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1.
Am J Physiol Regul Integr Comp Physiol ; 320(3): R268-R275, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33356877

ABSTRACT

The modified Campbell diagram provides one of the most comprehensive assessments of the work of breathing (Wb) during exercise, wherein the resistive and elastic work of inspiration and expiration are quantified. Importantly, a necessary step in constructing the modified Campbell diagram is to obtain a value for chest wall compliance (CCW). To date, it remains unknown whether estimating or directly measuring CCW impacts the Wb, as determined by the modified Campbell diagram. Therefore, the purpose of this study was to evaluate whether the components of the Wb differ when the modified Campbell diagram is constructed using an estimated versus measured value of CCW. Forty-two participants (n = 26 men, 16 women) performed graded exercise to volitional exhaustion on a cycle ergometer. CCW was measured directly at rest via quasistatic relaxation. Estimated values of CCW were taken from prior literature. The measured value of CCW was greater than that obtained via estimation (214 ± 52 mL/cmH2O vs. 189 ± 18 mL/cmH2O; P < 0.05). At modest-to-high minute ventilations (i.e., 50-200 L/min), the inspiratory elastic Wb was greater and expiratory resistive Wb was lower, when modified Campbell diagrams were constructed using estimated compared with measured values of CCW (P = 0.001). These differences were however small and never exceeded ±5%. Thus, although our findings demonstrate that estimating CCW has a measurable impact on the determination of the Wb, its effect appears relatively small within a cohort of healthy adults during graded exercise.


Subject(s)
Exercise , Lung/physiology , Models, Theoretical , Respiration , Respiratory Muscles/physiology , Thoracic Wall/physiology , Work of Breathing , Adolescent , Adult , Aged , Bicycling , Compliance , Female , Humans , Male , Middle Aged , Time Factors , Young Adult
2.
Sensors (Basel) ; 20(6)2020 Mar 13.
Article in English | MEDLINE | ID: mdl-32182977

ABSTRACT

This paper presents a novel adaptive recursive least squares filter (ARLSF) for motion artifact removal in the field of seismocardiography (SCG). This algorithm was tested with a consumer-grade accelerometer. This accelerometer was placed on the chest wall of 16 subjects whose ages ranged from 24 to 35 years. We recorded the SCG signal and the standard electrocardiogram (ECG) lead I signal by placing one electrode on the right arm (RA) and another on the left arm (LA) of the subjects. These subjects were asked to perform standing and walking movements on a treadmill. ARLSF was developed in MATLAB to process the collected SCG and ECG signals simultaneously. The SCG peaks and heart rate signals were extracted from the output of ARLSF. The results indicate a heartbeat detection accuracy of up to 98%. The heart rates estimated from SCG and ECG are similar under both standing and walking conditions. This observation shows that the proposed ARLSF could be an effective method to remove motion artifact from recorded SCG signals.


Subject(s)
Accelerometry/methods , Electrocardiography/methods , Signal Processing, Computer-Assisted , Thoracic Wall/physiology , Adult , Algorithms , Artifacts , Female , Heart Rate/physiology , Humans , Least-Squares Analysis , Male , Motion , Vibration , Young Adult
3.
J Manipulative Physiol Ther ; 43(9): 891-900, 2020.
Article in English | MEDLINE | ID: mdl-32896419

ABSTRACT

OBJECTIVE: The purpose of this study was to identify factors contributing to normal mobility or hypermobility of the chest wall. METHODS: Seventy-eight young adults were divided into 2 groups: patients with normal mobility (group 1, n = 40) and hypermobility of the chest wall (group 2, n = 38). The mean mobility of the chest wall in groups 1 and 2 was 9.9 and 6.1 cm, respectively. The mean age of groups 1 and 2 was 22.2 and 21.5 years, respectively. The Brief Symptom Inventory, State-Trait Anxiety Inventory, Beck Depression Inventory, and the Perceived Stress Scale were used to evaluate the psychometric properties. Quality of life was assessed using 12-Item Short Form Health Survey. Smoking status was determined via self-report of current smoking status. Chest wall mobility was measured using thoracic and axillary cirtometry. Pulmonary functions were evaluated using a Spirobank II device. Subsequently, forced vital capacity (FVC), forced expiratory volume in 1 second, peak expiratory flow, and forced expiratory flow 25% to 75% were verified. Carefusion Micro RPM and the 6-minute walk test were used to evaluate maximal respiratory pressures and functional capacity, respectively. RESULTS: With backward linear regression models, FVC and obsessive-compulsive traits were significant predictors of chest wall mobility (R²â€¯= 0.27; P < .001 and P = .01, respectively). In logistic regression models, FVC, maximum inspiratory pressure, and obsessive-compulsive traits were significant predictors of normal mobility/hypermobility of the chest wall (R²â€¯= 0.42; P < .001, P = .01, and P = .03, respectively). CONCLUSION: Forced vital capacity, maximum inspiratory pressure, and obsessive-compulsive traits are significant predictors of chest wall mobility and normal mobility or hypermobility of the chest wall.


