It appears to be a good correlation between a low-frequency blood pressure variation (about 0.1 Hz – 6 cycles/minutes) and the CranioSacral wave – see below ref (1-5).

This pressure variation can be achieved by photoplethysmography (PPG), a non-invasive optical technique at the skin surface that can be used to detect blood volume changes in the microvascular bed of tissue.

This low-frequency pressure wave (which is called Mayer Wave) can then be a good indicator of the cranioSacral wave pattern, rhythm and evolution.

 

CranioSacral wave is a blood pressure wave and can only be displayed with a light sensor
like Berry Med finger sensor, IOS camera

(can NOT be displayed with HRV sensors like Polar Chest Strap or KYTO Ear clip sensor)

 

More on Cranio-Sacral Waves

http://craniosacral-app.com/index.html

(1) D. FERNANDEZ, A. LECINE
L’enregistrement de l’onde de Traube-Hering et de la palpation crânienne simultanée. Revue Ostéo n°9 – November 1990.
http://www.osteopathie-france.net/comprendre-losteopathie/osteo-cranien/616-cranien091

(2) KENNETH E. NELSON, DO; NICETTE SERGUEEF; CELIA M. LIPINSKI, MSII; ARINA R. CHAPMAN, MSII; THOMAS GLONEK, PhD
Cranial rhythmic impulse related to the Traube-Hering-Mayer oscillation: comparing laser-Doppler flowmetry and palpation
JAOA * Vol 101 * No 3 * March 2001 * 163  http://www.iahe.com/images/pdf/Traube.pdf

(3) Kenneth E. Nelson, DO, FAAO, FACOFP
The Primary Respiratory Mechanism, The AAO Journal Winter 2002, p24  https://www.researchgate.net/publication/266617625_The_primary_respiratory_mechanism

(4) Kenneth E. Nelson, DO; Nicette Sergueef, DO (France); Thomas Glonek, PhD
Recording the Rate of the Cranial Rhythmic Impulse, JAOA * Vol 106 * No 6 * June 2006 * 337-341  http://jaoa.org/article.aspx?articleid=2093282

(5) Continuous noninvasive arterial pressure
https://en.wikipedia.org/wiki/Continuous_noninvasive_arterial_pressure