Design And Implementation Of Wireless Heart Rate Monitor Data Transmission Node Based On Bluetooth Low Energy

With the rapid development of wireless transmission technology, wireless networking technology has been widely introduced into various industries, including the medical field. By using of wireless sensor network, hospital can collect and summary patient information.The wireless heart rate monitor adopts infrared heart rate sensor to collect data, Bluetooth low energy chip to process and transmit data. Collected data transmit to main chip after amplified and filtered, and then data transmits to RF module after processed by MCU. The system work mechanism is based on multi-task and event trigger, tasks scheduled is according to the priority order. DABTC protocol algorithm expands the number of network nodes through a symmetric link formation agreement, which however introduces some new problems such as infinite inqury and network fracture. A improved DABTC algorithm in the networking is used in this thesis.In this algorithm the inqury and scan feedback mechanism are added into the algorithm, when the system finds the failure routing table or exceeds inquiry scan time, that node will be deleted, which simplifies the route discovery and solves the problem of infinite inquiry effectively. By means of pseudo random inquiry of root nodes, the tree structure of the root node is replaced by the root node, so that the most congested tree node load can be minimized, which can solve the problem of network fracture. When the value of the rate of transmission data exceeds the threshold value, sub node can interact with the root node in priority, in this way the time to deal with abnormal information can be reduced.At the end of this paper, the hardware and software of the low power Bluetooth wireless heart rate monitor are tested. The results show that, the design of Bluetooth low energy wireless heart rate meter operating power consumption is 73.6mW, When the packet loss rate is less than 1% receiving sensitivity is-92.5dBm. The heart rate transmission network support the network communication of the maximum field device.40 devices are used to test this system, The improved network is superior to the traditional network for the transmission delay of abnormal information.