Subject(s)
Lung , Thoracic Wall , Vital Capacity/physiology , Adult , Compulsive Behavior/physiopathology , Humans , Lung/physiology , Lung/physiopathology , Maximal Respiratory Pressures , Obsessive Behavior/physiopathology , Quality of Life , Thoracic Wall/physiology , Thoracic Wall/physiopathology , Young Adult
4.
Electromagn Biol Med ; 39(2): 123-128, 2020 Apr 02.
Article in English | MEDLINE | ID: mdl-32131642

ABSTRACT

Chest wall mobility decreases with age in community-dwelling women aged 65 years or older. Thermotherapy is used to improve soft-tissue extensibility. However, its effects on chest wall mobility are unclear. This study aimed to examine the effect of thermotherapy on chest wall mobility in healthy elderly women. Twenty-eight elderly women participated in this study. Chest wall mobility at three levels (axillary, xiphoid, and tenth rib), respiratory function (forced vital capacity and forced expiratory volume), and tissue temperature (skin temperature (ST)) and deep temperature (DT) with 10 mm and 20 mm depth from the skin (10 mm DT and 20 mm DT)) were measured before and after 15 minutes of thermotherapy. The subjects randomly received one of the three interventions (capacitive and resistive electric transfer (CRet), hot pack (HP), and sham CRet (sham)). Chest wall mobility at all levels significantly increased after CRet intervention. Hot pack significantly increased tenth rib excursion; it also significantly increased ST, 10 mm DT, and 20 mm DT, whereas CRet significantly increased 10 mm DT and 20 mm DT. There were significant differences between CRet, HP, and sham in ST, 10 mm DT, and 20 mm DT. Furthermore, 20 mm DT had increased more in CRet than in HP. CRet improved chest wall mobility at all levels and HP improved at the tenth rib level. This implies that CRet can be one of the approaches to improve chest wall mobility.


Subject(s)
Healthy Volunteers , Hyperthermia, Induced , Movement , Thoracic Wall/physiology , Aged , Female , Humans , Respiration
5.
Sensors (Basel) ; 19(4)2019 Feb 21.
Article in English | MEDLINE | ID: mdl-30795595

ABSTRACT

There is an ever-growing demand for measuring respiratory variables during a variety of applications, including monitoring in clinical and occupational settings, and during sporting activities and exercise. Special attention is devoted to the monitoring of respiratory rate because it is a vital sign, which responds to a variety of stressors. There are different methods for measuring respiratory rate, which can be classed as contact-based or contactless. The present paper provides an overview of the currently available contact-based methods for measuring respiratory rate. For these methods, the sensing element (or part of the instrument containing it) is attached to the subject's body. Methods based upon the recording of respiratory airflow, sounds, air temperature, air humidity, air components, chest wall movements, and modulation of the cardiac activity are presented. Working principles, metrological characteristics, and applications in the respiratory monitoring field are presented to explore potential development and applicability for each method.


Subject(s)
Monitoring, Physiologic/methods , Respiration , Respiratory Rate/physiology , Exercise/physiology , Humans , Thoracic Wall/physiology
6.
Surg Radiol Anat ; 41(11): 1369-1375, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31616984

ABSTRACT

PURPOSE: The aim of the study is to evaluate the difference in shape of the upper part and lower part of the Scapulothoracic Gliding Surface (STGS). METHODS: 3D-CT images of the thoracic cage of 50 patients were created in MIMICS ®. Three anatomical landmarks (insertion m. serratus anterior on 5th rib; transverse process of 2th and 7th vertebra) were used as an anteroposterior cutting plane to define the STGS. The upper part of the STG was defined as rib 2-5 and the lower part as 5-8. Next, in MATLAB ®, a script was used to create the sphere with best fit for upper and lower parts of STGS. The Root-Square-Mean Error (RSME) (mm) between two closest points on the fitted sphere and the STGS of both parts were calculated to determine the goodness-of-fit. RESULTS: The RSME was found to be significantly lower for the area ribs 2-5 (mean 7.85 mm, SD 1.86) compared the area of ribs 5-8 (mean 10.08 mm, SD 1.90). CONCLUSION: The STGS of the upper thoracic wall (2-5) is more spherical shaped than the STGS of the lower thoracic wall (rib 5-8).


