Needle-based interventions are pervasive in Minimally Invasive Surgery (MIS), and are often used in a number of diagnostic and therapeutic procedures, including biopsy and brachytherapy seed placement. Magnetic Resonance Imaging (MRI) which can provide high quality, real time and high soft tissue contrast imaging, is an ideal guidance tool for image-guided therapy (IGT). Therefore, a MRI-guided needle-based surgical robot proves to have great potential in the application of percutaneous interventions. Presented here is the design of reconfigurable fiducial-integrated modular needle driver for MRI-guided percutaneous interventions. Further, an MRI-compatible hardware control system has been developed and enhanced to drive piezoelectric ultrasonic motors for a previously developed base robot designed to support the modular needle driver. A further contribution is the development of a fiber optic sensing system to detect robot position and joint limits. A transformer printed circuit board (PCB) and an interface board with integrated fiber optic limit sensing have been developed and tested to integrate the robot with the piezoelectric actuator control system designed by AIM Lab for closed loop control of ultrasonic Shinsei motors. A series of experiments were performed to evaluate the feasibility and accuracy of the modular needle driver. Bench top tests were conducted to validate the transformer board, fiber optic limit sensing and interface board in a lab environment. Finally, the whole robot control system was tested inside the MRI room to evaluate its MRI compatibility and stability.

BACKGROUND: Static and dynamic dental implant guidance systems have established themselves as effective choices that result in predictable and relatively accurate dental implant placement. Generally, studies assess this accuracy using a postoperative CBCT, which has disadvantages such as additional radiation exposure for the patient. This pilot study proposed a scanbody-agnostic method of implant position assessment using intraoral scanning technology and applied it as an accuracy test of robotically assisted dental implant placement using the Neocis Yomi. MATERIALS AND METHODS: All of the robotically assisted dental implant surgery was performed in the Postdoctoral Periodontology clinic at Boston University Henry M. Goldman School of Dental Medicine. Completely edentulous patients were excluded. A total of eleven (11) implants were included in the study, eight (8) of which were fully guided. An optical impression of each implant position was obtained using a CEREC Omnicam (SW 5.1) intraoral scanner. Each sample used either a DESS Lab Scan Body or an Elos Accurate Scan Body as a means to indirectly index the position of the implant. A comparison of planned implant position versus executed surgical implant position was performed for each placement using Geomagic Control X software. Global positional and angular deviations were quantified using a proposed scanbody-agnostic method. Intraoral directionality of deviation was visually qualified by the author (D.K). RESULTS: Mean global positional deviations at the midpoints of the top of each scanbody were 1.7417 mm in the partially guided samples and 1.1300 mm in the fully guided samples. Mean global positional deviations at the midpoints of the restorative platforms of each implant were 1.3142 mm in the partially guided sample and 1.27045 mm in the fully guided samples. Mean global positional deviations at the midpoints of the apex of each implant were 1.455 mm in the partially guided samples and 1.574 mm in the fully guided samples. Mean angular deviations were 3.7492 degrees in the partially guided samples and 2.6432 degrees in the fully guided samples. CONCLUSION: Within the sample size limitations, robotically assisted dental implant surgery offers similar implant placement accuracy compared to published static and dynamic implant placement guidance systems. Intraoral optical assessment of dental implant position used in this study allows comparable analysis to other methods without requiring additional exposure to radiation and should be considered the default method of assessing guidance accuracy.

Image-guided surgeries employ advanced imaging and computing technologies to assist the surgeon when direct visualization is inadequate or unavailable. As modern surgeries continue to move toward minimally invasive procedures, tracked ultrasound (US), an emerging technology that uniquely combines US imaging and position tracking, has been increasingly used for intraoperative guidance in surgical interventions. The intrinsic accuracy of a tracked US system is primarily determined by a unique procedure called ``probe calibration", where a spatial registration between the coordinate systems of the transducer (provided by a tracking device affixed to the probe) and the US image plane must be established prior to imaging. Inaccurate system calibration causes misalignments between the US image and the surgical end-effectors, which may directly contribute to treatment failure. The probe calibration quality is further reduced by the "elevation beamwidth" or "slice thickness", a unique feature of the ultrasound beam pattern that gives rise to localization errors and imaging uncertainties. In this thesis, we aim to provide an automated, pure-computation-based, intraoperative calibration solution that also incorporates the slice thickness to improve the calibration accuracy, precision and reliability. The following contributions have been made during the course of this research. First, we have designed and developed an automated, freehand US calibration system with instant feedback on its calibration accuracy. The system was able to consistently achieve submillimeter accuracy with real-time performance. Furthermore, we have developed a novel beamwidth-weighted calibration framework (USB-FW) that incorporates US slice thickness to improve the estimation of calibration parameters. The new framework provides an effective means of quality control for calibration results. Extensive phantom validation demonstrated that USB-FW introduces statistically significant reduction (p = 0.001) in the calibration errors and produces calibration outcomes that are less variable than a conventional, non-beamwidth-weighted calibration. Finally, we were the first to introduce an automated, intraoperative Transrectal Ultrasound (TRUS) calibration technology for needle guidance in prostate brachytherapy. Our tests with multiple commercial TRUS scanners and brachytherapy stepper systems demonstrated that the proposed method is practical in use and can achieve high calibration accuracy, precision and robustness. / Thesis (Ph.D, Computing) -- Queen's University, 2012-10-22 16:18:55.439

