Quantitative Analysis of Mother Wavelet Function Selection for Wearable Sensors-Based Human Activity Recognition

Recent advancements in the Internet of Things (IoT) wearable devices such as wearable inertial sensors have increased the demand for precise human activity recognition (HAR) with minimal computational resources. The wavelet transform, which offers excellent time-frequency localization characteristics, is well suited for HAR recognition systems. Selecting a mother wavelet function in wavelet analysis is critical, as optimal selection improves the recognition performance. The activity time signals data have different periodic patterns that can discriminate activities from each other. Therefore, selecting a mother wavelet function that closely resembles the shape of the recognized activity's sensor (inertial) signals significantly impacts recognition performance. This study uses an optimal mother wavelet selection method that combines wavelet packet transform with the energy-to-Shannon-entropy ratio and two classification algorithms: decision tree (DT) and support vector machines (SVM). We examined six different mother wavelet families with different numbers of vanishing points. Our experiments were performed on eight publicly available ADL datasets: MHEALTH, WISDM Activity Prediction, HARTH, HARsense, DaLiAc, PAMAP2, REALDISP, and HAR70+. The analysis demonstrated in this paper can be used as a guideline for optimal mother wavelet selection for human activity recognition.

The effect of ziltivekimab on the neutrophil-lymphocyte ratio: analysis from RESCUE

Background

The neutrophil-lymphocyte ratio (NLR), derived from the complete blood count, independently predicts atherosclerotic events and is a potential biomarker for residual inflammatory risk. A previous study showed that interleukin (IL)-1β inhibition reduces the NLR, but whether inhibition with IL-6, a cytokine downstream of IL-1, also lowers the NLR is unknown.

Purpose

To evaluate whether ziltivekimab, a monoclonal antibody targeting the IL-6 ligand, dose-dependently lowers the NLR compared to placebo.

Methods

The phase II RESCUE trial randomized 264 patients with moderate to severe chronic kidney disease (CKD) and high-sensitivity CRP (hsCRP) >2mg/L in a 1:1:1:1 ratio to placebo or ziltivekimab 7.5 mg, 15 mg, and 30 mg subcutaneously once every four weeks. As previously reported, the trial met its primary endpoint as demonstrated by hsCRP reductions of 4% in the placebo group as compared to 77%, 88%, and 92% at 12 weeks in the ziltivekimab 7.5, 15, and 30 mg groups, respectively. Using RESCUE trial data, we further evaluated the percent change from baseline in the NLR at 12 weeks and sought evidence of correlation between any observed changes in the NLR with changes in other measured biomarkers.

Results

Ziltivekimab dose-dependently reduced the NLR starting at week one and sustained through week 12 (Table). The median change in the NLR at 12 weeks, the primary pre-specified endpoint, was −13.5% in the 7.5 mg group, −14.3% in the 15 mg group, and −22.4% in the 30 mg group compared to 1.56% in the placebo group. The estimated treatment difference was −14.6% (p=0.004), −15.3% (p=0.004), and −23.6% (p<0.0001) in the ziltivekimab 7.5, 15, and 30 mg groups respectively. These changes were driven largely by reductions in the absolute neutrophil count with minimal change in lymphocyte count. The change in NLR with ziltivekimab correlated modestly with the changes in hsCRP (R=0.26, p=0.0006), fibrinogen (R=0.18, p=0.02), and haptoglobin (R=0.17, p=0.03), but not serum amyloid A, ApoA1, ApoB, ApoB/ApoA ratio, or traditional risk markers.

Conclusions

IL-6 inhibition with ziltivekimab lowers the NLR. The ongoing ZEUS cardiovascular (CV) outcomes trial will assess whether ziltivekimab can reduce CV event rates among individuals with stage 3 to 4 CKD, known atherosclerotic disease, and elevated hsCRP. If ziltivekimab reduces CV risk, it would provide further evidence for critical inter-relationships between bone marrow function and atherothrombosis.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novo Nordisk

Correlation of arterial PaCO2 to end tidal CO2 in children undergoing laparoscopic abdominal surgery: An observational study

Background and Aims

The reliability of end tidal carbon dioxide (ETCO2) as a measure of arterial carbon dioxide (PaCO2) in pediatric laparoscopy is unclear. We evaluated the correlation of arterial to end tidal P(a-ET) CO2 during pediatric laparoscopy at two hours of pneumoperitoneum as the primary objective. We also compared P(a-ET) CO2 and alveolar to arterial oxygen gradient P(A-a) O2 and haemodynamics at fixed time points during surgery.

Material and Methods

A cross-sectional study was conducted in 25 children undergoing laparoscopic abdominal surgery. Arterial blood gases were drawn at T0, baseline, T10: ten minutes, T1h: 1 hour, T2h: 2 hours of pnuemoperitoneum and T 10d: 10 mins after deflation. The P(a-ET) CO2, P(A-a) O2, were measured from the blood gas and ETCO2 and FiO2 values on the monitor. The Pearson's correlation coefficient, the Wilcoxon rank test and Chi square test were used for statistical analysis.

Results

At T2h moderate correlation of P(a-ET) CO2 (r = 0.605, P = 0.001) with 40% children documenting accurate P(a-ET) CO2, -1 to +1 mm Hg was seen. Moderate correlation was also seen at T0, T10, T 10d but poor correlation at T 1h. The P(A-a) O2 increased progressively with surgery and did not correlate with P(a-ET) CO2. Heart rate was stable, but systolic blood pressures at T 10 and diastolic at T10, T 1h, T 2h were higher than baseline.

Conclusion

Moderate correlation was seen between PaCO2 and ETCO2 at 2 h of pnuemoperitoneum and at T0, T 10, and T 10d. P(A-a) O2 increased with surgery but did not correlate with P(a-ET) CO2.

