WO2017036890A1

WO2017036890A1 - Method for determining at least a cardiac stress duration and/or a cardiac recovery duration from a heartbeat signal

Info

Publication number: WO2017036890A1
Application number: PCT/EP2016/070016
Authority: WO
Inventors: Maximilian Moser; Thomas Hassler; Matthias FRÜHWIRTH
Original assignee: Human Research Institut Für Gesundheitstechnologie Und Präventionsforschung Gmbh; Joysys Gmbh
Priority date: 2015-08-28
Filing date: 2016-08-24
Publication date: 2017-03-09
Also published as: AT517071B1; EP3340870A1; AT517071A4

Abstract

In a method for determining, in particular continuously, at least a cardiac stress duration and/or cardiac recovery duration and, preferably, a cardiac stress quotient and/or a cardiac recovery quotient from a heartbeat signal, in particular from an electrocardiogram (3) and/or a magnetocardiogram and/or an impedance cardiogram and/or a ballistocardiogram and/or a seismocardiogram and/or a phonocardiogram, it is proposed that a heartbeat signal is recorded from a human or animal subject, wherein, subsequently from the heartbeat signal, at least an atrial contraction duration and/or a ventricular contraction duration and/or an atrioventricular contraction duration is determined as cardiac stress duration and/or an atrial dilatation duration and/or a ventricular dilatation duration and/or an atrioventricular dilatation duration is determined as cardiac recovery duration.

Description

Method for determining at least one cardiac load duration and / or a cardiac recovery period from a heartbeat signal

The invention relates to a method for determining at least one

Cardiac load and / or cardiac recovery from one

Heartbeat signal according to the preamble of claim 1.

It is known to observe or monitor the activities of the heart of a subject by means of a so-called ECG, therefore of an electrocardiogram. The thus determined curves of the heart activity are usually assessed only visually by a physician.

Although the ECG is the most widely used method for detecting a heartbeat signal, other methods are known or found

Use.

It has been shown that considerably more information could be obtained from a heartbeat signal of a test person, which may be helpful for the diagnosis of a physician than has hitherto been the case. In particular, the conventional ECG devices have not proven to be suitable

To provide information. As a result, only a fraction of the information that is possible per se about the condition of the subject is made available to a doctor. Thus, this provides a diagnosis, which is based on a poor history. This makes the creation of an appropriate diagnosis difficult or prevented, which in turn a poor therapy or

Treatment of the subject in question. This has a negative impact on the subject. It also represents a wrong or unnecessary

Treatment is an avoidable burden on the healthcare system.

Thus, for example, the perfusion of the heart can currently be detected from a heartbeat signal, in particular an ECG signal, only incompletely and only in extreme situations, such as a change in stimulus conduction due to lack of oxygen in the course of a myocardial infarction.

The detection of the blood circulation by means of ultrasound methods and devices has considerable disadvantages. The equipment is complex, cost-intensive, heavy and voluminous, which stands in the way of mobile use as far as possible. In addition, an ultrasound examination is a higher burden on the heart of a subject than the creation of a heartbeat signal, for example by means of ECG.

The object of the invention is therefore to provide a method of the type mentioned, with which the mentioned disadvantages can be avoided, with which the medical history of a doctor can be improved, and with which unnecessary therapies of a subject can be avoided.

This is achieved by the features of claim 1 according to the invention.

As a result, a better history and diagnosis of a subject can be made. This may make therapy more responsive to the actual situation

Needs of a subject or patient are matched. As a result, misjudgements can be avoided, as these are due to poor

Measurement results were made. As a result, the condition of a subject can be determined considerably more accurately than was previously the case. As a result, a better tailored to the actual condition of the subject therapy can be developed and carried out, if such appears necessary, and in return, unnecessary therapies of a subject can be avoided. As a result, additional information can be easily and accurately determined from a recorded heartbeat signal, such as information or values for the blood circulation state, the duration of the systole, the duration of diastole, the different stress on the heart during the day and night, the

different recovery of the heart by day and night. The corresponding values or information can easily be determined in the course of a 24-hour recording of a heartbeat signal, with no additional burden for the subject, as would be the case with an ultrasound examination, which also can not be done over 24 hours.

As a result, the blood circulation state can be determined again with each heartbeat. Furthermore, it has been shown that numerous drugs lead to an extension of the ventricular contraction period. This can lead to a metabolic imbalance with a tendency to fibrillation and cardiac arrest to lead. By the subject method, such an extension of the ventricular contraction period can be easily determined.

By means of the present method, a respective current or

situational recovery state of the heart are determined. In particular, in physically demanding activities, such as these are exposed to firefighters, steel workers, it may lead to acutely dangerous prolongations of the ventricular contraction period, or has been shown that very high individual loads due to an extension of the ventricular

Contraction period can be detected before serious damage to the subject occurred. Through this knowledge, a person can stop the stress situation in good time before life-threatening conditions develop in the heart. It has been shown, for example, in the increased disaster relief operations of recent years that help people are often no longer able to detect a state of fatigue in time, so it comes again and again to fatigue-related death of firefighters or soldiers in the relief operation, which victims through the Objective procedures can be avoided.

