• Title/Summary/Keyword: Arterial

Search Result 2,642, Processing Time 0.032 seconds

A Study on the Optimum Design of the Arterial-Based Signal System for the Relief of Transportation Problems in Metropolitan Areas (대도시 교통문제 완화를 위한 간선도로별 신호체계의 최적설계에 관한 연구)

  • Kim, T.G.
    • Journal of Korean Port Research
    • /
    • v.8 no.2
    • /
    • pp.1-35
    • /
    • 1994
  • The main arterial which runs through the in City of Pusan, carries about 60% of downtown traffic or more, maintains about 20% yearly increase in traffic is severely suffering from the traffic congestion because of concentrated traffic volumes regardless of peak-time periods. The purpose of this study was to grasp the traffic, geometric, and signal conditions of the main arterial through the Videologging System Techniques, perform the transportation system analyses, and finally suggest the improvements which could increase the travel capacity, reduce the average delay and fuel consumption with the optimal conditions of signal system. The following conclusions were drawn : firstly the traffic system should be shifted for the travel distribution on the arterial during the peak time periods, secondly the roadway system of the arterial reviewed for left-turn traffic during the peak time periods, and thirdly the signal system of intersection reconstructed for signal optimization or progression within the range of cycle length suggested.

  • PDF

The Effects of Cortex Phellodendri on Prostatic Urethral Pressure and Mean Arterial Blood Pressure in an Experimental Rabbit Model (황백(黃柏)이 토끼의 전립선요도압 및 혈압에 미치는 영향)

  • Kim, Eun-ji;Han, Yang-hee
    • The Journal of Internal Korean Medicine
    • /
    • v.38 no.2
    • /
    • pp.110-117
    • /
    • 2017
  • Objective: This study was undertaken to examine the effect of Cortex Phellodendri on prostatic urethral pressure and mean arterial blood pressure of rabbits. Methods: To measure prostatic urethral pressure and mean arterial blood pressure, a Mikro-Tip catheter transducer was inserted and positioned in the prostatic urethra and left carotid artery. After a stabilizing period, phenylephrine ($1{\mu}/kg$) was intravenously administered two or three times to increase the urethral pressure and mean arterial blood pressure. Cortex Phellodendri (2.5 mg/kg and 5 mg/kg doses of Cortex Phellodendri extracted from 80% Ethanol) was administered intravenously, followed by phenylephrine, with no time interval between the doses. The urethral pressure and mean arterial blood pressure were then measured to determine whether they had stabilized. Results and Conclusion: Cortex Phellodendri appeared to inhibit phenylephrine-induced increases in prostatic urethral pressure and mean arterial blood pressure.

A Study on Arterial Characterization using Finger-Toe Index (FTI) (지첨-족지 지수에 의한 동맥 혈관 특성화 연구)

  • Byeon, M.K.;Han, S.W.;Huh, W.
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.6
    • /
    • pp.777-785
    • /
    • 2007
  • In this paper, Finger-Toe Index (FTI) is proposed as an analytic parameter for the characterization of arterial vessel. Different from the currently being employed pulse wave velocity (PWV) information of the volume pulse wave measured from 4 arterial channels, the proposed FTI uses the ratio of the shorter of the two up-stroke time of PPG from fingers ($UT_{finger}$) and that of PPG (Photoplethysmography) from toes ($UT_{toe}$). To verify the usefulness of the proposed method, Finger-Toe Indexes were derived from the volume pulse waves acquired from 50 people under examination aged from 12 to 81 years old, and they were then compared with blood pressure ankle-brachial index (ABI). It was successfully demonstrated that the arterial stiffness can be estimated with respect to age and FTI is more strongly correlated with the pulse transit time than ABI. From the regression analysis, we also found that FTI has significant correlation PWV for a quantitative index of arterial stiffness and provides more accurate information than ABI for the characterization of arterial vessel.

Cerebral Hemodynamics in Premature Infants

  • Rhee, Christopher J.;Rios, Danielle R.;Kaiser, Jeffrey R.;Brady, Ken
    • Neonatal Medicine
    • /
    • v.25 no.1
    • /
    • pp.1-6
    • /
    • 2018
  • Extremely low birth weight infants remain at increased risk of intraventricular hemorrhage from the fragile vascular bed of the germinal matrix; the roles of hypotension (ischemia) and reperfusion (hyperemia) in the development of intraventricular hemorrhage are still debated. Cerebrovascular pressure autoregulation protects the brain by maintaining constant cerebral blood flow despite changes in blood pressure. The ontogeny of cerebrovascular pressure autoregulation has not been well established and uncertainty remains about the optimal arterial blood pressure required to support brain perfusion. Another important aspect of premature cerebral hemodynamics is the critical closing pressure--the arterial blood pressure at which cerebral blood flow ceases. Interestingly, in premature infants, the critical closing pressure approximates the mean arterial blood pressure. Often in this unique population, cerebral blood flow occurs only during systole when the diastolic arterial blood pressure is equal to the critical closing pressure. Moreover, the diastolic closing margin, a metric of cerebral perfusion that normalizes diastolic arterial blood pressure to the critical closing pressure, may be a better measure than arterial blood pressure for defining cerebral perfusion in premature infants. Elevated diastolic closing margin has been associated with intraventricular hemorrhage. This review summarizes the current state of understanding of cerebral hemodynamics in premature infants.

