METHOD FOR DETERMINING A PERSON'S SLEEPING PHASE WHICH IS FAVOURABLE FOR WAKING UP

• US 20160007931A1
• Filed: 09/25/2015
• Published: 01/14/2016
• Est. Priority Date: 04/05/2013
• Status: Active Grant

• Current Assignee: Healbe Corporation
• Original Assignee: Healbe Corporation
• Inventors: RUBIN, Mikhail S., SVIRYAEV, Yury V.
• Granted Patent: US 11,224,385 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: G04C 3/001 Electromechanical switches for setting or display in general H01H
• CPC Class Codes: G04G 13/023 Adjusting the duration or amplitude of signals

Abstract

A pulse wave signal is registered and an occurrence of human limb movements detected during sleep using a pulse wave sensor and an accelerometer. The values of RR intervals and respiratory rate are measured at preset time intervals Δt_i based on pulse wave signal. Mean P₁, minimal P₂, and maximal P₃ values of RR intervals, the standard deviation of RR intervals P₄, average respiratory rate P₅ and average number of limb movements P₆ are determined based on the above measured values. Function value F(Δt_i) is determined thereafter as:

F(Δt_i)=−K₁P₁−K₂P₂−K₃P₃+K₄P₄+K₅P₅+K₆P₆,

where K₁-K₆ are weight coefficients characterizing the contribution of the corresponding parameter to function value F(Δt_i); whereat the onset and termination of sleep phase favorable to awakening is determined by increments of function F(Δt_i).

Claims

1. A method for determining a human sleep phase favorable to awakening, the method comprising:

registering a pulse wave signal and an occurrence of limb movements of the human during sleep using a pulse wave sensor and at least one motion sensor attached to a body of the human;

measuring values of RR intervals and a respiratory rate; and

determining values of function F(Δ

t_i) over preset time intervals Δ

t_i and determining an onset and termination of the sleep phase favorable to awakening based on an increment of function F(Δ

t_i), where i is a serial number of a time interval, wherein;

F(Δ

t_i)=−

K₁P₁−

K₂P₂−

K₃P₃+K₄P₄+K₅P₅K₆P₆,

wherein;

P₁ is a mean value of the RR intervals over a time interval Δ

t_i;

P₂ is a minimal value of the RR intervals over the time interval Δ

t_i;

P₃ is a maximal value of RR intervals over the time interval Δ

t_i;

P₄ is a standard deviation of the RR intervals over a preceding time interval of 3 to 20 min;

P₅ is a mean value of the respiratory rate over the time interval Δ

t_i;

P₆ is an average number of human limb movements over a preceding time period ranging from 0.5 minutes to 10 minutes; and

K₁-K₆ are weight coefficients characterizing contribution of parameters P₁-P₆ to the values of the function F(Δ

t_i).

2. The method of claim 1, comprising selecting a time interval over which a value of parameter P₄ is measured in a range from 4 minutes to 6 minutes.

3. The method of claim 1, comprising selecting a time interval over which parameter value P₆ is measured in a range from 4 minutes to 6 minutes.

4. The method of claim 1, wherein the value of weight coefficient K₁ for parameter P₁, measured in ms, is selected in the range from 0.6 ms⁻

1 to 3 ms<sup>−

1</sup>;

the value of weight coefficient K₂ for parameter P₂, measured in ms, is selected in the range of 0.1 ms<sup>−

1</sup> to 0.7 ms<sup>−

1</sup>;

the value of weight coefficient K₃ for parameter P₃, measured in ms, is selected in the range of from 0.01 ms<sup>−

1</sup> to 0.3 ms<sup>−

1</sup>;

the value of weight coefficient K₄ for parameter P₄, measured in ms, is selected in the range from 0.5 ms<sup>−

1</sup> to 3 ms<sup>−

1</sup>;

the value of weight coefficient K₅ for parameter P₅, measured in min<sup>−

1</sup>, is selected in the range from 1 min to 10 min; and

the value of weight coefficient K₆ for parameter P₆ is selected in the range from 5 to 50.

5. The method of claim 4, comprising selecting the value of the weight coefficient K₁ in a range from 0.9 ms⁻

1 to 1.05 ms<sup>−

1</sup>.

6. The method of claim 4, comprising selecting the value of the weight coefficient K₂ in a range from 0.1 ms⁻

1 to 0.2 ms<sup>−

1</sup>.

7. The method of claim 4, comprising selecting the value of the weight coefficient K₃ in a range from 0.02 ms⁻

1 to 0.05 ms<sup>−

1</sup>.

8. The method of claim 4, comprising selecting the value of the weight coefficient K₄ in a range from 1.3 ms⁻

1 to 1.5 ms<sup>−

1</sup>.

9. The method of claim 4, comprising selecting the value of the weight coefficient K₅ is selected in a range from 1.5 min to 2.3 min.

10. The method of claim 4, comprising selecting the value of the weight coefficient K₆ is selected in a range from 18 to 24.

11. The method of claim 1, wherein the pulse wave sensor is a piezoelectric sensor, a strain gauge, or an optical sensor attached to a wrist or a forearm.

12. The method of claim 1, wherein the at least one motion sensor is an accelerometer attached to an arm or leg.

13. The method of claim 1, wherein the time intervals Δ

t_i are selected in a range from 1 minute to 6 minutes.

14. The method of claim 1, comprising identifying the onset of the sleep phase favorable to awakening if the increment of function F(Δ

t_i) over the time period Δ

t_i exceeds a first preset threshold value.

15. The method of claim 1, comprising identifying the termination of the sleep phase favorable to awakening if the increment of function F(Δ

t_i) over the time period Δ

t_i becomes smaller than a second preset threshold value.