Effectiveness and Safety of Ultrasound-guided Percutaneous Microwave Ablation for a Single Uterine Fibroid Greater than 300 cm3.

STUDY OBJECTIVE: To evaluate the effectiveness and safety of ultrasound-guided percutaneous microwave ablation (MWA) for a single uterine fibroid greater than 300 cm3. DESIGN: Retrospective observational study. SETTING: China-Japan Union Hospital of Jilin University, China. PATIENTS: Thirty-seven patients each with a single fibroid greater than 300 cm3 diagnosed by ultrasound and core needle biopsy. INTERVENTIONS: Ultrasound-guided percutaneous MWA. MEASUREMENTS AND MAIN RESULTS: All patients were followed up for 12 months postoperatively to assess the postoperative lesion volume reduction rate, degree of symptomatic relief, improvements in quality of life, and occurrence of adverse events. All 37 patients met the criteria for complete ablation, and the lesion volume significantly decreased from 334.28 cm3 (95% confidence interval [CI] 326.75-366.73) preoperatively to 52.01 cm3 (95% CI, 46.95-74.69) at the 12-month follow-up (difference: 280.15 cm3; 95% CI, 267.92-294.65; p <.001). The lesion volume reduction rates at 1, 3, 6, and 12 months postoperatively were 27.30% (95% CI, 24.12-31.45), 52.90% (95% CI, 47.95-55.80), 67.90% (95% CI, 63.03-70.77), and 84.00% (95% CI, 80.22-85.94), respectively. The differences in the preoperative and postoperative Uterine Fibroid Symptom and Health-Related Quality of Life Questionnaire scores were significant (p <.01). The hemoglobin levels of the anemic patients were significantly elevated after the procedure (p <.001). Of the 37 patients in this study, 29 patients (78.38%) had a highly significant treatment effect, and 8 patients (21.62%) had a significant treatment effect. Seventeen patients (45.95%) had Society of Interventional Radiology grade A to B adverse effects that required no clinical intervention or only simple clinical intervention. CONCLUSION: Ultrasound-guided percutaneous MWA has good clinical efficacy and high safety in the treatment of a single uterine fibroid greater than 300 cm3.

Testing and Evaluation of Flexural Tensile Strength of Prestressed CFRP Cables.

To expand the application scope of prestressed carbon fiber-reinforced polymer (CFRP) cables in civil engineering, the ultimate tensile strength of these cables was tested and evaluated under bending conditions. First, the study analyzed the tensile failure mechanism of CFRP cables under bending conditions based on elastic bending analysis theory. Thereafter, the ultimate stress state of individual tendons and cables was derived and a calculation model for the tensile strength of bent CFRP cables was established. Second, 14 sets of test conditions were created for CFRP cables under bending angles of 20-40° and bending radii of 1.5-3 m. Then, bending tensile tests were conducted to evaluate the effects of the above factors on the ultimate tensile strength, and the correctness of the computational model was verified using experiments. Finally, the ultimate performance of CFRP cables was theoretically predicted using the established model. The results showed that the cable bending tensile strength was associated with the radius r, tensile strength f, and elastic modulus E of the reinforced material and the bending radius R, but was not correlated with the interface buffer material or the bending angle of the steering system. Moreover, the flexural tensile residual strength was only affected by R/r and E/f. When E/f involved conventional material parameters, the residual strength increased nonlinearly with increased R/r. When R/r ≥ 600, the residual strength reached more than 80%. Therefore, R/r at 600 could be used as the design basis for a safe critical radius.

Modeling and control of operator functional state in a unified framework of fuzzy inference petri nets.

BACKGROUND AND OBJECTIVE: In human-machine (HM) hybrid control systems, human operator and machine cooperate to achieve the control objectives. To enhance the overall HM system performance, the discrete manual control task-load by the operator must be dynamically allocated in accordance with continuous-time fluctuation of psychophysiological functional status of the operator, so-called operator functional state (OFS). The behavior of the HM system is hybrid in nature due to the co-existence of discrete task-load (control) variable and continuous operator performance (system output) variable. METHODS: Petri net is an effective tool for modeling discrete event systems, but for hybrid system involving discrete dynamics, generally Petri net model has to be extended. Instead of using different tools to represent continuous and discrete components of a hybrid system, this paper proposed a method of fuzzy inference Petri nets (FIPN) to represent the HM hybrid system comprising a Mamdani-type fuzzy model of OFS and a logical switching controller in a unified framework, in which the task-load level is dynamically reallocated between the operator and machine based on the model-predicted OFS. Furthermore, this paper used a multi-model approach to predict the operator performance based on three electroencephalographic (EEG) input variables (features) via the Wang-Mendel (WM) fuzzy modeling method. The membership function parameters of fuzzy OFS model for each experimental participant were optimized using artificial bee colony (ABC) evolutionary algorithm. Three performance indices, RMSE, MRE, and EPR, were computed to evaluate the overall modeling accuracy. RESULTS: Experiment data from six participants are analyzed. The results show that the proposed method (FIPN with adaptive task allocation) yields lower breakdown rate (from 14.8% to 3.27%) and higher human performance (from 90.30% to 91.99%). CONCLUSION: The simulation results of the FIPN-based adaptive HM (AHM) system on six experimental participants demonstrate that the FIPN framework provides an effective way to model and regulate/optimize the OFS in HM hybrid systems composed of continuous-time OFS model and discrete-event switching controller.