Saturday, June 25, 2011

Australian re-engineers century-old artificial limb

From The Billings Gazette in Montana:


Two amputees -- one American, one Australian -- are linked by sheer determination, and by an artificial arm patented in 1904.

Australian Mark Lesek (pictured) arrived in Billings on June 24 to strengthen the common thread that connects him to the grandfather of Nancy Kinsey, of Park City.

As a young man, Kinsey's grandfather, William T. Carnes Sr., lost his arm after it got caught in a cog in a machine shop accident. Carnes went on to become an inventor credited with several U.S. patents, including a forerunner of the jukebox.

After losing his arm at the Pennsylvania machine shop, Carnes engineered a sturdy artificial limb that strapped to the shoulder and relied on gears, springs and cogs to flex, rotate and grip objects. A mechanism designed like a revolver's firing pin allowed the wrist to rotate and lock into position. The prosthesis had movable fingers and 250 moving parts.

"Carnes tried out various arms that were on the market, and like me, found nothing very suitable," Lesek said. "So he invented one himself. With his left arm and his mouth, he put his first arm together."

Carnes began manufacturing the artificial arms after another amputee set him up with a factory in Kansas City, Mo. Advertisements billed the Carnes Arm as the artificial limb that "puts you back on the payroll."

"It was way ahead of its time," Lesek said.

Advertisements claimed amputees could tip their hat using the arm and carry a suitcase. But most of all, the arm was touted as allowing amputees to do manual labor in a machine shop.

Many were sold to veterans returning from World War I, and the company remained in business until the end of World War II.

Lesek, a 54-year-old who runs a machine shop, lost his right arm in a car crash in 2003. Because his amputation was so close to his shoulder, most sophisticated prosthetic arms weren't suitable. State-of-the art prosthetics rely on sensitive electronics to trigger nerve impulses, which initiate movement.

Lesek tried a cosmetic arm, but nicknamed it "Dudley" because it was a nearly useless dud. Six years ago, he bought a sophisticated arm built in Germany. But the $80,000 arm was too fragile for machine-shop work, and when it broke, it had to be sent back to Germany for repairs.

Three years ago, Lesek sought another solution. Doctors in Sweden screwed a bolt into the few centimeters of bone in his upper arm. The bone implant surgery, known as osseointegration, is not approved in the United States or Australia.

"The bolt gave me the shoulder function back," Lesek said.

Using the bolt as a base allows him to point the arm and feel connected to it.

About six years ago, Lesek ran across the Carnes Arm in a display case filled with antique prosthetic devices. Lesek was intrigued by online blueprints for the Carnes Arm.

Through friends and Internet connections, he found a Carnes Arm manufactured in 1920. The arm had been tucked away for 60 years after someone found the artificial limb after a flood hanging in a tree beside the Arkansas River.

"It started life as a left hand, I had to convert it to a right hand," Lesek said.

He later bought two other Carnes arms on eBay from different model years and meant to be worn with below-the-elbow amputations.

The Carnes Arm had a unique clockwork mechanism in the hand with finely beveled gears. But the top part of the arm was made out of willow wood, a material so heavy that Lesek doubted the arm could be used for any length of time.

Inspired by the century-old device, Lesek decided to refashion the arm, replacing certain parts. His Carnes Arm has new, lightweight materials above the elbow, but uses the original fingers and wrist rotation system.

"The actual moving parts are pretty well-original," said his wife, Angela.

Lesek intends to reinvent the arm with lightweight carbon fiber materials and modern machining techniques at his shop in Hobart, which is on the island of Tasmania, at the southernmost tip of Australia. His goal is to produce an arm that's simple and extremely sturdy.

Lesek contacted the descendants of William Carnes because he felt a kinship to the arm's inventor.

"They encouraged me to research the history of their family," Lesek said. "They're proud of their grandfather's achievements and were encouraging me to tell the world."

Last year, he visited the Kinseys in Montana. Last week, he returned to Montana with his wife before heading back to Australia on Sunday.

"We support all he does," said Nancy Kinsey.

She and her husband, Jim, are both aware of the daily hurdles faced by amputees. Jim had a leg amputated after battling deadly infections and other health problems.

Lesek intends to "reverse engineer" the artificial limbs, using a casting of an amputee's sound arm to tailor as a model for the missing arm.

He hopes to be able to begin putting out copies of the re-engineered Carnes Arm within a year.

For him, Park City was the last stop on a swing through the United States that included showing his arm at the Amputee Coalition of America conference in Kansas City and at Walter Reed Army Medical Center in Washington, D.C.

Lesek is intent on stirring support for approval of the bone implant surgery in America, which he thinks could benefit injured soldiers and other amputees.