Accuracy of a video strain measurement system

W. P. Smutz, M. Drexler, L. J. Berglund, E. Growney, Kai N. An

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The purpose of this study was to determine the accuracy of a video system which our laboratory has been using to measure soft tissue strain. Both static and dynamic error analyses were performed to assess the accuracy of our video system. Static error was defined as the amount of movement reported by the video system for markers that were stationary. Dynamic error was defined as the difference between the motion of the markers as reported by the video system and their actual motion. Two sets of fluorescent markers were attached to a servo-hydraulic materials test machine. One marker set was attached to the hydraulic actuator (moving markers) and the other set was attached to the base of the machine (stationary markers). Five different marker sizes, five camera distances, and seven different loading rates were studied. Results indicated that the static error was independent of marker size, and that the dynamic error was independent of the loading rate and marker size for loading rates of 50% of the camera field of view (CFV) per second or slower. For loading rates greater than 50% of CFV per second, the marker size did have an affect on the dynamic error. The mean static error was found to be 0.026% of CFV and the mean dynamic error was found to be 0.062% of CFV.

Original languageEnglish (US)
Pages (from-to)813-817
Number of pages5
JournalJournal of Biomechanics
Volume29
Issue number6
DOIs
StatePublished - Jun 1996

Fingerprint

Strain measurement
Cameras
Hydraulic actuators
Hydraulics
Tissue

Keywords

  • Soft tissue
  • Strain measurement
  • Video

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Smutz, W. P., Drexler, M., Berglund, L. J., Growney, E., & An, K. N. (1996). Accuracy of a video strain measurement system. Journal of Biomechanics, 29(6), 813-817. https://doi.org/10.1016/0021-9290(95)00131-X

Accuracy of a video strain measurement system. / Smutz, W. P.; Drexler, M.; Berglund, L. J.; Growney, E.; An, Kai N.

In: Journal of Biomechanics, Vol. 29, No. 6, 06.1996, p. 813-817.

Research output: Contribution to journalArticle

Smutz, WP, Drexler, M, Berglund, LJ, Growney, E & An, KN 1996, 'Accuracy of a video strain measurement system', Journal of Biomechanics, vol. 29, no. 6, pp. 813-817. https://doi.org/10.1016/0021-9290(95)00131-X
Smutz WP, Drexler M, Berglund LJ, Growney E, An KN. Accuracy of a video strain measurement system. Journal of Biomechanics. 1996 Jun;29(6):813-817. https://doi.org/10.1016/0021-9290(95)00131-X
Smutz, W. P. ; Drexler, M. ; Berglund, L. J. ; Growney, E. ; An, Kai N. / Accuracy of a video strain measurement system. In: Journal of Biomechanics. 1996 ; Vol. 29, No. 6. pp. 813-817.
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