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PubMed1981

Diaphragmatic and genioglossal electromyogram responses to CO2 rebreathing in humans.

To assess the relationship between central control of upper airway and respiratory muscle, simultaneously recorded diaphragmatic electromyogram (EMGdi) and genioglossal EMG (EMG ge) responses to CO2 rebreathing were compared in five supine volunteers. Both EMGs were quantitated in terms of inspiratory peak moving time-average activity. In all subjects both EMGdi and EMGge increased linearly with increasing alveolar CO2 pressure (r = 0.93 +/- 0.04 and 0.87 +/- 0.07, respectively), resulting in a significantly linear EMGge vs. EMGdi relationship (r = 0.91 +/- 0.04). CO2 response slopes of both EMGs were similar and linearly related (r = 0.96, P less than 0.001) such that subjects with low EMGdi response also had a low EMGge response and vice versa. Although the onset of EMGge activity preceded that of EMGdi, and the pattern of both EMGs were different, inspiration duration of both EMGs were similar. These data indicate that in humans both diaphragm and genioglossus muscle share similar control mechanisms and suggest that upper airway function is intimately related to the regulation of breathing.

Adult↗

PubMed2004

The neuromuscular effects and tracheal intubation conditions after small doses of succinylcholine.

UNLABELLED: Succinylcholine 1.0 mg/kg usually produces excellent tracheal intubation conditions in 60 s. Recovery of respiratory muscle function after this dose, however, is not fast enough to forestall oxyhemoglobin desaturation when ventilation cannot be assisted. In this study, we investigated whether smaller doses of succinylcholine can produce satisfactory intubation conditions fast enough to allow rapid sequence induction with a shorter recovery time. Anesthesia was induced with fentanyl/propofol and maintained by propofol infusion and N(2)O in O(2). After the induction, 115 patients were randomly allocated to five groups according to the dose of succinylcholine (0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg, 0.6 mg/kg, or 1.0 mg/kg). Evoked adductor pollicis responses to continuous 1-Hz supramaximal ulnar nerve stimulation were recorded using acceleromyography. Tracheal intubation conditions were graded 60 s after succinylcholine administration. Onset time, maximal twitch depression, time to initial twitch detection after paralysis, and to 10%, 25%, 50%, and 90% twitch height recovery were recorded. Time to initial diaphragmatic movement as well as time to resumption of regular spontaneous respiratory movements were calculated. Onset times ranged between 82 s and 52 s, decreasing with increasing doses of succinylcholine but not differing between 0.6 and 1 mg/kg. Maximum twitch depression was similar after 0.5, 0.6, and 1 mg/kg (98.2%-100%). Recoveries of twitch height and apnea time were dose-dependent. Intubation conditions were often unacceptable after 0.3- and 0.4-mg/kg doses. Acceptable intubation conditions were achieved in all patients receiving a 0.5, 0.6, and 1 mg/kg dose of succinylcholine. Intubation conditions in patients receiving 0.6 and 1 mg/kg were identical, whereas times to T(1) = 50% and 90% and time to regular spontaneous reservoir bag movements were significantly shorter in the 0.6-mg/kg dose group (5.78, 7.25, and 4.0 min, respectively) versus patients receiving 1 mg/kg (8.55, 10.54, and 6.16 min, respectively). The use of 0.5 to 0.6 mg/kg of succinylcholine can produce acceptable intubation conditions 60 s after administration. The conditions achieved after 0.6 mg/kg are similar to those after 1.0 mg/kg. These smaller doses are associated with faster twitch recovery and shorter apnea time. IMPLICATIONS: In normal healthy patients, succinylcholine 0.6 mg/kg produces clinical intubation conditions identical to the traditional 1.0-mg/kg dose but is associated with a shorter recovery time.

Adult↗

PubMed1999

The use of pleuroperitoneal shunts in the management of persistent chylothorax in infants.

