Model Mathematics

Component: strain_control

Component: environment

Component: cell_geom

rho=A_capV_myo

Component: membrane

Cm=CmFA_cap ddtimeV=-I_H+I_Cl+i_Na+I_CaL+i_t+i_ss+i_f+i_K1+I_Cab+I_SAC_Na+i_B_K+i_B_Na+I_Ko+I_SAC_K+i_NaK+I_NaCa+I_pCa+i_StimCm

Component: I_stimulus

i_Stim=stim_amplitudeA_capiftime-⌊timestim_period⌋⁢stim_period≥0∧time-⌊timestim_period⌋⁢stim_period≦stim_duration0otherwise

Component: SAC_current

gamma_SLSAC=ExtensionRatio-1⁢10ifSAC_on=10otherwise r=-E_R+85E_R-65 I_SAC_Na=g_SAC⁢gamma_SLSAC⁢V-E_NaA_cap⁢r I_SAC_K=g_SAC⁢gamma_SLSAC⁢V-E_KA_cap I_SAC=I_SAC_K+I_SAC_Na

Component: KSA_current

gamma_SLKO=0.7+ExtensionRatio-1⁢3ifSAC_on=10.7otherwise I_Ko=g_Ko1+ⅇ-10+V45⁢V-E_K⁢gamma_SLKOA_cap

Component: sodium_current

g_Na_endo=1.33⁢g_Na E_Na=R⁢TF⁢ln⁡Na_oNa_i i_Na=g_Na_endo⁢m3⁢h⁢j⁢V-E_NaA_cap

Component: sodium_current_m_gate

m_infinity=11+ⅇV+45-6.5 tau_m=0.00136e30.32⁢V+47.131-ⅇ-0.1⁢V+47.13+0.08⁢ⅇ-V11 ddtimem=m_infinity-mtau_m

Component: sodium_current_h_gate

h_infinity=11+ⅇV+76.16.07 tau_h=0.0004537e3⁢1+ⅇ-V+10.6611.1ifV≥-400.00349e30.135⁢ⅇ-V+806.8+3.56⁢ⅇ0.079⁢V+310000⁢ⅇ0.35⁢Votherwise ddtimeh=h_infinity-htau_h

Component: sodium_current_j_gate

j_infinity=11+ⅇV+76.16.07 tau_j=0.01163e3⁢1+ⅇ-0.1⁢V+32ⅇ-0.0000002535⁢VifV≥-400.00349e3V+37.781+ⅇ0.311⁢V+79.23⁢-127140⁢ⅇ0.2444⁢V-0.00003474⁢ⅇ-0.04391⁢V+0.1212⁢ⅇ-0.01052⁢V1+ⅇ-0.1378⁢V+40.14otherwise ddtimej=j_infinity-jtau_j

Component: Ca_independent_transient_outward_K_current

g_t_endo=0.4647⁢g_t E_K=R⁢TF⁢ln⁡K_oK_i i_t=g_t_endo⁢r⁢a_endo⁢s+b_endo⁢s_slow⁢V-E_KA_cap

Component: Ca_independent_transient_outward_K_current_r_gate

r_infinity=11+ⅇV+10.6-11.42 tau_r=1e345.16⁢ⅇ0.03577⁢V+50+98.9⁢ⅇ-0.1⁢V+38 ddtimer=r_infinity-rtau_r

Component: Ca_independent_transient_outward_K_current_s_gate

s_infinity=11+ⅇV+45.36.8841 tau_s_endo=0.55e3⁢ⅇ-V+70252+0.049e3 ddtimes=s_infinity-stau_s_endo

Component: Ca_independent_transient_outward_K_current_s_slow_gate

s_slow_infinity=11+ⅇV+45.36.8841 tau_s_slow_endo=3.3e3⁢ⅇ-V+70302+0.049e3 ddtimes_slow=s_slow_infinity-s_slowtau_s_slow_endo

Component: steady_state_outward_K_current

i_ss=g_ss⁢r_ss⁢s_ss⁢V-E_KA_cap

Component: steady_state_outward_K_current_r_ss_gate

r_ss_infinity=11+ⅇV+11.5-11.82 tau_r_ss=10e345.16⁢ⅇ0.03577⁢V+50+98.9⁢ⅇ-0.1⁢V+38 ddtimer_ss=r_ss_infinity-r_sstau_r_ss

Component: steady_state_outward_K_current_s_ss_gate

s_ss_infinity=11+ⅇV+87.510.3 tau_s_ss=2.1e3 ddtimes_ss=s_ss_infinity-s_sstau_s_ss

