Quantitative analysis of breathing patterns based on wearable systems / 生物医学工程学杂志

Breathing pattern parameters refer to the characteristic pattern parameters of respiratory movements, including the breathing amplitude and cycle, chest and abdomen contribution, coordination, etc. It is of great importance to analyze the breathing pattern parameters quantificationally when exploring the pathophysiological variations of breathing and providing instructions on pulmonary rehabilitation training. Our study provided detailed method to quantify breathing pattern parameters including respiratory rate, inspiratory time, expiratory time, inspiratory time proportion, tidal volume, chest respiratory contribution ratio, thoracoabdominal phase difference and peak inspiratory flow. We also brought in "respiratory signal quality index" to deal with the quality evaluation and quantification analysis of long-term thoracic-abdominal respiratory movement signal recorded, and proposed the way of analyzing the variance of breathing pattern parameters. On this basis, we collected chest and abdomen respiratory movement signals in 23 chronic obstructive pulmonary disease (COPD) patients and 22 normal pulmonary function subjects under spontaneous state in a 15 minute-interval using portable cardio-pulmonary monitoring system. We then quantified subjects' breathing pattern parameters and variability. The results showed great difference between the COPD patients and the controls in terms of respiratory rate, inspiratory time, expiratory time, thoracoabdominal phase difference and peak inspiratory flow. COPD patients also showed greater variance of breathing pattern parameters than the controls, and unsynchronized thoracic-abdominal movements were even observed among several patients. Therefore, the quantification and analyzing method of breathing pattern parameters based on the portable cardiopulmonary parameters monitoring system might assist the diagnosis and assessment of respiratory system diseases and hopefully provide new parameters and indexes for monitoring the physical status of patients with cardiopulmonary disease.

Inductive plethysmography potential as a surrogate for ventilatory measurements during rest and moderate physical exercise

Background: Portable respiratory inductive plethysmography (RIP) systems have been validated for ventilatory assessment during resting conditions and during incremental treadmill exercise. However, in clinical settings and during field-based exercise, intensity is usually constant and submaximal. A demonstration of the ability of RIP to detect respiratory measurements accurately during constant intensity conditions would promote and validate the routine use of portable RIP devices as an alternative to ergospirometry (ES), the current gold standard technique for ventilatory measures. Objective: To investigate the agreement between respiratory variables recorded by a portable RIP device and by ES during rest and constant intensity exercise. Method: Tidal volume (VT), respiratory rate (RR) and minute ventilation (VE) were concurrently acquired by portable RIP and ES in seven healthy male volunteers during standing rest position and constant intensity treadmill exercise. Results: Significant agreement was found between RIP and ES acquisitions during the standing rest position and constant intensity treadmill exercise for RR and during the standing rest position for VE. Conclusion: Our results suggest that portable RIP devices might represent a suitable alternative to ES during rest and during constant submaximal exercise.

Breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises

The objective of the present study was to evaluate breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises: diaphragmatic breathing (DB), flow-oriented (Triflo II) incentive spirometry and volume-oriented (Voldyne) incentive spirometry. Seventeen healthy subjects (12 females, 5 males) aged 23 ± 5 years (mean ± SD) were studied. Calibrated respiratory inductive plethysmography was used to measure the following variables during rest (baseline) and breathing exercises: tidal volume (Vt), respiratory frequency (f), rib cage contribution to Vt (RC/Vt), inspiratory duty cycle (Ti/Ttot), and phase angle (PhAng). Sternocleidomastoid muscle activity was assessed by surface electromyography. Statistical analysis was performed by ANOVA and Tukey or Friedman and Wilcoxon tests, with the level of significance set at P < 0.05. Comparisons between baseline and breathing exercise periods showed a significant increase of Vt and PhAng during all exercises, a significant decrease of f during DB and Voldyne, a significant increase of Ti/Ttot during Voldyne, and no significant difference in RC/Vt. Comparisons among exercises revealed higher f and sternocleidomastoid activity during Triflo II (P < 0.05) with respect to DB and Voldyne, without a significant difference in Vt, Ti/Ttot, PhAng, or RC/Vt. Exercises changed the breathing pattern and increased PhAng, a variable of thoracoabdominal asynchrony, compared to baseline. The only difference between DB and Voldyne was a significant increase of Ti/Ttot compared to baseline. Triflo II was associated with higher f values and electromyographic activity of the sternocleidomastoid. In conclusion, DB and Voldyne showed similar results while Triflo II showed disadvantages compared to the other breathing exercises.

Design of a Wearable Respiratory Inductive Plethysmograph and Its Applications / 航天医学与医学工程

Objective To develop a new type of respiratory inductive plethysmograph to achieve high signal-noise rate(SNR)and low system power cost,and also to eliminate the cross-talk between chest and abdominal band sensors.Method Either of the two bands was powered by a very high power oscillator in a very short time,and these two bands were switched on in turn.The sensor structure of the respiratory inductive plethysmograph was modified so that these two bands could be embeded in a shirt conveniently.Result With these new designs,the cross-talk between these two bands was greatly eliminated and high SNR and low system power cost were achieved.This new wearable respiration monitoring system is easy to use,and can be used for long time and ambulatory monitoring.Conclusion This new system meets the design requirement with excellent performance.With this new wearable respiration monitoring system,non-invasive measurement of ventilation and non-intrusive detection of sleep apnea event can be achieved.

Wearable Concurrent Monitoring System for Physiological Parameters / 航天医学与医学工程

Objective To design a wearable physiological monitoring system for acquiring and monitor-ing vital signs non-intrusively and concurrently.Methods All bio-sensors were embedded in an elastic shirt for detecting physiological parameters with wearable technology.A patented respiratory inductive plethysmography technology was used to measure respiratory function,two sensors were woven into the jerkin around the patient's chest and abdomen.A three-lead,single channel ECG measures heart rate,and a three-axis accelerometer records posture and activity level.An NTC thermometer embedded in the shirt measures the body temperature.Results An elastic jerkin with embedded sensors that collect and continuously monitor respiration,cardiac,temperature,posture and activity signals was fabricated.Conclusion This wearable physiological monitoring system can record multiple parameters non-intrusively and concurrently.It can act as an useful platform for further researches.

Application of breathing pattern parameters to extraction of REM sleep information / 医疗卫生装备

Objective To extract breathing pattern parameters during sleep and get the varying law of NREM and REM sleep stages. Method A newly designed respiratory inductive plethysmography (RIP) and a polysomnography (PSG) are utilized to record whole-night-sleep data simultaneously. The breathing pattern parameters obtained by RIP are dealt with according to the results of sleep stages and sleep apnea by PSG. Then the rule found out and summarized from the experiment is applied to distinguish REM sleep. Conclusion RC/VT can be used as an effective parameter to differentiate NREM and REM sleep. Using this parameter, the results of RIP totally accord with the results of PSG.