ASTER - Acute Stroke Care
Telematics for Ambulance Vehicles
Franziska Wolf
1
, Carsten Edelberger
2
and Thomas Wolf
2
1
Institut f. Automation und Kommunikation e.V. Magdeburg Werner-Heisenberg-Str. 1, 39106 Magdeburg, Germany
2
SBSK GmbH & Co. KG, Zackmünderstr. 4, 639218 Schönebeck-Elbe, Germany
Keywords: Networks in Vehicles, Secure Communication Systems, Medical Services, Stroke Care.
Abstract: In the collaboration project ASTER secure communication structures for ambulance vehicles are developed
in order to optimize care processes for paramedics in cases of stroke. Ambulance vehicles will be equipped
with various communication devices and technologies in order to enhance the care procedures in the pre-
clinical phase. IT-security and communication availability are the essential aspects of high-sensitive and
mobile communications developed for this case, because wireless transfer of sensitive data such as patient
and case related data will be involved. The structure and communication networks is designed and validated
using different scenarios of acute stroke care in order to answer the requirements towards the new
communication structure needed for security demands. In order to secure this high level data the project is
using certificated encrypted connections and a central communication node, which will be presented in
detail. The upcoming demonstrator of the ASTER project, a full applicable ambulance vehicle will be
equipped with the proposed technologies and systems in order to enhance the emergency procedures for
paramedics and patients suffering stroke.
1 INTRODUCTION
Stroke is one of the leading causes of death in
Germany, responsible for permanent disability and
dependencies (Heuschmann et al., 2010).
In 81% of strokes immediate medical
intervention can potentially offer a better success of
treatment. But for now only about 3% of all stroke
patens can benefit from this special treatment due to
a therapeutic timeslot of only about 4 hours after the
occurrence of symptoms. Furthermore special
diagnosis is required including CT scans of the head
by experienced doctors best performed in a stroke
specialist unit (stroke unit).
This is why especially rural regions such as the
north of Saxony-Anhalt suffer from the disastrous
consequences of strokes today. Because of the
demographic change it is expected that the direct
treatment costs will even rise, covering over 100
billion EUR in 2030 (Klebingat et al., 2010). An
acceleration of the procedures in cases of emergency
could increase this rate significantly, in all regions
(Kwon et al., 2008) As a consequence the
enhancement of preclinical emergency care
structures, especially for stroke patients are of
particular importance: Especially reliable detection
of strokes, a semi-automatic selection of the best
available hospitals and an early involvement of the
hospital staffs have a high potential of enhancing the
care procedures. The German research project
ASTER - Acute Stroke
care -Telematical platform for ambulance
vehicles - is a two year project which aims to
develop solutions for the optimization of stroke care
within the rescue chain. For this purpose a
communication platform is being developed,
connecting all kinds of stakeholders - ambulance
vehicles, control centres, paramedics, hospitals,
experts, external data sources such as traffic
information centres - to one another in order to
enhance the communication flow in the pre-clinical
field. The ambulance vehicle shall furthermore be
connected to traffic infrastructures e.g. for active
prioritisation at traffic light systems
(Kwon et al., 2008) and (Wolf et al., 2008).
Based on different radio standards, the information
exchange between target hospitals, paramedics and
other external data sources is designed to achieve
both: Optimal communication availability and IT-
security. In the following the actors of the ASTER
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Wolf F., Edelberger C. and Wolf T. (2013).
ASTER - Acute Stroke Care - Telematics for Ambulance Vehicles.
In Proceedings of the 10th International Conference on Informatics in Control, Automation and Robotics, pages 562-567
DOI: 10.5220/0004623305620567
Copyright
c
SciTePress
system are described along with the needed data
communication structures.
The use cases will lead to the functional
requirements derived. The concept of secure
communication architecture and its modules are
presented. Furthermore the design of the full
functional emergency vehicles which is currently
being equipped with all devices is shown.
1.1 Aims of the ASTER Project
The goal of the ASTER project is to develop a
telemedical platform for ambulance vehicles in order
to optimize the emergency care with the focus on
stroke emergencies.
