Circuits et systèmes de modélisation analogique de neurones biologiques

L'objectif de cette thèse est la réalisation de calculateurs analogiques basés sur des modèles neurophysiologiques de type Hodgkin et Huxley. Ces simulateurs sont bâtis autour d'ASICs (Application Specific Integrated Circuits) analogiques spécifiquement conçus pour résoudre ces équations. Construits avec une approche modulaire, ils permettent la simulation réaliste en temps réel et continu de l'activité électrophysiologique de neurones biologiques. Afin de garder une souplesse d'utilisation maximale, les paramètres des modèles et les interconnexions de ses différents éléments sont programmables. L'application première des systèmes présentés est la réalisation de "réseaux hybrides", où neurones biologiques et artificiels interagissent, des exemples d'utilisation de cette technique sont présentés.This thesis deals with the realization of analog calculators based on neurophysiological models of the Hodgkin and Huxley type. At the heart of the simulators are analog ASICs (Application Specific Integrated Circuits) specially designed to solve those equations. They are built using a modular approach and allow for a realistic, real time and continuous time simulation of the neurophysiological activity of biological neurons. In order to achieve a maximum flexibility, parameters of the models and connections between its different elements are programmable within the system. The main application of the presented systems is the making of "hybrid networks", where biological and artificial neurons interact. Some examples of the use of this technique are presented

Evaluating the GeoSnap 13-μ\mum Cut-Off HgCdTe Detector for mid-IR ground-based astronomy

New mid-infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10-$\mu$m sensors for space- and ground-based observatories. Building on the successful development of longwave HAWAII-2RGs for space missions such as NEO Surveyor, we characterize the first 13-$\mu$m GeoSnap detector manufactured to overcome the challenges of high background rates inherent in ground-based mid-IR astronomy. This test device merges the longwave HgCdTe photosensitive material with Teledyne's 2048x2048 GeoSnap-18 (18-$\mu$m pixel) focal plane module, which is equipped with a capacitive transimpedance amplifier (CTIA) readout circuit paired with an onboard 14-bit analog-to-digital converter (ADC). The final assembly yields a mid-IR detector with high QE, fast readout (>85 Hz), large well depth (>1.2 million electrons), and linear readout. Longwave GeoSnap arrays would ideally be deployed on existing ground-based telescopes as well as the next generation of extremely large telescopes. While employing advanced adaptive optics (AO) along with state-of-the-art diffraction suppression techniques, instruments utilizing these detectors could attain background- and diffraction-limited imaging at inner working angles <10 $\lambda/D$, providing improved contrast-limited performance compared to JWST MIRI while operating at comparable wavelengths. We describe the performance characteristics of the 13-$\mu$m GeoSnap array operating between 38-45K, including quantum efficiency, well depth, linearity, gain, dark current, and frequency-dependent (1/f) noise profile.Comment: 17 pages, 17 figures. Accepted for publication in special addition of Astronomische Nachrichten / Astronomical Notes as a contribution to SDW202

Circuits et systèmes de modélisation analogique de neurones biologiques

BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF