An mHealth App for the Non-contact Measurement of Pulmonary Function Using the Smartphone's Built-in Depth Sensor.

The use of smartphones in clinical practice is referred to as mobile health (mHealth). This has attracted great interest in both academia and industry because of its potential to augment healthcare. In this study, we developed an mHealth app for the non-contact measurement of chest-wall movements using the iPhone ' s built-in depth sensor, thereby enabling a pulmonary self-monitoring function for personal use. The depth sensor provides depth values for each pixel and 2D mapping of the chest-wall movements. To extract respiratory signals from the right and left thoracic regions and abdomen, a 2D-depth image-segmentation method was implemented. The method was based on the anatomy and physiology of chest-wall movements, assuming differences in the anterior displacement in the thoracic and abdominal regions. It was observed that the differences were significant in the segmented regions of interest (ROIs) of the right and left thoracic region and abdomen. Respiratory signals extracted from each ROI were compared with the contact bio-impedance signals, which were highly correlated (r=0.94).

Respiratory physiology in pregnancy and assessment of pulmonary function.

A progressive chest wall adaptation occurs during pregnancy driven by the hormones and the expanding uterus. The effect of the former is more prevalent in the first weeks of pregnancy, while the latter is more evident in the last trimester. The combination of the hormonal-induced joint loosening together with the progressively enlarging uterus produces changes in the whole chest wall geometry, with the thoracic alterations being the most fundamental. The ribcage changes in size, but not in volume, secondary to an upward bucket handle shift centred in the xiphoidal process so that the lung is not restricted. A virtuous cycle of stretching and muscle conditioning seems to be established between the enlarging uterus, the diaphragm, and the abdominal muscles to prepare these muscles for the expulsive phase. From the respiratory point of view, the supine position seems to hinder the action of the abdominal muscles during forced expiration at the end of pregnancy.

Cirugías por traumatismo torácico: caracterización y variables asociadas a mortalidad / Thoracic trauma surgery: indications, findings and mortality associated variables

Resumen Introducción: El traumatismo torácico (TT) es la causa de aproximadamente un cuarto de las muertes por traumatismos. Los pacientes tratados con cirugía por traumatismo torácico (CTT) presentan un amplio espectro de características y pronósticos. Objetivos: Describir características clínicas, indicaciones, temporalidad, morbilidad, mortalidad y las variables asociadas a mortalidad en pacientes con CTT. Materiales y Método: Estudio observacional de pacientes tratados con CTT, período enero-1981 a diciembre-2019. Revisión de protocolos prospectivos de TT y base de datos. Se realizó regresión logística para variables asociadas a mortalidad. Se utilizó SPSS25® con prueba chi-cuadrado para comparar clasificación, tipo de TT y su distribución temporal, considerando significativo p < 0,05. Resultados: En total 808 casos (18,2%) de 4.448 TT requirieron CTT. Fueron hombres 767 (94,9%) y la edad promedio fue 31,5 ± 13,8 años. El traumatismo fue penetrante y por arma blanca en la mayoría de los casos. Fueron politraumatizados 164 (20,3%). La cirugía fue urgente en 474 (58,7%), precoz en 41 (5,0%) y diferida en 293 (36,3%) casos. La mortalidad global fue de 6,7% y fue significativamente mayor en TT contusos, politraumatizados y en cirugía urgente. La mortalidad fue 9,7% en CTT urgente, 4,9% en precoz y 2,0% en diferida (p < 0,001). Se observaron variables independientes asociadas a mortalidad. Conclusión: En nuestra serie, las CTT se realizaron principalmente en hombres jóvenes con TT penetrantes. Correspondieron a un grupo heterogéneo en cuanto a las indicaciones, hallazgos y lesiones intratorácicas y/o asociadas. Múltiples variables demostraron influir significativamente en la mortalidad de los pacientes tratados con CTT.

