Forced Breathing Research Articles

Quantitative measurement of the flow depending nasal valve function by elastography with electro-optical distance sensors. A pilot study

Nasal valve function depends on the intensity of the inspiratory nasal airflow, the geometry of the nasal entrance and the mechanical properties of the lateral nasal wall. It is desirable to obtain objective information on the relation between flow and valve movement. In this study, the deflection of the lateral nasal wall and the inspiratory flow were measured on 30 healthy volunteers, aged 18 to 82 without a history of severe trauma or nasal surgery. Electro-optical distance sensors were housed under a full-face protective mask attached to an analogue inspiratory flowmeter. The mean values for normal breathing were assessed at 675 [cm3/s] for the bilateral flow and −0.57 mm for the total movement. With forced breathing, the mean values for the flow of both nostrils were found to be 1434 cm3/s and for the total movement −1.21 mm. Statistically significant differences between normal and forced breathing were found in all participants and in both sexes, but no significant correlation by age. Electro-optical distance measurement, representing a novel technical way for the ‘elastography’ of the nasal valve should be added to advanced 4-phase-rhinomanometers.

Dynamic process of forced breathing in a patient with right diaphragm paralysis.

Dynamic process of forced breathing in a patient with right diaphragm paralysis.

Assessment of pulmonary function in COPD patients using dynamic digital radiography: A novel approach utilizing lung signal intensity changes during forced breathing

ObjectivesTo investigate the association of lung signal intensity changes during forced breathing using dynamic digital radiography (DDR) with pulmonary function and disease severity in patients with chronic obstructive pulmonary disease (COPD). MethodsThis retrospective study included 46 healthy subjects and 33 COPD patients who underwent posteroanterior chest DDR examination. We collected raw signal intensity and gray-scale image data. The lung contour was extracted on the gray-scale images using our previously developed automated lung field tracking system and calculated the average of signal intensity values within the extracted lung contour on gray-scale images. Lung signal intensity changes were quantified as SImax/SImin, representing the maximum ratio of the average signal intensity in the inspiratory phase to that in the expiratory phase. We investigated the correlation between SImax/SImin and pulmonary function parameters, and differences in SImax/SImin by disease severity. ResultsSImax/SImin showed the highest correlation with VC (rs = 0.54, P < 0.0001), followed by FEV1 (rs = 0.44, P < 0.0001), both of which are key indicators of COPD pathophysiology. In a multivariate linear regression analysis adjusted for confounding factors, SImax/SImin was significantly lower in the severe COPD group compared to the normal group (P = 0.0004) and mild COPD group (P=0.0022), suggesting its potential usefulness in assessing COPD severity. ConclusionThis study suggests that the signal intensity changes of lung fields during forced breathing using DDR reflect the pathophysiology of COPD and can be a useful index in assessing pulmonary function in COPD patients, potentially improving COPD diagnosis and management.

Respiratory homeostasis features in female students with idiopathic arterial hypotension and hyperventilation syndrome

Aim. To assess the condition of pulmonary ventilation and diaphragmatic excursion in female students with idiopathic arterial hypotension in the context of hyperventilation syndrome and excessive anxiety. Materials and methods. In total, 62 female students aged 18–24 diagnosed with idiopathic arterial hypotension were examined. The patients were randomly assigned to three groups based on clinical symptoms. Group 1 consisted of 34 students with idiopathic arterial hypotension accompanied by excessive anxiety and hyperventilation syndrome. Group 2 comprised 28 students with arterial hypotension without signs of neurogenic hyperventilation. Group 3, the control one, included 11 apparently healthy age-matched students. The manifestations of hyperventilation syndrome were determined using the Nijmegen Questionnaire. The level of anxiety was assessed using the Spielberger–Hanin scale. Primary indicators of pulmonary ventilation were examined using a Spirolab spirometer (Italy). The diaphragm dynamic function was evaluated by assessing the excursion of its right dome using a Chison QBIT 5 apparatus (China). Results. Through the survey, signs of neurogenic hyperventilation syndrome and excessive anxiety have been identified in the students of Group 1 showing changes in pulmonary ventilation parameters, such as significantly decreased vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1), compared to the results obtained in Groups 2 and 3, indicating restrictive respiratory disorders. It has been found that diaphragmatic excursion values (18.29 ± 3.26 mm) at rest in Group 1 were significantly lower compared to those obtained in the control group (26.82 ± 2.32 mm) (p ˂ 0.05). During forced breathing, diaphragmatic excursion (56.86 ± 4.35 mm) in Group 1 was lower than that (80.18 ± 3.19 mm) in the control group (p &lt; 0.05). In Group 2, a significant initial decrease in diaphragmatic excursion was revealed only in 26.67 % of the girls. Conclusions. In female students with idiopathic arterial hypotension accompanied by hyperventilation syndrome and excessive anxiety, restrictive pattern of decreased pulmonary ventilation parameters and reduced diaphragmatic excursion were observed.

