Real-time en-face Gabor optical coherence tomographic angiography on human skin using CUDA GPU

Chaoliang Chen; Weisong Shi; Victor X D Yang

doi:10.1364/BOE.392499

Real-time en-face Gabor optical coherence tomographic angiography on human skin using CUDA GPU

Biomed Opt Express. 2020 Apr 28;11(5):2794-2805. doi: 10.1364/BOE.392499. eCollection 2020 May 1.

Authors

Chaoliang Chen¹, Weisong Shi^{1

2}, Victor X D Yang^{1

3

4}

Affiliations

¹ Biophotonics and Bioengineering Lab, Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, Ontario, Canada.
² Department of Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.
³ Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
⁴ Division of Neurosurgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.

Abstract

We recently proposed an optical coherence tomographic angiography (OCTA) algorithm, Gabor optical coherence tomographic angiography (GOCTA), which can extract microvascular signals from a spectral domain directly with lower computational complexity compared to other algorithms. In this manuscript, we combine a programmable swept source, an OCT complex signal detecting unit, and graphics process units (GPU) to achieve a real-time en-face GOCTA system for human skin microvascular imaging. The programmable swept source can balance the A-scan rate and the spectral tuning range; the polarization-modulation based complex signal detecting unit can double the imaging depth range, and the GPU can accelerate data processing. C++ and CUDA are used as the programming platform where five parallel threads are created for galvo-driving signal generation, data acquisition, data transfer, data processing, and image display, respectively. Two queues (for the raw data and en-face images, respectively) are used to improve the data exchange efficiency among different devices. In this study, the data acquisition time and data processing time for each 3D complex volume (256×304×608 pixels,) are 405.3 and 173.7 milliseconds respectively. To the best of our knowledge, this is the first time to show en-face microvascular images covering 3×3 mm² at a refresh rate of 2.5 Hz.