Background: Thoracic Trauma (TT) is the cause of approximately a quarter of trauma deaths. The patients who undergo Thoracic Trauma Surgery (TTS) present a wide spectrum of characteristics and prognosis. Aim: To describe clinical characteristics, indications, temporality, morbidity, mortality and mortality associated variables in TTS patients. Materials and Method: Observational study of TT hospitalized patients, period January-1981 to December-2019. A review of operation notes and database was done. A logistic regression for mortality associated variables was made. To compare classification, type of TT and its temporal distribution, SPSS25® with chi-square test was used, considering significant p < 0.05. Results: A total of 808 (18.2%) of 4.448 TT patients required TTS, 767 (94.9%) were men with average age: 31.5 ± 13.8. The trauma was penetrating trauma due to a stab in most cases, 164 (20.3%) were polytraumatized. The surgery was urgent in 474 (58.7%), early in 41 (5.0%) and delayed in 293 (36.3%) cases. The global mortality was 6.7% and was significantly higher in the blunt TT, polytrauma, urgent and early surgery patients. Mortality in urgent TTS was 9.7%, early 4.9% and 2.0% in delayed (p < 0.001). Independent variables associated with mortality were observed. Conclusions: In our series, TTS were performed mainly in young men with penetrating TT. The group was heterogeneous regarding surgical indications, findings and intrathoracic or associated injuries. Multiple variables showed to influence significantly on mortality in patients who underwent TTS.

Effect of pursed-lip breathing and forward trunk lean positions on regional chest wall volume and ventilatory pattern in older adults: An observational study.

ABSTRACT: Pursed-lip breathing (PLB) and forward trunk lean posture (FTLP) are commonly used to relieve dyspnea and improve ventilation in a rehabilitation program. However, their effect on chest wall volumes and movements in older adults without chronic obstructive pulmonary disease has never been investigated. This observational study aimed to identify the effect of combined PLB and FTLP on total and regional chest wall volumes, ventilatory pattern, and thoracoabdominal movement using in older adults. It was hypothesized that the combined PLB with FTLP would result in the highest chest wall volumes among the experimental tasks. Twenty older adults performed 2 breathing patterns of quiet breathing (QB) and PLB during a seated upright (UP) position and FTLP. An optoelectronic plethysmography system was used to capture the chest wall movements during the 4 experimental tasks. Tidal volume (VT) was separated into pulmonary ribcage, abdominal ribcage, and abdomen volume. The changes in anterior-posterior (AP) and medial-lateral (ML) chest wall diameters at 3 levels were measured and used to identify chest wall mechanics to improve chest wall volumes. The PLB significantly improved ventilation and chest wall volumes than the QB (P < .05). VT of pulmonary ribcage, VT of abdominal ribcage, and VT were significantly higher during the PLB + UP (P < .05) and during the PLB + FTLP (P < .01) as compared to those of QB performed in similar body positions. However, there was no significant in total and regional lung volumes between the PLB + UP and the PLB + FTLP. The AP diameter changes at the angle of Louis and xiphoid levels were greater during the PLB + UP than the QB + UP and the QB + FTLP (P < .01). The AP diameter changes at the umbilical level and the ML diameter changes at the xiphoid level were significantly larger during the PLB + FTLP than the QB + FTLP and the QB + UP (P < .05). The ML diameter changes at the umbilical level were significantly greater during the PLB + FTLP than the QB + UP (P < .05). However, no significant difference in the relative regional chest wall volumes and phase angle among the experimental tasks (P > .05). In conclusion, a combined PLB performed in an FTLP or UP sitting could be used as a strategy to improve chest wall volumes and ventilation in older adults.

Measurement of chest wall motion using a motion capture system with the one-pitch phase analysis method.

