Medical Informatics
Representation and
Computation on Medical and
Health Care Information
Medical Informatics
•Health records in paper
Problems:
•High chances of damage of patient records.
•Automated processing of records is impossible.
•Increased use of electronic media, devices.
Advantages:
•Less chances of damage, ease of maintenance.
•Data insertion and retrieval is simple.
•Easily interoperable.
•Migration of healthcare industry to electronic
domain.
Targeted at Design and Development of
Information System for



Medical Science and Technology
Health Care Services
Business world involving health care
Health Care Informatics
Suppliers’
Enterprise Systems
Pharmacies
Medical
suppliers
Insurance
providers
•
•
•
E
X
T
R
A
N
E
T
S
Providers’
Enterprise
Systems
ERP
GDSS
DSS
CDSS
•
•
•
•
I
N
T
R
A
N
E
T
S
Physicians
And
Specialists
P
R
M
Patients
Internet
Src: K.Siau, “Health Care Informatics”, IEEE trans. On
Info. Tech. In Biomedicine, 7(1), March, 2003, pp. 1-7
Enterprise Resource Planning





Full integration of an organization's information
from pay-roll and human resources to
accounting and finance.
Database integration (Information Sharing)
Information logged once and accessed by
different modules maintaining the data
consistency.
Track inventory, order information and
delivery requirements
Determine equipment usage and
maintenance schedule
Decision Support System (DSS)



Conventional DSS: financial and scheduling.
Clinical DSS (CDSS): diagnosis, pharmacy,
emergency and nursing practices.
CDSS used to send alerts and reminders to
patients about preventive care.
Patient Relationship Management (PRM)



Primary focus on determining and meeting patients'
needs.
Tracking patients’ information from diet and
exercise data to past diagnosis information from
family history and allergy information.
Send E-mails satisfying queries, informing newly
published health care studies and reminding about
preventive measures.
Medical Informatics and Teleconsultation
•In early days tele-consultation means
•Sending all hardcopies of patient records.
•takes significant amount of time.
•Send the patient to a remote center.
•nearly impossible for emergency patient.
•Using medical informatics tele-consultation
means
•Sending the medical records only.
•Most of the time, no need to send the patient.
•Online consultation among doctors.
•Large scope of knowledge sharing.
Standards
HL7: Health Level Seven. It is an international healthcare standard for medical
data exchange between computer systems in healthcare. http://www.hl7.org/
LOINC: Logical Observation Identifiers Names and Codes. These identify the
test results or clinical observations uniquely. http://www.loinc.org/
ICD-10: International Statistical Classification of Diseases and Related Health
Problems. ICD provides codes to classify diseases and a wide variety of signs,
symptoms etc. Every health condition can be assigned to a unique category and
given a code. http://www.who.int/classifications/icd/en/
ICD-10-PCS: ICD-10 Procedure Coding System. This is a system of medical
classification used for procedural codes which is developed as a replacement of
ICD-9-CM volume 3 (contains inpatient procedures).
DICOM: Digital Imaging and Communications in Medicine. This is a standard
for handling, storing, printing, and transmitting information on medical
imaging. http://medical.nema.org/
Message Transmission
HL7
Standard
Sender
Data
HL7
Message
Creation
HL7-enabled system
Hospital A
MSH|^~\&|REGA
EVN|A05|199901
PID|1||191919^
NK1|1|MASSIE^E
NK1|2|MASSIE^I
…
HL7
Message
HL7
Standard
Receiver
HL7
Message
Parsing
HL7-enabled system
Hospital B
Data
HL7 Message Structure
Event
Message
N
Message1
SegN
Seg1
Field1
Field1
Comp
1
Terminated by <CR>
Comp
N
Separated by '|'
Separated by '^'
Message Encoding





