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C H Massen

Publications and source records attributed to C H Massen.

9 recordsLinked to original sources
PubMed1982

An application of mathematical models in posturography.

The measurement of the horizontal displacements (HD) of the centre of mass of the human body when standing still, is often performed by means of a platform. The resulting measured HD as a function of time, both in the left-right or sinister-dexter and the posterior-anterior direction, are known as stabilograms. Such stabilograms are being more widely used to obtain the so called measured statokinesigram, similar to a Lissajous-figure, by eliminating time from the sinister-dexter stabilogram and the posterior-anterior stabilogram. It is shown that in using mathematical models of the standing person to obtained the stabilograms, the resulting statokinesigram is very different from the measured statokinesigram. It is also shown that the quantity line-integral calculated from a statokinesigram is much smaller when determined from a statokinesigram corrected by means of the mathematical models.

Humans↗
PubMed1975

An instrument for the accurate and continuous measurement of halothane concentrations in nitrous oxide-oxygen mixtures.

An instrument is described which measures continuously both the halothane concentration and the composition of the carrier gas when the vaporizer is situated outside the breathing circuit. The instrument is an adapted katharometer in which the out-of-balance voltage is used to measure the concentration of one compound in a three-component mixture, and the total voltage reduction across the constant-current-supplied bridge is used to indicate the proportions of the other two components. Halothane concentrations can be determined with an inaccuracy of 0.1% for concentrations up to 6%. Nitrous oxide (N2O) concentration in the nitrous oxide-oxygen mixture, serving as carrier gas, can be determined with an accuracy of 1% over the whole range up to 100% N2O. The 99% response time of the instrument is approximately 1 min.

Anesthesia, Inhalation↗