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:
Mar. 23, 1999
Filed:
Apr. 15, 1997
Paul J Lingane, Redwood City, CA (US);
John F Burd, San Diego, CA (US);
Karen A Goins, San Diego, CA (US);
Michael D Goins, San Diego, CA (US);
LXN Corporation, San Diego, CA (US);
Abstract
The present invention provides a method of using a reflectance-reading device to determine an initiation time point for measuring the chemical reaction of an analyte from a biological liquid sample on a test surface. The initiation time point is determined by using a device to read a reflectance of a test surface at a plurality of time points, and calculating the K/S ratio of the test surface at each time point according to the Kubelka-Munk equation. As the device continues to calculate a K/S ratio for each time point, the device monitors the rate of change of the K/S ratio with respect to time. The device then determines the initiation time point to be when the rate of change of the K/S ratio is maximal. The present invention also provides a method of measuring the concentration of an analyte on a test surface. The concentration is measured by determining an initiation time point according to the method described above and then measuring the concentration of the analyte at a variable end point. The variable end point is essentially determined to be the time at which the rate of change of a concentration parameter is less than a threshold value.