Wireless sensor networks (WSN) have received much attention during the last few years especially with regard to energy consumption. Many Medium Access Control (MAC) protocols were proposed to minimize the energy consumption in WSN, however they cannot be applied in all application contexts. Healthcare monitoring is an important application requiring adapted MAC protocol. This paper presents a new MAC protocol, called T-TMAC, based on simple mechanisms that organize data exchange and reduce collisions in many-to-one architecture. It includes maintenance mechanisms that permit mobility management and topology reconfiguration, which are needed for healthcare. We evaluated the performance of the protocol by analytical model. We propose also real prototyping using Imote2 platforms. We studied the impact of position of nodes and sleep modes on energy and delay. The results emphasize the interest of the protocol.