INFO-I530 (Foundation of Health Informatics)

1. INFO-I530 (Foundation of Health Informatics) Communication Systems in Healthcare Lecture #2

2. Lecture in a Nutshell • Communication System Basics • The Communication Space • Communication System Elements • Basic Contexts of Communication Systems • Sample Systems • Communication Technology • Layered Protocols • Dedicated versus Shared Channels • Wireline Communication Systems • Wireless Communication Systems • Standards for Exchanging Clinical Messages (HL7)

3. Communication System Basics

4. The Communication Space • Need is apparent: Telephone vs mail in emergency • Cause  Mobility - Patient and Healthcare staff (radiology, labs, …) • Communication space is that portion of all the information interactions between people that involves direct interpersonal interactions. • Quantifying the size of the communication space: about 50% of information transactions occurred face-to-face between colleagues. • Communication failures are a large contributor to adverse clinical events and outcomes. In a retrospective review of 14 000 in-hospital deaths, communication errors were found to be the lead cause, twice as frequent as errors due to inadequate clinical skill. • Healthcare system suffers enormous inefficiencies because the communication systems that are in place are often of poor quality. One recent estimate suggested that the US health system could save $30 billion per annum if it improved its telecommunication systems

5. Communication System Elements • A communication system is a set of processes or components assembled to provide support for interpersonal communication. For example, hospitals have paging systems that provide a mechanism for contacting specified individuals. • The number of possible conversations that could take place at anyone time is determined by the number of individuals who may have a need to communicate (n is the total number of individuals, and r is the number of individuals involved in a single conversation): • Given the number of individuals who might be involved in the care of a single patient, even for a single episode, it becomes clear why communication is so complex, and can be so difficult.

6. Communication System Elements cont. The number of possible conversations increases combinatorially with the number of individuals who need to communicate Some of the possible transactions and data flows associated with a discharge summary from a hospital.

7. Communication System Elements cont. • Communication Components: • Communication channel: face-to-face conversation, through to telecommunication channels like the telephone or e-mail, and computational channels like the medical record. • Types of message: data-, task- and template-oriented • Communication policies: A hospital may have many different policies that shape their communication system performance, independent of the specific technologies used. • Agents: Agents have attributes such as their understanding of specific tasks and language. • Communication services: a communication system providing a number of different communication services (e.g. fax uses phone lines) • Communication device: Different devices are suited to handle different situations and tasks. • Interaction mode: determines much of the utility of communication systems (interrupting vs non-interrupting systems).

8. Communication System Elements cont. A communication channel can support many kinds of communication service. Public switched voice circuits support voice transmissions, but through the use of additional components can support many other services like fax, voicemail and e-mail.

9. Basic Contexts of Communication Systems • The benefit of a given communication system is largely determined by the needs individuals have at the time and space they need to communicate. • Same time – same place: face-to-face meeting which is the gold standard (while it is not perfect). • Same time – different place: synchronous communication. Example Telephone bidirectional synchronous channel, while TV is unidirectional synchronous. Interruptive and for urgent matters. • Different time – same place & Different time – different place: asynchronous channels - across computer networks. Example email and text messaging in place work or remotely. Non-interruptive and not urgent.

10. Basic Contexts of Communication Systems cont. Communication needs can be characterized by the separation of participants over time or distance Communication services can be classified according to the media they support, and whether they are asynchronous message based systems, or operate synchronously in real time.

11. Sample Systems • Voice/Mobile Telephony • Real-time interaction allows problem-solving and negotiation to take place. • The combination of mobile telephony and paging systems can reduce the 5-10 minutes out of every hour many clinicians spend answering pagers. • Video Conferencing • Videophone was first launched by AT&T in 1971 but the channel capacity needed to deliver real-time images cannot be supported by the circuits in place in most public telephone networks. • Email • E-mail is typically used to send short textual messages between computer users across a computer network. • Voicemail • Voicemail allows the asynchronous exchange of recorded voice messages. • They are created and operated on computers connected to the telephone system. It’s more complex from s simple answering machine. • Dictation systems, dial tone multi-frequency (DTMF) and voice-recognition systems can be integrated.

