Both Ryan and Maloney mentioned the oversupply of physicians nationwide and noted that most are in narrow specialties. The traditional family general practitioner is a thing of the past, they observed, and hospitals have been forced to assume a greater proportion of the services those doctors offered.

"I sympathize with the institutions that will be affected by us in the short run, but we are part of the solution, not the problem," Maloney said.

A major feature of the neighborhood health centers and the old family doctor is the long-term relationships formed between physicians and patients. Dr. David A. Mann, one of the Cambridge Health Stop physicians, said yesterday the center is best suited for "episodic things where you need to see a physician probably on short notice."

But he noted that the centers do have the capacity to monitor simple chronic conditions such as high blood pressure, and that as people got familiar with the system they will begin to use it on a regular basis. "Even, if the long-term or chronic problem doesn't become a common type of patient the acute patient will always be here," he said.

By mid-afternoon yesterday, the Cambridge Health Stop had treated four patients. When working at capacity, it is designed to handle about 70 patients per day.

Since October, Health Stops have opened in Revere, Woburn, Medford, Watertown and now Cambridge. Six more are scheduled to open in the next few months and about a dozen more are in the works. Hachikian said the company expects to lose money for the first year while it builds a patient base, but it plans to expand to a nationwide operation