Internet and the World Wide Web: A Primer for Practitioners

*Visiting Fellow in Medical Informatics, Decision Systems Group chandak@dsg.harvard.edu
**Technical editor, BrighamRAD project, gmammone@dsg.harvard.edu
+Director, Decision Systems Group, greenes@harvard.edu
++Chairman, Dept of Radiology, holman@ulna.bwh.harvard.edu

Abstract:

Computer-supported high speed digital communication networks are increasingly influencing the retrieval and exchange of scientific and medical information. Of the many Internet-based communication resources, the World Wide Web has emerged as the single most powerful medium for collecting, updating, referencing, and disseminating knowledge. Its uses and benefits in clinical medicine, medical research, medical education, and patient education are already manifold, and more medicine-related sites are in the offing. This article introduces the Internet and describes what the World Wide Web is, how to get connected to the Web, where to find medicine-related Web sites, and how to develop Web-based resources.

Key words: Internet, World Wide Web, Computers

The Internet is an international network linking millions of personal computers and thousands of smaller computer networks throughout the world. This 'network of networks' allows various computer systems that work on different operating platforms (such as PCs, Macs and UNIX workstations) to communicate through a common channel. Unlike traditional methods of information exchange that require far greater time to process and reach their destination, the Internet is capable of transmitting large amounts of data at high speeds. Currently available Internet-based communication methods include electronic mailing lists, newsgroups, bulletin boards, File Transfer Protocol (FTP), and more recently, various forms of groupware, gopher, and the World Wide Web (also known as W3, WWW, or the Web). These resources permit information exchange in a fast, simple, and reliable way.

Compared with other forms of electronic data transfer, the World Wide Web allows documents to be presented in highly attractive and appealing formats. Users can access or duplicate information contained anywhere and also create their own documents on the Web. The Web has now become a dominant model for large scale collection, storage, retrieval, and dissemination of information, and its use has become commonplace in research and educational institutions in several countries.

In addition to supporting text-based information exchange, the Web also allows transfer of high-quality images, audio clips, animations, and digital video, making it the most versatile information system currently deployed on the Internet. Because it is accessible and easy to navigate, the Web is now being routinely used for referencing, updating, teaching, advertising, and a host of other activities in academia, commerce and banking, sports and entertainment, arts, sciences, defense, politics, travel, and transport. Internet traffic overload has not yet become a major constraint because access has been limited until recently. Widespread development of commercial links to the World Wide Web could create severe access problems in the future. In coming years, however, optical fiber networks are expected to replace most of the current connections and greatly improve data exchange speeds.

How does the Web work ?

The World Wide Web began as a set of definitions of document formatting and transfer conventions arising from work at CERN, the high energy physics center in Geneva. Documents are formatted using computer-independent markup tags identifying styles such as bold or italic, and sections of a document such as titles, headers, and paragraphs. This set of conventions, known as HTML (HyperText Markup Language), is a variant of SGML (Standard Graphic Markup Language), which is a typographic and printing standard. The variations introduced with HTML also include conventions for identifying format elements that can be treated as links to other documents. In other words, a text element such as a word or phrase can be designated as a link to another document. Links from text create what is called a hypertext document, which has a nonlinear format by virtue of its connections to multiple other documents. Images and other elements may also be linked by HTML, creating hypermedia rather than simply hypertext. With HTML, hyperlinks are constructed by specifying the Internet address of the host computer along with additional information needed to identify and access the target document.

The other important convention of the Web is the protocol for transmitting HTML documents to other computers. This is referred to as HTTP (HyperText Transfer Protocol). If a computer capable of recognizing HTTP receives a message in that format, it knows that the document is of a specific type, namely one that is coded as a HTML document.

The Web is based on a client-server model, where information that is hosted and maintained on collections of server computers can be accessed by individual personal computers connected to the network. The client is the interface program (Web client or browser) that allows the personal computer to receive HTTP messages over the Internet and interpret and display the HTML formatted information as hypertext documents. World Wide Web servers must be capable of responding to requests for documents, incorporating HTML documents into HTTP messages, and sending them to the client. The speed of this information exchange is determined by the number of requests received at any given time, the network communication speed or bandwidth available, and the capacity of the server to handle and process information requests.

