Glossary of Telehealth Terms

Glossary of Telehealth Terms

Glossary

of Telehealth Related Terms, Acronyms and Abbreviations

The following Glossary has been developed to encompass items that explain technical, research, and evaluation aspects of telehealth. We hope you find it useful!

A B C D E F G H I J K L M
        N O P Q R S T U V W X Y Z

Both published and unpublished definitions, and some contributed by members of the Telehealth Program, have been included. We wish to acknowledge the following sources from which many entries have been located or adapted (see Useful Links): Government of Canada - Office of Health and the Information Highway (OHIH), Statistics Canada (StatCan), Telemedicine Today, and Telemedicine Glossary, 3rd Edition.

Access Control

Protection against unauthorized access to a computer network. A less restrictive tool than a firewall. Using access controls, a HIN will check its access control list to see if a computer requesting service from the outside world is permitted to use that service. See also Encryption.

ADSL

Asymmetric Digital Subscriber Line. Currently under trial in several metropolitan areas. Uses existing copper phone lines. With proper retooling by phone companies, these can supply 6 Mbps downstream delivery of data.

Age

Age refers to the age of a person at his or her last birthday.

Age by Life Cycle Groupings

Age by life cycle groupings refers to the age of a person within general life cycle groupings, that is, whether he or she is a child, a youth, an adult or a senior. in this context, children are considered to be aged from 0 to 14, youth from 15 to 24, adults from 25 to 64 and seniors 65 and over. See StatCan for a standard classification.

Analog

Information (electronic or otherwise) that is created and transmitted as a continuous stream. Wave forms (e.g., on oscilloscopes) are analog. Compare this to digital information generated by computers. Modems are used to convert digital computer data to analog form for sending over standard POTS lines.

Bandwidth

The capacity of an electronic transmission medium to transmit data per unit of time. The higher the bandwidth, the more data can be transmitted. Typically measured in kilobits per second (Kbps) or megabits per second (Mbps). Standard telephones are low bandwidth devices (maximum bandwidth = 33.6 Kbps). Cable television uses high bandwidth (up to 140 Mbps).

Bit depth

The number of colors or levels of gray scale a scanner or monitor supports. An 8-bit scanner can differentiate between 256 (28) levels of gray. A 12-bit scanner supports 212 = 4,096 levels of gray.

CCITT

Consultative Committee for International Telegraphy and Telephony. The forerunner of the ITU’s Telecommunications Standardization Sector (TSS).

CODEC

COder/DECoder (also COmpression/DECompression) hardware and/or software used with interactive video systems that converts an analog signal to digital, then compresses it so that lower bandwidth telecommunications lines can be used. The signal is decompressed and converted back to analog output by a compatible CODEC at the receiving end. The compression method (algorithm) may be proprietary or (much preferred) standards-based.

Commercialization

The adoption of a commercial approach to the delivery of public services. Commercialization helps to improve services by increasing responsiveness and reducing costs while protecting the public interest. It can also involve cost recovery from users. Commercialization has been used to improve the management of Crown corporations, mixed private-public enterprises, transfers to other levels of government and privatization. For example, the National Airports Policy leased Canada's 26 busiest airports to local, not-for-profit organizations that manage them towards self-sufficiency.

Competitiveness

The ability to sell goods or services profitably relative to other producers of the same goods or services. A number of factors contribute to competitiveness including technological change, a highly skilled labour force, low inflation and a sound public policy environment. As competitiveness improves, costs are reduced and exports expand across international markets.

Confidential

The status accorded to data or information indicating that it is sensitive for some reason, and therefore needs to be protected against theft, disclosure, or improper use, or both, and must be disseminated only to authorized individuals or organizations with a ‘need to know’.

Cost Recovery

The full or partial financing of programs or services through fees or other charges. It is applied primarily to services that confer a private benefit.

DS3

A leased line (non-switched) running at 45 Mbps. Compare OC3, T1, ISDN.

