Simulation of the Blood Pressure Estimation Using the Artery Compliance Model and Pulsation Waveform Model

Ah Young Jeon,Jung Hoon Ro,Jae Hyung Kim,Seong Wan Baik,Gyer Ok Jeon 한국센서학회 2013 센서학회지 Vol.22 No.1

In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

Pressure Pulsation Characteristics of a Model Pump-turbine Operating in the S-shaped Region: CFD Simulations

Xia, Linsheng,Cheng, Yongguang,Cai, Fang Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.3

The most detrimental pressure pulsations in high-head pump-turbines is caused by the rotor-stator interaction (RSI) between the guide vanes and runner blades. When the pump-turbine operates in the S-shaped region of the characteristic curves, the deteriorative flow structures may significantly strengthen RSI, causing larger pressure pulsations and stronger vibration with an increased risk of mechanical failure. CFD simulations were carried out to analyze the impacts of flow evolution on the pressure pulsations in the S-shaped region of a model pump-turbine. The results show that the reverse flow vortex structures (RFVS) at the runner inlet have regular development and transition patterns when discharge reduces from the best efficiency point (BEP). The RFVS first occur at the hub side, and then shift to the mid-span near the no-load point, which cause the strongest pressure pulsations. The locally distributed RFVS at hub side enhance the local RSI and makes the pressure fluctuations at the corresponding sections stronger than those at the rest sections along the spanwise direction. Under the condition of RFVS at the mid-span, the smaller flow rate make the smaller difference of pressure pulsation amplitudes in the spanwise direction. Moreover, the rotating stall, rotating at 35.7%-62.5% of the runner rotational frequency, make the low frequency components of pressure pulsations distribute unevenly along the circumference in the vaneless space. However, it have little influence on the distributions of high components.

Pressure Pulsation Characteristics of a Model Pump-turbine Operating in the S-shaped Region

Linsheng Xia,Yongguang Cheng,Fang Cai 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.3

The most detrimental pressure pulsations in high-head pump-turbines is caused by the rotor-stator interaction (RSI) between the guide vanes and runner blades. When the pump-turbine operates in the S-shaped region of the characteristic curves, the deteriorative flow structures may significantly strengthen RSI, causing larger pressure pulsations and stronger vibration with an increased risk of mechanical failure. CFD simulations were carried out to analyze the impacts of flow evolution on the pressure pulsations in the S-shaped region of a model pump-turbine. The results show that the reverse flow vortex structures (RFVS) at the runner inlet have regular development and transition patterns when discharge reduces from the best efficiency point (BEP). The RFVS first occur at the hub side, and then shift to the midspan near the no-load point, which cause the strongest pressure pulsations. The locally distributed RFVS at hub side enhance the local RSI and makes the pressure fluctuations at the corresponding sections stronger than those at the rest sections along the spanwise direction. Under the condition of RFVS at the mid-span, the smaller flow rate make the smaller difference of pressure pulsation amplitudes in the spanwise direction. Moreover, the rotating stall, rotating at 35.7%-62.5% of the runner rotational frequency, make the low frequency components of pressure pulsations distribute unevenly along the circumference in the vaneless space. However, it have little influence on the distributions of high components.

The pulsating pressure in the intake and exhaust manifold of a single cylinder engine by the various of engine revolutions

Chung, Han-Shik,Choi, Seuk-Cheun,Jong, Hyo-Min,Lee, Chi-Woo,Kim, Chi-Won The Korean Society of Marine Engineering 2004 한국마린엔지니어링학회지 Vol.28 No.1

In this research, a computer analysis has been developed for predicting the Pipe pressure of the intake and exhaust manifold in a small single cylinder engine. To get the boundary conditions for a numerical analysis one dimensional and unsteady gas dynamic calculation is performed by using the MOC(Method Of Characteristics). The main numerical parameters are engine revolutions. to calculate the Pulsating flow which the intake and exhaust valves are working. The distributions of the exhaust pipe pressures were influenced strongly to the cylinder pressures and the shapes of exhaust pressure variation were similar to the Inside of cylinder pressure As the engine revolutions are increased. the intake pressure was lower than ambient pressure. The amplitude of exhaust pressure had increased and the phase of cylinder pressure $P_c$ is delayed and the amplitude of cylinder pressure were increased.

Design of Port Plate in Gerotor Pump for Reduction of Pressure Pulsation

Sang-Yeol Kim,Yun-Joo Nam,Myeong-Kwan Park 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.10

The pressure pulsation due to the gear geometry of the gerotor (generalized rotor) pump mainly occurs in an instant that the chamber of the gerotor enters the delivery port and leaves the suction one. Such a pressure pulsation may result in undesirable vibration and noise of pump components as well as cavitation in hydraulic system. Therefore, it is very important to examine the pressure characteristic of the gerotor pump at its design and analysis stages. In this paper, in order to reduce the pressure pulsation in the gerotor pump, the port plate with the relief grooves is designed by referring to as notch of vane pump and relief groove of piston pump. A series of the theoretical analyses on the pressure pulsation is performed in consideration of various design parameters of the port plate, including the installation positions of the port inlet/outlet and the groove width, and the operating conditions such as rotational velocity and delivery pressure.