Breathing Right… or Left! The Effects of Unilateral Nostril Breathing on Psychological and Cognitive Wellbeing: A Pilot Study.

The impact of controlled breathing on cognitive and affective processing has been recognized since ancient times, giving rise to multiple practices aimed at achieving different psychophysical states, mostly related to mental clarity and focus, stress reduction, and relaxation. Previous scientific research explored the effects of forced unilateral nostril breathing (UNB) on brain activity and emotional and cognitive functions. Some evidence concluded that it had a contralateral effect, while other studies presented controversial results, making it difficult to come to an unambiguous interpretation. Also, a few studies specifically addressed wellbeing. In the present study, we invited a pilot sample of 20 participants to take part in an 8-day training program for breathing, and each person was assigned to either a unilateral right nostril (URNB) or left nostril breathing condition (ULNB). Then, each day, we assessed the participants' wellbeing indices using their moods and mind wandering scales. The results revealed that, after the daily practice, both groups reported improved wellbeing perception. However, the effect was specifically related to the nostril involved. URNB produced more benefits in terms of stress reduction and relaxation, while ULNB significantly and increasingly reduced mind-wandering occurrences over time. Our results suggest that UNB can be effectively used to increase wellbeing in the general population. Additionally, they support the idea that understanding the effects of unilateral breathing on wellbeing and cognition requires a complex interpretive model with multiple brain networks to address bottom-up and top-down processes.

Increased Musculoskeletal Deformities And Decreased Lung Volume In Patients After Ea/Tef Repair - A Real-Time Mri Study.

This study aims to assess morphological and functional postoperative changes after open or minimally invasive (MIS) repair of esophageal atresia (EA) compared to healthy controls by thoracic real-time MRI. Musculoskeletal deformities and pulmonary morbidity are common in children after EA repair. The real-time MRI is a novel technique that provides ultrafast, high-quality images during spontaneous breathing, without sedation even in young children. Children aged 3-18 years were prospectively examined with a 3 Tesla MRI. Musculoskeletal deformities, static thoracic cross-sectional areas (CSA) at three different levels and lung volumes, as well as dynamic right-to-left ratio of CSA of hemithoraces and lung volumes during forced breathing were evaluated. 72 children (42 open, 8 MIS, 22 controls) were recruited. In the EA group, rib fusions and adhesions (78%, P<0.01) and scoliosis (15%, P=0.32) were found after thoracotomy, but not after MIS. Mean right-to-left ratio of CSA and lung volumes were lower after EA repair compared to controls (P <0.05), indicating impaired thoracic and lung development. The number of thoracotomies was a significant risk factor for smaller thoracic volumes (P<0.05). For the first time, morphological changes and thoracic motility after EA repair were visualized by dynamic real-time MRI. Children after EA repair show decreased right-sided thoracic and lung development compared to controls. Open repair leads to significantly more musculoskeletal deformities. This study emphasizes that musculoskeletal morbidity following a thoracotomy in infancy is high.

ABOLITION OF SAGITTAL T7-T10 DYNAMICS DURING FORCED VENTILATION IN AIS PATIENTS WITH LENKE 1A CURVES

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7-T10 segment. In AIS, the abolition of T7-T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case-control study. 20 AIS patients (18 girls, Cobb angle, 54.7±7.9°; Risser 1.35±1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 yr. mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12) and the global T1-T12 ROM were measured. In healthy subjects, the mean T1-T12 ROM during forced breathing was 16.7±3.8. AIS patients showed a T1-T12 ROM of 1.1±1.5 (p&lt;0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7-T10 ROM (15.3±3.0) was found in healthy controls (91.6% of the T1–T12 ROM). AIS patients showed only 0.4±1.4 ROM at T7-T10 (36.4% of the T1-T12 ROM) (p&lt;0.001). There was a significant positive correlation between the magnitude of T7-T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment for deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients.

