EVALUATION SYSTEM FOR A VENTILATOR AND PROCEDURE

Description

[0001] The present invention relates to an evaluation system for at least one ventilator intended for the mechanical ventilation of a patient, and to a method for operating such an evaluation system. The evaluation system comprises at least one evaluation unit which, by means of at least one sensor, records at least one ventilation parameter over time.

[0002] To monitor the success and quality of mechanical ventilation, data analysis is typically performed, requiring advanced staff expertise. Such an evaluation usually involves a time-consuming analysis of numerous measurement signals and ventilation parameters and their trends. EP 2216063 A2 discloses a ventilation device that monitors and evaluates parameters during ventilation and includes complication monitoring. US 2011 / 0029248 A1 discloses a device for predicting patient respiratory stability based on various respiratory and cardiac parameters. US 2014 / 330155 A1 discloses a system for monitoring respiratory stability and effectiveness.

[0003] Monitoring the quality of ventilation is particularly problematic when the patient is ventilated at home. Unlike in a hospital, frequent check-ups are difficult to implement in home care.

[0004] In contrast, the object of the present invention is to improve the monitoring and evaluation of ventilation.

[0005] In particular, the system should enable even inexperienced users or patients to reliably assess the quality of ventilation. Ideally, monitoring should also be more convenient and reliable for healthcare professionals.

[0006] This problem is solved using an evaluation system of claim 1 and a method according to claim 18.

[0007] Further developments and advantageous embodiments are the subject of the dependent claims. Further advantages and features will become apparent from the general description and the description of the exemplary embodiments.

[0008] The evaluation system according to the invention serves to evaluate at least one ventilation parameter and / or other treatment data acquired by sensors during ventilation. The evaluation system is designed for use with at least one ventilator or comprises at least one such ventilator. The ventilator is used in particular for the mechanical ventilation of a patient. According to the invention, this can be understood as controlled ventilation and / or assisted ventilation.The evaluation system comprises at least one evaluation device which is suitable and configured to record at least two different ventilation parameters detected by means of at least one sensor over time, wherein the two different ventilation parameters are selected from the group respiratory rate, tidal volume, respiratory gas flow, respiratory gas pressure, characterized in that the evaluation device is suitable and configured to calculate at least one stability rate from the temporal course of the at least two different ventilation parameters, and to determine at least one indicator for the respiratory stability of the patient from the stability rate, such that the indicator provides an assessment of the quality of ventilation during a period of time.This means that the indicator preferably provides an assessment of the quality of ventilation over a period of time, in particular a defined period and, for example, a period of at least 2 hours or more. According to the invention, the evaluation device is suitable and configured to determine the indicator during ventilation and to update it continuously at specific intervals, so that the indicator at least partially takes into account past periods and the values ​​assigned to these periods.

[0009] The key figure is determined, in particular, by a statistical evaluation of a breathing pattern recorded over time. The breathing pattern is provided by the temporal progression of at least one ventilation parameter. The key figure can also be referred to as an indicator or index. According to the invention, a key figure is understood to be not only a number, but also, in particular, a symbol or the like.

[0010] The evaluation system according to the invention offers many advantages. A significant advantage is the provision of the key performance indicator (KPI) by the evaluation system. By considering this KPI, and in particular just a single KPI, a user receives a particularly meaningful and, for example, statistical assessment of the quality of the ventilation performed. Thus, a highly reliable evaluation of the ventilation quality can be obtained virtually at a glance. Furthermore, the invention enables even inexperienced users or patients to make a particularly helpful assessment of the ventilation. Moreover, the invention allows for safe and convenient monitoring and evaluation of ventilation in home care or home ventilation settings, even when qualified personnel are not present or are only rarely on site. The invention can be particularly advantageously used, for example, in telemedicine.Furthermore, the invention offers a significant time saving, as the often tedious and time-consuming evaluation of ventilation parameters over longer periods is no longer necessary, or only necessary when the indicator warrants it.

