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Biomedical subjects

H Tsuruta

Publications and source records attributed to H Tsuruta.

At least 127 records · Page 7Linked to original sources
PubMed1983

Theoretical analysis of "metabolic indices" of blood buffer system.

The well-known base excess (BE) and buffer base (BB) curves of Siggaard-Andersen's nomogram are based on their empirical finding that the blood buffer lines in the pH-log PCO2 coordinates with the same BE (or BB) always pass through a single point irrespective of the hemoglobin concentration. We have analytically derived the BE and BB curves on the assumption of a two-compartmental model of blood buffer system comprised of plasma and red blood cells. These hyperbolic functions of BE and BB curves fitted the Siggaard-Andersen's observation very well. The simple formulas derived from the buffer equation with the parameters obtained on the least-square basis were shown to estimate "metabolic indices" of blood as accurately as the computer reading of the nomographic curves. These results seem to indicate that the buffer equation based on the two-compartmental model describes the acid-base status of blood satisfactorily, and that it can entirely replace the Siggaard-Andersen's nomogram.

Acid-Base Equilibrium↗
PubMed1981

Difference equation model of the entrainment of myocardial pacemaker cells based on the phase response curve.

As a method for investigating entrainment phenomena found in biological oscillations, a model is presented which is formulated as a set of difference equations on the basis of "phase response curves" of biological oscillators. Properties of the model are discussed and synchronization of cardiac pacemaker cells to the external periodic stimuli is analyzed by use of the model. It is shown that the model is reducible to an equivalent system to the mathematical neuron model of Nagumo et al. under a specific parametric condition of the phase response curve. As an application to the cardiac arrhythmias, the model of ventricular parasystoles studied by Moe et al. is described mathematically in terms of a system of difference equations. In addition, a more comprehensive model of ventricular parasystoles is proposed.

Animals↗