Surface Recordings of Respiratory Muscle Activity during Speech

1989 ◽  
Vol 32 (3) ◽  
pp. 657-667 ◽  
Author(s):  
David H. McFarland ◽  
Anne Smith

Bipolar electromyographic (EMG) recordings were made from six chest wall and nasal sites with disk electrodes attached to the skin. Electrode locations were based on previous studies of nonspeech breathing and were designed to sample the activity of both primary and accessory respiratory muscles. EMG activity was sampled while subjects performed a series of speech and nonspeeeh tasks. The results revealed that surface electrodes could sample the activity of respiratory muscles during speech and other ventilatory tasks, particularly during the expiratory phases of the breathing cycle.

2022 ◽  
Vol 12 ◽  
Author(s):  
Antenor Rodrigues ◽  
Luc Janssens ◽  
Daniel Langer ◽  
Umi Matsumura ◽  
Dmitry Rozenberg ◽  
...  

Background: Respiratory muscle electromyography (EMG) can identify whether a muscle is activated, its activation amplitude, and timing. Most studies have focused on the activation amplitude, while differences in timing and duration of activity have been less investigated. Detection of the timing of respiratory muscle activity is typically based on the visual inspection of the EMG signal. This method is time-consuming and prone to subjective interpretation.Aims: Our main objective was to develop and validate a method to assess the respective timing of different respiratory muscle activity in an objective and semi-automated manner.Method: Seven healthy adults performed an inspiratory threshold loading (ITL) test at 50% of their maximum inspiratory pressure until task failure. Surface EMG recordings of the costal diaphragm/intercostals, scalene, parasternal intercostals, and sternocleidomastoid were obtained during ITL. We developed a semi-automated algorithm to detect the onset (EMG, onset) and offset (EMG, offset) of each muscle’s EMG activity breath-by-breath with millisecond accuracy and compared its performance with manual evaluations from two independent assessors. For each muscle, the Intraclass Coefficient correlation (ICC) of the EMG, onset detection was determined between the two assessors and between the algorithm and each assessor. Additionally, we explored muscle differences in the EMG, onset, and EMG, offset timing, and duration of activity throughout the ITL.Results: More than 2000 EMG, onset s were analyzed for algorithm validation. ICCs ranged from 0.75–0.90 between assessor 1 and 2, 0.68–0.96 between assessor 1 and the algorithm, and 0.75–0.91 between assessor 2 and the algorithm (p < 0.01 for all). The lowest ICC was shown for the diaphragm/intercostal and the highest for the parasternal intercostal (0.68 and 0.96, respectively). During ITL, diaphragm/intercostal EMG, onset occurred later during the inspiratory cycle and its activity duration was shorter than the scalene, parasternal intercostal, and sternocleidomastoid (p < 0.01). EMG, offset occurred synchronously across all muscles (p ≥ 0.98). EMG, onset, and EMG, offset timing, and activity duration was consistent throughout the ITL for all muscles (p > 0.63).Conclusion: We developed an algorithm to detect EMG, onset of several respiratory muscles with millisecond accuracy that is time-efficient and validated against manual measures. Compared to the inherent bias of manual measures, the algorithm enhances objectivity and provides a strong standard for determining the respiratory muscle EMG, onset.


2020 ◽  
Vol 65 (9) ◽  
pp. 1285-1294
Author(s):  
Jéssica Danielle Medeiros da Fonsêca ◽  
Vanessa Regiane Resqueti ◽  
Kadja Benício ◽  
Valéria Soraya de Farias Sales ◽  
Luciana Fontes Silva da Cunha Lima ◽  
...  

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Tom Schepens ◽  
Koen Janssens ◽  
Sabine Maes ◽  
Davina Wildemeersch ◽  
Jurryt Vellinga ◽  
...  

