Approaching long term cardiac rhythm monitoring using advanced arm worn sensors and ECG recovery techniques.

According to recent British Heart Foundation statistics, one in six men and more than one in tenwomen die from coronary heart disease (CHD) in the UK. This equates to almost 74,000 deaths perannum from CHD alone. More worryingly, every week, 12 apparently fit and healthy young peopleaged 35 and under, die from undiagnosed cardiac conditions. In both circumstances, monitoring ispreformed only when triggered by an event. Unfortunately, this may be too late in the large majorityof cases. For instance, there is evidence suggesting that most indiscernible cardiac abnormalitiesare made detectable by ECG through the act of suddenly standing upright. This infers that thecondition would be detectable during the course of everyday ambulatory activity and highlights theneed for a long term monitoring device. Current diagnostic equipment consists of the Holter monitor for extended periods up to 36 hours and the implantable loop recorder (ILR) for monitoring up to 3years. The diagnostic yield of the ECG monitoring strategy is greatly increased as the monitoringperiod increases. Therefore, for subjects that exhibit symptoms of cardiac involvement that aretransient in nature, the ILR offers the best opportunity for diagnosis. However, the ILR is insertedunder the surface of the skin in the upper chest area and requires a surgical procedure, withassociated risks, which makes ILR’s a costly and inconvenient option in many cases.The need for a non-invasive long term monitoring device, which is comfortable to wear along thearm and able to provide reliable ECG monitoring, has been addressed by many, in several lines ofapproach to a solution. This review details the current state of the art and any pending limitations. Itthen presents key multidisciplinary solutions on the different aspects of the problem, which will stillrequire integration in order to realise such a device

Beyond the Libet clock: modality variants for agency measurements

The Sense of Agency (SoA) refers to our capability to control our own actions and influence the world around us. Recent research in HCI has been exploring SoA to provide users an instinctive sense of “I did that” as opposed to “the system did that”. However, current agency measurements are limited. The Intentional Binding (IB) paradigm provides an implicit measure of the SoA. However, it is constrained by requiring high visual attention to a “Libet clock” onscreen. In this paper, we extend the timing stimulus through auditory and tactile cues. Our results demonstrate that audio timing through voice commands and haptic timing through tactile cues on the hand are alternative techniques to measure the SoA using the IB paradigm. They both address limitations of the traditional method (e.g., lack of engagement and visual demand). We discuss how our results can be applied to measure SoA in tasks involving different interactive scenarios common in HCI

Resistance to paclitaxel in a cisplatin-resistant ovarian cancer cell line is mediated by P-glycoprotein

The IGROVCDDP cisplatin-resistant ovarian cancer cell line is also resistant to paclitaxel and models the resistance phenotype of relapsed ovarian cancer patients after first-line platinum/taxane chemotherapy. A TaqMan low-density array (TLDA) was used to characterise the expression of 380 genes associated with chemotherapy resistance in IGROVCDDP cells. Paclitaxel resistance in IGROVCDDP is mediated by gene and protein overexpression of P-glycoprotein and the protein is functionally active. Cisplatin resistance was not reversed by elacridar, confirming that cisplatin is not a P-glycoprotein substrate. Cisplatin resistance in IGROVCDDP is multifactorial and is mediated in part by the glutathione pathway and decreased accumulation of drug. Total cellular glutathione was not increased. However, the enzyme activity of GSR and GGT1 were up-regulated. The cellular localisation of copper transporter CTR1 changed from membrane associated in IGROV-1 to cytoplasmic in IGROVCDDP. This may mediate the previously reported accumulation defect. There was decreased expression of the sodium potassium pump (ATP1A), MRP1 and FBP which all have been previously associated with platinum accumulation defects in platinum-resistant cell lines. Cellular localisation of MRP1 was also altered in IGROVCDDP shifting basolaterally, compared to IGROV-1. BRCA1 was also up-regulated at the gene and protein level. The overexpression of P-glycoprotein in a resistant model developed with cisplatin is unusual. This demonstrates that P-glycoprotein can be up-regulated as a generalised stress response rather than as a specific response to a substrate. Mechanisms characterised in IGROVCDDP cells may be applicable to relapsed ovarian cancer patients treated with frontline platinum/taxane chemotherapy

Deep Learning to Automatically Interpret Images of the Electrocardiogram: Do We Need the Raw Samples?