The Numerical Anylysis for Pressure Prediction in Intake and Exhaust Manifold of a Single Cylinder Engine

( Hyo Min Jeong ),( Han Shik Chung ),( Jong Soo Seo ),( Moung Gook Ji ),( Yong Hun Lee ),( Seuk Cheun Choi ) 경상대학교 해양산업연구소 2003 해양산업연구소보 Vol.16 No.-

ANALYTICAL STUDY OF PRESSURE PULSATION CHARACTERISTICS ACCORDING TO THE GEOMETRIES OF THE FUEL RAIL OF AN MPI ENGINE

H. S. HEO,S. J. BAE,H. K. LEE,K. S. PARK 한국자동차공학회 2012 International journal of automotive technology Vol.13 No.2

In a conventional MPI engine, a pulsation damper is usually mounted on the fuel rail to diminish undesirable noise in the vehicle cabin room; however, pulsation dampers are quite expensive. Therefore, several studies have focused on reducing fuel pressure pulsation by increasing the self-damping characteristics of the fuel rail. This paper details the development of a fuel rail that reduces pulsation using a self-damping effect. Using an oil hammer simulation technique, pressure pulsation characteristics were investigated with respect to the aspect ratio of the cross-section, wall thickness, and fuel rail material. Increasing the aspect ratio and decreasing the wall thickness efficiently reduced the pressure pulsation. In addition, the pressure pulsation characteristics were investigated with respect to the resonant engine speed and injection period. These simulated data can be used to reduce the pressure pulsation peak and to avoid the resonant point in the design stage during the development of a fuel rail.

Numerical Analysis on Various Model of Pressure Snubber in the Hydrogen Gas Compressing System

Hyo Min Jeong,Han Shik Chung,Wanda Ali Akbar,Gyeong Hwan Lee,Kyu Jin Shim,Yong Hun Lee 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.4

This paper explains about numerical modeling of gas flow passing through a snubber, pulsation damper, in a hydro-gen gas compressor system. The verification of the preliminary model was done successfully by comparing it with experimental results. Numerical analysis for various snubber dimensions is the focus of this present study. Thirty mod-els of snubber were created by varying snuber height and buffer angle, and then simulated with the real working con-dition of a hydrogen gas compressing system. The CFD code k-ε/ high Reynolds number as the turbulence model. The study was done by comparing pressure loss and pressure pulsation, since these two parameters are the objective functions in snubber optimization. The best snubber is the one that has the minimum pressure loss and pressure pulsation. Numerical result shows that the pressure loss grows with the increment of snubber volume. To the contrary, however, the pressure pulsation is decreased. Determining the buffer angle as the adjusted variable, the minimum presure loss occurred at 30o

흡기관 분사 방식 연료 레일의 압력 맥동 저감을 위한 연료 레일 형상 최적화

이상철(Sangcheol Lee),정재엽(Jaeyoup Jung),김홍기(Honggi Kim) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

Fuel Line Hammer is defined as the audible noise heard in the vehicle passenger compartment resulting from fuel pressure pulsations in the fuel subsystem. The pressure pulsations are a result of injector-firing events and fuel line dynamics. The pressure pulsations consist of a multiple frequencies. Low frequency pulsations are the result of injector firing. High frequency pulsations are a result of line dynamics. Line dynamics are impacted by line diameter, length and stiffness of the fuel system components. Since the fuel feed line diameter and length are typically set by vehicle architecture, the stiffness (or compliance) of the fuel subsystem components is one of the few fuel system design variables available for effecting the pressure pulsations. Some kind of designs for fuel rails have been developed and introduced to reduce fuel pulsation for MPI (intake manifold port injection) system such as fuel rails with external damper or internal damper or integrated damping effect (called as self-damped fuel rail) in accordance with engine room design and noise requirements. Fuel rails integrated with internal dampers are introduced to reduce fuel pulsation effectively now a days instead of self-damped fuel rails even though they lead cost increase significantly. However some papers have introduced that the fuel rails with integrated damping effect (self-damped fuel rail) can reduce fuel pulsation effectively. This study focused on finding key parameter on fuel rail design with integrated damping effect to reduce fuel pulsation experimentally. It was found that the shape and volume are key factor to reduce fuel pulsation and the shape of fuel rail is more effective than the volume of fuel rail. : Static response, minimum the best, was characterized as parameter design.

가솔린 기관 연료 펌프 계통의 유량·압력 특성

오재민(J. M. Oh),최세령(S. R. Choi),이일영(I. Y. Lee) 유공압건설기계학회 2014 유공압건설기계학회 학술대회논문집 Vol.2014 No.9

In this study, the flow and pressure pulsation in a high pressure fuel pump for gasoline engine is investigated. The pump changes a low pressure flow supplied from fuel transfer pump to high pressure flow in order to improve the engine efficiency. The pump supplies a high pressure fuel to common rail. It is the core part in the fuel supply system. It is essential to have a excellent durability because it should be operated in poor working condition. Pulsation and vibration is related on the pump durability. In this study, the author analyzes the operating principle of this pump and performs the experiment focusing on pulsation. The characteristics of the fuel pump is investigated and a reliable simulation model is developed by AMESim software. The simulation model is verified by comparing simulation results with experiments.