Miniature standoff Raman probe for neurosurgical applications

Area of Science:

• Biomedical Engineering
• Neuroscience
• Spectroscopy

Background:

• Intraoperative guidance is crucial for accurate brain tumor removal.
• Current methods lack specificity, risking damage to healthy brain tissue.
• Optical biopsies using Raman spectroscopy offer a minimally invasive, cost-effective alternative.

Purpose of the Study:

• To develop and evaluate a miniature Raman probe for intraoperative optical biopsies of human brain tissue.
• To assess the probe's compatibility with conventional stereotactic biopsy systems.
• To compare the probe's performance against existing Raman probe designs.

Main Methods:

• A miniature stand-off Raman probe was designed for integration into a 1.8 mm inner diameter stereotactic biopsy needle.
• The probe's silica background was minimized while optimizing Raman signal collection.
• Performance was evaluated by comparing photon collection and signal-to-background ratio with a fiber-optic probe.
• Tissue discrimination capabilities were tested on healthy porcine brain tissue.

Main Results:

• The miniature probe successfully sampled human brain tissue within a stereotactic biopsy system.
• It achieved a comparable photon collection efficiency to fiber-optic probes.
• The stand-off design significantly reduced internal silica background.
• A five-fold improvement in the Raman signal to background ratio was observed below 500 cm⁻¹.
• The probe effectively discriminated between different types of healthy porcine brain tissue.

Conclusions:

• The developed miniature Raman probe is suitable for intraoperative optical biopsies of brain tissue.
• Its design enhances specificity in tumor removal by providing real-time tissue differentiation.
• This technology represents a promising advancement for minimally invasive neurosurgery and improved patient outcomes.