[0011] Providing a key performance indicator for the quality of ventilation, or preferably an assessment of the quality of ventilation over a period of time, offers a significant advantage, as optimal respiratory stability without asynchronies or other disturbances is medically beneficial for the patient and / or also minimizes the energy consumption or control effort of the ventilator, thereby extending the battery life of the ventilator, or, due to the reduced control effort, minimizes wear and tear, for example on the electric blower.

[0012] Preferably, the evaluation unit is suitable and configured to output the identifier as at least one number and / or at least one graphic and / or at least one symbol and / or at least one word, and in particular to display it using at least one display device. The number can be output with or without units. In all embodiments, it is possible for the display device to be provided by the evaluation system and / or the ventilator and / or other devices, such as a PC or computer, a mobile device, or the like. It may be advantageous for the identifier to be output using only a single number and / or graphic and / or only a single symbol and / or word.

[0013] In an advantageous embodiment, the determined parameter corresponds to or comprises at least one value on a scale. In particular, one end of the scale is assigned a higher, or high, and especially maximum respiratory stability, and the other end of the scale a lower, or low, and especially minimum, respiratory stability. The evaluation device is preferably designed and configured to output the value and / or the scale with the value positioned on it, and preferably to display it on the display device. A scale between zero and 100 or one and 100 is particularly preferred. It is also possible to provide a scale between zero and ten or one and ten. Such numerical ranges allow for a particularly clear and intuitive scale. Scales with other numerical ranges are also possible.

[0014] In particular, a dimensionless scale is provided. A scale with units is also possible. The determined metric can also correspond to at least one range of values ​​on the scale. It is also possible that the scale and / or the value are defined by at least one word and / or at least one symbol and / or at least one graphic or the like. For example, a scale from very good through good and average to poor or the like can be provided. Symbols can be, for example, arrows pointing downwards, upwards, and horizontally. Other symbols are also possible. It is possible and advantageous for the scale to be presented graphically.

[0015] In all embodiments, it is particularly advantageous and preferred that the evaluation unit is suitable and configured to calculate at least one stability rate from the time course of the ventilation parameter. Preferably, the evaluation unit can determine the key figure from at least the stability rate. In particular, the key figure is calculated from the stability rate using at least one assignment function. The stability rate corresponds, in particular, to a time course of the stability and / or variability of respiration. For example, the stability rate is high if the at least one ventilation parameter is stable over time or fluctuates little. For example, the stability rate is low if the at least one ventilation parameter is unstable or fluctuates more significantly over time.

[0016] The stability rate can also be expressed as a variability rate. It is possible that the stability rate then describes a variability in ventilation or respiration and, in particular, corresponds to the inverse of the key figure. In this case, the previously mentioned examples are analogously reversed (a high value corresponds to high variability or low stability). Alternatively, another suitable mapping function between the stability rate and the key figure can be provided.

[0017] In a particularly advantageous embodiment, the evaluation device is suitable and configured to assign a key figure with a value intended for maximum respiratory stability to at least one period in which the stability rate exceeds a threshold for stability. It is also possible and advantageous for the evaluation device to be suitable and configured to assign a key figure with a value intended for minimum respiratory stability to at least one period in which the stability rate exceeds a threshold for instability. The value intended for maximum respiratory stability is, in particular, the highest value on the scale provided for the key figure. The value intended for minimum respiratory stability is, in particular, the lowest value on the scale provided for the key figure.

[0018] It is also advantageous and preferred that the evaluation device is suitable and configured to assign a key figure with at least one value to at least one period in which the stability rate lies between the threshold for stability and the threshold for instability. The evaluation device is particularly suitable and configured to calculate the value from the stability rate using at least one assignment function, preferably using linear interpolation. Other types of assignment functions are also possible.

[0019] The evaluation unit is preferably designed and configured to determine the key performance indicator (KPI) during ventilation and, in particular, to update it at specific intervals and / or continuously. For example, a KPI indicating low respiratory stability may, after a prolonged period of good respiratory stability, assume a value that reflects the improved respiratory stability. Specifically, the updated KPI is averaged from previous KPIs and / or derived statistically in another way.

