Opto-mechatronics instrumentation of a specialty optical fiber based optogenetic probe

• Main Author: Gokulnath, Rajendran
• Other Authors: Yoo Seong Woo
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/76866
• Institution: Nanyang Technological University

The neurodegenerative diseases are considered to be incurable as it is caused due to the progressive degradation of the function or death of neuronal cells and loss of structure of neurons. The recent advancement in the research of optogenetics is considered to be of greater significance as it is a new path for researchers to understand the comprehensive function of the brain to find a therapy for neurodegenerative diseases. The discovery of light-gated proteins that can be expressed with neuronal cells for targeted stimulation made optogenetics a powerful tool. Recently, the integration of fiber bundle as a waveguide made it possible for optogenetics to move from in vitro slide studies to the in vivo brain stimulation studies. The galvanometric mirrors in the conventional targeted neuronal stimulation studies were replaced by the Spatial Light Modulators (SLM) in the state of the art optogenetics system due to its superior beam modulation options and response time. However, most of the SLM integrated with the optogenetic systems using coherent fiber bundle are the reflective type which suffers from a major drawback of complex optical configuration. In this dissertation, a high-resolution optogenetic system using Transmissive LC SLM to selectively illuminate the fibers inside the fiber bundle for targeted neuronal stimulation studies was developed. The developed system has several advantages over the reflective SLM system in terms of size, weight and complexity. The individual pixel control of the LC SLM is desirable to understand how the LC SLM can be used with the fiber bundle for neuronal stimulation. Hence a MATLAB based tool was also developed in this work for LC SLM and it was verified experimentally that the developed tool can be used to control the individual LC SLM pixels. Finally, a reference scheme was proposed for the developed system to identify the pixels that need to be activated in the LC SLM for selective illumination of fibers inside the fiber bundle.