Portable system for fast lung function test

The analysis of gas-concentration changes at mouth during normal breathing is nowadays a routine exam to infer lung functionality and several commercial instruments are available to carry out this kind of measurement. Unfortunately, most of these measuring systems are very specific, designed to be used in the hospital and costly. This paper describes a complete and versatile system which is designed for field use and can be tailored to several different measurement situations. The proposed system employs commercial sensors coupled to a versatile conditioning and acquisition board, which is designed to be connected to a conventional PC. A skeleton of the software which carries out the routine tasks (acquisition, storing, calibrations, and visualization) has been designed and installed on the PC. The skeleton can be easily adapted to the different applications, thus enabling the fast development of new clinical methodics. As an example, in this paper, an application is described that performs an oxygen/carbon dioxide analysis on a multi-breath basis and estimates the result uncertainty. The skeleton contains routines to save both results and raw data according to the DICOM standard format, so that the analyses can be easily shared among the different physicians involved in the patient's care.