CD-ROM Prototype Applications Within the Department of Veterans Affairs James E. Demetriades, M.S., P.E., and Enrique Gomez, B.S. Albany Information Systems Center Department of Veterans Affairs Frear Building, Suite 301 2 Third St., Troy NY 12180
Abstract
The Department of Veterans Affairs (VA) has been actively involved in examining the benefits of Compact Disc Read Only Memory (CD-ROM) to its operations. Approximately twenty VA titles either have been produced or are scheduled for production by Summer of 1991. Both textual and database CDs have been prototyped. Several of the CDs have been integrated directly into the VA's MUMPS-based hospital information systems. Titles which contain patient information employ the Data Encryption Standard (DES) for sensitive information. A related project involves the installation of a system which allows common VDTs on the hospital system to access commercial CDs such as MEDLINE, PDR, and CCIS. The prototypes have been successful and very favorably received by users.
technologies. Our responsibilities include performing general assessment, prototyping, and where indicated, field testing of select prototypes which might then be recommended for deployment throughout the VA Decentralized Hospital Computer Program (DHCP). The optical assessment areas extend beyond CDROMs and include optical patient cards, and Write Once Read Many (WORM) drive applications. [1] The project is guided by several VA expert groups. The closest working committee has members from various clinical, technical, and management backgrounds. They regularly discuss the direction and progress of the project frequently offering key suggestions. Other groups such as the VA expert Clinical Record (CR) group and Medical Administration Service (MAS) experts from the field are contributors.
Department of Veterans Affairs Introduction Health care facilities have long struggled with the need to provide large amounts of diverse and frequently fragmented information to many individuals across various disciplines. In the VA case the challenge is even more severe due to its size and geographical distribution of its users. The fairly recent emergence of optical storage technologies which are commercially available appear to offer some very attractive benefits and are being assessed by the VA. Compact Disc-Read Only Memory (CDROM) is one of those technologies which we anticipate will be vastly successful.
Assessment Team The Optical Technology Assessment Team at the Albany Information Systems Center (ISC) is charged with examining various optical storage 0195-4210/91/$5.00 © 1992 AMIA, Inc.
Information distribution is especially difficult in the case where the requirements encompass a multi-facility organization such as the VA. With over 172 medical centers and 200 outpatient clinics, VA handles several million inpatient admissions and over 22 million outpatient visits each year. Associated with this are 56 million prescriptions. Considering that each facility largely operates independently, information delivery becomes even more complex and difficult. The cost in not having integrated information available, however, is greatly taxing upon finite resources. The DHCP system which services these facilities is a highly integrated MUMPS-based hospital information system. Local clinical, administrative, and resource information is available to virtually all workers with a need-to-know from any terminal on the system. Most hospital ancillary
338
services are supported under DHCP. Many of the software components are in the public domain.
MUMPS implementations. The entire collection of all these files consumed less than 18 percent of the total available space on the disc. The disc has been successfully read from a variety of systems including IBM PC DOS, Apple, Unix, and others which have ISO-9660 CD extension utilities.
CD-ROM Technology CD-ROM discs are 12 centimeters in diameter (4.72"), made of plastic and contain over 600 Megabytes of data, 550 of which are allocated to user data, and the remainder consumed by error correction data. The equivalent text content is roughly 150,000 printed pages, or 250 large books. A low intensity laser is used to retrieve the data. One technical limitation of CDs is their slow access time which is on the order of 300-1000 mSec, less than a typical floppy diskette. [2], [3]
A second issue evaluation CD is now well underway and targeted for replication in Winter 1991. The original scope was to assess the use of the CD as software and documentation distribution media for VA. The public interest in the VA software led to a wide variety of users, non-VA, institutional, and foreign countries, to acquire this CD. This expanded assessment showed that the specific requirements from these groups pointed out some limitations to the first release which are being corrected for the second: Installation Guide must be incorporated into user document, software installation must be possible on new accounts or volumes, and software installation must account for package dependencies.
