Energy efficient intra-hospital multi-patient cardiac monitoring through ZigBee network This paper presents an energy efficient intrahospital telemedicine scenario for multi-patient cardiac monitoring using ZigBee network. A telemedicine scenario is proposed in which Electrocardiogram (ECG) signals of patients are acquired through ECG sensor nodes having transmission capability and these ECG signals are received by Personal Digital Assistant (PDA) kept at nursing station throughZigBee network. ECG signals are further transmitted to Doctor’s PDA. Energy efficiency of proposed network is investigated by evaluating the performance of various routing protocols in terms of Packet Delivery Ratio (PDR), Battery life, Energy Consumption, End to End delay by varying the transmission power of ECG sensor nodes and for different routing protocols.