Fault Tolerance Structures in Wireless Sensor Networks (WSNs): Survey, Classification, and Future Directions.

The Industrial Revolution 4.0 (IR 4.0) has drastically impacted how the world operates. The Internet of Things (IoT), encompassed significantly by the Wireless Sensor Networks (WSNs), is an important subsection component of the IR 4.0. WSNs are a good demonstration of an ambient intelligence vision, in which the environment becomes intelligent and aware of its surroundings. WSN has unique features which create its own distinct network attributes and is deployed widely for critical real-time applications that require stringent prerequisites when dealing with faults to ensure the avoidance and tolerance management of catastrophic outcomes. Thus, the respective underlying Fault Tolerance (FT) structure is a critical requirement that needs to be considered when designing any algorithm in WSNs. Moreover, with the exponential evolution of IoT systems, substantial enhancements of current FT mechanisms will ensure that the system constantly provides high network reliability and integrity. Fault tolerance structures contain three fundamental stages: error detection, error diagnosis, and error recovery. The emergence of analytics and the depth of harnessing it has led to the development of new fault-tolerant structures and strategies based on artificial intelligence and cloud-based. This survey provides an elaborate classification and analysis of fault tolerance structures and their essential components and categorizes errors from several perspectives. Subsequently, an extensive analysis of existing fault tolerance techniques based on eight constraints is presented. Many prior studies have provided classifications for fault tolerance systems. However, this research has enhanced these reviews by proposing an extensively enhanced categorization that depends on the new and additional metrics which include the number of sensor nodes engaged, the overall fault-tolerant approach performance, and the placement of the principal algorithm responsible for eliminating network errors. A new taxonomy of comparison that also extensively reviews previous surveys and state-of-the-art scientific articles based on different factors is discussed and provides the basis for the proposed open issues.

Medication incident recovery and prevention utilising an Australian community pharmacy incident reporting system: the QUMwatch study.

PURPOSE: To identify factors in community pharmacy that facilitate error recovery from medication incidents (MIs) and explore medication safety prevention strategies from the pharmacist perspective. METHODS: Thirty community pharmacies in Sydney, Australia, participated in a 30-month prospective incident reporting program of MIs classified in the Advanced Incident Management System (AIMS) and the analysis triangulated with case studies. The main outcome measures were the relative frequencies and patterns in MI detection, minimisation, restorative actions and prevention recommendations of community pharmacists. RESULTS: Participants reported 1013 incidents with 831 recovered near misses and 165 purported patient harm. MIs were mainly initiated at the prescribing (68.2%) and dispensing (22.6%) stages, and most were resolved at the pharmacy (76.9%). Detection was efficient within the first 24 h in 54.6% of MIs, but 26.1% required one month or longer; 37.2% occurred after the patient consumed the medicine. The combination of specific actions/attributes (85.5%), appropriate interventions (81.6%) and effective communication (77.7%) minimised MIs. An array of remedial actions were conducted by participants including notification, referral, advice, modification of medication regimen, risk management and documentation corrections. Recommended prevention strategies involved espousal of medication safety culture (97.8%), better application of policies/procedures (84.6%) and improvements in healthcare providers' education (79.9%). CONCLUSION: Incident reporting provided insights on the human and organisational factors involved in the recovery of MIs in community pharmacy. Optimising existing safeguards and redesigning certain structures and processes may enhance the resilience of the medication use system in primary care.

FaTEMa: A Framework for Multi-Layer Fault Tolerance in IoT Systems.

Fault tolerance in IoT systems is challenging to overcome due to its complexity, dynamicity, and heterogeneity. IoT systems are typically designed and constructed in layers. Every layer has its requirements and fault tolerance strategies. However, errors in one layer can propagate and cause effects on others. Thus, it is impractical to consider a centralized fault tolerance approach for an entire system. Consequently, it is vital to consider multiple layers in order to enable collaboration and information exchange when addressing fault tolerance. The purpose of this study is to propose a multi-layer fault tolerance approach, granting interconnection among IoT system layers, allowing information exchange and collaboration in order to attain the property of dependability. Therefore, we define an event-driven framework called FaTEMa (Fault Tolerance Event Manager) that creates a dedicated fault-related communication channel in order to propagate events across the levels of the system. The implemented framework assist with error detection and continued service. Additionally, it offers extension points to support heterogeneous communication protocols and evolve new capabilities. Our empirical results show that introducing FaTEMa provided improvements to the error detection and error resolution time, consequently improving system availability. In addition, the use of Fatema provided a reliability improvement and a reduction in the number of failures produced.

