Basic Study on Relationship between Respiratory Flow Volume and Volume Change of Thorax Surface

The pulmonary function test by spirometer is generally conducted. The test subject, especially child, woman and older person, feels uncomfortable as the mouthpiece and nasal plug must be attached to the face of them. We have studied the nonrestraint pulmonary function test using the dot matrix pattern projection in order to decrease the burden to the examinee. In our proposed system, the pattern light projector illuminates the thorax with the dot matrix pattern light. And the CCD camera takes a series of images of the dot matrix pattern. The three dimensional shape of the thorax surface can be calculated by the distribution of light dots. And the respiratory waveform is calculated by the time-series change of the three dimensional shape. The respiratory waveform of our system was similar to one of spirometer. Therefore, we clarified that our proposed system can equivalently measure the respiration with spirometer in previous research. In this paper, we compared the volume change of the three dimensional shape calculated by our system with the flow volume. And we examined the relationship between the flow volume and the volume change of the thorax surface.