ventilator

Abstract

Ventilator, consisting of at least: • a breathing gas pump (1), • a connection (2) for a ventilation device, • a connection for external and / or integrated measuring devices (3) for measuring respiratory and / or device measurements, • Storage devices (4) for measurement data, • a data processing device (5) for calculating and / or transmitting control parameters which at least temporarily influence at least one device function; characterized in that the ventilator is designed such that during its operation: • temporarily perform measurements with the measuring instruments (3), the measurement data of which are stored in the storage instruments (4), without the data processing device (5) calculating control parameters from this and without the measurement data stored during this time being able to influence the device control; • temporary measurement data from the measuring means (3) and / or storage data from the storage means (4) are provided by the data processing device (5) as control parameters with or without further calculations, wherein the data processing device (5) performs an analysis of the flow history, and influence at least one device function, wherein a separate control device (6) or a control device integrated into the data processing device (5) is designed to determine whether and when the data processing device (5) provides control parameters and whether and when such control parameters influence at least one device function.

Description

[0001] The invention relates to a ventilator.

[0002] Comfortable modern ventilators often allow for assisted, mandatory, and mixed assisted / mandatory ventilation. Assisted ventilation, in which the ventilator's breathing cycle is controlled based on the patient's own measured respiratory activity, has the advantage that the patient finds the ventilation comfortable and only minimally disruptive. However, it only partially relieves the patient of the work of breathing. Mandatory ventilation largely relieves the patient of the work of breathing, but the patient finds this type of breathing—especially in the initial phase of treatment—extremely disruptive and unpleasant. It is also frequently observed that patients attempt to maintain their own breathing rhythm against the ventilator, even during mandatory ventilation.This type of operation leads to an additional increase in the patient's respiratory effort.

[0003] To synchronize the operation of the ventilator with the patient's natural breathing rhythm during assisted ventilation, it is already known to measure the patient's respiratory drive and use it as a trigger signal for the ventilator to initiate pressure or volume increase. With this type of ventilation, the patient typically consumes 60% of the ingested oxygen in the respiratory muscles compared to spontaneous breathing, because the respiratory cycle continues subliminally despite the triggering.

[0004] In patients with respiratory insufficiency, achieving the greatest possible muscular relief proves advantageous. With this goal in mind, fully mandatory control of the ventilator is superior to assisted control. When the ventilator is controlled in such a way that well-adapted and controlled ventilation is achieved, it is possible to reduce the oxygen consumption of the patient's inspiratory muscles by up to 90%. This oxygen consumption correlates directly with the patient's biological work of breathing. Even with sensitive and optimally adjusted triggering, assisted ventilation modes currently only achieve a maximum reduction of 40%.

[0005] The advantage of muscular relief with mandatory device control is offset by the disadvantage that patients often have low acceptance of it. Suppressing their own respiratory drive poses a significant problem for patients. The less the pressure and flow profiles implemented by the device control system match the patient's current needs, the lower their acceptance of controlled ventilation. Furthermore, it proves to be an additional disadvantage if, for example, the phase and the temporal relationship between inspiratory and expiratory phases deviate significantly from the patient's desired ventilation pattern.

[0006] It is known, for example, from EP 1132 106, to work using a previously adapted assisted ventilation. For this purpose, a separate learning period in the awake state precedes the ventilation period, in which control parameters are calculated which are then used after manual switching during the ventilation period. This is intended to achieve individual adaptation to the needs of the person being ventilated.

[0007] However, a disadvantage of this approach is that the learning period is strictly separated from the ventilation period, and the control parameters determined during the learning period cannot be adjusted to changing circumstances. Furthermore, a manual switch between the two separate periods is required, necessitating the use of an external operator.

[0008] This type of device control is therefore unsuitable for optimizing patient relief, particularly for mandatory device control. Neither a separation between a learning period that is definitively completed at the start of ventilation and a subsequent ventilation period, nor the necessity of manual external switching, is feasible. It is therefore not possible to solve the aforementioned problems by improving the approach described above; rather, this is only possible through a fundamental departure from the concept of the aforementioned state of the art.

[0009] The procedure or the necessary equipment, in particular a mandatory device control, therefore requires, contrary to the aforementioned solution, greater flexibility and automation into the ventilation phase in order to achieve the desired patient relief.

[0010] A ventilator that can switch between a learning mode and a ventilation mode is already known from US 2005 / 0133032 A1.

[0011] US Regulation 2004 / 01 18 403 A1 describes a procedure for performing CPAP ventilation. This procedure allows for the identification and consideration of different mask systems.