The invention further relates to an ECG device according to the preamble of

Patent claim 30.

The object of the invention is therefore to provide an ECG device of the aforementioned type, with which the mentioned disadvantages can be avoided, with which the medical history of a doctor can be improved, and with which unnecessary therapies of a subject can be avoided.

This is achieved by the features of claim 30 according to the invention.

This achieves the advantages set forth above for the method.

The subclaims relate to further advantageous embodiments of the invention.

It is hereby expressly referred to the wording of the claims, whereby the claims at this point are incorporated by reference into the description and are considered to be reproduced verbatim. The invention will be described in more detail with reference to the accompanying drawings, in which only a preferred embodiment is shown by way of example. Showing:

1 shows a time course of the heart rate; and

Fig. 2 is a block diagram of a subject ECG device.

The subject invention relates to a method for, in particular

continuous, determination of at least one cardiac load duration and / or a cardiac recovery period, and preferably a cardiac stress quotient and / or a cardiac recovery quotient, from a heartbeat signal, in particular an electrocardiogram and / or magnetocardiogram and / or

Impedance cardiogram and / or ballistocardiogram and / or

Seismocardiogram and / or phonocardiogram, in which the heartbeat signal is recorded on a human or animal subject, wherein subsequently at least one atrial contraction period and / or one ventricular contraction period and / or one atrio-ventricular contraction period is determined from the heartbeat signal as cardiac loading duration and / or as

Cardiac recovery is determined an atrial dilatation and / or a ventricular dilatation and / or atrio-ventricular dilatation.

Measurement results were made. As a result, the condition of a subject can be determined considerably more accurately than was previously the case. As a result, a better tailored to the actual condition of the subject therapy can be developed and carried out, if such appears necessary, and in return, unnecessary therapies of a subject can be avoided. As a result, additional information can be easily and accurately determined from a recorded heartbeat signal, such as information or values for the blood circulation state, the duration of the systole, the duration of diastole, the different stress on the heart during the day and night, the different recovery of the heart by day and night. The corresponding values or information can easily be determined in the course of a 24-hour recording of a heartbeat signal, with no additional burden for the subject, as would be the case with an ultrasound examination, which also can not be done over 24 hours.

As a result, the blood circulation state can be determined again with each heartbeat. Furthermore, it has been shown that numerous drugs lead to an extension of the ventricular contraction period. This can lead to a metabolic imbalance with a tendency to fibrillation and cardiac arrest. By the subject method, such an extension of the ventricular contraction period can be easily determined.

By means of the present method, a respective current or

It is provided to determine a cardiac output duration and / or a cardiac recovery period from a heartbeat signal.

The indices used in each case indicate whether the respective wave or tine is a wave or a tine which is assigned to a first heartbeat or to a second heartbeat immediately following it. The cardiac load duration is at least one atrial contraction duration and / or one ventricular contraction duration and / or one atrio-ventricular contraction duration. The atrial contraction duration is the loading duration of the atrium. In an ECG signal this corresponds to the interval P ₁ -Q ₁ . The ventricular contraction time is the load duration of the ventricles. In an ECG signal, this corresponds to the interval QrTV. The atrio-ventricular contraction duration is the duration of loading of the atrium or ventricle. In an ECG signal, this essentially corresponds to the interval Ρ ₁ -ΤΊ.

The cardiac recovery time is an atrial dilation duration and / or a ventricular dilation duration and / or an atrio-ventricular dilation duration. The atrial dilation duration is the recovery time of the atrium, or

Atriumsdiastole. In an ECG signal this corresponds to the interval Oj-P ₂ . The ventricular dilatation time is the recovery time of the ventricles, or

Ventricular diastole. In an ECG signal, this corresponds to the interval T ₁ -Q. The atrial-ventricular dilation time is the recovery time of atrium and

Ventricle, or heart diastole. In an ECG signal this corresponds to the interval T ₁ -P ₂ .

The durations concerned were explained above for a quick orientation on the basis of an ECG signal, and the usual designations of the waves and spikes. This will be explained in more detail later. In addition to a heartbeat signal in the form of an ECG signal, the relevant

Each time periods are also determined from differently derived heartbeat signals. In particular, it is provided that the heartbeat signal

Magnetocardiogram or impedance cardiogram or ballistocardiogram or seismocardiogram or phonocardiogram is.

The course of a magnetocardiogram or impedance cardiogram is very similar to the course of an ECG signal.

Furthermore, the use of capacitive electrodes can be provided.

A ballistocardiogram, a seismocardiogram or a phonocardiogram are time-delayed or out-of-phase with respect to an ECG signal, however, the corresponding intervals can also be determined therefrom. However, since, in contrast to the ECG, the points at which the decrease takes place are not standardized to the same extent, a correspondingly unified and unambiguous nomenclature can not be given, especially as the rashes in a ballistocardiogram, a seismocardiogram or a phonocardiogram are clearly dependent on the location. where each will be recorded. Due to the representational general naming of the individual durations or intervals, it is easily possible for a person skilled in the art or a doctor for a specifically accepted ballistocardiogram, seismocardiogram and / or phonocardiogram to be the respective ones

Identify cardiac load durations and / or cardiac recovery durations.

