scholarly journals Performance Evaluation of Fixed Sample Entropy in Myographic Signals for Inspiratory Muscle Activity Estimation

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 183 ◽  
Author(s):  
Manuel Lozano-García ◽  
Luis Estrada ◽  
Raimon Jané
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Cardiac Activity ◽  
Sample Entropy ◽  
Inspiratory Muscle ◽  
Chronic Obstructive ◽  
Inspiratory Muscles ◽  
Fixed Sample ◽  
Cross Covariance ◽  
Activity Estimation

Fixed sample entropy (fSampEn) has been successfully applied to myographic signals for inspiratory muscle activity estimation, attenuating interference from cardiac activity. However, several values have been suggested for fSampEn parameters depending on the application, and there is no consensus standard for optimum values. This study aimed to perform a thorough evaluation of the performance of the most relevant fSampEn parameters in myographic respiratory signals, and to propose, for the first time, a set of optimal general fSampEn parameters for a proper estimation of inspiratory muscle activity. Different combinations of fSampEn parameters were used to calculate fSampEn in both non-invasive and the gold standard invasive myographic respiratory signals. All signals were recorded in a heterogeneous population of healthy subjects and chronic obstructive pulmonary disease patients during loaded breathing, thus allowing the performance of fSampEn to be evaluated for a variety of inspiratory muscle activation levels. The performance of fSampEn was assessed by means of the cross-covariance of fSampEn time-series and both mouth and transdiaphragmatic pressures generated by inspiratory muscles. A set of optimal general fSampEn parameters was proposed, allowing fSampEn of different subjects to be compared and contributing to improving the assessment of inspiratory muscle activity in health and disease.

Chronic Obstructive Pulmonary Disease: Strategies to Improve Functional Status

1998 ◽  
Vol 16 (1) ◽  
pp. 253-286 ◽  
Author(s):  
JANET L. LARSON ◽  
NANCY K. LEIDY
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Functional Status ◽  
Pulmonary Disease ◽  
Functional Capacity ◽  
Functional Performance ◽  
Inspiratory Muscle ◽  
Pharmacologic Therapy ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Inspiratory Muscles

People with chronic obstructive pulmonary disease (COPD) experience deterioration in functional status, therefore improving functional status is a major goal of treatment. We reviewed interventions to improve functional status in people with COPD published from 1980 through September 1996. Randomized controlled clinical trials were reviewed to document outcomes in terms of functional capacity and functional performance for the following interventions: pharmacologic therapy including theophylline, inhaled bronchodilators, steroids, antianxiolytics and antidepressants; general exercise strategies including exercise training, exercise and comprehensive pulmonary rehabilitation, and upper extremity training; inspiratory muscle therapy including inspiratory muscle training and inspiratory muscle rest; nutritional therapy; oxygen therapy; and specialized nursing care. Improvements for functional capacity were documented in terms of strength of the inspiratory muscles and upper extremities, walking tests, and peak oxygen uptake. Most interventions were targeted to enhance functional capacity, and few were aimed at enhancing functional performance. Further research is needed to examine the relationship between functional capacity and functional performance and to design and test interventions to improve functional performance.

Inspiratory muscle activity during unloaded and obstructed rebreathing in dogs

1988 ◽  
Vol 64 (1) ◽  
pp. 90-101 ◽  
Author(s):  
E. D'Angelo ◽  
N. Garzaniti ◽  
F. Bellemare
Keyword(s):  
Muscle Activity ◽  
Moving Average ◽  
Inspiratory Muscle ◽  
Central Control ◽  
Control Mechanisms ◽  
Peak Activity ◽  
Airway Occlusion ◽  
Inspiratory Muscles ◽  
Thoracic Muscles ◽  
Proprioceptive Inputs

