InventorsEye
Inventors Eye
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October 2013. Volume four, issue five.0


The USPTO's bimonthly publication for the independent inventor community

Old patent drawings of prosthetics lying on table.

Tracking Innovation: Prosthetics

With rapid advances in technology for prosthetics in recent years, the field offers a good study in how patents help spur innovation. Prosthetic limbs available on the market today incorporate developments found in multiple fields, from biomechanical and precision engineering to rapid prototyping and electronic microprocessors. The synthesis of new technologies and scientific principles has led to devices that offer better mobility and comfort for users.

The origins of prosthetics predate history, but Ancient Greek and Roman records indicate that early artificial limbs were fashioned from bronze, iron, or wood. Trends in early prosthetics focused on either cosmetic appearance or functionality, but rarely both. These designs sought to appear lifelike, often carved from wood or leather and painted in flesh tone colors but without articulation. Function trumped appearance. All of these devices were uncomfortable. Not much changed for centuries.

The American Civil War is often regarded as a watershed moment in the development of prosthetics. As new weaponry, particularly the “Minie ball” bullet, regularly inflicted destructive wounds, advances in surgery allowed field doctors to amputate as a common treatment for limb injuries. These advances led to more soldiers surviving combat with amputated limbs. After four years of fighting, some 70,000 soldiers on both sides of the conflict had lost a limb. The U.S. government, recognizing a significant medical need among war veterans, initiated a program to supply prosthetic devices to every amputee. Almost overnight, a large demand for prosthetics emerged.

Patents played an important role in the rise of the prosthetics industry. The incentive provided by patents to exclude others from making or selling their technology encouraged inventors to take new approaches in design and manufacture. Patents for artificial limbs and improvements to artificial limbs turn up frequently in prior art in the years following the Civil War. Among these is U.S. patent no. 111,741, a hinged design for a leg prosthesis invented by James E. Hanger. Hanger, reportedly the first documented soldier amputee of the Civil War, was awarded a government contract to manufacture and supply his invention to war veterans. The company he founded is still a leading manufacturer of prosthetics 150 years later.

Today, examiners at the United States Patent and Trademark Office (USPTO) continue to see new innovations in prosthetic technology. Among the trends is a shift from passive devices to those powered and controlled through electronic means. These microprocessor-controlled devices have advanced articulation and are able to analyze wearers’ movements and make adjustments on the fly. Such devices allow users to perform movements and tasks with heightened agility and sensitivity. Also exciting is the incorporation of new manufacturing techniques that allow for better-fitted devices: doctors can use computer imaging to model the bones and physical features of a patient, design a custom prosthesis, and have a rapid prototype created in a matter of hours.

During the Civil War, the Old Patent Office Building in Washington, D.C., doubled as a hospital for Union soldiers. Surrounded by agony and suffering, patent examiners must have found it heartening to review applications for new devices that would soon offer improved conditions for the wounded men around them.

Alex Camarota : Office of Innovation Development