scholarly journals The Effect of Silver Nanofibers on the Deformation Properties of Blood Vessels: Towards the Development of New Nanotechnologies to Prevent Rupture of Aneurysms

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Miguel Gonzalez ◽  
Daniel Rivera ◽  
Alam Marcelino ◽  
Gabriela Agront ◽  
Rafael Rodriguez ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Mechanical Stress ◽  
Blood Vessels ◽  
Human Body ◽  
Clinical Setting ◽  
Failure Strength ◽  
Clinical Tool ◽  
Deformation Properties ◽  
Clinically Significant

An aneurysm is the result of a widening or ballooning of a portion of a blood vessel. The rupture of an aneurysm occurs when the mechanical stress acting on the inner wall exceeds the failure strength of the blood vessel. We propose an innovative approach to prevent the rupture of an aneurysm based on the use of nanotechnology to improve the strength of the blood vessel. We present results on the effect of silver nanofibers on the resistance toward deformation of blood vessels. The silver nanofibers are grown on the surface of the blood vessels. The nanofibers are120±30 nm in diameter and2.7±0.8 μm in length. The deformation per applied force of blood vessels was found to decrease from 0.15 m/N in control blood vessels to 0.003 m/N in blood vessels treated with the nanofibers. This represents an increase in the resistance towards deformation of a factor of 50. The increase in the resistance towards deformation is clinically significant since blood pressure increases by factors slightly larger than one in the human body. Treatment of blood vessels with silver nanofibers is a potential translational clinical tool for preventing rupture of aneurysms in a clinical setting.

COMPARISON OF ANTIHYPERTENSIVE EFFECT OF MOXONIDINE VERSUS CLONIDINE IN RENAL FAILURE PATIENTS.

2018 ◽  
Vol 6 (9) ◽  
Author(s):  
DR.MATHEW GEORGE ◽  
DR.LINCY JOSEPH ◽  
MRS.DEEPTHI MATHEW ◽  
ALISHA MARIA SHAJI ◽  
BIJI JOSEPH ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Failure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Antihypertensive Effect ◽  
The Body ◽  
Ability To Work ◽  
Blood Flows

Blood pressure is the force of blood pushing against blood vessel walls as the heart pumps out blood, and high blood pressure, also called hypertension, is an increase in the amount of force that blood places on blood vessels as it moves through the body. Factors that can increase this force include higher blood volume due to extra fluid in the blood and blood vessels that are narrow, stiff, or clogged(1). High blood pressure can damage blood vessels in the kidneys, reducing their ability to work properly. When the force of blood flow is high, blood vessels stretch so blood flows more easily. Eventually, this stretching scars and weakens blood vessels throughout the body, including those in the kidneys.

Self-Cleansing Flexible Stent for Prevention of Clogging of Blood Vessels

2007 ◽  
Author(s):  
Solomon W. Leung ◽  
Arya Ebrahimpour ◽  
Marco P. Schoen ◽  
James C. K. Lai
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Mechanical Design ◽  
Physiological Model ◽  
Shear Stresses ◽  
Optimized Design ◽  
Tissue Fluid ◽  
The One ◽  
Pressure Changes

Different types of stents are available to be implanted into blood-vessels (e.g., cardiovascular stent) or organs to maintain unobstructed blood flow or flow of tissue fluid through ducts (e.g., biliary and uretic stents and others). On the one hand, it is imperative to use smart material such that its mechanical and elastic properties meet those of the ideal stent. A smart stent can change the orientation of the material(s) either by sensing control, temperature, or blood pressure, thus alter the overall shape of the stent (wiggling). These wiggling motions can prevent or reduce the deposit of cholesterol inside the stent’s lumen. On the other hand, there is a need for a better physiological model of how the tensile and shear stresses of a blood vessel are altered as the blood pressure changes along a defined length of that vessel and how the shape changes of the blood vessel could prevent the deposits of lipid material on the vessel wall thereby possibly decrease the likelihood of stenosis. However, the design of an ideal stent is complicated by the lack of proper materials and modeling studies, and difficulties to have an optimized design because of complexities of environmental factors. In this literature review, we therefore propose that an optimal stents design should incorporate the use of highly biocompatible material(s) of well characterized properties and with an adequately modeled mechanical design. We have discussed the importance and relevance of these issues for future stent design and fabrication.

scholarly journals INFLUENCE OF AGE AND GENDER ON THE STRENGTH OF BLOOD VESSELS

2016 ◽  
Vol 4 ◽  
pp. 719-726
Author(s):  
Zyta Kuzborska
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Flow Velocity ◽  
Blood Vessels ◽  
Blood Flow Velocity ◽  
Vessel Wall ◽  
Blood Vessel Wall ◽  
Critical Stresses ◽  
And Gender