A new tidal breathing measurement device detects bronchial obstruction during methacholine challenge test

PurposeBronchial hyperresponsiveness (BHR), a hallmark of bronchial asthma, is typically diagnosed through a methacholine inhalation test followed by spirometry, known as the methacholine challenge test (MCT). While spirometry relies on proper patients' cooperation and precise execution of forced breathing maneuvers, we conducted a comparative analysis with the portable nanomaterial-based sensing device, SenseGuard™, to non-intrusively assess tidal breathing parameters. Materials and methodsIn this prospective study, 37 adult participants with suspected asthma underwent sequential spirometry and SenseGuard™ measurements after inhaling increasing methacholine doses. ResultsAmong the 37 participants, 18 were MCT responders, 17 were non-responders and 2 were excluded due to uninterpretable data. The MCT responders exhibited a significant lung function difference when comparing the change from baseline to maximum response. This was evident through a notable decrease in forced expiratory volume in 1 ​s (FEV1) levels in spirometry, as well as in prominent changes in tidal breathing parameters as assessed by SenseGuard™, including the expiratory pause time (Trest) to total breath time (Ttot) ratio, and the expiratory time (Tex) to Ttot ratio. Notably, the ratios Trest/Ttot (∗p ​= ​0.02), Tex/Ttot (∗p ​= ​0.002), and inspiratory time (Tin) to Tex (∗p ​= ​0.04) identified MCT responders distinctly, corresponding to spirometry (∗p ​< ​0.0001). ConclusionsThis study demonstrates that tidal breathing assessment using SenseGuard™ device reliably detects clinically relevant changes of respiratory parameter during the MCT. It effectively distinguishes between responders and non-responders, with strong agreement to conventional spirometry-measured FEV1. This technology holds promise for monitoring clinical respiratory changes in bronchial asthma patients pending further studies.

A preliminary study of dynamic interactive simulation and computational CT scan of the ideal alveolus model.

While the development of CT imaging technique has brought cognition of in vivo organs, the resolution of CT images and their static characteristics have gradually become barriers of microscopic tissue research. Previous research used the finite element method to study the airflow and gas exchange in the alveolus and acinar to show the fate of inhaled aerosols and studied the diffusive, convective, and sedimentation mechanisms. Our study combines these techniques with CT scan simulation to study the mechanisms of respiratory movement and its imaging appearance. We use 3D fluid-structure interaction simulation to study the movement of an ideal alveolus under regular and forced breathing situations and ill alveoli with different tissue elasticities. Additionally, we use the Monte Carlo algorithm within the OpenGATE platform to simulate the computational CT images of the dynamic process with different designated resolutions. The resolutions show the relationship between the kinematic model of the human alveolus and its imaging appearance. The results show that the alveolus and the wall thickness can be seen with an image resolution smaller than 15.6μm. With ordinary CT resolution, the alveolus is expressed with four voxels. This is a preliminary study concerning the imaging appearance of the dynamic alveolus model. This technique will be used to study the imaging appearance of the dynamic bronchial tree and the lung lobe models in the future.

Diagnostics of disturbances in the functional state of the diaphragm in patients with chronic obstructive pulmonary disease after COVID-19

