DE202009012470U1 - Apparatus for the acoustic detection of nocturnal teeth grinding and pressing as well as feedback - Google Patents

Abstract

Device for detection, detection and feedback of nocturnal teeth grinding and crunching, characterized in that the teeth grinding and -rn pressing acoustically detected and detected by sound-technical signal analysis and distinguished from other noises and fed back.

Description

The The invention relates to a device for acoustic detection of the nocturnal teeth grinding and crunching (bruxism), the recognition and distinction of these crunching noises from other noises as well as the feedback to the Affected (biofeedback) to prevent teeth grinding.

nocturnal Teeth grinding and crunches (bruxism) is a common one Symptom. Approximately 20% of the adult German population is affected. It generally depends on orthodontic Exceptions excepted, with mental health problems and stress together. Bruxism leads to damage Enamel, periodontium and temporomandibular joint and chronic headache.

From the dental side bite splints are often used to prevent bruxism. In scientific investigations ( Alvarez-Arenal et al. 2002 . Raphael et al. 2003 ), the successful use of bite splints in bruxism is increasingly called into question. In addition, studies have shown that the use of bite splints only temporarily relaxes the jaw musculature ( Dao & Lavigne, 1998 ).

In the treatment of nocturnal teeth grinding with biofeedback methods, various studies have shown that during treatment and afterwards the bruxist activities have decreased and the effect has stabilized ( Clarke et al. 1981 . Moss et al. 1982 . Feehan & Marsh 1989 ).

Some Systems for reducing nocturnal teeth grinding Capture Electromylography (EMG) with electrodes attached Kaumuskulatur to feedback about her tension to give to the patient. Others measure over in pressure bars or in palate plates introduced pressure sensors the teeth grinding and pressing. In these biofeedback systems the feedback is sent to the patient during of teeth grinding and pressing over acoustically Speaker or by electrostimulation over the head or body glued electrodes.

sensory Bite splints are customized to the patient and in the adaptation of the form and the sensory properties very time-consuming for the patient. In addition, they have the problem due to the limited space, the power supply and the wireless signal transmission, if no energy and signal lines from the mouth opening to the outside should be moved. This would be for the patient very uncomfortable.

The Capturing the EMG requires that in everyday use the electrodes are always in the right place by the patient himself are glued and the electrical contact is ensured. With the very low voltages of the EMG and the different ones Skin conditions (moist, dry, creamed) this is for Not easy to assure the patient when going to bed and awkward. Especially the contact with dry skin is very critical and with creamy skin even more difficult.

The Problem of the acoustic detection is that the teeth grinding and -presses while producing a characteristic noise, which is different in each patient, but in a frequency analysis broadband and thus no specific frequency as a control signal or trigger signal can be used.

moreover in the bedroom also other sounds such. B. Snoring of the spouse, street noise, etc., which superimpose the sound of teeth grinding.

task It is therefore an object of the present invention to provide a device the teeth grinding and pressing (bruxism) acoustically recorded and despite other sounds realizes that it is actually is about the gnashing of teeth and the squeezing of the person concerned, as well as an acoustic or electro-stimulating feedback gives. This is to reduce the teeth grinding and pressing and prevented. The device needs very little effort Can be used in everyday life by the person concerned.

The The object of the present invention is essentially achieved by a Device solved according to claim 1. The dependent claims define advantageous ones Embodiments of the present invention.

According to the invention with acoustic sensors z. B. one or more microphones in one mobile, a tabletop device or on the body z. B. in the clothing, in a band, integrated in a chain or on Ear detects the sounds of teeth grinding. Despite the existence of various sounds such. B. from Breathing, snoring, movements, bed neighbors, etc. with the device according to the invention, the noise of the teeth grinding recognized.

To differentiate the bruxism noise from the other noises, the device absorbs the typical crunching, creaking and clicking noises of the affected person. These noise patterns are automa in the use of the invention with the recorded noise (Microprocessor technology, software) sound-technically analyzed and compared and generated when detected, for example, an acoustic message or electrical stimulation.