Spirometry is a standard method for assessing lung function. However, its use is challenging in some patients, and it has limitations such as risk of infection and inability to assess regional chest wall motion. A three-dimensional motion capture system using the one-pitch phase analysis (MCO) method can facilitate high precision measurement of moving objects in real-time in a non-contacting manner. In this study, the MCO method was applied to examine thoraco-abdominal (TA) wall motion for assessing pulmonary function. We recruited 48 male participants, and all underwent spirometry and chest wall motion measurement with the MCO method. A significant positive correlation was observed between the vital capacity (Spearman's ρ = 0.68, p < 0.0001), forced vital capacity (Spearman's ρ = 0.62, p < 0.0001), and tidal volume (Spearman's ρ = 0.61, p < 0.0001) of spirometry and the counterpart parameters of MCO method. Moreover, the MCO method could detect regional rib cage and abdomen compartment contributions and could assess TA asynchrony, indicating almost complete synchronous movement (phase angle for each compartment: - 5.05° to 3.86°). These findings suggest that this technique could examine chest wall motion, and may be effective in analyzing chest wall volume changes and pulmonary function.

Thoracic shape changes in newborns due to their position.

The highly compliant nature of the neonatal chest wall is known to clinicians. However, its morphological changes have never been characterized and are especially important for a customised monitoring of respiratory diseases. Here, we show that a device applied on newborns can trace their chest boundary without the use of radiation. Such technology, which is easy to sanitise between patients, works like a smart measurement tape drawing also a digital cross section of the chest. We also show that in neonates the supine position generates a significantly different cross section compared to the lateral ones. Lastly, an unprecedented comparison between a premature neonate and a child is reported.

Ultrasound-guided serratus plane block as an effective adjunct to systemic analgesia in four dogs undergoing thoracotomy.

Background: Ultrasound-guided serratus plane block (UGSPB) is a loco-regional anesthesia technique designed to desensitize the thoracic wall. It is a compartmental block, where local anesthetic is delivered to the fascial, inter-muscular plane. Since its original description in humans, two cadaveric veterinary studies, redefining the technique, have been performed. Taking into account the successful use of the UGSPB in human medicine, we employed the veterinary description to perform this block in four dogs undergoing thoracotomy. The case series described below aims to share our experience of the clinical application of this new loco-regional anesthesia technique in dogs. Case Description: Four dogs, with different underlying medical conditions underwent cranial lateral thoracotomy. The analgesia protocol consisted of intravenous methadone and UGSPB performed half an hour before the beginning of the procedure. The cardiovascular system was closely monitored for any signs of nociception. Fentanyl, although available as rescue analgesia, was not required in any of these cases as no signs of nociception were present. Conclusion: To the authors' knowledge, this is the first veterinary clinical report using the UGSPB as a part of a multimodal analgesia protocol in dogs undergoing thoracotomy. Based on this observation, UGSPB has the potential to prevent nociception and reduce the intraoperative opioid requirements in dogs undergoing thoracotomy. A prospective randomized clinical trial is required to confirm these promising results.

The effect of estimating chest wall compliance on the work of breathing during exercise as determined via the modified Campbell diagram.

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.

Fisiología respiratoria: contribución de la estructura de la vía aérea y el pulmón a la función del aparato respiratorio / Contribution of the airways and lung structure to the respiratory system function

Conocer la estructura del sistema respiratorio es fundamental para comprender cómo realiza sus funciones, desde la principal, el intercambio gaseoso, hasta otras funciones no respiratorias tales como el equilibrio ácido-base, fonación, defensa pulmonar, metabolismo pulmonar y procesamiento de materiales bioactivos. El objetivo de esta revisión es describir los conocimientos actuales de la anatomía del aparato respiratorio y mencionar sus funciones tanto respiratorias como no respiratorias.

Knowing the structure of the respiratory system is essential to understand how it performs its various functions, from the main, gas exchange, to its non-respiratory functions such as acid-base balance, phonation, lung defense, pulmonary metabolism, and the handling of bioactive materials. The main objective of this review is to describe the updated knowledge of the respiratory system's anatomy and to mention its various respiratory and non-respiratory functions.

