Healthcare is an ideal environment for the use of wireless and mobile computing technologies. From a process perspective, the hospital of today can be compared to a logistical or supply chain operation. There are multiple departments through which the patient moves, while at the same time, critical patient-specific information is needed for real-time decision support. Clinicians must have access to this information at the right time wherever they are without increasing their workload.
Consumers and industry alike have enthusiastically
embraced wireless technology because it greatly expands
our freedom to communicate and exchange data, bringing
unprecedented productivity and convenience to our business and
Driven by the lower cost of wireless components, the healthcare
sector is following suit and the growth of wireless networking in
hospitals is skyrocketing. Today, the adoption of wireless standards
such as IEEE 802.11b/g (also known as wireless fidelity or “WiFi”),
and the use of mobile computing platforms form the basis of this
wireless revolution (see Figure 1). At the same time, clinical caregivers
want to do more on a mobile basis and have grown accustomed
to receiving information in real time via cell phones, pagers
and personal digital assistants (PDAs). These factors have converged
and are providing the impetus for a wide acceptance of
wireless technologies within the healthcare industry.
Why Hospitals Are Adopting Wireless Solutions
The healthcare sector has been familiar with wireless for many
years, but its use has largely been confined to traditional telemetry-
based patient monitoring, where the patient’s vital signs are
only displayed at a central monitoring location. In the past few
years, however, a proliferation of wireless carts has been deployed
for clinical information system charting and patient admitting
applications. Hospital information system companies that have
traditionally offered various productivity applications for clinicians
are now realizing that it makes sense to adapt their applications
to operate on PDAs or similar devices.
mobile computing technologies. From a process perspective, the
hospital of today can be compared to a logistical or supply chain
operation. There are multiple departments through which the
patient moves, while at the same time, critical patient-specific
information is needed for real-time decision support. Clinicians
must have access to this information at the right time – wherever
they are – without increasing their workload.
Healthcare providers look to wireless solutions for a variety of
reasons. Among the desired goals are reduced risk when monitoring
patients, better patient outcomes, increased staff efficiency and continuity
of care, improved response time, decreased costs associated
with the care process and compliance with government regulations
and standards. Another goal is to reduce the cost and complexity of
network management by leveraging existing wireless infrastructures
and by deploying clinical and other value-added applications.
A New Approach to Integrated Wireless Monitoring
As a leader in patient monitoring, Dräger Medical was the first
enterprise patient monitoring vendor to offer IEEE 802.11b WiFibased
wireless technology across its line of patient monitors.
With Infinity Wireless, all vital patient data is transmitted to
the Infinity Network for a continuous flow of information to care
team members at the bedside, the central station or in remote
locations throughout the hospital. There are fewer information
gaps to leave doctors and nurses uninformed and hinder lifesaving
Wireless monitoring alleviates the difficulties and expenses
posed by hardwired monitors in some clinical environments. For
example, Infinity Wireless is ideal for neonatal intensive care units
and operating/recovery rooms where hardwiring can be impractical.
Wireless is also the answer for the emergency department,
where there can be an overflow of patients. To further the commitment
to compatibility with all hospitals, Dräger Medical patient
monitoring can share the hospital’s existing 802.11b/g access
points that are widely used in hospitals today.
What About 802.11a for Hospitals?
The 802.11a standard offers the same high-speed advantages as
802.11g (54 Mb/sec), but uses a higher 5.8 GHz frequency range.
This technology would appear to be well-suited to hospitals
because it offers an alternative to the popular 2.4 GHz frequency
range, in which many types of devices operate. However, 5.8 GHz
signals do not penetrate walls and other fixed obstacles as well as
signals that operate in the 2.4 GHz range. In fact, detailed site surveys
in hospitals clearly show that structured buildings typically
require up to seven times as many access points as compared to
802.11g deployments. This factor makes the decision to deploy
802.11a across an enterprise an expensive proposition.
Providing Vital Patient Data Hospitalwide
Traditionally, patient monitoring required its own discrete network to
carry life-critical patient information,which meant that the hospital
had to install and maintain two separate wireless networks. Dräger
Medical’s Infinity OneNet solution enables hospitals to run patientmonitoring
information on the hospital’s existing infrastructure.
By supporting wireless monitoring, the Infinity OneNet
architecture enhances central surveillance. Infinity wireless
monitoring maintains a continuous connection to external systems
to create a seamless patient record. As a result of
Infinity’s automated process, other care areas can have immediate
access to this patient data. Access can be provided from
the in-house clinical information system, or remotely via the
wireless network to mobile clinical workers. Commonly available
PDAs with wireless-enabled 802.11b/g cards could access
this vital information, as well as waveform and trend information,
for specific patients.
Addressing Security Concerns
The steady growth of WiFi in healthcare enterprise demands that
IT teams learn and adopt new security methodologies tailored to
the unique requirements and weaknesses of wireless networks.
