I'm not sure the HN title of this posting does the article justice. What caught my eye was that a retired doctor interviews hundreds of poor Third World 'custom

I'm not sure the HN title of this posting does the article justice. What caught my eye was that a retired doctor interviews hundreds of poor Third World 'customers' to get an idea what they need. Then he has low-tech, low-cost products developed, and figures out how to get local people to manufacture, market, and sell the products.