Component: inward_rectifier

i_K1=48e-3ⅇV+3725+ⅇV+37-25+10e-3⁢0.0011+ⅇV-E_K+76.77-17+g_K1⁢V-E_K+1.731+ⅇ1.613⁢F⁢V-E_K+1.73R⁢T⁢1+ⅇK_o-0.9988-0.124A_cap

Component: hyperpolarisation_activated_current

f_K=1-f_Na i_f_Na=g_f⁢y⁢f_Na⁢V-E_NaA_cap i_f_K=g_f⁢y⁢f_K⁢V-E_KA_cap i_f=i_f_Na+i_f_K

Component: hyperpolarisation_activated_current_y_gate

y_infinity=11+ⅇV+138.610.48 tau_y=1e30.11885⁢ⅇV+8028.37+0.5623⁢ⅇV+80-14.19 ddtimey=y_infinity-ytau_y

Component: background_currents

i_B_Na=scale_Na⁢g_B_Na⁢V-E_NaA_cap i_B_K=scale_K⁢g_B_K⁢V-E_KA_cap

Component: sodium_potassium_pump

p_nai=11+K_m_NaNa_i4 sigma=ⅇNa_o67.3-17 p_v=11+0.1245⁢ⅇ-0.1⁢V⁢FR⁢T+0.0365⁢sigma⁢ⅇ-V⁢FR⁢T i_NaK=i_NaK_maxA_cap⁢p_v⁢K_oK_o+K_m_K⁢p_nai

Component: J_CO2

jco2=V_myo⁢rho⁢Pco2⁢CO2e-CO2i

Component: comp_v_nhe_exchanger

gamma_NHE=1-2.804⁢ExtensionRatio-1ifpH_on=11otherwise K_Hs=K_Hi⁢gamma_NHE km2=kp1⁢kp2km1 Be=10-pH_e⁢1e3 Bi=10-pH_i⁢1e3 ap1=KB⁢Ae⁢kp1KA⁢KB+KB⁢Ae+Ae⁢Be+KA⁢Be am1=KB⁢Ai⁢km1KA⁢KB+KB⁢Ai+Ai⁢Bi+KA⁢Bi ap2=KA⁢Bi⁢kp2KA⁢KB+KB⁢Ai+Ai⁢Bi+KA⁢Bi am2=KA⁢Be⁢km2KA⁢KB+KB⁢Ae+Ae⁢Be+KA⁢Be reg=Bin_HiBin_Hi+K_Hsn_Hi flux_nhe=reg⁢ap1⁢ap2-am1⁢am2ap1+ap2+am1+am2 v_nhe=flux_nhe⁢V_myo⁢Q_10Scaler

Component: comp_v_che_exchanger

km2=kp2⁢km1kp1 OHe=1000⁢10-14+pH_e OHi=1000⁢10-14+pH_i a=1+K_OHOHe+K_OH⁢CleOHe⁢K_Cl b=1+K_ClCle+K_Cl⁢OHeCle⁢K_OH c=1+K_ClCli+K_Cl⁢OHiCli⁢K_OH d=1+K_OHOHi+K_OH⁢CliOHi⁢K_Cl s1=1a+d⁢kp1+kp2⁢abkm1+km2⁢dc s6=1d+a⁢km1+km2⁢dckp1+kp2⁢ab v_che=V_myo⁢km1⁢s6-kp1⁢s160⁢1000⁢Q_10Scaler

Component: comp_v_nbc

km2=kp2⁢km1kp1 a=1+NaeK_Na+Nae⁢HCO3eK_Na⁢K_HCO3 b=1+K_HCO3HCO3e+K_Na⁢K_HCO3HCO3e⁢Nae c=1+K_HCO3HCO3i+K_Na⁢K_HCO3HCO3i⁢Nai d=1+NaiK_Na+Nai⁢HCO3iK_Na⁢K_HCO3 He=1000⁢10-pH_e Hi=1000⁢10-pH_i s1=1a+d⁢kp1+kp2⁢abkm1+km2⁢dc s6=1d+a⁢km1+km2⁢dckp1+kp2⁢ab reg=Hin_HiHin_Hi+K_Hin_Hi⁢1-Hen_HeHen_He+K_Hen_He v_nbc=V_myo⁢reg⁢km1⁢s6-kp1⁢s160⁢1000⁢Q_10Scaler

