This technique uses light which is transmitted through tissue to look at collagen fiber alignment. tQPLI has been used to map region specific collagen alignment and mechanics of tendons and ligaments.
Test Setup
The typical test setup includes a light source at the bottom followed by a linear polarizer and quarter wave plate. This light passes through the tissue and resulting light is acquired and analyzed by the bio inspired polarization camera.
Representative Sample
Example of fiber alignment data from an anteromedial (AM) anterior cruciate ligament bundle: grayscale, degree of linear polarization (DoLP) and angle of polarization (AoP) images of a 40-year-old male sample at zero, transition, and linear strain states during ramp-to-failure. Note: the horizontal axis of the image corresponds to 90°
DoLP and AoP
Alignment is quantified using parameters that describe alignment direction (AoP) and strength of alignment in that direction (DoLP).
Publications
9. Castile RM, Jenkins MJ, Lake SP, Brophy RH: Microstructural and mechanical properties of grafts commonly used for cruciate ligament reconstruction. In press.
8. Bernholdt DL, Lake SP, Castile RM, Papangelou C, Hauck O, Smith MV: Biomedical comparison of docking ulnar collateral ligament reconstruction with and without an internal brace. J Shoulder Elbow Surgery. 2019 Jul 24. pii: S1058-2746(19)30331-3: doi: 10.1016/j.jse.2019.04.061 [PubMed]
7. Skelley NW, Lake SP, Brophy RH: Microstructural properties of the anterior cruciate ligament. Annals of Joint, 2:19, 2017. [Journal Website]
6. Skelley NW, Castile RM, Weber CI, Brophy RH, Lake SP: Regional variance in the mechanical and microstructural properties of the human ACL. American Journal of Sports Medicine, 44(11):2892-2899, 2016. [PubMed]
5. Wright JO, Skelley NW, Schur RP, Castile RM, Lake SP, Brophy RH: Microstructural and mechanical properties of the anterolateral and posteromedial bundles of the posterior cruciate ligament. Journal of Bone & Joint Surgery, 98:1656-64, 2016. [PubMed]
4. Castile RM, Skelley NW, Babaei B, Brophy RH, Lake SP: Microstructural properties and mechanics vary between bundles of the human anterior cruciate ligament during stress-relaxation. Journal of Biomechanics, 49(1):87-93, 2016. [PubMed]
3. Skelley NW, Castile RM, York T, Gruev V, Lake SP, Brophy RH: Differences in the microstructural properties of the anteromedial and posterolateral bundles of the anterior cruciate ligament. American Journal of Sports Medicine, 43(4):928-936, 2015. [PubMed]
2. York T, Powell SB, Gao S, Kahan L, Charanya T, Saha D, Roberts NW, Cronin TW, Marshall J, Achilefu S, Lake SP, Raman B,Gruev V: Bio-inspired polarization imaging sensors: from circuits and optics to signal processing algorithms and biomedical applications. Proceedings of IEEE, 102(10):1450-1469, 2014. [PubMed] — Awarded the 2016 IEEE Donald G. Fink Prize Paper Award
1. York T, Kahan L, Lake SP, Gruev V: Real-time high-resolution measurement of collagen alignment in dynamically loaded soft tissue. Journal of Biomedical Optics, 19(6):66011, 2014. [PubMed]