The sonic analysis, evaluation via a Frequency analysis, a fast Fourier transform (FFT), with or without further analysis of the spectral intensities the recorded signal. To capture and analyze short-term Noise patterns will be the FFT analysis with the spectral Intensity in short time windows. This kind The digital signal evaluation is in the range of automatic Speech recognition used. To the sound of the permanent or recurring teeth grinding and pressing analyze with high security and other sounds to be able to differentiate in an advantageous way Embodiment of the device according to the invention in an automated form of short-time Fourier transforms (STFT) made the noise evaluations. It will be Fast Fourier transforms (FFT) and spectral intensities in short, constant and consecutive or overlapping Time blocks or time steps from the recorded signals calculated.

In Another embodiment will be further Improvement of the detection of teeth grinding and pressing Wavelet transformations are calculated. This implies that the frequency-intensity-time behavior in short, variable signal dynamics adapted, and successively following or overlapping time blocks or time steps be calculated from the recorded signals.

The mentioned transformation calculations are in the technical Signal processing applied.

about simple signal comparisons of the recorded individual reference sounds of teeth grinding and pressing, according to the transformation calculations analyzed, with the recorded and analyzed sounds during monitoring or via cohort analyzes, these are recorded Teeth grinding and squeezing noises from other sounds and ambient noise differentiated and recognized as such and assigned.

The sound analysis, evaluation and comparison of the deposited and the recorded noises of the teeth crunching and -pressens as well as the ambient noise can be permanent expire during the monitoring time or through Triggering z. B. due to / the noise level, duration or frequency can be started.

In a further embodiment of the device is for analysis and automatic recognition of personal information Bruxism sounds a fuzzy knob, from mathematical theory the fuzzy logic (blur logic) her known uses. about the assignment of noise analysis values for the criteria such. B. volume, intensities, Frequency, frequency ranges, duration, time blocks to fuzzy sets as medium, big small and a processing in the fuzzy controller with setpoint correction, d. H. that in the initial learning runs in the sleep laboratory or according to instructions at home by an awake person is input to the controller, whether the noise values detected during sleep and determined fuzzy quantity values of teeth grinding and crushing noises to be assigned or not. After several recorded bruxism sounds is an automatic detection in this embodiment of bruxism sounds of the person whose teeth grinding and -pressure noises detected in the learning phase of the device possible. The larger the number the detected bruxism sounds, the safer later the acoustic bruxism recognition.

Another embodiment of the apparatus includes a neural network for analysis and automatic detection of tooth grinding and crushing noises. Artificial neural networks are novel calculation models, each with a predetermined structure and a learning process. They are used in particular in a problem in which a clear mathematical model does not lead to a solution or is too time-consuming. For example, neural networks are used in the representation of complex physical models or in biological structures and processes. A neuronal network consists of software so-called neurons, which are interconnected in different layers or levels. In the embodiment of the device in the first layer of neurons, each neuron a characteristic of the sound analysis z. As volume, intensities, frequency, frequency ranges, duration, time blocks. In the second layer, weighted values of the features are summed differently in the neurons via the signal line from the first neurons, forwarded into a further neuron layer and combined into one or a few neurons via specific algorithms in the output layer. For the issue of bruxism, yes or no, a neuron is sufficient in this layer. For the automatic learning phase, a nominal-actual comparison of the measured and analyzed noise, which has performed the passage through the neural network via the values of the analysis features by means of a physical signal or measured value input, is carried out automatically and as yes or no information So, actually, bruxism is up entered or not, deposited in the algorithm. To enter the measured value whether teeth grinding and pressing has actually taken place, a manual or automatic message input device is available for the learning phase in terms of software or hardware. With the use of the device according to the invention are used for the automatic measurement recording to confirm the teeth grinding and crunching during the learning phase in the sleep laboratory or the first nights at home, measuring devices via pressure sensors in the mouth or via EMG electrodes on the masticatory muscles teeth grinding and recognize pressing. The more frequently teeth grinding and press events have been recorded and processed in the learning phase in the device, the safer is the feedback whether bruxism has occurred or not exclusively due to the noise detection. If the above neural network is extensively provided with sufficient information or setpoint-actualization values during the creation and the configuration, the specification, ie learning phase, can be omitted for the respective person concerned. In this case, the manual and automatic message input devices with the corresponding sensors are no longer required.

