Detection of blood oxygen level by noninvasive passive spectral imaging of skin

Neelam Gupta, Jessica C. Ramella-Roman

Research output: Chapter in Book/Report/Conference proceedingConference contribution

9 Scopus citations


A compact optical hyperspectral imager that can detect both spectral and polarization signatures was used for passive noninvasive imaging of human skin. This vibration-insensitive imager uses an acousto-optic tunable filter (AOTF) as a spectral selection element and an electronically tunable liquid crystal variable retarder (LCVR) as a polarization device. Such an imager is ideally suited to provide both agile spectral and polarization signatures and can be readily used for real time in vivo medical imaging applications. Operation of this imager and image acquisition is fully computer controlled. This imager covers visible to near-infrared (VNIR) region from 400 to 800 nm with a 10 nm spectral resolution at 600 nm and uses a TeO2 AOTF with a 15×15 mm2 linear aperture and a 4.2° angular aperture. At each wavelength 640×480 images with two orthogonal polarization are captured and a total of 41 spectral images are collected to form an image cube. A commercial Si CCD camera was used along with off-the-shelf lenses, mirrors and irises. We carried out experiments with a human subject and controlled the blood perfusion in the individual arm and finger by using a pressure cuff and a rubber band, respectively. Images were captured by illuminating the subject with a white light lamp source and imaging it from a distance. When the hyperspectral image analysis was performed we could observe the effects of skin deoxygenation. In this paper we will described our instrument, the experimental setup, the images obtained and the analysis results.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2008
Externally publishedYes
EventPhotonic Therapeutics and Diagnostics IV - San Jose, CA, United States
Duration: Jan 19 2008Jan 19 2008


OtherPhotonic Therapeutics and Diagnostics IV
Country/TerritoryUnited States
CitySan Jose, CA


  • AOTF
  • Deoxygenation
  • Hyperspectral
  • Image cube
  • Imager
  • Liquid crystal variable retarder
  • Oxygen level
  • Polarization
  • TeO

ASJC Scopus subject areas

  • Engineering(all)


Dive into the research topics of 'Detection of blood oxygen level by noninvasive passive spectral imaging of skin'. Together they form a unique fingerprint.

Cite this