diff --git a/api/dicom-web/controller/QIDO-RS/service/query-dicom-json-factory.js b/api/dicom-web/controller/QIDO-RS/service/query-dicom-json-factory.js
index 3a020c86..93e37f23 100644
--- a/api/dicom-web/controller/QIDO-RS/service/query-dicom-json-factory.js
+++ b/api/dicom-web/controller/QIDO-RS/service/query-dicom-json-factory.js
@@ -52,6 +52,7 @@ function getWildCardQuery(value) {
 }
 
 /**
+ * TODO: separate this function to single file
  * convert all request query object to to $or query and push to $and query
  * @param {Object} iQuery
  * @returns
@@ -204,9 +205,17 @@ class QueryInstanceDicomJsonFactory extends QueryDicomJsonFactory {
     }
 }
 
+class QueryUpsDicomJsonFactory extends QueryDicomJsonFactory {
+    constructor(queryOptions) {
+        super(queryOptions);
+        this.model =  require("@dbModels/workitems.model").WorkItemModel;
+    }
+}
+
 module.exports.QueryDicomJsonFactory = QueryDicomJsonFactory;
 module.exports.QueryPatientDicomJsonFactory = QueryPatientDicomJsonFactory;
 module.exports.QueryStudyDicomJsonFactory = QueryStudyDicomJsonFactory;
 module.exports.QuerySeriesDicomJsonFactory = QuerySeriesDicomJsonFactory;
 module.exports.QueryInstanceDicomJsonFactory = QueryInstanceDicomJsonFactory;
+module.exports.QueryUpsDicomJsonFactory = QueryUpsDicomJsonFactory;
 module.exports.convertRequestQueryToMongoQuery = convertRequestQueryToMongoQuery;
diff --git a/api/dicom-web/controller/UPS-RS/service/get-workItem.service.js b/api/dicom-web/controller/UPS-RS/service/get-workItem.service.js
index 1b90158d..17f9c561 100644
--- a/api/dicom-web/controller/UPS-RS/service/get-workItem.service.js
+++ b/api/dicom-web/controller/UPS-RS/service/get-workItem.service.js
@@ -1,7 +1,6 @@
 const _ = require("lodash");
-const { WorkItemModel } = require("@dbModels/workitems.model");
 const { 
-    convertRequestQueryToMongoQuery
+     QueryUpsDicomJsonFactory
 } = require("../../QIDO-RS/service/query-dicom-json-factory");
 const { convertAllQueryToDicomTag } = require("@root/api/dicom-web/service/base-query.service");
 
@@ -28,16 +27,15 @@ class GetWorkItemService {
     }
 
     async getUps() {
-        let mongoQuery = (await convertRequestQueryToMongoQuery(this.query)).$match;
-
         let queryOptions = {
-            query: mongoQuery,
+            query: this.query,
             skip: this.skip_,
             limit: this.limit_,
             requestParams: this.request.params
         };
+        let queryFactory = new QueryUpsDicomJsonFactory(queryOptions);
 
-        let docs = await WorkItemModel.getDicomJson(queryOptions);
+        let docs = await queryFactory.getDicomJson();
         
         return this.adjustDocs(docs);
     }