In in addition to HTTP, many Web clients are actually capable of supporting a variety of protocols for sending email (SMTP protocol), receiving file transfers (ftp protocol), accessing UNIX newsgroups (bulletin boards, UseNet News protocol), or obtaining information from gopher servers (gopher protocol). Clients software is available for various operating systems with similar access capabilities.

Getting connected to the Web

In order to surf the Internet, a Web client or browser such as NCSA Mosaic( (National Center for Supercomputing Applications, University of Illinois in Urbana-Champaign) or Netscape (© 1994-95 Netscape Communications Corporation) must be installed on the computer. The minimum hardware and software requirements for PC-based browsing through Windows are listed in Table 1. A direct connection to the Internet is preferable to a dial-up link through a modem due to considerably improved access speed.

Surfing the Web

The World Wide Web is far more interactive than paper-based media. Information on the Web is continuously expanded or updated. In some cases, users may enter opinions, send contributions, or otherwise interact with people elsewhere in the world. Countless information and other resources are available to be explored as one moves across topics and locations. One can learn more about tap-dancing, find out how beer is brewed, solve crosswords, take a personality test, look up baby names, get information on subway routes, make hotel reservations, purchase clothing, order food to be delivered, check the weather forecast, or dive into more serious business such as filing tax returns, writing to newspapers and groups, or sending mail to President Clinton. One can even take a virtual tour of the Whitehouse and hear the First Cat's voice!

Medical resources on the Web

The Web allows access to a large and ever-expanding collection of medical information. Many educational, clinical, and research hospitals and universities have set up Web servers to publish or disseminate information about their resources, personnel, research, and special events.

The Web is also a powerful educational tool. Due to its multimedia handling capabilities and provision for user-provider exchange, the Web is far more interactive than reading textbooks or journals. Educational institutions are now increasingly recognizing the Internet potential for student, physician, and patient education, and are promoting the development of Web-based educational resources. Certain sites have also started offering CME credits to physicians who study their teaching files.

Some medicine-related Web resources and their URLs (Uniform Resource Locator, or Internet addresses) are listed in table 2. The Web is also being increasingly used as a presentation tool in conferences and professional meetings. Since it supports transfer of high quality images such as CT and MRI scans, as well as video clips of procedures such as endoscopy or real-time ultrasound, the Web offers a simple and cost-effective method to obtain second opinions from physicians situated at remote locations and to practice telemedicine.

Many medical Web resources are currently run by radiology, pathology, or medical imaging departments due in part to their image-related databases. Several medical informatics departments also host Web pages due to their computer resources, whereas other general services are usually run by agencies such as the NIH, CDC, and WHO.

Web-based promotion and advertising are on the increase. Manufacturers of medical equipment such as Picker Inc. have established Web pages. Medical journals such as Radiology and the British Medical Journal are also on-line. Health institutions, HMOs and other group practices will soon establish a presence on the Web as well.

Taking a virtual tour

BrighamRAD is an example of a radiology information and educational resource on the Web available at the address http://www.med.harvard.edu/BWHRad/. To access the BrighamRAD server, type the above address using the 'Open-Location' or 'Open-URL' (URL=Uniform Resource Locator) option on your browser. Within seconds, the browser will connect with the home page of the Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, as shown in Figure 1.

Note that some text is underlined (on a color screen, these items may appear in blue or red). These are hyperlinks or pointers to other resources within or outside BrighamRAD. The difference in color or grey scale is to help you keep track of links that you have traversed recently using your browser. By continuing to click on these hyperlinks, you can begin exploring the Web.

The BrighamRAD site contains several teaching files related to radiology, nuclear medicine, and pathology. By clicking on the hypertext link Atlas of Brain Perfusion SPECT (as seen in Fig. 1), you can move to another educational resource available through BrighamRAD that contains several images as well as tutorials on brain perfusion SPECT imaging (Fig. 2).