Two-Dimensional Sampling-Recovery Algorithm of a Realization of Gaussian Processes on the Input and Output of Linear Systems.

Based on the application of the conditional mean rule, a sampling-recovery algorithm is studied for a Gaussian two-dimensional process. The components of such a process are the input and output processes of an arbitrary linear system, which are characterized by their statistical relationships. Realizations are sampled in both processes, and the number and location of samples in the general case are arbitrary for each component. As a result, general expressions are found that determine the optimal structure of the recovery devices, as well as evaluate the quality of recovery of each component of the two-dimensional process. The main feature of the obtained algorithm is that the realizations of both components or one of them is recovered based on two sets of samples related to the input and output processes. This means that the recovery involves not only its own samples of the restored realization, but also the samples of the realization of another component, statistically related to the first one. This type of general algorithm is characterized by a significantly improved recovery quality, as evidenced by the results of six non-trivial examples with different versions of the algorithms. The research method used and the proposed general algorithm for the reconstruction of multidimensional Gaussian processes have not been discussed in the literature.

"Attempting to protect self and patient": A grounded theory study of error recovery by intensive care nurses.

AIM: The aim of this study was to explore the process of error recovery (ER) by nurses in intensive care unit (ICU). DESIGN: This qualitative study was conducted in 2018-2020 using the grounded theory methodology. METHODS: Participants were 20 staff nurses, head nurses and nursing managers recruited from the ICUs. Sampling was started purposively and continued theoretically. Data were collected using semi-structured interviews and were analysed using the approach proposed by Corbin and Strauss. RESULTS: The findings indicated that nurses' primary concern was for the patient and their own personal/professional identity. Five strategies were found including evaluating situation, identifying error, analysing error and situation, determining the agent for error correction, and reducing error effects. Contextual factors were also highlighted as being important in the error recovery. "Attempting to protect self and patient" was the core category of the study. Nurses' concern about protecting patient life and their own personal/professional identity make them use unprofessional approaches for ER.

A survey on multimedia-based cross-layer optimization in visual sensor networks.

Visual sensor networks (VSNs) comprised of battery-operated electronic devices endowed with low-resolution cameras have expanded the applicability of a series of monitoring applications. Those types of sensors are interconnected by ad hoc error-prone wireless links, imposing stringent restrictions on available bandwidth, end-to-end delay and packet error rates. In such context, multimedia coding is required for data compression and error-resilience, also ensuring energy preservation over the path(s) toward the sink and improving the end-to-end perceptual quality of the received media. Cross-layer optimization may enhance the expected efficiency of VSNs applications, disrupting the conventional information flow of the protocol layers. When the inner characteristics of the multimedia coding techniques are exploited by cross-layer protocols and architectures, higher efficiency may be obtained in visual sensor networks. This paper surveys recent research on multimedia-based cross-layer optimization, presenting the proposed strategies and mechanisms for transmission rate adjustment, congestion control, multipath selection, energy preservation and error recovery. We note that many multimedia-based cross-layer optimization solutions have been proposed in recent years, each one bringing a wealth of contributions to visual sensor networks.

"It's a Big Part of Being Good Surgeons": Surgical Trainees' Perceptions of Error Recovery in the Operating Room.

BACKGROUND: The burden of surgical error is high - errors threaten patient safety, lead to increased economic costs to society, and contribute to physician and resident burnout. To date, the majority of work has focused on strategies for reducing the incidence of surgical error, however, total error eradication remains unrealistic. Errors are, to some extent, unavoidable. Adequate preparation for practice should include optimal ways to manage and recover from errors; yet, these skills are rarely taught or assessed. OBJECTIVES: This study aims to explore residents' perceptions and experiences of surgical error recovery. More specifically, we documented participant definitions of error recovery, and explored factors that were perceived to influence error recovery experiences and training in the operating room. METHOD: Guided by a qualitative descriptive approach, we conducted semi-structured interviews with residents and fellows in surgical specialties in Canada and the United States. Purposive and snowball sampling were used to recruit residents and fellows in postgraduate year 1 to 5. Interviews were transcribed, analyzed and inductively coded. RESULTS: A total of 15 residents and fellows participated. When exploring the importance of error recovery for the trainees, competency and safety emerged as main themes, with error recovery being considered an indicator of overall surgical competency. Data concerning factors perceived to influence error recovery training were grouped under 4 major themes: (1) supervision (supervisor-related factors such as attending behaviors and reactions to errors), (2) self (factors such as self-assessed competency), (3) surgical context (factors related to the specific surgery or patient), and (4) situation safeness. Situational safeness was identified as a transversal theme describing factors to be considered when balancing between patient safety and the learning benefits of error recovery training. CONCLUSION: Error recovery was considered to be an important skill for safe surgical practice and was considered an important educational target for learners during surgical training. Trainees' opportunities to learn to recover from technical errors in the OR are perceived to be influenced by several factors, leading to variable experiences and inconsistent opportunities to practice error recovery skills. Focusing on factors related to "supervision," "self," "surgery," and "situational safeness" may be an initial framework on which to build initial educational interventions to support the development of error recovery skills to better support safe surgical practice.