Component: comp_v_ae

gamma_AE=1+2.5⁢ExtensionRatio-1ifpH_on=11otherwise K_Hs=K_Hi⁢gamma_AE km2=kp2⁢km1kp1 He=1000⁢10-pH_e Hi=1000⁢10-pH_i a=1+K_HCO3HCO3e+K_HCO3⁢CleHCO3e⁢K_Cl b=1+K_ClCle+K_Cl⁢HCO3eCle⁢K_HCO3 c=1+K_ClCli+K_Cl⁢HCO3iCli⁢K_HCO3 d=1+K_HCO3HCO3i+K_HCO3⁢CliHCO3i⁢K_Cl s1=1a+d⁢kp1+kp2⁢abkm1+km2⁢dc s6=1d+a⁢km1+km2⁢dckp1+kp2⁢ab reg=K_Hsn_HiHin_Hi+K_Hsn_Hi⁢Hen_HeHen_He+K_Hen_He v_ae=V_myo⁢reg⁢km1⁢s6-kp1⁢s160⁢1000⁢Q_10Scaler

Component: intracellular_ion_concentrations

E_Cl=R⁢TF⁢ln⁡CliCle I_Cl=g_Cl⁢V-E_Cl H_o=1000⁢10-pH_e H_i=1000⁢10-pH_i E_H=R⁢TF⁢ln⁡H_oH_i I_H=g_H⁢V-E_H K_Nak=i_NaK⁢-2⁢A_capV_myo⁢F K_flux=-I_SAC_K+i_ss+I_Ko+i_t+i_K1+i_f_K+i_NaK⁢-2+i_B_K⁢A_capV_myo⁢F nai_flux=-i_B_Na+I_SAC_Na+i_Na+I_NaCa⁢3+i_NaK⁢3+i_f_Na⁢A_capV_myo⁢F nai_total=nai_flux+nai_NHE+nai_NBC nai_NHE=v_nheV_myo nai_NBC=v_nbcV_myo nai_Nak=i_NaK⁢3⁢A_capV_myo⁢F nai_NaCa=I_NaCa⁢3⁢A_capV_myo⁢F nai_na=i_Na⁢A_capV_myo⁢F nai_bg=i_f_Na⁢A_capV_myo⁢F beta_intr=ln⁡10⁢10-pH_i+10pH_i+pKa_ib1⁢ib110pH_i+10pKa_ib12+10pH_i+pKa_ib2⁢ib210pH_i+10pKa_ib22 CO2e=PP_co2e⁢CO_2sol⁢P_atm HCO3e=kf_co2hydkr_co2hyd⁢CO2e10-pH_e⁢1e3 v_co2hyd=V_myo+V_SR⁢kf_co2hyd⁢CO2i-kr_co2hyd⁢HCO3i⁢10-pH_i⁢1e3 ddtimeHCO3i=v_co2hydV_myo+V_SR+v_nbc-v_aeV_myo ddtimeCO2i=jco2V_myo-v_co2hydV_myo+V_SR+J_CO2 ddtimepH_i=1-beta_intr⁢-v_nhe+v_cheV_myo+v_co2hydV_myo+V_SR-I_H⁢A_capV_myo⁢F ddtimeNa_i=-i_B_Na+I_SAC_Na+i_Na+I_NaCa⁢3+i_NaK⁢3+i_f_Na⁢A_capV_myo⁢F+v_nhe+v_nbcV_myo ddtimeK_i=-i_Stim+I_SAC_K+i_ss+I_Ko+i_t+i_K1+i_f_K-2⁢i_NaK+i_B_K⁢A_capV_myo⁢F ddtimeCli=I_Cl⁢A_capV_myo⁢F+pH_scale⁢v_che+v_aeV_myo

Component: standard_ionic_concentrations

Component: SL_pump

I_pCa=g_pCa⁢Ca_iK_mpCa+Ca_i⁢2⁢V_myo⁢FA_cap

Component: Cab

E_Ca=log10⁡Ca_eCa_idelta I_Cab=g_Cab⁢V-E_Ca⁢2⁢V_myo⁢FA_cap

Component: I_Ca_L

I_CaL=-J_LC⁢2⁢V_myo⁢FA_cap

Component: NCX

edv=ⅇdelta⁢0.5⁢V⁢eta edv2=ⅇdelta⁢0.5⁢V⁢eta-1 Nai3=Na_i3 Nae3=Na_e3 I_NaCa=g_NCXNae3+K_mNa3⁢Ca_e+K_mCa⁢edv⁢Nai3⁢Ca_e-edv2⁢Nae3⁢Ca_i1+k_sat⁢edv2⁢V_myo⁢FA_cap

