Wireless Data Access in the Clinical Environment



Cedars Sinai Medical Center is using web and wireless technology to provide its physicians access to clinical records. It is available inside the building (through PCs linked to the network by cable or wireless access), as well as a pilot project to use ‘clamshell’ hand-held computers in a clinical area. (Clamshell is the term used to describe a computer that consists of two hinged components, the screen and keyboard, whereas the Palm consists of a touch sensitive screen only.) Outside the building, physicians can monitor their patients through Palm V and Palm VII computers, whether they are on the move, in their private offices or at home.

This case study details:
• the practical implications of getting critical information to remote employees
• the importance of starting with web-enabled applications and the relative ease of adapting them for use through a mobile browser
• practical experience of using Palm computers to present information
• contrasting experience with ‘clamshell’ computers, where data entry is important
• the benefits of quicker access to information.

These aspects are explained by Ray Duncan, a medical doctor, who is director of technology and architecture for the Department of Enterprise Information Services. He is uniquely qualified to give an insight into both the users’ requirements and the technology implications.



Creating the Mobile Enterprise


Founded in 1902, the world famous Cedars Sinai Health System is the largest non-profit hospital in western US. It occupies a campus close to Beverly Hills in Los Angeles. The Center is committed to providing the best outpatient, acute, sub-acute and home patient care, as well as breakthrough biomedical research, graduate and undergraduate medical education and community service.
The biggest business unit is the Cedars Sinai Medical Center, an 850-bed hospital providing tertiary treatment, including transplants and other advanced surgery and treatments. Each building has a wired network and all buildings on the campus are linked together into a single network by a fibre optic ring.
The Medical Center has completed four different wireless pilot projects. It has wireless network access in accident and emergency clinical area and communal business areas. Access to the network from outside the hospital is through Palm hand-held computers. Medical staff in the paediatric department are interacting with clinical systems through clamshell computers.

Wireless Network

As the first step to switching to a wireless network infrastructure, the hospital has wired all its conference rooms, meeting rooms and auditoria with wireless access points, using wireless Ethernet 802.11(b). Staff now use laptops with wireless cards to access electronic mail and medical information while working in these areas.
The system is also being used in the emergency department, so that patients’ registration details can be gathered and entered at their patient’s bedside.Duncan explains that this is a service that patients have been requesting for a long time.
The hospital is intending to go completely wireless for new networking areas. Says Duncan:“It is more economic, as at $200 per user it is expensive to pull cable. You can easily put up an access point and buy some wireless cards. It is much cheaper,and when you move people around you don’t have to pull cable again.”
The Medical Center is about to construct two new buildings and Duncan is considering networking them mainly with wireless access points. Cable will only be used for really high bandwidth applications that need 100m/bit Ethernet or fibre-channel connections, such as digital video and high-resolution diagnostic imaging workstations.

Web Access

The Medical Center has invested a considerable amount of effort in creating a Web Viewing System (Web/VS) for its clinical systems. This gives clinicians a user-friendly interface to legacy hospital information systems, bedside clinicalsystems, clinical data repositories and other sources of biomedical information.With 400 PCs in the clinical areas, no physician is ever more than six metres or so from access to the information they need.
However, there was a clear need to be able to access these systems quickly and easily from outside the hospital. Many of the hospital’s patients are treated by private doctors with their own offices away from the campus. Also, both private and staff doctors need access from home or when on the move.
With the use of hand-held computers spreading throughout the hospital, the solution was to provide remote access to medical systems through communications-enabled Palm VII machines that automatically connect to BellSouth’s Mobitex network. Duncan used these to access a Palm Viewing System (Palm/VS). He explains why: “We chose Palm VII because the networking was already built in, giving us a ‘one stop shopping’ solution. You just take it out of the box, turn it on, put in your credit card number and it works. With other solutions, you have to buy a hand-held computer from one supplier, a communications card from another and get a contract from third supplier and then make them all work together. With the Palm VII the integration just works immediately for the user.”
As the medical systems were already web-enabled, all that was required was to build special versions of the web applications for access through the Palm. Says Duncan:“Essentially you just tweak what you already have for the small screen sizes. If you already have web applications built and security figured out, it is really a very simple thing to convert it to the Palm VII. When you know how to do it, it only takes a few hours. We completed the task in a weekend. Security for the Web works just fine on the Palm using the same encrypted sessions.”
As well as being specially formatted for the Palm VII screen, the web pages include special ‘meta’ tags that embed version information and update the Palm VII’s ‘history list’. Another difference from conventional web applications is that the Palm architecture allows static text (such as on-line help), forms, images and icons to be resident on the device, increasing responsiveness and decreasing network traffic. Duncan says: “The design of Palm/VS is tightly constrained by the bandwidth of the wireless networking connection, the small screen size and the capabilities of the Palm VII’s ‘Clipper’ web browser. The functionality of Palm/VS is therefore only a small subset of the functionality and data types available in the Web/VS application for desktop personal computers.”
Once Duncan had ported the applications, it automatically utilized the Palm wireless networking and the BellSouth wireless Mobitex network. This is a packet data network with an ‘always on’ connection that provides a data rate of approximately 8kbps.
The ongoing subscription cost for the network connection ranges from $10 to $40 a month for traffic quotas ranging from 10 to 300 kilobytes per month. A flat-rate pricing plan for unlimited network traffic is also available for $45.

