1
|
Navaeipour F, Hepburn MS, Li J, Metzner KL, Amos SE, Vahala D, Maher S, Choi YS, Kennedy BF. In situ stress estimation in quantitative micro-elastography. BIOMEDICAL OPTICS EXPRESS 2024; 15:3609-3626. [PMID: 38867802 PMCID: PMC11166433 DOI: 10.1364/boe.522002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/20/2024] [Accepted: 04/22/2024] [Indexed: 06/14/2024]
Abstract
In quantitative micro-elastography (QME), a pre-characterized compliant layer with a known stress-strain curve is utilized to map stress at the sample surface. However, differences in the boundary conditions of the compliant layer when it is mechanically characterized and when it is used in QME experiments lead to inconsistent stress estimation and consequently, inaccurate elasticity measurements. Here, we propose a novel in situ stress estimation method using an optical coherence tomography (OCT)-based uniaxial compression testing system integrated with the QME experimental setup. By combining OCT-measured axial strain with axial stress determined using a load cell in the QME experiments, we can estimate in situ stress for the compliant layer, more accurately considering its boundary conditions. Our proposed method shows improved accuracy, with an error below 10%, compared to 85% using the existing QME technique with no lubrication. Furthermore, demonstrations on hydrogels and cells indicate the potential of this approach for improving the characterization of the micro-scale mechanical properties of cells and their interactions with the surrounding biomaterial, which has potential for application in cell mechanobiology.
Collapse
Affiliation(s)
- Farzaneh Navaeipour
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia
| | - Matt S. Hepburn
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
| | - Jiayue Li
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| | - Kai L. Metzner
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia
| | - Sebastian E. Amos
- School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia 6009, Australia
| | - Danielle Vahala
- School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia 6009, Australia
| | - Samuel Maher
- School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia 6009, Australia
| | - Yu Suk Choi
- School of Human Sciences, The University of Western Australia, 35 Stirling Highway, Perth, Western Australia 6009, Australia
| | - Brendan F. Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, Western Australia 6009, Australia
- Department of Electrical, Electronic and Computer Engineering, School of Engineering, The University of Western Australia, 35, Stirling Highway, Perth, Western Australia 6009, Australia
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| |
Collapse
|
2
|
Li J, Pijewska E, Fang Q, Szkulmowski M, Kennedy BF. Analysis of strain estimation methods in phase-sensitive compression optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2022; 13:2224-2246. [PMID: 35519281 PMCID: PMC9045929 DOI: 10.1364/boe.447340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 05/11/2023]
Abstract
In compression optical coherence elastography (OCE), deformation is quantified as the local strain at each pixel in the OCT field-of-view. A range of strain estimation methods have been demonstrated, yet it is unclear which method provides the best performance. Here, we analyze the two most prevalent strain estimation methods used in phase-sensitive compression OCE, i.e., weighted least squares (WLS) and the vector method. We introduce a framework to compare strain imaging metrics, incorporating strain sensitivity, strain signal-to-noise ratio (SNR), strain resolution, and strain accuracy. In addition, we propose a new phase unwrapping algorithm in OCE, fast phase unwrapping (FPU), and combine it with WLS, termed WLSFPU. Using the framework, we compare this new strain estimation method with both a current implementation of WLS that incorporates weighted phase unwrapping (WPU), termed WLSWPU, and the vector method. Our analysis reveals that the three methods provide similar strain sensitivity, strain SNR, and strain resolution, but that WLSFPU extends the dynamic range of accurate, measurable local strain, e.g., measuring a strain of 2.5 mɛ with ∼4% error, that is ×11 and ×15 smaller than the error measured using WLSWPU and the vector method, respectively. We also demonstrate, for the first time, the capability to detect sub-resolution contrast in compression OCE, i.e., changes in strain occurring within the strain axial resolution, and how this contrast varies between the different strain estimation methods. Lastly, we compare the performance of the three strain estimation methods on mouse skeletal muscle and human breast tissue and demonstrate that WLSFPU avoids strain imaging artifacts resulting from phase unwrapping errors in WLSWPU and provides improved contrast over the other two methods.
Collapse
Affiliation(s)
- Jiayue Li
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
- These authors contributed equally to this work
| | - Ewelina Pijewska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
- These authors contributed equally to this work
| | - Qi Fang
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
| | - Maciej Szkulmowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Torun, Poland
| | - Brendan F. Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre Nedlands and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia 6009, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Crawley 6009, Australia
- Australian Research Council Centre for Personalized Therapeutics Technologies, Australia
| |
Collapse
|