If necessary, an ECG for synchronization is required, therefore, to uniquely identify the respective cardiac events in the ballistocardiogram, the seismocardiogram or the phonocardiogram.

The respective intervals or periods of time include, at least at

Forming the heartbeat signal as an ECG signal, respectively, the associated waves substantially entirely. Therefore, if a certain interval has a wave as the beginning and / or end, then this wave is essentially entirely part of the interval in question.

The indicated intervals are each scheduled to begin at the event indicated by the former letter and terminate at the event indicated by the second letter. Thus, for example, an interval QT is not identical to an interval TQ.

It is preferably provided that, in addition to the already stated durations

Quotient certain durations are determined.

It is preferably provided that as heart stress quotient:

a load quotient atrium as the ratio of the atrial contraction durations to the atrial dilatation duration and / or

a load quotient ventricle as the ratio of the ventricular contraction duration to the ventricular dilatation duration and / or - a heart rate as a ratio of the atrio-ventricular contraction duration to the atrio-ventricular dilatation duration and / or

- Atrial-ventricular dilatation duration ratio related to cardiac diastole as a ratio of atrial traction duration to atrio-ventricular dilatation duration and / or

a ventricular load quotient related to cardiac diastole is determined as the ratio of the ventricular traction duration to the atrio-ventricular dilation duration.

Furthermore, it is preferably provided that as heart recovery quotient

a recovery ratio atrium as the ratio of the atrial contractions to the atrial dilation time and / or

a recovery ratio of the ventricle as the ratio of the ventricular contraction duration to the ventricular dilation duration and / or

a recovery ratio of the total heart as the ratio of the atrio-ventricular contraction duration to the atrio-ventricular dilation duration and / or

a recovery ratio atrium related to cardiac diastole as the ratio of the atrial contraction duration to the atrio-ventricular dilatation duration and / or

a recovery ratio of the ventricle relative to the heart diastole is determined as the ratio of the ventricular contraction duration to the atrio-ventricular dilation duration.

It is provided in particular that the at least one cardiac load duration and / or the at least one cardiac recovery period, and preferably the at least one cardiac stress quotient and / or the at least one cardiac exercise period

Cardiac recovery quotient, spent and / or stored.

Preference is given to the relevant cardiac load duration and / or the

Recovery time and, if applicable, the relevant

Cardiac stress quotients and / or cardiac recovery quotients continuously new educated. This leads to the output of constantly changing values for the individual cardiac load durations or heart recovery periods, which is sometimes undesirable. It is preferably provided, in particular in addition to the education and

Output of the current values of the cardiac load duration and / or the

Recovery time, furthermore, the at least one issued

Heart load duration or recovery time as an average and / or median to form a predetermined number to previous heartbeat intervals determined cardiac load and / or recovery periods, and

to spend accordingly.

It is particularly preferably provided that the at least one cardiac load duration and / or the at least one cardiac recovery period, and preferably the at least one cardiac stress quotient and / or the at least one

Cardiac recovery quotient, essentially parallel to the recording of the

Heartbeat signal output, in particular displayed is. The relevant at least one value is therefore determined substantially continuously or gradually from the measured heart rate signal and also displayed or

output. Particularly in the case of the particularly preferred mobile implementation of the subject method in a device which the test person carries with him on the body, it is provided that the cardiac load duration and / or the cardiac load duration

Cardiac recovery and / or the Herzbelastung quotient and / or the cardiac recovery quotient determined directly in the mobile device, and preferably also displayed on this device. In contrast to the known ones

Devices for receiving a 24-hour ECG can be responded directly by the subject on the determined values, for example, by immediate changes in his current life circumstances. According to a particularly preferred embodiment, it is provided that the display does not take place on the device itself, but on a smartphone of the subject. Due to the widespread distribution of such smartphones this can

expediently be used for display, which can be dispensed with a separate display in said device.

It is preferably provided in development of the subject method that at least one determined cardiac load duration and / or at least one determined cardiac recovery time, and preferably at least one determined cardiac stress quotient and / or at least one determined

Cardiac recovery quotient is compared with at least one predeterminable boundary condition, and that when the at least one boundary condition is exceeded by the cardiac load duration or the cardiac recovery period or the

Cardiac stress quotient or the heart stress quotient a signal

is issued. Thus, a subject can be warned in time of an impending critical condition in order to relinquish his present activity. In this case, provision is made in particular for a plurality of boundary conditions of different levels to be provided, so that a first signal is output, for example, when a first boundary condition is exceeded or reached, and that, in the event of further changes, the cardiac load duration and / or the

Cardiac recovery, which leads to exceeding a second boundary condition, a different signal from the first signal is output.