Abstract Background The use of neostigmine after neuromuscular blockade (NMB) has been associated with postoperative respiratory complications. In previous studies, we found lower diaphragmatic activity after neostigmine reversal of NMB, compared to sugammadex. It is still unclear whether the adequate use of neostigmine guarantees normal respiratory muscle function after NMB. In this study, we wanted to assess the effect of commonly used degrees of NMB and their possible reversal strategies on respiratory muscle activity after the return of normal neuromuscular transmission. Methods This is a randomized, controlled, parallel-group, single-centre, double-blind study in patients scheduled for intracranial surgery at a tertiary academic hospital in Belgium. All participants received target controlled propofol/remifentanil anesthesia and were randomized into one of five groups, receiving either a shallow NMB with no reversal (shallow/saline), a shallow NMB with sugammadex reversal (shallow/sugammadex), a moderate NMB with neostigmine reversal (moderate/neostigmine), a moderate NMB with sugammadex reversal (moderate/sugammadex), or a deep NMB with sugammadex reversal (deep/sugammadex). Primary and secondary outcome parameters were diaphragm and intercostal electromyographic (EMG) activity at the moment of resumed spontaneous breathing activity, defined as a maximal interval of 10 min after the first spontaneous breath. Results For the five groups, a total of 55 patients could be included in the final analysis. Median time of spontaneous breathing analyzed was 5 min (IQR 3–9.5 min). Both the moderate/sugammadex and the moderate/neostigmine groups had lower levels of diaphragm EMG compared to the shallow/sugammadex group. The moderate/neostigmine group had lower levels of intercostal EMG activity compared to the shallow/saline group. Conclusions In this study, the depth of neuromuscular blockade and type of reversal strategy impacts respiratory muscle activity at the moment of resumed spontaneous breathing and recovery of neuromuscular blockade. Both groups that received moderate NMB had lower levels of diaphragm EMG, compared to the shallow NMB group with sugammadex reversal. Compared to the shallow NMB group with no reversal, the moderate NMB with neostigmine reversal group had lower intercostal EMG activity. Trial registration Clinicaltrials.gov NCT01962298 on October 9, 2013 and EudraCT 2013–001926-25 on October 10, 2013.


1991 ◽  
Vol 70 (1) ◽  
pp. 158-168 ◽  
Author(s):  
K. G. Henke ◽  
J. A. Dempsey ◽  
M. S. Badr ◽  
J. M. Kowitz ◽  
J. B. Skatrud

To investigate the response of inspiratory and expiratory muscles to naturally occurring inspiratory resistive loads in the absence of conscious control, five male "snorers" were studied during non-rapid-eye-movement (NREM) sleep with and without continuous positive airway pressure (CPAP). Diaphragm (EMGdi) and scalene (EMGsc) electromyographic activity were monitored with surface electrodes and abdominal EMG activity (EMGab) with wire electrodes. Subjects were studied in the following conditions: 1) awake, 2) stage 2 sleep, 3) stage 3/4 sleep, 4) CPAP during stage 3/4 sleep, 5) CPAP plus end-tidal CO2 pressure (PETCO2) isocapnic to stage 2 sleep, and 6) CPAP plus PETCO2 isocapnic to stage 3/4 sleep. Inspired pulmonary resistance (RL) at peak flow rate and PETCO2 increased in all stages of sleep. Activity of EMGdi, EMGsc, and EMGab increased significantly in stage 3/4 sleep. CPAP reduced RL at peak flow, increased tidal volume and expired ventilation, and reduced PETCO2. EMGdi and EMGsc were reduced, and EMGab was silenced. During CPAP, with CO2 added to make PETCO2 isocapnic to stage 3/4 sleep, EMGsc and EMGab increased, but EMGdi was augmented in only one-half of the trials. EMG activity in this condition, however, was only 75% (EMGsc) and 43% (EMGab) of the activity observed during eupneic breathing in stage 3/4 sleep when PETCO2 was equal but RL was much higher. We conclude that during NREM sleep 1) inspiratory and expiratory muscles respond to internal inspiratory resistive loads and the associated dynamic airway narrowing and turbulent flow developed throughout inspiration, 2) some of the augmentation of respiratory muscle activity is also due to the hypercapnia that accompanies loading, and 3) the abdominal muscles are the most sensitive to load and CO2 and the diaphragm is the least sensitive.