[0020] It is possible and advantageous to calculate different stability rates and / or key performance indicators for at least two or more different ventilation parameters. Preferably, the respective stability rates and / or key performance indicators are then compared with each other. In particular, the evaluation unit can use this comparison to detect at least one respiratory disturbance and / or at least one respiratory event in the breathing pattern. For example, asynchronies, apneas, and / or flow limitations can be detected in this way.

[0021] The evaluation unit can be suitable and configured to use at least one statistical parameter for the trend of the ventilation parameter over time to determine the key figure. Preferably, the statistical parameter is a mean value, and particularly preferably a moving average, or includes at least one such moving average. Other statistical parameters for the trend are also possible.

[0022] In an advantageous embodiment, the evaluation unit is suitable and configured to determine the key figure from at least one statistical measure of dispersion for a distribution of values ​​of the ventilation parameter over the time course of the ventilation parameter. The statistical measure of dispersion is preferably a variance or comprises at least one such variance. Other suitable statistical measures of dispersion are also possible.

[0023] It is possible that the evaluation unit is suitable and equipped to calculate and, in particular, output at least a trend for a past and / or future development of the indicator. For example, it can show whether the indicator has developed towards higher or lower respiratory stability over a past period. Such a trend can be represented, for example, by a symbol and / or a graph and / or an arrow.

[0024] In all embodiments, it is preferred that the at least one ventilation parameter used to determine the key figure relates to at least one respiratory rate and / or one tidal volume and / or one respiratory gas flow and / or one respiratory gas pressure, or a combination of such parameters. In particular, the evaluation unit is suitable and configured to use at least one, and preferably at least two or more, or all of the aforementioned ventilation parameters to calculate the key figure and / or the stability rate. The evaluation unit can also selectively disregard at least one or more ventilation parameters. The evaluation unit can also assign different weights to certain ventilation parameters. The selection or weighting of the ventilation parameters can, for example, be determined by the evaluation unit based on a ventilation mode set on the ventilator.

[0025] In an advantageous embodiment, the evaluation unit is suitable and designed to change the indicator value towards poor respiratory stability based on at least one of the following causes: asynchrony between ventilator and patient; occurrence of partial or complete intermittent airway obstructions; insomnia; discomfort due to mask and / or therapy pressure; shortness of breath; heavy secretion; urge to cough; unstable respiratory drive; periodic breathing; heavy leakage.

[0026] In an advantageous advanced training, the evaluation unit is suitable and trained to execute at least one action when the key figure and / or the stability rate lies within at least one defined critical value range for respiratory stability and / or shows a tendency towards it. It is possible for the action to be executed when the key figure is below or above a defined threshold value or shows a tendency towards it.

[0027] Preferably, the action comprises at least one output of at least one warning message and / or at least one alarm and / or at least one action description. The action can be partially audible and / or visual and / or haptic. The action can include at least one output of the identification number in combination with at least one audible and / or visual and / or haptic highlight. It is possible and preferred that the action is executed on at least one device connected to the evaluation unit. For example, the action can be executed on a mobile device and / or on a computer or PC and / or the ventilator and / or another device.

[0028] In an advantageous embodiment, the action comprises at least one control of the ventilator. In particular, the control relates to at least one ventilation parameter. Specifically, the action controls the ventilator in such a way that a change in the characteristic value towards higher and, if necessary, also lower respiratory stability can be achieved. Specifically, the ventilator regulates at least one ventilation parameter to at least one setpoint value stored in the action.

[0029] It is advantageous and preferred that at least one critical value range for excessively high respiratory stability and at least one critical value range for excessively low respiratory stability are provided. This has the advantage that excessively rigid breathing or excessively high respiratory stability can also trigger an action. For example, respiratory disturbances associated with relatively high respiratory stability can also be indicated by an alarm.

