David Muir, Speech-Valve Inventor, Dies

A 28-year-old quadriplegic who was credited with inventing a valve that helped restore speech to thousands worldwide, died Thursday at his Arizona home.

David Muir lapsed into a coma Monday after he fell out of his wheelchair, knocking away an oxygen tube that allowed him to breathe.

At age 5, Muir’s condition was diagnosed as Duchenne’s disease, a progressive muscular dystrophy that left him without speech.

He had lived with his family in Anaheim Hills until 1987, when they moved to Arizona.

“He was just going to meet his nephew after his first day of school at the bus stop not far from the house when he lost control of the chair and fell,” said Sandra Whitten, Muir’s aunt. “Prior to that, he was OK.”

When Muir’s condition forced him to begin breathing through a ventilator, he lost his speech, said Patricia Passy, Muir’s business partner.

“This greatly frustrated him, so he began to study the equipment he was hooked up to,” Passy said. “From that, he designed a prototype for the valve that would allow him to speak.”

The device, called the Passy-Muir Tracheostomy Speaking Valve, redirects air flow and allows users to expel air through the mouth.

Passy and her husband, Victor Passy, an ear, nose and throat surgeon, helped market the device through their Irvine-based company. She added that since she and Muir began the business in 1985, more than 100,000 people who breathe with ventilators have used the device in hospitals throughout the country.

The company has also recently begun filling orders for hospitals in England, Sweden and Germany.

“He was very active in every phase of the business and did much to help people who had to deal with the same circumstances he did,” Passy said. “He even continued to visit hospitals and talk to people about it as his condition worsened. He only stopped when he had to.”

Passy said the business would continue to market the device, with Muir’s memory as inspiration.

“He revolutionized medical care for these patients and made it so much easier for people who are frustrated just like he was,” Passy said. “This device helps them tell the nurses and the doctors how they feel and keeps them in contact with the people around them.

“That’s what David wanted, and the business has always and will always have his stamp on it,” she said.

Muir is survived by his parents, June and Don Muir; his sister, Penny; one niece and two nephews.

Funeral services are planned Tuesday in Mesa, Ariz.