brain scan

Interferometric Diffuse Optical Spectroscopy (iDOS)

Combining interferometric near-infrared spectroscopy (iNIRS) and interferometric diffusing wave spectroscopy (iDWS), will advance novel Interferometric Diffuse Optical Spectroscopy (iDOS) technology for continuous and non-invasive blood flow monitoring in critical clinical scenarios. 

Diffuse Optical Spectroscopy (DOS) monitors deep tissue physiology with multiply scattered near-infrared light.  Although use of non-ionizing near-infrared radiation to assess deep tissue physiology seems simple, powerful, and appealing, superficial tissue contamination and quantitative inaccuracy plague DOS.  Benefitting from low cost and high throughput, continuous wave (CW) NIRS with caveats, can measure brain activity. But, in the clinical realm, low depth specificity, poor quantification and accuracy, and the ambiguity of tissue   oxygenation measures have limited its use.   Scenarios like traumatic brain injury (TBI), stroke,   reconstructive surgery, and perinatal obstetrics, could benefit from the non-invasive optical imaging and monitoring of DOS. 

Dr. Srinivasan has developed a paradigm-shifting approach, interferometric diffuse optical spectroscopy (iDOS), which surmounts barriers to blood flowmetry by combining interferometric Diffusing Wave Spectroscopy (iDWS) and interferometric NIRS (iNIRS) to allow massive parallelization and time-of-flight (TOF) resolution, respectively. Both iDOS core technologies are established and poised for further innovative development and dissemination.  TRD2 will further validate iDOS and advance use of diffuse optics in medicine.

TRD2 has four specific aims, illustrated in the image below.  Aims 1 and 2 improve the technical performance of iDOS and Aim 2 expands their utility through prototyping and standardization. Aim 3 links iDOS with other approaches and Aim 4 integrates all into the intraprocedural workflow and database/cluster formation.

iDOS Specific Aims


The iDOS research in this TRD seeks to accomplish the following deliverables:

  • Low-cost (4 orders-of-magnitude cheaper than photon counting), high throughput, iDWS technology for scalable blood flow monitoring based on a multi-exposure CMOS approach
  • A single fiber-based, multi-wavelength, picosecond TOF-resolved iNIRS platform, for quantitative measurements at sub-millimeter to centimeter spatial resolution
  • High density iDWS arrays to monitor tissues at multiple sites, at greater depths, and with improved specificity
  • Scanning and parallel iNIRS approaches for spatially resolved imaging
  • Methods for standardization and integration of hemodynamic measures with other data streams to both reduce noise, motion artifacts, and systemic physiological interference and inform clinical decisions
Postdoctoral Scholars
  • Dibbyan Mazumder, Ph.D., NYU Langone 
  • Santosh Aparanji, Ph.D., NYU Langone
  • Mingjun Zhao, Ph.D., NYU Langone
Graduate Students
  • Rishad Joarder  
  • Weitai Qian
  • Shing-Jiuan Liu


Collaborative Projects
  • Diffuse Optics for Pediatric Hydrocephalus Management
  • Perioperative diffuse optical imaging of tissue blood flow and oxygenation for optimization of mastectomy skin flap viability
  • Intravascular NIRF-IVUS imaging of inflammation-guided arterial therapy
  • In utero Repair of Fetal Myelomeningocele
Service Projects
  • Biomarker Signatures for Delayed Cerebral Ischemia and Outcome Following Subarachnoid Hemorrhage
  • Brain-based Metrics for Prolonged Field Care (PFC) Tasks
  • UC Davis Alzheimer’s Disease Research Center
  • OMX-CV, A Novel Oxygen Delivery Biotherapeutic for Hemorrhagic Shock in the Battlefield