[0030] The evaluation unit is specifically designed and configured to output the key figure in combination with at least one value for at least one ventilation parameter. Such a value is preferably statistically processed over time. For example, a mean value of the ventilation parameter can be output in combination with the key figure. For example, the key figure is output in combination with the respiratory rate and / or respiratory depth and / or respiratory gas pressure and / or respiratory gas flow and / or tidal volume. Respiratory depth corresponds in particular to the tidal volume or a quotient of the tidal volume and / or a quotient of the rate and tidal volume. The key figure can also be combined with at least one other key figure or with other indices, e.g., to indicate a need for intervention to optimize ventilation or due to an acute deterioration of the condition.

[0031] It is particularly preferred and advantageous that the evaluation unit is suitable and configured to control the ventilator based on the determined parameter and preferably to adjust at least one control variable of the ventilator in order to achieve, in particular, a change in the parameter towards greater respiratory stability. In particular, the evaluation unit and the ventilator are operatively connected. Specifically, the evaluation unit can control or regulate the ventilator taking the parameter into account and, for example, set it to a target value of at least one ventilation parameter.

[0032] In particular, the evaluation unit is suitable and designed to adjust the respiratory gas pressure and / or the respiratory gas flow to achieve greater respiratory stability or to achieve a key performance indicator (KPI) that represents greater respiratory stability. Alternatively or additionally, the evaluation unit can also adjust at least one of the following parameters: inspiratory pressure level; expiratory pressure level; trigger sensitivity; inspiratory duration; expiratory duration; steepness of pressure transitions between pressure levels.

[0033] The evaluation unit is specifically designed and configured to determine and / or output the key figure only after a defined minimum ventilation duration has been reached and / or to consider it for an action. In particular, the evaluation unit is designed and configured to output the key figure together with at least one warning message indicating that the minimum duration has been undershot and / or to consider it for an action together with at least one warning message indicating that the minimum duration has been undershot.

[0034] In particular, the minimum duration comprises at least two hours, preferably at least four hours, and most preferably at least six hours. The minimum duration may also be at least eight hours, at least ten hours, or even twelve hours or more. A minimum duration of half an hour, one hour, or one and a half hours is also possible. Most preferably, the minimum duration comprises at least one night sleep phase of the patient. This night sleep phase preferably includes at least one NREM phase and / or REM phase. In particular, the night sleep phase comprises at least one hour, preferably at least two hours, and most preferably at least four hours or more.

[0035] In an advantageous embodiment, the evaluation unit is suitable and configured to detect an acute exacerbation when the indicator shows an increase in the patient's respiratory stability, particularly above a defined rate of increase, and the recorded ventilation parameter simultaneously indicates an increasing respiratory rate and shallower breathing. Specifically, as a consequence of such detection, at least one action is executed, such as issuing a warning and / or an alarm and / or issuing instructions. In particular, at least two or more ventilation parameters are considered and evaluated to detect such an event.

[0036] The evaluation system may include at least one ventilator. The ventilator is specifically designed and configured to be operated in the manner described above and, in particular, to be controlled by the evaluation unit. Specifically, the ventilator is designed for ventilation in the form of CPAP and / or APAP. Specifically, the evaluation unit is designed and configured to determine the key performance indicator during CPAP and / or APAP and / or other mechanical ventilation. Specifically, the ventilator is designed and configured to generate at least one defined respiratory gas flow for ventilation by means of at least one ventilation device.

[0037] In particular, the evaluation system includes at least one

[0038] Sensor device. The sensor device can be provided by the ventilator. In particular, the ventilator has a sensor device that serves to control or regulate ventilation. For example, at least one flow sensor and / or pressure sensor is provided. The evaluation system may include further sensors for recording ventilation parameters.

[0039] The method according to the invention serves to operate an evaluation system as previously described. Such a method also solves the problem posed above particularly advantageously.

[0040] In particular, the method is designed such that the previously described actions of the evaluation unit are executed. Specifically, the previously described evaluation system is suitable and configured to be operated according to the method of the invention. Within the scope of the present invention, it is specifically provided that the evaluation unit is suitable and configured to execute the method features or steps described herein.