Data

Units of information that can be stored and analyzed.

Data Collection

The systematic assembly of clearly defined pieces of information, often with the goal of studying the relationship between two or more individual information elements. The value of collected data is increased when it can be compared to data collected from other studies, and for this reason use of accepted data definitions and existing classification systems is highly recommended. See StatCan for definitions and standard classification systems for many information or data elements.

e-Health

‘e-Health’ was first introduced as a term that distinguished web-based telehealth activities from the use of videoconferencing. It is now gaining in popularity as an over-arching term for the use of information and communications technology in health care.

Economic Activity

Economic activity is the production of goods and services. Economic activity may produce either marketed or non-marketed goods and services (products). While the non-market activity of households and volunteer work contribute to economic activity and are thus included in the broadest meaning of the concept, the definition used by national accounts to delineate the production boundary excludes these activities.

Economic Growth

An increase in the production of goods and services over a given period. Nominal growth is the increase including changes in prices while real growth is the increase excluding changes in prices. Statisticians and economists have developed a concept called constant dollars so that they can exclude price changes from measures of growth. Constant dollar gross domestic product (GDP) is a measure of growth using the prices of a base year. Changes in constant dollar GDP only capture changes in actual or real production.

Economic Indicator

Statistics that measure changing economic conditions. Changes in the consumer price index provide an indication of the rate of price inflation of consumer goods and services while changes in gross domestic product provide an indication of overall growth in output.

Educational Attainment

Educational attainment refers to the highest level of schooling a person has attained in terms of grades of elementary or secondary school completed and certificates or diplomas obtained. It also refers to post secondary institutions attended and certificates, degrees or diplomas granted. See StatCan for a standard classification.

Education - Highest Degree, Certificate or Diploma

Highest degree, certificate or diploma refers to the highest educational certification attained by a person. See StatCan for a standard classification.

Education - Number of Years of Education Completed

Number of years of education completed refers to the number of academic years a person completed in a formal program provided by elementary and secondary schools, universities, colleges or other formal post-secondary institutions. An academic year would be equivalent to a school year or a grade in elementary and secondary institutions or an eight to nine month course of study in a post-secondary institution (for example, the equivalent of two out of three semesters in a trimester program). Pre-kindergarten enrollment is not included. See StatCan for a standard classification.

e-Health policy

A set of statements, directives, regulations, laws, and judicial interpretations that direct and manage the life cycle of e-health.

Employment

People are considered employed when they work in a paid job, are self-employed or are doing unpaid work in a family business. Those absent from work on a sick leave or due to a strike are also considered as employed.

Encryption

A mathematical transposition of a file or data stream so that it cannot be deciphered at the receiving end without the proper key. Encryption is a security feature that assures that only the parties who are supposed to be participating in a videoconference or data transfer are able to do so. This has not been an essential feature for telemedicine systems, but with the growing concern about patient privacy in telemedicine networks it may become one. See Firewall.

Ethernet

A 10Mbps to 100 Mbps LAN data link protocol.

Extraterritoriality

The application of national laws, policies and practices beyond the national frontier. For example, the United States practices the extraterritorial application of its laws in the area of antitrust and strategic export controls through its influences over the head offices of US-owned multinational enterprises.

FCIF

Full Common Intermediate Format (“Full sif”). A measure of video resolution. Considered by some a requirement of telemedicine video. See QCIF.

Firewall

A computer connected both to the Internet and the local HIN that prevents the passing of Internet traffic, in the form of IP packets, to the internal hospital network. Provides an added layer of protection against “hackers.” There are two kinds of firewalls: external, which protect all hospital systems form the outside world, and internal, which protect only selected systems. Firewall disadvantages: it restricts information transfer in both directions, and makes file transfer (ftp) and telnet (remote login) more difficult. See Access Control, Encryption.