[0012] WO 2006 01 54 16 A1 describes a method and a device for humidifying breathing gas with a dynamically controlled humidifier.

[0013] German patent DE 114 427 A2 discloses a method and a device for controlling CPAP ventilation. Using a sensor, it is possible to detect airway constrictions.

[0014] The object of the present invention is to design a device of the type mentioned in the introduction in such a way as to support increased acceptance by the patient.

[0015] This problem is solved by the subject matter of the independent claim.

[0016] Due to the automatic, continuous adaptation of the control parameters to largely undisturbed measured values ​​from a pure measurement state, it is possible to closely approximate the mandatory ventilation pattern predefined by the control system to the patient's individual, current spontaneous breathing pattern. This results in a fully mandatory device control, decoupled from the patient and largely relieving the patient of the effort of breathing, while simultaneously allowing for individual adaptation of the device-predefined ventilation pattern. This ensures that the patient does not perceive the ventilation as forced and therefore unpleasant. During the execution of this procedure, or...Using this device allows the advantages of mandatory and assisted ventilation to be combined without their respective disadvantages. This highly flexible solution proves particularly advantageous under changing environmental conditions during ventilation, or even in the patient themselves.

[0017] Therefore, the invention can also be used outside of the medical application described as the main example, for sick or injured patients requiring ventilation. It is intended for use in ventilators for the protection and ventilation of persons (or other living beings) in environments that are hazardous to breathing (underwater, at high altitudes, underground, in space, in fire, smoke, or toxic gas emissions, etc.). Here, too, the focus is on rapid, continuous, and automated adaptation to optimized, current ventilation parameters in order to facilitate breathing as much as possible for individuals already under extreme strain due to the hostile or stressful environment and the demanding tasks.

[0018] A typical procedure involves a pure measurement phase, which is kept free from interventions by adaptive device control to avoid distorting the measured values. This is followed by a calculation phase and then an optimized ventilation phase, during which the current measured values ​​are continuously compared. If there are later significant deviations between the calculated profile and the current situation, another pure measurement phase is automatically initiated. A profile, in this context, refers to cyclically recurring signal and parameter patterns.

[0019] The method can also be used to optimize a device's self-test,

[0020] For example, it is possible to perform the measurement under ambient pressure. Furthermore, it is also possible to perform the measurement under continuous positive airway pressure.

[0021] The calculation and analysis, which calculates a profile for control purposes, can advantageously be based, for example, on the flow curve, a breathing rate and / or a ratio of inspiratory phases to expiratory phases.

[0022] Other options include performing a maximum flow analysis or a volume profile analysis.

[0023] In addition, it is also possible to perform an analysis of tidal volume, or an analysis of airway resistance, or an analysis of airway flow behavior.

[0024] According to further embodiments, it is provided that an analysis of PEEP is carried out, or that an analysis of ETCO2 is carried out, or that an analysis of SPO2 is carried out.

[0025] Finally, it is also possible to perform an analysis of the patient's body position, or an analysis of thoracic movement, or an analysis of abdominal movement.

[0026] To implement more complex analysis procedures, it is envisaged that an analysis of an ECG progression is carried out, or that an analysis of an EEG progression is carried out, or that an analysis of an EMG progression is carried out.

[0027] A simplified transformation of the analysis values ​​into target values ​​can be achieved by defining the ventilation pattern as the target value according to the equation P(t)=Resistance*Flow(t)+Elastance*Volume(t)+PEEP is calculated.

[0028] When transforming the recorded spontaneous breathing pattern into a ventilation pattern using the equation of motion, information regarding resistance, compliance, and PEEP is required. These parameters can either be defined through external data input or acquired using a specific measurement procedure. Of particular importance is the measurement of elastance, which refers to the elastic recoil forces of the patient's lungs and chest cavity.

[0029] To support more complex evaluation algorithms, it is intended that the control parameter is calculated by an expert system.

[0030] The control value can be calculated as a pressure pattern or a flow pattern. Particularly high patient acceptance can be achieved by transitioning to mandatory device control depending on the control parameter during a transition phase.

[0031] A continuous transition to full mandatory control can be achieved, for example, by a slow increase in the maximum pressure per breath from breath to breath during the transition phase.

[0032] Another implementation option involves mixing the individual target value pattern with a standard pattern.

[0033] An exact realization of a given ventilation pattern can be achieved, for example, by having the device control system specify the shape, rhythm, and speed of the ventilation pattern.

[0034] Short-term adaptation of the control is supported by a transition from mandatory device control to a measurement state upon detection of regular spontaneous breathing.

[0035] Another adaptation option involves transitioning from a measurement state to mandatory device control upon detection of patient activity above a predetermined threshold.

