@article {Seifabadi2015, title = {Toward teleoperated needle steering under continuous MRI guidance for prostate percutaneous interventions}, journal = {The International Journal of Medical Robotics and Computer Assisted Surgery}, year = {2015}, author = {Reza Seifabadi and Fereshteh Aalamifar and Iulian Iordachita and Gabor Fichtinger} } @conference {Monfaredi2013a, title = {Design of a Decoupled MRI-compatible Force Sensor using Fiber Bragg Grating Sensors for Robot-assisted Prostate Interventions}, booktitle = {SPIE}, volume = {8671}, year = {2013}, month = {03/2013}, address = {Orlando, Floirda}, abstract = {

{During prostate needle insertion, the gland rotates and displaces resulting in needle placement inaccuracy. To compensate for this error, we proposed master-slave needle steering under real-time MRI in a previous study. For MRI-compatibility and accurate motion control, the master (and the slave) robot uses piezo actuators. These actuators however, are non-backdrivable. To cope with this issue, force sensor is required. Force sensor is also required at the slave side to reflect the insertion force to clinician{\textquoteright}s hand through the master robot. Currently, there is no MRI-compatible force sensor commercially available. In order to generate a combination of linear and rotary motions for needle steering, this study is seeking to develop a MRI-compatible 2 Degrees of Freedom (DOF) force/torque sensor. Fiber Brag Grating (FBG) strain measuring sensors which are proven to be MRI-compatible are used. The active element is made of phosphor-bronze and other parts are made of brass. The force and torque measurements are designed to be entirely decoupled. The sensor measures -20 to 20 N axial force with 0.1 N resolution, and -200 to 200 Nmm axial torque with 1 Nmm resolution. Analytical and Finite Element (FE) analyses are performed to ensure the strains are within the measurable range of the FBG sensors. The sensor is designed to be compact (diameter =15 mm

}, keywords = {FBG, force sensor, MRI -compatible}, doi = {0.1117/12.2008160}, author = {Monfaredi, R and Reza Seifabadi and Gabor Fichtinger and Iulian Iordachita} } @article {Seifabadi2013a, title = {Real-Time 3D Needle Shape Tracking Using Fiber Bragg Grating Sensors for Prostate Percutaneous Interventions}, year = {2013}, address = {Crystal City, VA, USA}, abstract = {

During prostate needle insertion, the gland and therefore targets move resulting in targeting inaccuracy. To compensate for this error, in a previous study we proposed robotic bevel-tip needle steering under live MRI. One important drawback is that tracking a flexible (20G) needle under real-time MRI is inaccurate due to the needle artifact and the image update frequency is relatively slow (\>200 ms). As an alternative solution, we embedded some FBG strain sensors along the needle shaft at certain locations and reconstruct the needle shape from this information. Compared to the previous study on this topic by others, the following development have been done: 1) this study is extended to needle of higher gauge (thinner), 2) we guarantee below 0.5 mm accuracy at the needle tip for all insertion depth, 3) we extended it to bevel-tip needles (through modelling and mathematical formulation), 4) we visualized the 3D shape of the needle in 3D Slicer which is a commonly used planning and navigation software for prostate interventions, 5) our needle tracking is real-time.

}, keywords = {3D Slicer, MRI, needle tracking, real-time}, author = {Reza Seifabadi and Esteban Escobar Gomez and Fereshteh Aalamifar and Gabor Fichtinger and Iulian Iordachita} } @article {Siefabadi2012a, title = {Acuracy Study of a MRI-guided Robotic System for Prostate Needle Placement}, journal = {The International Journal of Medical Robotics and Computer Assisted Surgery (IJMRCAS)}, year = {2012}, abstract = {

