The article aims to discuss the feasibility of using respiratory sounds to monitor respiratory rate. The average power of respiratory sounds was created firstly, the autocorrelation algorithm was used to calculate the respiratory cycle. The respiratory cycle of nasal flow pressure signal was calculated simultaneously, and the result was taken as a reference standard, then, two groups of respiratory cycle data were analyzed by correlation analysis and Bland-Altman analysis. The respiratory rate is relatively stable, using respiratory sounds monitor respiratory rate is feasible, the respiratory rate changes obviously, the existing methods and algorithm using respiratory sounds are temporarily unable to accurately reflect the changes of respiratory rate, further research is needed.
Algorithms ; Humans ; Monitoring, Physiologic ; instrumentation ; Respiratory Rate ; Respiratory Sounds

No abstract available.
Acoustics ; Dental Scaling ; Noise ; Respiration ; Respiratory Rate

No abstract available.
Carbon Dioxide* ; Carbon* ; Respiratory Rate* ; Tidal Volume*

Traditional methods of non-contact human respiratory rate measurement usually require complex devices or algorithms. Aiming at this problem, a non-contact respiratory rate measurement method based on only the RGB video information was proposed in this paper. The method consisted of four steps. Firstly, spatial filtering was applied to each frame of the input video. Secondly, a gray compensation algorithm was used to compensate for the gray level change caused by the environmental light. Thirdly, the gray levels of each pixel over time were filtered separately by a low-pass filter. Finally, the region of interest was determined based on the filtering results, and the respiration rate of the human is measured. The physical measurement experiments were designed, and the measurement accuracy was compared with that of the biological radar. The error of the proposed method was between - 5.5% and 3% in different detection directions. The results show that the non-contact respiration rate measurement method can effectively measure the human respiration rate.
Algorithms ; Humans ; Radar ; Respiration ; Respiratory Rate

PURPOSE: To evaluate the effect f nebulized budensonide and intramuscular dexamethasone in relieving laryngeal obstruction of croup. METHODS: Forty patients with moderate croup (croup scores of 3 to 7 out of 17) were randomly assigned to budesonide group [1 mg(2 ml) of nebulized budesonide, N=15], dexamethasone group [intramuscular dexamethasone(0.5 mg/kg) and nebulized saline, N=10] and control group(2 ml of nebulized saline, N=15). The changes of croup scores, heart rate, respiratory rate, and arterial oxygen saturation(SaO2) were observed at post-treatment of 2, 24, 36 and 48 hours. The duration of admission and the rates of improvement to the croup score of < or = 1 at the post-treatments were compared. RESULTS: Croup scores at 12, 24 and 36 hours post treatments were 1.7+/-0.8, 1.1+/-0.7 and 0.8+/-0.7 in budensonide group and 2.2+/-0.7, 1.2+/-0.8 and 1.0+/-0.5 in dexamethasone group respectively, which were significantly lower rate, and SaO2 were not significantly different among the three groups. Improved rates to croup score of <1 in budesonide group at post-treatments of 12, 24, and 36 jpirs were 53%, 73% and 87%, which were significantly higher than 0%, 13%, and 47% in control group (p<0.05). Improved rate to croup score of < or = 1 in dexamethasone group was 60^ which was significantly hgier than 13% in control group only at post-treatment of 24 hours (p<0.05). CONCLUSION: Nebulized budesonide and intramusculan dexamethasone are both effective in reducing obstructive symptoms in patients with moderate croup. The effect of nebulized budesonide was more rapid than that of intramuscular dexamethasone.
Budesonide* ; Croup ; Dexamethasone* ; Heart Rate ; Humans ; Oxygen ; Respiratory Rate

Intrapulmonary percussive ventilation(IPV), developed by Forrest M. Bird, M.D., delivers high flow mini-bursts of air along with bronchodilator to the lung at a rate of more than 200 times per minute and has the theoretical potential for aiding in expectoration of secretions through internal percussion. To evaluate effects of IPV on respiratory therapy, we compared IPV with conventional chest physical therapy in patients with excess or retained pulmonary secretions. The results are follows. 1) There were no significant differences among the experimental group with respect to blood pressure, heart rate and respiratory rate. 2) Arterial oxygen tension was significantly increased after IPV. 3) ICU stay was slightly shortened in the experimental group as compared with that in the control group. However, there was no statistical significance. These results indicate that IPV may be effective in respiratory care of patients with excess or retained airway secretions.
Birds ; Blood Pressure ; Heart Rate ; Humans ; Lung ; Oxygen ; Percussion ; Respiratory Rate ; Respiratory Therapy ; Thorax ; Ventilation*

