device-related Realization is supported by the fact that at least one flow parameter metrologically over a Sensor detected becomes.

A further adaptation to different application requirements can be done by a Upper pressure level changed adaptively becomes.

Furthermore is also thought that a lower pressure level adaptively changed becomes.

A further reduction of the risk of collapse of the flow paths or obstructions can be achieved by having a third increased Pressure level specified at a pressure level of about 11 to 14 mbar becomes.

It is provided that at least two pressure levels ranging from 2 to 80 mbar can, can be specified. Additional pressure levels can optionally in the range of preferably +/- 5 mbar around the lower and / or upper preset level can be set.

In The drawings are exemplary embodiments represented the invention. Show it:

1 a perspective view of a ventilator according to an embodiment,

2 a typical flow during the execution of a ventilation process,

3 one too 2 corresponding pressure profile in a pressure control within an expiratory phase proportional to the flow,

4 one to the flow in 2 corresponding pressure control with linear pressure reduction in the expiration phase,

5 a representation of another flow course similar to 2 .

6 one to the flow in 5 corresponding pressure control with a beginning of the pressure reduction already before one end of the inspiration phase,

7 a further representation of corresponding pressure and flow profiles with proportional pressure reduction,

8th a representation of pressure and flow curves corresponding to one another when pressure peaks occur,

9 a further corresponding representation of pressure and flow patterns in mouth exhalations,

10 a further representation of corresponding pressure and flow progressions,

11 a representation of a breathing gas hose with elastically expandable compensation element in a ground state,

12 the compensation element according to 11 after a partial expansion,

13 the compensation element according to 11 and 12 after a full expansion,

14 a representation of a respiratory mask with a flexible component,

15 a further embodiment of the respiratory mask according to 14 .

16 a further modified embodiment for illustration in 14 and

17 an illustration of a flow profile and a pressure curve with substantially flow-proportional pressure reduction to a beginning of expiration and a pressure increase to a beginning of the inspiration phase.

1 shows the basic structure of a device for ventilation. In the area of a device housing ( 1 ) with control panel ( 2 ) as well as display ( 3 ) is arranged in a device interior, a breathing gas pump. Via a coupling ( 4 ) a connection hose ( 5 ) connected. Along the connecting tube ( 5 ), an additional pressure measuring hose ( 6 ), which via a pressure input port ( 7 ) with the device housing ( 1 ) is connectable. To enable data transmission, the device housing ( 1 ) an interface ( 8th ) on. A humidifier can be adapted.

In the area of the device housing ( 1 ) facing away from the expansion of the connecting tube ( 5 ) is an exhalation element ( 9 ) arranged. Also, an exhalation valve can be used.

1 also shows a ventilation mask ( 10 ) trained patient interface, which is realized as a nasal mask. A fixation in the region of a head of a patient can be achieved via a hood ( 11 ) respectively. In the area of their connection hose ( 5 ) facing the patient interface ( 10 ) a coupling element ( 12 ) on.

2 shows a typical flow ( 13 ) during the execution of inspiration phases ( 14 ) and expiratory phases ( 15 ).

3 shows a flow path ( 13 ) in 2 corresponding pressure curve ( 16 ), during which the pressure during the expiratory phase ( 15 ) substantially in proportion to the flow profile ( 13 ) is lowered. During the inspiration phase ( 14 ), the pressure typically has a value of about 10 mbar and is during the expiratory phase ( 15 ) lowered by a maximum of about 3 bar.

4 also shows a flow history ( 13 ) in 2 corresponding pressure curve ( 16 ), beginning with the expiratory phase ( 15 ) the pressure is first lowered substantially linearly. This can be done, for example, in a simple manner by switching off the operating energy of the respiratory gas delivery device used, for example a fan. With the beginning of the inspiration phase ( 14 ), the pressure is raised again, also in the embodiment according to 4 essentially with a linear increase.

5 again shows a flow history ( 13 ) similar to in 2 , each again subdivided into phases of inspiration ( 14 ) as well as expiratory phases ( 15 ).

