Rapid measurement of formed blood component sedimentation rate from small sample volumes
AssigneeTheranos, Inc.
InventorsMark Dayel, Samartha Anekal, Elizabeth A. Holmes
Life of this patent
Estimating the term…
Abstract
Devices and methods are described for measuring formed blood component sedimentation rate. Some of the methods may use (1) centrifugal techniques for separating red blood cells from plasma and (2) video and/or still imaging capability. Both may be used alone or in combination to accelerate formed blood component sedimentation and to measure its rate. In one example, the method may advantageously enable rapid measurement of sedimentation rate using small blood sample volumes. Automated image analysis can be used to determine both sedimentation rate and hematocrit. Automated techniques may be used to compensate for effects of hematocrit on uncorrected sedimentation rate data.
Claims34
A method comprising:
- centrifuging a blood sample in a vessel for a period of time;
- establishing a time-related compaction curve for at least one formed blood component in said blood sample after centrifuging has begun;
- correcting for impact of hematocrit on sedimentation rate of the formed blood component using a hematocrit correction factor based on the formula:
-
- =
- U
- uncorr
-
- (
- 1
- -
- φ
- φ
-
-
- max
- )
- γ
- ,
- where Uuncorr and Ucorr are the uncorrected (raw) and corrected sedimentation rates, φ is the volume fraction of cells (hematocrit), and φmax and γ are empirical parameters obtained by curve fitting.
Dependencies are inferred from the claim text.