One of the new and exciting standards emerging from HL7 is Fast Healthcare Interoperable Resource (FHIR). Its main purpose is to simplify the exchange of health information with a lightweight implementation framework that will bring smiles to implementers. It certainly put a smile on my face when I put this example together using Iguana!

My example is demonstrates the following actions: get a Patient resource, search all Patient resources, and add a Patient resource.

To get a patient resource, I defined a variable (‘Patient149XMLURL’) that points to a known fictitious patient named Henry Glover (ID: 149).  By using the net.http.get function, I was able to pull Henry Glover’s patient info:

-- The main function is the first function called from Iguana.
-- The Data argument will contain the message to be processed.
require 'patientFHIR'

Patient149XMLURL = 'http://hl7connect.healthintersections.com.au/svc/fhir/patient/@149?_format=xml'
AllPatientsXMLURL = 'http://hl7connect.healthintersections.com.au/svc/fhir/patient/search?_format=xml'
CreatePatientXMLURL = 'http://hl7connect.healthintersections.com.au/svc/fhir/patient?_format=xml'

function main(Data)

   print(patientFHIR,_G)
   local msg, name = hl7.parse({vmd = 'demo.vmd', data = Data})   

   -- read an individual patient in XML format from FHIR server
   -- reference http://www.hl7.org/implement/standards/fhir/patient.htm
   local R,C,H = net.http.get{url=Patient149XMLURL, live=true}
   print (C,R,H)

To search through Patient resources, I added a search keyword after the resource URL. FHIR defines a resource bundle as the return type:

 -- read all patient records in XML format from FHIR server
   -- reference http://www.hl7.org/implement/standards/fhir/http.htm#search
   R,C,H = net.http.get{url=AllPatientsXMLURL, live=true}
   print (C,R,H)

Finally, I added a patient resource by using net.http.post and passing in patient XML data created in a separate module, patientFHIR:

 -- create a new patient in FHIR server
   -- reference http://www.hl7.org/implement/standards/fhir/http.htm#create
   local P = patientFHIR.InsertTemplate()
   P = mapPatientData(P,msg,name)
   R,C,H = net.http.post{url=CreatePatientXMLURL, live=true,
                       headers={['Content-Type']='application/xml'},
                       body=P:S()
   }
   print (C,R,H) -- code 201 (c=201) is a successful insert

end

function mapPatientData(Xml,Msg,Name)
   if Name=='ADT' then
      Xml.Patient.active[1]='true'

      Xml.Patient.identifier.use[1]='official'
      Xml.Patient.identifier.label[1]='SSN'
      Xml.Patient.identifier.id[1]=Msg.PID[2][1]

      Xml.Patient.details.name.use.value='official'
      Xml.Patient.details.name.family.value=Msg.PID[5][1][1][1]
      Xml.Patient.details.name.given.value=Msg.PID[5][1][2]

      Xml.Patient.details.birthDate.value=Msg.PID[7][1]

      print(Msg.PID[8])
      Xml.Patient.details.gender.code[1]=Msg.PID[8]     
   end
   return Xml
end

Here is the module for creating XML containing patient info:

patientFHIR={}

function patientFHIR.InsertTemplate()
   return xml.parse
   {data = [[

      <Patient xmlns="http://hl7.org/fhir">
         <active>#</active>
         <identifier>
            <use>#</use>
            <label>#</label>
            <id>#</id>
         </identifier>
         <details>
            <name>
               <use value="official"/>
               <family value="family name"/>
               <given value="given name"/>
            </name>
            <gender>
               <system value="http://hl7.org/fhir/sid/v2-0001"/>
               <code value=""/>
               <display value=""/>
            </gender>
            <birthDate value="Date"/>
         </details>
      </Patient>
     ]]
   }
end

function node.S(ANode)
   return tostring(ANode)
end

If you want to try all this out, simply import this zip file (with the complete code) into your project: FHIR_Patient_Example_Filter.zip

Well, that’s it for today! Stay tuned as I’ll be posting a JSON example shortly…

Cheers!
Rolly