The physio-sensor was a component of the 24th century Starfleet bio-bed.

In 2374, The Doctor ordered Tom Paris to begin a thorough bio-bed diagnostic. As part of this diagnosis, there would be a recalibration of the physio-sensors. The Doctor emphasized that he wanted each of the metabolic referents for the sensors entered precisely. (VOY: "Vis à Vis")

According to the Star Trek Encyclopedia (4th ed., vol. 2, p. 141), the physio-sensor "scanned a patient, providing medical personnel with a continuous display of the patient's vital signs."
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