Resources - FAQ

1. What is the penetration limit for fNIRS in tissue? / How deep can you probe?

Light intensity is heavily attenuated in tissue and falls off exponentially from the illumination point. The maximum achievable probing depth is limited by the illumination strength - determined by the thermal damaging threshold - and the detection sensitivity. Imaging depth strongly depends on the tissue type and the application. Typical achievable transmission limits are about 12 cm for breast tissue and 8 cm on the arm or leg. For b rain imaging, the probing depth is about 3 cm.

2. What is the achievable spatial resolution?

Diffuse optical tomography is a low-resolution technique owing to the physics of light propagation in scattering media. Depending on the composition and size of the target tissue, the resolution is on the order of 5-10 mm.

3. What is the temporal resolution?

DYNOT employs a source switching rate of about 75 Hz. The actual imaging frame rate depends on the number of sources used in the particular application; for example, a brain scan with 30 sources results in 75 Hz/30 = 2.5 Hz imaging rate. Therefore, for a particular application scan speed can be traded off against the desired coverage area (field-of-view) or source density (image resolution). Typical imaging repetition rates are on the order of a 2-10 Hz for most applications.

4. Can you provide user references?

User references are available upon request.

5. What types of studies is your technology currently used in?

-Language, Cognition

-Learning, Memory

-Sensory, Motor, Visual

-Brain Machine Interface

-Acute Care, Ischemia

-Autism

-Animal Imaging: Rats

-Animal Imaging: Monkeys