Abstract: A method for testing the effect of a skin care product includes measuring a mechanical property of skin tissue using nonlinear stochastic system identification, applying the product to the skin, repeating the measurement of the mechanical property after the application of the product, and comparing the before and after measurements to quantify the effect of the product. Measuring the mechanical property of the skin can include placing a probe against a surface of the skin, perturbing the skin with the probe using a stochastic sequence, and measuring the response of the skin to the perturbation. Perturbing the skin can include indenting the skin with the probe, extending the skin with the probe, and sliding the probe across the skin surface. The mechanical property may be indicative of skin compliance, skin elasticity, skin stiffness, or skin damping. The mechanical property can be dependent on perturbation depth and may be measured at a plurality of anatomical locations.

Abstract: A method for testing the effect of a skin care product includes measuring a mechanical property of skin tissue using nonlinear stochastic system identification, applying the product to the skin, repeating the measurement of the mechanical property after the application of the product, and comparing the before and after measurements to quantify the effect of the product. Measuring the mechanical property of the skin can include placing a probe against a surface of the skin, perturbing the skin with the probe using a stochastic sequence, and measuring the response of the skin to the perturbation. Perturbing the skin can include indenting the skin with the probe, extending the skin with the probe, and sliding the probe across the skin surface. The mechanical property may be indicative of skin compliance, skin elasticity, skin stiffness, or skin damping. The mechanical property can be dependent on perturbation depth and may be measured at a plurality of anatomical locations.

Abstract: A method and apparatus for analyzing drowsiness of a subject. The monitor measures motion of the head of the subject and of one or both eyes of the subject in at least one dimension and derives at least one physiological indication such as gaze stability, saccade speed, saccade frequency, blink duration, and instrument-world scanning performance of the subject. The physiological indicator or indicators are compared with predetermined ranges of acceptable values in such a manner as to determine an onset of drowsiness in the subject.

Abstract: An apparatus and method for analyzing visual and vestibular responses of a subject. One or more targets undergoing slow random motion are presented to the subject while the head of the subject is simultaneous perturbed with perturbations statistically uncorrelated with the random motion of the target. The response of the motion of the head of the subject and the motion of the subject's eyes is measured and the visual and vestibular system response dynamics are estimated based on the measured response.