DR. LEMKE is a professor of computer graphics and computer-assisted medicine at Technical University in Berlin, Germany.Communication systems based on local area networks with ring topology were first developed
DR. LEMKE is a professor of computer graphics and computer-assisted medicine at Technical University in Berlin, Germany.
Communication systems based on local area networks with ring topology were first developed in Europe in the early 1970s, led by the University of Cambridge with a 10-Mbit/sec prototype system. Telecommunication companies and research institutions first made use of these systems for nonmedical applications. During the late '70s, attempts were also made at the Technical University of Berlin and elsewhere1 to use LANs for medical image communication, but these first system concepts never reached the stage of implementation in a clinical setting.
The first real clinical PACS implementations took place in the U.S. in the early '80s at the University of Pennsylvania, University of California, Los Angeles, and University of Kansas. Some more or less successful PACS developments also took place in Europe in the 1980s, particularly in the Netherlands, Belgium, France, Austria, the U.K., Italy, and Germany. Most systems could be characterized by their focus on a single clinical department, such as radiology or nuclear medicine. European hospital-wide PACS with high visibility evolved in the early '90s in London (Hammersmith Hospital) and Vienna (SMZO). These were followed in the late '90s by 10 to 20 PACS installations in each of the major industrialized countries in Europe.
During this early development phase of PACS, its implementation was mainly a matter of the radiology department. This is changing rapidly, and PACS planning is increasingly seen in the context of a hospital-wide or regional approach. With increased networking among healthcare institutions and the growing relevance of teleradiology scenarios, PACS strategies must take not only local but also regional and global factors into consideration.
PACS in Europe is moving toward a more strategic, rather than situational solution-seeking approach. This is best exemplified by a reference project in Saxony, Germany, called SaxTeleMed. The project was initiated by the Ministry of Social Welfare, Health, Youth and Family of the Free State of Saxony. It covers seven regional projects distributed throughout Saxony. Each regional project is organized around so-called lead hospitals, which network with other cooperating hospitals and medical practices. The regional reference projects are designed to be largely independent, although in some instances, a network connection between them is also considered. Altogether, 39 hospitals and medical centers are involved.
The aim of this program is to test the technical, organizational, legal, and economic problems in digitization and networking within Saxony. The knowledge gained from this project is expected to improve future PACS investment decisions in healthcare and, above all, to implement secure systems.
Two innovative aspects of the project are the development of a quality function deployment (QFD) method for PACS specification and selection and the introduction of a health professional card (HPC).
Public healthcare in the Free State of Saxony is represented by 90 hospitals and two university clinics. When the state government came into office in the autumn of 1990, fundamental deficiencies in the hospitals of Saxony had to be remedied and the in-patient medical care of the population needed substantial improvement.
The initial situation was characterized by a desolate state of repair in the hospitals, often unacceptable hygiene conditions, and the deficient quality of the medical equipment as well as the lack of modern medical-technical equipment. Hospital planning faced the task of adjusting the overcapacity of hospital beds from the German Democratic Republic period (which had arisen because of a shortage of nursing home places and a lack of outpatient care) to a level of capacity suited to regional demand. In this restructuring, not only were overcapacities eliminated, but necessary new services were created, in heart surgery and cancer therapy, for example.
As SaxTeleMed covers its seven telemedicine projects, the focus is on radiology. The seven hospitals in Saxony designated as lead hospitals correspond to the number of projects: Zwickau Heinrich Braun Hospital, Chemnitz General Hospital, Erlabrunn Hospital, Dresden-Neustadt City Hospital, Zittau District Hospital, Dresden-Friedrichstadt General Hospital, and Riesa District Hospital. In these lead hospitals, a restructuring into an almost filmless hospital is meant to take place by means of digitization and image communication that spreads out from radiology to other departments. Some of the aspects to be observed and investigated in this process include the following:
Supervision being carried out by a scientific advisory board is intended to ensure transparent and efficient project specification, selection, implementation and evaluation. Fifteen recognized experts from the fields of medicine, economics, and informatics have been appointed to this board from different regions of Germany. Appropriate standards and structural guidelines have been given by this board to the lead hospitals.
RFP AND QFD
A structural approach was seen to be particularly helpful in preparing the request for proposal (RFP) and, subsequently, in the product and system evaluations. A working approach for creating a RFP can be derived from QFD techniques. QFD is a concept introduced by Yoji Akao in Japan for developing design quality in production environments. It was modified and improved in the U.S. and Europe and is highly suitable for system specifications and evaluations. The QFD methodology is based on a strong involvement of the user in determining product/system requirements with clearly stated importance ratings.
Appropriate engineering attributes are selected to meet the user requirements (UR). The template constructed, sometimes referred to as the House of Quality, may also be applied to information technology environments such as the specification and selection of PACS. Further improvements to this method may be incorporated from material purchasing strategies. This type of PACS specification and selection method has been realized for some of the projects of SaxTeleMed.
The basic approach was to prepare an n-level hierarchical tree structure of the user requirements, referred to as the UR-tree. For a typical PACS, this may contain up to five levels of detail, with 0 as the highest and 4 as the lowest level. For one hospital of SaxTeleMed, almost 400 different requirements have been structured in this way. The selection of the requirements and their structure should reflect the basic content of the RFP.