The economics of CD-ROMs are very alluring. Once all the data has been collected, indexed and formatted, the cost to master the disc is currently in the range of $1700 and the replication of discs is around $1.80 each. These prices can vary greatly depending on many variables including the exact nature of services required such as data compression, fast turnaround, jewel cases, shrinkwrap packaging, etc. The cost for commercial retrieval engine software licenses, if necessary, for either text or databases is additional. Even so, the cost for producing a limited run of a few hundred inhouse prepared discs might run 5-15 dollars, and 50150 dollars per disc if a contractor were to premaster/master the data with a commercially supplied retrieval engine.
Currently the VA does not distribute the DHCP documentation to the medical centers in electronic form (tapes, diskettes, etc.), but in hardcopy. Typically, the VA User and Technical documentation, sent to the hospital end-users, is separate from the package installation guide sent to the computer center staff. This procedure works fine within the VA but is a problem for non-VA users. A simple standard operating procedure is being implemented requiring that documentation submitted for inclusion in the DHCP CD contain installation notes, user documentation, and technical guides in electronic form.
These characteristics are very appealing when large databases or textual information need to be distributed to many systems. The technology is stable and well defined within the ISO-9660 standard. It has found widespread popularity within the publishing community and suppliers of niche databases.
Many VA software releases and version updates are usually layered on top of existing software packages and not stand-alone. Version 5.1 of some package would need to be overlayed over 5.0. This created problems with non-VA users who are trying to install the VA public domain software for the first time. Another procedure is being implemented requiring that software releases install properly on MUMPS systems without requiring the existence of previous versions of the software.
Software and Documentation Prototype The first evaluation title produced in June 1990 by the optical team was a collection of virtually all DHCP public domain software and user documentation. Over 10,000 software routines and all associated user and technical documentation were included. The documentation was stored both as straight ASCII files and also in Microsoft WORD format. The routines were stored in files which may be directly uploaded by most, if not all, popular
Some of the DHCP packages require the existence of data dictionaries, callable routines, or data from other packages. These dependencies cause problems with non-VA sites whom are not running a full complement of the VA DHCP software. An additional requirement for inclusion in the next DHCP CD is that dependencies are addressed to
339
allow packages to install completely. This is a more difficult goal to achieve and in some cases may reduce the power and scope of some packages.
credit card sized devices with processing capabilities.
[5]
Current work includes the implementation of a custom text retrieval engine written in MUMPS. Functional specifications include the ability to operate as a standalone product or one which is fully integrated with the DHCP system. The integrated functionality permits any user of DHCP to access CD-ROM document text from their terminal either in the conventional BROWSE mode, or via direct context sensitive links from DHCP's "Help" command. Other features include: proximity queries, boolean operators, wildcards, selective database/document limiters and download abilities. The first operational prototype is expected to be complete in the second half of 1991.
The results have been that DHCP software and documentation releases on CD-ROM are extremely practical for the VA. The high cost of multiple magnetic tapes and hardcopy reproductions for a single medical center far outweigh the cost of replicating a single CD. CDs can be distributed to all hospitals on a monthly basis, although quarterly would be most likely, and continue to be costeffective.
Secure Database Pilot Project
Access is currently via a standalone 386 class PC, dual CD-ROM reader and a smart card reader. The user inserts their card into the reader and enters a personal identification code (PIC) much like a conventional ATM machine. Contained within the card is the DES algorithm. The authentication process between the smart card and workstation never allow data to be in the clear.
Some of the many titles being produced for this project include: inpatient treatment, outpatient clinic visits, fee for services, dental, and cost distribution databases. The outpatient clinic visit database with some 22 million records spans five CD-ROMs for a single year. Another feature is the ability to query across databases on common fields such as SSN. Frequency analysis and tabulation, export to other database formats, and download are also featured. In all some fourteen titles will be produced from eight different databases most which span multiple years. There are over 30 test sites and 93 workstations involved in this pilot. The first titles began arriving from the contractor in February and are expected to be complete in July. The results thus far have been very favorable. The entire evaluation will continue for the remainder of the calendar year.
