Optical Fiber-Based Needle Shape Sensing in Real Tissue: Single Core vs. Multicore Approaches

Area of Science:

• Biomedical Engineering
• Surgical Technology
• Optical Sensing

Background:

• Flexible needle insertion is crucial for minimally-invasive surgeries, particularly in prostate cancer diagnosis and treatment.
• Bevel-tip needles allow for steered insertions to avoid vital structures and minimize patient discomfort.
• Real-time 3D needle shape sensing is essential for accurate placement feedback during procedures.

Purpose of the Study:

• To directly compare the performance of single-core and multicore fiber-based optical shape sensors for needle insertion.
• To evaluate sensor performance in both phantom and ex-vivo tissue models.
• To present a standardized experimental platform for comparing needle shape-sensing technologies.

Main Methods:

• Development of similarly constructed, four-active area sensorized bevel-tip needles using both single-core and multicore fiber Bragg gratings.
• Insertion of sensorized needles into phantom and ex-vivo tissue models on a unified experimental platform.
• Statistical analysis of shape-sensing accuracy and performance in both tissue types.

Main Results:

• In phantom tissue, both single-core and multicore fiber sensors demonstrated statistically identical performance (p=0.164).
• In ex-vivo tissue, the single-core fiber sensor significantly outperformed the multicore fiber sensor (p=0.0005).
• The study presents a novel experimental platform for direct comparison of optical needle shape sensors.

Conclusions:

• Single-core fiber-based shape sensors offer superior performance for real-time needle tracking in biological tissues compared to multicore configurations.
• The findings provide critical insights for optimizing sensorized needles for enhanced surgical navigation and patient safety.
• Future research should focus on leveraging these findings for the constructive optimization of sensorized needles in clinical applications.