Breath Sound Intensity during Tidal Breathing in COPD Patients

Abstract

Objective There is a discrepancy in the intensity of breath sounds in chronic obstructive pulmonary disease (COPD) patients between subjective studies, which have reported a diminished intensity, and objective studies using airflow-standardized measurements, which have not demonstrated a diminished intensity. We herein evaluated the breath sound intensity in COPD patients during tidal breathing in order to obtain clinically relevant results. Methods The subjects included 20 stable COPD patients and 20 normal controls. Microphones were attached to six sites on the chest wall, and breath sounds at the chest wall and airflow in the mouth were measured during resting tidal and deep tidal breathing. The octave-band power values of the breath sounds were subsequently calculated. Results 1. During resting breathing, the intensity of breath sounds during both inspiration and expiration was significantly greater in the COPD group than in the control group; the difference was prominent at higher frequency bands (>400 Hz). In addition, the power of the high frequency bands tended to be positively correlated with the CT visual emphysema scores but not the forced expiratory volume in one second, The airflow during resting breathing did not differ between the two groups. 2. During deep breathing, the intensity of inspiratory breath sounds at the dominant frequency band (200-400 Hz) was diminished over the upper and middle lung fields in the COPD group compared to that observed in the control group, while the intensity during expiration was not. The airflow during deep breathing was lower in the COPD group than in the control group. Conclusion In the present study, the breath sound intensity in the COPD patients was diminished during deep inspiration due to a reduced airflow and increased during both resting inspiration and expiration.

Lung sound analysis helps localize airway inflammation in patients with bronchial asthma

“…In our analysis, there were significant differences in age and sex between the healthy and bronchial asthmatic populations. Lung sound data from the healthy volunteers presented in this article were previously published11 and did not include immunoglobulin E data. However, these factors may not have had an impact on these results, as previous data from our laboratory suggested that sex and age do not affect the E/I LF or E/I MF values7,8 and the primary outcomes of this study were evidently clarified by the asthmatic subject data.…”

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Regional Lung Sound Asynchrony in Chronic Obstructive Pulmonary Disease Patients

“…Although there are many investigations regarding lung sound amplitude, transmission, distribution, or adventitious sounds [3,4,5,6,7,10,12,14,20,21], there are only a few reports to study lung sound asynchrony [8,9,13,15]. Wang et al [9] revealed that asynchrony between the left and right lung in asthma exacerbations was significantly reduced after clinical improvement.…”

Validation of a Body-Conducted Sound Sensor for Respiratory Sound Monitoring and a Comparison with Several Sensors

“…Auscultation of respiratory sounds has long been an important physical assessment technique for medical workers [1], and with the influx of recent technology, auscultated respiratory sounds for pneumonia [2], bronchial asthma [3], and sleep apnea syndrome [4] are being used for chronic obstructive pulmonary disease (CODP) [5,6] diagnosis, tidal volume estimation [7], snoring detection [8], and apnea detection [9]. Moreover, respiratory rate monitoring using respiratory sounds [10] and snoring sensors [11] has become plausible due to unique advantages such as being a non-invasive technique and being based on low-cost, high-performance microphones that readily available in the market.…”

“…Moreover, respiratory rate monitoring using respiratory sounds [10] and snoring sensors [11] has become plausible due to unique advantages such as being a non-invasive technique and being based on low-cost, high-performance microphones that readily available in the market. Although the above-mentioned methods using respiratory sounds have been extensively studied via signal processing [3][4][5][6][7][8][9], the outcomes of these analyses have not often been practically implemented.…”