[0036] Measurement data can include not only measurements from the person being ventilated and the device itself, but also external measurements, e.g., those relating to light and weather conditions, time of day and external disturbances (such as noise levels).

[0037] The drawing schematically depicts a device according to the invention. It shows the basic structure of a ventilation device. A breathing gas pump (1) is arranged in an internal compartment of a device housing with a control panel and display (7). A connecting hose to ventilation equipment, e.g., a breathing mask, a breathing helmet, or a pressure suit, is connected via a coupling (2). A connection (3) exists to external and / or integrated measuring devices, the measured values ​​of which are stored in storage devices (4) so ​​that they are available for simultaneous or subsequent calculation in a data processing unit (5).

[0038] In addition, there is a control device which is either designed separately as shown in the sketch (6) and is only connected to the other components by means of data transmission or which can be integrated into the data processing device (5).

[0039] The procedure is typically carried out by first analyzing the flow pattern of the patient being ventilated in a measurement state, either at ambient pressure, at low pressure during CPAP, or at low pressure during BiLevel ventilation. The ventilation pattern can then be calculated, for example, according to the calculation method. P(t)=Resistance*Flow(t)+Elastance*Volume(t)+PEEP Furthermore, it is possible to perform more complex calculations that take into account the temporal progression of the recorded measurements and / or information regarding the condition of the person requiring ventilation. Data processing can be carried out, for example, using an expert system. The ventilation pattern can be specified as either a pressure pattern or a flow pattern. After the specified ventilation pattern has been calculated, the transition to mandatory ventilation occurs in a continuous and therefore smooth process.

[0040] This means that the calculated ventilation pattern is not immediately and exclusively used as the target value for device control, but rather that an approximation to the target pattern occurs during a transition phase. For example, it is possible to shift a pressure-controlled ventilation pattern to the previously calculated target level by slowly increasing the maximum pressure amplitude per breath over a defined period. It is also conceivable to combine the calculated ventilation pattern with a standard pattern. The standard pattern could, for example, be implemented as a rectangular pattern or a ramp. In particular, the system is designed to synchronize the activation of ventilation control with a predetermined rhythm.

[0041] After achieving full mandatory control of the ventilator, the respiratory gas pump (1) provides complete control of both the shape and the rate and speed of the respective target variable, namely the pressure or the flow.

[0042] During ventilation, it remains possible to automatically activate the measurement state based on the evaluation of measured values. In particular, such evaluation can be performed to detect spontaneous breathing, regardless of the patient's specific pattern. Criteria for this spontaneous breathing detection can be stored, for example, in an expert-based rule set. The evaluation can also be performed using fuzzy logic. The measured respiratory and non-respiratory parameters can be used as inputs for this rule set and then compared with corresponding thresholds for absolute values ​​or for specific ranges.

[0043] The transition from mandatory device control to measurement mode occurs, for example, when patient activity exceeding a predefined threshold is detected. Such detection can be achieved, for instance, by evaluating an identifier for inspiratory and expiratory phases. If a phase shift is identified over a predefined period, this indicates the need for pattern adaptation. The device control then automatically switches to measurement mode to obtain the measured values ​​for a subsequently calculated, updated ventilation pattern.

[0044] In a measurement state, for example, the respiratory rhythm, i.e., the respiratory rate and the respiratory-time ratio, or the specific durations of inspiration and expiration, can first be measured. Subsequently, the device control system, in phase and synchronized with spontaneous activity, initiates mandatory ventilation control using a standard pattern that was subsequently calculated from the stored measurements. Standard patterns can be defined, for example, as rectangular, ramp, parabolic, or sinusoidal waveforms.