12. Communication Technology

13. Layered Protocols • For communication to be effective, both conversing parties obviously need to understand the language spoken by the other. • The set of rules governing how a conversation may proceed is called a communication protocol, and the design of such protocols is central to understanding the operation of communication systems and computer networks. • To simplify the design of communication protocols, they are typically decomposed into a number of different layers, each of which accomplishes a different task. • Protocol layers are organized hierarchically, with the bottom layers carrying out tasks that then can be forwarded up the hierarchy to be processed by higher layers.

14. Layered Protocols cont. • One of the advantages of such decomposition is that individual layers do not need to understand how others actually work, but simply need to know how to interact with a layer (input and output). • Together the layers form a protocol stack, and at the bottom of the stack lies the physical medium.

15. Layered Protocols cont. • The International Organization for Standardization (ISO) has developed the open system interconnection (OSI) model that is used as a template to define 7 protocol layers for communicating between heterogeneous computers.

16. Dedicated versus Shared Channels • Dedicated • Dedicated physical wire for the transmission (local phones). • Systems like these are called circuit-switched, since they make connections by establishing a completed circuit between the communicating parties. • A circuit-switched system is not a very efficient way of transmitting data (bottleneck) • Shared • Allowing a channel to carry packets of data that may come from a number of different sources (packet-switched systems). • Computer networks are packet-based. Dedicated lines connect communicating parties in a circuit-switched system. In contrast, lines can be shared by exchanging data packets from different conversations across a common channel.

17. Dedicated versus Shared Channels cont. • Multiplexing: • One way of multiplexing a number of different conversations is to time the arrival of data and to divide time into a series of repeating 'slots'. Each call is pre-assigned a different time slot on the same circuit. • Another ways is to allocate each a frequency slot rather than a time slot. • Measure of a channel's capacity to carry data is called its bandwidth: Hz (analogue) and bits-per-second (digital) Channels can combine multiple calls by allocating each call a different slot from the frequencies available on the common channel. The concentration is achieved by assigning each circuit a time slot on data packets or frames, which are sent down the line. This concentration of signals is performed by a multiplexer (MUX).

18. Wireline Communication Systems • ISDN (Integrated Service Digital Network) • ISDN, unlike normal telephone circuits, provides direct digital connection between a subscriber and the telephone network  no need for a modem. • ISDN provides two independent data channels to a subscriber: One channel could be used to carry a voice conversation, while data are transmitted across the second. • A third signalling channel allows the user's equipment to communicate with the network, allowing for rapid call set-up and exchange of other information (called id) • B-ISDN or broadband ISDN system: These are able to sustain high-bandwidth transmission, up to several hundred Mbits/s. • This is an example of a synchronous transfer mode. For largely voice-based systems, because there is a fixed demand on capacity for each given channel (only one person is at the end of each line), this synchronous system suffices.

19. Wireline Communication Systems cont. • ATM (Asynchronous Transfer Mode) • ATM allows a communication system to be divided into a number of arbitrarily sized channels, depending on demand and the needs of individual channels. • Confusingly, ATM is an example of an isochronous system because, although packets are sent irregularly, there is a service guarantee that they will arrive within a certain time frame (e.g. IP protocol). • ATM is thus well suited for applications where a steady data stream is more important than accuracy. A good example is video-conferencing where irregular small 'blips' in the data stream are tolerable but long pauses are not. • If the network is busy, packets are delayed until traffic subsides. An isochronous service is thus not as rigid in its timing requirements as a synchronous service, but not as lenient as an asynchronous service. • Computer network the service 'intelligence' is distributed across the computers attached to the network, whereas in a telecommunications system it is centralized within the network.

