[Analysis of 2 cases of dyspnea happening after tracheotomy and the clinical application of Mimics 10.01].

Post-intubation tracheal stenosis was a late time complication after tracheotomy but the happening of dyspnea was unusual. Diagnosing tracheal stenosis after incubation, and figuring out the location and causes of the stenosis were important. Treatment of post-incubation tracheal stenosis relied on accurate diagnosis of the type of tracheal stenosis. Computed tomography (CT) and laryngoscope could be used for detecting the stenosis but not enough. Two patients who were already under the urgent tracheotomy over 1 year were reported. However apnea was found on these two patients for a long time after traheotomy. Obviously laryngeal obstruction appeared. CT virtual bronchoscope and laryngoscope examination showed that the cannula was obstructed and plenty of granulation tissue blocked the orificium. But the exact location of the cannula and the adjacent relationship of the tissue around the cannula was equivocal. Mimics 10.01 software was used to analyze the data of the CT scan and found that a pseudo cavity was formed by granulation tissue which partly blocked the cannula in 1 case; granulation tissue occupation and scar formation in the trachea were the reason of tracheal stenosis but not the collapse of the cartilage in case 2. The purpose of this report is to discuss the cause of dyspnea after emergency tracheotomy, its diagnostic method and their management. CT virtual bronchoscope and laryngoscope should be used as a regular examination after tracheotomy to clarify the location of cannula and avoid the failure of airway opening caused by the dislocation of cannula and the complication. Trachea tissue should be protected properly during and after the tracheotomy which might decline the rate of the tissue remodeling, tracheal stenosis and dyspnea after surgery. The clinical use of Mimics 10.01 made it possible to observe morphology more directly by invasive examination and provided a significant clue to make the operation plan so that it should be used widely. Meanwhile, the method to put the cannula into its right way under the guidance of rigid endoscope and the excision of granulation tissue by semiconductor laser should become one of the best treatments of this disease. Following the method above, laryngeal obstruction was relieved after the surgery. Postoperative follow-up lasted for 1 year and recurrence was not found.

A stable wireless energy transmission system for gastrointestinal microsystems.

A wireless energy transmission system using a Helmholtz primary coil outside and a 3-dimensional secondary coil inside the body is introduced. It is designed to transmit stable power to a gastrointestinal microsystem regardless of its position and orientation when working in the gastric tract. Up to 310 mW of usable DC power can be delivered under worst-case geometrical conditions. Measured data of the system performance are presented and evaluated.

Physical growth of Chinese school children 7-18 years, in 1985.

Physical development in Chinese school children was analysed based on a national survey in 1985. Close to half a million children and adolescents, aged 7-18, from Han ethnic group and 27 minority ethnic groups were assessed for height, weight, sitting-height, chest circumference, biacromial and biiliac diameters. Growth in Han children was greater than that in minority ethnic group children. The growth differences among minority ethnic groups were large. Growth in urban children was greater than that in rural children except in a few age groups of girls. A significant difference in children's growth was found between northern and southern divisions of China, it being greater in the north. The growth curves of physical characteristics demonstrated systematic regularity. Finally, the results of this study were compared with research reports from other world literature.