Controlling a Prosthetic Hand with Peripheral Neural Interfaces

Recent research in robotics has made the ancient need for functional limb replacement a reality. Historically, humans have replaced missing limbs with prostheses for cosmetics, vocational use, or personal autonomy. The hand, for example, is a powerful tool, and its loss causes severe physical, and often mental, debilitation. Thus, the need for a versatile prosthetic limb with intuitive motor control and realistic sensory feedback is huge, and its development is a must in the near future. Knowledge from robotics research has been transferred to the industry, and as a result, more functional prostheses have recently been introduced in the market. Nevertheless, surveys on using such artificial hands reveal that 30 to 50 percent of amputees do not use their prosthetic hands regularly, basically due to low functionality, poor cosmetic appearance, and low controllability. Therefore, one of the fundamental issues in limb replacement is the improvement of voluntarily controlled dexterity and the restoration of the ability to obtain sensory information while grasping to allow amputees to perform tasks that are required for daily activities. It is also necessary to (re)-establish a fast, intuitive, bidirectional flow of information between the user’s nervous system and the smart artificial device. The establishment of interfaces with the peripheral nervous system seems to be an interesting and promising solution to achieve this goal. In particular, intraneural electrodes represent an adequate choice because of their good selectivity with an acceptable level of invasiveness. In this presentation we will show the results achieved during our first two implants of intraneural electrodes into the median and ulnar nerves of the stumps of two amputees during a four-week trial. We showed the possibility of decoding motor commands suitable to control a dexterous hand prosthesis and to deliver sensory feedback to the user. These results open up new and promising possibilities for the development of neuro-controlled hand prostheses.