Method for improving calibration of an instrument for non-invasively measuring constituents in arterial blood
US6442411B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 2000 |
| Grant date | Aug 27, 2002 |
| Priority date | — |
| Expiry date | Apr 19, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/1495
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The absence of a defined optical pathlength for in vivo measurements creates problems for the noninvasive measurement of analyte concentration. These problems can be reduced by combining measurements made at several wavelengths and using the fact that normal renal function causes the concentration of water in whole blood to be tightly controlled. Hence, the concentration of water in arterial blood can serve as a useful internal standard for such measurements. The measurements are then procured so as to remove the dependency of concentration on path length traversed by the illuminating radiation and on the scattering properties of the volume through which the illuminating radiation propagates. Using this method, one can create improved calibration for measurements of absorbing constituents in arterial blood and thereby provide absolute concentration measurements of constituents such as hemoglobin and glucose in arterial blood.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.