VA has several very large centralized databases located at its Austin, Texas Data Processing Center. In recent years the VA has been able to increase its utilization of this operational patient data mainly through remote terminal access for a small but increasing select group of users. There exists an initiative termed the Integrated Patient Data Base (IPDB), which is attempting to allow more powerful and widespread access to these databases by distributing the data across four regional systems in which both the systems and the data are integrated. [4] In support of the IPDB initiative, an evaluation of using compact disks as an alternative is being made.
VA facilities operate largely independently from each other. The VA currently has no comprehensive electronic medical record. A fairly mobile veteran population and the geographic proximity of certain medical centers allow a veteran seeking care to frequent easily more than one facility. The result is the potential for a medical record which is distributed among several medical centers. The possibility that a medical center may not be aware of all episodes of care a veteran has experienced is an issue the VA takes seriously.
One of the more challenging requirements is that these CD-ROMs be secure. That is, any sensitive patient data be protected such that if the CDROM were to be examined by an unauthorized user the security would not be compromised. This requirement is met by using Data Encryption Standard (DES) encryption of sensitive fields on the CD combined with user issued smart cards which are
The MPD system allows medical centers to access a CD-ROM and determine dates, locations, and types of care a patient has received within the VA health care system. The CD-ROM is mounted on a microcomputer (PC) which is networked to the VA minicomputer system. Data is directly accessible to DHCP using Distributed Data Processing (DDP) protocols. The system in its current form is fast and
340
Minimal Patient Dataset (MPD)
easy to maintain. The information it provides is invaluable in establishing a comprehensive health care record. [6] The MPD component is also complementary to the optical patient card work. [7] It allows facilities to check patient cards independently for visit history completeness and serves as a registry for duplicate, lost or stolen cards. One limitation is that the information on a CD-ROM issued monthly is 6-8 weeks out of date, reducing its value for a very active and mobile patient. A second complementary initiative is DHCP's new Patient Data Exchange (PDX) module. PDX allows a medical center to electronically query another VA facility for DHCP administrative and clinical information. This approach relies on a VA wide area network among all facilities. A blind query to 172 facilities requesting patient visit information would be prohibitively inefficient. Use of the MPD however, can easily solve this need. It can determine all locations where care occurred and interface with the PDX module to generate requests for those facilities where information exists. The VA can, with the use of these modules, locate and acquire the various distributed components which comprise the veteran's medical record thereby enhancing quality of care.
MPD from a wide variety of MUMPS applications. Data is transferred between the PC and the minicomputer using DDP. User requests are placed in a global which is polled by the PC. Requests are processed and data is returned to the VAX via DDP. Status information is available for all processes. Although the PC is accessed remotely from the VAX, there are some functions which are available on the PC to allow for easier management. These include information on configuration, error log, and numerous statistics. One of the main uses of the MPD will be during DHCP registration. The patient NAME, SSN, and other demographic data will be available from either an Optical Patient Card, patient interview, or existing database. The MPD tool kit allows a call to the MPD search from the Patient registration option. The MPD returns information on other locations where care has been delivered. At this point, PDX can be accessed and electronic exchanges initiated to one, many or all sites the registration user requires. The MPD will complement the Patient Data Exchange function giving physicians a more comprehensive view of a patient's clinical history.
CD-ROM Network Servers A companion project the ISC is working on involves the evaluation of a commercial CD-ROM network server. The system allows multiple users to concurrently access multiple CD-ROMs. User access can be made through modem or in-house VT-220 terminals using the ISC VAX systems, or directly from local PCs on the network.