The at least one boundary condition can be taken from a database, for example as a function of age, gender, medical history,

Environmental parameters and the like. In such a database, corresponding boundary conditions can be based on experience with others

Subjects are filed. In particular, data may be contained in the database, which results from studies with substantially healthy

Subjects were won.

In addition to the selection of boundary conditions from a database is provided in particular that the at least one cardiac load duration and / or the

Cardiac recovery period and / or the cardiac stress quotient and / or the

Cardiac recovery quotient over a predefinable first period, which is preferably between one day and fourteen days is recorded, in particular by means of a mobile ECG device 1, that the first period in a predetermined plurality of second periods, which are preferably between 15 minutes and 2 hours, is divided, and that for at least a second period of time, at least the boundary condition from the determined cardiac load duration or cardiac recovery period or Herzerholungs quotient or heart recovery quotient is formed. Here, the at least one boundary condition of so-called. Historical Data of the subject himself or from data of a comparison database determined.

It is further provided that the at least one boundary condition is not constantly left the same, but is adapted over the course of the day.

Preferably, it is therefore provided that the at least one boundary condition is adapted to the respective prevailing time of day by selecting the boundary condition which was determined for the second time period in which the current time of day lies. This can affect different

Stress states of the subject are responding. If appropriate, a corresponding database or comparison database, which database or comparison database has data of the same or other subjects, may be provided for this purpose.

The present method will be described below with reference to the recording of a heartbeat signal in the form of an ECG signal 3. In addition to the most widespread and customary form of recording a heartbeat signal by means of an ECG, the subject invention can be modified accordingly, as already explained, also be applied to a differently determined heartbeat signal. The description based on an ECG signal 3 is therefore preferably not restrictive to an ECG signal 3 to understand.

The recorded heartbeat signal is recorded in the form of an ECG signal in a subject. The subject can be any kind of living being with at least one heart, in other words one

Humans as well as a corresponding animal.

The following is unless explicitly stated in each case when naming a

Cardiac load also the application of the described at one

Recovery time provided.

The processing of the ECG signal 3 preferably takes place in accordance with FIG

representational method in a suitably trained ECG device. 1

The ECG signal 3 received by the subject in a manner known per se is transmitted to the input of an analog-to-digital converter 4, which is preferably part of an ECG device 1, and digitized by the analog-to-digital converter 4. The acceptance points of the ECG are preferably selected such that the R wave R, the P wave P and the T wave T output as positive signals, and the Q wave Q and the S wave S as negative signals relative to a reference potential become.

It is preferably provided in the preferred digital signal processing in the context of the present invention that the analog-to-digital converter has a sampling rate greater than or equal to 6 kHz and a resolution greater than or equal to 12 bits. It is particularly preferred that the analog-to-digital converter has a sampling rate of 8 kHz and a resolution of 16 bits.

It should be noted that corresponding and commonly used

Signal conditioning circuits, such as input amplifiers may be provided. Furthermore, a low-pass filter is provided in front of the analog-to-digital converter 4, to comply with the sampling theorem.

Within the digital ECG signal 3, successive R waves R are preferably detected. It is provided in particular, the times of

Occurrence of the respective R-waves R, preferably to determine the times between the R-waves R, respectively.

Furthermore, at least one time duration between an R-wave R of the successive R-waves R and one of the R-waves R upstream and / or subsequent wave P, T and / or wave Q, S of the ECG signal 3 is determined. For this purpose, the at least one wave P, T and / or Zacke Q, S is also detected. From the at least one determined period of time, at least one cardiac load duration or

Recovery time determined.

As already mentioned in the previous paragraph, it is an indirect goal to determine the time periods between the teeth Q, S or waves P, T and in each case one R-wave R, in order to process them further. It is therefore particularly preferred to determine the times of occurrence of the spikes Q, S or waves P, T.

For processing reasons, in the implementation of the subject invention, in particular, the periods of anticipatory waves or spikes are calculated from the continuous signal. It is particularly preferred that the time position of the tips of the Q-wave Q, the R-wave R and the S-wave S is detected. It is preferably provided that the peaks Q, R, S are each also the largest positive and / or negative slope, therefore, the largest slope at rise and / or fall, is determined. Furthermore, it is preferably provided, the temporal positions of the beginning, middle and end of the P-wave, the T-wave and, if detectable, the U-wave. In this case, such a detection is preferably provided for each of the mentioned parameters, even if this is not stated in the following text in each case declined.

Preferably, a continuous detection of both the R-wave R and the at least one wave P, T and / or wave Q, S within the continuous ECG signal 3 is provided. Furthermore, it is preferably provided to detect all waves P, T and waves Q, S which are typical for an ECG, wherein a selection of individual waves P, T or waves Q, S may also be provided. The ECG signal 3 typically has the P wave P, the Q wave Q, the S wave, and the T wave T, as shown in FIG. 1, besides the R wave. In addition, in some subjects between the T-wave T and the P-wave P of the next heartbeat further exists a U-wave and also measurable. If such a U-wave appears, its detection is also provided.

