Systems and methods for filtering autocorrelation peaks and detecting harmonics
First Claim
1. A method comprising:
- receiving a photoplethysmograph (PPG) signal;
processing, with processing equipment, plural windows of the PPG signal to generate plural respiration information signals;
generating, with the processing equipment, plural autocorrelation sequences based on the plural respiration information signals;
identifying first and second respiration peak segments of respective first and second autocorrelation sequences where the first and second autocorrelation sequences are derived from different data windows of said PPG signal;
determining, with the processing equipment, whether the first and second autocorrelation sequences include an undesired harmonic; and
calculating, with the processing equipment, respiration information based at least in part on the first and second autocorrelation sequences when it is determined that the autocorrelation sequences do not include an undesired harmonic.
1 Assignment
0 Petitions
Accused Products
Abstract
Systems and methods are provided for determining respiration information from physiological signals such as PPG signals. A physiological signal is processed to generate at least one respiration information signal and an autocorrelation sequence is generated based on the at least one respiration information signal. In some embodiments, a respiration peak is identified based on the autocorrelation sequence and a composite peak is generated based on the identified peak and at least one previous respiration peak. Respiration information is calculated based on the composite peak. In some embodiments, a determination is made whether the autocorrelation sequence includes an undesired harmonic. When the autocorrelation sequence includes an undesired harmonic, the autocorrelation sequence may not be used in the calculation of respiration information.
193 Citations
20 Claims
-
1. A method comprising:
-
receiving a photoplethysmograph (PPG) signal; processing, with processing equipment, plural windows of the PPG signal to generate plural respiration information signals; generating, with the processing equipment, plural autocorrelation sequences based on the plural respiration information signals; identifying first and second respiration peak segments of respective first and second autocorrelation sequences where the first and second autocorrelation sequences are derived from different data windows of said PPG signal; determining, with the processing equipment, whether the first and second autocorrelation sequences include an undesired harmonic; and calculating, with the processing equipment, respiration information based at least in part on the first and second autocorrelation sequences when it is determined that the autocorrelation sequences do not include an undesired harmonic. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A system comprising:
-
an input for receiving a photoplethysmograph (PPG) signal; and processing equipment configured for; receiving a photoplethysmograph (PPG) signal; processing plural windows of the PPG signal to generate to generate plural respiration information signals; generating, with the processing equipment, plural autocorrelation sequences based on the plural respiration information signals; identifying first and second respiration peak segments of respective first and second autocorrelation sequences where the first and second autocorrelation sequences are derived from different data windows of said PPG signal; determining, with the processing equipment, whether the first and second autocorrelation sequences include an undesired harmonic; and calculating, with the processing equipment, respiration information based at least in part on the first and second autocorrelation sequences when it is determined that the autocorrelation sequences do not include an undesired harmonic. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification