Characterization of oviduct ciliary beat frequency using real time phase resolved Doppler spectrally encoded interferometric microscopy

Abstract

Ciliary activity, characterized by the coordinated beating of ciliary cells, generates the primary driving force for oviduct tubal transport, which is an essential physiological process for successful pregnancies. Malfunction of the cilium in the fallopian tube, or oviduct, may increase the risk of infertility and tubal pregnancy that can result in maternal death. While many ex-vivo studies have been carried out using bright field microscopy, this technique is not feasible for the in-vivo investigation of oviduct ciliary beating frequency (CBF). Optical coherence tomography (OCT) has been able to provide in-vivo CBF imaging in a mouse model, but its resolution may be insufficient to resolve the spatial and temporal features of the cilium. Our group has recently developed the phase resolved Doppler (PRD) OCT method to visualize ciliary strokes at ultra-high displacement sensitivity. However, the cross-sectional field of view (FOV) may not be ideal for visualizing the surface dynamics of ciliated tissue. In this study, we report on the development of phase resolved Doppler spectrally encoded interferometric microscopy (PRD-SEIM) to visualize the oviduct ciliary activity within an en face FOV. This novel real time imaging system offers micrometer spatial resolution, sub-nanometer displacement sensitivity, and the potential for in-vivo endoscopic adaptation. The feasibility of the approach has been validated through ex-vivo experiments where the porcine oviduct CBF has been measured across different temperature conditions and the application of a drug. CBF ranging from 8 to 12 Hz have been observed at different temperatures, while administration of lidocaine decreased the CBF and deactivated the motile cilia. This study will serve as a stepping stone to in-vivo oviduct ciliary endoscopy and future clinical translations.

Ultrahigh-sensitive optical coherence elastography

“…In 2017, Lan et al reported a high-phasestability OCE system using a common-path spectraldomain OCT (SD-OCT) to achieve a subnanometre displacement sensitivity, demonstrating the feasibility of common-path OCE; however, only phantom experiments were performed 19 . In addition, SD-OCT-based OCE systems are based on a static operation principle that provides phase-stable detection 15,[20][21][22][23][24] , but their performance is limited by the groove density of the diffraction grating, the center wavelength of the light source, and the resolution of the line-scan camera, hence the inherent disadvantages of phase washout, low imaging speed, shallow penetration depth, and short imaging range 25,26 .…”

Validation of spectrally encoded interferometric microscopy (SEIM) in finding ciliary beat frequency of human ex vivo upper airway tissue

“…In this study, our SEIM data was processed similarly to previous studies. 13 We used the Hilbert Transform to create the analytical form of the raw SEIM data. From this, the phase term can be extracted.…”

“…Spectrally encoded interferometric microscopy (SEIM) can detect displacement on the nanometer scale at a kilohertz frame rate and when coupled with a wavelength-swept laser and a spectral disperser, SEIM can image tissue en face. 13 Our group developed a SEIM system based on a swept source OCT system using a vertical-cavity surface emitting laser (VCSEL) with the intention of eventually measuring functional parameters of cilia across the surface of upper airway tissues. In this study, we aim to validate this SEIM system as a means of measuring ciliary beat frequency in ex vivo human upper airway tissue with high-speed video of phasecontrast microscopy.…”

Fixed-time artificial insemination protocols on brazilian locally adapted breed gilts on ovulatory response and embryo production

“…In some species as horses, rats and hamsters only embryos are transported to uterus, unfertilized eggs are retained in oviduct (Li and Winuthayanon, 2017). Failure to capture oocyte and embryo transport (He et al, 2019).…”