Body Position Affects Capillary Blood Flow Regulation Measured with Wearable Blood Flow Sensors

In this study we demonstrate what kind of relative alterations can be expected in average perfusion and blood flow oscillations during postural changes being measured in the skin of limbs and on the brow of the forehead by wearable laser Doppler flowmetry (LDF) sensors. The aims of the study were to evaluate the dynamics of cutaneous blood perfusion and the regulatory mechanisms of blood microcirculation in the areas of interest, and evaluate the possible significance of those effects for the diagnostics based on blood perfusion monitoring. The study involved 10 conditionally healthy volunteers (44 ± 12 years). Wearable laser Doppler flowmetry monitors were fixed at six points on the body: two devices were fixed on the forehead, on the brow; two were on the distal thirds of the right and left forearms; and two were on the distal thirds of the right and left lower legs. The protocol was used to record three body positions on the tilt table for orthostatic test for each volunteer in the following sequence: (a) supine body position; (b) upright body position (+75°); (c) tilted with the feet elevated above the head and the inclination of body axis of 15° (−15°, Trendelenburg position). Skin blood perfusion was recorded for 10 min in each body position, followed by the amplitude–frequency analysis of the registered signals using wavelet decomposition. The measurements were supplemented with the blood pressure and heart rate for every body position analysed. The results identified a statistically significant transformation in microcirculation parameters of the average level of skin blood perfusion and oscillations of amplitudes of neurogenic, myogenic and cardiac sensors caused by the postural changes. In paper, we present the analysis of microcirculation in the skin of the forehead, which for the first time was carried out in various positions of the body. The area is supplied by the internal carotid artery system and can be of particular interest for evaluation of the sufficiency of blood supply for the brain.

Laterality of Blood Perfusion in the Lower Extremities after Drinking Saline at Different Temperatures

Background: Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in the digestive system. However, the distribution and regulation of bilateral blood flow are not symmetrical but exhibit a certain laterality. The aim of this study was to analyze the laterality of SkBF after drinking saline (0.9%) at different temperatures by monitoring blood flux in the bilateral lower extremities.Methods: A total of 60 subjects were recruited for this study, and all subjects completed all measurements. Subjects were randomly divided into a 4 °C group, 10 °C group and 30 °C group. For every subject, skin blood perfusion of bilateral Zusanli acupoints (ST 36) was recorded simultaneously before and after drinking 500 ml of 0.9% saline using a PeriFlux System 5000. The electrogastrogram (EGG) was also monitored, and the dominant frequency of the EGG and heart rate variability were analyzed.Results: The results indicated that after drinking saline at different temperatures, the laterality index of SkBF at the lower extremities was different. Drinking 30 °C saline can increase the laterality index of the lower extremities. Stimulation at 4 °C and 10 °C resulted in a decrease in the DF of the EGG and an increased RMSSD of the RR interval. Although this laterality is mainly contributed to by frequency interval V, there was a weak negative correlation between the laterality index of frequency interval I or II and RMSSD.Conclusion: There was laterality of blood perfusion in the lower extremities after drinking saline at different temperatures.

Laterality of Blood Perfusion in the Lower Extremities after Drinking Saline at Different Temperatures

Background: Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in the digestive system. However, the distribution and regulation of bilateral blood flow are not symmetrical but exhibit a certain laterality. The aim of this study was to analyze the laterality of SkBF after drinking saline (0.9%) at different temperatures by monitoring blood flux in the bilateral lower extremities.Methods: A total of 60 subjects were recruited for this study, and all subjects completed all measurements. Subjects were randomly divided into a 4 °C group, 10 °C group and 30 °C group. For every subject, skin blood perfusion of bilateral Zusanli acupoints (ST 36) was recorded simultaneously before and after drinking 500 ml of 0.9% saline using a PeriFlux System 5000. The electrogastrogram (EGG) was also monitored, and the dominant frequency of the EGG and heart rate variability were analyzed.Results: The results indicated that after drinking saline at different temperatures, the laterality index of SkBF at the lower extremities was different. Drinking 30 °C saline can increase the laterality index of the lower extremities. Stimulation at 4 °C and 10 °C resulted in a decrease in the DF of the EGG and an increased RMSSD of the RR interval. Although this laterality is mainly contributed to by frequency interval V, there was a weak negative correlation between the laterality index of frequency interval I or II and RMSSD.Conclusion: There was laterality of blood perfusion in the lower extremities after drinking saline at different temperatures.

Laterality of Blood Perfusion in the Lower Extremities after Drinking Saline at Different Temperatures

Background: Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in the digestive system. However, the distribution and regulation of bilateral blood flow are not symmetrical but exhibit a certain laterality. The aim of this study was to analyze the laterality of SkBF after drinking saline (0.9%) at different temperatures by monitoring blood flux in the bilateral lower extremities.Methods: A total of 60 subjects were recruited for this study, and all subjects completed all measurements. Subjects were randomly divided into a 4 °C group, 10 °C group and 30 °C group. For every subject, skin blood perfusion of bilateral Zusanli acupoints (ST 36) was recorded simultaneously before and after drinking 500 ml of 0.9% saline using a PeriFlux System 5000. The electrogastrogram (EGG) was also monitored, and the dominant frequency of the EGG and heart rate variability were analyzed.Results: The results indicated that after drinking saline at different temperatures, the laterality index of SkBF at the lower extremities was different. Drinking 30 °C saline can increase the laterality index of the lower extremities. Stimulation at 4 °C and 10 °C resulted in a decrease in the DF of the EGG and an increased RMSSD of the RR interval. Although this laterality is mainly contributed to by frequency interval V, there was a weak negative correlation between the laterality index of frequency interval I or II and RMSSD.Conclusion: There was laterality of blood perfusion in the lower extremities after drinking saline at different temperatures.