The design of the MPD database utilizes an indexed sequential data file with a two level index. Social Security Number is the retrieval key. Name was discarded because of the many records which could be returned with a partial name query. The patient records are sorted by the encrypted SSN. By storing the first level index in RAM and performing block reads on the second level index stored on the CD, predictable retrieval times will result. Our initial tests without fine-tuning have yielded retrieval rates in the range of 5-6 seconds on the full 24 million record database. In most cases only one read to the database will be required to obtain all visit records for a patient from the database.
The system employs two PCs each which contain four CPU boards and 2 Megabytes of memory. Along with each CPU is a corresponding network card. The servers use virtual disks on the VAX to store retrieval software as well as various network and CD-ROM drivers. The CD-ROM readers are mounted in a tower configuration unit which also has nodes on the network, thus allowing direct tower access from PCs on the network and freeing up the server for VDT users.
There are two basic components to the software design of the MPD application. The first is a dedicated MUMPS based program on the PC which accesses patient data on the CD-ROM. The second is a tool kit of MUMPS routines residing on the DHCP VAX which is used to request patient data from the PC. These routines can be used by any number of simultaneous users. Programmer entry points are documented so programmers may call the
One of the main problems the VA faces with the integration of commercial CD-ROM databases and the MUMPS based DHCP is that many of the commercial systems are designed to run on PC platforms and they may use extended ASCII characters or graphics. This is incompatible with text
341
based DHCP systems and display hardware. The network platform also includes software which allows a re-map of the advanced PC keyboards and character sets to a more standard VT-100 compatible terminal. This allows VT-100 compatible terminals to access the same application that a PC would except for advanced display modes. This capability is necessary to VA hospitals where most of the display hardware is ASCII based text terminals. We are exami i g the benefits of using this configuration to allow user access to such commercial titles as: Physicians' Desk Reference (PDR), Medline, and Computerized Clinical Information System (CCIS).
REFERENCES [1] Demetriades, E. James, et al., Optical Storage Technology Assessment for MUMPS Based Systems. MUG Quarterly Vol XX No 1, pp 101-104, 1990 [2] Lambert, Steve, editor, CD ROM. The New Papyrus. Microsoft Press: Redmond, WA. 1986 [3] Ropiequet, Suzanne, editor, CD ROM v. 2. Optical Publishing. Microsoft Press: Redmond, WA. 1987
[4] Integrated Patient Database To Go National, VHS&RA IRM Newsletter, Vol. 3 No. 3, Sept. 1990.
[5] Data Encryption Algorithm, Federal Information Processing Standards Publication (FIPS PUB 46)
Conclusion
VA activity in examining the benefits of Compact Discs will have produced approximately twenty diversified titles by Spring of 1991. Both textual and database CDs have been prototyped, many which have been integrated directly into VA DHCP MUMPS-based hospital information systems. Titles which contain patient information successfully employ data encryption of sensitive information. Related work includes the installation of a system which allows common VDTs on a hospital system to access commercial CDs. These prototypes have all been successful and very favorably received by users.
The need to provide large amounts of diverse and frequently fragmented information to large numbers of individuals across many disciplines can be met to a large degree by CD-ROM. Compact disk technology can help resolve some very difficult problems common to organizations like the VA. Several opportunities have been identified and presented here, additional ones continue to present themselves to the optical-assessment team at the Albany ISC as we continue to explore this very rich technology.
[6] Gomez, Enrique, et al., A MUMPS Based CDROM Application: DHCP Minimal Patient Dataset. MUG Quarterly Vol XXI No 1, pp 29-31, 1991
[7] Demetriades, E. James, Gomez, Enrique., Optical Patient Card Prototype Within the Department of Veterans Affairs. MUG Quarterly Vol XX No 1, pp 109-112, 1990
APPLE is a registered trademark of Apple Co. IBM PC DOS is a registered trademark of IBM Co. MEDLINE is a registered trademark of The National Library of Medicine MICROSOFT WORD, MSCDEX are registered trademarks of Microsoft Co. MUMPS is a registered trademark of the Massachusetts General Hospital MSM is a registered trademark of the Micronetics
Corporation. PDR is a registered trademark of Medical Economics Co. UNIX is a registered trademark of AT&T Co. VAX, VAX-DSM, are registered trademarks of the
Digital Equipment Corporation.