Sequence of segments separated by '|'
Compulsory and optional segments
Segments as sequence of fields
separated by '^'
Compulsory and optional fields
A field is described by a data type (e.g.
AD data-type denoting an Address)
An example of HL7 message for patient
admission
MSH | ^~ \ & | Clinic || Central|Reg ||| ADT^A01
|MSG00005 | P | 2.3
EVN | A01 | 199601051530
PID ||| 2-687005 || Evans^Carolyn || 19620324 | F
||| 903 Diane Circle^^Phoenixville^PA^19460
|| (610) 555 – 1212 | (610) 555 – 1212 || S | C
||156 – 96 – 2542
PV1|| E | Emergency |||| 0148^Addison^James |||
SUR
Admit/Visit Notification
1. Message Header
(i) From: Clinic
(ii) To : Central
2. Event
(i) Date: 1996-01-05
(ii) Time: 15:30
3. Patient Identification
(i) Internal Patient ID Number: 2-687005
(ii) Family Name: Evans
(iii) Given Name: Carolyn
(iv) Birth Date: 1962-03-24
(v) Sex: F
Admit/Visit Notification (Contd.)
3. Patient Identification (contd.)
(vi) Street Address: 903 Diane Circle
(vii) City: Phoenixville
(viii) State of Province: PA
(ix) Zip or Postal Code: 19460
(x) Phone (Home): (610) 555 – 1212
(xi) Phone (Office): (610) 555-1212
(xii) Marital Status: S
(xiii) Religion: C
(xiv) Social Security Number: 156-96-2542
4. Patient Visit
(i) Patient Class: E
(ii) Point of Care: Emergency
(iii) Attending Doctor's ID: 0148
(iv) Family Name: Addison
(v) Given Name: James
(vi) Hospital Service: SUR
File as Reference Pointer (RP) of OBX
MSH|^~\&|TELEMEDICINE||TELEMEDICINE||200808141246||ORU^R01|SUR|P|2.4|
EVN|R01|200808141246|
PID|||SUR05032008000||Mandal^Pulin^Bihari||198003050000|M|||Block - D^VSRC, IIT Kharagpur^Kharagpur^West
Bengal^721302^India|91|754123||||Hindu|
NK1|1|Sumita Mandal|Mother|Parikpur, Hansda West Midnapore|
OBR|4|||ZIITKGP9903^Patient Images^HL7IITKGP|||200808141246|
OBX||RP|ZIITKGP9903-1^Sample blood slide^HL7IITKGP||SUR0503200800005032008BLD00.JPG^TELEMEDIK
2005^IM||||||X|||20080209||||||20080305|
OBX||RP|ZIITKGP9903-2^Routine Blood tests and Grouping {Blood
R/E}^HL7IITKGP||SUR0503200800005032008i0000.JPG^TELEMEDIK 2005^IM||||||X|||20080305||||||20080305|
•Multimedia file is not contained within HL7 message.
•Reference path to the file is kept in the message.
•Multimedia file has to be sent with HL7 message.
File as Encoded Data (ED) of OBX
MSH|^~\&|TELEMEDICINE||TELEMEDICINE||200705091251||ORU^R01|SUR|P|2.4|
EVN|R01|200705091251|
PID|||SUR17012007000||Kijhari^Punam^||196801170000|F|||aaaa^bbbb^eeee^West Bengal^897454^India|91|7855596||||Hindu|
NK1|1|kkkk|hhhh|gdagsv fg jfsgfgjadsg gdsa g fagsg|
OBR|6|||ZIITKGP9903^Patient Images^HL7IITKGP|||200705091251|
TXA|1|IM|multipart|200705091251||20040404||||||ZIITKGP9903-1|ZIITKGP9903||||AU|
OBX||ED|ZIITKGP9903-1^blood slide^HL7IITKGP||^multipart^related^A^MIME-Version: 1.0
Content-Type: multipart/related; boundary="HL7-CDA-border-CDA-HL7"
EXT:=JPG
TYPE:=BLD
ENTRYDATE:=20070117
SIZE:=16601
--HL7-CDA-border-CDA-HL7
Content-Location:SUR1701200700017012007BLD00.JPG
Content-Transfer-Encoding:BASE64
Content-Type:image/pjpeg
/9j/4AAQSkZJRgABAgEASABIAAD/7RBKUGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
DAwRDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAENCwsNDg0QDg4QFA4ODhQUDg4ODhQRDAwM
CgAyADAAMAAgADMANgAzAAoA
--HL7-CDA-border-CDA-HL7--||||||X|||200705091251|
Reference Information Model (RIM)

Root of all information models.

Provides a static view of the information.

A HL7-wide common reference model that integrates all
Technical Committees’ domain views.

Committees and SIGs generally work with a small subset of
the RIM - called Domain Information Model or DIM.
Reference Information Model (RIM)
contd..

Foundation Classes
 Acts  an intentional action in the business domain of
HL7. Ex: patient observation
 Participations  exists only in the scope of one act. Ex:
surgeon
 Roles  a socially expected behavior pattern usually
determined by an individual's status in a particular
society. Ex: doctor
 Entities  physical thing or organization and grouping of
physical things. Ex: a person
 Act Relationship  To relate 2 acts.
 Role Link  To relate 2 entity roles.
LOINC

Logical Observation Identifiers Names and Codes.

Names & codes uniquely identify observations.
 Laboratory Observations
 Clinical Observations
 Administrative Observations

Compatible with HL7 and SNOMED

Represent observation in HL7 message.
LOINC

The fully specified name of a test result or clinical
observation has five or six main parts






<Analyte / component>:
<kind of property of observation or measurement>:
<time aspect>:
<system (sample)>:
<scale>:
<method>
QRS AXIS representation in LOINC:
QRS AXIS : ANGLE : PT : HEART : QN : EKG  2951-2
LOINC in HL7

Message generator generates a message with
observation results using LOINC.

System supports LOINC, parse HL7 message,
retrieve observation result.
OBX-3: Observation Identifier
OBX||TX|2093-3^Total cholesterol^LN|0|78|^mg/dl|||||F|||20050223|
Code
Text
Coding System
DICOM

Digital Imaging and Communications in Medicine

Standard for handling, storing, printing, and transmitting
information on medical imaging.

