Dr. Murphy’s safe, reliable container replaced breakable glass bottles used in transfusions in the Korean War. He also helped improve pacemakers and artificial kidneys.Dr. William P. Murphy Jr., a biomedical engineer who was an inventor of the vinyl blood bag that replaced breakable bottles in the Korean War and made transfusions safe and reliable on battlefields, in hospitals and at scenes of natural disasters and accidents, died on Thursday at his home in Coral Gables, Fla. He was 100.His death was confirmed on Monday by Mike Tomás, the president and chief executive of U.S. Stem Cell, a Florida company for which Dr. Murphy had long served as chairman. He became chairman emeritus last year.Dr. Murphy, the son of a Nobel Prize-winning Boston physician, was also widely credited with early advances in the development of pacemakers to stabilize erratic heart rhythms, of artificial kidneys to cleanse the blood of impurities, and of many sterile devices, including trays, scalpel blades, syringes, catheters and other surgical and patient-care items that are used once and thrown away.But Dr. Murphy was perhaps best known for his work on the modern blood bag: the sealed, flexible, durable and inexpensive container, made of polyvinyl chloride, that did away with fragile glass bottles and changed almost everything about the storage, portability and ease of delivering and transfusing blood supplies worldwide.Developed with a colleague, Dr. Carl W. Walter, in 1949-50, the bags are light, wrinkle-resistant and tear proof. They are easy to handle, preserve red blood cells and proteins, and ensure that the blood is not exposed to the air for at least six weeks. Blood banks, hospitals and other medical storage facilities depend on their longevity. Drones drop them safely into remote areas.In 1952, Dr. Murphy joined the United States Public Health Service as a consultant and, at the behest of the Army, went to Korea during the war there to demonstrate, with teams of medics, the use of the blood bags in transfusing wounded soldiers at aid stations near the front lines.“It was the first major test of the bags under battlefield conditions, and it was an unqualified success,” Dr. Murphy said in a telephone interview from his home for this obituary in 2019. In time, he noted, the bags became a mainstay of the blood-collection and storage networks of the American Red Cross and similar organizations abroad.The vinyl blood bag developed with a colleague by Dr. Murphy, for use in transfusions. It ensures that blood is not exposed to the air for at least six weeks. Blood banks, hospitals and other medical storage facilities depend on blood’s longevity. Andreas Feininger/The LIFE Picture Collection, via Shutterstock(For years, researchers have said an ingredient in polyvinyl chlorides, diethylhexyl phthalate, or DEHP — used in making building materials, clothing and many health care products — poses a cancer risk to humans. Since 2008, Congress has banned DEHP in children’s products in the U.S.; the European Union has required labels; and alternative chemicals have replaced DEHP in blood bags.)In Korea, Dr. Murphy recalled, he saw Army medics reusing needles to transfuse patients, and medical instruments were often inadequately sterilized. Alarmed at the dangers of infection, he designed a series of relatively inexpensive medical trays equipped with drugs and sterilized surgical tools that could be discarded after a single use, greatly reducing the risks of cross-contaminating patients.In 1957, he founded the Medical Development Corporation, a Miami company that two years later became Cordis Corporation, a developer and maker of devices for diagnosing and treating heart and vascular diseases. With Dr. Murphy as chief engineer, president, chief executive and chairman, Cordis produced what he called the first synchronous cardiac pacemaker.As the use of implanted pacemakers became more common in the 1960s and ’70s, Dr. Murphy said, he saw that the devices might be improved upon to respond not only to irregular heart rhythms — usually an abnormally slow beat — but also to signs of bleeding, tissue damage, blood-clot formation or problems with the pacemaker’s electrode leads into the heart muscle.These complications led him and his team to develop a new generation of pacemakers that could be programmed externally. Out of this effort came the first “dual demand” pacemaker of the 1980s, with probes into two of the heart’s chambers for a fuller picture of the organ’s activity and creeping flaws.The advanced Cordis pacemaker contained a tiny computer that could detect heart problems and, in effect, have two-way electronic conversations