Process and apparatus for monitoring a ventilator

1 . A monitoring process for monitoring a ventilator, the process comprising the steps of:

providing a signal-processing monitoring unit for monitoring the ventilator, wherein the ventilator is configured to perform supportive artificial ventilation of a patient, the supportive artificial ventilation including receiving measured values from a sensor arrangement comprising a respiratory sensor configured and arranged to measure a respective indicator which correlates with the patient's own inspiratory efforts, the supportive artificial ventilation further including evaluating measured values of the sensor arrangement to generate a respiratory signal which is an indicator of the patient's own inspiratory efforts, and depending on the respiratory signal, to perform a sequence of ventilation strokes with an objective that a respective start and a respective end of each inspiratory effort of the patient trigger a respective start and a respective end, of exactly one ventilation stroke,

wherein at least two possible asynchrony types are predefined, which are different from each other, wherein a predefined possible asynchrony type has actually occurred if a ventilation stroke begins or ends earlier or later than an inspiratory effort triggering this ventilation stroke, or if the ventilation stroke is triggered without the inspiratory effort or if the inspiratory effort does not trigger the ventilation stroke;

the process of monitoring the ventilator with the monitoring unit is performed while the ventilator is performing supportive artificial ventilation of the patient;

the monitoring process further comprising the steps of:

within the monitoring unit, detecting the respective start and the respective end of each inspiratory effort of the patient, wherein the respiratory signal is evaluated for this detection;

within the monitoring unit, determining a respective start and a respective end of each ventilation stroke;

detecting with the monitoring unit any actual occurrence of one of the predefined possible asynchrony types at least if its duration is above a predefined asynchrony duration threshold; and

within the monitoring unit, determining a respective measure for a frequency and/or a duration of the actual occurrence of each predefined possible asynchrony type occurring during the sequence of ventilation strokes;

wherein a time asynchrony occurs if a ventilation stroke begins or ends earlier or later than the inspiratory effort triggering the ventilation stroke,

wherein an event asynchrony occurs if a ventilation stroke is triggered without an inspiratory effort or an inspiratory effort does not trigger a ventilation stroke, wherein a presentation is generated and provided as an output in a form configured to be perceptible by a human,

wherein the presentation is generated using two axes,

wherein the two axes are perpendicular or oblique to each other and

wherein a two-dimensional area is shown for each asynchrony type in the presentation,

wherein the two dimensions of the two-dimensional area depend on the measure for frequency and the measure for duration, respectively.

2 . The monitoring process of claim 1 , further comprising:

within the monitoring unit, determining which one of four possible situations is present at a sampling time point,

the four possible situations comprising:

the patient performs the inspiratory effort, and the ventilator performs the ventilation stroke;

neither the patient performs the inspiratory effort nor does the ventilator perform the ventilation stroke;

the patient performs the inspiratory effort, and the ventilator does not perform the ventilation stroke; and

the ventilator performs the ventilation stroke, and the patient does not perform the inspiratory effort,

for determining which situation is present at the sampling time point, evaluating the respiratory signal,

wherein the step of determining the measures for the frequency and/or the duration of the predefined possible asynchrony types comprises the step of determining a series of situations, wherein the series of situations comprises one situation per sampling time point of the series of sampling time points,

wherein, in the series of situations, a situation sequence is determined, wherein a determined situation sequence comprises at least two different immediately successive situations of the series of situations which successive situations differ from each other, and

wherein for each predefined possible asynchrony type, the measure for a frequency of asynchrony and/or the measure for a duration of asynchrony is determined by using the determined situation sequences in which the predefined possible asynchrony type is actually present.

3 . The monitoring process of claim 2 , wherein the measure for the frequency and/or the duration of each predefined possible asynchrony type is determined by the monitoring unit depending on the respective frequency and/or duration of the determined situation sequences in which this asynchrony type is present.

4 . The monitoring process according to claim 1 , wherein:

the ventilator is adapted to automatically detect when the patient starts and stops the inspiratory effort;

the ventilator is configured to apply a decision rule to the respiratory signal for detecting the inspiratory effort start and stop, said decision rule depends on a parameter;

the monitoring process further comprises the steps of:

with the monitoring unit, calculating a target setpoint for the parameter of the decision rule, the target setpoint is calculated depending on at least one determined measure for a frequency and/or a duration of a possible asynchrony type; and

transmitting a message to the ventilator or outputting the message in a form configured to be perceptible by a human, wherein the message comprises information about the calculated target setpoint and/or about a change in a currently used setpoint of the parameter wherein the change depends on the target setpoint, and

changing the applied decision rule of the ventilator in response to the received message or to a user input.

