Last month, Caroline Amplatz heard a presentation about the struggle to raise money for a new children's hospital at the University of Minnesota. The $275 million project was still $100 million short, and university officials were offering naming rights if the right donor came along.

Minutes later, Amplatz, an attorney from Golden Valley, had cut a deal: She pledged $50 million to name the hospital in honor of her father, Dr. Kurt Amplatz, a retired professor and a pioneer in Minnesota's medical device community.

The gift, announced Tuesday, is the second largest in the university's history.

Caroline Amplatz, 44, who is a member of the University Pediatrics Foundation board, said it wasn't a hard decision. "At that moment I realized this hospital needs to be the Amplatz Children's Hospital," she said at a news conference Tuesday to announce the gift.

The hospital, set to open in 2011, will be named the University of Minnesota Amplatz Children's Hospital.

University President Robert Bruininks called Kurt Amplatz, 84, "one of the great pioneers of medical research and of Minnesota's medical device industry."

The elder Amplatz, who lives in North Oaks, taught radiology at the university from 1957 until he retired in 1999. He holds more than 30 patents, and is best known for inventing a tiny device to repair congenital heart defects in children and adults. In 1995 he also founded a medical device company, AGA Medical, in Plymouth.

The donation will be paid over 12 years and will fund children's research and treatment, including a facility for children with damaged hearts. It represents a second key piece in the financing of the new hospital, which broke ground last summer. Fairview Health Services has agreed to finance $175 million of the $275 million overall cost for the building, which will be on the Riverside campus of the University of Minnesota Medical Center, Fairview.

This is the university's third multimillion-dollar donation for medical care in the last year. Last April, the Minnesota Masonic Charities announced the single largest donation, $65 million for cancer research. In December, Best Buy founder Richard Schulze pledged $40 million for diabetes research.

Caroline Amplatz declined to identify the source of the funds for her donation. She has two foundations of her own, one to support education in Latin America and one to support Twin Cities children in the performing arts.

Her former husband, Franck Gougeon, co-founded AGA with her father. Her father, however, was not at the news conference "because he is skiing in Aspen," she said. "He always goes at this time."

While teaching at the university, Amplatz merged his interests in radiology, engineering and cardiology to revolutionize the practice of pediatric cardiology. Perhaps his most famous invention is the Amplatzer Septal Occluder, which is used to repair a hole in the heart, a common congenital defect in infants.

The device became the foundation of AGA, and more than 90,000 units have been sold worldwide since 1996, according to the company's website. The company was later rocked by a series of feuds in top management, and a former executive, Michael Afremov, pleaded guilty in 2005 to operating a kickback scheme. Last year Gougeon stepped down as CEO, and the company agreed to pay a $2 million criminal fine in connection with payments to Chinese officials.

Speaking after the news conference Tuesday, Caroline Amplatz said the donation was her decision, not her father's. She said she had told her father about it, but doesn't know what he thinks of it. "He's keeping his thoughts to himself," she added with a smile.

Staff writer Janet Moore contributed to this report. Maura Lerner • 612-673-7384 Josephine Marcotty • 612-673-7394