The MICELI: an Impedance Aggregometer For Point-Of-Care Testing of Platelet Hemostatic Function in Whole Blood
Presenting Author: Yana Roka-Moiia1
Additional Authors: Gabriele Mantica2, Chiara Ferrari2, Alberto Redaelli2, Marvin J. Slepian1
1 Department of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ;
2 Department of Bioengineering, Politecnico di Milano, Milan, Italy
Background/Purpose: Bleeding trauma is a leading cause of death among young individuals. Nearly 20% of deaths could be prevented by improved timing of a hemostatic intervention. The implementation of a point-of-care (POC) diagnostic device for rapid monitoring of patient hemostatic capability will optimize the bleeding trauma management. We have designed the MICELI (MICrofluidic, ELectrical, Impedance): a portable and easy-to-use platelet function analyzer capable to assess platelet aggregation in a whole blood in <10 min. The aim of this study was to validate the precision of the MICELI platform as compared to commercial aggregometers and characterize its sensitivity to blood parameters, i.e. platelet count and hematocrit.
Methods: Whole blood of 30 healthy volunteers was collected via venipuncture and anticoagulated with hirudin (525 ATU/ml). Platelet aggregation induced by ADP, collagen, and TRAP-6 was measured using MICELI, optical aggregometer PAP-8 (BD, US), and impedance aggregometer Multiplate Analyzer (Roche, Switzerland). Platelet aggregation parameters, maximal amplitude, velocity, and area under the curve, were analyzed. Hematocrit was quantified using microhematocrit method, platelet count was measured on a particle counter (Beckman, US).
Results: The aggregation parameters obtained by MICELI were highly similar to those of the Multiplate analyzer for each agonist tested (Fig. 1). The values obtained from LTA differ from those obtained utilizing both impedance aggregometers, MICELI and Multiplate Analyzer, but follow a similar trend (Fig. 1, “MICELI” vs. “LTA”). The level of MICELI precision, calculated as a coefficient of variance (%) of aggregation parameters indicates its highly consistent performance. The MICELI showed modest sensitivity to platelet count (150-400,000 cells/uL) as illustrated by linear correlation of aggregation amplitude with platelet count in the blood (R2 > 0.8). Hematocrit did not significantly affect aggregation values within the range of hematocrit values of 0.35-0.45 (R2 < 0.5).
Conclusions: The MICELI platform has demonstrated high precision and reproducibility as compared to commercial aggregometers. Platelet aggregation parameters were affected by platelet account but not hematocrit in a blood sample. As miniature, easy-to-use and accurate device, the MICELI could be translated to the POC aggregometer capable to monitor patient platelet function for personalization of the hemostatic interventions.