External Pharyngeal Exerciser and Pharyngeal Phase of Swallowing

Inclusion Criteria: * Healthy volunteers must be at least 18 years of age or older. Exclusion Criteria: * Subjects with cervical spine disorders. * Subjects with neurological disorders like dementia, cerebrovascular diseases other than Parkinson's Disease * Subjects with carotid artery bruit or carotid vascular disorders. * Subjects suffering from muscle diseases like muscular dystrophies, myopathies. * Subjects with neuro-muscular junction disorders myasthenia gravis, Eaton-Lambert disorders. * Subjects with any current esophageal symptoms like heartburn, dysphagia, chest pain or regurgitation. * Subjects cannot have previous head or neck surgery or radiation. * Subjects unable to tolerate nasal intubation. * Subjects with significant bleeding disorders for whom nasal intubation has been deemed contraindicated. * Subjects with a known upper airway or esophageal obstruction preventing the passage of the manometry probe. * Subjects with autonomic dysfunction. * Subjects having a history of allergy to lidocaine and barium. * Subjects who are pregnant or lactating. * Subjects who have advanced medical disorders (e.g.: chronic obstructive pulmonary disease (COPD), congestive heart failure, cirrhosis, cancer, chronic renal failure, etc.). * Subjects who are medically unstable.