Additional connectivity is provided to Palm V machines using an OmniSky wireless modem that links to AT&T’s Cellular Digital Packet Data (CDPD) network at approximately 19.2kbps. It is otherwise functionally equivalent the Palm VII from the user’s perspective.

Palm VII

Unlike personal computers, the hospital does not take a centrally funded,standardized approach to hand-held computers. Each business unit is free to purchase whatever machines they wish out of their own budget. However, only the Palm VII and Palm V can have access to clinical systems. Duncan explains: “We don’t tell people what to buy, so they buy whatever they want. Every model of every personal digital assistant (PDA) that ever existed is out there somewhere, but if they want remote wireless access to laboratory results they have to buy a Palm VII.We don’t stop them buying any other machines because they can still get remote access to medical systems through a personal computer.”
In practice, between 100 and 200 physicians user Palm machines to give them completely mobile, web-based access to clinical information anytime, anywhere.
As well as using them for e-mail and schedules, the main clinical use is to obtain information, such as laboratory results, surgical reports, consultations, intensive care unit and emergency room visits. There is also a physician and employee directory for telephone numbers, e-mail and fax numbers.
Some specialist areas have no need for remote access, but the Palms are most popular with physicians taking care of very complex or very sick patients, such as intensive care specialists, cardiologists or anaesthesiologists. Duncan continues: “We do a lot of advanced surgery and have several large intensive care units. Physicians with very sick patients are often away from hospital and need results quickly. The Palm machines allow them to closely monitor their patients and extends their ability to provide medical care outside the building. They could get the same information by calling the hospital and getting the nurse to call the laboratory and then call them back, but that takes the nurse away from looking after the patient.”

Problems Experienced with the Palm Devices

Duncan’s practical experience with use of the Palm VII has identified a number of concerns and issues related to the Palm VII device. First, the Palm VII browser does not support JavaScript, cookies, caching programs, nested HTML tables, frames, horizontal scrolling or a number of other features found in desktop web browsers. Session state must be maintained by passing information back and forth in hidden fields between forms on the client and scripts on the server. This inevitably leads to the divergence of separate code bases for web browser clients and Palm VII wireless clients, increasing the overhead of program maintenance. Says Duncan: “The Palm VII’s provisions for security and encryption were better than we expected. Unique Device ID within wireless transactions that can be used to correlate the user’s login with the device itself. However, the local page cache or ‘history list’ persists from one launch of an application to the next, and cannot be cleared automatically by the application when the user logs out. This makes it possible for someone to view patient data from a previous session without logging in. The workaround is to put global password protection on the Palm VII, but users regard this as quite inconvenient.”
Another security weakness is inherent in the Palm’s handwritten input Handwritten passwords must be displayed on the screen so that the user can confirm that the individual characters were recognized correctly, so a user could inadvertently reveal their password. The Palm VII mitigates this risk by popping up a special dialogue box to accept passwords and removing the information from the screen immediately after the input is completed.