Moving-average electromyogram (EMG) of the diaphragm (DI), scalenes, and cranial and caudal parasternals was assessed in anesthetized, supine, and head-up dogs during rebreathing. The shape of EMG trajectory was similar for all muscles and conditions; activation of different muscles could be thus compared on the basis of changes in peak activity. In intact dogs changes in peak activity were greater for the scalenes and cranial parasternals than for the caudal parasternals and greater for the inspiratory thoracic muscles (ITM) than for the DI. Posture, vagotomy, and cordotomy at C7-T1 did not affect the rate of rise of DI activity. The relations between peak activity of ITM did not change because of posture, vagotomy, and phrenicotomy. Vagotomy selectively depressed the rate of rise of ITM activity, but relative changes in peak ITM activity for a given change in peak DI activity were independent of intact vagi. Differences in the pattern of activation between inspiratory muscles with rebreathing are largely independent of proprioceptive inputs and likely reflect properties of central control mechanisms. However, airway occlusion at end expiration caused a reflex fall of DI activity and reflex increase of ITM activity in intact and vagotomized dogs. Cordotomy at C7-T1 did not change DI response, whereas reduction of ITM activity occurred after phrenicotomy, indicating that both facilitatory and inhibitory segmental inputs are involved in ITM response to loading.

scholarly journals Efficacy of a Novel Method for Inspiratory Muscle Training in People With Chronic Obstructive Pulmonary Disease

2015 ◽  
Vol 95 (9) ◽  
pp. 1264-1273 ◽  
Author(s):  
Daniel Langer ◽  
Noppawan Charususin ◽  
Cristina Jácome ◽  
Mariana Hoffman ◽  
Alison McConnell ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Muscle Function ◽  
Inspiratory Muscle ◽  
Inspiratory Muscle Training ◽  
Chronic Obstructive ◽  
Muscle Training ◽  
Obstructive Pulmonary Disease ◽  
Inspiratory Muscles ◽  
Home Based

Background Most inspiratory muscle training (IMT) interventions in patients with chronic obstructive pulmonary disease (COPD) have been implemented as fully supervised daily training for 30 minutes with controlled training loads using mechanical threshold loading (MTL) devices. Recently, an electronic tapered flow resistive loading (TFRL) device was introduced that has a different loading profile and stores training data during IMT sessions. Objective The aim of this study was to compare the efficacy of a brief, largely unsupervised IMT protocol conducted using either traditional MTL or TFRL on inspiratory muscle function in patients with COPD. Design Twenty patients with inspiratory muscle weakness who were clinically stable and participating in a pulmonary rehabilitation program were randomly allocated to perform 8 weeks of either MTL IMT or TFRL IMT. Methods Participants performed 2 daily home-based IMT sessions of 30 breaths (3–5 minutes per session) at the highest tolerable intensity, supported by twice-weekly supervised sessions. Adherence, progression of training intensity, increases in maximal inspiratory mouth pressure (Pimax), and endurance capacity of inspiratory muscles (Tlim) were evaluated. Results More than 90% of IMT sessions were completed in both groups. The TFRL group tolerated higher loads during the final 3 weeks of the IMT program, with similar effort scores on the 10-Item Borg Category Ratio (CR-10) Scale, and achieved larger improvements in Pimax and Tlim than the MTL group. Limitations A limitation of the study was the absence of a study arm involving a sham IMT intervention. Conclusions The short and largely home-based IMT protocol significantly improved inspiratory muscle function in both groups and is an alternative to traditional IMT protocols in this population. Participants in the TFRL group tolerated higher training loads and achieved larger improvements in inspiratory muscle function than those in the MTL group.

Effect of CPAP on respiratory effort and dyspnea during exercise in severe COPD

1990 ◽  
Vol 69 (1) ◽  
pp. 179-188 ◽  
Author(s):  
B. J. Petrof ◽  
E. Calderini ◽  
S. B. Gottfried
Keyword(s):  
Lung Volume ◽  
Muscle Activation ◽  
Minute Ventilation ◽  
Inspiratory Muscle ◽  
Expected Improvement ◽  
Chronic Obstructive ◽  
Time Integral ◽  
Copd Patients ◽  
Pressure Time ◽  
Gastric Pressure

