Diagnosis of rheumatoid arthritis in vivo using a novel spectroscopic approach

US6424859B2 · kind B2 · utility

Inventors

• Michael Jackson · Morton, US
• Michael G. Sowa · Winnipeg, CA
• James Mansfield · Winnipeg, CA
• Hans H. Eysel · Winnipeg, CA
• Henry H. Mantsch · Potsdam, DE
• Hani El-Gabalawy · Winnipeg, CA
• Jan M. Canvin · Winnipeg, CA

Key dates

• Filing date: Jun 17, 1999
• Grant date: Jul 23, 2002
• Expiry date: Jun 17, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/359
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A novel near infrared spectroscopic technique was used to characterize the joints in arthritis with comparison against normal joints. A beam of near infrared light was passed to joints through a fibre optic cable. Scattered light was collected by the same fibre bundle and a spectrum of the joint computed. Multivariate pattern recognition techniques identified regions of the spectrum which allowed discrimination between healthy and affected joints. Linear discriminant analysis resulted in correct classification of 74% of the joints. The high degree of similarity between mean spectra representing the early, late and control groups along with the significant between—subject variability in the data make diagnosis based on visual assessment of the spectra impossible. Linear discriminant analysis was therefore applied to spectra to determine if spectra could be classified by statistical methods as arising from early or late RA. Application of LDA resulted in correct classification of 74% of the joints. Interestingly, the spectral regions in which diagnostic differences were found by the multivariate analysis contain absorption bands related to tissue oxygenation status (oxy and deo…