Resources for patient education are also available on the Web. Traditionally, information is provided free of charge, and anyone can view, print, or download the information for personal or educational use. Currently available topics for patient education include breast cancer, prostate cancer, AIDS, safer sex, and diabetes. These can be of great benefit to patients in gaining insight and solving queries about their health or disease. No standard peer review system monitors documents published on the Web, however, so patients and medical workers must be careful to use information only from reputable sources. Apart from valuable information, misinformation can also find its way onto the Web.

Creating your own Web resource

Use of the Web is not limited to just viewing or copying information. Users can 'build' their own pages and make them available on the Web from any location on the globe. Although it is not difficult to create Web pages, it should be remembered that maintaining and updating them can be quite time consuming. Hence, before providing a service on the Web, one should keep in mind that information should remain updated, and that the resource should be available at all times.

Web documents are written in HTML, and are fairly simple to create with editing software. Useful editors can be downloaded free from different Web sites. A useful strategy, in order to become versed in writing Web documents, is to explore the source code of different documents on the Web by using the 'View-Source' option from the pull-down menu on your Web-browser. Finally, before writing any document, it is also worthwhile to review the official HTML specifications and style guides, also available on the Web.

You don't need a server to create experimental pages. You can view documents on your own computer using your Web browser. Once satisfied with your pages and ready to publish them on the Web, only then will you require an on-line server to host your pages.

Advertising your services or publishing other information on the Web is becoming easier for any business. Professional Web-page development services can host your pages and can even help you develop them at nominal cost.

Concluding remarks

Due to its simple and easy to use interface, versatility, flexibility and multimedia handling capabilities, the World Wide Web has emerged as the most attractive and impressive of all communication channels available on the Internet. It is a highly useful and cost-effective resource for collection, display, dissemination and retrieval of knowledge within the medical community. Many institutions throughout the world have developed Web resources and offer valuable information on clinical practice, decision support, medical research, and medical education. In addition to being a versatile reference resource, the Web is a flexible and interactive teaching tool for physician, student, and patient education. Care seekers as well as providers should familiarize themselves with this simple yet powerful medium for obtaining professional information and begin to utilize it on a regular basis.

Physicians having information that can be of use to others should feel encouraged to contribute to the knowledge pool of the World Wide Web, making it the largest medical information repository that is open at all times and available free to everyone.

Table 1

• 386 microprocessor based computer
• Super VGA color monitor
• 4 MB (preferably 8 MB) RAM
• Windows 3.1 (enhanced mode)
• Win32s (32-bit Windows upgrade)
• File decompression programs e.g. PKZ204G
• TCP/ IP software (ask for most recent version)
• SLIP (Serial Line Internet Protocol) or PPP (Point to Point Protocol) connection over a telephone line
• 14.4 Kbps modem or faster
• Winsock1.1 compatible dynamic link library (winsock.dll)

• Adobe Acrobat (to view non-HTML text)
• SoundMachine |-
• Sparkle |- (to play audio and video)
• MoviePlayer |-
• JPEG or MPEG viewers (to view images)

TABLE 2.

General Resources URL address
National Institutes of Health (NIH) http://www.nih.gov/
National Library of Medicine (NLM) HyperDOC http://www.nlm.nih.gov/
Centers for Disease Control and Prevention http://www.cdc.gov/
RuralNet : Rural Health Resources gopher://ruralnet.mu.wvnet.edu/1
Stanford Medical School http://med-www.stanford.edu/
Stanford U. Medical Media & Info Tech Lab (SUMMIT) http://summit.stanford.edu/
US Medical Libraries List http://kufacts.cc.ukans.edu/hytelnet_html/US000MED.html
WHO Web Server http://www.who.ch/
WHO Gopher Menu gopher://gopher.who.ch/1
MEDICARE and MEDICAID http://www.ssa.gov/hcfa/hcfahp2.html
Food Safety and Applied Nutrition of FDA http://vm.cfsan.fda.gov/index.html
WWW Virtual Library: Medicine http://golgi.harvard.edu/biopages/medicine.html
Internet Clinical Resources http://www.arcade.uiowa.edu/hardin-www/clin-resources.html
Cornell Medical College Education Center http://edcenter.med.cornell.edu
Neurosciences Resource Guide http://http2.sils.umich.edu/Public/nirg/nirg1.html
Medical Education http://www.med.virginia.edu/med-ed/MedEdHome.html
Glaxo Virtual Anatomy Project http://www.vis.colostate.edu/library/gva/gva.html
The Visible Human Project http://www.nlm.nih.gov/extramural_research.dir/visible_human.html
Images from the History of Medicine http://www.nlm.nih.gov:8002
International Myeloma Foundation http://www.comed.com/IMF/imf.html
The Multimedia Medical Reference Library http://www.tiac.net/users/jtward/index.html