Fuerza muscular respiratoria y movilidad torácica en niños sanos. Relación con medidas antropométricas / Respiratory muscle strength and thoracic mobility in healthy children. Relationship with anthropometric measurements

INTRODUCCIÓN: La medición de la fuerza muscular respiratoria y la movilidad torácica tienen importancia en la evaluación clínica del sistema respiratorio en población pediátrica, sin embargo, sus valores pueden cambiar por las características de la población de cada país. El objetivo del estudio fue describir la fuerza muscular respiratoria y movilidad torácica en niños sanos de Cali, Colombia y analizar la correlación con medidas antropométricas. MATERIALES Y MÉTODOS: Estudio transversal. Se incluyeron niños sanos entre 8 y 11 años de un colegio de Cali, Colombia a quienes se les midió la fuerza muscular respiratoria con la Presión Inspiratoria Máxima (PIM) y Presión Espiratoria Máxima (PEM) y la movilidad torácica con la cirtometría axilar y xifoidea. También se tomaron las medidas antropométricas peso, talla e IMC para la edad. RESULTADOS: Se admitieron 89 niños, un 50,6% de sexo femenino y con IMC en normopeso para la edad del 62,9%. Mediana de PIM -60,0 cmH2O (Rango Intercuartílico [RIQ] 44,0) y PEM 49,0 cmH2O (RIQ 19,0). Mediana de cirtometría axilar 4,5 cm (RIQ 1,6) y xifoidea 4,7 cm (RIQ 1,7). La PIM tuvo correlación con el índice de masa corporal (IMC) para la edad (rs = 0,23 p = 0,030), la cirtometría axilar con el peso (rs = 0,35; p = 0,001) y el IMC para la edad (rs = 0,31; p = 0,003), la cirtometría xifoidea con el peso (rs = 0,24; p = 0,027) y la talla (rs = 0,22; p = 0,037). No hubo correlación entre la PIM-PEM y cirtometría. DISCUSIÓN: La fuerza muscular respiratoria y la movilidad torácica dependen de los cambios experimentados en el crecimiento del infante y de características diferenciales entre niños y niñas durante la pubertad

INTRODUCTION: The measurement of respiratory muscle strength and thoracic mobility are important in clinical assessment of the respiratory system in the paediatric population, however, their values can change according to the characteristics of the population of each country. The objective of the study was to describe respiratory muscle strength and thoracic mobility in healthy children from Cali, Colombia, and analyse their correlation with anthropometric measurements. MATERIALS AND METHODS: A cross-sectional study. We included healthy children between 8 and 11 years old, from a school in Cali, Colombia, whose respiratory muscle strength was measured with Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP) and thoracic mobility with axillary and xiphoid cirtometry. Anthropometric measurements were taken, such as weight, height and BMI-for-age. RESULTS: 89 children were admitted, most were female (50.6%) and with normal BMI-for-age (62.9%). Median MIP -60.0 cmH2O (IQR 44.0) and MEP 49.0 cmH2O (IQR 19.0). Median axillary cirtometry 4.5 cm (IQR 1.6) and xiphoid cirtometry 4.7 cm (IQR 1.7). MIP correlated with BMI-for-age (rs = 0.23 p = 0.030), axillary cirtometry with weight (rs = 0.35 p = 0.001) and BMI-for-age (rs = 0.31 p = 0.003), xiphoid cirtometry with weight (rs = 0.24 p = 0.027) and height (rs = 0.22 p = 0.037). There was no correlation between MIP-MEP and cirtometry. DISCUSSION: Respiratory muscle strength and thoracic mobility depend on changes in the growth of the infant and differential characteristics between boys and girls during puberty

Chest Wall Mobility: Identification of Underlying Predictors.

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.