It is preferably provided that in each case the time intervals or the time periods between the R-wave R and the waves P, T or waves Q, S of a "self-contained" first heartbeat are measured or determined It is therefore intended to determine the durations within a heartbeat, whereby it may further be preferred to determine the duration of the pulse between a wave and / or a prong of a first heartbeat and that of a wave and / or a prong of a second heartbeat immediately following the first heartbeat.

Hereinafter, a preferred method for detecting specifically the R-wave R is described, which can be used according to adapted also for the detection of the Q-wave Q and the S wave. It is preferably provided that the digital ECG signal 3 is filtered by means of a predefinable FIR filter. FIR stands for Finit Impulse Response in a familiar way. An original, untreated ECG signal 3 generally has a fluctuating baseline, which can be represented as a superposition of a low-frequency disturbance. The appropriate filtering can be used to smooth the baseline. In particular, the time intervals of the individual waves P, T and / or tines Q, S of the ECG signal 3 are relevant in the formation of the subject cardiac load duration or cardiac recovery time. It can therefore be used in the filtering according to a time or

be respected phased filtering. In this case, a gain of the waves P, T and / or tines Q, S can be implemented in order to simplify their subsequent detection.

Particularly preferably, it is provided that the FIR filter has filter components which are formed only by the integer values -1, 0 and / or + 1. As a result, a very fast processing and / or very low hardware requirements can be achieved, whereby an implementation of the

this process is supported on a mobile platform.

It is preferably provided that the subject method is or can be performed on a mobile platform. When implementing the individual algorithms and routines, it is therefore preferable to ensure low processor load and low energy consumption.

The, preferably filtered, digital ECG signal 3 is subsequently divided into segments of predefinable duration. The individual segments are preferably chosen with a length of 2 seconds to 3 seconds, with a length of 2.5 seconds has proven to be particularly advantageous. The individual segments preferably begin in each case with the last detected R wave, wherein

of course the first segment, in the absence of one previously

detected R-wave begins at a random time with respect to the heartbeat. Within each segment, a maximum value of the ECG signal 3 is subsequently determined. In the following, it is preferably provided that the median of the values in the respective segments is formed over a predeterminable number of preceding consecutive segments. In particular, the median is formed over three to seven, preferably over five, of such segments in order to average variations in respiration. It should be noted that the segments can overlap themselves.

The samples within a segment will now match the one from the

compared with the previous segments, which is preferably divided by a predefinable value, which value is greater than or equal to one. Only samples which have a value greater than this median are processed further. As a result, a constantly newly adapted limit is formed with the help of which the computational effort can be reduced. The samples which are larger than the divided median are used with the

immediately preceding sample of the same segment. In this case, only samples having an absolute value difference from the preceding sample value greater than a predefinable limit value are further processed as R-wave candidates for detecting the R wave. Preferably, the falling edge of the R-wave R is considered or evaluated. By the objective

Selection can be eliminated quickly and with little computational and energy expenditure, a large part of the samples.

The limit value with which the sampled values are compared is preferably selected to be greater than the noise and / or the jitter of the analog-to-digital converter.

Subsequently, further samples are eliminated from the group of R-wave candidates. For this purpose, samples which fall within periods in which, for physiological reasons, no R-wave R can occur, are deleted from the set of R-wave candidates. In this case, provision is made in particular for R-wave candidates to be discarded within a predefinable time span, of at most half the expected refractory period of the subject's heart, following a previously detected R wave. The refractory period of a human's heart is about 250 ms. However, the required time must also be taken into account when Which is platform-dependent, so that the length of the period in question in addition to the genus of the subject also depends on the existing processing power of the devices used.

In particular, in human subjects than in the practical

Implementation proved to be advantageous in that R-wave candidates, which appear within less than 80 ms after an already detected R-wave R, are deleted from the set of R-wave candidates.

Subsequently, the remaining R-wave candidates are preferably evaluated with at least one predeterminable evaluation criterion.

Upon satisfaction of the evaluation criterion, an R-wave candidate is output as a detected R wave R and / or stored and / or further processed.

In addition to the time of occurrence of the relevant R wave R, the amplitude to the following minimum, in the form of the following S wave S, is also detected and stored and / or output together with the time of the R wave.

It is preferably provided that for the detection of the S-wave S and / or the Q-wave Q, the respective minimum values in respectively predeterminable time windows around the detected R wave R are determined, that of the minimum value occurring immediately before the R wave R Q is output as Q-wave Q, and / or that the minimum value occurring immediately after the R-wave R is output as S-wave S. For this purpose, a simple comparison of the samples with the respectively adjacent samples is provided. Due to the strict coupling of the Q-wave Q and the S-wave S at the time of occurrence of the R-wave R, each case the search for the corresponding minima can be limited to a very short time interval before and after the R wave remain, whereby the computational effort can be kept low. In this case, it is further preferably provided to detect the minima occurring in each case at the time closest to the detected R peak R. Preferably, the time intervals to the associated R-wave R are determined to the respective prongs Q, S, and further processed or output respectively. With regard to the detection of the Q-wave Q, it has been shown that the distance of the Q-wave Q to the R-wave R is independent of the heart rate at a certain one

Subjects is very constant. It is therefore preferably provided that the time between the Q wave Q and the R-wave R be determined as accurately as possible in a specific subject, for example in a laboratory environment, and thereafter for the further detection in the context of the subject invention Position of the Q wave Q with respect to the R wave R constant to set the value determined thereby.

