=Paper=
{{Paper
|id=Vol-1337/paper6
|storemode=property
|title=Open Software Platform for Cyber-Physical Medical Systems
|pdfUrl=https://ceur-ws.org/Vol-1337/paper6.pdf
|volume=Vol-1337
|dblpUrl=https://dblp.org/rec/conf/se/Meyer15
}}
==Open Software Platform for Cyber-Physical Medical Systems==
https://ceur-ws.org/Vol-1337/paper6.pdf
Open Software Platform
for Cyber-Physical Medical Systems
Jörg-Uwe Meyer1
MT2IT Research
MT2IT GmbH & Co. KG
Ratzeburg, Germany
joerg-uwe.meyer@mt2it.com
Abstract: Fail-safe open software platforms for cyber-physical medical systems
(CPMS) are expected to securely host medical applications of medical devices,
clinical systems and health repositories for the purpose of safe healthcare delivery
to patients at the point of care. Secure and reliable ad-hoc connections to medical
systems and health records are mandatory when health professionals need
immediate access to the patient’s live vital data and electronic medical records
during individual medical procedures. Here, we report about a service-oriented
open software platform that has been developed for cyber-physical networks of
distributed medical systems. An automated data logging cyber-physical software
system for medical procedures is described, which is characterized by secure user
authorization, standardized device and system communication and software-
assisted guidance utilizing a WHO surgical safety checklist.
1 Introduction
Cyber Physical Systems (CPS) are defined as systems of collaborating
computational elements controlling physical entities [1]. Health related
applications of CPS include high confidence medical devices and systems,
assisted living, and telemedical applications [1]. Cyber-physical medical systems
(CPMS) are described as communicating networks of regulated medical systems
which can be accessed through the Web. The CPMS might resemble the
characteristics of an medical IT network, which is defined as a general purpose
information technology (IT) network in which at least one medical device is
incorporated and which is commonly connected to a clinical information system
[2]. A medical IT network is considered a point-of-care (PoC) medical device and
system network when healthcare is delivered live to the patients. This paper
describes an open software platform for a cyber-physical medical device data
system in surgery. An automated data logging software of connected medical
Copyright © by the paper's authors. Copying permitted for private and academic purposes.
24
systems is proposed which includes a surgical checklist application for enhancing
patient safety and objective documentation.
2 Service-Oriented Medical Platform
2.1 Vendor-neutral Interoperability Gateway
The central component of the service oriented medical platform is a vendor-neutral
interoperability gateway which hosts the middleware and orchestrates applications which
derive from medical systems in the point-of-care (PoC) network communicating with
disparate health-IT networks. A schematic of the interoperability gateway connecting
medical devices and systems in the IT and PoC network is illustrated in Fig. 1.
Figure 1: Schematic of an interoperability gateway which integrates systems and applications
in the health-IT and point-of-care networks.
Individual or Open SDC2 networked medical devices are connected to the Open Web Interface
(OWIN)3 middleware of the gateway through Web application programming interfaces (Web-
APIs) between Web server and the Web client applications. User agents are Web client
applications of browser programs, commonly found in frontend devices. A standard has been
proposed regarding the architecture for distributed systems of medical devices in high acuity
2
Open SDC: http://sourceforge.net/projects/opensdc/
3
Open Web Interface (OWIN): http://owin.org/
25
environments [3]. The openSDC effort has led to standardization documents which are proposed
by the IEEE EMBS 11073 & HL7 Health Care Devices (DEV) Working Group [4].
The user-specific surgical man-machine interfaces for the surgeons, anesthesiologists and nurses
employ the same connectivity paradigm as described above. The medical frontends provide user
access through a user-specific interactive browser interface. The frontend interface acts as a client
user-agent connected to the gateway through a Web-API. The Web-API interfaces applications in
both, the HTTP-based gateway Web server and the Web browser of the frontend client. The API is
designed as a RESTful4 interface to a defined request-response message system, expressed in
JSON5.
The Web-API can optionally be designed as a FHIR 6 interface between resources as JSON
representations. The Fast Healthcare Interoperability Resources (FHIR) implementations define a
set of resources that represent granular clinical concepts7. Each of the resources has a predictable
URL. The resources can be managed in isolation or bundled into complex documents. If suitable,
open internet standards are used for FHIR data representation.
2.2 Secure User Access to the Open HealthWeb Platform
The open service-oriented health software platform and its capability to implement
clinical workflow-based health services have been described elsewhere [5]. Here, we
illustrate individual user registration for securely accessing authorized patient
information. The system provides patient data to the individual user according to the
identified role and individually granted user authorization. The Web-API of the local
login scenario uses the standardized OAuth2 mechanism to authenticate the request and
to manage data flow according to authorization credentials. A simple scheme of the login
credential flow is depicted in Fig. 2. The OAuth2 credential flows are managed by the
gateway’s OWIN middleware. The OWIN defines a standard interface between .NET
Web servers and the implemented Web applications.
