bioMedical Electronics

MEDICAL
ELECTRONICS
PRESENTED BY
P.SUBATHRA DEVI,AP/ECE
WHAT?
 A branch of electronics
 Electronic instruments and equipment
are used
 Design concepts to medicine and
biology for healthcare purposes
 Application of Engineering principles
 Seeks to close the gap between
Engineering and Medicine



WHY?
 Electronic devices are increasingly
being seen in the field of medicine.
 For the better service of patients not
only in hospitals but also outside the
hospitals.
 For advance healthcare treatment,
including diagnosis, monitoring, and
therapy.

For eg:
Ultrasound representation of
Urinary bladder
Components - Medical Instrumentation
system
Display
Recorder
Signal
conditioner
Measurand
Sensor
Input
Output

 Measurand (Physical quantities):
Position, displacement
Temperature,pressure
 Sensor:
is a device that detects a change in a
physical stimulus and turns it into a signal
which can be measured or recorded
 Signal conditioning:
Amplifying,waveshaping,filtering,
rectifying,…
 Display & Recorder:
Oscilloscope,ECG,ERG,EMG,etc….


Common medical measurands

Bioelectric Signals

 ECG -Electro-Cardiogram, Heart activity
 EMG -Electro-Myogram, Muscle
movement
 EOG -Electro-Oculogram, Eye movement
 EEG -Electro-Encephalogram, Electrical
activity along the scalp


 Right arm, Left arm, Right Leg, Left
Leg
 Any three Electrodes will be active
 Lead I
 Lead II
 Lead III
 Einthoven Triangle



ECG Waveform
 P Wave -the right atrium to the left
atrium - 80ms
 PR interval - sinus node through the
AV node and entering the ventricles.-
120 to 200ms
 QRS Complex- depolarization of the
right and left ventricles. -80 to 120ms
 T Wave - repolarization (or recovery)
of the ventricles.-160 ms

ECG - applications

● Diagnostics
● Functional analysis
● Implants (pace maker)
● Biofeedback (Heart rate variability,
HRV)
● Monitoring

EMG - Electromyogram

EMG surface (glue-) electrodes EMG - signal (up to 3mV, 1kHz)
EMG Recording:
Recording locations for facial EMG
EMG - applications


● Rehabilitation
● Functional analysis
● Prothetics
Orthesis
● Biomechanics

EOG - Electrooculogram

Eye movements to the left and right
EOG - applications


● Diagnostics
● Functional analysis
● Human Computer Interfaces

EEG - Electroencephalogram

EEG Electrode – cap locations of
the 10/20 system


 EEG range is classified as
 Delta  0.5 to 4 Hz
 Theta  4-8 Hz
 Alpha  8-13 Hz
 Beta  13-22 Hz
 Gamma  22-30 Hz

EEG - applications

● Diagnostics (Epilepsy, Oncology, ..)
● Sleep Analysis
● Human Computer Interfaces
● Pharmacology
● Intensive Care, Monitoring
Other Bioelectrical signals
 Apexcardiograph
 Ballistocardiograph
 Electroretinograph
 Vectorcardiograph
Electrode & electrode paste
 To pickup the electrical signals of the
body
 Electrode paste is used to have a firm
contact between body & electrode.
 Types:
Based on the surface where we have
to get the bioelectrical signal.

Needle electrode
 To record the nerve’s action potentials.
 Insulated metal wire is bent at one end
& is inserted through the lumen of the
needle.
Surface electrode
 To sense EEG & EMG
 Types: Metal plate, suction cup,
Adhesive tape
Surface electrodes
Vagina / rectal electrodes
Depth electrode
 To study the electrical activities of
neuron
 To inject medicines into brain.
 To measure oxygen tension.

Multipoint & Floating electode
 Contains nearly 1000 fine active
contact pins
 The metal does not contact subject
directly.
Other Electrodes:
Singe disk gold
plated electrodes
Ear clip electrode
Other Electrodes:
 PH Electrode
 PCO2 Electrode
 PO2 Electrode
 Microelectrode
1.Metallic Micro electrode
2.Non-Metallic Microelectrode
Components
 Amplifiers
 Filters
 Rectifiers
 Transformers
 Oscillators
 ADC
 DAC
 Timing circuits
 Buffer
 Multiplexer

Defibrillators
 For life-threatening cardiac
dysrhythmias, ventricular fibrillation
 Electrical energy to the heart with a
device called a defibrillator
 Allows normal sinus rhythm
 Ventricular fibrillation results from:
 Coronary occlusion
 Electrical shock
 Abnormalities of body chemistry
Defibrillator
DC Defibrillators-Circuit
Recent trends
 Remote patient monitoring
 Radio pills
 E-health
 VLSI tools
 ASIC-application specific IC
 FPGA
 SOC


Expectations
 portability and miniaturization,
connectivity, safety, data security and
quality, and reliability.
 dynamic power path management
(DPPM)
 increased efficiency


Tips for healthy life
 Eat healthy.
 Exercise.
 Leave some time for leisure.
 Make the decision not to worry.
 Work to understand what stresses
you.
 Leave time to laugh.


Thank You