5 . The monitoring process according to claim 1 , further comprising:

with the monitoring unit, generating the presentation that shows the respective determined measures for the frequency and/or the duration of at least two of the predefined possible asynchrony types having occurred during the sequence of ventilation strokes; and

triggering the step that the generated presentation is output in the form configured to be perceived by a human.

6 . The monitoring process according to claim 5 , wherein:

for each predefined asynchrony type, which is shown in the presentation, a measure for the frequency and a measure for the duration of the predefined asynchrony type are determined; and

for each of the presented predefined asynchrony types both measures are shown in the presentation.

7 . The monitoring process according to claim 6 , wherein:

a measure for the frequency of the respective predefined possible asynchrony type is plotted on one axis and a measure for the duration of the same predefined possible asynchrony type is plotted on the other axis; and

each of the asynchrony types shown in the presentation is shown by means of a rectangular or trapezoidal surface area, with two dimensions of this area depending upon the two measures.

8 . The monitoring process according to claim 1 , wherein the monitoring unit detects any occurrence of the following eight predefined possible asynchrony types at least if occurring above a predefined asynchrony duration threshold:

the ventilation stroke triggers the inspiratory effort (reverse triggering);

the ventilation stroke is triggered too late (late triggering);

the ventilation stroke is ended too late (late cycling off);

the ventilation stroke is ended too early (premature cycling off);

the ventilation stroke is triggered without the inspiratory effort (auto triggering);

the inspiratory effort does not trigger the ventilation stroke (missed effort);

a first inspiratory effort is terminated during the ventilation stroke, and a second inspiratory effort is started during the same ventilation stroke (missed expiration); and

a first ventilation stroke is completed during an inspiratory effort, and a second ventilation stroke is started during the same inspiratory effort (double triggering).

9 . The monitoring process according to claim 8 ,

wherein the monitoring unit:

generates a first presentation which refers to first four of the eight predefined possible asynchrony types; and/or

generates a second presentation, which refers to remaining four of the eight predefined possible asynchrony types;

wherein the monitoring unit causes the first presentation and/or the second presentation to be output in a form configured to be perceptible by a human,

wherein depending on a user input, either the first presentation or the second presentation or both presentations are output.

10 . A computer program on a non-transitory computer-readable medium, the computer program being executable on a signal-processing monitoring unit with a data communication with a ventilator,

the ventilator configured to perform supportive artificial ventilation of a patient,

the ventilator configured during the supportive artificial ventilation to receive measured values from a sensor arrangement comprising a respiratory sensor configured and arranged to measure a respective indicator which correlates with the patient's own inspiratory efforts;

to generate a respiratory signal, which is an indication of the patient's own inspiratory effort, generating the signal by evaluating the measured values of the sensor arrangement;

depending on the respiratory signal, to perform a sequence of ventilation strokes with an objective that a respective start and a respective end of each inspiratory effort of the patient trigger a respective start and a respective end of exactly one ventilation stroke,

wherein at least two possible asynchrony types are predefined, which are different from each other,

wherein a predefined possible asynchrony type has actually occurred if a ventilation stroke begins or ends earlier or later than an inspiratory effort triggering this ventilation stroke, or if the ventilation stroke is triggered without the inspiratory effort or if the inspiratory effort does not trigger the ventilation stroke;

with execution of the computer program on the signal-processing monitoring unit, the computer program causes the signal-processing monitoring unit to:

monitor the ventilator with the monitoring unit while the ventilator is performing supportive artificial ventilation of the patient;

detect the respective start and the respective end of each inspiratory effort of the patient, wherein the respiratory signal is evaluated for the detection;

determine a respective start and end of each ventilation stroke;

detect any actual occurrence of each predefined possible asynchrony type at least if its duration is above a predefined asynchrony duration threshold; and

determine a measure for a respective frequency and/or a respective duration of the actual occurrence of each predefined possible asynchrony type occurring during the sequence of ventilation strokes,

wherein a time asynchrony occurs if a ventilation stroke begins or ends earlier or later than the inspiratory effort triggering the ventilation stroke,

wherein an event asynchrony occurs if a ventilation stroke is triggered without an inspiratory effort or an inspiratory effort does not trigger a ventilation stroke,

wherein a presentation is generated and provided as output in a form configured to be perceptible by a human,

wherein the presentation is generated using two axes,

wherein the two axes are perpendicular or oblique to each other,

wherein a two-dimensional area is shown for each asynchrony type in the presentation,

wherein the two dimensions of the two-dimensional area depend on the measure for frequency and the measure for duration, respectively.

