Various medical applications consisting of heterogeneous requirements are supported by WBA networks. For reliable data transmission it is required to use an efficient medium access control protocol. Here, in this project, a dynamic Super frame structure-based MAC protocol is proposed by extending the standard principles from IEEE 802.15.6 which is a standard protocol, a mechanism for allocating dedicated slots with prioritization is used which is known to be Criteria Importance Through Inter-criteria Correlation, inorderto assign the allocation of slots for every sensor device. Values of sensor devices are calculated based on different sensors parameters by using CRITIC method. There by we compare our proposed work with the standard IEEE 802.15.6 MAC and other MAC protocols. By simulating it is shown that our proposed MAC protocol has performed better in Reliability, Throughput, Energy Efficiency and also Packet Delivery Delay. In the results it is shown that Reliability of data transmission has increased over more than 50% over the standard IEEE 802.15.6 MAC