In the 1973 blockbuster ‘Enter the Dragon, the legendary Bruce Lee is seen competing in a martial arts championship fighting against crime-lord Han who is armed with razor-sharp prosthetic arm. A decade later, in Terminator we see a cyborg assassin played by Arnold Schwarzenegger repair his robotic arm, and later in the climax is seen in his partly burnt robotic skeletal arms and face….
This on-screen Hollywood fictional journey from ‘metallic’ arm to ‘robotic’ arm in many ways is also the journey of the modern day, bionic technology. A journey that started centuries ago with artificial ‘wooden’ implants seems to be closer to its climax of ‘bio-mechanical’ ones.
Centuries ago…
In fact, the term ‘prosthetic’ has been derived from ancient Greek word prosthesis, which denoted an addition, application or attachment that is used to replace a missing body part. Not only the term, even the concept of using ‘prosthetic body parts’ is centuries old. Archeologists have found a wide range of crude body implants – wooden peg legs, strap-on toes, metallic limbs with hinged joints… though are primitive in nature, nevertheless are impressive attempts.
Modern day story….
Specialist prosthesist have donned the herculean task of precisely fitting a prosthetic part on the amputee’s stump, nonetheless even a job well done may not guarantee success as the stump can slip the surface owing to sweat or mere body pressure. While the most advanced prostheses have some degree of mental control, but expecting in-built sensory feedback mechanism – the wait could be just about a long one.
Future Challenges
One of the biggest challenges that modern-day bionic engineers are faced with is to match ‘nature’. To develop devices/tools that are able to perform exactly the same functions as a natural body part does, in a real-life scenario. Thus we use this technology to replace a missing body part. The two major challenges that every engineer is likely to face whilst developing a prosthetic that is closer to nature are: complex mechanics and multi-dimensional interface. In the first case, he has to design a mechanical limb using a range of miniaturized electric motors and advance computing power, and in the second try establishing an interface between these small machines and also the amputee’s body.
Journey Ahead
Owing to rapid advancements in modern science and computation technology, today it’s possible to think about moving a ‘bionic’ prosthetic arm or leg in perfectly synchronized manner using just brain power. We may be even getting closer to nature in the near future, as use of sophisticated bio-sensors coupled with new-age bionics will allow us to mimic the hand’s original sense of touch. Moreover, using the ‘Osseointegration’ technique it is now possible to graft some metal system onto the skeleton. Thereafter the metal system attached to the shaft of a bone activates the body’s innate healing process allowing the bone to grow directly onto and into the metal. Later, using 3D printing technology it is possible to cover the metal system using customized textures in accordance to the shape suited for bone tissue to look real.
In Conclusion
In future, bionic prosthetics directly attached to the skeleton would have several advantages. For instance, as they are fixed there would be a lower risk of slippages and there would be no incidences of sores being developed on the skin of the stump. The stress of movement would be directly passed onto the skeleton, reducing future complications. Also, neural connection already established through use of implants similar to cochlear implants, the system’s movements would be more sturdy and coherent.
Definitely, the sensory inputs from a synthetic system may not match the richness of a natural neural system, but the fact that the mind would be able to ‘send’ and ‘receive’ information to a bionic prosthetic would make an amputee function just about normal.
The terminator robot straight out of the sci-fi movie is no more a pipe-dream, we may be closer than we all think!
-Noel Fernandes