One Another embodiment of the device includes for the analysis and automatic recognition of teeth grinding and -press sounds a fuzzy knob and a neural Network that are combined with each other.

at Detection of a toothache or crushing sound is with the acoustic message of the invention Table or mobile device the person concerned on the Teeth grinding or pressing made aware or aroused. This message can also be worn by the body Parts, small appliances such. As ear speakers or other Actors are transmitted so that the bed neighbor not disturbed or awakened.

about the permanent feedback of teeth grinding the affected (biofeedback) creates a learning effect, through after a certain period of use in non-physiological condition Bruxism reduces or prevents tooth crunching.

The Advantages of the invention are for the detection and feedback the teeth grinding and pressing, that no elaborate Preliminary work as in the patient-adapted production of sensory Bite rails, the reusability of the equipment, none Stick electrodes or other sensors on the skin, small Device on the bedside table or if portable on the body, then not disturbing and inconspicuous, takes place. Just in the design form with the feedback by electrostimulation is the application of a stimulation electrode via an elastic Tape or by gluing required. The feedback can also have a mechanical vibration unit that over the device is electrically controlled and the affected person over the pajamas or an elastic band on the body or attached to one of the limbs done.

With the device according to the invention can in a design the results are recorded and statistical Evaluations of frequency and duration of bruxism events being represented.

A further design includes optical signal transmitter, z. B. light emitting diodes, Display for medical monitoring.

in the The following is the invention with reference to the drawings explained. Show it:

1 a schematic representation of the functional structure according to an embodiment of the present invention with device internal and external microphone and acoustic signal generator

2 , a schematic representation of the functional structure according to an embodiment of the present invention with device-internal and external microphone and acoustic and electro-stimulating signal generators.

3 , a schematic representation of the functional structure according to an embodiment of the present invention with manual and automatic message signal input device for the learning phase of the device as well as with device internal and external microphone and acoustic signal generator.

• – Frequenzanalysen, insbesondere Fast-Fourier-Transformationen (FFT),
• – Frequenzanalysen (Fast-Fourier-Transformationen (FFT) in nacheinander folgenden Zeitabschnitten,
• – Fast-Fourier-Transformationen (FFT) und spektrale Intensitäten,
• – Short-Time-Fourier-Transformationen (STFT), das beinhaltet dass Fast-Fourier-Transformationen (FFT) und spektrale Intensitäten in kurzen, konstanten sowie nacheinander folgenden oder überlappenden Zeitblöcken bzw. Zeitschritten aus den aufgenommen Signalen berechnet werden.
• – Wavelet-Transformationen, das beinhaltet, dass das Frequenz-Intensitäts-Zeitverhaltens in kurzen, variabel der Signaldynamik angepassten, sowie nacheinander folgenden oder überlappenden Zeitblöcken bzw. Zeitschritten aus den aufgenommen Signalen berechnet werden.

According to one in 1 illustrated functional structure and processing sequence of a first embodiment of the present invention of a device 1 for the acoustic detection and detection of nocturnal teeth grinding and pressing as well as feedback recorded in the device 2 existing microphone 3 or an external microphone 9 the sounds of the sleeping person and his surroundings. The analogue noise signal recorded via the microphone is used for the digital, software-technical evaluation of the analog / digital converter 4 converted into a digital signal. In the microprocessor 5 is about a special software 6 or by a dedicated special processor (ASIC), not shown, the sound-technical signal analysis, evaluation and the comparison of the deposited and the recorded noises of teeth grinding and -pressens and ambient noise made. In the special software 6 or in the special processor, various evaluation and recognition algorithms can be present as described above:

• Frequency analyzes, in particular fast Fourier transforms (FFT),
• Frequency analyzes (Fast Fourier Transforms (FFT) in successive time periods,
• Fast Fourier transforms (FFT) and spectral intensities,
• Short-time Fourier transforms (STFT), which means that fast Fourier transforms (FFT) and spectral intensities in short, constant and consecutive or overlapping time blocks or time steps are calculated from the recorded signals.
• Wavelet transformations, which include calculating the frequency-intensity-time behavior in short time-variable or time steps that are adapted to the signal dynamics as well as consecutively or overlappingly from the recorded signals.