Detection of Atrial Fibrillation in Compressively Sensed Electrocardiogram for Remote Monitoring

The objective of this paper is to develop an optimized system to detect Atrial Fibrillation (AF) in compressively sensed electrocardiogram (ECG) for long-term remote patient monitoring. A three-stage system was developed to 1) reject ECG of poor signal quality, 2) detect AF in compressively sensed ECG, and 3) detect AF in selectively reconstructed ECG. The Long-Term AF Database (LTAFDB), sampled at 128 Hz using a 12-bit ADC with a range of 20 mV, was used to validate the system. The LTAFDB had 83,315 normal and 82,435 AF rhythm 30 s ECG segments. Clean ECG from the LTAFDB was artificially contaminated with motion artifact to achieve −12 to 12 dB Signal-to-Noise Ratio (SNR) in steps of 3 dB. The contaminated ECG was compressively sensed at 50% and 75% compression ratio (CR). The system was evaluated using average precision (AP), the area under the curve (AUC) of the receiver operator characteristic curve, and the F1 score. The system was optimized to maximize the AP and minimize ECG rejection and reconstruction ratios. The optimized system for 50% CR had 0.72 AP, 0.63 AUC, and 0.58 F1 score, 0.38 rejection ratio, and 0.38 reconstruction ratio. The optimized system for 75% CR had 0.72 AP, 0.63 AUC, and 0.59 F1 score, 0.40 rejection ratio, and 0.35 reconstruction ratio. Challenges for long-term AF monitoring are the short battery life of monitors and the high false alarm rate due to artifacts. The proposed system improves the short battery life through compressive sensing while reducing false alarms (high AP) and ECG reconstruction (low reconstruction ratio).

Signal Quality Assessment of Compressively Sensed Electrocardiogram

Objective Develop a signal quality index (SQI) to determine the quality of compressively sensed electrocardiogram (ECG) by estimating the signal-to-noise ratio (SNR). Methods The SQI used random forests, with the ratio of the standard deviations of an ECG segment and a clean ECG, and the Wasserstein metric between the amplitude distributions of an ECG segment and a clean ECG, as features. The SQI was tested using the Long-Term Atrial Fibrillation Database (LTAFDB) and the PhysioNet/CinC Challenge 2011 Database Set A (CinCDB). Clean ECG segments from the LTAFDB were corrupted using simulated motion artifact, with preset SNR between -12 dB and 12 dB. The CinCDB was used as-it-is. The databases were compressively sensed using three types of sensing matrices at three compression ratios (50%, 75%, and 95%). For LTAFDB, the RMSE and Spearman correlation between the SQI and the preset SNR were used for evaluation, while for CinCDB, accuracy and F1 score were used. Results The average RMSE was 3.18 dB and 3.47 dB in normal and abnormal ECG, respectively. The average Spearman correlation was 0.94 and 0.93 in normal and abnormal ECG, respectively. The average accuracy and F1 score were 0.90 and 0.88, respectively. Conclusion The SQI determined the quality of compressively sensed ECG and generalized across different databases. There was no consequential effect on the SQI due to abnormal ECG or compression using different sensing matrices and different compression ratios. Significance Without reconstruction, the SQI can inform which ECG should be analyzed to reduce false alarms due to contamination.

Image Super-Resolution Through Compressive Sensing-based Recovery

The primary aim of image super-resolution techniques is to produce a high resolution (HR) image from a low resolution (LR) image efficiently. Deep learning algorithms are being extensively used to address the ill-posed problem of single image super-resolution which requires extremely large data-sets and high processing power. When one does not have access to large data-sets or have limited processing power, an alternative technique may be in order. In this study, we have developed a novel positive scale image resizing method inspired by compressive sensing (CS). We have considered the image super-resolution as a CS recovery problem in which a low resolution image is assumed as a compressed measurement and the required interpolated image is treated as output of the CS-based recovery. In the proposed HR recovery method, a deterministic binary block diagonal measurement matrix, (DBBD), is used as measurement matrix since it maintains the visual similarity between the low and high resolution images. Then along with a sparsification matrix, the sparse representation of HR image is first recovered and subsequently the dense HR image is obtained. The proposed method is applied to medical and non-medical images. The HR images obtained using the traditional proximal, bilinear and bi-cubic interpolation techniques are compared with those obtained using the proposed method. The proposed CS inspired method delivers superior HR images than the traditional techniques. The superiority of the proposed method is attributed to the unique usage of the DBBD matrix and the CS recovery algorithm to obtain a high resolution image without any prior training data-set.

Neutrophil-to-lymphocyte ratio predicts cardiovascular events in patients with type 2 diabetes: post hoc analysis of SUSTAIN 6 and PIONEER 6

Background

Inflammation plays an important role in atherosclerosis. The neutrophil-to-lymphocyte ratio (NLR) may serve as a clinically useful biomarker of inflammation and cardiovascular (CV) disease, although this relationship has not been studied in people with type 2 diabetes (T2D).

Purpose

This post hoc analysis investigated the relationship between NLRs and CV outcomes in T2D CV outcomes trials for two formulations of semaglutide, a glucagon-like peptide-1 receptor agonist.

Methods

In pooled analyses of the SUSTAIN 6 and PIONEER 6 trials, 6,480 patients with T2D at high CV risk received placebo or semaglutide (once-weekly subcutaneously up to 1.0 mg, or once-daily orally up to 14 mg). NLRs were calculated from complete blood counts at randomisation. Adjudicated outcomes included 3-point major adverse CV events (MACE: composite of CV death, non-fatal myocardial infarction [MI] or non-fatal stroke; primary outcome), expanded MACE, CV death and all-cause death (secondary outcomes). Patient characteristics and CV outcomes were analysed according to baseline NLR tertiles using pooled trial data. Estimation of hazard ratios (HRs) for all outcomes across NLR tertiles used a Cox proportional hazards model. A Cox spline regression with continuous NLR as covariate adjusted for treatment was used to predict the event rate of first MACE at 2 years.