Frequency Response

Measured in cycles/second (Hz); a relative measure of audio quality. Generally the broader the response the better. To approximate a standard acoustic stethoscope, an electronic stethoscope should be able to send and receive sounds as low as 30 Hz (for low-pitched heart murmurs) and as high as 1000 Hz (for squeaks, wheezes and pops heard in lung sounds). Many electronic stethoscopes can have their frequency response optimized for either heart or lung sounds by flipping a switch.

Full Motion Video

Video running at 25 (PAL, SECAM) or 30 (NTSC) frames per second, down to 1015 fps. Any frame rate less than about 10 fps is approaching slow-scan video.

GATT (General Agreement on Tariffs and Trade)

Established in 1947, GATT is a multilateral institution that was created to oversee the global trading system. It set out rights and obligations aimed at promoting world trade. GATT was superseded by the World Trade Organization in January 1995. For more information, visit the World Trade Organization Web site.

GATS (General Agreement on Trade in Services)

A set of multilaterally agreed and legally enforceable rules and disciplines negotiated under the auspices of the World Trade Organization to cover international trade in services. For more information, visit the WTO's Services Trade Web page.

Gender

"Gender" refers to the socially-constructed differences between men and women, as distinct from "sex", which refers to their biological differences. In all societies, men and women play different roles, have different needs, and face different constraints. Gender roles differ from the biological roles of men and women, although they may overlap. These roles can and do shift with social, economic, and technological change.

Geographic Location

Geographic location is identified by a point location indicator (for example, a civic address, a postal code or a place name) whose geometric form refers to a specific point (geographic coordinate or area). The point location indicator allows assignment of other variables to the defined geographic coordinate or area. Geographic areas are commonly administrative or statistical. Administrative areas are defined, with a few exceptions, by federal and provincial statutes, whereas statistical areas are defined by Statistics Canada as part of the spatial frame used to collect and disseminate data. For more detailed information on standardized geographic variables (Canada by Province/Territory , Census Division, Census Subdivision, Census Metropolitan Area, Census Agglomeration, Economic Region; or outside Canada by country) see StatCan .

Ghosting

A motion artifact in monitor displays of compressed video images. As an image moves quickly across the field of view (e.g., an arm waving) it leaves a trail of “ghost” images that resolve as the movement stops. See tiling.

Global e-Health

The sustainable global integration of information and communications technologies into the practice of protecting and promoting health across geo-political, temporal, social, and cultural barriers - including research and education - to facilitate health, public and community health, health systems development, and epidemiology.

Globalization

The integration of international markets as a result of advances in communications and transportation, the liberalization of trade, and the emergence of new competitors in the developing world.

Graphic Equalizer

Allows user to accentuate or de-emphasize selected frequencies within an audio sample. An example is the different “tuning” for heart and lung sounds in electronic stethoscopes. See frequency response.

Gray Scale

The levels (shades) of gray that a screen or pixel within a screen can display. See bit depth.

Group of Seven (G-7)

The G-7 consists of the world's seven largest industrial market economies: the United States, Japan, Germany, France, Britain, Italy and Canada. The leaders of these countries meet annually to discuss political and economic issues of mutual concern. In addition, G-7 finance ministers meet several times a year to discuss economic policy. Their work is supported by regular, functional meetings of officials, including the G-7 Finance Deputies.

HDTV

High Density TeleVision. High resolution broadcast video. See MPEG-2. Vertical resolution about 4 times that of a standard television (1,125 lines compared to 352 lines in a standard NTSC television output) and an aspect ratio of 16:9, similar to a movie screen.

HIN

Hospital Information Network

HL7

Health Level 7. A standard interface between hospital information systems. The HL7 standard defines the format for interchange of text files between health care databases.

Health Problems - Self-reported

Health problems, self-reported refers to whether or not a person has reported that a health professional has diagnosed him or her with a long-term or chronic medical condition. Long-term or chronic conditions are those which have lasted, or are expected to last, six months or more. See StatCan for a standard classification.

