By definition, “Medical Electronics” is the study of electronic
instruments and devices used for diagnosing and curing health. It is the
design of embedded systems applied to medicine and biology.
• Sensors play a predominant role in bringing medical applications
to the real world. Sensing elements such as Airflow, Temperature, Humidity,
Pressure transducers, Thermistors etc. are proven to be necessary things to
carry out medical solutions.
GROWING ROLE OF ELECTRONICS IN THE HEALTH SECTOR
• Healthcare sector is gradually achieving digital integration at all
steps of a patient’s journey from lookout for symptomatic information,
diagnosis, treatment and follow ups.
• Innovations in Information and Communication technology (ICT)are
redefining medical processing the country from patient registration to data
monitoring, from lab tests to self-care tools.
• The technology, apart from sharing information provides help in
diagnostics, management, counselling, education, and support.It has begun to
replace conventional monitoring and recording systems, with people given the
option of undergoing full consultation in the privacy of their own homes.
• Thanks to technological advancements in healthcare, services have
been taken out of the confines of hospital walls, labs and integrated with
user-friendly, accessible electronic devices, providing crucial linkage between
healthcare providers and patients.
OVERVIEW OF SOME SECTOR HAVING EXTENSIVE USE OF ELECTRONICS
1. ANESTHESIA MACHINE
It is a method of delivering drugs to relax
and make the patient unconscious during a surgery or an operation. It will
block the related nerves that carry pain signals to the brain.
But during sleepy state, required gases like
oxygen levels, air, nitrous oxide, and isoflurane have to be maintained. For
this purpose, sensors are required to control temperature, humidity, and
pressure.
WORKING PRINCIPLE
• Three known parameters Air, Nitrous oxide, and oxygen are given to a
filter individually through the ventilators. The filtered output is given to a
pressure sensor. Here the pressure sensor may be digital or analog one
depending upon the psi range and accuracy. This is given to a regulator for
restricting the incorrect amount of gases.
• The pressure sensor output is passed through an anesthetic vapor
(isoflurane). The combined output from all the valves sends to the oxygen
sensor. This will provide the required oxygen levels to the patient.
• Moreover, the humidifier is used for temperature and humidity
control of the oxygen sensor in the heater assembly.
• Thermistor sensor for monitoring and control of the air temperature.
Magnetically operated switch [Hall Sensor] is used for motor control in the
heater assembler.
• Airflow (Breath) sensors are used for measuring the air and oxygen
levels of the patient. The amount of mixture gases given to the patient is
displayed on the graphical display.
2. PACEMAKER
The Pacemaker is a device used to resolve the missing heartbeat or slow heartbeat by generating electrical pulses and bringing back the heart to working condition.
The voltage source generates power for the pacemaker device. The sensing amplifier amplifies the low-power ECG signal. The amplified output is given to Timer for providing accurate timing pulses. The output driver injects the timed electrical pulse via electrodes to the patient. This makes the heartbeat count in normal working condition.
3. ELECTROCARDIOGRAPHY(ECG) MACHINE
Electrocardiogram refers to the recording of electrical changes that occur in the heart during a cardiac cycle. It may be abbreviated as ECG or EKG.
It is an instrument that picks up the electric currents produced by the heart muscle during a cardiac cycle of contraction and relaxation
WORKING
PRINCIPLE
• It works on the principle that a contracting muscle generates a
small electric current that can be detected and measured through electrodes
suitably placed on the body.
• For a resting electrocardiogram, a person is made to lie in the
resting position and electrodes are placed on arms, legs and at six places on
the chest over the area of the heart. The electrodes are attached to the
person’s skin with the help of a special jelly.
• The electrode picks up the current and transmit them to an amplifier
inside the electrocardiograph. Then electrocardiograph amplifies the current
and records them on a paper as a wavy line.
• In an electrocardiograph, a sensitive lever traces the changes in
current on a moving sheet of paper.
• A modern electrocardiograph may also be connected to an
oscilloscope, an instrument that display the current on a screen
Normal ECG
WAVE
A normal ECG
makes a specific pattern of three recognizable waves in a cardiac cycle. These
wave are- P wave, QRS wave and T-wave, P-R interval, S-T segment
APPLICATIONS
• It indicates the rate and rhythm or pattern of contraction of heart
• It gives a clue about the condition of heart muscle and is used to
diagnose heart disorders
• It helps the doctors to determine whether the heart is normal,
enlarged or if its certain regions are damaged
• It can also reveal irregularities in heart’s rhythm known as
‘arrhythmia’
• It is used by doctors to diagnose heart damage in conditions like
high blood pressure, rheumatic fever and birth defects
• An ECG also helps to determine the location and amount of injury
caused by heart attack and later helps to assess the extent of recovery
4. BRAIN WAVE MACHINE
•
A mind
machine (aka brain-machine or light and sound
machine) uses pulsing rhythmic sound, flashing light, electrical or magnetic
fields, or a combination of these, to alter the frequency of the user's brainwaves.
