DEVICE FOR DETERMINING SLEEP APNEA

Description

Technical field:

[0001] The present invention relates to a device for determining sleep apnea, in particular a device for the automated determination of sleep apnea. A method for determining sleep apnea using such a device is part of the description, but not part of the invention.

[0002] The invention is defined by the attached patent claims. State of the art:

[0003] Sleep apnea is a nighttime breathing disorder characterized by repeated, prolonged pauses or partial pauses in breathing during sleep. Prolonged pauses or partial pauses are defined as those lasting longer than 10 seconds. Short pauses of less than 10 seconds are generally considered harmless. However, if pauses or partial pauses occur more than five times per hour during sleep, this can have serious health consequences.

[0004] Sleep apnea, or rather its severity, is usually diagnosed in a sleep laboratory using cardiorespiratory polysomnography. The severity is currently classified into three groups.

[0005] In established methods, breathing and respiratory events such as hypopneas (partial pauses in breathing) or apneas (complete pauses in breathing) are recorded during sleep using a respiratory flow sensor, two piezoelectric stretch belts around the chest and abdomen, and a pulse oximeter that measures arterial oxygen saturation in the blood. Brain activity is recorded using electroencephalography (EEG), and eye movements are recorded using electrooculography (EOG). Finally, muscle tone in the chin area is monitored by attaching adhesive electrodes to the chin.

[0006] Measuring respiratory flow using a respiratory flow sensor involves nasal pressure measurement via nasal cannula and / or measurement of oral airflow using an oral thermistor.

[0007] Electroencephalography (EEG) requires a large number of electrodes placed on the patient's head to measure brain activity. EEG serves to differentiate between sleep and wake phases during the night (or during the recording), to classify sleep stages during sleep, and thus to determine sleep architecture as well as respiratory, motor, and physiological arousals.

[0008] The large number of sensors used significantly disrupts a test subject's sleep, raising the question of whether the measurements obtained in the sleep lab are representative of sleep in a home or familiar environment. For this reason, measurements are sometimes taken over two consecutive nights.

[0009] Due to the large number of recorded measurement data points, the evaluation of respiratory events, even with automated analysis, is comparatively time-consuming. Since existing automated analyses are often not error-free, expert review is generally necessary. This review, which in some cases may involve a complete visual evaluation, is very time-consuming. Therefore, a reliable classification of respiratory events in a diagnosed case of sleep apnea is currently only possible with the assistance of an expert.

[0010] Because the reliable determination of breathing pauses or partial breathing pauses due to sleep apnea is currently still very time-consuming, breathing pauses or partial breathing pauses due to sleep apnea are often diagnosed late, so that people only receive therapeutic help very late.

[0011] From EP2767235 a device for determining sleep apnea is known, comprising a head covering with EEG electrodes at, among other things, positions C3 and C4, as well as a separate chin part with an EMG electrode. Depiction:

[0012] It is therefore an object of the present invention to provide a device for the automated detection of sleep apnea in humans, which disturbs the patient's sleep less than previously known devices. Furthermore, a method is part of the description, but not of the invention itself, by which it is possible to reliably and automatically detect sleep apnea in a simple manner and which is also capable of determining the severity of a detected sleep apnea.

[0013] Ultimately, the object of the present invention is to provide a device for the treatment of apneas or partial apneas associated with sleep apnea. A corresponding method is part of the description, but not part of the invention.

[0014] The invention is based on the finding that coherence between electroencephalography signals and electromyography signals allows for a statement about sleep apnea conditions, in particular about the severity of sleep apnea.

[0015] In particular, the invention is based on the finding that the coherence of EEG signals at the electroencephalography sites C3 and C4 and the muscle tone at the chin enables a classification of the severity of sleep apnea in humans.

[0016] The device according to the invention for determining the severity of sleep apnea thus uses electroencephalography (EEG) and electromyography (EMG), which can be used to determine muscle tone.

[0017] The device itself comprises a head covering with a headpiece that covers the head of a patient at least at the points where the measuring points C3 and C4 of the electroencephalography are located, and with a chin piece, wherein the headpiece has two electrodes for recording EEG signals of the electroencephalography at the electroencephalography points C3 and C4 and the chin piece has at least one electrode for recording the EMG signal of the electromyography at the chin.

