The woman who can feel roughness or smoothness in her artificial hands for the first time in years; the child whose artificial leg lengthens as he grows; the previously armless man who can reach into a cabinet above his head to prepare dinner; machines that will some day register sensations in much the same way that people can — thanks to research that will culminate this year in a major set of new designs, procedures and prototypes for artificial limbs, some of these miracles might eventually become commonplace, perhaps in another generation.