Abstract 125: Automated External Defibrillator Shock Advisement Performance Among Multiple Human Electrocardiographic Rhythms and Devices

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Xavier J Szigethy ◽  
Connor J Willson ◽  
David D Salcido ◽  
Dylan A Defilippi ◽  
James J Menegazzi
Keyword(s):  
Sensitivity And Specificity ◽  
Real World ◽  
Peak Frequency ◽  
Lead Wire ◽  
Digital To Analog Converter ◽  
Automated External Defibrillators ◽  
Signal Characteristics ◽  
Rhythm Analysis ◽  
High Degree ◽  
Median Slope

Background: Automated external defibrillators (AEDs) perform rhythm analysis in order to facilitate defibrillation. The effectiveness of AEDs is dependent on the accuracy of their rhythm classification, which includes differentiation of shockable rhythms from non-shockable rhythms Independent (i.e. non-industry) evaluation of the performance of AEDs against real-world ECG could lead to improvements in their performance. Objective: To evaluate the sensitivity and specificity characteristics of commercial AEDs with respect to quantitative properties of the ECG waveform in several rhythm presentations using real world ECG data. Methods: We conducted a prospective simulation study evaluating three commercially available AEDs from Defibtech, Phillips, and Zoll on the determination of ECG rhythm shockability. Performance was evaluated for 181 human ECG recordings (101 ventricular fibrillation-VF, 55 PEA, and 25 asystole) ranging widely in signal characteristics, obtained from the Pittsburgh site of the Resuscitation Outcomes Consortium. We used a commercially available digital-to-analog converter (National Instruments USB-6001) to inject the recordings into each AED through a direct lead-wire interface, recording shock advisement decisions in a best-out-of-three approach for each device/rhythm pairing. We calculated the sensitivity and specificity for discriminating VF and non-VF rhythms for each device and overall. VF signal characteristics were calculated, including peak frequency, median amplitude, and peak amplitude, and the VF quantitative waveform measures AMSA and median slope. Results: The 101 VF trials featured signals with mean peak frequency 10.02 Hz(IQR 4.80 Hz), mean AMSA 9.13(IQR 7.29), mean median slope 6.72 (IQR 3.66). The sensitivities were: Defibtech 99.0%; Philips 97.0%; Zoll 98.0%. The specificities were: Defibtech 98.7%; Philips 96.2%; Zoll 97.4%. Defibtech recorded 5 discordant advisements and Philips and Zoll recorded eight each. The overall sensitivity was 98.0%, and the specificity 97.4%. Conclusion: Evaluated against a wide variety of real-world signal presentations, commercial AEDs demonstrated a high degree of sensitivity and specificity for shockable ECG rhythms.

scholarly journals Internal Leakage Predicition of Hydraulic Spool valves Based on Acoustic Emission Technology

2021 ◽  
Vol 2113 (1) ◽  
pp. 012016
Author(s):  
Fei Song ◽  
Likun Peng ◽  
Jia Chen ◽  
Benmeng Wang
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
Peak Frequency ◽  
Leakage Rate ◽  
High Frequency Band ◽  
Signal Characteristics ◽  
Spool Valves ◽  
The Relationship ◽  
Ae Signals ◽  
Acoustic Emission Technology

Abstract In order to realize the nondestructive testing (NDT) of the internal leakage fault of hydraulic spool valves, the internal leakage rate must be predicted by AE (acoustic emission) technology. An AE experimental platform of internal leakage of hydraulic spool valves is built to study the characteristics of AE signals of internal leakage and the relationship between AE signals and leakage rates. The research results show the AE signals present a wideband characteristic. The main frequencies are concentrated in 30~50 kHz and the peak frequency is around 40 kHz. When the leakage rate is large, there are significant signal characteristics appearing in the high frequency band of 75~100 kHz. The exponent of the root mean square(RMS) of AE signals is positively correlated with the exponent of the leakage rate only if the leakage rate is greater than 2~3 mL/min. This find could be used to predict the internal leakage rate of hydraulic spool valves.

Real-World Contexts

2015 ◽  
Author(s):  
Diana C. Mutz
Keyword(s):  
Real World ◽  
Production Quality ◽  
Political Conflict ◽  
The Political ◽  
Causal Inferences ◽  
Camera Perspective ◽  
Degree Of Control ◽  
Experimental Treatments ◽  
High Degree ◽  
The Impact

This chapter looks at the characteristics of the experimental treatments that are used to manipulate incivility, as well as the kinds of people used in the experiments. Because of the high degree of control over the political content of the broadcasts, the participants involved in the conflicts, and the way in which the cameras covered the dispute, it is possible to draw strong causal inferences about the impact that incivility and camera perspective have on viewers' experiences of political conflict. Although the professional production quality meant that none of the subjects voiced suspicions about the programs themselves, it is still plausible that other, unidentified differences between the real world and this exchange may have altered the outcomes.