6 shows a flow path ( 13 ) in 5 corresponding pressure curve ( 16 ), in which a pressure reduction already at the beginning of a lead time ( 17 ) before an expiration ( 18 ) is started.

According to the embodiment 6 is the pressure in the inspiratory phase ( 14 ) at the beginning of the lead time ( 17 ) initially lowered substantially linearly from an initial level of about 10 mbar. The pressure drop is determined after the beginning of the exhalation ( 18 ) first and then from a switching time ( 19 ) started a pressure increase. According to the embodiment 6 the pressure increase is also substantially linear. Already before an inspiration start ( 20 ), the pressure at the end of an expiratory pressure rise again substantially reaches its initial level and remains at this initial level for the remainder of the expiratory phase (FIG. 15 ) as well as within the following inspirational phase ( 14 ) until the next lead time ( 17 ).

The pressure reduction during the lead time ( 17 ) and within the first part of the expiratory phase ( 15 ) until reaching a base pressure ( 22 ) can be done in different ways. For example, it is pos sible to idle a drive motor of an air conveyor or a blower by completely or partially switching off energy.

The pressure increase in the expiratory phase ( 15 ) after reaching the switching time ( 19 ) is preferably carried out in the form of a slow ramp, since a user of the ventilation device a sudden switching to a higher pressure is perceived as unpleasant. The ramp steepness and the times relevant to the pressure reduction and the pressure increase can be adapted automatically as a function of a respiratory rate of the user. In addition, it is also possible to evaluate characteristic time courses in the respiratory curve of the user and to make an adjustment of the switching times thereto. For example, the average durations between the inspiratory and expiratory peak flows and the phase changes can be evaluated.

By suitable choice of the lead time ( 17 ) as well as the inspiratory pressure reduction ( 21 ), a mean pressure profile can be achieved, which according to an embodiment within the expiratory phase ( 15 ) to a higher average pressure than during the inspiratory phase ( 14 ) leads. This proves to be particularly advantageous for avoiding obstructions of the breathing gas flow paths.

The special pressure control makes it possible to reach an end of the expiratory phase during periods in which there is typically an increased risk of obstruction ( 15 ) and at the beginning of the inspiration phase ( 14 ) to provide sufficient pressure to counteract such obstructions. During the remaining time of the ventilation cycle, the lowest possible pressure level or the lowest possible mean ventilation pressure is specified.

In terms of device technology, the pressure control takes place using a sensor with which, for example, a vertex of the flow profile (FIG. 13 ) during the inspiratory phase ( 14 ) is detected. Following the metrological detection of such a vertex, the beginning of the lead time ( 17 ) started and the pressure reduction can be performed. Regardless of the metrological detection of such a vertex of the flow path ( 13 ), the beginning of the lead time ( 17 ) as a function of a maximum distance or a minimum distance to the beginning of the expiration ( 18 ) or at the start of inspiration. This would mean that even without detection of a vertex of the flow path ( 13 ) upon reaching a minimum time interval from the beginning of the expiration ( 18 ) the pressure reduction is started and that at a very early reaching the vertex of the flow path ( 13 ) the beginning of the lead time ( 17 ) until a maximum time is reached at the beginning of the expiration ( 18 ) is delayed.

The sensory acquisition of the flow profile ( 13 ) can be done directly or indirectly via a measurement signal related to the flow. It is also thought to recognize the breathing phases by means of non-flow signals. For example, pressure or temperature.

Alternatively to the in 6 illustrated linear ramped pressure reduction and the likewise linear and ramp-shaped pressure increase, it is also possible to realize the pressure reduction and / or the pressure increase according to predetermined linear or non-linear control profiles.

This can be in the form of a pure control or in the form of a scheme with direct pressure detection or detection of one with the pressure in Related signal occur.

The Pressure control can in various ways device technology will be realized. For example, it is possible the conveying speed the engine of the breathing gas conveyor to control or regulate. It is also possible to control the pressure to realize by Atemgasumlenkung, for example, using a valve.

When For example, the flow related signal may be the engine speed are evaluated, for example in combination with the pressure or the motor current. Another measuring variant for detecting the Flows is the realization of a differential pressure measurement.