[0018] Because the present device only uses the measurement signals from electroencephalography and electromyography, the device for determining sleep apnea can be designed much more simply.

[0019] In particular, the respiratory flow sensors can be dispensed with. The previously required piezoelectric stretch belts around the chest and abdomen, as well as the pulse oximeter, which measures arterial oxygen saturation in the blood, are also no longer necessary. It goes without saying that if recording these values ​​is desired, the present device for diagnosing sleep apnea can still be combined with these measuring devices.

[0020] The electrodes for recording EEG signals and the at least one electrode for recording the EMG signal are measuring electrodes. The number of measuring electrodes required for electroencephalography has thus been reduced to a minimum. In total, only three are necessary. According to the invention, as described below, four measuring electrodes are required: two electrodes for recording EEG signals for electroencephalography, located at electroencephalography sites C3 and C4, and two electrodes for recording the EMG signal for electromyography, located on the chin, to perform a measurement for determining sleep apnea and its severity.

[0021] The headgear, in which the headpiece and chin piece are connected in one piece, is relatively easy to wear, so that the sleeping conditions during the examination hardly differ from those under normal circumstances.

[0022] To reliably and accurately record EEG signals in connection with electroencephalography, a reference electrode and a grounding electrode are preferably provided. Preferably, the headgear also covers the areas of the patient where the reference and grounding electrodes are positioned during use.

[0023] In a preferred embodiment, at least one electrode is permanently integrated into the headgear, so that the at least one electrode does not accidentally detach from the cap during the nighttime examination. It is understood that all electrodes can be permanently integrated into the headgear to ensure that no electrode accidentally detaches during sleep.

[0024] It has been found that the diagnosis of sleep apnea is particularly successful when two electrodes are provided for recording the EMG signal, each measuring the muscle tone at the chin on the right and left sides of the patient's face. Therefore, it is advantageous for the head covering of the device according to the invention to have a first half, a second half, and a longitudinal axis separating the first and second halves, with two electrodes for recording the EMG signal being provided, each arranged on one half of the head covering. In a preferred embodiment, the two electrodes are arranged symmetrically to the longitudinal axis to obtain two comparable measurement signals.

[0025] To minimize disturbance to a patient's sleep caused by measuring devices or accessories, it is advantageous for the electrode for recording the EEG signal and / or the electrode for recording the EMG signal to be a wireless electrode.

[0026] Furthermore, it has proven advantageous that the electrode used to record the EMG signal is an adhesive electrode. Using an adhesive electrode has the advantage that the electrode is held particularly securely at the desired measurement point on the patient's chin during sleep.

[0027] In a preferred training program, a data processing device is provided that automatically evaluates the EEG signals and at least one EMG signal in order to detect respiratory events without significant time expenditure.

[0028] A further advantage is the wireless communication between the data processing device and the electrodes. This communication between the electrodes, which acquire the measurement data, and the data processing device, which analyzes the acquired data, facilitates easy data analysis. With regular data transmission during the nightly measurement process, the data is available for analysis shortly after the examination is completed in the morning. Continuous transmission of the measurement data to a data processing device during the nightly examination even enables online monitoring of the patient. The wireless communication simplifies the setup of the measurement device, ensuring that the patient's sleep is not, or only minimally, affected by the data transmission.

[0029] To prevent the device for determining sleep apnea from slipping during the sleep process, it is advantageous that the head covering is cap-like and, in particular, covers the back of the head essentially completely.

[0030] In order to keep the electrodes for determining muscle tone, especially the electrodes for determining the EMG signal, securely at the desired measuring point, it is advantageous that the chin part is designed as a chin strap.

[0031] As mentioned above, it is preferred that two EMG measuring electrodes are provided, each located on one half of the headgear. Therefore, it is advantageous to have a first chin strap on the first half of the headgear and a second chin strap on the second half.

