Clinical Evaluation of the ECG Noise Extraction Tool as a Component of ECG Analysis Algorithms Evaluation.

OBJECTIVE: The aim of this work is to demonstrate the performance of the ECG noise extraction tool (ECGNExT) which provides estimates of ECG noise that are not significantly different from the inherent noise in an ECG generated by motion artifacts and other sources. In addition, this paper elaborates on use of ECGNExT in an algorithm evaluation context comparing two QRS detection algorithms. METHODS: 140 simultaneous pairs of clean ECGs and ECGs corrupted with motion-induced noise from 29 participants under five different and separate motion conditions were collected and analyzed. Estimates of the noise component of the ECGs recorded with noise were obtained using ECGNExT and were then added to the clean ECGs yielding estimated ECGs with noise. Root mean squared error (RMSE) between the recorded and estimated ECGs with noise was calculated for temporal comparison, and band powers of the signals were calculated for spectral comparison. RESULTS: A t-test revealed that the mean RMSE < 150-microvolts with p-value < 0.001 and, and equivalence tests showed that the band powers of the two ECGs were statistically equivalent with . CONCLUSION: ECGNExT can reliably estimate the underlying ECG noise while preserving temporal and spectral features. SIGNIFICANCE: We previously proposed ECGNExT as a component of ECG analysis algorithm testing during noise conditions and reported its performance based on simulated ECG data. This work provides additional support of the performance and functionality of the ECGNExT algorithm from a study with pairs of simultaneously recorded ECGs with and without noise from human subjects.

Effects of Ballistocardiogram Peak Detection Jitters on the Quality of Heart Rate Variability Features: A Simulation-Based Case Study in the Context of Sleep Staging.

Heart rate variability (HRV) features support several clinical applications, including sleep staging, and ballistocardiograms (BCGs) can be used to unobtrusively estimate these features. Electrocardiography is the traditional clinical standard for HRV estimation, but BCGs and electrocardiograms (ECGs) yield different estimates for heartbeat intervals (HBIs), leading to differences in calculated HRV parameters. This study examines the viability of using BCG-based HRV features for sleep staging by quantifying the impact of these timing differences on the resulting parameters of interest. We introduced a range of synthetic time offsets to simulate the differences between BCG- and ECG-based heartbeat intervals, and the resulting HRV features are used to perform sleep staging. Subsequently, we draw a relationship between the mean absolute error in HBIs and the resulting sleep-staging performances. We also extend our previous work in heartbeat interval identification algorithms to demonstrate that our simulated timing jitters are close representatives of errors between heartbeat interval measurements. This work indicates that BCG-based sleep staging can produce accuracies comparable to ECG-based techniques such that at an HBI error range of up to 60 ms, the sleep-scoring error could increase from 17% to 25% based on one of the scenarios we examined.

Noninvasive cardiovascular monitoring based on electrocardiography and ballistocardiography: a feasibility study on patients in the surgical intensive care unit.

The time interval between the peaks in the electroccardiogram (ECG) and ballistocardiogram (BCG) waveforms, TEB, has been associated with the pre-ejection period (PEP), which is an important marker of ventricular contractility. However, the applicability of BCG-related markers in clinical practice is limited by the difficulty to obtain a replicable and consistent signal on patients. In this study, we test the feasibility of BCG measurements within a complex clinical setting, by means of an accelerometer under the head pillow of patients admitted to the Surgical Intensive Care Unit (SICU). The proposed technique proved capable of capturing TEB based on the R peaks in the ECG and the BCG in its head-to-toe and dorso- ventral directions. TEB detection was found to be consistent and repeatable both in healthy individuals and SICU patients over multiple data acquisition sessions. This work provides a promising starting point to investigate how TEB changes may relate to the patients' complex health conditions and give additional clinical insight into their care needs.

Smart bed based daytime behavior prediction in Children with autism spectrum disorder - A Pilot Study.