BACKGROUND: Digitization and computerised analysis of ECG images allows researchers to derive new insights from historic records and overcomes issues arising from proprietary signal formats, but digitized signals suffer from a worse signal to noise ratio (SNR) than raw signals and can produce inferior results. Deep learning (DL) models can be particularly robust to poor SNRs and we propose that they may provide exceptionally robust analysis of image-derived ECG signals. We aim to benchmark image-based ECG analysis against raw signal analysis on a particularly challenging, ambulatory ECG task. METHODS: The 2017 Physionet AF Challenge data was downloaded and ECG records were plotted into human-readable images at 50% resolution. The ECG images were then digitized using established techniques. The image-derived signals were used to train a deep convolutional neural network for a four-class rhythm recognition task. Results from 5-fold cross validation on the public training set were directly compared with results from leading competition scorers, who used raw signals. RESULTS: A combined F1 score of 0.78 was obtained. This represents minimal performance loss compared with raw signal analysis, where six top competitors attained a mean combined F1 score of 0.83. CONCLUSION: Our findings show that DL-based analysis of ECG images is particularly robust. We advocate for a renewed interest in ECG image analysis using a DL approach

Ventricular fibrillation waveform properties influenced by thoracic impedance guided chest compressions in a porcine model

Background and objective: Quantitative measures extracted from ventricular fibrillation (VF) waveform reflect the metabolic state of the myocardium and are associated with survival outcome. The quality of delivered chest compressions during cardiopulmonary resuscitation are also linked with survival. The aim of this research is to explore the viability and effectiveness of a thoracic impedance (TI) based chest compression (CC) guidance system to control CC depth within individual subjects and influence VF waveform properties. Methods: This porcine investigation includes an analysis of two protocols. CC were delivered in 2-minute episodes at a constant rate of 110 CC min-1. Subject-specific CC depth was controlled using a TI-thresholding system where CC were performed according to the amplitude (ZRMS, 0.125 to 1.250 Ω) of a band-passed TI signal (ZCC). Protocol A was a retrospective analysis of a 12-porcine study to characterise the response of two VF waveform metrics: amplitude spectrum area (AMSA) and mean slope (MS), to varying CC quality. Protocol B was a prospective 12-porcine study to determine if changes in VF waveform metrics, due to CC quality, were associated with defibrillation outcome. Results: Protocol A: A directly proportional relationship was observed between ZRMS and CC depth applied within each subject (r = 0.90; p &lt;0.001). A positive relationship was observed between ZRMS and both AMSA (p &lt;0.001) and MS (p &lt;0.001), where greater TI thresholds were associated with greater waveform metrics. Protocol B: MS was associated with return of circulation following defibrillation (odds ratio = 2.657; p = 0.043). Conclusion: TI-thresholding was an effective way to control CC depth within-subjects. Compressions applied according to higher TI thresholds evoked an increase in AMSA and MS. The response in MS due to deeper CC resulted in a greater incidence of ROSC compared to shallow chest compressions. <br/

Assessing the effect of lay-rescuer gender on chest compression quality when using an automated external defibrillator in a simulated sudden cardiac arrest

Introduction: Survival from sudden cardiac arrest (SCA) relies on prompt defibrillation and effective cardiopulmonary resuscitation (CPR). The effect of SCA patient gender has been assessed, but there has been little research into the effect of rescuer gender. An update to the resuscitation guidelines recommends lay-rescuers perform chest compression (CC) only CPR. This study was conducted to assess quality of CCs performed by male and female lay-rescuers

A Data-Driven Simulator for the Strategic Positioning of Aerial Ambulance Drones Reaching Out-Of-Hospital Cardiac Arrests: A Genetic Algorithmic Approach

Objective: The Internet of Things provide solutions for many societal challenges including the use of unmanned aerial vehicles to assist in emergency situations that are out of immediate reach for traditional emergency services. Out of hospital cardiac arrest (OHCA) can result in death with less than 50% of victims receiving the necessary emergency care on time. The aim of this study is to link real world heterogenous datasets to build a system to determine the difference in emergency response times when having aerial ambulance drones available compared to response times when depending solely on traditional ambulance services and lay rescuers who would use nearby publicly accessible defibrillators to treat OHCA victims.Method: The system uses the geolocations of public accessible defibrillators and ambulance services along with the times when people are likely to have a cardiac arrest to calculate response times. For comparison, a Genetic Algorithm has been developed to determine the strategic number and positions of drone bases to optimize OHCA emergency response times.Conclusion: Implementation of a nationwide aerial drone network may see significant improvements in overall emergency response times for OHCA incidents. However, the expense of implementation must be considered.</p