Dr. Mark Gaynor, Dr. Feliciano Yu, Bryan Duepner

 Layered standards to exchange data  The entire ISO/Internet stack Defines how to exchange data between applications on computers on different networks  Simple web standards HTTP to transfer web pages  XML to encode just about everything including EHRs

 Needed to exchange EHRs within and between organizations  ISO Open Standards Interconnection (OSI) Seven Layers Conceptual model, not a set of actual specifications OSI as a set of standards is dead, and has been dead for 20 years

 Standards to exchange Health information are above the transport layer  Internet Model—Often referred to as Transmission Control Protocol/Internet Protocol (TCP/IP) stack However the stack consists of many protocols at different layers Layered model Group of protocols at each layer Domain Specific Standards (i.e. Health Care)

IP Internet Layer UDP/TCP HTTP(web), FTP(file), SMTP(mail) … Ethernet/ATM… Fiber(light), wire(electricity), air(waves) Transport Layer Link Layer Physical Layer Application Layer Information about application (get web page, get file, get ) Get data from application-to-application (web server to web browser) Get from one computer on the Internet to another computer on the Internet Most important layer Only required layer From one computer to another computer on a local network Get bits across a wire, light beam, or wave Health care messaging standard standards – HL7 Clinical Vocabulary and coding standards – ICD-10, SNOMED, LOINC Define set and content of messages to exchange medical information Define the terms used to describe medical events

 Some low level protocols Ethernet—Local Area Networks (Interface layer on TCP/IP protocol stack) Asynchronous Transfer Mode (ATM)—fast transmission speeds Bluetooth—wireless devices IEEE (Wi-Fi)—popular for wireless computers IEEE (Zigbee) – small wireless sensors

 Standards Govern the Exchange of Messages  Messages must be governed by strict rules  Because computers can only follow rules Message

Web page Give me a web page Client PC Webserver BrowserWebserver Application HTTP Response is web page HTTP request for web page

 HTTP Request Message GET / HTTP/1.1[CRLF] GET is the method that requests a web page is the web site with the web pagewww.cnn.com mapofus is the web page to get Version of HTTP is 1.1

 HTTP Response Message HTTP/ OK[CRLF] [CRLF] Web page Version 1.1 of HTTP Request was statisfied (OK code) Web page is in HTML format that tells broswer how to display the page

 HTTP is used to exchange healthcare information between a web server and person  HTTP is also used to exchange healthcare information between two computers via web services (The API for MS health vault)  HTTP and HL7 are messaging protocols with similar functions

 HTML is used to format web pages text => text Can be used to display pictures and links on web pages  Inflexible  Focus on formatting not content  Presentation of information not contextual definition of data

 XML (eXtensible Markup Language)  XML is a standard for designing data formats and structured documents such as EHRs. CDA/CCD is XML based  XML is defined by The World Wide Web Consortium (W3C).

 XML makes it easy for a computer to: Read data Generate data Ensure that the data is defined unambiguously  XML allows you to define your own tags and attributes (looks like HTML) tags ( ) attributes is some type of data Name value pair: (name="value")  CDA example codeSystemname = “SNOMED CT” defines SNOMED as the medical terminology used

 HL7v3 is XML based  Standards for EHRs such as CCR, CCD, CCA are XML based  Google and MS healthvault are XML based  Example of a body temp 99.9F encoded in XML using SNOMED CT coding at 10:40:33 on 05/01/2008 ,/code>   (year,mo,day,h,m,s)   …….

 Layered standards are used to exchange information between computers across a network  The Internet set of standards get data from one application (i.e. web browser) to another application (i.e. web server)  Higher layer standards are used to exchange domain specific information HTTP for general web HL7 for healthcare