Monitoring the sleep patterns of children with autism spectrum disorders (ASD) and understanding how sleep quality influences their daytime behavior is an important issue that has received very limited attention. Polysomnography (PSG) is commonly used as a gold standard for evaluating sleep quality in children and adults. However, the intrusive nature of sensors used as part of PSG can themselves affect sleep and is, therefore, not suitable for children with ASD. In this study, we evaluate an unobtrusive and inexpensive bed system for in-home, long-term sleep quality monitoring using ballistocardiogram (BCG) signals. Using the BCG signals from this smart bed system, we define "restlessness" as a surrogate sleep quality estimator. Using this sleep feature, we build predictive models for daytime behavior based on 1-8 previous nights of sleep. Specifically, we use two supervised machine learning algorithms namely support vector machine (SVM) and artificial neural network (ANN). For all daytime behaviors, we achieve more than 78% and 79% accuracy of correctly predicting behavioral issues with both SVM and ANN classifiers, respectively. Our findings indicate the usefulness of our designed bed system and how the restlessness feature can improve the prediction performance.

Bed-Based Ballistocardiography: Dataset and Ability to Track Cardiovascular Parameters.

BACKGROUND: The goal of this work was to create a sharable dataset of heart-driven signals, including ballistocardiograms (BCGs) and time-aligned electrocardiograms (ECGs), photoplethysmograms (PPGs), and blood pressure waveforms. METHODS: A custom, bed-based ballistocardiographic system is described in detail. Affiliated cardiopulmonary signals are acquired using a GE Datex CardioCap 5 patient monitor (which collects ECG and PPG data) and a Finapres Medical Systems Finometer PRO (which provides continuous reconstructed brachial artery pressure waveforms and derived cardiovascular parameters). RESULTS: Data were collected from 40 participants, 4 of whom had been or were currently diagnosed with a heart condition at the time they enrolled in the study. An investigation revealed that features extracted from a BCG could be used to track changes in systolic blood pressure (Pearson correlation coefficient of 0.54 +/- 0.15), dP/dtmax (Pearson correlation coefficient of 0.51 +/- 0.18), and stroke volume (Pearson correlation coefficient of 0.54 +/- 0.17). CONCLUSION: A collection of synchronized, heart-driven signals, including BCGs, ECGs, PPGs, and blood pressure waveforms, was acquired and made publicly available. An initial study indicated that bed-based ballistocardiography can be used to track beat-to-beat changes in systolic blood pressure and stroke volume. SIGNIFICANCE: To the best of the authors' knowledge, no other database that includes time-aligned ECG, PPG, BCG, and continuous blood pressure data is available to the public. This dataset could be used by other researchers for algorithm testing and development in this fast-growing field of health assessment, without requiring these individuals to invest considerable time and resources into hardware development and data collection.

Performance Evaluation of Processing Methods for Ballistocardiogram Peak Detection.

Several methods are proposed in the literature to detect ballistocardiogram (BCG) peaks. There is a need to narrow these methods down in terms of their performance under similar conditions. This study reports early results from a systematic performance evaluation. To date, we have replicated three methods from the literature and compared their performance using data from five volunteers. A basic cross-correlation approach was also included as a baseline level of performance. The best-performing method had an average peak-detection success rate of 95.0{%, associated with 0.1090 average false alarms per second and 0.0078 s mean standard deviation between real and detected peaks.

Activities to Invigorate a Student Chapter of the IEEE Engineering in Medicine and Biology Society.

An IEEE Engineering in Medicine and Biology Society (EMBS) student chapter can play an important service role for collegiate biomedical curricula, supporting (a) faculty and administrators as they offer biomedical programs and work to strengthen industry/community relationships, and (b) students as they engage in engineering skill development and seek industry employment, graduate school opportunities, or medical school placement. This paper summarizes recent projects and activities sponsored by the Kansas State University (KSU) Student Chapter of the IEEE EMBS - efforts intended to maintain interest in the student chapter while supporting its service role. Such a role will become more important in upcoming years in light of the increasing demand for biomedical engineers, especially in the Midwest United States, a reality which motivated the inception of a new KSU undergraduate degree in Biomedical Engineering starting in Fall 2018. The KSU IEEE EMBS student chapter can play a large role in the overall success of this new curriculum, and the projects and activities summarized in this paper are offered as examples to programs that may wish to benefit from an IEEE EMBS student chapter in a similar and meaningful way.