[0041] The evaluation unit contains, in particular, at least one algorithm by which the key figure can be calculated from one or more ventilation parameters. In particular, the evaluation unit comprises at least one electronic computing unit.

[0042] It is possible that the evaluation system is designed separately from the ventilator. For example, the evaluation unit is housed in a separate enclosure from the ventilator and can be connected to it via at least one interface, either wired and / or wirelessly.

[0043] The evaluation system can include at least one (own) display unit and / or use a display unit of the ventilator to output the key figure and / or other information. The display unit of the evaluation system can be supplemented by the display unit of the ventilator. The evaluation system can also be connected to at least one computer and / or at least one mobile device or similar device to output the key figure and / or other information. The evaluation system can use such a device as a display unit.

[0044] In particular, at least one ventilation parameter is recorded during ventilation. Preferably, at least two or at least three, and especially a plurality of, ventilation parameters are recorded during ventilation by means of the sensor. It is also possible that further ventilation parameters are recorded by external sensor units and registered over time, and in particular used to determine the key performance indicator. Such further ventilation parameters can be, for example, pulse rate, blood oxygen saturation, blood carbon dioxide saturation, blood pressure, body temperature, activity, and / or other parameters. If, for example, the patient is active and using their mobile ventilator on a wheelchair, etc., high variability during this phase is evaluated differently than at night during physical rest.

[0045] The ventilation parameter detected by the sensor can be derived directly and / or indirectly from at least one sensor parameter. In all embodiments, it is preferred that at least two or at least three, and preferably a plurality, of ventilation parameters are detected and taken into account for determining the key figure.

[0046] Further advantages and features of the present invention will become apparent from the description of the exemplary embodiments, which are explained below with reference to the accompanying figures.

[0047] The figures show: Fig. 1 is a purely schematic representation of an evaluation system according to the invention in a perspective view; Fig. 2 is a highly schematic diagram with curves of ventilation parameters to illustrate the determination of a key figure in the invention; and Figs. 3-7 are further highly schematic diagrams with curves of ventilation parameters to illustrate the determination of the key figure in the invention.

[0048] The Figure 1Figure 1 shows an evaluation system 1 according to the invention, comprising an evaluation unit 3 for assessing respiratory stability during mechanical ventilation with a ventilator 2. The ventilator 2 is part of the evaluation system 1 and provides the housing for the evaluation unit 3. Alternatively, the evaluation unit 3 can also be arranged as a separate device outside the ventilator 2. The system 1 shown here is operated according to the method of the invention. The evaluation system 1 is configured here as a home ventilator. However, the evaluation system 1 can also be used for clinical ventilation.

[0049] The ventilator 2 has a ventilation unit 12 inside its housing, which is equipped with a fan unit 22 for generating a breathing gas flow. The breathing gas flow is supplied to the patient via a tubing unit 103 connected to the ventilation unit 12 and a breathing mask 102. Alternatively, other patient interfaces can be used instead of the breathing mask 102. A pressurized gas source can also be provided in addition to or as an alternative to the fan unit 22.

[0050] The ventilator 2 comprises a display unit 5 and an operating unit 6. Combinations of operating unit 6 and display unit 5 are also possible, for example, in the form of a touch-sensitive display surface or a touchscreen. The display unit 5 also serves to display information from the evaluation unit 3. The evaluation unit 3 can also output its information on other display units not shown here, such as a computer display, tablet, smartphone, or the like.

[0051] The ventilation device 12 is operatively connected to a sensor device 4, which has one or more sensors for recording ventilation parameters and, if applicable, other quantities characteristic of ventilation. For example, the sensor device 4 includes a pressure sensor (not shown in detail here) which records the pressure conditions of the respiratory gas flow. The sensor device 4 is also operatively connected to the evaluation device 3, so that the recorded quantities can be processed, at least partially, by the evaluation device 3. The evaluation device 3 may also include its own sensor devices 4.

