Method and apparatus for non-invasive detection of physiological and patho-physiological sleep conditions

Abstract

Method and apparatus for the non-invasive detection of certain breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility and its dynamic changes, comprising steps of: determining the sleep or wake status of a person, monitoring circulatory pulse waveforms and amplitude normalized pulse wave systolic upstrokes recorded from a person's body and determining at least one index of the upstroke to characterize the strength of the contraction of the heart during the systolic upstroke during a series of heart beats relating to a breathing cycle or an absent anticipated breathing cycle of the patient, and determining that a certain change in a breathing condition, a sleep disordered breathing condition, or assessment of the person's myocardial contractility and its dynamic changes, has occurred when a specific change in the sleep disordered breathing analysis, and the at least one index of the upstroke has been detected.

We claim: 
     
         1 . A method for the non-invasive detection of certain medical conditions and physiological states, comprising the steps of:
 monitoring circulatory pulse waveforms recorded from a person's body;   monitoring circulatory pulse systolic upstroke waveforms recorded from a person's body;   normalizing said circulatory pulse systolic upstroke waveforms such that the magnitude of the trough to peak amplitude of each such systolic upstroke is set to a predetermined value;   determining at least one index of the upstroke to characterize the strength of the contraction of the heart during the systolic upstroke phase of a heart beat;   determining changes of said at least one index of the upstroke to characterize the strength of the contraction of the heart during a series of heart beats related to a breathing cycle or to an absent anticipated breathing cycle of the patient,   and determining the certain medical conditions and physiological states based on changes of the at least one index of the upstroke related to a breathing cycle of the patient or to an absent anticipated breathing cycle.   
     
     
         2 . The method of  claim 1 , wherein the medical conditions and physiological states include one or more of: breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes. 
     
     
         3 . The method of  claim 1  wherein said at least one index of the upstroke is determined utilizing any detected changes in said systolic upstroke, including one or more of: (a) changes in the dynamic signal time-course thereof, (b) the relative fraction of the entire systolic upstroke amplitude occurring within a prescribed period of time, (c) the relative fraction of the entire systolic upstroke amplitude occurring within a prescribed period of time commencing at a predetermined fraction of the entire systolic upstroke amplitude, (d) the time between predetermined fractions of the normalized upstroke, (e) as a rate of change moment of the systolic upstroke, or (f) as a moment of the systolic upstroke, and wherein the normalized systolic upstroke index is substantially unaffected by spontaneous changes in the pulse amplitude. 
     
     
         4 . The method of  claim 2  wherein said breathing conditions, said certain sleep disordered breathing conditions, and said assessment of the myocardial contractility, and its dynamic changes, are determined by at least one of (a), analysis of time series patterns of derived upstroke index values, and (b), sleep disordered breathing analysis based on monitoring at least circulatory pulse waveforms recorded from a person's body 
     
     
         5 . The method of  claim 1  wherein said monitoring circulatory pulse waveforms recorded from a person's body and said monitoring circulatory pulse systolic upstroke waveforms recorded from a person's body are made using one or more of: a peripheral arterial tone (PAT) measurement, volumetric change measurement, an optical density measurement, a surface-reflectivity measurement, a pulse oximetry measurement, an electrical resistivity measurement, a Doppler ultrasound measurement, a laser Doppler measurement, a flow meter device, a segmental plethysmograph, a circumferential strain gauge device, an optical plethysmograph, an optical plethysmograph signal derived from a pulse oximeter, an isotope washout device, a thermal washout device, a temperature measurement, a temperature change measurement, an electromagnetic measurement device, a sensor affected by a change in finger geometry or red blood cell alignment or flux associated with pulsatile volume changes, or Hall effect sensors. 
     
     
         6 . The method of  claim 2  wherein said certain breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes are selected from one or more of: sleep state, wake state, REM stage sleep, non-REM state sleep, non-REM light sleep state, non-REM deep sleep state, obstructive sleep apnea, central sleep apnea, mixed sleep apnea, obstructive sleep hypopnea, upper airway resistance syndrome, fixed or transient elevated respiratory resistance, respiratory effort related arousal (RERA), Chenye-Stokes breathing, Valsalva and Mueller maneuvers, or periodic limb movement syndrome. 
     
     
         7 . The method of  claim 2  wherein said sleep disordered breathing condition is one or more of: an obstructive, a central or of a mixed nature sleep disordered breathing condition based on the magnitude of change of the said analysis of a time series pattern of derived upstroke index values. 
     
