TRANSHUMANISM
Background
18 million dollar project (Niesel and Herzog, 2006-2007)
Robotic prosthetic arm was invented by Dean Kamen (Adee, 2008).
The Deka Arm is also known as the “Luke Arm”, inspired from the character Luke Skywalker in Star Wars, the movie (Niesel and Herzog, 2006-2007).
Currently, prosthetic legs are much more advanced and more available than that of prosthetic arm. He says, “Prosthetic legs are in the 21st century. With prosthetic arms, we’re in the Flintstones.” (Adee, 2008). Why is this so? The human arm and hand is more complex than the human leg. Therefore, the Defense Advanced Research Project Agency issued a grant to fund this research on prosthetic arms, as well as hands that are able to perform simple functions such as pinching, gripping and flexing. (Niesel and Herzog, 2006-2007).
Demand for this technology
Despite the comparatively small market, where for example, in the Americas, only about 6000 people require arm prostheses each year (Adee, 2008), there is an increasing need for prosthetic arms, especially with disabled soldiers from the wars in Iraq and Afghanistan (Niesel and Herzog, 2006-2007). That is because troops are encountering explosive devices where their body armours are only able to protect their vital organs but not their limbs (Niesel and Herzog, 2006-2007).
DEKA ARM
Features
Light-weight (3.6kg/ statistically average female arm) (Adee, 2008)
Adjustable for different body frame sizes, customized to match the user
Modular (can be utilized by anyone with any degree of amputation due to separate sets of electronics for different parts of arm) (Adee, 2008)
Arm has fine motor control, with six preconfigured grip settings. It also changes its grip depending on the amount of weight the user is lifting (Adee, 2008). For example, grips get harder when the user lifts something heavy.
Thought-controlled (Adee, 2008)
Currently the Luke Arm offers 18 out of 22 degrees of freedom of a normal human arm (Niesel and Herzog, 2006-2007), with the intention to increase this number over time.
Current price: $100,000 or more, depending on the degree of amputation (Adee, 2008). (Mass production for the parts of the arm will make it more affordable)
How it works
Agility
As of 2008, the user of a state-of-the-art prosthetic arm is only able to move at three joints, by flexing or extending at the elbow, rotating of the wrist and simple open and close gripping. Essentially, there are only three degrees of freedom. Comparatively, the Deka arm is more agile. It allows 18 degrees of freedom, due to the vast circuitry inside the arm through the fine motor control (Adee, 2008).
Invasive prosthetic arm (where surgery is required)
During this project, Deka collaborated with neuroscientist Todd Kuiken of Rehabilitation Institute of Chicago, who had recently managed to successfully reattach an amputee’s remaining nerves via surgery to re-instill in him/her once again the sensation to “feel” the stimulation of the phantom limb. The patient only has to think about moving his/her arm, and signals would be emitted to his chest muscles instead. The chest muscles would in turn contract, and the electrodes which are connected to it, would send signals back to the arm – which moves. Kuiken’s surgery now allows users to take charge of the Luke arm with their own muscles, as though the arm were an extension of their flesh (Adee, 2008).
Non-invasive prosthetic arm (where no surgery is required)
However, it should be noted that the Deka arm can also provide feedback to the user even without surgery. This is done via a vibrating motor, called a tactor, fastened onto the user. The sensor of the Deka arm, which is linked to a microprocessor, would send signals to the tactor, of which is dependent on the strength of the user’s grip. The tactor vibrates when a user grips on to something and the frequency of vibrations increases upon a tighter grip (Adee, 2008).
Drawbacks
Before the Deka arm can be put into the market, it is required to be approved by the FDA, which is impossible without conducting clinical trials. As of 2008, there is no specific or clear plans on who will fund these trials. The funding that DARPA provides usually stops after another organization invest in the project. Deka is lacking of a transition partner as of now (Adee, 2008).
Reproduced from Lam (2010)
Reproduced from Robertson (2009)
Reproduced from Kamen (2009)