ABSTRACT
In recent years, with the wide application of magnetic resonance imaging (MRI) equipment in clinical practice, the quality of the equipment causes adverse events, which put pressure on manufacturers, at the same time, it puts forward higher requirements for medical device supervisors. In order to help the medical device supervisors to clarify the key points of verification, this paper analyzes the main risk points in the production process of the product according to the medical device good manufacturing practice(GMP), and puts forward the suggestions for field verification, which has practical significance for the submission of verification efficiency.
Subject(s)
Commerce , Magnetic Resonance ImagingABSTRACT
PET/MR is a high-end medical imaging equipment with integrating PET and MR equipment into the highly sophisticated one and has rich clinical and molecular diagnosis functions, can obtain comprehensive information about the human body structure, function and metabolism, is of great value for the diagnosis and treatment of disease improvement. In this paper, through the analysis of existing production risk points on one of the primary stages of the whole product life cycle, combining with the medical device good manufacture practice, some suggestions have been put forward exploratively to field inspection for PET/MR manufacturers. It has certain significance for regulators of medical devices to clear the production risk point and improve verification efficiency during field inspection.
Subject(s)
Humans , Equipment Design , Magnetic Resonance Imaging , Positron-Emission TomographyABSTRACT
In recent years, the R&D and production level for Computed Tomography(short for CT) have been greatly improved and developed in China. In fact, it leads to higher requirements for medical device regulators. In order to clear key points in field inspection for regulators, this article analyzes the risk prevention and control points in the production process of CT based on the 5M1E analysis, and combined with medical device good manufacturing practice (short for GMP), presents exploratively some suggestions on the field inspection of CT manufacturers. This article also has important sense for regulators to clear the pertinence and improve the efficiency during the field inspection.
Subject(s)
China , Equipment Safety , Tomography, X-Ray Computed , X-RaysABSTRACT
An adult patient with skeletal crossbite and mandibular deviation was treated by mandibular molar distalization using micro-im-plant and intermaxillary traction.After treatment,the facial contour of the patient was improved,the Class Ⅰ molar and cuspid relationship was achieved.
ABSTRACT
<p><b>UNLABELLED</b>To construct a three-dimensional finite element model comparing between one-step and two-step methods in torque control of anterior teeth during space closure.</p><p><b>METHODS</b>Dicom image data including maxilla and upper teeth were obtained though cone-beam CT. A three-dimensional model was set up and the maxilla, upper teeth and periodontium were separated using Mimics software. The models were instantiated using Pro/Engineer software, and Abaqus finite element analysis software was used to simulate the sliding mechanics by loading 1.47 Nforce on traction hooks with different heights (2, 4, 6, 8, 10, 12 and 14 mm, respectively) in order to compare the initial displacement between six maxillary anterior teeth (one-step method) and four maxillary anterior teeth (two-step method).</p><p><b>RESULTS</b>When moving anterior teeth bodily, initial displacements of central incisors in two-step method and in one-step method were 29.26 × 10⁻⁶ mm and 15.75 × 10⁻⁶ mm, respectively. The initial displacements of lateral incisors in two-step method and in one-step method were 46.76 × 10(-6) mm and 23.18 × 10(-6) mm, respectively. Under the same amount of light force, the initial displacement of anterior teeth in two-step method was doubled compared with that in one-step method. The root and crown of the canine couldn't obtain the same amount of displacement in one-step method.</p><p><b>CONCLUSIONS</b>Two-step method could produce more initial displacement than one-step method. Therefore, two-step method was easier to achieve torque control of the anterior teeth during space closure.</p>