In this scenario, Web-API controllers act as resource servers. An authentication filter
validates access tokens. When a controller or action has an “Authorize” attribute, all
requests to that controller must be authenticated. Otherwise, authorization is denied, and
the Web-API returns an error for unauthorized access 8
4
RESTful Interface: http://en.wikipedia.org/wiki/Representational_state_transfer
5
JSON: http://en.wikipedia.org/wiki/JSON
6
FHIR-API: http://www.hl7.org/implement/standards/fhir/http.html
7
FHIR: http://wiki.hl7.org/index.php?title=FHIR
8
OAuth2 API Controller: http://www.asp.net/web-api/overview/security/individual-accounts-in-web-api
26
Figure 2: Illustration of the fail-safe OAuth2 login procedure of multiple users (e.g. doctors,
nurses, caretakers) requesting access to resources in the cyber-physical IT network which hold
patient data. The depicted platform is composed of 1) user frontends and the Open SDC network
of medical devices at the point of care 2) the gateway for managing the Web-APIs between the
systems and orchestrating the data flow and 3) the communication server with authentication and
authorization components responsible for securely accessing patient data. The OAuth2 standard is
employed which is particularly suited to provide user-specific authorization flows for web
applications9.
Automated Surgical Safety Checklist
An automated data logging system is built in software, which automatically records user
interactions, events and alerts from data communication between the devices and
systems. The software includes a graphic user interface that is specifically designed to
assist the OR safety manager of maintaining live a surgical safety checklist (SSC) as
promoted by the World Health Organization (WHO). The WHO SSC was developed
after extensive consultation with health professionals aiming to decrease errors and
adverse events, and to increase teamwork and communication in surgery . The checklist
is designed to guide communication among the health professionals and with the patient
9
OAuth2 http://oauth.net/2/
27
aimed to enhance patient safety in surgery. Implementation of SSC in surgical routines
has proven to significantly reduce morbidity and mortality in surgery. The WHO SSC
application is implemented in software as a request/response routine with the OWIN
middleware as a standard interface between the gateway server and the SSC application.
Figure 3: Integration of the WHO Surgical Safety Checklist (SSC) as a software module in the
Open Web Interoperability (OWIN) middleware of the Interoperability Gateway. The OWIN
middleware provides cross domain request/reponse functionalities of the SSC module between the
frontend user agents and the gateway server. The software supports the role of an OR safety
manager guiding and documenting communication with the patient before induction of anesthesia
and among the surgical team before skin incision and until the end of the intraoperable procedure.
Discussion and Perspectives
Our work concerns the development of a fail-safe open software platform for cyber-
physical medical systems in surgery. This paper has described a concept and technical
implementations of users securely accessing the medical IT network during live surgical
procedures. The OAuth2 standard is employed which is particularly suited for healthcare
28
delivery organizations (HDOs) to grant user specific authorization flows when accessing
medical device and Health IT system networks. The deployment of a Health IT
communication server and a vendor-neutral interoperability gateway has proven to be a
feasible infrastructure for the open software platform. Multiple Web-APIs to medical
device networks and health IT systems are managed through implementing an
established standardized open web interface middleware as a request and response
pipeline across device and systems domains.
The WHO Surgical Safety Checklist application is presently built as a demonstrator for
automated device, system and workflow integration in the surgical room.
The SSC application under development is a project in the framework of the German
federally funded flagship project “OR.NET”, in which more than 50 partners from
industry and research participate [6]. OR.NET objectives include the development of a
service-oriented medical platform which promotes fail-safe and secure interoperable
interactions of medical device networks in the operation room (OR). The DKE standard
working group 1000.8.3 has been established that contributes to the Open SDC
standardization process and endorses the proposed HL7 IEEE standards p11073-10207,
p11073-20701 and p11073-20702.
Future works concerns the development of software routines for testing the health Web
platforms in clinical environments and for verifying routines for compliance with ISO
and IEC standards and with profiles of the “Integrating the Healthcare Enterprise (IHE)
association including FHIR.
Acknowledgment
This work was supported by the German Federal Ministry of Education and Research in
the framework of the ICT flagship project OR.NET10
10
OR.NET German Federal Research Project: www.ornet.org
29
References
[1] E. A. Lee, “Cyper Physical Systems: Design Challenges”,
http://www.eecs.berkeley.edu/Pubs/TechRpts/2008/EECS-2008-8.html, EECS
Department, University of California, Berkeley, January 23, 2008.
[2] M. Janssen and R. Schrenker, “Guidelines From 80001 Maintaining a Medical IT
Network”, in Biomedical Instrumentation & Technology, July/Aug 2011, pp. 295-
299.
[3] S. Schlichting and S. Pöhlsen, “An architecture for distributed systems of medical
devices in high acuity environments - A Proposal for Standards Adoption”;
http://www.hl7.org/documentcenter/public_temp_C17326F5-1C23-BA17-
0C77F7AEBDCABB5C/wg/healthcaredevices/20140121%20An%20architecture%
20for%20distributed%20systems%20of%20medical%20devices%20in%20high-
acuity%20environments.pdf
[4] S. Schlichting, “openSDC Update”, Joint meeting of IEEE EMBS 11073 & HL7
Health Care Devices (DEV) WG, San Antonio, 2015/01/20.
http://www.hl7.org/Special/committees/healthcaredevices/docs.cfm
[5] J.-U. Meyer, “Open SOA Health Web Platform for Mobile Medical Apps, 8th
IEEE International Workshop on Service-Oriented Cyber-Physical Systemsin
Converging Networked Environments (SOCNE) in conjunction with ETFA 2014,
Barcelona, Spain, September 16st, 2014
[6] OR.NET Flagship Project, http://www.ornet.org/?lang=en, Kick-off meeting,
October 2, 2012, Heidelberg, Germany.
[7] Integrating the Healthcare Enterprise (IHE), www.ihe.net , retrieved on 2014-06-
13.
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