Intracardiac Impedance as a Method for Ventricular Volume Monitoring - Investigation by a Finite-Element Model and Clinical Data
نویسندگان
چکیده
A method for monitoring left ventricular (LV) volume changes of the human heart by intracardiac impedance measurement was developed. In order to model this method, we simulated the ventricular contraction using a finite-element model (FEM). The myocardium comprised three layers with anatomical fiber orientation. During excitation propagation contraction forces were applied, taking into account the myocardial elastic properties and the blood pressure time course. For a set of 21 contraction stages we calculated the intracardiac impedance Z between the right ventricular (RV) and LV leads for a set of common LV lead positions. The FEM results were compared to clinical data. Impedance and stroke volume were determined during overdrive pacing and end diastolic volume (EDV) at rest in 14 patients. All clinical EDV values were in the range of 147-394ml. Both the clinical data and the FEM in this volume range showed a linear correlation between admittance Y=1/Z and ventricular volume. For a quantitative comparison end diastolic impedance EDZ and the slope dY/dV were calculated. The model results across all LV lead positions were EDZ=0.16-1.2Ω, and dY/dV=3.3-21mS/ml, corresponding to clinical values of EDZ=0.14-1.46Ω and dY/dV=1-64mS/ml. In conclusion, the FEM resembled the clinical measurement data and serves as theoretical basis for ventricular volume monitoring via intracardiac impedance.
منابع مشابه
Thermo-Electro Mechanical Impedance based Structural Health Monitoring: Euler- Bernoulli Beam Modeling
In recent years, impedance measurement method by piezoelectric (PZT) wafer activesensor (PWAS) has been widely adopted for non-destructive evaluation (NDE). In this method, theelectrical impedance of a bonded PWAS is used to detect a structural defect. The electro-mechanicalcoupling of PZT materials constructs the original principle of this method. Accordingly, the electricalimpedance of PWAS c...
متن کاملFinite element model updating of a geared rotor system using particle swarm optimization for condition monitoring
In this paper, condition monitoring of a geared rotor system using finite element (FE) model updating and particle swarm optimization (PSO) method is onsidered. For this purpose, employing experimental data from the geared rotor system, an updated FE model is obtained. The geared rotor system under study consists of two shafts, four bearings, and two gears. To get the experimental data, iezoel...
متن کاملNumerical Simulation of the Hydrodynamics of a Two-Dimensional Gas—Solid Fluidized Bed by New Finite Volume Based Finite Element Method
n this work, computational fluid dynamics of the flow behavior in a cold flow of fluidized bed is studied. An improved finite volume based finite element method has been introduced to solve the two-phase gas/solid flow hydrodynamic equations. This method uses a collocated grid, where all variables are located at the nodal points. The fluid dynamic model for gas/solid two-phase flow is based on ...
متن کاملAn Investigation on the Behavior of Retaining Structure of Excavation Wall Using Obtained Result from Numerical Modeling and Monitoring Approach. (A Case Study of International "Narges Razavi 2 Hotel", Mashhad)
With the growing population and density in metropolitan areas, higher tendency to live in high-rise buildings, and increasing demand for parking lots, it seems necessary to excavate soil to construct underground spaces. During excavation work, as the height of the wall increases, special care should be taken to the wall stabilization to avoid any consequent damage including extensive property d...
متن کاملDevelopment of a Predictive Finite Element Model For Investigation of Phases Behavior After Cold Rolling Process
One of the surface defects that arise in sheet metal working is when the part removes from the die. Since there are no external forces to make this defect, the origin of such fail is known as residual stress. Residual stress can develop in sheet metal forming due to non uniform deformation. In this paper, the workpiece is carbon steel with different volume fractions and arrangement of ferrite ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2010