Hardware realisation of nonlinear dynamical systems for and from biology

Hamid Soleimani, Emmanuel M. Drakakis, Kings College London
2021
The focus of this thesis is on the applications of nonlinear dynamical systems in bioengineering which are mainly used in large-scale and generally categorised into two groups: (1) dynamical systems from biology (2) dynamical systems for biology. The mathematical models describing the dynamical systems used in the above systems can be simulated with the use of powerful software such as MATLAB, however, for large-scale simulations software begins to collapse. Besides, computer-based simulations
more » ... re not always suitable for interfacing with biological/physical systems where continuous monitoring with low power and area consumption might be required. To alleviate these issues, a few novel hardware techniques for both aforementioned groups are proposed and their hardware results compared and validated by software simulations. Under group (1), a compact and fully reconfigurable digital hardware model capable of mimicking 1-D, 2-D and 3-D nonlinear dynamical systems in real-time and large-scale is presented. Results, and theoretical analysis confirm that the proposed model can mimic the biological behaviour with considerably low hardware overhead and is, on average, ~83 times faster than the CPU version. The proposed model has been also fabricated in the AMS 0.35 um technology capable of emulating slow intracellular calcium dynamics. The fabricated chip occupies an area of 1.5 mm^2 and consumes 18.93 nW for each calcium unit from a power supply of 3.3 V. In addition, under the same group, a novel analog circuit supporting a systematic synthesis procedure of log-domain and strong inversion circuits capable of computing bilateral fast/slow dynamical systems is proposed. The application of the method is demonstrated by synthesising four different case studies. The validity of our approach is verified by nominal and Monte Carlo simulated results with realistic process parameters from the AMS 0.35 um technology. The resulting circuits exhibit various bifurcation phenomena, time-domain responses in good agreement with their m [...]
doi:10.25560/89911 fatcat:tsghgcjkuvgj7ntbq4og4m7bvq