title: Micro-elastometry on whole blood clots using actuated surface-attached posts (ASAPs).
abstract: We present a novel technology for microfluidic elastometry and demonstrate its ability to measure stiffness of blood clots as they form. A disposable micro-capillary strip draws small volumes (20 μL) of whole blood into a chamber containing a surface-mounted micropost array. The posts are magnetically actuated, thereby applying a shear stress to the blood clot. The posts' response to magnetic field changes as the blood clot forms; this response is measured by optical transmission. We show that a quasi-static model correctly predicts the torque applied to the microposts. We experimentally validate the ability of the system to measure clot stiffness by correlating our system with a commercial thromboelastograph. We conclude that actuated surface-attached post (ASAP) technology addresses a clinical need for point-of-care and small-volume elastic haemostatic assays.
authors.affiliation: University of North Carolina at Chapel Hill Department of Physics & Astronomy, Chapel Hill, NC, USA. rsuper@physics.unc.edu.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Judith
authors.forename: Jay K
authors.initials: JK
authors.lastname: Fisher
authors.forename: Richard Chasen
authors.initials: RC
authors.lastname: Spero
authors.forename: Briana L
authors.initials: BL
authors.lastname: Fiser
authors.forename: Adam
authors.initials: A
authors.lastname: Turner
authors.forename: Bruce
authors.initials: B
authors.lastname: Oberhardt
authors.forename: R M
authors.initials: RM
authors.lastname: Taylor
authors.forename: Michael R
authors.initials: MR
authors.lastname: Falvo
authors.forename: Richard
authors.initials: R
authors.lastname: Superfine
mesh_terms: D001777:Blood Coagulation; D006801:Humans; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D012212:Rheology; D013314:Stress, Mechanical; D013499:Surface Properties