Farhanahani Mahmud

Real-time simulations for resetting and annihilation of reentrant activity using hardware-implemented cardiac excitation modeling

In this paper, real-time simulations of reentrant excitation conduction of cardiac cells are realized by coupling 80 active circuits of the hardware-implemented cardiac excitation cell models in a one-dimensional loop. The hardware-implemented cardiac excitation model is designed by using analog circuits and a dsPIC microcontroller that could reproduce time-dependent and time-independent nonlinear current-voltage characteristics of six-type of ionic currents in Luo Rudy phase 1 (LR1) model. LR1 is a numerical model described with nonlinear ordinary differential equation (ODE) functions for generating the action potential (AP) wave in a mammalian cardiac ventricle. In the simulations of AP conduction using a one dimensional loop of the anatomical reentry in a cardiac tissue, quantitative correspondence between the hardware cable model and LR-I cable model was demonstrated with various conditions which are phase resetting by single impulsive stimulations and annihilations of the reentry by appropriately timed single stimulations.

FPGA-in-the-Loop Simulation of Cardiac Excitation Modeling towards Real-Time Simulation

Cardiac excitation is a fundamental mechanism within the heart’s function. One way to understand this mechanism is by using numerical modeling techniques. However, an immense amount of computational time has been required in the simulation that generally involves a large number of parameters. In this paper a simulation study of Luo Rudy Phase I (LR-I) mathematical model by using MATLAB Simulink to solve ordinary differential equations (ODEs) using field programmable gate array (FPGA) towards a real-time simulation of cardiac excitation has been presented. The FPGA could be the best solutions because it is able to provide high performance in solving higher order ODEs for real-time hardware implementation. In fact, the FPGA hardware design can be accelerated by using MATLAB Simulink HDL Coder that automates the hardware description language (HDL) code generation from designed MATLAB Simulink blocks. Furthermore, HDL designed implementation can be verified by using HDL Verifier such as co-simulation and FPGA-in-the-Loop (FIL) approaches to simulate the generated HDL code and verify the results. In this paper, results show that the LR-I cardiac excitation modeling is successfully simulated by the MATLAB Simulink and by using the HDL Coder the designed MATLAB Simulink model is successfully converted into VHDL code and verified through the FIL. These have given a positive outlook towards the FPGA hardware implementation for real-time simulation.

Luo Rudy Phase I excitation modeling towards HDL coder implementation for real-time simulation

This paper presents the simulation study of nonlinear dynamic of cardiac excitation based on Luo Rudy Phase I (LR-I) model towards numerical solutions of ordinary differential equations (ODEs) responsible for cardiac excitation on field programmable gate arrays (FPGAs). As computational modeling needs vast of simulation time, a real-time hardware implementation using FPGA could be the solution as it provides high configurability and performance. For rapid prototyping, MATLAB Simulink that offers a link with the FPGA has been used. Through Simulink HDL Coder, a tool in the MATLAB software that capable to convert the MATLAB Simulink blocks into hardware description language (HDL) code and an FPGA-in-the-loop (FIL) and co-simulation for verification, FPGA hardware implementation can be done. As a result, the LR-I excitation model is successfully simulated by using the MATLAB Simulink and the VHDL code has been successfully generated by the HDL Coder after fixed-point optimization is done. The FIL verification on actual FPGA board also has shown quantitatively comparable results to the MATLAB Simulink simulation. Therefore, the design flow has given a positive outlook in developing this FPGA stand-alone implementation.

FPGA Implementation for Cardiac Excitation-Conduction Simulation Based on FitzHugh-Nagumo Model

The paper examines a method for development of a Field Programmable Gate Array (FPGAs)-based implementation of hardware model for the electrical excitation-conduction in cardiac tissue based on FitzHugh-Nagumo (FHN) mathematical model towards real-time simulation. The FHN model is described by a set of nonlinear Ordinary Differential Equations (ODEs) that includes two dynamic state variables for describing the excitation and the recovery states of a cardiac cell and the model is able to reproduce many characteristics of electrical excitation in cardiac tissues. In this paper, one dimensional (1D) FHN cable model is designed using MATLAB Simulink in order to simulate the conduction of cardiac excitation in coupled nonlinear systems of the heart dynamics. The designed MATLAB Simulink model is then being used for Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL) code generation by using HDL Coder that will be implemented on a hardware design FPGA platform of Xilinx Virtex-6 FPGA board. In order to verify and analyze the designed algorithm on the platform, HDL Verifier is used through co-simulation with FPGA-in-the-loop (FIL) simulation and it has shown a significant result which has increased confidence that the algorithm will work in the real FPGA stand-alone application. Therefore, these approaches provide an effective FPGA design flow towards a stand-alone implementation to perform real-time simulations of the cellular excitation-conduction in a large scale cell models.