Surgical Errors Happen, but Are Learners Trained to Recover from Them? A Survey of North American Surgical Residents and Fellows.

BACKGROUND: Surgical training necessitates graded supervision and supported independence in order to reach competence. In developing surgical skills, trainees can, and will, make mistakes. A key skill required for independent practice is the ability to recover from an error or unexpected complication. Error recovery includes recognizing and managing a technical error in order to ensure patient safety and may be underrepresented in current educational approaches. OBJECTIVE: The purpose of this study is to explore residents' experiences and perceptions of error recovery training in surgical procedures. METHOD: An online survey was sent to surgical program directors in the United States and Canada using the Accreditation Council for Graduate Medical Education and the Royal College of Physicians and Surgeons of Canada distribution lists. Participating programs distributed the survey to their residents and fellows. The survey was composed of Likert-scale items, yes/no questions as well as open-ended questions focused on perceptions, experiences, and factors that influence to error recovery training in the operating room. RESULTS: A total of 206 surveys were completed. Overall, 99% (n = 203) agreed or strongly agreed that error recovery is an important competency for future practice. This was reflected in free-text response: "Errors can be minimized but they are inevitable, so certainly believe a surgical curriculum that addresses error recovery is of paramount importance." While 83% (n = 170) feel confident recovering from minor errors, only 34% (n = 68) feel confident that they could recover from major errors that are likely to have serious consequences on patient safety. Overall, residents do not consider that they have adequate training in error recovery, with only 37% (n = 72) felt they were adequately trained to recover from major errors. It was also mentioned "The quality of learning regarding error recovery depends entirely on the attending." CONCLUSIONS: Opportunities to learn to recover from technical errors in the operating room are valued by surgical trainees, but they perceive their training to be both inadequate and variable. This contributes to a lack of confidence in error recovery skills throughout their surgical training. There is a need to explore how best to integrate error recovery into more formal surgical curricula in order to better support learners and, ultimately, contribute to increased surgical safety.

Who Is Responsible for a Dialogue Breakdown? An Error Recovery Strategy That Promotes Cooperative Intentions From Humans by Mutual Attribution of Responsibility in Human-Robot Dialogues.

We propose a strategy with which conversational android robots can handle dialogue breakdowns. For smooth human-robot conversations, we must not only improve a robot's dialogue capability but also elicit cooperative intentions from users for avoiding and recovering from dialogue breakdowns. A cooperative intention can be encouraged if users recognize their own responsibility for breakdowns. If the robot always blames users, however, they will quickly become less cooperative and lose their motivation to continue a discussion. This paper hypothesizes that for smooth dialogues, the robot and the users must share the responsibility based on psychological reciprocity. In other words, the robot should alternately attribute the responsibility to itself and to the users. We proposed a dialogue strategy for recovering from dialogue breakdowns based on the hypothesis and experimentally verified it with an android. The experimental result shows that the proposed method made the participants aware of their share of the responsibility of the dialogue breakdowns without reducing their motivation, even though the number of dialogue breakdowns was not statistically reduced compared with a control condition. This suggests that the proposed method effectively elicited cooperative intentions from users during dialogues.

Exploring Senior Residents' Intraoperative Error Management Strategies: A Potential Measure of Performance Improvement.