Health Satisfaction - Self-assessed

Health satisfaction, self-assessed refers to the perception of a person of his or her satisfaction with his or her health status or condition. See StatCan for a standard classification.

Health Status - Self-assessed

Health status, self-assessed refers to the perception of a person of his or her health status or condition compared to other persons in his or her age group. See StatCan for a standard classification.

IATV

InterActive TeleVideo (=ITV)

IMUX

Inverse multiplexer. Re-aggregates split sub channels in a data stream into a single channel. See ISDN.

INMARSAT

An international global telecommunications satellite network established by government treaty in 1979, with 79 member countries. Land Earth Stations (fixed or portable, even to suitcase-sized) provide links between rural sites and telecom networks. Can provide low-bandwidth digital services anywhere on the earth’s surface for as little as $1/minute.

Information

Meaningful and useful facts extracted from data.

Information and Communications Technology (ICT)

The application of modern electronic and computing capabilities (technology) to the creation and storage of meaningful and useful facts or data (information), and to its transmission to users by various electronic means (communication). The ultimate goal is for ICT to transform data into information, and information into knowledge.

Information Economy

A knowledge-based economy dominated by knowledge-based industries such as computers, pharmaceuticals and consulting services.

International Monetary Fund (IMF)

An agency of the United Nations established in 1944 along with the World Bank to promote post-war economic recovery, development and trade principally by helping to ensure a stable system of international exchange. The IMF has evolved since its inception, but remains focused on overseeing the international monetary system, which includes promoting balance of payments stability (e.g. helping to resolve debt problems) and encouraging member governments to implement appropriate macroeconomic and structural policies. For more information visit the International Monetary Fund and the World Bank web sites.

Internet

A loose aggregation of thousands of computer networks forming an enormous worldwide WAN (although some would not use the term WAN for this generally low-bandwidth system).

Intranet

A “private Internet” that employs TCP/IP communications protocols used over the Internet. The intranet may be linked to the public Internet through a tightly managed, controlled gateway.

ISDN

Integrated Services Digital Network, a low-to-medium speed technology for digital telephony. Usually transmits at 64-128Kbps, although higher speeds are possible. ISDN is broken into 64 Kbps bearer channels (B-channels) and 16 Kbps data channels (D-channels). Basic Rate Interface (BRI) generally provides a 128 Kbps data rate (“2B+D”), while Primary Rate Interface (PRI) can provide up to 1.54 Mbps (the equivalent of a T1 circuit). To combine channels to provide a virtual circuit at greater than the basic 64 Kbps an inverse multiplexer may be needed.

ISO

International Organization for Standardization is an international organization composed of national standards bodies from more than 75 countries. ISO has defined a number of important computer standards, the most significant of which is perhaps OSI (Open Systems Interconnection), a standardized architecture for designing networks. Note that ISO is not an acronym; the name derives from the Greek word iso, which means equal.

ISP

Internet Service Provider. The local, regional, or national (AOL, CompuServe, etc.) company that provides dial-up connections to the Internet, as well as hosting of home pages

ITU-T Standards

International Telecommunications Union (the T is for TSS). Founded in 1865 as a telegraphy standards body. Now a United Nations agency. H series (videoconferencing): H.320 defines how the whole H series works together & contains instructions for ISDN and some G (audio) algorithms as well; H.323 are LAN standards; H.324 permits video, voice, and data over a single analog phone line; H.261 is a video compression protocol for dissimilar CODECs; H.230 for multipoint control; H.263 is a video coding interface subset of H.324 and supports html; H.723 is a dual speech coder that transmits at 6.4 and 5.3 Kbps; H.242 is an audio conference setup and termination protocol. T.120 series: image capture, annotation and transfer in videoconferences. G series (G.721, G.722, G.728): audio conferencing. See CCITT, TSS.

JPEG

Joint Photographic Experts Group. This international group, a joint effort of the ISO and TSS, has developed standards for still image compression. Motion JPEG applies JPEG compression to each frame of a video clip.

