As engineering and technology attained new heights of advancement, scientists devised a method to connect bionic devices to the muscular and nervous systems through electric signals. The most common method that can be used to achieve this synergy between the human body’s movements and the bionic prostheses is an EMG control system that uses biosignal processing to enhance the control of the hand. EMG signals are used to interpret the intensity and desired movement which is then used to control Zeus. These signals allow the user to open and close the hand, along with changing grip patterns and the speed in which the hand operates.
Another method that has gained popularity is targeted muscle reinnervation method was utilized successfully in the case of Jesse Sullivan, a former electric lineman who lost both his arms above the elbow in an accident. In 2001, Sullivan underwent TMR surgery to have the nerves from his amputated arms rerouted to his chest muscles. This allowed him to control a pair of robotic arms called the DEKA Arm System. The DEKA Arm System uses sensors to detect the electrical signals from Sullivan's chest muscles, which are then translated into movements of the robotic arms. With this system, Sullivan was able to perform a variety of tasks that were previously impossible with traditional prosthetics, such as using a knife to slice a tomato and using a drill to make a hole in a wall. Sullivan's success with the DEKA Arm System demonstrated the potential of the TMR procedure and bionic prosthetics to improve the lives of amputees and provide them with greater independence and functionality.
While largely quite effective in their approach, these two methods fail to provide something crucial to the human experience – touch. And the solution to this is fulfilled through the third and final methodology- direct nerve interfacing. The nerves left over after amputation are directly connected to implantable neural interfaces, with sensory signals being received by neural electrodes. This device contains sensors, which generate electric signals, which are then subsequently transferred to the nerves. Thus, the patient feels as if he or she has a “phantom limb”, which performs the functions of the amputated section. The generation of sensation from artificial touch sensors allows the patient to experience touch and recognize texture.
Being the most sophisticated design in the field of bionic prostheses, direct nerve interfacing was successfully utilized in the case of Johnny Matheny, an amputee who lost his left arm to cancer.
Matheny underwent a revolutionary surgical procedure in 2015, which involved having his arm amputated and replaced with a bionic arm that was directly connected to the nerves in his residual limb. The procedure was performed by researchers at Johns Hopkins University Applied Physics Laboratory, who developed a novel technology called Modular Prosthetic Limb (APL). The arm can perform a wide range of complex movements, such as grasping and manipulating objects with different shapes and sizes.
After the surgery, Matheny spent several months training to use his new bionic arm. He underwent targeted muscle reinnervation (TMR), in which the nerves that used to control the muscles in his amputated arm were rerouted to nearby muscles that were still functional. This allowed him to use his residual nerves to control the prosthesis. Matheny was able to perform tasks that were previously impossible with traditional prosthetics. Matheny's direct nerve interfacing technology represents a major breakthrough in the field of bionic prosthetics, paving the way for more advanced prostheses that can be intuitively controlled. His story is inspirational, showing that with determination and the development of cutting-edge technology, people with disabilities can achieve remarkable things.
This is just one of many stories that would have seemed unbelievable. And now, the integration of bionic prosthesis and humans is closer than ever. Helping amputees regain their lost capabilities, bionic limbs are harbingers of hope: testaments to the resilience and innovation of man.