This article examines the effects of cardiovascular diseases that alter the diameter, wall thickness, and length of blood vessels. Depending on form and size of the damage, blood flow velocity, blood pressure, and stresses are affected in areas of diseased blood vessels. Through stimulating the deviations in the geometric shape of a blood-vessel wall, local blood pressure and stresses can arise from flow variation of blood vessels. This rise affects the blood-vessel wall and causes critical stresses likely to produce fissures in the blood vessels. It was found, that blood vessel pathology could cause blood flow velocity to increase up to 2.2 times and local blood pressure up to 3.4 times, and that human aging may have a significant influence on blood-vessel strength.

scholarly journals Implementation of MEMS Capacitive Pressure Sensor Design using COMSOL Software

2019 ◽  
Vol 8 (2S8) ◽  
pp. 967-972 ◽  
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Real Time ◽  
Pressure Sensor ◽  
Vital Signs ◽  
Capacitive Pressure Sensor ◽  
Sensor Design

This paper is based on the research of emerging implantable medical instrumentations. An implantable Blood Pressure (BP) monitoring Microsystems is very essential to monitor patient’s BP continuously and gives warning when they are extreme and interim levels. The instrument should be accurately measure the both systolic and diastolic values. Based on the readings the BP is categorized in to four (Ideal BP: diastolic=120 and systolic=80, low BP 90 and 60, Pre-hyper values are 140 and 90 and hyper tension values are 190 and 100). BP consists one of the principle vital signs referring to the force entered by circulating blood on the walls of blood vessels. The system consists of instrumented elastic cuff, wrapped around a blood vessel, to sense real time blood pressure. In this paper, a MEMS based capacitor pressure sensor is to be designed with less than the dimensions of 0.4x0.5x0.4mm 3 , and with the approximate capacitance of less than 2pF and 1fF per mmHg.

scholarly journals A Comparative Study on “Mai” and “Blood Vessels” in Early Chinese and Western Medicine: Based on Hippocratic Corpus and Cauterization Canon of the Eleven Vessels of the Foot and Forearm

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Chang Huang ◽  
Jiankang Liang ◽  
Qicheng Zhang ◽  
Tao Lu
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Human Body ◽  
Western Medicine ◽  
Medical Literature ◽  
Cultural Backgrounds ◽  
Internal Organs ◽  
Hippocratic Corpus ◽  
Time Period ◽  
The Ancient Chinese

This study compared the theory describing the “four pairs of blood vessels” in the Hippocratic Corpus with the description of vessels (Mai, 脉) in the Cauterization Canon of the Eleven Vessels of the Foot and Forearm. The two theories are comparable because of the time period in which they were written, the similarities between the descriptions of the Mai and blood vessels, and the treatment methods for symptoms corresponding to their dysfunctions. We discovered that the Mai theory and the blood vessel theory in the Hippocratic Corpus were conceived with similar motivations. They had a lot of coinciding information with regard to the route of flow, but they proposed opposite cyclic directions. Interestingly, neither of them had established that a definitive relationship exists between the vessels and the heart, but other internal organs, such as the liver, were considered to have connections with the Mai and blood vessels in the two literatures. Furthermore, there were similarities among the descriptions of symptoms, and the ancient Western treatments for these symptoms were largely the same as those recorded in the ancient Chinese medical literature, especially the treatment for backache. The comparisons put forward in this study not only reflect the consistencies between the understanding of the human body and the way diseases were treated in Chinese and Western medicine in the early days, but also demonstrate that the two types of medicine had finally embarked on different developmental paths because of the differences in the philosophies and cultural backgrounds in their respective regions.

Living Well to Keep Your Pressure Down

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Linda B. Bobroff
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Health Problems ◽  
Fact Sheet ◽  
Living Well ◽  
Heart Work ◽  
Major Revision ◽  
Reduce Risk

High blood pressure, or hypertension, can cause serious health problems. It makes your heart work harder and can damage your blood vessels even if you feel okay. Everyone should have their blood pressure checked regularly. If you have certain risk factors, you are more likely to have high blood pressure. This 6-page fact sheet is a major revision that discusses risk factors and ways to reduce risk.

