Portable coagulation monitoring device and method of assessing coagulation response

Inventors

Dennis, Robert Glenn • Fischer, Thomas H. • DaCorta, Joseph Anthony

Assignees

Entegrion Inc

Abstract

A device, system and method is disclosed in which small volume blood samples are subjected to shear forces and shear stresses between two parallel planar surfaces to which linear motion trajectories are imparted. The formation of clots or coagulation of the sample is measured from dynamic mechanical coupling which occurs between the two parallel planar surfaces. Detection of the coagulation response can be achieved through optical probing or by measurement of physical effects of the blood sample binding to the planar surfaces, and restricting movement thereof.

Core Innovation

The invention provides a portable method of measuring coagulation response in a blood sample by placing a sample droplet of whole blood between and in contact with first and second facing surfaces of two oppositely disposed parallel glass plates. At least one plate is moved linearly with respect to the other plate at a predetermined speed sufficient to activate platelets through exposure to shear forces. The method optically detects, via measurement of mechanical displacement, the interaction between the first and second surfaces resulting from changes in the viscosity of the sample fluid and binding to the plate surfaces.

The approach measures coagulation response using dynamic mechanical coupling and optical interrogation to quantify platelet adherence and response and fibrin polymerization within the droplet. The method includes moving at least one plate linearly at a first speed to determine a first coagulation response indicative of platelet response, and then moving at least one plate linearly at a second speed to measure a terminal coagulation response indicative of rate and completeness of fibrin polymerization. The interaction is detected via measurement of mechanical displacement and coupling.

In addition, the method detects strain rates produced by movement of the two plates mechanically coupled through visco-elasticity caused by the blood sample, and determines a coagulation state using inference analysis based on the visco-elasticity derived from the mechanical coupling and the measured strain rates. The method further includes optically detecting a blood sample droplet by transmitting electromagnetic waves and measuring transmission, absorption, reflection, and/or refraction to produce analog signals representing coagulation properties for primary and secondary coagulation mechanisms.

Claims Coverage

The document includes two independent methods of measuring coagulation response: one for optically detecting mechanical displacement during shear activation, and a second for measuring both a first platelet response and a terminal response via sequential plate motions at different speeds. Across these, the claims reference a total of inventive features including platelet activation through shear, mechanical-displacement optical detection of viscosity and binding, sequential speed-dependent platelet and fibrin responses, coupling-based terminal fibrin polymerization measurement, optional visco-elasticity and strain-rate inference, and electromagnetic-wave optical interrogation modes.

Overall, the claim coverage centers on shearing whole blood between oppositely disposed parallel glass plates to activate platelets, while optically detecting mechanical displacement associated with viscosity changes and binding for platelet-related coagulation response, and using sequential plate motion and mechanical coupling to measure terminal fibrin polymerization response. Additional covered refinements include strain-rate detection with inference from visco-elastic coupling and electromagnetic-wave optical interrogation to generate analog signals for coagulation mechanisms.

Stated Advantages

Documented Applications

No documented applications found