Lingyun Wang

Lingyun Wang

PhD student at the University of Pittsburgh BioE & UPMC, interested in advanced Optical Coherence Tomography

Sitemap

A list of all the posts and pages found on the site. For you robots out there is an XML version available for digesting as well.

Pages

Posts

Future Blog Post

less than 1 minute read

Published:

This post will show up by default. To disable scheduling of future posts, edit config.yml and set future: false.

Blog Post number 4

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 3

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 2

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

Blog Post number 1

less than 1 minute read

Published:

This is a sample blog post. Lorem ipsum I can’t remember the rest of lorem ipsum and don’t have an internet connection right now. Testing testing testing this blog post. Blog posts are cool.

news

A paper is published in Journal of Biophotonics!

Published:

A method based on compressive sensing (CS) is proposed for reducing the acquisition time and noise of optical coherence tomography angiography (OCTA). It is aimed at making up for the disadvantages of OCTA including motion-induced artifact and noise. The results show that vasculature structures can be reconstructed well through CS on B-scans with a sampling rate of 70%. Moreover, the noise can be significantly eliminated by CGM filter.

A paper is published in Lasers in Surgery and Medicine!

Published:

In this study, we propose to use optical coherence tomography (OCT) to monitor ADS in vivo through three‐dimensional imaging. A swept source OCT system with a handheld probe was developed for in vivo skin imaging. Moreover, a cell in‐growth, vascular regeneration, and scaffold degradation rate (IRDR) was defined with the volume reduction rate of the scaffold’s collagen sponge layer. To measure the IRDR, a semiautomatic image segmentation algorithm was designed based on U‐Net to segment the collagen sponge layer of the scaffold from OCT images.

One conference paper was accepted by SPIE Photonics West!

Published:

The high resolution of optical coherence tomography (OCT) allows for imaging micro-structure features in tissues. Broad-band light source is typically used to improve the axial resolution of OCT but leads to an increased cost. Many real-valued networks were employed to achieve OCT super-resolution. However, they ignore the phase which contains structural information. Therefore, we proposed a complex-valued enhanced deep super-resolution network (Cv-EDSR) based on EDSR to achieve axial super-resolution. The Cv-EDSR and EDSR were evaluated on two datasets. The results show that the SR images generated by the Cv-EDSR have more realistic structures and better image metrics.

A paper is accepted by Physics in Medicine & Biology!

Published:

Optical coherence tomography (OCT) is a fast and non-invasive optical interferometric imaging technique that can provide high-resolution cross-sectional images of biological tissues. OCT’s key strength is its depth resolving capability which remains invariant along the imaging depth and is determined by the axial resolution. The axial resolution is inversely proportional to the bandwidth of the OCT light source. Thus, the use of broadband light sources can effectively improve the axial resolution and however leads to an increased cost. In recent years, real-valued deep learning technique has been introduced to obtain super-resolution optical imaging. In this study, we proposed a complex-valued super-resolution network (CVSR-Net) to achieve an axial super-resolution for OCT by fully utilizing the amplitude and phase of OCT signal. The method was evaluated on three OCT datasets. The results show that the CVSR-Net outperforms its real-valued counterpart with a better depth resolving capability. Furthermore, comparisons were made between our network, six prevailing real-valued networks and their complex-valued counterparts. The results demonstrate that the complex-valued network exhibited a better super-resolution performance than its real-valued counterpart and our proposed CVSR-Net achieved the best performance. In addition, the CVSR-Net was tested on out-of-distribution domain datasets and its super-resolution performance was well maintained as compared to that on source domain datasets, indicating a good generalization capability.

Awarded SPIE Photonics West 2024 Travel Grant!

Published:

I received Travel Grant for SPIE Photonics West 2024 for my conference paper “Axial super-resolution optical coherence tomography imaging by complex-valued enhanced deep residual network” from SPIE and MKS Instruments, Inc. Thanks for their kind support!
LOGO

Abstract Selected for Oral Presentation at 2024 ARVO Imaging in the Eye Conference!

Published:

Abstract Selected for Oral Presentation at 2024 ARVO Imaging in the Eye Conference!
Presentation Title: Reveal retinal ultra-structure with self-supervised denoising in vis-OCT
Presentation Number: PP009
Session Title: Artificial Intelligence & Hemodynamics
Session Date/Time: May 4, 2024 from 10:15 AM to 12:00 PM

portfolio

publications

Compressive‐sensing swept‐source optical coherence tomography angiography with reduced noise

Published in Journal of Biophotonics, 2022

Optical coherence tomography angiography (OCTA), as a functional extension of optical coherence tomography (OCT), has exhibited a great potential to aid in clinical diagnostics. Currently, OCTA still suffers from motion artifact and noise. Therefore, in this article, we propose to implement compressive sensing (CS) on B-scans to reduce motion artifact by increasing B-scan rate. Meanwhile, a noise reduction filter is specially designed by combining CS, Gaussian filter and median filter. Specially, CS filtering is realized by averaging multiple CS repetitions on en-face OCTA images with varied sampling functions. The method is evaluated on in vivo OCTA images of human skin. The results show that vasculature structures can be reconstructed well through CS on B-scans with a sampling rate of 70%. Moreover, the noise can be significantly eliminated by the developed filter. This implies that our method has a good potential to expedite OCTA imaging and improve the image quality.

