The Evolution of Prosthetic Devices: A Patent History

By Steve Brachmann
December 1, 2014

The past decade has been a very interesting time in the area of developing prosthetic devices which can help a person regain some of the motion and motor skills they lost because of an amputation. On December 9th, the Intellectual Property Owners Education Foundation will convene to recognize the achievements of Dr. Hugh Herr, who is the IPOEF’s selection for its 41st Inventor of the Year. The contributions of Dr. Herr to prosthetic device development has led to revolutionary developments in foot and calf bionics, allowing those who haven’t walked for years to take their first steps on their own. As the press release linked above states, Dr. Herr is of the belief that disability can be eliminated within this century through greater research and development in bionics.

With this honor being bestowed upon a developer of prosthetic devices, we thought it would provide a good opportunity to return to our Evolution of Technology series for an in depth look at the development of prosthetic devices. Our story of the history of prosthetic devices takes us from decorative beginnings in ancient societies through the high-tech devices being constructed to enable the mind to more easily control bionic limbs which have an incredible range of function. A long and sometimes very difficult road has been traveled for millennia towards a current atmosphere where hope for the future of bionic development is very high.

[Bio-Pharma]

 

Prostheses in the Ancient World and the Middle Ages

The oldest known prosthetic device existing in our world is also one of the smallest. Scientists have dated a wooden prosthetic toe found in mummified remains in Cairo to somewhere around the year 950 BC. The “Cairo Toe,” as it came to be known, was a prosthetic used to replace the wearer’s big toe. It is intriguingly lifelike, being shaped, carved and stained to imitate the natural look of an ancient Egyptian’s big toe, and much of that natural aesthetic is still evident when looking at pictures of the primitive device. The toe consisted of two wooden pieces which were lashed together by leather thread through holes bored into the wood; the toe also had a leather strap which secured the toe to the foot through more leather threads.

This attention to the aesthetic appeal of prostheses is fairly common among ancient devices and may even have been more important than helping to improve function. Another prosthetic device from the ancient world known as the “Cartonnage Toe,” which dates to about 600 BC, may have been made strictly for cosmetic purposes.

The medical practice of amputation goes back as far as the 4th century, when Hippocrates described the procedure in his medical text “On Joints.” Amputations in the ancient world and through the Middle Ages occurred for many reasons which are, thankfully, not common practice today. The taking of a limb could have resulted from a ritual sacrifice or a punishment for stealing just as well as a battlefield wound, and in fact many centuries would pass before battlefield medicine reached the point where it could save those who needed amputation. Through the Middle Ages, the medical procedures involved such brutal practices which, coupled with no practical knowledge of germ theory and patient care, resulted in an 80 percent mortality rate.

Other early prosthetic devices either exist or are known. Although it was destroyed during an air raid in World War II, the “Capua Leg” is the world’s oldest prosthetic leg, dating back to 300 BC and found in Capua, Italy. A replica of the leg exists and it has been shown at the London Science Museum. Records from the Roman scholar Pliny the Elder, writing in the 1st century AD, describes a right arm prosthetic designed to hold a shield used by a general in the Second Punic Wars (218 BC – 200 BC). Medical development during the Middle Ages was very limited, however, and there was little work to be done in this field until the next major period of cultural development would occur in Europe.

The Renaissance and Ambroise Paré

In order to increase development of prosthetic devices, more patients undergoing amputations had to live through the medical procedure. That didn’t start to happen until the 1500s. Many of the medical discoveries that enabled those undergoing major limb amputations to enjoy much better survival rates came from the work of one French doctor, Ambroise Paré. By 1529, the surgeon-barber began to employ the practice of more effective amputation procedures which he had learned himself. By 1536, he was creating prosthetic devices for patients with either upper-body or lower-body amputations.