[0052] The ventilation unit 12 includes a control unit, concealed within the housing, for controlling the fan unit 22. This allows, for example, CPAP or APAP ventilation to be performed. For ventilation, the ventilation unit 12 is set to a defined respiratory gas flow and / or respiratory gas pressure. The control unit 12 can provide a necessary minimum pressure and / or compensate for pressure fluctuations caused by the user's breathing. For example, the control unit 12 uses the sensor 4 to detect the current pressure in the breathing mask 102 and adjusts the output of the fan unit 22 accordingly until the desired ventilation pressure is reached.

[0053] Furthermore, the ventilation unit 12 can also be controlled by the evaluation unit 3. For this purpose, the evaluation unit 3 is operatively connected to the control unit.

[0054] To assess the quality of ventilation, the evaluation unit 3 uses the sensor 4 to record several ventilation parameters during ventilation and registers them over time. A key figure for the patient's respiratory stability is then calculated from the temporal progression of these parameters and displayed on the display unit 5. Thus, the user receives an assessment of the quality of ventilation at a glance.

[0055] Respiratory stability is calculated here through statistical analysis of the breathing pattern (e.g., in CPAP or APAP mode). During ventilation, the breathing pattern can be significantly altered. Ideally, the breathing pattern would be completely rigid during mechanical ventilation. With assisted ventilation, a certain degree of variability by the patient is possible and desirable. However, over the course of ventilation over an extended period, preferably including at least part of the night's sleep, sufficiently long periods of stable breathing should be achieved with proper ventilation settings. If this is not the case, it indicates that the ventilation settings are not optimal.

[0056] The calculated indicator, preferably between 0 and 100, for respiratory stability serves as a guide / basis for an alarm indicating a need for ventilation optimization or an acute deterioration in the patient's condition. Consistently low respiratory stability can be caused, for example, by: asynchrony between the ventilator (2) and the patient; occurrence of partial or complete intermittent airway obstructions; insomnia; discomfort from the mask (102) and / or therapy pressure; shortness of breath; excessive secretion; coughing; unstable respiratory drive; periodic breathing; and significant leaks.

[0057] The value of the respiratory stability indicator provides a quick indication of whether further patient analysis is required. In combination with other measured parameters such as AHI or asynchrony events, individual causes of unstable breathing can be either confirmed or ruled out. Preferably, System 1 can automatically adjust ventilation settings such as inspiratory pressure level, expiratory pressure level, trigger sensitivity, inspiratory duration, expiratory duration, or the steepness of pressure transitions between pressure levels and measure the success of these adjustments by observing improvements in respiratory stability. Furthermore, a warning can be issued for an acute worsening of the patient's condition / exacerbation, preferably in combination with other parameters such as respiratory rate or tidal volume (the ratio of rate to tidal volume).Possible rule: Increasing frequency, shallower breathing and more rigid breathing (increase in respiratory stability) can be an indicator of an acute exacerbation.

[0058] The Figure 2 This shows an example of the determination and output of a key figure 208, as well as the ventilation parameters on which its calculation is based. The ventilation parameters were recorded by sensor 4 during ventilation and registered as trends over time 200. The measurement period here is 6:30 h.

[0059] The ventilation parameters here are the respiratory gas pressure 201, the respiratory gas flow 202, the tidal volume 203, and the respiratory rate 204. A stability rate 205 was determined from their curves, which in the example shown here is expressed as a variability rate 215 and describes respiratory variability. The variability rate 215 thus assumes a higher value when breathing becomes more variable or unstable, and vice versa. Such a variability rate 215 can, for example, correspond to the inverse of the desired parameter 208.

[0060] If the variability rate (VRR) value is high, the airflow / volume / respiratory rate fluctuates significantly between breaths. If the value is low, breathing is regular.

[0061] The two lines along the stability rate 205 and the variability rate 215 mark a threshold 207 for stability and a threshold 206 for instability. Periods in which curve 215 lies below the lower line 207 are considered completely stable. The indicator 208 then receives the maximum value intended for evaluation (e.g., a score of 100).

