Astro-Med Inc., of West Warwick, has announced that its Grass Technologies Product Group has received U.S. Food and Drug Administration clearance to sell its neuromonitoring software system for recording electroencephalogram trends of patients over extended periods so that health-care professionals can observe long-term changes. The company will begin to sell the product for new applications in continuous EEG monitoring. Neuromonitoring of patients in intensive-care units of hospitals is in growing demand as a means of continuously assessing brain function in critically ill and often comatose patients. Astro-Med is a manufacturer of specialty high-tech printing systems, electronic medical instrumentation and test and measurement instruments.