Recent work has demonstrated the ability of continuous positive airway pressure (CPAP) to relieve dyspnea during exercise in patients with severe chronic obstructive pulmonary disease (COPD). The present study examined the effects of CPAP (7.5-10 cmH2O) on the pattern of respiratory muscle activation and its relationship to dyspnea during constant work load submaximal bicycle exercise [20 +/- 4.8 (SE) W] in eight COPD patients (forced expiratory volume in 1 s = 25 +/- 3% predicted). Tidal volume, respiratory rate, minute ventilation, and end-expiratory lung volume increased with exercise as expected. There was no change in breathing pattern, end-expiratory lung volume, or pulmonary compliance and resistance with the addition of CPAP. CPAP reduced inspiratory muscle effort, as indicated by the pressure-time integral of transdiaphragmatic (integral of Pdi.dt) and esophageal pressure (integral of Pes.dt, P less than 0.01 and P less than 0.05, respectively). In contrast, the pressure-time integral of gastric pressure (integral of Pga.dt), used as an index of abdominal muscle recruitment during expiration, increased (P less than 0.01). Dyspnea improved with CPAP in five of the eight patients. The amelioration of dyspnea was directly related to reductions in integral of Pes.dt (P less than 0.001) but inversely related to increases in integral of Pga.dt (P less than 0.01). In conclusion, CPAP reduces inspiratory muscle effort during exercise in COPD patients. However, the expected improvement in dyspnea is not seen in all patients and may be explained by more marked increases in expiratory muscle effort in some individuals.

Role of the respiratory muscles in acute respiratory failure of COPD: lessons from weaning failure

2009 ◽  
Vol 107 (3) ◽  
pp. 962-970 ◽  
Author(s):  
Martin J. Tobin ◽  
Franco Laghi ◽  
Laurent Brochard
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Respiratory Muscles ◽  
Inspiratory Muscle ◽  
Voluntary Activation ◽  
Airflow Limitation ◽  
Chronic Obstructive ◽  
Inspiratory Muscles ◽  
Weaning Failure ◽  
Expiratory Muscles

It is problematic to withhold therapy in a patient with chronic obstructive pulmonary disease (COPD) who presents with acute respiratory failure so that detailed physiological measurements can be obtained. Accordingly, most information on respiratory muscle activity in patients experiencing acute respiratory failure has been acquired by studying patients who fail a trial of weaning after a period of mechanical ventilation. Such patients experience marked increases in inspiratory muscle load consequent to increases in resistance, elastance, and intrinsic positive end-expiratory pressure. Inspiratory muscle strength is reduced secondary to hyperinflation and possibly direct muscle damage and the release of inflammatory mediators. Most patients recruit both their sternomastoid and expiratory muscles, even though airflow limitation prevents the expiratory muscles from lowering lung volume. Even when acute hypercapnia is present, patients do not exhibit respiratory center depression; indeed, voluntary activation of the diaphragm, in absolute terms, is greater in hypercapnic patients than in normocapnic patients. Instead, the major mechanism of acute hypercapnia is the development of rapid shallow breathing. Despite the marked increase in mechanical load and decreased force-generating capacity of the inspiratory muscles, patients do not develop long-lasting muscle fatigue, at least over the period of a failed weaning trial. Although the disease originates within the lung parenchyma, much of the distress faced by patients with COPD, especially during acute respiratory failure, is caused by the burdens imposed on the respiratory muscles.

scholarly journals Effects of Inspiratory Muscles Training Plus Rib Cage Mobilization on Chest Expansion, Inspiratory Accessory Muscles Activity and Pulmonary Function in Stroke Patients

2020 ◽  
Vol 10 (15) ◽  
pp. 5178
Author(s):  
Shin Jun Park
Keyword(s):  
Pulmonary Function ◽  
Muscle Activity ◽  
Inspiratory Muscle ◽  
Inspiratory Muscle Training ◽  
Control Group ◽  
Muscle Training ◽  
Rib Cage ◽  
Joint Mobilization ◽  
Chest Expansion ◽  
Inspiratory Muscles

