Based on a prior anesthetized model, we developed an unanesthetized model to evaluate the effects of hypoglossal nerve stimulation (HNS) during sleep. We prepared three rabbits with injections of Hyaluronic Acid in the base of tongue to produce upper airway obstruction followed by HNS implant. Two rabbits were saline controls, and one, a passive control. Measures were sleep, airflow, effort, oxygen saturation and heart rate. HNS with electrodes around the right hypoglossal nerve were adjusted to a level without behaviorally disturbing the animal. During HNS stimulation in the tongue-base injected rabbits, obstructive apneas and hypopneas of intermediate (3 to 7 cycles of respiratory effort) or longer (≥8 cycles) duration were largely eliminated while less clinically relevant shorter events (<3) were unaffected, and oxygen saturation was improved. Control animals exhibited no intermediate or long events. In this model HNS can relieve induced sleep apnea, without disturbing the animal: however, despite being non-canine and of substantial size, the model has its challenges.

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