A tale of two interfaces: vitrivr at the lifelog search challenge

The past decades have seen an exponential growth in the amount of data which is produced by individuals. Smartphones which capture images, videos and sensor data have become commonplace, and wearables for fitness and health are growing in popularity. Lifelog retrieval systems aim to aid users in finding and exploring their personal history. We present two systems for lifelog retrieval: vitrivr and vitrivr-VR, which share a common retrieval model and backend for multi-modal multimedia retrieval. They differ in the user interface component, where vitrivr relies on a traditional desktop-based user interface and vitrivr-VR has a Virtual Reality user interface. Their effectiveness is evaluated at the Lifelog Search Challenge 2021, which offers an opportunity for interactive retrieval systems to compete with a focus on textual descriptions of past events. Our results show that the conventional user interface outperformed the VR user interface. However, the format of the evaluation campaign does not provide enough data for a thorough assessment and thus to make robust statements about the difference between the systems. Thus, we conclude by making suggestions for future interactive evaluation campaigns which would enable further insights.

Healthy lifestyle and atrial fibrillation recurrence after pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Data on the relationship of a healthy lifestyle at the time of atrial fibrillation (AF) ablation with AF recurrence is limited.

Purpose

We investigated the association of healthy lifestyle markers with AF recurrence after ablation.

Methods

In 1439 patients undergoing AF ablation at a tertiary university hospital, a lifestyle score was built. The score included categories of BMI, smoking, blood pressure, fish intake, fruits/vegetable intake, alcohol consumption and physical activity. A higher score indicated a healthier lifestyle and patients were grouped into tertiles. Follow-up included 24h-Holter ECGs at 3 and 6 months and 7d-Holter ECGs at 12 months. Survival analyses and Cox-regression models were used to assess associations of individual factors and score-tertiles with AF recurrence.

Results

Mean age was 61.5 years, 25.9% were female and 59.1% had paroxysmal AF. In 941 patients all lifestyle score variables were available: 129, 675 and 137 patients were in the low, intermediate and high lifestyle group, respectively. Over increasing lifestyle groups, patients were more often female (9.3, 23.3, 38.7%; p<0.0001), had less hypertension (70.5, 53.3, 32.9%; p<0.0001), diabetes (15.5, 6.2, 3.7%; p=0.0002), a smaller left atrial diameter (44.1, 41.0, 37.6mm; p<0.0001) and numerically more paroxysmal AF (56.6, 62.4, 69.4%; p=0.32) with no differences in anti-arrhythmic drugs. In survival analyses (Figure), we saw a trend of more recurrences in the healthiest group compared to the unhealthiest group (logrank p=0.06 for low vs high group). Individually, higher fish intake (logrank p=0.04) and lower blood pressure (logrank p=0.02) were associated with AF recurrence. In Cox-regression models the HR (95% CI) for increasing lifestyle groups was 1.21 (0.98; 1.50, p=0.07). In individual models only higher fish intake (1.25 [1.01; 1.55], p=0.045) was associated with AF recurrence.

Conclusion(s): AF recurrence was numerically more frequent in patients with a healthier lifestyle, despite less comorbidities and smaller LA diameters. This paradoxical relationship might be due to lifestyle changes after PVI, differences in PVI efficacy or residual confounding. Further studies are needed to better understand this association.

Clinical validation of a novel smartwatch for automated detection of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The Withings Scanwatch is a novel smartwatch able to record an intelligent (i)ECG with automated detection of AF. While the iECG function from three major manufacturers have been extensively investigated, there is a paucity of data regarding the performance of the iECG function of the Withings Scanwatch.

Methods

We performed a prospective, observational study enrolling consecutive patients presenting to a cardiology service at a tertiary referral center. The aim was to assess the diagnostic performance of the iECG function of the Withings Scanwatch to detect AF compared to a simultaneously acquired cardiologist-interpreted 12-lead ECG. All iECG rhythm strips and 12-lead ECGs were anonymized and distributed to two blinded cardiologists who independently interpreted each tracing and assigned a diagnosis of sinus rhythm, AF or unclassified.

