Method and System for Identifying Respiratory Events

A method for identifying respiratory events whereby,

• a sound signal and a motion signal, which are generated during respiration, are recorded by a wireless sensor equipped with a microphone sensor and a motion sensor;
• signals from sensors are converted into a digital data stream by a microcontroller;
• the digital data stream is sent to a monitoring station by a wireless transmission module;
• wherein, the digital data stream from the wireless sensor is received in the monitoring station and then digital data representing sound and motion signals are pre-filtered;
• in a segmentation module, the digital data representing a sound signal are divided into time windows and transformed to a frequency domain and then the sound signal is divided into segments corresponding to respiratory episodes on the basis of signal changes in the frequency domain in the time windows of the sound signal for specific sound signal frequencies;
• input vectors are created containing sound signal parameters in a time domain and in the frequency domain, statistical parameters specified on the basis of historical data as well as motion signals parameters in the time domain, and then the input vector containing sound signal parameters is fed into inputs of an assembly of at least three independent and different detection modules which have been designed to generate a signal classifying a respiratory event on the basis of the sound signal,
• the vector containing motion signal parameters is fed into an input of a motion signals classification module which has been designed to generate a motion/position classification signal;
• data obtained at an output of the respiratory event of the classification module and the motion signals classification module are fed into an inference module at the output of which a respiratory event identification signal is output.

A system for identifying respiratory events during examination constructed from

• a wireless sensor comprising:
• a microphone and a motion sensor, which record sound signals and motion signals generated during respiration,
• a microcontroller, which converts signals from the sensors into a digital data stream, and
• a wireless transmission module;
• a monitoring station comprising,
• a wireless transmission module,
• a signals pre-processing module, which has been designed to pre-filter the data stream from the wireless transmission module, divided into time windows, and transforms both the sound signal and the motion signal into a frequency domain for subsequent time windows;
• wherein the monitoring station further comprises,
• a segmentation module, which has been designed to divide the sound signal and the motion signal into segments corresponding to respiratory episodes on the basis of sound signal changes in the frequency domain as well as into sound signal and motion signal time windows;
• a transformation module, which has been designed to create an input vector containing sound signal parameters in the time and frequency domains, historical data and statistical parameters;
• a classification module, consisting of at least three independent and different detection modules which have been designed to generate a signal classifying a respiratory event on the basis of the input vector and a motion signal classification module, which has been designed to generate a position classification signal;
• and
• an inference module, which has been designed in such a manner that a position identification output signal is output at its output.