var object = {};
//Create JSON Object from HL7 Message.
object.mrn = msg['PID']['PID.3']['PID.3.1'].toString();
object.firstName = msg['PID']['PID.5']['PID.5.2'].toString();
object.lastName = msg['PID']['PID.5']['PID.5.1'].toString();
object.dob = msg['PID']['PID.7']['PID.7.1'].toString();
object.ssn = msg['PID']['PID.19']['PID.19.1'].toString();
//Create string from JSON Object.
var objjson = JSON.stringify(object);
logger.info(objjson);
//Create Json Object From JSON string.
var tt = JSON.parse(objjson);
Output
{"mrn":"1001","firstName":"COLLEEN","lastName":"OHALLAHAN","dob":"19850704","ssn":"123456789"}
HL7Message Sample
MSH|^~\&|ADT1|SHM|SHMADT|SHM|200812091126|SECURITY|ADT^A01^ADT_A01|MSG00001|P|2.5|
EVN|A01|200812091126||
PID|1|1001|1001^5^M11^ADT1^MR^SHM||OHALLAHAN^COLLEEN^^||19850704|F||2106-3|1200 N ELM STREET^^NEWPORT BEACH^CA^92660-1020^US^H|OC|(949) 555-1234|(949) 555-5678||S||PATID1001^2^M10^ADT1^AN^A|123456789|U1234567^CA|
NK1|1|OHALLAHAN^BRITTANY^M|SIS^SISTER||||N^NEXT-OF-KIN
PV1|1|I|2000^2012^01||||001122^ZOIDBERG^JOHN^|||SUR||||1|A0|