Location: Fenton, Karma, 1998 @ 44953f69d444 / fenton_karma_1998.cellml

Author:
pmr2.import <nobody@models.cellml.org>
Date:
2009-06-17 14:11:08+12:00
Desc:
committing version05 of fenton_karma_1998
Permanent Source URI:
https://staging.physiomeproject.org/workspace/5bb/rawfile/44953f69d44434d15c10bdf3fcbb4be64c140efd/fenton_karma_1998.cellml

<?xml version='1.0' encoding='utf-8'?>
<!-- FILE : fenton_karma_model_1998.xml

CREATED : 24th June 2003

LAST MODIFIED : 29th June 2003

AUTHOR : Catherine Lloyd
         Bioengineering Institute
         The University of Auckland
         
MODEL STATUS : This model conforms to the CellML 1.0 Specification released on
10th August 2001, and the 16/01/2002 CellML Metadata 1.0 Specification.

DESCRIPTION : This file contains a CellML description of the Fenton-Karma simplifid ionic model with three membrane currents, 1998. 

CHANGES: 
29/07/2003 - CML - Altered some parameter values in accordance with some published errata.   
--><model xmlns="http://www.cellml.org/cellml/1.0#" xmlns:cmeta="http://www.cellml.org/metadata/1.0#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:bqs="http://www.cellml.org/bqs/1.0#" xmlns:cellml="http://www.cellml.org/cellml/1.0#" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" cmeta:id="fenton_karma_1998_version02" name="fenton_karma_1998_version02">

<documentation xmlns="http://cellml.org/tmp-documentation">
<article>
  <articleinfo>
  <title>A Simplified Ventricular Myocyte Model</title>
  <author>
    <firstname>Catherine</firstname>
          <surname>Lloyd</surname>

    <affiliation>
      <shortaffil>Bioengineering Institute, University of Auckland</shortaffil>
    </affiliation>
  </author>
</articleinfo>
  <section id="sec_status">
    <title>Model Status</title>
    <para>

            This is the original unchecked version of the model imported from the previous
            CellML model repository, 24-Jan-2006.
          </para>
  </section>
  <sect1 id="sec_structure">
<title>Model Structure</title>

<para>
Ventricular fibrillation (VF) is a disorganised electrical wave activity that disrupts the regular and synchronised contraction of the ventricular muscle and consequently destroys the main pumping function of the heart.  Research to date has suggested that electrical vortices are the mechanism underlying VF.  These are manisfested in the 2D heart as spiral waves, and in the 3D heart as scroll waves of action potential.  Compared with the extensive knowledge available on vortex filament behaviour in an isotropic medium, relatively little is known about how the vortices behave in the anisotropic ventricular muscle.  This 1998 publication by Fenton and Karma (fully referenced below) explores the dynamics of the vortex filament in continuous myocardium via numerical simulation.    </para>

<para>
Over the past 25 to 30 years, mathematical models that describe ventricular action potential have become increasingly complex as new experimental data has become available and has been incorporated into the mathematical equations.  Although these complex models are more realistic, they are also computationally expensive to run, and isolating subsets of essential parameters from the model is difficult.  One traditional method for avoiding this complexity is to use simplified models such as <ulink url="${HTML_EXMPL_FN_SIMPLE}">the FitzHugh-Nagumo model, 1961</ulink>.  However, these simplified models have been criticised as being too simple and as not having the capacity to fully capture certain important features of the ventricular action potential.

</para>  

<para>
The modelling approach that Fenton and Karma take is to use a simplified ionic model of ventricular action potential with three membrane currents.  This model retains enough detail to quantitatively reproduce the behaviour of the ventricular action potential captured by the more complex ionic models of cardiac action potential (such as <ulink url="${HTML_EXMPL_BR_MODEL}">the Beeler-Reuter 1977 model</ulink>, and <ulink url="${HTML_EXMPL_LR_I_MODEL}">the original Luo-Rudy 1991 model</ulink>), but it is less computationally expensive than these other models.
</para>

<para>
The three currents in the Fenton-Karma model are: 
</para>
<itemizedlist>
  <listitem>
            <para>

              <emphasis>I<subscript>fi</subscript>
              </emphasis>, a fast inward current which corresponds to the <emphasis>I<subscript>Na</subscript>
              </emphasis> current</para>
          </listitem>;
  <listitem>
            <para>

