At the height of the Covid-19 pandemic, when many hospitals ran out of beds and ventilators, the fingertip pulse oximeter — a $20 neighborhood drugstore purchase — became a primary arbiter of whether a patient was “sick enough” to gain admission to an emergency room. This spring, surrounded by antique telescope models in a classroom tucked inside the MIT Museum, 10 students bent over a square-shaped seminar table. They were building basic pulse oximeters from low-cost do-it-yourself (DIY) kits of assorted wirelings from TinyCircuits. This was just one meeting from MIT…