Network staff and security staff must first evaluate the myriad set
of authentication and encryption mechanisms that can be used in
the network. Depending on the security selected, IT needs to
establish and document the corporate WLAN security policy,
including mechanisms to validate user compliance and monitor
for network vulnerabilities.
A secure network is the result of an ongoing security
process and not simply the installation of security technology.
This means that even with a strong security policy in place, IT
must also actively monitor and enforce compliance with that
policy and be aware of the vulnerabilities inherent in the strategy
that they have chosen.
As a result of using standards-based wireless 802.11b, Dräger
Medical is able to use enterprise tools to monitor the health and
integrity of the network in real time, 24 hours a day, seven days a
week, 365 days a year. This includes, but is not limited to, identifying
authentication and encryption problems, as well as configuration
vulnerabilities, rogue device issues, wireless intrusions, denial
of service attacks, overloaded hardware and channels, and deployment
and operational issues.
Enterprise IDS (intrusion detection systems) can provide the
final layer in a wireless security solution. With a distributed
architecture of remote smart sensors that work in tandem with
a server appliance, an enterprise IDS architecture can passively
monitor all wireless LAN activity in real time for the highest
level of security, policy enforcement and operational support.
This IDS architecture can provide the secure foundation that will
offer a scalable and manageable solution for wireless LANs in a
single healthcare facility or the complete IDN. While this system proactively notifies IT personnel of alarms for security threats,
policy violations and performance issues, these systems also
allow for network administrators to access a single interface for
a complete view of the wireless LAN and the management of
critical intelligence. Identification of potential rogue wireless
LANs is paramount for all organizations and such systems provide
full rogue detection that goes beyond simple alerts of
broadcasting access points.
With “stateful” monitoring of all wireless LAN activity-based
attack signatures, protocol analysis, statistical anomaly and policy
violations, these systems can identify network reconnaissance
activity, suspicious WLAN activity, impending threats and attacks
against the wireless LAN. Because these systems do not rely solely
on attack signatures, recognition is made of documented and
undocumented attacks. “Stateful” means that these systems can
provide continuous monitoring of the “state” of communication
between all access points and stations transmitting on the airwaves.
With a minute-by-minute account of all WLAN traffic,
intruders are immediately recognized, attacks are quickly detected
and appropriate measures can be taken to secure the network.
Stateful monitoring also allows the system to understand the full
context of wireless LAN.
Ensuring Quality of Service
As with wired LANs and other networks, WLANs can leverage
quality of service (QoS) capabilities to enable prioritization
schemes for traffic types, geographic locations and specific individuals
or departments. In a life-critical patient monitoring
environment, it is imperative that QoS be guaranteed. Dräger
Medical has chosen a methodology that will ensure the primacy
of patient monitoring data within a wireless infrastructure. In
order to accomplish this goal, Dräger Medical has employed
an application traffic management system from Packeteer, Inc. –
the leading provider of application traffic management solutions
Mitigating Potential Interference to Medical Devices
A wireless phone at 860 MHz has a power output of 600 mW EIRP
(effective isotropically radiated power), while a WLAN PCMCIA
card at 2.4 GHz has a power output of 100 mW EIRP. Direct
sequence 802.11b radios have some advantages to frequency
hopping in interference mitigation. Direct sequence radios can be
programmed to operate on select channels to reduce interference.
Unlike frequency-hopping radios that hop the entire spectrum,
the direct sequence radios can be programmed to operate on dedicated
channels to avoid interfering with devices that might be
susceptible to radios operating in certain parts of the band.
Meeting HIPAA Requirements
Combined with the proper security and network monitoring strategies,
standards-based wireless technologies will contribute to the
hospital’s ability to comply with HIPAA requirements. The Dräger
Medical OneNet architecture enables hospitals to deploy solutions
for authentication, encryption and open systems interoperability.
Part of this architecture is a role-based approach that provides
convenient management of privileges for different categories of
users. For instance, IT administrators can define destinations such
as an IP subnet; services such as HTTP, FTP, POP3; user locations;
time/date schedules; and available bandwidth to control which
users have access to each resource. Multiple service and destination
groups can simplify policy creation and reduce the complexity
and cost of the administration of large-scale networks.
Properly designed and implemented, a shared wireless infrastructure
enables hospitals to:
- Deploy wireless applications on a common WiFi network and
leverage their existing investment in wireless networks and
equipment. A common WiFi network strategy allows hospitals
to amortize the cost of their wireless infrastructure across
- Utilize mainstream standards-based wireless technologies
with best radio technologies;
- Leverage existing security strategies and solutions; and
- Efficiently manage quality of service for patient monitoring
as well as other wireless applications deployed across their
- More efficiently support and troubleshoot wireless network
and associated applications.
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