P1457Preliminary results of the FLASH-AF: Validation of the device independent nature of a pulse deriving smartphone application for the detection of atrial fibrillation

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Proesmans ◽  
C Smeets ◽  
P Dreesen ◽  
J Vanhaeren ◽  
P Vandervoort
Keyword(s):  
Atrial Fibrillation ◽  
Diagnostic Accuracy ◽  
Medical Information ◽  
Low Cost ◽  
Smartphone Application ◽  
Cardiac Monitoring ◽  
Attractive Alternative ◽  
Handheld Device ◽  
The Mean ◽  
Quality Measurements

Abstract Background Smartphone applications using photoplethysmography (PPG) technology through their camera are becoming an attractive alternative for atrial fibrillation (AF) screening due to their low cost, convenience, and broad accessibility. However, some important questions concerning their diagnostic accuracy, robustness and device independent nature remain to be answered. Purpose This study evaluated the diagnostic accuracy of a PPG-based pulse-deriving smartphone application with respect to handheld single-lead ECG and 12-lead ECG. In addition, the device dependent nature and robustness of the performance of the application was assessed. Methods 300 Patients who are scheduled for a regular consultation or procedure (i.e. ablation or cardioversion) will be recruited from the cardiology ward. Additionally, patients hospitalized for continuous cardiac monitoring will be recruited to enrich the database with AF measurements. After obtaining written informed consent, the patients fill in a questionnaire collecting demographic and medical information. The pulse-deriving application will be tested on total of 14 different smartphones, 7 iOS devices and 7 Android devices. In total, each device will be measured with 150 times. The patients will additionally perform a single-lead ECG measurement with a handheld device. Subsequently, a 12-lead ECG will be recorded to obtain the reference diagnosis. Results A total of 164 patients already participated in the study. The mean age was 64 (±19) years, 58% was male. The AF-prevalence was 37%. On average, patients in AF had a higher CHA2DS2-VASc score; 3.93 (±1.80) compared to 2.02 (±1.63) for non-AF patients. The amount of insufficient quality measurements recorded with the pulse-deriving smartphone application ranged from 4% (iOS) to 13% (Android). Averaged for all the smartphone devices, the pulse-deriving application scored 81.2% (±5%) sensitivity, 97.1% (±1%) specificity, 88.8% (±2%) NPV, 95.0% (±1%) PPV, and 90.9% (±2%) accuracy. The handheld single-lead ECG device had 78.2% sensitivity, 95.5% specificity, 87.6% NPV, 91.5% PPV, and 88.9% accuracy. The same calculations were preformed after excluding regular atrial flutter measurements. On average, the pulse-deriving application scored 90.1% (±2%) sensitivity, 97.1% (±1%) specificity, 95.2% (±1%) NPV, 94.0% (±1%) PPV, and 94.8% (±1%) accuracy. The handheld single-lead ECG device had 90.2% sensitivity, 97.7% specificity, 97.7% NPV, 95.1% PPV, and 96.9% accuracy. Conclusion The diagnostic accuracy of the pulse-deriving smartphone application and the handheld single-lead ECG device was strongly influenced by the presence of regular atrial flutters, stressing the importance of further thorough validation. For the pulse-deriving smartphone application, there was no significant influence from device type in terms of diagnostic accuracy for the detection of AF. Insufficient quality measurements were more frequently performed on Android devices.

scholarly journals Mobile Phone–Based Use of the Photoplethysmography Technique to Detect Atrial Fibrillation in Primary Care: Diagnostic Accuracy Study of the FibriCheck App (Preprint)

2018 ◽  
Author(s):  
Tine Proesmans ◽  
Christophe Mortelmans ◽  
Ruth Van Haelst ◽  
Frederik Verbrugge ◽  
Pieter Vandervoort ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Primary Care ◽  
Diagnostic Accuracy ◽  
Mobile Phone ◽  
Low Cost ◽  
Attractive Alternative ◽  
Signal Quality ◽  
Convenience Sample ◽  
Ecg Signals ◽  
Accuracy Study