The residence time of the pressure within the expiratory phase ( 15 ) to the minimum pressure between the times ( 22 and 19 ) can be chosen to be different depending on the application. In extreme cases, the corresponding residence time can be selected to zero, but it is also possible to the beginning and / or end of the residence time provide a fixed time to derive from a respiratory rate of the user, a derivative of the time from a mean expiratory, a mean time between the beginning of expiration and an expiratory peak flow, expiratory peak flow detection, a derivative of the flow or a combination of one or more of the above To carry out criteria.

The same criteria for setting the residence time to the minimum pressure in the expiratory phase ( 15 ) apply mutatis mutandis to the residence time at the maximum pressure level, starting from the end of the expiratory pressure increase ( 21 ) until the beginning of the lead time ( 17 ). Likewise, the criteria listed above can be used individually or in an optional combination to specify the shape of the pressure rise profile and / or the pressure drop profile.

According to a further embodiment, it is also contemplated, at least temporarily after the end of the expiratory pressure increase and before the start of the lead time ( 17 ) provide an additional level of pressure to even better balance airflow path obstructions during inspiration and / or to affect inspiratory volume. In a therapeutic application, this can be done especially in the presence of central hypopneas.

The higher Pressure level and the lower pressure level and, where appropriate also the above explained additional Pressure level can be predefined manually, for example. It is also thought to specify only one of the pressure values and the other pressure automatically derive from this predetermined pressure level. The default value For example, the upper pressure, the lower pressure or a medium pressure be. The determination of the rest Pressure values are then based on this base value by reading from a Table or over computational functional relationships.

According to one Another variant is thought of that for fixing the difference between the higher Pressure level and the lowered pressure level and / or criteria the respective time periods and the slopes of the pressure reduction and the pressure increase predetermined parameter sets can be manually selected to to set a respective optimal setting criterion.

at a combination of the phase-shifted pressure reduction with a APAP procedures are used on detected obstructions or on appearance of snoring sounds either the higher one Pressure level as well as the lower pressure level or only the lower one or only raised the upper pressure level.

Also is at a combination of the phase-shifted pressure control with an APAP procedure, in obstructions or a Occurrence of snoring sounds, those from the flow or when using modulated test signals be detected to turn off the respectively activated device control mode and permanently increase the pressure at the upper elevated pressure level leave.

A further embodiment in such a combination of procedures, it is the times the pressure drop and the pressure increase to change such that the proportion of the higher one Pressure per respiratory cycle extended becomes.

A further embodiment refers to respiratory rate regulation. At a high measured Respiratory rate is a change the time periods for the duration of the raised pressure level and the lowered pressure level as well as additional a change the fall or rise rates such that a lower Spontaneous breathing is caused. In particular, this is thought to extend the residence time at the upper pressure level and the To slow pressure rise within the expiratory phase.

Also In respiratory rate regulation, it is possible at too high respiratory rates the selected one Disable operating mode and constant on the in this case lower pressure level to remain.

at An occurrence of apnea or with a longer respite, it is possible, constant the higher one To activate pressure level.

The 7 to 10 illustrate mutually corresponding pressure and flow progressions each with textually explained in the drawings boundary conditions. The fluid dynamic relationships are further illustrated by these diagrams.

11 shows according to an alternative embodiment, a connecting tube ( 5 ), the sections of a balloon-like expanding material ( 23 ) consists. The expandable material ( 23 ), for example, the connection hose ( 5 ) form themselves and / or represent a separate element on or in the hose. According to the embodiment in 11 extends the expandable material ( 23 ) along a segment of the longitudinal extent of the connecting tube ( 5 ). In the limit, it is also thought the entire connecting tube ( 5 ) of the expandable material ( 23 ) train. The constructive realization and dimensioning of the expandable material ( 23 ) is performed such that at a given pressurization a defined volume of gas is absorbed by the expansion.

