Subject(s)
Eyelids/abnormalities , Eye Abnormalities/genetics , Eyelids/surgery , Humans , Infant, Newborn , MaleSubject(s)
Eye Foreign Bodies/complications , Eye Injuries, Penetrating/etiology , Retinal Perforations/etiology , Adult , Eye Foreign Bodies/diagnosis , Eye Foreign Bodies/surgery , Eye Injuries, Penetrating/diagnosis , Eye Injuries, Penetrating/surgery , Humans , Laser Therapy , Male , Metals , Retinal Perforations/diagnosis , Retinal Perforations/surgery , VitrectomyABSTRACT
OBJECTIVE: To assess the feasibility of using an electromagnetic tracking for both registration and navigation in endovascular aneurysm repair. MATERIALS AND METHODS: A registration process was implemented to align computed tomography (CT) data and electromagnetic tracking data. Two abdominal aortic aneurysm (AAA) phantoms were used, a rigid plastic AAA model (phantom A) and a soft silicon AAA model (phantom B). A pre-procedural CT volume was acquired for each phantom. Intra-operative simulation was performed by placing each phantom in the magnetic field of the tracking device. Using a modified electromagnetic catheter, a set of three-dimensional positions was acquired in the phantom's aortic lumen. Pre-procedural CT images and intra-procedural tracked positions were registered. Four reference points were used to calculate the registration accuracy of phantom A. Three surgeons simulated catheterisation of the left renal artery with phantom B using only image-guided procedure software. RESULTS: The mean registration error was 1.3 mm (range 0.88-1.89). The median time for left renal catheterisation was 22 s (range 15-59). CONCLUSION: Registration of CT data and electromagnetic tracking data is feasible using catheter positions in the aorto-iliac structure as landmark. This navigation system could reduce X-ray exposure time and the use of contrast medium injections.
Subject(s)
Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/surgery , Aortography/instrumentation , Blood Vessel Prosthesis Implantation , Electromagnetic Phenomena , Endovascular Procedures , Phantoms, Imaging , Surgery, Computer-Assisted , Tomography, X-Ray Computed/instrumentation , Aortography/methods , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/instrumentation , Catheters , Computer Simulation , Endovascular Procedures/instrumentation , Equipment Design , Feasibility Studies , Fiducial Markers , Humans , Imaging, Three-Dimensional , Predictive Value of Tests , Prosthesis Design , Radiographic Image Interpretation, Computer-Assisted , Software , Surgery, Computer-Assisted/instrumentationABSTRACT
INTRODUCTION: microbial keratitis is a significant health concern for the one million wearers of contact lenses and their ophthalmologists, with some potentially modifiable risk factors. The number of risk factors for contact lens-related microbial keratitis has been described, but many of them still remain assumed or unknown. PATIENTS AND METHODS: a multicenter prospective case-control study was conducted in 12 French university hospitals (Besançon, Bordeaux, Dijon, Fort-de-France, Grenoble, Limoges, Lyon, Nancy, Nantes, Paris, Marseille and Strasbourg) beginning in July 2007 on contact lens wearers presenting with microbial keratitis and on healthy contact lens wearers. Patients and healthy wearers were interviewed using a 51-item anonymous standardized questionnaire to determine subject demographics and contact lens wear history. RESULTS: two hundred and fifty-six patients with microbial keratitis were included. One hundred and thirteen healthy contact lenses wearers were surveyed. Cosmetic contact lens wear highly increased the relative risk (RR) of microbial keratitis (RR, 16.5). Time since the last visit to an ophthalmologist longer than 1 year (RR, 3.4) or prescription by someone other than an ophthalmologist (RR, 7.6) also increased the risk of microbial keratitis. Education on lens care and handling was deficient (hand washing: RR, 2.2; rub and rinse: RR, 2.7). DISCUSSION: a standardized questionnaire is a powerful tool to determine risk factors for contact lens-related microbial keratitis, but also to analyze individual mistakes in contact lenses use and care.