Subject(s)
Scapula/diagnostic imaging , Shoulder/diagnostic imaging , Thoracic Wall/diagnostic imaging , Adult , Aged , Computer Simulation , Female , Humans , Imaging, Three-Dimensional , Male , Middle Aged , Models, Biological , Movement/physiology , Positron Emission Tomography Computed Tomography , Scapula/anatomy & histology , Scapula/physiology , Shoulder/anatomy & histology , Shoulder/physiology , Thoracic Wall/anatomy & histology , Thoracic Wall/physiology , Thorax/anatomy & histology , Thorax/diagnostic imaging , Thorax/physiology , Young Adult
7.
BMC Neurol ; 18(1): 124, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-30143022

ABSTRACT

BACKGROUND: Respiratory system elastance (ERS) is an important determinant of the responsiveness of intracranial pressure (ICP) to positive end-expiratory pressure (PEEP). However, lung elastance (EL) and chest wall elastance (ECW) were not differentiated in previous studies. We tested the hypothesis that patients with high ECW or a high ECW/ERS ratio have greater ICP responsiveness to PEEP. METHODS: An esophageal balloon catheter was placed to measure esophageal pressure. PEEP was increased from 5 to 15 cmH2O. Airway pressure and esophageal pressure were measured and EL, ECW and ERS were calculated at the two PEEP levels. Patients were classified into either an ICP responder group or a non-responder group based on whether the change of ICP after PEEP adjustment was greater than or less than the median of the overall study population. RESULTS: The magnitude of the increase in esophageal pressure (median [interquartile range]) at end-expiratory occlusion was significantly increased in the responder group compared with that in the non-responder group (4.1 [2.7-4.1] versus 2.7 [0.0-2.7] cmH2O, p = 0.033) after PEEP adjustment. ECW and the ECW/ERS ratio were significantly higher in ICP responders than in non-responders at both low PEEP (p = 0.021 and 0.017) and high PEEP (p = 0.011 and 0.025) levels. No significant differences in ERS and EL were noted between the two groups at both PEEP levels. CONCLUSIONS: Patients with greater ICP responsiveness to increased PEEP exhibit higher ECW and a higher ECW/ERS ratio, suggesting the importance of ECW monitoring.


Subject(s)
Intracranial Pressure/physiology , Positive-Pressure Respiration , Subarachnoid Hemorrhage/physiopathology , Subarachnoid Hemorrhage/therapy , Thoracic Wall/physiology , Female , Humans , Male , Middle Aged
8.
Br J Anaesth ; 120(4): 860-867, 2018 04.
Article in English | MEDLINE | ID: mdl-29576127

ABSTRACT

BACKGROUND: Postoperative pulmonary complications are common. Between patients there are differences in lung and chest wall mechanics. Individualised mechanical ventilation based on measurement of transpulmonary pressures would be a step forward. A previously described method evaluates lung and chest wall mechanics from a change of ΔPEEP and calculation of change in end-expiratory lung volume (ΔEELV). The aim of the present study was to validate this PEEP-step method (PSM) during general anaesthesia by comparing it with the conventional method using oesophageal pressure (PES) measurements. METHODS: In 24 lung healthy subjects (BMI 18.5-32), three different sizes of PEEP steps were performed during general anaesthesia and ΔEELVs were calculated. Transpulmonary driving pressure (ΔPL) for a tidal volume equal to each ΔEELV was measured using PES measurements and compared to ΔPEEP with limits of agreement and intraclass correlation coefficients (ICC). ΔPL calculated with both methods was compared with a Bland-Altman plot. RESULTS: Mean differences between ΔPEEP and ΔPL were <0.15 cm H2O, 95% limits of agreements -2.1 to 2.0 cm H2O, ICC 0.6-0.83. Mean differences between ΔPL calculated by both methods were <0.2 cm H2O. Ratio of lung elastance and respiratory system elastance was 0.5-0.95. CONCLUSIONS: The large variation in mechanical properties among the lung healthy patients stresses the need for individualised ventilator settings based on measurements of lung and chest wall mechanics. The agreement between ΔPLs measured by the two methods during general anaesthesia suggests the use of the non-invasive PSM in this patient population. CLINICAL TRIAL REGISTRATION: NCT 02830516.