Results

Overall, baseline NLR was recorded in 6,364 patients. Mean baseline NLRs were 1.5, 2.2 and 3.6 in the low, middle and high tertiles, respectively. Patients in the high NLR tertile were older (66.6 years), more likely to be male (70.0%), had longer duration of diabetes (15.3 years), higher body weight (93.3 kg), lower diastolic blood pressure (75.5 mmHg) and estimated glomerular filtration rate (70.4 mL/min/1.73m2) vs those in the lower NLR tertiles (all p<0.0001). Higher NLR was associated with an increased risk of MACE (HR [95% confidence interval (CI)]: 1.37 [1.05; 1.80; p=0.02] and 1.86 [1.45; 2.41; p<0.0001] for the middle and high tertiles, respectively, vs the low tertile). The high NLR tertile was also associated with a 74% increased risk of expanded MACE and twofold risk for CV death and all-cause death vs the low NLR tertile (Figure 1). Spline regression indicated that NLR values >5 increased the risk of first MACE substantially (Figure 2). Further analysis of NLR and MACE by tertiles showed a more pronounced association in patients without prior MI and/or stroke (HR [95% CI]: 1.64 [1.07; 2.56]; p=0.03 and 2.09 [1.38; 3.21]; p=0.0006 in the middle and high tertiles, respectively, vs the low tertile).

Conclusion

Baseline NLR predicts MACE, CV death and all-cause death in patients with T2D and high CV risk. NLR is readily accessible from routinely obtained and inexpensive blood counts; it could offer a convenient, clinically useful inflammatory biomarker for CV risk prediction in this population.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novo Nordisk A/S Figure 1Figure 2

P33: PROPOSAL OF A NEW SCORING TOOL FOR PREDICTION OF HYPOCALCEMIA IN PATIENTS UNDERGOING SURGERY FOR PAPILLARY THYROID CANCER

Introduction

Post-operative hypocalcemia occurs more frequently in certain high-risk patients. The aim of our study is to propose a preliminary scoring system to identify patients who are more likely to develop hypocalcemia following surgery for papillary thyroid cancer.

Method

The study was performed with a retrospective developmental cohort(n=131) and a prospective validation cohort(n=71). Patients underwent either Total Thyroidectomy(TT), TT+Central Neck Dissection(CND) or TT+CND+Modified Radical Neck Dissection(MRND). Significant pre-operative variables and operative findings were converted into categorical variables for analysis. Univariate, multivariate analysis and a logistic regression were used to select significant predictors. The score was constructed by converting into integer, the regression coefficients of independently predictive factors in the logistic regression model. This score was validated prospectively in the validation cohort.

Result

24(18%) out of 131 patients in the developmental cohort and 16(22.5%) out of 71 patients in the validation cohort had symptomatic hypocalcemia. Thyroiditis, positive lymph node metastasis, central and lateral compartment dissection, Neutrophil-to-lymphocyte ratio(NLR)>3.35 and platelet-to-lymphocyte ratio(PLR)>135 were selected as significant predictors. A score with a range of 0-11 was created. The cut-off value for the score was 6 points(sensitivity of 92.0% and specificity of 89.0%). Areas under the ROC curve for the scores were 0.926 and 0.901 in the developmental and validation cohorts, respectively.

Conclusion

This score could be a tool in the prediction of hypocalcemia and could help in identifying patients at a higher risk of post-operative hypocalcemia and guide calcium/Vitamin D treatment, as well as facilitate a safe earlier hospital discharge for low risk patients.

Take-home message

The proposed scoring system could help in identification of patients at a higher risk of post-operative hypocalcemia.

P32: POST-OPERATIVE RELATIVE PARATHORMONE DECLINE (ΔPTH%) AND ABSOLUTE PARATHORMONE DECLINE (ΔPTH) LEVELS ARE BETTER MARKERS OF SYMPTOMATIC HYPOCALCEMIA FOLLOWING TOTAL THYROIDECTOMY THAN POST-OPERATIVE PTH ALONE

Introduction

Hypocalcemia is a frequent complication following thyroidectomy which can delay discharge and increase overall treatment expenditure. We aimed to assess the predictive value of absolute and relative intact Parathormone(iPTH) decline levels as reliable markers of post-operative hypocalcemia.

Method

This prospective study included 95 consecutive patients at our tertiary care centre. Patients underwent either Total Thyroidectomy(TT), TT+Central Neck Dissection(CND) or TT+CND+Modified Radical Neck Dissection(MRND). iPTH levels were measured four hours after surgery and the following morning after surgery(POD 1). iPTH, absolute iPTH decline(ΔPTH) and relative iPTH decline(ΔPTH%) were calculated and correlated with hypocalcemia. Comparisons between groups were measured by chi-square test, Fischer's exact test and Mann-Whitney U test.

Result

Of the 95 patients, 59 had malignant disease, while 36 patients had benign histopathology. TT was performed in 69 patients, TT+CCLND in 7, and TT+CCLND+MRND in 19. 32.6% of patients(n=31) had biochemical hypocalcemia and 20%(n=19) had symptomatic hypocalcemia. The mean calcium of the cohort on Post-operative day(POD)-1 was 8.3±0.66(range=6.5-9.9) and POD-3 was 8.4±0.69(range=6.3–10.7). Median PTH, measured 4 hours after surgery was 24pg/ml(IQR–23.4;range 2.5–85.5), and measured on POD-1 was 28pg/ml(IQR–27.6;range=2-79). The ΔPTH(U=206;p<0.001) & ΔPTH% (U=127;p<0.001) were significantly higher in patients with symptomatic hypocalcemia. A ΔPTH% of 20%(sensitivity=84%;specificity=91%) and ΔPTH of 3.75 pg/ml(sensitivity = 74%; specificity=87%) were good predictors of symptomatic hypocalcemia.

