Our Services

What is a Sleep Study?

A sleep study may involve the following:

  • Polysomnogram (PSG) – a diagnostic test which monitors brain activity, breathing and leg movements which helps to evaluate sleep apnea (obstruction of air flow) or a condition known as periodic leg movements of sleep.
  • Multiple Sleep Latency Test (MSLT) – a daytime sleep study which evaluates how fast a person falls asleep.

What to Expect?

The first step will be an initial visit with our sleep specialist who will review your medical and sleep history.  You will then schedule an appointment for an overnight visit.  To help determine if a sleep disorder exists, your physician will need to know what physiologic changes occur during your typical night of sleep.  We do this by recording your brainwave pattern (known as the EEG) as well as your eye movements and degree of muscle tone.  Using an EKG monitor, we will measure your heart rate and check for irregular heart beats during the night.  Other measurements will include oxygen saturation, snoring, leg movements or jerking and respiratory effort.  An intercom in the room will allow communication with the technician should you have any questions or require assistance.  Studies will usually begin between 8:00pm and 9:30 pm and will conclude at about 6am.  You will then follow up with your physician who will make recommendations for treatment of the disorder.

How to Prepare

In order to feel more comfortable with your stay, feel free to bring your toiletries and usual sleepwear as well as your own pillow if you prefer.  (It is helpful to avoid using hair products or skin lotions on the night of the study).  It is recommended that you eat a meal prior to your study and continue to take medications as prescribed (unless your physician specifies otherwise). It is also preferred that you not consume foods or beverages containing caffeine after 5pm.

Other Services

  • Continuous Positive Airway Pressure (CPAP) ClinicCPAP Therapy - The treatment of sleep apnea is most commonly accomplished by the use of CPAP (continuous positive airway pressure).   By the use of air pressure the upper airway tissue is kept apart so that the patient can breathe normally. A soft nasal piece is worn to direct the air pressure to the obstructed portion of the upper airway.  This allows the patient to breathe easily and comfortably while asleep - just as when awake!
  • Pulmonary Function Testing - PFT’s or pulmonary function testing may be suited for sleep patients that may have other contributing lung problems affecting their sleep.  These tests can be performed before or after the sleep study.  PFT’s may also be used to rule out other breathing issues in conjunction with ABG’s or arterial blood gases.  Function tests can evaluate a patients lung volumes, flows, diffusing capacities, oxygenation, and ventilation; all of which can have an affect on the patients breathing.

Our Physicians


Gary R. Polk, M.D., D, ABSM

Amarillo Diagnostic Clinic staff since 1984

Expertise: Internal Medicine, Pulmonary Diseases, Sleep Medicine

Education: University of Texas Southwestern Medical School, Dallas, Texas,1979.

Internship/Residency: University of Texas Health Science Center, San Antonio, Texas, 1979 - 1982.

Pulmonary Disease Fellowship: University of Texas Health Science Center, San Antonio, Texas, 1982 - 1984.

Board Certification: American Board of Internal Medicine, 1982, Diplomate American Board of Sleep Medicine, 2003, Pulmonary Diseases, 1984

Memberships: Potter-Randall Medical Society


Timothy S. Mooring, M.D

Amarillo Diagnostic Clinic staff since 2006

Expertise:  Pulmonary Diseases, Critical Care, Sleep Medicine

EducationTexas Tech University Health Sciences Center School of Medicine, Lubbock, TX, 2000

Internship/ResidencyScott & White Hospital & Clinics, Temple, TX, 2003

Pulmonary Disease & Critical Care Medicine FellowshipScott & White Hospital & Clinics, Temple, TX,  2003

Sleep Medicine FellowshipScott & White Hospital & Clinics, Temple, TX, 2004

Board Certification:  American Board of Internal Medicine, 2003, Pulmonary Diseases, 2005, Critical Care Medicine, 2006

Memberships:  American College of Chest Physicians