Sleep apnea is a prevalent sleep-related breathing disorder characterized by abnormal breathing patterns and ventilation. Apneic periods, or pauses in breathing, occur at different frequencies and durations in the sleep cycle depending on the severity of the disorder, resulting in sleep disturbances and a reduction in gas exchange. Consequently, cardiovascular issues may develop as a result of repeated oxygen-starvation in the body, as well as a range of behavioral health problems brought on by persistent interruptions in the sleep cycle.
CONSCIOUS MONITORING. SPONTANEOUS BREATHING.
Plethysmography utilizes a non-invasive technique which allows conscious polysomnography, or sleep studies, in unanaesthetized, spontaneously breathing subjects. This technique provides continuous high-fidelity respiratory recordings during sleep and wakefulness based on measures of tidal volume, respiratory rate and minute ventilation.
Integration of electroencephalogram (EEG) & electromyography (EMG) recordings with respiratory signals offer a detailed characterization of the cardiopulmonary contributions in a sleep-disordered breathing state. Plethysmography systems may also integrate with a mass flow controller to measure these respiratory effects under chronic intermittent periods of hypoxia, a key feature of sleep apnea.
- Novel whole body plethysmography system for the continuous characterization of sleep and breathing in a mouse. – Hernandez et al. Journal of Applied Physiology Published 15 February 2012 Vol. 112 no. 4, 671-680
- The nuclear progesterone receptor reduces post-sigh apneas during sleep and increases the ventilatory response to hypercapnia in adult female mice. – Marcouiller F et al. PLoS One. 2014 Jun 19;9(6):e100421. doi: 10.1371/journal.pone.0100421. eCollection 2014.
MEASURING UPPER AIRWAY RESISTANCE.
The flexiVent provides sensitive and reproducible measurements of respiratory mechanics and inflammation necessary to characterize various phenotypes of genetic or environmentally-manipulated animal models of sleep apnea. The most common occurrence is obstructive sleep apnea which affects the upper airways. Using a specialized configuration, the flexiVent can offer resistance measurements of both the upper and lower airways in the same subject.
- Characterization of nasal obstruction in the allergic guinea pig using the forced oscillation method. – McLeod et al. J Pharmacol Toxicol Methods, 48: 153, 2002.
- Physiologic assessment of allergic rhinitis in mice: Role of the high-affinity IgE receptor (FcɛRI) – Miyahara et al. J All Clin Immunol., 116: 1020, 2005.
- Contribution of allergen-specific and nonspecific nasal responses to early-phase and late-phase nasal responses. – Miyahara et al. J All Clin Immunol., 121: 718, 2008.