Aim. Assessment of the functional state of the diaphragm in patients with COPD who underwent COVID-19.Materials and methods. The study included 35 patients with COPD complicated by compensated chronic cor pulmonale (CCP): group 1 included 15 patients with COPD who had COVID-19, group 2 included 20 patients with COPD. Patients were examined 3 months after suffering COVID-19. The functional state of the diaphragm was studied using the VIVID S70N ultrasound diagnostic system.Results. The greatest decrease in the diaphragm dome height was detected in the 1st group (p=0.001). The excursion of the diaphragm during quiet breathing was increased in both groups, in the 2nd group the indicator was 11% more than in the 1st group. The diaphragm excursion during forced breathing was reduced in the 1st group (p=0.02). The rate of diaphragm excursion during inhalation and exhalation during quiet and forced breathing in both groups was significantly increased compared to the control group. However, in the 1st group, the rate of diaphragm excursion on expiration was 49% higher. These changes may indicate respiratory muscle fatigue in COPD patients who have had COVID-19. The thickness of the muscular part of the diaphragm during inhalation and exhalation during quiet breathing in both groups compared to the control group was significantly higher. These indicators in both groups did not significantly differ from each other. There was a decrease in the thickening fraction of the muscular part of the diaphragm during calm (p=0.01) and forced breathing (p=0.001) in both groups, which indicates the onset of fatigue of the muscles of the diaphragm in the 2nd group and the initial development of weakness of the diaphragm in the 1st group who had the greatest decrease in this indicator during forced breathing.Conclusion. Ultrasonic diagnostic methods significantly expand the possibilities for assessing the functional state of the diaphragm. Patients with COPD who have undergone COVID-19 are characterized by a significant increase in the thickness of the diaphragm, limitation of its mobility, and a slowdown in the rate of relaxation of the muscular part of the diaphragm.

Clinical implications of the concentration of alveolar nitric oxide in non-small cell lung cancer.

Clinical implications of the concentration of alveolar nitric oxide in non-small cell lung cancer.

Four-dimensional reconstruction and characterization of bladder deformations

Background and ObjectivePelvic floor disorders are prevalent diseases and patient care remains difficult as the dynamics of the pelvic floor remains poorly understood. So far, only 2D dynamic observations of straining exercises at excretion are available in the clinics and 3D mechanical defects of pelvic organs are not well studied. In this context, we propose a complete methodology for the 3D representation of non-reversible bladder deformations during exercises, combined with a 3D representation of the location of the highest strain areas on the organ surface. MethodsNovel image segmentation and registration approaches have been combined with three geometrical configurations of up-to-date rapid dynamic multi-slice MRI acquisitions for the reconstruction of real-time dynamic bladder volumes. ResultsFor the first time, we proposed real-time 3D deformation fields of the bladder under strain from in-bore forced breathing exercises. The potential of our method was assessed on eight control subjects undergoing forced breathing exercises. We obtained average volume deviations of the reconstructed dynamic volume of bladders around 2.5% and high registration accuracy with mean distance values of 0.4 ± 0.3 mm and Hausdorff distance values of 2.2 ± 1.1 mm. ConclusionsThe proposed framework provides proper 3D+t spatial tracking of non-reversible bladder deformations. This has immediate applicability in clinical settings for a better understanding of pelvic organ prolapse pathophysiology. This work can be extended to patients with cavity filling or excretion problems to better characterize the severity of pelvic floor pathologies or to be used for preoperative surgical planning.

Assessment of diaphragmatic function through surface electromyography in healthy individuals. A cross-section observational study

Introduction: Diaphragmatic surface electromyography is a procedure designed to assess the diaphragm. The physiological values of the electrical activity may have potential use in rehabilitation, sports training, ventilatory support withdrawal in critical care units and follow-up of respiratory disease.&#x0D; Objective: To assess and describe the diaphragmatic function through surface electromyography in a population of individuals during spontaneous and forced breathing.&#x0D; Methods: Observational, exploratory cross-sectional study including subjects with no comorbidities. Diaphragmatic surface EMG was performed measuring the mean quadratic root during tidal volume and vital capacity breathing. The body composition of the participants was also assessed.&#x0D; Results: 28 males and 22 females were included in the study. The mean quadratic root of the tidal volume for two minutes was 13.94 µV for females and 13.31 µV for males. The vital capacity was 23.24 µV for males and 22.4 µV for females. A correlation was identified between the mean quadratic root, weight, and body surface.&#x0D; Conclusion: Mean quadratic root values of tidal volume in two minutes in healthy females and males have been documented. The mean quadratic root values are correlated with the physiological and functional characteristics of the participants.

