Thorax Physiological Monitoring and Modeling for Diagnosis of Pulmonary Edema

In this paper, the authors prove that variations in thoracic volumes are greatly responsive to the act of breathing (i.e., inspiration and expiration). These variations may be adopted for diagnosing various respiration related diseases and pulmonary edema. In this study, the authors present a method to estimate the thoracic volume non-invasively using anthropometric dimensions. The change in the geometry of thorax with the act of breathe is recorded by measuring the anthropometric parameters for nine healthy human subjects. The model based approach shows the extent of its sensitivity in terms of volumetric variations with the state of inspiration and expiration. Many deaths occur due to unavailability of health care and monitoring systems in rural areas and developing countries. The technique presented in this paper takes care of these situations and the volumetric estimation of thorax is independent of any instrumentation, expensive equipment, and clinical environment. and expensive electronic circuitry. Above all these set-ups are available only in urban and developed area. Model based approaches are also encountered in the survey of literature but most of them are based on involvement of electrical impedance plethysmography and deep study of other input quantities. A simple cylindrical model is also discussed in sub-sequent section which is also based on a lot of physiological aspects of cardiac cycles. Keeping in view, all these points a non-invasive, simple and fairly adoptable model based technique is presented in this paper for diagnosis of various diseases. The considered methodology is sensitive to DOI: 10.4018/ijmtie.2011040104 International Journal of Measurement Technologies and Instrumentation Engineering, 1(2), 54-60, April-June 2011 55 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. the act of breathe and hence able to estimate volume of thorax in the state of inspiration and expiration. Pulmonary edema is fluid accumulation in the lungs, which collects in air sacs. This fluid collects in air sacs in the lungs, making it difficult to breathe. It leads to impaired gas exchange and may cause respiratory failure. According to medical dictionary it is defined as the edema of lungs usually resulting from mitral stenosis or left ventricular failure. Pulmonary Edema occurs in the same way that edema occurs elsewhere in the body. When the lungs expand and contract during normal breathing, they slide back and forth within the pleural cavity. To facilitate this, a thin layer of mucoid fluid lies between the parietal and visceral pleurae. The pleural membrane is a porous, mesenchymal, serous membrane through which small amounts of interstitial fluid carry with them tissue proteins, giving the pleural fluid a mucoid characteristic, which is what allows extremely easy slippage of the moving lungs. The total amount of fluid in each pleural cavity is normally slight, only a few milliliters. Whenever the quantity becomes more than barely enough to begin flowing in the pleural cavity, the excess fluid is pumped away by lymphatic vessels opening directly from the pleural cavity. Thus by analyzing the work of breathe the amount of fluid can be predicted in terms of thoracic volume variations.