CHARLES PENSULO WHEN Malawian engineer Ruth Mtuwa was a child, she visited a sick family member in hospital and was shocked to see that barely any of the medical equipment worked. That realisation pushed her to want to help, leading her on the path to becoming a biomedical engineer. Today, the 21-year-old research assistant has managed to bring a number of medical innovations to life - including a low-cost nebuliser and a hypertension tracking device - despite tight funding and crushing foreign competition. "I thought if we design on our own equipment, it should be easy to fix on our…