It may further be provided, if this is not possible or

is impracticable or appears that the time position of the Q-wave Q is determined by this 100ms is defined in time before the determined R-wave R. It has been shown that the time span in question for most

Subjects are very close to this value of 100ms, and consequently a very small and defensible error occurs.

It has also been shown that in certain types of intake of the

Heartbeat signal in particular the Q-wave Q and the S-wave S, or the underlying processes of the heart are not clearly recognizable by corresponding rash of the respective heartbeat signal. However, it has been shown that these, or the times of their occurrence, can be determined by mathematical derivation of the heartbeat signal. It is therefore further preferred that the Q-wave Q, the R-wave R and / or the S-wave S each from the largest positive and / or negative change in the slope of

Heartbeat signal is determined.

It is further preferably provided that for the detection of the T-wave T and / or the P-wave P, the respective maximum values are determined in respectively predeterminable time windows around the detected R-wave R, wherein the maximum value occurring immediately before the R-wave is outputted as P-wave P, and the maximum value occurring immediately after the R-wave R is output as T-wave T. It is the same as the one described above

preferred detection of the Q-wave Q and the S-wave S provided that only in a limited expectation window, the respective maximum values are searched. It is further preferably provided, each time on next to the detected R peak R occurring maxima to detect.

Preferably, the time intervals are determined to the respective waves P, T, the associated R-wave R and each further processed or

output.

It is preferably provided that the duration of the successive segments and / or the duration of the expected refractory period of the heart and / or the length of the predeterminable time windows around the detected R wave R are selected as a function of the heart rate. As a result, a significantly better performance of the described algorithm can be achieved, since the expected values are already better adapted to the real conditions, and consequently the one used

numerical method converges faster.

It can also be provided to perform the prongs Q, S and / or waves P, T in accordance with the described detection of the R wave.

Particularly preferred in the described preferred detection of the spikes Q, S and / or waves P, T is provided to check the ECG signal 3 in principle for abnormal changes out, such as cardiac arrhythmia, and optionally for the detection of the individual waves P, T. or jags Q, S adjust the respective expected time windows accordingly.

2 shows an ECG device 1 with at least one input 2 for a

electrical and / or magnetic ECG signal 3, wherein the input 2 is connected to an input of an analog-to-digital converter 4, wherein an output of the analog-to-digital converter 4 is connected to an R-wave detection unit 5, and wherein an output of the R-wave detection unit 5 with a

Cardiac load duration and / or cardiac recovery duration and / or

Cardiac stress quotient and / or cardiac recovery quotient determination unit 6 is connected.

The input 2 of the ECG device 1 is connected in a manner known per se with corresponding electrodes 8.

The Herzbelastungsdauer- and / or Herzerholungsdauer- and / or

Cardiac stress quotient and / or cardiac recovery quotient determination unit 6 is preferably formed comprising a microcontroller, and for carrying out at least one embodiment of the subject

Method for determining at least one cardiac load duration and / or at least one cardiac recovery period and / or at least one

Cardiac burden quotient and / or at least one cardiac recovery quotient formed from an ECG signal 3 or provided.

The subject ECG device 1 is preferably designed as a mobile device, and preferably has a wireless data interface for transmitting the ECG signals 3 or the at least one cardiac load duration and / or at least one cardiac recovery period and / or the at least one cardiac stress quotient and / or at least one Heart recovery quotient, as well as an accumulator for energy supply.

It is further preferably provided that the determined cardiac load duration and / or cardiac recovery period and / or the cardiac stress quotient and / or the

Not only to display or store cardiac recovery quotients, but also to carry out control and / or regulation processes on the basis of these data. In this case, provision is made in particular for at least one setting of the device to be predetermined by a control and / or regulating unit when a predefinable control and / or regulating criterion is met.

In this case, the device may in principle be any type of device which is activated or deactivated, for example on the basis of the condition of the subject, or changed in another setting, wherein it is provided in particular to increase the well-being of the subject by means of said change.

Preferred embodiments of the device include devices for

Flow of an essential oil, or the regulation of the lighting, or the room climate.

Accordingly, according to a preferred embodiment it is provided that the device is an HVAC system, and that settings of the HVAC system are modified such that the cardiac recovery time and / or the Cardiac recovery quotient of the subject rises. HVAC is the abbreviation for Heating, Ventilating and Air-Conditioning, which is commonly used in the English language area, and refers to a generic term for building services systems for the heating, ventilation and air-conditioning of rooms. It is provided that the room climate is modified by changes to the HVAC system so that the cardiac recovery and / or the recovery rate of the, in the

room-occupying subjects.