[0062] Periods during which curve 215 lies above the upper line 206 are considered completely unstable. Indicator 208 then receives the minimum value intended for evaluation (e.g., score 0).

[0063] Linear interpolation is performed between the two threshold values ​​206 and 207, ranging from 0 to 100. For the patient's ventilation shown here as an example, the resulting average stability score (key figure 208) is 82. This is a good value; breathing remains consistent over extended periods.

[0064] For example, to determine the stability rate 205 or variability rate 215 from recorded ventilation parameters, the following formula can be stored and used in evaluation unit 3: "Variability rate = Moving mean over 2 min (Amount ((Ventilation parameter current breath - Ventilation parameter mean over 2 min) / Ventilation parameter mean over 2 min) * 100)".

[0065] For example, to derive the key figure 208 from the stability rate 205 or variability rate 215, the following formula can be stored and used in the evaluation unit 3: "Key figure_total_measurement = 100-mean_total_measurement (variability rate)".

[0066] The evaluation unit 3 can be configured to calculate and compare different stability rates 205 and variability rates 215 for two or more ventilation parameters. For example, if the respiratory rate fluctuates more than the tidal volume in a given phase, this indicates asynchrony. If the volume fluctuates more than the rate, this indicates apneas or flow limitations.

[0067] The Figure 3 This shows another example of the determination and output of key figure 208, as well as the ventilation parameters on which its calculation is based. The patient exhibits many apneas / breathing pauses. These are represented here by the vertical lines in the airflow diagram 202. The patient's breathing is almost never truly stable. For the patient's ventilation shown here as an example, key figure 208 yields a mean score of 41.

[0068] The Figures 4 to 7Examples of situations that can lead to respiratory distress are shown. Therefore, significantly increased variability rates are observed here. The variability rates describe, as in the Figures 2 and 3 Previously, respiratory variability.

[0069] The Figure 4 shows a breathing pattern with apneas.

[0070] The Figure 5 The image shows a breathing pattern with flow limitations interrupted by arousals. The flow limitations may be due to increased resistance in the upper airways.

[0071] The Figure 6 shows a breathing pattern with significant asynchrony, so that here device 1 and the patient are working against each other.

[0072] The Figure 6This shows a breathing pattern with particularly regular breathing. The stability rate 205, expressed here as the variability rate 215, remains consistently below the threshold value 207, so that the indicator 208 assumes its maximum possible value. Reference symbol list:

[0073] 1 Evaluation system 2 Ventilator 3 Evaluation device 4 Sensor device 5 Display device 6 Operating device 12 Ventilation device 22 Fan device 102 Breathing mask 103 Tubing device 200 Time 201 Pressure 202 Flow 203 Volume 204 Frequency 205 Stability rate 206 Threshold 207 Threshold 208 Key figure 215 Variability rate

Claims

1. An evaluation system (1) for at least one ventilator (2) intended for mechanically ventilating a patient, comprising at least one evaluation apparatus (3) which is suitable and designed for recording over time at least two different ventilation parameters detected by means of at least one sensor means (4), wherein the two different ventilation parameters are selected from the group consisting of respiratory rate, breathing volume, breathing gas flow, breathing gas pressure, wherein the evaluation apparatus (3) is suitable and designed for calculating at least one stability rate from the time course of the at least two different ventilation parameters and for determining at least one index for a respiratory stability of the patient from the stability rate, such that the index provides an assessment of the quality of the ventilation over a time period, wherein the evaluation apparatus (3) is suitable and designed for determining the index during ventilation and for updating it at specific time intervals and continuously, characterized in that the index at least partially takes into account past time periods and the values for the index assigned to those time periods.

2. The evaluation system (1) according to the preceding claim, wherein the evaluation apparatus (3) is suitable and designed for outputting the index as at least one number and / or graphic and / or at least one symbol and / or word and preferably for displaying it on at least one display apparatus (5).

