Demonstrating Advantages of Neuromorphic Computation: A Pilot Study

Neuromorphic devices represent an attempt to mimic aspects of the brain's architecture and dynamics with the aim of replicating its hallmark functional capabilities in terms of computational power, robust learning and energy efficiency. We employ a single-chip prototype of the BrainScaleS 2 neuromorphic system to implement a proof-of-concept demonstration of reward-modulated spike-timing-dependent plasticity in a spiking network that learns to play the Pong video game by smooth pursuit. This system combines an electronic mixed-signal substrate for emulating neuron and synapse dynamics with an embedded digital processor for on-chip learning, which in this work also serves to simulate the virtual environment and learning agent. The analog emulation of neuronal membrane dynamics enables a 1000-fold acceleration with respect to biological real-time, with the entire chip operating on a power budget of 57mW. Compared to an equivalent simulation using state-of-the-art software, the on-chip emulation is at least one order of magnitude faster and three orders of magnitude more energy-efficient. We demonstrate how on-chip learning can mitigate the effects of fixed-pattern noise, which is unavoidable in analog substrates, while making use of temporal variability for action exploration. Learning compensates imperfections of the physical substrate, as manifested in neuronal parameter variability, by adapting synaptic weights to match respective excitability of individual neurons.Comment: Added measurements with noise in NEST simulation, add notice about journal publication. Frontiers in Neuromorphic Engineering (2019

Versatile emulation of spiking neural networks on an accelerated neuromorphic substrate

We present first experimental results on the novel BrainScaleS-2 neuromorphic architecture based on an analog neuro-synaptic core and augmented by embedded microprocessors for complex plasticity and experiment control. The high acceleration factor of 1000 compared to biological dynamics enables the execution of computationally expensive tasks, by allowing the fast emulation of long-duration experiments or rapid iteration over many consecutive trials. The flexibility of our architecture is demonstrated in a suite of five distinct experiments, which emphasize different aspects of the BrainScaleS-2 system

Cryo-CMOS for Analog/Mixed-Signal Circuits and Systems

CMOS circuits operating at cryogenic temperature (cryo-CMOS) are required in several low-temperature applications. A compelling example is the electronic interface for quantum processors, which must reside very close to the cryogenic quantum devices it serves, and hence operate at the same temperature, so as to enable practical large-scale quantum computers. Such cryo-CMOS circuits must achieve extremely high performance while dissipating minimum power to be compatible with existing cryogenic refrigerators. These requirements asks for cryo-CMOS electronics on par with or even exceeding their room temperature counterparts. This paper overviews the challenges and the opportunities in designing cryo-CMOS circuits, with a focus on analog and mixed-signal circuits, such as voltage references and data converters

Microdosed midazolam for the determination of cytochrome P450 3A activity: Development and clinical evaluation of a buccal film

Cytochrome P450 3A (CYP3A) isozymes metabolize about 50% of all marketed drugs. Their activity can be modulated up to 400-fold, which has great impact on individual dose requirements for CYP3A substrates. The activity of CYP3A can be monitored using the CYP3A substrate midazolam. To avoid pharmacological midazolam effects during phenotyping, a microdosing approach is preferred. However, the preparation of microdosed dosage forms remains a challenge. Fast dissolving buccal films are therefore proposed to facilitate this task. It was the aim of the present study to clinically evaluate a novel buccal film containing microdoses of midazolam for assessment of CYP3A activity. In a randomized, open-label crossover design, the pharmacokinetics of midazolam and its active hydroxy-metabolite, 1'‑OH‑midazolam, was assessed in 12 healthy volunteers after administration of single microdoses of midazolam (30 μg) as buccal film or buccal solution. The buccal film did rapidly disintegrate, was well tolerated, and no adverse events occurred. The film and the solution showed very similar midazolam plasma concentration-time profiles but were not bioequivalent according to EMA and FDA guidelines. For C; max; , AUC; 0-12h; , and AUC; 0-∞; the geometric mean ratios of film to solution, with their 90% confidence intervals in parentheses, were 1.15 (1.00-1.32), 1.16 (1.04-1.28), and 1.19 (1.08-1.31), respectively. As a proxy for CYP3A activity, molar metabolic ratios of midazolam and 1'‑OH‑midazolam were analyzed over time, which revealed good correlations already 1 h or 2 h after application of the film or the solution, respectively. The tested midazolam buccal film is a convenient dosage form that facilitates administration of a phenotyping probe considerably and may potentially be used in special patient populations such as pediatric patients. Clinical Trials.gov Identifier: NCT03204578