•
It processes the data that has
taken from the electrodes which are placed on the scalp and can be displayed
within the screen
• It is helpful in the treatment of disorders of brains like sleeping
disorder, brain death, and mental unhealthiness, also in emergency units at
hospitals.
• These types of electronic devices are used in the medical field in
the treatment of mental issues.
• Brain wave machine is one type of instrument in medical electronics
which is used to record the electrical activity of the scalp with
Electroencephalography by firing of neurons within the brain
• Photic mind machines work with flickering lights embedded in
sunglasses or a lamp that sits on a tripod above your head or facing you. You
then "Watch" with your eyes closed.
5. DEFIBRILLATOR
• Defibrillator is used in emergency conditions like heart attack
occurs.
• It affects the rhythm of the heart such as ventricular fibrillation,
cardiac arrhythmia and pulseless ventricular tachycardia.
• The working procedure of the Defibrillator involves, when the
electric shock delivers to the heart, it causes depolarization of the muscles
of the heart and regenerates normal conduction of the electrical pulse of the
heat.
• There are different types of defibrillators include implanted, trans
venous and external defibrillators.
• They include implantable cardioverter defibrillators (ICDs), which
are surgically placed inside your body, and wearable cardioverter
defibrillators (WCDs), which rest on the body.
Automated external defibrillators (AEDs), which are in many public spaces, were developed to save the lives of people experiencing sudden cardiac arrest
6. MRI (Magnetic Resonance Imaging)
• The medical resonance imaging technique is used in radiology, to
review the natural object of inner elements of the body.
• They use strong magnetic fields to make pictures of the body.
Magnetic resonance imaging includes a big selection of applications in
diagnosing and there calculable to be over scanners in use worldwide.
• Magnetic resonance imaging has an effect on identification and treatment in several specialties, though the effect on improved health outcomes is unsure.
7. SPHYGMOMANOMETER
The sphygmomanometer is a device used to measure blood pressure(BP), composed of an inflatable cuff to control blood
flow and a mercury to measure the pressure. The standard unit of measurement of
BP is millimeters of mercury (mmHg) as directly measured with a manual
sphygmomanometer. These devices are classified into two types they are Mercury
Sphygmomanometers and Aneroid Sphygmomanometers.
SPHYGMOMANOMETER WORKING
• A digital sphygmomanometer blood pressure monitor uses an air
pump to inflate a cuff surrounding an upper arm or a wrist with sufficient
pressure to prevent blood flow in the local main artery. This pressure is then
gradually released using a digitally-controlled solenoid valve until the moment
that the blood begins to flow through the artery.
• The blood pressure measured by a pressure sensor at this point
determines the systolic pressure. Pulse rate is also sensed at this time.
The measurement is taken when the blood flow is no longer restricted determines
the diastolic pressure. This complete measurement cycle is controlled
automatically by the microcontroller.
• The signal from the pressure sensor is conditioned with an instrumentation amplifier before data conversion by an analog-to-digital converter (ADC). The systolic pressure, diastolic pressure, and pulse rate are then calculated in the digital domain using an algorithm appropriate for the type of monitor and sensor utilized. The resulting systolic, diastolic, and pulse-rate measurements are displayed on a liquid-crystal display (LCD), time-stamped, and stored in non-volatile memory.
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| FUNCTIONAL DIAGRAM AND MODULE OF SPHYGMOMANOMETER |
8. BLOOD GAS ANALYZER
• The best application of electronics in the medical field is gas
analyzer. It is used to calculate the pressure of the chemical elements like
carbon monoxide, nitrogen, oxygen in blood.
• By analyzing results we able to understand if any disorder in blood,
particularly after we feel sick quite 2days.
• By exploiting results we are able to observe if any disorder when we feel sickness within the basic level solely within the home. It is often enforced as medical electronics projects.
WORKING OF BLOOD GAS ANALYZER
• Blood collected from the person is introduced within the chemical
device strip that has particle selective electrodes, by exploitation by device
amplifiers and analog electronic devices, the results are going to be shown in a digital manner with ADC for a microcontroller.
• Then the output is going to
be displayed within the digital display module in terms of millimeters of
mercury (mmHg), kilopascals (kPa), typical values for the carbon monoxide and
dioxide measure thirty four(34) to thirty-five (35) mm Hg, which of Oxygen in
between eighty(80) to ninety (90) mm Hg.
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DIAGRAM OF BLOOD GAS ANALYZER
This Blog is made by the following students of VIT, PUNE
Abhay Joshi (01)
Gauri Asole (04)
Bhargav Mahajan (07)
Samruddha Bharti (08)
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