Recommended citation: Wang, L., Chen, Z., Zhu, Z., Yu, X., Mo, J., Compressive-sensing swept-source optical coherence tomography angiography with reduced noise. J. Biophotonics 2022, 15(8), e202200087. https://doi.org/10.1002/jbio.202200087

Optical coherence tomography for in vivo longitudinal monitoring of artificial dermal scaffold

Published in Lasers in Surgery and Medicine, 2023

Objectives. Artificial dermal scaffold (ADS) has undergone rapid development and been increasingly used for treating skin wound in clinics due to its good biocompatibility, controllable degradation, and low risk of disease infection. To obtain a good treatment efficacy, ADS needs to be monitored longitudinally during the treatment process. For example, scaffold-tissue fit, cell in-growth, vascular regeneration and scaffold degradation are the key properties to be inspected. However, to date, there are no effective, real-time and noninvasive techniques to meet the requirement of the scaffold monitoring above. Materials and Methods. In this study, we propose to use optical coherence tomography (OCT) to monitor ADS in vivo through three-dimensional imaging. A swept source OCT system with a handheld probe was developed for in vivo skin imaging. Moreover, a cell in-growth, vascular regeneration and scaffold degradation rate (IRDR) was defined with the volume reduction rate of the scaffold’s collagen sponge layer. To measure the IRDR, a semi-automatic image segmentation algorithm was designed based on U-Net to segment the collagen sponge layer of the scaffold from OCT images. Results. The results show that the scaffold-tissue fit can be clearly visualized under OCT imaging. The IRDR can be computed based on the volume of the segmented collagen sponge layer. It is observed that the IRDR appeared to a linear function of the time and in addition the IRDR varied among different skin parts. Conclusion. Overall, it can be concluded that OCT has a good potential to monitor ADS in vivo. This can help guide the clinicians to control the treatment with ADS to improve the therapy.

Recommended citation: Chen, Z., Cheng, Q., Wang, L., Mo, Y., Li, K., Mo, J., Optical coherence tomography for in vivo longitudinal monitoring of artificial dermal scaffold. Lasers Surg Med. 2023; 1– 11. https://doi.org/10.1002/lsm.23645

Axial super-resolution optical coherence tomography via complex-valued network

Published in Physics in Medicine & Biology, 2023

Objectives. Optical coherence tomography (OCT) is a fast and non-invasive optical interferometric imaging technique that can provide high-resolution cross-sectional images of biological tissues. OCT’s key strength is its depth resolving capability which remains invariant along the imaging depth and is determined by the axial resolution. The axial resolution is inversely proportional to the bandwidth of the OCT light source. Thus, the use of broadband light sources can effectively improve the axial resolution and however leads to an increased cost. In recent years, real-valued deep learning technique has been introduced to obtain super-resolution optical imaging. This study is aimed to achieve axial super-resolution OCT imaging with complex-valued deep learning technique. Approach. A complex-valued super-resolution network (CVSR-Net) was designed to fully utilize the amplitude and phase of OCT signal to reconstruct an OCT image with an improved axial resolution. Main results. The method was evaluated on three OCT datasets. The results show that the CVSR-Net outperforms its real-valued counterpart with a better depth resolving capability. Furthermore, comparisons were made between our network, six prevailing real-valued networks and their complex-valued counterparts. The results demonstrate that the complex-valued network exhibited a better super-resolution performance than its real-valued counterpart and our proposed CVSR-Net achieved the best performance. In addition, the CVSR-Net was tested on out-of-distribution domain datasets and its super-resolution performance was well maintained as compared to that on source domain datasets, indicating a good generalization capability. Significance. The good performance of the CVSR-Net in both axial super-resolution and generalization indicate that this method has a good potential to reduce OCT system cost by utilizing narrow-band light source while retaining the axial resolution.

Recommended citation: Wang, L., Si, C., Liu, L., Yin, X., Shi, G., Mo, J., Axial super-resolution optical coherence tomography via complex-valued network. Physics in Medicine & Biology. 2023. https://doi.org/10.1088/1361-6560/ad0997

Sub2Full: split spectrum to boost optical coherence tomography despeckling without clean data

Published in Optics Letters, 2024

Optical coherence tomography (OCT) suffers from speckle noise, causing the deterioration of image quality, especially in high-resolution modalities such as visible light OCT (vis-OCT). Here, we proposed an innovative self-supervised strategy called Sub2Full (S2F) for OCT despeckling without clean data. This approach works by acquiring two repeated B-scans, splitting the spectrum of the first repeat as a low-resolution input, and utilizing the full spectrum of the second repeat as the high-resolution target. The proposed method was validated on vis-OCT retinal images visualizing sublaminar structures in the outer retina and demonstrated superior performance over state-of-the-art Noise2Noise (N2N) and Noise2Void (N2V) schemes.

Recommended citation: Wang, L., Sahel, J., Pi, S., Sub2Full: split spectrum to boost optical coherence tomography despeckling without clean data. Optics Letters. 2024. https://doi.org/10.1364/OL.518906

talks

teaching

Teaching experience 1

Undergraduate course, University 1, Department, 2014

This is a description of a teaching experience. You can use markdown like any other post.

Teaching experience 2

Workshop, University 1, Department, 2015

This is a description of a teaching experience. You can use markdown like any other post.