Telemedicine Glossary


Accountable Care Organization (ACO): A healthcare organization characterized by a payment and care delivery model that seeks to tie provider reimbursements to quality metrics and reductions in the total cost of care for an assigned population of patients. (Wikipedia)

Analog: A continuous signal where the time varying variable is represented by another time varying quantity. It differs from a digital signal where a continuous quantity is represented by a discrete function that only takes on one of a finite number of values. 

Application Service Provider (ASP): An ASP hosts a variety of applications on a central server. For a fee, customers can access the applications over secure Internet connections or a private network. This means that they do not need to purchase, install or maintain the software themselves; instead they rent the applications they need from the ASP.  New releases, such as software upgrades, are generally included in the price.

Asynchronous:  Term  describing store and forward transmission of medical images and/or data because the  data transfer takes place over a period of time, and typically in separate time frames. The transmission typically does not take place simultaneously. This is the opposite of synchronous (see below).

Asynchronous Transfer Mode (ATM): A telecommunications standard to support voice, video and data communications. The mode uses asynchronous time-division multiplexing and encodes data into small, fixed-sized cells rather than packets or frames.

Authentication: A method of verifying the identity of a person sending or receiving information using passwords, keys and other automated identifiers. 


Bandwidth: A measure of the information carrying capacity of a communications channel; a practical limit to the size, cost, and capability of a telemedicine service.

Basic Rate Interface: An ISDN (see below) configuration that provides two bearer (B) channels at 64 kilobits/second (kbit/s) each and one data (D) channel at 16 kbit/s. B channels are for voice data and D channels for any combination of data, control/signaling, and X.25 packet networking. B channels can be aggregated to provide128 kbit/s.

Bits Per Second (bps): Number of electronic data bits conveyed or processed per unit of time.

Bluetooth Wireless: An industrial specification for wireless personal area networks (PANs) that provides the means to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras and video game consoles over a secure, globally unlicensed short-range radio frequency. The specifications are developed and licensed by the Bluetooth Special Interest Group (

Bridge: Device for linking multiple videoconferencing sites in a single videoconference session.
It is also often referred to as a multipoint control unit (MCU).

Broadband: Communications (e.g., broadcast television, microwave, and satellite) capable of carrying a wide range of frequencies; refers to transmission of signals in a frequency-modulated fashion over a segment of the total bandwidth available, thereby permitting simultaneous transmission of several messages.


Cascading: Means to accommodate more videoconference participants than using one MCU by joining another MCU into a session hosted by the primary MCU. 

Certification Commission for Health Information Technology (CCHIT): Founded in 2004 with the public mission of accelerating the adoption of health IT, it certifies electronic health records (EHRs) using comprehensive, practical definitions of what capabilities were needed in these systems. (

Centers for Medicare & Medicaid Services (CMS): A federal agency within the United States Department of Health and Human Services (DHHS) that administers the Medicare program and works in partnership with state governments to administer Medicaid, the State Children's Health Insurance Program (SCHIP), and Health Insurance Portability and Accountability Act (HIPAA) standards. (Wikipedia)

Channel Service Unit/Data Service Unit (CSU/DSU): A digital-interface device for connecting Data Terminal Equipment devices (DTE) (e.g., router) to a digital circuit (e.g., T1 line). CSU connects to the network and the DSU handles the DTE interface.

Circuit Switched Network: A method for implementing a telecommunications network where two nodes have a dedicated communications channel through the network for communication, guaranteeing full bandwidth for the session. 

Class of Service (CoS): Used in data and voice protocols to differentiate payloads in the transmitted packets to help assign priorities to the data payload.

Clinical Decision Support System (CCDS): Systems (usually electronically based and interactive) that provide clinicians, staff, patients, and other individuals with knowledge and person-specific information, intelligently filtered and presented at appropriate times, to enhance health and health care. (

Clinical Information System: Hospital-based information system designed to collect and organize data relating exclusively to information regarding the care of a patient rather than administrative data. .

Cloud computing: The use of computing resources (hardware and software) that are delivered as a service over a network (typically the Internet). The name comes from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams. Cloud computing entrusts remote services with a user's data, software and computation. (Wikipedia)

CODEC: Acronym for coder-decoder. This is the videoconferencing device that converts analog video and audio signals to digital video and audio code and vice versa. CODECs typically compress the digital code to conserve bandwidth on a telecommunications path.