Subject(s)
Anesthesia, General , Lung/drug effects , Positive-Pressure Respiration , Respiratory Mechanics/drug effects , Thoracic Wall/drug effects , Adult , Aged , Female , Humans , Lung/physiology , Lung Compliance/drug effects , Lung Compliance/physiology , Male , Middle Aged , Reference Values , Reproducibility of Results , Respiratory Mechanics/physiology , Thoracic Wall/physiology , Young Adult
9.
Lung ; 196(5): 601-608, 2018 10.
Article in English | MEDLINE | ID: mdl-29926179

ABSTRACT

PURPOSE: Airway protective behaviors, like cough and swallow, deteriorate in many populations suffering from neurologic disorders. While coordination of these behaviors has been investigated in an animal model, it has not been tested in humans. METHODS: We used a novel protocol, adapted from previous work in the cat, to assess cough and swallow independently and their coordination strategies in seven healthy males (26 ± 6 years). Surface electromyograms of the submental complex and external oblique complex, spirometry, and thoracic and abdominal wall kinematics, were used to evaluate the timing of swallow, cough, and breathing as well as lung volume (LV) during these behaviors. RESULTS: Unlike the cat, there was significant variability in the cough-swallow phase preference; however, there was a targeted LV range in which swallow occurred. CONCLUSION: These results give insight into the differences between the cat and human models in airway protective strategies related to the coordination of cough and swallow behaviors, allowing for better understanding of dystussia and dysphagia.


Subject(s)
Abdominal Wall/physiology , Cough , Deglutition , Lung/physiology , Respiratory Aspiration/prevention & control , Respiratory Mechanics , Thoracic Wall/physiology , Adult , Animals , Biomechanical Phenomena , Cats , Electromyography , Healthy Volunteers , Humans , Male , Respiratory Aspiration/etiology , Respiratory Aspiration/physiopathology , Species Specificity , Spirometry , Time Factors , Young Adult
10.
Biomed Eng Online ; 15(1): 112, 2016 Oct 06.
Article in English | MEDLINE | ID: mdl-27716248

ABSTRACT

BACKGROUND: Thoracoabdominal asynchrony is often adopted to discriminate respiratory diseases in clinics. Conventionally, Lissajous figure analysis is the most frequently used estimation of the phase difference in thoracoabdominal asynchrony. However, the temporal resolution of the produced results is low and the estimation error increases when the signals are not sinusoidal. Other previous studies have reported time-domain procedures with the use of band-pass filters for phase-angle estimation. Nevertheless, the band-pass filters need calibration for phase delay elimination. METHODS: To improve the estimation, we propose a novel method (named as instantaneous phase difference) that is based on complementary ensemble empirical mode decomposition for estimating the instantaneous phase relation between measured thoracic wall movement and abdominal wall movement. To validate the proposed method, experiments on simulated time series and human-subject respiratory data with two breathing types (i.e., thoracic breathing and abdominal breathing) were conducted. Latest version of Lissajous figure analysis and automatic phase estimation procedure were compared. RESULTS: The simulation results show that the standard deviations of the proposed method were lower than those of two other conventional methods. The proposed method performed more accurately than the two conventional methods. For the human-subject respiratory data, the results of the proposed method are in line with those in the literature, and the correlation analysis result reveals that they were positively correlated with the results generated by the two conventional methods. Furthermore, the standard deviation of the proposed method was also the smallest. CONCLUSIONS: To summarize, this study proposes a novel method for estimating instantaneous phase differences. According to the findings from both the simulation and human-subject data, our approach was demonstrated to be effective. The method offers the following advantages: (1) improves the temporal resolution, (2) does not introduce a phase delay, (3) works with non-sinusoidal signals, (4) provides quantitative phase estimation without estimating the embedded frequency of breathing signals, and (5) works without calibrated measurements. The results demonstrate a higher temporal resolution of the phase difference estimation for the evaluation of thoracoabdominal asynchrony.