BACKGROUND/PURPOSE: The development of chylothorax is a serious and often life-threatening clinical entity that may cause profound respiratory, nutritional, and immunologic complications and has become increasingly common in recent years. Optimal management of this problem has not been well defined because medical therapy has a significant failure rate. Surgical treatment of complicated chylothorax has become a mainstay of care. METHODS: Over the last 36 months, seven infants had a pleuroperitoneal shunt placed for the management of refractory chylothorax. Ages ranged from 10 to 66 days with a weight between 1,000 to 4,850 g. Five of the seven infants were ventilator dependent. The etiologies were congenital in four and acquired in three with one related to a cardiothoracic procedure, one related to superior vena caval thrombosis, and one postoperative diaphragmatic hernia repair with superior vena caval thrombosis. Associated conditions included a left congenital diaphragmatic hernia, asplenia, isolated renal agenesis, bronchopulmonary dysplasia, and a patent ductus arteriosus. Each patient was unresponsive to thoracentesis, tube thoracostomy, and dietary manipulation with preoperative volume of chest tube output ranging from 50 to 162 cc/kg/d. The duration of preoperative therapy in congenital occurrences ranged from 10 to 46 days (average, 22 days). A Denver double-valved shunt system was used and catheters were implanted under general anesthesia. Manual pumping was required postoperatively on an hourly basis. RESULTS: All seven patients had excellent results with the elimination of the chylothorax and resolution of symptoms. There were two complications. Shunt survival rate was six of seven (86%). Shunt removal ranged from 24 to 79 days (average, 44 days). Patient survival rate was five of seven (71%) with one infant dying of progressive pulmonary disease and one infant dying from viral sepsis; both had functioning shunts. One patient remains ventilator dependent secondary to chronic lung disease from prematurity. CONCLUSIONS: Pleuroperitoneal shunting is safe, simple, and an effective treatment of chylothorax in infants despite their size, age, or degree of prematurity.

Catheters, Indwelling↗

PubMed2002

[Diaphragmatic motor evoked potential in amyotrophic lateral sclerosis patients].

OBJECTIVE: To investigate the features and application of diaphragmatic motor evoked potential (DMEP) in amyotrophic lateral sclerosis (ALS) patients. METHODS: To record the latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) from 37 ALS patients and 31 control subjects with surface electrodes after transcranial and transcervical magnetic stimulation, central motor conduction time (CMCT) was calculated. The percentage of forced vital capacity (%FVC) was performed in 22 ALS patients simultaneously. RESULTS: Cortical and cervical latencies of the ALS patients were longer than those of the controls, and cortical and cervical amplitudes of the ALS patients were lower than those of the controls. CMCT of the ALS patients were longer than that of the controls. Cortical latency, cortical amplitude and CMCT were all correlated with the dysfunction of the pyramidal tract. Cortical latency and CMCT were also correlated with the clinical respiratory dysfunction, cervical latency was correlated with %FVC. CONCLUSIONS: CMCT, Cortical and cervical latencies are sensitive index in DMEP parameters reflecting respiratory dysfunction in ALS, CMCT reflects cortical spinal tract function of ALS patients associated with respiration. It would be helpful to detect the neurological basis of the respiratory disturbance in ALS combining CMCT with cervical latency.

Adolescent↗

PubMedDate not supplied

[Value of bidimensional echocardiography in the diagnosis of early mechanical complications of myocardial infarction].

Thirteen patients with myocardial infarction were investigated with two-dimensional echocardiography because of the appearance of signs of cardio-circulatory failure associated with a systolic murmur during the first 15 days following the infarct. The precise diagnosis was obtained by surgical or autopsy examination in 11 cases and by haemodynamic investigations in 2 cases. These mechanical complications were: 8 septal ruptures and 5 cases of acute mitral incompetence, due to papillary rupture in 2 cases and to papillary dysfunction in 3 cases. The 8 cases of septal rupture, complicating 6 cases of anterior infarct and 2 cases of diaphragmatic infarct, were diagnosed by 2-D echocardiography, which revealed 3 apical perforations (one of which was only visible via a sub-costal approach), 3 superior perforations or lacerations, 2 inferior perforations in the middle or the base of the septum; all visible in an apical view of the 4 cavities. The injection of ultrasonic contrast in 4 patients demonstrated negative lavage, which confirmed the diagnosis, in one case, even before the perforation could be visualised. The 2 cases of ruptured papillary muscles were visualised directly on the 2-D echocardiography. However, only one of the three cases of papillary muscle dysfunction was diagnosed by echocardiography. 2-D echocardiography has an important place in the investigation of complicated myocardial infarction, not only as a means of diagnosing ruptures of the septum or papillary muscles, but also to evaluate the deterioration in left ventricular contractile function, which enabled surgical repair without left haemodynamic investigations, in two cases.