BACKGROUND Mobile phone apps using photoplethysmography (PPG) technology through their built-in camera are becoming an attractive alternative for atrial fibrillation (AF) screening because of their low cost, convenience, and broad accessibility. However, some important questions concerning their diagnostic accuracy remain to be answered. OBJECTIVE This study tested the diagnostic accuracy of the FibriCheck AF algorithm for the detection of AF on the basis of mobile phone PPG and single-lead electrocardiography (ECG) signals. METHODS A convenience sample of patients aged 65 years and above, with or without a known history of AF, was recruited from 17 primary care facilities. Patients with an active pacemaker rhythm were excluded. A PPG signal was obtained with the rear camera of an iPhone 5S. Simultaneously, a single‑lead ECG was registered using a dermal patch with a wireless connection to the same mobile phone. PPG and single-lead ECG signals were analyzed using the FibriCheck AF algorithm. At the same time, a 12‑lead ECG was obtained and interpreted offline by independent cardiologists to determine the presence of AF. RESULTS A total of 45.7% (102/223) subjects were having AF. PPG signal quality was sufficient for analysis in 93% and single‑lead ECG quality was sufficient in 94% of the participants. After removing insufficient quality measurements, the sensitivity and specificity were 96% (95% CI 89%-99%) and 97% (95% CI 91%-99%) for the PPG signal versus 95% (95% CI 88%-98%) and 97% (95% CI 91%-99%) for the single‑lead ECG, respectively. False-positive results were mainly because of premature ectopic beats. PPG and single‑lead ECG techniques yielded adequate signal quality in 196 subjects and a similar diagnosis in 98.0% (192/196) subjects. CONCLUSIONS The FibriCheck AF algorithm can accurately detect AF on the basis of mobile phone PPG and single-lead ECG signals in a primary care convenience sample.

scholarly journals EVALUATING SMARTPHONES COLOR FIDELITY AND METRIC ACCURACY FOR THE 3D DOCUMENTATION OF SMALL ARTIFACTS

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 539-547 ◽  
Author(s):  
M. Gaiani ◽  
F. I. Apollonio ◽  
F. Fantini
Keyword(s):  
Low Cost ◽  
Smartphone Application ◽  
Image Resolution ◽  
Museum Collections ◽  
Chromaticity Diagram ◽  
Color Representation ◽  
The Mean ◽  
3D Documentation ◽  
Textured Models

<p><strong>Abstract.</strong> Smartphone camera technology has made significant improvements of sensors quality and software camera performance in recent years. Devices as Apple iPhone X and the Samsung Galaxy S9 Plus, allow to reach levels of image resolution, sharpness and color accuracy very close to prosumer SLR cameras, enabling also on-the-fly processing and procedures which were considered impossible to achieve until a few years ago. Starting from these premises, a series of issues and opportunities concerning smartphone application to artifacts documentation will be discussed. In particular, consistency and reliability of both shape and color representation achievable for small-medium artifacts belonging to exhibitions and museum collections. A low-cost, easy-to-use workflow based on low-cost widespread devices will be compared to consolidated digitization pipelines. The contribution focus is based on color accuracy of textured models achievable through smartphones by means of an internally developed application for the achievement of highly reliable developments of raw formats (.DNG) from Apple iPhone X. Color consistency will be calculated in terms of the mean camera chroma relative to the mean ideal chroma in the CIE color metric (&amp;Delta;E*<sub>00</sub>) as defined in 2000 by the CIE on the CIEXYZ chromaticity diagram.</p>

scholarly journals Head-to-head comparison of proprietary PPG and single-lead ECG algorithms for atrial fibrillation detection

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
H Gruwez ◽  
S Evens ◽  
T Proesmans ◽  
C Smeets ◽  
P Haemers ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Atrial Flutter ◽  
Sensitivity And Specificity ◽  
Diagnostic Performance ◽  
Interquartile Range ◽  
Smartphone App ◽  
Smartphone Apps ◽  
Handheld Device ◽  
Detection Algorithms ◽  
Quality Measurements