Vascular health late after Kawasaki disease: implications for accelerated atherosclerosis

  • Cheung, Yiu-Fai
    • Clinical and Experimental Pediatrics
    • /
    • v.57 no.11
    • /
    • pp.472-478
    • /
    • 2014
  • Kawasaki disease (KD), an acute vasculitis that primarily affects young children, is the most common acquired paediatric cardiovascular disease in developed countries. While sequelae of arterial inflammation in the acute phase of KD are well documented, its late effects on vascular health are increasingly unveiled. Late vascular dysfunction is characterized by structural alterations and functional impairment in term of arterial stiffening and endothelial dysfunction and shown to involve both coronary and systemic arteries. Further evidence suggests that continuous low grade inflammation and ongoing active remodeling of coronary arterial lesions occur late after acute illness and may play a role in structural and functional alterations of the arteries. Potential importance of genetic modulation on vascular health late after KD is implicated by associations between mannose binding lectin and inflammatory gene polymorphisms with severity of peripheral arterial stiffening and carotid intima-media thickening. The changes in cholesterol and lipoproteins levels late after KD further appear similar to those proposed to be atherogenic. While data on adverse vascular health are less controversial in patients with persistent or regressed coronary arterial aneurysms, data appear conflicting in individuals with no coronary arterial involvements or only transient coronary ectasia. Notwithstanding, concerns have been raised with regard to predisposition of KD in childhood to accelerated atherosclerosis in adulthood. Until further evidence-based data are available, however, it remains important to assess and monitor cardiovascular risk factors and to promote cardiovascular health in children with a history of KD in the long term.

The Correlation of Pulse Wave Velocity and Atherosclerotic Risk Factor in Stroke Patients

  • Jin, Bok Hee;Han, Min Ho
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.47 no.1
    • /
    • pp.28-34
    • /
    • 2015
  • Pulse wave velocity (PWV) is used to non-invasively estimate the severity of arteriosclerosis by measuring arterial stiffness. Increased arterial stiffness measured by PWV stands for progressive arteriosclerosis and is caused by atherosclerotic risk factors. This study is focused on how brachial-ankle pulse wave velocity (baPWV) is related to the leading risk factors for arteriosclerosis or atherosclerosis. Subjects were 114, 69 males and 45 females who are in 60's and had baPWV test for acute stroke. The results are as follows: the group with increased arterial stiffness showed significant increase in HbA1c, total cholesterol, BSBP (brachial artery systolic blood pressure), BDBP (brachial artery diastolic blood pressure), CSBP (central artery systolic blood pressure), CDBP (central artery diastolic blood pressure), augmentation index (AIx) and diabetes mellitus. Correlation analysis between baPWV and atherosclerotic risk factor showed significant relationship in age, HbA1c, LDL cholesterol, BSBP, BDBP, CSBP, CDBP and augmentation index. baPWV was independently related to age and BSBP in multiple linear regression analysis. The group with increased arterial stiffness was independently related to BDBP in multiple logistic regression analysis. This study might be meaningful in evaluating the relationship between arterial stiffness and atherosclerotic risk factor in a new way, and be helped to make various studies for cardiovascular disease.

Blood Pressure Simulation using an Arterial Pressure-volume Model

  • Yoon, Sang-Hwa;Kim, Jae-Hyung;Ye, Soo-Young;Kim, Cheol-Han;Jeon, Gye-Rok
    • Transactions on Electrical and Electronic Materials
    • /
    • v.9 no.1
    • /
    • pp.38-43
    • /
    • 2008
  • Using an arterial pressure-volume (APV) model, we performed an analysis of the conventional blood pressure estimation method using an oscillometric sphygmomanometer with computer simulation. Traditionally, the maximum amplitude algorithm (MAA) has been applied to the oscillation waveforms of the APV model to obtain the mean arterial pressure and the characteristic ratio. The estimation of mean arterial pressure and characteristic ratio was significantly affected by the shape of the blood pressure waveforms and the cutoff frequency of high-pass filter (HPF) circuitry. Experimental errors result from these effects when estimating blood pressure. To determine an algorithm independent of the influence of waveform shapes and parameters of HPF, the volume oscillation of the APV model and the phase shift of the oscillation with fast Fourier transform (FFT) were tested while increasing the cuff pressure from 1 mmHg to 200 mmHg (1 mmHg/s). The phase shift between ranges of volume oscillation was then only observed between the systolic and the diastolic blood pressures. The same results were obtained from simulations performed on two different arterial blood pressure waveforms and one hyperthermia waveform.

