Alarm Response Time Research Articles

Simulation and application of a detecting rapid response model for the leakage of flammable liquid storage tank

The oil terminal is a facility for oil transportation and storage. Flammable gas detectors (FGDs) are able to reliably detect the release of hazardous liquid chemical materials in the tank area, but it cannot accurately obtain the key detecting parameters at the alarm time. This work analyzes the three stages of storage tank leakages under a static storage state. Firstly, the key elements affecting the leakage and detection are analyzed after considering the relative–position relationship of the horizontal distance from the jet point on ground level to the leak hole (Xjet), which denoted by the FGD’s coordinate and the wind direction. Secondly, the denser–than–air dispersion is calculated by the SLAB model based on the liquid–pool radius determined by the bisection method (r), the liquid pool area corresponding to the alarm–response time can be ascertained, and then the detecting rapid response model (DRRM) for the leakage of the flammable liquid storage tank is established. Finally, the model was verified by a small–scale tank leakage and some crucial parameters such as Xjet, r and area of liquid pool, mass accumulating during the continuous leakage period (M) and total leaking time that corresponds to the time to alarm (Ttotal) are obtained. These findings provide scientific data for providing early warning and emergency response.

Diffusion process simulation and ventilation strategy for small-hole natural gas leakage in utility tunnels

The utility tunnel provides enough spaces, dry environment, better monitoring and maintenance for municipal pipelines. When gas pipelines are incorporated into the utility tunnel, the flammability and explosion property of the natural gas would threaten its safe operation. At present, the safety prevention technology and the safety design specifications for gas pipeline in utility tunnels are not mature. To investigate the gas diffusion characteristics in the utility tunnel, and to propose an emergency accident ventilation strategy, in this paper, the mechanism of small-hole gas leakage diffusion under natural and mechanical ventilation is studied, and the influential factors are simulated and analyzed in detail using the Fluent software. The results indicate that under the natural ventilation, the gas spreads to the whole compartment at the leakage time of 300 s, while under the normal ventilation scheme, the leaked natural gas fills the downstream half of the compartment at the time of 120 s. When the leak size and pressure increase, the alarm response time shortens, the concentration of test point increases, and the danger zone expands. To prevent alarm failure and gas gathering for the near-outlet leakage, it is recommended that the last detector and the air outlet should be placed as close as possible to the fireproof wall. In addition, when a leak occurs, increasing the air change rate can greatly reduce the overall gas concentration. When the leak size is no more than 5 mm, and the pipeline pressure is lower than 0.4 MPa, the minimum accident ventilation scheme could guarantee the safe operation of the utility tunnel. When the pipeline pressure grows to 0.8 MPa, the effective air change rates of the emergency accident ventilation are 15 times/h, 18 times/h, and 24 times/h, respectively for the leak sizes of 4 mm, 5 mm, and 6 mm. Moreover, for the pipeline pressure of 1.6 MPa, the effective air change rates are 21 times/h, 30 times/h, and 36 times/h, respectively for the leak sizes of 4 mm, 5 mm, and 6 mm.

The influence of nursing activities score on clinical alarms service.

to estimate the magnitude of the Nursing Activities Score effect on multiparametric monitor alarm response and staff response time. an observational, cross-sectional study outlined as an open cohort, performed in an Adult General Intensive Care Unit. The time taken for alarms triggered by the multi-parameter monitors was timed and characterized as attended or not. the study obtained a total of 254 alarms triggered from the multiparameter monitors of 63 patients. The mean number of alarms triggered was 4.5 alarms per period/observation and 1.5 alarms/hour. The study showed that the Nursing Activities Score is associated with an additional probability of 4% (p < 0.05) of an alarm being met, for each additional point in the scale, and reduction in team response time. it has been verified that Nursing Activities Score has a direct relationship with the attendance and with the response time to the alarms triggered.

