PhD Dissertation Defense
Towards Hands-On Cooperative Control for
Closed-Loop MRI-Guided Targeted Prostate Biopsy
Abstract: Intra-operative imaging is sometimes available to assist in needle biopsy, but typical open-loop insertion does not account for unmodeled needle deflection or target shift. Robotic closed-loop compensation for deviation from an initial straight-line trajectory can reduce the targeting error, using image-guidance for rotational control of an asymmetric bevel tip. When incorporating robotics into interventional procedures, often physician interaction with the patient is reduced and tactile feedback typically used for anatomical localization is lost. By pairing closed-loop trajectory compensation with a hands-on cooperatively controlled needle insertion, a physician's control of the procedure can be maintained while incorporating benefits of robotic accuracy.
Hardware and software subsystems were developed for clinical translation, and after each was tested in the lab they were integrated into the clinical environment to mimic the workflow of MRI-guided targeted biopsy. The full system was validated in-bore at Brigham and Women’s Hospital, performing SNR evaluation as well as a series of MR image-guided targeted needle insertions under cooperative control. Results showed overall targeting accuracy was 3.42mm rms, comparable to in-lab trial results of 3.56mm rms.