Single-channel Electrocardiogram Research Articles

Prenatal and Perinatal Complications: Is It the Link Between Race and SES and Childhood Sleep Disordered Breathing?

Recent evidence has suggested that low socioeconomic status (SES), race, prematurity, and maternal smoking during pregnancy are associated with childhood sleep disordered breathing (SDB). We investigated (1) the association of SDB with a wide range of risk factors, including prenatal and perinatal complications; (2) the association of these complications with SES and race; and (3) the association of SDB with developmental milestones. Six hundred thirteen school-aged children (105 clinically referred and 508 community control subjects) underwent overnight polysomnography and had a complete history and physical examination. A comprehensive child development questionnaire was completed by a parent. We compared clinically referred children with SDB to population-based control children without SDB from The Penn State Children's Cohort. Maternal smoking during pregnancy; maternal age and weight gain during pregnancy; prenatal complications, such as maternal high blood pressure and gestational diabetes; perinatal complications related to prematurity; delayed motor milestones; race and SES were significantly associated with the presence of childhood SDB. Most of the risk factors became nonsignificant when analyses controlled for race and SES. Delayed motor milestones remained significantly associated with SDB after controlling for race and SES. These data suggest that there is a significant association between children who experience prenatal or perinatal distress and the development of moderate to severe childhood SDB. SES and race may be mediating the impact on SDB through increased prenatal and perinatal risks. The significant delay in motor milestones suggests that prenatal and perinatal distress may result in neurologic insult, which could influence the development of SDB in later childhood.

Design of 100 μW Wireless Sensor Nodes for Biomedical Monitoring

Wireless sensor nodes span a wide range of applications. This paper focuses on the biomedical area, more specifically on healthcare monitoring applications. Power dissipation is the dominant design constraint in this domain. This paper shows the different steps to develop a digital signal processing architecture for a single channel electrocardiogram application, which is used as an application example. The target power consumption is 100 μW as that is the power energy scavengers can deliver. We follow a bottleneck-driven approach: first the algorithm is tuned to the target processor, then coarse grained clock-gating is applied, next the static as well as the dynamic dissipation of the digital processor is reduced by tuning the core to the target domain. The impact of each step is quantified. A solution of 11 μW is possible for both radio and DSP running the electrocardiogram algorithm.

Enhancement of sleep stability with Tai Chi exercise in chronic heart failure: Preliminary findings using an ECG-based spectrogram method

Objective To assess the effects of a 12-week Tai Chi exercise program on sleep using the sleep spectrogram, a method based on a single channel electrocardiogram (ECG)-derived estimation of cardiopulmonary coupling, previously shown to identify stable and unstable sleep states. Methods We retrospectively analyzed 24-h continuous ECG data obtained in a clinical trial of Tai Chi exercise in patients with heart failure. Eighteen patients with chronic stable heart failure, left ventricular ejection fraction ⩽40% (mean [±standard deviation] age, 59 ± 14 years, mean baseline ejection fraction 24% ± 8%, mean) were randomly assigned to receive usual care ( N = 10), which included pharmacological therapy and dietary and exercise counseling, or 12 weeks of Tai Chi training ( N = 8) in addition to usual care. Using the ECG-based sleep spectrogram, we compared intervention and control groups by evaluating baseline and 12-week high (stable) and low (unstable) frequency coupling (HFC & LFC, respectively) as a percentage of estimated total sleep time (ETST). Results At 12 weeks, those who participated in Tai Chi showed a significant increase in HFC (+0.05 ± 0.10 vs. −0.06 ± 0.09 % ETST, p = 0.04) and significant reduction in LFC (−0.09 ± 0.09 vs. +0.13 ± 0.13 % ETST, p < 0.01), compared to patients in the control group. Correlations were seen between improved sleep stability and better disease-specific quality of life. Conclusions Tai Chi exercise may enhance sleep stability in patients with chronic heart failure. This sleep effect may have a beneficial impact on blood pressure, arrhythmogenesis and quality of life.

A Wrist-Worn Integrated Health Monitoring Instrument with a Tele-Reporting Device for Telemedicine and Telecare

In this paper, the prototype development of a wrist-worn integrated health monitoring device (WIHMD) with tele-reporting function for emergency telemedicine and home telecare for the elderly is reported. The WIHMD consists of six vital biosignal measuring modules, which include a fall detector, a single-channel electrocardiogram, noninvasive blood pressure, pulse oximetry (SpO2), respiration rate, and body surface temperature measuring units. The size of the WIHMD is 60times50times20 mm, except the wrist cuff, and the total system weighs 200 g, including two 1.5-V AAA-sized batteries. The functional objective of the WIHMD is to provide information concerning current condition, such as vital biosignals and locational information, with compromised fidelity to experts at a distance through the commercial cellular phone network. The developed system will provide the facility for rapid and appropriate directions to be given by experts in emergency situations and will enable the user or caregiver to manage changes in health condition with helpful treatment

Multichannel ECG compression using multichannel adaptive vector quantization.

Adaptive vector quantization (AVQ) is a recently proposed approach for electrocardiogram (ECG) compression. The adaptability of the approach can be used to control the quality of reconstructed signals. However, like most of other ECG compression methods, AVQ only deals with the single-channel ECG, and for the multichannel (MC) ECG, coding ECG signals on a channel by channel basis is not efficient, because the correlation across channels is not exploited. To exploit this correlation, an MC version of AVQ is proposed. In the proposed approach, the AVQ index from each channel is collected to form a new input vector. The vector is then vector quantized adaptively using one additional codebook called index codebook. Both the MIT/BIH database and a clinical Holter database are tested. The experimental results show that, for exactly the same quality of reconstructed signals, the MC-AVQ performs better than single-channel AVQ in terms of bit rate. A theoretical analysis supporting this result is also demonstrated in this paper. For the same and relatively good visual quality, the average compressed data rate/channel is reduced from 293.5 b/s using the single-channel AVQ to 238.2 b/s using the MC-AVQ in the MIT/BIH case.

Environmental Noise and Sleep—A Study of Arousals, Cardiac Arrhythmia and Urinary Catecholamines

Nine adult subjects with documented cardiac arrhythmia were studied during 4 nights of sleep in a laboratory. A sleep polygraph and single-channel electrocardiogram were recorded continuously throughout each night. After the 1st night's familiarization, the subjects were presented with 1 night each of 50 calibrated aircraft or truck noise events. One other night was noise-free. Intervals containing noise and paired quiet intervals were examined for sleep stage at interval onset, number of sleep stage changes and ventricular premature contractions (VPCs). Overnight urinary catecholamines were also assayed. It was found that noise increased the likelihood of arousal responses to the same extent in all sleep stages (p < 0.05). Four subjects showed frequent VPCs during the experiment. These VPCs were significantly related to sleep stage (p < 0.05) but not to noise events. Excretion of urinary catecholamines did not differ between noise and quiet nights.