Browsing by Author "Wu, Yi"

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GHz Optical Time-Stretch Microscopy by Compressive Sensing
(2017-04-01)
Lei, Cheng
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Wu, Yi
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Sankaranarayanan, Aswin C.
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Chang, Shih-Min
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Guo, Baoshan
Optical time-stretch microscopy has recently attracted intensive attention for its capability of acquiring images at an ultrahigh frame rate. Unfortunately, its achievable frame rate is limited by the requirement of having no overlap between consecutive frames, which leads to a tradeoff between the frame rate (pulse repetition rate) and the amount of the temporal dispersion used for optical image serialization. In this paper, we demonstrate compressive sensing on the platform of optical time-stretch microscopy to overcome the tradeoff between frame rate and temporal dispersion (time stretch) and achieve 50 times higher frame rate than conventional optical time-stretch microscopy. Specifically, we computationally perform compressed optical time-stretch microscopy with an experimental dataset acquired by conventional optical time-stretch microscopy and demonstrate its effects in terms of spatial resolution and cell classification accuracy. Our results indicate that the spatial resolution and cell classification accuracy reach 780 nm and 95% at a line scan rate of 675 MHz and 6.75 GHz, respectively, which correspond to five times and 50 times higher frame rates than what conventional optical time-stretch microscopy can achieve with the same dispersion amount and digitizer sampling rate.
Intelligent whole-blood imaging flow cytometry for simple, rapid, and cost-effective drug-susceptibility testing of leukemia
(2019-08-21)
Kobayashi, Hirofumi
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Lei, Cheng
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Wu, Yi
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Huang, Chun-Jung
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Yasumoto, Atsushi
Drug susceptibility (also called chemosensitivity) is an important criterion for developing a therapeutic strategy for various cancer types such as breast cancer and leukemia. Recently, functional assays such as high-content screening together with genomic analysis have been shown to be effective for predicting drug susceptibility, but their clinical applicability is poor since they are time-consuming (several days long), labor-intensive, and costly. Here we present a highly simple, rapid, and cost-effective liquid biopsy for ex vivo drug-susceptibility testing of leukemia. The method is based on an extreme-throughput (>1 million cells per second), label-free, whole-blood imaging flow cytometer with a deep convolutional autoencoder, enabling image-based identification of the drug susceptibility of every single white blood cell in whole blood within 24 hours by simply flowing a drug-treated whole blood sample as little as 500 mu L into the imaging flow cytometer without labeling. Our results show that the method accurately evaluates the drug susceptibility of white blood cells from untreated patients with acute lymphoblastic leukemia. Our method holds promise for affordable precision medicine.
Statistical Study of RRAM MLC SET Variability Induced by Filament Morphology
(2017-01-01)
Hsu, Chung-Wei
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Zheng, Xin
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Wu, Yi
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Hou, Tuo-Hung
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Wong, H. -S. Philip
This paper establishes the correlation between RRAM multilevel-cell (MLC) stochastic SET variability and random telegraph noise (RTN). We show that a smaller diameter (d(D)) of locally connecting/rupturing conductive filament (CF) and larger distance of gap (d(G)) between CF and electrode demonstrate both steeper Weibull slope beta with a relaxed SET-disturb margin by 0.4 V and 36x improvement in RTN robustness. This is achieved by lower current compliances (I-COMP) of 100 mu A and larger RESET stopping voltage (V-RESET) of -4.5 V for smaller dD and larger dG with leaving less residual oxygen vacancies (V-o(+2)) in the gap region. Results from the Kinetic Monte Carlo (KMC) modeling also support these findings.