Biology (Jun 2022)

The Effects of Silicone Enclosure Colour on the Function of Optical Sensors

  • Garrett Frank,
  • Shahbaz Askari,
  • Katharina Raschdorf,
  • Sadra Khosravi,
  • Brian K. Kwon,
  • Babak Shadgan

DOI
https://doi.org/10.3390/biology11060932
Journal volume & issue
Vol. 11, no. 6
p. 932

Abstract

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The colour of the silicone enclosure of an implantable reflectance-based optical probe plays a critical role in sensor performance. Red-coloured probes that are highly reflective to near-infrared light have been found to increase photodetector power by a factor of 6 for wavelengths between 660 and 950 nm and triple the magnitude of measured cardiac pulsations compared to traditional black probes. The increase in photodetector power and cardiac pulsation magnitude is presumably due to increased spatial range resulting from a higher magnitude of superficial tissue scattering. Conversely, probes with highly absorbent colours such as black and blue result in more stable signals and are expected to have higher spatial resolution and depth of penetration.

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