The document outlines the importance of medical informatics standards, focusing on HL7 (Health Level 7), which facilitates electronic data exchange in healthcare. It details HL7's origins, various versions, and message structures designed for interoperability within healthcare information systems. Additionally, it covers encoding schemes and common protocols used in HL7 implementations.

1. MEDICAL INFORMATICS
STANDARDS

2. What is a standard?
• A standard comprises a set of rules and
definitions that specify how to carry out a
process or produce a product.

3. • Data models and structures for
communication between various applications
should be standardized
• computer architecture and networking
standards set the framework for computer
components and communications

5. Some standards
• HL7
• DICOM
• IEEE 11073
• IRMA
• HIPAA
• LOINC
• EDI
• ASTM
• AWG

6. What is HL7?
• Health Level-7 or HL7 is a specification for electronic
data exchange between hospitals and between
different computer systems within hospitals
• These standards focus on the application layer,
which is "layer 7" in the OSI model.
• Health Level Seven (HL7) standards are crucial for
ensuring interoperability in healthcare information
systems.
• These standards facilitate the exchange, integration,
sharing, and retrieval of electronic health
information.

7. • Health Level-7 or HL7 refers to a set of
international standards for transfer of clinical
and administrative data between software
applications used by various healthcare
providers.

8. • Origins: Established in 1987, HL7 aims to
create standards for electronic health
information.
• A nonprofit organization with members in
more than 50 countries, HL7 was founded in
1987 and accredited by the
American National Standards Institute in 1994.

9. • HL7 V2.x: Messaging standard for healthcare data exchange.
• HL7 V3: A more comprehensive and structured standard
based on XML.
• HL7 FHIR (Fast Healthcare Interoperability Resources):
Modern standard for data exchange using RESTful APIs and
JSON/XML formats.
• Message Structure: Composed of segments, fields, and
components.
• Common Use Cases: Patient registration, orders, and results
reporting.

10. • Protocol for data exchange between computer
systems in health care environments.
• Defines messages as they are exchanged and the
procedures used for exchanging them.
• Refers to the top layer (Level 7) of OSI/ISO layer
model.
• Health Level Seven is one of several American national
standard Institute (ANSI)
• ANSI standard since 1997 most widely used in
USA, Canada, Australia, New Zealand and Japan.
Contd..,

11. What is HL7 (Health Level Seven)?
Application
Type of network communication
(e-mail, telnet, FTP, HL7)
Data conversion, encryption
Presentation
Session
Controlling dialogues (sessions).
Establishing, terminating and
restarting connection.
Transport
Network
Data-Link
Physical
Network adapter: Ethernet, wireless
Ethernet
Physical link: Ethernet cable, RS-232,
optical link
TCP/IP
Routing, reliable data
transport between two
computers

12. HL7 contains message standards covering:
• Patient Administration
• Orders for Clinical Services and Observations,
Pharmacy, Nutrition and Supplies order entry
• Patient Accounting and Charges
• Observation Reporting
• Document Management Services
• Appointment Scheduling
• Laboratory Automation
• Personnel Management
• …

13. • HL7's Vision
• To create the best and most widely used
standards in healthcare.

16. HL7 in Healthcare
Management System

18. Message structure
HL7 messages are made up of segments
• Segments are units that comprise messages.
• A segment is defined as a sequence of fields.
• Both segments and fields may appear more than once in a message.
• HL7 messages are in human-readable (ASCII) format,
• Examples of HL7 message segments:
• MSH - Message Header
information about a message
• EVN - Event Type
event information
• PID - Patient Identification
information about a patient
• NK1 - Next of Kin
information about the patient's other related parties
• OBR - Observation Request
information about an order
• OBX - Observation Report
information about a result

19. Message structure
HL7 Message Example

20. [Square Brackets] indicate something is optional; and
{Curly Brackets} indicate something is repeatable.

22. Message Header Segment(MSH)

23. PID SEGMENT (1/3)

24. PID SEGMENT(2/3)

25. Message structure
Types of messages
Most applicable HL7 messages for communicating HIS
and diagnostic systems:
• ACK – General Acknowledgment message
• ORM – General Order message
• ORR – General Order Response message
• ORU – Unsolicited Transmission of Observation

26. Message structure
Data Exchange
• No data exchange, messaging and communication
technologies are determined by HL7.
• Frequently used protocols in HL7 implementations:
LLP (Lower Layer Protocol) – TCP/IP based
SOAP (Simple Object Access Protocol) – XML
based
Batch Files – messages in text files exchanged
by FTP and SMTP or offline via a tape or a
diskette

27. Message encoding schemes
HL7 uses two encoding schemes:
• HL7 ER, also known as 'traditional' HL7 format;
 used for HL7 versions 2.x
• XML
 primary encoding scheme for HL7 v 3.0
 can be used for HL7 v 2.x in environments
where sender and receiver both understand
XML