Population ageing needs health-enabling technologies for delivering pervasive health care. Home care plays an import role in pervasive health care. In this paper, we aim to construct a home-centered health information system architecture which can efficiently manage multi sensors, actuators and decision support systems. Open Services Gateway initiative (OSGI) was used for constructing the service oriented architecture. HL 7 Arden Syntax for medical logic module (MLM) was used to describe the medical knowledge; An Arden compiler was used to interpret the MLMs. The Arden compiler was packed in an OSGI bundle. All of the knowledge bases can share the compiler within the OSGI platform. System within the OSGI-based architecture can change their behaviors during runtime. The proposed prototype architecture was deployed in a case study.