To meet the stringent quality of service (QoS) requirements of wireless body area sensor networks, a new adaptive duty cycle and IEEE 802.15.4-based medium access control protocols have been developed. Time-sensitive data transmission services, data rate, dependability, and power consumption are all examples of QoS requirements. However, it is challenging to provide a complete set of QoS with existing protocols. To further reduce energy consumption, these protocols adjust duty cycle values depending on assumptions such as active times, buffer occupancy, and collision rates. These estimations are too laborious and time-consuming to be used in a clinical context. We introduce an IoT-based health care protocol (RDTP) that, by optimizing duty cycles based on fine-tuning MAC layer settings, can be used with IEEE 802.15.4 slotted CSMA/CA in beacon-enabled mode. The RDTP’s operational schedule is determined by three factors: the availability of network traffic, the reliability of delays, and the length of superframes. The suggested protocol offers low latency, high availability, and low power consumption, all of which are required for patient monitoring applications. The performance of the proposed protocol may be measured in terms of average end-to-end delay, reliability, packet delivery ratio, collision rate, and energy usage by varying the number of nodes in the network and the quantity of traffic offered. Within the constraints of patient monitoring applications, the RTDP performed favorably in terms of delay, reliability, energy usage, and collision rate compared to other contemporary protocols.