Medical technologists have successfully fitted an artificial fingertip to a patient that has allowed the man to touch again. This novel process required the fingertip to be surgically connected to nerves in his upper arm. The fingertip was made up of electrodes that sent a signal to the brain.
With the process, nerves in the patient’s arm were wired to an artificial fingertip equipped with sensors. Next, a machine controlled the movement of the fingertip over various types of surfaces, engraved with different patterns, ranging from smooth to rough. Each time the fingertip moved across the textured plastic, the sensors produced an electrical signal. The signal was converted into a series of electrical spikes (approximating what as the nervous system functions), and the electrical signals were delivered to the nerves.
The patient reported a 96 percent success rate. By comparing the patient’s brainwaves to non-amputees it appeared that the responses to touch were very similar.
The process was developed by Dr. Silvestro Micera who works at the Swedish Ecole polytechnique fédérale de Lausanne). It was the first process in the world to successfully bio-engineer a functional fingertip.
Speaking with Laboratory Manager magazine, the person who received the surgery, Dennis Aabo Sørensen said: “The stimulation felt almost like what I would feel with my hand,” says amputee about the artificial fingertip connected to his stump. He continues, “I still feel my missing hand, it is always clenched in a fist. I felt the texture sensations at the tip of the index finger of my phantom hand.”
Further work with the electrodes will take place to consider differences between shapes and degrees of hardness and softness.
The success with the fingertip not only opens up this specialty field, it could also lead to the development of bionic prostheses and enhanced with sensory feedback for other body parts. This all forms part of an emerging field called ‘neuroprosthetics.’
The findings are published in the journal eLife. The research is titled “Intraneural stimulation elicits discrimination of textural features by artificial fingertip in intact and amputee humans.”