2001 ◽  
Vol 204 (24) ◽  
pp. 4185-4197
Author(s):  
Winston C. Lancaster ◽  
J. R. Speakman

SUMMARY Echolocating bats use respiratory muscles to power the production of biosonar vocalisations. The physical characteristics of these calls vary among species of bat, and variations also exist in the timing and patterns of respiratory muscle recruitment during echolocation. We recorded electromyograms from the respiratory muscles of three species of bat (Family Vespertilionidae) while the animals vocalised from stationary positions. Activity was recorded consistently from the lateral abdominal muscles (internal abdominal oblique and transversus abdominis) from all calling bats, but we found much variation within and among species. Bats in the family Vespertilionidae devoted longer periods of expiratory muscle activity to each call than did the mormoopid bat Pteronotus parnellii. These differences correlate negatively with the duration of calls. We suggest that morphological adaptations in some bats may facilitate the economic production of echolocation calls at rest.


1985 ◽  
Vol 59 (3) ◽  
pp. 847-852 ◽  
Author(s):  
W. A. Carlo ◽  
M. J. Miller ◽  
R. J. Martin

The effect of end-expiratory occlusion on respiratory muscle activity was studied in 10 unsedated preterm infants during sleep. Electromyograms (EMG) of the upper airway were recorded from surface electrodes placed over the submental (SM) area; diaphragm (DIA) EMGs were obtained with identical electrodes over the right subcostal margin. Phasic SM EMG accompanied 56 +/- 36% of breaths during spontaneous breathing and increased to 80 +/- 26% (P less than 0.05) on the first inspiratory effort after occlusion. Occlusion increased peak amplitude (P less than 0.001) and total duration (P less than 0.005) of the SM EMG without significant changes in its initial rate of rise. In contrast, only the total duration of the DIA EMG increased (P less than 0.005) during occlusion. Inspiratory time increased from 470 +/- 120 to 720 +/- 210 ms (P less than 0.001) during the first occluded effort, but expiratory time did not change. With sustained occlusion, peak amplitude of the SM EMG progressively increased, but DIA EMG only significantly increased by the third occluded effort. Pharyngeal patency was invariably maintained throughout the induced airway occlusions. Sharp bursts of SM EMG activity coincided with resolution of spontaneous obstructive apneic episodes in four infants. The immediate increase in SM EMG associated with airway occlusion may be a mechanism that prevents the development of obstructive apnea.


1990 ◽  
Vol 68 (4) ◽  
pp. 1435-1442 ◽  
Author(s):  
J. C. Hendricks ◽  
L. R. Kline ◽  
R. O. Davies ◽  
A. I. Pack

Muscle atonia is a feature of normal rapid-eye-movement sleep (REMS). The suppression of accessory respiratory muscle activity has been investigated and a role for sleep-disordered breathing hypothesized, but the suppression of diaphragmatic activity has rarely been considered. We hypothesized that the activity of the diaphragm was suppressed by an area of the dorsolateral pons during REMS. Lesions in this region have previously been shown to abolish the atonia of REMS. The diaphragmatic electromyogram (EMG) activity was analyzed in five naturally sleeping cats before and after pontine lesions leading to REMS without atonia. Although respiratory timing parameters were not altered by the lesion, the inspiratory rate of rise was significantly increased in all cats, and the brief pauses (40-100 ms) in the diaphragmatic EMG normally seen in REMS were virtually abolished. We conclude that the dorsolateral pons has a role in suppressing diaphragmatic activation during REMS. This suppression affects the average rate of rise of diaphragmatic activity and also leads to brief intermittent complete cessation of ongoing muscle activity. These decrements in diaphragm activity could jeopardize ventilation during REMS.


1995 ◽  
Vol 82 (1) ◽  
pp. 6-19 ◽  
Author(s):  
David O. Warner ◽  
Mark A. Warner ◽  
Erik L. Ritman