[0032] Even when only one EMG electrode is used on one side of the face, it is advantageous to have a chin strap on the first half of the headgear and a second chin strap on the second half. This allows for a secure fit to the patient's chin in both cases, as the first and second chin straps can be connected. For example, the two chin straps can be connected with a belt or simply knotted together using the attached cords. Alternative connection methods, such as Velcro fasteners, are also acceptable.

[0033] In a preferred further development of the device for determining sleep apnea, means for stimulating respiration are provided. Thus, the device for determining sleep apnea serves not only to determine sleep apnea, in particular to determine the severity of sleep apnea, but also as a therapeutic device.

[0034] A particularly effective and compact therapy device has proven to be a device for determining sleep apnea, in which the means for stimulating respiration include at least one implantable stimulation electrode, a data processing device for evaluating the EEG and / or EMG signals, a control unit and a device for stimulating the stimulation electrodes.

[0035] To activate an implanted stimulation electrode, it is advantageous for both the implanted stimulation electrode and the device for activating the stimulation electrode to each have a magnetic coil, with the coil of the device preferably being connected to a battery or rechargeable battery. When the coil of the device for activating the stimulation electrode is connected to a battery or rechargeable battery, the implanted stimulation electrode is powered externally. This allows for easy charging or replacement of the battery.

[0036] The content of the present description also includes a method for determining sleep apnea using a device according to the invention, comprising the following steps: Recording the electrical activity of the brain using electroencephalography, wherein the EEG measurement signals recorded by electroencephalography are the measurement signals at electroencephalography sites C3 and C4; recording the electrical muscle activity using electromyography, wherein the EMG measurement signal recorded by electromyography is a measurement signal in the chin area; correlating the recorded EEG measurement signals at sites C3 and C4 and the recorded EMG signal in the chin area; evaluating the correlated EEG measurement signals at sites C3 and C4 and the EMG signal in the chin area with regard to the occurrence of sleep apnea-associated respiratory events.

[0037] In a preferred advanced training, the correlation of the recorded EEG measurement signals at points C3 and C4 and the recorded EMG signal in the area of ​​the chin, and the evaluation of the correlated EEG measurement signals at points C3 and C4 and the EMG signal in the area of ​​the chin with regard to the occurrence of sleep apnea-associated respiratory events, is performed automatically.

[0038] The described methods can be used not only to determine the presence of sleep apnea but also its severity.

[0039] In a preferred further development of the described method, the EEG signals at points C3 and C4 and the EMG signals in the chin region are correlated and evaluated immediately after their acquisition. The evaluated data are then transmitted to a control unit. Depending on the evaluated data received, the control unit sends control signals to a device for stimulating implanted stimulation electrodes.

[0040] This method, in which implanted stimulation electrodes are activated during a detected pause in breathing, is suitable not only for diagnosing sleep apnea but also for treating patients with sleep apnea. Diagnosis and treatment can be performed simultaneously, offering significant advantages for the patient.

[0041] Signal transmission from the device for stimulating implanted stimulation electrodes to the implanted stimulation electrodes can be wireless, inductive, or capacitive. The use of excitation coils is preferred.

[0042] It is possible to activate the stimulation electrodes with each breathing cycle, thus ensuring that the patient never experiences pauses in breathing. However, this method has been found to have the disadvantage of requiring a significant amount of electrical energy, as the stimulation electrodes essentially need a continuous supply of relatively high power. In a preferred advanced design, the control unit only sends control signals to the device for activating the implanted stimulation electrodes when the data received from the data processing unit indicates a state of apnea, whether a complete cessation of breathing or a partial apnea. This significantly reduces the energy consumption required for the treatment of sleep apnea. Brief description of the drawings:

[0043] Preferred embodiments of the present invention are explained with reference to the accompanying drawings, which show: Fig. 1 a first embodiment of a device for determining the severity of sleep apnea, which is worn by a patient, Fig. 2 a second embodiment of a device for determining the severity of sleep apnea, which is worn by a patient and which is additionally suitable for controlling muscle functions, Fig. 3 a section of the in Fig. 2 The illustrated embodiment and Fig. 4 show a cross-section through a device for stimulating the stimulation electrodes. Best way to implement the invention and its industrial applicability:

[0044] Fig. 1Figure 1 shows a head covering 10 of a first embodiment of a device for determining the severity of sleep apnea using electroencephalography and electromyography. The head covering 10 includes only four measuring points at which patient-related measurement data are recorded, with two measuring points each serving to record patient-related measurement data in connection with electroencephalography and the other two measuring points serving to record patient-related measurement data in connection with electromyography.

