Objective: Wearable technologies for functional brain monitoring in freely behaving subjects can advance our understanding of cognitive processing and adaptive behavior. Existing technologies are lacking in this capability or need procedures that are invasive and/or otherwise impede brain assessments during social behavioral conditions, exercise, and sleep. Methods: In response a complete system was developed to combine relative cerebral blood flow (rCBF) measurement, O2 and CO2 supplies, and behavior recording for use on conscious, freely behaving mice. An innovative diffuse speckle contrast flowmetry (DSCF) device and associated hardware were miniaturized and optimized for rCBF measurements in small subject applications. The use of this wearable, fiber-free, near-infrared DSCF head-stage/probe allowed no craniotomy, minimally invasive probe implantation, and minimal restraint of the awake animal. Results and Conclusions: Significant correlations were found between measurements with the new DSCF design and an optical standard. The system successfully detected rCBF responses to CO2-induced hypercapnia in both anesthetized and freely behaving mice. Significance: Collecting rCBF and activity information together during natural behaviors provides realistic physiological results and opens the path to exploring their correlations with pathophysiological conditions.

Original languageEnglish
Pages (from-to)1838-1848
Number of pages11
JournalIEEE Transactions on Biomedical Engineering
Issue number6
StatePublished - Jun 1 2023

Bibliographical note

Publisher Copyright:
© 1964-2012 IEEE.


  • Cerebral blood flow
  • diffuse speckle contrast
  • freely moving mice
  • wearable sensor

ASJC Scopus subject areas

  • Biomedical Engineering


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