Description of Research Expertise

Dr. Schwab’s research has focused on the pathogenesis of obstructive sleep apnea utilizing novel upper airway imaging techniques. His studies help elucidate the role of the motion of key structures of the upper airway in mediating airway closure. By examining dynamic state-related changes in the upper airway and soft tissue structures surrounding the upper airway he has begun to understand the biomechanics of apneic events. He has studied patients with both magnetic resonance imaging and electronic beam computed tomography during wakefulness and sleep. Several novel findings have resulted from these studies: 1) the anatomic significance of the lateral pharyngeal walls in mediating airway caliber in normals and apneics; and 2) the characterization of the changes in upper airway caliber during the respiratory cycle and the importance of end-expiratory airway narrowing. Dr. Schwab collaborates closely with members of the Departments of Radiology and Biomechanical and Computer Engineering. They have developed state-of-the-art, computer graphics-based analysis software to help model in three dimensions the biomechanical interrelationships between the soft tissue structures and the upper airway.

Selected Publications

Benjamin M. Smith, Andrew Wiemken, Eric A. Hoffman, Brendan T. Keenan, Norrina B. Allen, Alain G. Bertoni, David R. Jacobs Jr., Erin D. Michos, Karol E. Watson, Susan Redline, Richard J. Schwab, R. Graham Barr, Susan R. Heckbert: Upper and Lower Airway Dysanapsis and Airflow Obstruction among Older Adults American Journal of Respiratory and Critical Care Medicine 206 : 2022.

Pei-Hsin Wu, Ana E Rodriguez-Soto, Andrew Wiemken, Erin K Englund, Zachary B Rodgers, Michael C Langham, Richard J Schwab, John A Detre, Wensheng Guo, Felix W Wehrli: MRI evaluation of cerebral metabolic rate of oxygen (CMRO2) in obstructive sleep apnea J Cereb Blood Flow Metab : 2022.

Vikas L Bommineni, Guray Erus, Jimit Doshi, Ashish Singh, Brendan T Keenan, Richard J Schwab, Andrew Wiemken, Christos Davatzikos: Automatic Segmentation and Quantification of Upper Airway Anatomic Risk Factors for Obstructive Sleep Apnea on Unprocessed Magnetic Resonance Images Acad Radiol : 2022.

Jason L Yu, Andrew Wiemken, Susan M Schultz, Brendan T Keenan, Chandra M Sehgal, Richard J Schwab: A comparison of ultrasound echo intensity to magnetic resonance imaging as a metric for tongue fat evaluation Sleep : 2022.

Weaver TE, Pepin JL, Schwab R, Shapiro C, Hedner J, Ahmed M, Foldvary-Schaefer N, Strollo PJ, Mayer G, Sarmiento K, Baladi M, Bron M, Chandler P, Lee L, Malhotra A: Long-term effects of solriamfetol on quality of life and work productivity in participants with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea J Clin Sleep Med : 2021.

Keenan BT, Webster JC, Wiemken AS, Lavi-Romer N, Nguyen T, Svenson KL, Galante RJ, Churchill GA, Pickup S, Pack AI, Schwab RJ: Heritability of fat distributions in male mice from the founder strains of the Diversity Outbred mouse population G3 (Bethesda) : 2021.

Keenan BT, Schwab RJ: Using the Remote Monitoring Framework to Promote Adherence to Continuous Positive Airway Pressure Sleep Med Clin. : 2021.

Xu L, Keenan BT, Maislin D, Gislason T, Benediktsdóttir B, Gudmundsdóttir S, Gardarsdottir M, Staley B, Pack FM, Guo X, Feng Y, Chahwala J, Manaktala P, Hussein A, Reddy-Koppula M, Hashmath Z, Lee J, Townsend RR, Schwab RJ, Pack AI, Kuna ST, Chirinos JA: Effect of Obstructive Sleep Apnea and Positive Airway Pressure Therapy on Cardiac Remodeling as Assessed by Cardiac Biomarker and Magnetic Resonance Imaging in Nonobese and Obese Adults Hypertension : 2021.

Cielo CM, Keenan BT, Wiemken A, Tapia IE, Kelly A, Schwab RJ: Neck fat and obstructive sleep apnea in obese adolescents Sleep : 2021.

Holfinger SJ, Lyons MM, Keenan BT, Mazzotti DR, Mindel J, Maislin G, Cistulli PA, Sutherland K, McArdle N, Singh B, Chen NH, Gislason T, Penzel T, Han F, Li QY, Schwab R, Pack AI, Magalang UJ: Diagnostic Performance of Machine Learning-Derived Obstructive Sleep Apnea Prediction Tools in Large Clinical and Community-based Samples Chest : 2021.

Academic Contact Information

University of Pennsylvania Medical Center
3624 Market Street, Suite 205
Philadelphia, PA 19104
Phone: 215-662-7772
Patient appointments: 800-789-7366