Method, apparatus and system for characterizing sleep

A method of determining a Rapid-Eye-Movement (REM) sleep and a Non-REM (NREM) sleep from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the method comprising:

• extracting a plurality of electromyogram (EMG) parameters from the signals;
• and
• using said plurality of EMG parameters to determine at least one REM period;
• thereby determining the REM sleep and the NREM sleep of the sleeping subject.

A method of determining a Rapid-Eye-Movement (REM) sleep and a Non-REM (NREM) sleep from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the method comprising:

• extracting a series of cardiac R-R intervals from the signals;
• constructing a Poincare plot of said series of cardiac R-R intervals;
• and
• using said Poincare plot to determine the REM sleep and the NREM sleep of the sleeping subject.

A method of determining sleep stages from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the method comprising:

• extracting a series of cardiac R-R intervals from the signals and obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• using said time-frequency decomposition to determine at least one Slow-Wave-Sleep (SWS) period and at least one Non-SWS (NSWS) period;
• from said at least one NSWS period, determining at least one sleep-onset (SO) period and a plurality of non-sleep periods;
• extracting a plurality of electromyogram (EMG) parameters from a portion of the signals, said portion corresponds to a NSWS period other than said at least one SO period and other than said plurality of non-sleep period;
• using said plurality of EMG parameters to determine at least one REM period, thereby obtaining also at least one light-sleep (LS) period defined as a NSWS period other than said at least one SO period, other than said plurality of non-sleep periods and other than said at least one REM period;
• thereby determining the sleep stages of the sleeping subject.

A method of determining a sleep apnea from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the method comprising:

• (a) extracting a series of cardiac R-R intervals from the signals;
• (b) determining awakening periods of the sleeping subject and excluding cardiac R-R intervals corresponding to said awakening periods from said series of cardiac R-R intervals;
• (c) obtaining a power spectrum from said series of cardiac R-R intervals;
• and
• (d) using said power spectrum to determine the sleep apnea of the sleeping subject.

An apparatus for determining a Slow-Wave-Sleep (SWS) period and a Non-SWS (NSWS) period from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the apparatus comprising:

• an R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a decomposer for obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• and
• an SWS determinator, for using said time-frequency decomposition so as to determine a SWS period defined over a plurality of SWS epochs, thereby also determining NSWS period defined by all epochs other than said SWS epochs, said NSWS period encompassing at least one Rapid-Eye-Movement (REM) sleep period and at least one Non-REM (NREM) sleep period;
• thereby to determine the SWS period and the NSWS period of the sleeping subject.

An apparatus for determining a Rapid-Eye-Movement (REM) sleep and a Non-REM (NREM) sleep from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the apparatus comprising:

• an R-R extractor, for extracting a series of cardiac R-R intervals from the signals;
• a plotter, for constructing a Poincare plot of said series of cardiac R-R intervals;
• and
• a REM determinator, for using said Poincare plot to determine the REM sleep and the NREM sleep of the sleeping subject.

An apparatus for determining sleep stages from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the apparatus comprising:

• a R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a decomposer, for obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• a Slow-Wave-Sleep (SWS) determinator for using said time-frequency decomposition to determine at least one SWS period and at least one Non-SWS (NSWS) period;
• a sleep-onset (SO) determinator for determining at least one SO period onset period from said at least one NSWS period;
• a non-sleep determinator for determining plurality of non-sleep periods from said at least one NSWS period;
• an electromyogram (EMG) extractor, for extracting a plurality of EMG parameters from a portion of the signals, said portion corresponds to a NSWS period other than said at least one SO period and other than said plurality of non-sleep periods;
• a Rapid-Eye-Movement (REM) determinator for using said plurality of EMG parameters to determine at least one REM period, thereby to obtain also at least one LS period defined as a NSWS period other than said at least one SO period, other than said plurality of non-sleep periods and other than said at least one REM period;
• thereby to determine the sleep stages of the sleeping subject.

