Instrumented assessment of FNS hand control during specific manipulation tasks

Describes tests that quantitatively assess the operation of FNS hand grasp neuroprostheses and the ability of spinal cord injury patients to use these systems to perform specific tasks simulating activities of daily living. An integrated measurement system monitors internal variables within the neuroprosthesis, the kinematics of the patient´s arm and the grasped object, and interactions of the subject´s hand with the object and the environment. Two tasks, drinking and eating, are broken down into sequential elemental states based on the measurements. The durations of each state, determined from the data, show that 1) patients using the neuroprosthesis take more time than normals to perform nearly all states of the two tasks, 2) the command control scheme has a large effect on the time a patient takes to pick up an object, 3) patients compensate for paralyzed forearm pronators by increasing shoulder abduction, and 4) patients use forces in the same range as normals during grasp