• Advanced diffraction pattern analysis. The ellipticity of the diffraction pattern is determined from an iso- or multi-intensity curve. A slight misalignment of the camera with respect to the orthogonal diffraction pattern is compensated for with the new tilted ellipse fit. An iterative algorithm rejects distant edge coordinates. This causes the ellipse fit to be less sensitive to outliers. The average distance of the edge coordinates to the best-fit ellipse is given and serves as an error-of-fit parameter.
• RBC stability test. During a stability test, RBCs are highly deformed by a high (user defined) shear stress in the same Couette geometry. The high shear stress slowly changes the mechanical properties of the cell membrane finally resulting is cell lysis. The stability test reveals the shear stress and time dependent RBC deformability curve.
• Time registration for elongation measurements. The exact time at the beginning and end of a single EI measurement (consisting of a number of diffraction pattern analyses), is recorded in order to include time dependency in RBC-deformability determinations.
• Optional display of Error Of Fit vectors. This function draws lines (eof vectors) between accepted iso-intensity pixels and the accompanying nearest points on the ellipse that resulted from them. This gives an indication of image quality.

RBC aggregation

• Advanced syllectogram analysis. The investigator is enabled to select a syllectogram-fitting model containing one to three exponents. The uni-exponential model is interesting to study, e.g., RBC-shape recovery in buffer solution. The conventional bi-exponential model describes the aggregation process while the tri-exponential model includes both RBC-shape recovery and aggregation. Unlike other models, the tri-exponential model describes the whole syllectogram, including the upstroke.
• Automatic start when sample has reached 37 C. The program allows the investigator enter sample data while the software automatically starts measuring when the sample has reached the desired (user defined) temperature.
• Reload measurements from disk. Aggregation measurements can be stored to disk and be reloaded afterwards to, e.g., review or export the measurement or to print a measurement RBC aggregation: