scholarly journals Multi-Channel Bioimpedance System for Detecting Vascular Tone in Human Limbs: An Approach

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 138
Author(s):  
Ahmad Hammoud ◽  
Alexey Tikhomirov ◽  
Galina Myasishcheva ◽  
Zein Shaheen ◽  
Alexander Volkov ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Vascular Tone ◽  
Cardiac Cycle ◽  
Coronary Circulation ◽  
Vital Role ◽  
Graphical Interface ◽  
Peripheral Vascular ◽  
Future Studies ◽  
Perivascular Nerves

Vascular tone plays a vital role in regulating blood pressure and coronary circulation, and it determines the peripheral vascular resistance. Vascular tone is dually regulated by the perivascular nerves and the cells in the inside lining of blood vessels (endothelial cells). Only a few methods for measuring vascular tone are available. Because of this, determining vascular tone in different arteries of the human body and monitoring tone changes is a vital challenge. This work presents an approach for determining vascular tone in human extremities based on multi-channel bioimpedance measurements. Detailed steps for processing the bioimpedance signals and extracting the main parameters from them have been presented. A graphical interface has been designed and implemented to display the vascular tone type in all channels with the phase of breathing during each cardiac cycle. This study is a key step towards understanding the way vascular tone changes in the extremities and how the nervous system regulates these changes. Future studies based on records of healthy and diseased people will contribute to increasing the possibility of early diagnosis of cardiovascular diseases.

scholarly journals Vascular resistance arm of the baroreflex: methodology and comparison with the cardiac chronotropic arm

2020 ◽  
Vol 128 (5) ◽  
pp. 1310-1320
Author(s):  
J. Krohova ◽  
L. Faes ◽  
B. Czippelova ◽  
R. Pernice ◽  
Z. Turianikova ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular Resistance ◽  
Vascular Tone ◽  
Heart Rate Response ◽  
Peripheral Vascular Resistance ◽  
Noninvasive Measurement ◽  
Peripheral Vascular ◽  
Pressure Changes

Baroreflex response consists of several arms, but the cardiac chronotropic arm (blood pressure changes evoking heart rate response) is usually analyzed. This study introduces a method to assess the vascular baroreflex arm with the continuous noninvasive measurement of peripheral vascular resistance as an output considering causality in the interaction between oscillations and slower dynamics of vascular tone changes. We conclude that although vascular baroreflex arm involvement becomes dominant during orthostasis, gain of this interaction is relatively stable.

Reflex control of vasopressin during hemorrhage in hypertensive rabbits

1995 ◽  
Vol 269 (5) ◽  
pp. H1570-H1577
Author(s):  
C. A. Courneya ◽  
G. Weichert
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Arterial Pressure ◽  
Vascular Tone ◽  
Cardiac Denervation ◽  
Baroreceptor Function ◽  
Arterial Baroreceptors ◽  
Reflex Control

Hypertensive (HT) rabbits have impaired reflex control of heart rate and vascular tone, which is, at least in part, related to dysfunctional baroreceptors. We hypothesized that reflex control of vasopressin (AVP) would also be impaired in the HT rabbit. To test this, we compared hemorrhage-induced increases in AVP between conscious normotensive (NT) and HT rabbits. The hemorrhage-induced rise in AVP was found to be significantly (P < 0.05) attenuated in the HT rabbits. We tested a second hypothesis, that the observed impairment was related to arterial baroreceptor function, by hemorrhaging the same rabbits after reversible cardiac denervation. Under these conditions, only the arterial baroreceptors would be expected to contribute to reflex control of AVP. Impairment was still evident after cardiac denervation; that is, the hemorrhage-induced rise in AVP was significantly (P < 0.01) attenuated in the cardiac-denervated HT rabbits compared with NT rabbits. Thus impairment was, at least in part, related to arterial baroreceptors. Previously, we showed in NT rabbits that AVP only contributed to maintenance of arterial pressure (during hemorrhage), after the autonomic nervous system (ANS) had been blocked. Thus, in the present study, we compared the maintenance of arterial pressure during hemorrhage between NT and HT rabbits after ANS blockade. Blood pressure maintenance was significantly attenuated in the HT rabbits (P < 0.05). In addition, for a given fall in pressure, significantly less AVP (P < 0.05) was released in the ANS-blocked HT rabbits as compared with NT rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Systemic Rho‐kinase Inhibition Reduces Blood Pressure and Influences Peripheral Vascular Tone in Healthy Older Adults

