Supposedly the first intubation of babies was done by a Brighton company in the 60s. They appoached me about ten years ago to make a sensor to be put on the tube to stop damage. ( I have made many 1m range sensors for robotic arms that is a similar task.) The company was sold to a US company soon after so the project wasn't done. I think the US company just wanted the name and stopped production here. I would like to contribute to your project if possible with small proximity or pressure sensors or improved AC constant current sources. I developed one that is much higher frequency, lower output capacitance and higher voltage, than improved Howland, for work I did with the University of Sussex on EIT for breast cancer destection.