These evaluations can be carried out in the special software 6 or in the special processor (not shown) are supported by coherence analysis of the signals.

• – Fuzzy-Regler (siehe oben),
• – neuronales Netzwerk (siehe oben),
• – Fuzzy-Regler und neuronales Netzwerk kombiniert.

In the special software 6 or in the special processor also adaptive controllers and calculation systems can be stored:

• - fuzzy controller (see above),
• - neural network (see above),
• - Fuzzy controller and neural network combined.

The special software 6 For example, via a USB interface (not shown) or wireless interface z. B. Bluetooth (not shown) in the microprocessor 5 getting charged. The device can be used via these interfaces 2 Also be connected to other devices and computers for information feed, -weitergabe or further evaluations.

One in the device 2 existing speaker 7 or an external speaker 10 give recognized acknowledgment of teeth and pressing noises acoustic feedback to the person concerned, according to the special software 6 programmed acoustic signal with the same or different settings of key, strength, duration, intervals etc ..

The feedback, rather for a medical monitoring, takes place in the device 2 existing light-emitting diodes (not shown) or via a in the device 2 existing display 8th , On the display can also z. For example, the frequency and duration of the recognized bruxism events for medical purposes and for the self-monitoring of the person concerned.

The microphone in the device 3 or the external microphone 9 can also be supplemented by several microphones, so that a better capture even quiet teeth grinding and -pressgeräusche is possible. This can be achieved by designing the microphones with directional characteristics and directional arrangement in the device and the correct installation of the device 2 To further improve the acoustical detection of teeth grinding and crushing noises, the external microphones may also be placed closer to the subject, e.g. B. on the headboard of the bed, on pajamas or on a necklace, etc.

The same applies to the acoustic feedback via the external loudspeaker 10 this one or more attached to the affected person's ear, pajamas or necklace to not disturb or disturb the bed neighbor (s).

2 shows the functional structure and processing flow of another embodiment of the present invention of a device 1 for the acoustic detection and detection of nocturnal teeth grinding and pressing as well as feedback. The structure and the procedure is the same as in 1 However, here is the embodiment with a device 2 existing electrostimulator 11 fitted. The feedback on the detected and ongoing teeth grinding and pressing is done by the electrical stimulation of the attached to the body or limbs of the person concerned electrodes 12 ,

The electrostimulator could also be externally (not shown) with the electrodes, which may also be attached directly to the external stimulator, to the affected person z. B. be attached via an elastic band on the wrist. In this case, the electrical stimulator is wired or wirelessly connected to the device 2 connected. For a wireless connection, the electrostimulator needs its own power supply (battery or rechargeable battery).

The feedback could be used as a replacement or in addition to electrostimulation via a mechanical vibration unit (not shown) that is above the device 2 is electrically activated and applied to the affected person by the pajamas or an elastic band on the body or on one of the limbs done.

• – einem Fuzzy-Regler, (siehe oben),
• – einem neuronalen Netzwerk (siehe oben),
• – oder Fuzzy-Regler und neuronales Netzwerk kombiniert

die Durchführung einer auf die betroffene Person bezogene Lernphase im Schlaflabor oder in den ersten Nächten zu Hause. 3 shows the functional structure and Processing flow of another embodiment of the present invention of a device 1 for the acoustic detection and detection of nocturnal teeth grinding and pressing as well as feedback. The structure and the procedure is the same as in 1 However, here is the embodiment with manual and automatic message signal input device for the learning phase of the device and equipped with sounders. This embodiment allows for the provided in the device sound analysis, evaluation and comparison of the recorded noises of teeth grinding and pressing with the ambient noise with the help of

• - a fuzzy controller, (see above),
• A neural network (see above),
• - or fuzzy controller and neural network combined

the implementation of a learning phase related to the person concerned in the sleep laboratory or on the first nights at home.

The manual message input device 13 is software or hardware technology, available to the device 2 To report whether the acoustically recorded noise was caused by teeth grinding and pressing or not. The signal of the message input, for example, via the multi-channel analog / digital converter 4 to the microprocessor 5 for further signal processing for the analysis, evaluation and comparison of the recorded noises.

