For decades, the intensive care unit has demanded a difficult bargain: to know a critically ill patient's blood pressure in real time, clinicians have had to pierce an artery, accepting the risks of infection, clotting, and immobility as the cost of vigilance. Researchers at Johns Hopkins University are now challenging that bargain with MOSAIC, a wearable two-sensor system guided by artificial intelligence that reconstructs continuous blood pressure waveforms without breaking the skin. In early trials, the technology matched the precision of arterial catheters closely enough to suggest that me