              <emphasis>I<subscript>so</subscript>
              </emphasis>, a slow outward current which corresponds to the <emphasis>I<subscript>K</subscript>
              </emphasis> current</para>
          </listitem>; and     
  <listitem>
            <para>

              <emphasis>I<subscript>si</subscript>
              </emphasis>, a slow inward current which corresponds to the <emphasis>I<subscript>Ca</subscript>
              </emphasis> current</para>
          </listitem>.
</itemizedlist> 
<para>

(see <xref linkend="fig_cell_diagram"/> below).
The authors choose to use these labels as opposed to Na, K and Ca, as a reminder that <emphasis>I<subscript>fi</subscript>
          </emphasis>, <emphasis>I<subscript>so</subscript>
          </emphasis>, and  <emphasis>I<subscript>si</subscript>
          </emphasis> do not actually represent measured currents, but only their activation, inactivation and reactivation dynamics which are needed to quantitatively reproduce restitution properties.

</para>

<para>
Model validation indicates that this simplified model is able to faithfully reproduce the 2D patterns of reentry of the more complex models.
</para>

<para>
The complete original paper reference is cited below:
</para>

<para>
<ulink url="http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&amp;id=CHAOEH000008000001000020000001&amp;idtype=cvips&amp;gifs=Yes">Vortex dynamics in three-dimensional continuous myocardium with fiber rotation: Filament instability and fibrillation</ulink>, Flavio Fenton and Alain Karma, 1998, <ulink url="http://ojps.aip.org/journals/doc/CHAOEH-home/top.jsp">
            <emphasis>Chaos</emphasis>

          </ulink>, 8, 20-47.  (Full text (HTML) and PDF versions of the article are available to subscribers on the <emphasis>Chaos</emphasis> website.)  <ulink url="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&amp;db=PubMed&amp;list_uids=12779708&amp;dopt=Abstract">PubMed ID: 12779708</ulink>
</para>

<informalfigure float="0" id="fig_cell_diagram">
<mediaobject>
  <imageobject>
    <objectinfo>
      <title>cell diagram</title>

    </objectinfo>
    <imagedata fileref="fenton_1998a.png"/>
  </imageobject>
</mediaobject>
<caption>A schematic diagram of the three ionic currents described by the Fenton-Karma model of a ventricular myocyte.</caption>
</informalfigure>

<para>
The Fenton-Karma model has been described here in CellML (the raw CellML description of the Fenton-Karma model can be downloaded in various formats as described in <xref linkend="sec_download_this_model"/>).  The parameter values used in this version of the Fenton-Karma model are consistent with the modified Beeler-Reuter (see Table 1 of the 1998 model errata).  Simulations of this CellML model can be run using CMISS.        
</para>

</sect1>

</article>
</documentation>

  <!--
    Below, we define some additional units for association with variables and
    constants within the model. 
  -->
  
  <units name="ms">
    <unit units="second" prefix="milli"/>
  </units>
  
  <units name="per_ms">
    <unit units="second" prefix="milli" exponent="-1"/>
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    <unit units="volt" prefix="milli"/>
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    <unit units="metre" prefix="milli" exponent="-3"/>
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  <!--
    The "environment" component is used to declare variables that are used by
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  -->
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    <variable units="ms" public_interface="out" name="time"/>
  </component>
  
  <component name="membrane" cmeta:id="mebrane">
    

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    <variable units="uF_per_mm2" public_interface="out" name="Cm" initial_value="0.01"/>
    <variable units="mV" name="Vm"/>
    <variable units="mV" name="V_o" initial_value="-85.0"/>
    <variable units="mV" name="V_fi" initial_value="15.0"/>
    <variable units="uA_per_mm2" name="I_stim"/>
    <variable units="uA_per_mm2" name="I_fi"/>
    <variable units="uA_per_mm2" name="I_si"/>
    <variable units="uA_per_mm2" name="I_so"/>
    
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    <math xmlns="http://www.w3.org/1998/Math/MathML" cmeta:id="u_calculation_eq">
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        <ci>I_stim</ci>
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    <math xmlns="http://www.w3.org/1998/Math/MathML">
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    <math xmlns="http://www.w3.org/1998/Math/MathML" cmeta:id="tau_d_calculation_eq">
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        <eq/>
        <ci>tau_d</ci>
        <apply>
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          <ci>g_fi_max</ci>
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    </math>
      
