Correction to: Nature Biomedical Engineering https://doi.org/10.1038/s41551-017-0083, published online 13 June 2017.

In this Article, in the left panel of Fig. 1b, the lower right laser Doppler image was mistakenly a duplicate of the lower middle image, but taken at a different exposure. The corrected version of the figure is shown below; the original Article has not been corrected.

Fig. 1
figure 1

Corrected.