The focus of the development is the
establishment of a digital mobile assistant for
paramedics (DIMAP), which assists the rescue staff
in order to enhance quality of diagnosis concerning
the type and severity of strokes. The DIMAP will be
used to collect data concerning patient and the
rescue case, to give assistance in choosing the best
hospital and in order to gain necessary support of a
stroke specialist in a stroke unit using a bi-
directional multimedia telemedical connection
(video conference). Here a camera and microphone
shall connect the paramedics on the case, which can
be the house or
flat of the patient or on-track during the trip to
the hospital, with the data sources they currently
need. The consultation of the expert can help in
various situations in order to assess the severity of
the stroke. Apart from the staff assistance the
DIMAP shall provide intelligent traffic telematics to
the ambulance vehicles in order to choose an
optimized route to the best hospital for the special
case of emergency. Factors of the different
accessible destinations like the occupancy rate,
specialization and availability of emergency rooms
and doctors will be taken into account. Then the
choice of route is actively made based on online
traffic data such as traffic, distances and further
more.
Active acceleration on-trip is realized by
activating a priority route through a sequence of
traffic lights (Pohlmann, 2010). These prioritisation-
routes are especially marked in the DIMAP in order
to choose the best route in order to assure the
optimal response time, one of the main optimisation
characteristics for operating procedures for
paramedics (Pons et al., 2005). The traffic telematics
module combines this information and generates a
route to the destination hospital optimized in way
and time for the diagnosed kind of emergency. Then,
the collected information is transmitted to the
destination hospital in order to make the necessary
preparations. The telemedical platform developed
for ambulance vehicles provides a link from mobile
emergency medical services to hospitals and
transport telematics. A practical use and a
comprehensive diagnosis will be possible wherever
needed. Therefore a real and full functional
ambulance vehicle will be equipped with different
modules of telematics as a prototype for
demonstrations and tests. The planned modular
design of the telemedical platform allows to be
extended for other emergencies such as heart attack
or polytrauma and highly integrates into the
workflows of other entities such as emergency
departments, emergency management and logistics.
2 ACTORS AND USE CASES
A use case defines the interactions between external
actors and the system under consideration to
accomplish a goal. The actors of the ASTER system
are mainly from the medical field. As stakeholders
they are interested in the enhancement of care
procedures, but not necessarily depending on such a
new system. Therefore the analysis of the current
working and caring procedures are essential in order
to integrate the ASTER system and it’s usage into
the normal working procedures of paramedics and
their infrastructure.
2.1 Actors of the ASTER System
The following actors interact with the ASTER
system:
Control Centre - it provides information on the
emergency situation and communication to the
paramedics via established radio systems (POCSAG,
etc.) and maintains contact to the hospitals and the
available emergency vehicles.
Paramedics and Ambulance - The paramedics
often are the first actors on the scene of emergency.
They are therefore the most important source of
information for the ASTER system. Here the data of
the case and the patients are collected.
The Medical Expert - The medical expert (stroke,
cardiac, trauma, etc.) is positioned in a specialised
hospital, such as a stroke unit. He or she provides
the paramedics medical and logistical help with a
video conference based of telemedical monitoring
stations.
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The Target Hospital - The target hospital and the
doctors on duty need information about the
emergency case of stroke and the initial diagnosis of
the patients arriving in the emergency room in order
to prepare the emergency rooms specifically.
2.2 Actors of the ASTER System
Figure 1: ASTER use cases.
According to the formally described actors
following use cases or applications are identified for
the ASTER system. Listed in chronological order
the following use cases of the Aster system are:
1. Case of Emergency - A case of emergency with
a suspected stroke occurs and the control centre
is informed. In the ASTER system potentially
applicable ambulances are displayed on a digital
map and appropriate notifications are given to
the ambulance vehicle and the paramedics using
the DIMAP.
2. Drive to the Scene of Emergency - The ASTER
system gives the optimal driving route to the
paramedics. This optimal route consists of
current traffic and route conditions. Furthermore
active prioritisations at traffic lights could lead to
an acceleration of the ambulance vehicle along
the res-cue route.
3. Intervention at the Scene of Emergency - It is
taken care of the and the relevant data such as
medical background of the patient and his/her
personal data is collected using a mobile device
the DIMAP. A specific decision support system
installed on the DIMAP enhances the estimation
of the severity of the stroke. If any doubts remain
a medical expert in a special stroke unit can be
consulted via a video conference.
4. Drive to the Best Hospital - Like the drive to
the scene of emergency the drive to the hospital
will be based on an optimized route. Furthermore
a prioritised selection of reachable hospitals will
be provided by the system, depending on the
hospitals current treatment capacities (available
doctors and CTs), specializations and current
journey times to the destination. When selected,
the emergency case and basic data of the patient
will be presented at the emergency room using
an arrival board.
5. At the Hospital - The patient is given to the
hospital staff. Through an automated data
transfer and authorization during the transport
the hospital is al-ready informed about the case.
6. Documentation - The processing of the case is
finished by the paramedics and the control
centre. The documentation and billing can be
done quickly based on digital, matched data.
