Introduction
As technology has progressed, so too has our application and usage of technology. Society has applied technology to everyday uses such as, smart phones, personal GPSs for our cars, even on-line classes. An equally more important area in which technology has been applied to in recent years has been in the use of prosthetic limbs, or robotic limbs. But how would you connect a machine to human? What would be the ethical as well as technological issues associated with applying humans to technology? This paper will introduce robotic prosthetics, how they work and their benefits, what types are used, and what developmental hurdles are encountered. As well as cover any legal, security, ethical, and social issues due to the advancements in robotic prosthetics.
How Robotic Limbs Work and Their Benefits
In 1945 the National Academy of Sciences established the Artificial Limb Program, in order to advance the design and implantation of artificial limbs (Artificial/Prosthetic). Since then many programs and institutes have been researching and experimenting in order to make prosthetics fully functional, as well as practical in usage. Modern day prosthetics, or robotic limbs, are defined as mechanical limbs that are controlled by microprocessors and nerve impulses (Resnick, 2010). There are currently many ways in which the signals from a human nervous system are transmitted to the electronic parts within the prosthetic.
One of the most common forms in which signals are sent from an amputee to the prosthetic is through the use of electromyography sensors (EMG). When an amputee flexes his muscles the sensors are then translated into the prosthetic (Rewire the Nervous System, 2010). Another form to transmit signals from the amputee to the prosthetic is known as “targeted reinvention” (Rewire the Nervous System, 2010). This involves surgery in which the patient’s nerves of another part of his body are rewired to control where the missing limb may be. Both of these forms require brain plasticity. This means that the robotic limbs rely to an extent on a user training a certain movement, i.e. shrugging, to close the hand. Surgically implementing sensors into the stump of an amputee is also another way to connect the human nervous system to the microprocessors in the prosthetic (Doshi, 2011). These robotic prosthetics use these different methods of transmission in order to give back some form of former functionality that an amputee lost.
Types and Designs of Robotic Limbs
As with most technology, there are many different designs of robotic limbs. The company iWalk (using technology developed at MIT) developed the PowerFoot One, a robotic ankle and foot (Bogue, 2005 p. 425). The PowerFoot One operates by:
Several thousand times each two microprocessors and six sensors evaluate and adjust ankle position, stiffness, damping and power. Control algorithms generate human like force while traversing ground, slopes, and stairs, providing active amputees with near-normal gait and lower energy expenditure than existing, passive prosthetics. (Bogue, 2005) .
Another example of a lower body robotic limb is Ossur’s Rheo Knee. The Rheo Knee uses a learning matrix system, or artificial intelligence, to learn an amputee’s walking pattern. The Rheo Knee is powered by a lithium-ion battery and uses a force sensor and microprocessor to balance the knee (Bogue, 2005).
However, as in the case of feet and knees, robotic hands and arms have also been developed. Two such cases are Touch Bionic’s iLIMB, and the IOWA IOWA
Hurdles and Developments in Robotic Prosthetics
As with any technology, there are many problems that must be dealt with in order to work properly. Robotic prosthesis is no exception to the above rule. The most common problem with prosthetics is economics. This means that most prosthetics are not economically feasible for the average amputee. The reasons for this are size variations and the cost to produce the robotic components. Each prosthetic limb must be custom fitted or adapted to the amputee (Resnick, 2010). As no human is the exact same height, weight, and proportion to the next, then each one must have measurements taken to asses which modifications need to be made. Also robotic limbs can range from the high thousands to the millions of dollars; most of them easily costing more than “$100,000” (Resnick, 2010). Currently new materials are being tested that could more easily be shaped to fit an individuals needs and size (Resnick, 2010).
A more important technological problem is in the sensory itself, or connecting the living nerve’s signals to the machines. DARPA’s second generation arm, Proto 2, relies heavily on brain plasticity. Even Proto 2, which has the capacity to sense signals from nerves on the surface, still relies on training the mind to react a certain way in order to manipulate the machine (Sofge, 2008). A common thought solution to this problem would be for an amputee to be injected with tiny sensors that would then connect to the prosthetic, making communication easier(Sofge, 2007). However when scientists surgically connected sensors to a patient’s nervous system, the sensors failed within months harming the body’s tissue as well (Doshi, 2011). But a project led by a group of engineers at Southern Methodist, have found that by shinning infrared light they can stimulate a neuron to send messages. They also plan to user fiber optic cables, which would allow for faster transmission and possibly let prosthetics “speak” to the brain (Doshi, 2011).
Legal and Security Issues
Whenever humans and technology combine, topics regarding legality and security always come up. Robotic prosthetics is no exception. One of the main security, as well as legal, issues going on right now is between current robotic prosthetic users and the TSA. When an amputee goes through security at an airport he or she is almost always pulled aside for further screening. “A survey of 7300 amputees conducted by the Amputee Coalition of America in June showed that travelers with limb loss have been subjected to inconsistent, unfair, abusive and often embarrassing screenings by TSA employees” (Trimble 2010). One of these additional forms of screening is a CastScope, which stated by the TSA website is, “backscatter technology to produce an X-ray image of casts, braces, heavy bandages, and/or prostheses, allowing TSA to quickly and non-invasively identify any potential threats” (Castscope). The TSA states that this procedure is non-invasive and is required to insure that no harmful devices and/or substances are concealed (Castscope). However as previously stated many amputees feel that these practices are invasive, embarrassing, and unjust. They feel that they are being targeted due to their handicap. The opposite argument states that possible weapons or devices can easily be hidden in robotic limbs and the alternative of learning all the new types of prosthetics isn’t feasible due to the ever advancing technology of artificial limbs.
