To extract main aspects of the coupling between a ventricle and its arterial load simple analog models may be used: the input impedance of the arterial systems may be modelled by resistors, compliance and inductance i...
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To extract main aspects of the coupling between a ventricle and its arterial load simple analog models may be used: the input impedance of the arterial systems may be modelled by resistors, compliance and inductance in advanced or simple lumped 3 or 4 component models;the heart, since the instantaneous pressures of the different compartments essentially depend on their instantaneous volumes, may be modelled by time-varying capacitors. The components may be connected by uni-directional valves at the appropriate sites and the whole system programmed and solved by computer. Heart models incorporating ventricular interaction across the septal wall indicate that energy produced in the right ventricular free wall is partly transferred to the left ventricle.
The human vestibulo-ocular reflex was studied using sweep-frequencies of active head-eye movements, and autoregressive-moving average (ARMA) parameter estimation. Ten 18-second test epochs from one subject were used o...
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The human vestibulo-ocular reflex was studied using sweep-frequencies of active head-eye movements, and autoregressive-moving average (ARMA) parameter estimation. Ten 18-second test epochs from one subject were used over a frequency range from 2 to 6 Hz. An ARMA model of the (3,3) order, i.e., with three output lags and three input lags, was found to best fit the subject's data for all ten runs. Mean parameters from the ten runs showed relatively small variance. This method provides accurate predictions of eye-velocity response during active head movement conditions.
Because of non-optimal glycemic control, many type I diabetic patients on non-feedback controlled insulin regimes are subject to life-threatening secondary complications. Therefore, to assist both closed-loop and open...
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Because of non-optimal glycemic control, many type I diabetic patients on non-feedback controlled insulin regimes are subject to life-threatening secondary complications. Therefore, to assist both closed-loop and open-loop (pumps, injections) insulin therapy, an appropriate computer-aided procedure was developed and verified. It comprises the following components: (1) a manageable and validated model of the glucose-insulin system, (2) a test procedure for identifying the metabolic situation of an individual patient in terms of the model, (3) a method of estimating (a) the pharmacokinetics of insulin on any route of application and (b) the absorption profiles of ingested glucose equivalents, and (4) computer-aided procedures of prospective simulation of glycemic profiles around the day under the influence of stipulated therapeutic regimes.
A closed-loop lumped-parameter model of the cardio-vascular system (CVS) requiring little computational power has been developed. The model has the following features: (1) nonlinear elastic characteristics of arteries...
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A closed-loop lumped-parameter model of the cardio-vascular system (CVS) requiring little computational power has been developed. The model has the following features: (1) nonlinear elastic characteristics of arteries and veins;(2) detailed ventricle model, with autonomic regulation, for proper testing of the vascular system (VS);(3) simplified neural and local regulation system;(4) easy simulation of respiratory and muscular pump, gravity and hemorrhaging effects. Some simulation results, which show good agreement with experimental measurements, are presented. This CVS simulation model is an efficient tool both for the determination of the influence of artificial devices and for computer-aided teaching in medical education. It can also be used to develop regulation algorithms for the TAH. An example is presented.
Mathematical modelling of dynamic processes is often considered an intricate and time-consuming task. Program packages for simulation, time series analysis and identification in combination with a modern data logging ...
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ISBN:
(纸本)0080325572
Mathematical modelling of dynamic processes is often considered an intricate and time-consuming task. Program packages for simulation, time series analysis and identification in combination with a modern data logging equipment allow the task to be handled in a simpler and more efficient way. This paper gives a description of the different tools, and several examples illustrate how they can be utilized in modelling and design of controlsystems for metallurgic processes.
The paper describes the development of a computer-aided modelling and control-system-design facility for power generation plant. This has been implemented on a laboratory model turbogenerator, and tests have been cond...
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ISBN:
(纸本)0080325572
The paper describes the development of a computer-aided modelling and control-system-design facility for power generation plant. This has been implemented on a laboratory model turbogenerator, and tests have been conducted on full-scale plant. The system is based on a dedicated PDP 11-23 microcomputer, with background processing on a VAX 11-780 minicomputer, using specially-written software packages. Results obtained both in the laboratory and from site tests are presented.
CODE (control DEfinition language) is a formal language designed and used for implementation of control strategies in sequence control applications, such as found in industrial control. CODE treats processes as finite...
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ISBN:
(纸本)0080325572
CODE (control DEfinition language) is a formal language designed and used for implementation of control strategies in sequence control applications, such as found in industrial control. CODE treats processes as finite state machines (FSM), by defining transition conditions that determine when a state change will occur, and the consequent transition action. A control definition consists of a hierarchical model, each layer of which consists of a number of FSMs. The CODE concept is proposed for use in a formal specification language that would form part of a specification work bench, including syntax-checking editors, consistency and completeness checks, automatic simulation and documentation systems. This work bench will provide a powerful tool for specification and development of process control and other systems. It will help increase the effectiveness of software designers and engineers;it will also contribute to increased formality in system specification, helping to eliminate a major source of error. The CODE concept is thus part of the current trend towards increased automation of software development.
Forced by university curriculum reform the introductory control engineering course has been shifted from the 3rd year to the 2nd year and the total teaching program has been reconstructed. Therefore the idea originate...
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ISBN:
(纸本)0080325424
Forced by university curriculum reform the introductory control engineering course has been shifted from the 3rd year to the 2nd year and the total teaching program has been reconstructed. Therefore the idea originated to concentrate the laboratory experiments around one central process, on which sequentially various aspects can be studied, such as measurements, modelling, identification, stochastic characteristics, analog control, digital control, etc. This central process consists of three cascaded water reservoirs. The students are required to study this process over a period of five afternoons. They have to develop their own models, make the measurements, identify the system, estimate the parameters and verify the results under unprescribed circumstances. They themselves will conclude that, due to very big time constants, simulation is necessary. In these simulations comparisons of analog and digital simulations are made and an optimal controller has to be developed. Attention has been paid to the various tasks that can be done using the available small digital computers. The process and some preliminary experiences are reported.
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