LAN

Local Area Network. A computer network linking computers, printers, servers, and other equipment within an enterprise. Can support audio, video, and data exchange. Typically runs at 10-100 Mbps.

LAN Connectivity

The ability to connect the video system to a LAN within the health care facility. This can allow access to and sharing of patient records, test reports, demographics, etc. during a videoconference. Currently few institutions are capitalizing on this potential.

LATA

Local Access and Transport Areas. The areas within which the RBOC and LEC can provide telephony services. Inter-LATA connections are provided by IECs.

Lavaliere

A small microphone that is typically clipped to clothing at breast pocket level. May be wired or wireless. Coined from the Duchesse de La Vallière (1644-1710), a mistress of Louis XIV, who wore a jeweled pendant on a chain around her neck.

MCU

Multipoint Control (or Conferencing) Unit = Bridge. A device that enables participants at more than two sites to participate in voice or video calls.

Marital Status

The concept of marital status applies to the conjugal arrangements of a person. It includes persons who are living together as husband and wife, regardless of whether they are legally married or in a common-law relationship. The statement living together implies that both persons in the relationship live in the same household. In the majority of cases this is true, but also included are couples who are temporarily separated for work-related reasons or couples temporarily separated because one is institutionalized for a short term. Persons living in a conjugal relationship are identified as spouses. Spouses may be legally married spouses or common-law partners. Three types of marital status are identified and defined: legal marital status, common-law status, and conjugal status. Definitions also apply to specific ‘living arrangements’ and for gay and lesbian unions. See StatCan for standard classifications.

Mini-PACS

An image management system that focuses one or more of the digital modalities, such as an ultrasound mini-PACS, or one application areas such as neuroradiology.

Modem

Modulator/Demodulator. Enables transmission of digital data (by transforming it to and from analog waveforms) over standard analog phone lines and cable video systems.

Monetary Policy

The process of managing the supply of money and credit to contribute to economic performance. The Bank of Canada manages Canadian monetary policy mainly through its influence on short-term interest rates, though it is ultimately answerable to the federal government for its actions. The Bank influences short-term interest rates by adjusting its own bank rate. A rise in the bank rate is an act of "tightening" the supply of money and credit, at once restraining elements in the economy which contribute to inflation and elements which contribute to economic performance. The reverse is also true. The bank rate and the money supply influence interest rates and the exchange rate of the Canadian dollar and determine the monetary conditions in which the Canadian economy operates. For more information on the monetary policy, visit the Bank of Canada Monetary Policy Web page.

Most favoured nation (MFN) treatment

Article I of the General Agreement on Tariffs and Trade 1994 (GATT 1994) requiring countries not to discriminate between goods on the basis of country of origin or destination. The MFN principle has provided the foundation of the world trading system since the end of World War II. Article XXIV of the GATT excludes regional trade agreements from the application of this rule.

MPEG

Moving Picture Experts Group. A group of standards for compression and storage of motion video. MPEG-1 provides images of 240 lines x 360 pixels/line, digital transfer rates up to 1.5 Mbps, and compression ratios of about 100:1. MPEG-2 provides a higher quality picture - 720 horizontal lines x 480 vertical lines (pixels/line). The MPEG-2 standard is used for HDTV, and will be used for cable broadcasts.

Multiplexer

“MUX.” A hardware device that divides a digital transmission stream into two or more sub channels. This can be done by frequency division (splitting the single band into multiple narrower bands) or by time division (allotting a common channel to several different transmitting devices one at a time). Compare IMUX.

