The National Library of Medicine (NLM) and several thousand medical libraries, covering a broad spectrum ranging from major academic health science center libraries to small rural hospital libraries, constitute a large community entrusted with providing timely and accurate information to practitioners and researchers in biomedicine. Such information can take the form of bibliographic and factual databases, digital images of documents and medical x-rays, video sequences of medical procedures, digitized color images of dermatologic conditions, procedural rules found in expert systems, output of medical devices such as ultrasound, EKG, EMG and many others. These information types reside in many types of storage systems and some of them, mainly bibliographic databases, are routinely accessed via telephone modem and value-added public networks (Telenet, Tymnet). The potential and problems faced by medical databases are indicative of many other database applications.
As a consequence of several trends, professionals (end users) seek easy and rapid access to these diverse resources. These trends include: (a) the rapidly increasing global connectivity of the NREN/Internet; (b) the increasing availability of public domain software, both server (e.g., WWW, Gopher) and client (e.g., Mosaic); and (c) increasing power on the desktop, making true multimedia workstations possible.
Projects that address some of these application goals are being conducted at the NLM's R& center, the Lister Hill National Center for Biomedical Communications, as at many other universities, major libraries, medical centers and other institutions. The projects at NLM deal with document imaging, x-ray imaging, 3D visualization of anatomic data and others. Document imaging projects include SAIL and DocView. SAIL (System for Automated Interlibrary Loan) is a multi-workstation system connected via a token ring LAN. It accesses the NLM's mainframe computer for interlibrary loan (ILL) requests, parses the requests into document information and user information, passes the document descriptor to a store of about 200,000 already scanned journal page images on optical media, extracts the requested images, and uses an internal fax board along with the user's fax number (previously extracted from the ILL request) to fax the images out to the user's fax machine. The SAIL pilot system is designed to reduce or eliminate the manual activities that are routinely required to fill interlibrary loan requests.
In contrast to SAIL which relies on indirect access to images through the nationwide medical interlibrary loan service, DocView is a direct access system, anticipating the eventual availability of document image databases. It consists of client software running under MS Windows 3.1 that accesses images stored in servers, both inhouse-developed as well as public domain (such as WWW, Gopher, FTP), and retrieves the images over the Internet. DocView enables an end user to preview, display, manipulate, electronically bookmark, segment, cut and paste, and print the document received. DocView has the full capability of communications, document display and manipulation, but it can also use the WWW-Mosaic communications protocol to transfer the images over the Internet, and serve as the necessary viewer or browser.
Since most documents requested by users of their libraries will be in paper form for the foreseeable future, the NLM is also designing a multimodal transmission system that limits the manual activity of an operator to simply scanning a document. This system, called WILL, automatically retrieves ILL requests from NLM's mainframe computer, parses the requests, recognizes the recipient's fax number, mailing address or Internet IP address, and automatically sends the scanned images to the right place by the method requested by the user. The system is designed to place no burden on the operator beyond the scanning.
An x-ray imaging project, DXPNET, is motivated by the 17,000 x-rays taken as part of the nationwide NHANES II survey and 10,000 x-rays taken in the NHANES III survey (NHANES: National Health and Nutrition Examinations Survey). These x-ray films (cervical and lumbar spine; hands and knees) need to be preserved, and furthermore need to be read by radiologists. The NLM is scanning and archiving these in an optical disk jukebox, and building the server and client workstations to allow access to the images over the Internet. The user (radiologist) will be able to access and retrieve the images, and enter numeric readings and free text comments in a form on the screen. These readings and comments will then go to the jukebox where they will be stored in a database for access by other interested parties, e.g., epidemiologists, demographers, insurance companies, and government agencies.
Motion video is also of interest to the biomedical user. The NLM and other medical libraries have repositories of videotapes of surgical procedures, grand rounds, ultrasound examinations, educational seminars and others. The current procedure to gain access to such collections is for a user first to search index databases that provide information about the tapes, such as title, brief textual abstract, general topic, creator, institution, etc. The artifact itself, when requested, has to be packaged and mailed out to the requester. A project is under way in which the tapes are being digitized and compressed via MPEG, stored on optical disks, and accessed automatically by a link from a database search. Potentially important SP methods for video include compression by MPEG or motion JPEG and methods to link up of a citation received from a bibliographic database to a video sequence or some part of a sequence.