PURPOSE: This study was preformed to demonstrate the improvement of respiratory symptoms and pulmonary function parameters after albuterol inhalation in asthmatic bronchitis using pneumotachography. METHODS: Fifteen asthmatic bronchitis patients admitted to Ewha Womans University Hospital from September in 1998 to July in 1999 were enrolled in this study. Clinical symptoms and pulmonary function parameters including respiratory rate, heart rate, inspiratory tidal volume(Vi), expiratory tidal volume(Ve), peak tidal expiratory flow(PTEF), tidal expiratory flow at 25% of tidal volume(TEF25), mid-expiratory flow(MEF) and mid-inspiratory flow(MIF), compliance, and pulmonary resistance were evaluated by clinical symptom score and pneumotachography before and after albuterol inhalation treatment. RESULTS: The clinical score was decreased significantly after treatment, but heart rate did not show a significant difference. By flow-volume curve, Ve were 7.39+/-2.11 mL/kg, 9.39+/-3.20 mL/kg, and Vi were 7.44+/-2.08 mL/kg, 9.46+/-3.26 mL/kg, and PTEF were 130.1+/-82.1 mL/kg, 123.1+/-64.8 mL/kg before and after treatment, respectively. All the pulmonary function parameters showed no significant differences before and after treatment. CONCLUSIONS: Clinical symptoms were improved after albuterol inhalation treatment in asthmatic bronchitis, but pulmonary function was not recovered after a short-term treatment.
Albuterol ; Bronchitis* ; Compliance ; Female ; Heart Rate ; Humans ; Inhalation ; Respiratory Function Tests* ; Respiratory Rate

BACKGROUND: Pressure-controlled ventilation (PCV) is frequently used recently as the initial mode of mechanical ventilation in the patients with respiratory failure. Theoretically, because of its high initial inspiratory flow, pressure-controlled ventilation has lower peak inspiratory pressure and improved gas exchange than volume-controlled ventilation (VCV). But the data from previous studies showed controversial results about the gas exchange. Moreover, the comparison study between PCV and VCV with various inspiration:expiration time ratios (I:E ratios) is rare. So this study was performed to compare the respiratory mechanics and gas exchange between PCV and VCV with various I:E raitos. METHODS: Nine patients receiving mechanical ventilation for respiratory failure were enrolled. They were ventilated by both PCV and VCV with various I:E ratios (1:2, 1:1.3 and 1.7:1). FiO2, tidal volume, respiratory rate and external positive end-expiratory pressure (PEEP) were kept constant throughout the study. After 20 minutes of each ventilation mode, arterial blood gas, airway pressures, expired CO2 were measured. RESULTS: In both PCV and VCV, as the I:E ratio increased, the mean airway pressure was increased, and PaCO2 and physiologic dead space fraction were decreased. But P(A-a)O2 was not changed. In all three different I:E ratios, peak inspiratory pressure was lower during PCV, and mean airway pressure was higher during PCV. But PaCO2 level, physiologic dead space fraction and P(A-a)O2 were not different between PCV and VCV with three different I:E ratios. CONCLUSION: There was no difference in gas exchange between PCV and VCV under the same tidal voulme, frequency and I:E ratio.
Humans ; Positive-Pressure Respiration ; Respiration, Artificial ; Respiratory Insufficiency ; Respiratory Mechanics* ; Respiratory Rate ; Tidal Volume ; Ventilation*