A novel series of near-infrared fluorescent contrast agents was developed and characterized. Their physicochemical and optical properties were measured. By altering functional groups of cyanine fluorophores, the selective targeting of endocrine glands, exocrine glands, cartilage and bone using NIR fluorescence to visualize the targeted tissue has been reported. These agents have high specificity for tissue targeting inherent to the chemical structure of the fluorophore. After a single low-dose intravenous injection these agents have high specificity for tissue targeting inherent to the chemical structure of the fluorophore. The results lay the foundation for future improvements in optical imaging in endocrine surgery, tissue engineering, joint surgery, and cartilage-specific drug development.

Recent progress in the overlay and registration of digital information on the users workspace in a spatially meaningful way has allowed mixed reality (MR) to become a more effective operational medium. In the area of medical surgery, surgeons are conveyed with information such as the incisions location, regions to be avoided, diseased tissues, etc, while staying in and keeping their original working environment. The main objective of this Thesis is identifying theoretical and practical basis for how mixed reality interfaces might provide support and augmentation maximizing the continuity of interaction. We start proposing a set of design principles organized in a design space which allows to identify continuity interaction properties at an early stage of the development system. Once the abstract design possibilities have been identified and a concrete design decision has been taken, an implementational strategy can be developed. Two approaches were investigated: markerless and marker-based. The last one is used to provide surgeons with guidance on an osteotomy task in the maxillo-facial surgery. The evaluation process applies usability tests with users to validate the augmented guidance in different scenarios and to study the influence of different design variables in the final user interaction. As a result we have found a model to describe the contribution factors of each variable for the continuity of the user interaction. We suggest that this methodology can be applied mainly to those applications in which smooth connections and interactions, with virtual and real environments, are critical for the system; i.e. surgery, drivers applications or pilot simulations.

Recent progress in the overlay and registration of digital information on the users workspace in a spatially meaningful way has allowed mixed reality (MR) to become a more effective operational medium. In the area of medical surgery, surgeons are conveyed with information such as the incisions location, regions to be avoided, diseased tissues, etc, while staying in and keeping their original working environment. The main objective of this Thesis is identifying theoretical and practical basis for how mixed reality interfaces might provide support and augmentation maximizing the continuity of interaction. We start proposing a set of design principles organized in a design space which allows to identify continuity interaction properties at an early stage of the development system. Once the abstract design possibilities have been identified and a concrete design decision has been taken, an implementational strategy can be developed. Two approaches were investigated: markerless and marker-based. The last one is used to provide surgeons with guidance on an osteotomy task in the maxillo-facial surgery. The evaluation process applies usability tests with users to validate the augmented guidance in different scenarios and to study the influence of different design variables in the final user interaction. As a result we have found a model to describe the contribution factors of each variable for the continuity of the user interaction. We suggest that this methodology can be applied mainly to those applications in which smooth connections and interactions, with virtual and real environments, are critical for the system; i.e. surgery, drivers applications or pilot simulations.

Objectives: To evaluate and compare an experimental surgical navigation system (ESNS) in implant placement accuracy to static planning and transfer systems. Material and Methods: Partially edentulous, surgical typodonts were used to simulate prosthetically-driven osteotomies in preclinical setting. After cbCT acquisition the DICOM files were used to reverse plan and fabricate surgical guides. Manual placement, three static guiding systems and ESNS were compared. Eight osteotomies per jaw were transferred to 10 typodonts in five series, resulting in 400 osteotomies by 3 operators, each modality. Lateral, vertical, total and angular deviations were measured and compared. Results: Computer-assisted systems were comparable and provided superior precision laterally and in angulation, but not vertically; implants placed in free-end positions were less accurate. Conclusions: All computer-aided methods showed less than 2 mm or 5 degrees error on average, which needs to be considered in clinical practice.

Objectives: To evaluate and compare an experimental surgical navigation system (ESNS) in implant placement accuracy to static planning and transfer systems. Material and Methods: Partially edentulous, surgical typodonts were used to simulate prosthetically-driven osteotomies in preclinical setting. After cbCT acquisition the DICOM files were used to reverse plan and fabricate surgical guides. Manual placement, three static guiding systems and ESNS were compared. Eight osteotomies per jaw were transferred to 10 typodonts in five series, resulting in 400 osteotomies by 3 operators, each modality. Lateral, vertical, total and angular deviations were measured and compared. Results: Computer-assisted systems were comparable and provided superior precision laterally and in angulation, but not vertically; implants placed in free-end positions were less accurate. Conclusions: All computer-aided methods showed less than 2 mm or 5 degrees error on average, which needs to be considered in clinical practice.

