Jump Technique versus Seton Method for Anal Fistula Repair: A Randomized Controlled Trial.

BACKGROUND: The treatment of anal fistula has been a conundrum for surgeons over the years. Various methods such as fistulotomy, fistulectomy, seton, ligation of the intersphincteric fistula tract (LIFT), advancement flaps, fibrin glue, and plugs are well-known techniques. Yet, they may be followed by several considerable complications, including incontinency and recurrence. METHODS: In this study, the outcomes of the "Jump" and "Seton" techniques are compared. A randomized controlled trial consisting of 130 cases with cryptoglandular anal fistula randomly sorted into two groups was conducted. Group A underwent the "Jump technique" while group B underwent the "Seton technique." Outcomes, incontinency and recurrences in particular, were evaluated after a year of treatment. Data were analyzed by Fisher Exact, Chi-Square and Mann Whitney Tests. RESULTS: Group A with 65 cases underwent the "Jump technique" while group B with 65 cases underwent the "Seton Method." Recurrence was reported in 12 (20%) cases in group A and 10 (15.6%) cases in group B (p=0.687). Overall incontinence was reported in 3 (4.6%) cases in group A and 18 (27.7%) cases in group B (P=0.001). The total St. Mark's scores for incontinency of group A (0.092±0.52) and group B (1.8±02.47) significantly differed (p<0.001). CONCLUSIONS: The "Jump technique", named after a runner who jumped over hurdles, has obviated these complications. The "Jump technique" had satisfactory results and can be utilized as a first-line approach for all types of fistulas. Moreover, it can be redone for cases with recurrences without affecting the continence, paving the way to change the technique during operations.

A new control structure to reduce time delay of tracking sensors by applying an angular position sensor.

In this paper, a new tracking control structure is proposed to decrease the time-delay effect of tracking sensor. To achieve this purpose, an angular position sensor, which generally exists in tracking systems, is used together with the tracking sensor. Also, a compensator is designed and applied to a system with time-delay in order to obtain a behavior same as a system without time-delay. Relying only on tracking sensor may lead to reduce the tracking speed and to increase tracking error. However, it is shown that by using the proposed reformative structure, the speed of tracking and the tracking error can be compensated significantly. In the next step, the performance of the new structure in two cases of constant time-delay and variable time-delay are evaluated and their stability conditions are analyzed. Finally, robustness of the proposed structure is analyzed.

Detection of broken rotor bars in induction motors using nonlinear Kalman filters.

This paper presents a model-based fault detection approach for induction motors. A new filtering technique using Unscented Kalman Filter (UKF) and Extended Kalman Filter (EKF) is utilized as a state estimation tool for on-line detection of broken bars in induction motors based on rotor parameter value estimation from stator current and voltage processing. The hypothesis on which the detection is based is that the failure events are detected by jumps in the estimated parameter values of the model. Both UKF and EKF are used to estimate the value of rotor resistance. Upon breaking a bar the estimated rotor resistance is increased instantly, thus providing two values of resistance after and before bar breakage. In order to compare the estimation performance of the EKF and UKF, both observers are designed for the same motor model and run with the same covariance matrices under the same conditions. Computer simulations are carried out for a squirrel cage induction motor. The results show the superiority of UKF over EKF in nonlinear system (such as induction motors) as it provides better estimates for rotor fault detection.