This system is built around an ancient Nikon inverted microscope. Two cameras are connected with the microscope: a Spot Insight Monochrome camera from Diagnostic Instrument (14 bit AD with 20 MHz capture), and a Canon digital Rebel (for movies and large color images).
The images from the Spot camera are captured by the computer on the left of the microscope. On the right side of the microscope, the computer controls a microscopic indenter, which can compress cartilage either in discrete steps or continuously. The final devices on the right control a load sensor.
The initial test data on a prototype system was published in the Szarko 2012 paper. The Kahn 2015 paper contains the detailed description of this updated system. By measuring the locations and deformations of the individual cells throughout the entire depth of cartilage, we can calculate the localized strains and several other biomechanical properties of the tissue in 2D.
Representative Publications
M Szarko, Y Xia, “Direct Visualisation of the Depth-Dependent Mechanical Properties of Full-Thickness Articular Cartilage”, Open Journal of Orthopedics, 2, 34-39 (2012).
D Kahn, C Les, Y Xia, “Effects of Cryopreservation on the Depth-Dependent Elastic Modulus in Articular Cartilage and Implications for Osteochondral Grafting”, Journal of Biomechanical Engineering, 137, 054502 (2015).