Subject(s)
Abdominal Wall/physiology , Movement , Respiration , Signal Processing, Computer-Assisted , Thoracic Wall/physiology , Female , Humans , Male , Time Factors , Young Adult
11.
J Manipulative Physiol Ther ; 39(6): 443-449, 2016.
Article in English | MEDLINE | ID: mdl-27346860

ABSTRACT

OBJECTIVE: The purposes of this study were to (1) evaluate the reliability and reproducibility of chest expansion (CE) measurement on 2 different levels and (2) observe relationships between upper and lower CE measurements and lung function. METHODS: Fifty-three healthy subjects aged between 18 and 39 years were recruited. Chest expansion measurements were taken with a cloth tape measure at 2 levels of the rib cage (upper and lower). Reproducibility of the measurement was measured for 2 physiotherapists and on 2 different days. Lung function (ie, forced expiratory volume in 1 second [FEV1], forced vital capacity (FVC), vital capacity and, inspiratory capacity) was measured for all subjects by a spirometer (MEC Pocket-spiro USB100, Medical Electronic Construction, Brussels, Belgium). RESULTS: Upper CE was less than lower CE (5.4 cm and 6.4 cm, respectively; P < .001). Intrarater and interrater reliability were good for upper and lower CE. Reproducibility between physiotherapists was verified for both CE measurements. Reproducibility between days was only verified for upper CE. Sex influenced lower CE. Upper and lower CE values were correlated (r = 0.747; P < .01). Lower and upper CE were significantly and positively correlated with all lung function parameters and inspiratory muscle strength (moderately and weakly, respectively) except to inspiratory capacity for upper CE (P = .051) and for FEV1/FVC for both CE measurements. CONCLUSION: Upper and lower CE measurements showed good intra- and interrater reliability and reproducibility in healthy subjects. Although both measurements were correlated with lung functions (ie, FEV1, FVC, and vital capacity), the findings of this study showed that upper CE measurements may be more useful in clinical practice to evaluate chest mobility and to give indirect information on lung volume function and inspiratory muscle strength.


Subject(s)
Thoracic Wall/anatomy & histology , Vital Capacity , Adolescent , Adult , Belgium , Female , Humans , Lung , Male , Reproducibility of Results , Thoracic Wall/physiology , Young Adult
12.
Clin Sci (Lond) ; 128(8): 507-16, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25387977

ABSTRACT

Respiratory sinus arrhythmia (RSA) is an acceleration of heart rate during inspiration and deceleration with expiration. We asked whether or not in humans some of the volume-related information necessary for RSA originated from the chest wall. Men and women, 19-20 years old, were breathing supine. Rib cage and abdomen displacement provided an index of tidal volume (VT) and RSA was computed breath-by-breath from the peak and trough of instantaneous heart rate. First, measurements were taken during breathing at rest (protocol a, 129 male and 164 female). Then, in subgroups of the original subject population, measurements were collected for the first five breaths immediately following a brief breath-hold period (protocol b), predominantly with the rib cage or predominantly with the abdomen (protocol c), above functional residual capacity or below it (protocol d). As long as VT was constant, severe chest wall distortion (protocol c) did not modify RSA. A drop in absolute lung volume (protocol d) or an increase in VT (protocol b) respectively decreased and increased RSA. The results, globally taken, are compatible with the notion that in humans changes in lung volume are detected by lung mechanoreceptors, whereas chest wall reflexes play no role in RSA. No difference in RSA emerged between genders during resting breathing or modest breath-hold hyperventilation.


Subject(s)
Respiratory Sinus Arrhythmia/physiology , Thoracic Wall/anatomy & histology , Thoracic Wall/physiology , Body Weight/physiology , Breath Holding , Female , Functional Residual Capacity , Heart Rate/physiology , Humans , Male , Rest , Tidal Volume/physiology , Young Adult
13.
Crit Care ; 19: 9, 2015 Jan 13.
Article in English | MEDLINE | ID: mdl-25583125

