This document describes a life detection system that uses microwaves to locate human victims trapped under earthquake rubble. The system works by transmitting microwave beams through rubble and detecting the modulated reflection caused by a person's breathing and heartbeat. It operates by cancelling out the static clutter reflection from rubble while distinguishing the modulated reflection from a person's body. This allows it to detect breathing and heartbeat signals and locate trapped victims within a few seconds from a distance, providing a more effective solution than existing search methods.

1. Life Detection System
Using Microwaves
By:
Suhail Ahmad Dar
ECE-13-58

2.  “An earthquake causes loss of many human lives every year as
humans are trapped under collapsed earthquake rubble”
 Exiting methods for detecting such victims are the utilization of
dogs or some optical devices or robots.
 These existing devices are ineffective in recovering human
victims lying much below a few feet, especially for the cases
when the victims are completely trapped below or very weak to
respond to the signals sent by the rescues. This problem have
been efficiently solved by using life detection system.
Why this project…?

3. The main aim is to locate the human beings buried
under earthquake.
This system operating at certain frequency can
remotely detect the breathing and heartbeat signals
of human beings buried under earthquake rubble.
The entire process takes place within a few seconds
as the system is controlled by a microcontroller.
INTRODUCTION

4.  The basic principle is that when microwave beam of certain
frequency [L (or) S band (or) UHF band] is aimed at a
portion of rubble under which a person has been trapped
,the microwave beam can penetrate through the rubble to
reach the person .
 When the microwave beam focuses the person, the
reflected wave from the person’s body will be modulated
(or) changed by his movements ,which include breathing
and heartbeat.
Principle of operation

7. So, if the reflected waves from the immovable debris
are cancelled and the reflected wave from the
person’s body is properly distinguished ,the breathing
and heartbeat signals can be detected.
It can work on different range of frequencies from L-
band (2GHz) to X-band (10GHz).

8. Block diagram

9. The microwave life detection system has four major
components
A microwave circuit .
A microwave controlled controlled clutter
cancellation system.
A dual antenna system.
A laptop which controls the microprocessor.
Major components of the circuit

10. The microwave life detection system
has four major components
A microwave circuit .
A microwave controlled controlled
clutter cancellation system.
A dual antenna system.
A laptop which controls the
microprocessor.

11. Phase locked loop.
Directional coupler 1(10 dB).
Directional coupler 2(3 dB).
Antenna system.
A clutter cancellation circuit (forms the heart of life
detection system).
Circuit description

12.  Antenna 1
 Antenna 2
 The large clutter from the rubble can be cancelled by a
clutter cancelling signal.
 The reflected wave from person’s body could not be
cancelled by a pure sinusoidal cancelling because his
movements modulate it.
 The output of the clutter cancellation circuit is
automatically adjusted to be of equal amplitude and
opposite phase as that of the clutter from the rubble.
Working

13. Operation of clutter
cancelled circuit.

15. It is not desirable to disturb a subject’s
physiological or emotional state during
detection.
The frequency 2.45 GHz i.e. L-band frequency
and this is free for use by commercial
applications, so we expect a minimum
interference with other devices during our
tests.
Advantages

16. Project is expensive.
L-band frequency is unable to
penetrate more metal like
structures but it can penetrate
over ten layers of bricks.
Disadvantages

17. Result

18. Thus a new sensitive life detection system using
microwave radiation for locating human beings
buried under earthquake rubble or hidden behind
various barriers has been designed. This system
operating either at L or s band can detect the
breathing and heartbeat signals of human beings
buried under earthquake rubble. By the advent of this
system the world death rate may decrease to great
extend.
Conclusion

19. END

20. Thank you