Embrace
Featured
Linus Liang
Rahul Alex Panicker
Razmig Hovaghimian
Imran Akbar
Jane Chen
Fabio Tran
Rahul Alex Panicker
Razmig Hovaghimian
Imran Akbar
Jane Chen
Fabio Tran
Four million premature infants die each year in the developing world due to lack of access to incubators. We are a team of Stanford students working on a $25 solution, to be used in rural areas where more than 90% of these avoidable deaths occur. Our design uses no electricity and has no moving parts. It incorporates a phase change material into a sleeping bag-like design, and is intuitive to use, highly functional and culturally sensitive. Our early users are parents in remote
villages of Nepal who, without resources
to access major hospitals, are left helpless with their
premature infants. We plan on proving the concept in Nepal,
and then rolling it out in the rest of the developing world.
The basic design resembles a sleeping bag. Temperature is maintained by a pouch containing phase change material (PCM), placed in a compartment below the baby. It is embedded with a thermochromatic ink which changes color to indicate when the PCM is too cold or too warm. This device uses no electricty, and has no moving parts. When the color of the PCM, visible through a transparent window on the side, indicates that the pouch is too cold, the parent pulls it out, drops the pouch into some hot water, till the pouch just turns red. The parents waits a few minutes till the pouch turns green, indicating a safe range, and places the pouch in the incubator.Our design is expected to keep the baby warm for more than 4 hrs at a stretch before needing reheating. This is less frequent than how often the baby needs to be breast fed.
Phase Change Material
The phase change material used in the current iteration is n-eicosane. It is a hydrocarbon which melts at 37 degrees C. We use a slurry of microencapsulated PCM in a water base. This ensures that, even after the PCM solidifies within the microcapsules, water acts as a heat transfer medium, distributing heat evenly. Earlier iterations used bulk PCM, which solidified on the surface of the enclosing pouch, thereby insulating the PCM in the interior and obstructing effective heat transfer.
The PCM is first heated so that it melts. Now, when placed in the incubator, as the baby needs heat, the PCM solidifies, and releases its latent heat of fusion in the process. However, this happens at a constant temperature because phase change happens at a constant temperature. In practice, this happens in a narrow temperature range.
A premature infant loses roughly 1.5 Watts of heat. By our calculations, this means that, if the PCM does not lose heat to the exterior, 44g of fully melted PCM is sufficient to keep the baby warm for one hour. Accounting for heat loss to the environment and the necessity to keep the baby warm for at least 4 hrs at a stretch, we use about 500g of PCM in our design.
Thermochromatic Ink
We use a thermochromatic ink to indicate time to reheat the PCM pouch. Thermochromatic inks are pigments which change color with temperature. This portion of our prototype needs further iteration at this point. Our objective is have the pouch blue when the PCM is too cold, green when it is safe, and red when it is too hot. Thermochromatic inks are available in a wide variety of colors and temperature ranges to enable this.
Humidity Control
Most present day incubators have humidity control. This is because premature infants lose water through skin evaporation. However, our design does not require explicit humidity control. This is because the baby is enclosed in a small volume, and there isn’t this large volume of warm air around the baby to draw moisture through the skin. This has been validated with Dr. William Benitz, Professor of Neonatology at the Stanford University Medical Center.
www.embraceglobal.org
The basic design resembles a sleeping bag. Temperature is maintained by a pouch containing phase change material (PCM), placed in a compartment below the baby. It is embedded with a thermochromatic ink which changes color to indicate when the PCM is too cold or too warm. This device uses no electricty, and has no moving parts. When the color of the PCM, visible through a transparent window on the side, indicates that the pouch is too cold, the parent pulls it out, drops the pouch into some hot water, till the pouch just turns red. The parents waits a few minutes till the pouch turns green, indicating a safe range, and places the pouch in the incubator.Our design is expected to keep the baby warm for more than 4 hrs at a stretch before needing reheating. This is less frequent than how often the baby needs to be breast fed.
Phase Change Material
The phase change material used in the current iteration is n-eicosane. It is a hydrocarbon which melts at 37 degrees C. We use a slurry of microencapsulated PCM in a water base. This ensures that, even after the PCM solidifies within the microcapsules, water acts as a heat transfer medium, distributing heat evenly. Earlier iterations used bulk PCM, which solidified on the surface of the enclosing pouch, thereby insulating the PCM in the interior and obstructing effective heat transfer.
The PCM is first heated so that it melts. Now, when placed in the incubator, as the baby needs heat, the PCM solidifies, and releases its latent heat of fusion in the process. However, this happens at a constant temperature because phase change happens at a constant temperature. In practice, this happens in a narrow temperature range.
A premature infant loses roughly 1.5 Watts of heat. By our calculations, this means that, if the PCM does not lose heat to the exterior, 44g of fully melted PCM is sufficient to keep the baby warm for one hour. Accounting for heat loss to the environment and the necessity to keep the baby warm for at least 4 hrs at a stretch, we use about 500g of PCM in our design.
Thermochromatic Ink
We use a thermochromatic ink to indicate time to reheat the PCM pouch. Thermochromatic inks are pigments which change color with temperature. This portion of our prototype needs further iteration at this point. Our objective is have the pouch blue when the PCM is too cold, green when it is safe, and red when it is too hot. Thermochromatic inks are available in a wide variety of colors and temperature ranges to enable this.
Humidity Control
Most present day incubators have humidity control. This is because premature infants lose water through skin evaporation. However, our design does not require explicit humidity control. This is because the baby is enclosed in a small volume, and there isn’t this large volume of warm air around the baby to draw moisture through the skin. This has been validated with Dr. William Benitz, Professor of Neonatology at the Stanford University Medical Center.
www.embraceglobal.org
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