According to a further preferred embodiment it is provided that the device is a lighting system and / or a sound system, and that settings of the lighting system and / or the sound system are modified such that the cardiac recovery and / or the recovery rate of the subject increases. It is intended to regulate lighting effects, the room lighting and / or sounds, sounds and / or music, in such a way that the cardiac recovery and / or the recovery rate of the, staying in the room in question

Subjects is improved.

According to a further preferred embodiment, it is provided that the device is a system for the predeterminable release of fragrances, and that settings of the system for the predeterminable release of fragrances are modified such that the cardiac recovery period and / or the cardiac recovery quotient of the subject increases. Such a device is designed in accordance to be able to deliver different fragrances specifiable in the room, it being provided that the device emits such scents that the

Cardiac recovery time and / or cardiac recovery quotient in which

room-occupying subjects.

Claims

PATENT APPLICATIONS

1 . Method for, in particular continuous, determination of at least one cardiac load duration and / or a cardiac recovery period, and preferably a cardiac stress quotient and / or a cardiac recovery quotient, from a heartbeat signal, in particular an electrocardiogram (3) and / or

Magnetocardiogram and / or impedance cardiogram and / or

Ballistocardiogram and / or seismocardiogram and / or phonocardiogram, wherein on a human or animal subject, the heartbeat signal is recorded, hereinafter from the heartbeat signal as

Cardiac load duration at least one atrial contraction period and / or a ventricular ontraktionsdauer and / or atrio-ventricular contraction period is determined and / or a cardiac recovery duration atrial dilatation and / or a ventricular dilatation and / or an atrioventricular dilatation is determined.

2. The method according to claim 1, characterized in that as

Cardiac stress quotient:

a load quotient ventricle as the ratio of the ventricular contraction duration to the ventricular dilatation duration and / or

- a heart rate as a ratio of the atrio-ventricular contraction duration to the atrio-ventricular dilatation duration and / or

Atrial contraction duration atrium related to cardiac diastole as the ratio of atrial contraction duration to atrio-ventricular dilatation duration and / or

a ventricular stress quotient related to cardiac diastole is determined as the ratio of the ventricular contraction duration to the atrio-ventricular dilation duration.

3. The method according to claim 1 or 2, characterized in that as a cardiac recovery quotient

a recovery ratio atrium related to cardiac diastole as the ratio of the atrial traction duration to the atrio-ventricular dilation duration and / or

- A recovery ratio of the ventricle related to cardiac diastole is determined as the ratio of the ventricular traction duration to the atrial-ventricular dilation period.

4. The method according to any one of claims 1 to 3, characterized in that the at least one cardiac load duration and / or the at least one cardiac recovery period, and preferably at least one

Cardiac stress quotient and / or the at least one cardiac recovery quotient, issued and / or stored.

5. The method according to any one of claims 1 to 4, characterized in that the at least one cardiac load duration and / or the at least one cardiac recovery period, and preferably at least one

Cardiac stress quotient and / or the at least one cardiac recovery quotient, as mean value and / or as median of the cardiac load durations determined at a prescribable number of preceding heartbeat intervals and / or

Heart recovery is formed.

6. The method according to claim 4 or 5, characterized in that the at least one cardiac load duration and / or the at least one

Cardiac recovery, and preferably at least one Cardiac stress quotient and / or the at least one cardiac recovery quotient, issued substantially in parallel with the recording of the heartbeat signal,

in particular, is displayed.

7. The method according to any one of claims 1 to 6, characterized in that at least one determined cardiac load duration and / or at least one determined cardiac recovery period, and preferably at least one determined cardiac stress quotient and / or at least one determined

Cardiac stress quotient and the cardiac recovery quotient a signal

is issued.

8. The method according to claim 7, characterized in that the at least one cardiac load duration and / or the cardiac recovery period and / or the cardiac stress quotient and / or the cardiac recovery quotient over a predefinable first period, which is preferably between one day and fourteen days, is recorded the first time period is divided into a predeterminable plurality of second time periods, which are preferably between 15 minutes and 2 hours, and that for at least a second time period at least the limit condition is determined from the determined

Herzbelastungsdauern or cardiac recovery periods or cardiac stress quotients or cardiac recovery quotients is formed.

9. A method according to claim 8, characterized in that the at least one boundary condition is adapted to the prevailing time of day by selecting the boundary condition determined for the second time period in which the current time of day lies.

10. The method according to any one of claims 1 to 9, characterized in that the heartbeat signal is an ECG signal that detects at least one R-wave (R), preferably a time of occurrence of the R-wave (R) in the heartbeat signal with at least one time period between the R-wave (R) and one of the R-wave (R) preceding and / or following wave (P, T) and / or Zacke (Q, S) of the heartbeat signal is determined, and thus the at least one

Cardiac stress duration and / or the at least one cardiac recovery period, and preferably the at least one cardiac stress quotient and / or the at least one cardiac recovery quotient is determined.

