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A method for obtaining the core positions of fiber array is described. The technique is based on the use of calibrated mask. Because the mask and the fiber array are simultaneously moved and imaged, the measuring system is relatively simple in image processing, location, and vibration isolation. A prototype system with common components has been built for testing a number of commercial fiber arrays.

Our objective was to examine and correlate 99mTcdiethylenetriaminopentaacetic acid 99mTcDTPA ventilation and 99mTcmacroaggregated albumin 99mTcMAA perfusion VQ lung scans with spirometry in asymptomatic asthmatic children. We evaluated 89 subjects age range, 6–15 years mean age, 9.4 years, all with at least 70 predicted forced expiratory volume in 1 s FEV1. There were four VQ scan patterns normal in 38 42.7, inhomogeneous ventilation in 11 12.4, matched defects in 25 28.3 and mismatched perfusion defects in 13 14.6. The maximal midexpiratory flow rate MMEF of the normal scan group was significantly different from that in the other groups. The MMEF of the inhomogeneous group was significantly different from that in the matched defect group and the mismatched perfusion defect group. No other significant differences in spirometric indices were found. In two children with perfusion defects, pulmonary arteriograms demonstrated no obstructive lesions. In conclusion, lung scans provide diagnostic information in asymptomatic asthmatic children, even when they are uncooperative. Abnormal scans are common in these children and are significantly correlated with reduced MMEF predicted, reflecting small airway flow obstruction. The pathophysiology of VQ defects in asymptomatic asthmatic children warrants further investigation.

The winding current exciting responses of brushless DC motors significantly affect their torque generating characteristics and hence the whole drive control performance. To obtain a quick and accurate current command tracking response, the application of control strategies for compensating the effects of key parameter variations is necessary. Robust control for achieving improved current response is studied. First, the model parameters for performing the current control loop design are estimated. Then a novel current control scheme is proposed, which consists of a feedback controller, a command feedforward controller and a robust disturbance cancellation feedforward controller. The former two controllers are designed to fulfil the desired current control characteristics at nominal case, and the robust controller is employed to reduce the effects of back electromotive force and parameter variations. The theoretic basis and design of the proposed control scheme are presented in detail. Through applying the designed current controller, the winding current response is speeded up and thus the motor drawn line current is decreased owing to the improved torque generating characteristics. The effectiveness of the proposed robust current control approach is demonstrated by simulation and measured results.

The frequency of allergic diseases, such as asthma, has increased rapidly during the past decade; however, the exact mechanisms have not been established. In this study we tried to establish an in vivo system to investigate immune regulation of allergic diseases by using severe combined immunodeficient (SCID) mice. Peripheral blood mononuclear cells isolated from asthmatic children or normal adults were injected into peritoneal cavities of SCID mice. Human IgG, IgA, IgM, and IgE could be detected in SCID mice reconstituted with human PBMCs (SCID-PBL-hu mice) 3 weeks later. Moreover, the mice injected with peripheral blood mononuclear cells from asthmatic children had much higher IgE levels than mice reconstituted with cells from normal adults. Phenotypic analysis of spleen cells and peritoneal exudate cells from SCID-PBL-hu mice demonstrated that human lymphocytes could survive in the peritoneal cavity and spleen for several months. After intraperitoneal immunization, mite-specific IgE antibodies could also be detected in SCID-PBL-hu mice. This study indicates that the human IgE system can be established in SCID mice and that this model can be used to study the regulation of IgE production and the immunopathogenesis of human allergic disease. (J ALLERGY CLIN IMMUNOL 1995;95:69-76.)

Totally implantable venous access ports (TIVAPs) are frequently used in oncology patients who require long-term courses of chemotherapy. We report a silent, but potentially hazardous complication of catheter fracture and hepatic migration in a 64-year-old male. The patient presented with a painful, rapid swelling of subcutaneous tissue around the port area during a saline flush. A chest radiograph showed that the disconnected catheter had separated from the port and was no longer in its original location. A chest CT scan revealed that the disconnected catheter was found to be embolized to the right atrium, inferior vena cava and right hepatic vein. The patient was treated successfully with percutaneous transfemoral retrieval of the catheter under fluoroscopic guidance. To our knowledge, there have been no previous reports of migration of the fractured catheter of a TIVAP into the right hepatic vein. This case highlights that the integrity of TIVAPs should be ascertained before chemotherapeutic drugs are administered.