Radiology and Nuclear Medicine Resources URL Address
Official Server for the RSNA http://www.rsna.org
Brigham and Women's Hospital, Harvard Medical Sch http://count 51.med.harvard.edu/BWHRad/
Indiana University http://foyt.indyrad.iupui.edu/HomePage.html
University of Iowa Virtual Hospital http://vh.radiology.uiowa.edu
University of Pennsylvania http://www.rad.upenn.edu/
University of Washington http://www.rad.washington.edu/
Mallinckrodt Institute of Radiology http://www.mir.wustl.edu
Penn State University http://www.xray.hmc.psu.edu/
Joint Program in Nuclear Medicine, Harvard Med Sch http://count 51.med.harvard.edu/JPNM

Pathology resources URL Address
U. of Illinois Urbana-Champaign Pathology Atlas http://www.med.uiuc.edu/titlePage.html
U. of Utah Atlas of Pathology http://www-medlib.med.utah.edu/WebPath/webpath.html
Osaka Med College Image Library of Pathology http://www.osaka-med.ac.jp/omc-lib/path.html
U. of Rochester Dep of Path and Lab Medicine http://wwwminer.lib.rochester.edu/wwwml/Leon/URPLM.html

Cancer resources URL Address
Information About Cancer for Patients & Families http://asa.ugl.lib.umich.edu/chdocs/cancer/CANCERGUIDE.HTML
Cansearch: A Guide to Cancer Resources http://www.access.digex.net/~mkragen/cansearch.html
Breast Cancer Information Clearinghouse http://nysernet.org/bcic/

Other patient education resources URL Address
Emotional Support Guide http://asa.ugl.lib.umich.edu/chdocs/support/emotion.html
Medical Education Page http://www.primenet.com/~gwa/med.ed/
Preventive Medicine and Environmental Health http://www.pmeh.uiowa.edu
Parents helping Parents of children wth special needs http://www.portal.com/~cbntmkr/php.html
Cutaneous Drug Reaction Database gopher://gopher.dartmouth.edu:70/11/Research/BioSci/CDRD
MCW Travel Health Information http://www.intmed.mcw.edu/travel.html

Pediatric resources URL Address
Interesting Places for Kids http://www.crc.ricoh.com/people/steve/kids.html
Children's Educational Resources http://bettyj.caps.maine.edu/educational.html
VaCCINe: U. of Virginia http://galen.med.virginia.edu/~smb4v/vaccine.html
UNICEF Gopher gopher://hqfaus01.unicef.org/
Dept. of Pediatrics, Marshall U School of Medicine http://musom.mu.wvnet.edu/0u:/peds/general.html

Brain Related Sites URL Address
Atlas of Brain perfusion SPECT http://www.med.harvard.edu/BWHRad/BrainSPECT/BrSPECT.html
The Whole Brain Atlas http://www.med.harvard.edu/AANLIB/home.html
"On brains, evolution, and where we're heading" http://weber.u.washington.edu/wcalvin/

Medical Journals URL Address
Radiology http://www.rsna.org/edu/publications/radiology/rad.html
British Medical Journal http://www.bmj.com/bmj/

LEGENDS

Fig. 2
Opening page of the Atlas of Brain Perfusion SPECT, an educational resource at the home page of the Department of Radiology, Brigham and Womens Hospital, Harvard Medical School. URL: http://www.med.harvard.edu/BWHRad/BrainSPECT/BrSPECT.html