Retrospective analysis of failures of ambulatory elastomeric pumps containing 5-FU in a hospital pharmacy unit

Introduction Ambulatory chemotherapy is an important and major advance in clinical oncology practice since it allows the administration of chemotherapy in the comfort of the patient's home without the assistance of a health professional by means of an elastomeric pump. However, these pumps are not without risks and can be the cause of incidents due to technical failures. Our objective is to study the technical failures of elastomeric pumps in the Cytotoxic Preparation Unit and in the patient's home, to evaluate the possible impact of these failures on the patient and on the staff and to propose measures to reduce them. Materials and methods This is a retrospective study conducted at the pharmacy of the National Institute of Oncology in Rabat. It gathered all the specific reports on elastomeric pumps issued during the period (January 2017–May 2021) by the cytotoxic preparation unit to the materiovigilance cell via a notification form. Results 205 cases of elastomeric pump materialovigilance were identified during the study period. The main technical failures were: chemotherapy product leakage (44%), flow rate anomalies (30%) and injection difficulties (20%). Following these incidents, certain actions were undertaken such as alerts sent to the supplier and letters sent to the competent health authorities. Conclusion Despite the failures that may have occurred, elastomeric pumps have revolutionized home chemotherapy delivery. They are considered reliable, consistent, easy to use and handle, and are well accepted in the population.

Analysis of time-resolved thermal responses in Lock-In thermography by independent component analysis (ICA) for a 3D-spatial separation of weak thermal sources and defects

Lock-In Thermography is an established non-destructively operating method for the analysis of failures in microelectronic devices. In recent years a major improvement was achieved allowing the acquisition of the time-resolved temperature responses of weak thermal spots that enhances defect localization in 3D stacked semiconductor architectures. The assessment of a defect's depth based on the numerical estimation of the delay between excitation and thermal response by analyzing the value of the lock-in phase is often prone to thermal noise and parasitic effects. In sample structures that contain partial or full transparence for the infrared signal between the origin and the sample surface, the interference of the direct (radiated) and the conducted signal component largely falsifies the phase value on which the classical depth estimation relies. In the present study blind source separation based on independent component analysis of the thermal signals was successfully applied to separate interfering signal components arising from direct thermal radiation and conduction for a precise estimation of the defect depth.

Applying Reverse Engineering Principles on Analysis of Failures Occurred in Ship Production

In the current work, a new error evaluation methodology is introduced based on error analysis in ship production with reverse engineering data. The aim is to determine the errors and prevent or reduce the occurrence in other projects. First step is to compose a database of the errors; then, group the similar errors and calculate the Error Priority Number (EPN) by the evaluation of the predetermined criteria. The radar diagrams, which are suitable for representing a number of parameters having the same variables, were used to present the error groups in a simple way. The error groups were created on the diagram with the scores taken from the specific criteria. With the aid of the radar diagram, valuable information is given by presenting similarities and dissimilarities of these errors with other error groups. After examining the radar diagrams and evaluating the results, the cause and effect diagrams were prepared for these error groups from the field experts. Thus, the methodology should be customized for the shipyard to ensure maximum efficiency.

Materials Selection for Failure Prevention

Materials selection is closely related to the objectives of failure analysis and prevention. This article briefly reviews the general aspects of materials selection as a concern in both proactive failure prevention during design and as a possible root cause of failed parts. Coverage is more conceptual, with general discussions on the following topics: design and failure prevention, materials selection in design, materials selection for failure prevention, and materials selection and failure analysis. Because materials selection is just one part of the design process, the overall concept of design is discussed. The article also describes the role of the materials engineer in the design and materials selection process. It provides information on the significance of materials selection in both the prevention and analysis of failures.

Analysis of Failures of Pumps to be Used in Agricultural Sprayers of Various Types

The most common failures of piston diaphragm pumps are described and analyzed. Based on the data obtained, a generalized table has been prepared, including the name of the malfunctions, the reason for their occurrence and remedies. In the future, these data can serve as the main one when organizing the repair station of piston diaphragm pumps.

Improving the efficiency of relay protection at a mining and processing plant

The paper presents the results of constructing effective relay protection in the power supply system of a mining and processing plant (MPP). A brief description of the MPP is given, the power supply and substitution circuits used to calculate the short-circuit currents are given. A statistical analysis of failures in the electric network of the MPP has been carried out, which makes it possible to draw conclusions about the nature of failures ranges. Analysis of the registered faults shows that a significant part of them are line-to-earth faults, which in most cases turn into multiphase short circuits, which are interrupted by overcurrent protection. In order to improve the efficiency and reliability of the relay protection, the power supply scheme of the MPP was refined and analyzed. The calculation of the short-circuit currents was made, which made it possible to calculate the settings of the relay protection and give recommendations on the place of its installation and adjustment in order to ensure the normal operation of electricity consumers. To reduce the number of failures to the cable insert on the line leaving the administrative and household complex (AHC), and to increase the reliability of power supply to consumers, it is advisable to divide the capacities of the existing 10 kV line into two parallel ones by laying a second line. It is recommended to install a current cut-off on the line outgoing to the AHC, the feasibility of the installation of which was shown by calculations. This will reduce the chance of failures to the cable gland. Data on the setting currents of overcurrent protection and current cut-off are given on the selectivity card.

Stochastic models for ensuring parametric reliability of the construction machines

The solution of technical problems to ensure the working capacity is largely determined by the effectiveness of theoretical and applied developments in an area of estimation and prediction of their reliability indicators. An effective approach to the analysis of failures and the development of operability and parametric reliability models provides an opportunity to obtain more adequate models of reliability of hydraulic drives of machines, as they more fully take into account the specifics of the structure and functioning of the hydro drive elements of construction machines, their relationships and features of the formation of parameters failures. And this will allow to get more real and accurate results of estimation of reliability indicators of hydraulic drives of both construction and other hydraulic machines. They do not exhaust all possible variants of models that can take place when analyzing the reliability of hydraulic drives of machines, but at the same time they to a certain extent extend and refine the set of known reliability models. Specific in terms of formation of parametrical failures are such consistently connected in terms of the layout of hydraulic elements, as working sections of hydraulic distributors and hydraulic cylinders, which are part of the subsystems of GPs and form the so-called functional areas (FA). Reaching the FA limit is a compatible result of the combined random process of evolution of the volumetric efficiency JCUA these elements, and the technical condition of the FA is estimated to be generalized by the JCUA, which equals the product of the JCUA of consecutively connected elements: . In this case, the probability of maintaining the capacity of the FA will be: . The processing of diagnostic information and the study of the reliability of GPs in real conditions of their operation showed that the distribution of JCUD hydraulic elements with a sufficient degree of consistency can be described under several theoretical laws. It is considered when the JCUA sections of the hydraulic distributor and hydraulic cylinder are distributed by gamma distribution and exponential distribution. The use of the general methodological approach to the analysis of failures and the construction of models of operability and parametric reliability provides an opportunity to obtain more adequate models of reliability of hydraulic drives of machines, as they more fully take into account the specifics of the structure and functioning of the hydraulic drive elements, They don't exhaust all possible models that can take place when analyzing the reliability of hydraulic drives, but at the same time they are to some extent expanding and refining the range of already known models of reliability.