Abolition of sagittal T7–T10 dynamics during forced ventilation in AIS patients with Lenke 1A curves

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7–T10 segment. In AIS, the abolition of T7–T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case–control study. 20 AIS patients (18 girls, Cobb angle, 54.7 ± 7.9°; Risser 1.35 ± 1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 years mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1–T7, T7–T10, T10–T12) and the global T1–T12 ROM were measured. In healthy subjects, the mean T1–T12 ROM during forced breathing was 16.7 ± 3.8. AIS patients showed a T1–T12 ROM of 1.1 ± 1.5 (p < 0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7–T10 ROM (15.3 ± 3.0) was found in healthy controls (91.6% of the T1–T12 ROM). AIS patients showed only 0.4 ± 1.4 ROM at T7–T10 (36.4% of the T1–T12 ROM) (p < 0.001). There was a linear relationship between the magnitude of T7–T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7–T10 ROM, a crucial segment for deep breathing. T7–T10 stiffness could explain the ventilatory limitations found in AIS patients.

ABOLITION OF SAGITTAL T7-T10 DYNAMICS DURING FORCED VENTILATION IN LENKE 1A AIS PATIENTS AS COMPARED WITH HEALTHY SUBJECTS: AN UNDERLYING FACTOR OF RESPIRATORY LIMITATION IN AIS

To analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls.Case-control cross-sectional study. 20 AIS patients (18 girls, Cobb angle, 54.7±7.9°; Risser 1.35±1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 yr. mean age) were included. In AIS curves, the apex was located in T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and expiration. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12), the global T1–T12 ROM were measured. Respiratory function was assess by forced vital capacity (FVC), expiratory volume (FEV1), FEV1/FVC, inspiratory vital capacity (IVC) and peak expiratory flow (PEF).In healthy subjects, the mean T1–T12 ROM during forced breathing was 16.7±3.8. AIS patients showed a T1-T12 ROM of 1.1±1.5 (p&lt;0.05) indicating a sagittal stiffness of thoracic spine. A wide T7–T10 ROM (15.3±3.0) was found in healthy controls (91.6% of the T1–T12 ROM). AIS patients showed only 0.4±1.4 ROM at T7-T10 (36.4% of the T1–T12 ROM) (p&lt;0.001). There was a significant correlation between T7-T10 ROM and IVC.Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment participating in the deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients.

Clinical values of diaphragmatic movement in patients with chronic obstructive pulmonary disease

BackgroundThe limitation of activity due to dyspnea in chronic obstructive pulmonary disease (COPD) patients is affected by diaphragmatic dysfunction and reduced lung function. This study aimed to analyze the association between diaphragm function variables and forced expiratory volume in the first second (FEV1) and to estimate the clinical significance of diaphragm function in the correlation between COPD severity and lung function.MethodsThis prospective, single-center, cross-sectional observational study enrolled 60 COPD patients in a respiratory outpatient clinic. Data for baseline characteristics and the dyspnea scale were collected. Participants underwent a pulmonary function test (PFT), a 6-minute walk test (6MWT), and diaphragm function by ultrasonography.ResultsThe right excursion at forced breathing showed the most significant correlation with FEV1 (r = 0.370, p = 0.004). The cutoff value was 6.7 cm of the right diaphragmatic excursion at forced breathing to identify the FEV1 above 50% group. In the group with a right diaphragmatic excursion at forced breathing < 6.7 cm, modified Medical Research Council (mMRC), St. George's Respiratory Questionnaire and the total distance of 6MWT showed no difference between groups with FEV1 under and above 50% (p > 0.05). In the group with ≥ 6.7 cm, mMRC and the total distance of 6MWT showed a significant difference between FEV1 under and above 50% (p = 0.014, 456.7 ± 69.7 m vs. 513.9 ± 60.3 m, p = 0.018, respectively).ConclusionThe right diaphragmatic forced excursion was closely related to FEV1, and analysis according to the right diaphragmatic forced excursion-based cut-off value showed a significant difference between both groups. When the diaphragm function was maintained, there was a lot of difference in the 6MWT’s factors according to the FEV1 value. Our data suggest that diaphragmatic function should be performed when interpreting PFT.

