Respiratory training and guiding system using head mount display device to improve the regularity of breathing

Purpose: In order to enhance the efficiency of respiratory gated 4-dimensional radiation therapy, a respiration training system using head mounted display device was developed and its efficacy was evaluated. Material and Methods: The experiment was designed to measure differences in respiration regularity by using the developed system. Three groups of patients were involved in the experiments. An experiment was designed to measure the differences in respiration regularity before and after the training. Three patient groups were involved in the experiments. First group was a group of patients who breath freely without any training or guiding (No-action group: NAG), and second group was patients who did training before simulation but was treated without guiding signals (Without guiding group: WOGG), and third group was a group of patients who had respiration training session and was treated with guiding signals (With guiding group; WGG). Respiration signals of 30 patients in each group were recorded by RPM system and the regularity was evaluated by using a home-made analysis tool. Results: The temporal regularity of WGG was improved (NAG vs WOGG vs WGG was 2.449 vs 2.296 vs 1.490). The reduction of SD of periods for WOGG was not statistically significant (NAG 2.449 vs. WOGG 2.296, p=ns), while reduction of SD of WGG was significant. For amplitudes, SD was significantly decreased in WGG compared with NAG (NAG 0.663 vs. WGG 0.509, p=0.01). The signal pattern of breathing was not much different in three groups, since the average area of breathing curve and its RMS in WGG was smaller just by 7.16% and 5.38%, respectively, compared to those of NAG. Conclusion: The developed respiratory training system, which uses a head mounted display device, is capable of improving the temporal regularity and maintaining the tidal air volume evenly compared with free respiration.