The Development of a Laser Reflectance System to Measure the Cross-Sectional Area of Soft Tissues

Determination of the biomechanical properties of soft tissues such as tendons and ligaments is dependent on the accurate measurement of their cross-sectional area (CSA). Measurement of these tissues is problematic because they are easily deformed and possess complex cross-sectional shapes.

To overcome these problems, a non-contact laser reflectance system (LRS) was developed. This system is designed to fit in a servo-hydraulic test machine and measures CSA by orbiting a laser transducer in a circular path around a soft tissue specimen held by tissue clamps. The system was validated using several machined metallic specimens, as well as different sizes of bovine tendons. The metallic specimens could be measured to within 4% accuracy, and the larger tendons to within 7%. The LRS was successfully used to measure the changing CSA of bovine tendons during uniaxial tensile testing.

The LRS developed in this work represents a simple, quick, and accurate way of reconstructing complex cross-sectional profiles and calculating cross-sectional areas. In addition, the LRS represents the first system capable of automatically measuring changing CSA of soft tissues during tensile testing, facilitating the calculation of more accurate biomechanical properties.

Year	Entry
1969	Ellis DG. Cross-sectional area measurements for tendon specimens: a comparison of several methods. J Biomech. 1969;2(2):175-186.
2008	Prajapati M. Non-Invasive Strain Measurement of Orthopaedic Soft Tissue Using Texture Correlation [Master's thesis]. University of Guelph; January 2008.
1936	Cronkite AE. The tensile strength of human tendons. Anat Rec. January 1936;64(2):173-186.
1990	Woo SL-Y, Danto MI, Ohland KJ, Lee TQ, Newton PO. The use of a laser micrometer system to determine the cross-sectional shape and area of ligaments: a comparative study with two existing methods. J Biomech Eng. November 1990;112(4):426-431.
1987	Iaconis F, Steindler R, Marinozzi G. Measurements of cross-sectional area of collagen structures (knee ligaments) by means of an optical method. J Biomech. 1987;20(10):1003-1010.
1964	Walker LB Jr, Harris EH, Benedict JV. Stress-strain relationship in human cadaveric plantaris tendon: a preliminary study. Med Electron Biol Eng. March 1964;2:31-38.
1988	Lee TQ, Woo SL-Y. A new method for determining cross-sectional shape and area of soft tissues. J Biomech Eng. May 1988;110(2):110-114.
1959	Rigby BJ, Hirai N, Spikes JD, Eyring H. The mechanical properties of rat tail tendon. J Gen Physiol. November 1959;43(2):265-283.
1984	Butler DL, Grood ES, Noyes FR, Zernicke RF, Brackett K. Effects of structure and strain measurement technique on the material properties of young human tendons and fascia. J Biomech. 1984;17(8):579-596.
1981	Woo SL-Y, Gomez MA, Amiel D, Ritter MA, Gelberman RH, Akeson WH. The effects of exercise on the biomechanical and biochemical properties of swine digital flexor tendons. J Biomech Eng. February 1981;103(1):51-56.
1974	Noyes FR, DeLucas JL, Torvik PJ. Biomechanics of anterior cruciate ligament failure: an analysis of strain-rate sensitivity and mechanisms of failure in primates. J Bone Joint Surg. March 1974;56A(2):236-253.
1981	Woo SL-Y, Gomez MA, Akeson WH. The time and history-dependent viscoelastic properties of the canine medical collateral ligament. J Biomech Eng. November 1981;103(4):293-298.
2005	Hashemi J, Chandrashekar N, Cowden C, Slauterbeck J. An alternative method of anthropometry of anterior cruciate ligament through 3-D digital image reconstruction. J Biomech. May 2005;38(3):551-555.
1996	Race A, Amis AA. Cross-sectional area measurement of soft tissue: a new casting method. J Biomech. September 1996;29(9):1207-1212.
1993	Danto MI, Woo SL. The mechanical properties of skeletally mature rabbit anterior cruciate ligament and patellar tendon over a range of strain rates. J Orthop Res. January 1993;11(1):58-67.

Year

Entry

1969

Ellis DG. Cross-sectional area measurements for tendon specimens: a comparison of several methods. J Biomech. 1969;2(2):175-186.

2008

Prajapati M. Non-Invasive Strain Measurement of Orthopaedic Soft Tissue Using Texture Correlation [Master's thesis]. University of Guelph; January 2008.

1936

Cronkite AE. The tensile strength of human tendons. Anat Rec. January 1936;64(2):173-186.

1990

Woo SL-Y, Danto MI, Ohland KJ, Lee TQ, Newton PO. The use of a laser micrometer system to determine the cross-sectional shape and area of ligaments: a comparative study with two existing methods. J Biomech Eng. November 1990;112(4):426-431.

1987

Iaconis F, Steindler R, Marinozzi G. Measurements of cross-sectional area of collagen structures (knee ligaments) by means of an optical method. J Biomech. 1987;20(10):1003-1010.