Algorithm-based mathematical normalization

The practice of using aerobic specimens for the measurement of free calcium should be abandoned because of the widespread availability of blood gas analyzers measuring free calcium and the use of evacuated gel tubes by reference laboratories. In the past, specialized free calcium analyzers equilibrated aerobic specimens with a carbon dioxide (5.3 kPa) air mixture to adjust their pH to near 7.4 (7.2-7.6), and then mathematically corrected the free calcium to pH 7.4, using an algorithm relating free calcium and In the event that aerobic free calcium results are corrected to pH 7.4 after equilibration with a mixture of CO2 and air, only the free calcium at pH 7.4 should be reported with appropriate identification. The normalized or adjusted free calcium at pH 7.4 has been reported to accurately reflect the free calcium status of normal persons and individuals without acid-base disturbances. However, aerobic handling of specimens with correction of the free calcium to pH 7.4 has been increasingly criticized. The free calcium value... 

The key limitations in the development of the discriminate functions for classification purposes, are the data-driven nature of the algorithms and the lack of theoretical orientation in the process of development and validation of these models. It is suggested that the mathematical simulation of flexion or extension trunk movement may identify an objective basis for the evaluation and assessment of trunk kinematic performance. A catalog of movement patterns that are optimal with respect to physical and biomechanical quantities may contribute to the emergence of a more theoretically based computational paradigm for the evaluation of kinematic performance of normal subjects and patients. It must be emphasized that in this paradigm one has no intention to claim that the central nervous system actually optimizes any single or composite cost function. 

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