342
Abstract
The Department of Veterans Affairs (VA) has been actively involved in examining the benefits of Compact Disc Read Only Memory (CD-ROM) to its operations. Approximately twenty VA titles either have been produced or are scheduled for production by Summer of 1991. Both textual and database CDs have been prototyped. Several of the CDs have been integrated directly into the VA's MUMPS-based hospital information systems. Titles which contain patient information employ the Data Encryption Standard (DES) for sensitive information. A related project involves the installation of a system which allows common VDTs on the hospital system to access commercial CDs such as MEDLINE, PDR, and CCIS. The prototypes have been successful and very favorably received by users.
technologies. Our responsibilities include performing general assessment, prototyping, and where indicated, field testing of select prototypes which might then be recommended for deployment throughout the VA Decentralized Hospital Computer Program (DHCP). The optical assessment areas extend beyond CDROMs and include optical patient cards, and Write Once Read Many (WORM) drive applications. [1] The project is guided by several VA expert groups. The closest working committee has members from various clinical, technical, and management backgrounds. They regularly discuss the direction and progress of the project frequently offering key suggestions. Other groups such as the VA expert Clinical Record (CR) group and Medical Administration Service (MAS) experts from the field are contributors.
Department of Veterans Affairs Introduction Health care facilities have long struggled with the need to provide large amounts of diverse and frequently fragmented information to many individuals across various disciplines. In the VA case the challenge is even more severe due to its size and geographical distribution of its users. The fairly recent emergence of optical storage technologies which are commercially available appear to offer some very attractive benefits and are being assessed by the VA. Compact Disc-Read Only Memory (CDROM) is one of those technologies which we anticipate will be vastly successful.
Assessment Team The Optical Technology Assessment Team at the Albany Information Systems Center (ISC) is charged with examining various optical storage 0195-4210/91/$5.00 © 1992 AMIA, Inc.
Information distribution is especially difficult in the case where the requirements encompass a multi-facility organization such as the VA. With over 172 medical centers and 200 outpatient clinics, VA handles several million inpatient admissions and over 22 million outpatient visits each year. Associated with this are 56 million prescriptions. Considering that each facility largely operates independently, information delivery becomes even more complex and difficult. The cost in not having integrated information available, however, is greatly taxing upon finite resources. The DHCP system which services these facilities is a highly integrated MUMPS-based hospital information system. Local clinical, administrative, and resource information is available to virtually all workers with a need-to-know from any terminal on the system. Most hospital ancillary
338
services are supported under DHCP. Many of the software components are in the public domain.
MUMPS implementations. The entire collection of all these files consumed less than 18 percent of the total available space on the disc. The disc has been successfully read from a variety of systems including IBM PC DOS, Apple, Unix, and others which have ISO-9660 CD extension utilities.
CD-ROM Technology CD-ROM discs are 12 centimeters in diameter (4.72"), made of plastic and contain over 600 Megabytes of data, 550 of which are allocated to user data, and the remainder consumed by error correction data. The equivalent text content is roughly 150,000 printed pages, or 250 large books. A low intensity laser is used to retrieve the data. One technical limitation of CDs is their slow access time which is on the order of 300-1000 mSec, less than a typical floppy diskette. [2], [3]
A second issue evaluation CD is now well underway and targeted for replication in Winter 1991. The original scope was to assess the use of the CD as software and documentation distribution media for VA. The public interest in the VA software led to a wide variety of users, non-VA, institutional, and foreign countries, to acquire this CD. This expanded assessment showed that the specific requirements from these groups pointed out some limitations to the first release which are being corrected for the second: Installation Guide must be incorporated into user document, software installation must be possible on new accounts or volumes, and software installation must account for package dependencies.