scholarly journals Slow-pull compared to suction technique for EUS-guided sampling of pancreatic solid lesions: a meta-analysis of randomized controlled trials

2020 ◽  
Vol 08 (05) ◽  
pp. E636-E643 ◽  
Author(s):  
Gabriele Capurso ◽  
Livia Archibugi ◽  
Maria Chiara Petrone ◽  
Paolo Giorgio Arcidiacono
Keyword(s):  
Randomized Controlled Trials ◽  
Sensitivity And Specificity ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Blood Contamination ◽  
Randomized Controlled ◽  
Bibliographic Search ◽  
Accuracy Difference ◽  
Solid Lesions ◽  
High Degree

Abstract Background and study aims Current ESGE guidelines suggest employing the suction (SU) technique for endoscopic ultrasound (EUS)-guided sampling of pancreatic solid lesions. Nonetheless, recent randomized controlled trials (RCT) have reported that the slow-pull (SP) technique has similar diagnostic accuracy with possibly less blood contamination. However, these results are heterogeneous and limited to small cohorts. The aim of this meta-analysis was to compare adequacy, accuracy, sensitivity and specificity of the SU and SP techniques for EUS-guided sampling of solid pancreatic lesions. Methods A computerized bibliographic search was restricted to RCTs. Pooled effects were calculated using a random-effects model and expressed in terms of pooled sensitivity and specificity and OR (95 % CI) for adequacy and accuracy. Results Overall, seven RCTs were included, for a total of 475 patients (163 lesions sampled with SU, 164 with SP and 148 by both). The adequacy was similar (OR = 0.98) without heterogeneity (I2 = 0 %), but a high degree of blood contamination was more common with SU than SP (pooled rate 27.6 % vs 19.7 %). A non-significant superiority of SP in terms of pooled accuracy (OR = 0.82; 95 % CI 0.36–1.85) was recorded, with moderate heterogeneity (I2 = 52.4 %). The SP technique showed a slightly higher pooled sensitivity compared to SU (88.7 % vs 83.4 %), while specificity was similar (97.2 % SP vs 96.9 % SU), with considerable heterogeneity. Conclusion The current meta-analysis reveals non-superiority of SU over SP, while SP results in reduced blood contamination. If the 5 % accuracy difference favouring SP is true, with alfa error = 0.05 and beta = 0.20, a RCT of 982 patients per arm is needed to confirm significance.

P6541Wrist band photoplethysmography pulse morphology-based autocorrelation analysis enables atrial fibrillation detection without the need of pulse detection

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E.-S Valiaho ◽  
P Kuoppa ◽  
J A Lipponen ◽  
T J Martikainen ◽  
H Jantti ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Sensitivity And Specificity ◽  
Detection Accuracy ◽  
Pulse Detection ◽  
Golden Standard ◽  
Study Population ◽  
Pulse Waves ◽  
Promising Solution ◽  
Rhythm Analysis

Abstract Background Atrial fibrillation (AF) is often asymptomatic and intermittent making its detection a major clinical challenge. A photoplethysmography (PPG) wrist band with algorithm-based detection of AF provides a promising solution for screening of AF. However, the shapes of individual pulse waveforms vary in AF decreasing pulse detection accuracy. Purpose The purpose of this study was to evaluate the utility of PPG wrist band pulse morphology in detection of AF. Methods A 5-minute PPG was recorded with a PPG wrist band from patients with AF or sinus rhythm. A simultaneously registered ECG served as the golden standard for the rhythm analysis and was interpreted by two cardiologists. In addition to using the inter-beat-interval (IBI) based AFEvidence algorithm in comparison, we extracted a feature straight from the PPG signal, without the need of pulse detection. This feature was calculated as the average of absolute autocorrelation values over different lags. The feature describes the regularity of the PPG signal and is decreased if the shape and periodicity of pulse waves vary. The performance of this PPG morphology-based method in detection of AF was evaluated and compared to the AFEvidence. Results The study population consisted of 213 patients (106 AF, 107 sinus rhythm). The sensitivity and specificity of PPG morphology-based autocorrelation AF detection method were 98.1% and 94.4%. For AFEvidence, the sensitivity and specificity were 96.2% and 98.1%, respectively (p=0.146 between the methods, McNemar test). PPG samples of AF and sinus rhythm Conclusions The PPG morphology-based autocorrelation method detects AF with good accuracy without the need of pulse detection. The method seems promising in detection of AF and should be studied further. Acknowledgement/Funding None

A Pressure-Based Technique for the Detection of Acute and Chronic Venous Obstruction

1988 ◽  
Vol 3 (4) ◽  
pp. 207-216 ◽  
Author(s):  
Seshadri Raju
Keyword(s):  
Sensitivity And Specificity ◽  
Clinical Settings ◽  
Venous Obstruction ◽  
Routine Procedure ◽  
Chronic Venous Obstruction ◽  
Vascular Laboratory ◽  
High Degree

A simple pressure-based technique for the detection of venous obstruction is described. The severity of obstruction can be graded utilizing the technique outlined. The method has a high degree of sensitivity and specificity and is easily employed as a routine procedure in the vascular laboratory. The technique provides invaluable haemodynamic information in venous obstruction in a variety of clinical settings as illustrated.