    
    <math xmlns="http://www.w3.org/1998/Math/MathML" cmeta:id="J_fi_calculation_eq">
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        <eq/>
        <ci> J_fi </ci>
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  <component name="fast_inward_current_v_gate" cmeta:id="fast_inward_current_v_gate">
    

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  <group>
    <relationship_ref relationship="containment"/>
    <component_ref component="membrane">
      <component_ref component="fast_inward_current">
        <component_ref component="fast_inward_current_v_gate"/>
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      <component_ref component="slow_outward_current"/>
      <component_ref component="slow_inward_current">
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    <component_ref component="slow_inward_current">
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  </connection>
  
  <connection>
    <map_components component_2="environment" component_1="slow_outward_current"/>
    <map_variables variable_2="time" variable_1="time"/>
  </connection>
  
  <connection>
    <map_components component_2="environment" component_1="slow_inward_current"/>
    <map_variables variable_2="time" variable_1="time"/>
  </connection>
  
  <connection>
    <map_components component_2="fast_inward_current" component_1="membrane"/>
    <map_variables variable_2="u" variable_1="u"/>
    <map_variables variable_2="J_fi" variable_1="J_fi"/>
    <map_variables variable_2="Cm" variable_1="Cm"/>
  </connection>  
  
  <connection>
    <map_components component_2="slow_outward_current" component_1="membrane"/>
    <map_variables variable_2="u" variable_1="u"/>
    <map_variables variable_2="J_so" variable_1="J_so"/>
  </connection>
  
  <connection>
    <map_components component_2="slow_inward_current" component_1="membrane"/>
    <map_variables variable_2="u" variable_1="u"/>
    <map_variables variable_2="J_si" variable_1="J_si"/>
  </connection>
  
  <connection>
    <map_components component_2="p" component_1="membrane"/>
    <map_variables variable_2="u" variable_1="u"/>
  </connection>
  
  <connection>
    <map_components component_2="q" component_1="membrane"/>
    <map_variables variable_2="u" variable_1="u"/>
  </connection>
  
  <connection>
    <map_components component_2="fast_inward_current" component_1="p"/>
    <map_variables variable_2="p" variable_1="p"/>
    <map_variables variable_2="u_c" variable_1="u_c"/>
  </connection>
  
  <connection>
    <map_components component_2="slow_outward_current" component_1="p"/>
    <map_variables variable_2="p" variable_1="p"/>
  </connection>
  
  <connection>
    <map_components component_2="slow_inward_current" component_1="p"/>
    <map_variables variable_2="p" variable_1="p"/>
  </connection>
  
  <connection>
    <map_components component_2="fast_inward_current" component_1="q"/>
    <map_variables variable_2="q" variable_1="q"/>
  </connection>
  
  <connection>
    <map_components component_2="fast_inward_current_v_gate" component_1="fast_inward_current"/>
    <map_variables variable_2="v" variable_1="v"/>
    <map_variables variable_2="p" variable_1="p"/>
    <map_variables variable_2="q" variable_1="q"/>
    <map_variables variable_2="time" variable_1="time"/>
    <map_variables variable_2="u" variable_1="u"/>
  </connection>
  
  <connection>
    <map_components component_2="slow_inward_current_w_gate" component_1="slow_inward_current"/>
    <map_variables variable_2="w" variable_1="w"/>
    <map_variables variable_2="p" variable_1="p"/>
    <map_variables variable_2="time" variable_1="time"/>
    <map_variables variable_2="u" variable_1="u"/>
  </connection>






