During the Mercury, Gemini, and Apollo missions, one of NASA’s concerns was the safety of its crews, something it monitored rigorously through the use of biomedical instrumentation. As initial flight planning commenced in 1959, biomedical equipment capable of transmitting from space did not exist. NASA quickly brought together medical staff and hardware engineers to develop biomedical technology.
https://airandspace.si.edu/stories/editorial/inventing-apollo-spaceflight-biomedical-sensors