According to the formally described actors
following use cases or applications are identified
for the ASTER system.
3 REQUIREMENTS OF
COMMUNICATIONS
ARCHITECTURE – DESIGN
OF A SECURE NETWORK
Each of the actors and use cases of the ASTER
system requires a specific data collection, processing
technology, and above all a secure data
communication. Especially the interoperability and
harmonization of the different data types, devices
and connections have to be integrated into existing
security concepts. Here, a continuous redundancy of
the infrastructure is necessary in order to provide an
availability of 99% or more.
Furthermore Aster has special requirements for
availability and reliability, particularly for the
mobile applications of ambulances on their way to
the scenes of emergency or the target hospitals.
Therefore the design has to involve dynamically the
best available connections such as GPRS, UMTS,
LTE, Wi-Fi and Ethernet.
A main interest of the Aster communication is
the secure transfer of particularly sensitive case-
related and personal data. They are classified as the
most sensitive data (Level E) of the Federal Office
for Information Security in Germany (BSI), because
they are directly linked to information about health,
life and economic existence of the patient, including
real name. Therefore, it is essential that this class of
data is only stored temporarily on the mobile devices
DIMAP in the ambulance vehicle. After completion
of the transport of the patient the data is immediately
archived, locked or freed of sensitive personal data.
A long-term storage of personal data shall not take
place on the DIMAP. The data communication itself
is to be certified. Therefore established encryption
protocols (IPSEC), primarily EAL 4 + certified
technology shall be used.
Furthermore the authentication of all users of the
ASTER system is set as mandatory. This is because
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of both: privacy reasons and for legal and liability
reasons.
4 IT SECURITY AND MOBILE
DATA COMMUNICATIONS
In order to answer the challenges of the
communication system and the system architecture
in ASTER concerning the mobile IT security
(Stumpf et al., 2007) a communication concept is
presented based on a centralized and scalable
instance. The developed system design is based on
the interaction of major functional blocks, their
spatial distribution and organization (hardware and
software units inside the ambulance vehicle and their
connections to the outside world) as well as basic
applications (including external data). Especially the
essential high security requirements are regarded
along the requirements of the BSI.
One of the basic requirements of security in the
project is the transmission restriction towards
sensitive or privacy relevant data which assures a
solely encrypted transmission in order to ensure the
end-to-end security within the communication
architecture. Because it is not feasible to distinguish
the different levels of sensitivity of the data during
the normal operational process, the general
encryption of all data is required. Therefore the
IPSEC protocol suite (Elkeelany et al., 2008) shall
be used for encryption, because it.
- transfers all IP packets
- is already certified in Router systems as
Common Criteria EAL 4 +
- provides strong encryption algorithms
- is already in use for similar applications in the
medical field,
- is a multi-vendor industry standard and
- is subject to a constant process of development.
4.1 The Central Communication Unit
Intermediary
An intermediary (Latin intermedius ”intermediary”)
is a mediating between the individual data sources
and subsystems of the ASTER system. The type of
placement can range from simple forwarding of IP
packets for individual services (e.g. voice and video)
over the caching of messages and data, to the
provision of supportive applications for paramedics
or other project partners. For the application to the
intermediary the requirements of the terms of
availability of the operation must be very high
(99.95%), also concerning the confidentiality and
privacy (category D + E BSI), same is true for the
software and hardware clients of the ambulance
vehicle. The system concept provides a strict
encapsulation of the data flows within the
intermediary and to the connected modules. Is can
be also used to for monitoring incoming and
outgoing data streams in real time in order to detect
attacks and viruses (IDS / IPS). The intermediary
and its communication structure is designed modular
and expandable and is based solely on currently
available device types and operating systems. Only
hardware and software components are considered
that are already certified according to Common
Criteria EAL4. The intermediary has to be stored in
a secure data centre providing a broadband internet
connection and the availability of official IP
addresses. The use of cloud technologies is possible,
providing that the strict protection of privacy and
confidentiality can be guaranteed, e.g. by having
already audited standards according to ISO27001 of
the BSI Protection Certificate.
Figure 2: The communications and modules of the
intermediary.
4.2 Basic Structure of the Intermediary
and the Communication Interfaces
The intermediary currently consists of the following
components:
VPN: This VPN router performs the centralized
handling of all encrypted connections to all
ambulance clients and external data sources. It
also realizes the routing of data traffic (IP traffic)
from clients to external data and vice versa. The
VPN realizes the distribution of data streams
(routing), the implementation of IP addresses
(NAT) and the protection of security and
confidentiality. Furthermore, the individual
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network structures (such as private IP addresses)
of the connected partner and external data
sources will not be affected. The network traffic
from and to the intermediary is encapsulated by
the firewall rules restrictively configured and
verified by the proposed IDS / IPS functionality
permanently concerning malware and attacks.
