Study of dorsal wall of sacrum

Background: Sacrum is a large triangular bone formed by fusion of five sacral vertebrae. The opening present at the caudal end of sacral canal is known as sacral hiatus and is formed due to the failure of fusion of lamina of fifth sacral vertebra. Objective of current study was to study the anatomical variations of dorsal wall of sacrum in order to clarify the structural variations of sacral hiatus and surrounding structures for improving the reliability of caudal epidural blockMethods: The present study was done on 50 male and 50 female dry human sacra after calculating the sacral indices and sexing of sacra. The dorsal wall of sacrum was studied with respect to composition of sacrum, level of sacral hiatus, deficiencies and apertures in the bony dorsal wall and also for the presence and absence of sacral cornua.Results:The level of apex of sacral hiatus can vary from upper part of S2 to lower part of S5. The most common position was at S4 (64%). Elongated sacral hiatus at the level of S2 was present in 4% of cases. Sacrum had normal 5 segments in 70% of cases, 4 segmented sacra were observed in 4% of cases, sacralization of 5th lumbar vertebra in 7%, coccygeal ankylosis in 19% of cases. Less extensive apertures in the bony dorsal wall of sacral canal were observed in 29% of sacra.Conclusion:The dorsal wall of sacrum has anatomical variations. Understanding these variations may improve the reliability and success of caudal epidural anesthesia.

Morphological Analysis of the Human Internal Iliac Artery in South Indian Population

Objectives: The accidental hemorrhage is common due to erroneous interpretation of the variant arteries during surgical procedures, hence the present study has been undertaken with reference to its morphological significance. The objectives were to examine the level of origin, length and the branching pattern of the human internal iliac artery in South Indian population. Methods: The study included 60 human bisected pelvises irrespective of their side and sex. The specimens were collected from the anatomy laboratory and were fixed with the formalin. The branching patterns were studied and demonstrated as per the guidelines of Adachi. Results: The origin of internal iliac artery was at the level of S1 vertebra in majority (58.3%) of the cases. The average length of internal iliac artery was 37 ± 4.62 mm (range, 13-54 mm). The type I pattern of the internal iliac artery was most common (83.5%) followed by types III and II. The type IV and V pattern of adachi were not observed. Conclusions: The results of this study were different from those reported by others and may be because of racial and geographical variations. Prior knowledge of the anatomical variations is beneficial for the vascular surgeons ligating the internal iliac artery or its branches and the radiologists interpreting angiograms of the pelvic region

Architecture Level Safety Analyses for Safety-Critical Systems

The dependency of complex embedded Safety-Critical Systems across Avionics and Aerospace domains on their underlying software and hardware components has gradually increased with progression in time. Such application domain systems are developed based on a complex integrated architecture, which is modular in nature. Engineering practices assured with system safety standards to manage the failure, faulty, and unsafe operational conditions are very much necessary. System safety analyses involve the analysis of complex software architecture of the system, a major aspect in leading to fatal consequences in the behaviour of Safety-Critical Systems, and provide high reliability and dependability factors during their development. In this paper, we propose an architecture fault modeling and the safety analyses approach that will aid in identifying and eliminating the design flaws. The formal foundations of SAE Architecture Analysis & Design Language (AADL) augmented with the Error Model Annex (EMV) are discussed. The fault propagation, failure behaviour, and the composite behaviour of the design flaws/failures are considered for architecture safety analysis. The illustration of the proposed approach is validated by implementing the Speed Control Unit of Power-Boat Autopilot (PBA) system. The Error Model Annex (EMV) is guided with the pattern of consideration and inclusion of probable failure scenarios and propagation of fault conditions in the Speed Control Unit of Power-Boat Autopilot (PBA). This helps in validating the system architecture with the detection of the error event in the model and its impact in the operational environment. This also provides an insight of the certification impact that these exceptional conditions pose at various criticality levels and design assurance levels and its implications in verifying and validating the designs

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

Resource management and performance analysis of model-based control system software engineering using AADL

The key principles involved in abstraction, encapsulation, design and development phases of the software structures of a system is, management of their complexities. These structures consist of the necessary components defining the concept of architecture of the system. Complex embedded systems, evolving with time, comprise of complex software and hardware units for its execution. This requires effective and efficient software model-based engineering practices. The complex systems are evolving in-terms of its resources and contemplating the operational dynamics. In this paper we emphasize on the formal foundations of Architecture Analysis and Design Language (AADL) for model-based engineering practices. This engineering process involves models as the centralized and the indispensible artifacts in a product’s development life-cycle. The outcome of the approach features the techniques along with the core capabilities of AADL and managing the evolving resources considering impact analysis. A suitable case study, Power Boat Autopilot is considered. The details on the use of AADL capabilities for architectural modeling and analysis are briefly presented in this paper

Transaction-based models (TBM) and evaluation of their throughput

The perception of the system-level design, based on a modeling approach involving series of asynchronous events, for the preferred system specifications, articulates as a befitting solution. These models highlight approaches involved in developing heterogeneous complex embedded systems, with formal foundations. These models composed with distinct components, representing the behavioral integrant and calculative modes for the system. Such a modeling approach proves to be efficient in contending the possible clogging bottlenecks in the design and development cycle. This approach and analytical methodology uniquely strategizes the references for various abstraction levels in the development-cycle as in; early software development associated with the system, architecture analysis, functional & performance verification. In this paper we propose a novel transaction-based high-level modeling approach in verifying and validating the architecture, as well as evaluating the performance of a system suitable for avionics application. The novel approach is proven by means of a case study of the avionics software scheduler. VisualSim is used for transaction-based evaluation and provides an emulative platform providing a combinatorial link between the hardware and its underlying software, deriving a more realistic solution for the feature of development