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Lower Body Negative Pressure

NSSDCA ID: 1973-027A-51

Mission Name: Skylab
Principal Investigator:Dr. Richard L. Johnson


The purpose of this experiment was to provide information concerning the time course of cardiovascular adaption during flight, and to provide inflight data for predicting the degree of orthostatic intolerance and impairment of physical capacity to be expected upon return to earth environment. The data collected in support of M092 were blood pressure, heart rate, body temperature, vectorcardiogram, LBNPD pressure, leg volume changes, and body weight. The lower body negative pressure device (LBNPD) consisted of a cylinder which enclosed the lower half of the subject. A diaphragm formed an air seal around the subject's waist. Provisions were made to lower the pressure in the cylinder to expose the lower body to a series of negative pressures. This negative pressure simulated the effects of the normal hydrostatic pressure of the blood in the cardiovascular tree, or a person standing erect on a one-g field. Two leg volume plethysmographs (one for each leg) were required. These devices were capacitance gauges for measuring the expansion was a measure of the amount of blood pooling in the legs. The blood pressure assembly consisted of a pressure cuff affixed around the upper arm, a microphone to pick up the korotkoff's sounds, and signal conditioners. These interfaced with a programming unit to cycle the pressure cuff automatically, the electronic circuitry for blood pressure decisions and displays, and calibration circuitry in the experiment support system (ESS).

Alternate Names

  • M092
  • Skylab/LowerBodyNegativePressure

Funding Agency

  • NASA-Office of Space and Terrestrial Applications (United States)


  • Life Science: None assigned

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Col John W. OrdOther InvestigatorUS Air Force School of Aerospace Medicine
Dr. Richard L. JohnsonPrincipal InvestigatorNASA Johnson Space Center
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