Compressed video: Video images that have been encoded using fewer bits of information than the original dataset (either lossless or lossy) to reduce the amount of bandwidth needed to capture the necessary information so that the information can be sent over a network. 

Computer-based Patient Record (CPR): An electronic form of individual patient information designed to provide access to complete and accurate patient data.


Data Compression: A method to reduce the volume of data using encoding that results in the data having fewer bits of information than the original dataset (either lossless or lossy) to reduce image processing, transmission times, bandwidth requirements, and storage requirements. Some compression techniques result in the loss of some information while others do not, which may or may not be clinically important.

Diagnostic Equipment (Scopes, Cameras and Other Peripheral Devices): A piece of hardware or device not part of the central computer (e.g., digitizers, stethoscope, or camera) that can provide medical data input to or accept output from the computer.

Digital: Data technology using discrete values as opposed to continuous or analog signals.

Digital Camera (still images): A camera that stores images digitally rather than recording them on film allowing data to be downloaded to a computer system, manipulated with a graphics program and printed or transmitted electronically. It is typically used to take still images of a patient for dermatology, ophthalmology, and wound care.

Digital Imaging and Communication in Medicine (DICOM): The international standard for medical images and related information (ISO 12052).  DICOM consists of a set of protocols describing how images are identified, formatted, transmitted and displayed that is vendor-independent. It was developed by the American College of Radiology and the National Electronic Manufacturers Association (

Digital Signal-X Transmission Standards (DSx): A series of standard digital transmission rates or levels based on DS0, a transmission rate of 64 Kbps (i.e., bandwidth normally used for one telephone voice channel). 

Digital Signature: Mathematical scheme for authenticating digital messages or documents. Valid signatures give the recipient evidence that the message was created by a known sender and not altered in transit.

Digital Subscriber Line (DSL): Technologies providing internet access by transmitting digital data over local telephone networks. The data bit rate typically is 256 kbit/s to 40 Mbit/s in the direction to the customer (downstream) depending on technology, line conditions, and service-level implementation.
Disease Management: A continuous coordinated health care process that seeks to manage and improve the health status of a carefully defined patient population over the entire course of a disease (e.g., Congestive Heart Failure, Diabetes Mellitus) The patient populations targeted are high-risk, high-cost patients with chronic conditions that depend on appropriate care for proper maintenance.

Distance Learning: The incorporation of video and audio technologies, allowing students to "attend" classes and training sessions that are being presented at a remote location. Distance learning systems are usually interactive and are a tool in the delivery of training and education to widely dispersed students, or in instances in which the instructor cannot travel to the student's site.

Distant Site: Site at which the physician or other licensed practitioner delivering the service is located at the time the service is provided via telecommunications system.  ( Other common names for this term include hub site, specialty site, provider/physician site and referral site. The site may also be referred to as the consulting site.

Document Camera: Visual presenters, visualizers, digital overheads, or docucams, are real-time image capture devices for displaying an object to a large audience. Like an opaque projector it is able to magnify and project images of three-dimensional objects as well as transparencies. It can display written or typed information (e.g., lab results), photographs, graphics (e.g., ECG strips) and in some cases x-rays.


e-Pharmacy: The use of electronic information and communication technology to provide and support comprehensive pharmacy services when distance separates the participants.

eHealth: Healthcare practice supported by electronic processes and communication.

Electronic Data Interchange (EDI): The sending and receiving of data directly between trading partners without paper or human intervention.

Electronic Health Record (EHR): A systematic collection of electronic health information about individual patients or populations that is recorded in digital format and capable of being shared across health care settings via network-connected enterprise-wide information systems and other information networks or exchanges. EHRs generally include patient demographics, medical history, medication, allergies, immunization status, laboratory test results, radiology and other medical images, vital signs, characteristics such as age and weight, and billing information.

Electronic Medical Record (EMR): A computerized medical record generated in an organization that delivers health care, such as a hospital or physician's office. EMRs are often part of a local stand-alone health information system that allow storage, retrieval and modification of records.

Electronic Patient Record (EPR): An electronic form of individual patient information that is designed to provide access to complete and accurate patient data, alerts, reminders, clinical decision support systems, links to medical knowledge, and other aids.