Some or all levels of the UR are assigned importance ratings (IR) and impact factors (IF). This facilitates the evaluation of the PACS technology and viability of the potential vendor solution. The IR parameter is given in percentages and describes the weight with which a specific requirement contributes to the UR of the next higher level in the hierarchy. It should be determined by experts in the PACS project team independently of any expected solution offered in the tenders by the vendors.
Engineering attributes (EA) are features in the offering or tender of the vendor that are examined in relation to the fulfillment of the URs. The degree of fulfillment may be parameterized by means of a linear or progressive evaluation scale. In the QFD-derived method, a progressive scale is recommended with the following parameter setting:
0: no fulfillment
1: low degree fulfillment
3: satisfactory fulfillment
9: complete fulfillment
This scale allows for a strong differentiation between no and complete fulfillment of the URs. After the successful implementation of the SaxTeleMed project, this RFP methodology has been used for PACS planning in other hospitals, such as the Zurich University Hospital in Switzerland.
HEALTH PROFESSIONAL CARD
An overall requirement enforced by the scientific advisory board was that digital data have to be secured, primarily for medical reasons. This clearly leads to the establishment of an electronic signature in the healthcare environment. In SaxTeleMed, the following security sensitive applications will be integrated:
The decision to use a digital signature was facilitated by the availability of a specification for a digital signature card in the healthcare environment, the so-called health professional card. Three of the seven projects of SaxTeleMed will use the HPC. The working group of the scientific advisory committee, with members of Sächsische Landesärztekammer, supported its specification from the beginning. The primary decision criterion was to meet the requirements of the German signature law (SigG), however, including the requirements of the so-called qualified digital signature. Only with this type of digital signature can physicians meet the requirements of legal equivalence to handwritten signed documents.
In its basic directive, the signature law requires each user to contact a trust center for requesting a HPC card. As long as the user is paying a regular fee to the trust center, it will maintain the services for the validity of the personal HPC attributes. External third parties such as employers or contracting partners are responsible only for the validation of additional attributes. Possible reasons for this are that the usage of the digital signature is tied to the attribute features (e.g., signature of authorized government officials) or that an additional functionality like an ID card is combined with the digital signature. This is the envisioned main usage of the qualified digital signature, according to the new signature law.
The outcome of the SaxTeleMed model program is expected to have the following effects:
The scientific advisory board has worked out three main levels for the evaluation of the SaxTeleMed model program:
Level 1: Verification of the standardization achieved in all projects in regard to the communication of images and reports.
Level 2: Evaluation of the work processes in all projects of internal and external communication of images and reports based on a uniform project-wide process structure, including cost-benefit analyses.
Level 3: Evaluation of the project-specific issues:
Some evaluation results are already available, and others are expected to be ready at the beginning of 2002.
OTHER REGIONAL PACS PROJECTS
The SaxTeleMed project is not unique. Similar endeavors for wide area or regional PACS can be found. In Siena, Italy, a RIS/PACS project implementation being carried out at a provincial level includes four heterogeneous hospitals and two healthcare centers, representing approximately 290,000 radiological procedures per year. The implementation of RIS/PACS is seen as a highly complex project that introduces a cultural change in the radiology department's organization and management.
"Work flow model comparisons (analog and digital) require a global radiology reengineering in terms of redrawing the distribution of physical spaces, redefining the human resources allocation, redefining the data, information and image flows, and replanning the staff and patient flows," according to this project.2
Another project in Hordaland County in Norway integrates eight hospitals to facilitate transmission of images and data between their radiological departments. The county is expected to carry out more than 350,000 procedures per year for improved patient care in this "seamlessly integrated system."3
A wide area approach has also been followed in Sweden with Pax Vobiscum, an intranet-based system for the modern radiology department. With the conviction that "digital radiology in its most extreme form . . . has until recently not really been established as a routine phenomenon, but rather as a business for pioneers, visionaries, and crazy people in general," 4 emphasis has been given to providing PACS with added value to the users.
The Pax Vobiscum project built one virtual filmless radiology department through a total digitalization and integration of five independent radiology departments within Örebro County in Sweden. This virtual department performing approximately 180,000 procedures a year is one of the largest PACS installations in Europe, with 48 radiology rooms forming a functional unit.
Europe is trying to be at the forefront in mobile medicine by extending the functionality of PACS to mobile teleradiology. A project on mobile teleradiology called MTM (Multimedia Terminal Mobile) is being funded by the European Union (EU) with the University of Heidelberg being prime contractor, building on experiences gained with the CHILI system (a software architecture that provides a PACS and teleradiology infrastructure).5 The CHILI radiology network has more than 50 medical installations in Germany and seven installations in the U.S. Extending the CHILI concept, mobile teleradiology software will use personal digital assistants (PDAs), pen-based computers, or Webpads for wireless access to medical images stored in the archive of a PACS or DICOM compatible workstation, based on the Universal Mobile Communication System. A survey carried out mostly in radiology departments in Spain and Germany came up with various application scenarios:
"From local to mobile" is the theme of next year's annual EuroPACS conference in Oulu, Finland. Telemedicine has played a key role in Oulu's technological development for more than 10 years, and award-winning mobile medicine projects specifically have been pioneered in the medical faculty of the University of Oulu.