Photoacoustic-based visual servoing of a needle tip

Area of Science:

• Medical Imaging
• Robotics
• Biomedical Engineering

Background:

• Ultrasound imaging is limited in surgical settings by acoustic clutter and metallic tool reflections.
• Accurate localization of surgical tool tips is crucial for effective intraoperative guidance.

Purpose of the Study:

• To develop and validate a robotic system augmenting ultrasound with photoacoustic imaging for improved surgical tool tracking.
• To enhance navigation and localization in acoustically challenging environments.

Main Methods:

• Integrated a light source for photoacoustic imaging and a robot for autonomous probe control with ultrasound systems.
• Utilized an optical fiber within the surgical tool to generate photoacoustic signals for segmentation and tracking.
• Validated the system across various tissue types and simulated perturbations, including acoustic clutter and motion.

Main Results:

• Achieved mean signal tracking errors <2 mm and probe centering errors <1 mm.
• Demonstrated successful recovery from ultrasound perturbations (patient motion, image switching).
• Photoacoustic imaging proved effective for needle tip detection, especially where ultrasound failed.

Conclusions:

• The novel robotic and photoacoustic system combination shows significant promise for surgical guidance in difficult acoustic conditions.
• This approach offers a robust solution for overcoming traditional ultrasound imaging limitations in intraoperative navigation.