Results

iECGs and 12-lead ECGs were simultaneously recorded in 319 patients (67 yo (IQR 54-76), 48% female, Figure 1). Using the automated algorithm, rhythm was deemed inconclusive in 44 patients (14%). Overall, AF was present in 34 patients (11%). Among the tracings where the algorithm provided a diagnosis, it correctly identified AF with 76% (95%CI 55-91%) sensitivity, 99% (95%CI 97-100%) specificity, and a Kappa (K) coefficient of 0.72 when compared with cardiologist-interpreted 12-lead ECGs. Among patients in sinus rhythm, 3 were labeled AF (false-positive). From the 44 unclassified recordings, blinded cardiologists were able to correctly diagnose AF with 100% (95%CI 59-100%) sensitivity, 93% (95%CI 77-99%) specificity, and a K coefficient of 0.49. A total of 13 iECG recordings (4.1%) were determined to be noninterpretable by the cardiologists. Of the remaining 306 patients with simultaneous recordings, cardiologist interpretation of the iECG tracings demonstrated 97% (95%CI 84-100%) sensitivity, 99% (95%CI 96-100%) specificity and a K coefficient of 0.75.

Conclusion

Automatic rhythm classification was inferior to manual interpretation of iECGs. We found a lower sensitivity for the detection of AF using the Withings iECG function compared to data published on other devices. Cardiologist-iECG interpretation, however, was highly reliable with a diagnostic accuracy of 98% (95%CI 96-100%). Clinical interpretation of iECG readings by a cardiologist is therefore strongly encouraged

Choroid Plexus Volume in Multiple Sclerosis vs Neuromyelitis Optica Spectrum Disorder

Background and Objectives

The choroid plexus has been shown to play a crucial role in CNS inflammation. Previous studies found larger choroid plexus in multiple sclerosis (MS) compared with healthy controls. However, it is not clear whether the choroid plexus is similarly involved in MS and in neuromyelitis optica spectrum disorder (NMOSD). Thus, the aim of this study was to compare the choroid plexus volume in MS and NMOSD.

Methods

In this retrospective, cross-sectional study, patients were included by convenience sampling from 4 international MS centers. The choroid plexus of the lateral ventricles was segmented fully automatically on T1-weighted MRI sequences using a deep learning algorithm (Multi-Dimensional Gated Recurrent Units). Uni- and multivariable linear models were applied to investigate associations between the choroid plexus volume, clinically meaningful disease characteristics, and MRI parameters.

Results

We studied 180 patients with MS and 98 patients with NMOSD. In total, 94 healthy individuals and 47 patients with migraine served as controls. The choroid plexus volume was larger in MS (median 1,690 µL, interquartile range [IQR] 648 µL) than in NMOSD (median 1,403 µL, IQR 510 µL), healthy individuals (median 1,533 µL, IQR 570 µL), and patients with migraine (median 1,404 µL, IQR 524 µL; all p < 0.001), whereas there was no difference between NMOSD, migraine, and healthy controls. This was also true when adjusted for age, sex, and the intracranial volume. In contrast to NMOSD, the choroid plexus volume in MS was associated with the number of T2-weighted lesions in a linear model adjusted for age, sex, total intracranial volume, disease duration, relapses in the year before MRI, disease course, Expanded Disability Status Scale score, disease-modifying treatment, and treatment duration (beta 4.4; 95% CI 0.78–8.1; p = 0.018).

Discussion

This study supports an involvement of the choroid plexus in MS in contrast to NMOSD and provides clues to better understand the respective pathogenesis.

Interactive video retrieval evaluation at a distance: comparing sixteen interactive video search systems in a remote setting at the 10th Video Browser Showdown

The Video Browser Showdown addresses difficult video search challenges through an annual interactive evaluation campaign attracting research teams focusing on interactive video retrieval. The campaign aims to provide insights into the performance of participating interactive video retrieval systems, tested by selected search tasks on large video collections. For the first time in its ten year history, the Video Browser Showdown 2021 was organized in a fully remote setting and hosted a record number of sixteen scoring systems. In this paper, we describe the competition setting, tasks and results and give an overview of state-of-the-art methods used by the competing systems. By looking at query result logs provided by ten systems, we analyze differences in retrieval model performances and browsing times before a correct submission. Through advances in data gathering methodology and tools, we provide a comprehensive analysis of ad-hoc video search tasks, discuss results, task design and methodological challenges. We highlight that almost all top performing systems utilize some sort of joint embedding for text-image retrieval and enable specification of temporal context in queries for known-item search. Whereas a combination of these techniques drive the currently top performing systems, we identify several future challenges for interactive video search engines and the Video Browser Showdown competition itself.

