In this report we present an architectural approach to add quality-of-service (QoS) assurance and location awareness to service-based systems within existing clinical infrastructures. To address typical design requirements of such systems (e.g., cooperating services, performance and availability) the work proposes a service-oriented architecture (SOA) as architectural concept and architectural translucency to provide stable QoS. We evaluate position sensing systems, QoS assurance approaches and present design principles for service-based health care applications. Furthermore, we present a clinical application scenario and an architectural approach to integrate existing infrastructure into a human centric assistance system.