Millions of babies die each year of complications related to prematurity and low birth weight, including hypothermia. In the first few weeks of life, premature infants lack the body fat needed to regulate their temperature. Room temperature can feel ice cold to a preemie. In the developed world, these babies are typically placed in an incubator until they’re able to make it on their own. But in developing countries, health care workers caring for hypothermic infants rarely have that option. The solutions at hand in many rural locations, hot water bottles and light bulbs, are ineffective and even dangerous.
In 2007, graduate students in a class at Stanford University’s Institute of Design were challenged to help families in the poorest regions of the world by designing an infant warmer that cost less than 1% of the $20,000 incubators found in leading hospitals. In a brainstorming session, the team – Jane Chen, Linus Liang, Naganand Murty and Rahul Panicker – decided to focus on a sleeping bag design. The initial prototype was a terry cloth bag containing tubing for hot water to heat ZipLoc bags filled with margarine, a phase change material that melts at body temperature.
After graduating, Chen and Panicker began working on the product full time, securing funding and conducting field research in India. Liang and Murty rejoined the team and helped refine the design based on feedback from small-town doctors, midwives and mothers in India.
By then, prototypes included a separate warming device and removable packets of eicosane, a pure, nontoxic hydrocarbon with a melt point near that of the temperature of the human body. But eicosane proved to be too expensive.
In 2009, on a suggestion from engineers at a Seattle nonprofit, the Embrace team began testing Entropy Solutions’ PureTemp phase change material in prototypes. The team was delighted with the results.
The final working model consisted of a hypoallergenic bag, a removable pouch containing PureTemp 37 and an electric warmer to heat the pouch. Here’s how it works: Before each use, the pouch is placed the warmer to melt the PCM. The heated pouch is zipped into the bag and the baby is placed inside. The pouch remains at 98.6 degrees for at least four hours. If the baby gets too hot, PureTemp absorbs heat. If the baby gets too cold, PureTemp releases heat. An indicator on the pouch shows when it must be reheated, and the pouch can be reheated hundreds of times.
In 2011, after years of research, prototyping and testing, the first Embrace infant warmer was delivered to Little Flower Hospital in Bangalore, India.