<rdf:RDF>
  <rdf:Seq rdf:about="rdf:#citationAuthorsSeq">
    <rdf:li rdf:resource="rdf:#author1Vcard"/>
    <rdf:li rdf:resource="rdf:#author2Vcard"/>
  </rdf:Seq>
  <rdf:Description rdf:about="#dv_dt_eq">
    <cmeta:comment rdf:resource="rdf:#9296b789-2109-42e7-a660-c9d1e5fc58bf"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#7336ba4b-b37e-42c5-9848-63baae2b6fe2">
    <rdf:value>
            The scaled slow inward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#56ec53d9-5d54-4dd6-a09c-5cf723ac88fc">
    <rdf:value>
            Calculate the non-dimensional membrane potential variable.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="#J_fi_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#c65c2a45-f65c-4f43-84cb-43a7b0f586d5"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#13a1751d-2d8f-4dab-bcd4-aeb6eebeb2ea">
    <vCard:Given>David</vCard:Given>
    <vCard:Family>Nickerson</vCard:Family>
  </rdf:Description>
  <rdf:Description rdf:about="#tau_v_minus_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#3c3630fe-8bff-46b9-8176-83218ea828cc"/>
  </rdf:Description>
  <rdf:Description rdf:about="#slow_inward_current_w_gate">
    <cmeta:comment rdf:resource="rdf:#292a7421-294e-462c-891e-dd31322ccd7d"/>
  </rdf:Description>
  <rdf:Description rdf:about="#mebrane">
    <cmeta:comment rdf:resource="rdf:#68677fad-70fa-4f9f-9d5a-932d9986e130"/>
  </rdf:Description>
  <rdf:Description rdf:about="#fast_inward_current_v_gate">
    <cmeta:comment rdf:resource="rdf:#8d4c6039-7148-449d-9883-08bae4d2efc4"/>
  </rdf:Description>
  <rdf:Description rdf:about="#I_fi_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#12b44f5c-071f-4bbe-a4d4-8d386f4d38d8"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#author1Vcard">
    <rdf:type rdf:resource="http://www.cellml.org/bqs/1.0#Person"/>
    <vCard:N rdf:resource="rdf:#author1VcardN"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#8d4c6039-7148-449d-9883-08bae4d2efc4">
    <rdf:value>
            The inactivation-reactivation gate for the fast inward current.
            Analogous in role to the product of the h and j gates of the BR and
            LR models.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#8e308af6-ac3c-4f29-beee-324c2856a0fe">
    <rdf:value>
            Equivalent to the Heaviside step function H(u-uc) from the original
            paper.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="#Vm_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#64ec14a6-3243-488c-83c7-ed3c5a72ff73"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#2a58cd7e-e682-4fff-a3e3-65226c715b50">
    <rdf:value>
            The kinetics of the inactivation-reactivation gate for the slow
            inward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#292a7421-294e-462c-891e-dd31322ccd7d">
    <rdf:value>
            The inactivation-reactivation gate variable for the slow outward
            current, analogous to the f gate in the BR and LR models.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#19962ee8-3f04-4ccf-959b-55c11b226c1c">
    <dc:creator rdf:resource="rdf:#citationAuthorsSeq"/>
    <dc:title>Vortex dynamics in three-dimensional continuous myocardium with fiber rotation: Filament instability and fibrillation</dc:title>
    <bqs:volume>8</bqs:volume>
    <bqs:first_page>20</bqs:first_page>
    <bqs:Journal rdf:resource="rdf:#9ec70fab-943a-4cb8-9f4a-4edc6f2b1902"/>
    <dcterms:issued rdf:resource="rdf:#d47ad1d6-ac8c-471f-a75b-d6be6bc75755"/>
    <bqs:last_page>47</bqs:last_page>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#a95a4128-a36c-40e3-8ef6-14e49f5f602d">
    <rdf:value>
            Calculation of the slow inward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#f3d9a993-bcb5-4b09-9c2e-e6b4ae7b6ddf">
    <dcterms:W3CDTF>2003-07-29</dcterms:W3CDTF>
  </rdf:Description>
  <rdf:Description rdf:about="#IStim_for_cmiss_eq">
    <cmeta:comment rdf:resource="rdf:#51d59fe5-0c55-4509-8a16-bac66c39e896"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#author2VcardN">
    <vCard:Given>Alain</vCard:Given>
    <vCard:Family>Karma</vCard:Family>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#9296b789-2109-42e7-a660-c9d1e5fc58bf">
    <rdf:value>
            The kinetics of the fast current's inactivation-reactivation