Encryption: A system of encoding electronic data where the information can only be retrieved and decoded by the person or computer system authorized to access it.

e-Prescribing: The electronic generation, transmission and filling of a medical prescription, as opposed to traditional paper and faxed prescriptions. E-prescribing allows for qualified healthcare personnel to transmit a new prescription or renewal authorization to a community or mail-order pharmacy. 


Firewall: Computer hardware and software that block unauthorized communications between an institution's computer network and external networks.

Fractional T1/T3: A digital phone line leased at a fraction of its data-carrying capacity and thus lower cost. 

Frame Rate: Frequency (rate) at which imaging devices produces individual consecutive images or frames. It is most often expressed in frames per second (FPS) or with progressive scan monitors as hertz (Hz).

Full Common Intermediate Format (FCIF or CIF): Format first proposed in the H.261 standard used to standardize horizontal and vertical resolutions in pixels of YCbCr (color) sequences in video signals and.

Full-motion Video:  A standard video signal that allows video to be shown at the distant end in smooth, uninterrupted images.


Guideline: A statement of policy or procedures to determine a course of action, or give guidance for setting standards (

G.711: ITU (International Telecommunication Union) standard for compression of 8-bit audio in the voice range used in standard telephony and low-end videoconferencing connections.

G.722: ITU standard for wideband speech encoding for high-quality audio in videoconferencing systems.

G.723: ITU standard for dual-rate voice compression in videoconferencing.

Gatekeeper: Device for managing videoconferencing traffic typically in an IP-based (H.323) network that eliminates bottlenecks and simplifies addressing of videoconferencing endpoints.

Gateway: Device providing protocol translation between H.320 (ISDN) and H.323 (IP)
networking environments that allows endpoints using ISDN to interconnect with those over IP.

Graphics Interchange Format (GIF): Bitmap image format supporting up to 8 bits per pixel and allowing a single image to reference a palette of up to 256 colors.


H.239: ITU standard for multiple video streams within a single videoconference. Endpoints that support H.239 receive the streams and display them in separate windows and those that do not
display the graphics in a single window.

H.261: ITU standard for video compression over ISDN connections. It was the first digital video compression standard and the newer MPEG, H.263, and H.264 standards are based on H.26.

H.263: ITU standard specifying video coding at low bit rates. Originally designed for H.324 (POTS) systems, but is useful in ISDN, IP, etc. 

H.264: ITU standard (a.k.a., MPEG-4 Part 10) that governs video coding at very high compression rates. It was designed to produce acceptable video quality at half the bit rate required by previous standards.

H.320: ITU standard for videoconferencing compression standards that allow different equipment to interoperate via T1 or ISDN connections.

H.323: ITU standard for videoconferencing compression standards that allow different equipment to interoperate via the Internet Protocol (see below).

H.324: ITU standard for videoconferencing compression standards that allow different equipment to interoperate via Plain Old Telephone Service (POTS).

Health Information Exchange (HIE): the mobilization of healthcare information electronically across organizations within a region, community or hospital system. (Wikipedia)

Health Level-7 Data Communications Protocol (HL-7):  Communication standard that guides the transmission of health-related information. HL7 allows the integration of various applications, such as bedside terminals, radiological imaging stations, hospital census, order entries, and patient accounting, into one system.

High-Def (HD): A video of higher resolution than what is standard. There is no specific definition or criterion for HD but video images with more than 480 horizontal lines (North America) or 570 lines (Europe) is HD. 720 scan lines is generally the minimum. Standard resolution images acquired at rates faster than normal (60 fps North America, 50 fps Europe) by a high-speed camera are often regarded as high-definition as are non-interlaced or progressive scan video.

HIPAA: Acronym for Health Information Portability and Accountability Act. The HIPAA Privacy Rule protects the privacy of individually identifiable health information,  the HIPAA Security Rule  sets national standards for the security of electronic protected health information, and the confidentiality provisions of the Patient Safety Rule protect identifiable information being used to analyze patient safety events and improve patient safety. (

Home Health Care and Remote Monitoring Systems:  Care  provided to individuals and families in their place of residence for promoting, maintaining, or restoring health or for minimizing the effects of disability and illness, including terminal illness. In the Medicare Current Beneficiary Survey and Medicare claims and enrollment data, home health care refers to home visits by professionals including nurses, physicians, social workers, therapists, and home health aides. Use of remote monitoring and interactive devices allows the patient to send in vital signs on a regular basis to a provider without the need for travel.

