04-07-2012, 11:09 AM
A ZigBee Network based Heart Rate Monitoring System for Pre-mature babies
A ZigBee Network based Heart Rate Monitoring System for Pre-mature babies.ppt (Size: 3.48 MB / Downloads: 113)
Project Goal
Develop a remote heart beat monitoring system using wireless technology for new-born premature babies kept in hospital incubators.
The main goal is to alert hospital staff in case a babies’ heart rate is detected as abnormal.
Currently most hospitals use ECG (Electrocardiography ) for monitoring a baby’s heart rate but do not have remote monitoring system. Our project proposes a solution to upgrade existing health monitoring systems in hospitals by providing remote monitoring capability.
Why ZigBee?
Long range (10-100 meters)
Long Battery Life (low power consumption)
Secure communication (128 AES plus application layer security)
Low complexity at application layer (lot of features available in the ZigBee stack)
Quick network formation (Devices can join an existing network in under 30ms)
Experiments: Implementing a remote ZigBee monitoring system
We implemented a ZigBee wireless network using 1 ZigBee Co-ordinator and 3 end-devices.
A ZigBee Coordinator establishes the ZigBee network, and collects heart rate information from various end-devices within the network.
A ZigBee end-device transmits the heart rate information to the Coordinator periodically. On detecting, an abnormal heart rate (above 160 beats/min and below 120 beats/min) for new-born babies, it sends the information immediately.
ZigBee Coordinator transmits the received heart rate information to a computer using RS232 serial communication. The computer will have a software that will display the heart rate information.
Each end-device has a unique device address, which is used to map heart rate information to a particular baby in the incubator room.
Ideally, heart rate sensor would be based on electrodes attached to a baby. An analog input on the Zigbee device would collect electric signals from the sensor and Analog-to-Digital converter would provide digital data.
In our experiment, we have used a random number generator on the Zigbee device to simulate baby’s heart rate.
An extension of this work would be to develop a software that transmits heart rate information to a central monitoring system over Ethernet LAN.
Reliability and Fail Safe measures
Since the heart rate is reported periodically, the receiver /coordinator can detect if any node in the ZigBee network has failed (whatever be the reason).
The computer receiving periodic data from the receiver/coordinator, can detect if the receiver failed.
According to battery life (depends on battery), the software running on the computer attached to zigbee coordinator, can estimate if one of the zigbee nodes is going to die.
Hardware Specification
CC2430 system on a chip with 8051 microcontroller, an RS232 interface, a USB Slave interface, an open A/D converter line plus an integrated accelerometer, light sensor, LEDs, a joystick and buttons.
CC2430 System-on-Chip (SoC) is specifically tailored for IEEE 802.15.4 and ZigBee™ applications. Combined with the industry leading ZigBee™ protocol stack (Z-Stack) the CC2430 provides the market’s most competitive ZigBee™ solution.
Zigbee Network used for experimentation
Picture below shows the Zigbee network we used for the project. The coordinator is the board with the serial cable attached to it. The end devices/nodes are the other three devices.
Conclusion
We have proposed a low-cost solution to enhance the remote monitoring capability of existing health care system.
We conducted a feasibility study of using ZigBee network based heart rate monitoring system.
It is secure, robust and low-power consuming.
It can operate on multiple channels so as to avoid interference with other wireless devices or equipments in the hospital.