20. Wireline Communication Systems cont. Wired channels: plain old telephony services (POTS) across public telecommunication networks are the basis for most communication. Integrated services digital network (ISDN) provides a digital connection with twice the bandwidth of POTS. Asynchronous transfer mode (ATM) systems are designed for high bandwidth computer networks. When higher bandwidths are needed private trunks like E1, provide guaranteed connections. (V - voice, D - data, c - control.)

21. Wireline Communication Systems cont. Communication protocols according to the coordination of messages between sending and receiving parties.

22. Wireless Communication Systems • GSM (The Global System for Mobile Communications) • The digital nature of GSM allows it to serve more users than analogue systems. Deployed on 900 MHz and 1.8 GHz (DCS or PCS) with roaming capabilities. • Includes asynchronous packet data channels as well (SMS, Web browsing…) • Like any other cellular system, a GSM network is created by dividing up a geographic area into a number of 'cells'. Thus, the territory over which GSM can be used is limited by the size of the local networks. The GSM mobile digital cellular system provides channels for voice and data connections. The data link allows a mobile computer to connect remotely, via the mobile telephone, to local computer networks. An asynchronous short-message system provides a mobile text-based e-mail service.

23. Wireless Communication Systems cont. • Bluetooth • Bluetooth is designed to allow personal devices to interact using short range wireless communication. For an individual, it means all one's personal devices may connect together to create a personal area network (PAN). • Bluetooth is named after the Danish King Blaatand ('Bluetooth'). • A set of Bluetooth devices sharing a common channel is called a piconet, in which the device at the centre performs the role of master and all other devices operate as slaves. Bluetooth also defines a structure called scatternet, which is formed by interconnecting multiple piconets to allow communication between them. A device that joins two piconets is called a bridge node.

24. Standards for Exchanging Clinical Messages (HL7) • HL7 is an international standard for electronic data exchange in healthcare, and defines the format and content of the messages that pass between medical applications (e.g. EMR/Lab integration). • The HL7 standard covers messages for patient admissions, registration, discharge or transfer, queries, orders, results, clinical observations, billing and master file update information. • By adopting HL7 as the message format for an information system, system developers hope that their system will be able to interoperate more easily with systems developed by others. • HL7 is an abbreviation of ‘Health Level Seven’, indicating that it defines a protocol within OSI layer 7. • There is no single HL7 standard, but an evolving set of standards that are released by the HL7 organization, Health Level Seven, Inc., which was founded in 1987 and is a not-for-profit standards developing organization. • The wide uptake of HL7 Version 2 has made it de facto the international standard for healthcare messaging.

25. Wireless Communication Systems cont. • The HL7 messaging standard defines: • message triggering events, which initiate message exchanges between systems, e.g. the act of admitting a patient on a hospital EMR. • message structures, which define a limited form of message semantics using a restricted terminology of recognized data types, i.e. how different types of data are to be labeled and arranged so that their meaning is understood. • encoding rules, which define message syntax or grammar, i.e. how data structure is to be actually presented, for example the use of different special ASCll characters to delimit the data types defined in the message structure. • In version 2 the HL7 message structure is simple and hierarchical, being built up from segments, fields and composites: • In version 3 the HL7 message structure is based on XML schemas. XML is also used in Clinical Document Architecture (CDA). XMLs derive their semantics from the HL7 Reference Information Model (RIM) and use RIM data types. The RIM is HL7's information model of the health care domain. • Please visit HL7.org for more information.

26. Wireless Communication Systems cont. Sample HL7 XML (version 3)

27. Summary • Communication System Basics • The Communication Space • Communication System Elements • Basic Contexts of Communication Systems • Sample Systems • Communication Technology • Layered Protocols • Dedicated versus Shared Channels • Wireline Communication Systems • Wireless Communication Systems • Standards for Exchanging Clinical Messages (HL7)