The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1998
Filed:
Apr. 09, 1997
Richard F Weir, Chicago, IL (US);
Dudley S Childress, Wilmette, IL (US);
Joseph N Licameli, Camillus, NY (US);
Northwestern University, Evanston, IL (US);
Abstract
A portable ranging system for analyzing gait is disclosed comprising a transponder having an infrared receiver and an ultrasound emitter, a base unit having an infrared emitter and an ultrasound receiver, and a computer terminal. During gait analysis, the transponder is worn by a subject at approximately the level of the body center of mass. As the subject walks away from the base unit, the base unit continuously causes, at a constant sampling rate, the ultrasound emitter to emit ultrasound pulses. These ultrasound pulses are received by the ultrasound receiver of the base unit. The computer terminal, by counting during the flight of each ultrasound pulse, is able to calculate the time of flight of each ultrasound pulse, and thus calculate and display in real time the forward progression of the subject. At the end of the walking trial, the computer terminal displays the instantaneous velocity profile, or gait velocigram (GVG), for that trial. From the GVG, the computer terminal calculates and displays gait parameters such as gait speed, cadence, step time, step length, peak-to-peak variation, and time to achieve steady state walking. From the displayed data, gait pathologies can be readily identified.