From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

Student Projects

cancel
Showing results for 
Search instead for 
Did you mean: 

Frequency-Domain Optical Coherence Tomography (FD-OCT)

Please complete the following information

Contact Information

University and Department:      School of Life Sciences and Biotechnology, Shanghai Jiao Tong University

Team Members:                      Xiaowei Wu, Tobias Braeuler, Cuixia Dai, Peng Xi, Chuanqing Zhou, Qiushi Ren

Faculty Advisors:                      Peng Xi

Primary Email Address:            xipeng@sjtu.edu.cn

Primary Telephone Number (include area and country code):    +86 21 3420 4076

Project Information

Project Title:          Frequency-Domain Optical Coherence Tomography (FD-OCT)

List all parts (hardware, software, etc.) you used to design and complete your project:

NI DAQ PCI 6731

NI IMAQ PCI-1428 image acquisition card

LabVIEW 8.5

Describe the challenge your project is trying to solve.

OCT is a high-resolution optical cross-sectional imaging technology. We need to develop a FD-OCT system for the imaging of the retina of the human eye.

      In our experiment, the following challenges need to be solved:

    (1)  a constant timing clock for each galvanometric scanning.

    (2)  Two voltage signals to drive the galvanometer pair and continuous galvanometric scanning driving;

    (3)  Synchronization with the line-CCD camera;

    (4)  Post-processing of the interferogram for visualization;

    (5)  A user-friendly GUI for easy operation of the system.

Describe how you addressed the challenge through your project.

In our system, a FD-OCT is constructed for the imaging of the retina of the human eye. (Fig.1)

A broad band light sources beam is employed as the low coherent light source. The incidence was split in a fiber coupler and focused on the background of the eye and on a reference mirror, respectively. The reflected beams are recombined in the fiber coupler and interfere there, coding the information of the retina in the interferogram. Afterwards, the interferogram is recorded by a grating-based spectrometer. The spectrometric data was taken with a line CCD camera (Aviiva e2V). Together with NI IMAQ PCI-1428 image acquisition card, the data for each A-scan is recorded and then processed for visualization by a custom-designed program written with Labview.

Each shot gives us on depth scan (A-scan) of the eye, with two galvanometric scanning mirrors the beam is scanned across the surface of the retina to record A-scans at different positions to reconstruct the 3-D morphological structure of the retina in vivo (Fig. 2).

At several core parts of our system, NI products are used:

l  First of all, the scanning mirror in the galvanometer are driven and controlled by a NI PCI 6731 data acquisition card, allowing an easy to control and precise beam positioning.

l  The intferogram, recorded by a line-scan CCD camera, is transferred to the PC by use of the NI IMAQ PCI 1428 image acquisition card, allowing an exact triggering and fast image transfer.

l  The mirror in the reference arm is mounted on a motorized actuator stage, making fine adjustment of the mirror position possible. The stages motion controller is connected to a NI PCI-GBIP card.

All of these parts are controlled by NI Labview 8.5. The post processing is also done with Labview. Furthermore, we also designed a Labview based, custom made, graphical user interface, allowing an easy access to the system and suiting the demands of medical professionals. (Fig.3)

Please upload photos below:

Fig 1.JPG

Fig. 1  Diagram of the FD_OCT system.

Fig 2.JPG

Fig. 2  Our OCT imaging result revealed the biological structures of the human retina.

Fig 3.jpg

Fig. 3  The FD-OCT GUI.

Please insert video below:

[Click on video icon on task bar]

\\spanky\CDG-Shared\China\Web\video.avi

or

http://down.qiaomeng.cn/xipeng/20090515/video.mpg

Contributors