Sleep is an important biological processes that has been studied extensively to date. Research
in sleep typically involves mice experiments that use heavy benchtop equipment or basic neural
loggers to record ECoG/EMG signals which are then processed offline in workstations. These
systems limit the complexity of experiments that can be carried out to only simple open loop
recordings, due to either the tethered setup used, which restricts animal movements, or the
lack of devices that can offer more advanced features without compromising its portability.
With rising popularity in exploring more physiological features that can affect sleep, such as
temperature, whose importance has been highlighted in several papers [1][2][3] and advances
in optogenetic stimulation, allowing high temporal and spatial neural control, there is now an
unprecedented demand for experimental setups using new closed loop paradigms.
To address this, this thesis presents compact and lightweight neural logging devices that are
not only capable of measuring ECoG and EMG signals for core sleep analysis but also capable
of taking high resolution temperature recordings and delivering optogenetic stimulus with fully
adjustable parameters. Together with its embedded on-board automatic sleep stage scoring
algorithm, the device will allow researchers for the first time to be able to quickly uncover the
role a neural circuit plays in sleep regulation through selective neural stimulation when the
animal is under the target sleep vigilance state.
Original contributions include: the development of two novel multichannel neural logging devices, one for core sleep analysis and another for closed loop experimentation; the development
and implementation of a lightweight, fast and highly accurate automatic on-line sleep stage
scoring algorithm; and the development of a custom optogenetic coupler that is compatible
with most current optogenetic setups for LED-Optical fibre coupling.