11 . A ventilating process for supportive artificial ventilation of a patient by a ventilator, the ventilating process comprising the steps of:

providing a signal-processing monitoring unit;

during supportive artificial ventilation, receiving with the ventilator measured values from a sensor arrangement comprising a respiratory sensor configured and arranged to measure a respective indicator which correlates with the patient's own inspiratory efforts;

generating with the ventilator a respiratory signal, which respiratory signal is an indicator for the patient's own inspiratory effort, the respiratory signal is generated by evaluating the measured values;

with the ventilator, performing a sequence of ventilation strokes based on the respiratory signal with an objective that a respective start and a respective end of each inspiratory effort of the patient trigger a respective start and a respective end of exactly one ventilation stroke,

wherein at least two possible asynchrony types are predefined, which are different from each other,

wherein a predefined possible asynchrony type has actually occurred if a ventilation stroke begins or ends earlier or later than an inspiratory effort triggering this ventilation stroke, or the ventilation stroke is triggered without the inspiratory effort or the inspiratory effort does not trigger the ventilation stroke;

with the monitoring unit, detecting the respective start and the respective end of each inspiratory effort of the patient, wherein the respiratory signal is evaluated for the detection;

with the monitoring unit, determining a respective start and a respective end of each ventilation stroke;

with the monitoring unit, detecting every actual occurrence of each predefined possible asynchrony type at least if its duration is above a predefined asynchrony duration threshold; and

with the monitoring unit, determining a respective measure for a frequency and/or a respective duration of the actual occurrence of each predefined possible asynchrony type occurring during the sequence of ventilation strokes,

wherein a time asynchrony occurs if a ventilation stroke begins or ends earlier or later than the inspiratory effort triggering the ventilation stroke,

wherein an event asynchrony occurs if a ventilation stroke is triggered without an inspiratory effort or an inspiratory effort does not trigger a ventilation stroke,

wherein a presentation is generated and provided as output in a form configured to be perceptible by a human,

wherein the presentation is generated using two axes,

wherein the two axes are perpendicular or oblique to each other,

wherein a two-dimensional area is shown for each asynchrony type in the presentation and

wherein the two dimensions of the two-dimensional area depend on the measure for frequency and the measure for duration, respectively.

12 . A signal-processing monitoring unit for monitoring a ventilator, wherein the ventilator is configured to perform supportive artificial ventilation of a patient, the supportive artificial ventilation including receiving measured values from a sensor arrangement comprising a respiratory sensor configured and arranged to measure a respective indicator which correlates with the patient's own inspiratory efforts, wherein the ventilator is configured to generate a respiratory signal, which is an indicator of the patient's own inspiratory effort by evaluating the measured values, wherein the ventilator is configured to perform, depending on the respiratory signal, a sequence of ventilation strokes with an objective that a respective start and a respective end of each inspiratory effort of the patient trigger a respective start and a respective end of exactly one ventilation stroke,

wherein at least two possible asynchrony types are predefined, which are different from each other,

wherein a predefined possible asynchrony type has actually occurred if a ventilation stroke begins or ends earlier or later than an inspiratory effort triggering the ventilation stroke, or the ventilation stroke is triggered without the inspiratory effort or the inspiratory effort does not trigger the ventilation stroke,

wherein the monitoring unit is configured to:

detect the respective start and the respective end of each inspiratory effort of the patient by evaluating the respiratory signal;

determine a respective start and a respective end of each ventilation stroke;

detect any actual occurrence of one of the predefined possible asynchrony types at least if its duration is above a predefined asynchrony duration threshold; and

determine a measure for a frequency and/or a duration of the actual occurrence of each predefined possible asynchrony type occurring during a sequence of ventilation strokes,

wherein a time asynchrony occurs if a ventilation stroke begins or ends earlier or later than the inspiratory effort triggering the ventilation stroke,

wherein an event asynchrony occurs if a ventilation stroke is triggered without an inspiratory effort or an inspiratory effort does not trigger a ventilation stroke,

wherein a presentation is generated and provided as output in a form configured to be perceptible by a human,

wherein the presentation is generated using two axes,

wherein the two axes are perpendicular or oblique to each other,

wherein a two-dimensional area is shown for each asynchrony type in the presentation and

wherein the two dimensions of the two-dimensional area depend on the measure for frequency and the measure for duration, respectively.

