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The Lief biosensing patch measures heart rate, heart rate variability, and breathing to better understand your health and state.   

Heart rate variability is the physiological phenomenon of variation in the time interval between heart beats. This means that every time your heart beats, there’s a small variation from it’s last beat. If your average heart beat is 60 beats per minute (bpm), it may fluctuate from 50-70 bpm at any given moment. This fluctuation of HRV is controlled by the Autonomic Nervous System (ANS), which stimulates or inhibits various body systems (i.e. perspiration, digestion, respiration, immune system functioning) depending on the perceived demands of a given situation.  


There are two branches of the ANS:

  • Sympathetic Nervous System (SNS) - speeds up the heart rate, Fight or Flight.
  • Parasympathetic Nervous System (PNS) - responsible for slowing the heart rate, Rest or Digest.

The ANS and heart are tightly coupled with our personal experience (i.e. emotions, thoughts, sensations). When we perceive a stressor our bodies react as though we are under imminent danger and the sympathetic (Fight or Flight) response becomes dominant, which can increase heart rate, and lower HRV.


Using HRV as a bio signal, the balance between SNS and PNS can be measured and decisively improved over time, which can increase personal flexibility, stability, and resiliency to effectively face the situations that life brings our way.

Lief patch being used to regain control during an anxiety episode