Low-Power Wireless Transmission of Biosignals Using the Slotted ALOHA Mechanism

The collection of physiological signals such as electrocardiogram, electroencephalogram, respiration, blood pressure, body accelerations etc. in a body area network is beneficial for revealing vital signs and investigating spontaneous physiological responses. However, the wire connection between the recording sites and the processing unit may disturb subject´s daily activities. Up to now, several multi-users communication protocols such as IEEE 802.11, Bluetooth, etc. have been proposed for this purpose. In this paper we employed the slotted ALOHA for multi-users wireless data transmissions. The slotted ALOHA is so simple that it can be implemented by a 2.4-GHz RF transceiver (nRF2401, Nordic) incorporated on a 16-bit microcontroller (MSP430, Texas Instruments) for the consideration of low-power consumption. In this paper we proposed a modified slotted ALOHA for multi-biosignals transmission and built its simulation model using SIMULINK 2.0 to simulate and evaluate the performance of the proposed algorithm.