The economics of CD-ROMs are very alluring. Once all the data has been collected, indexed and formatted, the cost to master the disc is currently in the range of $1700 and the replication of discs is around $1.80 each. These prices can vary greatly depending on many variables including the exact nature of services required such as data compression, fast turnaround, jewel cases, shrinkwrap packaging, etc. The cost for commercial retrieval engine software licenses, if necessary, for either text or databases is additional. Even so, the cost for producing a limited run of a few hundred inhouse prepared discs might run 5-15 dollars, and 50150 dollars per disc if a contractor were to premaster/master the data with a commercially supplied retrieval engine.
Currently the VA does not distribute the DHCP documentation to the medical centers in electronic form (tapes, diskettes, etc.), but in hardcopy. Typically, the VA User and Technical documentation, sent to the hospital end-users, is separate from the package installation guide sent to the computer center staff. This procedure works fine within the VA but is a problem for non-VA users. A simple standard operating procedure is being implemented requiring that documentation submitted for inclusion in the DHCP CD contain installation notes, user documentation, and technical guides in electronic form.
These characteristics are very appealing when large databases or textual information need to be distributed to many systems. The technology is stable and well defined within the ISO-9660 standard. It has found widespread popularity within the publishing community and suppliers of niche databases.
Many VA software releases and version updates are usually layered on top of existing software packages and not stand-alone. Version 5.1 of some package would need to be overlayed over 5.0. This created problems with non-VA users who are trying to install the VA public domain software for the first time. Another procedure is being implemented requiring that software releases install properly on MUMPS systems without requiring the existence of previous versions of the software.
Software and Documentation Prototype The first evaluation title produced in June 1990 by the optical team was a collection of virtually all DHCP public domain software and user documentation. Over 10,000 software routines and all associated user and technical documentation were included. The documentation was stored both as straight ASCII files and also in Microsoft WORD format. The routines were stored in files which may be directly uploaded by most, if not all, popular
Some of the DHCP packages require the existence of data dictionaries, callable routines, or data from other packages. These dependencies cause problems with non-VA sites whom are not running a full complement of the VA DHCP software. An additional requirement for inclusion in the next DHCP CD is that dependencies are addressed to
339
allow packages to install completely. This is a more difficult goal to achieve and in some cases may reduce the power and scope of some packages.
credit card sized devices with processing capabilities.
[5]
Current work includes the implementation of a custom text retrieval engine written in MUMPS. Functional specifications include the ability to operate as a standalone product or one which is fully integrated with the DHCP system. The integrated functionality permits any user of DHCP to access CD-ROM document text from their terminal either in the conventional BROWSE mode, or via direct context sensitive links from DHCP's "Help" command. Other features include: proximity queries, boolean operators, wildcards, selective database/document limiters and download abilities. The first operational prototype is expected to be complete in the second half of 1991.
The results have been that DHCP software and documentation releases on CD-ROM are extremely practical for the VA. The high cost of multiple magnetic tapes and hardcopy reproductions for a single medical center far outweigh the cost of replicating a single CD. CDs can be distributed to all hospitals on a monthly basis, although quarterly would be most likely, and continue to be costeffective.
Secure Database Pilot Project
Access is currently via a standalone 386 class PC, dual CD-ROM reader and a smart card reader. The user inserts their card into the reader and enters a personal identification code (PIC) much like a conventional ATM machine. Contained within the card is the DES algorithm. The authentication process between the smart card and workstation never allow data to be in the clear.
Some of the many titles being produced for this project include: inpatient treatment, outpatient clinic visits, fee for services, dental, and cost distribution databases. The outpatient clinic visit database with some 22 million records spans five CD-ROMs for a single year. Another feature is the ability to query across databases on common fields such as SSN. Frequency analysis and tabulation, export to other database formats, and download are also featured. In all some fourteen titles will be produced from eight different databases most which span multiple years. There are over 30 test sites and 93 workstations involved in this pilot. The first titles began arriving from the contractor in February and are expected to be complete in July. The results thus far have been very favorable. The entire evaluation will continue for the remainder of the calendar year.
