Neuromorphic Computing Group

Brain-Inspired Systems at UC Santa Cruz

Neuromorphic Computing Group

New Paper: “Neuromorphic cytometry: implementation on cell counting and size estimation” led by Ziyao Zhang and Omid Kavehei in Neuromorphic Computing and Engineering

See the full paper here.

Abstract

Imaging flow cytometry (FC) is a powerful analytic tool that combines the principles of conventional FC with rich spatial information, allowing more profound insight into single-cell analysis. However, offering such high-resolution, full-frame feedback can restrain processing speed and has become a significant trade-off during development. In addition, the dynamic range (DR) offered by conventional photosensors can only capture limited fluorescence signals, which compromises the detection of high-velocity fluorescent objects. Neuromorphic photo-sensing focuses on the events of interest via individual-firing pixels to reduce data redundancy and latency. With its inherent high DR, this architecture has the potential to drastically elevate the performance in throughput and sensitivity to fluorescent targets. Herein, we presented an early demonstration of neuromorphic cytometry, demonstrating the feasibility of adopting an event-based resolution in describing spatiotemporal feedback on microscale objects and for the first time, including cytometric-like functions in object counting and size estimation to measure 8 µm, 15 µm microparticles and human monocytic cell line (THP-1). Our work has achieved highly consistent outputs with a widely adopted flow cytometer (CytoFLEX) in detecting microparticles. Moreover, the capacity of an event-based photosensor in registering fluorescent signals was evaluated by recording 6 µm Fluorescein isothiocyanate-marked particles in different lighting conditions, revealing superior performance compared to a standard photosensor. Although the current platform cannot deliver multiparametric measurements on cells, future endeavours will include further functionalities and increase the measurement parameters (granularity, cell condition, fluorescence analysis) to enrich cell interpretation.

Brain-Inspired Machine Learning at UCSC: Class Tape-out Success

This quarter, I introduced Brain-Inspired Machine Learning as a course to University of California, Santa Cruz. And while machine learning is cool and all, it’s only as good as the hardware it runs on.

31 students & first time chip designers all took the lead on building DRC/LVS clean neuromorphic circuits. Students came from grad & undergrad backgrounds across various corners of the university. ECE, CSE, Math, Computational Media, Bioengineering, Psychology, etc. Many had never even taken an ECE 101 class, and started learning from scratch 2 weeks ago.

Their designs are now all being manufactured together in the Sky130 Process. Each design is compiled onto the same piece of silicon with TinyTapeout, thanks to Matt Venn and Uri Shaked.

We spent Friday night grinding in my lab while blaring metalcore tunes. All students managed to clear all checks. The final designs do a heap of cool things like accelerate sparse matrix-multiplies, event denoising, to simulating reservoir networks. I naturally had to squeeze in a Hodgkin-Huxley neuron in the 6 hours before the deadline (pictured).

Not sure if it’s the cost of living, or the mountain lions on campus, but damn. UCSC students have some serious grit.

Hodgkin-Huxley Neuron Model GDS Art