Component: SERCA

I_SERCA=g_SERCA⁢Ca_i2K_SERCA2+Ca_i2

Component: ionic_concentrations

Ca_b=B_TRPN-TRPN J_SR=-J_RY+I_SERCA-g_SRl⁢Ca_SR-Ca_i ddtimeCa_SR=V_myoV_SR⁢J_SR ddtimeCa_i=11+B_CMDN⁢K_CMDNCa_i+K_CMDN⁢Ca_i+K_CMDN⁢J_TPRN-J_SR+2⁢I_NaCa-I_pCa-I_Cab-I_CaL⁢A_cap2⁢V_myo⁢F ddtimeTRPN=J_TPRN

Component: Ca_conductances

Component: Ca_voltage

dV=delta⁢V expmdV=ⅇ-dV expVL=ⅇV-V_L0delta_VL

Component: C_ij

C_cc=Ca_i C_co=Ca_i+J_Rg_D⁢Ca_SR1+J_Rg_D C_oc=Ca_i+J_Lg_D⁢Ca_e⁢dV⁢expmdV1-expmdV1+J_Lg_D⁢dV1-expmdVif|dV|>0.000000001Ca_i+J_Lg_D⁢Ca_e1+J_Lg_Dotherwise C_oo=Ca_i+J_Rg_D⁢Ca_SR+J_Lg_D⁢Ca_e⁢dV⁢expmdV1-expmdV1+J_Rg_D+J_Lg_D⁢dV1-expmdVif|dV|>0.000000001Ca_i+J_Rg_D⁢Ca_SR+J_Lg_D⁢Ca_e1+J_Rg_D+J_Lg_Dotherwise

Component: J_ij

J_Rco=J_R⁢Ca_SR-Ca_i1+J_Rg_D J_Roo=J_R⁢Ca_SR-Ca_i+J_Lg_D⁢dV1-expmdV⁢Ca_SR-Ca_e⁢expmdV1+J_Rg_D+J_Lg_D⁢dV1-expmdVif|dV|>0.00001J_R⁢Ca_SR-Ca_i+J_Lg_D⁢0.000011-ⅇ-0.00001⁢Ca_SR-Ca_e⁢ⅇ-0.000011+J_Rg_D+J_Lg_D⁢0.000011-ⅇ-0.00001otherwise J_Loc=J_L⁢dV1-expmdV⁢Ca_e⁢expmdV-Ca_i1+J_Lg_D⁢dV1-expmdVif|dV|>0.00001J_L⁢0.000011-ⅇ-0.00001⁢Ca_e⁢ⅇ-0.00001-Ca_i1+J_Lg_D⁢0.000011-ⅇ-0.00001otherwise J_Loo=J_L⁢dV1-expmdV⁢Ca_e⁢expmdV-Ca_i+J_Rg_D⁢Ca_e⁢expmdV-Ca_SR1+J_Rg_D+J_Lg_D⁢dV1-expmdVif|dV|>0.00001J_L⁢0.000011-ⅇ-0.00001⁢Ca_e⁢ⅇ-0.00001-Ca_i+J_Rg_D⁢Ca_e⁢ⅇ-0.00001-Ca_SR1+J_Rg_D+J_Lg_D⁢0.000011-ⅇ-0.00001otherwise

Component: Ca_tau

t_R=1.17⁢t_L

Component: epsilon

epsilon_pco=1tau_L⁢C_coK_L⁢expVL+aexpVL+1 epsilon_pcc=1tau_L⁢Ca_iK_L⁢expVL+aexpVL+1 epsilon_m=1tau_L⁢b⁢expVL+ab⁢expVL+a

Component: alpha

alpha_p=expVLt_L⁢expVL+1 alpha_m=phi_Lt_L

Component: RyR_param

gamma_NO=1+22.41⁢ExtensionRatio-1ifNO_on=11otherwise phi_R=phi_R_base⁢gamma_NO

Component: beta

beta_poc=1t_R⁢C_oc2C_oc2+K_RyR2 beta_pcc=1t_R⁢Ca_i2Ca_i2+K_RyR2 beta_m=phi_Rt_R

Component: mu_ij

mu_poc=1tau_R⁢C_oc2+c⁢K_RyR2C_oc2+K_RyR2 mu_pcc=1tau_R⁢Ca_i2+c⁢K_RyR2Ca_i2+K_RyR2 mu_moc=theta_Rtau_R⁢d⁢C_oc2+c⁢K_RyR2d⁢C_oc2+c⁢K_RyR2 mu_mcc=theta_Rtau_R⁢d⁢Ca_i2+c⁢K_RyR2d⁢Ca_i2+c⁢K_RyR2