Abstract Funding Acknowledgements Type of funding sources: None. Background Population based screening for atrial fibrillation (AF) has been suggested to reduce stroke. Photoplethysmography (PPG) deriving smartphone apps and single-lead electrocardiography (ECG) tools are attractive devices for screening due to their low cost, convenience, and accessibility. Automated algorithm analysis can serve as pre-screening or remote monitoring for AF, while confirmation on an ECG trace &gt;30s is required to establish the diagnosis. This work directly compares the performance of proprietary algorithms on PPG vs single-lead ECG for the detection of AF. Purpose To evaluate and compare the diagnostic performance of a PPG-deriving smartphone app and a single-lead ECG-deriving handheld device for AF detection. Methods Patients were recruited from the cardiology ward. After obtaining written informed consent, demographic and medical information were collected. Patients were instructed to perform one measurement using a pulse-deriving smartphone app and one via a single-lead ECG handheld device. A 12-lead electrocardiogram (ECG) was collected and interpreted by a cardiologist as gold standard. Patients with atrial flutter were excluded, with additional exclusions for insufficient quality measurements and unsuccessful measurements resulting due to technical errors. Unclassified single-lead ECG measurements were handled as test-negative. Sensitivity, specificity and accuracy were calculated with respect to the reference diagnosis. McNemar’s analysis was performed to compare the sensitivity and specificity of the proprietary PPG and single-lead ECG AF detection algorithms. Results The median age in the study population (n = 300) was 70 years (interquartile range: 51-78), 56.3% were men, and the median CHA2DS2-VASc was 3 (interquartile range: 1-4) with an AF-prevalence of 32.3%. PPG signal and single‑lead ECG quality was sufficient in 272/300 (91.0%) and 278/298 (93.3%) participants, respectively. After excluding atrial flutter patients (n = 25) and insufficient quality measurements, the sensitivity and specificity were 97.6% (95% CI 93.8 to 99.3) and 94.1% (95% CI 86.8 to 98.1) for the PPG signal versus 95.7% (95% CI 91.4 to 98.3) and 91.1% (95% CI 83.2 to 96.1) for the single‑lead ECG signal, respectively. Results demonstrated a 96.4% (95% CI 93.2 to 98.3) accuracy for PPG and 94.1% (95% CI 90.4 to 96.6) for single-lead ECG. No significant differences in sensitivity (P = 0.453) or specificity (P = 0.219) between the proprietary PPG and single-lead ECG algorithms were found. Conclusion This study demonstrated equivalent diagnostic performance of PPG and single-lead ECG proprietary AF detection algorithms in smartphone apps.

scholarly journals Comparison of two smartphone based atrial fibrillation screening application in Indonesian population

2021 ◽  
Author(s):  
Alexander Edo Tondas ◽  
Rolando Agustian Halim ◽  
Muhammad Rizki Felani ◽  
Fianirazha Primesa Caesarani ◽  
Indash Puspita ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pacemaker Implantation ◽  
Smartphone Application ◽  
Adverse Outcomes ◽  
Diagnostic Ability ◽  
Indonesian Population ◽  
The Mean ◽  
Convenience Sampling ◽  
Hospital General ◽  
Distinct Method

Background: Due to its adverse outcomes and thromboembolic complications, early detection of atrial fibrillation (AF) is advisable in the general population. This study aims to compare the diagnostic ability of two distinct method in smartphone application format, namely : AliveCor KardiaMobile and FibriCheck. Methods: This study was conducted in Mohammad Hospital General Hospital Palembang with convenience sampling of 170 participants aged 18 years or older. The subjects underwent Fibricheck and KardiaMobile recordings followed by 12 lead electrocardiogram read by board-certified cardiologist as the diagnostic standard. Results: After the exclusion of previous pacemaker implantation (n=7), 163 patients were included in the study. The mean age was 51±15 years with gender distribution of 74.8% men and 25.2% women. Most of the subjects were asymptomatic (87.1%) with mean blood pressure of 130/80 mmHg. The Fibricheck readings showed sensitivity of 73% and specificity of 93%, meanwhile Kardiamobile was able to detect AF with sensitivity of 77% and specificity of 98%.  Conclusion: In our study, KardiaMobile demonstrated overall greater sensitivity and specificity when compared to FibriCheck. However, KardiaMobile requires an external metal sensor that must be puchased separately. To the best of our knowledge, this is the first study to directly compare both methods in the Indonesian population.

Smartphone Application with Wireless Cardiac Monitoring Device to Analyze Real-Time ECG Using Modified Pan Tompkins Algorithm

2018 ◽  
Author(s):  
Usama Pervaiz ◽  
Saed Khawaldeh ◽  
Tajwar Abrar Aleef ◽  
Vu Hoang Minh
Keyword(s):  
Heart Rate ◽  
Real Time ◽  
Low Cost ◽  
Smartphone Application ◽  
Ease Of Use ◽  
Cardiac Monitoring ◽  
Health History ◽  
Heart Patients ◽  
History Of ◽  
Care Assistance

Heart patients are constantly at risk of a heart failure, therefore, it is crucial to track their vitals. There is also a dire need to make a single platform which has patients and doctors on board, provides health-care assistance remotely, and have a low-cost and accessible solution that would cater large masses, both in terms of its buying accessibility as well as its ease of use. We are bringing a one stop solution, with a wearable device which monitors Electrocardiogram (ECG) and consequently measure heart rate. The wearable wireless device have an application compatibility on Smartphone which allows real time monitoring of ECG as well as it gives various post processing options, in which heart rate would be measured using modified Pan-Tompkins Algorithm and kept overtime for maintaining health history of the patient.