Hub Site: Location from which specialty or consultative services originate.


Informatics: The use of computer science and information technologies for the management and processing of data, information and knowledge. The field encompasses human-computer interaction, information science, information technology, algorithms, areas of mathematics, and social sciences.

Integrated Services Digital Network (ISDN):  A common dial-up transmission path for videoconferencing. Since ISDN services are used on demand by dialing another ISDN based device, per minute charges accumulate at some contracted rate and then are billed to the site placing the call. It is analogous to using the dialing features associated with a long distance telephone call. The initiator of the call pays the bill. ISDN permits connections up to 128Kbps.

Integrated T1: A T1 circuit leased for exclusive use by one customer.

Interactive Video/Television:  Video conferencing technologies that allow for two-way, synchronous, interactive video and audio signals for the purpose of delivering telehealth, telemedicine or distant education services. It is often referred to by the acronyms ITV, IATV or VTC (video teleconference).

Internet Protocol (IP): Protocol by which data is sent from one computer to another over the Internet. Each computer has at least one address that uniquely identifies it from all other computers on the Internet. IP is a connectionless protocol, which means that there is no established connection between the end points that are communicating. The IP address of a videoconferencing system is its phone number.

Interoperability:  The ability of two or more systems (computers, communication devices, networks, software, and other information technology components) to interact with one another and exchange data according to a prescribed method in order to achieve predictable results (ISO ITC-215). There are three types of interoperability: human/operational, clinical, and technical. 

ISDN Basic Rate Interface (BRI):  Interface that provides 128k of bandwidth for videoconferencing or simultaneous voice and data services. Multiple BRI lines can be linked together using a multiplexer to achieve higher bandwidth levels; for example, one can combine 3 BRI lines to provide 384k of bandwidth. BRI services are not available in some rural locations.

ISDN Primary Rate Interface (PRI):  Interface standard that operates using 23, 64k channels and one 64k data channel. With the proper multiplexing equipment the ISDN PRI channels can be selected by the user for a video call; for example, for a videoconference at 384k of bandwidth  the multiplexer can be set up to use channels 1 through 6 (6 x 64k = 384k). The fewer channels used to obtain a quality video signal, the less expensive the call.


JCAHO: Acronym for Joint Commission on Accreditation of Healthcare Organizations, an independent, not-for-profit organization that accredits and certifies health care organizations and programs in the United States.  Joint Commission accreditation and certification is recognized nationwide as a symbol of quality that reflects an organization’s commitment to meeting certain performance standards. (

JPEG (Joint Photographic Experts Group): Method of lossy compression for digital imaging. The degree of compression can be adjusted allowing for tradeoffs between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality.


Kiosk: Specifically designed computer system for accessing specific programs or search sites that is typically part of a structure designed to prevent theft or tampering and withstand unattended public use and promote privacy and security during use.


Latency: The perceptible delay between transmission and receipt of data across a connection, generally due to high network activity or a poor/slow connection. 

Licensure: a restricted practice requiring a license, which gives a "permission to practice." Such licenses are usually issued in order to regulate some activity that is deemed to be dangerous or a threat to the person or the public or which involves a high level of specialized skill. (Wikipedia)

Local Area Network (LAN): Computer network within an organization, supporting devices, linking computers, printers, servers, etc. and supporting audio, video, and data exchange. It generally operates at 10, 100, or 1,000 Mbps.

Lossless: A form of data compression, typically of an order of less than 10:1, in which none of the original data information is lost when the image is reproduced.

Lossy: A form of data compression using relatively high ratios that results in permanent loss of information upon reconstruction.


m-Health: Practice of medicine and public health supported by mobile communication devices, such as mobile phones, tablet computers and PDAs for health services and information.

Meaningful use: the set of standards defined by the Centers for Medicare & Medicaid Services (CMS) Incentive Programs that governs the use of electronic health records and allows eligible providers and hospitals to earn incentive payments by meeting specific criteria. (

Medical Codes: A process of describing medical diagnoses and procedures using specific universal medical code numbers.  States may select from a variety of HCPCS codes (T1014 and Q3014), CPT codes and modifiers (GT, U1-UD) in order to identify, track and reimburse for telemedicine services. ( 

Medical/ Nursing Call Center: A  centralized office that answers incoming telephone calls from patients, but may also respond to letters, faxes, e-mails and similar written correspondence. Usually staffed by nurses, call centers provide basic health information and instructions to callers but do not provide an official diagnosis of conditions or prescribe medicine. Call centers act as an initial triage point for patients.