Measuring respiratory and cardiac influences on blood and cerebrospinal fluid flow with real-time MRI

Background. A link between various pathological conditions and blood and cerebrospinal fluid (CSF) flow alterations has been suggested by numerous studies.1 The blood and CSF dynamics are influenced by many factors, such as posture,2 heart beating, and thoracic pressure changes during respiration.2,3 The blood/CSF can be estimated using phase-contrast (PC) – magnetic resonance imaging (MRI). However, the clinical cardiac-gated cine PC-MRI requires several heartbeats to form the time-resolved flow images covering the entire cardiac cycle, not allowing to assess beat-by-beat variability differences and respiratory-driven flow changes. To overcome these limitations, we recently used a real-time (RT)-PC prototype for the study of blood and CSF flow rate modulations, showing low-frequency oscillations (Mayer waves).4 With the same MRI technique, in the current study we focused on assessing the cardiac and respiratory modulations on the blood and CSF flow rates, and the effects of different respiration modes.&#x0D; Methods. Thirty healthy volunteers (21 females, median age=26 years old, age range= 19-57 years old) were examined with a 3 T scanner. RT-PC sequences (Figure 1) allowed for a quantification of the flow rates of internal carotid arteries (ICAs), internal jugular veins (IJVs), and CSF at the first cervical level. The superior sagittal sinus (SSS) was also studied in 16 subjects.5 The flow rates were estimated with a temporal resolution of 58.5 ms for the blood, and 94 ms for the CSF. Each RT-PC lasted 60 seconds and was repeated three times: while the subject breathed with free (F) breathing, at a constant rate with a normal (PN) or forced (PD) strength. The systolic, diastolic and average flow rates and their power spectral densities were computed. High and very-high frequency peaks were identified on the spectra. Frequencies associated to the identified peaks were compared to the respiratory and cardiac frequencies estimated by a thoracic band and a pulse oximeter. The area under the spectra, normalized by the flow rate variance, was computed in the respiratory and cardiac frequency ranges (0.5 Hz-wide ranges, centered on the cardiac or breathing frequency peaks, respectively).&#x0D; Results. The frequencies associated with the spectral peaks were not significantly different compared to the respiratory and cardiac frequencies, for all regions and breathing modes. The average blood flow rate and the diastolic CSF peak progressively decreased from F to PN to PD breathing, the flow rate variance remained stable, and only the ICAs cross-sectional area decreased. The respiratory modulation increased with PD breathing compared with F and PN, while the cardiac modulations were less predominant for all the structures of interest.&#x0D; Conclusions. Using the RT-PC sequence we showed that the blood and CSF flow rates were modulated at the respiratory and cardiac frequencies. The observed reduced blood flow rate during forced breathing in the arteries and consequently in the extra and intracranial veins are suggestive of compensatory vasoconstriction in response to decreased CO2 blood concentration. Breathing modulation of flow rates was observed both in the extracranial and intracranial compartments, and it was greater during forced breathing than free breathing, due to the greater thoracic pump effect on the flow rates.

Abdominal and Pelvic Floor Activity Related to Respiratory Diaphragmatic Activity in Subjects with and without Non-Specific Low Back Pain.

One of the advances in physiotherapy in recent years is the exploration and treatment by ultrasound imaging. This technique makes it possible to study the relationship between the musculature of the anterolateral wall of the abdomino-pelvic cavity, the pelvic floor muscles and the diaphragm muscle, among others, and thus understand their implication in non-specific low back pain (LBP) in pathological subjects regarding healthy subjects. Objective: To evaluate by RUSI (rehabilitative ultrasound imaging) the muscular thickness at rest of the abdominal wall, the excursion of the pelvic floor and the respiratory diaphragm, as well as to study their activity. Methodology: Two groups of 46 subjects each were established. The variables studied were: non-specific low back pain, thickness and excursion after tidal and forced breathing, pelvic floor (PF) excursion in a contraction and thickness of the external oblique (EO), internal oblique (IO) and transverse (TA) at rest. Design: Cross-sectional observational study. Results: Good-to-excellent reliability for measurements of diaphragm thickness at both tidal volume (TV) (inspiration: 0.763, expiration: 0.788) and expiration at forced volume (FV) (0.763), and good reliability for inspiration at FV (0.631). A correlation was found between the EO muscle and PF musculature with respect to diaphragmatic thickness at TV, inspiration and expiration, and inspiration at FV, in addition to finding significant differences in all these variables in subjects with LBP. Conclusion: Subjects with LBP have less thickness at rest in the OE muscle, less excursion of the pelvic diaphragm, less diaphragmatic thickness at TV, in inspiration and expiration, and in inspiration to FV.

Quantitative evaluation of diaphragmatic motion during forced breathing in chronic obstructive pulmonary disease patients using dynamic chest radiography.

