In 2001, Dr. Simmons formed REST Technologies, Inc., (REST), to perform diagnostic sleep testing services in the greater Houston area, providing service in the home, hotel, and hospital. Because of its success Comprehensive Sleep Medicine Associates, PA (CSMA) developed a clinical practice in 2006 to partner with REST. Now, CSMA has four Texas locations, all accredited by the American Academy of Sleep Medicine (AASM).

REST Technologies, Inc has also been involved in research and development of new technologies. Recently the NIH awarded REST Technologies a Phase 1 grant to study the ability to monitor pregnant women to identify the onset of obstructive sleep apnea. This newest research effort stems from REST Technologies, Inc's development of the REST Tracker, designed for Remote Patient Monitoring (RPM). Under development since 2020, REST Technologies has been developing an application platform, coupled with a wearable device, that allows for nightly monitoring of patients' sleep. This has proven extremely helpful in managing complex clinical cases, allowing for decision making of treatment modifications without the need for patients to return to the lab.

REST Technologies, Inc. has innovation carved in its DNA to develop the newest technologies for the future of sleep medicine.