A Novel Adaptive Recursive Least Squares Filter to Remove the Motion Artifact in Seismocardiography.

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.

Effects of deep thermotherapy on chest wall mobility of healthy elderly women.

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.

Thoracoabdominal mobility evaluation of asthmatic patients in physiotherapy practice: Intra-rater reliability.

BACKGROUND: The evaluation of thoracoabdominal mobility is a tool extensively used in the physiotherapy practice in different populations. Photogrammetry may be a simple tool to analyse thoracoabdominal mobility; however, it is unclear whether this assessment can be a reliable method. AIM: To test the reliability intra-examinator by photogrammetry in asthmatic patients and in health controls. METHODS: Twenty-six asthmatic patients (29 ± 9 years) and 14 healthy matched controls (27 ± 8 years) were assessed by thoracoabdominal mobility. Photographs during rest, during inspiration and expiration maximum were used to calculate latero-lateral and antero-posterior diameters of the thorax (at axillary and xiphoid levels) and umbilical by markers positioned in osseous structures. An evaluator obtained the same measurements in an 8-day interval. RESULTS: We found a moderate reliability for axillary, xiphoid and umbilical mobility (average intraclass correlation coefficient [ICC] respectively [0.68, 0.55 and 0.73]) for asthmatic group. In addition, for control group, we found a moderate reliability for axillary mobility (average ICC respectively [0.68] and a good reliability for xiphoid and umbilical mobility) (average ICC 0.81 and 0.70). Bland-Altman plots showed goods limit of agreement in photos 1 and 2 in both groups. CONCLUSION: The photogrammetric analysis of thoracoabdominal mobility presented itself as a reliable method and may be used in clinical practice in asthmatic patients and in controls.

Thoracoabdominal motion in newborns: Reliability between two interactive computing environments.

BACKGROUND: Quantifying the chest wall is useful in documenting thoracoabdominal synchrony during the neonatal period. Subjective measures are often used rather than gold-standard methods due to their practicality in clinical practice. The aim of the present study is to compare the reliability between a newly proposed method (video analysis in MATLAB) and image analysis using AutoCad tools, both applied to assess thoracoabdominal motion in newborns (NBs). MATERIALS AND METHODS: This is an observational cross-sectional study of full-term NBs. A digital camera was used to film thoracoabdominal motion for 2 minutes in the supine position, with movements measured by the two aforementioned methodologies. RESULTS: A total of 139 images were used, showing agreement between AutoCAD and MATLAB (BIAS = -1.68; CI = -6.59:3.22, Bland-Altman plot). CONCLUSION: The programs were interchangeable and the routine developed in MATLAB was simpler and faster, allowing dynamic analysis and suggesting its clinical utility in quantifying respiratory motion in NBs.

Breathing retraining with chest wall mobilization improves respiratory reserve and decreases hyperactivity of accessory breathing muscles during respiratory excursions: A randomized controlled trial.

PURPOSE: The aim of this paper was to evaluate the effects of breathing retraining with chest wall mobilization on the onset of accessory breathing muscle recruitment and respiratory reserve in individuals with chronic neck pain. METHODS: Thirty-two participants with non-specific chronic neck pain were randomly assigned into intervention and control groups. The intervention group received 30 minutes of breathing retraining with chest wall mobilization and the control group was assigned to rest for 30 minutes. Electromyography (EMG) of upper trapezius (UT), scalene (SC), and sternocleidomastoid (SCM) muscles were recorded during respiratory excursions by cycling for 12 minutes. Measurement of maximum voluntary ventilation (MVV), chest expansion, and pain intensity were taken during normal breathing. The immediate effects within each group and between two groups were analyzed. RESULTS: Significant improvement in respiratory reserve was observed in the intervention group compared to control group through prolonged EMG onset of accessory breathing muscles. Moreover, increase of MVV, chest expansion and decrease in pain intensity were observed. CONCLUSIONS: This research suggests that breathing patterns and chest expansion should be considered within the physical assessment of breathing retraining, and that chest wall mobilization offers clinically important improvements in patients with chronic neck pain.

