Measuring latencies of IEEE 11073 compliant service-oriented medical device stacks

Vendor-independent interoperability is one of the key-enablers for medical devices in future operating rooms, intensive care units, and medical care in general. Using the paradigm of a Service-Oriented Architecture (SOA) is a promising approach realized by the new IEEE 11073 SDC family of standards. Standard compliant communication stacks will be used to build up systems of networked medical devices. The performance of the stack implementation is crucial for the usability in real-world medical environments. Therefore, we investigate the latency of currently available middleware stacks: SoftICE, openSDC, and OSCLib. The aim is to evaluate the suitability of the underlying concepts, understanding the communication behavior using different hard- and software platforms, and finding problems to support future development. For the latency measurements we build up a use-case independent testbed and instrument the libraries to get more information. On the one hand, our investigations substantiate the suitability of the underlying concept and the available middleware stack implementations. On the other hand, unexpected results occurred, like a strong dependency of communication latency on the combination of hardware platform, Java Virtual Machine (JVM), and JVM configuration and even a strong dependency on the intensity of exchanged data when using Java middleware implementations.