WORCESTER, Mass. — Progress in the development of an indoor personal locator and tracking device for firefighters has accelerated so much in the last year that researchers are hopeful of commercialization within the next two years, and of its technology being used by military and other emergency responders. During a talk with researchers at Worcester Polytechnic Institute yesterday, Stephanie Tompkins, program manager for the Strategic Technology Office of the Defense Advanced Research Projects Agency, said her federal agency wants to take advantage of advances being made in the locator and tracking technology for military applications. Her comments came after Worcester firefighters tested tracking components from two private companies, SEER Technology Inc. and Q-Track Corp., and the University of Michigan, to see how they could be used to guide firefighters to a comrade playing the role of a firefighter lost on the fourth floor of a classroom building during a fire where there was no visibility for the rescuers. Yesterday's demonstrations and workshops were part of the second and final day of the WPI conference and workshop.  "Precision Indoor Personnel Location and Tracking for Emergency Responders," had about 140 participants from public, private and academic research organizations. Research began at WPI after the December 1999 fire at the former Worcester Cold Storage and Warehouse Co. building that claimed the lives of six Worcester firefighters who became lost in the windowless structure. "I was more than pleased," said WPI engineering professor David Cyganski, who has overseen development of a component that would warn firefighters of a fire flashover inside a building. "In the 12 months since the last conference, we've seen more progress than in the previous three or four years that preceded it.  It's all beginning to add up now.  We all get together and share this information with one another, and we have the companies and universities that were brave enough to step up and actually show everybody how it's working. "Everyone's work is adding up to an actual solution." Worcester Deputy Fire Chief John F. Sullivan said the technology demonstrated yesterday showed marked improvement from previous years.  They were successful in a controlled situation in tracking the location of a firefighter, then using the same devices to guide rescuers to his location. The rescuers, wearing full fire turnout gear, wore breathing masks with the face shields blacked out so they could not see. They were guided by radio by an incident commander monitoring the computer screen displaying the locations of the stranded firefighter and the rescuers. The rescue teams walked and crawled up four flights, then crawled along hallways, using their hands and ax handles to feel their way along the floor and under desks until they found the lost comrade. "If we tried this same thing a few years ago, none of you would have made it," Chief Sullivan said to the research teams who demonstrated their technology. "Every year we make it more challenging.  When we're searching for someone if you can get us there a few minutes faster, that's what we're looking for."