Much of Paré’s work overturned many of the widely held medical beliefs of the time, some of which actually did more harm than good. For example, Paré found that the application of oils to the site of a gunshot wound or other injury, which was thought to help induce healing, actually had a negative effect on the wounds. So did cauterization, which was another widely practiced technique that Paré proved ineffective. Instead, Paré found success in tying arteries, becoming possibly the first doctor to do so.

Prosthetic devices of the period again evidenced aesthetic concern on behalf of the wearer. A metal arm developed in the early 1500s, before Paré’s developments, was worn by Götz von Berlich, a Franconian Knight who lost his arm in battle in 1504 when he was hit by a cannonball. Although the arm’s function is limited, an incredible attention to detail is evidenced in the crafting of the nail beds and knuckles of this hand.

From U.S. Patent No. 18021, entitled “Artificial Hand.”

After Paré, however, the development and use of prostheses would again stagnate for a couple of centuries, although a few useful improvements were learned along the way. Dutch surgeon Pieter Verduyn created a non-locking below-knee prosthesis in 1696. A little more than 100 years later, in 1800, James Potts of London developed an articulated knee-and-foot prosthesis which became popular. By the 1840s, these developments had reached America through William Selpho, an apprentice of James Potts. Selpho would eventually go on to apply for patents for his prosthetic devices and was awarded at least U.S. Patent No. 18021, entitled Artificial Hand. The prosthesis is secured to an arm by securing a loop around the shoulder of the opposite arm. As this patent discusses, cat tendons were often used in these devices to provide actuation of the fingers and other articulated portions of the prosthetic device.

[Varsity-2]

 

American Prosthetics and the Civil War

The Civil War lives on in America’s collective consciousness as the bloodiest conflict in our history, though that’s not entirely true; more American soldiers died in battle in World War II, even when combining Union and Confederate losses. However, more American soldiers died overall during the Civil War than in World War II, and poor medical knowledge relevant to wound care was a major reason for this.

In fact, the Civil War may have helped spawn the first major explosion of the United States’ prosthetic device industry. About 70 percent of all wounds sustained by Civil War soldiers affected their limbs and the decision to amputate was often the choice when a quick decision was needed on the battlefield to save a life. Some 70,000 soldiers serving on either side of the Civil War lost limbs during the four years of the conflict.

From U.S. Patent No. 951989, which is titled “Artificial Limb.”

The ghastly nature of the condition of many soldiers returning from conflict led to the federal government taking action in the form of its “Great Civil War Benefaction” program. This little-remembered project made a commitment on behalf of the government to provide prosthetic devices to every Civil War soldier who needed one. Manufacturers building devices on government contracts often overstated the comfort level and practicality of the limb, but some important innovations were experienced during this time. For example, the use of rubber in prosthetic devices was new to this period. Beginning in 1863, rubber began to find use along with, or instead of, wood and metal, providing a more natural appearance, better resiliency and more flexibility.

Dissatisfaction with the prosthetic devices available at the time led the first documented amputee of the Civil War to become one of the earliest successes of the prosthetic device industry in America. James Edward Hanger, a Confederate soldier, lost his leg above the knee after he was shot by a cannonball. Although the J.E. Hanger & Company is listed in a few patents issued during the late 1800s that we found, the earliest patent assigned to James E. Hanger as an inventor that we found was U.S. Patent No. 951989, which is titled Artificial Limb. The patent protected a foot prosthetic with pneumatic functions which was designed to work noiselessly.

Work, Cosmetics and the U.S. Military in Prosthetics Research and Development 

Although World Wars I and II did not produce the same focus on prosthetic development that the Civil War did, the U.S. Department of Defense has maintained some development activities or strategic partnerships with organizations in prosthesis fields. One result of World War I was the development of the American Orthotics and Prosthetics Association, an organization responsible for research and development in prosthetic fields and one which is still in operation today. More veteran dissatisfaction over the prosthetic devices available after World War II also pushed the government to invest more in prosthetics developments in their contracts with defense technology manufacturers.