An infant monitoring system with the support of accurate real-time indoor positioning

ABSTRACT This article presents an indoor infant monitoring system based on Android system which employs a low-cost Bluetooth Low Energy (BLE) pseudolite to accurately locate the infants in the activity indoors and timely remind the parents. It can achieve a positioning accuracy better than 2 m and effectively reduce the risk of injury to infants and young children. The performance of the proposed system, using false negative rate, false alarm rate, and alarm response time as indicators, is compared with that of the system using Quuppa as a positioning source. The experiment results show that both BLE pseudolite and Quuppa as a positioning source can basically meet the positioning accuracy for the infant monitoring system, but the BLE-pseudolite-based system provides a more cost-efficient solution.

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

Alarm fatigue is an ongoing problem that has received increasing attention as a patient safety concern. Recently the Joint Commission issued a Sentinel Event Alert that named frequent exposure to nonactionable alarms “the most common contributing factor to alarm related sentinel events.” This quality problem affects all institutions, but pediatrics in particular. Not only are high number of children placed on monitors, but their differing vital signs by age and smaller body size can create a high volume of alarms needing assessment. QI initiatives tailored to this population are needed to address this workforce and safety concern. The primary aim …

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

A Novel ECG Ward Telemetry System with Smartphone Based Alarm Escalation

Background: Need for a permanent control person and alarm fatigue are limitations of telemetry surveillance systems ending at the central surveillance monitor. This study evaluated an escalation system expanding the alarm sequence by smartphones. Methods: Telemetry system with 26 monitoring units and WLAN based alarm escalation system to three smartphones (Care Event, Philips) was evaluated during 128 days regarding major arrhythmia alarm (MAA) frequency, escalation of alarms within the system and response times. ECG triggering the MAA, patient name and position are shown on the smartphone display. MAA are forwarded initially to smartphone one. Forwarding of MAA to two further smartphones is actively triggered or occurs automatically after 20 sec without response by smartphone one. Results: During the analysis period 11576 MAA were forwarded, ranging from 15 to 238 alarms/day. The number of MAA was minimal at 11 pm and maximal at 8 am (ratio 1:1.8). In 69% only smartphone 1 was involved, in 31% occurred an escalation to smartphone 2 and in 13% to smartphone 3. The median MAA response time at the smartphone was 8 sec at daytime and 9 sec at nighttime. 14 min of running time could be saved on average every day by direct visit of the patient triggering an alarm and omission of the central monitoring system. Conclusions: A smartphone based alarm escalation system redundancies the permanent presence of nursing staff at the central surveillance system. The multilevel surveillance system with smartphone based escalation allows low alarm response times and warrants excellent surveillance quality

Independence of old and new item processing in recognition judgment

This study investigated the independence of old and new item processing in recognition judgment. Conventional recognition studies have focused on the “memory” aspects of recognition judgment, while new item processing has been treated as a “residual response” of old item processing. However, prior studies on confidence ratings and the brain research suggest the possibility that old and new items are independently processed. This study conducted recognition judgment tests with the number of learned items as independent variables, and response times for four answer categories (hit, miss, correct rejection, and false alarm) as dependent variables. Hit response times were consistently shorter than misses for all old items, while correct rejection (CR) and false alarm (FA) response times approached equivalence (CR = FA) for new items as the number of old (memorized) items increased. These results suggest that recognition judgment changes according to the number of old (memorized) items. We discuss the idea that new item and old item processing in recognition judgment occur independently.

Field test of optical and electrical fire detectors in simulated fire scenes in a cable tunnel

This paper presents the testing results of three types of fire detectors: electrical heat sensing cable, optical fiber Raman temperature sensing detector, and optical fiber Bragg grating (FBG) temperature sensing detector, in two simulated fire scenes in a cable tunnel. In the small-scale fire with limited thermal radiation and no flame, the fire alarm only comes from the heat sensors which directly contact with the heat source. In the large-scale fire with about 5 °C/min temperature rising speed within a 3-m span, the fire alarm response time of the fiber Raman sensor and FBG sensors was about 30 seconds. The test results can be further used for formulating regulation for early fire detection in cable tunnels.

