Refreshable scanning tactile graphic display for localized sensory stimulation
Pressure-based refreshable scanning tactile graphic display apparatus and methods are disclosed for localized sensory stimulation. The apparatus include a display array having stimulus points embedded in a matrix, an energy source applied at the stimulus points through a modulator, a control unit, and a position sensing and feedback unit or units (such as a mouse-type device or data glove, for example). The energy source is preferably stored and pressurized fluid with application to selected stimulus points (pins, for example) preferably directed at a microvalve array under the control of a computer-based control unit.
1. A method for localized sensory stimulation to tactilely simulate a virtual display comprising the steps of:
providing for delivery of stimulus at a high density set of points at a selected body location of a user;
modulating said stimulus delivery at different said points for selective actuation including applying variable differential pressure stimulus at said points; and
controlling said modulation responsive to selected input to control which portion of the virtual display should be tactilely simulated at said points to simulate a sensation of lateral motion across the selected body location thereby to communicate to the user a detailed impression of either movement of a patterned surface across the selected body location or movement of the selected body location across the patterned surface without relative movement between said set of points and the selected body location of the user.
2. The method for localized sensory stimulation of claim 1 wherein the step of controlling said modulation includes applying differential force signals to represent tactile information.
3. The method for localized sensory stimulation of claim 1 wherein stimulus delivery is by a working fluid application at said points, the step of controlling modulation of stimulus delivery at different said points including at least one of causing varying pressure of said working fluid before modulating said stimulus delivery, causing selective temporal modulation of working fluid application at said points, and causing selective working fluid throughput operation to each of said points.
4. The method for localized sensory stimulation of claim 1 wherein stimulus delivery is by one of piston operated pins and fluid jets equal in number to said points.
5. The method for localized sensory stimulation of claim 1 wherein stimulus delivery is by piston operated pins, said method further comprising providing a stimulus neutral position for said pins, user's skin elasticity employed to return said pins to said stimulus neutral position.
6. The method for localized sensory stimulation of claim 1 further comprising sensing selected body position information and utilizing said information as said selected input for controlling said modulation to thereby control speed and direction of virtual display scanning.
7. The method for localized sensory stimulation of claim 1 wherein said set of points at a selected body location of a user includes about 400 stimulus points in about one square centimeter.