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An adaptive framework for real-time ECG transmission in mobile environments.

Kang K - ScientificWorldJournal (2014)

Bottom Line: According to this observation, we have devised a simple and efficient real-time scheduling algorithm based on the earliest deadline first (EDF) policy, which decides the order of transmitting or retransmitting packets that contain ECG data at any given time for the delivery of scalable ECG data over a lossy channel.The algorithm takes into account the differing priorities of packets in each layer, which prevents the perceived quality of the reconstructed ECG signal from degrading abruptly as channel conditions worsen, while using the available bandwidth efficiently.Extensive simulations demonstrate this improvement in perceived quality.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Hanyang University, Ansan 426-791, Republic of Korea.

ABSTRACT
Wireless electrocardiogram (ECG) monitoring involves the measurement of ECG signals and their timely transmission over wireless networks to remote healthcare professionals. However, fluctuations in wireless channel conditions pose quality-of-service challenges for real-time ECG monitoring services in a mobile environment. We present an adaptive framework for layered coding and transmission of ECG data that can cope with a time-varying wireless channel. The ECG is segmented into layers with differing importance with respect to the quality of the reconstructed signal. According to this observation, we have devised a simple and efficient real-time scheduling algorithm based on the earliest deadline first (EDF) policy, which decides the order of transmitting or retransmitting packets that contain ECG data at any given time for the delivery of scalable ECG data over a lossy channel. The algorithm takes into account the differing priorities of packets in each layer, which prevents the perceived quality of the reconstructed ECG signal from degrading abruptly as channel conditions worsen, while using the available bandwidth efficiently. Extensive simulations demonstrate this improvement in perceived quality.

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Related in: MedlinePlus

Layer-based EDF scheduling algorithm.
© Copyright Policy - open-access
Related In: Results  -  Collection


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alg1: Layer-based EDF scheduling algorithm.

Mentions: Owing to the proposed layered representation of ECG data, it is intuitive to consider relative “importance” of the data in the scalable ECG stream in order to avoid abrupt degradation in the quality of the ECG signal. The loss of consecutive ECG symbols has a greater effect on the ECG signal than the loss of a few random symbols. Therefore, it is desirable to prioritize the delivery of packets in the BL or lower ELs, even under severe channel conditions. For this purpose, we assign higher priority to packets in the lower layer; these can then be transmitted earlier, with a greater opportunity for retransmission in the case of loss. Packets in the same layer are served according to earliest deadline first (EDF) policy. The scheme improves bandwidth utilization and the readability of the ECG signal in the case of some data loss via the prioritization of the low-frequency data in the BL or lower ELs. A detailed description of the algorithm is provided in Algorithm 1.


An adaptive framework for real-time ECG transmission in mobile environments.

Kang K - ScientificWorldJournal (2014)

Layer-based EDF scheduling algorithm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4109261&req=5

alg1: Layer-based EDF scheduling algorithm.
Mentions: Owing to the proposed layered representation of ECG data, it is intuitive to consider relative “importance” of the data in the scalable ECG stream in order to avoid abrupt degradation in the quality of the ECG signal. The loss of consecutive ECG symbols has a greater effect on the ECG signal than the loss of a few random symbols. Therefore, it is desirable to prioritize the delivery of packets in the BL or lower ELs, even under severe channel conditions. For this purpose, we assign higher priority to packets in the lower layer; these can then be transmitted earlier, with a greater opportunity for retransmission in the case of loss. Packets in the same layer are served according to earliest deadline first (EDF) policy. The scheme improves bandwidth utilization and the readability of the ECG signal in the case of some data loss via the prioritization of the low-frequency data in the BL or lower ELs. A detailed description of the algorithm is provided in Algorithm 1.

Bottom Line: According to this observation, we have devised a simple and efficient real-time scheduling algorithm based on the earliest deadline first (EDF) policy, which decides the order of transmitting or retransmitting packets that contain ECG data at any given time for the delivery of scalable ECG data over a lossy channel.The algorithm takes into account the differing priorities of packets in each layer, which prevents the perceived quality of the reconstructed ECG signal from degrading abruptly as channel conditions worsen, while using the available bandwidth efficiently.Extensive simulations demonstrate this improvement in perceived quality.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Hanyang University, Ansan 426-791, Republic of Korea.

ABSTRACT
Wireless electrocardiogram (ECG) monitoring involves the measurement of ECG signals and their timely transmission over wireless networks to remote healthcare professionals. However, fluctuations in wireless channel conditions pose quality-of-service challenges for real-time ECG monitoring services in a mobile environment. We present an adaptive framework for layered coding and transmission of ECG data that can cope with a time-varying wireless channel. The ECG is segmented into layers with differing importance with respect to the quality of the reconstructed signal. According to this observation, we have devised a simple and efficient real-time scheduling algorithm based on the earliest deadline first (EDF) policy, which decides the order of transmitting or retransmitting packets that contain ECG data at any given time for the delivery of scalable ECG data over a lossy channel. The algorithm takes into account the differing priorities of packets in each layer, which prevents the perceived quality of the reconstructed ECG signal from degrading abruptly as channel conditions worsen, while using the available bandwidth efficiently. Extensive simulations demonstrate this improvement in perceived quality.

Show MeSH
Related in: MedlinePlus