20-09-2016, 02:47 PM
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Introduction
Epilepsy is a very fatal condition which is caused as a result of
imbalance in the nervous system. The very common
symptoms of epilepsy includes sudden fluctuations in heart
beat rate and involuntary muscular movements (seizures).
The aura (practical symptom) of epilepsy includes fluctuations
in heartbeat, nausea, dizziness etc.
The wireless electronic diagnosing system designed here is
exclusively meant for epilepsy patients. The system helps
them in accurately predicting the occurrence of seizures.
Sudden occurrence of seizures during driving may lead to
accidents and its occurrence during sleeping hours can even
lead to the patient’s death, if no immediate, proper attention
is provided by a bystander or a doctor. With the aid of this
system, the patient can lead a normal life. Since the
occurrence of seizures is unpredictable, it will be a very risky
task to leave the patient alone.
The electronic system presented here is a wearable device
which predicts the occurrence of epilepsy in a few minutes
advance. The device utilizes the signals from human body to
detect the occurrence of epilepsy. As soon as the device
detects the symptoms, it transmits a coded signal. The signal
is decoded by a wireless receiver to produce control signals
for switching an alarm device, mobile messaging device and
an automatic vehicle control system appropriately. In future, GPS could be incorporated to trace out the exact location of
the patient.
Current technologies for acquiring signals from the patient’s
body are very much developed. Many sensors are available
which can detect the heart beat and muscular movements
non-invasively and accurately.
Such non invasive technique for measuring heart beat is
pulse oximetry. Using this technique, heart beat can be
accurately monitored. Muscular convulsions are collected
using micro electromechanical sensors (MEMS) firmly
attached to the body. The sensors used are small in size and
can be firmly attached to the body. The accelerations
resulting from epileptic convulsions are sensed using MEMS
accelerometer which is very accurate, precise and small in
size.
To provide wireless communication channel low cost network
using MiWi protocol is utilized. MiWi is a standard protocol
developed by Microchip Inc, USA, based on IEEE 802.15.4.
Heart beats are to be monitored continuously. Any sudden
variation in heart beat which is caused by the onset of
epileptic seizures is detected and confirmed with the MEMS
signal. When the seizure is confirmed, message is transmitted
to the surroundings for initiating necessary protective
measures for the patient.
The device is designed as a wireless, wearable and personal
equipment. The device can sense the aura of pre ictal stage in
a few minutes advance and takes the necessary safety
measures automatically. Hence a technician’s assistance is
not required for the patient. Therefore this device will be
extremely useful for patients (especially youngsters) who
wish to be active in their life. The user gets absolute freedom
from wires and can be used when moving.
To practically implement the epilepsy prediction system, the
following aspects should be implemented.
1. Sensing biometric signals: Two types of biological signals
are required for processing. They are heart beat and
muscular convulsions. The heart beat can be measured using pulse oxy meter and muscular movements can be
measured using mems sensor.
2. Processing it and taking decisions: Processing of the
signals is done by software programmed into a
microcontroller. The software is designed in such a way
that it detects the exact symptom of epilepsy.
3. Communication: Communication is set up using a
transmitter and receiver module with MiWi protocol
4. Controlling: Automatic vehicle control system, mobile
messaging device and an alarm device is integrated to the
receiver for protecting the patient.
2. Constraints
1. Smaller size and weight requirement
2. Low power consumption requirement as the device is
battery operated.
3. Suitable long life battery
4. Accurate technique or algorithm for foolproof detection
of seizure
5. Secure communication between the wearable
equipment and the receiving unit
6. Signal processing requirement
7. Cost effectiveness
The application of this system focus on epilepsy patients who
wish to move freely without the assistance of others in their
life. The system is a wearable device which can detect the
aura of seizure in an epilepsy victim very much precisely in
time by processing the signals available from the patient’s
body at the pre ictal state. The system uses a processing
device to process the signals from the human body and
activates a wireless transmitter which transmits a coded
signal. The receiver decodes the signal using another
processing unit which results in the production of control
signals for activating various safety devices mounted on the
vehicle or on the dormitory where the patient commonly
resides. For e.g, if the seizure occurs while the victim driving
a vehicle or while sleeping the device automatically generates control signals for the control of vehicle, setting off an alarm
circuit and messaging the doctor about the patient’s condition
via short messaging Service (SMS). The system can be
expanded easily in such a way to include Global Positioning
System (GPS) for tracing out the exact position of the victim
of epilepsy in the future. Thus the device saves the patient
from accident or even death and acts as a “LIFE SAVER”
3. Design
The design consists of hardware and software sections. The
device hardware mainly consist of three parts namely, (i)
Heart beat sensor, (ii) Seizure detector, (iii) Processor and
(iv) Wireless transceiver
(i) Heart beat sensor: The heart beat of the patient is to be
monitored accurately. For this purpose, a pulse oxy meter is
used. Pulse oxy meter measures heart beat by sensing the
difference in absorbance of infrared radiation by blood during
systolic and diastolic activities of heart. The volume of blood
flowing through arteries varies widely during each heart beat.
Hence if infrared radiation is incident on it, the absorbance of
IR also varies according to the heart beat. These variations
are sensed using a photo detector to determine the heart
beat.
. Advantages and benefits
The benefit of the project is that a lightweight, rugged, lowcost,
wearable (on the wrist) device is developed which helps
a victim of epilepsy to do all sorts of activities like others do.
• The device will be extremely cost effective since it uses
simple sensors and technology for the detection.
• The sensors are small in size and can be firmly attached
to the body
• Batteries can last long as the device consumes only little
energy
• The device doesn’t restrict the movement of the patient.
• The system is easily expandable paving the way to
incorporate much more sophisticated devices like ECG
detector in the future
• Standalone application
12. Improvements
The system is easily expandable to incorporate GPS system
and to capture and transmit various patient parameters like
ECG , body temperature etc.
13. Conclusion
A light weight, rugged, cost-effective wearable device is
developed which helps millions of victims of epilepsy around globe. With the device in possession an epilepsy victim
can move around freely like normal people sans worries.