Acute Disease↗

PubMed1990

A method for estimating endocardial electrode stability.

Assessment of cardiac pacing electrode stability following implantation is of major importance. We describe a method of testing electrode stability using a provocative test. The method includes synchronized electrical pacing of the left phrenic nerve by an especially designed external pacemaker. A positive response is abrupt, a diaphragmatic contraction, which in turn induces an abrupt heart movement in its diastole, its relaxation phase. Fifty-six various endocardial electrodes were tested in this fashion. Seven electrodes, one with flange tip, two tined, and four had no fixation dislodged after this pacing test. Insignificant elevation of acute ventricular pacing threshold was observed. While this method appears to be advantageous, additional clinical data is necessary.

Animals↗

PubMed1983

Postnatal developmental alterations following prenatal exposure to the herbicide 2,4-dichlorophenyl-p-nitrophenyl ether: a dose response evaluation in the mouse.

Although nitrofen, 2,4-dichlorophenyl-p-nitrophenyl ether, is a relatively nontoxic herbicide, prenatal exposure to doses considerably less than the LD50 value for adult rats and mice produces numerous developmental defects that become apparent as the animals mature. In the present study postnatal development was observed following prenatal exposure during Days 7 to 17 of gestation at doses of 0, 6.25, 12.5, 25, 50, 100, 150, and 200 mg/kg/day. These doses did not cause maternal toxicity as indicated by the viability of the dams or maternal weight gain during pregnancy. By 3 days of age all pups in the two highest dose groups were dead and 50% had died in the 100 mg/kg/day dose group. Some of the dead and moribund pups from the 200 mg/kg/day exposure group necropsied at three days of age had cleft palate (15%) or diaphragmatic hernia (6%). In addition, about 22% of the pups at 200 mg/kg/day developed a distended abdomen from gasping and swallowing air. These pups did not suckle and eventually died. Body weights of offspring were reduced at birth in the 150 and 200 mg/kg/day groups and at 3 days of age in the 100 mg/kg/day group. Growth rates were subsequently retarded at 12.5, 25, 50, and 100 mg/kg. The Harderian glands were reduced or absent in 97, 65, and 4% of the mice in the 100, 50, and 25 mg/kg dosage groups, respectively, and the gland weights were reduced at all dosages, including the lowest dose of 6.25 mg/kg/day. Weights of other organs including lung and liver (at 6.25 and above), seminal vesicle (at 12.5 and above), and testes (at 100 mg/kg/day) were also reduced by prenatal nitrofen exposure. In addition, prenatal treatment with nitrofen produced functional deficits of the reproductive system; puberty was delayed in females and litter sizes were reduced at 50 and 100 mg/kg/day. A cross-fostering experiment with 100 mg/kg/day of nitrofen demonstrated that the effects noted in the present study were produced solely by prenatal exposure; pups exposed to nitrofen in the milk alone as a consequence of any accumulation of nitrofen in the dam during gestation were unaffected.

Abnormalities, Drug-Induced↗

PubMed1997

Percutaneous balloon catheter closure of a patent foramen ovale in a patient with pulmonary disease, profound hypoxemia, and normal right heart pressures.

Right-to-left intracardiac shunting across a patent foramen ovale (PFO) has been reported in patients with pulmonary embolism, right ventricular (RV) infarction, positive pressure ventilation with positive end-expiratory pressure, heart failure with left ventricular assist devices, cardiac tamponade, and unilateral diaphragmatic paralysis. The primary driving force for these shunts is a reduction in the compliance of the pulmonary bed or right ventricle; right atrial pressure is usually elevated and pulmonary hypertension is frequently present. Significant shunting and hypoxemia are unusual in the absence of these diseases. We encountered a patient with normal pulmonary pressures, severe hypoxemia, pulmonary disease, and intracardiac shunting across a PFO in whom it was difficult to determine how great a role intracardiac shunting was playing in his hypoxemia. To assess this, we performed percutaneous balloon catheter occlusion of the PFO, using transthoracic echocardiography with contrast to confirm closure of the PFO. Therapeutic balloon occlusion has been reported in severe hypoxemia due to shunting across a PFO in a patient with RV infarction. Our case is unique, however, in two respects. First, this patient had normal right-sided cardiac pressures and normal RV function and, thus, no obvious driving force for a significant right-to-left shunt. Second, transthoracic echocardiography with contrast was used before and after balloon inflation to confirm closure of the PFO. This technique helped to answer the important clinical question of whether surgical closure of the PFO in this patient with both lung disease and intracardiac shunting would significantly improve his oxygenation.

