Transillumination imaging of physiological functions by NIR light

Y. Taka*, Y. Kato, K. Shimizu

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


With a near-infrared (NIR) light, we can get transillumination image of a living body. Further, we can quantify the physiological change in the body as the change in light attenuation. A fundamental study has been conducted to visualize the functional change inside a living biological body using the NIR light. A technique was developed to visualize the attenuation change occurred in a diffuse scattering medium. Transillumination images are obtained before and after the physiological change. By taking the ratio of transmitted intensity of these two images, we can obtain the spatial distribution of attenuation change while suppressing the effect of scattering. This principle was derived in theoretical analysis and its effectiveness was verified in experiments. To examine the applicability of this principle to a biological body, localized physiological changes were made in the mouse abdomen and the rat brain. The hypoxia in one of the mouse kidneys was visualized selectively from another normal kidney. The local increase in the blood volume was detected in the somatosensory area of a rat brain when its forelimb was electrically stimulated. The blood increase occurred in a symmetrical position with respect to the sagittal plane, when the forelimb of the opposite side was stimulated. Through these experiments, it was found that the changes in the tissue oxygenation and the blood volume could be detected noninvasively and that they are visualized in the transillumination images using the NIR light.

Original languageEnglish
Pages (from-to)771-774
Number of pages4
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Publication statusPublished - 2000 Dec 1
Externally publishedYes
Event22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society - Chicago, IL, United States
Duration: 2000 Jul 232000 Jul 28


  • Functional imaging
  • Imaging
  • Light
  • Near-infrared
  • Scattering
  • Transillumination

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics


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