The document discusses the development of wearable biosensors and smart shirts. Wearable biosensors allow for continuous, non-obtrusive monitoring of physiological signals to detect changes in a patient's condition. A ring sensor monitors heart rate and oxygen saturation using a pulse oximetry sensor. A smart shirt developed at Georgia Tech integrates vital sign sensors into a shirt and provides an unobtrusive way to monitor users for medical care, combat casualty monitoring, and other applications. Future trends include smart shirts that can adaptively respond based on the user's condition and environment.