Use of Pagers With an Alarm Escalation System to Reduce Cardiac Monitor Alarm Signals

Alarm fatigue desensitizes nurses to alarm signals and presents potential for patient harm. This project describes an innovative method of communicating cardiac monitor alarms to pagers using an alarm escalation algorithm. This innovation was tested on 2 surgical progressive care units over a 6-month period. There was a significant decrease in mean frequency and duration of high-priority monitor alarms and improvement in nurses' perception of alarm response time, using this method of alarm communication.

A fast anomaly detection system using probabilistic artificial immune algorithm capable of learning new attacks

In this paper, we propose anomaly based intrusion detection algorithms in computer networks using artificial immune systems, capable of learning new attacks. Unique characteristics and observations specific to computer networks are considered in developing faster algorithms while achieving high performance. Although these characteristics play a key role in the proposed algorithms, we believe they have been neglected in the previous related works. We evaluate the proposed algorithms on a number of well-known intrusion detection datasets, as well as two new real datasets extracted from the data networks for intrusion detection. We analyze the detection performance and learning capabilities of the proposed algorithms, in addition to performance criteria such as false alarm rate, detection rate, and response time. The experimental results demonstrate that the proposed algorithms exhibit fast response time, low false alarm rate, and high detection rate. They can also learn new attack patterns, and identify them the next time they are introduced to the network.

Assessment of the key factors for ergonomic design of management information systems in coal mines

Using an analytic-synthetic model of ergonomic research of management information systems (MIS) in coal mines, we identified 13 elements which were used to define eight factors that impact operator’s performance. These eight factors were further reduced to five key factors after the application of expert assessment. We have defined 23 indicators for these key factors, ranked by means of the analytic hierarchy process method. This paper includes a detailed ergonomic analysis of the five key operator quality indicators, namely, shape and size of the control panel, functionality of the video display terminal, keyboard functionality, alarm response time and expansion of the MIS with environmental parameters. Based on the condition prior to and after the proposed changes, we were able to use this approach to determine and discuss the operator quality index.

Pulse oximetry desaturation alarms on a general postoperative adult unit: A prospective observational study of nurse response time

BackgroundContinuous pulse oximetry monitoring is recommended to improve safety during postoperative opioid use, however concerns with monitoring on general care units remain, given potential system barriers to alarm transmission, recognition, and nursing response. MethodsThis prospective, observational study evaluated unit and hospital-level factors affecting nurses’ response to monitor desaturation alarms in postoperative patients on a general postoperative unit. With exemption and waiver of consent granted from the Institutional Review Board, monitoring data were downloaded from bedside monitors of postoperative patients. Alarm notification data and response times were recorded from the continuous capture of institutional surveillance data. Paging notifications were coded as clinically relevant (i.e., true oxygen desaturation with SpO2<89 for >15s) or irrelevant (i.e., artifact, inappropriate alarm threshold, or failure to delay page). Linear mixed models, and correlation coefficients were used to examine the relationships between unit staffing, shift, paging burden and response time. Means and [95% confidence intervals] are presented. Results1616 monitoring hours in 103 patients yielded 342 desaturation events (duration 23.6s [20.99, 26.1]) and 710 notification pages, 36% of which were for clinically relevant desaturation. Nursing response time was 52.1s [46.4, 57.7], which was longer at night (63.8 [51.2, 76.35]; p=0.035), but not related to unit staffing. Missed alarm events (i.e., no notification page transmitted) occurred for 26% of the clinically relevant events, and were associated with higher paging burden (p=0.04), lower SpO2 values (81.8 [80.5, 83.0] vs. 83.2 [82.6, 83.8]; p=0.026), and higher odds of intervention (OR 3.5 [1.38, 8.9]). 65% of patients with desaturation events received interventions which correlated with the number of pages (rho=0.422; p<0.01) and events (rho=0.57; p<0.01), desaturation duration (rho=0.505; p<0.01), and SpO2 (rho=−0.324; p<0.01). ConclusionsOne-third of pulse oximetry alarm notifications were for clinically relevant oxygen desaturation, facilitating timely nursing response and intervention for most patients. Unit staffing and false alarm frequency were not associated with response time, suggesting a high level of attention on this unit. The nature and degree of missed alarm events suggests patient safety concerns posed by hospital-level transmission systems warranting further strategies to ensure monitoring safety.

