On the Measurement of Roller Skew of Tapered Roller Bearings

Roller skew in roller bearings can cause heat generation and reduce bearing life. Therefore, design to minimise its occurrence is essential in bearing development. This study investigated the roller skew of a double row tapered roller bearing under various running conditions. A new system of measurement using two differential variable reluctance transducers (DVRT) was developed. It is evident that the roller skew of the double row tapered roller bearing can be measured. The shaft rotational speed has a significant effect on roller skew but the radial load has little effect.Peer reviewedFinal Accepted Versio

Bruise chromophore concentrations over time

Presented at the IEEE - SPIE Medical Imaging. 2008. San Diego, California USA.During investigations of potential child and elder abuse, clinicians and forensic practitioners are often asked to offer opinions about the age of a bruise. A commonality between existing methods of bruise aging is analysis of bruise color or estimation of chromophore concentration. Relative chromophore concentration is an underlying factor that determines bruise color. We investigate a method of chromophore concentration estimation that can be employed in a handheld imaging spectrometer with a small number of wavelengths. The method, based on absorbance properties defined by Beer-Lambert's law, allows estimation of differential chromophore concentration between bruised and normal skin. Absorption coefficient data for each chromophore are required to make the estimation. Two different sources of this data are used in the analysis- generated using Independent Component Analysis and taken from published values. Differential concentration values over time, generated using both sources, show correlation to published models of bruise color change over time and total chromophore concentration over time

Design of a Robotic System to Measure Propulsion Work of Over-ground Wheelchair Maneuvers

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.DOI: 10.1109/TNSRE.2014.2371339A wheelchair-propelling robot has been developed to measure the efficiency of manual wheelchairs. The use of a robot has certain advantages compared to the use of human operators with respect to repeatability of measurements and the ability to compare many more wheelchair configurations than possible with human operators. Its design and implementation required significant engineering and validation of hardware and control systems. The robot can propel a wheelchair according to pre-programmed accelerations and velocities and measures the forces required to achieve these maneuvers. Wheel velocities were within 0.1 m/s of programmed values and coefficients of variation (CV) < 2%. Torque measurements were also repeatable with CV <10%. By determining the propulsion torque required to propel the wheelchair through a series of canonical maneuvers, task-dependent input work for various wheelchairs and configurations can be compared. This metric would serve to quantify the combined inertial and frictional resistance of the mechanical system

Multispectral Image Analysis of Bruise Age

Copyright 2007 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Presented at the Medical Imaging 2007: Computer-Aided Diagnosis 2007. San Diego, CA, USA SPIE.DOI:10.1117/12.709930The detection and aging of bruises is important within clinical and forensic environments. Traditionally, visual and photographic assessment of bruise color is used to determine age, but this qualitative technique has been shown to be inaccurate and unreliable. Spectroscopy and multi-spectral imaging have demonstrated objectivity in identifying age-dependent features. However these devices are not well suited for clinical environments. The purpose of this study was to develop a technique to spectrally-age bruises that minimizes the filtering and hardware requirements while achieving acceptable accuracy. This approach will then be incorporated into a handheld, point-of-care technology that is clinically-viable and affordable. Sixteen bruises from elder residents of a long term care facility were imaged over time. A multi-spectral system collected images at 11 wavelengths ranging between 370-970 nm that corresponded to skin and blood chromophores. Normalized bruise reflectance (NBR)- defined as the ratio of optical reflectance coefficient of bruised skin over that of normal skin- was calculated for all bruises at all wavelengths. The smallest mean NBR, regardless of bruise age, was found at wavelength between 555 & 577nm suggesting that contrast in bruises are from the hemoglobin chromophores, and that they linger for a long duration. A contrast metric, based on the NBR at 460nm and 650nm, was found to be sensitive to age and requires further investigation. Overall, the study identified four key wavelengths that have promise to characterize bruise age. However, the high variability across bruises complicates the development of a handheld detection system until additional data is available

A Data Processing Method to Measure the Use of Manual Wheelchairs

Presented at the BMES Annual Meeting. 2009. Pittsburgh, PA

Anatomical Model Propulsion System: Measuring Manual Wheelchair Efficiency

Presented at the Georgia Tech Research and Innovation Conference, 2010. Atlanta, GA.The goal of this project was to produce a test device and methodology capable of measuring the mechanical efficiency of manual wheelchairs. The result would provide an objective measure of wheelchair performance that are required to effectively prescribe wheelchairs and to code wheelchairs properly for reimbursement

Anatomical Model Propulsion System (AMPS): Measuring Manual Wheelchair Efficiency

Presented at the BMES Annual Meeting. 2009. Pittsburgh, PA.The goal of this project was to produce a test device and methodology capable of measuring the mechanical efficiency of manual wheelchairs. The result would provide an objective measure of wheelchair performance that are required to effectively prescribe wheelchairs and to code wheelchairs properly for reimbursement