A Pilot Study of an Unobtrusive Bed-Based Sleep Quality Monitor for Severely Disabled Autistic Children.

The link between daytime performance and sleep quality for severely disabled autistic children is not entirely understood. This paper presents nighttime data collected from a child with severe disabilities during a three-night pilot study conducted at Heartspring, Wichita, KS, using a bed-based system capable of unobtrusively tracking parameters for sleep quality assessment. The 'average sample correlation coefficient signal-to-noise ratio' is compared for ballistocardiograms acquired using four electromechanical film sensors versus four load cell sensors. The "best" signal or sensing modality depends on the subject's sleeping position. These results affirm the importance of a bed system that is robust in its ability to track sleep quality accurately regardless of sleeping position.

The prevalence of abnormal leukocyte count, and its predisposing factors, in patients with sickle cell disease in Saudi Arabia.

INTRODUCTION: High white blood cell (WBC) count is an indicator of sickle cell disease (SCD) severity, however, there are limited studies on WBC counts in Saudi Arabian patients with SCD. The aim of this study was to estimate the prevalence of abnormal leukocyte count (either low or high) and identify factors associated with high WBC counts in a sample of Saudi patients with SCD. METHODS: A cross-sectional and retrospective chart review study was carried out on 290 SCD patients who were routinely treated at King Fahad Hospital in Hofuf, Saudi Arabia. An interview was conducted to assess clinical presentations, and we reviewed patient charts to collect data on blood test parameters for the previous 6 months. RESULTS: Almost half (131 [45.2%]) of the sample had abnormal leukocyte counts: low WBC counts 15 (5.2%) and high 116 (40%). High WBC counts were associated with shortness of breath (P=0.022), tiredness (P=0.039), swelling in hands/feet (P=0.020), and back pain (P=0.007). The mean hemoglobin was higher in patients with normal WBC counts (P=0.024), while the mean hemoglobin S was high in patients with high WBC counts (P=0.003). After adjustment for potential confounders, predictors of high WBC counts were male gender (adjusted odds ratio [aOR]=3.63) and patients with cough (aOR=2.18), low hemoglobin (aOR=0.76), and low heart rate (aOR=0.97). CONCLUSION: Abnormal leukocyte count was common: approximately five in ten Saudi SCD patients assessed in this sample. Male gender, cough, low hemoglobin, and low heart rate were associated with high WBC count. Strategies targeting high WBC count could prevent disease complication and thus could be beneficial for SCD patients.

Saudi SCD patients' symptoms and quality of life relative to the number of ED visits.

BACKGROUND: Individuals living with sickle cell disease (SCD) have significantly increased emergency department (ED) use compared to the general population. In Saudi Arabia, health care is free for all individuals and therefore has no bearing on increased ED visits. However, little is known about the relationship between quality of life (QoL) and frequency of acute care utilization in this patient population. METHODS: A cross-sectional study was conducted on 366 patients with SCD who attended the outpatient department at King Fahad Hospital, Hofuf, Saudi Arabia. Data were collected through self-administered surveys, which included: demographics, SCD-related ED visits, clinical issues, and QoL levels. We assessed the ED use by asking for the number of SCD-related ED visits within a 6-month period. RESULTS: The self-report survey of ED visits was completed by 308 SCD patients. The median number of SCD-related ED visits within a 6-month time period (IQR) was four (2-7 visits). According to the unadjusted negative binomial model, the rate of SCD-related ED visits increased by (46, 39.3, 40, and 53.5 %) for patients with fever, skin redness with itching, swelling, and blood transfusion, respectively. Poor QoL tends to increase the rate of SCD-related ED visits. Well education and poor general health positively influenced the rate of SCD-related ED visits. Well education tends to increase the rate of SCD-related ED visits by 50.2 %. The rate of SCD-related ED visits decreased by 1.4 % for every point increase in general health. CONCLUSION: Saudi patients with sickle cell disease reported a wide range of SCD-related ED visits. It was estimated that six of 10 SCD patients had at least three ED visits within a 6-month period. Well education and poor general health resulted in an increase in the rate of SCD-related ED visits.