Adult↗

PubMed1981

Static transdiaphragmatic pressures in normal subjects and in patients with chronic hyperinflation.

Transdiaphragmatic pressure (Pdi) during static maximal inspiratory effort was measured in 11 normal subjects and in 4 patients with severe chronic hyperinflation (mean total lung capacity, 138% predicted). The Pdi varied widely among subjects, some production positive abdominal pressure (Pab) at all volumes and some producing Pab close to zero or negative. During modified maximal inspiratory efforts in which the abdomen was protruded, several subjects produced greater Pdi, but in none was pleural pressure (Ppl) more negative, possibly because of inhibition of diaphragmatic activation during spontaneous inspiratory efforts. In the hyperinflated patients, spontaneous maximal inspiratory inspiratory efforts produced smaller values of Pdi, but the diaphragm retained an inspiratory effect and Pdi could still be increased by abdominal protrusion during the effort. Although Pdi during such modified maneuvers probably gives a better index of the strength of the diaphragm, this may not be directly related to its effective capacity as an inspiratory muscle, which may be best assessed by comparing Pdi with Ppl during spontaneous maximal inspiratory efforts.

Abdomen↗

PubMed1993

Intractable singultus: a diagnostic and therapeutic challenge.

Hiccup or singultus is a repeated involuntary, spasmodic contraction of the diaphragm accompanied by a sudden closure of the glottis mediated by sensory branches of the phrenic and vagus nerves as well as dorsal sympathetic afferents. The principle efferent limb and diaphragmatic spasms are mediated by motor fibers of the phrenic nerve. Hiccup has been classified as a respiratory reflex and the central connection probably consists an interaction among the brainstem respiratory centers, phrenic nerve nuclei, medullary reticular formation and the hypothalamus. Chronic intractable hiccup may be due to brainstem seizures, and baclofen may be the long-awaited remedy for intractable hiccup as demonstrated in three illustrative cases.

Afferent Pathways↗

PubMed1980

Surgery for oesophageal reflux and hiatus hernia. Long-term results in 250 patients.

A series of 250 patients with oesophageal reflux and hiatus hernia were treated at North Middlesex Hospital, London, the Regional Cardiothoracic Centre, between 1968-72. These patients received surgical treatment by the "Belsey Mark IV technique" and there were no significant complications. The 7--10 year follow-up showed in 8.4% actual recurrence which was of a combined functional and anatomical nature. In 2% of the cases hernia was demonstrated only by radiology, but there was no evidence of recurrent reflux. The majority of recurrences occurred within two years of initial operation. The patients with recurrences, who underwent the second Mark IV repair, had excellent results. The improving quality of the life in the successful cases was dramatic. This series indicates that the Belsey Mark IV repair is a safe and reliable procedure and gives excellent results with relief of all symptoms.

Adolescent↗

PubMed1980

Right myocardial infarction with predominant right ventricular dysfunction.

Two patients with right ventricular myocardial infarction are described. In both cases, the hemodynamic criteria established for this diagnosis were fulfilled, namely, right-side pressure values (central venous pressure and right atrial pressure) equal to or higher than left-side pressure values (pulmonary capillary wedge pressure and left ventricular end-diastolic pressure). ECG tracings showed acute diaphragmatic myocardial infarction. The lungs were clear both clinically and radiologically. The diagnosis of right ventricular myocardial infarction was confirmed in the first patient by hemodynamic studies and at autopsy, and in the second patient, by hemodynamic and echocardiographic studies. Only in the second care was the administration of massive quantities of fluids and dopamine followed by good results. The importance of establishing a precise diagnosis of right ventricular myocardial infarction is emphasized, since therapy for this condition is different than that for left ventricular myocardial infarction.

Aged↗

PubMed2005

[Cardiac function alterations in pectus excavatum].