Specifies the following


protocols for devices claiming conformance to DICOM
syntax and semantics of data to be exchanged.
format for storing media in DICOM compatible devices etc.
DICOM Composite Image
IOD Information Model
Patient
1
is
subject
of
1,n
Study
1
1
1,n
1
creates
Frame of Reference
contains
Equipment
1,n
0,n
series
1
Spatially or
Temporally
defines
contains
0,n
Image
(Pixels)
0,n
Curve
0,n
VOIL
UT
0,1
Modality
LUT
0,n
Overlay
0,n
Waveform
DICOM Waveform IOD Information Model
Patient
1
is subject
of
1,n
Study
1
Equipment
contains
1
1,n
creates
1,n
Frame of Reference
1
0,n
series
1
contains
1,n
Waveform
temporally
defines
DICOM Waveform Information Model
Patient
1
is
subjec
of
Waveform
Attribute
Waveform
1
1,n
Study
1
contains
1,n
Series
contains
1,n
Multiplex
Group
1
Time of Acquisition
Acquisition Context
Annotation
Multiplex Group
Attributes
Number of Channels
Sampling Frequency
Timing
contains
1
Contains
1,n
Waveform
1,n
Channel
1
contains
1,n
Sample
Channel Definition
Attributes
Channel Source
Metric
Anatomic Location(s)
Function
Technique
Channel Sensitivity
Baseline
Skew
Filter Characteristics
DICOM File Structure
Preamble (128 bytes)
DICM (4 bytes)
DE1
DEn
Dicom
Structure
DICOM DataInformation
format
Data Element
Tag
< 4 bytes >
Tag
Data Element
DE
VR
VL
< 2 bytes >
……………
Data Element
VF
Explicit VR
VF
Implicit VR
< 2 bytes >
VL
< 4 bytes >
An Example of Data Element
Patient
Information
Patient
Name
0010 0010
0010 0010
VR
VL
VF
PN
000C
Sridhar Raja
Explicit VR
0000 000C
Sridhar Raja
Implicit VR
Some vital tags for rendering images in DICOM Standard
Tag Description
Transfer Syntax Tag
Samples per pixel
Numbers of Frames
Number of Rows
Number of Columns
Number of Bits Allocated
Number of Bits Stored
Pixel Data
Hex Encoding (Group, Element)
(0x0002, 0x0010)
(0x0028, 0x0002)
(0x0028, 0x0008)
(0x0028, 0x0010)
(0x0028, 0x0011)
(0x0028, 0x0100)
(0x0028, 0x0101)
(0x7FE0, 0x0010)
PACS





Picture Archiving and Communication Systems.
Goals of PACS are to improve operational efficiency
while maintaining or improving diagnostic ability
Computers or networks dedicated to the storage,
retrieval, distribution and presentation of images.
PACS network consists of a central server that stores a
database containing the images. Web based PACS
system is becoming more and more common.
Based on DICOM standard, also accepts other media
formats.
PACS
(Ref: http://www.advantech.com.cn/)
ICD-10

International Statistical Classification of Diseases
and Related Health Problems.

Provides codes to classify





Diseases
Signs, symptoms
Abnormal finding
Complaints
External cause for injury and disease etc.
ICD-10

Every health condition can be assigned to a unique
category and a given code.

Can be used for



Morbidity, mortality statistics
Clinical decision support system.
The limitations of ICD-9-CM


Lack of specificity and details.
Can’t support transition of IHDE etc.
ICD-10 in HL7

Segment for diagnosis: DG1




2nd field of DG1: diagnosis coding method (deprecated).
4th field of DG1: diagnosis description (deprecated).
3rd field of DG1: diagnosis code
ICD-10 is used to construct 3rd field
Identifier
Code
DG1-3: Diagnosis Code
DG1|||H11.2^Conjunctival scars^ICD10|||F|||||||||||||20050223|
Diagnosis
description.
Coding
System
ICD-10-PCS (ICD-10 Procedure Coding System.)
Medical
classification used for procedural codes.
Codes are comprised of seven components. Each
component is called a “character”.
All codes are seven characters long
Individual units for each character are represented
by a letter or number.
Each unit is called a “value”
34 possible values for each character
Digits 0- 9
Letters A-H, J-N, P-Z
SNOMED

Systematized Nomenclature of Medicine.

Collection of medical terminology covering most
areas of clinical information.





Diseases
Findings
Procedures
Microorganisms
Pharmaceuticals etc.
Standardization: Complexity in Medical
World


Vast and dynamic knowledgebase.
Close interaction of different complex systems.
Patient Management, Diagnosis and Investigations,
Treatment and Procedures, Drug and pharmacology, Disease
classification etc.



Process Standardization.
Regional and demographic variations.
Adjustment with real-life constraints.
Infrastructure, Human resource, Material resource.