            variable.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#ecf9c463-027f-4ff7-99a1-ad98a9857e9c">
    <dc:creator rdf:resource="rdf:#0b6e6ae3-a91f-4275-96fc-00838ae8ff19"/>
    <rdf:value>This is the CellML description of the Fenton-Karma simplified ionic model with three membrane currents, 1998. The default parameter values provided correspond to the modified-BR parameter set provided by Fenton and Karma in their corrected Table I.</rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#1016fda8-d88d-40b4-a1b6-ab87a2c3b5ce">
    <rdf:type rdf:resource="http://imc.org/vCard/3.0#internet"/>
    <rdf:value>c.lloyd@auckland.ac.nz</rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#author2Vcard">
    <rdf:type rdf:resource="http://www.cellml.org/bqs/1.0#Person"/>
    <vCard:N rdf:resource="rdf:#author2VcardN"/>
  </rdf:Description>
  <rdf:Description rdf:about="#u_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#56ec53d9-5d54-4dd6-a09c-5cf723ac88fc"/>
  </rdf:Description>
  <rdf:Description rdf:about="#slow_outward_current">
    <cmeta:comment rdf:resource="rdf:#5588e266-f22f-4fa2-ac8d-48e8905cefc7"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#d84e83dd-7ccb-467d-a4df-87d0b037c007">
    <vCard:N rdf:resource="rdf:#13a1751d-2d8f-4dab-bcd4-aeb6eebeb2ea"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#95116376-cc65-4150-9101-ce0aa07dbe71">
    <rdf:value>
            Calculation of the scaled slow outward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="">
    <dc:publisher>
        The University of Auckland, Bioengineering Institute
      </dc:publisher>
    <cmeta:modification rdf:resource="rdf:#49262c29-46dd-490e-bbd7-3de3038f80e3"/>
    <cmeta:modification rdf:resource="rdf:#c34d2ced-96ec-4400-b9a3-eb9c59a4f223"/>
    <dcterms:created rdf:resource="rdf:#3090892a-6fe1-485e-b923-a9daeff586b8"/>
    <dc:creator rdf:resource="rdf:#3a781f43-623d-4a6a-bf56-08881ee845be"/>
  </rdf:Description>
  <rdf:Description rdf:about="#J_si_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#a95a4128-a36c-40e3-8ef6-14e49f5f602d"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#49262c29-46dd-490e-bbd7-3de3038f80e3">
    <dcterms:modified rdf:resource="rdf:#f3d9a993-bcb5-4b09-9c2e-e6b4ae7b6ddf"/>
    <rdf:value>
          Altered some parameter values in accordance with some published errata.
        </rdf:value>
    <cmeta:modifier rdf:resource="rdf:#55003383-0662-4fd7-9f6e-3dcfd55c425e"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#883648bf-546b-479f-8710-88fe7f51f3a6">
    <dcterms:W3CDTF>2003-11-08</dcterms:W3CDTF>
  </rdf:Description>
  <rdf:Description rdf:about="#fenton_karma_1998_version02">
    <dc:title>
        The Fenton-Karma simplifid ionic model with three membrane currents, 1998. 
      </dc:title>
    <cmeta:bio_entity>Ventricular Myocyte</cmeta:bio_entity>
    <cmeta:comment rdf:resource="rdf:#ecf9c463-027f-4ff7-99a1-ad98a9857e9c"/>
    <bqs:reference rdf:resource="rdf:#4496e1c3-46d5-4533-ac38-b282bfed0e50"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#f1a4f785-8928-4621-9012-396bcd7440f2">
    <vCard:Given>Catherine</vCard:Given>
    <vCard:Family>Lloyd</vCard:Family>
    <vCard:Other>May</vCard:Other>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#3c3630fe-8bff-46b9-8176-83218ea828cc">
    <rdf:value>
            Fenton and Karma found it necessary to define the time constant that
            governs the reactivation of the fast inward current separately over
            two voltage ranges (uv&lt;u&lt;uc and u&lt;uv).
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#c65c2a45-f65c-4f43-84cb-43a7b0f586d5">
    <rdf:value>
            Calculation of the current scaled fast inward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#d47ad1d6-ac8c-471f-a75b-d6be6bc75755">
    <dcterms:W3CDTF>1998-03-01</dcterms:W3CDTF>
  </rdf:Description>
  <rdf:Description rdf:about="#J_so_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#95116376-cc65-4150-9101-ce0aa07dbe71"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#fd2cd0eb-2d96-487f-9712-05fe72f86b57">
    <rdf:value>
            Component representing the scaled fast inward current.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#0b6e6ae3-a91f-4275-96fc-00838ae8ff19">
