Chapter 3: Evaluating Global Hemostasis with the Sonoclot Analyzer 3-3
Clot Retraction Phase
During this phase, clot retraction causes a
peak or peaks on the Sonoclot Signature. The
Sonoclot Analyzer produces an automated
result called “Platelet Function.” The Platelet
Function number quantifies the quality of the
clot retraction process. Results range between
0 (no clot retraction) and approximately 5
(strong clot retraction).
Historically, platelet function was manually
calculated from the Sonoclot Signature.
Different researchers used different techniques
and terms for quantifying clot retraction.
Some of those terms include: Time-to-Peak, R2, Peak Angle, Upslope, or Downslope. While some of
these terms generated useful results, the range of shapes of Sonoclot Signatures resulted in problems
with consistent interpretation between users. The quantitative Platelet Function result provides an
automated and convenient result for characterizing clot retraction within a test sample.
Reference Signature
Minutes
0.0
5.0
10.0
15.0
20.0
25.0
30.0
Clot
Signal
0
25
50
75
100
125
Group Description
Style Time Test Application Result Range Comment
∆Clot Signal
∆minutes
Clot Rate
( )
Clot Formation Phase
