title: Tolerance of centrifuge-simulated suborbital spaceflight by medical condition.
abstract: BACKGROUND
  We examined responses of volunteers with known medical disease to G forces in a centrifuge to evaluate how potential commercial spaceflight participants (SFPs) might tolerate the forces of spaceflight despite significant medical history.
  
  
  METHODS
  Volunteers were recruited based upon suitability for each of five disease categories (hypertension, cardiovascular disease, diabetes, lung disease, back or neck problems) or a control group. Subjects underwent seven centrifuge runs over 2 d. Day 1 consisted of two +G(z) runs (peak = +3.5 G(z), Run 2) and two +G(x), runs (peak = +6.0 G(x), Run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z), peak = +6.0 G(x)/+4.0 G(z)). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular exams, and post-run questionnaires regarding motion sickness, disorientation, grayout, and other symptoms.
  
  
  RESULTS
  A total of 335 subjects registered for participation, of which 86 (63 men, 23 women, age 20-78 yr) participated in centrifuge trials. The most common causes for disqualification were weight and severe and uncontrolled medical or psychiatric disease. Five subjects voluntarily withdrew from the second day of testing: three for anxiety reasons, one for back strain, and one for time constraints. Maximum hemodynamic values recorded included HR of 192 bpm, systolic BP of 217 mmHg, and diastolic BP of 144 mmHg. Common subjective complaints included grayout (69%), nausea (20%), and chest discomfort (6%). Despite their medical history, no subject experienced significant adverse physiological responses to centrifuge profiles.
  
  
  CONCLUSIONS
  These results suggest that most individuals with well-controlled medical conditions can withstand acceleration forces of launch and re-entry profiles of current commercial spaceflight vehicles.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Blue
authors.forename: James M
authors.initials: JM
authors.lastname: Pattarini
authors.forename: David P
authors.initials: DP
authors.lastname: Reyes
authors.forename: Robert A
authors.initials: RA
authors.lastname: Mulcahy
authors.forename: Alejandro
authors.initials: A
authors.lastname: Garbino
authors.forename: Charles H
authors.initials: CH
authors.lastname: Mathers
authors.forename: Johnené L
authors.initials: JL
authors.lastname: Vardiman
authors.forename: Tarah L
authors.initials: TL
authors.lastname: Castleberry
authors.forename: James M
authors.initials: JM
authors.lastname: Vanderploeg
mesh_terms: D000328:Adult; D000337:Aerospace Medicine; D000367:Age Factors; D000368:Aged; D001007:Anxiety; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000503:physiopathology; D002637:Chest Pain / Q000503:physiopathology; D003371:Cough / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006112:Gravitation; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008171:Lung Diseases / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000503:physiopathology; D010092:Oximetry; D011446:Prospective Studies; D013026:Space Flight; D013122:Spinal Diseases / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology; D018474:Weightlessness Simulation; D055815:Young Adult