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Instantaneous Respiratory Estimation from Thoracic Impedance by Empirical Mode Decomposition.

Wang FT, Chan HL, Wang CL, Jian HM, Lin SH - Sensors (Basel) (2015)

Bottom Line: This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring.Moreover, large motion artifacts disable the EMD to decompose respiratory components.A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Hwa Hsia University of Technology, 111, Gongzhuan Rd., Zhonghe, New Taipei City 23568, Taiwan. wft.intuitive@seed.net.tw.

ABSTRACT
Impedance plethysmography provides a way to measure respiratory activity by sensing the change of thoracic impedance caused by inspiration and expiration. This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring. The empirical mode decomposition (EMD) can decompose a signal into several intrinsic mode functions (IMFs) that disclose nonstationary components as well as stationary components and, similarly, capture respiratory episodes from thoracic impedance. However, upper-body movements usually produce motion artifacts that are not easily removed by digital filtering. Moreover, large motion artifacts disable the EMD to decompose respiratory components. In this paper, motion artifacts are detected and replaced by the data mirrored from the prior and the posterior before EMD processing. A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation. Based on the experiments performing a series of static and dynamic physical activates, our results showed the proposed method had higher cross correlations between respiratory frequencies estimated from thoracic impedance and those from oronasal airflow based on small window size compared to the Fourier transform-based method.

No MeSH data available.


Related in: MedlinePlus

(a) Cheyne–Stokes respiration and its instantaneous amplitude (red line) reconstructed from the thoracic impedance by the proposed EMD-based method in a patient with congestive heart failure; (b) detailed respiratory properties displayed in the Hilbert spectrum estimated from respiration-related intrinsic mode functions (IMFs) individually; (c) a clear time-related respiratory pattern displayed in the aggregated spectrum from all respiration-related IMFs.
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sensors-15-16372-f008: (a) Cheyne–Stokes respiration and its instantaneous amplitude (red line) reconstructed from the thoracic impedance by the proposed EMD-based method in a patient with congestive heart failure; (b) detailed respiratory properties displayed in the Hilbert spectrum estimated from respiration-related intrinsic mode functions (IMFs) individually; (c) a clear time-related respiratory pattern displayed in the aggregated spectrum from all respiration-related IMFs.

Mentions: Figure 8 illustrates an example of shortness of breath, also named Cheyne–Stokes respiration, in a patient with congestive heart failure. Figure 8a shows the reconstructed respiration from the thoracic impedance by the proposed EMD-based method. Its instantaneous amplitude (red line) was computed based on Equation (14). The Hilbert spectrum derived from respiration-related IMFs individually displays detailed respiratory properties (Figure 8b), whereas the aggregated spectrum from all respiration-related IMFs shows a clear time-related respiratory pattern (Figure 8c).


Instantaneous Respiratory Estimation from Thoracic Impedance by Empirical Mode Decomposition.

Wang FT, Chan HL, Wang CL, Jian HM, Lin SH - Sensors (Basel) (2015)

(a) Cheyne–Stokes respiration and its instantaneous amplitude (red line) reconstructed from the thoracic impedance by the proposed EMD-based method in a patient with congestive heart failure; (b) detailed respiratory properties displayed in the Hilbert spectrum estimated from respiration-related intrinsic mode functions (IMFs) individually; (c) a clear time-related respiratory pattern displayed in the aggregated spectrum from all respiration-related IMFs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541883&req=5

sensors-15-16372-f008: (a) Cheyne–Stokes respiration and its instantaneous amplitude (red line) reconstructed from the thoracic impedance by the proposed EMD-based method in a patient with congestive heart failure; (b) detailed respiratory properties displayed in the Hilbert spectrum estimated from respiration-related intrinsic mode functions (IMFs) individually; (c) a clear time-related respiratory pattern displayed in the aggregated spectrum from all respiration-related IMFs.
Mentions: Figure 8 illustrates an example of shortness of breath, also named Cheyne–Stokes respiration, in a patient with congestive heart failure. Figure 8a shows the reconstructed respiration from the thoracic impedance by the proposed EMD-based method. Its instantaneous amplitude (red line) was computed based on Equation (14). The Hilbert spectrum derived from respiration-related IMFs individually displays detailed respiratory properties (Figure 8b), whereas the aggregated spectrum from all respiration-related IMFs shows a clear time-related respiratory pattern (Figure 8c).

Bottom Line: This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring.Moreover, large motion artifacts disable the EMD to decompose respiratory components.A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Hwa Hsia University of Technology, 111, Gongzhuan Rd., Zhonghe, New Taipei City 23568, Taiwan. wft.intuitive@seed.net.tw.

ABSTRACT
Impedance plethysmography provides a way to measure respiratory activity by sensing the change of thoracic impedance caused by inspiration and expiration. This measurement imposes little pressure on the body and uses the human body as the sensor, thereby reducing the need for adjustments as body position changes and making it suitable for long-term or ambulatory monitoring. The empirical mode decomposition (EMD) can decompose a signal into several intrinsic mode functions (IMFs) that disclose nonstationary components as well as stationary components and, similarly, capture respiratory episodes from thoracic impedance. However, upper-body movements usually produce motion artifacts that are not easily removed by digital filtering. Moreover, large motion artifacts disable the EMD to decompose respiratory components. In this paper, motion artifacts are detected and replaced by the data mirrored from the prior and the posterior before EMD processing. A novel intrinsic respiratory reconstruction index that considers both global and local properties of IMFs is proposed to define respiration-related IMFs for respiration reconstruction and instantaneous respiratory estimation. Based on the experiments performing a series of static and dynamic physical activates, our results showed the proposed method had higher cross correlations between respiratory frequencies estimated from thoracic impedance and those from oronasal airflow based on small window size compared to the Fourier transform-based method.

No MeSH data available.


Related in: MedlinePlus