As material for the expandable material ( 23 For example, plastic can be used. In particular, the use of silicone and / or latex is intended. According to a further embodiment, a flexible component is used, which is equipped with a pressure relief valve. The pressure relief valve can be realized replaceable. In particular, it is intended to provide a plurality of pressure relief valves with different characteristics. For example, it is possible to use pressure relief valves which open staggered from a pressure of 4, 5, 6, ..., 48, 49 and 50 mbar. A typical opening range for the pressure relief valves is in a pressure range of 4 mbar to 50 mbar. It is also thought to make the pressure relief valve adjustable, so that the opening pressure can be predetermined.

According to the embodiment in FIG 12 an expansion of the expandable material ( 23 ) by one opposite 11 higher pressure. Due to the inherent elasticity of the expandable material ( 23 ) the expansion decreases with decreasing pressure and the expansion process reverses. Typically, the expandable material is tuned to a working pressure range, for example a pressure range of 10 mbar.

A typical dimensioning is such that the expandable material at a base pressure at 10 mbar the in 11 illustrated unexpanded state occupies. When exhaling a user of the ventilation device is a short-term pressure increase, the expandable material ( 23 ) deflects from the rest position. It is here first in 12 shown intermediate positioning and then at a maximum expiratory pressure in 13 shown final positioning taken.

Using the expandable material ( 23 In particular, it is possible to perform an expansion proportional to the pressure increase. At one end of the exhalation process, the pressure decreases again and the expandable material ( 23 ) returns to the 11 shown starting position back.

According to a further embodiment, it is contemplated that the expandable material ( 23 ) is successively expanded with increasing pressure and contracted with decreasing pressure. It is thereby provided for the user of the respiratory device, a lesser back pressure against which the exhalation must occur.

By using the expandable material ( 23 ), a slightly increased pressure is provided to the user during inspiration since the intrinsic elasticity of the expandable material ( 23 ) returns this with decreasing back pressure in the starting position. Thus, during inspiration, adequate pressure is immediately provided which reduces the risk of contraction of the flow paths.

at In a preferred embodiment, the upper pressure level is in one Range from 4 to 18 mbar, the pressure reduction to the lower Pressure level is about 3 mbar. With additional realization of a further pressure increase relative to the first pressure level is this additional Raising about 1 to 4 mbar.

14 to 16 show embodiments in which an expandable material ( 23 ) or a differently designed flexible element in the region of the patient interface ( 10 ), for example a respiratory mask. A trained as a respiratory mask patient interface be typically consists of a mask body ( 24 ) and a flexible contour element ( 25 ). The mask body ( 24 ) and the flexible contour element ( 25 ) are in the range of an edge ( 26 ) preferably joined together in a form-fitting manner.

The expandable material ( 23 ) is preferably in the region of the mask body ( 24 ) arranged. 14 shows a ground state, 15 a part expansion and 16 the maximum expanded state.

17 shows an embodiment in which, in addition to a pressure drop within the expiratory phase, a pressure increase is provided within the inspiratory phase. The pressure increase takes place shortly after a change from the expiratory phase into the inspiration phase. Typically, the pressure reduction and / or the pressure increase is performed at least in sections proportional to the flow.

Claims (37)

