Swept-source Phase-Stabilized Optical Coherence Tomography Setup for Elastography

Batista, Ana; Correia, Carlos; Barbeiro, Sílvia; Cardoso, João R.; Domingues, José Paulo; Henriques, Rafael; Loureiro,; Santos, M. C.; Serranho, Pedro; Bernardes, Rui; Morgado, Miguel

doi:10.5220/0011126500003209

Cited by 4 publications

(3 citation statements)

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“…The former is limited by the system's temporal stability and is inherently related to the instrument's setup. The measured temporal stability of the system was 396.9 ± 46.7 𝑝𝑠 [23]. No changes were observed in the system's temporal stability with a decrease in the system SNR.…”

Section: Static Conditionsmentioning

confidence: 89%

Phase-Resolved Optical Coherence Elastography: An Insight into Tissue Displacement Estimation

Batista

Serranho

Santos

et al. 2023

Sensors

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Robust methods to compute tissue displacements in optical coherence elastography (OCE) data are paramount, as they play a significant role in the accuracy of tissue elastic properties estimation. In this study, the accuracy of different phase estimators was evaluated on simulated OCE data, where the displacements can be accurately set, and on real data. Displacement (∆d) estimates were computed from (i) the original interferogram data (Δφori) and two phase-invariant mathematical manipulations of the interferogram: (ii) its first-order derivative (Δφd) and (iii) its integral (Δφint). We observed a dependence of the phase difference estimation accuracy on the initial depth location of the scatterer and the magnitude of the tissue displacement. However, by combining the three phase-difference estimates (Δdav), the error in phase difference estimation could be minimized. By using Δdav, the median root-mean-square error associated with displacement prediction in simulated OCE data was reduced by 85% and 70% in data with and without noise, respectively, in relation to the traditional estimate. Furthermore, a modest improvement in the minimum detectable displacement in real OCE data was also observed, particularly in data with low signal-to-noise ratios. The feasibility of using Δdav to estimate agarose phantoms’ Young’s modulus is illustrated.

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Section: Static Conditionsmentioning

confidence: 89%

Phase-Resolved Optical Coherence Elastography: An Insight into Tissue Displacement Estimation

Batista

Serranho

Santos

et al. 2023

Sensors

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“…Nonetheless, the high cost of MRE hinders its widespread adoption. We are currently developing an OCE system to evaluate changes in retinal elastic properties induced by neurodegeneration in animal models of disease ( 42 ). Moreover, we are developing novel approaches to retrieve tissue elastic properties with a higher degree of accuracy, allowing the detection of slight variations ( 43 ).…”

Section: Discussionmentioning

confidence: 99%

Retinal imaging in animal models: Searching for biomarkers of neurodegeneration

et al. 2023

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There is a pressing need for novel diagnostic and progression biomarkers of neurodegeneration. However, the inability to determine disease duration and stage in patients with Alzheimer’s disease (AD) hinders their discovery. Because animal models of disease allow us to circumvent some of these limitations, they have proven to be of paramount importance in clinical research. Due to the clear optics of the eye, the retina combined with optical coherence tomography (OCT) offers the perfect opportunity to image neurodegeneration in the retina in vivo, non-invasively, directly, quickly, and inexpensively. Based on these premises, our group has worked towards uncovering neurodegeneration-associated changes in the retina of the triple-transgenic mouse model of familial AD (3×Tg-AD). In this work, we present an overview of our work on this topic. We report on thickness variations of the retina and retinal layers/layer aggregates caused by healthy aging and AD-like conditions and discuss the implications of focusing research efforts solely on retinal thickness. We explore what other information is embedded in the OCT data, extracted based on texture analysis and deep-learning approaches, to further identify biomarkers that could be used for early detection and diagnosis. We were able to detect changes in the retina of the animal model of AD as early as 1 month of age. We also discuss our work to develop an optical coherence elastography system to measure retinal elasticity, which can be used in conjunction with conventional OCT. Finally, we discuss the potential application of these technologies in human patients and the steps needed to make OCT a helpful screening tool for the detection of neurodegeneration.

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“…The system has been described in detail elsewhere. 7 Briefly, it consists of a swept-source laser, sweeping between 985 nm and 1095 nm at a frequency of 100 kHz (A-scan rate), with a central wavelength of 1040 nm, coupled with a piezoelectric actuator (P-287, Physik Instrumente GmbH & Co. KG, Karlsruhe, Germany) to induce tissue displacements. Transient pulses triggered mechanical vibrations with an amplitude of 50 mVpp, 500 μs duration, and a 100 μs delay.…”

Section: Oce Image Acquisitionmentioning

confidence: 99%

Evaluation of skin care products using optical coherence elastography

Bernardo

Domingues²,

Bernardes³

et al. 2023

Optical Elastography and Tissue Biomechanics X

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The biomechanical properties of the human skin are intrinsically correlated with changes associated with pathological conditions, aging, and hydration. Quantitative measurements can improve diagnostic tools, treatments, and cosmetic product evaluation. Using optical coherence elastography (OCE), an emerging imaging modality combining optical coherence tomography (OCT) with a localized excitation source to induce mechanical disturbances, a quantitative evaluation of tissue biomechanics can be achieved. OCE complements the structural information with elasticity data to attain a complete overview of skin status. In this study, we employed a home-built OCE system, combining a swept-source OCT system with a piezoelectric actuator for tissue displacement, to evaluate changes to the skin biomechanical properties due to the application of an anti-aging cream. Skin elasticity was monitored for a total of five weeks. Anti-aging cream was applied daily for four weeks. OCE measurements continued for one additional week to assess the effect of cream application interruption. Three female volunteers were included in this proof-of-principle investigation. Their counter-arm was used as control. Although no statistical significance was reached, a decrease in skin Young’s modulus was observed with the cream application, indicating an increase in skin elasticity.

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Swept-source Phase-Stabilized Optical Coherence Tomography Setup for Elastography

Cited by 4 publications

References 0 publications

Phase-Resolved Optical Coherence Elastography: An Insight into Tissue Displacement Estimation

Phase-Resolved Optical Coherence Elastography: An Insight into Tissue Displacement Estimation

Retinal imaging in animal models: Searching for biomarkers of neurodegeneration

Evaluation of skin care products using optical coherence elastography

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