[0045] Patient-related measurement data are measurement data used to determine sleep apnea conditions.

[0046] The headgear comprises a headpiece 12 and a chinpiece 14. The headpiece 12 and chinpiece 14 are connected to each other, so that the headgear is formed in one piece.

[0047] The head section 12 fits snugly against the patient's head and completely covers the upper and lateral head areas. Although not shown, the head section can also extend over the back of the patient's head.

[0048] To ensure comfortable wear, the head covering is made of a textile material or a similar flexible material.

[0049] On the headpiece 12, electrodes 16 are provided at the positions that, when the patient is wearing the head covering, correspond to electroencephalography sites C3 and C4, for recording an electroencephalographic signal (EEG signal). These electrodes serve to record patient-related measurement data and are therefore measuring electrodes.

[0050] The electrodes 16 for recording an EEG signal are wireless electrodes that transmit data via a radio link to a data processing device (not shown). The electrodes 16 for recording an EEG signal are permanently connected to the headpiece 12.

[0051] Although not shown, in addition to the electrodes 16 for recording an electroencephalographic signal (EEG signal), which are designed as measuring electrodes, a grounding electrode and a reference electrode are provided, which are permanently connected to the headpiece 12. The grounding electrode and the reference electrode are useful in electroencephalography to obtain correct, and in particular absolute and not just relative, measurement signals from the measuring electrodes. The grounding electrode and the reference electrode thus do not serve to record patient-related measurement data, but rather to ensure the quality of the signals recorded by the electrodes 16 for recording an EEG signal.

[0052] Two electrodes 18 for recording an electromyography signal (EMG signal) are positioned symmetrically to the facial axis in the chin area. These two electrodes 18 are integrated into the chin section 14 of the headgear 10 and are thus permanently attached to it. The two electrodes 18 are adhesive electrodes that, like the electrodes 16 for recording an EEG signal, wirelessly transmit data to a data processing device (not shown).

[0053] The chin piece 14 is designed as a chin strap and is integrally connected to the head piece 12, so that the head covering 10 is designed like a balaclava.

[0054] In an embodiment not shown, the chin strap can have two chin straps, each attached to one half of the headpiece 12. The two free ends of the chin straps can be firmly connected to each other by means of a strap, a buckle, or simply by means of cords.

[0055] To determine the severity of sleep apnea, EEG signals are recorded at C3 and C4 points during sleep. Additionally, muscle tone signals at the chin are recorded as EMG signals using electromyography during the overnight study. The collected data is transmitted wirelessly at regular intervals to a data processing unit (not shown). There, it is analyzed for the occurrence of respiratory events. This analysis can be performed online during the overnight recording or offline after sleep has ended. Both visual evaluation by an expert and automated analysis using software are possible.

[0056] The evaluation is carried out in particular by correlating the EEG signals at the C3 and C4 points with the EMG signals recorded at the patient's chin.

[0057] The EEG / EMG signal combination in healthy individuals differs significantly from that recorded in patients suffering from hypopnea or apnea. Therefore, the EEG / EMG signal combination allows for the classification of the severity of apnea.

[0058] Since the number of recorded measurements is significantly reduced in the described method compared to conventional methods for classifying the severity of apnea, the evaluation is much faster and simpler without increasing the susceptibility to errors.

[0059] In the illustrated headgear of the device for determining the severity of sleep apnea, a headgear was chosen in which the headpiece essentially covers the entire head. However, within the scope of the invention, it is sufficient if the headpiece of the headgear covers the areas necessary for measuring the C3 and C4 signals of the electroencephalogram. It should be ensured, however, that the headgear does not shift during the examination, i.e., during sleep.