Conclusion

Post-operative ΔPTH and ΔPTH% are reliable predictors of hypocalcemia following thyroid surgery and have the potential to facilitate a safe early discharge for patients undergoing TT. 20% fall in the PTH level(ΔPTH%) can be useful as a marker of hypocalcemia.

Take-home message

Post-operative ΔPTH and ΔPTH% are better predictors of hypocalcemia following thyroid surgery than a single value of post-operative PTH alone.

Short-course radiotherapy with consolidation chemotherapy versus conventionally fractionated long-course chemoradiotherapy for locally advanced rectal cancer: randomized clinical trial

BACKGROUND

The trial hypothesis was that, in a resource-constrained situation, short-course radiotherapy would improve treatment compliance compared with conventional chemoradiotherapy for locally advanced rectal cancer, without compromising oncological outcomes.

METHODS

In this open-label RCT, patients with cT3, cT4 or node-positive non-metastatic rectal cancer were allocated randomly to 5 × 5 Gy radiotherapy and two cycles of XELOX (arm A) or chemoradiotherapy with concurrent capecitabine (arm B), followed by total mesorectal excision in both arms. All patients received a further six cycles of adjuvant chemotherapy with the XELOX regimen. The primary endpoint was treatment compliance, defined as the ability to complete planned treatment, including neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy to a dose of six cycles.

RESULTS

Of 162 allocated patients, 140 were eligible for analysis: 69 in arm A and 71 in arm B. Compliance with planned treatment (primary endpoint) was greater in arm A (63 versus 41 per cent; P = 0.005). The incidence of acute toxicities of neoadjuvant therapy was similar (haematological: 28 versus 32 per cent, P = 0.533; gastrointestinal: 14 versus 21 per cent, P = 0.305; grade III-IV: 2 versus 4 per cent, P = 1.000). Delays in radiotherapy were less common in arm A (9 versus 45 per cent; P < 0.001), and overall times for completion of neoadjuvant treatment were shorter (P < 0.001). The rates of R0 resection (87 versus 90 per cent; P = 0.554), sphincter preservation (32 versus 35 per cent; P = 0.708), pathological complete response (12 versus 10 per cent; P = 0.740), and overall tumour downstaging (75 versus 75 per cent; P = 0.920) were similar. Downstaging of the primary tumour (ypT) was more common in arm A (P = 0.044). There was no difference in postoperative complications between trial arms (P = 0.838).

CONCLUSION

Reduced treatment delays and a higher rate of compliance were observed with treatment for short-course radiotherapy with consolidation chemotherapy, with no difference in early oncological surgical outcomes. In time- and resource-constrained rectal cancer units in developing countries, short-course radiotherapy should be the standard of care.

An Investigation of Rotary Drone HERM Line Spectrum under Manoeuvering Conditions

Detecting and identifying drones is of great interest due to the proliferation of highly manoeuverable drones with on-board sensors of increasing sensing capabilities. In this paper, we investigate the use of radars for tackling this problem. In particular, we focus on the problem of detecting rotary drones and distinguishing between single-propeller and multi-propeller drones using a micro-Doppler analysis. Two different radars were used, an ultra wideband (UWB) continuous wave (CW) C-band radar and an automotive frequency modulated continuous wave (FMCW) W-band radar, to collect micro-Doppler signatures of the drones. By taking a closer look at HElicopter Rotor Modulation (HERM) lines, the spool and chopping lines are identified for the first time in the context of drones to determine the number of propeller blades. Furthermore, a new multi-frequency analysis method using HERM lines is developed, which allows the detection of propeller rotation rates (spool and chopping frequencies) of single and multi-propeller drones. Therefore, the presented method is a promising technique to aid in the classification of drones.

Transfer Learning for Detection of Atrial Fibrillation in Deterministic Compressive Sensed ECG

Atrial Fibrillation (AF) is a cardiac condition resulting from uncoordinated contraction of the atria which may lead to an increase in the risk of heart attacks, strokes, and death. AF symptoms may go undetected and may require longterm monitoring of electrocardiogram (ECG) to be detected. Long-term ECG monitoring can generate a large amount of data which can increase power, storage, and the wireless transmission bandwidth of monitoring devices. Compressive Sensing (CS) is compression technique at the sampling stage which may save power, storage, and wireless bandwidth of monitoring devices. The reconstruction of compressive sensed ECG is a computationally expensive operation; therefore, detection of AF in compressive sensed ECG is warranted. This paper presents preliminary results of using deep learning to detect AF in deterministic compressive sensed ECG. MobileNetV2 convolutional neural network (CNN) was used in this paper. Transfer learning was utilized to leverage a pre-trained CNN with the final two layers retrained using 24 records from the Long-Term Atrial Fibrillation Database. The Short-Term Fourier Transform was used to generate spectrograms that were fed to the CNN. The CNN was tested on the MIT-BIH Atrial Fibrillation Database at the uncompressed, 50%, 75%, and 95% compressed ECG. The performance of the CNN was evaluated using weighted average precision (AP) and area under the curve (AUC) of the receiver operator curve (ROC). The CNN had AP of 0.80, 0.70, 0.70, and 0.57 at uncompressed, 50%, 75%, and 95% compression levels. The AUC was 0.87, 0.78, 0.79, and 0.75 at each compression level. The preliminary results show promise for using deep learning to detect AF in compressive sensed ECG.Clinical Relevance-This paper confirms that AF can be detected in compressive sensed ECG using deep learning, This will facilitate long-term ECG monitoring using wearable devices and will reduce adverse complications resulting from undiagnosed AF.

No change in life expectancy: the devil is in the detail

Background

The rate of improvement in life expectancy in high income countries has slowed down over the past few years, and instances where life expectancy is lower than a year before are increasingly common. This paper aims to analyse changes in life expectancy over the last decade to better understand what causes and age groups contribute to the slowdown.