Ethical and Social Issues
As robotic limbs become more functional and capable, the question arises when they may give an amputee an unfair advantage. This question is what originally barred Oscar Pistorius from trying out in track and field for the 2008 Summer Olympics. Oscar Pistorius is a double amputee, who in 2007 sought to try out for the national track team. However the International Association of Athletics Federations (IAAF) ruled that his prosthetic limbs gave him an unfair advantage (Oscar, 2008). The report issued stated that Oscar Pistorius’s limbs return three times as much energy than a normal limb, and that they have twenty-five percent less expenditure than normal limbs (Oscar, 2008). Therefore giving Oscar Pistorius a clear advantage over the other runners.
Oscar Pistorius soon after filed an appeal with the Court of Arbitration for Sports (CAS) to appeal the decision. A report made by many renowned doctors and developers of robotic limbs convinced the CAS to over turn the decision. The report showed that when you consider the disadvantages as well as the advantages of prosthetics limbs, “lower-limb sprinting prostheses appears to be physiologically similar, but mechanically different than running with intact limbs” (Bundle, 2009). Even thought this report proved that prosthetics limbs gave Oscar Pistorius no clear advantage, it still raised the question. When will artificial limbs give individuals an unfair advantage?
Conclusion
By using microprocessors, with different types of sensors, as well as algorithms, we can build robotic parts that attach and even combine to an amputee. The progress and development of prosthetic limbs have been massive within the past ten years. Even though there are many developmental problems with robotic prosthetics, scientists and doctors are continually experimenting and building to create the next and better prosthetic. But as with any progression in technology there will always be concerns to how these progressions will effect and define society. Regardless of these concerns, modern prosthetics show us that technology has progressed to such a point that we can now combine robotic parts to humans to replace those originally lost, at near fully functional levels.
References
Artificial/ Prosthetic Limbs. (n.d) Retrieved February 13, 2011, from http://www.medindia.net/patients/patientinfo/artificial-limbs-history.htm
This is a website, aimed towards patients, giving historical background on prosthetics.
Bogue, Robert. (2009). Exoskeletons and robotic prosthetics: a review of recent developments. The Industrial Robot, 36(5), 421-427. Retrieved February 27, 2011, from ABI/INFORM Global. http://proquest.umi.com.mutex.gmu.edu/pqdweb?index=0&did=805601871&SrchMode=1&sid=5&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1298861776&clientId=31810
This article was aimed at introducing the many types of exoskeletons and robotic prosthetics currently in use and in development.
Bundle, M., Herr, H., Weynad, P., Brown, M., Kram, R., Grabowski, A.,(2009) The fastest runner on artificial legs:
different limbs, similar function? Journal of Applied Physiology 10. Vol 107 Issue 3 P. 907 Retrieved February 13, 2011, from, http://jap.physiology.org/content/107/3/903.full
This was a report made by many renowned doctors and scientists proving how an amputee did not have an advantage due to his prosthetics. This was a major report in regards to a social and ethical issue.
CastScope (n.d.) Retrieved February 13, 2011, from, http://www.tsa.gov/approach/tech/castscope.shtm
This was the TSA’s website detailing what a Castscope is and why it is necessary to perform.
Doshi, Rajeev. (2011, March) Talk to the Hand. Popular Science, 44.
This is a recent article detailing a new method that is being used in robotic prosthetics and sensory information.
How to rewire the nervous system;. (2010, September). The Economist, 396(8698), 21.
Retrieved February 13, 2011, from ABI/INFORM Global.
This article gave a brief background on the types of sensory detection and processing between humans and robotics.
Oscar Pistorius - Independent Scientific study concludes that cheetah prosthetics offer clear mechanical advantages (January 14, 2008) Retrieved February 13, 2011, from, http://www.iaaf.org/news/kind=101/newsid=42896.html
This was a statement released by IAAF on their own website detailing how a scientific report showed how an amputee had a clear advantage.
Jingzhou Yang, Karim Abdel-Malek, & Jason Potratz. (2005). Design and prototyping of an active hand prosthetic device. The Industrial Robot, 32(1), 71-78. Retrieved February 13, 2011, from ABI/INFORM Global. http://proquest.umi.com.mutex.gmu.edu/pqdweb?index=0&did=805601871&SrchMode=1&sid=5&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1298861776&clientId=31810
The above writing gave information of different types of hand prosthetics and methods of operation.
Resnick, Brian. (2010). The Problem with Modern-Day, High Tech Prosthetics. Popular Mechanics. Retrieved February 13, 2011, from, http://www.popularmechanics.com/science/health/prosthetics/high-tech-prosthetics-fitting?click=main_sr
This article gave details on the sizing and cost problems associated will robotic prosthetics.
Sofge, Erik. (2007). DARPA's Better Bionic Arm: Our Most Limb-Like Prosthetic. Popular Mechanics. Retrieved February 13, 2011, from, http://www.popularmechanics.com/science/health/prosthetics/4218218?click=main_sr
This article details DARPA’s efforts to develop a fully functional robotic arm.
Sofge, Erik. (2008). For Future of Mind Control, Robot-Monkey Trials Are Just a Start. Popular Mechanics. Retrieved February 13, 2011, from, http://www.popularmechanics.com/science/health/prosthetics/4272246
This was an article that continued detailing DARPA’s development and issues with their robotic arm.
Trimble, Tgyhe. (2010) The Problem With Prosthetics and Airport Security. Popular Mechanics. Retrieved February 13, 2011, from, http://www.popularmechanics.com/technology/aviation/safety/the-problem-with-prosthetics-and-airport-security
This article detailed robotic prosthetic users problems and concerns