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Nate P. Bachman ◽  
Janée D. Terwoord ◽  
Mathew L. Racine ◽  
Nathaniel B. Ketelhut ◽  
Jennifer C. Richards ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Older Adults ◽  
Vascular Tone ◽  
Rho Kinase ◽  
Peripheral Vascular ◽  
Kinase Inhibition ◽  
Healthy Older Adults ◽  
Peripheral Vascular Tone

Modulation of Sympathetic Vascular Tone by Prostaglandins in Corticosterone-Induced Hypertension in Rats

1979 ◽  
Vol 57 (s5) ◽  
pp. 235s-237s ◽  
Author(s):  
W. Rascher ◽  
R. Dietz ◽  
A. Schömig ◽  
G. Burkart ◽  
J. B. Lüth ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Vascular Tone ◽  
Plasma Concentrations ◽  
Prostaglandin I2 ◽  
Induced Hypertension ◽  
Sympathetic Nervous ◽  
Peripheral Sympathetic Nervous System ◽  
Supersensitivity To Noradrenaline ◽  
Normotensive Control

1. In corticosterone-induced hypertension in rats the activity of the peripheral sympathetic nervous system and its modulation by prostaglandins was studied. 2. Plasma concentrations of noradrenaline were reduced if compared with those in normotensive control rats. 3. The sensitivity of the isolated perfused hindlimb preparation to noradrenaline was enhanced before blood pressure rose and increased further with the development of hypertension. 4. Arachidonic acid, prostacyclin (prostaglandin I2), but not 6-keto-prostaglandin F1α, reversed the supersensitivity to noradrenaline. 5. These results suggest that corticosterone induces a supersensitivity to noradrenaline by inhibiting the biosynthesis of prostaglandins. Changes in the sensitivity of the vascular smooth muscle may play a role in the development of glucocorticoid hypertension.

Implications of Prostacyclin Generation for Modulation of Vascular Tone

1978 ◽  
Vol 55 (s4) ◽  
pp. 195s-198s ◽  
Author(s):  
G. J. Dusting ◽  
S. Moncada ◽  
K. M. Mullane ◽  
J. R. Vane
Keyword(s):  
Blood Pressure ◽  
Prostaglandin E2 ◽  
Vascular Tone ◽  
Thromboxane A2 ◽  
Cardiovascular Effects ◽  
Peripheral Vascular ◽  
Arterial Blood ◽  
Vascular Beds ◽  
Organ Technique

1. The biotransformation of arachidonic acid and prostacyclin in the circulation was studied in anaesthetized dogs, using the blood-bathed organ technique. 2. In passage through the lungs, arachidonate (50–800 μg kg−1 min−1) was transformed into prostacyclin. No thromboxane A2 or prostaglandin E2 could be detected in arterial blood. 3. In dogs treated with indomethacin (5 mg/kg), intravenous infusions of arachidonate had no cardiovascular effects and no prostacyclin was produced. Therefore, the vasodilator effects of arachidonate in vivo may be attributable to prostacyclin formation. 4. Prostacyclin, unlike prostaglandin E2, is not inactivated by passage across the lungs, and only about 50% disappears in one passage through peripheral vascular beds. 5. Thus prostacyclin released from the lungs could function as a circulating vasodilator and contribute to the regulation of blood vessel tone and blood pressure.

Risk assessment of occupational and occupationally conditioned diseases connection to noise when exceeding maximum permissible levels

2019 ◽  
pp. 17-19
Author(s):  
Vladimir A. Fokin ◽  
Dmitrii M. Shlyapnikov ◽  
Svetlana V. Red’ko
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
High Blood Pressure ◽  
Noise Exposure ◽  
Physical Factors ◽  
Autonomic Nervous ◽  
Permissible Levels ◽  
The Relationship ◽  
Perm Region

In accordance with the requirements of paragraph 3.2.6 of sanitary rules and norms «Sanitary and epidemiological requirements for physical factors at workplace», in the event of exceeding noise level at workplace above 80 dBA, an employer is obliged to assess the health risk of workers and confirm an acceptable risk to their health. The connection between the incidence of occupational and occupationally conditioned diseases with noise exposure exceeding the maximum permissible levels (80 dBA) was estimated. The assessment was carried out at a food industry enterprise of Perm Region. Assessing the relationship between morbidity and noise exposure is the first step in evaluation of occupational health risks for workers exposed to noise exceeding MAL. If a reliable relationship between morbidity and noise exposure is established, an assessment of occupational risk is conducted. The odds ratio (OR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1 (confidence interval CI=0.11–1.61 and CI=0.08–2.78, respectively). The relative risk (RR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1. The received data testify absence of connection of morbidity with exposure to industrial noise, calculation of etiological share of responses and levels of risk is not required.

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