Design Factors in the Characterization and Identification of Otitis Media and Certain Related Conditions

1979 ◽  
Vol 88 (5_suppl) ◽  
pp. 13-28 ◽  
Author(s):  
Charles D. Bluestone ◽  
Erdem I. Cantekin
Keyword(s):  
Otitis Media ◽  
Sensitivity And Specificity ◽  
Middle Ear ◽  
Otitis Media With Effusion ◽  
Interobserver Reliability ◽  
Diagnostic Value ◽  
The State ◽  
Related Condition ◽  
Muscle Reflex ◽  
High Degree

Because the state of our knowledge of many aspects of the etiology and pathogenesis of otitis media and related conditions is deficient, precise characterizations of certain aspects of the disease may not be possible. In fact although most studies in the past have failed to define the specific disease state to be investigated, the specific type of otitis media or related condition to be studied must be as clearly defined as is clinically possible in order for any prospective study of otitis media to be valid. The state of the art of the presently available methods to identify these conditions also poses certain limitations; at present, there are five methods to identify otitis media and related conditions: history, audiometry, tympanocentesis/myringotomy, otoscopy (including otomicroscopy), and impedance measurements (tympanometry and assessment of the middle ear muscle reflex), and they all have inherent elements of unreliability. Historical information obtained from parents or the child is usually unreliable; a positive history may aid in defining the problem, but a negative otologic history does not rule out the presence of otitis media since it is frequently asymptomatic. Audiometry has been shown to be a poor method of identifying otitis media. Although tympanocentesis or myringotomy is the most reliable way to identify otitis media with effusion (OME), it is invasive, frequently requires an anesthetic, and is usually a confounding variable. In an effort to establish the diagnostic value of otoscopy, tympanometry, and the presence or absence of the middle ear muscle reflex in identifying OME, the diagnostic findings by these three methods were compared with the findings at myringotomy in 239 children (425 ears). The study showed that even experienced clinicians had some difficulty in identifying those ears with effusion (sensitivity) and had even greater difficulty in making a diagnosis of those ears without an effusion (specificity). Tympanometry employing patterns that have been validated with myringotomy findings was found to be as accurate as expert otoscopy. On the other hand, the presence or absence of the middle ear muscle reflex was found not to be a useful method of diagnosing the presence of OME due to its extremely low specificity. An algorithm derived from the combination of the three methods had highest sensitivity and specificity. From this study, the following recommendations regarding the identification of OME are suggested. All investigators who employ otoscopy should be validated by comparing their assessments either with the findings at myringotomy or with a previously validated otoscopist. Interobserver reliability of all otoscopists should be established prior to and maintained during clinical studies of OME. Only electroacoustic impedance instruments in which the tympanometric patterns have been validated should be used. Tympanometry employing validated tympanometric patterns has a high degree of sensitivity and specificity, and as such can provide an objective method to identify OME. Middle ear muscle reflex measurements should not be used as the only method to identify OME. An algorithm that includes otoscopy, tympanometry, and, to a lesser degree, the middle ear muscle reflex measurement should be employed for research purposes when a noninvasive method to identify OME is required.

Nasal Endoscopy and the Definition and Diagnosis of Chronic Rhinosinusitis

2002 ◽  
Vol 126 (6) ◽  
pp. 623-627 ◽  
Author(s):  
James A. Stankiewicz ◽  
James M. Chow
Keyword(s):  
Computed Tomography ◽  
Chronic Rhinosinusitis ◽  
Sensitivity And Specificity ◽  
Nasal Polyps ◽  
Ct Scanning ◽  
Current Treatment ◽  
Current Definition ◽  
Treatment Paradigm ◽  
Definition Of ◽  
High Degree