13 . The monitoring unit according to claim 12 , wherein the monitoring unit is configured to:

determine which one of following four possible situations exists at a sampling time point:

the patient performs the inspiratory effort, and the ventilator performs the ventilation stroke;

neither the patient performs the inspiratory effort nor does the ventilator perform the ventilation stroke;

the patient performs the inspiratory effort, but the ventilator does not perform the ventilation stroke;

the ventilator performs the ventilation stroke, but the patient does not perform the inspiratory effort,

wherein the monitoring unit is configured to use the respiratory signal for determining if and which one of the four possible situations is present at a sampling time point,

wherein the monitoring unit is configured, in determining the measures of the frequency and/or the duration for each of the predefined possible asynchrony types, to determine a series of situations,

wherein the series of situations comprises one situation per each sampling time point of the series,

wherein in the series of situations, the monitoring unit is configured to determine a situation sequence,

wherein a determined situation sequence comprises at least two different immediately successive situations which differ from each other, and

wherein the monitoring unit is configured, for each predefined possible asynchrony type, to determine the measure for the frequency and/or duration of the predefined possible asynchrony type using those determined situation sequences in which that asynchrony type is actually present.

14 . The monitoring unit according to claim 12 , wherein:

the ventilator is configured to apply a decision rule to the respiratory signal, to decide when the patient starts and stops the inspiratory effort, said decision rule depending on a parameter;

the monitoring unit is configured to:

calculate a target setpoint for the parameter of the decision rule; and

cause a message to be transmitted to the ventilator or output in a form perceptible by a human;

wherein the message comprises information about the calculated target setpoint and/or about a change in a currently used setpoint of the parameter;

the ventilator is configured to automatically change the applied decision rule in response to the received message or on a user input.

15 . A ventilation arrangement comprising:

a sensor arrangement comprising one or more respiratory sensors configured and arranged to measure a respective indicator which correlates with the patient's own inspiratory efforts to provide measured values;

a ventilator configured to perform supportive artificial ventilation of the patient, and while doing so receive the measured values from the sensor arrangement to generate a respiratory signal, which is an indicator of the patient's own inspiratory effort,

wherein the ventilator is configured, depending on the respiratory signal, to perform a sequence of ventilation strokes with an objective that a respective start and a respective end of each inspiratory effort of the patient trigger a respective start and a respective end of exactly one ventilation stroke,

wherein at least two possible asynchrony types are predefined, which are different from each other, wherein a predefined possible asynchrony type has actually occurred if a ventilation stroke begins or ends earlier or later than an inspiratory effort triggering this ventilation stroke, or the ventilation stroke is triggered without the inspiratory effort or if the inspiratory effort does not trigger the ventilation stroke; and

a signal-processing monitoring unit configured to:

detect a respective start and a respective end of each inspiratory effort of the patient by evaluating the respiratory signal;

determine the respective start and end of each ventilation stroke;

detect any occurrence of one of the predefined possible asynchrony types at least if its duration is above a predefined asynchrony duration threshold; and

determine a measure for a respective frequency and/or a respective duration of the actual occurrence of each predefined possible asynchrony type occurring during a sequence of ventilation strokes,

wherein a time asynchrony occurs if a ventilation stroke begins or ends earlier or later than the inspiratory effort triggering the ventilation stroke,

wherein an event asynchrony occurs if a ventilation stroke is triggered without an inspiratory effort or an inspiratory effort does not trigger a ventilation stroke,

wherein a presentation is generated and provided as output in a form configured to be perceptible by a human,

wherein the presentation is generated using two axes,

wherein the two axes are perpendicular or oblique to each other,

wherein a two-dimensional area is shown for each asynchrony type in the presentation and

wherein the two dimensions of the two-dimensional area depend on the measure for frequency and the measure for duration, respectively.

16 . The ventilation arrangement according to claim 15 , wherein:

the monitoring unit is a component of the ventilator; and

the ventilator further comprises a further signal-processing unit configured:

to receive the measured values from the sensor arrangement and to generate the respiratory signal by evaluating the measured values; and

to trigger the sequence of ventilation strokes.