Dyna Paper Calcium Transient

The following (written in pseudocode) adapted¹ equation gives the calcium transient used in the paper “Force-Dependent Recruitment From Myosin OFF-State Increases End-Systolic Pressure-Volume Relationship in Left Ventricle”².

t_p = cardiac_period*cycle + self.t_act+0.01 fCa = 25 fCa_2 = 2.5

if t <= self.t_act:
  pCa = 7
  calcium_value = 10^-pCa
elif ((cardiac_period)(cycle)+self.t_act) < t) and (t < (t_p)):
  pCa = (t - (cardiac_period)(cycle)+self.t_act))/0.02
  calcium_value = (1 + 9sin(3.14pCa))1E-7
elif (t >= t_p):
  pCa = 0.5exp(-np.power((t - t_p)fCa, fCa_2))
  calcium_value = (1+9np.sin(3.14*pCa))1E-7

This yields the following:

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