Jaesung Hong

An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy

A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target.

A Motion Adaptable Needle Placement Instrument Based on Tumor Specific Ultrasonic Image Segmentation

This paper suggests an ultrasound guided needle insertion instrument which can track target motion in real-time. Under traditional ultrasound guided needle insertion therapies, surgeons have had much burden to find out the precise targeting position, particularly when the organ is moving due to the respiration or heartbeat. We developed a new needle insertion instrument which can track moving target based on visual servo control. In addition, this paper proposed a tumor specific active contour model which can conduct a fast and robust segmentation for tumor, and utilized Hough transform for needle recognition. In the experiment, the proposed system could track a moving phantom successfully at speed of 3 frames/sec processing.

Medical Navigation System for Otologic Surgery Based on Hybrid Registration and Virtual Intraoperative Computed Tomography

An image-guided surgical system for otologic surgery was developed and clinically evaluated. With reliable hybrid registration, real-time patient movement compensation and virtual intraoperative computed tomography imaging have been originally proposed. In contrast to the commercially available systems that mainly use 2-D images for pointing probes, in this system, the surgical drill position is navigated and displayed in the 3-D space with real-time surface rendering. In a temporal bone model study, the navigation accuracy was 1.12 plusmn 0.09 mm with regard to the target registration error. Initial clinical evaluation of the proposed method was performed in five cochlea implantation surgeries. Accurate insertion of the electrodes into the cochlea was achieved, and the facial nerve was protected from injury in all surgeries. The proposed method could be applied to various surgeries for accurate targeting and protection of critical organs.

Interventional navigation for abdominal therapy based on simultaneous use of MRI and ultrasound

An interventional navigation system designed for percutaneous abdominal therapies was proposed, and a pilot study was carried out to assess the proposed system. Integration of US to MRI-based segmentation and 3D display of tumours can help physicians deal with instabilities such as respiratory motion and soft tissue shift that are inherent in abdominal interventions. In addition to the 3D display of the needle and tumours, we adapted the system for the abdominal applications and incorporated a process to correct the mismatch in needle path between MRI and US. The preliminary results of phantom and animal experiments indicated that the proposed method could combine the advantages of both MRI and US. The time required to determine the optimal needle insertion path by using this system was significantly less than that required when either US or MRI guidance alone was employed. The developed system was applied in two patients who underwent PEIT therapy, and its clinical feasibility was partially confirmed.

A minimally invasive registration method using surface template-assisted marker positioning (STAMP) for image-guided otologic surgery.

OBJECTIVE: A new, minimally invasive registration method was developed for image-guided otologic surgery. We utilized laser-sintered template of the patients bone surface to transfer the virtual markers to the patients bone intraoperatively and eliminated the necessity for preoperative marker positioning or additional CT scan. STUDY DESIGN: Simulation surgeries and clinical application. SUBJECTS AND METHODS: We measured registration errors in 10 trials using replicas and six ear surgeries (two cochlear implant insertions, four translabyrinthine acoustic tumor removals). RESULTS: The target registration errors varied among the surgical targets. Errors were less than 1 mm near the cochlear implant insertion target both in phantom study and in actual surgeries. CONCLUSION: Our newly developed method reduced the preoperative procedures for patients but did not reduce the accuracy in cochlear implant surgery. Our method would be a useful image-guided surgery method in the field of otology, where both accuracy and noninvasiveness are required.

Development of a needle insertion manipulator for central venous catheterization.

Central venous catheterization is a procedure in which a doctor inserts a catheter into a patients vein for transfusions. Risks of this procedure include bleeding from the puncture of blood vessels and pneumothorax caused by pleural puncture. To avoid these and other risks, physicians are required to ensure that the needle is inserted securely and that it stops within the vein.

Cochlear Implantation Assisted by Noninvasive Image Guidance

Objective We recently developed a new noninvasive registration method for image-guided otologic surgery (STAMP method). We investigated the benefit and potential drawback of our new method in clinical application and tested the feasibility of routine image-guided surgery. Study Design Retrospective case review. Setting Tertiary referral university hospital. Patients Forty-six cases (45 patients) that underwent cochlear implantation in Kyushu University Hospital during the period of 2007 and 2010 were informed of the option to use navigated surgery. Intervention Twenty-five cochlear implantations were performed using STAMP-registered image-guided surgery. Main Outcome Measure The error of image-guided surgery and time of surgery were collected and analyzed. Results STAMP method offered serviceable accuracy in 18/25 cochlear implantations. The learning curve suggested that the accuracy is at least stabilizing, if not improving, and the success rate is expected to rise. Time of cochlear implant surgery was not significantly extended by the use of image guidance. Conclusion STAMP method had comparable errors with minimal invasiveness. Our new method potentially enables routine use of image-guided surgery.

Image-guided robotic mastoidectomy using human-robot collaboration control

This work proposes an image-guided robotic Mastoidectomy. A surgical navigation software was developed to guide the robot without damaging the critical area. A forbidden-region virtual fixture is implemented for safety. A human-robot collaboration control mode is used to allow the human intervention during surgery, to compensate tremor by operator, and to protect the relevant organs. A temporal bone replica was used as a phantom for the robotic Mastoidectomy. Through the phantom studies, it was shown that the image-guided robotic approach is effective for safe and precise Mastoidectomy.

Real-time magnetic resonance imaging driven by electromagnetic locator for interventional procedure and endoscopic therapy.

BackgroundSurgical navigation systems using an optical position sensor have the occlusion problem due to a person or instrument in the line of sight of the camera. In this study, occlusion-free real-time magnetic resonance (MR) scanning with a passive electromagnetic locator is proposed.MethodsA newly developed converter transforms the data of an electromagnetic locator into that of an optical sensor. Registration between the two different coordinate systems is performed for the electromagnetic locator to substitute the optical sensor without modifying the MRI system.ResultsAn oil marker attached to the electromagnetic locator was identified in real-time MR images. Preliminary results demonstrated the high usability of the electromagnetic locator as an alternative position tracking method in the MR gantry.ConclusionsThe occlusion problem of optical sensors is resolved by the proposed method.

Advanced Imaging and Robotics Technologies for Medical Applications

Due to the importance of surgery in the medical field, a large amount of research has been conducted in this area. Imaging and robotics technologies provide surgeons with the advanced eye and hand to perform their surgeries in a safer and more accurate manner. Recently medical images have been utilized in the operating room as well as in the diagnostic stage. If the image to patient registration is done with sufficient accuracy, medical images can be used as “a map” for guidance to the target lesion. However, the accuracy and reliability of the surgical navigation system should be sufficiently verified before applying it to the patient. Along with the development of medical imaging, various medical robots have also been developed. In particular, surgical robots have been researched in order to reach the goal of minimal invasiveness. The most important factors to consider are determining the demand, the strategy for their use in operating procedures, and how it aids patients. In addition to the above considerations, medical doctors and researchers should always think from the patients point of view. In this article, the latest medical imaging and robotic technologies focusing on surgical applications are reviewed based upon the factors described in the above.