ESTIMATING THE VALUE OF THE VOLUME FROM ACCELERATION ON THE DIAPHRAGM MOVEMENTS DURING BREATHING

Abstract

Information related to the movements of the diaphragm is very important and it is used in the detection of some respiratory diseases, which are common in all over the world, such as chronic obstructive pulmonary disease (COPD), asthma, and bronchitis. This article describes a practical method for estimating the value of the volume using the acceleration information on the diaphragm movements. The main goal of this paper is to develop a data collection system that measures acceleration values and to estimate the acceleration-volume relationship by examining the obtained data. Thus, two important parameters (TVC and FVC) in the diagnosis of COPD are measured in a more practical way. In the present case, these two parameters can be measured in a hospital environment by an expensive medical device called “spirometry”. For this purpose, our device is placed on the abdomen region of the patient, diaphragm movements are examined and values of the volume are estimated from acceleration data (total 416 accelerometric data). Measurements are performed simultaneously by the spirometry and the developed device. Pearson coefficient (p<0.01) is calculated to determine the correlation between the measured data by using devices. Results show us that there is a positive correlation between measured values of the two devices (accelerometric and spirometric). It can be concluded that there is an acceptable correlation (91.4%) between accelerometric and spirometric results and the estimate error margin is quite low (0.08). In this respect, this study is considered to be an alternative method to spirometry tests, which is used in diagnosing COPD.

Keywords

• Acceleration sensor
• Spirometry
• Inspiration-expiration
• Diaphragm
• statistical analysis