scholarly journals Assessment of Health Monitoring Trustworthiness of Avionics Systems

Author(s):  
Vladimir Ulansky ◽  
Igor Machalin ◽  
Iryna Terentyeva

The article provides a methodology for assessing the trustworthiness of health monitoring the dismounted avionics systems with automated test equipment (ATE). The indicators include the probabilities of false-positive, false-negative, true-positive, and true-negative. For the first time, we introduced into consideration the instability of the source of stimulus signal (SSS), the random and systematic component of the measuring channel error, and the reliability characteristics of the systems themselves. We consider a specific case of an exponential distribution of permanent failures and intermittent faults and derive formulas for calculating the trustworthiness indicators. Numerical calculations illustrate how the probabilities of correct and incorrect decisions depend on accuracy parameters. We show that the probabilities of false-positive and false-negative increase much faster than the probabilities of true-positive and true-negative decrease when the standard deviation of stimulus signal increases. For a Very High-Frequency Omni-Directional Range (VOR) receiver, we demonstrate that even with a zero random error generated by the source of the stimulus signal, the probabilities of false-positive and false-negative are different from zero.

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P42-P43
Author(s):  
Peter Zbaren ◽  
Heinz Loosli ◽  
Edouard Stauffer

Objective Assess the difficulties of preoperative and intraoperative tumor typing of parotid neoplasms. Know the advantages and pitfalls of fine-needle-aspiration cytology (FNAC) and frozen section (FS) analysis in primary parotid neoplasms. Methods In 113 parotid neoplasms (70 malignancies and 43 benign tumors) preoperative FNAC as well as intraoperative FS analysis were performed. FNAC and FS findings were analyzed and compared with the final histopathologic diagnosis. Results The FNAC smear was non-diagnostic in 6 tumors. In 2 FS specimens, it was not possible to determine the tumor dignity. FNAC findings and FS findings were both available in 105 neoplasMS The FNAC findings were true positive for malignancy in 54, true negative in 36, false positive in 4, and false negative in 11 tumors. The accuracy, sensitivity, and specificity were 86%, 83%, and 90% respectively. The FS findings were true positive in 60, true negative in 38, false positive in 2, and false negative in 5 tumors. The accuracy, sensitivity, and specificity were 93%, 92% and 95% respectively. The exact histologic tumor typing by FNAC was correct, false or not mentioned in 58%, 20% and 22% true positive or true negative evaluated tumors, and by FS in 83%, 5% and 12% true positive or true negative evaluated tumors. Conclusions The current analysis showed a superiority of FS compared with FNAC regarding the diagnosis of malignancy and especially of tumor typing. FNAC alone is not prone in many cases to determine the surgical management of primary parotid carcinomas.


2019 ◽  
Vol 5 (1) ◽  
pp. 49-56
Author(s):  
Gede Surya Mahendra ◽  
Kadek Yota Ernanda Aryanto

Persaingan industri perbankan saat ini semakin meningkat, baik dalam hal penyediaan inovasi produk serta peningkatan kualitas transaksi dan pelayanan. Untuk mengatasi masalah tersebut diciptakan sebuah terminal yang dikenal dengan ATM. Namun fungsionalitas dan efektifitas ATM tersebut belum memenuhi kebutuhan nasabah dikarenakan pengambilan keputusan penentuan lokasi ATM belum menggunakan SPK sehingga banyak kriteria yang terlupakan dalam penentuan lokasi ATM terbaik. Metode AHP yang merupakan sebuah hierarki fungsional dengan input utamanya adalah persepsi manusia sedangkan metode SAW dengan konsep dasar mencari penjumlahan terbobot dari rating kinerja pada setiap alternatif pada semua atribut. AHP digunakan untuk memberikan pembobotan pada masing-masing kriteria dan SAW untuk melakukan perangkingan dari masing-masing alternatif. Terdapat 7 kriteria dengan 11 sub kriteria pada pembobotan dan 76 data alternatif. Pengujian dilakukan dengan membandingkan hasil delpoyment ATM dengan hasil perhitungan sistem. Dari 76 data alternatif yang diujikan, terdapat 38 lokasi deployment ATM. Dari hasil pengujian yang ditampilkan dalam confusion matrix, pada kriteria yang tidak teruji signifikansi didapatkan 33 data True Positive, 38 True Negative, 5 False Negative dan 5 False Positive dengan akurasi sebesar 86,84%, dan pada kriteria yang teruji signifikansi didapatkan 35 data True Positive, 35 True Negative, 3 False Negative dan 3 False Positive memiliki akurasi 92,11%.


2003 ◽  
Vol 50 (2) ◽  
pp. 25-29 ◽  
Author(s):  
Vera Artiko ◽  
Branka Davidovic ◽  
Nadezda Nikolic ◽  
Milorad Petrovic ◽  
Nebojsa Petrovic ◽  
...  