Methods

We use WHO mortality data by age and cause to construct life tables, and we use Arriaga decomposition method to analyse the contribution of specific causes and age groups to changes in life expectancy in Australia, Canada, France, Germany, Netherlands, United Kingdom and the United States of America. We look at the change between 2007-2012 and 2012-2017 (or latest available).

Results

All countries experienced a slowdown in life expectancy in the past 5 years (2012-2017), in comparison to the preceding period. Slowdown in under 65s was particularly pronounced, with younger age groups only contributing minimally (between 0.4 years for males in Germany and -0.4 years for males in the United States) to changes in life expectancy. Among people aged 65 and over, gains ranged between 0.05 years for females in France and 0.6 years for males in the Netherlands. Certain causes of death contributed negatively to change in life expectancy between 2012 and 2017, with notable increases in deaths from accidental poisonings in males (up to -0.09 year in the UK and Canada, and -0.34 in the US) and suicides (up to -0.08 year in Australia and -0.07 in the US).

Conclusions

While recent slowdown in life expectancy gains in high income countries is often attributed to lack of improvement in people of older ages, we show that, beyond this, there are increases in mortality in younger age groups from external causes, that contribute negatively to change in life expectancy in some countries. This pattern is of a particular concern, as deterioration in preventable mortality points to broader worsening of socio-economic climate.

Key messages

Improvements in life expectancy in high income countries slowed down markedly over the past few years, but contributing mortality patterns differ for age groups and causes of death across countries. Persistent increases in preventable mortality from certain external causes in younger age groups in Australia, Canada, US and UK point to broader deterioration of socio-economic climate.

Machine Learning-Based Segmentation of Left Ventricular Myocardial Fibrosis from Magnetic Resonance Imaging

PURPOSE OF REVIEW

Myocardial fibrosis (MF) arises due to myocardial infarction and numerous cardiac diseases. MF may lead to several heart disorders, such as heart failure, arrhythmias, and ischemia. Cardiac magnetic resonance (CMR) imaging techniques, such as late gadolinium enhancement (LGE) CMR, enable non-invasive assessment of MF in the left ventricle (LV). Manual assessment of MF on CMR is a tedious and time-consuming task that is subject to high observer variability. Automated segmentation and quantification of MF is important for risk stratification and treatment planning in patients with heart disorders. This article aims to review the machine learning (ML)-based methodologies developed for MF quantification in the LV using CMR images.

RECENT FINDINGS

With the availability of relatively large labeled datasets supervised learning methods based on both conventional ML and state-of-the-art deep learning (DL) methods have been successfully applied for automated segmentation of MF. The incorporation of ML algorithms into imaging techniques such as 3D LGE CMR permits fast characterization of MF on CMR imaging and may enhance the diagnosis and prognosis of patients with heart disorders. Concurrently, the studies using cine CMR images have revealed that accurate segmentation of MF on non-contrast CMR imaging might be possible. The application of ML/DL tools in CMR image interpretation is likely to result in accurate and efficient quantification of MF.

Uncertainty in Blood Pressure Measurement Estimated Using Ensemble-Based Recursive Methodology

Automated oscillometric blood pressure monitors are commonly used to measure blood pressure for many patients at home, office, and medical centers, and they have been actively studied recently. These devices usually provide a single blood pressure point and they are not able to indicate the uncertainty of the measured quantity. We propose a new technique using an ensemble-based recursive methodology to measure uncertainty for oscillometric blood pressure measurements. There are three stages we consider: the first stage is pre-learning to initialize good parameters using the bagging technique. In the second stage, we fine-tune the parameters using the ensemble-based recursive methodology that is used to accurately estimate blood pressure and then measure the uncertainty for the systolic blood pressure and diastolic blood pressure in the third stage.

Screening of Weight-Loss Herbal Products for Synthetic Anti-Obesity Adulterants: A Target-Oriented Analysis by Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND

The medical and social impact of being overweight, as well as the difficulty in making long-term changes in diet, physical activity, and pitfalls associated with allopathic management, lure obese individuals to over-the-counter weight-loss herbal products (WHPs). However, the safety of herbals is questionable, as reports from all over the world suggest adulteration with synthetic weight loss agents. Objective: The present study was carried out to develop a rapid and sensitive method to screen potential weight loss adulterants in WHPs. Methodology: We procured 33 licensed brands of WHPs that are available in Puducherry (India) and through web stores. Drug-free spiked herbal matrices were used for internal proficiency testing. Spiked herbal matrices and samples were extracted and centrifuged. The supernatant was collected and subjected to liquid chromatography-tandem mass spectrometry analyses. Isocratic elution was carried out by the mobile phase of methanol: 0.1% v/v formic acid (70%:30% v/v) through a C₁₈ column. Analytes were monitored in electrospray ionization positive and negative modes, and an multiple reaction monitoring (MRM) scan was used. Results: Run time was 12 min. Intra- and inter-day precision was < 15% and recoveries were in the range of 99% to 115%. Limit of quantification (LOQ) of the analytes were in the range of 0.1 to 0.3 ng/ml. Conclusion: We developed a sensitive and rapid validated method for the detection of potential adulterants in WHPs. None of the WHPs analyzed were found to contain adulterants. The proposed method will be useful for routine monitoring. WHPs analyzed in this study were not adulterated indicating that WHPs from licensed sources are reliable.

