London ( CNN ) -- What do will.i.am and Iron Man have in common ? They 're both rather partial to bionic limbs . In his latest music video , `` Scream & Shout , '' a human hand can be glimpsed clasping what appears to be a sophisticated robot hand stolen from the set of a high-budget sci-fi film . What many of the video 's 97 million ( and counting ) viewers may not realize , however , is that the appendage in question is a genuine prosthetic hand that , its makers claim , has taken us one step closer to truly simulating the real thing . Unlike conventional prosthetics , the i-limb Ultra boasts five individually-powered articulating digits , as well as a fully rotatable thumb and wrist , enabling the user to perform a variety of complex grips . `` The first generation ( of prosthetics ) had what I call a pincer grip -- the fingers are reflexed so they do not change shape and they move in one plane , '' explains David Gow , the British inventor and engineer behind i-limb . `` Whereas what we produced is something that rotates at the knuckles . '' The i-limb is the latest in `` myoelectric prosthesis '' -- a process that uses electrical sensors to detect tiny muscular movements in the residual limb , which are then translated by an on-board computer into natural , intuitive movement of the mechanized hand . In practice , this requires the wearer to learn a language of muscle movements around the wrist , which correspond to a vast array of pre-programmed hand and finger motions . Although it requires a fair bit of concentration to begin with , Gow says that -- much like playing an instrument -- the mechanism is intuitive once muscle memory takes over . As well as the practical benefits afforded by the added range of grips , Gow believes the i-limb carries a significant psychological advantage because finger movements are what most people associate with the human hand . `` When you have only one shape for the hand and it is not a particularly everyday natural one , it looks strange , '' he says . People who 've used the i-limb `` say they see the digit as what gives them the sense of having a hand back . '' Donald McKillop lost his right arm in an accident at home 35 years ago . He was one of the first amputees to try an initial version of the i-limb back in 2007 . `` Every day I 'm finding new things with it -- it 's absolutely amazing ... It 's the hand I thought I 'd never have again , '' he said . But of course , although it can rotate 360 degrees , the i-limb is still far from measuring up to the real thing . `` We ca n't approach the subtlety of skin , sensation of temperature , touching things yet , '' admits Gow . `` But we 've broken through the barrier of making a hand that looks like a medical device . '' As things stand , the i-limb is also prohibitively expensive . Including fitting and training , a hand costs in the region of $ 100,000 . Perhaps in part because of this , most of the 4,000 or so i-limb users in the world are war veterans from Iraq and Afghanistan . Gow notes , however , that the potential market is huge : there are presently an estimated two million upper limb amputees across the globe . Touch Bionics , the company that Gow founded to produce the i-limb , is looking to take its share . Gow , who left the company in 2009 , says sales are accelerating and 2012 saw turnover reach over $ 16 million . For the Scotland-based engineer , who abandoned his career in the defense industry to dedicate himself to the study of prosthetics , the i-limb is much more than a business . `` I have seen hundreds of people ... I have seen the father that says 'thank you ' on behalf of his son , '' Gow says , wiping a tear from his eye . `` That means an awful lot because you do n't , as an engineer , get many moments where you articulate human emotions about these things . ''
The i-Limb is the first prosthetic hand that has five individually-powered articulating digits . Wearers control hand via an electrical sensor that detects muscle movements in residual limb . A team of researchers from MIT and Harvard Medical School have developed a new way to measure brain activity using magnetic resonance imaging (MRI) technology. + i-Limbs in operation have been fitted to veterans from wars in Iraq and Afghanistan .