Pss0 stands for the airbag pressure data when pulsewave amplitude is 0.
So,we can get below equals:
Therefore,Pss0 is the highest pressure (SBP)
When start to measure with the pulsewave cuff, the upper airbag gets enough pressure to block the blood flow of the brachial artery, then it gradually released the pressure of upper airbag until the moment that the blood flow rushes into vessel (we call this moment as Pss0),at this moment, the pulse will generate an intensity wave,this wave compared with the airbag pressure wave,there will be a LINER DATA,we call Pss0 as the highest pressure,that is SYSTOLIC PRESSURE (SBP)
How to get the Diastolic (DBP)
Psz1 & Psz2 & Psz3 & Psz4 : Separately stands for lower airbag pressure data (which also means the pulsewave pressure data) at each SBP points.
T1 & T2 & T3 & T4 : Separately stands for the TIME DELAY of pulsewave according to Psz1/2/3/4.
PszA & PszB : Separately stands for lower airbag pressure data when upper airbag pressure data is smaller than DBP data.
TA & TB : Separately stands for the matching time delay
Psz0 stands for upper airbag pressure data at DBP point
T0 stands for the matching pulsewave time delay on this DBP point.
When blood rushes into vessel,with the pressure released from the upper airbag, there is a time delay for blood flow from heart to brachial artery , and the moment when this time delay gradually approaches zero,it means the blood can flow freely without any external pressure,just flow by the heart beats pressure,this moment stands for the lowest blood pressure (DBP),we call it Psz0.