Viewing Virtual Hospital Content on a Personal Digital Assistant

James J. Choi, M.D.
Assistant Professor
Department of Radiology
University of Wisconsin - Madison

Peer Review Status: Internally Peer Reviewed
First Published: March 2004
Last Revised: March 2004

Introduction:

Computers and the Internet have revolutionized the way information is disseminated. These two technologies have allowed users to conveniently access information at anytime and from anywhere. The use of portable devices such as notebook computers, personal digital assistants (PDA), and smart phones has greatly expanded the ease of remote information access.

The following information will deal with retrieving Web based information and storing it on a PDA.

This article will focus on two specific approaches: the first method requires a personal computer (PC) and a program called Plucker (www.plkr.org), which converts Web information to a PDA-viewable format. The second method relies on the Web service – AvantGo (www.avantgo.com), which acts as your Web translation assistant. Both of these methods have advantages and disadvantages, which will be discussed within their respective sections.

The first method used to view Web information on a PDA utilizes a computer program. There are various software packages that can perform this task. The most common programs are Plucker and iSilo (www.isilo.com). At the time of this writing, Plucker is preferred for several reasons: it is free, translation can be performed on Windows, Mac OS, Unix and Linux based operating system (OS), and the program is open source. This program was developed for viewing information on a Palm OS based PDA; currently there is no Pocket PC version. Owners of Pocket PC can utilize an alternative program such as iSilo.

The second method to view Web information on a PDA does not require a computer application; instead a Web-based service performs the translation function. The most popular service is AvantGo (www.avantgo.com). This service supports a variety of devices such as Palm, Pocket PC and Win CE OS based PDAs, as well as smart phones.

1. Do you want the Web information to retain as much of the original formatting possible?
2. Are you proficient with a computer and do you understand the Web formatting technology?
3. Do you want to avoid advertising?
4. Do you primarily use a PDA and not a smart phone to view the Web information?
5. Do you want a free Web translation application and service to do most of the work?

If you have answered yes to the majority of these questions, you will more likely be comfortable with the robust features offered by Plucker. If you have answered mostly no, you would benefit from the simplicity of the AvantGo Web service.

Plucker

Plucker is a free and open source application. It translates Web pages for PDA viewing with the assistance of a PC. Plucker supports the majority of Operating Systems (Microsoft Windows, Apple Mac OS X, and Linux). Currently, Plucker only supports Palm OS based PDAs. To utilize Plucker, two applications (translator and viewer) need to be installed. (It is assumed that for this article, the user knows how to install applications on both the PC and on the PDA, and also knows how to synchronize between a PC and a PDA.) The translation application is for the PC and the viewer is for the PDA; both of which can be found at the Plucker Website: (www.plkr.org/index.plkr?a=dl).

Plucker provides a great deal of flexibility with Website translation, such as limiting the amount of information obtained from the intended site; management of the image quality and font; and scheduling automatic translation and updates. Plucker provides an almost dizzying array of options for Website translation. The program simplifies the translation process by providing an intuitive user interface that is divided into logical components. The following is a tutorial that translates the main Virtual Hospital (www.vh.org) page to a PDA viewable format.

Launching the Plucker application on the PC will bring up the Plucker Desktop. To be consistent with the Plucker terminology, a Website will be referred to as a channel. From the desktop, many options are available including adding, deleting, and editing of a new channel. Additionally, a channel can be scheduled for automatic updates. The process of creating a new channel is simplified with the Channel Wizard. Assign a unique name to the new Channel and provide the Web site address. Once the channel is selected, it is important to define the amount of Web content to be translated, such as the addition of referring pages from the original page. The referral page is known as depth. Most of the time, you will want to stay on the original page. The addition of referral pages will increase the translated document size and often require more time to complete. It is best to set the maximum depth to "1" and stay on the same server by choosing "Ignore links to a server that is different from starting page's server" and "Limit to the exact server only." Once the translation is complete, a Plucker document is ready to be synchronized with the PDA. The final step in the channel wizard is to determine where to store the PDA document: in the PDA's internal memory or on an expansion memory card. Obviously, if the PDA does not allow for expansion memory this is a moot point. If possible, it is best for users to store the file on the expansion memory. The main advantage of expansion memory is that it is often larger than the internal memory, thus it has the capacity to store a large document and also frees up the internal memory for critical operation.

