Methods of determining initiation and variable end points for measuring a chemical reaction
US5885839A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Apr 15, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/144444
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.