A compact mechatronic system for 3D ultrasound guided prostate interventions

Area of Science:

• Medical Imaging
• Robotics
• Oncology

Background:

• Prostate brachytherapy relies on accurate radioactive seed placement.
• Ultrasound imaging quality has improved, aiding in sophisticated targeting procedures.
• Precise needle insertion is critical to avoid damaging surrounding tissues.

Purpose of the Study:

• To develop a mechatronic system for guiding and controlling transperineal needle insertion into the prostate.
• To reduce pubic arch interference by allowing oblique 3D needle guidance.
• To offer manual or computer-controlled adjustment of needle trajectory and location.

Main Methods:

• Development of a compact mechatronic system for needle guidance.
• Implementation of a method for controlling transperineal needle insertion.
• Testing the system using 3D scans of string phantoms and agar prostate phantoms.

Main Results:

• String phantom 3D scans showed minimal geometric error (<0.4 mm).
• Agar phantom tests demonstrated mean bead placement error <1.6 mm for parallel paths (within 1.2 mm of target, 1° of trajectory).
• Oblique needle guidance (up to 15°) achieved placement within 3.0 mm of target (2.0 mm) with <2° angular error.

Conclusions:

• Combining 3D ultrasound imaging with needle tracking linkage improves targeting accuracy.
• Physicians retain direct control, enabling safe maneuvering around obstacles like existing needles.
• The system enhances the physician's ability to accurately guide needles without direct computer manipulation.