public function getRespondentRelationFields() {
        $fields = array();
        $relationFields = $this->getFieldsOfType('relation');

        if (!empty($relationFields)) {
            $fieldNames = $this->getFieldNames();
            $fieldPrefix = FieldMaintenanceModel::FIELDS_NAME . FieldsDefinition::FIELD_KEY_SEPARATOR;
            foreach ($this->getFieldsOfType('relation') as $key => $field)
            {
                $id = str_replace($fieldPrefix, '', $key);
                $fields[$id] = $fieldNames[$key];
            }
        }

        return $fields;
    }