High-throughput space-time Fourier ptychography for motile microorganisms

High-fidelity imaging of live microorganisms is essential for understanding dynamic biological processes but remains limited by motion blur and insufficient temporal resolution. We present a space-time Fourier ptychography (ST-FP) system optimized for high-throughput, time-resolved quantitative phase imaging of fast-evolving biological specimens. To overcome photon budget and timing constraints, we develop a custom shift-register-based LED panel that enables direct, flicker-free control of illumination patterns, achieving a ∼1100× increase in effective irradiance over normal LED panels. This allows for stable imaging at exposure times as short as 800 μs. On the computational side, we formulate an auto-differentiable complex-valued reconstruction framework with GPU acceleration for the object set solution. Our temporal regularization can improve consistency and robustness under complex motion with different illumination conditions. The computational pipeline achieves a ∼23× speedup, reducing reconstruction time for a 120 × 1200 × 1200 sequence from 13.7 to 0.59 hours (CPU vs. GPU). We first evaluate our optimized ST-FP through simulations of swirling motion patterns. Then, in a real experiment with a translation motion condition, a ∼45× improvement in space-bandwidth-time product (SBP-T) over our prior ST-FP implementation is quantitatively demonstrated using a binary phase target. We further validate the system on grayscale phase samples. We finally test our system for live imaging of vinegar eels and brine shrimp with uncontrolled motion at up to 260 Hz, demonstrating its capability to push the dynamic upper limits of high-throughput Fourier ptychography. The motion-aware reconstruction further enables trajectory tracking and flow field analysis of dynamic biological behaviors.