CRADLE 1 incorporated field studies in Tanzania, Zambia and Zimbabwe, funded by a $100,000 Bill and Melinda Gates Foundation (BMGF) grant. Pregnant women were more commonly referred from community to facility following the introduction of the device to local clinics than previously. It was also well accepted by users.
Based on qualitative findings of the study, we adapted the power supply from replaceable batteries, prone to loss and theft. After considering a number of possibilities including solar power, we settled on a micro-USB charger with a sealed lithium battery, which proved to be ubiquitous with the explosion of mobile phone use, even in low-resource settings.