The portable digital assistant (PDA) has been in use for well over a decade. The first devices were large, cumbersome, unreliable, and not very useful; however, with time PDAs have grown technologically in step with personal computers. Today’s PDA is the equivalent of a handheld personal computer with a built-in high-resolution display. Contained within this small form factor is a powerful central processing unit (CPU), reasonable memory allocation with capabilities for inexpensive memory expansion, a bright, crisp color display capable of displaying thousands of colors, wireless Ethernet and telephony support for e-mail, instant messaging and web browsing, as well as the capability for recording and displaying multimedia (video and audio). A form of shorthand is traditionally used to efficiently enter textual content on the touch-sensitive display. Today’s hybrid PDA devices combine the capabilities of a PDA with wireless Internet (WiFi), e-mail, telephony, and digital dictation capabilities. Users now have the option to enter information using either the shorthand approach or small built-in keyboards that are designed for efficient entry with the thumbs instead of touch typing. For large volume data entry, full-size detachable keyboards are available, which allow the user to enter large amounts of textual information into their handheld using more traditional methods.
Projected sales growth for PDAs and hybrid devices has been exponential with expectations of a $6 billion market by 2006. PDAs have found use in almost every profession. Despite the extensive development of PDA hardware and software, the most popular applications are personal information management (PIM). These include personal datebook, memo pad, address list, and to-do list. While PIM applications have existed since the birth of the practical handheld computer, they remain the most widely used among PDA owners because they provide a handy and more convenient replacement for more cumbersome alternatives (eg, Rolodex, address book, meeting planner, notebook). In keeping with the evolution of the handheld computer, PIM applications have changed drastically since their inception. Today’s PIM applications are designed to be an extension of more powerful project and personal management software products that reside on large corporate servers. Today’s mobile professional can keep in constant contact with the home office via their handheld hybrid PDA/phone through a number of avenues including conventional telephony, e-mail, digital dictation, and document sharing.
 Figure 1. PDA display of neuroradiology workload by location. An automated script queries the PACS database every 15 minutes, totals only the neuroradiology CT and MRI examinations that are awaiting dictation at each office/location, and generates dynamic web pages that publish periodic updates to an internal web server. These are then accessible through the conventional web route on the desktop as pop-ups or through a PDA via wireless or telephony. Total number of pending cases is displayed as well as a graphic representation (red bar). When the total exceeds a specific threshold, a pointing finger icon is added automatically for emphasis. |
Medical students and physicians in training were early adopters of handheld devices primarily because of their inherent capability to store reference materials that were easily accessible and modifiable, giving the user the freedom to supplement the informational repository as needed. Instead of a table of contents or index, the data is freely queried by search terms. The handheld device serves as a replacement for stacks of index cards and pocket reference books that used to bulge from the pockets of student physicians. Moreover, homebuilt reference libraries are shared or combined with other repositories to create larger references. With the advent of wired and wireless synchronization capabilities, handheld reference libraries are kept constantly up-to-date. Hundreds of medical and surgical reference texts are available in a handheld format that incorporates ease of access and readability on the small screen. In addition, extracts of journal articles suitable for the PDA are available for download from a number of sources. Replacement of an outdated, cumbersome textbook library with a portable, customizable, and up-to-date reference library is one of the most compelling reasons for use of PDAs by physicians at all levels of practice.
As hospitals and health systems move toward implementation of a full electronic health record (EHR), there is an even greater need to develop solutions that provide access to that data in a convenient method. This includes strategic placement of portable computers at the point-of-care, including nursing stations, hallways, examination areas, and even patient rooms. These capabilities are improved by availability of secure wireless networks in the hospital/clinic setting and the development of the integrated/hybrid handheld device. While extensive textual data entry presents a challenge for handheld devices, many of the EHR solutions for handheld computers offer menu-driven options for order entry and transcription. While there are still practical barriers for replacing pen and paper with a PDA, most of the disadvantages are overshadowed by the convenience of secure access to the patient record and timely decision support tools at the point-of-care.