Background Data concerning chest wall configuration and the activities of the major respiratory muscles that determine this configuration during anesthesia in humans are limited. The aim of this study was to determine the effects of halothane anesthesia on respiratory muscle activity and chest wall shape and motion during spontaneous breathing. Methods Six human subjects were studied while awake and during 1 MAC halothane anesthesia. Respiratory muscle activity was measured using fine-wire electromyography electrodes. Chest wall configuration was determined using images of the thorax obtained by three-dimensional fast computed tomography. Tidal changes in gas volume were measured by integrating respiratory gas flow, and the functional residual capacity was measured by a nitrogen dilution technique. Results While awake, ribcage expansion was responsible for 25 +/- 4% (mean +/- SE) of the total change in thoracic volume (delta Vth) during inspiration. Phasic inspiratory activity was regularly present in the diaphragm and parasternal intercostal muscles. Halothane anesthesia (1 MAC) abolished activity in the parasternal intercostal muscles and increased phasic expiratory activity in the abdominal muscles and lateral ribcage muscles. However, halothane did not significantly change the ribcage contribution to delta Vth (18 +/- 4%). Intrathoracic blood volume, measured by comparing changes in total thoracic volume and gas volume, increased significantly during inspiration both while awake and while anesthetized (by approximately 20% of delta Vth, P < 0.05). Halothane anesthesia significantly reduced the functional residual capacity (by 258 +/- 78 ml), primarily via an inward motion of the end-expiratory position of the ribcage. Although the diaphragm consistently changed shape, with a cephalad displacement of posterior regions and a caudad displacement of anterior regions, the diaphragm did not consistently contribute to the reduction in the functional residual capacity. Halothane anesthesia consistently increased the curvature of the thoracic spine measured in the saggital plane. Conclusions The authors conclude that (1) ribcage expansion is relatively well preserved during halothane anesthesia despite the loss of parasternal intercostal muscle activity; (2) an inward displacement of the ribcage accounts for most of the decrease in functional residual capacity caused by halothane anesthesia, accompanied by changes in diaphragm shape that may be related to motion of its insertions on the thoracoabdominal wall; and (3) changes in intrathoracic blood volume constitute a significant fraction of delta Vth during tidal breathing.


1994 ◽  
Vol 76 (4) ◽  
pp. 1411-1416 ◽  
Author(s):  
S. Stick ◽  
D. Turner ◽  
P. LeSouef

During the rapid thoracic compression maneuver in infants, the transmission of pressure from compression jacket to pleural space and airway is less at functional residual capacity than at end inspiration. To examine whether reduced pressure transmission at functional residual capacity vs. higher lung volumes is explained by passive characteristics of the chest wall rather than by respiratory muscle activity, we assessed the pressure transmitted across the chest wall in nine anesthetized infants and young children after muscle relaxation. We measured esophageal and airway occlusion pressure during chest compressions at different lung volumes determined by varying distending pressure. In six subjects studied under static conditions, there was an approximately linear relationship between distending pressure and the proportion of pressure transmitted to the airway and esophagus from the compression jacket. The mean r2 value (95% confidence interval) was 0.80 (0.09) for pressure transmission to the airway and 0.85 (0.04) for pressure transmission to the esophagus. This relationship between lung volume and pressure transmission observed under static conditions was also demonstrated dynamically. Thus the reduced transmission of pressure from compression jacket to airway and pleural space at low lung volumes occurs independently of respiratory muscle activity.


1992 ◽  
Vol 72 (4) ◽  
pp. 1355-1361 ◽  
Author(s):  
D. M. Ainsworth ◽  
C. A. Smith ◽  
B. D. Johnson ◽  
S. W. Eicker ◽  
K. S. Henderson ◽  
...  

We examined the effects of reversible vagal cooling on respiratory muscle activities in awake chronically instrumented tracheotomized dogs. We specifically analyzed electromyographic (EMG) activity and its ventilatory correlates, end-expiratory lung volume (EELV) and diaphragmatic resting length via sonomicrometry. Elimination of phasic and tonic mechanoreceptor activity by vagal cooling doubled the EMG activity of the costal, crural, and parasternal muscles, with activation occurring sooner relative to the onset of inspiratory flow. Diaphragmatic postinspiration inspiratory activity in the intact dog coincided with a brief mechanical shortening of the diaphragm during early expiration; vagal blockade removed both the electrical activity and the mechanical shortening. Vagal blockade also doubled the EMG activity of a rib cage expiratory muscle, the triangularis sterni, but reduced that of an abdominal expiratory muscle, the transversus abdominis. Within-breath electrical activity of both muscles occurred sooner relative to the onset of expiratory flow during vagal blockade. Vagal cooling was also associated with a 12% increase in EELV and a 5% decrease in end-expiratory resting length of the diaphragm. We conclude that vagal input significantly modulates inspiratory and expiratory muscle activities, which help regulate EELV efficiently and optimize diaphragmatic length during eupneic breathing in the awake dog.


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