Computer-Based Substance Use Reporting and Acceptance of HIV Testing Among Emergency Department Patients

More than 10 years after the Centers for Disease Control and Prevention recommended routine HIV testing for patients in emergency departments (ED) and other clinical settings, as many as three out of four patients may not be offered testing, and those who are offered testing frequently decline. The current study examines how participant characteristics, including demographics and reported substance use, influence the efficacy of a video-based intervention designed to increase HIV testing among ED patients who initially declined tests offered by hospital staff. Data from three separate trials in a high volume New York City ED were merged to determine whether patients (N = 560) were more likely to test post-intervention if: (1) they resembled people who appeared onscreen in terms of gender or race; or (2) they reported problem substance use. Chi Square and logistic regression analyses indicated demographic concordance did not significantly increase likelihood of accepting an HIV test. However, participants who reported problem substance use (n = 231) were significantly more likely to test for HIV in comparison to participants who reported either no problem substance use (n = 190) or no substance use at all (n = 125) (x² = 6.830, p < 0.05). Specifically, 36.4% of patients who reported problem substance use tested for HIV post-intervention compared to 30.5% of patients who did not report problem substance use and 28.8% of participants who did not report substance use at all. This may be an important finding because substance use, including heavy alcohol or cannabis use, can lead to behaviors that increase HIV risk, such as sex with multiple partners or decreased condom use.

Post-mitotic odontoblasts in health, disease, and regeneration

OBJECTIVE

Description of the odontoblast lifecycle, an overview of the known complex molecular interactions that occur when the health of the dental pulp is challenged and the current and future management strategies on vital and non-vital teeth.

METHODS

A literature search of the electronic databases included MEDLINE (1966-April 2019), CINAHL (1982-April 2019), EMBASE and EMBASE Classic (1947-April 2019), and hand searches of references retrieved were undertaken using the following MESH terms 'odontoblast*', 'inflammation', 'dental pulp*', 'wound healing' and 'regenerative medicine'.

RESULTS

Odontoblasts have a sensory and mechano-transduction role so as to detect external stimuli that challenge the dental pulp. On detection, odontoblasts stimulate the innate immunity by activating defence mechanisms key in the healing and repair mechanisms of the tooth. A better understanding of the role of odontoblasts within the dental pulp complex will allow an opportunity for biological management to remove the cause of the insult to the dental pulp, modulate the inflammatory process, and promote the healing and repair capabilities of the tooth. Current strategies include use of conventional dental pulp medicaments while newer methods include bioactive molecules, epigenetic modifications and tissue engineering.

CONCLUSION

Regenerative medicine methods are in their infancy and experimental stages at best. This review highlights the future direction of dental caries management and consequently research.

P4439Increased risk of out-of-hospital cardiac arrest in patients with psoriasis - a nationwide case-control study

Background

Chronic inflammatory disorders such as psoriasis have been associated with cardiovascular diseases and linked to proarrhythmogenic electrocardiographic changes, including QT-prolongation. However, evidence regarding the risk of out-of-hospital cardiac arrest with a history of psoriasis is lacking.

Purpose

To investigate the association between psoriasis and out-of-hospital cardiac arrest.

Methods

Through the nationwide Danish Cardiac Arrest Registry, we identified adult out-of-hospital cardiac arrest patients of presumed cardiac cause with and without psoriasis between June 2001 and December 2014. The odds of cardiac arrest were estimated using conditional logistic regression in a case-control design where we matched up to nine controls per case on age, sex and ischemic heart disease. The models were adjusted for comorbidities, concomitant pharmacotherapy and socioeconomic position.

Results

A total of 32,447 out-of-hospital cardiac arrest cases were included and matched with 291,999 controls from the general population. The median age was 72 years, 67% were male and 29% had ischemic heart disease. A total of 607 (1.9%) cases and 4662 (1.6%) controls had psoriasis. Compared with cardiac arrest cases without psoriasis, cases with psoriasis had same age (p=0.718) and gender distribution (p=0.794), higher prevalence of comorbidities such as congestive heart failure (25.7% vs 20.2%, p=0.001), chronic kidney disease (8.9% vs 6.2%, p=0.008) and chronic obstructive pulmonary disease (19.0% vs 14.7%, p=0.005) but had same prevalence of cerebral vascular disease (15.8% vs 14.5%, p=0.351) and peripheral vascular disease (13.3% vs 11.1%, p=0.078). In unadjusted and adjusted analyses, psoriasis was significantly associated with increased odds of cardiac arrest (odds ratio (OR) 1.18 [95% confidence interval (CI) 1.08–1.28] and OR 1.13 [95% CI 1.04–1.23], respectively) (Figure 1).

Conclusion

In this nationwide case-control study, psoriasis was significantly associated with increased odds of out-of-hospital cardiac arrest. Focus on risk factors and prevention of cardiovascular disease in patients with psoriasis is warranted.

Acknowledgement/Funding

None

5225Bystander cardiopulmonary resuscitation and survival in out-of-hospital cardiac arrest of non-cardiac origin

Background

Knowledge about the effect of bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) of non-cardiac origin is lacking. We aimed to investigate the association between bystander CPR and survival in OHCA of presumed non-cardiac origin.

Methods

From the Danish Cardiac Arrest Registry and through linkage with national Danish healthcare registries we identified all adult patients with OHCA of presumed non-cardiac origin in Denmark (2001–2014). These were categorized further into OHCA of medical and non-medical cause. We analyzed temporal trends in bystander CPR and 30-day survival during the study period. Multiple logistic regression was used to examine the association between bystander CPR and 30-day survival and reported as standardized 30-day survival chances with versus without bystander CPR standardized to the prehospital OHCA-factors and patient characteristics of all patients in the study population.

Results

We identified 10,761 OHCAs of presumed non-cardiac origin. Bystander CPR was associated with an increased 30-day survival chance of 3.4% (95% confidence interval [CI]: 2.9–3.9) versus 1.8% (95% CI: 1.4–2.2) with no bystander CPR, corresponding to a significant difference of 1.6% (95% CI: 0.9–2.3). During the study period, the overall bystander CPR rates increased from 13.6% (95% CI: 11.2–16.5) to 62.7% (95% CI: 60.2–65.2). 30-day survival increased overall from 1.3% (95% CI: 0.7–2.6) to 4.0% (95% CI: 3.1–5.2). Similar findings were observed in subgroups of medical and non-medical OHCA.