The aim of the study is detection of the abdominal infective foci using 99mTc-ciprofloxacin, radiopharmaceutical supposed to distuinguish inflammation from infection. Twenty one patient was investigated. There were 11 true positive findings, 7 true negative, two were false negative, while 1 was false positive. Sensitivity of the method was 79% and specificity 91%. According to our results, scintigraphy with infecton is a useful method for detection and assessment of exact localization of deep seated bacterial infections, which might be useful for (differential) diagnosis, surgical treatment in due time as well as monitoring of the treatment of conservative therapy.


2020 ◽  
Vol 4 (1) ◽  
pp. 01-05
Author(s):  
Ahmed Siddiqi

Background: In our practice 24 hours urine collection for free cortisol (24Hr UFC) and overnight dexamethasone suppression test (ONDST) are initial investigations to screen patients for hyper-cortisolism. I audited our practice to find our clinicians’ and patients’ choice of first screening investigation for hyper-cortisolism. Method & material: Electronic and paper medical records of patients who underwent 24Hr UFC and/or ONDST at our hospital over previous consecutive twenty four months were examined. 62 such patients were identified but 12 patients were excluded from analysis. We tried to contact 30 patients over consecutive 48 hours over the phone who underwent both 24Hr UFC and ONDST. We managed to contact 18 patients and asked them two study questions. Data & results: 33 (66%) patients were female and 17 (33%) were male. 20 (40%) had 24Hr UFC alone and 30 (60%) patients had both. In total 80 such investigations completed 30 being ONDST and 50 24hr UFC. 53 (66%) of the investigations were requested by Endocrinologists, 21 (26%) by Hospital General Physicians and 6 (8%) by General practitioners (GP). For UFC 10 (20%) were true positive, 31 (62%) were false positive, 6 (12%) were true negative and 0% false negative. 3 (6%) 24Hr UFC samples were not collected properly and were not processed for results. Out of the total false positives (31 patients), 6 (19.3%) cases were of alcohol excess, 4 (13%) of dépression, 3 (9.7%) of inhaled steroids and 1 (3.2%) of sleep apnea. For the ONDST 7 (23.3%) true positive, 4 (13.3%) false positive 19 (63.4%) true negative and 0% false negative. All 18 patients contacted over the phone answered both questions. 16 preferred ONDST over 24Hr UFC, 1 patient had no preference and 1 patient preferred 24Hr UFC over ONDST. Conclusion: Patients overwhelmingly preferred ONDST as first screening test in contrast to physician’s choice of 24Hr UFC.


2021 ◽  
pp. 219256822110114
Author(s):  
Hiroki Ushirozako ◽  
Go Yoshida ◽  
Shiro Imagama ◽  
Kazuyoshi Kobayashi ◽  
Kei Ando ◽  
...  

Study Design: Multicenter prospective study. Objectives: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. Methods: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. Results: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. Conclusions: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs.


2014 ◽  
Vol 63 (3) ◽  
pp. 12-20
Author(s):  
Irina Yuryevna Bayeva

Оbjective: Establish the diagnostic value of ultrasound examination in prenatal diagnosis of macrosomia among the women without diabetes and to determine its effect on birth outcomes. Мethods: This is a retrospective cohort study done at the Orenburg municipal perinatal center and maternity hospital № 2 since 2006 to 2012. In this study 3760 pregnant women were analyzed who delivered term, singleton, live born infants. The estimated fetal sonographic weight by the formula Hadlock’s was obtained within the last week prior to delivery. The study population was divided into 4 groups (true positive, true negative, false positive, false negative) according to the estimated fetal weight (EFW) and regarding the birth weight (BW). Receiver-operating characteristics (ROC) curves were generated to compare the prediction of macrosomia when using different observation methods. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated. The mean value of two groups were compared using two sample t test and χ² test for comparison of proportions. Results: In order to assess the accuracy of the ultrasound in prenatal diagnosis of macrosomia the study population was divided into 4 groups according to the estimated fetal weight (EFW) and regarding the birth weight (BW): true positive (n-147), false negative (n-229 ), false positive (n-353), true negative (n-3031). Results of the study showed no statistically significant differences between the birth weight and estimated fetal weifht by ultrasound alone only in the macrosomia group with true-positive results (p = 0.9). In applying the ROC (Receiver Operating Characteristic curve) performance analysis sensitivity and spesificity in the prediction of the macrosomia by ultrasound revealed the average predictive power of the method. Area under the curve (Area under ROC curve, AUC) made 0.7295 (95 % CI: 0.695-0.781), which corresponds to a predetermined average accuracy. The accuracy of macrosomia prediction by ultrasound methods was 90 %, sensitivity - 35 %, specificity - 93,5 %. Сesarian sections were performed for 40 % of the pregnant women, where fetal macrosomia was truly ruled in (true positive) and 16% of the women who delivered normal weight infants (true negative). Overestimation of fetal weight (false positive) has led to the 30 % rate of cesarean sections. Underestimation of fetal weight (false negative) has decreased to the 24% rate of cesarean sections but in this case perinatal complications have increased. Conclusion: Results showed an average accuracy in predicting macrosomia by the formula Hadlock’s. The results of the study have proved that the inappropriate prediction macrosomia of fetal weight has influence on the mode of delivery. Overestimation of fetal weight has led the proportion of cesarian sections. Underestimation of fetal macrosomia has increased perinatal complications.