BACKGROUND: Cosmetic deformity and psychological repercusion are the main surgical indications in pectus excavatum. However cardiopulmonary function is subclinically abnormal in some patients. The goal of this paper is to demonstrate that heart response during physical activity improves after surgical correction of pectus excavatum. PATIENTS AND METHODS: Fifty five patients were operated upon for pectus excavatum during the last 10 years at our institution. Baseline ecocardiography and isometric effort test (Handgrip) were preoperatively performed in 15 patients (11 males and 4 females) aged from 6 to 15 years (median 9,63). An increase below 12% in cardiac index was considered as positive. In those patients with positive tests, a new test was made 6 months after surgical correction. Pre and postoperative results were compared using non-parametric tests. RESULTS: Baseline cardiac index values were normal in all cases (11). Four patients were not included, 2 because of no collaboration (aged 6 and 7 years) and 2 because difficult ecocardiography interpretation (both operated upon for congenital diaphragmatic hernia). Overall, preoperative test was negative in 6 patients and positive in the remaining 5. Postoperative test was made in these 5 patients, and all of them showed an improvement in cardiac index (medium 40,6%, range 25-70) when compared to preoperative values. There was statistically significant association between test values and patient ages. CONCLUSIONS: Baseline cardiac index values were normal in children with pectus excavatum, albeit 45,5% of them showed a limited response to exercise. Pectus excavatum repair improves these values, so physiopathological indication as well as cosmetic one should be considered specially in children.

Adolescent↗

PubMed1994

The effects of psychological stress on the esophagogastric junction pressure and swallow-induced relaxation.

BACKGROUND/AIMS: Short-term psychological stress increases pressure in the upper esophageal sphincter and increases esophageal contraction amplitude. The effects of short-term psychological stress on the two sphincteric mechanisms at the esophagogastric junction (EGJ), the lower esophageal sphincter (LES) and crural diaphragm, were studied. METHODS: Studies were performed in 20 normal, healthy subjects. LES and crural diaphragm functions were measured simultaneously using an electrode sleeve sensor. Three psychological stress tasks, math, cold, and stress interview, were tested. The data were analyzed for tonic (end expiratory) and phasic (inspiratory increase) EGJ pressure and electromyographic changes during the stress period. Spontaneous swallow-induced EGJ relaxation was also assessed. RESULTS: A significant decrease in tonic EGJ pressure occurred during the math and cold tasks. The tonic EGJ pressure was 19 +/- 2 and 14 +/- 2 during baseline and the math task, respectively. Stress caused no change in the phasic EGJ pressures. Tonic and phasic crural diaphragm electromyographic activity increased during all three stress periods. Spontaneous swallow-induced relaxation at the EGJ during the stress periods was reduced from 60% +/- 2% in the baseline to 39% +/- 5% during the stress periods. CONCLUSIONS: Short-term psychological stress lowers EGJ pressure through inhibition of the LES and increases tonic and phasic crural diaphragmatic contraction. Diminished swallow-induced relaxation at the EGJ during stress may lead to changes in esophageal contractions.

Adult↗

PubMed1965

Some aspects of abdominal surgery in the elderly patient.

Most operations on elderly patients are of an urgent nature. If time permits, measures to improve cardiac, respiratory and renal functions in the appropriate ways should be undertaken. During recovery from anesthesia careful but adequate sedation will reduce the risk of myocardial ischemia. Throughout the postoperative period constant encouragement of the older patient is particularly helpful.Transverse abdominal incisions and the frequent use of temporary gastrostomy are advocated.External hernia, hiatus hernia, peptic ulcer, carcinoma of the stomach, biliary disease, appendicits, intestinal obstruction, and carcinoma of the large intestine are discussed specifically, with special reference to the practical details of management in the elderly patient.

Abdomen↗

PubMed2000

Assignment of a form of congenital muscular dystrophy with secondary merosin deficiency to chromosome 1q42.