ABSTRACT

INTRODUCTION: The stress index (SI), a parameter derived from the shape of the pressure-time curve, can identify injurious mechanical ventilation. We tested the hypothesis that adjusting tidal volume (VT) to a non-injurious SI in an open lung condition avoids hypoventilation while preventing overdistension in an experimental model of combined lung injury and low chest-wall compliance (Ccw). METHODS: Lung injury was induced by repeated lung lavages using warm saline solution, and Ccw was reduced by controlled intra-abdominal air-insufflation in 22 anesthetized, paralyzed and mechanically ventilated pigs. After injury animals were recruited and submitted to a positive end-expiratory pressure (PEEP) titration trial to find the PEEP level resulting in maximum compliance. During a subsequent four hours of mechanical ventilation, VT was adjusted to keep a plateau pressure (Pplat) of 30 cmH2O (Pplat-group, n = 11) or to a SI between 0.95 and 1.05 (SI-group, n = 11). Respiratory rate was adjusted to maintain a 'normal' PaCO2 (35 to 65 mmHg). SI, lung mechanics, arterial-blood gases haemodynamics pro-inflammatory cytokines and histopathology were analyzed. In addition Computed Tomography (CT) data were acquired at end expiration and end inspiration in six animals. RESULTS: PaCO2 was significantly higher in the Pplat-group (82 versus 53 mmHg, P = 0.01), with a resulting lower pH (7.19 versus 7.34, P = 0.01). We observed significant differences in VT (7.3 versus 5.4 mlKg(-1), P = 0.002) and Pplat values (30 versus 35 cmH2O, P = 0.001) between the Pplat-group and SI-group respectively. SI (1.03 versus 0.99, P = 0.42) and end-inspiratory transpulmonary pressure (PTP) (17 versus 18 cmH2O, P = 0.42) were similar in the Pplat- and SI-groups respectively, without differences in overinflated lung areas at end- inspiration in both groups. Cytokines and histopathology showed no differences. CONCLUSIONS: Setting tidal volume to a non-injurious stress index in an open lung condition improves alveolar ventilation and prevents overdistension without increasing lung injury. This is in comparison with limited Pplat protective ventilation in a model of lung injury with low chest-wall compliance.


Subject(s)
Lung Injury/therapy , Positive-Pressure Respiration/methods , Thoracic Wall/physiology , Tidal Volume , Animals , Bronchoalveolar Lavage , Disease Models, Animal , Hemodynamics , Swine
14.
Paediatr Respir Rev ; 16(1): 3-10, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25468220

ABSTRACT

Assessing chest wall motion is a basic and vital component in managing the child with respiratory problems, whether these are due to pathology in the lungs, airways, chest wall or muscles. Since the 1960s, clinical assessment has been supplemented with an ever-growing range of technological options for measuring chest wall motion, each with unique advantages and disadvantages. Measurements of chest wall motion can be used to: (1) Assess respiratory airflow and volume change, as a non-invasive alternative to measurement at the airway opening, (2) Monitor breathing over long periods of time, to identify apnoea and other types of sleep-disordered breathing, (3)Identify and quantify patterns of abnormal chest wall movement, whether between ribcage and abdominal components (thoracoabdominal asynchrony) or between different regions of the ribcage (eg in scoliosis and pectus excavatum). Measuring chest wall motion allows us to do things which simply cannot be done by more mainstream respiratory function techniques measuring flow at the airway opening: it allows respiratory airflow to be measured when it would otherwise be impossible, and it tells us how the different parts of the chest wall (eg ribcage vs abdomen, right vs left) are moving in order to generate that airflow. The basis of the different techniques available to assess and measure chest wall motion will be reviewed and compared, and their relevance to paediatric respiratory practice assessed.


Subject(s)
Lung/physiology , Respiration , Thoracic Wall/physiology , Child , Humans
15.
Biomed Eng Online ; 14: 16, 2015 Feb 26.
Article in English | MEDLINE | ID: mdl-25884476