[0060] The described device for determining the severity of sleep apnea is relatively simple in design and therefore inexpensive to manufacture. The fixed integration of the measuring electrodes into a cap- or hat-like head covering means that the patient's sleep is hardly affected during the nighttime examination, resulting in measurement results that would very likely have been obtained even during undisturbed sleep. The simple design of the described device even allows it to be used in a home environment, so that the recorded measurement data reflects the actual sleep situation at home as accurately as possible.

[0061] In the Figures 2 to 4A second embodiment of a device for determining the severity of sleep apnea, worn by a patient, is shown. With the aid of this second embodiment, it is possible to additionally control muscle and / or nerve functions and thus treat pauses in breathing or partial apneas.

[0062] Like the in Fig. 1 The headgear shown in 10 includes the one shown in the Figs. 2 to 4The headgear shown comprises a headpiece 112 and a chinpiece 114. The headpiece 112 and chinpiece 114 are connected, so that the headgear 110 is formed as a single piece. Furthermore, electrodes 116 for recording an electroencephalographic signal (EEG signal) are provided on the headpiece 112 at the positions that, when the patient is wearing the headgear, correspond to electroencephalography sites C3 and C4. Two electrodes 118 for recording an electromyographic signal (EMG signal) are provided symmetrically to the facial axis in the chin area.

[0063] In addition to the one in Fig. 1 In the illustrated embodiment, the headgear 110 comprises a first amplifier 120, which serves to amplify the measurement signals of the electroencephalography signals (EEG signal) and is placed between the two electroencephalography sites C3 and C4.

[0064] A second amplifier 122 is provided between the two electrodes for recording the electromyography signal 118.

[0065] Furthermore, a microprocessor 124 is arranged on each side of the face between the respective electrodes 116 for recording an electroencephalographic signal (EEG signal) and electrodes 118 for recording an electromyographic signal (EMG signal). The microprocessor 124 houses a data processing device and a control unit.

[0066] On one side of the face, a device for stimulating a stimulation electrode 126 is provided below the lower jaw line.

[0067] The first and second amplifiers 120, 122, the microprocessors 124 and the device for stimulating a stimulation electrode 126 are each firmly connected to the headgear 110.

[0068] The electrodes 116 for recording an electroencephalographic signal (EEG signal), the electrodes 118 for recording an electromyographic signal (EMG signal), the first and second amplifiers 120, 122, the microprocessors 124, and the device for stimulating a stimulation electrode 126 are interconnected via a cable connection. Alternatively, communication between the aforementioned components can be carried out entirely or partially wirelessly.

[0069] As in Fig. 4 The device for stimulating stimulation electrodes 126 is shown to comprise a shell 130 integrated into the head covering 110, in which a coil 132 and a battery 134 are arranged.

[0070] The magnetic induction coil 146, which is connected to an implanted stimulation electrode, is located either between the subcutaneous tissue 142 and the platysma muscle layer 144 (as in Fig. 4) or below the platysma muscle layer 144 (not shown). The implanted stimulation electrode surrounds the respective nerve. It is, for example, a so-called cuff electrode.

[0071] The battery 134 or the rechargeable battery is replaceable and located in the casing 130 of the device for stimulating implanted stimulation electrodes 126, so that the implanted stimulation electrode can be powered externally. This offers significant advantages for the patient.

[0072] The exact position of the device for stimulating the stimulation electrode 126 is thus chosen such that it is arranged on the subcutaneously implanted coil 146, which is connected to the implanted stimulation electrode of a patient.

[0073] The two electrodes for recording EEG signals 116 and the two electrodes for recording EMG signals 118, the two amplifiers 120, 122, the two microprocessors 124, and the device for stimulating implanted stimulation electrodes 126 communicate as follows: The signals recorded by the two electrodes for recording EEG signals 116 and the two electrodes for recording EMG signals 118 are amplified by the respective amplifiers 120, 122 and transmitted to the microprocessors 124. In the microprocessor 124, the EEG and EMG signals are evaluated with regard to the presence of sleep apnea. The control unit contained in the microprocessor 124 sends signals to the device for stimulating implanted stimulation electrodes 126 to stimulate respiration, in particular to stimulate muscles involved in breathing.By means of the coil 132 in the device for exciting implanted stimulation electrodes 126 and the coil 146, which is connected to the stimulation electrode, an excitation signal is given to the muscle or nerve to stimulate respiration.