NTSC

National Television Systems Committee. This body adopted a video-signaling standard for black and white television in 1953 (EIA RS-170 specification). The NTSC standard defines all of the parameters that allow television sets in N. America to receive broadcast signals. NTSC has a display rate of 30 frames per sec (fps) in interlaced fashion: odd lines in one pass, even lines in the next. The vertical resolution is determined by the number of rasters (scan lines). It actually consists of 525 scan lines, but due to “vertical blanking intervals” many of these drop out, resulting in 484 lines. In actual practice this is usually reduced to 352 lines. Thus, many systems advertise “352 x 288 lines of resolution.” Horizontal resolution is determined by how small the scanning point is in the camera and the number of vertical lines that can alternate between white and black in an area as wide as the overall image is tall. (see PAL, SECAM, Video format)

OC3

A high-speed digital transmission capability of 155 Mbps. Compare DS3, T1, ISDN.

OHIH

The Office of Health and the Information Highway (OHIH) is the body that, on behalf of Health Canada, coordinates, facilitates and manages health infostructure-related matters. OHIH facilitates the development of policy in the areas of electronic health records, protection of personal health information, telehealth and facilitates the sharing of information about ICTs in health. In addition, OHIH acts as Secretariat to the Advisory Committee on Health Infostructure and works in cooperation with key partners, including provincial and territorial governments.

Occupation

An occupation refers to the kind of paid work performed. The kind of work is described in terms of tasks, duties and responsibilities, often including factors such as materials processed or used, the industrial processes used, the equipment used, and the products or services provided. Occupations are generally homogeneous with respect to skill type and/or skill level. Occupational classification is designed for the classification of data relating to jobs, however, the classification can also be used to classify persons. They may be categorized by the occupation of the job that they currently perform or of a job that they have previously performed. Occupations are organized in hierarchical classifications, whose classes are mutually exclusive and exhaustive of the universe of paid work. See Standard Occupational Classification (SOC 1991) – StatCan Catalogue No. 12-585E/F.

PACS

Picture Archiving and Communication System, an image system that embraces all modalities (X-ray, CT, MR, nuclear medicine, ultrasound) and links users with display workstations over a high-speed network to an image server, an archive, printers, and radiology information systems (RISs).

PAL

Phase Alternation Line. A European alternative to NTSC composite video signaling used in N. America, adopted in 1967. Provides greater bandwidth for chrominance, yielding better color resolution. Also, the number of scan lines is increased to 625 over NTSC’s 525 (or less on the monitor). However, the frame rate is reduced to 25 fps from NTSC’s 30. See SECAM, video format.

Peripheral Devices

Attachments to telehealth systems that augment their communications or medical capabilities. Examples include: electronic stethoscopes, blood pressure monitors, oxygen saturation monitors, oto-/ophthalmo-scopes, dermascopes, graphic stands, and scanners.

PIP (Picture-In-Picture)

PIP allows both ends of the videoconference to be viewed simultaneously on a single monitor. Picture in picture swap allows the two video pictures to change positions so that the local video fills the largest portion of the screen. On some two monitor systems, PIP allows both live video images to be seen simultaneously on one screen while higher resolution graphic images are seen on the other.

Pixel

The smallest unit of a raster display. A picture cell with specific color and/or brightness. The more pixels an image has, the more detail, or resolution, it can display. The pixel size in a high-end computer monitor's screen (a “1K x 1K monitor”) is approximately 0.28 x 0.28 mm. The pixel size for diagnostic teleradiology monitors (“2K x 2K”) is much smaller than this.

POTS

Plain Old Telephone System. The analog, public switched telephone network in common use throughout the world. Also known as Public Switched Telephone Network (PSTN). Enables voice phone calls and data transmission of up to 33.6 Kbps, as well as limited videoconferencing.

Privacy

The right of individuals to be left alone and to be protected against physical or psychological invasion or the misuse of their property. It includes freedom from intrusion or observation into one’s private affairs, the right to maintain control over certain personal information, and the freedom to act without outside influence.

Px64

“P time 64.” Synonymous with the ITU H.261 standard.

QCIF

Quarter Common Intermediate Format (“Q-sif”). A measure of video resolution, displaying 176 pixels by 144 lines. Has half of the CIF spatial resolution of FCIF. This is the “default” minimum H.261 format. Typically used in desktop videoconferencing.