The automatic message input device uses EMG (Electromyogram) electrodes 15 recorded the electromyogram of the masticatory muscles and the measuring device 14 in the device 2 for example, to the multi-channel analog / digital converter 4 for further evaluation to the microprocessor 5 passed. With this signal receives with appropriate evaluation of the microprocessor 5 or the special software 6 an input for automatic assignment of the via the microphones 3 or 9 recorded noises to the actual teeth grinding and pressing.

The automatic message input device may, among other things, also be designed such that instead of via EMG electrodes 15 About pressure sensors in the mouth between lower and upper jaw or between the lower and the upper row of teeth, z. B. integrated in a bite splint, the teeth grinding and pressing detected and the signal through the appropriate measuring device to the analog / digital converter 4 or to the microprocessor 5 is reported.

The measuring device 14 with the electrodes 15 or other sensors may be an external device that uses cable or radio temporarily for the learning phase to the device 2 is connected.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• Alvarez-Arenal et al. 2002 [0003]
• - Raphael et al. 2003 [0003]
• - Dao & Lavigne, 1998 [0003]
• Clarke et al. 1981 [0004]
• - Moss et al. 1982 [0004]
• - Feehan & Marsh 1989 [0004]

Claims (35)

Device for detection, detection and feedback of nocturnal teeth grinding and crunching, characterized in that the teeth grinding and -rn pressing acoustically detected and detected by sound-technical signal analysis and distinguished from other noises and fed back. Apparatus according to claim 1, characterized in that with one or more microphones 3 in a device 2 The sounds of the person suffering from bruxism (mostly sleeping) recorded acoustically. Device according to one of the preceding claims, characterized in that the microphones are designed with directional characteristics and in the device 2 are directionally oriented to properly set up and align the device 2 z. B. on the dessert to the affected person (person suffering from bruxism) to record the sounds of teeth crunching and pressing directionally oriented with less interference from extraneous noise. Device according to one of the preceding claims, characterized in that one or more microphones 9 external with connection to the device 2 closer to the person concerned (as for example: on the dessert) can be attached to the bed frame on the headboard, for example Device according to one of the preceding claims, characterized in that one or more microphones 9 externally from the device 2 are attached to the person concerned in a portable manner, e.g. As in clothing, attached to a band, a chain or integrated and attached to the ear. Device according to one of the preceding claims, characterized in that the or the external / n microphone / e 9 Wired or wirelessly to the device 2 are connected. Device according to one of the preceding claims, characterized in that the device 2 is designed portable so that it z. B. can be attached to the clothing in a breast pocket without being able to fall out. Device according to one of the preceding claims, characterized in that in the device 2 an A / D converter 4 that of the microphone (s) 3 . 9 incoming analog signal converts into a microprocessor-compatible digital signal. Device according to one of the preceding claims, characterized in that in the device 2 a microprocessor 5 with a special software 6 The digitized noise signal is processed and evaluated. Device according to one of the preceding claims, characterized in that in the device 2 a special microprocessor circuit z. For example, a special processor (ASIC) processes and evaluates the digitized speech signal faster and more effectively. Device according to one of the preceding claims, characterized in that in the device 2 the digital noise signal processing and evaluation of special software 6 Noises of the person's teeth grinding and squeezing as well as recognition algorithms used in the special software 6 are stored in advance with those recorded during the monitoring and digitized sounds of the affected person or his direct sleep environment using the detection algorithms and compares. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the deposited and the recorded noises of teeth grinding and pressing and ambient noise permanently during the monitoring time runs or by triggering z. B. due to / the noise level, duration or frequency starts. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the deposited and the recorded noises of the teeth crunching and pressing and the ambient noise via frequency analyzes, in particular fast Fourier transforms (FFT) done. