Device, method, and computer program product for determining a material parameter of a blood coagulation cascade based on parameters of light diffused at a biofluid sample. In one example, the biofluid sample includes a blood sample. Laser light scattered by the sample is collected by the optical system in reflection and/or transmission mode. An image of the sample in so collected light is formed, and data representing fluctuations of laser speckle intensity with is processed to derive numerical descriptors associated with blood coagulation and fibrinolysis. In a specific case, such numerical descriptors are derived based on temporal dynamic of a viscoelastic characteristic of the blood sample.