Cardiac excitation modeling: HDL coder optimization towards FPGA stand-alone implementation

The aim of this paper is to discuss the optimization of the hardware description language (HDL) design using fixed-point optimization and speed optimization through a pipelining method. This optimization is very crucial to achieve the best performance in terms of speed, area and power consumption of the generated HDL code before deploying the field programmable gate array (FPGA) stand-alone implementation. As computational mathematical modeling needs immense amounts of simulation time, FPGA could bring the solutions as it provides high performance, and able to perform real-time simulations and compute in parallel mode operation. In this study, in order to ease verification, prototyping, and implementation FPGA, rapid prototyping model-based design approach of HDL Coder from MathWorks has been used to automate HDL codes generation from a designed MATLAB Simulink blocks of Luo-Rudy Phase I (LR-I) model towards FPGA hardware-implemented for numerical solutions of ordinary differential equations (ODEs) responsible in generating the action potential (AP) waveform of mammalian cardiac ventricle cell. By using HDL Coder, the model is successfully converted into an optimal fixed-point VHDL design and the operating frequency is increased from 9.819 MHz to 23. 613MHz by pipelining optimization.

FPGA-in-the-loop co-simulation of reentrant arrhythmia mechanism in one dimensional (1D) ring-shaped based on FitzHugh-Nagumo model

This paper presents the simulation of reentrant excitation-conduction of cardiac cells realized by coupling 80 active circuits in one dimensional (1D) ring-shaped based on FitzHugh-Nagumo (FHN) model. 1D ring-shaped cable model is designed using Simulink in order to simulate an action potential signal and its conduction for a hardware design by using HDL Coder to automate the model for Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL) code generation. Then, the VHDL design is functionally verified on a Field Programmable Gate Array (FPGA) Xilinx Virtex-6 board using HDL Verifier proving the model through FPGA-in-the-Loop (FIL) co-simulation approach. It can then be downloaded into a target FPGA device for real-time simulations. This novel approach of prototyping cardiac reentrant excitation-conduction provides a fast and effective FPGA-based hardware implementation flow towards a stand-alone implementation to perform complex real-time simulations compared with manual HDL designs.

Synthesis and Characterization of Zinc Oxide Nanostructures by Different Sonication Period

Zinc oxide (ZnO) is a wide band gap semiconductor material (3.37 eV) with numerous present applications such as varistors, surface acoustic wave devices and future biomedical applications. ZnO nanorods were grown under specific growth condition by an inexpensive and simple, chemical bath deposition method on ZnO seeded glass substrates. Study of the ZnO nanorods over different precursors, i.e zinc acetate dehydrate and zinc nitrate hexahydrate, and sonication period ranging from 0 to 120 seconds by field emission scanning electron microscope (FESEM), including the nanorod size and the surface morphology, will be demonstrated in this paper. Characterization of the ZnO film using both X-ray diffraction (XRD) and UV-Vis spectroscopy will be established in determining the optimal composition along with the optical properties, respectively.

FUZZY LOGIC SYSTEM FOR BBT BASED FERTILITY PREDICTION

This paper introduce a fuzzy logic system for fertility prediction to improve the BBT technique based on FAM. The development of the fertility prediction system using fuzzy logic is motivated by its ability to conduct a complex relationships that exist between the input and its factors, which can address the issue of imprecision in the fertility prediction. According to the reference sets of BBT data tested on the fuzzy logic system for the prediction of ovulation and pregnancy, a significant result have been obtained with the accuracy of 95 % and 80 % respectively. Besides, this prediction system using fuzzy logic could improve the current practice in the FAM technique by integrating it with an Internet of Things (IoT) technology for automatic BBT charting and monitoring.

FPGA in-the-loop simulations of cardiac excitation model under voltage clamp conditions

Voltage clamp technique allows the detection of single channel currents in biological membranes in identifying variety of electrophysiological problems in the cellular level. In this paper, a simulation study of the voltage clamp technique has been presented to analyse current-voltage (I-V) characteristics of ion currents based on Luo-Rudy Phase-I (LR-I) cardiac model by using a Field Programmable Gate Array (FPGA). Nowadays, cardiac models are becoming increasingly complex which can cause a vast amount of time to run the simulation. Thus, a real-time hardware implementation using FPGA could be one of the best solutions for high-performance real-time systems as it provides high configurability and performance, and able to executes in parallel mode operation. For shorter time development while retaining high confidence results, FPGA-based rapid prototyping through HDL Coder from MATLAB software has been used to construct the algorithm for the simulation system. Basically, the HDL Coder is capable to conver...

Evaluation of PD/PID controller for insulin control on blood glucose regulation in a Type-I diabetes

This project introduces a simulation of Proportional-Derivative (PD) and Proportional-Integral-Derivative (PID) controller based on a virtual Type 1 Diabetes Mellitus (T1DM) patient: Hovorka diabetic model using MATLAB-Simulink software. The results of these simulations are based on three tuning responses for each controller which are fast, slow and oscillation responses. The main purpose of this simulation is to achieve an acceptable stability and fastness response towards the regulation of glucose concentration using PD and PID controller response with insulin infusion rate. Therefore, in order to analyze and compare the responses of both controller performances, one-day simulations of the insulin-glucose dynamic have been conducted using a typical day meal plan that contains five meals of different bolus size. It is found that the PID closed-loop control with a short rise time is required to retrieve a satisfactory glucose regulation.