Early detection of lung cancer usually markedly increases the efficiency of therapy. However, the currently employed diagnostic approaches are not sufficiently effective, resulting in late detection of the disease and high patient mortality. Therefore, development of a high-throughput and reliable diagnostic method is a priority task requiring fast solution. Analysis of exhaled air for a number of organic compounds recognized as lung cancer biomarkers seems to be a promising approach for early diagnosis of the disease. This issue attracts growing interest, as indicated by increasing number of publications on this topic. This review surveys contemporary analytical techniques for analysis of exhaled air, including various spectroscopic and mass spectral methods and also gas sensor-based methods. The key benefits and shortcomings of the techniques, sample injection and pre-concentration methods, and the potential applicability of the methods for lung cancer detection are discussed. The prospects of simultaneous application of several analytical techniques and approaches for the early diagnosis are demonstrated. The bibliography includes 147 references.

No abstract

In the report are represented the results of an experimental study of the movement of air both through the human respiratory system and through the natural model. The model copies the structure of nasopharynx and human nose. The velocity and temperature were measured in to the human nose and in different parts of the model. The dimensionality and entropy for the patient and for the model were calculated on the basis of these measurements. The results of comparison helped to better understand nonlinear phenomena with the movement of air on the nasal passages. Control of the process of treating some illnesses of respiratory system was accomplished on this base.

A gas sensor based on spontaneous Raman scattering is proposed for the compositional analysis of single breath events. A description of the sensor as well as of the calibration procedure, which also allows the quantification of condensable gases, is presented. Moreover, a comprehensive characterization of the system is carried out in order to determine the measurement uncertainty. Finally, the sensor is applied to consecutive breath events and allowed measurements with 250 ms time resolution. The Raman sensor is able to detect all the major gas components, i.e. N 2 , O 2 , CO 2 , and H 2 O at ambient pressure with a high temporal resolution. Concentration fluctuations within a single breath event could be resolved.

No abstract