Sleep Apnea and Congestive Heart Failure: Perspective from Control System and Physiological Modeling

Dr. Song-Won Koh
 

Advanced Research Center, St. Jude Medical Cardiac Rhythm Management Division

2003. 1. 22

 
PHYSIOLOGICAL FEEDBACK CONTROL SYTEM: SLEEP APNEA AND CONGESTIVE HEART FAILUREHOW PACEMAKER CAN HELP?
Sleep apnea is frequently observed in elderly peoples. Sleep apnea patients forget to breathe for about 1 minute. As a result, blood oxygen level goes down and carbon dioxide level goes up. Brain would notice this life threatening condition and wake a patient up. Patient starts to breathe. As dangerous condition is over, patient falls into sleep setting a stage of onset of sleep apnea. Sleep apnea cause a fragmented sleep preventing a person to take a deep sleep.
Congestive Heart Failure (CHF) is one of leading heart diseases. As blood vessel supplying oxygen to the heart itself is blocked, some of heart muscles start to die. Once Heart muscle is dead, it is irreversible. Now remaining heart muscle must work harder. As a result, heart muscle become thicker and the size of heart enlarged. This enlarged heart cannot pump out blood effectively.
Apparently unrelated diseases known as sleep apnea and congestive heart failure are very closely related. Using an approach from the control system theory, I will attempt to explain (1) the mechanism behind sleep apnea itself, and (2) the relation between sleep apnea and heart failure.
Using physiological modeling, parameter identification and system identification approach, researchers have build numerical model governing the human respiratory control system and explained the mechanism behind the sleep apnea-CHF.
Now we can improve the quality of life by inserting a pacemaker in human feedback controller!

 

This page is maintained by Ho-Jin Chung (hjchung@bi.snu.ac.kr).
Last update: Jan. 22, 2003