Adaptation of lung, chest wall, and respiratory muscles during pregnancy: preparing for birth.

A plethora of physiological and biochemical changes occur during normal pregnancy. The changes in the respiratory system have not been as well elucidated, in part because radioimaging is usually avoided during pregnancy. We aimed to use several noninvasive methods to characterize the adaptation of the respiratory system during the full course of pregnancy in preparation for childbirth. Eighteen otherwise healthy women (32.3 ± 2.8 yr) were recruited during early pregnancy. Spirometry, optoelectronic plethysmography, and ultrasonography were used to study changes in chest wall geometry, breathing pattern, lung and thoraco-abdominal volume variations, and diaphragmatic thickness in the first, second, and third trimesters. A group of nonpregnant women were used as control subjects. During the course of pregnancy, we observed a reorganization of rib cage geometry, in shape but not in volume. Despite the growing uterus, there was no lung restriction (forced vital capacity: 101 ± 15% predicted), but we did observe reduced rib cage expansion. Breathing frequency and diaphragmatic contribution to tidal volume and inspiratory capacity increased. Diaphragm thickness was maintained (1st trimester: 2.7 ± 0.8 mm, 3rd trimester: 2.5 ± 0.9 mm; P = 0.187), possibly indicating a conditioning effect to compensate for the effects of the growing uterus. We conclude that pregnancy preserved lung volumes, abdominal muscles, and the diaphragm at the expense of rib cage muscles.NEW & NOTEWORTHY Noninvasive analysis of the kinematics of the chest wall and the diaphragm during resting conditions in pregnant women revealed significant changes in the pattern of thoracoabdominal breathing across the trimesters. That is, concomitant with the progressive changes of chest wall shape, the diaphragm increased its contribution to both spontaneous and maximal breathing, maintaining its thickness despite its lengthening due to the growing uterus. These results suggest that during pregnancy the diaphragm is conditioned to optimize its active role provided during parturition.

Respiratory muscle activation and action during voluntary cough in healthy humans.

Cough is a defensive airway reflex consisting of a modified respiratory act which involves the sequential activation of several laryngeal and respiratory muscles. The contraction of the latter results in thoraco-abdominal volume variations in order to provide enough amount of air available, the operating volume (OV), to be expelled. Because both posture and OV could influence muscular activation and thoraco-abdominal displacements during voluntary cough, we aimed to verify if and how they play a role during inspiratory (ICP) and expiratory (ECP) cough phases, in terms of flow, volumes and surface electromyography activity (sEMG). In 10 healthy subjects, we measured sEMG of 7 muscles (scalene, sternocleidomastoid, parasternal, intercostal, diaphragm (assessed at the 8th intercostal space), external abdominal oblique and rectus abdominis) in supine and seated position during cough maneuvers performed at 4 different OV measured by opto-electronic plethismography: total lung capacity (TLC), functional residual capacity and two intermediate volumes. The amplitude of sEMG signals tended to be maximal at TLC (p < 0.005) during ICP in the neck and parasternal muscles and during ECP in abdominal muscles. Postures slightly affected only sEMG of the thoracic muscles. sEMG data were similar (p > 0.05) in the other OV, but cough peak flow increased with OV. Thoraco-abdominal volume variations during cough were unaffected by posture and OV as well, being predominantly thoracic (supine: 60 and 64%; seated: 68 and 69%, respectively during ICP and ECP). Our results suggest that voluntary cough OV or posture do not have an important effect on voluntary cough that seems more likely to be resulting from a motor mechanism that activates a synergetic antagonistic contraction of inspiratory and expiratory muscles leading to a specific thoraco-abdominal pattern, in which the rib cage is the predominant.

Defining the shape of the scapulothoracic gliding surface.

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).