     
         8 . The method of  claim 2  wherein said determination of certain breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes are made by one or more measuring devices selected from: a peripheral arterial tone (PAT) signal, a pulsewave signal, pulse oximetry determined arterial blood oxygen saturation level (SaO 2 ), a sleep wake detection method such as an actigraph device, an accelerometric signal measurement device, and at least one body position sensor and an acoustic sensor. 
     
     
         9 . The method of  claim 7 , further comprising the steps of: (a) detecting an accelerometric signal of the person, (b) analyzing the accelerometric signal, and (c) determining the person's certain breathing condition, or certain sleep disordered breathing condition based on one or more of: the upstroke changes analysis, the sleep disordered breathing analysis, and the accelerometric signal analysis. 
     
     
         10 . The method of  claim 2 , wherein the assessment of the person's myocardial contractility is determined as one of: an absolute value of said upstroke index or a mean value of a series of upstroke index values, during at least one breathing cycle or an absent anticipated breathing cycle. 
     
     
         11 . The method of  claim 10 , wherein the change over time of an absolute value of said upstroke index or a mean value of a series of upstroke index values during at least one breathing cycle or at least one absent anticipated breathing cycle, is a function of changes in a person's myocardial contractility over time. 
     
     
         12 . The method of claim of  claim 7 , wherein a high level of variability in the time series of upstroke index during sleep indicates the presence of obstructive sleep apnea, and wherein a low level or no change in variability in the time series of upstroke index in the upstroke index during sleep indicates the presence of central sleep apnea and wherein a combination of high and low, or high and no variability, in the time series of upstroke index during sleep indicates the presence of mixed obstructive and central sleep apnea. 
     
     
         13 . The method of  claim 12 , wherein the incorporation of one or more of; accelerometric information, breathing sound information, pulse transit time (PTT) information, or factors which confirm a diagnosis based on the systolic upstroke analysis, and thereby to indicate the presence of an obstructive or central sleep apnea or a mixed obstructive and central sleep apnea event. 
     
     
         14 . The method of  claim 12 , wherein the said high and low variability of the at least one upstroke index is determined based on comparison to the cyclic variability of upstroke index of a subject during: (a) at least one normal breathing cycle while asleep, (b) during at least one normal breathing cycle while awake, or (c) to a predefined threshold value. 
     
     
         15 . The method of  claim 7 , wherein the determination of said sleep disordered breathing condition as being one of an obstructive, central or mixed nature based on the magnitude of change of the said analysis of a time series pattern of derived upstroke index values is further based on a predefined decline in blood oxygen saturation of the patient. 
     
     
         16 . A system for the non-invasive detection of certain medical conditions and physiological states in a person, comprising:
 a device that monitors circulatory pulse waveforms recorded from the person's body and monitors circulatory pulse systolic upstroke waveforms recorded from the person's body;   wherein the device:   normalizes said circulatory pulse systolic upstroke waveforms such that the magnitude of the trough to peak amplitude of each such systolic upstroke is set to a predetermined value;   determines at least one index of the upstroke to characterize the strength of the contraction of the heart during the systolic upstroke phase of a heart beat;   determines changes of said at least one index of the upstroke during a series of heart beats wherein said at least one upstroke index is related to the breathing cycle, or to an absent anticipated breathing cycle, of the person; and,   determines that the certain medical conditions and physiological states based upon the at least one index of the upstroke has been detected.   
     
     
         17 . The system of  claim 16 , wherein the medical conditions and physiological states include one or more of: breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes. 
     
     
         18 . The system of  claim 16  wherein the device determines said at least one index of the systolic pulse waveform upstroke by utilizing any detected changes in said systolic upstroke, including one or more of: (a) changes in the dynamic signal time-course thereof, (b) the relative fraction of the entire systolic upstroke amplitude occurring within a prescribed period of time, (c) the relative fraction of the entire systolic upstroke amplitude occurring within a prescribed period of time commencing at a predetermined fraction of the entire systolic upstroke amplitude, (d) the time between predetermined fractions of the normalized upstroke, or (e) as a rate of change moment of the systolic upstroke, or (f) as a moment of the systolic upstroke, and wherein the normalized systolic upstroke index is substantially unaffected by spontaneous changes in the pulse amplitude. 
     
     
         19 . The system of  claim 17 , wherein said breathing conditions, said certain sleep disordered breathing conditions, and said assessment of the myocardial contractility, and its dynamic changes, are determined by at least one of (a), analysis of time series patterns of derived upstroke index values, and (b), sleep disordered breathing analysis based on monitoring at least circulatory pulse waveforms recorded from a person's body. 
     