Megapixel (MP or Mpx): One million pixels, referring to the number of pixels in an image, image sensor elements of digital cameras or the number of display elements of digital displays
Mobile Telehealth: The provision of health care services with the assistance of a van, trailer, or other mobile unit in which the health care provider might provide patient services at a distance from a normal medical facility. Services may also be provided through mobile technologies attached to an existing health care facility.

MPEG: Family of standards used for coding audio-visual information (e.g., movies, video, music) in a digital compressed format producing files that are much smaller for the same quality.

MP3: Encoding format for digital audio using lossy data compression. It is the de facto standard of digital audio compression for the transfer and playback of music on most digital audio players.

Multiplexer (MUX): A device that combines multiple inputs (ISDN PRI channels or ISDN BRI lines) into an aggregate signal to be transported via a single transmission path.

Multi-point Control Unit (MCU): A device that can link multiple videoconferencing sites into a single videoconference. An MCU is also often referred to as a “bridge.”

Multi-point Teleconferencing: Interactive electronic communication between multiple users at two or more sites which facilitates voice, video, and/or data transmission systems: audio, graphics, computer and video systems. Multi-point teleconferencing requires a MCU or bridging device to link multiple sites into a single videoconference.

Multiple Label Switching (MPLS): Method in high-performance telecommunications networks that directs data from one network node to next based on short path labels rather than network addresses. MPLS supports T1/E1, ATM, Frame Relay, and DSL.


National Health Information Infrastructure (NHII): Initiative to improve effectiveness, efficiency and overall quality of health and health care in the US. (

Network Integrators: Organizations specializing in the development of software and related services that allow devices and systems to share data and communicate to one another.

Noise Cancellation: Method for reducing unwanted sound during videoconferencing or other electronic audio transmission.


Originating Site: Location of the Medicaid patient at the time the service being furnished via a telecommunications system occurs. Telepresenters may be needed to facilitate the delivery of this service. ( Other common names for this term include spoke site, patient site, remote site, and rural site.


Packet Switched Network (PSN): Digital communications network that groups transmitted data, irrespective of content, type, or structure, into suitably sized blocks, called packets.  Packets are transmitted over a shared network that routes packets independently and allocates transmission resources as needed.

Patient Exam Camera (video):  Digital or analog camera used to examine patients during a real-time teleconsult or acquire images for a store-forward teleconsult. Types of cameras include those embedded with set-top videoconferencing units, handheld video cameras, gooseneck cameras, camcorders, etc. 

Patient Protection and Affordable Care Act (PPACA): United States federal statute signed into law by President Barack Obama on March 23, 2010, commonly called Obamacare (or the federal health care law).. Together with the Health Care and Education Reconciliation Act, it represents the most significant regulatory overhaul of the U.S. healthcare system since the passage of Medicare and Medicaid in 1965. (Wikipedia)

Peripheral Devices: Any device attached externally to a computer (e.g., scanners, mouse pointers, printers, keyboards, and clinical monitors such as pulse oximeters, weight scales).

Personal Health Record (PHR): Health record maintained by the patient to provide a complete and accurate summary of an individual's medical history accessible online.

Picture Archiving and Communications System (PACS):  Combination of hardware and software dedicated to short and long term storage, retrieval, management, distribution and presentation of digital medical images. 

Picture-in-Picture (PIP): Feature of videoconferencing devices where one channel is displayed on the full screen at the same time as one or more other channels are displayed in inset windows. Sound is usually from the main program only.

Pixel (picture element): Smallest addressable element in a display device.

Portable Network Graphics (PNG): Bitmapped image format employing lossless data compression (designed to replace GIF).

POTS: Acronym for Plain Old Telephone Service.

Presenter (Patient Presenter): An individual with a clinical background (e.g., LPN, RN, etc) trained in the use of telehealth equipment who must be available at the originating site to “present” the patient, manage the cameras and perform any “hands-on” activities to complete the tele-exam successfully. In certain cases, a licensed practitioner such as an RN or LPN might not be necessary, and a non-licensed provider such as support staff, could provide tele-presenting functions. Requirements (legal) for presenter qualifications differ by location and should be followed.

