Temporally and spatially adaptive Doppler analysis for robust handheld optical coherence elastography

Abstract

Optical coherence elastography (OCE), a functional extension of optical coherence tomography (OCT), can be used to characterize the mechanical properties of biological tissue. A handheld fiber-optic OCE instrument will allow the clinician to conveniently interrogate the localized mechanical properties of tissue, leading to better informed clinical decision making. During handheld OCE characterization, the handheld probe is used to compress the sample and the displacement of the sample is quantified by analyzing the OCT signals acquired. However, the motion within the sample inevitably varies in time due to varying hand motion. Moreover, the motion speed depends on spatial location due to the sample deformation. Hence, there is a need for a robust motion tracking method for manual OCE measurement. In this study, we investigate a temporally and spatially adaptive Doppler analysis method. The method described here strategically chooses the time interval () between signals involved in Doppler analysis to track the motion speed (,) that varies temporally and spatially in a deformed sample volume under manual compression. Enabled by temporally and spatially adaptive Doppler analysis, we report the first demonstration of real-time manual OCE characterization of tissue to the best of our knowledge.

Quantitative Optical Coherence Elastography for Robust Stiffness Assessment

“…Spatially resolved qOCE imaging is beyond the scope of this study. Imaging results can be found in our previous publications [12][13][14]. as the material's response to the excitation.…”

“…Compared to other elastography technologies, OCE has much higher spatial resolution and allows mechanical characterization on a small volume of breast tissue. An OCE instrument can be fabricated using fiber-optic components and can be integrated into a handheld probe that is compact and lightweight [12]. Therefore, an OCE instrument will allow convenient assessment of tissue malignancy for margin assessment during breast conserving surgery, and has the potential to significantly improve patient outcome by ensuring negative margin.…”

A review of low-cost and portable optical coherence tomography

“…In recent years, applications of OCT continue to expand including utilization in the fields of dermatology [26][27][28], the pulmonary system [29,30], the brain [31,32], the urinary tract [33], the middle ear [34][35][36], among numerous others. Further, functional extensions of OCT [37], including angiography [38,39], elastography [40,41], Doppler-OCT [40,42,43], spectroscopic-OCT [44], adaptive optics [45,46], and combined modalities [47][48][49], are continually advanced in efforts to better identify and understand disease. Clinical adoption in these fields depends not just on imaging capabilities but also on adapting OCT to the clinical workflow, including the financial implications of instrument cost and use.…”

First Clinical Application of Low-Cost OCT

“…Recently, development of handheld OCT probes has accelerated, driven by increased commercial availability of miniaturized optics and the need for the flexibility of manual manipulation in many clinical applications 4. Various scanning-based handheld OCT probes have been demonstrated for a wide range of applications, such as inner ear imaging,4 retinal angiography,5 elastography,6 and with combined modalities 7. Typically, handheld probes enclose the OCT scanner arm within a manufactured housing 8.…”