VA has several very large centralized databases located at its Austin, Texas Data Processing Center. In recent years the VA has been able to increase its utilization of this operational patient data mainly through remote terminal access for a small but increasing select group of users. There exists an initiative termed the Integrated Patient Data Base (IPDB), which is attempting to allow more powerful and widespread access to these databases by distributing the data across four regional systems in which both the systems and the data are integrated. [4] In support of the IPDB initiative, an evaluation of using compact disks as an alternative is being made.
VA facilities operate largely independently from each other. The VA currently has no comprehensive electronic medical record. A fairly mobile veteran population and the geographic proximity of certain medical centers allow a veteran seeking care to frequent easily more than one facility. The result is the potential for a medical record which is distributed among several medical centers. The possibility that a medical center may not be aware of all episodes of care a veteran has experienced is an issue the VA takes seriously.
One of the more challenging requirements is that these CD-ROMs be secure. That is, any sensitive patient data be protected such that if the CDROM were to be examined by an unauthorized user the security would not be compromised. This requirement is met by using Data Encryption Standard (DES) encryption of sensitive fields on the CD combined with user issued smart cards which are
The MPD system allows medical centers to access a CD-ROM and determine dates, locations, and types of care a patient has received within the VA health care system. The CD-ROM is mounted on a microcomputer (PC) which is networked to the VA minicomputer system. Data is directly accessible to DHCP using Distributed Data Processing (DDP) protocols. The system in its current form is fast and
340
Minimal Patient Dataset (MPD)
easy to maintain. The information it provides is invaluable in establishing a comprehensive health care record. [6] The MPD component is also complementary to the optical patient card work. [7] It allows facilities to check patient cards independently for visit history completeness and serves as a registry for duplicate, lost or stolen cards. One limitation is that the information on a CD-ROM issued monthly is 6-8 weeks out of date, reducing its value for a very active and mobile patient. A second complementary initiative is DHCP's new Patient Data Exchange (PDX) module. PDX allows a medical center to electronically query another VA facility for DHCP administrative and clinical information. This approach relies on a VA wide area network among all facilities. A blind query to 172 facilities requesting patient visit information would be prohibitively inefficient. Use of the MPD however, can easily solve this need. It can determine all locations where care occurred and interface with the PDX module to generate requests for those facilities where information exists. The VA can, with the use of these modules, locate and acquire the various distributed components which comprise the veteran's medical record thereby enhancing quality of care.
MPD from a wide variety of MUMPS applications. Data is transferred between the PC and the minicomputer using DDP. User requests are placed in a global which is polled by the PC. Requests are processed and data is returned to the VAX via DDP. Status information is available for all processes. Although the PC is accessed remotely from the VAX, there are some functions which are available on the PC to allow for easier management. These include information on configuration, error log, and numerous statistics. One of the main uses of the MPD will be during DHCP registration. The patient NAME, SSN, and other demographic data will be available from either an Optical Patient Card, patient interview, or existing database. The MPD tool kit allows a call to the MPD search from the Patient registration option. The MPD returns information on other locations where care has been delivered. At this point, PDX can be accessed and electronic exchanges initiated to one, many or all sites the registration user requires. The MPD will complement the Patient Data Exchange function giving physicians a more comprehensive view of a patient's clinical history.
CD-ROM Network Servers A companion project the ISC is working on involves the evaluation of a commercial CD-ROM network server. The system allows multiple users to concurrently access multiple CD-ROMs. User access can be made through modem or in-house VT-220 terminals using the ISC VAX systems, or directly from local PCs on the network.
The design of the MPD database utilizes an indexed sequential data file with a two level index. Social Security Number is the retrieval key. Name was discarded because of the many records which could be returned with a partial name query. The patient records are sorted by the encrypted SSN. By storing the first level index in RAM and performing block reads on the second level index stored on the CD, predictable retrieval times will result. Our initial tests without fine-tuning have yielded retrieval rates in the range of 5-6 seconds on the full 24 million record database. In most cases only one read to the database will be required to obtain all visit records for a patient from the database.
