Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Computers, Analog”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1975

Model of an oculomotor subsystem.

One of the complex control systems present in the human body is the oculomotor control system. There are two major modes of ocular movements, viz. saccadic and smooth pursuit. More knowledge about the neuromuscular mechanisms controlling these eye movements is obtained if experiments are carried out on subjects whose two types of eye movements are differentially affected due to disorders at their higher centres of control. Eye movements of patients with a novel form of Heredo-familial Spinocerebellar Degeneration have been measured and quantified. These have been compared with those of normal subjects. Subsequent analysis indicates a continuous fourth order transfer function for the smooth pursuit eye-in-skull movements in the horizontal plane with head stationary.

Cerebellar Ataxia↗
PubMed1975

Kinematics of spontaneous breathing: the ventilatory system as a non-linear oscillator.

The kinematics of spontaneous breathing at rest and during moderate exercise is described exactly by a non-linear differential equation, the parameters of which are determined by observation with a pneumotachograph. Analogue circuits are used for the determination of the coefficients and for the comparison by superimposition of the actual spirogram with its simulation. The ventilatory system, taken as a whole and without any assumption concerning its structure, works as a non-linear oscillator. If the classical distinction between a passive and an active ventilatory system is accepted, the concept of a linear equivalent of a non-linear oscillator is valid for the description of the properties of the passive system. It affords some of the advantages of linear mechanics and indicates the restrictions put upon the use of a linear hypothesis. The role of the different terms in determining the pattern of breathing is displayed and the correlation of scale factors with body size is shown. The physiological meaning of the components of muscle action is discussed.

Computers, Analog↗
PubMed1976

Analysis of the human respiratory system in hypoxic and anoxic hypoxia by analogue computer simulation.

The goal of this work is to synthesise a model of an adaptive system of respiration control in man, which could be used for the prognosis of human performance under extreme conditions. The model was partly based on 428 experimental results from hypoxic and anoxic hypoxia. Simulation of the oxygen regulatory circuit was realised on the NADAC 100 and MEDA T 80 analogue computers with satisfactory results. Equations constituting a new version of the model are presented in some detail, together with the results of the simulation of ventilatory mechanics.

Computers, Analog↗
PubMed1978

An interface to input analogue signals to a digital computer.

An electrical control unit is described which permits analogue signals from most sources to be made compatible with, and optimise the use of, an A/D converter. This circuitry enables the signal to be offset, relative to the electrical zero, and to be reset to zero using a push button. Extension of this unit has enabled mechanical movement, such as rotation of a shaft, to be measured. In order to make the most efficient use of the A/D converter the gain of the output can be varied.

Computers↗
PubMed1979

Results of simulation of non-homogeneous ventilatory mechanics for a patient-computer arrangement.

A model of the ventilatory mechanic system was realised on the MEDA TC 41 analogue computer; it consists of 2 structurally identical compartments, differing in the values of their coefficients. By changing the values of coefficients and the relations between the 2 compartments, it was possible to simulate the non-homogeneity of a real, pathologically-changed system of the body afflicted by disease. Complex resistance loops with phase shifts. identical with those really registered from patients, were realised; this was impossible for models with only 1 compartment. By changing the non-homogeneity of the model., it was possible to simulate the past and future development of the state of the diseased patient with sufficient reliability.

Airway Resistance↗
PubMed1980

A program library for computing the parameters of linear compartment models in pharmacokinetics.

A program library is presented with which explicit solutions of linear compartment models can be fitted to pharmacokinetic experimental data. Use is made of the fact that transport constants can be calculated from the numberical solution of such a problem without ambiguity. The non-linear regression is carried out using the Powell-method. A report of our experience with, e.g. choice of objective function, lag-time, accuracy of the numerical solution is included.

Computers↗