New methods for the estimation of Takagi–Sugeno model based extended Kalman filter and its applications to optimal control for nonlinear systems

This paper describes new approaches to improve the local and global approximation (matching) and modeling capability of Takagi–Sugeno (T‐S) fuzzy model. The main aim is obtaining high function approximation accuracy and fast convergence. The main problem encountered is that T‐S identification method cannot be applied when the membership functions are overlapped by pairs. This restricts the application of the T‐S method because this type of membership function has been widely used during the last 2 decades in the stability, controller design of fuzzy systems and is popular in industrial control applications. The approach developed here can be considered as a generalized version of T‐S identification method with optimized performance in approximating nonlinear functions. We propose a noniterative method through weighting of parameters approach and an iterative algorithm by applying the extended Kalman filter, based on the same idea of parameters’ weighting. We show that the Kalman filter is an effective tool in the identification of T‐S fuzzy model. A fuzzy controller based linear quadratic regulator is proposed in order to show the effectiveness of the estimation method developed here in control applications. An illustrative example of an inverted pendulum is chosen to evaluate the robustness and remarkable performance of the proposed method locally and globally in comparison with the original T‐S model. Simulation results indicate the potential, simplicity, and generality of the algorithm. An illustrative example is chosen to evaluate the robustness. In this paper, we prove that these algorithms converge very fast, thereby making them very practical to use. Copyright © 2011 John Wiley & Sons, Ltd.     

Simultaneous nephrectomy and coronary artery bypass grafting through extended sternotomy

A 37-year-old man with end-stage idiopathic dilated cardiomyopathy underwent an orthotopic heart transplant followed by a reoperation with mitral annuloplasty for severe mitral regurgitation. Shortly thereafter, he developed severe tricuspid regurgitation and severe recurrent mitral regurgitation due to annuloplasty ring dehiscence. The dehisced annuloplasty ring was refixated, followed by tricuspid annuloplasty through a right anterolateral thoracotomy. After four years of follow-up, there are no signs of recurrent mitral or tricupid regurgitation and the patient remains in NYHA class II. Pushing the envelope on conventional surgical procedures in marginal donor hearts (both before and after transplantation) may not only improve the patient??s functional status and reduce the need for retransplantation, but it may ultimately alleviate the chronic shortage of donor hearts.     

Equine Babesiosis: Seroprevalence,Risk Factors and Comparison of Different Diagnostic Methods in Jordan

The purposes of this study were to estimate the seroprevalence and distribution of horse piroplasmosis, to evaluate risk factors associated with the occurrence of the disease and to compare the different diagnostic methods used for this disease. A total of 253 clinically normal horses were sampled, and a collection form was completed for each horse from five of six different climatic zones of Jordan. The sixth zone was not sampled because it did not include horse population. Competitive enzyme‐linked immunosorbent assay (cELISA) revealed 37 horses (14.6%) positive for Theileria equi, and none of the horses was positive for Babesia caballi. Microscopic examination of thin blood smears and PCR test revealed no positive results for either parasite. Grazing was the only risk factor that was associated with being seropositive to the disease; horses that graze are 11.5 more likely to be seropositive (P < 0.05, OR = 11.5, CI: 3.292, 39.962). This is the first study to estimate the prevalence of horse babesiosis using serological test and to identify risk factors associated with the disease in Jordan. Competitive enzyme‐linked immunosorbent assay (cELISA) test appears to be more reliable than microscopic examination and PCR in estimating the seroprevalence of the disease as well as identifying carrier horses to babesiosis.     

Robotic uretero-ureterostomy of the retrocaval ureter without excision of the retrocaval segment

Robotic reconstruction of the retrocaval ureter is gaining momentum as the method of choice for surgically treating this rare condition. Maintaining the retrocaval ureteric segment further facilitates the procedure. We report a case of a 23-year-old man who underwent intraperitoneal robotic resection anastomosis and repositioning of the retrocaval ureter. We also discuss the advantages of this technique.     

Abdominal apoplexy: A rare case of spontaneous rupture of the superior mesenteric artery in a hypertensive patient

INTRODUCTIONSpontaneous rupture of an intra-abdominal visceral artery is an exceptionally rare and potentially fatal cause of abdominal apoplexy.PRESENTATION OF CASEWe present a case of a 54-year-old hypertensive male who developed hypovolemic shock in our Emergency Department after presenting with abrupt onset of abdominal pain and diarrhea. Intra-operative findings revealed rupture of the superior mesenteric artery with massive hemoperitoneum. The bleeding vessel was ligated and the patient made a full recovery after 3 weeks in the Intensive Care Unit.DISCUSSIONHigh index of suspicion is necessary for early preoperative diagnosis and must be considered in any patient with a history of hypertension presenting with abrupt abdominal pain, signs of peritoneal irritation and unexplained hypovolemic shock. Immediate resuscitation and prompt surgical control of bleeding is paramount in patient prognosis.CONCLUSIONThe seemingly unpredictable nature of abdominal apoplexy must be noted, a precipitating cause in most cases is untraceable and early diagnosis relies solely on awareness of the condition.