Revolutionary mechanical hand adds a sense of touch to mind-controlled prostheses
A mechanical hand utilizing DARPA-developed neural technologies has become the first to allow a paralyzed patient to feel physical sensations through a prosthesis. The 28 year-old test subject was able to determine which mechanical finger was being touched whilst blindfolded, with total accuracy.
The identity of thepatient has not been disclosed for privacy reasons, however a DARPApress release states that he was left paralyzed due to severe spinalinjuries. In the past, test subjects have been able to manipulateprostheses via thought alone, but the technology had been a one-waystreet. An individual could send signals to the hand from the brainin order to control the prosthesis but received no tactile sensorydata in return, making it difficult to direct precise movements.
The new study takes thescience of prosthetic technology to a new level, allowing two-waycommunication between a mechanical hand and its user. The feat wasaccomplished by running wires connectedto electrodes on the patient's sensory cortex (the part of the brain responsible for identifying tactile sensations) and motor cortex (the part that directs body movements) to the prosthesis.
The mechanical handthat interfaces with the DARPA tech was developed by the AppliedPhysics Laboratory at Johns Hopkins University. Torque sensorsintegrated into the device are able to detect when pressureis being applied to the prosthesis, converting force into electricalsignals which are transmitted to, and interpreted by the subject'sbrain.
During laboratorytesting, the patient was blindfolded while researchers touched eachof the hand's bionic fingers. Thepatient described the sensation, stating that it was as if his ownhand were being touched.
"At one point,instead of pressing one finger, the team decided to press two withouttelling him," comments program manager for DARPA's RevolutionizingProsthetics program, Justin Sanchez. "He responded in jest askingwhether somebody was trying to play a trick on him. That is when weknew that the feelings he was perceiving through the robotic handwere near-natural."
It is hoped thatdevelopments based on the technology could one day see amputees andthose suffering from paralysis have access to mind controlprostheses that allow individuals to feel once more.