11. The method according to claim 10, characterized in that, as the R-wave (R) leading and / or trailing wave (P, T) and / or tine (Q, S), at least one, in particular directly, before the R wave occurring P wave (P) and / or Q wave (Q) and / or an immediately after the R wave (R) occurring S wave (S) and / or T wave (T), in particular a time of occurrence of the respective wave (P, T) and / or tine (Q, S) is detected.

12. The method according to claim 10 or 11, characterized in that the ECG signal is recorded as an analog ECG signal, and is subsequently converted with an analog-to-digital converter into a digital ECG signal.

13. The method according to claim 12, characterized in that the digital ECG signal is filtered by means of a predefinable FIR filter, wherein preferably filter components of the FIR filter are only selected from the group -1, 0 and / or +1.

14. The method according to any one of claims 10 to 13, characterized

characterized in that in the R-wave detection, the ECG signal is divided into segments of predeterminable duration, preferably between 2 seconds and 3 seconds, and that within each segment, a maximum value is determined.

15. The method according to claim 14, characterized in that over a predetermined number, preferably three to seven, preceding successive segments of the median of the values is formed in the respective segments.

16. The method according to claim 15, characterized in that the

Sample values within a segment are compared with the median divided by a predefinable value such that only samples having a value greater than the shared median are compared with the previous one

Be compared sample, and that only samples with a Amount difference to the preceding sample greater than a predeterminable limit value as R-wave candidates for detection of the R wave (R)

be further processed.

17. The method according to claim 16, characterized in that the limit greater than the noise and / or the jitter of the analog-to-digital converter (4) is selected.

18. The method according to claim 16 or 17, characterized in that R-wave candidates within a predetermined period of time, of a maximum of half expected refractory period of the subject's heart, following a previously detected R-wave (R) are discarded.

19. The method according to claim 18, characterized in that the remaining R-wave candidates with at least one predetermined

Evaluation criteria are evaluated, and that an R-wave candidate on satisfaction of the evaluation criterion as a detected R-wave (R) output and / or stored and / or further processed.

20. The method according to any one of claims 11 to 19, characterized

in that, in order to detect the S wave (S) and / or the Q wave (Q), the respective minimum values in respectively predeterminable time windows around the detected R wave (R) are determined, which is immediately before the R wave (R) occurring minimum value as Q-wave (Q) is output, and that the time immediately after the R wave (R) occurring minimum value as an S wave (S) is output.

21. The method according to any one of claims 11 to 20, characterized

characterized in that the time position of the Q wave (Q) is determined by this 100ms is defined in time before the determined R wave (R).

22. The method according to any one of claims 11 to 21, characterized

in that the Q wave (Q), the R wave (R) and / or the S wave (S) are each determined from the largest positive and / or negative change in the slope of the heartbeat signal.

23. The method according to any one of claims 11 to 22, characterized

in that, in order to detect the T-wave (T) and / or the P-wave (P), the respective maximum values in respectively predeterminable time windows around the detected R wave (R) are determined, which is immediately before the R wave (R) occurring maximum value as a P-wave (P) is output, and that the time occurring immediately after the R-wave (R) maximum value as a T-wave (T) is output.

24. The method according to any one of claims 11 to 23, characterized

in that the highest positive and / or negative slope of the heartbeat signal is determined in each case for the Q wave (Q), the R wave (R) and the S wave (S).

25. The method according to any one of claims 18 to 24, characterized

in that the duration of the successive segments and / or the duration of the expected refractory period of the heart and / or the length of the heart

predeterminable time window can be selected around the detected R wave (R) as a function of the heart rate.

26. Method for controlling and / or regulating at least one

Device, wherein a heartbeat signal of a subject is recorded, characterized in that from the heartbeat signal a cardiac load and / or a cardiac recovery and / or a cardiac stress quotient and / or a cardiac recovery quotient is determined according to one of claims 1 to 25, and that in fulfilling a predefinable Control and / or Regelkriteriums at least one setting of the device by a control and / or regulating unit is changed specifiable.

27. The method according to claim 26, characterized in that the

Device is a HVAC system, and that settings of the HVAC system are modified so that the cardiac recovery period and / or the

Cardiac recovery quotient of the subject rises.

28. The method according to claim 26 or 27, characterized in that the

Device is a lighting system and / or sound system, and that settings the lighting system and / or the sound system are changed so that the cardiac recovery and / or the recovery rate of the subject increases.

29. The method according to claim 26, 27 or 28, characterized in that the device is a system for the predeterminable release of fragrances, and that settings of the system for the predeterminable release of fragrances are modified such that the cardiac recovery period and / or the cardiac recovery quotient of the subject increases.

30. ECG device (1) with at least one input (2) for an electrical and / or magnetic ECG signal (3), characterized in that the input (2) is connected to an R-wave detection unit (5) in that an output of the R-wave detection unit (5) has a cardiac load duration and / or

Cardiac recovery duration and / or cardiac stress quotient and / or

Cardiac recovery quotient determination unit (6) is connected, which

is preferably designed for carrying out a method according to one of claims 1 to 29.