Table 1. Patient and arrest characteristics according to cause of out-of-hospital cardiac arrest Overall Medical OHCA Non-medical OHCA Patient characteristics   Total patients 10761 7625 3136   Median age,y 67 70 50   Male, n (%) 6357 (59.1) 4154 (54.5) 2204 (70.4) OHCA factors   Witnessed arrest, n (%) 4306 (40.0) 3574 (46.9) 732 (23.3)   Public location, n (%) 6979 (64.9) 5494 (72.1) 1485 (47.4) OHCA, out-of-hospital cardiac arrest; CPR, cardiopulmonary resuscitation.

Figure 1. Temporal trends

Conclusion

Bystander CPR was associated with a higher chance of 30-day survival among OHCA of presumed non-cardiac origin regardless of the underlying cause (medical/non-medical). Rates of bystander CPR and 30-day survival improved during the study period.

Screening of herbal medicines for potential allopathic antidiabetic adulterants: An analytical study

Background:

There are several reports worldwide on adulteration of herbal medicines (HMs) with allopathic drugs. In India, only a few studies have reported adulteration of HMs with antidiabetics and there are no systematic studies.

Aims:

To develop a rapid and validated method for detection of allopathic antidiabetic adulterants and to explore the extent of adulteration in HMs sold in South India.

Materials and Methods:

Standards and solvents were purchased from Sigma-Aldrich. Different brands of antidiabetic HM samples with manufacturing licenses were procured from dispensaries. Spiked drug free psyllium husk as solid and flask seed oil as liquid herbal matrices were used for method development. The spiked matrices with different concentrations were extracted with methanol and subjected to centrifugation. The supernatant was collected and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Isocratic elution was carried on a C18 column with 0.1% (v/v) formic acid:methanol (3:7, v/v) as a mobile phase. All drugs were monitored for two ion products in positive electrospray ionization mode using multiple reaction monitoring scans.

Results:

The retention time was 9 min. Limit of detection is 10 Pictograms (pg) for all analytes except for metformin, which was 370 pg. Recoveries of analytes range from 96% to 117%. Forty different brands of antidiabetic HMs were analyzed. Adulterant peaks were not observed in the mass chromatograms of HMs.

Conclusions:

A single-run method was developed by LC-MS/MS for the detection of proposed antidiabetics in HMs from licensed manufacturing units and online sold HMs across herbal dispensaries in Puducherry union territory, India. None of the HMs was found to be adulterated with proposed allopathic antidiabetic adulterants.

Evaluation of the signal quality of wrist-based photoplethysmography

OBJECTIVE

Wearable devices with embedded photoplethysmography (PPG) sensors enable continuous monitoring of cardiovascular activity, allowing for the detection cardiovascular problems, such as arrhythmias. However, the quality of wrist-based PPG is highly variable, and is subject to artifacts from motion and other interferences. The goal of this paper is to evaluate the signal quality obtained from wrist-based PPG when used in an ambulatory setting.

APPROACH

Ambulatory data were collected over a 24 h period for 10 elderly, and 16 non-elderly participants. Visual assessment is used as the gold standard for PPG signal quality, with inter-rater agreement evaluated using Fleiss' Kappa. With this gold standard, 5 classifiers were evaluated using a modified 13-fold cross-validation approach.

MAIN RESULTS

A Random Forest quality classification algorithm showed the best performance, with an accuracy of 74.5%, and was then used to evaluate 24 h long ambulatory wrist-based PPG measurements.

SIGNIFICANCE

In general, data quality was high at night, and low during the day. Our results suggest wrist-based PPG may be best for continuous cardiovascular monitoring applications during the night, but less useful during the day unless methods can be identified to improve low quality signal segments.

Bystander cardiopulmonary resuscitation and survival in patients with out-of-hospital cardiac arrest of non-cardiac origin

BACKGROUND

Knowledge about the effect of bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) of non-cardiac origin is lacking. We aimed to investigate the association between bystander CPR and survival in OHCA of presumed non-cardiac origin.

METHODS

From the Danish Cardiac Arrest Registry and through linkage with national Danish healthcare registries we identified all patients with OHCA of presumed non-cardiac origin in Denmark (2001-2014). These were categorized further into OHCA of medical and non-medical cause. We analyzed temporal trends in bystander CPR and 30-day survival during the study period. Multiple logistic regression was used to examine the association between bystander CPR and 30-day survival and reported as standardized 30-day survival chances with versus without bystander CPR standardized to the prehospital OHCA-factors and patient characteristics of all patients in the study population.

RESULTS

We identified 10,761 OHCAs of presumed non-cardiac origin. Bystander CPR was associated with a significantly higher 30-day survival chance of 3.4% (95% confidence interval [CI]: 2.9-3.9) versus 1.8% (95% CI: 1.4-2.2) without bystander CPR. A similar association was found in subgroups of both medical and non-medical OHCA. During the study period, the overall bystander CPR rates increased from 13.6% (95% CI: 11.2-16.5) to 62.7% (95% CI: 60.2-65.2). 30-day survival increased overall from 1.3% (95% CI: 0.7-2.6) to 4.0% (95% CI: 3.1-5.2).

CONCLUSION

Bystander CPR was associated with a higher chance of 30-day survival among OHCA of presumed non-cardiac origin regardless of the underlying cause (medical/non-medical). Rates of bystander CPR and 30-day survival improved during the study period.

