Caterpillar Inc.

University of Illinois

Caterpillar Tractor Co.

Chester S Gardner

Kirk S Schroeder

Louis G Alster

William E Streight

Richard Kast

Method and apparatus are disclosed for determining pupillary response parameters, such as latency, time of acceleration of constriction, and speed of constriction. In a form of the disclosed method a signal is derived which is representative of measured pupil size as a function of time after a visible light stimulus. The signal is modified to remove therefrom artifacts due to eye movement. Pupillary response parameters can be obtained from the modified signal. In a preferred embodiment, the modifying of the signal includes fitting curves to different portions of the signal, correcting at least one of the fitted curves, and deriving the modified signal from the curves, as corrected.

Method and apparatus for determining pupillary response parameters

An apparatus and method for measuring the profile of a curvilinear surface is provided. The apparatus includes a light source for substantially uniformly delivering radiant energy along an illumination plane substantially tangent to the curvilinear surface. The delivered radiant energy is optically imaged at a first image plane. A first portion of the delivered radiant energy is blocked by an optical field stop having an accurately straight reference profile edge portion, and a second portion of the imaged radiant energy is focused on a transducer located at a second image plane. The transducer produces a coded data signal in response to the focused radiant energy. A microprocessor receives the coded data signal, determines the deviation of the profile of the curvilinear surface from the reference profile edge portion, and produces a straightness signal in response to the determined deviation. Nonuniformities of the apparatus are automatically compensated for. The apparatus is simple to operate and facilitates 100% inspection in a production environment.

Optical straightness gauge and method

A compact gauge (10) for effectively measuring the surface roughness of an article (14) in any direction of lay includes: first means (30) for directing a light beam (32) upon a surface (12) of the article (14), second means (34) for providing a first signal proportional to the specular light reflected from the surface (12), the first and second means (30,34) defining a common plane (40), third means (58) for providing a second signal proportional to the diffused light reflected from the surface (12) in the common plane (40), and fourth means (61) for providing a third signal proportional to the diffused light reflected from the surface (12) to the side of the common plane (40). The subject gauge (10) includes a sensor head (28) that can be miniaturized and electrical circuit means (66,104) that can process the signals and provide a direct reading in micrometers independent of the reflectivity level of the surface.

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Champaign, IL, United States of America

Chester S Gardner