ABSTRACT
Accurate and reliable registration is one of the most important issues in computer-aided surgery, as small errors may have a large influence on the overall accuracy of the system. The restricted surface-matching algorithm (RSM), initially developed for periacetabular osteotomy surgery (PAO), has been improved to become numerically more stable and reliable. To assess the accuracy and sensitivity of registration, a framework is presented that evaluates two aspects of registration: the sensitivity and raw performance of the registration algorithm are tested in a stand-alone environment, and the integration into a CAS system is analyzed by evaluating the accuracy of the complete system. For the latter tests, spherical-headed titanium screws used as fiducial landmarks provide a reference transformation for the registration. This framework was used to analyze the performance of RSM for PAO surgery. The sensitivity analysis showed the algorithm to be insensitive to noise up to a magnitude of 3 mm. Both the sensitivity analysis and simulated surgical environment tests showed that an accuracy can be attained of better than 2 mm in the region of interest, and better than 4 mm far away from the region of interest. This is sufficient for safely assisting PAO surgeries.
Subject(s)
Algorithms , Osteotomy/standards , Surgery, Computer-Assisted/standards , Humans , Osteotomy/instrumentation , Sensitivity and Specificity , Surgery, Computer-Assisted/methodsABSTRACT
The establishment of the faecal flora of 39 full-term infants fed exclusively on breast milk (n = 20) or with two different modern adapted cow's milk formulas (n = 19) was studied during the first 3 months of life. One formula investigated was based on 100% bovine casein as the protein source whereas the other formula contained bovine milk proteins with a whey/casein ratio of 60:40. A faecal flora rich in bifidobacteria was found in all study groups; the growth of putrefactive bacteria (especially Bacteroides spp.), however, was limited. In formula-fed infants, significantly higher bacterial counts of enterococci and clostridia were detected compared to breast milk-fed infants. Similarities and differences due to the feeding regimen were particularly reflected in the pattern of the anaerobic bacterial species. Bifidobacterium bifidum, B. infantis and B. breve constituted the majority of the bifidobacterial flora independent of the type of milk feeding. Other bifidobacterial species such as B. longum, B. adolescentis, B. parabifidum and B. pseudo-catenulatum were detected in high numbers and at low frequencies in breastfed infants. The latter three were observed in infants fed the whey/casein formula as well. It seems that infants fed a casein formula develop a faecal flora more like that of breastfed infants concerning Lactobacillus spp. (especially L. fermentum and L. brevis).
Subject(s)
Bifidobacterium/growth & development , Colony Count, Microbial , Feces/microbiology , Infant Food , Milk Proteins/administration & dosage , Milk, Human , Animals , Cattle , Female , Humans , Hydrogen-Ion Concentration , Infant , Infant, Newborn , Intestinal Mucosa/microbiology , Male , Reference Values , Species SpecificityABSTRACT
For a therapy of the pilonidal sinus there are different surgical and non-surgical methods to be found in literature. In our surgical wing 140 male patients have been operated on this disease from September 1990 to July 1992. 16 cases out of these 140 were re-operations. Using a special surgical technique we applied the excision with a primary closure under single-shot antibiosis in 139 cases. By modifying this antibiosis prophylaxis we could reach a primary success healing rate of up to 96%. A retrospective study among our patients showed a recurrence rate of 5%.
Subject(s)
Abscess/surgery , Bacterial Infections/surgery , Drug Therapy, Combination/therapeutic use , Pilonidal Sinus/surgery , Premedication , Abscess/microbiology , Adult , Bacterial Infections/microbiology , Humans , Infusions, Intravenous , Male , Metronidazole/administration & dosage , Mezlocillin/administration & dosage , Pilonidal Sinus/microbiology , Postoperative Complications/microbiology , Postoperative Complications/surgery , Recurrence , Sulbactam/administration & dosage , Suture Techniques , Wound Healing/drug effectsABSTRACT
This paper presents a new automatic technique for left ventricle boundary detection from a set of three-dimensional (3D) computed tomography (CT) volumetric cardiac images. The goals of this paper are to incorporate the temporal information into LV boundary detection, to link the shape modeling and LV boundary detection together, and to provide a compact representation of recovered LV boundaries to cardiac imaging. The proposed technique introduces spatio-temporal boundary detection and iterative model-based boundary refinement to left ventricular boundary extraction. The proposed technique has been applied to two sets of four-dimensional (4D) computed tomography images. Experimental results are compared with the manually edited images.
Subject(s)
Heart Ventricles/diagnostic imaging , Image Processing, Computer-Assisted , Models, Cardiovascular , Tomography, X-Ray Computed , Ventricular Dysfunction, Left/diagnostic imaging , Algorithms , Animals , Arrhythmias, Cardiac/diagnostic imaging , Arrhythmias, Cardiac/etiology , Atrial Fibrillation/complications , Cardiac Volume , Dogs , Fuzzy Logic , Heart Ventricles/anatomy & histology , Ventricular Function, LeftABSTRACT
Wilson's disease is a rare genetic disorder of copper metabolism with autosomal recessive inheritance. It occurs between the 6th and 45th year of life. An early and reliable diagnosis, if possible in the preclinical stage, is the prerequisite for starting therapy in time. By the treatment the quality of life and the expectation of life are raised considerably. If consistent treatment is given, there will be no objections to pregnancy in Wilson's disease. It should be interrupted only in case of marked portal hypertension and in the presence of oesophageal varices. The examination of the breast milk of a patient suffering from Wilson's disease showed a reduction in the trace elements copper and zinc. It may be necessary to think of copper and zinc substitution in children fed with breast milk only.
Subject(s)
Copper/metabolism , Hepatolenticular Degeneration/metabolism , Milk, Human/metabolism , Zinc/metabolism , Adult , Female , HumansSubject(s)
Food Hypersensitivity/diagnosis , Milk Proteins/adverse effects , Animals , Cattle , Diagnosis, Differential , Humans , InfantABSTRACT
A system for obtaining a complete diagnostic description of an image sequence taken in nuclear medicine from the human heart has been developed, implemented, and tested. The knowledge about these images is represented in a semantic net, conclusions are drawn by a production rule approach, and scoring of alternative diagnoses is based on fuzzy membership functions. On the low level, image pixels are smoothed and organ contours are extracted; these are the input for the high level processing. Tests with several image sequences gave correct descriptions as compared to the diagnosis of a physician.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Infant, Newborn, Diseases/drug therapy , Bacterial Infections/microbiology , Dose-Response Relationship, Drug , Ear, External/microbiology , Feces/microbiology , Gastric Juice/microbiology , Humans , Infant, Newborn , Infant, Newborn, Diseases/microbiologyABSTRACT
Attributed programmed graph grammars are introduced in this paper and their application to the interpretation of schematic diagrams is proposed. In contrast with most of the approaches to syntactic pattern recognition, where the grammar controls a parser, the grammar in our system is used as a generative tool. Two classes of diagrams are studied, namely circuit diagrams and flowcharts. The task is in either case to extract a description from an input diagram.
