Towards Reliable and Intelligent Alarms by Using Median Filters

摘要

In the last two decades there has been a rapid development of the equipment used for monitoring of critically ill patients at intensive care units. The monitoring has become more invasive, and concurrently new parameters have become available to routine bed-side monitoring. The automatic alarm systems employed in these monitors have not, however, developed at the same pace. The measurement and processing of values of the intensively monitored physiological parameters were studied. The reliability of the existing limit alarms was assessed clinically. The use of median filters to accomplish more reliable limit alarming was suggested. Suitable filters were selected on the basis of clinical experimentation. A novel dual-limit alarm was proposed and evaluated clinically. This alarm allows reliable automatic monitoring of therapy and a rapid response to catastrophic failures of the physiology. On basis of the clinical tests, the proposed method was found very reliable compared with the existing methods. (Copyright (c) Valtion teknillinen tutkimuskeskus (VTT) 1989.)