2017 ◽  
Vol 15 (2) ◽  
pp. 14-20
Author(s):  
Tamanna Binta Hasan ◽  
Shoibul Karim ◽  
Mohammad Ismail Hossain ◽  
Md Quamrul Hassan ◽  
Sayeda Nasreen ◽  
...  

Background: The study aimed to evaluate the efficacy of AgNORs on FNAC smears of breast lesion.Methods: FNAC were done in 200 female patients of breast lump consecutively, Papanicolau and AgNOR staining was done in all 200 cases of FNA smears.Among them biopsy and histopathology were done in 99 cases. The findings of FNAC and AgNOR analysis were compared to histopathological findings.Results: By FNAC, 53 (26.5%) cases were non-neoplastic benign, 89(44.5%) cases were benign neoplasm, 07 (3.5%) cases were atypical ductal hyperplasia and 51(25.5%) cases were malignant (Duct cell carcinoma).Among them histopathology was done in 99 cases.Out of 40 FNAC malignant cases, histopathologically all were proved malignant. Out of 42 benign cases, 1 was found malignant. 4 atypical ductal hyperplasia were also diagnosed as malignant histopathologically. True positive cases are 40, True negative cases are 36, false positive are nil (0), and false negative is 01. The sensitivity is 97.56%, specificity is 100%, positive predictive value is 100%, Negative predictive value is 97.3%, and accuracy is 98.7%. AgNOR impression were analysed in 99 histopathologically confirmed cases. The results showed benign impression in 50 cases and malignant impression in 48 cases. 01 histopathologically malignant case was impressed as benign by AgNOR and 01 as suspicious which may be included as malignant by AgNOR impression. 2 histopathologically benign cases showed higher proliferative activities and counted as malignant. True positive cases are 46, True negative 49, false positive is 02 and false negative is 01. The sensitivity is 97.87%, Specificity 96.07%, PPV 95.83%, NPV 98%, Overall accuracy is 96.93%.Conclusion: The efficacy of FNAC and AgNOR analysis in the diagnosis of breast lesion was found more or less similar and mild over lapping.Chatt Maa Shi Hosp Med Coll J; Vol.15 (2); Jul 2016; Page 14-20


Author(s):  
Jelena Saponjski ◽  
Djuro Macut ◽  
Nebojša Petrovic ◽  
Sanja Ognjanovic ◽  
Bojana Popovic ◽  
...  

IntroductionThe aim was to assess the diagnostic value of 99mTc-Tektrotyd scintigraphy (TCT) and positron emission tomography/computed tomography using F-18 fluorodeoxyglucose (18F-FDG PET/CT) in the detection and follow-up of neuroendocrine tumors (NETs), and their predictive value for disease progression.Material and methodsIn this retrospective cohort, TCT and 18F-FDG PET/CT were performed in 90 patients (37 men, 53 women, mean age 52.7 ±15.1), with NET. Correlation of Ki67 and tumor grade versus Krenning score and SUVmax was assessed, Kaplan-Meier analysis was used for progression-free survival (PFS), and Cox regression analysis was performed to identify the association between progression-related factors and PFS.ResultsOut of 90, true positive TCT was detected in 56 (62.2%) patients, true negative in 19 (21.1%), false positive in 4 (4.4%), false negative in 11 (12.2%), while 18F-FDG PET/CT was true positive in 69 (76.7%) patients, true negative in 10 (11.1%), false positive in 5 (5.5%), false negative in 6 (6.7%). Mean 18F-FDG PET/CT SUVmax was 6.8 ±6.2. Diagnostic sensitivity of TCT was 83.6%, specificity 82.6%, accuracy 83.3% vs. 18F-FDG PET/CT sensitivity was 92.0%, specificity 66.7%, accuracy 87.8%. A significant correlation between Ki67 and SUVmax was found in positive 18F-FDG PET/CT findings, unlike the correlation between Ki67 and Krenning score. Median PFS was 25 months (95% CI: 18.2–31.8), in 18F-FDG PET/CT positive patients 23 months (95% CI: 16.3–29.7) and 18F-FDG PET/CT negative 26 months (p = 0.279). Progression-free survival predictors were SUVmax and Krenning score.ConclusionsIn our study, TCT and 18F-FDG PET/CT have high diagnostic accuracy in detection of NET. Higher Krenning score on TCT and SUVmax in positive 18F-FDG PET/CT findings are predictors of disease progression. 99mTc-Tektrotyd scintigraphy and 18F-FDG PET/CT can be useful complementary tools in management of patients with NETs and in predicting patients’ outcome.


