Date of Award
Master of Science in Biomedical Engineering - (M.S.)
Biomedical Engineering Committee
Stanley S. Reisman
David S. Kristol
Thomas W. Findley
Spectral analysis of heartrate variability (HRV) provided an estimate of the sympathetic and parasympatheticinfluences on heart rate without drugs or other invasive procedures.However, there are many situations where heart rate changed rapidlyover time and the control of those changes was of considerable interest.Time-frequency analysis was utilized to expand the concept of spectralanalysis of HRV to describe changes in vagal tone and sympatho-vagalbalance as a function of time. As a result the assessment of the autonomicnervous system during rapid changes in heart rate was made.
There were three advantagesto calculating vagal tone and sympatho-vagal balance by using timefrequencyanalysis. First, vagal tone and sympatho-vagal balance were describedas functions of time. Hence, a better understanding was attained aboutautonomic control of rapidly changing signals. Second, the rate of increaseor decrease of vagal tone and sympatho-vagal balance was derived. Theserates were used to determine the integrity of the autonomic system.Third, a mental component affecting vagal tone was suggested. It isanticipated that the effects of anxiety on vagal tone can be revealedusing time-frequency analysis.
Fernando, Sanjay, "Autonomic nervous system evaluation using time-frequency analysis" (1994). Theses. 1210.