February 1999 Bulletin

Telemedicine: An expensive technology

'Sustaining the project may be dependent on the commitment of operational funds or grants. . . .'

Equipment, software, manpower, medical peripherals add up

Second in a series

By Howard Mevis

Telemedicine technology is largely dependent on advanced telecommunication networks, high-quality television cameras and monitors and advanced computer systems. Ideally, high-speed digital signals are carried on broad bandwith, fiber-optic cable transmission lines, providing a telemedicine project the highest quality display of images. However, some areas of the country, notably rural areas where telemedicine can be valuable, may not served by this technology. There are several transmission systems that can be used for telemedicine projects. These include:

The "utility" costs for projects requiring live, interactive sessions, can be significant, if the present telecommunications service uses POTS (narrow band with) rather than fiber-optic lines. The best digital transmission system now available is ISDN. This transmission system is capable of carrying signals at high speed, 128Kbps. Developing technologies, including cable modems and asynchronous digital subscriber line (ASDL), hold the promise for faster data transmission, up to 10Mbps.

Some telemedicine projects use dedicated lines between sites on the system and there may be many sites. Some projects have more than 20 sites on the network. Other projects may use a shared line approach. Scheduling patient sessions becomes a critical issue for shared systems. Protocols are needed to establish how regularly scheduled meetings might be interrupted for an emergency medical consultation. Additionally, equipment needs to be installed in a room appropriate for multiple uses if the system is shared.

Telemedicine consultations

Typically, there are two forms of telemedicine consultations. The live, interactive form provides the physician and patient an opportunity to speak to and see each other. An orthopaedic surgeon may need a very sophisticated display unit capable of showing fine gradations, for example, when evaluating gait. The live format requires significant transmission band with (information carrying capacity of the cable expressed as hertz (Hz) or bits per second). The second is a delayed format where data is stored or archived prior to transmission via the Internet, dedicated lines, satellite or microwave. The delayed transmission of digitized images and other data requires much less signal bandwith and is less expensive to use. POTS may be the most suitable technology for this format.

Consultation equipment

The cost of television (cameras, VCRs, and audio ) and computer equipment (codecs, computers, printers, scanners, workstations and servers) is another factor for the physician and hospital. Equipment and software required to view and interpret radiographs and other imaging studies and viewing a patient examination is expensive. When combined with transmission equipment, a telemedicine project might require an investment of as much as $40,000-50,000 for high quality to outfit a hub site and more than $20,000 to outfit network sites, especially if live interactive sessions are planned. Adding up these "capital" costs makes telemedicine an expensive proposition, on a start-up basis. Further, equipment at all sites must be compatible and "able to talk" to all other site(s). Each site in the network requires the capability of send and receive.

A variety of medical diagnostic peripherals to connect to telemedicine system are commercially available. These range from X-ray scanners to ophthalmoscopes and microscopes to stethoscopes.

No matter how large or small, no matter the distance, each telemedicine network site must have the equipment to communicate within the network for the specific applications it has established.

Standards

Two standards govern telemedicine programs. First, the HL7 standard (Health Level 7) defines the interchange of data regarding patient admissions, discharges, transfers, etc. "HL7 provides the greatest possible degree of standardization consistent with site variation in the use and management of data."1 Second, DICOM (Digital Imaging and Communication in Medicine) is the industry standard for the transfer of medical information and radiographic images from one computer to another. Among the organizations supporting these standards are American College of Radiology (ACR), Mallinckrodt Institute of Radiology, the National Electrical Manufacturers Association and Radiological Society of North America. DICOM also provides a means for users of imaging equipment to assess if equipment is capable of exchanging meaningful information."2

To help organizations ensure their telemedicine projects meet recognized standards, the ACR has developed equipment guidelines for teleradiology systems. The standards include the requirements for image management, transmission of images and patient data, display capabilities, maintaining a patient database and security. Some consideration must be given for security equipment to ensure the storage of patient records is confidential. The ACR standards note that "important parameters should accompany the transmitted study when used for official interpretation. These should include, at a minimum, the matrix size, bit depth, compression (if used), and what kind of image processing, if any, was used (edge enhancement, etc.)."3

In addition, there are technical standards defining how computers and audio/video conferencing equipment communicate with each other. These international standards (H.320 and H.323) facilitate conferencing over a telephone network and ensure that data compression and encryption use the same algorithms. For computers, the standard ensures that communications software from different vendors can work well together.

Personnel requirements

Telecommunications systems used for telemedicine projects require considerable technical expertise. Personnel are needed to setup, operate and maintain the equipment. Major hospitals may have image management systems specialists responsible for picture archiving and communication systems (PACS). These costs, along with operational costs for transmission, must be considered in planning and operating a telemedicine project. Sustaining the project may be dependent on the commitment of operational funds or grants, if reimbursement for clinical services is not available.

References

1., 2. The Telemedicine Frontier: going the extra mile, V. Garshnek, J.S. Logan, L.H. Hassell, http://www.quasar.org/21698/knowledge/telemedicine_frontier.html

3. American College of Radiology: Standards for Teleradiology

Howard Mevis is director of the Academy's department of electronic media, evaluation and course operations

Telemedicine interactions and applications

Purpose

Interaction mode

Information transferred

Minimum bandwidth required

Applications (examples)

Diagnostic or therapeutic consultation

Real-time one-way or two-way interactive motion video

Voice, sound, motion video, images, text

Moderate to High

Telepsychiatry, remote surgery, interactive exams

Diagnostic or therapeutic consultation

Still images or video clips with real-time telephone voice interaction

Voice, sound, motion video, images, text

Low to moderate

Dermatology, cardiology, otolaryngology, orthopaedics, etc.

Diagnostic or therapeutic consultation

Still images, video clips, text, 'store-and-forward' with data acquired and sent for later review

Sound, still video images, video clips, text

Low

Dermatology, cardiology, otolaryngology, orthopaedics, etc.

Medical education

One-way or two-way real-time or delayed video

Voice, sound, motion video, images, text

Full Spectrum: Low to High

Distance education and training

Documentation administration

Transfer of electronic text, image, or other data

Text, images, documents, related data

Low to High

Health information networks, medical records

Source: The Telemedicine Frontier: going the extra mile, V. Garshnek, J.S. Logan, L.H. Hassell, http://www.quasar.org/21698/knowledge/telemedicine_frontier.html


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