Classification of Human Posture from Radar Returns Using Ultra-Wideband Radar

There is a great need for new technology that helps ensure the well-being of senior citizens who have compromised health and are at an elevated risk of injury due to falls. Being able to detect posture and postural changes may be helpful in prediction and prevention of impending falls. Ultra-Wideband (UWB) radar is an attractive means for patient monitoring because it is inexpensive, capable of penetrating obstacles, privacy preserving and it consumes little power. In this paper, classification of postures, namely sitting, standing and lying is presented using stand-off sensing using UWB radar in an indoor environment. It is found that using location specific classifiers, overall accuracy can be improved. In this paper, a decision tree classifier capable of achieving 85% overall accuracy is proposed. This classifier uses 33 features from 10 second data sample segments.

A Fast-Iterative Data Association Technique for Multiple Object Tracking

A massive amount of video data is recorded daily for forensic post analysis and computer vision applications. The analyses of this data often require multiple object tracking (MOT). Advancements in image analysis algorithms and global optimization techniques have improved the accuracy of MOT, often at the cost of slow processing speed which limits its applications only to small video datasets. With the focus on speed, a fast-iterative data association technique (FIDA) for MOT that uses a tracking-by-detection paradigm and finds a locally optimal solution with a low computational overhead is introduced. The performance analyses conducted on a set of benchmark video datasets show that the proposed technique is significantly faster (50–600 times) than the existing state-of-the-art techniques that produce a comparable tracking accuracy.

Molecular analysis of anthocyanin biosynthesis pathway genes and their differential expression in mango peel

Mango fruit is cherished by masses for its taste and nutrition, contributed by color, flavor, and aroma. Among these, peel color is an important trait contributing to fruit quality and market value. We attempted to elucidate the role of key genes of the anthocyanin biosynthesis pathway related to fruit peel color from the leaf transcriptome of mango cultivar Amrapali. A total of 108 mined transcript sequences were assigned to the phenylpropanoid-flavonoid pathway from which 15 contigs representing anthocyanin biosynthesis genes were annotated. Alternate splice variants were identified by mapping against genes of Citrus clementina and Vitis vinifera (closest relatives) and protein subcellular localization was determined. Phylogenetic analysis of these pathway genes clustered them into distinct groups aligning with homologous genes of Magnifera indica, C. clementina, and V. vinifera. Expression profiling revealed higher relative fold expressions in mature fruit peel of red-colored varieties (Arunika, Ambika, and Tommy Atkins) in comparison with the green-peeled Amrapali. MiCHS, MiCHI, and MiF3H alternate splice variants revealed differential gene expression. Functionally divergent variants indicate availability of an allelic pool programmed to play critical roles in peel color. This study provides insight into the molecular genetic basis of peel color and offers scope for development of biomarkers in varietal improvement programs.

Steroid administration after anaesthetic induction with etomidate does not reduce in-hospital mortality or cardiovascular morbidity after non-cardiac surgery

BACKGROUND

We tested the primary hypothesis that corticosteroid administration after etomidate exposure reduces a composite of in-hospital mortality and cardiovascular morbidity after non-cardiac surgery.

METHODS

We evaluated ASA physical status III and IV patients who had non-cardiac surgery with general anaesthesia at the Cleveland Clinic. Amongst 4275 patients in whom anaesthesia was induced with etomidate, 804 were also given steroid intraoperatively, mostly dexamethasone at a median dose of 6 mg. We successfully matched 582 steroid patients with 1023 non-steroid patients. The matched groups were compared on composite of in-hospital mortality and cardiovascular morbidity using a generalized-estimating-equation model. Secondly, the matched groups were compared on length of hospital stay using a Cox proportional hazard model, and were descriptively compared on intraoperative blood pressures using a standardized difference.

RESULTS

There was no significant association between intraoperative steroid administration after anaesthetic induction with etomidate and the composite of in-hospital mortality or cardiovascular morbidity; the estimated common odds ratio across the two components of the composite was 0.86 [95% confidence interval (CI): 0.64, 1.16] for steroid vs non-steroid, P=0.33. The duration of postoperative hospitalisation was significantly shorter amongst steroid patients [median (Q1, Q3): 6 (3, 10) days] than non-steroid patients [7 (4, 11) days], with an estimated hazard ratio of 0.89 (0.80, 0.98) for steroid vs non-steroid, P=0.01. Intraoperative blood pressures were similar in steroid and non-steroid patients.

CONCLUSIONS

Steroid administration after induction of anaesthesia with etomidate did not reduce mortality or cardiovascular morbidity.

Dichloro-naphthoquinone as a non-classical inhibitor of the mycobacterial carbonic anhydrase Rv3588c

The soluble mycobacterial carbonic anhydrases Rv3588c and Rv1284 belong to a different class of carbonic anhydrases than those found in humans, making them attractive drug targets by using the inherent differences in the folds of the different classes. By screening a natural product library, we identified naphthoquinone derivatives as a novel non-classical inhibitor scaffold of mycobacterial carbonic anhydrases that lack the sulfonamide/sulfamate group and thus did not affect human carbonic anhydrase II.

Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering

Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44⁺, αSMA⁺, Vimentin⁺ and CD105^- human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children.

Bayesian fusion algorithm for improved oscillometric blood pressure estimation

A variety of oscillometric algorithms have been recently proposed in the literature for estimation of blood pressure (BP). However, these algorithms possess specific strengths and weaknesses that should be taken into account before selecting the most appropriate one. In this paper, we propose a fusion method to exploit the advantages of the oscillometric algorithms and circumvent their limitations. The proposed fusion method is based on the computation of the weighted arithmetic mean of the oscillometric algorithms estimates, and the weights are obtained using a Bayesian approach by minimizing the mean square error. The proposed approach is used to fuse four different oscillometric blood pressure estimation algorithms. The performance of the proposed method is evaluated on a pilot dataset of 150 oscillometric recordings from 10 subjects. It is found that the mean error and standard deviation of error are reduced relative to the individual estimation algorithms by up to 7 mmHg and 3 mmHg in estimation of systolic pressure, respectively, and by up to 2 mmHg and 3 mmHg in estimation of diastolic pressure, respectively.