3. The evaluation system (1) according to one of the preceding claims, wherein the determined index corresponds to at least one value on a scale, and wherein one end of the scale is associated with a higher or rather maximum respiratory stability and the other end of the scale is associated with a lower or rather minimum respiratory stability, wherein the evaluation apparatus (3) is suitable and designed for outputting the value and / or the scale with the value positioned thereon and preferably for displaying same on at least one display apparatus (5).

4. The evaluation system (1) according to claim 1, wherein the evaluation apparatus (3) is suitable and designed for assigning, to a time period in which the stability rate exceeds a threshold value (207) for stability, an index having a value provided for a maximum respiratory stability and / or for assigning, to a time period in which the stability rate exceeds a threshold value (206) for instability, an index having a value provided for a minimum respiratory stability.

5. The evaluation system (1) according to the preceding claim, wherein the evaluation apparatus (3) is suitable and designed for assigning an index having a value to a time period in which the stability rate lies between the threshold value for stability and the threshold value for instability, and for calculating the value from the stability rate by means of at least one mapping function and preferably by means of linear interpolation.

6. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for using at least one statistical characteristic value for a trend in the time course of the ventilation parameter in order to determine the index, and wherein the statistical characteristic value is preferably a mean value and, particularly preferably, a moving mean value, or at least comprises such a value.

7. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for determining the index at least from at least one statistical measure of dispersion for a distribution of values over the time course of the ventilation parameter, and wherein the statistical measure of dispersion is preferably a variance or at least comprises such a variance.

8. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for calculating and outputting a trend for a past and / or future development of the index.

9. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for changing the index in the direction of poor respiratory stability on the basis of at least one of the following causes: asynchrony between the ventilator (2) and the patient; occurrence of partial or complete intermittent airway obstructions; insomnia; discomfort due to the mask (102) and / or treatment pressure; dyspnea; excessive secretion; urge to cough; unstable respiratory drive; periodic breathing; severe leaks.

10. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for performing at least one action when the index lies in at least one defined critical value range for the respiratory stability and / or shows a trend toward that, and wherein the action comprises an output of at least one warning notice and / or alarm and / or an instruction for action.

11. The evaluation system (1) according to the preceding claim, wherein at least one critical value range is provided both for excessively high and for excessively low respiratory stability, such that excessively rigid breathing can also trigger an action.

12. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for outputting the index in combination with at least one value for at least one ventilation parameter, for example respiratory rate and / or breathing depth, wherein the value is preferably statistically processed over time.

13. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for controlling the ventilator (2) depending on the determined index and, in particular, for adjusting at least one control variable of the ventilator (2) in order to effect a change of the index in the direction of higher respiratory stability.

14. The evaluation system (1) according to the preceding claim, wherein the evaluation apparatus (3) is suitable and designed, in order to achieve a higher respiratory stability, for adjusting the breathing gas pressure and / or the breathing gas flow and / or for adjusting at least one of the following parameters: inspiratory pressure level; expiratory pressure level; trigger sensitivity; inspiration duration; expiration duration; slope of the pressure transitions between the pressure levels.

15. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for outputting the index and / or for taking same into account for an action only after a defined minimum duration of the ventilation has elapsed, and / or wherein the evaluation apparatus (3) is suitable and designed for outputting the index together with at least one warning notice indicating that the minimum duration has not been reached and / or for taking the index into account for an action together with at least one warning notice indicating that the minimum duration has not been reached, wherein the minimum duration comprises at least two hours and / or at least one night sleep phase of the patient.

16. The evaluation system (1) according to one of the preceding claims, wherein the evaluation apparatus (3) is suitable and designed for identifying an acute exacerbation when the index indicates an increase of the respiratory stability of the patient and the detected ventilation parameter simultaneously indicates an increasing respiratory rate and shallower breathing.

17. The evaluation system (1) according to one of the preceding claims, comprising at least one ventilator (2).

18. A method for operating an evaluation system (1) according to claim 1.