The formulas used to calculate each parameter available in the
Blood Pressure add-on for
LabChart can be found in LabChart's help documentation under Blood Pressure > Blood Pressure Parameters. The list of parameters and their calculation methods are below:
Ventricular Parameters
| · | Max Pressure: The maximum pressure during the
cycle. |
| · | Min Pressure: The minimum pressure during the
cycle. |
| · | Mean Pressure: The arithmetic mean pressure in the
current cycle. |
| · | Max-Min Pressure: The difference between minimum and
maximum pressures. |
| · | Heart Rate: Calculated as 60 / (Cycle
Duration). |
| · | Max dP/dt: The steepest slope during the upstroke of the
pressure curve. |
| · | Min dP/dt: The steepest slope during the downstroke of
the pressure curve. |
| · | EDP: Pressure at the end of diastole. |
| · | Systolic Duration: Elapsed time between the start of the
cycle (at EDP) and the time of Min dP/dt. |
| · | Diastolic Duration: Elapsed time between the time of Min
dP/dt and the end of the cycle. |
| · | Cycle Duration: Elapsed time between two alignment
points. |
| · | Tau: The exponential time
constant of relaxation. |
| · | Pressure Time Index: Also known as tension–time index.
The average ventricular pressure during systole, multiplied by the systolic
duration. |
| · | Contractility Index: Max dP/dt divided by the pressure
(P) at the time of Max dP/dt. |
| · | IRP Average dP/dt: The slope of a straight line fitted to
the pressure over the Isovolumic Relaxation Period used for estimation of
tau. |
Arterial Parameters
| · | Systolic Pressure: The maximum pressure during the
cycle. |
| · | Diastolic Pressure: The pressure at the start of the
cycle. |
| · | Dicrotic Notch Pressure: Pressure at the time of the
dicrotic notch (if detected). |
| · | Mean Pressure: The arithmetic mean pressure in the
current cycle. |
| · | Pulse Pressure: The difference between diastolic and
systolic. |
| · | Ejection Duration: Elapsed time between the start of
cycle and the dicrotic notch (if
detected). |
| · | Non-Ejection Duration: Elapsed time between the dicrotic
notch (if detected) and the end of cycle. |
| · | Cycle Duration: Elapsed time between two alignment
points. |
| · | Heart Rate: 60 / (Cycle
Duration). |
| · | Time to Peak: Elapsed time between the start of the cycle
and time of systolic pressure. |
| · | Mean Diastolic Pressure: The average pressure between the
dicrotic notch (if detected) and the end of cycle. |
