Method and apparatus for determining dynamic deformation characteristics of an object

A device for determining dynamic, in-vivo, elastic and viscoelastic properties of a cornea of an eye, comprising:

• a topographer component that is capable of making a spatially resolved measurement of a selected topographical characteristic of the in-vivo cornea both before and during a deformation time interval;
• a non-contact corneal surface-deformer component disposed along a first, directionally-independent device axis that can deliver a controlled in vivo corneal surface deformation during the deformation time interval;
• and
• a controller/processor component connected to the topographer component and the non-contact surface-deformer component,
• wherein the topographer component and the non-contact surface-deformer component are operationally integrated so as to provide the in-vivo corneal surface deformation via the non-contact object surface-deformer component during the deformation time interval and make the spatially resolved measurement of the selected topographical characteristic of the in-vivo corneal surface via the topographer component both before and during the deformation time interval over which the object surface is deformed,
• further wherein the determined dynamic, in-vivo, elastic and viscoelastic properties comprises viscoelasticity of the cornea.

A method for determining quantitative elastic and viscoelastic properties of an in-vivo cornea of an eye, comprising:

• obtaining at least only a single measurement image of a selected topographical characteristic of the in-vivo cornea in an undeformed state;
• deforming the in-vivo cornea with a known amount of a non-contact force applied over at least a portion of a deformation time interval;
• obtaining at least only a single measurement image of the selected topographical characteristic of the in-vivo cornea in a deformed state being due to the known amount of the non-contact force applied during at least the portion of the deformation time interval;
• determining a difference between the measured pre- and intra-deformation topographical characteristics of the in-vivo cornea at least only a single spatial location on the cornea;
• and
• deriving a biomechanical and/or a biodynamic measurement using this measured data, wherein the biomechanical and/or biodynamic measurement of the in-vivo cornea is selected from a group consisting of stiffness, strain, elasticity, viscosity, and viscoelasticity.