Background: Accurate needle placement is the first concern in percutaneous MRI-guided prostate interventions. In this phantom study, different sources contributing to the overall needle placement error of a MRI-guided robot for prostate biopsy have been identified, quantified, and minimized to the possible extent. Methods and Materials: The overall needle placement error of the system was evaluated in a prostate phantom. This error was broken into two parts: the error associated with the robotic system (called before-insertion error) and the error associated with needle-tissue interaction (called due-to-insertion error). The before-insertion error was measured directly in a soft phantom and different sources contributing into this part were identified and quantified. A calibration methodology was developed to minimize the 4-DOF manipulator{\textquoteright}s error. The due-toinsertion error was indirectly approximated by comparing the overall error and the beforeinsertion error. The effect of sterilization on the manipulator{\textquoteright}s accuracy and repeatability was also studied. Results: The average overall system error in phantom study was 2.5 mm (STD=1.1mm). The average robotic system error in super soft phantom was 1.3 mm (STD=0.7 mm). Assuming orthogonal error components, the needle-tissue interaction error was approximated to be 2.13 mm thus having larger contribution to the overall error. The average susceptibility artifact shift was 0.2 mm. The manipulator{\textquoteright}s targeting accuracy was 0.71 mm (STD=0.21mm) after robot calibration. The robot{\textquoteright}s repeatability was 0.13 mm. Sterilization had no noticeable influence on the robot{\textquoteright}s accuracy and repeatability. Conclusions: The experimental methodology presented in this paper may help researchers to identify, quantify, and minimize different sources contributing into the overall needle placement error of an MRI-guided robotic system for prostate needle placement. In the robotic system analyzed here, the overall error of the studied system remained within the acceptable range.

}, doi = {10.1002/rcs.1440}, url = {http://onlinelibrary.wiley.com/doi/10.1002/rcs.1440/abstract}, author = {Reza Seifabadi and Nathan Bongjoon Cho and Sam Sang-Eun Song and Junichi Tokuda and Nobuhiko Hata and Clare M Tempany and Gabor Fichtinger and Iulian Iordachita} } @conference {Siefabadi2012b, title = {Design of a Teleoperated Needle Steering System for MRI-guided Prostate Interventions}, booktitle = {IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob 2012)}, year = {2012}, publisher = {IEEE}, organization = {IEEE}, address = {Rome, Italy}, abstract = {

Accurate needle placement plays a key role in success of prostate biopsy and brachytherapy. During percutaneous interventions, the prostate gland rotates and deforms which may cause significant target displacement. In these cases straight needle trajectory is not sufficient for precise targeting. Although needle spinning and fast insertion may be helpful, they do not entirely resolve the issue. We propose robot-assisted bevel-tip needle steering under MRI guidance as a potential solution to compensate for the target displacement. MRI is chosen for its superior soft tissue contrast in prostate imaging. Due to the confined workspace of the MRI scanner and the requirement for the clinician to be present inside the MRI room during the procedure, we designed a MRI-compatible 2-DOF haptic device to command the needle steering slave robot which operates inside the scanner. The needle steering slave robot was designed to be integrated with a previously developed pneumatically actuated transperineal robot for MRI-guided prostate needle placement. We describe design challenges and present the conceptual design of the master and slave robots and the associated controller.

}, keywords = {MRI-compatible, Needle Steering, Real-time MRI, Teleoperation}, author = {Reza Seifabadi and Iulian Iordachita and Gabor Fichtinger} } @article {Tokuda2012, title = {Preclinical evaluation of an MRI-compatible pneumatic robot for angulated needle placement in transperineal prostate interventions}, journal = {International Journal of Computer Assisted Radiology and Surgery (IJCARS)}, year = {2012}, abstract = {

Purpose. To support transperineal prostate biopsies in a closed-bore magnetic resonance imaging (MRI) scanner, we developed a small profile MRI-compatible pneumatic needle placement robot that can angulate a needle insertion path into a large accessible target volume. We performed a preclinical evaluation of the robot{\textquoteright}s targeting accuracy with angulated needle insertion in a 3 Tesla clinical MRI. Methods. Angulation of the needle insertion path is achieved by a four degrees-of-freedom (4-DOF) mechanism with two parallel triangular structures. The robot is integrated with navigation software that allows an operator to plan angulated needle insertion by selecting a target and an entry point. The targeting error was evaluated while the angle between the needle insertion path and the static magnetic field was between -5.7{\textdegree} and 5.7{\textdegree} horizontally and between -5.7{\textdegree} and 4.3{\textdegree} vertically in the MRI scanner after sterilizing and draping the device. Results. The needle placement robot successfully positioned the needle with angulated insertion as specified on the navigation software. The overall targeting error was 0.8 {\textpm} 0.5 mm along the horizontal axis and 0.8 {\textpm} 0.8 mm along the vertical axis. The two-dimensional root-mean-square targeting error on the axial slices as containing the targets was 1.4 mm. Conclusions. Our preclinical evaluation demonstrated that the MRI-compatible pneumatic needle placement robot with the 4-DOF parallel kinematic structure with the capability to angulate the needle insertion path provides sufficient targeting accuracy for clinical MRI-guided prostate interventions.