with a cardiologist. The cardiologist could, in turn, devise noninvasive solutions and program the computer to carry them out.In addition, Dr. Murphy said, his team devised better ways to virtually “see” inside the vascular system. His motorized-pressure device injected, with precision, a small dose of liquid, containing iodine for color, into a selected vessel. There, the liquid showed up on an X-ray image, called an angiogram, providing a window into nooks and crannies where blockages might be lurking.To remove blockages, Dr. Murphy and a colleague, Robert Stevens, devised sterile vascular catheters, or probes, that allowed access to obstructions in vessels. (Today’s angiographic injectors have a space-age robotic look, with tiny cameras and lights in the probes and a television screen outside to guide the doctor’s way through the tunnels.)Under Dr. Murphy, Cordis also ventured into artificial kidneys, which cleanse the blood of waste products that accumulate normally in the body. Vital to sustaining life, the cleansing occurs when blood flows on one side of a membrane while a bath of chemicals flows on the other side. Impurities in the blood pass through tiny pores in the membrane into the bath, and are carried away.Dr. Willem J. Kolff, a Dutch physician, made the first artificial kidney during World War II. It was a Rube Goldberg contraption: sausage casings wrapped around a wood drum rotating in a salt solution. Dr. Murphy’s device used densely packed hollow fibers of synthetic resins as filters. Despite its inefficiencies, it was widely used in wearable or implanted artificial kidneys.Later advancements in artificial kidneys and dialysis have given thousands of patients with failing kidneys access to treatment and prolonged lives. But the devices still do not measure up to the efficient human kidney; bioengineered kidneys are still a hope of the future.Dr. Murphy retired from Cordis in 1985 to pursue other commercial medical interests. By then, he held 17 patents, had written some 30 articles for professional journals and had received the Distinguished Service Award of the North American Society of Pacing and Electrophysiology. He received the Lemelson-MIT Lifetime Achievement Award in 2003 and was inducted into the National Inventors Hall of Fame in 2008.A wounded American soldier receiving a transfusion during the Korean War. Dr. Murphy’s vinyl blood bag was tested under battlefield conditions. Bettmann/Getty ImagesWilliam Parry Murphy Jr. was born on Nov. 11, 1923, in Boston. His father, a hematologist, shared the 1934 Nobel Prize in Physiology or Medicine for a study that showed that a diet of raw liver could ameliorate the effects of pernicious anemia. His mother, Harriett (Adams) Murphy, was the first woman to become a licensed dentist in Massachusetts.William Jr. and his older sister, Priscilla, grew up in Brookline, the Boston suburb. As a teenager Priscilla became the youngest qualified female pilot in the country but died shortly afterward in the crash of a small plane in a snowstorm near Syracuse, N.Y., on a nighttime medical-mercy flight from Boston.Fascinated as a boy with mechanics, William devised a gasoline-powered snow blower, whose design he sold to a company.After graduating from Milton Academy in Massachusetts, he studied pre-medicine at Harvard, where his father taught, and graduated in 1946. He earned his medical degree from the University of Illinois at Chicago in 1947. While studying mechanical engineering for a year at the Massachusetts Institute of Technology, he developed a film projector to display enlarged X-ray images to medical audiences.Dr. Murphy interned at St. Francis Hospital in Honolulu, then practiced medicine briefly at Peter Bent Brigham Hospital (now Brigham and Women’s Hospital) in Boston before taking up his career in biomedical engineering.In 1943, he married Barbara Eastham, an American linguist who had been born in China. They divorced in the early 1970s. In 1973, Dr. Murphy married Beverly Patterson. She survives him, along with three daughters from his first marriage, Wendy Sorakowski and Christine and Kathleen Murphy; two grandchildren; and one great-grandson.Dr. Murphy delivered the keynote address in 2016 at a conference held by the Academy of Regenerative Practices in Fort Lauderdale, Fla. Regenerative therapy using stem cells became a particular interest in his later years. via U.S. Stem CellAfter retiring from Cordis, Dr. Murphy and a colleague, John Sterner, in 1986 bought Hyperion Inc., which designed, manufactured and marketed medical laboratory and diagnostic devices. In 2003, he joined the board of Bioheart, which developed stem