Optical Blood-Coagulation Sensor

A hand-held optical thromboelastographer operable at a point-of-case without access to a central cerver, comprising:

• an assembly including a housing unit that contains
• a sample cartridge having a chamber in a plane-parallel substrate, said chamber being optically accessible through a superstate sealingly overlaying the chamber, said chamber being fluidly accessible through a channel, said cartridge being removably reinsertable into the housing unit;
• an optical train transmitting light that has traversed said chamber, the optical train devoid of optical power and including an array of optical apertures;
• and
• a detector disposed to acquire light scattered by a medium within the chamber through the array of optical apertures and to provide a data output representing a cross-polarized speckle pattern generated by the medium;
• a hand-held data-processing unit that includes electronic circuitry that is in operable communication with the detector and that is programmed
• to measure, based on the data output, an optical thickness of the medium within the chamber;
• to calculate, on said optical thickness and an autocorrelation function of the cross-polarized speckle pattern, a mean square displacement associated with optical scatterers of the medium;
• and
• to produce an output representing, when the medium includes a stationary sample of blood, a platelet aggregation function and at least first and second parameters including a clotting time, a rate of clot formation, a clot strength, and a fibrinolysis function;
• and
• an output device operably cooperated with the electronic circuitry to display a visually-perceivable representation of the output, said assembly being removably attached to the output device during operation of the optical thromboelastographer.
• a time-dependent product of a time-dependent effective radius of an optical scatterer of the medium and a viscoelastic modulus of the medium.

A method for determining a descriptor of coagulation of a stationary blood sample at a point-of-care with an optical thromboelastographer, the method comprising:

• with an optical detector, disposed in a housing removably attachable to a hand-held data-processing unit, acquiring light scattered by the stationary blood sample,
• said blood sample positioned in a chamber formed by a void in a base substrate and an optically-transparent superstrate layered over a surface of the base substrate such as to prevent access to said void through an aperture defined by the void in the surface;
• producing data output representing a cross-polarized speckle pattern produced by the stationary blood sample;
• and
• calculating, with a data-processing electronic circuitry, a plurality of time-dependent parameters associated with the coagulation of the stationary blood sample based on a time-dependent parameter representing a product of a viscoelastic parameter of the stationary blood sample and a time-dependent radius of an optical scatterer of said blood sample,
• the plurality of time-dependent parameters including a clotting time, a clot rate, a clot strength, a fibrinogen function, a fibrinolysis function, and a platelet aggregation function.