Projects in human haptics range from developing computer models of the fingerpad to recording the neural signals sent from receptors in the finger to the brain (a collaboration with Yale University). "Touch begins in the fingertips but ends in the brain," Dr. Srinivasan explained. The research spans the fields of biomechanics (the study of properties such as fingerpad stiffness and friction), neurophysiology, and psychophysics (a branch of psychology that relates physical quantities such as force applied on the fingerpad to perception).
Basic research on human haptics could lead to better ways of evaluating hand impairments. "Audio and visual tests are very sophisticated," Dr. Srinivasan said, "but the tests clinicians have for the sense of touch, for example, are very primitive." This is primarily because the human haptic system is so complex and because "there's been no dominant clinical need," Dr. Srinivasan said. It's easier to live with a damaged hand than with a loss of sight or hearing.
Nevertheless, as Touch Lab scientists and others learn more about the hand, Dr. Srinivasan foresees "a suite of devices that could be common for hand evaluations." (He doubts that in the near future a single device could do everything because the hand is too complex.) Such machines might, for example, "measure how quickly functionality is returning to a hand transplant," and if problems arise they "could give doctors hints as to what's responsible."
ULTRASOUND MICROSCOPE
Last year Touch Lab scientists completed an ultrasound microscope that
takes images of the layers of skin at the fingertip much like diagnostic
ultrasound images fetuses. The microscope is helping the
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Contact: Elizabeth Thomson
thomson@mit.edu
617-258-5402
Massachusetts Institute of Technology
18-Mar-1999