Heart rate variability (HRV) is a well-established cardiovascular and autonomic health metric in the medical literature. However, its applicability is limited by the difficulty of analysis and interpretation in clinical practice. Given that the intracranial pressure (ICP) waveform is the manifestation of the vascular pulse wave that originates from cardiac muscle contraction, we will evaluate whether the interval between ICP pulse waves assessed noninvasively with Brain4care technology is the same as the R-R interval assessed by electrocardiography in healthy patients, in an attempt to universalize autonomic analysis in clinical practice.

Inclusion Criteria:

• Healthy adults from 18 to 60 years old.

Exclusion Criteria:

• The exclusion criteria were as follows: (1) diagnosed cardiovascular disease, including arrythmia (2) symptoms of illness during the recruitment time, (3) restriction in physical activity, and (4) restriction on using wearable devices.

Healthy adults from 18 to 60 years old.

Anonymous autonomic data (EKG, ICP waveform monitor, Photoplethysmography).

from 2026 after article publication.