Hammond-Henry Hospital

Sleep Studies

Depending on the nature of the disorder, testing for sleep problems may include an overnight sleep study and/or a special daytime study. Studies are performed in a homelike atmosphere, under the direct observation of experienced sleep technologists using state-of-the-art equipment. 

Polysomnograph (PSG) - a test usually performed at night and is used to diagnose many sleep disorders. Keep in mind that none of the measuring devices are not painful and no needles are involved.

  • EEG (electroencephalograph) -  monitors brain waves to help determine your stage of sleep.
  • EOG (electrooculograph) -  monitors eye movements.
  • EMG (electromyograph) - monitors limb movements and chin activity.
  • ECG (electrocardiograph) - measures heart rate and rhythm.
  • Sensors called thermocouples or pressure transducers are used to monitor breathing from the nose and mouth.
  • Oxygen is monitored by a finger probe that clips to the finger.


CPAP (Continuous Positive Airway Pressure) Titration

Once polysomnography establishes that a patient has Obstructive Sleep Apnea, the next step is to determine the level of CPAP the patient requires. The same PSG measurements described above are taken while CPAP is applied. Pressure is started at a low level and increased throughout the night by the sleep technologist until a therapeutic level is reached - this is called titration. CPAP titration is only performed on patients who have Obstructive Sleep Apnea. For more information on CPAP treatment, follow this link to Obstructive Sleep Apnea.


Split Polysomnograph

Split PSG combines diagnostic polysomnography and CPAP titration into one night. A portion of the night is used to establish that the patient has Obstructive Sleep Apnea using the PSG measurements described above. The second portion of the night is used for CPAP titration to determine the optimum pressure. CPAP titration requires approximately four hours. Hammond-Henry Hospital Sleep Disorder Center strives to perform diagnostic polysomnography and CPAP titration on the same night whenever possible. There are reasons why performing diagnostic polysomnography and CPAP titration on the same night are either not possible or not desirable.


Multiple Sleep Latency Test (MSLT)

MSLT is used to diagnose narcolepsy and idiopathic hypersomnia. This test involves taking a series of naps throughout the day. Most patients will also spend the night prior to the MSLT in the lab for a PSG the monitoring devices described in the PSG section are already in place. During each nap opportunity, the patient is allowed a certain amount of time to fall asleep, then, a certain amount of time to sleep. The sleep tech monitors to make sure the patient is not sleeping between nap opportunities.

600 North College Avenue
Geneseo, IL 61254
Phone: (309) 944-9290
Email: sleepcenter@hammondhenry.com