[0074] Preferably, the control unit sends signals to the device for stimulating implanted stimulation electrodes 126 only when the EEG or EMG signal data acquired by the microprocessor 124 have detected a breathing pause in the form of sleep apnea or sleep hypopnea. Alternatively, the device for stimulating implanted stimulation electrodes 126 can only transmit a signal to the implanted stimulation electrode if sleep apnea or hypopnea is present.

[0075] For example, an adaptive closed-loop system can be used to determine EEG-EMG coherence values ​​every 5-10 seconds in real time, and this data can then be used for the next 5-10 seconds to stimulate the respiratory cycle during sleep.

[0076] Although the device has been described in connection with a stimulation electrode in the oral cavity, it is also possible to position the device for stimulating implanted stimulation electrodes at other locations. The device for stimulating implanted stimulation electrodes is preferably arranged in the headgear so that, when worn by the patient, it rests against the implanted stimulation electrode. The implanted electrodes can stimulate both muscles and nerves.

[0077] The data captured and transmitted by the microprocessor can be stored and made available for later analysis, for example by medical personnel. It goes without saying that the analysis of the captured and transmitted data can also be carried out online or directly after the measurement.

[0078] Although not shown, the stimulation electrodes can also be stimulated in another way known in the prior art.

[0079] It goes without saying that the descriptions in connection with the characters

[0080] The various embodiments can be combined with one another. The invention is defined by the attached claims.

Claims

1. A device for determining sleep apnea by means of electroencephalography and electromyography comprising a headgear (10; 110) having a head part (12; 112) covering the head of a patient at least at the locations where the measuring points C3 and C4 of the electroencephalography are located, and having a chin part (14; 114), wherein the head part (12; 112) comprises two electrodes (16; 116) for detecting EEG signals of the electroencephalography at the electroencephalography points C3 and C4, and the chin part (14; 114) comprises at least one electrode (18; 118) for detecting the EMG signal of the electromyography on the chin, wherein the head gear (10; 110) has a first half, a second half, and a longitudinal axis separating the first and second halves, and wherein two electrodes (18; 118) for detecting the EMG signal are provided, each of which is arranged on one half of the headgear (10; 110).

2. The device according to claim 1, characterized in that a reference electrode and a ground electrode are provided in connection with the electroencephalography.

3. The device according to one of the preceding claims, characterized in that at least one electrode (16, 18) is securely integrated into the headgear.

4. The device according to one of the preceding claims, characterized in that the two electrodes (18; 118) for detecting the EMG signal are arranged symmetrically to the longitudinal axis of the headgear (10; 110).

5. The device according to one of the preceding claims, characterized in that the electrode (16; 116) for detecting the EEG signal and / or the electrode (18; 118) for detecting the EMG signal is a wireless electrode.

6. The device according to one of the preceding claims, characterized in that the electrode (18; 118) for detecting the EMG signal is an adhesive electrode.

7. The device according to one of the preceding claims, characterized in that a data processing device is provided which automatically evaluates the EEG signals and the at least one EMG signal, wherein preferably a wireless communication is provided between the data processing device and the electrodes (16, 18; 116, 118).

8. The device according to one of the preceding claims, characterized in that the headgear is designed as a cap and, in particular, covers the back of the head essentially completely.

9. The device according to one of the preceding claims, characterized in that the chin part (14; 114) is designed as chin strap.

10. The device according to one of the preceding claims, characterized in that a first chin strap is provided on the first half of the headgear and a second chin strap is provided on the second half of the headgear, wherein the first and the second chin straps are connectable to each other.

11. The device according to one of the preceding games, characterized in that means for stimulating respiration are provided.

12. The device according to claim 11, characterized in that the means for stimulating respiration comprise at least one implantable stimulation electrode, a data processing device for evaluating the EEG signals and / or EMG signals, a control unit, and a device for stimulating the stimulation electrodes (126).

13. The device according to claim 12, characterized in that the stimulation electrode and the device for stimulating the stimulation electrode (128) each have a magnetic coil (132, 146).