Over the last few years, the contactless acquisition of cardiovascular parameters using
cameras has gained immense attention. The technique provides an optical means to …

Motivated by analyzing complicated time series, nonlinear-type time–frequency analysis has
become an active research topic in the past decades. Those developed tools have been …

The continuous wavelet transform (CWT) has played a key role in the analysis of time-
frequency information in many different fields of science and engineering. It builds on the …

The task is to identify differences in phase synchronization between the intermittent photic
stimulation and a response of the brain of patients with arterial hypertension and …

Synchrosqueezing transform (SST) has been proposed to characterize frequency-
modulated signals with slow varying instantaneous frequency (IF). However, it cannot …

Despite the population of the noninvasive, economic, comfortable, and easy-to-install
photoplethysmography (PPG), it is still lacking a mathematically rigorous and stable …

We apply the recently developed adaptive non-harmonic model based on the wave-shape
function, as well as the time-frequency analysis tool called synchrosqueezing transform …

Accurate heart rate estimation from reflectance photoplethysmography (PPG) during intense
physical activity is difficult given unpredictable motion artifacts (MAs). Recent research has …

Dynamic time warping (DTW) is a distance measure to compare time series that exhibit
similar patterns. In this paper, we will show how the warping path of the DTW algorithm can …

Background and purpose With the emergence of long-term electrocardiogram (ECG)
recordings that extend several days beyond the typical 24–48 h, the development of new …