The red cell volume is considered to be controlled by two principal factors that
control the production of erythropoietin:
(1) the arterial blood oxygen saturation (OSA) and renal function as determined by
renal blood flow (RFN), and
(2) the fraction (REK) of the renal mass that is functional.
Encapsulation grouping component containing all the components in the Red Cells and Viscosity Model.
The inputs and outputs of the Red Cells and Viscosity Model must be passed by this component.
Containment grouping component for "hematocrit_fraction", "viscosity_due_to_RBCs"
and "blood_viscosity".
RC6:
Calculation of blood volume (VB) by adding the volume of the red blood cells (VRC)
to the plasma volume (VP).
RC7:
The fraction of the blood that is composed of red blood cells (HM1) is equal to
the volume of red blood cells (VRC) divided by the blood volume (VB).
RC8:
The hematocrit (HM) equals the fraction of the blood that is red cells (HM1)
times 100.
RC6:
Calculation of blood volume (VB) by adding the volume of the red blood cells (VRC)
to the plasma volume (VP).
RC7:
The fraction of the blood that is composed of red blood cells (HM1) is equal to
the volume of red blood cells (VRC) divided by the blood volume (VB).
RC8:
The hematocrit (HM) equals the fraction of the blood that is red cells (HM1)
times 100.
$\mathrm{VB}=\mathrm{VP}+\mathrm{VRC}\mathrm{HM1}=\frac{\mathrm{VRC}}{\mathrm{VB}}\mathrm{HM}=100\mathrm{HM1}$
RC9, RC10, and RC11:
Curve-fitting blocks to calculate the portion of the viscosity of the blood that
is caused by red blood cells (VIE). The two variables (HMK and HKM) are
curve-fitting constants.
RC9, RC10, and RC11:
Curve-fitting blocks to calculate the portion of the viscosity of the blood that
is caused by red blood cells (VIE). The two variables (HMK and HKM) are
curve-fitting constants.
$\mathrm{VIE}=\frac{\mathrm{HM}}{(\mathrm{HMK}-\mathrm{HM})\mathrm{HKM}}$
RC12:
The viscosity of the blood (VIB) when calculated as a multiple of the viscosity
of water is equal to the viscosity effect caused by the red cells (VIE) plus a
constant determined by the viscosity of the plasma.
RC13:
Calculation of a normalized viscosity multiplier factor (VIM) that is used elsewhere
in the circulation to calculate the effect of changes in the viscosity from normal
(assumed to be 1.0) on various circulatory effects.
RC12:
The viscosity of the blood (VIB) when calculated as a multiple of the viscosity
of water is equal to the viscosity effect caused by the red cells (VIE) plus a
constant determined by the viscosity of the plasma.
RC13:
Calculation of a normalized viscosity multiplier factor (VIM) that is used elsewhere
in the circulation to calculate the effect of changes in the viscosity from normal
(assumed to be 1.0) on various circulatory effects.
$\mathrm{VIB}=\mathrm{VIE}+1.5\mathrm{VIM}=0.3333\mathrm{VIB}$
Containment grouping component for "oxygen_stimulation", "RBC_production",
"RBC_destruction" and "blood_viscosity".
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
RC1, RC1A, RC1B, RC1C, RC1D, RC2, RC2C, and RC2D:
Calculation of the effect of atmospheric O2 pressure (PO2AMB) on the
driving force (HM7) for production of red blood cells. RC1A, RC1B, and RC1D
calculate the effect of pressures below the level of 80 mmHg, and RC1 the effect
of pressures above 80. Blocks RC2, RC2C, and RC2D provide limits to the effects.
$\mathrm{PO2AM1}=\begin{cases}80 & \text{if $\mathrm{PO2AMB}> 80$}\\ \mathrm{PO2AMB} & \text{otherwise}\end{cases}\mathrm{HM3}=(\mathrm{PO2AM1}-40)\mathrm{HM}\mathrm{HM4}=\mathrm{PO2AMB}-40\mathrm{HM5}=\begin{cases}0 & \text{if $\mathrm{HM3}+\mathrm{HM4}< 0$}\\ \mathrm{HM3}+\mathrm{HM4} & \text{otherwise}\end{cases}\mathrm{HM7}=\mathrm{HM6}-\mathrm{HM5}$
RC2A, RC2B, and RC2E:
Calculation of the rate of red blood cell production (RC1), with a lower limit
of zero set by Block RC2E, and the rate of production partly determined by the
amount of kidney mass available (REK) to produce erythropoition.
RC2A, RC2B, and RC2E:
Calculation of the rate of red blood cell production (RC1), with a lower limit
of zero set by Block RC2E, and the rate of production partly determined by the
amount of kidney mass available (REK) to produce erythropoition.
$\mathrm{RC1}=\begin{cases}0 & \text{if $\mathrm{HM7}\mathrm{HM8}\mathrm{REK}+0.000005< 0$}\\ \mathrm{HM7}\mathrm{HM8}\mathrm{REK}+0.000005 & \text{otherwise}\end{cases}$
RC5:
Calculation of the rate of red cell volume destruction (RC2) caused by the presence
of an already large red cell volume (VRC). The rate factor for this effect is (RKC).
Also increased blood viscosity is considered to cause increased destruction.
RC5:
Calculation of the rate of red cell volume destruction (RC2) caused by the presence
of an already large red cell volume (VRC). The rate factor for this effect is (RKC).
Also increased blood viscosity is considered to cause increased destruction.
$\mathrm{RC2}=\mathrm{VRC}\mathrm{RKC}\mathrm{VIM}$
RC3:
Calculation of the rate of change of red blood cell volume (RCD) by adding
the rate of RBC production (RC1) and subtracting the rate of destruction (RC2).
NB - Parameter TRRBC is not in diagram.
RC4:
Calculation of the instantaneous volume of red blood cells by integrating the rate
of change in total volume of red cells (RCD).
RC3:
Calculation of the rate of change of red blood cell volume (RCD) by adding
the rate of RBC production (RC1) and subtracting the rate of destruction (RC2).
NB - Parameter TRRBC is not in diagram.
RC4:
Calculation of the instantaneous volume of red blood cells by integrating the rate
of change in total volume of red cells (RCD).
$\mathrm{RCD}=\mathrm{RC1}-\mathrm{RC2}+\mathrm{TRRBC}\frac{d \mathrm{VRC}}{d \mathrm{time}}=\mathrm{RCD}$