With the right technology, a doctor can now display a good (or a bad) bedside manner with patients without having to actually be with them.

That was made clear last week at a booth at the huge Communications Networks '91 trade show at the Washington Convention Center, where Dr. James Lear conferred by closed-circuit video with patients going under a diagnostic device called a gamma camera at a Colorado hospital 1,500 miles away. After the tests, Lear turned to a Macintosh computer screen to view the resulting 3-D color images, transferred to him by telephone lines in a minute or two.

Actors are often used for trade show demos of this sort. But this one, set up by long-distance carrier US Sprint Communications Co., featured real illnesses and real people, all of whom in this age of litigation were asked to sign waivers before going on camera. The point was to show off new ways of merging telecommunications and the medical arts. Phone lines can also carry X-ray pictures and sonogram results to distant specialists. With live video thrown in, they can talk with and see the patient first-hand.

Lear, who heads up nuclear medicine at the University of Colorado Health Sciences Center, joked that the system can give him closer relationships with patients than he otherwise would get. Normally, he said, "You never see the radiologist. He's in the dim-lit room in the back." The experiment goes on -- Lear is about to have video equipment installed at his home.