A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

An overview of the self-organizing map algorithm, on which the papers in this issue are based, is presented in this article.

The Self-Organizing Map

A new statistic has been developed to quantify the amount of regularity in data. This statistic, ApEn (approximate entropy), appears to have potential application throughout medicine, notably in electrocardiogram and related heart rate data analyses and in the analysis of endocrine hormone release pulsatility. The focus of this article is ApEn. We commence with a simple example of what we are trying to discern. We then discuss exact regularity statistics and practical difficulties of using them in data analysis. The mathematic formula development for ApEn concludes the Solution section. We next discuss the two key input requirements, followed by an account of a pilot study successfully applying ApEn to neonatal heart rate analysis. We conclude with the important topic of ApEn as a relative (not absolute) measure, potential applications, and some caveats about appropriate usage of ApEn. Appendix A provides example ApEn and entropy computations to develop intuition about these measures. Appendix B contains a Fortran program for computing ApEn. This article can be read from at least three viewpoints. The practitioner who wishes to use a "black box" to measure regularity should concentrate on the exact formula, choices for the two input variables, potential applications, and caveats about appropriate usage. The physician who wishes to apply ApEn to heart rate analysis should particularly note the pilot study discussion. The more mathematically inclined reader will benefit from discussions of the relative (comparative) property of ApEn and from Appendix A.

A regularity statistic for medical data analysis

Biosensor, communicator, and/or controller apparatus, systems, and methods are provided for monitoring movement of a person's eye. The apparatus includes a device configured to be worn on a user's head, a light source for directing light towards one or both eyes of the user, one or more image guides on the device for viewing one or both eyes of the user, and one or more cameras carried on the device and coupled to the image guides for acquiring images of the eyes and/or the user's surroundings. The apparatus may include a cable and/or a transmitter for transmitting image data from the camera to a remote location, e.g., to processor and/or display for analyzing and/or displaying the image data. A system including the apparatus may be used to monitor one or more oculometric parameters, e.g., pupillary response, and/or to control a computer using the user's eyes instead of a mouse.

Biosensors, communicators, and controllers monitoring eye movement and methods for using them

Systems and methods for providing authentication using an arrangement of dynamic graphical images, which may display a popup element while a pointing device indicator is over a graphical image. The graphical images can be arranged as a grid or matrix for presentation on a device display for authentication of a user. The kinds of graphical images can be derived from a designated authentication category and non-authenticating categories. A series of password elements corresponding to the graphical images can be displayed with the graphical images. The user may enter the series of one or more password elements corresponding to graphical images from the authentication category which combine to form a password entry. An authentication server can compare the password entry to an authentication password corresponding to the particular arrangement of dynamic graphical images. The selection of graphical images, their arrangement and their corresponding password elements, may dynamically change in between authentication processes.

Methods and systems for graphical image authentication

In this paper, we use the optical-type eye tracking system to control powered wheelchair. The useris eye movements are translated to screen position using the optical-type eye tracking system. The pupil-tracking goggles with a video CCD camera and a frame grabber analyzes a series of human pupil images when the user is gazing at the screen. A new calibration algorithm is then used to determine the direction of the eye gaze in real time. We design an interface with nine command zones to control powered wheelchair. The command at the calculated position of the gazed screen is then sent to move the powered wheelchair.

Powered Wheelchair Controlled by Eye-Tracking System

Design of a computer game using an eye-tracking device for eye's activity rehabilitation

http://140.134.32.129/cvision/paper/pcb.pdf

An image system for fast positioning and accuracy inspection of ball grid array boards

http://140.134.32.129/cvision/paper/2007Wearable.pdf

Wearable device for real-time monitoring of human falls

https://ir.nctu.edu.tw:443/bitstream/11536/24589/1/000337118300042.pdf

Chern-Sheng Lin

Papers

Powered Wheelchair Controlled by Eye-Tracking System

Design of a computer game using an eye-tracking device for eye's activity rehabilitation

An image system for fast positioning and accuracy inspection of ball grid array boards

Wearable device for real-time monitoring of human falls

Automatic defect recognition of TFT array process using gray level co-occurrence matrix