Neuroscience Research Australia (NeuRA), Barker St, Sydney, NSW, Australia.
Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
PLoS One. 2018 Apr 16;13(4):e0195884. doi: 10.1371/journal.pone.0195884. eCollection 2018.
Twenty healthy subjects (10 males, age 28±5 years [mean ± SD]) lay supine, awake, with the head in a neutral position. Ventilation was monitored with inductance bands. Real-time B-mode ultrasound movies were analysed. We measured genioglossus motion (i) during spontaneous breathing, voluntary targeted breathing (normal tidal volume Vt), and voluntary hyperpnoea (at 1.5Vt and 2 Vt); (ii) during inspiratory flow resistive loading; (iii) with changes in end-expiratory lung volume (EELV).
Average peak inspiratory displacement of the infero-posterior region of genioglossus was 0.89±0.56 mm; 1.02±0.88 mm; 1.27±0.70 mm respectively for voluntary Vt, and during voluntary hyperpnoea at 1.5Vt and 2Vt. A change in genioglossus motion was observed with increased Vt. During increasing inspiratory resistive loading, the genioglossus displaced less anteriorly (p = 0.005) but more inferiorly (p = 0.027). When lung volume was altered, no significant changes in genioglossus movement were observed (p = 0.115).
In healthy subjects, we observed non-uniform heterogeneous inspiratory motion within the inferoposterior part of genioglossus during spontaneous quiet breathing with mean peak displacement between 0.5-2 mm, with more displacement in the posterior region than the anterior. This regional heterogeneity disappeared during voluntary targeted breathing. This may be due to different neural drive to genioglossus during voluntary breathing. During inspiratory resistive loading, the observed genioglossus motion may serve to maintain upper airway patency by balancing intraluminal negative pressure with positive pressure generated by upper airway dilatory muscles. In contrast, changes in EELV were not accompanied by major changes in genioglossus motion.
20 名健康受试者（10 名男性，年龄 28±5 岁[平均值±标准差]）仰卧，清醒，头部保持中立位置。通过感应带监测通气。实时 B 型超声电影进行分析。我们测量颏舌肌运动：（i）在自主呼吸、有目标的自愿呼吸（正常潮气量 Vt）和自愿深呼吸（在 1.5Vt 和 2Vt 时）期间；（ii）在吸气阻力负荷期间；（iii）在呼气末肺容积（EELV）变化时。
在有目标的自愿 Vt 呼吸、自愿深呼吸在 1.5Vt 和 2Vt 时，颏舌肌下后区的平均吸气峰位移分别为 0.89±0.56mm、1.02±0.88mm 和 1.27±0.70mm。随着 Vt 的增加，颏舌肌运动发生变化。随着吸气阻力增加，颏舌肌向前移位减少（p = 0.005），但向下移位增加（p = 0.027）。当肺容积改变时，颏舌肌运动没有明显变化（p = 0.115）。
在健康受试者中，我们观察到在自主安静呼吸期间颏舌肌下后区的吸气运动不均匀，呈异质性，平均峰值位移在 0.5-2mm 之间，后区位移大于前区。在有目标的自愿呼吸期间，这种区域异质性消失。这可能是由于在自愿呼吸时颏舌肌的神经驱动不同。在吸气阻力负荷期间，观察到的颏舌肌运动可能通过平衡管腔内负压与上气道扩张肌产生的正压来维持上气道通畅。相比之下，EELV 的变化并没有伴随着颏舌肌运动的重大变化。
