Ambulatory clearance function monitor

摘要

Accurate and continuous monitoring of clearance function is obtained by determining the depletion of a labelled substance from the extracellular body fluid using an external monitor which detects label from within a defined tissue volume. The detector of the external monitor is contained within a collimator which functions to both exclude external influences and to functionally isolate the volume of extracellular fluid to be monitored. Also, a method for determining and expressing a clearance function in a subject includes steps of allowing a time sufficient to permit establishment of equilibrium of a detectable substance in the extracellular space in the subject, obtaining first and second measures, at first and second times, of the detectable substance in the extracellular fluid within a defined tissue volume in the subject, and determining the slope of the measures over the time interval.