APPLICATIONS SCARCE
While PDA ownership by radiologists is on a par with the rest of the medical community, the number of commercially available radiology-specific applications is surprisingly minimal. The reason for this paradox is related primarily to the fact that the point-of-care for the practicing radiologist is very different from that for the clinician. In the fully digital world of modern radiology, the practicing radiologist is surrounded by an array of workstations that provide rapid access to an entire library of medical images; speech recognition; multiple information systems for radiology, laboratory, and hospital; as well as network resources for decision support tools. Because of their proximity to their “tools of the trade,” radiologists are less “mobile” than their clinical counterparts. Moreover, the quality and performance of the generic radiology PACS (picture archiving and communications system) and related information systems far exceed those of the handheld computer. For all of these reasons, the industry has not been quick to develop handheld versions of conventional radiology applications because the PDA versions of typical radiology applications offer no distinct advantages over the desktop or workstation versions.
Although development of PDA radiology applications has been modest in comparison to the growth of medical and surgical PDA tools, sufficient technologic improvements in PDA hardware performance will foster easier development of tools that may be specifically useful to radiologists. These improvements include faster processing speed, greater memory capacity, higher resolution screen displays, integrated telephony, 802.11 WiFi capabilities, and digital recording capabilities.
BEYOND THE OBVIOUS
The most obvious potential radiologic application is the display of imaging studies on a handheld computer. The status of the current technology is that while single images of “consultative” or educational quality can be displayed with reasonable fidelity, a PDA does not offer display capabilities that match the current size, spatial, and contrast resolution of a clinical PACS workstation. Moreover, limitations in networking, processing speed, and memory prevent efficient display of entire series of images. Commercial solutions for PDA medical image display may not be beneficial to the radiologist; however, they are useful to the mobile clinician who may want to reinforce a clinical point with a sample image. Many of these limitations are addressed by the tablet PC.
While display of imaging studies is not the most compelling type of application for radiologists, there are other tools that have yet to be commercially developed that could be of great value to the radiologist. Since greater capacity for mobility is the single technologic advantage to handheld or mobile computing, radiology-centric applications should combine the convenience of mobility with specific tools that the radiologist might need in transit or when away from the reading room environment.
Although dictation (either through conventional analog schemes or via speech recognition) is generally performed in the reading room environment, in certain circumstances, radiologists may find themselves in need of dictation facilities in another setting. The most likely circumstance is in a procedure suite (eg, biopsy), in an operating room (eg, intraoperative ultrasound), or when reviewing outside studies at an office or clinic. Many handheld devices have digital dictation capabilities that when uploaded to a central server can be either transcribed or processed with a speech engine. Using a simple text editor and a transcription web server that is configured to process wireless markup language (WML), a radiologist can potentially review and approve transcription on a web-enabled PDA.
Handheld tools that monitor radiology workflow and practice management tools are additional applications that leverage the power and convenience of the PDA for radiologists. The transformation of entire radiology departments into the all-digital domain has brought tremendous gains in efficiency and has allowed practices to grow. There is a vast flow of data between information systems both within the radiology department and between outlying imaging centers, clinics, and hospitals. Extraction of key elements of the communications data stream can provide direct measures of practice efficiency. This “digital dashboard” concept has been used for many years in factory settings to create custom tools that monitor principle metrics of how the company functions. These displays are often role based, designed to reveal information that is relevant to the individual’s role in the organization. For example, an individual radiologist may be interested only in monitoring factors that relate to their own workflow (eg, number of outstanding studies or reports), whereas the group president/chairman or administrator may be interested in the overall health of the practice at any given moment, looking for, perhaps, inefficiencies. Alternatively, the radiology system administrator may have interest only in the overall health of the information systems, modalities, and archives and would use the portable dashboard to anticipate hardware malfunctions before they occur. Custom graphical displays are used to monitor specific functions and alert personnel when specific metrics are beyond a designated threshold. Periodic data extractions from a RIS/PACS system displayed on a PDA can show, for example, how many orders are pending by modality, the number of studies waiting for interpretation at each location in the practice (Figure 1), and the number of examinations completed by each modality in the practice in a given period of time. Access to this data is valuable to the mobile radiologist while on their way to work, at a meeting, or traveling between offices.
The ultimate portable computing device for the radiologist has yet to be realized. The tablet PC, however, may provide the ideal workspace for a true portable reading room. Larger than a conventional PDA, the tablet PC offers a large writing surface and viewing area to display certain types of imaging studies at close to diagnostic resolution. The improved computing power of tablets over PDAs also permits simultaneous execution of additional applications such as speech recognition software.
Adam E. Flanders, MD, is a neuroradiologist at Thomas Jefferson University Hospital, Philadelphia.
