Journal of clinical monitoring and computing
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A review of the literature shows that current "standard" laboratory measurements for hemoglobin are subject to numerous factors that affect both accuracy and reliability. In addition, total hemoglobin concentration measurements are subject to numerous factors that affect the "true" hemoglobin value. This article discusses both the physiologic factors that influence hemoglobin levels and the technical aspects and variability among the different measurement methodologies currently available.
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J Clin Monit Comput · Oct 2013
Review Meta AnalysisHeart rate variability indices for very short-term (30 beat) analysis. Part 1: survey and toolbox.
Heart rate variability (HRV) analysis over very short (<60 s) periods may be useful for monitoring dynamic changes in autonomic nervous system activity where steady-state conditions are not maintained (e.g. during drug administration, or the start or end of exercise). From the 1980s there has been a wealth of HRV indices produced in the quest for better measures of the change in parasympathetic and sympathetic activity. Many of the indices have been sparingly used and have not been investigated for application to short-term use. ⋯ The survey identified a comprehensive list of 115 indices that were subsequently coded and screened. Of these, 70 were unique and produced a finite number with 60 s data, so are included in the Toolbox. These indices require validation against physiological data before they can be applied to short-term HRV analysis of cardiac autonomic nervous system activity.