HP Jornada

The second pilot involving hand-held computers is in the paediatric ward and clinics, where junior doctors (‘residents’) use them to interact with clinical systems. Although they need to look up results, which the Palm users do, they also needed to enter information about patients.
Duncan purchased a range of different hand-held devices for the residents to try out and they selected the Hewlett-Packard Jornada 680 ‘clamshell’ running Microsoft’s Windows CE operating system. Duncan says: “That was the one they liked best. It had a full keyboard for entering information and fits in the pocket of their white coats.”
This machine has a PCMCIA slot that takes a Lucent WaveLan card to access the wireless network. Sixteen machines are in use and four act as spares. Instead of having their own machines, the residents pass them on as they change shifts.
Duncan finds that the Jornada web browser works very well, but the machines have suffered quite a bit of breakage, with all four spares in use some of the time. He explains: “It isn’t the fault of the Jornadas, because they get a different kind of use from the Palms. The hospital is a hostile environment.They get carried around open, people type with one hand and hold it with the other, they get lost, they get dropped.They are heavier than the Palm so when they fall there is more chance that they break.These users are very busy people and their minds are on patient care, not protecting their PDA.”

Business Benefits

Duncan explains what he feels is the main benefit in the hospital’s use of wireless devices:“The main benefit of wireless technology is that it is the most flexible and economic way to enable our goal of getting information to the point of care. We
have really seen a huge difference in the last year in the affordability and stability of wireless technology and when the picture is fully stabilized it will be inexpensive and easy to deploy.”
Duncan explains that as the incremental cost of wirelessly enabling hand-held computers is so small, he did not attempt a business case. Having already built the web applications, getting them to run on the hand-held machines required very little work. He adds, “we didn’t make a big effort to cost justify it, we just went ahead and did it”.
Nevertheless, the machines are giving users quicker and easier access to clinical information in order to support patient care. It saves both physicians and nurses the time involved in chasing the information by telephone. That they find this valuable is shown by the tremendous ‘pull through’ demand. As they start to use hand-helds to access clinical information, physicians are asking for more and more functionality to be added.

The Future

The medical system has no immediate plans to standardize the use of hand-held computers. The next major goal is to deploy wireless networking throughout all of the patient care areas in the medical centre. Says Duncan: “The Palms and Jornadas are a convenience but our real focus for this year will be to fully build out our wireless infrastructure inside the hospital.”


Duncan remains enthusiastic about the scheme: “The acceptance of wireless applications among the attending staff and faculty
has been excellent. The clinicians really love it and the more functionality we give them the more they want.”
Duncan has learned a lot about the Palm and Windows CE machines, as he explains: “They each have their strength. We like the Palms because they are extremely lightweight and elegant, yet rugged.They have excellent battery life and we have had excellent support from Palm Computers. They are very good at displaying information, but there are situations when people really want a keyboard so we also use clamshell machines.”
It is clear to Duncan that the wireless deployment of clinical applications has many compelling advantages. He expects such applications to proliferate rapidly over the next few years as wireless technology improves, hand-held computers and cellular phones converge and bandwidth costs decrease. However, he adds a warning: “It would be an exaggeration to say that hand-held computers are life savers. We are tying to make information available to doctors, though whatever route they prefer to use. Nevertheless, these machines save them time and make life their easier, so they are very excited about them. Most doctors want to make people well and care very deeply about the quality of care they give. Our goal is to get information to the bedside so they can use it to make the right decisions and wireless enables us to do that.”


Key Learning Points

1. Wireless access to a network can be an economical way to provide information to customer-facing staff at the point of service, whether medical care or any other type of service. However, it cannot yet cope with high bandwidth traffic.
2. Providing web access through a personal computer is an important first step to providing wireless access to information.
3. There is value in a solution that pre-integrates computer, communications device and mobile network.
4. Functionality may be constrained by the bandwidth of the wireless networking connection, the small screen size and the capabilities of the mobile computer’s web browser.
5. The Palm form factor is very good for viewing information, but a ‘clamshell’ is better for entering information, in terms of ease of use.


Editors note: This case study is an excerpt from a larger 250-page research and case study-based report entitled "Creating the Mobile Enterprise - how to achieve competitive advantage through wireless technologies." And was produced by:

The Business Intelligence Corporation of the UK http://www.business-intelligence.co.uk

The full 250 page report can be purchased directly from this link

PDA cortex wishes to extend our thanks to Fiona McShane of Business Intelligence for her kind permission to reprint the CEDARS SINAI case study.

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