SEC: The security application handles the
authentication of users and the rights issues. In
addition, at the SEC component all the necessary
services are localized. This relates to the time
synchronization (NTP), the internal name
resolution (DNS), the self-monitoring (SNMP)
and logging (syslog) of the system components
of the intermediary.
DATA: This component serves as data storage
and archiving. It thus provides a backup and
configuration management of the MDM (see
below) and for the provision of information of
navigation and traffic control systems.
MDM Mobile Device Management: This
component implements the management of
mobile devices (e.g., configuration, maintenance,
backup, and update).With this component, the
operator is able to keep the mobile devices
available and secure. These include condition
monitoring Smart File Sync, File Push, backup,
restore, device management, software updates
and device localization (GPS). Necessary
maintenance actions are predictable and thus can
be realized automatically and unattended at
appropriate times.
Central Hospital Node: It is to be examined in
the project, whether the existing functions of
hospital systems can be implemented in the
intermediary.
VER: A Traffic Telematics Server, which
contains all the current traffic data and also the
communication with the light systems [11] can
be integrated via a secure connection or
alternatively installed as a separate instance.
The proposed communications architecture has been
designed based on the requirement analysis and the
use cases, focussing particularly on the security
requirements. A crucial factor was the seamless
communication of the backbone databases to time-
specific traffic data, clinic characteristics and stroke
characteristics in order to support all modules of the
ASTER-system: the software systems of the DIMAP
(medical and traffic modules) and the components of
the backbone systems. The goal of the overall
system design is a generic clinical supply
management, which opens the communication
components of emergency vehicles as preclinical
systems and passes through interfaces to hospitals,
centres and transport infrastructure. For every rescue
case, every control centre, every hospital and every
other external data source an encrypted connection
must be realised. For the external data sources, this
connection can be terminated on existing security
systems (firewalls and routers). Such a procedure is
already used widely by hospitals and industry
partners. But for the ambulance vehicles, the
connection must be held available as long it is
needed. This shall be automatically performed on
the best available internet technology (GSM, UMTS,
WLAN, etc.) using VIPRI net as an automatic
device.
5 SUMMARY AND FUTURE
STEPS
Each Stroke is the third leading cause of death in
Germany and often leads to permanent disability.
A quick consultation of experts on the case and
diagnosis of the patient based on his case data are
necessary to achieve rapid treatment and thus
recovery of the patient.
However, such time-optimized transportation
plans and treatment strategies are due to lacks of
communication infrastructures in the pre-clinical
environment.
Nevertheless they are essential in order to
improve chances of treatment, especially for stroke
patients. As the main objective of the project
ASTER a special secure IT communication
architecture has been set up in order to satisfy
various requirements of a mobile communication of
emergency vehicles on their way to the patients and
the hospitals.
Based on the requirements analysis and use cases
presented here, high secure communication
architecture has been realised. A crucial factor has
been the seamless communication of the backbone
databases (offering on-time traffic data; hospital
characteristics and stroke related knowledge to
support the decision support system) and the mobile
components of the emergency. This integrated
telematics platform will enable paramedics in the
future an accelerated, efficient and safe patient
transport.
For now the communication system is integrated
in a real ambulance vehicle with connection to the
intermediary. Therefore a cable and communication
plan has been set up, which will be built in till
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summer of 2013.
Figure 3: Communication infrastructures in the ambulance
vehicle demonstrator.
Other services that may be incorporated into the
ASTER system in future in order to expand the
medical rescue scenarios on other application
scenarios are:
Chat / Instant Messaging application. The
implementation could be realized by a freeware
server in the intermediary. The protocol XMPP
protocol (Jabber) is favoured.
Governikus. Optionally, the usability of certified
services (e.g. Gouvernikus) to the qualified
delivery of information is to be examined. This
service is based on the OSCI protocol. The aim
of the overall system design is the design of a
generic pre-clinical supply management, which
opens the communications components of
emergency vehicles as a preclinical system via
interfaces to hospitals, command centres and
transport infrastructure. The sentence must end
with a period.
ACKNOWLEDGEMENTS
The authors would like to express their
acknowledgement to the German Federal ministry
for Education and Research (BMBF) for granting the
national ASTER under the code 03WKP20F. The
results of which contributed to this paper.
If any, should be placed before the references
section without numbering.
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