Component: y_ij

denom=alpha_p+alpha_m⁢beta_m+beta_poc+alpha_m⁢beta_m+beta_pcc+alpha_p⁢beta_m+beta_poc y_oc=alpha_p⁢beta_m⁢alpha_p+alpha_m+beta_m+beta_pccdenom y_co=alpha_m⁢beta_pcc⁢alpha_m+beta_m+beta_poc+beta_poc⁢alpha_pdenom y_oo=alpha_p⁢beta_poc⁢alpha_p+beta_m+beta_pcc+beta_pcc⁢alpha_mdenom y_cc=alpha_m⁢beta_m⁢alpha_m+alpha_p+beta_m+beta_pocdenom

Component: r_i

r_1=y_oc⁢mu_poc+y_cc⁢mu_pcc r_2=alpha_p⁢mu_moc+alpha_m⁢mu_mccalpha_p+alpha_m r_3=beta_m⁢mu_pccbeta_m+beta_pcc r_4=mu_mcc r_5=y_co⁢epsilon_pco+y_cc⁢epsilon_pcc r_6=epsilon_m r_7=alpha_m⁢epsilon_pccalpha_p+alpha_m r_8=epsilon_m

Component: z_i

z_4=1-z_1-z_2-z_3 ddtimez_1=-r_1+r_5⁢z_1+r_2⁢z_2+r_6⁢z_3 ddtimez_2=r_1⁢z_1-r_2+r_7⁢z_2+r_8⁢z_4 ddtimez_3=r_5⁢z_1-r_6+r_3⁢z_3+r_4⁢z_4

Component: J_values

J_R1=y_oo⁢J_Roo+J_Rco⁢y_co J_R3=J_Rco⁢beta_pccbeta_m+beta_pcc J_L1=J_Loo⁢y_oo+J_Loc⁢y_oc J_L2=J_Loc⁢alpha_palpha_p+alpha_m

Component: L_flux

J_LC=z_1⁢J_L1+z_2⁢J_L2⁢NV_myo

Component: R_flux

J_RY=z_1⁢J_R1+z_3⁢J_R3⁢NV_myo

Component: troponin

betaCab=k_off⁢1-Tensiongamma_trpn⁢T_refif1-Tensiongamma_trpn⁢T_ref>0.1k_off⁢0.1otherwise J_TPRN=B_TRPN-TRPN⁢betaCab-Ca_i⁢TRPN⁢k_on

Component: Myofilaments

lambda_prev=ExtensionRatio dExtensionRatiodt=0 lamda=ExtensionRatioifExtensionRatio>0.8∧ExtensionRatio≦1.151.15ifExtensionRatio>1.150.8otherwise

Component: thinfilaments

Component: tropomyosin

K_2=alpha_r2⁢z_pn_Relz_pn_Rel+K_zn_Rel⁢1-n_Rel⁢K_zn_Relz_pn_Rel+K_zn_Rel K_1=alpha_r2⁢z_pn_Rel-1⁢n_Rel⁢K_zn_Relz_pn_Rel+K_zn_Rel2 z_max=alpha_0Ca_TRPN_50TRPN_totn_Hill-K_2alpha_r1+K_1+alpha_0Ca_TRPN_50TRPN_totn_Hill Ca_50=Ca_50ref⁢1+beta_1⁢lamda-1 Ca_TRPN_50=Ca_50⁢TRPN_totCa_50+k_offk_on⁢1-1+beta_0⁢lamda-1⁢0.5gamma_trpn alpha_Tm=alpha_0⁢Ca_bCa_TRPN_50n_Hill beta_Tm=alpha_r1+alpha_r2⁢zn_Rel-1zn_Rel+K_zn_Rel ddtimez=alpha_Tm⁢1-z-beta_Tm⁢z

Component: filament_overlap

overlap=1+beta_0⁢lamda-1

Component: length_independent_tension

T_Base=T_ref⁢zz_max

Component: isometric_tension

T_0=T_Base⁢overlap

Component: Cross_Bridges

Q=Q_1+Q_2+Q_3 Tension=T_0⁢a⁢Q+11-QifQ<0T_0⁢1+a+2⁢Q1+Qotherwise ddtimeQ_1=A_1⁢dExtensionRatiodt-alpha_1⁢Q_1 ddtimeQ_2=A_2⁢dExtensionRatiodt-alpha_2⁢Q_2 ddtimeQ_3=A_3⁢dExtensionRatiodt-alpha_3⁢Q_3

Component: Calcium_Handling

Component: Calcium_membrane

Component: pH_regulation