How much do we Remember after CPR Training? � Experience from a Sub-Saharan Teaching Hospital

How much do we Remember after CPR Training? – Experience from a Sub-Saharan Teaching Hospital In-hospital survival rate after cardiac arrest is low and depends on the quality of cardiopulmonary resuscitation (CPR), the alarm response time, and the time to defibrillation. All medical practitioners should be able to perform CPR with competence. Level of competence has been linked to the knowledge and skill of CPR, which is a factor of continuous training. The 2010 guidelines on the initiation of BLS during a cardiac arrest consists of recognizing the cardiac arrest, calling for help, initiating chest compressions and ventilations.

Experiment study of alarm response time in a blood leakage sensor during an extracorporeal ultrafiltration method

Experiment study of alarm response time in a blood leakage sensor during an extracorporeal ultrafiltration method

Communication strategies and timeliness of response to life critical telemetry alarms.

A centralized electrocardiogram telemetry monitoring system (TMS) facilitates early identification of critical arrhythmias and acute medical decompensation. Timely intervention can only be performed if abnormalities are communicated rapidly to the direct caregiver. The study objectives were to measure effectiveness of bi-directional voice communication badges versus one-way alphanumeric pagers for telemetry alarm response and communication loop closure. A sequential observational pilot study of nursing response to TMS alarms compared communication technologies on four nursing units in a 1,061 bed tertiary care hospital with 264 TMS channels of telemetry over a 2-year period. Subsequently, the communication technologies were compared in a randomized fashion on a 68-bed progressive cardiac care unit. Caregivers were blinded to the protocol. All alarm responses were recorded during two periods using either pagers or voice communication devices. Alarm response time and closure of the communication loop were analyzed in a blinded fashion. The direct communication functionality of the badge significantly shortened the time to first contact, time to completion, and rate of closure of the communication loop in both the pilot and study phases. Median time to first contact with the communication badge was 0.5 min, compared to 1.6 min with pager communication (p < 0.0003). Communication loop closure was achieved in 100% of clinical alarms using the badge versus 19% with the pager (p < 0.0001). Communication badge technology reduced alarm time to first contact and completion as well as facilitated communication loop closures. Immediate two-way communication significantly impacted practice, alarm management, and resulted in faster bedside care.

Verbal collision avoidance messages during simulated driving: perceived urgency, alerting effectiveness and annoyance

Matching the perceived urgency of an alert with the relative hazard level of the situation is critical for effective alarm response. Two experiments describe the impact of acoustic and semantic parameters on ratings of perceived urgency, annoyance and alerting effectiveness and on alarm response speed. Within a simulated driving context, participants rated and responded to collision avoidance system (CAS) messages spoken by a female or male voice (experiments 1 and 2, respectively). Results indicated greater perceived urgency and faster alarm response times as intensity increased from −2 dB signal to noise (S/N) ratio to +10 dB S/N, although annoyance ratings increased as well. CAS semantic content interacted with alarm intensity, indicating that at lower intensity levels participants paid more attention to the semantic content. Results indicate that both acoustic and semantic parameters independently and interactively impact CAS alert perceptions in divided attention conditions and this work can inform auditory alarm design for effective hazard matching. Matching the perceived urgency of an alert with the relative hazard level of the situation is critical for effective alarm response. Here, both acoustic and semantic parameters independently and interactively impacted CAS alert perceptions in divided attention conditions. This work can inform auditory alarm design for effective hazard matching. Statement of Relevance: Results indicate that both acoustic parameters and semantic content can be used to design collision warnings with a range of urgency levels. Further, these results indicate that verbal warnings tailored to a specific hazard situation may improve hazard-matching capabilities without substantial trade-offs in perceived annoyance.

