lifesignal

Lifesignal is a term used in several disciplines to refer to any measurable indicator that life is present or active within a system or environment. While not a formal single discipline term, it is commonly employed in contexts where researchers seek rapid, noninvasive confirmation of life or activity, distinguishing specific signals from general biological processes.

In medical practice, lifesigns or vital signs include heart rate, respiratory rate, blood pressure, body temperature, oxygen saturation, and sometimes brain activity. Continuous lifesign monitoring through sensors and wearables supports patient management, early detection of deterioration, and chronic disease tracking. The concept emphasizes real-time status over isolated measurements.

In astrobiology and space exploration, lifesigns denote evidence that life exists or once existed beyond Earth. This can include biosignatures such as atmospheric gases or surface chemistry patterns, as well as technosignatures like artificial signals. The term covers both biological indicators and indicators of technological activity.

In ecology and animal monitoring, lifesigns refer to observable activity such as movement, vocalizations, or metabolic markers captured by cameras, accelerometers, or acoustic sensors. Such indicators are used to estimate population health, welfare, or behavioral states in wildlife and livestock management.

Measurement and interpretation of lifesignals rely on context and methodological safeguards. Signals can be ambiguous or artifact-prone, so robust conclusions typically require multiple indicators and corroborating evidence. Ethical and privacy considerations also arise in human and animal monitoring.

Related terms include vital signs, biosignatures, biosignals, and technosignatures.