OBJECTIVES: Although endoscopy has been shown by a few authors to be a valuable tool for the diagnosis of chronic rhinosinusitis, its true role in the evaluation of the patient with chronic rhinosinusitis has not been elucidated. The current definition of chronic rhinosinusitis is a symptom-based definition, and objective testing such as endoscopy or computed tomography (CT) is not included. However, the current treatment paradigm for chronic rhinosinusitis is dependent on the definition for diagnosis. Patients are treated with 4 weeks of antibiotics and decongestant/antihistamines/steroids based on the definition. This study aims to evaluate in a prospective fashion the place of endoscopy in the diagnosis of chronic rhinosinusitis. STUDY DESIGN: A group of 78 patients meeting the definition of chronic rhinosinusitis were subjected to same-day endoscopy and CT scanning. RESULTS: Seventeen (22%) of 78 patients had positive endoscopic and CT results. There were 20 (26%) of 78 patients with negative endoscopic and positive CT results. Six (8%) patients had positive endoscopic and negative CT results, and 35 (45%) had negative endoscopic and negative CT results. Overall, 37 (47%) patients had positive CT results, and 41 (53%) patients had negative CT results. Endoscopy showing the presence of purulence, nasal polyps, or watery congested mucosa correlated well with CT results. Negative endoscopy correlated with CT results in 65% of patients. CONCLUSION: The use of endoscopy to corroborate the diagnosis in nonpolypoid or nonpurulent rhinosinusitis in previously unoperated patients is questioned. Patients who meet the subjective definition of chronic rhinosinusitis should have a high degree of sensitivity and specificity with endoscopy or CT. The fact this is not the case questions the accuracy of the definition and the treatment paradigm. SIGNIFICANCE: According to this study, positive endoscopic results correlated well with CT, and negative endoscopic results correlated in 71% of patients with negative CT results.

Echolocation and foraging behaviour in the Hawaiian hoary bat, Lasiurus cinereus semotus

1984 ◽  
Vol 62 (11) ◽  
pp. 2113-2120 ◽  
Author(s):  
Jacqueline J. Belwood ◽  
James H. Fullard
Keyword(s):  
Prey Availability ◽  
Weather Conditions ◽  
Peak Frequency ◽  
Social Signals ◽  
Lasiurus Cinereus ◽  
Social Signal ◽  
Term Basis ◽  
Strong Winds ◽  
High Degree ◽  
Lasiurus Cinereus Semotus

Free-flying individual Lasiurus cinereus semotus were observed as they foraged near incandescent lights on the island of Kauai, Hawaii. Two types of vocalizations were recorded from the bats: an echolocation–hunting signal with peak frequency of 27.8 kHz and an agonistic social signal, emitted while the bats were in aggressive pursuit of one another, with a peak frequency of 9.6 kHz. The tendency to vocalize agonistically increased with increased numbers of bats in the foraging area and increased as the density of insects available to the hunting bats decreased. Our observations suggest that the bats may gather echolocation information from their social signals. The bats at the site foraged under most weather conditions, including fog, moderate rain, strong winds, and temperatures as low as 13 °C. Groups of up to eight animals were common, although bats hunted in airspaces that were vigorously defended against other individuals. Small flies and small moths (< 10 mm body length) were the most common insects available as prey, but larger moths (16–20 mm) made up the bulk of the bats' diet. Moths larger than 20 mm were available but not fed on by the bats. This unique study site provides a rare opportunity to compare both prey availability to prey consumption in a population of bats. Our results suggest that this bat, at least on a short-term basis, exhibits a high degree of selectivity in its foraging, a behaviour similar to the mainland subspecies.

scholarly journals Detection of Francisella tularensis-Specific Antibodies in Patients with Tularemia by a Novel Competitive Enzyme-Linked Immunosorbent Assay

2012 ◽  
Vol 20 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Neekun Sharma ◽  
Akitoyo Hotta ◽  
Yoshie Yamamoto ◽  
Osamu Fujita ◽  
Akihiko Uda ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Francisella Tularensis ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Novel ◽  
Serum Samples ◽  
Content Type ◽  
Microagglutination Test ◽  
Highly Sensitive ◽  
High Degree

ABSTRACTA novel competitive enzyme-linked immunosorbent assay (cELISA) was developed and evaluated for detection of antibodies againstFrancisella tularensisin humans. The assay is based on the ability of serum antibodies to inhibit the binding of monoclonal antibodies (MAbs) directed againstF. tularensislipopolysaccharide antigens. The assay was evaluated using serum samples of tularemia patients, inactivatedF. tularensis-immunized rabbits, andF. tularensis-infected mice. Antibodies againstF. tularensiswere successfully detected in serum samples of tularemia patients as well as the immunized and infected animals. The cELISA method was compared to indirect ELISA (iELISA) and the commonly used microagglutination test (MA) using serum samples of 19 tularemia patients and 50 healthy individuals. The sensitivity and specificity of cELISA were 93.9 and 96.1%, respectively, in comparison to the iELISA. MA was less sensitive than cELISA with a sensitivity and specificity of only 81.8 and 98.0%, respectively. A high degree of correlation (R2= 0.8226) was observed between cELISA and iELISA results. The novel cELISA developed in this study appears to be highly sensitive and specific for serodiagnosis of human tularemia. The potential of the MAb-based cELISA to be used in both human and animal samples emphasizes its usefulness for serological survey of tularemia among multiple animal species.

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