RESUMEN
This paper considers the problem of finding the position of a passive target using noisy time difference of arrival (TDOA) measurements, obtained from multiple transmitters and a single receiver. The maximum likelihood (ML) estimator's objective function is extremely nonlinear and non-convex, making it impossible to use traditional optimization techniques. In this regard, this paper proposes the chaos-enhanced adaptive hybrid butterfly particle swarm optimization algorithm, named CAHBPSO, as the hybridization of butterfly optimization (BOA) and particle swarm optimization (PSO) algorithms, to estimate passive target position. In the proposed algorithm, an adaptive strategy is employed to update the sensory fragrance of BOA algorithm, and chaos theory is incorporated into the inertia weight of PSO algorithm. Furthermore, an adaptive switch probability is employed to combine global and local search phases of BOA with the PSO algorithm. Additionally, the semidefinite programming is employed to convert the considered problem into a convex one. The statistical comparison on CEC2014 benchmark problems shows that the proposed algorithm provides a better performance compared to well-known algorithms. The CAHBPSO method surpasses the BOA, PSO and semidefinite programming (SDP) algorithms for a broad spectrum of noise, according to simulation findings, and achieves the Cramer-Rao lower bound (CRLB).
Asunto(s)
Algoritmos , Dinámicas no Lineales , Simulación por Computador , ProbabilidadRESUMEN
BACKGROUND: The objective of our study was to assess the rate and causes for Essure® micro-insert system removal and patients' long term satisfaction rate with the procedure. METHODS: All patients who underwent Essure® hysteroscopic sterilization at our tertiary centre between years 2007 and 2018 were included in this follow-up study. A questionnaire was sent to all patients per standard mail. Patients who did not respond to questionnaires per mail, were called by phone. The satisfaction with the Essure® sterilization, as well as any additional procedures after the insertion or insertion-related complications were analysed. RESULTS: From the year 2007 to 2018, we performed 427 Essure® hysteroscopic sterilizations and of these, 329 patients responded to the questionnaire (response rate 77%). Ten patients (3%) had Essure® removal, two of them due to pain (0.6%). Patients were very satisfied with the procedure (9.5 on scale 0-10). Most patients (95.3%) would recommend the procedure to their friend. CONCLUSIONS: Essure® hysteroscopic sterilization is a procedure with a very high satisfaction rate and a very low removal rate due to sterilization-related complications. Trial registration Institutional review board of University medical centre Maribor approved the study, approval number UKC-MB-KME-73/19.
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Esterilización Tubaria , Femenino , Estudios de Seguimiento , Humanos , Histeroscopía/métodos , Satisfacción del Paciente , Complicaciones Posoperatorias , Embarazo , Estudios Retrospectivos , Esterilización , Esterilización Tubaria/métodosRESUMEN
OBJECTIVES: Hysterosalpingo-foam sonography (HyFoSy) has been suggested to be a possible less invasive alternative to hysterosalpingography (HSG), which is the reference standard for confirmation of tubal occlusion after Essure (Bayer AG, Leverkusen, Germany) hysteroscopic sterilization. The purpose of our study was to evaluate the accuracy of HyFoSy compared to HSG for confirmation of tubal occlusion after Essure hysteroscopic sterilization. METHODS: A prospective study included 90 patients who underwent Essure hysteroscopic sterilization. Twelve weeks after the sterilization, 2-dimensional transvaginal ultrasonography was performed to assess the microinsert position and was followed by HyFoSy and HSG for evaluation of tubal occlusion. Patients with patent fallopian tubes on HSG were scheduled for additional HSG procedures at 3-month intervals until tubal occlusion was documented. RESULTS: Of 90 enrolled patients, 86 patients with 170 fallopian tubes underwent the complete imaging protocol. Tubal occlusion was evaluated by HyFoSy as an index test and HSG as a reference standard. The accuracy of HyFoSy was 97.1% (95% confidence interval [CI], 93%-99%). The sensitivity and specificity were 100% (95% CI, 97%-100%) and 54.6% (95% CI, 23%-83%), whereas the positive and negative predictive values were 97.0% (95% CI, 93%-99%) and 100% (95% CI, 42%-100%), respectively. No long-term complications were reported for HyFoSy or HSG. CONCLUSIONS: Given that the concordance rate for tubal occlusion between HyFoSy and HSG was not 100%, an occluded fallopian tube on HyFoSy should be confirmed by HSG, which remains the reference standard for confirmation of tubal occlusion after Essure hysteroscopic sterilization.