A method for pressure control in ventilation equipment, wherein in response to a detected metrologically ventilation parameter, the pressure on at least two different pressure levels can be adjusted at least as characterized by, that the pressure during an inspiration phase prior to the start of the expiratory phase diminishes becomes. Method according to claim 1, characterized in that that the Pressure reduction after exceeding a flow maximum performed becomes. Method according to claim 1 or 2, characterized that the Pressure reduction is performed after a specifiable flow reduction. Method according to one of claims 1 to 3, characterized that the Pressure reduction with a minimum time interval to a phase change carried out becomes. Method according to one of claims 1 to 3, characterized that the Pressure reduction with a maximum time to a phase change carried out becomes. Method according to one of claims 1 to 5, characterized that the Pressure reduction is continued after a phase change. Method according to one of claims 1 to 6, characterized that the Pressure reduction is carried out according to a predetermined lowering profile. Method according to one of claims 1 to 7, characterized that the Pressure reduction is carried out according to a substantially linear ramp. Method according to one of claims 1 to 8, characterized that the Pressure reduction essentially passively by idling the conveyor carried out becomes. Method according to one of claims 1 to 8, characterized that the Pressure reduction active using at least one control element carried out becomes. Method according to one of Claims 1 to 10, characterized that the Pressure reduction active in a first lowering phase and then passive carried out becomes. Method according to one of claims 1 to 10, characterized that the Pressure reduction in a first reduction phase passive and then active carried out becomes. Method according to one of claims 1 to 12, characterized that after the implementation the pressure drop the pressure for a predetermined or automatically determined range to a substantially constant lower pressure level is maintained. Method according to one of claims 1 to 13, characterized the existence Pressure increase is performed before one end of the expiratory phase. Method according to one of claims 1 to 14, characterized that the Pressure increase in dependence is performed by an evaluation of the flow profile. Method according to one of claims 1 to 15, characterized that the Pressure increase is carried out according to a predetermined increase profile. Method according to one of claims 1 to 16, characterized that the Pressure increase is carried out substantially linearly. Method according to one of claims 1 to 17, characterized the existence higher first pressure level at a pressure level of about 10 mbar becomes. Method according to one of claims 1 to 18, characterized the existence second lower pressure level at a pressure level of about 7 to 8 mbar is given. Method according to one of claims 1 to 19, characterized that at least a flow parameter metrologically via a Sensor detected becomes. Method according to one of claims 1 to 20, characterized the existence Upper pressure level changed adaptively becomes. Method according to one of claims 1 to 20, characterized the existence lower pressure level adaptively changed becomes. Method according to one of claims 1 to 22, characterized the existence third increased pressure level at a pressure level of about 11 to 14 mbar. Method for pressure control in ventilators, in in dependence of at least one metrological detected Ventilation parameters the pressure on at least two different ones pressure levels is adjustable, characterized in that the pressure during the Expiration within a time period following inspiration is reduced substantially in proportion to the flow and that the pressure control using a flow guide takes place, the at least partially from an expandable Material that expands at an acting internal pressure to increase the volume becomes. Device for pressure control in ventilators, the a control unit and at least one sensor for a Has ventilation parameters and those with a breathing gas supply coupled, which is adjustable to at least two different pressure levels is, characterized in that the Control unit the timing of inspiration phases and expiratory phases evaluates and a pressure drop within the inspiratory phase pretend before the beginning of the expiratory phase. Device for pressure control in ventilators, the a control unit and at least one sensor for a Has ventilation parameters and those with a breathing gas supply coupled, which is adjustable to at least two different pressure levels is, characterized in that a at least connected to a breathing gas supply flow guide partially from a balloon at an internal pressure to increase the volume expandable material is formed. Device according to claim 26, characterized in that that this expandable material arranged in the area of a breathing tube is. Device according to claim 26, characterized in that that this expandable material arranged in the area of a patient interface is. Method for pressure control in ventilators, in in dependence of at least one metrological detected Ventilation parameters the pressure on at least two different ones pressure levels is adjustable, characterized in that a pressure change while the inspiratory phase will and the pressure during the exhalation phase remains substantially constant. Method according to claim 29, characterized that one Pressure reduction is carried out in the inspiration phase. Method according to claim 29, characterized that one pressure increase is performed in the inspiratory phase. Method for pressure control in ventilators, in in dependence of at least one metrological detected Ventilation parameters the pressure on at least two different ones pressure levels is adjustable, characterized in that a pressure change is carried out in the expiratory phase and the pressure during the Inspiratory phase remains essentially constant. Method according to claim 32, characterized in that that in the exhalation phase a pressure reduction is performed. Method according to claim 32, characterized in that that in the expiratory phase is carried out a pressure increase. Method according to one of Claims 29 to 34, characterized that during the essentially constant pressure profile of the pressure level substantially remains constant. Method according to one of Claims 29 to 34, characterized that during the constant pressure phase of the pressure compared to a previous one Respiratory phase remains substantially constant. Method for pressure control in ventilators, in in dependence of at least one metrological detected Ventilation parameters the pressure on at least two different ones pressure levels is adjustable, characterized in that the mean pressure during a Expiratory phase substantially above the mean pressure during the Inspiration phase is.