@article {Fichtinger2008b, title = {Robotic assistance for ultrasound-guided prostate brachytherapy}, journal = {Medical Image Analysis}, volume = {12}, number = {5}, year = {2008}, month = {06/2008}, pages = {535}, publisher = {Queen{\textquoteright}s University; 25 Union Street;725 Goodwin Hall; Kingston; ON; Canada gabor@cs queensu ca}, abstract = {

We present a robotically assisted prostate brachytherapy system, test results in training phantoms, Phase-I clinical trials The system consists of a transrectal ultrasound (TRUS), a spatially co-registered robot,fully integrated with an FDA-approved commercial treatment planning system The salient feature of the system is a small parallel robot affixed to the mounting posts of the template The robot replaces the template interchangeably,using the same coordinate system Established clinical hardware,workflow, calibration remain intact In all phantom experiments,we recorded the first insertion attempt without adjustment All clinically relevant locations in the prostate were reached Non-parallel needle trajectories were achieved The pre-insertion transverse, rotational errors (measured with a Polaris optical tracker relative to the template{\textquoteright}s coordinate frame) were 0 25 mm (STD=0 17 mm), 0 75 degrees (STD=0 37 degrees) In phantoms,needle tip placement errors measured in TRUS were 1 04 mm (STD=0 50mm) A Phase-I clinical feasibility, safety trial has been successfully completed with the system We encountered needle tip positioning errors of a magnitude greater than 4mm in only 2 of 179 robotically guided needles,in contrast to manual template guidance where errors of this magnitude are much more common Further clinical trials are necessary to determine whether the apparent benefits of the robotic assistant will lead to improvements in clinical efficacy, outcomes

}, keywords = {Brachytherapy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, instrumentation, instrumentation/methods, Interventional, Male, Prostatic Neoplasms, Radiotherapy, radiotherapy/ultrasonography, Robotics, Ultrasonography}, doi = {10 1016/j media 2008 06 002}, url = {http://dx doi org/10 1016/j media 2008 06 002}, author = {Gabor Fichtinger and Jonathan Fiene and Christopher Kennedy and Gernot Kronreif and Iulian Iordachita and Danny Y Song and E. Clif Burdette and Peter Kazanzides} } @article {Fichtinger2007c, title = {Robotic assistance for ultrasound guided prostate brachytherapy}, journal = {Medical Image Computing and Computer-Assisted Intervention (MICCAI)}, volume = {4791}, year = {2007}, pages = {119{\textendash}127}, publisher = {The Johns Hopkins University, Baltimore, Maryland, USA gabor@cs jhu edu}, abstract = {

We present a robotically assisted prostate brachytherapy system, test results in training phantoms The system consists of a transrectal ultrasound (TRUS), a spatially co-registered robot integrated with an FDA-approved commercial treatment planning system The salient feature of the system is a small parallel robot affixed to the mounting posts of the template The robot replaces the template interchangeably, uses the same coordinate system Established clinical hardware, workflow, calibration are left intact In these experiments, we recorded the first insertion attempt without adjustment All clinically relevant locations were reached Non-parallel needle trajectories were achieved The pre-insertion transverse, rotational errors (measured with Polaris optical tracker relative to the template{\textquoteright}s coordinate frame) were 0 25mm (STD = 0 17mm), 0 75 degrees (STD = 0 37 degrees) The needle tip placement errors measured in TRUS were 1 04mm (STD = 0 50mm) The system is in Phase-I clinical feasibility, safety trials, under Institutional Review Board approval

}, keywords = {Brachytherapy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, instrumentation/methods, Interventional, Male, Prostatic Neoplasms, Radiotherapy, Radiotherapy Planning, radiotherapy/ultrasonography, Robotics, Ultrasonography}, author = {Gabor Fichtinger and Jonathan Fiene and Christopher Kennedy and Gernot Kronreif and Iulian Iordachita and Danny Y Song and E. Clif Burdette and Peter Kazanzides} } @article {Boctor2006a, title = {Bootstrapped ultrasound calibration}, journal = {Studies in health technology and informatics}, volume = {119}, year = {2006}, pages = {61{\textendash}66}, publisher = {Engineering Research Center, Johns Hopkins University, USA}, abstract = {

This paper introduces an enhanced (bootstrapped) method for tracked ultrasound probe calibration Prior to calibration, a position sensor is used to track an ultrasound probe in 3D space, while the US image is used to determine calibration target locations within the image From this information, an estimate of the transformation matrix of the scan plane with respect to the position sensor is computed While all prior calibration methods terminate at this phase, we use this initial calibration estimate to bootstrap an additional optimization of the transformation matrix on independent data to yield the minimum reconstruction error on calibration targets The bootstrapped workflow makes use of a closed-form calibration solver, associated sensitivity analysis, allowing for rapid, robust convergence to an optimal calibration matrix Bootstrapping demonstrates superior reconstruction accuracy

}, keywords = {Calibration, Imaging, standards, Three-Dimensional, Ultrasonography, United States}, author = {Emad Boctor and Iulian Iordachita and Michael Choti and Gregory D. Hager and Gabor Fichtinger} } @article {Boctor2005, title = {Real-time quality control of tracked ultrasound}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {8}, number = {Pt 1}, year = {2005}, pages = {621{\textendash}630}, abstract = {

The overwhelming majority of intra-operative hazard situations in tracked ultrasound (US) systems are attributed to failure of registration between tracking, imaging coordinate frames We introduce a novel methodology for eal-time in-vivo quality control of tracked US systems, in order to capture registration failures during the clinical procedure In effect, we dynamically recalibrate the tracked US system for rotation, scale factor, and in-plane position offset up to a scale factor We detect any unexpected change in these parameters through capturing discrepancies in the resulting calibration matrix, thereby assuring quality (accuracy, consistency) of the tracked system No phantom is used for the recalibration We perform the task of quality control in the background, transparently to the clinical user while the subject is being scanned We present the concept, mathematical formulation, and experimental evaluation in-vitro This new method can play an important role in guaranteeing accurate, consistent, and reliable performance of tracked ultrasound

}, keywords = {Algorithms, Computer Systems, Computer-Assisted, Health Care, Humans, Image Enhancement, Image Interpretation, Interventional, methods, Quality Assurance, Quality Control, Reproducibility of Results, Sensitivity, Specificity, Surgery, Ultrasonography, User-Computer Interface}, author = {Emad Boctor and Iulian Iordachita and Gabor Fichtinger and Gregory D. Hager} }