Microfluidics of blood in blood vessels stenosis

2016 ◽  
Vol 11 (2) ◽  
pp. 210-217 ◽  
Author(s):  
A.T. Akhmetov ◽  
A.A. Valiev ◽  
A.A. Rakhimov ◽  
S.P. Sametov ◽  
R.R. Habibullina
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Hydraulic Resistance ◽  
Microfluidic Device ◽  
Human Body ◽  
Vascular System ◽  
Hydrodynamic Conditions ◽  
Microstructure Change ◽  
Healthy Part

It is mentioned in the paper that hydrodynamic conditions of a flow in blood vessels with the stenosis are abnormal in relation to the total hemodynamic conditions of blood flow in a vascular system of a human body. A microfluidic device developed with a stepped narrowing for studying of the blood flow at abnormal conditions allowed to reveal blood structure in microchannels simulating the stenosis. Microstructure change is observed during the flow of both native and diluted blood through the narrowing. The study of hemorheological properties allowed us to determine an increasing contribution of the hydraulic resistance of the healthy part of the vessel during the stenosis formation.

scholarly journals Physiological and Psychological Effects of Watching Videos of Different Durations Showing Urban Bamboo Forests with Varied Structures

2020 ◽  
Vol 17 (10) ◽  
pp. 3434
Author(s):  
Yuqian Wang ◽  
Mingyan Jiang ◽  
Yinshu Huang ◽  
Zhiyi Sheng ◽  
Xiao Huang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Skin Conductance ◽  
Human Body ◽  
Stable State ◽  
Mean Value ◽  
Psychological Effects ◽  
Physiological Indicators ◽  
Psychological Indicators ◽  
Before And After ◽  
Long Time

This study illustrated the physiological and psychological effects of watching videos of different durations showing bamboo forests with varied structures. Physiological indicators, including EEG (electroencephalogram), blood pressure, skin conductance, and pulse, were monitored in 180 Chinese university students (mean age: 20.72 ± 2.56 years) while they were watching bamboo videos. Before and after watching the videos, their psychological indicators, including positive and negative moods, were measured using the Profile of Mood States questionnaire. After watching the bamboo videos of different durations, all of the physiological indicators responded to the stimulation after only 1 min. The indicators showed different trends at 1, 3 and 5 min. EEG decreased and then was maintained at a stable level after 1 min, and the high β, low β, and α waves had no significant differences between 1, 3 and 5 min. Blood pressure dropped to a stable state after 3 min, and the decline was significantly different greater after 3 min than after 1 min. Skin conductance increased for 1 to 5 min, and it did not stabilize after a long time (5 min). Pulse decreased after 1 min but increased after 5 min. After watching the videos with bamboo of varying structures, the physiological and psychological indicators showed significantly different changes. Skin conductance significantly increased (mean value: 6.78%), and the amount of sweat was more effectively reduced, thereby reducing tension, when the students viewed videos of sympodial bamboo forests compared with monopodial bamboo forests. Bamboo forests with a higher canopy density (0.83–0.85) could significantly decrease α waves (mean value: 1.50 Hz), relaxing the human body. High β and low β waves showed greater decreases, with tension reduced more effectively, when bamboo forests with a low tilt ratio (< 1.5%) were viewed. Bamboo forests with neat undergrowth could have more beneficial physiological and psychological effects on the human body.

scholarly journals Retinal Vessel Segmentation by Deep Residual Learning with Wide Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yuliang Ma ◽  
Xue Li ◽  
Xiaopeng Duan ◽  
Yun Peng ◽  
Yingchun Zhang
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Area Under The Curve ◽  
Retinal Vessel ◽  
Vessel Segmentation ◽  
Superior Performance ◽  
Retinal Blood Vessel ◽  
Low Contrast ◽  
Blood Vessel Segmentation ◽  
Small Vessels

Purpose. Retinal blood vessel image segmentation is an important step in ophthalmological analysis. However, it is difficult to segment small vessels accurately because of low contrast and complex feature information of blood vessels. The objective of this study is to develop an improved retinal blood vessel segmentation structure (WA-Net) to overcome these challenges. Methods. This paper mainly focuses on the width of deep learning. The channels of the ResNet block were broadened to propagate more low-level features, and the identity mapping pathway was slimmed to maintain parameter complexity. A residual atrous spatial pyramid module was used to capture the retinal vessels at various scales. We applied weight normalization to eliminate the impacts of the mini-batch and improve segmentation accuracy. The experiments were performed on the DRIVE and STARE datasets. To show the generalizability of WA-Net, we performed cross-training between datasets. Results. The global accuracy and specificity within datasets were 95.66% and 96.45% and 98.13% and 98.71%, respectively. The accuracy and area under the curve of the interdataset diverged only by 1%∼2% compared with the performance of the corresponding intradataset. Conclusion. All the results show that WA-Net extracts more detailed blood vessels and shows superior performance on retinal blood vessel segmentation tasks.

Sign in / Sign up

Export Citation Format

Share Document