Minimum spectral resolution for continuous-wave hyperspectral near-infrared tissue spectroscopy

Area of Science:

• Biomedical Optics
• Spectroscopy
• Medical Devices

Background:

• Continuous-wave hyperspectral near-infrared spectroscopy (h-NIRS) offers noninvasive tissue monitoring.
• Current h-NIRS devices often rely on expensive custom spectrometers, hindering widespread adoption.
• Developing low-cost, miniature spectrometers requires defining a standard for spectral resolution.

Purpose of the Study:

• To determine the minimum spectral resolution required for accurate oxy- and deoxy-hemoglobin (HbO and Hb) concentration measurements using h-NIRS.
• To establish a guideline for the development of cost-effective h-NIRS devices.

Main Methods:

• Acquired h-NIRS measurements from blood-lipid phantoms at 13 different spectral resolutions.
• Simulated data for various oxygenation levels using NIRFAST software.
• Estimated HbO and Hb concentrations at each resolution and compared them to ground truth values.

Main Results:

• High accuracy in estimating deoxy-hemoglobin (Hb) concentration was achieved with resolutions up to 10 nm.
• Oxy-hemoglobin (HbO) concentration estimates showed more variability.
• Accuracy for both Hb and HbO estimations decreased with spectral resolutions exceeding 10 nm.

Conclusions:

• Spectral resolutions up to 10 nm are suitable for h-NIRS applications.
• This resolution range maintains the accuracy of tissue blood content and oxygenation measurements.
• Findings support the development of more accessible h-NIRS technology.