Tom Coburn, an ultraconservative Oklahoma Republican and family physician who in 16 years in Congress crusaded for limited government, using a rule-book technicality to block so many bills that frustrated legislators called him “Dr. No,” died on Saturday. He was 72. His death was announced on Twitter by his former communications director, John Hart. He provided no details, but Mr. Coburn has said in 2013 that he was being treated for a recurrence of prostate cancer, and in 2014 he announced that declining health would force him to retire. Senator and a Representative from Oklahoma; born in Casper, Wyo., March 14, 1948; graduated Central High School; graduated Oklahoma State University, B.S. 1970; graduated Oklahoma State University Medical School 1983; manufacturing manager, Coburn Opthalmic Division, Coburn Optical Industries 1970-1978; intern in general surgery, St. Anthony's Hospital, Oklahoma City, Okla.; family practice residency, University of Arkansas, Fort Smith; physician, Muskogee, Okla.; past chair, Muskogee Regional Medical Center; participant in medical mission trips to Haiti 1985, and Iraq 1992; elected as a Republican to the One Hundred Fourth and to the two succeeding Congresses (January 3, 1995-January 3, 2001); elected as a Republican to the U.S. Senate in 2004; reelected in 2010 and served from January 3, 2005, until his resignation on January 3, 2015. Thomas Allen Coburn was born in Casper, Wyo., on March 14, 1948, to Orin Wesley and Anita (Allen) Coburn. In Muskogee, where the family settled, his father was an optician who founded Coburn Optical Industries, which made ophthalmic equipment and eyeglass lenses. The company was sold in 1975 to Revlon for $57 million, although the elder Mr. Coburn continued as president of the subsidiary. Tom Coburn graduated from Central High School in Muskogee in 1966. In 1968, he married Carolyn Denton, the 1967 Miss Oklahoma. They had three daughters: Callie, Katie and Sarah, the operatic soprano. His wife and his daughters survive him.