14-04-2011, 04:07 PM
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ABSTRACT
HEART RATE DISPLAY USING 8051 MICROCONTROLLER
AIM:
The aim of this project is to implement an ECG and Digital Heart Rate counter. The main challenges include amplifying the desired weak signal in the presence of noise from other muscles and electrical sources. A display of the heart rate will be obtained by measuring the time between signal peaks and then calculating the frequency of the peaks in units of beats per minute.
PURPOSE:
The heart is one of the most vital organs within the human body. It acts as a pump that circulates oxygen and nutrient carrying blood around the body in order to keep it functioning. When the body is exerted the rate at which the heart beats will vary proportional to the amount of effort being exerted. By detecting the voltage created by the beating of the heart, its rate can be easily observed and used for a number of health purposes
BLOCK DIAGRAM:
DESCRIPTION:
A heart rate monitor is a personal monitoring device that allows a subject to measure their heart rate in real time or record their heart rate for later study. This can be used to monitor the heartbeats in digital display format. The heart beat information available in digital format is easy to understand. In our heartbeat monitor project we have used two electrodes to sense the blood pumping done by heart which are proportional to heartbeats.
The sensing electrode sense the blood pumping cycles and send the signal to amplifier.An accelerometer measures instantaneoussacceleration of the object on which accelerometer is bounded. It transduces the acceleration which results from thevibration to corresponding analog signal. Here we use piezoelectric type accelerometer is used.
We are using stages of amplifiers to amplify weak signals sensed by sensing electrodes. The amplified signals are processes to extract the cycles of blood through our body. The average value of sensed cycles of blood pumps are displayed per minute interval. We have used microcontroller AT89S51 to process the sensed signal from sensor and displayed on 16x2lcddisplay
HARD WARE COMPONENTS:
• Piezo-electric accelerometer
• +5v dc supply
• Amplifier
• Micro controller
• Lcd
SOFT WARE TOOLS:
• Proteus
• Keil u-vision
• Embedded C
• Express pcb
INTRODUCTION
The project is to monitor pulse rate, strength of the heart beats and assessment of the pulse conditions. The heart beats are to be sensed from wrist through a wrist band clip sensor. This information is to be displayed on LCD display
A heart rate monitor is a personal monitoring device which allows a subject to measure his heart rate in real time or record his heart rate for later study. Early models consisted of a monitoring box with a set of electrode leads which attached to the chest.
Modern heart rate monitors usually comprise of two elements: a chest strap transmitter and a wrist receiver or mobile phone (which usually doubles as a watch or phone). In early plastic straps water or liquid was required to get good performance. Later units have used conductive smart fabric with built in microprocessors which analyse the EKG signal to determine heart rate.Strapless heart rate monitors now allow the user to just touch two sensors on a wristwatch display for a few seconds to view their heart rate. These are popular for their comfort and ease of use though they don't give as much detail as monitors which use a chest strap.
More advanced models will offer measurements of heart rate variability, activity, and breathing rate to assess parameters relating to a subject's fitness. Another style of heart rate monitor replaces the plastic around-the-chest strap with fabric sensors - the most common of these is a sports bra for women which includes sensors in the fabric. In old versions, when a heart beat is detected a radio signal is transmitted, which the receiver uses to determine the current heart rate. This signal can be a simple radio pulse or a unique coded signal from the chest strap (such as Bluetooth, ANT, or other low-power radio link); the latter prevents one user's receiver from using signals from other nearby transmitters (known as cross-talk interference).
Newer versions include a microprocessor which is continuously monitoring the EKG and calculating the heart rate, and other parameters. These may include accelerometers which can detect speed and distance eliminating the need for foot worn devices. There are a wide number of receiver designs, with various features.
These include average heart rate over exercise period, time in a specific heart rate zone, calories burned, and breathing rate, built in speed and distance, and detailed logging that can be downloaded to a computer.
The Heart Rate Monitor Interface (HRMI) is an intelligent peripheral device that converts the ECG signal from Polar Electro. Heart Rate Monitor (HRM) transmitters into easy-to-use heart rate data.
It implements a sophisticated algorithm for computing an average heart rate even with noisy or intermittent data from the transmitter. The HRMI also provides analog inputs and a digital input/output utility port to ease integration into custom applications.
We will be implementing an ECG and Digital Heart Rate counter. The main challenge of the project would be to amplify the desired weak signal in the presence of noise from other muscles and electrical sources.
A display of the heart rate will be obtained by measuring the time between signal peaks and then calculating the frequency of the peaks in units of beats per minute. The device is most useful if it is portable.
This requires a battery to be able to power all of the necessary components as well as the power output of the battery to be regulated.
Desired signal
The heart pulse received on the skin by electrodes is a result of traveling electrical activity from the heart. At the skin, this signal has a relative potential in the range of about ~2mV