Protected Health Information (PHI): Part of the HIPAA Privacy Rule that protects all "individually identifiable health information" held or transmitted by a covered entity or its business associate, in any form or media, whether electronic, paper, or oral. The Privacy Rule calls this information "protected health information (PHI).” Individually identifiable health information” is information, including demographic data, that relates to the individual’s past, present or future physical or mental health or condition, the provision of health care to the individual, or the past, present, or future payment for the provision of health care to the individual, and that identifies the individual or for which there is a reasonable basis to believe it can be used to identify the individual. Individually identifiable health information includes many common identifiers (e.g., name, address, birth date, Social Security Number).The Privacy Rule excludes from protected health information employment records that a covered entity maintains in its capacity as an employer and education and certain other records subject to, or defined in, the Family Educational Rights and Privacy Act, 20 U.S.C. §1232g


Remote Monitoring: Type of ambulatory healthcare where patients use mobile medical devices to perform a routine test and send the test data to a healthcare professional in real-time.  Remote monitoring includes devices such as glucose meters for patients with diabetes and heart or blood pressure monitors for patients receiving cardiac care.  

RHIO: The terms Regional Health Information Organization (RHIO) and Health Information Exchange (HIE) are often used interchangeably. RHIO is a group of organizations with a business stake in improving the quality, safety, and efficiency of healthcare delivery. RHIOs are the building blocks of the proposed National Health Information Network (NHIN) initiative at the Office of the National Coordinator for Health Information Technology (ONCHIT).

Router:  device that provides an interface between two or more networks or connects sub-networks within a single organization. The router directs network traffic between multiple locations and it can find the best route between  sites. For example, PCs or H.323 videoconferencing devices tell the routers where the destination device is located and the routers find the best way to get the information to that distant point.

Rural Health Care Division (RHCD): Component of the Universal Service Administrative Company (USAC) that manages a support mechanism to provide reduced rates to rural healthcare providers for telecommunications and Internet services necessary for the provision of healthcare.


Session Initiation Protocol (SIP): An IETF-defined (Internet Engineering Task Force) signaling protocol used for controlling voice and video communication sessions such as calls over Internet Protocol (IP). It can be used for creating, modifying and terminating two-party (unicast) or multiparty (multicast) sessions. The sessions can consist of one or several media streams. Other common applications include video conferencing, streaming multimedia distribution, instant messaging, presence information, and file transfer. It is an Application Layer protocol designed to be independent of the Transport Layer. It can run on Transmission Control Protocol (TCP), User Datagram Protocol (UDP), or Stream Control Transmission Protocol (SCTP). It is text-based and incorporates Hypertext Transfer Protocol (HTTP) and the Simple Mail Transfer Protocol (SMT) elements.

Spoke Site: Remote site where the patient is presented during telemedicine encounter or where the professional requesting consultation with a specialist is located.

Standard: A statement established by consensus or authority that provides a benchmark for measuring quality and that is aimed at achieving optimal results.

Store and Forward (S&F):   Type of telehealth encounter or consult that uses still digital images of patient data for  rendering a medical opinion or diagnosis.  Common  services include radiology, pathology, dermatology, ophthalmology, and wound care. Store and forward includes the asynchronous transmission of clinical data from one site  to another.

Switch: An electrical device that selects the path of a video transmission. 

Synchronous:  Interactive video connections that transmit information in both directions   during the same time period.

System/Network Integration: The use of software that allows devices and systems to share data and communicate with one another.

Systemized Nomenclature for Medicine: Clinical Terms (SNOMED CT): Provides core general terminology for EHRs and contains more than 311,000 active concepts with unique meanings and formal logic-based definitions organized into hierarchies. When implemented in software it can be used to represent clinically relevant information consistently, reliably and comprehensively as an integral part of producing electronic health records. (


T1/DS1: A digital carrier or type of telephone line service offering high-speed data, voice, or compressed video access in two directions, with a transmission rate of 1.544 Mbps.

T.120: ITU standard for videoconferencing that covers compatibility requirements for multipoint conferencing, including specifications for file transfer, program sharing, and whiteboard functions. 

T3/DS3: A digital carrier of 45 Mbps.

Tagged Image File Format (TIFF): File format for digital images that are generally uncompressed, often used for document imagery (e.g., fax and scanner applications).

