Historical clue formulations

• Vital signs — 2022-12-13
• Rhythmic heartbeats — 2020-04-20
• Signs of life — 2011-06-07
• Nurses take these — 2010-10-28
• They're checked for life — 2010-04-16
• Beats — 2004-04-17
• Beats — 1995-04-09