Mini-FlatScope: A Miniaturized Lensless Microscope for Neural Recording in Freely-Behaving Mice
Robinson, Jacob T.
Master of Science
Optical neural recording is recognized among all neural recording methods for its high resolution, large field of view (FOV) and low invasiveness. An ideal neural recording device would enable a resolution sufficiently high to identify the activity of each individual neuron, a FOV sufficiently large to cover all neurons within the cortex region of interest for a certain study, and a form factor sufficiently small to allow the studied animal to freely behave. Realizing that the trade-oﬀ between size and weight, resolution, and FOV of lens-based microscopes prevents the possibility to simultaneously achieve cellular resolution and large FOV with a small and lightweight lens-based microscope, our lab developed a lens-less microscope, “Bio-FlatScope”. By replacing lenses with a phase-shifting mask and image reconstruction algorithms, we demonstrated large FOV, cellular-resolution ﬂuorescence imaging of ﬁxed biological samples, as well as in vivo imaging of stimulus-evoked calcium activity from neuron clusters in the cortex of head-fixed mice. In this thesis, we show an upgraded version of Bio-FlatScope, termed “MiniFlatScope”, with an integrated illumination module, further decreased form factor, and a finer reconstruction algorithm. We demonstrate near-cellular resolution and large FOV in a resolution test target and fixed biological samples, and show the ability of this prototype to be carried by a mouse, enabling the future in vivo behavioral study in freely-behaving mice.
Neuroengineering; Calcium imaging; Lensless imaging; Computational imaging