ObjectiveTo quantitatively evaluate the bilateral diaphragmatic motion difference during forced breathing between chronic obstructive pulmonary disease (COPD) patients and healthy individuals using dynamic chest radiography technique.MethodsThis prospective study included the COPD patients (n: 96, f/m: 17/79, age: 66 ± 8 years old) and healthy individuals (n: 50, f/m: 42/8, age: 53 ± 5 years old) that underwent dynamic chest radiography with a flat panel X-ray detector system during forced breathing in a standing position. After analyzing the excursions, duration and velocity of diaphragmatic motion were automatically calculated using the postprocessing software. The parameters of diaphragmatic motion including excursion, duration, velocity, inhalation/exhalation times were assessed in all subjects for both diaphragms. The correlation between lung function parameters and diaphragmatic motion excursions were further evaluated.ResultsThe excursions of diaphragmatic motion in COPD patients were significantly decreased in COPD patients compared with healthy individuals during forced breathing (P < 0.05). The excursion in COPD patients was 35.93 ± 13.07 mm vs. 41.49 ± 12.07 mm in healthy individuals in the left diaphragm, and 32.05 ± 12.29 mm in COPD patients vs. 36.88 ± 10.96 mm in healthy individuals in the right diaphragm. The duration of diaphragmatic motion significantly decreased in COPD patients, compared with the healthy individuals (P < 0.05). The inhalation time in COPD patients was 2.03 ± 1.19 s vs. 2.53 ± 0.83 s in healthy individuals in the left diaphragm and 1.94 ± 1.32 s in COPD patients vs. 2.23 ± 1.21 s in healthy individuals in the right diaphragm. The exhalation time was 4.77 ± 1.32 s in COPD patients vs. 6.40 ± 2.73 s in healthy individuals in the left diaphragm and 4.94 ± 3.30 s in COPD patients vs. 6.72 ± 2.58 s in healthy individuals in the right diaphragm. The peak velocity of diaphragmatic motion showed no significant difference between COPD and healthy groups. The excursions of bilateral diaphragmatic motion showed moderate correlation with FEV1/FVC (r = 0.44, P < 0.001). Multi-linear regression analysis showed that the excursions of bilateral diaphragm are significantly associated with COPD occurrence (P < 0.05).ConclusionThe excursions and duration of diaphragmatic motion during forced breathing are significantly decreased in COPD patients, compared with healthy individuals. Our study showed that precise bilateral diaphragmatic motion activity can be evaluated by dynamic chest radiography.

Projected lung area using dynamic X-ray (DXR) with a flat-panel detector system and automated tracking in patients with chronic obstructive pulmonary disease (COPD)

ObjectivesTo assess the association of projected lung area (PLA) measured by DXR with demographic data, pulmonary function, and COPD severity, and to generate PLA over time curves using automated tracking. MethodsThis retrospective study recruited healthy volunteers and COPD patients. Participants were classified into three groups: normal, COPD mild and COPD severe. PLA was calculated from the manually traced bilateral lung contours. PLA over time curves were produced using automated tracking, which was used to calculate slope and intercept by approximate line during forced expiration. The correlation of PLA, difference of PLA between end-inspiration and end-expiration (ΔPLA), slope, and intercept with demographic data and pulmonary function tests were investigated. The difference of PLA, ΔPLA, intercept, and slope among three groups were also evaluated. ResultsThis study enrolled 45 healthy volunteers and 32 COPD patients. COPD severe group had larger PLA in both lungs at tidal/forced end-inspiration/expiration, smaller slope, and larger intercept than normal group (p < 0.001). PLA was correlated with % forced expiratory volume in one second (%FEV1) (rs from −0.42 to −0.31, p ≤ 0.01). ΔPLA in forced breathing showed moderate correlation with vital capacity (VC) (rs = 0.58, p < 0.001), while ΔPLA in tidal breathing showed moderate correlation with %FEV1 (rs = -0.52, p < 0.001) as well as mild correlation with tidal volume (rs = 0.24, p = 0.032). Intercept was slightly underestimated compared with manually contoured PLA (p < 0.001). ConclusionCOPD patients had larger PLA than healthy volunteers. PLA and ΔPLA in tidal breathing showed mild to moderate correlation with %FEV1.