2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Dino Rumoro ◽  
Shital Shah ◽  
Marilyn M. Hallock ◽  
Gillian S. Gibbs ◽  
Gordon Trenholme ◽  
...  

ObjectiveTo develop and validate a Zika virus disease syndrome definitionwithin the GUARDIAN (Geographic Utilization of ArtificialIntelligence in Real-Time for Disease Identification and AlertNotification) surveillance system.IntroductionIn 2016, the World Health Organization declared Zika virus aglobal public health emergency. Zika infection during pregnancycan cause microcephaly and other fetal brain defects. To facilitateclinicians’ ability to detect Zika, various syndrome definitions havebeen developed.MethodsTo create and validate a detailed syndrome definition for Zika,we utilized the literature based methodology developed anddocumented by GUARDIAN researchers.1,2The syndrome definitionutilized clinical signs and symptoms that were documented inhistorical Zika cases.A testing sample of 1000 randomly selected emergency departmentcases (i.e., true negative cases) and 200 synthetically generated cases(i.e., true positive cases) was created. These 1,200 sample cases wereevaluated by the GUARDIAN surveillance system to determine theprobability of matching the Zika syndrome definition. A probabilityof≥90% was utilized to designate positive Zika cases.We identified the main signs and symptoms contributing to theidentification of Zika cases and conducted statistical performancemetrics. Clinical review of the false positive and false negative casesalong with a sample of true positive and true negative cases wasconducted by a board certified emergency physician.ResultsThe Zika syndrome definition was developed with eleven articles(six used for developing the syndrome definition, and five used fortesting the definition). The sample size for these articles was between1 and 72 positive Zika cases, with a total of 139 cases across the11 articles. The article with the most number of Zika cases wasbased on pregnant women with rash. The publication timeframefor the articles was from 1962 to 2016. Some of the main signsand symptoms from the historical cases that contribute to the Zikasyndrome definition are presented in Table 1. The initial results forthe sample testing data showed accuracy, sensitivity, and specificitywere 94.7%, 93%, and 95% respectively. There were a total of14 false negative and 50 false positive cases.ConclusionsThe initial Zika syndrome definition utilized by the GUARDIANsurveillance system contains similar signs and symptoms to thecurrent CDC case definition, but also includes additional signs andsymptoms such as pruritus/itching, malaise/fatigue/generalizedweakness, headache, retro-orbital pain, myalgia/muscle pain, andlymphadenopathy In addition, the GUARDIAN system provides therelative importance of identified signs and symptoms and allows forproactive surveillance of emergency department patients in real-time.Though we did not include epidemiologic risk factors, such as travel toan infected region or contact with an infected person in the syndromedefinition, GUARDIAN has above 90% sensitivity and specificity.Thus, inclusion of epidemiologic risk factors would further enhancethe early detection of Zika, when used with the appropriate high riskpopulation.Table 1. Main signs and symptoms of Zika syndrome definition*Signs and symptoms included in the Centers for Disease Control andPrevention (CDC)’s Zika clinical case definition


2020 ◽  
pp. 096914132095320
Author(s):  
Heinrich A Backmann ◽  
Marthe Larsen ◽  
Anders S Danielsen ◽  
Solveig Hofvind

Objectives To analyse how reader performance varied by time during the day in a population-based breast cancer screening programme. Methods A total of 2,937,312 readings from 148 radiologists and 1,468,656 women were included in this study from Norway. Number and percentages of mammographic readings, positive scores, true and false positive readings, true and false negative readings, sensitivity and specificity were presented for categories of time of day and for each day of the week. Multilevel mixed effect logistic regression models with restricted cubic splines were fitted to the data, and used to predict the odds ratio of the different performance measures. Results The following distribution was found for the performance measures during the study period: true positive: 12,463 (0.4%); false positive: 128,419 (4.4%); true negative: 2,794,636 (95.1%); and false negative: 1794 (0.06%). The percentage of positive readings (true positive and false positive) was highest before lunch and in the early afternoon (4.9%): false positive was highest in both periods (4.5%) and true positive was highest in the early afternoon (0.5%). The percentage of true negative was highest in the evening (95.6%), and of false negative was highest at lunchtime (0.07%). This corresponds to a gradually decreasing predicted sensitivity throughout the day. The opposite was observed for specificity. Conclusions Screen-reading early versus late during the day resulted in higher sensitivity, although at the cost of specificity. Despite small differences in the performance measures during the day, the results may be important in the discussion of optimal management of screening programmes.


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