Staff Bios

Colleen G. Lance, M.D.
TSSP President

Dr. Lance obtained her medical doctorate at the Baylor College of Medicine in Houston, Texas.  She then went on to Internal Medicine training at the University of Texas at Houston, and remained as Chief Medical Resident in that program.  After 5 years of practicing Internal Medicine, she returned to the University of Texas at Houston for her Sleep Medicine Fellowship.  She is now a Diplomat of the American Board of Sleep Medicine, and certified by the American Board of Internal Medicine in Sleep Medicine.  After completing her fellowship, she joined the faculty at the M.D. Anderson Cancer Center where she began a Sleep Medicine Program.  Dr. Lance is the medical director of the Memorial Hermann Sugar Land Sleep Disorders Center.  In addition, she has started the Sleep Heart Synergy Program in which all in-patients with cardiovascular disease at Memorial Hermann Sugar Land Hospital are screened for sleep-disordered breathing.  She practices Sleep Medicine full-time with the Memorial Hermann Medical Group in Sugar Land and the Texas Medical Center, providing care for the full spectrum of sleep disorders that affect all age groups.  She has particular interest in sleep disorders that affect both women and children.

Chris Speigner, BS, RPSGT
TSSP Vice President

Chris began home respiratory care in 1990 in Dothan, AL, with Breathing Care Associates.  His formal sleep career began in 1992 while performing sleep studies for rural hospitals in Southeast Alabama and Northwest Florida.  He trained at Flowers Hospital under Byron Jameson, RPSGT, and Alan Purvis, MD.    He moved to Houston, TX in 1999 to build the Sleep Medicine Institute at Diagnostic Clinic.  After 10 years in Texas, he is currently serving as Practice Manager at Children’s Medical Center in Dallas.

He has been married to Nena for 22 years and has a beautiful 15 year old daughter, Dani.  The family enjoys motorcycling and playing music.

Dzu Dao, RPSGT
TSSP Treasurer

Dzu has been a Polysomnographic Technologist since 1991 starting out in sleep research at the University of Texas Health Science Center in Dallas.  He moved to Fort Worth in 1993 to work for Sleep Consultants, Inc. where he remains as an Associate Technical Director.  He achieved RPSGT in 1994.

He is married with two children; one a freshman at Texas A & M University, the other a sophomore at Nolan Catholic High School.

Ruth Willis-Linn, BS, RRT, RPSGT
TSSP Secretary

Ruth has been in Sleep and Respiratory Care as a Clinical Manager and Educator for 35 years.  She can relate to all of her fellow sleep community members as she functioned for more than 10 years as either a sleep night technologist or as a rotating Respiratory Therapist.  She moved to Texas in 1995 and has been continuously involved in research, education, and good clinical sleep practice since becoming a Texan.

She has raised a family and now hopes to help raise the Texas Sleep community toward licensure and establishing the profession as a recognized part of the medical community.

Tracy Scheel, RPSGT
TSSP Central Region President

Tracy is a 20 year veteran in sleep who began with UTMB in Galveston under the direction of Samuel T. Kuna, M.D.  She became registered in sleep in 2001.  Her well-rounded career has allowed her to perform all administrative and technical sleep lab duties.  She is currently a member of the AAST and Southern Sleep Society and works in Austin, Texas as a Scoring Technologist.

Rob Castro, RPSGT
TSSP Northeast Region President

Rob began his career in sleep disorders medicine in 2006 at Medical Sleep Solutions in Dallas.  He became a Registered Polysomnographic Technologist in 2008.  Rob’s duties at Medical Sleep Solutions have included, but are not limited to conducting studies, scoring studies, managing the night technologists, marketing and establishing the transportation division at Medical Sleep Solutions.  He currently serves as the historian for the Dallas/Fort Worth Council of Safety Professionals and is an active member in both the Oak Cliff Chamber of Commerce in Dallas and the Greater Dallas Hispanic Chamber of Commerce.  Rob grew up in Georgetown, Texas, and attended the University of Texas at Austin.  He is an avid sports fan who has attended three BCS National Championship Games and numerous other NCAA and Big 12 Conference championship events throughout the country.  He is also a volunteer for the AT&T Cotton Bowl Classic and the inaugural TicketCity.com Bowl as well as other sporting events in the Dallas area.

