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At least 19 recordsLinked to original sources
PubMed1979

Comparative distribution of two antidepressant drugs (imipramine and indalpine) in the rat as determined by analog computer simulation.

A ten-compartment analog computer model is presented to determine the precise distribution and excretion of two antidepressant drugs, LM 5008 AND Imipramine. Eight patterns were simulated using experimental data and drug distribution in the two undetermined compartments were obtained by the analog model. Close agreement with existing experimental data lends confidence in the model as a valuable tool for predictions in a variety of therapeutic situations.

Animals↗
PubMed1975

The precision of a special purpose analog computer in clinical cardiac output determination.

Three hundred dye-dilution curves taken during our first year of clinical experience with the Waters CO-4 cardiac output computer were analyzed to estimate the errors involved in its use. Provided that calibration is accurate and 5.0 mg of dye are injected for each curve, then the percentage standard deviation of measurement using this computer is about 8.7%. Included in this are the errors inherent in the computer, errors due to baseline drift, errors in the injection of dye and acutal variation of cardiac output over a series of successive determinations. The size of this error is comparable to that involved in manual calculation. The mean value of five successive curves will be within 10% of the real value in 99 cases out of 100. Advances in methodology and equipment are discussed which make calibration simpler and more accurate, and which should also improve the quality of computer determination. A list of suggestions is given to minimize the errors involved in the clinical use of this equipment.

Cardiac Output↗
PubMedDate not supplied

Thermal dilution measurement of cardiac output in dogs using an analog computer.

Thermal dilution cardiac output determinations in dogs were compared to simultaneously performed Fick oxygen measurements. The purpose of this study was to validate in dog experiments a method for thermal dilution measurement which employs a double-thermistor catheter combined with an automatic computer as described by Olsson et al. Dilution and injectate temperature are entered directly into the calculation. The method does not employ logarithmic extrapolation, integration of the dilution signal being terminated when a preset cut-off level is reached. Errors due to recirculation, thermal capacitance of the right heart and heat exchange with the catheter's dead space require the use of an empirically derived correction factor, which in dogs was found to be significantly different from the factor used for human thermal dilution curves. With the appropriate cut-off level and correction factor a good agreement was found between the results of the thermal dilution and the Fick method. The regression equation for 47 experiments was found to be COtd = 0.95 COFick + 0.08; the correlation coefficient was 0.94.

Animals↗
PubMed1979

A 200-point analog computer of average transients for electrophysiological measurements.

A 200-point computer of average transients uses capacitors as the memory devices and MOS-FET switches. The averaged wave form is stored exponentially and the memory decays exponentially when that input is removed. The memory exponential time constant (i.e. the number of sweeps averaged) can be varied with one resistor. Read-out to an oscilloscope occurs simultaneously with read-in of each new signal. This linear circuit computes a highly accurate average, even though 10% components are used. It is more cost-effective than commercial digital averagers for many applications and can average evoked potentials, field potentials, weak single units and intracellularly recorded postsynaptic potentials.

Animals↗
PubMed1975

[Analog computer analysis of radioactivity kinetics in man following oral administration of tilidine HCl-14C].

Models for studying the absorption and elimination kinetics of 14-C labelled DL-Ethyl-trans-2-dimethylamino-1-phenyl-cyclohex-3-ene-trans-1-carboxylate-hydrochloride (Tilidine - HCl, Valoron) are developed, based on the concentration vs. time of radioactivity in the plasma following a single oral administration in man. For this purpose, the average concentration values in the plasma of 3 healthy adults, as given by Vollmer and Poisson [12] were employed. 1. Two three-compartment-models were developed which simulate with sufficient accuracy the 14-C-Valoron concentration curve in the plasma. 2. Computer analysis enables one to determine the distribution of 14-C-Valoron among the intra- and extravasal compartments and the half life for absorption t1/2 equals 0.57 h, for transport from plasma into the extravasal compartment t1/2 equals 3.31 h, for resorption t1/2 equals 4.11 h, for elimination with feces t1/2 equals 29.5 h and for elimination in urine t1/2 equals 8.75 h. 3. The use of two different models allows one to draw conclusions concerning the participation of parenchymatous organs in storage and elimination. 4. The probable radioactivity curve is calculated for repeated oral application of 14-C-Valoron in 8 hours intervals.

Administration, Oral↗
PubMedDate not supplied

[A complex method for determining age by tooth status using analog computers].

Combination of roentgenography with direct image magnification and its analysis by medical iconics methods increase significantly possibility of age determination by teeth status (prediction accuracy by upper canine tooth is 99.8% +/- 0.81 year). Adaptive character of change in teeth density over the period of their functioning was detected. Integrative metric index--age metric index--is an objective criterion of age status of a tooth.

Age Determination by Teeth↗