cell therapies. He became chairman of Bioheart in 2010 and later chairman of U.S. Stem Cell, a successor company. In 2019, a federal court empowered the Food and Drug Administration to stop U.S. Stem Cell from injecting patients with an extract made from their own belly fat. The action came after three patients suffered severe, permanent eye damage resulting from fat extracts injected into their eyes to treat macular degeneration. The company had maintained that the extract contained stem cells with healing and regenerative powers, but medical experts disputed that claim.Dr. Murphy had by then become enthusiastic about the promise of stem cell research. In 2014, he spoke to a Miami conference about the rapidly growing and controversial field of using stem cells derived from bone marrow and umbilical cord blood to treat neurodegenerative conditions, diabetes and heart disease. “That’s a whole new world of regenerative therapy that’s going to be critical to our future,” he said.Alex Traub

Often called the father of the health maintenance organization, he coined the term in 1970, envisioning a system that would compete for patients by providing the best care at the lowest price.Dr. Paul M. Ellwood Jr., who changed the way millions of Americans receive private medical services by developing — and naming — the model for managed care known as the health maintenance organization, died on Monday in Bellingham, Wash. He was 95.His wife, Barbara Ellwood, said his death, at a care center, was caused by organ failure.Dr. Ellwood, who gave up practicing pediatric neurology in the late 1960s to devote himself to national health reform, was often called the father of the H.M.O., although many others made important contributions to the concept and some localized prepaid health plans had existed for decades.But it was Dr. Ellwood who conceived of — and in 1970 coined the term H.M.O. to describe — a partnership in which doctors are paid for the number of patients they see, not for each service given, and whose enrolled members are guaranteed access to network doctors and comprehensive care for fixed annual premiums.Dr. Ellwood envisioned large nonprofit organizations that would compete for patients by providing the best care at the lowest price and that would contain costs by keeping patients healthy to begin with, through an emphasis on preventive medicine, like regular physical exams, well-baby checkups, mammograms and immunizations.The elements of a system based on market forces were not new, but the integrated concept was.His plan got a fateful hearing in a chance meeting on an airplane with a Nixon administration official, and after extensive consultations with the White House, it became a cornerstone of national policy, with the aim of giving consumers a wider choice of health plans, stimulating cost-saving competition and raising the quality of care.Many of Dr. Ellwood’s ideas were incorporated into the Health Maintenance Organization Act of 1973. It required employers with 25 or more workers to offer H.M.O. options with their health insurance plans, and provided for incentives to start or expand H.M.O.s. Businesses, workers and unions were attracted by the cost-containment features in the law, and after a slow start, millions of Americans signed up.More than 70 million people in the United States are enrolled in H.M.O.s., which take many forms under an array of federal and state regulations. In a nation where medical expenditures exceed $3.6 trillion annually — 18 percent of the gross domestic product — H.M.O.s are among the most dominant and least expensive providers of medical care, although their impact on overall costs is still debated.H.M.O.s say they provide high-quality services while cutting overlapping medical consultations and unnecessary treatments and hospitalizations. But for decades critics have argued that prepaid plans invite cursory examinations and skimpy care. Studies have shown that elderly and poor patients fare worse in H.M.O.s, and some patients complain that the rules unfairly limit their choice of doctors and their access to specialists and costlier treatments.Dr. Ellwood, too, worried about the effects of cost controls on quality of care, especially after federal and state policy changes encouraged the growth of for-profit H.M.O.s. As H.M.O.s grew, merged and became enormously profitable, he repeatedly voiced disappointment with the way his original ideas had worked out in practice.