Gerald George, MBBS, RPSGT
TSSP Southeast Region President

Though Dr. George was brought up in the United States, he obtained his medical degree at Bangalore University in India.  After practicing medicine in India for a few years, he returned to the United States to pursue his medical license.  During this period, he was exposed to the field of Sleep Medicine and Sleep Technology.  After becoming a Registered Polysomnographic Technologist (RPSGT) in 2005 he has been actively involved in the field of Sleep Medicine and Sleep Technology, and has worked in several of the hospital-based sleep centers around the Houston Area.  In 2007, Dr. George had the opportunity to start the Baylor College of Medicine Sleep Center.  He successfuly put together and managed this center and its staff, managed the physician’s clinic and started and managed its CPAP clinic.  He also had this center accredited by the American Academy of Sleep Medicine (AASM) in less than a year of operation.  Currently, Dr. George is employed with one of the largest Sleep and Home Respiratory companies in the world.

Jeff Tangman, BA
TSSP Elections and Nominations Chair

Jeff has been in the medical field for over 30 years.  He started with Baxter Travenol representing the Respiratory Division calling on hospital RT departments.  While working for Baxter he was the industrial representative to the Louisiana Society of Respiratory Care and a board member of Camp Sunshine, a summer camp for children suffering from Cystic Fibrosis and Asthma.  From there he went to VHA Home Healthcare as a Regional Director of Operations for durable medical equipment companies and home health agencies in Virginia and Georgia.  He has spent the past 19 years with Respironics selling respiratory and sleep products to DME’s, sleep labs and physicians.  During that time he served as a founding participant and board member for the Louisiana Academy of Sleep Medicine.  After a move to Texas in 2006, he also helped get the TSSP off the ground utilizing his experience from Louisiana.

Brian Gaden, RRT, RPSGT
TSSP Membership Chair

Brian is a Sleep Consultant for Philips Home HealthCare Solutions.  He covers the Southeast Texas region that includes most of the greater Houston area.

Brian received his A.A.S. degree in Respiratory Care from San Jacinto College and he received his B.S.R.C. degree from UTMB.  He has been a Registered Respiratory Therapist since 1996 and a Registered Sleep Technologist since 2003.  He formerly held the position of Manager of Respiratory Care Services at the Methodist Hospital in the Texas Medical Center.  At Methodist, he managed the respiratory care department and he directed the accredited sleep laboratory.

Shari Hilterbran, BS
TSSP Publications Chair

Shari began working in the medical field as an Office Manager for Dr. Diane Gasbarra, a pulmonologist in Oklahoma City.  After working for the physician for 9 years, she obtained her bachelor’s degree in 2000 and moved in to a position as a manager for a durable medical equipment company.  She was then promoted to Area Manager and moved to the Dallas area.  In 2006 she moved to Health Management Services as a District Manager and sales rep for the Dallas/Fort Worth area.  HMS was founded in 1989 and specializes in medical equipment for patients with sleep disordered breathing.  Shari hopes to use the experience she has gained over the past 19 years to support the industry which has provided her so many opportunities.  She is married and has two teenage children.

Tom Zymowski
TSSP Judicial Committee Chair

Tom began his sleep career in 1987 while serving his country in the US Air Force.  He was fortunate enough to be enrolled in the Neurophysiology and Sleep Technician School offered by the United States Navy through the Uniformed Services University of Health Sciences.  Tom proudly served his country being deployed to Panama for Operation Just Cause and England for Operation Desert Storm.  In 1990 he was the recipient of the USAF Achievement Medal.  Since his separation from the USAF, he has worked in several prominent hospitals as a sleep tech, as well as lab coordinator and manager.  Since the late 90s Tom has worked in sales and marketing roles for several major industry leading companies including Resmed, Embla, and most recently Philips Respironics.

Becky Delgado, BSRC, CRT, RPSGT

Becky graduated from Texas State University in 1998 with a Bachelor of Science degree in Respiratory Care.  She entered into the sleep field doing an internship at LYNAY Healthcare as a night technologist.  She received her registry in sleep in 1999 and stayed with the company until 2001.  A management opportunity presented itself with Vital Sleep of Austin at that time.  She worked for the Shreveport, LA based company as their Area Manager.  Vital Sleep is the provider for EEG, sleep, and long term monitoring services for most of the HCA Hospitals in the Austin and surrounding areas.  From 2005-2010 she worked as a successful independent contractor providing consulting, scoring and accreditation help to local and out of town labs.  Currently she is working again for Vital Sleep of Austin as their Area Manager.