Safety-critical platform for medical device design

The Enea Embedded Medical Platform (EE-Med) is a safety-critical software platform for embedded medical devices.

The Enea Embedded Medical Platform (EE-Med) is a safety-critical software platform for embedded medical devices.

EE-Med provides all of the software components needed to design safety-critical medical devices, including a hard real-time operating system, secure wireless and wireline networking, an embedded GUI, a fault tolerant database, and comprehensive development environment.

This software platform, together with Enea's medical reference boards and hardware/software engineering services, encompasses all phases of design, development and deployment, from initial planning to FDA certification.

"OSE's real-time response, secure partitioning, and guaranteed resource availability make it the ideal platform for building safety-critical embedded medical devices", said Adrian Leufven, Vice President Marketing of Enea Embedded Technology.

"Now we are bundling our RTOS with comprehensive engineering services and all the networking, database, GUI, and development tools components needed to take an embedded medical device from concept to production, including FDA certification".

The foundation for EE-Med is the safety-critical OSE real-time operating system, which combines fast, deterministic, real-time response with memory protection facilities that enable medical OEMs to isolate safety- and life-critical Level A functions.

This secure partitioning guarantees that failures in non-critical services such as networking do not impair life-critical services such as dispensing medication or monitoring vital signs.

OSE also provide guaranteed resource availability, which enhances reliability by ensuring that critical Level A functions always have prompt access to necessary CPU and memory resources.

OSE further enhances reliability by providing built-in fault detection and response mechanisms that initiate fault analysis and recovery as soon as one of the processes it is supervising fails to respond.

This fast response enables OSE to reconnect applications more quickly after failure occurs.

It also enables OSE to isolate the defective process, reducing the likelihood that other users will interact with it, and minimising the opportunity for the failure to propagate through the system.

To enhance data storage reliability, OSE provides an atomic file manager that prevents interruptions (such as a power outage) that occur during the write process from corrupting the file system data.

The atomic file manager ensures that once a write operation is initiated, it either completes, or has no affect on the file system data, thereby preventing faulty or incomplete data from being written to the file system.

EE-Med further increases data storage reliability by providing a relational database management system (RDBMS) known as Polyhedra, which provides a secure, fault-tolerant data repository.

The active Polyhedra RDMS features a small code footprint and a memory-resident design that boosts performance by an order of magnitude relative to conventional disk-based RDBMSs, without sacrificing data security.

Today's sophisticated safety-critical medical systems are increasingly employing multiple processors to provide redundancy, increase performance, and partition critical and noncritical functions.

OSE simplifies multiprocessor design and enhances reliability by using direct message passing to establish communications between multiple processes running on one or more processors.

This consistent process-to-process communications mechanism, which is independent of the underlying hardware, makes remote processes appear to reside on the same processor or DSP, when in fact they may actually span multiple processors or DSPs.

EE-Med features a complete networking solution, which includes TCP/IP and secure networking protocols such as IPV6, SSH, SSL, Radius and IPSec.

OSE also supports wireless networking protocols such as 802.11 and Bluetooth that simplify the design of mobile medical devices.

EE-Med's integrated development environment greatly simplifies all aspects of medical software development, from kernel debugging and board bring-up to application creation and testing.

The comprehensive development environment supports UML state machine design and code generation, RTOS-aware source-level and system debugging, and an RTOS simulator that enables designers to develop OSE-based medical applications on Linux, Windows, and Solaris host operating systems in advance of hardware availability.

EE-Med also features a system-level analysis tool known as Illuminator, which enables programmers to monitor, control and collect data for applications viewed as a sequence of events (such as context switches and message passing between processes).

Illuminator also supports system profiling, which enables programmers to track CPU and memory resource utilisation at the process level.

Swell Software's PEG GUI development tool, also included in EE-Med, makes it easy to add custom GUIs to embedded medical devices.

The 100Kbyte, event-driven GUI, occupying only 8Kbyte of RAM, provides a complete development kit and class library for creating professional quality GUIs.

The PEG GUI provides full support for OSE memory protection, multitasking, message-passing and interrupt processing, and includes tools for building visual screens, generating custom fonts, and compressing and ROMing arbitrary images.

It also provides hardware and OS encapsulation classes that enable custom OSE PEG user interfaces to run as a standard 32bit Windows application.

This enables designers to develop, simulate, debug and test their custom PEG GUIs on a standard Windows PC.

One of the most challenging aspects of bringing a medical device to market is obtaining FDA certification of the end product.

To assure approval, FDA approved design and development methodologies must be used from the beginning to the end of the project.

EE-Med includes comprehensive engineering and medical certification services including an FDA-approved roadmap and development process, full code validation and verification, hardware design and development, and product certification.

Enea's medical product specialists will guide OEMs through all aspects of the development project, from board bring up through FDA certification of the final product.

Also available for EE-Med is a DSP-optimised version of OSE known as OSEck (OSE Compact Kernel).

Optimised for deeply embedded medical devices with stringent memory constraints, OSEck is event driven, fully pre-emptive, and occupies less than 4Kbyte of memory in a minimal configuration.

OSE and OSEck share the same API and interprocess communications framework, making it easy to combine the two RTOSs in medical systems using multiple processors.

EE-Med is available immediately on several ARM- and PowerPC-based FDA certifiable hardware reference platforms.

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