ABSTRACT
OBJECTIVE@#The patient monitors were used to explore the alarm fatigue in a cardiac care unit and to investigate the awareness and reaction of nurse to alarms.@*METHODS@#A semi-structured survey was taken to acquire nurses' feeling and knowledge about monitoring alarm. Three full-time researchers were scheduled to track the alarms with annotations, and analyze the alarm data of 12 patient monitors using central monitoring system.@*RESULTS@#A total of 72 310 unique alarms occurred in the 67-day study period. About 75.7% of them were physiological alarms and less than 10% of medium-low alarms were false positives. The average alarm rate was 128 alarms/patient-day.@*CONCLUSIONS@#There remains alarm fatigue in CCU, the alarm accuracy has improved than the past by applying new technologies. In some cases, clinicians will pay more attention to trend alarm and combination alarm.
Subject(s)
Humans , Arrhythmias, Cardiac , Clinical Alarms , Electrocardiography , Monitoring, Physiologic , Surveys and QuestionnairesABSTRACT
The performance of the CA-CFAR processor is affected by certain clutter variations. Although problems caused by sudden clutter changes have already been corrected in multiple CFAR proposals, the influence of slow statistical variations in the background signal is often ignored. To solve this problem, the authors estimated the optimal CA-CFAR threshold multiplier values necessary to adapt the processor to the clutter slow statistical changes. The application of the results guarantees that the operational false alarm probability of the processor will only exhibit a small deviation from the value conceived in the design. The clutter was simulated with a Pareto distribution with a known fluctuating shape parameter according to recent papers that strongly suggest the use of this distribution. The current research completes an important step in the design of an adaptive detector that operates without a priori knowledge of the shape parameter In addition, the authors provide mathematical expressions that allow the direct application of the results in the design of radar detectors.
El desempeño del procesador CA-CFAR es afectado por ciertas variaciones del clutter Mientras que los problemas causados por los cambios repentinos del clutter han sido corregidos por múltiples propuestas CFAR, se ignora frecuentemente la influencia de las variaciones estadísticas lentas de la señal de fondo. Para resolver este problema, los autores estimaron los valores óptimos del multiplicador del umbral CA-CFAR necesarios para adaptar el procesador a los cambios estadísticos lentos, garantizando por tanto que la probabilidad de falsa alarma del detector exhibirá solamente una ligera desviación con respecto al valor concebido en el diseño. El clutter fue simulado con una distribución Pareto con parámetro de forma conocido de antemano, de acuerdo a publicaciones recientes que sugieren fuertemente el uso de esta distribución. La investigación actual completa un paso importante en el diseño de detectores adaptativos que operan sin el conocimiento a priori del parámetro de forma. Adicionalmente, los autores proporcionan expresiones matemáticas que permiten la aplicación directa de los resultados en el diseño de detectores de radar.
O desempenho do processador CA-CFAR está afectada por certas variações da desordem. Enquanto os problemas causados por mudanças bruscas de lixo foram corrigidos para múltiplas propostas CFAR, é muitas vezes ignorado a influ-ência de variações estatísticas lento do sinal de fundo. Para resolver esse problema, os autores estimaram os valores ideais do limiar necessário multiplicador CA-CFAR para adaptar o processador para retardar alterações estatísticas, garantizando, portanto, a probabilidade de falsa detector de alarme apenas um ligeiro desvio da valor concebido no design. A desordem foi simulado com um parâmetro de distribuição de Pareto conhecidos na maneira previamente, de acordo com publicações recentes que sugerem fortemente a utilização desta distribuição. A investigação actual complete um passo importante na concepção de detectores adaptativas que operam sem conhecimento a priori do parâmetro de forma. Addi-cionalmente, os autores fornecem expressões matemáticas que permitem a aplicação direta dos resultados do projeto de detectores de radar.
ABSTRACT
Background: Aim of the study was to compare the speed of response, false-alarm rate, and subject preference of different response methods i.e. raising a hand, using response switch, and oral response mode for measuring pure-tone thresholds. Methods: Forty five participants (female-21 and 24 male) were included in the study with sensorineural hearing loss of various degree. Response method order was randomly assigned to 3 different sessions. Air-conduction thresholds were measured thrice for each participant in octave intervals between 250 Hz and 8000 Hz. The 2nd and 3rd session were performed for different response method on a different day but within 2 weeks of the 1st session. Results: Difference in the time was noted when compared with the extent of time required to complete the test for each response method. On an average, using the pushbutton method took 3.02 to 3.42 minutes less than using hand-raise or verbal response methods. There was also a significant participant preference for using the response button. No significant difference between response method for threshold level and number of false positives (P = 0.15) was found. Conclusion: This study supports the use of the response button when measuring auditory thresholds for sensorineural hearing loss.