A review on development trends of arterial pulse simulators (맥파 재현장치 개발 동향)

  • Min, Sang-Won;Ko, Bok-Yung;Chang, Jae-Soon;Kim, Ki-Wang
    • The Journal of the Society of Korean Medicine Diagnostics
    • /
    • v.16 no.2
    • /
    • pp.1-10
    • /
    • 2012
  • Objectives : Recently, for over ten years, various arterial pulse simulators have been developed for training of pulse palpation technique. In this paper, we summarized development trends of those apparatuses. Materials and methods : To search the cases of development, we mainly used China Knowledge Infrastructure (CNKI), National Discovery for Science Leaders (NDSL), Korean Traditional Knowledge Portal, Patent Search by Baidu (百度專利搜索), and some general search engines. Some domain cases introduced were collected based on personal experience. Results : It was found that there were two types of arterial pulse simulators. The first type uses fluids and pumps, while the second type uses actuators without fluid circulation parts. Conclusion : From year 2000, various arterial pulse simulators have been developed. In general, they could be classified two types. Further effort toward Maixiang (脈象) simulation and validation in field is needed.

Study on Reorganization of the Functional Hierarchy of Arterial Road in CBD : Seomyeon Area in Pusan Metropolitan City (도심부 도로 기능별 위계 재편에 관한 연구 : 부산광역시 서면 도심을 중심으로)

  • Roh, You-Jin;Ko, sang-sun;Bae, sang-hoon
    • International Journal of Highway Engineering
    • /
    • v.19 no.6
    • /
    • pp.155-164
    • /
    • 2017
  • PURPOSES : Owing to the growth of income and socio-economic levels, demands from road users have diversified. Accordingly, new road policies are being actively sought. The metropolitan city government of Busan has been focused on constructing and expanding roads to accommodate the increasing traffic demand. Given the increase in functional characteristics, we need to re-evaluate the hierarchy and function of roads, and specifically remodel the road planning and operations that fit into their functions. METHODS : First, this study focuses on introducing the minimum condition required to redefine the hierarchy of the roads. Second, the authors propose a new model that identifies the impact level of road hierarchy adopting discriminated analysis technique. RESULTS : Authors suggest that we redefine the hierarchy of roads in the central business distinct in Busan, and specifically the arterial roads in Busan, namely, Joonang-daero and Gaya-ro. These roads need to be reequipped with cross walks, a lower speed limit, and exclusive bus lanes to improve their accessibility. CONCLUSIONS : The authors found that the sub-arterial and collector roads have been subjected to excessive loads, owing to inappropriate functions being assigned to the main arterial road. Moreover, given that through traffic is concentrated on the sub-arterial and collector roads, over-speeding and other safety issues are consequently created.

Comparison of Clinical Laboratory Data and Prevalence according to Arterial Stiffness in Stroke Patients

  • Jin, Bok Hee;Han, Min Ho
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.46 no.4
    • /
    • pp.143-149
    • /
    • 2014
  • Pulse wave velocity (PWV) is used to non-invasively estimate the severity of arteriosclerosis by measuring the patient's arterial stiffness comparing with each normal reference range according to their ages. Increased arterial stiffness is closely related to both atherosclerosis and arteriosclerosis, which have been known for causes of cardiovascular disease and stroke, also negatively affects the prognosis and the re-occurrence in patients with stroke. The study is focused on how brachial-ankle pulse wave velocity (baPWV) is related to cardiovascular disease risk factors in patients with acute stroke. There were 114 subjects, 69 males and 45 females, all in their 60's and had PWV test for acute stroke. The results are as follows: the group with increased arterial stiffness showed significant increase in HbAlc, total cholesterol, RSBP (resting systolic blood pressure), CSBP (central systolic blood pressure) and CDBP (central diastolic blood pressure). Cross tabulation test showed that there was a significant relationship only between the group with increased arterial stiffness and diabetes mellitus (DM). Therefore, it might be useful for preventing re-occurrence and making a favorable prognosis to promptly adjust DM and hypertension-related risk factors in patients with acute stroke.