Research ArticleENGINEERING

A minimally invasive lens-free computational microendoscope

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Science Advances  06 Dec 2019:
Vol. 5, no. 12, eaaw5595
DOI: 10.1126/sciadv.aaw5595
  • Fig. 1 Imaging using a multicore fiber and coded aperture.

    (A) Simplified illustration of widefield illumination imaging using a multicore fiber and lens. (B) Our distal lensless imaging approach using a coded aperture.

  • Fig. 2 Experimental imaging results.

    (A to C) Object images acquired using a bulk microscope. Experimental results shown throughout have a 980-μm-wide field of view. (D to F) Objects imaged using a conventional lens-based multicore fiber microendoscope. Scene is demagnified to fit within the fiber’s image circle diameter of 270 μm. (G to I) Raw images captured from the proximal end of the multicore fiber in our distal lensless microendoscope using a distal coded aperture and used to reconstruct (J) to (L). (J to L) Objects imaged using our distal lensless microendoscope.

  • Fig. 3 Test for spatial resolution.

    (A to C) Images of the resolution target objects acquired using a bulk microscope. Experimental results shown throughout have a 980-μm-wide field of view. (D to F) Objects imaged using a conventional lens-based multicore fiber microendoscope. (G to I) Objects imaged using our lensless multicore fiber microendoscope using a distal coded aperture. (A, D, and G) Linewidths are 44, 40, and 33 μm, respectively. (B, E, and H) Linewidths are 32, 29, 26, and 22 μm, respectively. (C, F, and I) Linewidths are 21, 19, 17, and 14 μm, respectively.

  • Fig. 4 Computational refocusing.

    (A and B) Bulk microscope images of the test subject, which consists of two planar objects separated in depth by 1.5 mm. The image volume is reconstructed from a single image of the multicore fiber’s proximal end, shown in (C). (D) shows volumetric reconstruction with 11 depth layers, separated in depth by 300 μm, using the system response shown in (C). (E and F) Images from the volumetric reconstruction corresponding to the two depths that the objects are in the best focus.

  • Fig. 5 Demonstration of color imaging.

    (A and B) Images of multicolor objects acquired using a bulk microscope. (C and D) Color image reconstructions of the same objects using our lensless microendoscope.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/12/eaaw5595/DC1

    Fig. S1. Detailed schematic of our approach consisting of calibration optics and the imager.

    Fig. S2. Determining the axial resolution of the lensless microendoscope.

    Fig. S3. Volumetric reconstruction of two planar objects separated by 1.5 mm in depth (shown in Figure 4 and movie S2).

    Fig. S4. Comparison of spatial resolution between lens-based and lensless multicore fiber microendoscopes.

    Fig. S5. Demonstration of time-varying scene reconstruction.

    Fig. S6. Demonstration of insensitivity towards bending of the multicore fiber of the lensless microendoscope.

    Movie S1. Dynamic scene reconstruction, acquired at 50 frames per second.

    Movie S2. Computational refocusing of planar objects separated in depth.

  • Supplementary Materials

    The PDFset includes:

    • Fig. S1. Detailed schematic of our approach consisting of calibration optics and the imager.
    • Fig. S2. Determining the axial resolution of the lensless microendoscope.
    • Fig. S3. Volumetric reconstruction of two planar objects separated by 1.5 mm in depth (shown in Figure 4 and movie S2).
    • Fig. S4. Comparison of spatial resolution between lens-based and lensless multicore fiber microendoscopes.
    • Fig. S5. Demonstration of time-varying scene reconstruction.
    • Fig. S6. Demonstration of insensitivity towards bending of the multicore fiber of the lensless microendoscope.

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    Other Supplementary Material for this manuscript includes the following:

    • Movie S1 (.gif format). Dynamic scene reconstruction, acquired at 50 frames per second.
    • Movie S2 (.avi format). Computational refocusing of planar objects separated in depth.

    Files in this Data Supplement:

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