Beat-to-beat and spectral analyses of the noninvasive radial pulse and laser-Doppler signals in patients with hypertension

Abstract

This study performed beat-to-beat and spectral analyses of 20-minute skin-surface laser-Doppler-flowmetry (LDF) and radial blood-pressure-waveform (BPW) signals in order to compare the blood-flow perfusion condition and regulatory mechanisms between essential-hypertension (EHT) patients and aged-matched control subjects. Beat-to-beat LDF analyses yielded the pulse width (PW), AC-to-DC ratio (AD), and their corresponding variability indices (coefficients of variation [CVs]). The relative energy contributions (RECs) of five characteristic frequency peaks (defined as FR1–FR5) were also calculated. Spectral BPW analysis obtained the amplitude proportion (C n ) and phase angle (P n ) of each harmonic component n. PW, AD, AD_CV, and REC of FR2 were significantly smaller in the EHT group than in the control group. Regarding BPW indices, C 1, C 2, C 4, and C 5 were significantly larger and P 2–P 8 were significantly smaller in EHT patients than in controls. The present results indicate that BPW and LDF indices can be used to evaluate the blood-flow perfusion efficiency and microcirculatory regulatory activities in EHT. Sex differences were found, with the effects being more prominent in female patients. These findings may be partly attributable to impairment of endothelial and neural regulatory functions. The present findings might aid the development of new noninvasive methods for reducing the risk of EHT-induced damage.

Abnormalities in Cutaneous Microcirculation in Patients with Alzheimer’s Disease, Mild Cognitive Impairment, and Chronic Insomnia Disorder

“…Laser Doppler flowmetry (LDF) is a non-invasive method to measure local microvascular blood flow in tissues [1,2]. LDF has been used in scientific research to measure cutaneous microvascular damage in certain diseases, such as systemic sclerosis, diabetes mellitus, and hypertension [2][3][4][5]. In these circumstances, cutaneous microvasculopathy is a known potential complication of these diseases, and LDF is used to detect the occurrence or extent of microvasculopathy.…”

Peripheral pulse harmonic analysis and its clinical application: A systematic review

“…Dr. Hsiu's research team has employed these disks to develop a pulse diagnosis recording device. 40 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 Furthermore, a self-designed device equipped with a strain-gauge pressure sensor has been used to capture arterial pulse waves. 67 Photoplethysmography (PPG): PPG, a technique that gauges volume changes in peripheral blood vessels by detecting alterations in light absorption, has also been harnessed to measure pulse waves for harmonic analysis.…”

“…Dr. Hsiu's research team has employed these disks to develop a pulse diagnosis recording device. 40 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 Furthermore, a self-designed device equipped with a strain-gauge pressure sensor has been used to capture arterial pulse waves. 67 …”

Machine Learning Analyses Revealed Distinct Arterial Pulse Variability According to Side Effects of Pfizer-BioNTech COVID-19 Vaccine (BNT162b2)

“…Details of the present experimental setup and the signal processing methods are available elsewhere [ 20 , 21 , 22 , 23 ] and in the Supplemental Materials. Blood pressure waveform (BPW) signals of the subjects were measured noninvasively (typical waveforms are shown in Figure 1 ).…”

“…Pulse measurement also has application advantages, such as being noninvasive, fast, user-friendly, and objective. Previous studies have analyzed pulse waveforms in the time domain [ 14 , 15 , 16 , 17 ] and frequency domain to capture the information buried in the waveform changes induced by CVDs, such as hypertension, stroke, coronary artery disease, vascular aging, and metabolic syndrome, or applying various types of simulation [ 18 , 19 , 20 , 21 , 22 ].…”