A system for determining a Slow-Wave-Sleep (SWS) period and a Non-SWS (NSWS) period of a sleeping subject, the system comprising:

• an apparatus for providing signals of electrical activity of a chest of the sleeping subject, measured over a plurality of epochs;
• an R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a decomposer for obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• and
• an SWS determinator, for using said time-frequency decomposition so as to determine a SWS period defined over a plurality of SWS epochs, thereby also determining NSWS period defined by all epochs other than said SWS epochs, said NSWS period encompassing at least one Rapid-Eye-Movement (REM) sleep period and at least one Non-REM (NREM) sleep period;
• thereby to determine the SWS period and the NSWS period of the sleeping subject.

A system for determining a Rapid-Eye-Movement (REM) sleep and a Non-REM (NREM) sleep of a sleeping subject, the system comprising:

• an apparatus for providing signals of electrical activity of a chest of the sleeping subject, measured over a plurality of epochs;
• an electromyogram (EMG) extractor for extracting a plurality of EMG parameters from the signals;
• and
• a REM determinator for using said plurality of EMG parameters to determine the REM sleep and the NREM sleep of the sleeping subject.

A system for determining a Rapid-Eye-Movement (REM) sleep and a Non-REM (NREM) sleep of a sleeping subject, the system comprising:

• an apparatus for providing signals of electrical activity of a chest of the sleeping subject, measured over a plurality of epochs;
• an R-R extractor, for extracting a series of cardiac R-R intervals from the signals;
• a plotter, for constructing a Poincare plot of said series of cardiac R-R intervals;
• and
• a REM determinator, for using said Poincare plot to determine the REM sleep and the NREM sleep of the sleeping subject.

A system for determining sleep stages of a sleeping subject, the system comprising:

• an apparatus for providing signals of electrical activity of a chest of the sleeping subject, measured over a plurality of epochs;
• an R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a decomposer, for obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• a Slow-Wave-Sleep (SWS) determinator for using said time-frequency decomposition to determine at least one SWS period and at least one Non-SWS (NSWS) period;
• a sleep-onset (SO) determinator for determining at least one SO period onset period from said at least one NSWS period;
• a non-sleep determinator for determining a plurality of non-sleep periods from said at least one NSWS period;
• an electromyogram (EMG) extractor, for extracting a plurality of EMG parameters from a portion of the signals, said portion corresponds to a NSWS period other than said at least one SO period and other than said plurality of non-sleep period;
• a Rapid-Eye-Movement (REM) determinator for using said plurality of EMG parameters to determine at least one REM period, thereby to obtain also at least one LS period defined as a NSWS period other than said at least one SO period, other than said plurality of non-sleep periods and other than said at least one REM period;
• thereby to determine the sleep stages of the sleeping subject.

An apparatus for determining a sleep apnea from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the apparatus comprising:

• an R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a non-sleep determinator for determining awakening periods of the sleeping subject and excluding cardiac R-R intervals corresponding to said awakening periods from said series of cardiac R-R intervals;
• a decomposer for calculating a power spectrum from said series of cardiac R-R intervals;
• and
• a sleep apnea determinator for using said power spectrum and determining the sleep apnea of the sleeping subject.

A system for determining a sleep apnea of a sleeping subject, the system comprising:

• an apparatus for providing signals of electrical activity of a chest of the sleeping subject, measured over a plurality of epochs;
• an R-R extractor for extracting a series of cardiac R-R intervals from the signals;
• a non-sleep determinator for determining awakening periods of the sleeping subject and excluding cardiac R-R intervals corresponding to said awakening periods from said series of cardiac R-R intervals;
• a decomposer for calculating a power spectrum from said series of cardiac R-R intervals;
• and
• a sleep apnea determinator for using said power spectrum and determining the sleep apnea of the sleeping subject.

A method of determining sleep stages from signals of electrical activity recorded of a chest of a sleeping subject, the signals being measured over a plurality of epochs, the method comprising:

• extracting a series of cardiac R-R intervals from the signals and obtaining a time-frequency decomposition from said series of cardiac R-R intervals;
• using said time-frequency decomposition to determine at least one Slow-Wave-Sleep (SWS) period and at least one Non-SWS (NSWS) period;
• constructing a Poincare plot of at least a portion of said series of cardiac R-R intervals, and using said Poincare plot and said time-frequency decomposition for determining at least one REM period, thereby obtaining also at least one light-sleep (LS) period defined as a NSWS period other than said at least one SO period, other than said plurality of non-sleep periods and other than said at least one REM period;
• thereby determining the sleep stages of the sleeping subject.