The task was daunting Create a process for producing medical-grade saline solution in a zero gravity environment. The implications could be far-reaching. If successful, astronauts could manufacture their own IV bags while in space. The military could apply the technology in war zones without immediate access to clean water. Natural disaster regions, such as earthquake-stricken areas, could use the process to create much-needed medical supplies in relief efforts.
The project, titled IV Gen, began in 2007 with funding through NASA’s Human Research Program. As a joint collaboration of NASA’s Glenn Research Center, Kennedy Space Center, and Johnson Space Center, with support service contractor ZIN Technologies,Inc., the combined team sought to develop a prototype to test on the International Space Station.
Responding to a Need
Currently, saline and other pharmaceuticals are available on the space station for medical emergencies. Yet, the shelf life of premade saline, glucose, and other medical solutions is shorter than most exploratory space cycles. As space journeys expand—with potential plans to explore the moon, then Mars (which would take more than six months, one-way)—the premade IV bags would expire well before the conclusion of the mission.
In addition, mass and volume storage constraints point to a need to produce “on-demand” IV solution.
Once the need for the technology was identified, the process of converting potable water into purified water (via a custom purifier), combining it with sodium chloride, and sterilizing the resulting saline ran into obstacles.
To meet U.S. Pharmacopeia standards, several components of the assembly need to withstand gamma irradiation for sterilization. Additionally, mixing the solution sufficiently in a reduced or zero gravity environment proves challenging. The lack of buoyancy also creates difficulties in separating gas from liquid and eliminating bubbles from the bags.
Through experimentation, ZIN Technologies developed an “in-the-bag” agitation device using a magnetic stir bar and remote motor. Then our team stepped in to provide a unique customized assembly that other companies could not offer. One bag was preloaded with sodium chloride and the magnetic stir bar. After assembly and packaging, we saw to it that everything was sterilized to 10-6 SAL by gamma irradiation.
Putting it to the test
Once the team developed a viable prototype, it had to be tested to determine if the IV bags met U.S. Pharmacopeia standards. Among other data, a test demonstration also would help verify if the filters in the assembly perform the same in zero gravity as on Earth.
While it is expensive to send hardware to the International Space Station, other test methods would not prove adequate. Using a plane to make parabolic flights, for example, would provide only 20 to 30 seconds of zero gravity. Yet, it takes one to one-and-a-half hours to produce one bag of saline solution.
Given this, a technology demonstration was scheduled. After the shuttle docked on the International Space Station, astronauts unloaded and installed hardware in the Microgravity Science Glovebox (MSG). For testing purposes, diagnostic instrumentation including a flowmeter, temperature and pressure sensors, conductivity meters, and other hardware delivered immediate data to scientists on Earth.
The trained astronauts then attempted to make two bags of saline, each holding about 1.5 liters. The solution was saved to be analyzed after the shuttle returned. If the process proved valid, the instrumentation could be stripped away and the system scaled down to only a pump, filters, and a bag.
The next phase of testing would then focus on determining the filters’ operating life and how it compares to operation on Earth.
A potentially bright future
With inquiries from the U.S. military about the technology, IV Gen is already gaining momentum. The potential to draw water from a muddy puddle, drive it through filters with a compressed gas cartridge, and remotely produce saline IV bags has multiple applications.
And it all comes down to a brilliant team that overcame a series of obstacles. . .and tapped into the right resources to deliver a pump, filters, and a bag.
Dan Brown, Mechanical Engineer for ZIN Technologies, Inc., contributed to this case study.
For more information on ZIN Technologies, go to http://www.zin-tech.com/Home.ASP. For Glenn Research Center, click on http://www.nasa.gov/centers/glenn/home/index.html.
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