Ο σκοπός της διπλωματικής εργασίας ήταν η ανάπτυξη ενός μοντέλου Επαυξημένης Πραγματικότητας για την υποβοήθηση του χειρουργού-χειριστή ρομποτικού μηχανήματος. Το μοντέλο αυτό παρουσιάστηκε για την εύρεση του οπτικού πεδίου του ειδικού ενδοσκοπίου. Για τον σκοπό αυτό κατασκευάστηκαν δύο προγράμματα τα οποία μπορούν να χειριστούν ιατρικά δεδομένα και να προσφέρουν εικόνες από το εσωτερικό του μοντέλου του ασθενούς. Συγκεκριμένα, έγινε μελέτη των βασικών μεθόδων εφαρμογής Επαυξημένης Πραγματικότητας στην χειρουργική, όπως η εγγραφή του ασθενούς, η κατάτμηση των ιατρικών δεδομένων, η τρισδιάστατη ανακατασκευή τους και η ανίχνευση των ενδοσκοπικών εργαλείων και της κάμερας. Παρουσιάστηκε το πλήρες θεωρητικό μοντέλο εφαρμογής επαυξημένης πραγματικότητας και έγινε ανάλυση των επιμέρους διαδικασιών. Κατασκευάστηκαν με την βοήθεια της Matlab δύο προγράμματα με τα αντίστοιχα GUIs για τον προεγχειρητικό σχεδιασμό και την διεγχειρητική καθοδήγηση/επαύξηση αντίστοιχα. Τέλος έγινε δοκιμή των προγραμμάτων χρησιμοποιώντας 22 τομές μαγνητικής τομογραφίας (μορφής DICOM) εγκεφάλου με εμφανή καρκίνο στην αριστερή κοιλία. Επίσης καταγράφηκαν οι εικόνες και τα δεδομένα που παίρνουμε σε κάθε βήμα εφαρμογής των προγραμμάτων με στόχο την αξιολόγηση τους. Το μοντέλο αυτό κατασκευάστηκε με στόχο την εφαρμογή του σε επεμβάσεις μέσω του ρομποτικού μηχανήματος daVinci. Παρόλα αυτά η γενικότερη εφαρμογή της μεθοδολογίας που αναπτύσσεται μπορεί να βρει εφαρμογές και σε άλλες ενδοσκοπικές επεμβάσεις. / The purpose of this thesis was to develop a model of Augmented Reality to assist the surgeon-operator of a robotic machine. The model has been presented for finding the field of special endoscope. For this purpose we built two programs that can manipulate medical data and provide images of the interior of the patient’s model. Specifically, a study was done in the basic methods of Augmented Reality application in Surgery such as, the registration of the patient, the segmentation of medical data, their 3D reconstruction and the detection of endoscopic instruments and the camera. Has been presented the complete theoretical model for applying augmented reality and an analysis of individual procedures was done. Moreover we constructed with the help of Matlab two programs with their GUIs, for preoperative planning and intraoperative guidance/augmentation, respectively. Finally the programs were tested, using 22 MRI slices (format DICOM) with visible brain cancer in the left ventricle. Also were recorded images and data that we get at each step of programs implementation in order to evaluate them. This model was constructed to implement the operations through the daVinci robotic machine. Nevertheless, the general application of the methodology developed in this study may find applications also in other endoscopic procedures

La perfusion intestinale est un facteur clé dans la guérison des anastomoses digestives. L'évaluation clinique de la perfusion demeure subjective et s’avère insuffisante pour prédire les complications anastomotiques, quelle que soit l'expérience du chirurgien. La vidéographie par fluorescence peut fournir une évaluation en temps réel de la perfusion intestinale. Suite à l'administration systémique d'une substance fluorescente, il est possible d’évaluer les unités de fluorescence, lorsque la zone d'intérêt est illuminée par une source de lumière spécifique. La présence de fluorescence est un marqueur de perfusion tissulaire mais cela reste une donnée subjective. Pour obtenir des données quantitatives, nous avons mis au point une solution d'analyse assistée par ordinateur permettant l'évaluation intraopératoire du site optimal de résection. Le logiciel peut générer une cartographie virtuelle de perfusion et celle-ci peut être superposée aux images laparoscopiques en pour obtenir l'effet de réalité augmentée. Cette thèse décrit le développement progressif de ce concept. / Pre-anastomotic bowel perfusion is a key factor for a successful healing process. Clinical evaluation of bowel perfusion is subjective and not accurate at predicting anastomotic complications, irrespective of the surgeon’s experience. Fluorescence videography analysis can provide real-time evaluation of bowel perfusion. Following the systemic administration of a fluorescent substance, fluorescence videography can compute the units of fluorescence, when the area of interest is illuminated by a specific light source. Fluorescence intensity is a marker of blood supply to the tissue. However, fluorescence intensity alone remains a subjective approach. We have developed a software solution enabling quantitative estimation of bowel perfusion, for intra-operative evaluation of the optimal resection site. The software can generate a “virtual perfusion cartography”, which can be overlapped onto real-time laparoscopic images to obtain the Enhanced Reality effect. This thesis describes the stepwise development of such concept.