Electronic Circuit to Mimic the Neural Network for the Saccade Controller Team 8

The proposed device is an electronic circuit that mimics the neural network controlling fast eye movements, or saccades. The device simulates the signals produced by each neuronal population during the control of a horizontal saccade and allows for observing and recording. It will serve as a valuable teaching tool in the field of neural control. Furthermore, the device will have applications in the realm of diagnosing and properly treating brain injury. Finally, this device could be incorporated into a system for controlling the eye movements of a realistic, artificially intelligent robot. The FitzHugh-Nagumo model of the action potential will be used as a foundation to mimic the signals produced by the neurons in question. This is a proven framework, and provides a simple empirical model that can be customized according to the properties of a given neuron. Each neuron will be printed on a circuit board that can be bypassed to simulate a lesion. A current pulse will serve as an input, but in the future, this may be replaced with feedback from a robot. This product is unique in that an analog circuit model of this neural network has not been built before. Table of Contents Abstract ..................................................................................................................................... 0 1 Introduction ........................................................................................................................ 1 1.1 Background ............................................................................................................................... 1 1.2 Project Purpose ...................................................................................................................... 2 1.3 Previous Work Done by Others ..................................................................................... 2 1.3.1 Products .................................................................................................................................................... 4 1.3.2 Patents ...................................................................................................................................................... 4 2 Project Design .................................................................................................................... 5 2.1 Background ............................................................................................................................... 5 2.2 Optimal Design ....................................................................................................................... 9 2.2.1 Objective .................................................................................................................................................. 9 2.2.2 Generalized Neuron Circuit ........................................................................................................ 11 2.2.3 Superior Colliculus .......................................................................................................................... 21 2.2.4 Cerebellum ............................................................................................................................................ 22 2.2.5 Excitatory Burst Neuron ................................................................................................................. 22 2.2.6 Long-­‐Lead Burst Neuron ................................................................................................................ 23 2.2.7 Omnipause Neuron ........................................................................................................................... 23 2.2.8 Tonic Neuron ....................................................................................................................................... 24 2.2.9 Inhibitory Burst Neuron ................................................................................................................. 25 2.2.10 Abducens Nucleus ........................................................................................................................... 25 2.2.11 Oculomotor Nucleus ...................................................................................................................... 25 2.2.12 Circuitry Case .................................................................................................................................. 26 2.2.13 Observation of Signals ................................................................................................................ 26 2.3 Prototype ................................................................................................................................. 27 2.3.1 Multisim ................................................................................................................................................ 27 2.3.2 NI Ultiboard and PCB Design ........................................................................................................ 30 2.3.3 LabVIEW Acquisition Program .................................................................................................... 31 3 Realistic Constraints ................................................................................................... 32 4 Safety Issues .................................................................................................................... 34 5 Impact of Engineering Solutions ......................................................................... 35 6 Life-Long Learning ...................................................................................................... 36 7 Budget ................................................................................................................................. 38 8 Team Member Contributions ................................................................................ 39 8.1 Justin Morse .......................................................................................................................... 39 8.2 Dean Poulos ........................................................................................................................... 39 8.3 Edward Ryan ......................................................................................................................... 40 9 Conclusion ........................................................................................................................ 41 10 References ...................................................................................................................... 42 11 Acknowledgements .................................................................................................... 43 12 Appendix ......................................................................................................................... 45 12.1 Project Specifications ..................................................................................................... 45 12.2 Purchase Requisitions and Price Quotes ............................................................ 46 12.3 Circuit Schematics ........................................................................................................... 51 BME 4910 FINAL REPORT 1 Team 8