Journal article
Joint Center Estimation Using Single-Frame Optimization: Part 2: Experimentation
Sensors, Vol.18(8), 2563
0
08/01/2018
DOI: 10.3390/s18082563
PMCID: PMC6112042
PMID: 30081601
Abstract
Human motion capture is driven by joint center location estimates, and error in their estimation can be compounded by subsequent kinematic calculations. Soft tissue artifact (STA), the motion of tissue relative to the underlying bones, is a primary cause of error in joint center calculations. A method for mitigating the effects of STA, single-frame optimization (SFO), was introduced and numerically verified in Part 1 of this work, and the purpose of this article (Part 2) is to experimentally compare the results of SFO with a marker-based solution. The experimentation herein employed a single-degree-of-freedom pendulum to simulate human joint motion, and the effects of STA were simulated by affixing the inertial measurement unit to the pendulum indirectly through raw, vacuum-sealed meat. The inertial sensor was outfitted with an optical marker adapter so that its location could be optically determined by a camera-based motion-capture system. During the motion, inertial effects and non-rigid attachment of the inertial sensor caused the simulated STA to manifest via unrestricted motion (six degrees of freedom) relative to the rigid pendulum. The redundant inertial and optical instrumentation allowed a time-varying joint center solution to be determined both by optical markers and by SFO, allowing for comparison. The experimental results suggest that SFO can achieve accuracy comparable to that of state-of-the-art joint center determination methods that use optical skin markers (root mean square error of 7.87-37.86 mm), and that the time variances of the SFO solutions are correlated (r = 0.58-0.99) with the true, time-varying joint center solutions. This suggests that SFO could potentially help to fill a gap in the existing literature by improving the characterization and mitigation of STA in human motion capture.
Details
- Title: Subtitle
- Joint Center Estimation Using Single-Frame Optimization: Part 2: Experimentation
- Creators
- Eric Frick - University of IowaSalam Rahmatalla - University of Iowa, Civil and Environmental Engineering
- Resource Type
- Journal article
- Publication Details
- Sensors, Vol.18(8), 2563
- Event
- 0
- DOI
- 10.3390/s18082563
- PMID
- 30081601
- PMCID
- PMC6112042
- NLM abbreviation
- Sensors (Basel)
- ISSN
- 1424-8220
- eISSN
- 1424-8220
- Publisher
- MDPI AG
- Copyright
- © 2018 by the authors.
- Grant note
- This work was partially funded by the US Department of Defense, Army, under grant number W911QY-12-C-0009. The authors received funds from the Libraries and Provost’s Open Access Fund of the University of Iowa for covering the costs to publish in open access. The authors declare no conflict of interest.
- Language
- English
- Date published
- 08/01/2018
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Civil and Environmental Engineering; Iowa Technology Institute; Injury Prevention Research Center
- Record Identifier
- 9983756979202771
Metrics
22 File views/ downloads
27 Record Views