ABSTRACT

BACKGROUND: Seismocardiography is the noninvasive measurement of cardiac vibrations transmitted to the chest wall by the heart during its movement. While most applications for seismocardiography are based on unidirectional acceleration measurement, several studies have highlighted the importance of three-dimensional measurements in cardiac vibration studies. One of the main challenges in using three-dimensional measurements in seismocardiography is the significant inter-subject variability of waveforms. This study investigates the feasibility of using a unified frame of reference to improve the inter-subject variability of seismocardiographic waveforms. METHODS: Three-dimensional seismocardiography signals were acquired from ten healthy subjects to test the feasibility of the present method for improving inter-subject variability of three-dimensional seismocardiograms. The first frame of reference candidate was the orientation of the line connecting the points representing mitral valve closure and aortic valve opening in seismocardiograms. The second candidate was the orientation of the line connecting the two most distant points in the three dimensional seismocardiogram. The unification of the frame of reference was performed by rotating each subject's three-dimensional seismocardiograms so that the lines connecting the desired features were parallel between subjects. RESULTS: The morphology of the three-dimensional seismocardiograms varied strongly from subject to subject. Fixing the frame of reference to the line connecting the MC and AO peaks enhanced the correlation between the subjects in the y axis from 0.42 ± 0.30 to 0.83 ± 0.14. The mean correlation calculated from all axes increased from 0.56 ± 0.26 to 0.71 ± 0.24 using the line connecting the mitral valve closure and aortic valve opening as the frame of reference. When the line connecting the two most distant points was used as a frame of reference, the correlation improved to 0.60 ± 0.22. CONCLUSIONS: The results indicate that using a unified frame of reference is a promising method for improving the inter-subject variability of three-dimensional seismocardiograms. Also, it is observed that three-dimensional seismocardiograms seem to have latent inter-subject similarities, which are feasible to be revealed. Because the projections of the cardiac vibrations on the measurement axes differ significantly, it seems obligatory to use three-dimensional measurements when seismocardiogram analysis is based on waveform morphology.


Subject(s)
Accelerometry/methods , Ballistocardiography/methods , Individuality , Myocardial Contraction , Signal Processing, Computer-Assisted , Accelerometry/instrumentation , Adult , Aortic Valve/physiology , Ballistocardiography/instrumentation , Electrocardiography , Feasibility Studies , Humans , Imaging, Three-Dimensional , Male , Mitral Valve/physiology , Respiration , Rotation , Sternum/physiology , Thoracic Wall/physiology , Vibration
16.
J Radiol Prot ; 35(1): 63-73, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25517347

ABSTRACT

In vivo lung counting aims at assessing the retained activity in the lungs. The calibration factor relating the measured counts to the worker's specific retained lung activity can be obtained by several means and strongly depends on the chest wall thickness. Here we compare, for 374 male nuclear workers, the activity assessed with a reference protocol, where the material equivalent chest wall thickness is known from ultrasound measurements, with two other protocols. The counting system is an array of four germanium detectors.It is found that non site-specific equations for the assessment of the chest wall thickness induce large biases in the assessment of activity. For plutonium isotopes or (241)Am the proportion of workers for whom the retained activity is within ± 10% of the reference one is smaller than 10%.The use of site-specific equations raises this proportion to 20% and 58% for plutonium and (241)Am, respectively.Finally, for the studied population, when site-specific equations are used for the chest wall thickness, the standard uncertainties for the lung activity are 42% and 12.5%, for plutonium and (241)Am, respectively. Due to the relatively large size of the studied population, these values are a relatively robust estimate of the uncertainties due to the assessment of the chest wall thickness for the current practice at this site.


Subject(s)
Americium/analysis , Lung/physiology , Models, Biological , Plutonium/analysis , Radiometry/methods , Thoracic Wall/physiology , Absorption, Radiation , Adult , Computer Simulation , France/epidemiology , Humans , Male , Middle Aged , Nuclear Power Plants , Occupational Exposure/analysis , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity
17.
Folia Phoniatr Logop ; 67(4): 202-11, 2015.
Article in English | MEDLINE | ID: mdl-26771452

ABSTRACT

OBJECTIVE: To develop a standardized paediatric protocol for acquiring simultaneous chest wall kinematics and surface electromyography (EMG) of chest wall muscles during maximum performance and speech tasks. PATIENTS AND METHODS: Eighteen healthy participants included: (a) a younger age group (n = 6; ages 4.0-6.5 years), (b) an older age group (n = 6; ages 7.0-10.5 years), and (c) an adult group (n = 8; ages 21-33 years). A child (age 10 years) with spastic-type cerebral palsy (CP) served as a 'proof of protocol feasibility'. Chest wall kinematics and surface EMGs (intercostals, rectus abdominus, external oblique, latissimus dorsi, and erector spinae) were acquired during maximum performance and speech tasks. RESULTS: Successful calibration of the EMG signal and reliable detection of muscle activation onset, offset, and amplitude relative to vital capacity and percent maximum voluntary contraction in children were demonstrated. Kinematic and surface EMG measurements were sensitive to non-speech and speech tasks, age, and neurological status (i.e. CP). CONCLUSION: The simultaneous measurement of kinematics and EMG of the chest wall muscle groups provides a more comprehensive description of speech breathing in children. This protocol can be used for the observation and interpretation of clinical outcomes seen in children with motor speech disorders following treatments that focus on increasing overall respiratory and vocal effort.


