Clinical Physiology Laboratory
In the Department of Orthopaedic Surgery
Visit UC San Diego Department of Orthopaedic Surgery
Explore other UCSD Health Sciences Sites
UC San Diego Clinical Physiology Laboratory • 9452 Medical Center Drive • La Jolla, CA 92037-0863 • 858-534-4655
About the Lab | Research | People | Publications | Contact
Official Web Site of the University of California, San Diego. Copyright ©2017 Regents of the University of California. All rights reserved.
Legal | Policy Notices | Site Feedback
Home / Research / Space Physiology
Space Physiology Research Projects
Risk of Intervertebral Disc Damage After Prolonged Space Flight
Purpose: Microgravity significantly reduces normal spinal compression and the diurnal loading
cycle, increasing the risk of disc prolapse or herniation when returning to a gravitational
environment. Long term (6 months) microgravity exposure may also have adverse effects that
can ultimately weaken disc tissues. The purpose of this study is to address and quantify the
physiological changes occurring in the spine after prolonged space flight to help reduce the
incidences of disc damage.
Hypothesis: We hypothesize that microgravity effects biological patho-mechanisms, which ultimately
result in altered disc cell metabolism as well as pain and potential disc degradation.
Technologies Used: Standard and upright MRI, Spinal kinematics
Fluid Distribution Before, During and After Long Duration Space Flight
Purpose: Over 30% of American astronauts have developed ocular refraction change after long duration space flight on
the International Space Station (ISS). Other findings have shown structural changes of the eye, as well as elevated
intracranial pressure (ICP) via lumbar puncture data. These physiological changes are thought to be due space-flight
induced cephalad fluid shifts and transiently elevated ICP. The fluid distribution patterns and their effects on intracranial
pressure or the structure and function of the sensory organs in the course of long-duration space flight are not well known.
The purpose of the proposed work is to objectively characterize the changes in fluid
distribution, including intra/extracellular and intra/extravascular fluid shifts, by applying
advanced non-invasive assessment technologies before, during and after long duration
Hypothesis: We hypothesize the symptoms (ex: headaches, nasal congestion, altered
vision, increased intracranial pressure) experienced by the crew members could be due to
the cephalad fluid shifts.
Technologies Used: Lower body negative pressure and Standard and upright MRI
Fluid Shifts with Head Down Tilt and Lower Body Negative Pressure
Purpose: Simulated microgravity and long duration flights induce a head-ward fluid
shift which results in facial puffiness, nasal congestion, headache and decrease in calf
circumference. Although it is known that in reduced gravity, fluid shifts from the lower
extremities to the head, the mechanism is poorly understood. In this study we will use
non-invasive techniques to measure changes in tissue oxygenation/ deoxygenation
and the blood perfusion levels in human skin (head, arms, legs) and underlying tissues
(Muscle, bone). A tilt table will be used to perform head-down whole body tilt followed
by application of add-on lower body negative pressure.
Hypothesis: We hypothesize that use of lower body negative pressure (LBNP), will counteract simulated microgravity
(head-down-tilt) induced changes in head and legs. The changes in tissue oxygenation and skin along with bone blood flow
will provide data to determine how regulation of tissue blood flow functions in spaceflight.
Technologies used: NIRS, PPG, ultrasound technology, LBNP chamber