     
         20 . The system of  claim 16  wherein the device that monitors circulatory pulse waveforms recorded from a person's body and monitors circulatory pulse systolic upstroke waveforms recorded from a person's body effects such monitoring by a measuring device using one or more of: a peripheral arterial tone (PAT) measurement, volumetric change measurement, an optical density measurement, a surface-reflectivity measurement, a pulse oximetry measurement, an electrical resistivity measurement, a Doppler ultrasound measurement, a laser Doppler measurement, a flow meter device, a segmental plethysmograph, a circumferential strain gauge device, an optical plethysmograph, an optical plethysmograph signal derived from a pulse oximeter, an isotope washout device, a thermal washout device, a temperature measurement, a temperature change measurement, an electromagnetic measurement device, a sensor affected by a change in finger geometry or red blood cell alignment or flux associated with pulsatile volume changes, or Hall effect sensors. 
     
     
         21 . The system of  claim 17 , wherein said certain breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes are selected from one or more of: sleep state, wake state, REM stage sleep, non-REM state sleep, non-REM light sleep state, non-REM deep sleep state, obstructive sleep apnea, central sleep apnea, mixed obstructive and central apnea, obstructive sleep hypopnea, upper airway resistance syndrome, fixed or transient elevated respiratory resistance, respiratory effort related arousal (RERA), Chenye-Stokes breathing, Valsalva and Mueller maneuvers, or periodic limb movement syndrome. 
     
     
         22 . The system of  claim 17 , wherein said sleep disordered breathing condition is one or more of an obstructive, a central or a mixed nature sleep disordered breathing condition based on the magnitude of change of the said analysis of a time series pattern of derived upstroke index values. 
     
     
         23 . The system of  claim 17 , wherein said determination of certain breathing conditions, certain sleep disordered breathing conditions, or assessment of the person's myocardial contractility, and its dynamic changes are made using a measuring device employing one or more of: a peripheral arterial tone (PAT) signal, a pulsewave signal, pulse oximetry determined arterial blood oxygen saturation level (SaO 2 ), a sleep wake detection method including an actigraph device, an accelerometric signal measurement device, and at least one body position sensor and an acoustic sensor. 
     
     
         24 . The system of  claim 22 , wherein the device further detects an accelerometric signal of the person, analyzes the accelerometric signal, and determines the person's certain breathing condition, or certain sleep disordered breathing condition based on: the upstroke changes analysis, the sleep disordered breathing analysis and the accelerometric signal analysis. 
     
     
         25 . The system of  claim 17 , wherein the assessment of the person's myocardial contractility is determined as one of: an absolute value of said upstroke index or a mean value of a series of upstroke index values during at least one breathing cycle or at least one absent anticipated breathing cycle. 
     
     
         26 . The system of  claim 25 , wherein the change over time of an absolute value of said upstroke index or a mean value of a series of upstroke index values, during at least one breathing cycle or at least one absent anticipated breathing cycle, reflects the changes in a person's myocardial contractility over time. 
     
     
         27 . The system of  claim 22 , wherein a high level of variability in the time series of upstroke index during sleep indicates the presence of obstructive sleep apnea, and wherein a low level or no changes in variability in the time series of upstroke index in the upstroke index during sleep indicates the presence of central sleep apnea and wherein a combination of high and low or high and no variability in the time series of upstroke index during sleep, indicates the presence of mixed obstructive and central sleep apnea. 
     
     
         28 . The system of  claim 27 , wherein the incorporation of one or more of: accelerometric information, breathing sound information, or pulse transit time (PTT) information are factors that confirm a diagnosis based on the systolic upstroke analysis, and thereby indicate the presence of an obstructive or central sleep apnea or a mixed obstructive and central sleep apnea event. 
     
     
         29 . The system of  claim 27 , wherein the said high and low variability of the at least one upstroke index is determined based on comparison to the cyclic variability of upstroke index of a person during: (a) at least one normal breathing cycle while asleep, or (b) during at least one normal breathing cycle while awake, or (c) to a predefined threshold value. 
     
     
         30 . The system of  claim 22 , wherein the determination of said sleep disordered breathing condition as being one of: an obstructive, central or mixed nature based on the magnitude of change of the said analysis of a time series pattern of derived upstroke index values are further based on a predefined decline in blood oxygen saturation of the patient.