The system employs two PCs each which contain four CPU boards and 2 Megabytes of memory. Along with each CPU is a corresponding network card. The servers use virtual disks on the VAX to store retrieval software as well as various network and CD-ROM drivers. The CD-ROM readers are mounted in a tower configuration unit which also has nodes on the network, thus allowing direct tower access from PCs on the network and freeing up the server for VDT users.
There are two basic components to the software design of the MPD application. The first is a dedicated MUMPS based program on the PC which accesses patient data on the CD-ROM. The second is a tool kit of MUMPS routines residing on the DHCP VAX which is used to request patient data from the PC. These routines can be used by any number of simultaneous users. Programmer entry points are documented so programmers may call the
One of the main problems the VA faces with the integration of commercial CD-ROM databases and the MUMPS based DHCP is that many of the commercial systems are designed to run on PC platforms and they may use extended ASCII characters or graphics. This is incompatible with text
341
based DHCP systems and display hardware. The network platform also includes software which allows a re-map of the advanced PC keyboards and character sets to a more standard VT-100 compatible terminal. This allows VT-100 compatible terminals to access the same application that a PC would except for advanced display modes. This capability is necessary to VA hospitals where most of the display hardware is ASCII based text terminals. We are exami i g the benefits of using this configuration to allow user access to such commercial titles as: Physicians' Desk Reference (PDR), Medline, and Computerized Clinical Information System (CCIS).
REFERENCES [1] Demetriades, E. James, et al., Optical Storage Technology Assessment for MUMPS Based Systems. MUG Quarterly Vol XX No 1, pp 101-104, 1990 [2] Lambert, Steve, editor, CD ROM. The New Papyrus. Microsoft Press: Redmond, WA. 1986 [3] Ropiequet, Suzanne, editor, CD ROM v. 2. Optical Publishing. Microsoft Press: Redmond, WA. 1987
[4] Integrated Patient Database To Go National, VHS&RA IRM Newsletter, Vol. 3 No. 3, Sept. 1990.
[5] Data Encryption Algorithm, Federal Information Processing Standards Publication (FIPS PUB 46)
Conclusion
VA activity in examining the benefits of Compact Discs will have produced approximately twenty diversified titles by Spring of 1991. Both textual and database CDs have been prototyped, many which have been integrated directly into VA DHCP MUMPS-based hospital information systems. Titles which contain patient information successfully employ data encryption of sensitive information. Related work includes the installation of a system which allows common VDTs on a hospital system to access commercial CDs. These prototypes have all been successful and very favorably received by users.
The need to provide large amounts of diverse and frequently fragmented information to large numbers of individuals across many disciplines can be met to a large degree by CD-ROM. Compact disk technology can help resolve some very difficult problems common to organizations like the VA. Several opportunities have been identified and presented here, additional ones continue to present themselves to the optical-assessment team at the Albany ISC as we continue to explore this very rich technology.
[6] Gomez, Enrique, et al., A MUMPS Based CDROM Application: DHCP Minimal Patient Dataset. MUG Quarterly Vol XXI No 1, pp 29-31, 1991
[7] Demetriades, E. James, Gomez, Enrique., Optical Patient Card Prototype Within the Department of Veterans Affairs. MUG Quarterly Vol XX No 1, pp 109-112, 1990
APPLE is a registered trademark of Apple Co. IBM PC DOS is a registered trademark of IBM Co. MEDLINE is a registered trademark of The National Library of Medicine MICROSOFT WORD, MSCDEX are registered trademarks of Microsoft Co. MUMPS is a registered trademark of the Massachusetts General Hospital MSM is a registered trademark of the Micronetics
Corporation. PDR is a registered trademark of Medical Economics Co. UNIX is a registered trademark of AT&T Co. VAX, VAX-DSM, are registered trademarks of the
Digital Equipment Corporation.
342