Bed-based instrumentation for unobtrusive sleep quality assessment in severely disabled autistic children.

The relationship between sleep quality and daytime wellness and performance in severely disabled, autistic children is not well understood. While polysomnography and, more recently, actigraphy serve as means to obtain sleep assessment data from neurotypical children and adults, these techniques are not well-suited to severely autistic children. This paper presents recent progress on a bed sensor suite that can unobtrusively track physiological and behavioral parameters used to assess sleep quality. Electromechanical films and load cells provide data that yield heart rate, respiration rate, center of position, in-and-out-of-bed activity, and general movement, while thermocouples are used to detect bed-wetting events.

Health-related quality of life in patients with sickle cell disease in Saudi Arabia.

BACKGROUND: There is a lack of research concerning health-related quality of life (HRQoL) in Saudi patients with sickle cell disease (SCD), particularly among adult populations. The aim of the current study was to describe the characteristics of SCD patients and their impact on their quality of life (QoL). METHODS: Six hundred twenty-nine adult SCD patients who attended King Fahad Hospital in Hofuf and King Fahad Central Hospital in Jazan were included in the analysis. Demographic/clinical data were collected and an Arabic version of the Medical Outcomes 36-Item Short-Form Health Survey (SF-36) questionnaire was used to assess QoL. RESULTS: SCD patients who hold a university degree reported positive impacts on the following domains of SF-36: physical role function, vitality, emotional well being, social function, pain reduction, and general health (P = .002, P = .001, P = .001, P = .003, P = .004, and P = .001, respectively). In general, patients with fever, skin redness, swelling, or history of blood transfusion tended to impair the health status of the SF-36. A multivariate analysis revealed that patients with a university degree tended to report high scores of physical role functions, emotional role function, and vitality. Patients with regular exercise tend to increase vitality, social function, general health, and reduce pain. Unemployment tends to lessen vitality and worsen pain. On average, pain, social function, and physical function scores tended to worsen in patients with swelling or history of blood transfusion. CONCLUSIONS: This study highlighted that poor education, fever, skin redness, and swelling were negatively associated with specific components of SF-36. SCD patients with a history of blood transfusion found their QoL poorer, whereas regular exercise tended to improve QoL.

Prevalence of beta-thalassemia trait in premarital screening in Al-Hassa, Saudi Arabia.

BACKGROUND: The Al-Hassa area is one of the regions in Saudi Arabia where hemoglobinopathies are prevalent. The Saudi Ministry Of Heath designed a protocol for premarital testing after the royal decree in December 2003. The protocol was implemented in a February 2004 order. The aim of this study was to determine the prevalence of beta-thalassemia trait among subjects coming for premarital screening in the Al-Hassa area. SUBJECTS AND METHODS: From February 2004 to November 2004, healthy subjects coming to six marriages consultation centers in the Al-Hassa area underwent routine mandatory tests. Subjects were considered to have beta-thalassemia trait if they had a mean corpuscular volume (MCV) <80 fL and/or a mean corpuscular hemoglobin (MCH) <27 pg and a hemoglobin A2 level >3.2%. Venous blood was taken into an EDTA tube and the complete blood count and red blood cell indices were measured by a Coulter automated cell counter on the same day of hemoglobin collection. Electrophoresis was done on cellulose acetate. RESULTS: All Saudi participants (n=8918), including 4218 (47.3%) males and 4700 (52.7%) females were screened. The prevalence of beta-thassemia trait with high hemoglobin A2 and microcytic hypochromic anemia was 3.4% (307/8918). CONCLUSION: In countries with a high prevalence of hemoglobinopathies, a premarital screening program is helpful for identification and prevention of high-risk marriages. With a 3.4% prevalence of beta-thalassemia trait in premarital couples, future comprehensive programs are needed to know the actual prevalence of beta-thalassemia in Al-Hassa.