From U.S. Patent No. 3638243, issued under the title “Surgically Implantable Prosthetic Joint.”

Designing artificial limbs to accomplish some very specific tasks was a hallmark of many of the turn of the 20th century prosthetic devices we came across. In 1906, a female pianist played a show at London’s Royal Albert Hall using a right-hand prosthetic with fingers spaced to play an octave on the piano. Other photos we came across demonstrated people wearing prosthetic devices designed to aid in blacksmithing or manufacturing work. Taking a quick look at patents protecting prosthetic devices through the middle part of the 20th century, we found prostheses for replacing a wide array of extremities. Many of these reflected the appeal of providing a cosmetic replacement for a surgically-removed appendage, which can be seen in the technology protected by U.S Patent No. 3651522, which is titled Prosthetic Brassiere for Use After Surgical Breast Removal. Assigned to the Berger Brothers Company of New Haven, CT, in March 1972, it protected a device that utilized an inflatable bladder to simulate a bustline. Hip joint replacements were also being developed, which we saw in U.S. Patent No. 3698017, which is titled Prosthetic Acetabular Devices, assigned to the National Research Development Corporation of London in October 1972. Methods of incorporating prosthetic devices on humans were also becoming more sophisticated, as is evidenced in U.S. Patent No. 3638243, issued under the title Surgically Implantable Prosthetic Joint. The technology enables the implantation of hinge-type joints within the human body for the replacement of knee, elbow or finger joints. The patent was assigned to Ohio State University in February 1972.

Advances in bionics and massive investment through the U.S. Department of Defense’s Defense Advanced Research Projects Agency (DARPA) has brought about an intriguing new wave in prosthetic technology within the past decade. In May of this year, the DEKA Arm system developed by DARPA and Dean Kamen, inventor of the Segway, was awarded approval by the U.S. Food and Drug Administration. This prosthetic system utilizes a series of electrodes capable of reading muscle movement so that a wearer feels as though the appendage is being naturally operated by the brain. (see YouTube video below). This system can handle fine motor operations like picking one grape from a bunch and bringing it to a person’s mouth. Vibrations generated by the prosthetic device can tell a person if they are gripping fruit, keys or some other item too hard. DARPA has invested more than $100 million into the technology and more than 300 scientists have contributed to the project; Army colonel Dr. Geoffrey Ling, head of the Pentagon’s “Revolutionizing Prosthetics” program, likened the scope of the government’s involvement in prosthetics to the Manhattan Project.

The history of prosthetic device development has shown that people are interested in prostheses both for regaining mobility lost through amputation or for cosmetic cover-ups, and that the two aren’t always intertwined. Many of the inventors spending years to develop these medical aids were the very people those devices were intended to help, throwing an interesting light on how necessity truly can be the mother of invention. In our next piece, we’ll take a greater in-depth look at the work of this year’s IPOEF Inventor of the Year and how Dr. Hugh Herr’s developments follow squarely in the footsteps of this technology’s evolution.

The Author

Steve Brachmann

Steve Brachmann is a freelance journalist located in Buffalo, New York. He has worked professionally as a freelancer for more than a decade. He writes about technology and innovation. His work has been published by The Buffalo News, The Hamburg Sun, USAToday.com, Chron.com, Motley Fool and OpenLettersMonthly.com. Steve also provides website copy and documents for various business clients and is available for research projects and freelance work.

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  1. Bob O'Connor December 11, 2014 7:22 am

    Great article! I study James Hanger and wrote a book about him — “The Amazing Legacy of James E. Hanger, Civil War Soldier”. His first two artificial limb patents were actually filed with the Confederate patent office — #155 and #201 — in 1863 — Hanger artificial limb and Improvement on Hanger limb. Both documents and the drawings were destroyed with the fires at the end of the war in Richmond. His first US Patent was December 22, 1871 — #465,698 Artificial Leg.
    Bob O’Connor