Real Time

Sends and receives audio / video / data simultaneously, without more than a fraction of a second delay. Applications that are transmitted within a few seconds are sometimes called near real time. Compare store-and-forward, slow-scan.

Resolution

The level of detail that can be captured or displayed. For video displays (teleradiology or interactive video) resolution is measured in pixels x lines x bit depth.

RGB

Red Green Blue. A coding language that controls the electron gun in CRT (Cathode Ray Tube) monitors. The video signal that comes into the monitor is separated into its component parts and converted to RGB; the video images are then rendered on the monitor’s screen.

RIS

Radiology Information System. A specialized system that supports radiology charge capture and billing, storage of patient data, scheduling, and reporting. May be a part of a larger Hospital Information System (HIS).

RJ-11 Jack

The connector jack used for standard telephone and FAX lines.

Router

A device which routes data to the segment of the network it was meant to go to, rather than be broadcast to all segments.

SECAM

Sequential Couleur Avec Memoire. A color television signaling standard with 625 scan lines and 25 interlaced frames/second. Used in France, the Newly Independent States (NIS) of the former Soviet Union, and parts of the Middle East. See PAL, NTSC.

Security

Security is the process that protects both the system and the information contained within the system from unauthorized access from without, and from misuse from within. Security thereby protects the privacy of the individuals who are the subjects of the stored information.

Security - Data Security

The result of effective data protection measures. Data security exists when data are protected from accidental or intentional disclosure to unauthorized persons and from unauthorized or accidental alteration.

Security - System Security

The totality of safeguards including hardware, software, personnel policies, information practice policies, disaster preparedness, and oversight of these components.

Sex

Sex refers the biological sex of a person. Some use the terms male and female while others use what is considered the more polite or politically correct men and women. It is recommended to use the former, primarily because the terms men and women imply that only the adult population is included.
[NOTE: ‘Gender’ is now the term preferred to ‘sex’. The above has been provided as it remains a parameter in common use, and defined by Statistics Canada].

Simultaneous playing of pre-recorded tape and recording of conference

Concerns the ability to have one VCR playing a pre-recorded tape into the system as a video source, while simultaneously having another VCR connected and recording the videoconference in progress. This is necessary for those telemedicine programs that maintain a policy of recording all consults and which periodically use pre-recorded tapes of patient procedures or educational tapes as part of a videoconference.

Slow-scan

“Still video.” A slow progression of freeze-frames (less than 1 or 2 per second). Compare full motion video.

Spooling

As one image or data set is being reviewed, additional images can be received and stored for sequential review without “locking up” the computer.

Store-and-forward

Captured audio clips, video clips, still images, or data that are transmitted or received at a later time (sometimes no more than a minute). E-mail is a store-and-forward system. Enables dissynchronous communication, with the advantage of not needing concurrent participant involvement. Compare to real time.

Strategic Alliance

Alliance between companies or other organizations, primarily for the purpose of achieving cost efficiencies, and to allow them to become more competitive in the face of rapid changes and pressures in the market.

Sustainable Development

Long-term sustainable economic growth based on environmentally sound policies and practices. Environmental degradation at the local, national and international level undermines prospects for continued economic development. Ultimately, sustainable development means meeting the needs of the present without compromising our ability to meet the needs of future generations. Sustainable development requires that public policy account for economic, environmental and social objectives at the earliest possible stages of policy development.

S-Video

Similar to component video, but closer to the RGB signaling required by monitors.

Switched 56

A dial-up 56 Kbps digital line, billed at a monthly rate + cost/minute, as with a regular POTS phone line.

T.120

A standard for audio and graphics exchange, supporting higher resolutions and pointing and annotation (which the H.320 standard does not).

T1

A leased T1 line, marketed and serviced by LECs, that provides 1.544 Mbps data rate (in North America; the European T1 provides 2.048 Mbps). T1 is available almost everywhere, and can be fractionated. Fractional T1 services are less expensive than full T1. Typical interactive video-mediated telemedicine programs transmit video images at “1/4 T1” rates (384 Kbps).

