Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array

Zachary F Phillips; Michael V D'Ambrosio; Lei Tian; Jared J Rulison; Hurshal S Patel; Nitin Sadras; Aditya V Gande; Neil A Switz; Daniel A Fletcher; Laura Waller

doi:10.1371/journal.pone.0124938

Multi-Contrast Imaging and Digital Refocusing on a Mobile Microscope with a Domed LED Array

PLoS One. 2015 May 13;10(5):e0124938. doi: 10.1371/journal.pone.0124938. eCollection 2015.

Affiliations

¹ Graduate Group in Applied Science and Technology, University of California, Berkeley, CA 94720, USA.
² Department of Bioengineering, University of California, Berkeley, CA 94720, USA.
³ Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA.
⁴ Graduate Group in Applied Science and Technology, University of California, Berkeley, CA 94720, USA; Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA.

Abstract

We demonstrate the design and application of an add-on device for improving the diagnostic and research capabilities of CellScope--a low-cost, smartphone-based point-of-care microscope. We replace the single LED illumination of the original CellScope with a programmable domed LED array. By leveraging recent advances in computational illumination, this new device enables simultaneous multi-contrast imaging with brightfield, darkfield, and phase imaging modes. Further, we scan through illumination angles to capture lightfield datasets, which can be used to recover 3D intensity and phase images without any hardware changes. This digital refocusing procedure can be used for either 3D imaging or software-only focus correction, reducing the need for precise mechanical focusing during field experiments. All acquisition and processing is performed on the mobile phone and controlled through a smartphone application, making the computational microscope compact and portable. Using multiple samples and different objective magnifications, we demonstrate that the performance of our device is comparable to that of a commercial microscope. This unique device platform extends the field imaging capabilities of CellScope, opening up new clinical and research possibilities.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Equipment Design
Fourier Analysis
Humans
Image Processing, Computer-Assisted / methods
Image Processing, Computer-Assisted / statistics & numerical data*
Imaging, Three-Dimensional / instrumentation*
Imaging, Three-Dimensional / methods
Microscopy / instrumentation*
Microscopy / methods
Point-of-Care Systems
Smartphone / instrumentation
Software*

Grants and funding

This work was supported by USAID Cooperative Agreements AID-OAA-A-13-00002 and AID-OAA-A-12-00011, part of USAID's Higher Education Solutions Network, and by the Gordon and Betty Moore Foundation's Data-Driven Discovery Initiative through grant GBMF4562 to Laura Waller.