Recent technological advances in sensors and wireless communications have enabled the design of inexpensive, portable and intelligent physiological sensor nodes for health care or patient monitoring. In this work, a new flexible Internet-based real time biosignal monitoring system has been design and implemented. A new wireless body sensor network (WBSN) node platform has been developed based on Zigbee technology for this system. In order to seamlessly connect the distributed WBSN together with Internet, a Zigbee/Internet gateway has also been development. An online database for storing sensor data, network management user interface (Server program) and client monitoring/analysis tools (Viewer program) have also integrated in this system. Moreover, in order to enhance the mobility of sensor node real time monitoring, a Hybrid Handoff algorithm has been proposed and implemented. Several experiments have been performed to evaluate the latency and packet losses during handoff of the proposed algorithm. Measurements results show that the proposed handoff is able to reduce both of the latency and packet losses much for Zigbee than without it.