After stroke, limited ribcage movement may lead to impaired respiratory function. Combining threshold inspiratory muscle training with rib cage joint mobilization has been shown to enhance the recovery of respiratory function in patients with stroke. The present study investigated whether the combination of rib cage joint mobilization and inspiratory muscle training would improve chest expansion, inspiratory muscle activity, and pulmonary function after stroke. Thirty stroke patients were recruited and randomly assigned to one of the two groups, namely 6-week rib cage joint mobilization with inspiratory muscle training (experimental group) or inspiratory muscle training alone (control group). Outcome measures included upper and lower chest expansion, activity of accessory inspiratory muscles (latissimus dorsi (LD) and upper trapezius (UT)), and pulmonary function (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow (PEF)). All evaluations were conducted at baseline and after 6 weeks of inspiratory muscle training. Significant increases were observed in upper and lower chest expansion, LD and UT muscle activity, FVC, FEV1, and PEF in both the groups. Upper and lower chest expansion and muscle activity of UT and LD were significantly higher in the experimental group than in the control group. No significant differences were observed in FVC, FEV1, and PEF between the groups. Inspiratory muscle training is effective in improving chest expansion, inspiratory muscle activity, and pulmonary function after stroke. The addition of rib cage joint mobilization further increases chest expansion and inspiratory muscle activity.

Breathing in Singing

2014 ◽  
pp. 86-108
Author(s):  
Alan Watson
Keyword(s):  
Abdominal Wall ◽  
Muscle Activity ◽  
Abdominal Muscle ◽  
Inspiratory Muscle ◽  
Lung Volumes ◽  
Inspiratory Muscles

Accounts of breathing in methodological books on singing are often confusing or inaccurate rather than helpful. This chapter provides an overview of the principles ofrespiration and how this is modified for singing. Inspiration results from an increase inthoracic dimensions caused by activity in the diaphragm and external intercostal muscles.At high lung volumes the sternocleidomastoids and scalenes also aid chest expansion.Subglottic pressure is created during expiration by the contraction of the abdominal wall,predominantly as a result of lateral abdominal muscle activity, which drives the relaxeddiaphragm upwards while simultaneously the internal intercostals pull the ribsdownwards. When the lungs are full and the inspiratory muscles release, elastic recoilforces alone can drive out the air and in order to regulate subglottic pressure theseforces must be resisted by gradually reducing inspiratory muscle activity. How different patterns of activity in these and other muscles contribute to singing is described and theway in which similar ends can be achieved by different means in different singers isexplained.

Reflex compensation of spontaneous breathing when immersion changes diaphragm length

1985 ◽  
Vol 58 (4) ◽  
pp. 1136-1142 ◽  
Author(s):  
M. B. Reid ◽  
R. B. Banzett ◽  
H. A. Feldman ◽  
J. Mead
Keyword(s):  
Muscle Activation ◽  
Inspiratory Muscle ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Voluntary Response ◽  
Afferent Information ◽  
Reflex Compensation ◽  
Muscle Groups ◽  
End Tidal ◽  
Spontaneously Breathing

We measured tidal volume (VT), chest wall dimensions, end-tidal PCO2, and respiratory muscle electromyograms as seated subjects were immersed in water. We studied nine spontaneously breathing subjects; five were uninformed. Raising the water to xiphoid level pushed the abdomen in and expanded the rib cage at end expiration. This increased the diaphragm's operating length, giving it a contractile advantage, and shortened the inspiratory intercostals, giving them a contractile disadvantage. Peak inspiratory activities of both muscle groups decreased; inspiratory time (TI), respiratory frequency (f), and VT were unchanged. The experiments thus demonstrated operational length compensation during immersion and further showed that inspiratory muscle activation is not adjusted locally, according to changes in each muscle's length, but rather that the response is global. Xiphoid-to-shoulder immersion was less easily interpreted, since both rib cage and abdomen were compressed, lengthening both inspiratory muscles. Our subjects continued to maintain VT, f, and TI. Peak inspiratory activities of both muscles were further reduced. We do not attribute the change in inspiratory muscle activation to altered chemical drive or to voluntary response. Rather, the response appears to be a mechanoreceptive reflex that employs afferent information from the lungs or diaphragm to adjust all inspiratory muscle activities.