TCP/IP

Transmission Control Protocol / Internet Protocol. The most popular open-standard protocols used in data networks today. The Internet Protocol is used to route packets of data on a network.

TELCO

Telephone Company

Telehealth

Telehealth is the use of information and communication technology (ICT) to deliver health services, expertise and information over distance. It includes Internet or web-based “e-health” and video-based applications, and can be delivered “real-time” or through “store-and-forward” mode. Telehealth is unique in having the capability to cross-geographical, temporal, political, social and cultural barriers within the health sector.

Telemedicine

Telemedicine is often used interchangeably with telehealth, however, the term telemedicine generally implies a physician mediated interaction with patients, and is used more in the USA.

Teleradiology

A system that transmits images over a distance, using leased or switched transmission lines. See PACS and RIS.

Tiling

An artifact of digitization and compression. Portions of the on-screen video image break into smudged squares. Tends to happen when there is too much on-screen motion, overwhelming the ability of the compression algorithm adequately to apportion system resources to both motion handling and resolution. See Ghosting.

TSS

Telecommunications Standardization Sector of the ITU (International Telecommunications Union).

Twisted pair

A pair of copper wires that have been twisted to minimize electronic interference. Standard phone wire.

Universal C-Mount

Enables a video camera to be attached to any medical peripheral device that uses the same connector. These are increasingly common.

Unsharp Mask

Despite the name, this is an edge-enhancing filter frequently used in teleradiology. It is created by first generating a low-pass filtered image, which is then subtracted from the original image. This effectively removes part of the background, leaving an image where contours are emphasized.

URL

Universal Resource Locator. The World Wide Web address (typically in the form: http://www.name-of-site) of an Internet home page or other document.

Video format

NTSC, PAL, HDTV, SECAM

Video on Demand

The ability to provide instantaneous access to remotely stored sources of video. A video server stores and manages large amounts of multimedia data and delivers it on demand to one, or many, users. Limitations to deployment are bandwidth availability, video server price, and video compression protocols.

Video Output

Composite, S-video.

WAN

Wide Area Network. Wider in geographic scope than a LAN. Provides digital communications (voice / video / data) over switched (ISDN, switched 56) or unswitched (fractional T1, T1) networks. Some consider commercial dial-up networks (America OnLine, the Internet) to be WANs.

Wavelets

An image compression technique that enables more or less lossless compression ratios of 10:1 or even 20:1, compared to the standard 3:1 maximum for lossless JPEG compression.

Whiteboard

Shared notebook. The shared whiteboard feature provides the electronic equivalent of an onscreen blackboard. This feature’s greatest utility is when a video call is established but the audio portion is not functioning. One can then write a note on the white board for one end to make a phone call to the other to discuss the problem. May have modest utility.

Windowing

A software manipulation technique, using mathematical algorithms, to compensate for a teleradiology monitor’s inability to provide the same contrast and bit depth as the original hardcopy X-ray. Pixels within a certain range of bit-depth values are assigned the full range of possible grayscale values, while those outside that range are either white or black. This allows emphasis of contrast for those structures that lie within the grayscale “window.”

World Bank

An agency of the United Nations established at the end of the Second World War to promote post-war economic recovery, development and trade, principally by providing development finance. The Bank promotes economic development and growth in developing countries by providing investment resources (e.g. capital and expertise) in support of development projects and microeconomic policy reforms that contribute to growth. For more information, visit the World Bank web site.

World Trade Organization (WTO)

Established on January 1, 1995 to replace the Secretariat of the General Agreement on Tariffs and Trade, the WTO is the cornerstone of the world trading system. It provides the principal contractual obligation determining how governments frame and implement trade legislation and regulations. It is also the multilateral platform on which trade relations among countries evolve through collective debate, negotiation and adjudication. For more information, visit the World Trade Organization web site.





Last updated: February 26, 2008

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