We have previously reported an autosomal recessive form of congenital muscular dystrophy, characterized by proximal girdle weakness, generalized muscle hypertrophy, rigidity of the spine, and contractures of the tendo Achilles, in a consanguineous family from the United Arab Emirates. Early respiratory failure resulting from severe diaphragmatic involvement was present. Intellect and the results of brain imaging were normal. Serum creatine kinase levels were grossly elevated, and muscle-biopsy samples showed dystrophic changes. The expression of the laminin-alpha2 chain of merosin was reduced on several fibers, but linkage analysis excluded the LAMA2 locus on chromosome 6q22-23. Here, we report the results of genomewide linkage analysis of this family, by use of homozygosity mapping. In all four affected children, an identical homozygous region was identified on chromosome 1q42, spanning 6-15 cM between flanking markers D1S2860 and D1S2800. We have identified a second German family with two affected children having similar clinical and histopathological features; they are consistent with linkage to the same locus. The cumulative LOD score was 3.57 (straight theta=.00) at marker D1S213. This represents a novel locus for congenital muscular dystrophy. We suggest calling this disorder "CMD1B." The expression of three functional candidate genes in the CMD1B critical region was investigated, and no detectable changes in their level of expression were observed. The secondary reduction in laminin-alpha2 chain in these families suggests that the primary genetic defect resides in a gene coding for a protein involved in basal lamina assembly.

Antigens, CD↗

PubMed1995

Stability of evoked parasternal intercostal muscle electromyogram at increased end-expiratory lung volume.

The diaphragmatic electromyogram has been measured as an index of the level of diaphragmatic activation. The diaphragmatic electromyogram, however, even when measured by intramuscular electrodes, can be artifactually altered by a change in lung volume (A. Brancatisano, S. M. Kelly, A. Tully, S. H. Loring, and L. A. Engel. J. Appl. Physiol. 66: 1699-1705, 1989) or by a change in body position. The parasternal intercostal muscle may be less subject to the mechanisms that are believed to produce this artifactual change. We asked whether the parasternal intercostal electromyographic activity could be reliable when lung volume changes. Six supine rabbits were anesthetized with ketamine and xylazine. Fine bipolar copper wires, with their tips exposed, were inserted into the left parasternal intercostal muscle in the third interspace. A stimulus that was three times maximal was applied to the corresponding intercostal nerve, and the resulting action potential (AP) was photographed. Parasternal intercostal muscle length was measured by sonomicrometry over the vital capacity range. There were small nonsignificant changes in the AP from functional residual capacity (FRC) to total lung capacity. From FRC to residual volume there was variation in the AP. The AP was also quite stable when regional conductivity was altered but showed variation when the parasternal intercostal muscle length change was accentuated by traction on the rib cage. We conclude that the parasternal intercostal electromyographic activity can be reliably used to measure inspiratory motoneuron output to it over the range of lung volumes from FRC to total lung capacity.

Animals↗

PubMed2001

Fluoroscopic evaluation of diaphragmatic motion reduction with a respiratory gated radiotherapy system.

We report on initial patient studies to evaluate the performance of a commercial respiratory gating radiotherapy system. The system uses a breathing monitor, consisting of a video camera and passive infrared reflective markers placed on the patient's thorax, to synchronize radiation from a linear accelerator with the patient's breathing cycle. Six patients receiving treatment for lung cancer participated in a study of system characteristics during treatment simulation with fluoroscopy. Breathing synchronized fluoroscopy was performed initially without instruction, followed by fluoroscopy with recorded verbal instruction (i.e., when to inhale and exhale) with the tempo matched to the patient's normal breathing period. Patients tended to inhale more consistently when given instruction, as assessed by an external marker movement. This resulted in smaller variation in expiration and inspiration marker positions relative to total excursion, thereby permitting more precise gating tolerances at those parts of the breathing cycle. Breathing instruction also reduced the fraction of session times having irregular breathing as measured by the system software, thereby potentially increasing the accelerator duty factor and decreasing treatment times. Fluoroscopy studies showed external monitor movement to correlate well with that of the diaphragm in four patients, whereas time delays of up to 0.7 s in diaphragm movement were observed in two patients with impaired lung function. From fluoroscopic observations, average patient diaphragm excursion was reduced from 1.4 cm (range 0.7-2.1 cm) without gating and without breathing instruction, to 0.3 cm (range 0.2-0.5 cm) with instruction and with gating tolerances set for treatment at expiration for 25% of the breathing cycle. Patients expressed no difficulty with following instruction for the duration of a session. We conclude that the external monitor accurately predicts internal respiratory motion in most cases; however, it may be important to check with fluoroscopy for possible time delays in patients with impaired lung function. Furthermore, we observe that verbal instruction can improve breathing regularity, thus improving the performance of gated treatments with this system.

Diaphragm↗