Role of Impaired Inspiratory Muscle Function in Limiting the Ventilatory Response to Carbon Dioxide in Chronic Airflow Obstruction

1983 ◽  
Vol 64 (5) ◽  
pp. 487-495 ◽  
Author(s):  
H. R. Gribbin ◽  
I. T. Gardiner ◽  
G. J. Heinz ◽  
G. J. Gibson ◽  
N. B. Pride
Keyword(s):  
Muscle Activation ◽  
Ventilatory Response ◽  
Work Of Breathing ◽  
Airflow Obstruction ◽  
Normal Subjects ◽  
Inspiratory Muscle ◽  
Pleural Pressure ◽  
Pulmonary Mechanics ◽  
Respiratory Drive ◽  
Inspiratory Muscles

1. Twenty patients with severe chronic airflow obstruction (CAFO), four of whom were hypercapnic, had greatly reduced ventilatory responses to rebreathing CO2 under hyperoxic conditions, compared with the responses in normal subjects. 2. Mouth occlusion pressure (P0.1) responses to CO2 were also reduced in the patients compared with those of normal subjects but the reduction was less severe than in the ventilatory response. 3. in ten patients with CAFO minimum pleural pressure during tidal breathing [Ppl min. (dynamic)] at a Pco2 of 8.0 kPa was only slightly less negative than in the normal subjects (−16.2 cm water vs −23.4 cm water). 4. During rebreathing end-expiratory volume (EEV) fell progressively in the normal subjects (mean fall = 800 ml); in the patients there was a progressive rise in EEV (mean rise = 390 ml). 5. When Ppl min. (dynamic) was compared with minimum static pleural pressures at the same lung volume the patients were generating a much higher proportion of their available static pressure (47.0%) than the normal subjects (26.4%) at a Pco2 of 8.0 kPa, suggesting that despite the slightly less negative Ppl min. (dynamic), inspiratory muscle activation was greater in the patients than in normal subjects. Similar conclusions were reached from an analysis of the inspiratory work of breathing. 6. We conclude that hyperinflation, by impairing the capacity of the inspiratory muscles to lower pleural pressure, reduces the ventilatory response to CO2 and adds to the effects of abnormalities in pulmonary mechanics so that measurements of absolute pleural pressure or work of breathing underestimate inspiratory muscle activation in patients with severe CAFO. 7. Hyperinflation and severe airflow obstruction also reduce the change in P0.1 for a given degree of inspiratory muscle activation. 8. Our results suggest that, despite the impaired pressure and ventilatory response to rebreathing CO2 in the patients, their central respiratory drive was greater than that of the normal subjects.

Tonic inspiratory muscle activity as a cause of hyperinflation in asthma

1981 ◽  
Vol 50 (2) ◽  
pp. 279-282 ◽  
Author(s):  
N. Muller ◽  
A. C. Bryan ◽  
N. Zamel
Keyword(s):  
Muscle Activity ◽  
Inspiratory Muscle ◽  
Tonic Activity ◽  
Surface Electrodes ◽  
Inspiratory Muscles ◽  
Thoracic Gas Volume ◽  
Before And After ◽  
Male Patients ◽  
Gas Volume ◽  
Proportional Reduction

We studied tonic activity of the inspiratory muscles during exacerbation of asthma in five female and two male patients. Exacerbation was provoked by withholding bronchodilatory medication for 12 h prior to the study. Thoracic gas volume (TGV) at the end of resting expiration was determined before and after albuterol (salbutamol) inhalation with a body plethysmograph. Intercostal muscle electromyogram (EMG) was recorded with surface electrodes and diaphragmatic EMG with esophageal electrodes. Tonic activity was defined as electrical activity in the EMG present throughout expiration. After salbutamol the TGV decreased 13.4 +/- 2.9% (mean +/- SE) (P less than 0.01). This decrease in TGV was accompanied by a proportional reduction in tonic intercostal (r = 0.78, P less than 0.05) and diaphragmatic activity (r = 0.84, P less than 0.05). These findings suggest that the hyperinflation present during exacerbation of asthma is at least in part due to active inspiratory muscle activity present throughout expiration.

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