Patent ID: 9597022
Date: 2017-03-21
CPC Classifications: A61B

Claim:
1. A method for determining a respiration rate of a subject, the method comprising: transforming, using a signal processor, a first physiological signal based on light transmission at a first wavelength to generate a first transformed signal; transforming, using the signal processor, a second physiological signal based on light transmission at a second wavelength to generate a second transformed signal; deriving, using the signal processor, a ratio surface from the first transformed signal and the second transformed signal, wherein the ratio surface comprises three-dimensional data with dimensions including time and scale; identifying, using the signal processor, a first region of interest on the ratio surface indicative of venous perturbation; calculating, using the signal processor, a representative value for the first region of interest on the ratio surface; making, using the signal processor, a determination as to whether the calculated representative value for the first region of interest indicates respiration or motion of the subject based on the calculated representative value, wherein determining whether the representative value for the first region of interest indicates respiration or motion of the subject comprises: calculating, using the signal processor, the respiration rate of the subject when the calculated representative value for the first region of interest indicates respiration.