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In this paper, a combined control strategy with extended state observer (ESO) and finite time stable tracking differentiator (FTSTD) has been proposed to perform flexion and extension motion repetitively and accurately in the sagittal plane for shoulder and elbow joints. The proposed controller improves the tracking accuracy, performs state estimation, and actively rejects disturbance. A sinusoidal trajectory as an input has been given to a two-link multiple-input multiple-output (MIMO) upper limb robotic rehabilitation exoskeleton (ULRRE) for a passive rehabilitation purpose. The efficacy of the controller has been tested with the help of performance indices such as integral time square error (ITSE), integral square error (ISE), integral time absolute error (ITAE), and integral of the absolute magnitude of error (IAE). The system model is obtained through the Euler–Lagrangian method, and the controller’s stability is also given. The proposed controller has been simulated for ±20% parameter variation with constant external disturbances to test the disturbance rejection ability and robustness against parametric uncertainties. The proposed controller has been compared with already developed ESO-based methods such as active disturbance rejection control (ADRC), nonlinear active disturbance rejection control (NLADRC), and improved active disturbance rejection control (I-ADRC). It has been found that the proposed method increases tracking performance, as evidenced by the above performance indices.

Introduction: Surgical site infection (SSI) comes as third most common healthcare related infection which produces morbidity and deaths at large. Still many authors believe that it is better not to use prophylactic antibiotics in simple and uncomplicated cases. Laparoscope, now‑a‑days is a much used instrument for abdominal surgeries. Even after new aseptic techniques SSI remains to be a major problem. Aims and Objectives: To study the effect of antibiotics on superficial SSI in the cases of open and laparoscopic cholecystectomy. Observation and Results: One hundred patients were enrolled for cholecystectomy. The patients were divided into two groups, A and B. Group A consisted of patients in whom laparoscopic cholecystectomy was done and group B in whom open cholecystectomy was done. The male female ratio was 1: 2.23. The mean age of patients in Group A was 46 years and in Group B was 44; Standard deviation (SD) for age was 14.8% and 13.8% in groups A and B respectively; t‑value was 0.654 and P value was 0.515 and they were not significant. The number of males and females was 16 and 26 respectively in Group A and 11 and 31 in Group B. The Chi square X2 = 1.36 and P value was 0.248 and both were insignificant. The rate of superficial surgical site infection was 2.63% in both the groups. Conclusion: Our study concludes that there is no difference in the outcome of patients in cases of open as well as laparoscopic cholecystectomy. There is no significant difference in the surgical site infection rate in cases of open as well as laparoscopic cholecystectomy.Keywords: Antibiotics, laparoscopic cholecystectomy, open cholecystectomy, surgical site infection