Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Sep 27;12(10):13167-84.
doi: 10.3390/s121013167.

Development of a respiratory inductive plethysmography module supporting multiple sensors for wearable systems

Zhengbo Zhang  1 , Jiewen Zheng, Hao Wu, Weidong Wang, Buqing Wang, Hongyun Liu
Affiliations

Development of a respiratory inductive plethysmography module supporting multiple sensors for wearable systems

Zhengbo Zhang et al. Sensors (Basel). .

Abstract

In this paper, we present an RIP module with the features of supporting multiple inductive sensors, no variable frequency LC oscillator, low power consumption, and automatic gain adjustment for each channel. Based on the method of inductance measurement without using a variable frequency LC oscillator, we further integrate pulse amplitude modulation and time division multiplexing scheme into a module to support multiple RIP sensors. All inductive sensors are excited by a high-frequency electric current periodically and momentarily, and the inductance of each sensor is measured during the time when the electric current is fed to it. To improve the amplitude response of the RIP sensors, we optimize the sensing unit with a matching capacitor parallel with each RIP sensor forming a frequency selection filter. Performance tests on the linearity of the output with cross-sectional area and the accuracy of respiratory volume estimation demonstrate good linearity and accurate lung volume estimation. Power consumption of this new RIP module with two sensors is very low. The performance of respiration measurement during movement is also evaluated. This RIP module is especially desirable for wearable systems with multiple RIP sensors for long-term respiration monitoring.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Block diagram of how PAM works in the RIP module.
Figure 2.
Figure 2.
Description of how TDM works in the RIP module.
Figure 3.
Figure 3.
The structure of a parallel LC sensing unit and the impedance-frequency relationship of the transducer with variable inductance. (a) A parallel LC sensing unit; (b) Transfer function of the LC sensing unit.
Figure 4.
Figure 4.
System block diagram of the RIP module.
Figure 5.
Figure 5.
Illustration of the self-made apparatus for RIP performance test.
Figure 6.
Figure 6.
Relationship between RIP output voltage and coil cross-sectional area. Regression line is based on linear polynomial least-square fit.
Figure 7.
Figure 7.
The weighted sum of RC and AB band signals during normal breathing and simulated airway obstruction.
Figure 8.
Figure 8.
RC and AB respiration and accelerometer reference signal during standing and running. (a) respiration during standing; (b) respiration during running.
Figure 9.
Figure 9.
Output of adaptive filtering using least mean square (LMS) algorithm with accelerometer signal as reference.
Figure 10.
Figure 10.
RIP band signals at the level of the xiphoid and ECG during normal breathing and simulated breath holding.
See this image and copyright information in PMC

References

    1. Carry P.Y., Baconnier P., Eberhard A., Cotte P., Benchetrit G. Evaluation of respiratory inductive plethysmography: Accuracy for analysis of respiratory waveforms. Chest. 1997;111:910–915. - PubMed
    1. Fiamma M.N., Samara Z., Baconnier P., Similowski T., Straus C. Respiratory inductive plethysmography to assess respiratory variability and complexity in humans. Respir. Physiol. Neurobiol. 2007;156:234–239. - PubMed
    1. Bradley J., Kent M.L., O'Neill B., Nevill A., Boyle L., Elborn J.S. Cardiorespiratory measurements during field tests in CF: Use of an ambulatory monitoring system. Pediatr. Pulmonol. 2011;46:253–260. - PubMed
    1. Iber C., Ancoli-Israel S., Chesson A., Quan S. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications. 1st ed. American Academy of Sleep Medicine; Westchester, IL, USA: 2007.
    1. Grossman P. The LifeShirt: A multi-function ambulatory system monitoring health, disease, and medical intervention in the real world. Stud. Health Technol. Inf. 2004;108:133–141. - PubMed

Publication types

MeSH terms

LinkOut - more resources