Thorax Physiological Monitoring and Modeling for Diagnosis of Pulmonary Edema

Introduction

A number of methods existing for the diagnosis in the area of diagnosis of Pulmonary Edema with and without the involvement (Urooj & Khan, 2010) of transthoracic electrical impedance measurement. The available literature leads to the systems which are capable to workout strictly in a clinical environment and dependent on a lot of instrumental set-ups. These set-ups may include electrode configurations, bio-impedance analyzers based on bulky 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 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.