BACKGROUND: Pressure support(PS) is becomimg a widely accepted method of mechanical ventilation either for total unloading or for partial unloading of respiratory muscle. The aim of the study was to find out if PS exert different effects on respiratory mechanics in synchronized intermittent mandatory ventilation(SIMV) and continuous positive airway pressure (CPAP) modes. METHODS: 5, 10 and 15 cm H2O of PS were sequentially applied in 14 patients(69+/-12 yrs, M:F=9:5) and respiratory rate (RR), tidal volume(VT), work of breathing(WOB), pressure time product(PTP), P(0.1), and T(1)/T(TOT) were measured using the CP-100 pulmonary monitor(Bicore, USA) in SIMV and CPAP modes respectively. RESULTS: 1) Common effects of PS on respiratory mechanics in both CPAP and SIMV modes As the level of PS was increased(0, 5, 10, 15 cm H2O), VT was increased in CPAP mode(0.28+/-0.09, 0.29+/-0.09, 0.31+/-0.11, 0.34+/-0.12 L, respectively, p=0.001), and also in SIMV mode(0.31+/-0.15, 0.32+/-0.09, 0.34+/-0.16, 0.36+/-0.15 L, respectively, p=0.0215). WOB was decreased in CPAP mode(1.40+/-1.02, 1.01+/-0.80, 0.80+/-0.85, 0.68+/-0.76 joule/L, respectively, p=0.0001), and in SIMV mode(0.97+/-0.77, 0.76+/-0.64, 0.57+/-0.55, 0.49+/-0.49 joule/L, respectively, p=0.0001). PTP was also decreased in CPAP mode(300+/-216, 217+/-165, 179+/-187, 122+/-114cm H2O * sec/min, respectively, p=0.0001), and in SIMV mode(218+/-181, 178+/-157, 130+/-147, 108+/-129cm H2O.sec/min, respectively, p=0.0017). 2) Different effects of PS on respiratory mechanics in CPAP and SIMV modes By application of PS (0, 5, 10, 15 cm H2O), RR was not changed in CPAP mode(27.9+/-6.7, 30.0+/-6.6, 26.1+/-9.1, 27.5+/-5.7/min, respectively, p=0.505), but it was decreased in SIMV mode (27.4+/-5.1, 27.8+/-6.5, 27.6+/-6.2, 25.1+/-5.4/min, respectively, p=0.0001). P(0.1) was reduced in CPAP mode(6.2+/-3.5, 4.8+/-2.8, 4.8+/-3.8, 3.9+/-2.5 cm H2O, respectively, p=0.0061), but not in SIMV mode(4.3+/-2.1, 4.0+/-1.8, 3.5+/-1.6, 3.5+/-1.9 cm H2O, respectively, p=0.054). T(1)/T(TOT) was decreased in CPAP mode(0.40+/-0.05, 0.39+/-0.04, 0.37+/-0.04, 0.35+/-0.04, respectively, p=0.0004), but not in SIMV mode(0.40+/-0.08, 0.35+/-0.07, 0.38+/-0.10, 0.37+/-0.10, respectively, p=0.287). 3) Comparison of respiratory mechanics between CPAP+PS and SIMV alone at same tidal volume. The tidal volume in CPAP+PS 10 cm H2O was comparable to that of SIMV alone. Under this condition, the RR(26.1+/-9.1, 27.4+/-5.1/min, respectively, p=0.516), WOB(0.80+/-0.85, 0.97+0.77 joule/L, respectively, p=0.485), P0.1(3.9+/-2.5, 4.3+/-2.1 cm H2O, respectively, p=0.481) were not different between the two methods, but PTP(179+/-187, 218+/-181 cmH2O.sec/min, respectively, p=0.042) and T(1)/T(TOT)(0.37+/-0.04, 0.40+/-0.08, respectively, p=0.026) were significantly lower in CPAP+PS than in SIMV alone. CONCLUSION: PS up to 15 cm H2O increased tidal volume, decreased work of breathing and pressure time product in both SIMV and CPAP modes. PS decreased respiration rate in SIMV mode but not in CPAP mode, while it reduced central respiratory drive(P(0.1)) and shortened duty cycle (T(1)/T(TOT)) in CPAP mode but not in SIMV mode. By 10 cm H2O of PS in CPAP mode, same tidal volume was obtained as in SIMV mode, and both methods were comparable in respect to RR, WOB, P(0.1), but CPAP+PS was superior in respect to the efficiency of the respiratory muscle work (PTP) and duty cycle(T(1)/T(TOT)).
Continuous Positive Airway Pressure ; Respiration, Artificial ; Respiratory Mechanics* ; Respiratory Muscles ; Respiratory Rate ; Tidal Volume ; Work of Breathing

PURPOSE: Neonatal pulmonary function test(PFT) adds a new dimension to the understanding and care of the infant at risk for lung dysfunction. PFT can be identified the risk for pulmonary problems and safely and effectively diagnosed, quantified, and qualified the dysfunction. So it is possible to early institution of prophylatic respiratory therapy in such neonates and it can improved the dysfunction or reduce the incidence of both acute aand chronic complications. The purpose of this present study was to get the normal values of pulmonary function test in normal neonates METHODS: We evaluated 332 normal neonates at Ewha Womans University Hospital from Feb. 1994 to Oct. 1994. We performed PFT by tidal breathing flow-volume loop and non-invasive passive expiratory flow-volume technique. RESULTS: 1) The mean respiratory rate was 51.0+/-12.0/min and tidal volume 7.4+/-2.9 ml/kg. 2) In the tidal breathing pattern, %V PTEF was 0.42+/-0.17, PTEF/TV 2.36+/-0.76, TEF25/PTEF 0.80+/-0.10 and ME/MI 0.89+/-0.25, and the shape of loop was oval. 3) The mean respiratory system compliance by passive expiratory flow-volume technique in normal neonates was 1.52+/-0.93ml/cmH2O/kg and resistance 0.052+/-0.039 cmH2O/ml/sec. 4) The values of PFT were not different according to sex or postnatal age(p>0.05). CONCLUSIONS: The measured values of pulmonary function test in normal neonates could be used in the future as reference values of pulmonary function in neonates with variable respiratory diseases, and could be aid in understanding the respiratory physiology and pathology of neonates through companing the measured values of pulmonary function by other method.
Compliance ; Female ; Humans ; Incidence ; Infant ; Infant, Newborn* ; Lung ; Pathology ; Reference Values ; Respiration ; Respiratory Function Tests* ; Respiratory Physiological Phenomena ; Respiratory Rate ; Respiratory System ; Respiratory Therapy ; Tidal Volume