TCP/IP (Transmission Control Protocol/Internet Protocol): The underlying communications rules and protocols that allow computers to interact with each other and exchange data on the Internet.

Telecommunications Providers (Telco): An entity (the Federal Communications Commission in the US licenses Telcos) that provides telecommunications services to individuals or institutions.

Teleconferencing: Interactive electronic communication between multiple users at two or more sites that facilitates voice, video, and/or data transmission systems: audio, graphics, computer and video systems.

Teleconsultation: Consultation between a provider and specialist at distance using either store and forward telemedicine or real time videoconferencing.

Telehealth and Telemedicine: Telemedicine is the use of medical information exchanged from one site to another via electronic communications to improve patients' health status. Closely associated with telemedicine is the term "telehealth," which is often used to encompass a broader definition of remote healthcare that does not always involve clinical services. Videoconferencing, transmission of still images, e-health including patient portals, remote monitoring of vital signs, continuing medical education and nursing call centers are all considered part of telemedicine and telehealth. Telemedicine is not a separate medical specialty. Products and services related to telemedicine are often part of a larger investment by health care institutions in either information technology or the delivery of clinical care. Even in the reimbursement fee structure, there is usually no distinction made between services provided on site and those provided through telemedicine and often no separate coding required for billing of remote services. Telemedicine encompasses different types of programs and services provided for the patient. Each component involves different providers and consumers.  

TeleICU: TeleICU is a collaborative, interprofessional model focusing on the care of critically ill patients using telehealth technologies.

Telematics: The use of information processing based on a computer in telecommunications and the use of telecommunications to permit computers to transfer programs and data to one another.

Telementoring: The use of audio, video, and other telecommunications and electronic information processing technologies to provide individual guidance or direction. 

Telemetry: Remote acquisition, recording and transmission of patient data via a telecommunications system to a healthcare provider for analysis and decision making.

Telemonitoring: The process of using audio, video, and other telecommunications and electronic information processing technologies to monitor the health status of a patient from a distance.

 Telepresence: (a) The use of a set of technologies that allows individuals to feel as if they were present, to give the appearance of being present, or to have an effect at a place other than their true location. Telepresence generally means the use of means HD quality audio/video. In some cases, the user's position, movements, actions, voice, etc. may be transmitted and duplicated in the remote location to enhance the effect. Information often travels in both directions between the user and the remote location (i.e., feedback of some sort is provided). Telepresence via video generally uses greater technical sophistication and higher audio/video fidelity than traditional videoconferencing. (b)The method of using robotic and other instruments that permit a clinician to perform a procedure at a remote location by manipulating devices and receiving feedback or sensory information that contributes to a sense of being present at the remote site and allows a satisfactory degree of technical achievement. For example, this term could be applied to a surgeon using lasers or dental hand pieces and receiving pressure similar to that created by touching a patient so that it seems as though s/he is actually present, permitting a satisfactory degree of dexterity.

Teleradiology and Picture Archiving and Communications Systems (PACs): The electronic transmission of radiological images, such as x-rays, CTs, and MRIs, for interpretation and/or consultation. 

Throughput: Amount of data transmitted across a network over a period of time typically expressed in bits or bytes per second. 

Transmission Rate: Speed at which data travels over a communications channel typically
expressed in bits or bytes per second.


Unified Medical Language System (UMLS): Set of files and software that brings together many health and biomedical vocabularies and standards to enable interoperability between computer systems. (

Universal Service Administrative Company (USAC): The Universal Service Administrative Company administers the Universal Service Fund (USF), which provides communities across the country with affordable telecommunication services. The Rural Health Care Division (RHCD) of USAC manages the telecommunications discount program for health care.


Videoconferencing: Real-time transmission of digital video images between multiple locations.
Virtual Private Network (VPN): Method to carry private communications network traffic over the public Internet using tunneling or port forwarding which is the transmission of private data over public lines in an encapsulated form.


Wide Area Network (WAN): Network covering a wide geographic area, whether several company sites or services by a common Internet service provider.

WiFi: The underlying technology of wireless local area networks (WLAN) based on the IEEE 802.11 specifications. It is used for mobile computing devices, Internet and VoIP phone access, gaming, and basic connectivity of consumer electronics such as televisions and DVD players, or digital cameras.