High definition live 3D-OCT in vivo: design and evaluation of a 4D OCT engine with 1 GVoxel/s

Abstract

We present a 1300 nm OCT system for volumetric real-time live OCT acquisition and visualization at 1 billion volume elements per second. All technological challenges and problems associated with such high scanning speed are discussed in detail as well as the solutions. In one configuration, the system acquires, processes and visualizes 26 volumes per second where each volume consists of 320 x 320 depth scans and each depth scan has 400 usable pixels. This is the fastest real-time OCT to date in terms of voxel rate. A 51 Hz volume rate is realized with half the frame number. In both configurations the speed can be sustained indefinitely. The OCT system uses a 1310 nm Fourier domain mode locked (FDML) laser operated at 3.2 MHz sweep rate. Data acquisition is performed with two dedicated digitizer cards, each running at 2.5 GS/s, hosted in a single desktop computer. Live real-time data processing and visualization are realized with custom developed software on an NVidia GTX 690 dual graphics processing unit (GPU) card. To evaluate potential future applications of such a system, we present volumetric videos captured at 26 and 51 Hz of planktonic crustaceans and skin.

High-speed OCT light sources and systems [Invited]

“…However, for all scanners, standard galvanometer type or MEMS actuated ones, high speeds of a few kHz go hand in hand with small mirror sizes and / or limited scan angle. Resonant galvanometer scanners can provide very high scan speeds with large apertures and scan angles, so they are used for many multi-MHz applications [125]. Their main drawbacks are the fixed frequency, and limited phase stability, which usually requires active control of the driving waveform or data acquisition.…”

Review of intraoperative optical coherence tomography: technology and applications [Invited]

“…The advent of Fourier-domain detection for OCT [25][26][27][28] and confirmation of its sensitivity advantage over time-domain technologies [29][30][31] facilitated the progression from real-time B-scan imaging [32,33] to real-time volumetric imaging [34]- [36] while preserving OCT's diagnostic potential [37][38][39][40][41]. Consequently, the Fourier-domain OCT revolution of the early 2000's led to increased commercialization [42], widespread clinical adoption of OCT in ophthalmology [43][44][45], and increasing prominence of OCT in other specialties such as cardiology [46], gastroenterology [47], and cancer imaging [48][49][50][51].…”

“…GPUs were primarily used for rendering graphics prior to the advent of high level GPU programming languages such as NVIDIA's compute unified device architecture (CUDA) [134]. For OCT in particular, GPU processing became highly desirable as the repetition rate of OCT lasers increased to kilohertz [35,114,[135][136][137][138] and even megahertz [34], and researchers were no longer able to process OCT data on the CPU in real-time. Moreover, GPUs also allowed real-time volume rendering for visualization and manipulation of OCT 3D and 4D (volumes over time) data.…”

Feature tracking for automated volume of interest stabilization on 4D-OCT images

“…2 The integration of such an OCT into an operating microscope enables its use for high-accuracy intra-operative guidance with visibility of subcutaneous structures up to 3 mm in depth. 34 Within this setup, redundant combination or fusion of RGB camera and OCT data brings additional information to the live camera viewer.…”