# Development of Highly Parallelized Interferometric Near-Infrared Spectroscopy for the Real-Time Non-Invasive Measurement of Cerebral Blood Flow

> **NIH NIH R41** · NEURALENZ, INC · 2024 · $498,995

## Abstract

SUMMARY/ABSTRACT
Currently, stroke diagnosis requires advanced imaging (e.g., CT, MRI) to distinguish stroke from mimics, which
affect up to 58% of individuals presenting with clinical stroke symptoms. Lack of prompt diagnosis for ischemic
stroke, as well as exclusion criteria that stem from potentially severe risk factors associated with global tissue
plasminogen activator (tPA) administration, resulted in less than 4% of U.S. patients receiving thrombolytic
therapy. CT is typically used to rule out presence of a large hemorrhage or bleeding (10-15% of cases) yet
frequently cannot be performed in time for effective thrombolysis. Furthermore, while cerebral blood flow (CBF)
perfusion is a direct target parameter for management during acute initial intervention and throughout recovery
(12-72 hours post treatment), current hardware is either ‘snapshot’ (perfusion CT and ASL-MRI), or highly
invasive (EVD probes). As a result, neuro-intensivists are often left assessing brain perfusion indirectly using
systemic targets such as cerebral perfusion pressure. There is no currently available clinically effective
method to directly measure CBF rapidly, continuously, quantitatively, and non-invasively. Optical methods
hold promise for continuous assessment of CBF. However, absolute quantification of CBF has remained a
challenge, requiring high brain specificity in addition to time-of-flight information, which enables accounting for
head anatomy and optical properties. While interferometric Near-Infrared Spectroscopy (iNIRS), developed by
our team, has addressed the challenge of quantification by providing the time-of-flight dimension, it suffers from
low photon collection of a single mode fiber, requiring temporal averaging of 10 seconds or longer. On the other
hand, multi-speckle approaches demonstrated recently have unprecedented light collection efficiency but to date
do not provide absolute quantification of blood flow. A high throughput version of iNIRS is therefore required to
obtain rapid and accurate CBF data non-invasively in the adult human brain. To address this critical need,
Neuralenz is developing Neuralenz Flow: an integrated platform permitting rapid, non-invasive, real-time
measurement of critical factors used to diagnose and treat stroke patients, including CBF, cerebral blood
volume, intracranial pressure, and critical closing pressure. In this Phase 1 proposal we will further develop
a multi-channel long-wavelength (1064 nm) iNIRS technique with magnetic resonance compatible front-end
probe for achieving more than two orders of magnitude higher signal-to-noise ratio compared to our prior state-
of-the-art device. We will then comprehensively validate our measurements against gold-standard MR
technologies. The outcome of this Phase I study will result in a minimum viable product validated in healthy
human subjects capable of real-time measurement of CBF. This technology will have a significant clinical impact
on continuous monitoring of n...

## Key facts

- **NIH application ID:** 10920028
- **Project number:** 1R41NS137832-01
- **Recipient organization:** NEURALENZ, INC
- **Principal Investigator:** Oybek Kholiqov
- **Activity code:** R41 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $498,995
- **Award type:** 1
- **Project period:** 2024-09-10 → 2026-09-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10920028

## Citation

> US National Institutes of Health, RePORTER application 10920028, Development of Highly Parallelized Interferometric Near-Infrared Spectroscopy for the Real-Time Non-Invasive Measurement of Cerebral Blood Flow (1R41NS137832-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10920028. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*