OBJECTIVE: The study aim was to determine whether residents' error management strategies changed across 2 simulated laparoscopic ventral hernia (LVH) repair procedures after receiving feedback on their initial performance. We hypothesize that error detection and recovery strategies would improve during the second procedure without hands-on practice. DESIGN: Retrospective review of participant procedural performances of simulated laparoscopic ventral herniorrhaphy. A total of 3 investigators reviewed procedure videos to identify surgical errors. Errors were deconstructed. Error management events were noted, including error identification and recovery. SETTING: Residents performed the simulated LVH procedures during a course on advanced laparoscopy. Participants had 30 minutes to complete a LVH procedure. After verbal and simulator feedback, residents returned 24 hours later to perform a different, more difficult simulated LVH repair. PARTICIPANTS: Senior (N = 7; postgraduate year 4-5) residents in attendance at the course participated in this study. RESULTS: In the first LVH procedure, residents committed 121 errors (M = 17.14, standard deviation = 4.38). Although the number of errors increased to 146 (M = 20.86, standard deviation = 6.15) during the second procedure, residents progressed further in the second procedure. There was no significant difference in the number of errors committed for both procedures, but errors shifted to the late stage of the second procedure. Residents changed the error types that they attempted to recover (χ25=24.96, p<0.001). For the second procedure, recovery attempts increased for action and procedure errors, but decreased for strategy errors. Residents also recovered the most errors in the late stage of the second procedure (p < 0.001). CONCLUSION: Residents' error management strategies changed between procedures following verbal feedback on their initial performance and feedback from the simulator. Errors and recovery attempts shifted to later steps during the second procedure. This may reflect residents' error management success in the earlier stages, which allowed further progression in the second simulation. Incorporating error recognition and management opportunities into surgical training could help track residents' learning curve and provide detailed, structured feedback on technical and decision-making skills.

How do community pharmacies recover from e-prescription errors?

BACKGROUND: The use of e-prescribing is increasing annually, with over 788 million e-prescriptions received in US pharmacies in 2012. Approximately 9% of e-prescriptions have medication errors. OBJECTIVE: To describe the process used by community pharmacy staff to detect, explain, and correct e-prescription errors. METHODS: The error recovery conceptual framework was employed for data collection and analysis. 13 pharmacists and 14 technicians from five community pharmacies in Wisconsin participated in the study. A combination of data collection methods were utilized, including direct observations, interviews, and focus groups. The transcription and content analysis of recordings were guided by the three-step error recovery model. RESULTS: Most of the e-prescription errors were detected during the entering of information into the pharmacy system. These errors were detected by both pharmacists and technicians using a variety of strategies which included: (1) performing double checks of e-prescription information; (2) printing the e-prescription to paper and confirming the information on the computer screen with information from the paper printout; and (3) using colored pens to highlight important information. Strategies used for explaining errors included: (1) careful review of patient's medication history; (2) pharmacist consultation with patients; (3) consultation with another pharmacy team member; and (4) use of online resources. In order to correct e-prescription errors, participants made educated guesses of the prescriber's intent or contacted the prescriber via telephone or fax. When e-prescription errors were encountered in the community pharmacies, the primary goal of participants was to get the order right for patients by verifying the prescriber's intent. CONCLUSION: Pharmacists and technicians play an important role in preventing e-prescription errors through the detection of errors and the verification of prescribers' intent. Future studies are needed to examine factors that facilitate or hinder recovery from e-prescription errors.

Post-error action control is neurobehaviorally modulated under conditions of constant speeded response.

Post-error slowing (PES) is an error recovery strategy that contributes to action control, and occurs after errors in order to prevent future behavioral flaws. Error recovery often malfunctions in clinical populations, but the relationship between behavioral traits and recovery from error is unclear in healthy populations. The present study investigated the relationship between impulsivity and error recovery by simulating a speeded response situation using a Go/No-go paradigm that forced the participants to constantly make accelerated responses prior to stimuli disappearance (stimulus duration: 250 ms). Neural correlates of post-error processing were examined using event-related potentials (ERPs). Impulsivity traits were measured with self-report questionnaires (BIS-11, BIS/BAS). Behavioral results demonstrated that the commission error for No-go trials was 15%, but PES did not take place immediately. Delayed PES was negatively correlated with error rates and impulsivity traits, showing that response slowing was associated with reduced error rates and changed with impulsivity. Response-locked error ERPs were clearly observed for the error trials. Contrary to previous studies, error ERPs were not significantly related to PES. Stimulus-locked N2 was negatively correlated with PES and positively correlated with impulsivity traits at the second post-error Go trial: larger N2 activity was associated with greater PES and less impulsivity. In summary, under constant speeded conditions, error monitoring was dissociated from post-error action control, and PES did not occur quickly. Furthermore, PES and its neural correlate (N2) were modulated by impulsivity traits. These findings suggest that there may be clinical and practical efficacy of maintaining cognitive control of actions during error recovery under common daily environments that frequently evoke impulsive behaviors.