Journal article
Servo-controlled pneumatic pressure oscillator for respiratory impedance measurements and high-frequency ventilation
Annals of biomedical engineering, Vol.32(4), pp.596-608
04/2004
DOI: 10.1023/b:abme.0000019179.87974.7d
PMID: 15117033
Abstract
The ability to provide forced oscillatory excitation of the respiratory system can be useful in mechanical impedance measurements as well as high frequency ventilation (HFV). Experimental systems currently used for generating forced oscillations are limited in their ability to provide high amplitude flows or maintain the respiratory system at a constant mean pressure during excitation. This paper presents the design and implementation of a pneumatic pressure oscillator based on a proportional solenoid valve. The device is capable of providing forced oscillatory excitations to the respiratory system over a bandwidth suitable for mechanical impedance measurements and HVF. It delivers high amplitude flows (> 1.4 l/s) and utilizes a servo-control mechanism to maintain a load at a fixed mean pressure during simultaneous oscillation. Under open-loop conditions, the device exhibited a static hysteresis of approximately 7%, while its dynamic magnitude and phase responses were flat out to 10 Hz. Broad-band measurement of total harmonic distortion was approximately 19%. Under closed-loop conditions, the oscillator was able to maintain a mechanical test load at both positive and negative mean pressures during oscillatory excitations from 0.1 to 10.0 Hz. Impedance of the test load agreed closely with theoretical predictions. We conclude that this servo-controlled oscillator can be a useful tool for respiratory impedance measurements as well as HFV.
Details
- Title: Subtitle
- Servo-controlled pneumatic pressure oscillator for respiratory impedance measurements and high-frequency ventilation
- Creators
- David W Kaczka - Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. dkaczka1@jhmi.eduKenneth R Lutchen
- Resource Type
- Journal article
- Publication Details
- Annals of biomedical engineering, Vol.32(4), pp.596-608
- Publisher
- United States
- DOI
- 10.1023/b:abme.0000019179.87974.7d
- PMID
- 15117033
- ISSN
- 0090-6964
- eISSN
- 1573-9686
- Grant note
- R01 HL-62269-02 / NHLBI NIH HHS HL-050515 / NHLBI NIH HHS
- Language
- English
- Date published
- 04/2004
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Anesthesia
- Record Identifier
- 9984007286202771
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