Microcomputer-based respiratory function monitoring system using impedance pneumography
Although information concerned with ventilatory dynamics is indispensable, especially with regard to the care of a critically ill patient, the data available is often very limited, because the currently used methods of ascertaining data are invasive and not tolerable for patients who are still conscious and neither intubated nor tracheotomised. From this viewpoint, a respiratory function monitoring system was developed, using a non-invasive ventilatory volume monitor based on the electrical impedance method as a key component. The system is composed of two ventilatory volume monitors connected to two patients and a central monitor. The central monitor acquires online data transmitted from ventilatory volume monitors and stores then in floppy-disc memory together with off-line data, such as blood gases, blood chemistry and urine volume. These data may be retrieved and displayed on a visual display unit in the form of tables, trend graphs or specially designed graphs. Hard copies can be made on demand. According to the accumulated results obtained from respiratory failure patients, it is now clear that the introduction of the system into medical practice would facilitate more accurate analysis of respiratory and circulatory pathophysiology for the type of patient mentioned. Furthermore, the physical responses to various respiratory and circulatory treatments can be obtained in more detail and the course of these patients' illness can be reviewed more systematically.
KeywordsImpedance pneumography Microcomputer Monitoring system Respiratory function
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- Buchbinder, N. andGanz, W. (1976) Hemodynamic monitoring: invasive techniques.Anesthesiology,45, 146–155.Google Scholar
- Crane, R. A. andStuttard, B. (1976) A digital technique for linearizing the output of a turbine anemometer.Biomedical Eng., Jan. 19–21.Google Scholar
- Itoh, A., Ishida, A., Kikuchi, N., Okazaki, N., Ishihara, T. andKira, S. (1981) Non-invasive ventilatory volume monitor.Med. & Biol. Eng. & Comput.,20, 613–619.Google Scholar
- Osborn, J. J. (1977) Cardiopulmonary monitoring in the respiratory intensive care unit.Medical Instrumentation,11, 278–282.Google Scholar
- Sykes, M. K., McNicol, M. W. andCampbell, E. J. M. (1971)Respiratory failure. Blackwell Scientific Publications, London.Google Scholar
- Turney, S. Z. andBlumenfeld, W. (1973) Heated Fleich pneumotachometer: a calibration procedure.J. Appl. Physiol.,34, 117–121.Google Scholar
- Wilson, R. S. (1976) Monitoring the lung: Mechanics and volume.Anesthesiology,45, 135–145.Google Scholar