    <vCard:FN>Catherine Lloyd</vCard:FN>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#4496e1c3-46d5-4533-ac38-b282bfed0e50">
    <bqs:Pubmed_id>12779708</bqs:Pubmed_id>
    <bqs:JournalArticle rdf:resource="rdf:#19962ee8-3f04-4ccf-959b-55c11b226c1c"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#author1VcardN">
    <vCard:Given>Flavio</vCard:Given>
    <vCard:Family>Fenton</vCard:Family>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#35fb7c0c-701d-4931-985a-0bbcb5143f43">
    <vCard:Given>Catherine</vCard:Given>
    <vCard:Family>Lloyd</vCard:Family>
    <vCard:Other>May</vCard:Other>
  </rdf:Description>
  <rdf:Description rdf:about="#slow_inward_current">
    <cmeta:comment rdf:resource="rdf:#7336ba4b-b37e-42c5-9848-63baae2b6fe2"/>
  </rdf:Description>
  <rdf:Description rdf:about="#p">
    <cmeta:comment rdf:resource="rdf:#8e308af6-ac3c-4f29-beee-324c2856a0fe"/>
  </rdf:Description>
  <rdf:Description rdf:about="#fast_inward_current">
    <cmeta:comment rdf:resource="rdf:#fd2cd0eb-2d96-487f-9712-05fe72f86b57"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#55003383-0662-4fd7-9f6e-3dcfd55c425e">
    <vCard:N rdf:resource="rdf:#35fb7c0c-701d-4931-985a-0bbcb5143f43"/>
  </rdf:Description>
  <rdf:Description rdf:about="#q">
    <cmeta:comment rdf:resource="rdf:#7e4fedfd-0cc5-4ca4-a2b5-802a532f508d"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#3090892a-6fe1-485e-b923-a9daeff586b8">
    <dcterms:W3CDTF>2003-07-24</dcterms:W3CDTF>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#68677fad-70fa-4f9f-9d5a-932d9986e130">
    <rdf:value>
            The main component of the model, defining both the actual
            transmembrane potential and it's non-dimensional representation used
            in the model.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#9ec70fab-943a-4cb8-9f4a-4edc6f2b1902">
    <dc:title>Chaos</dc:title>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#5588e266-f22f-4fa2-ac8d-48e8905cefc7">
    <rdf:value>
            The slow outward current, responsible for the repolarisation of the
            membrane.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#7e4fedfd-0cc5-4ca4-a2b5-802a532f508d">
    <rdf:value>
            Equivalent to the Heaviside step function H(u-uv) from the original
            paper.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#c34d2ced-96ec-4400-b9a3-eb9c59a4f223">
    <dcterms:modified rdf:resource="rdf:#883648bf-546b-479f-8710-88fe7f51f3a6"/>
    <rdf:value>
          Corrected model.
        </rdf:value>
    <cmeta:modifier rdf:resource="rdf:#d84e83dd-7ccb-467d-a4df-87d0b037c007"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#64ec14a6-3243-488c-83c7-ed3c5a72ff73">
    <rdf:value>
            The standard membrane action potential formulation.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#9bdc8880-1fe9-4081-91e5-6f785f26a991">
    <rdf:value>
            Calculation of the current's time constant.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#51d59fe5-0c55-4509-8a16-bac66c39e896">
    <rdf:value>
            This is a dummy equation that we simply use to make grabbing the
            value in CMISS much easier.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="#dw_dt_eq">
    <cmeta:comment rdf:resource="rdf:#2a58cd7e-e682-4fff-a3e3-65226c715b50"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#3a781f43-623d-4a6a-bf56-08881ee845be">
    <vCard:ORG rdf:resource="rdf:#efea105c-eefd-48e6-b529-293d2814eb5b"/>
    <vCard:EMAIL rdf:resource="rdf:#1016fda8-d88d-40b4-a1b6-ab87a2c3b5ce"/>
    <vCard:N rdf:resource="rdf:#f1a4f785-8928-4621-9012-396bcd7440f2"/>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#efea105c-eefd-48e6-b529-293d2814eb5b">
    <vCard:Orgname>The University of Auckland</vCard:Orgname>
    <vCard:Orgunit>The Bioengineering Institute</vCard:Orgunit>
  </rdf:Description>
  <rdf:Description rdf:about="rdf:#12b44f5c-071f-4bbe-a4d4-8d386f4d38d8">
    <rdf:value>
            Convert the scaled currents to actual currents.
          </rdf:value>
  </rdf:Description>
  <rdf:Description rdf:about="#tau_d_calculation_eq">
    <cmeta:comment rdf:resource="rdf:#9bdc8880-1fe9-4081-91e5-6f785f26a991"/>
  </rdf:Description>
</rdf:RDF>
</model>