Alarms Pose Challenges to Healthcare Facilities

Medical device alarms provide essential warnings to alert caregivers of changes in a patient's condition. When alarms work well, the environment of care is enhanced. When alarms don't work well, they pull caregivers away from other duties and other patients—or worse, train caregivers to ignore the alarm sounds altogether. Alarms that are ignored can and have resulted in patient deaths.Today, by and large, medical device alarms don't work well. Too many devices sound too many alarms and are wrong too often. Why is that, and what can be done about it?As the number of devices in patient care areas have multiplied, so have the noises they make. Experts say that most alarms generated by medical devices don't require any action at the bedside—from 85% up to 99%. These “nonactionable” alarms add to the noise, confusion, and stress in an already-stressful environment.High false alarm rates intertwine with other alarm problems including:Some facilities have had astounding success at improving alarm performance. Dartmouth Hitchcock Medical Center in Lebanon, NH, undertook an alarms improvement initiative on a post-surgical orthopedic floor. It succeeded in reducing the average number of alarms per patient per day to only four. William Beaumont Hospital in Detroit, MI, reduced its mean alarm response time on a telemetry floor from 9.5 minutes to 39 seconds by implementing a new communication system. Johns Hopkins Hospital in Baltimore, MD, revamped alarm procedures in a medical step-down unit and achieved a 43% decrease in critical alarms.Experts agree that resolving problems with medical device alarms requires interdisciplinary effort and buy-in from a wide array of players at the highest levels. They also say that technology—the very devices that sound these alarms—can be used to alleviate the problems they have created.What can be done? Suggestions include:These topics and more will be considered at the fall Medical Device Alarms Summit, set for October 4–5, 2011 in Herndon, VA. Visit www.aami.org/alarms for details.

Sleep Deprivation Impairs Object-Selective Attention: A View from the Ventral Visual Cortex

BackgroundMost prior studies on selective attention in the setting of total sleep deprivation (SD) have focused on behavior or activation within fronto-parietal cognitive control areas. Here, we evaluated the effects of SD on the top-down biasing of activation of ventral visual cortex and on functional connectivity between cognitive control and other brain regions.Methodology/Principal FindingsTwenty-three healthy young adult volunteers underwent fMRI after a normal night of sleep (RW) and after sleep deprivation in a counterbalanced manner while performing a selective attention task. During this task, pictures of houses or faces were randomly interleaved among scrambled images. Across different blocks, volunteers responded to house but not face pictures, face but not house pictures, or passively viewed pictures without responding. The appearance of task-relevant pictures was unpredictable in this paradigm. SD resulted in less accurate detection of target pictures without affecting the mean false alarm rate or response time. In addition to a reduction of fronto-parietal activation, attending to houses strongly modulated parahippocampal place area (PPA) activation during RW, but this attention-driven biasing of PPA activation was abolished following SD. Additionally, SD resulted in a significant decrement in functional connectivity between the PPA and two cognitive control areas, the left intraparietal sulcus and the left inferior frontal lobe.Conclusions/SignificanceSD impairs selective attention as evidenced by reduced selectivity in PPA activation. Further, reduction in fronto-parietal and ventral visual task-related activation suggests that it also affects sustained attention. Reductions in functional connectivity may be an important additional imaging parameter to consider in characterizing the effects of sleep deprivation on cognition.

Screening Enhancements: Why don't they Enhance Performance?

Data obtained utilizing image enhancements in a carry-on bag x-ray screening task were analyzed to determine whether and how image enhancements affect performance. To complement earlier studies of experienced screeners, sixty-six novices to the screening task used six different overall enhancements. Results indicated a significant worsening of performance, A', between Original images and Negative images, but no performance differences for the other enhancements, similar to effects found for experienced screeners. There was little overall performance learning taking place on the task. More detailed analysis by splitting response times into search and non-search components revealed little more enhancement effect, but a reduction in False Alarm response time as the task progressed. It appears that the locus of lack of positive effects of enhancements is not just a function of familiarity with the current screen view.