Itch reduction using immersive virtual reality-An experimental pilot study

In a previous proof-of-concept study we have demonstrated that visual exposure to specific colors results in pruritic or antipruritic effects. To determine the effect of "antipruritic" colors when using immersive virtual reality (VR) and to assess whether psychometric values correlate with the response to the color exposure. In this cross-sectional interventional single-center study, itch patients were exposed to their subjective "antipruritic color" (defined by the Manchester Color Wheel) in a virtual monochromatic room for 10 min using a head-mounted display. Itch intensity rating (0-10 numerical rating scale [NRS]) was repeated at 1-min intervals. Additionally, dermatology life quality index, itch-related quality of life and the Hospital Anxiety and Depression Scale questionnaires were completed. Twenty-two patients (mean age 51.9 ± 23 years, 13 females) participated in the study. Following color exposure for 10 min itch intensity was significantly reduced compared to baseline (exact Wilcoxon signed-rank test, mdn-NRS 4.5 vs 3.0; z = -3.025, p = 0.001), confirmed by the area under the curve (z = -3.118; p = 0.001). No significant correlation between itch reduction and questionnaire scores was found (Spearman's Rho for all questionnaires). Visual exposure to the "antipruritic color" using immersive VR resulted in a significant decrease in itch intensity. This aligns with previous findings on the influence of colors on itch perception. The response of the intervention appeared independent of psychometric values. Thus, color exposure using immersive VR is a promising, low-cost, rapidly-acting, easily-applicable, non-pharmacological experimental antipruritic method.

P979Persistent atrial fibrillation terminated within the left atrium without recurrence at follow-up demonstrates a gradual intracardiac organization during stepwise ablation

Introduction

We previously reported that patients (pts) with recurrence (Rec) after stepwise catheter ablation (step-CA) of persistent atrial fibrillation (pAF) exhibit high bi-atrial intracardiac dominant frequencies (DF) values before ablation, indicative of a severe bi-atrial electro-anatomical remodeling.

Purpose

Herein, we hypothesized that a gradual decrease in DF values during step-CA is associated with pAF termination and maintenance of sinus rhythm (SR) on the long term.

Method

In 40 consecutive pts (61±8 yo, sustained AF duration 19±11 months), pulmonary vein isolation (PVI) and left atrium (LA) ablation were performed until pAF termination or cardioversion. 10-sec intracardiac electrograms (EGMs) epochs were recorded before ablation (BL), during PVI and during complex fractionated atrial electrograms (CFAEs) and linear ablation (post_PVI) in the right atrial (RAA) and left atrial (LAA) appendages and in the coronary sinus (CS). DF was defined as the highest peak within the [3–15] Hz EGM spectrum. Rec was defined as any atrial arrhythmia lasting >30 sec during follow-up (FU).

Results

pAF was terminated within the LA in 70% (28/40, LT) of the pts, while 30% (12/40, NLT) were not. After a mean FU of 34±14 months, all NLT pts had a Rec, while LT pts presented a Rec in 71% (20/28, LT_rec) and remained in SR in 29% (8/28, LT_norec). Figure 1 shows: 1) a gradient in DF values measured in the LAA (panel A), RAA (panel B) and CS (panel C) with the highest values in NLT pts (red), intermediate values in LT_rec pts (yellow) and lowest DF values in LT_norec pts (green); 2) all three groups displayed a gradual intracardiac organization during LA ablation as shown by decreasing DF values (p<0.05, BL vs post_PVI), but the LT_norec pts (green) exhibited the highest relative changes in DF from BL (p<0.05, LT_norec vs NLT, Δ range: −5.31 to −9.69%).

Figure 1. Effect of ablation on DF

Conclusion

Low DF values before ablation and gradual intracardiac organization until pAF termination are associated with maintenance of SR on the long term.

[Tetanus immunity in old age]

Among 1546 elderly persons (above 60 years of age) from a large town the immunity against tetanus was tested. 1043 persons (66.18%) had no antibodies against tetanus-toxoid in their serum. Almost half of the remaining positive sera (33.82%) showed antibody titers between 0.01 and 0.1 IU/ml. It is open to discussion if these titers warrant complete protection against the disease. On the contrary, children or young men serving in the army showed good immunity with high antibody titers. Tetanus has become a rare disease in the western countries, but cases still occur. The disease affects nowadays mainly adults. The older the patient the higher is its mortality. According to our study, many old people are not protected against tetanus. The risk of infection is widespread. It is strongly recommended to immunize also elderly persons at regular intervals. The vaccination against tetanus is cheap, well tolerated and yields a good immunity even in old age.