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the stored and recorded noises of teeth grinding and pressing as well as ambient noise via frequency analyzes (Fast Fourier Transformations (FFT) in successive time intervals. Device according to one of the preceding claims, characterized in that in the device 2 the acoustic analysis, evaluation and comparison of the stored and recorded noises of teeth grinding and pressing as well as ambient noise via Fast Fourier Transformations (FFT) and spectral intensities are performed. Device according to one of the preceding claims, characterized in that in the device 2 sound-technical analysis, evaluation and comparison of the stored and recorded noises of teeth grinding and pressing as well as ambient noise are made via short-time Fourier transforms (STFT). This means that fast Fourier transforms (FFT) and spectral intensities in short, constant and consecutive or overlapping time blocks or time steps are calculated from the recorded signals. Device according to one of the preceding claims, characterized in that in the device 2 the acoustic analysis, evaluation and comparison of the stored and recorded noises of teeth grinding and crunching as well as ambient noise via wavelet transformations take place. This means that the frequency-intensity-time response is calculated from the recorded signals in short time blocks or time steps which are adapted to the signal dynamics as well as successively or overlapping. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the stored and recorded noises of teeth grinding and crunching and ambient noise are supported by coherence analyzes of the signals. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the recorded noises of teeth grinding and pressing as well as the ambient noise via fuzzy controller takes place. Device according to one of the preceding claims, characterized in that in the device 2 the sound analysis, evaluation and comparison of the recorded noises of teeth grinding and pressing as well as the ambient noise via a neural network takes place. Device according to one of the preceding claims, characterized in that in the device 2 for the learning phase for sound analysis, evaluation and comparison of the recorded noises of teeth grinding and pressing and the ambient noise a manual message input device software or hardware technology is present to the device 2 To report whether the acoustically recorded noise was caused by teeth grinding and pressing or not. Device according to one of the preceding claims, characterized in that in the device 2 for the learning phase for sound analysis, evaluation and comparison of the recorded noises of teeth grinding and pressing as well as ambient noise, there is a device which automatically detects via EMG (electromyogram) detection of the masticatory muscles or via pressure sensors in the mouth, whether the acoustically recorded noise caused by teeth grinding and pressing or not. Device according to claim 22, characterized in that the device which automatically detects for the learning phase via EMG (electromyogram) detection of the masticatory muscles or via pressure sensors in the mouth, whether the acoustically recorded noise was caused by teeth grinding and crimping or not, is external and via cable or radio to the device 2 is connected. Device according to one of the preceding claims, characterized in that in the device 2 the acoustic analysis, evaluation and comparison of recorded noises of teeth grinding and crunching as well as ambient noise via fuzzy controllers and neuronal network takes place. Device according to one of the preceding claims, characterized in that one in the device 2 existing speaker 7 as a signaler gives the feedback to the teeth-grinding person. Device according to one of the preceding claims, characterized in that one on the device 2 connected external speaker 10 who is in the clothing or on a bracelet, a chain or on the ear as a signal generator gives the feedback to teeth grinding person. Device according to one of the preceding claims, characterized in that the external loudspeaker 10 via radio to the device 2 is connected. Device according to one of the preceding claims, characterized in that one in the device 2 existing electrostimulator via electrodes attached to the body of the person concerned by electrical stimulation feedback on the detected and ongoing teeth grinding and pressing. Device according to one of the preceding claims, characterized in that one in the device 2 existing or external mechanical vibration unit, which is electrically activated via the device, gives feedback on the detected and ongoing teeth grinding and pressing. Device according to one of the preceding claims, characterized in that one in the device 2 existing visual display or a display 8th Feedback gives. Device according to one of the preceding claims, characterized in that one in the device 2 existing visual display or a display 8th Information z. B. on the frequency and duration of a night or to static analysis over several nights of recorded teeth grinding and pressing represents. Device according to one of the preceding claims, characterized in that the device 2 can be connected to other devices or computers via USB. Device according to one of the preceding claims, characterized in that the device 2 over radio such. B. Bluetooth, ZigBee, etc. can be connected to other devices or computers. Device according to one of the preceding claims, characterized in that the device 2 a distributed intelligence device, e.g. B. that a simple signal analysis and feedback in a device is made and further signal analyzes z. B. according to one of the preceding claims, recording and storing the signals z. B. for medical assessment in a radio or cable connected in another device or more. Device according to one of the preceding claims characterized in that it is also suitable for recording, Detection and feedback of other sounds used can be, such. B. pathological abnormalities Sleeping with morbid acoustic phenomenon among other involuntary Vocalizations during sleep.