Subject(s)
Biomechanical Phenomena , Electromyography , Muscle Contraction/physiology , Respiration , Speech/physiology , Thoracic Wall/physiology , Adult , Cerebral Palsy/physiopathology , Child , Child, Preschool , Feasibility Studies , Female , Humans , Male , Phonation/physiology , Vital Capacity/physiology , Young Adult
19.
J Manipulative Physiol Ther ; 37(9): 719-25, 2014.
Article in English | MEDLINE | ID: mdl-25455836

ABSTRACT

OBJECTIVE: The purpose of this study was to investigate the effect of different recumbent positions on pulmonary function, chest wall motion, and feelings of discomfort in young nonobese healthy volunteers. METHODS: Twenty healthy volunteers (age, 28.0±1.4 years; height, 167.5±10.1 cm; weight, 62.3±10.2 kg) were studied in the sitting position and in the following 6 recumbent positions: supine, left retroversion at a 45° tilt, left anteversion at a 45° tilt, right retroversion at a 45° tilt, right anteversion at a 45° tilt, and prone. After 5 minutes of a selected position, pulmonary functions, including vital capacity (VC), forced expiratory volume in 1 second, maximal inspiratory and expiratory mouth pressures (MIP and MEP, respectively), and breathing pattern components at the chest wall were assessed. Discomfort was assessed using a modified Borg scale. RESULTS: When participants changed position from sitting to each of the 6 recumbent positions, forced expiratory volume in 1 second values decreased significantly (P < .05). None of the participants showed changes in the MIP or MEP in any of the 6 recumbent positions. Rib cage motion was restricted in all recumbent positions except supine, left anteversion at a 45° tilt, and prone. In all 6 recumbent positions, discomfort was experienced during the pulmonary tests. However, in the left retroversion at a 45° tilt position, no discomfort was experienced during the MIP and MEP assessments. CONCLUSION: In young, nonobese, healthy volunteers, recumbent positions caused diminished pulmonary functions and induced feelings of discomfort.


Subject(s)
Healthy Volunteers , Motion , Posture/physiology , Thoracic Wall/physiology , Vital Capacity/physiology , Adult , Anthropometry , Female , Humans , Male , Prone Position/physiology , Reference Values , Respiratory Function Tests , Sampling Studies , Statistics, Nonparametric , Supine Position/physiology , Young Adult
20.
J Bodyw Mov Ther ; 38: 368-374, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38763581

ABSTRACT

PURPOSE: The aim of this systematic review was to investigate the effectiveness of physiotherapy interventions on chest mobility in obstructive lung diseases. METHODS: Searches were performed in PEDro, Pubmed and Cochrane Central Register of Controlled Trials databases without language restrictions between 2010 and 25th December 2020. Randomized controlled trials (RCTs) investigating physiotherapy interventions on chest wall mobility were included. Two independent reviewers screened studies, extracted data, and assessed methodological quality of included studies. The assessment of risk of bias was conducted using the PEDro scale for RCTs. The articles were excluded if they have less than 5 out of 10 score. RESULTS: Five studies included had good to excellent quality. A total of 139 patients were included in all RCTs. Intervention duration ranged from a single session to 12 weeks and the intervention schedules varied, consisting of 1-24 sessions, lasting 5-45 min per sessions. Three studies used respiratory muscle stretching and releasing techniques, one study combined respiratory muscle stretching with aerobic training, and one study planned diaphragmatic breathing. Four studies assessed chest wall mobility with optoelectronic plethysmography, whereas one study used measuring tape. CONCLUSIONS: The result of this first systematic review that investigates the effects of physiotherapy interventions on chest wall mobility in obstructive lung diseases suggests that more and better quality RCTs with objective measurement tools are required.


Subject(s)
Physical Therapy Modalities , Thoracic Wall , Humans , Thoracic Wall/physiology , Lung Diseases, Obstructive/rehabilitation , Lung Diseases, Obstructive/therapy , Randomized Controlled Trials as Topic , Respiratory Muscles/physiopathology , Respiratory Muscles/physiology , Pulmonary Disease, Chronic Obstructive/rehabilitation , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/therapy
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