Artificial heart surgeon Dr. William C. DeVries said yesterday that he plans to move full speed ahead with more implants of the highly experimental device at Louisville's Humana Heart Institute, despite concerns about strokes and other serious blood complications in his first four patients.

"You learn from your failures and mistakes . . . I really think that we need to go ahead and get the series finished," said DeVries, who performed the world's first permanent artificial heart implant in late 1982 and has government permission to do three more, for a total of seven.

"As soon as I find a good patient, I'll do it," DeVries said in an interview here. He said another attempt might come within the next month.

In a speech before the Food and Drug Law Institute, DeVries acknowledged, "I think there are a lot of problems, but I'm confident that we're going in the right direction."

He said that there was "no question" that government regulation has slowed the speed of medical research but assured more safety for research subjects.

DeVries said later that he disagreed strongly with experts in the field who have called upon him to reconsider his research plan and pause before making another attempt. "What would pausing accomplish? . . . All pausing does is delay the answer," said the lanky, 41-year-old surgeon. "If you snooze, you lose."

Among those considering a possible delay is the head of DeVries' own institute, Dr. Allan M. Lansing, who told The Washington Post recently that "maybe we need to pause." DeVries said yesterday that although Lansing has "entirely different ideas than I do," he would not stand in the experiment's way.

In defense of experimentation, DeVries said that many of the widely accepted medical devices today -- from the kidney dialysis machine to heart-lung bypass machines and heart valves -- evolved from earlier versions that killed many initial experimental subjects. "You've got to be a bit callous as long as you're learning things."

He also said he "wouldn't hesitate to have it done to me," both for potential therapeutic benefits to the individual and the contribution such research may make to society.

DeVries said that despite recent problems, his two living artifical heart patients, Murray P. Haydon and William J. Schroeder, are now doing better than expected, well enough that "I foresee both of them getting out" of the hospital at some point.

Haydon, who suffered a minor stroke June 3, 107 days after his implant, is "now as good as he was before" the stroke, said DeVries. He is "up and around," going to physical therapy and using the respirator very little.

And Schroeder, who has had two strokes since his November 25 implant, is "considerably better. He's still severely impaired, but he's really coming along," said the Louisville surgeon. After a short stay in a nearby apartment, Schroeder returned to the hospital in May after a second stroke left him severely debilitated and unable to speak.

Now, said DeVries, Schroeder is "talking in short sentences," responding to questions and sometimes making spontaneous requests. Although his memory is impaired, DeVries said that the Jasper, Ind., patient recognizes family members, who visited him and took him outside on Father's Day.