Timothy I. Morgenthaler, M.D.

  1. Sleep Medicine Specialist
  2. Pulmonologist
  1. Central sleep apnea
  2. Obstructive sleep apnea
  3. Sleep disorders
  4. Venous thrombosis

Main clinical interests

  • Sleep-disordered breathing
  • Venous thromboembolism prevention and management

Main research interests

  • Complex sleep apnea syndrome
  • Healthcare delivery
  • Analytics for patient safety

Sleep medicine research

I have two main areas of research and academic interest: sleep-disordered breathing and patient safety. In sleep medicine, I have concentrated on special kinds of sleep-disordered breathing. Most sleep clinicians are familiar with the Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) and two syndromes with cyclic non-obstructive breathing patterns — the Central Sleep Apnea-Hypopnea Syndrome and the Cheyne-Stokes Breathing Syndrome (CSBS). A primary interest of my group has been a complex-pattern breathing abnormality that has been noted for many years but not previously described in terms of clinical behavior and implications, cause, and treatment. Patients exhibiting this disorder appear at first to have purely obstructive sleep apnea, but after the application of CPAP, they develop problematic central sleep apnea or Cheyne-Stokes breathing pattern. Little is known about this unclassified group of patients; they lack a common syndromic definition, clinical or pathophysiologic description. For our purposes, we term this type of sleep-disordered breathing "Complex Sleep Apnea Syndrome" (CompSAS). We have published a description of the clinical characteristics of this group of patients. Ongoing work includes studies to determine the underlying pathophysiology, the long term clinical sequellae, and the study of novel breathing assistance devices such as Adaptive Servo Ventilation that appear to show promise to treat this complex breathing pattern. Since the pattern resembles central sleep apnea syndrome (CSA) once the patient is treated with CPAP, we also have been adapting what we learn about treating CompSAS to our substantial population of patients who have CSA.

Patient safety research

I have been interested in the development of data analytics that help inform a practice on priority areas for improvement and that obtain an ability to be both predictive and prescriptive. Intrinsic in this work is developing the capability to measure important components of patient safety, such as preventable harm, aggregated near-miss analysis, and relationship between risk conditions and serious harm events.

  1. 1994
    Fellow - Thoracic Diseases and Critical Care MedicineMayo Graduate School of Medicine, Mayo Clinic College of Medicine
  2. 1991
    Resident - Internal MedicineMayo Graduate School of Medicine, Mayo Clinic College of Medicine
  3. 1985
    Internship - General SurgeryNaval Hospital, San Diego, CA
  4. 1984
    MDDartmouth Medical School
  5. 1980
    BS - Chemical engineeringMassachusetts Institute of Technology


  1. 2007
    Sleep MedicineAmerican Board of Internal Medicine
  2. 1997
    Sleep MedicineAmerican Board of Sleep Medicine
  3. 1994
    Pulmonary DiseaseAmerican Board of Internal Medicine


Research activities

See a description of research activities.