Claims

[1] Ventilator, consisting of at least: • a breathing gas pump (1), • a connection (2) for a ventilation device, • a connection for external and / or integrated measuring devices (3) for measuring respiratory and / or device measurements, • Storage devices (4) for measurement data, • a data processing device (5) for calculating and / or transmitting control parameters which at least temporarily affect at least one device function; characterized by that the ventilator is designed in such a way that during its operation: • temporarily perform measurements with the measuring instruments (3), the measurement data of which are stored in the storage instruments (4), without the data processing device (5) calculating control parameters from this and without the measurement data stored during this time being able to influence the device control; • temporary measurement data from the measuring means (3) and / or storage data from the storage means (4) are provided by the data processing device (5) as control parameters with or without further calculations, wherein the data processing device (5) performs an analysis of the flow history, and influence at least one device function, wherein a separate control device (6) or a control device integrated into the data processing device (5) is designed to determine whether and when the data processing device (5) provides control parameters and whether and when such control parameters influence at least one device function. [2] Ventilator according to claim 1, wherein the ventilator is used for patient treatment. [3] Ventilator according to claim 2, wherein the ventilator is designed to: • after commissioning, initially in a first functional state “measuring” to carry out therapy only according to specifications programmed by the operator or doctor and to store measured values ​​only in the storage means (4), but not to perform any calculations or therapy adjustments based on the measured values ​​obtained and / or stored during this time; • by means of the control device (6) then automatically switches to a second operating state “calculation” in which stored and newly acquired measured values ​​are incorporated into calculations for control parameters; • by means of the control device (6) then automatically switches to a third functional state “Verified Therapy”, in which existing and newly acquired control parameters are used to influence at least one device function for patient treatment; wherein the ventilator is further designed to automatically decide, by means of the control device (6), based on the measured values ​​and / or calculations for the control parameters, whether and when to switch from one of the aforementioned functional states to another functional state. [4] Ventilator according to claim 3, wherein the ventilator is designed to automatically switch to the "Measure" function by means of the control device (6) in the "Checked Therapy" function state whenever predefined limit values ​​of a maximum tolerable deviation stored in a memory are exceeded between the computationally expected parameters and the measured parameters of the patient's respiration. [5] Ventilator according to one of the preceding claims, wherein at least one device function comprises a device self-test. [6] Ventilator according to one of the preceding claims, wherein at least one device function comprises an analysis of respiration by means of the data processing device (5). [7] Ventilator according to one of the preceding claims, wherein at least one device function comprises an optimization of the ventilation of a living being. [8] Ventilator according to any of the preceding claims, wherein the ventilator is designed to: • After commissioning, initially in a first functional state “measuring” to carry out therapy only according to specifications programmed by the operator or doctor and to measure measured values ​​only with the measuring means (3) and to store them in the storage means (4), whereby the data processing device (5) does not perform any calculations and the control device (6) does not make any therapy adjustments based on the measured values ​​obtained and / or stored during this time; • then automatically switch to a second functional state “calculation”, in which measured values ​​stored in the storage means (4) and newly acquired with the measuring means (3) are incorporated into calculations for therapy profiles in the data processing unit (5); • then to automatically switch to a third functional state “Verified Therapy”, in which existing and newly acquired calculations of the data processing unit (5) are used to influence the patient treatment by means of the control device (6); wherein the ventilator is further designed to automatically decide, based on the measured values ​​and / or calculations, whether and when to switch from one of the aforementioned functional states to another functional state. [9] Ventilator according to claim 8, wherein the ventilator is designed to automatically switch to the "Measure" operating state in the "Verified Therapy" operating state whenever predetermined limit values ​​of a maximum tolerable deviation are exceeded between the computationally expected parameters and the parameters of the patient's respiration measured with the measuring means (3). [10] Ventilator according to one of the preceding claims, wherein the ventilator is designed to perform patient treatment in a functional state in which measurements and data storage are carried out without calculations, independently of these measurements and data storages under an acting ambient pressure. [11] Ventilator according to one of the preceding claims, wherein the ventilator is designed to perform patient treatment in a functional state in which measurements and data storage are carried out without calculations, independently of these measurements and data storages at a continuously positive airway pressure. [12] Ventilator according to one of the preceding claims, wherein an external specification of at least one ventilation parameter is carried out. [13] Ventilator according to any of the preceding claims, wherein the ventilator is configured to provide patient treatment according to the equation P(t)=Resistance*Flow(t)+Elastance*Volume(t)+PEEP [14] Ventilator according to one of the preceding claims, wherein a physician can specify a ventilation pressure before the treatment of the patient begins. [15] Ventilator according to any of the preceding claims, wherein the ventilator is designed to perform patient treatment according to the profile of expected spontaneous breathing. [16] Ventilator according to one of the preceding claims, wherein the ventilator is designed to measure external parameters such as day or night time and / or noise level and / or air temperature and / or humidity and / or air pressure and / or changes in the aforementioned values ​​by means of its own measuring means (3) or external measuring means and / or to receive them by means of a data connection and / or to store them with the storage means (4) and / or to take the aforementioned data into account by means of the data processing device (5) in the calculations and / or by means of the control device (6) in the device control. [17] Ventilator according to one of the preceding claims, wherein the ventilator is designed to measure oxygen (O2) and / or carbon dioxide (CO2) by means of its own measuring means (3) or external measuring means and / or to receive them by means of a data connection and / or to store them with the storage means (4) and / or to take the aforementioned data into account by means of the data processing device (5) in the calculations and / or by means of the control device (6) in the device control.

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