scholarly journals 319 Appropriate Duration of Extended Cardiac Monitoring for Atrial Fibrillation in Cryptogenic Stroke

2019 ◽  
Vol 48 (Supplement_3) ◽  
pp. iii17-iii65
Author(s):  
Kate Donlon ◽  
Robert Murphy ◽  
Edel Mannion ◽  
Ruairi Waters
Keyword(s):  
Atrial Fibrillation ◽  
High Risk ◽  
Ischaemic Stroke ◽  
Paroxysmal Atrial Fibrillation ◽  
Cryptogenic Stroke ◽  
Cardiac Monitoring ◽  
Loop Recorder ◽  
External Loop ◽  
The Mean ◽  
Time To Detection

Abstract Background Strokes due to cardio embolism are generally more severe and prone to early and long term recurrence. All forms of anticoagulant therapy are associated with a two thirds risk reduction in acute ischaemic stroke associated with atrial fibrillation. Establishing a diagnosis of paroxysmal atrial fibrillation can be a challenging one. Our study will attempt to answer the question as to what duration of extended cardiac monitoring is required when screening for atrial fibrillation in cryptogenic stroke. Methods We examined the time of atrial fibrillation initial diagnosis in 50 patients with an original working diagnosis of cryptogenic stroke but later have atrial fibrillation confirmed on extended monitoring. All patients wore the external loop recorder from 1 day to 3 weeks’ duration. On return of the device, data from the external loop recorder was downloaded, and reviewed by a consultant cardiologist. The total duration of monitoring using the external loop recorder was recorded. The time to first episode of algorithm detected atrial fibrillation was recorded. Results The mean duration of extended cardiac monitoring using the external loop recorder was 120.1days By seven days, atrial fibrillation had been detected in 94% of patients. By 72 hours, atrial fibrillation had been detected in 78% of patients. The mean age of participants was 58.3 years. 54.4% were female. The mean time to detection of atrial fibrillation was 52.9 hours. The median time to detection of atrial fibrillation was 34.2 hours. Conclusion External loop recorders present an opportunity for detection of paroxysmal atrial fibrillation in high risk individuals. Our study shows the feasibility and accuracy of a screening duration of seven days in the high risk post ischaemic stroke population. A one week screening timeframe allows us to screen twice as many patients for paroxysmal atrial fibrillation. Successful screening for atrial fibrillation in this high risk group allows the commencement of acceptable and safe anticoagulant therapy.

Features of Thrombi and Diagnostic Accuracy of Impedance Plethysmography in Symptomatic and Asymptomatic Deep Vein Thrombosis

1993 ◽  
Vol 70 (02) ◽  
pp. 266-269 ◽  
Author(s):  
Giancarlo Agnelli ◽  
Benilde Cosmi ◽  
Stefano Radicchia ◽  
Franca Veschi ◽  
Enrico Boschetti ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Diagnostic Accuracy ◽  
High Sensitivity ◽  
Impedance Plethysmography ◽  
Surveillance Programme ◽  
Vein Thrombosis ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
The Mean ◽  
Deep Vein

SummaryImpedance plethysmography (IPG) has high sensitivity and specificity in patients with symptomatic deep vein thrombosis (DVT) while it fails to detect asymptomatic DVT. The aim of this study was to determine whether the features of thrombi such as location, size and occlusiveness could explain the different accuracy of IPG in symptomatic and asymptomatic DVT patients. One-hundred and seventeen consecutive outpatients with a clinical suspicion of DVT and 246 consecutive patients undergoing hip surgery were admitted to the study. In symptomatic patients IPG was performed on the day of referral, followed by venography, while in asymptomatic patients IPG was performed as a surveillance programme, followed by bilateral venography.A venography proved DVT was observed in 37% of the symptomatic patients and 34% of the asymptomatic limbs. A significantly higher proportion of proximal DVTs was found in symptomatic patients than in asymptomatic patients (78% vs 46%; p = 0.001). The mean Marder score, taken as an index of thrombus size, was significantly higher in symptomatic patients than in asymptomatic patients (19.0 vs 9.6; p = 0.0001). A significantly higher proportion of occlusive DVTs was observed in symptomatic than in asymptomatic patients (69% vs 36%; p = 0.001).We conclude that the unsatisfactory diagnostic accuracy of IPG in asymptomatic DVT is due to the high prevalence of distal, small and non occlusive thrombi. Such thrombi are unlikely to cause a critical obstruction of the venous outflow and therefore to produce a positive IPG.

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