“Only a portion of the dream that I had for the American health care system has been realized,” he told The New York Times in 1996. “There’s a huge piece of unfinished business.”Paul Murdock Ellwood Jr. was born on July 16, 1926, in San Francisco, one of two children of his namesake and Mary (Logan) Ellwood. He grew up in Oakland, where his mother was a nurse and his father was a family doctor who cared for impoverished patients and made house calls well into his 80s.After graduating from Oakland High School, Paul joined the wartime Navy and was a pharmacist’s mate in the Philippines from 1944 to 1946. At Stanford University, he earned a bachelor’s degree in 1949 and a medical degree in 1953.He began his internship in pediatric neurology at the University of Minnesota but was soon posted to the Sister Kenny Institute in Minneapolis, where he took charge of a polio clinic. He eventually became director of the institute and a professor at the university. After the development of polio vaccines, the clinic became a rehabilitation hospital, the American Rehabilitation Foundation, and began filling its beds by admitting children with learning disabilities.One night on his rounds, Dr. Ellwood found weeping children pleading to go home. “I realized these children didn’t really need to be in the hospital,” he recalled. “The only reason they were there was because that’s how their bills were being paid” — insurance companies would pay for care only if the children were hospitalized. “There’s something crazy about incentive here,” he thought. Pondering incentives, he recognized that doctors made more money if they performed more services, whether needed or not; that most doctors and hospitals benefited from the illness of patients, not their health; and that they were organized to react to illness, not prevent it.In the 1960s, while still working for the American Rehabilitation Foundation, Dr. Ellwood formed a health policy research group called Interstudy, which explored ways to apply business management techniques to improve health care and cut costs. It set up an H.M.O. that years later became United Health Group, now one of the nation’s largest health companies.In the early 1970s, Dr. Ellwood, having given up his medical career, moved to Wyoming, got into real estate and founded the Jackson Hole Group — a cohort of doctors, economists, academics and policymakers who met at his home periodically for decades to talk about new health care strategies.The group produced many reports, but its most notable was used by Bill Clinton in his 1992 presidential campaign, when he pledged to reform a health care system of runaway costs and uninsured millions. After Mr. Clinton’s election, Dr. Ellwood, the economist Alain C. Enthoven and others devised the blueprint for the administration’s “managed competition” health reform proposal.It would have banded businesses and individuals into cooperatives to buy insurance from partnerships of doctors, hospitals and insurers competing for the business, and it would have covered almost all uninsured Americans. The plan, shepherded by Hillary Clinton, failed in 1994, but by then Dr. Ellwood and his colleagues had distanced themselves from the plan over conflicts about the levels of regulation it would have imposed.Dr. Ellwood, who lived in Bellingham, north of Seattle, retired as president of the Jackson Hole Group in 2002. He and his first wife, Elizabeth Ann (Schwenk) Ellwood, had three children, Deborah, Cynthia and David. They divorced in 1990 and Elizabeth Ann later died. In 2000, he married Barbara Winch. In addition to his wife, Dr. Ellwood is survived by his three children and five grandchildren.In later years he championed what he called “outcomes management” — a national database to show how the treatment of patients actually works out. Without such measures, he argued, health care providers and policymakers had no way of knowing whether care was being compromised to cut costs, and no way to evaluate proposals for reforms.Dr. Ellwood generally favored President Barack Obama’s Affordable Care Act, although he worried that it included some of the “fatal weaknesses” of H.M.O.s, as he put it in a 2010 interview with Dr. Anthony R. Kovner, and that its implementation would face “formidable barriers — too many options and loopholes, and a vastly more savvy and aggressive medical-industrial complex.”In that interview, Dr. Ellwood proposed a national health institution modeled on the Federal Reserve, which tracks and regulates the economy.“We need a similar thing in health care,” he said. “We have to create an agency to collect health outcomes data, isolate it from the rest of the government and the rest of the health system, and then use its findings to determine what it is that’s worth spending public or private money on for health care.”Maia Coleman contributed reporting.