@article{wu_pankow_onuma_huang_peters_2022, title={Comparison of High-Speed Polarization Imaging Methods for Biological Tissues}, volume={22}, ISSN={["1424-8220"]}, url={https://www.mdpi.com/1424-8220/22/20/8000}, DOI={10.3390/s22208000}, abstractNote={We applied a polarization filter array and high-speed camera to the imaging of biological tissues during large, dynamic deformations at 7000 frames per second. The results are compared to previous measurements of similar specimens using a rotating polarizer imaging system. The polarization filter eliminates motion blur and temporal bias from the reconstructed collagen fiber alignment angle and retardation images. The polarization imaging configuration dose pose additional challenges due to the need for calibration of the polarization filter array for a given sample in the same lighting conditions as during the measurement.}, number={20}, journal={SENSORS}, author={Wu, Xianyu and Pankow, Mark and Onuma, Taka and Huang, Hsiao-Ying Shadow and Peters, Kara}, year={2022}, month={Oct} } @article{wu_pankow_huang_peters_2018, title={High-speed polarization imaging of dynamic collagen fiber realignment in tendon-to-bone insertion region}, volume={23}, ISSN={1083-3668}, url={http://dx.doi.org/10.1117/1.JBO.23.11.116002}, DOI={10.1117/1.JBO.23.11.116002}, abstractNote={Abstract. A high-speed polarization imaging instrument is demonstrated to be capable of measuring the collagen fiber alignment orientation and alignment strength during high-displacement rate dynamic loading at acquisition rates up to 10 kHz. The implementation of a high-speed rotating quarter wave plate and high-speed camera in the imaging system allows a minimum measurement acquisition time of 6 ms. Sliced tendon-to-bone insertion samples are loaded using a modified drop tower with an average maximum displacement rate of 1.25  m  /  s, and imaged using a high-speed polarization imaging instrument. The generated collagen fiber alignment angle and strength maps indicate the localized deformation and fiber realignment in tendon-to-bone samples during dynamic loading. The results demonstrate a viable experimental method to monitor collagen fiber realignment in biological tissue under high-displacement rate dynamic loading.}, number={11}, journal={Journal of Biomedical Optics}, publisher={SPIE-Intl Soc Optical Eng}, author={Wu, Xianyu and Pankow, Mark and Huang, Hsiao-Ying Shadow and Peters, Kara}, year={2018}, month={Nov}, pages={1} } @article{wu_huang_pankow_peters_2017, title={Dynamic Polarization Microscopy for In-Situ Measurements of Collagen Fiber Realignment During Impact}, ISBN={["978-3-319-41350-1"]}, ISSN={["2191-5652"]}, DOI={10.1007/978-3-319-41351-8_9}, abstractNote={The long term goal of this work is to better understand the tendon-to-bone insertion injury due to medium strain rate impact (e.g. sports activity). Specifically, we imaged collagen fiber realignment during impact, to investigate the ability of the tendon-to-bone insertion to these survive harsh dynamic events. A polarized light microscopy (PLM) setup was built in the lab and used to monitor the birefringence property changes of a known material under changing stress conditions. Initially polycarbonate dogbone specimens were tested quasi-statically to validate the setup and analysis algorithm. Polarized light retardation and alignment direction images are generated to quantitatively analyze the birefringence property change under different stress and compared to theoretical predictions. To perform dynamic experiments a drop weight tower was modified for medium strain rate testing (10–100 %/s) and the PLM setup is being incorporated for imaging. Several dynamic experiments have been conducted using this modified drop tower on porcine tendon specimens. A high-speed camera is used to record their dynamic response and deformation.}, journal={MECHANICS OF BIOLOGICAL SYSTEMS AND MATERIALS, VOL 6}, author={Wu, Xianyu and Huang, Hsiao-Ying Shadow and Pankow, Mark and Peters, Kara}, year={2017}, pages={61–66} } @article{wu_peters_2015, title={Non-Destructive Inspection of Adhesively Bonded Joints using Amplitude Modulated Thermography}, volume={55}, ISSN={["1741-2765"]}, DOI={10.1007/s11340-015-9997-0}, number={8}, journal={EXPERIMENTAL MECHANICS}, author={Wu, X. and Peters, K.}, year={2015}, month={Oct}, pages={1485–1501} }