}, keywords = {Biopsy, Brachytherapy, medical robotics, MRI-guided therapy, prostate cancer}, doi = {10.1007/s11548-012-0750-1}, url = {http://www.springerlink.com/content/tl77lrh211608j70/}, author = {Junichi Tokuda and Sam Sang-Eun Song and Gregory Fischer and Iulian Iordachita and Reza Seifabadi and Nathan Bongjoon Cho and Kemal Tuncali and Gabor Fichtinger and Clare M Tempany and Nobuhiko Hata} } @article {Tokuda2012a, title = {Preclinical evaluation of MRI-compatible pneumatic robot for angulated needle placement in prostate interventions}, year = {2012}, month = {2012}, address = {Pisa, Italy}, keywords = {angulation, MRI compatiber robot, transprineal}, author = {Junichi Tokuda and Sam Sang-Eun Song and Gregory Fischer and Iulian Iordachita and Reza Seifabadi and Nathan Bongjoon Cho and Gabor Fichtinger and Clare M Tempany and Nobuhiko Hata} } @article {Escobar2012a, title = {Real-time needle tip tracking using Fiber Brag Grating sensors for MRI-guided prostate interventions: Design considerations}, year = {2012}, address = {Boston, USA, September}, author = {Esteban Escobar Gomez and Reza Seifabadi and Gabor Fichtinger and Iulian Iordachita} } @article {Siefabadi2012c, title = {Towards teleoperated needle steering in MRI-guided prostate interventions}, year = {2012}, address = {Boston, USA, September}, author = {Reza Seifabadi and Iulian Iordachita and Gabor Fichtinger} } @article {Seifabadi2011, title = {Robotic System for MRI-guided Prostate Biopsy: Feasibility of Teleoperated Needle Insertion and ex vivo Phantom Study}, journal = {International Journal of Computer Aided Radiology and Surgery (IJCARS)}, year = {2011}, abstract = {

"Purpose": Magnetic Resonance Imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. "Methods": We report the workspace optimization and phantom evaluation of a five Degree of Freedom (DOF) parallel pneumatically actuated modular robot for MRI-guided prostate biopsy. To shorten procedure time and consequently increase patient comfort and system accuracy, a prototype of a MRI-compatible master-slave needle driver module using piezo motors was also added to the base robot. "Results": Variable size workspace was achieved using appropriate link length, compared to the previous design. The 5-DOF targeting accuracy demonstrated an average error of 2.5 mm (STD=1.37 mm) in a realistic phantom inside a 3T magnet with a bevel-tip 18G needle. The average position tracking error of the master-slave needle driver was always below 0.1 mm. "Conclusion": Phantom experiments showed sufficient accuracy for manual prostate biopsy. Also, the implementation of teleoperated needle insertion was feasible and accurate. These two together suggest feasibility of accurate fully actuated needle placement into prostate while keeping the clinician supervision over the task.

}, keywords = {accuracy evaluation, MRI -compatible, phantom study, Pneumatic Robot, Teleoperation, Transperineal prostate biopsy}, doi = {10.1007/s11548-011-0598-9}, url = {http://www.springerlink.com/content/h53329764x605415/fulltext.pdf}, author = {Reza Seifabadi and Sam Sang-Eun Song and Axel Krieger and Nathan Bongjoon Cho and Junichi Tokuda and Gabor Fichtinger and Iulian Iordachita} } @article {Song2011c, title = {Robotic System for MRI-guided Prostate Intervention: Feasibility Study of Tele-operated Needle Insertion}, year = {2011}, publisher = {Springer}, address = {Berlin, Germany}, keywords = {MRI-compatible, Pneumatic Robot, Prostate Intervention, Teleoperation}, url = {http://www.cars-int.org/}, author = {Sam Sang-Eun Song and Reza Seifabadi and Axel Krieger and Junichi Tokuda and Gabor Fichtinger and Iulian Iordachita} }