A conceptual structural health monitoring (SHM) system to monitor fatigue damage is discussed in this study. The first part of the study is concerned with damage prognosis. A methodology to use the data from a pre-crack damage monitoring system to predict the number of cycles to macrocrack-initiation in a probabilistic sense, is presented. Issues related to quantifying damage, a damage evolution law, and numerical evaluation of the probability of macrocrack initiation are discussed. The second part of the study deals with quantifying the effects of imperfect inspections during the growth of a macrocrack. The probability that there eXists an undetected critical crack is the quantity of interest. An analytical eXpression for this quantity is derived for the case of a two-dimensional crack. A Monte Carlo simulation method to quantify the effects of imperfect inspections is also presented. Numerical results are presented for two eXamples of surface-breaking cracks with different geometries.

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A probabilistic method to predict macrocrack initiation due to fatigue damage is presented in this paper. Acoustic non-linearity is used to quantify pre-macrocrack initiation damage. This data is then used in a probabilistic analysis of fatigue damage. The probabilistic fatigue damage analysis consists of a suitably chosen damage evolution equation to model accumulated damage coupled with a procedure to calculate the probability of macrocrack initiation. The probability of macrocrack initiation is evaluated using the Monte Carlo Method with Importance Sampling. Numerical results for the probabilistic assessment of fatigue damage for a sample problem are presented and compared with experimental results.

Lee first described the concept of preoperative assessment testing (PAT) clinic in 1949. An efficiently run clinic is associated with increased cost-effectiveness by lowering preoperative admission time and thus reducing the length of stay and the associated costs. The setup of the PAT clinic should be based on the needs, culture, and resources of the institution. Various models for the setup of PAT clinic have been described, including the concept of a perioperative surgical home, which is a patient-centered model designed to improve health and the delivery of health care and to reduce the cost of care. Although there are several constraints in the development of PAT clinics, with increasing awareness about the usefulness of pre-operative risk assessments, growing bodies of literature, and evidence-based guidelines, these clinics are becoming a medical necessity for the improvement of perioperative care.

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