To view the document on the PDA, Plucker viewer must be installed. Upon launching the viewer, it will list all of the translated Web pages. To view a document, select the appropriate item. The document will resemble the original PC version, simply modified to fit the PDA screen. Viewing and navigating the document is intuitive, and common tasks are conveniently available from the menu bar located at the top of the screen. Occasionally, the Web page may not be useable because of small images or poor image quality and the loss of the original layout and formatting. These types of glitches are common with Web pages that use complex layout schemes, scripts or applets. There is no way to correctly translate these Web pages, which are not common. Fortunately, the majority of minor glitches can be corrected by adjusting the parameters from within the PC version of Plucker. Some trial and error may be necessary to correctly translate the desired Web page. Also certain parameters that work for a one Website may not work for all Websites. As a general rule, a Webpage may not be usable on a PDA if it contains a large number of images or uses cascading style sheets, JAVA applets or scripts.

AvantGo

If Plucker is too complex and you don't mind minor limitations, AvantGo (www.avantgo.com) may be a viable solution. Unlike Plucker, AvantGo is a free Web service solution that does not require a PC application to translate Web pages. AvantGo reduces the complexity associated with Website translation. On the otherhand, it is not as flexible as Plucker. Detailed documentation is available from the AvantGo Website: (www.avantgo.com/doc/ami.html).

There are several similarities between Plucker and AvantGo. They both require a computer and PDA-based viewer application to be present. AvantGo is semi-platform independent. Since the Web service does the translation, it does not require a dedicated PC based application. However, it does require a customized synchronizing conduit. As of this writing, there are conduits for Windows and Mac OS 9 based OS. There is no First party conduit for Mac OS X or Linux OS.

The main difference between AvantGo and Plucker is the simplification of Website conversion offered by AvantGo. The Website lists hundreds of brand-name Web sites preformatted into channels, specifically made for PDA devices.

To utilize AvantGo you must register and download the appropriate conduit and viewer for your PC and PDA, respectively. Links to the registration and software can be found at www.avantgo.com.

Once you register and install the appropriate software on your PC and PDA, AvantGo will do most of the Web site conversion. To add a premade AvantGo channel, simply click on the desired link. If AvantGo does not have a Webpage you want, you can still add it to your PDA. The process of adding a channel is simple. Log on to AvantGo which will then take you to your homepage. At the right side of the page, there are three tabs labeled "Find," "My Device," and "My Account." Contents found within these three tabs allow you to customize the Website and your PDA. To add a custom channel, click the "My Account" then "Create a custom channel." The Webpage will refresh to reveal a "Create Custom Channel" page. From there, fill in the appropriate information and select the appropriate options. At the first section, "Channel Title" name your channel and provide the Web address. The second section, "Channel Size" allows you to limit the size of the translated file. This option is handy as some sites contain large graphics that may overload a PDA and will be unwieldy to read. There are several options that will help with the optimal translation. Limit the file size by setting the "Maximum Channel Size" to about 100 kilobytes, do not include information that is not found within the intended Webpage by making the "Link Depth" to "0" and select "No" on the "Follow Off-Site Links" options. Unless images are required, you should select "No" in the "Include Images" option. The third section, "Channel Refresh" allows for scheduling of information from the intended Webpage when you synchronize the PDA. If you select the "on every sync" option, you will always have the latest information. Otherwise, you can schedule how frequently the information is refreshed. After completing the form, save it by clicking "Save Channel" near the bottom of the page. Now synchronize the PDA with your computer, which will transfer the information from the AvantGo service. Since AvantGo does the translation, you will need access to the Internet during the synchronization.

There are limitations to the AvantGo service that may detract from its usability. Since the service is free, the converted channels contain advertisements. Additionally, the Webpage is reformatted to fit on to a small PDA screen. Reformatting may make the page unviewable. It doesn't offer the robust options of Plucker. However for most users, AvantGo's limitations do not detract from its usefulness.

Conclusion

There are many applications that assist with convenient Web viewing. These are useful when there is no direct Internet access or carrying a PC is inconvenient. A PDA is a viable solution for Web page viewing. There are other solutions that will perform similar functions as described in this article and users should not be afraid to experiment with new programs.

All contents copyright © 1992-2004 the Author(s) and The University of Iowa. All rights reserved.

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