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A Step in the Right Direction: Advancement in Robotics Leading to Better Prosthetics

3356514403_e378d11342New strides in robotics technology have made it possible to create new types of prosthetics, which can function more naturally than a passive artificial leg. The H. Fort Flowers Professor of Mechanical Engineering at Vanderbilt University, Michael Goldfarb and his colleagues at the Vanderbilt’s Center for Intelligent Mechatronics are the leaders in lower-limb prosthetic research and have expressed their views on robotic prosthetics in an article in Science Translational Medicine‘s November issue. Goldfarb’s team developed the first robotic prosthesis, which included a powered knee and ankle joints. Their design became the first artificial leg controlled by thought after researchers at the Rehabilitation Institute of Chicago added a neural interface to it.

Technological advances, such as lithium-ion batteries, powerful brushless electric motors with rare-Earth magnets, and miniaturized sensors built into semiconductor chips, have allowed for new developments in robotic prosthetics. The electric motors, whose batteries store a single charge with enough power to last a full day, serve as the “muscles” of the prosthetic. The sensors function as its “nerves” like those in the peripheral nervous system by providing information like the angle between the thigh and lower leg and the force exerted on the bottom of the foot. The microprocessor acts as the central nervous system by providing coordination.

In order to recognize a user’s intent to do different activities, there must be and effective control system that provides some type of connection with the central nervous system. There are many different methods available, but it is still undecided which of these is best. The least invasive approach uses physical sensors to differentiate between the user’s intentions and his or her body language. Electromyography interface is a different approach that places electrodes within the user’s leg muscles. The most invasive techniques entail electrode implants inside the user’s peripheral nerves or directly into his or her brain.

Bionic legs seem to provide many possible advantages over passive artificial legs. Lower-limb prostheses with a powered knee and heel joints have demonstrated faster walking speed and decreased hip effort while using less energy. Robotic prosthesis could also decrease the rate of falls leading to hospitalization due to the leg’s natural movement, improved compensation for uneven ground, and ability to help users recover from stumbling. Despite their benefits, robotic legs face some issues before being launched in the United States. These challenges include approval from the United States Food and Drug Administration (FDA) and additional robotics training for clinicians prescribing these types of prostheses.

In spite of these challenges, this new development of robotic legs will surely prove beneficial to amputees across the country. Is there a more efficient way to help the public gain access to this type of technology? What can be learned from these new advances?

Photograph by Andy Polaine

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Can timing change everything?

A Map of Cambodia: Cambodia Map from CIA World Factbook

Amongst individuals living with HIV, twenty to thirty percent die because of an additional tuberculosis infection. This co-infection is extremely common in Cambodia, a nation with 63,000 out of 13.2-million individuals living with just the HIV diagnosis, which eventually leads to AIDS. The HIV/Tuberculosis co-infection makes up 6.4% of Cambodia’s 5% HIV diagnosed population.

Dr. Anne Goldfeld, who has done studies on this trial as a Harvard Medical School employee and as President of the co- founder of the Cambodian Health Committee, says,

“Tuberculosis claims the lives of more than half a million people with HIV worldwide every year…”


She also says,

“This is a tragedy, because TB is completely curable when diagnosed and treated properly even in a patient with advanced HIV, especially if the patient also receives anti-retroviral therapy.”


In the past, the treatment for the co-infection has been very consistent. The treatment for Tuberculosis has been given to a patient immediately upon diagnosis. Two months later, anti-retroviral (ART) therapy for HIV would be given. However, recently, a trial entitled CAMELIA , >Cambodian Early versus Late Introduction of Antiretroviral Drugs, has helped give hope to HIV patients. The trial, which was created by Cambodian, French, and


American doctors, began in 2006 and lasted until 2010, encouraged five Cambodian hospitals to give HIV treatment to co-infected diagnosed patients only two short weeks following anti-tuberculosis treatment. The five hospitals are Calmette Hospital, Khmero-Soviet Friendship Hospital, and three provincial hospitals in the Siem Reap, Svay Rieng, and Takeo regions. This trial cut down the waiting time for HIV treatment by six weeks and overtime, the trial increased the survival rate of co-infected individuals by 33%.  Could six weeks really change the chance of survival for tuberculosis and HIV co-infected patients by such a great percentage? The answer is: absolutely! Did all medical physicians involved in this field of medicine agree with these techniques used to aid co-infected individuals? The answer is: definitely not.


Many of those who were opposed to the trial’s process said that the two treatments of Tuberculosis and the HIV  would wear the body down if done at similar times. Additional difficulties could be created for the body, which could already face toxicity with the required seven pills a day. The treatment was not risk-free either. It was possible that the immune system could become increasingly inflamed as it “rebound[ed] from HIV’s suppressive influence.” This trial was also available to patients who had an extremely strong immune system (given their diagnosis) at the time of treatment. Nevertheless, the benefits of the treatment have been much greater and more substantial than those doctors’ fears holding co-infected individuals from getting treated.

Doctors are still learning how the CAMELIA treatment can be improved and altered for the future. However, there has been enormous success with moving the treatments of co – infected Tuberculosis and HIV patients closer by six weeks. In just Cambodia, 661 patients participated in the CAMELIA trial, and less than one percent of the population participating, missed an appointment of the 8,955 scheduled for the population at the five separate hospitals. Many doctors, Cambodian citizens, and observers wanted this trial to work, and it was happening! The World Health Organization (WHO) should be encouraging this treatment more! Thirty three more percent of the initially co-infected patients of Cambodia are living! So where will the trial go next to help co – infected Tuberculosis and HIV patients? Ethiopia.

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