Biomedical Instrumentation
Biomedical instrumentation and engineering is the
application of knowledge and technologies to
solve problems related to living biological systems.
It involves diagnosis, treatment and prevention of
disease in human. As the medical field is emerging,
the area of Biomedical Engineering is an
expanding field.
The term “ bio ” to denote something related to
life. When basics of physics and chemistry get
applied to the living things, and we name them as
Biophysics and Biochemistry. So when the
discipline of engineering and medicine interacts, it
is called Biomedical Engineering.
It involves measurement of biological signals like
ECG, EMG, or any electrical signals generated in
the human body.
Biomedical Instrumentation helps physicians to
diagnose the problem and provide treatment. To
measure biological signals and to design a medical
,instrument, concepts of electronics and
measurement techniques are needed.
Components of Biomedical Instrumentation
System
Any medical instrument consists of the following
functional basic parts:
1. Measurand: The measurand is the physical
quantity, and the instrumentation systems
measure it. Human body acts as the source for
measurand, and it generates bio-signals. Example:
body surface or blood pressure in the heart
2. Sensor / Transducer: The transducer converts
one form of energy to another form usually
electrical energy. For example, the piezoelectric
signal which converts mechanical vibrations into
the electrical signal.
The transducer produces a usable output
depending on the measurand. The sensor is used
to sense the signal from the source. It is used to
,interface the signal with the human.
3. Signal Conditioner: Signal conditioning circuits
are used to convert the output from the transducer
into an electrical value. The instrument system
sends this quantity to the display or recording
system. Generally, signal conditioning process
includes amplification, filtering, analogue to digital
and Digital to analogue conversions. Signal
conditioning improves the sensitivity of
instruments.
4. Display: It is used to provide a visual
representation of the measured parameter or
quantity. Example:Chart recorder, Cathode Ray
oscilloscope (CRO). Sometimes alarms are used to
hear the audio signals. Example: Signals generated
in Doppler Ultrasound Scanner used for Fetal
Monitoring.
5. Data Storage and Data Transmission: Data
storage is used to store the data and can be used
for future purpose. Recent days Electronic Health
records are utilized in hospitals. Data transmission
, is used in Telemetric systems, where data can be
transmitted from one location to another
remotely.
Bio Electrode Potential
Electrode Potential
The human body generates electrical signals on
the body surface. Recording electrodes picks the
bioelectric events produced in the body. The
picked up signals are given to the amplifier and
then to display. Electrodes transfer ionic
conduction in the tissue to electronic conduction
to measure the values. Generally, there are two
types of electrodes namely surface electrodes and
needle electrodes . A surface electrode picks the
potential difference from the tissue surface
without damaging the live tissue. Deep electrode
indicates the electric potential value from inside
the cell.
Characteristics of Biopotential Electrodes
Electric potential generated in the body are
Biomedical instrumentation and engineering is the
application of knowledge and technologies to
solve problems related to living biological systems.
It involves diagnosis, treatment and prevention of
disease in human. As the medical field is emerging,
the area of Biomedical Engineering is an
expanding field.
The term “ bio ” to denote something related to
life. When basics of physics and chemistry get
applied to the living things, and we name them as
Biophysics and Biochemistry. So when the
discipline of engineering and medicine interacts, it
is called Biomedical Engineering.
It involves measurement of biological signals like
ECG, EMG, or any electrical signals generated in
the human body.
Biomedical Instrumentation helps physicians to
diagnose the problem and provide treatment. To
measure biological signals and to design a medical
,instrument, concepts of electronics and
measurement techniques are needed.
Components of Biomedical Instrumentation
System
Any medical instrument consists of the following
functional basic parts:
1. Measurand: The measurand is the physical
quantity, and the instrumentation systems
measure it. Human body acts as the source for
measurand, and it generates bio-signals. Example:
body surface or blood pressure in the heart
2. Sensor / Transducer: The transducer converts
one form of energy to another form usually
electrical energy. For example, the piezoelectric
signal which converts mechanical vibrations into
the electrical signal.
The transducer produces a usable output
depending on the measurand. The sensor is used
to sense the signal from the source. It is used to
,interface the signal with the human.
3. Signal Conditioner: Signal conditioning circuits
are used to convert the output from the transducer
into an electrical value. The instrument system
sends this quantity to the display or recording
system. Generally, signal conditioning process
includes amplification, filtering, analogue to digital
and Digital to analogue conversions. Signal
conditioning improves the sensitivity of
instruments.
4. Display: It is used to provide a visual
representation of the measured parameter or
quantity. Example:Chart recorder, Cathode Ray
oscilloscope (CRO). Sometimes alarms are used to
hear the audio signals. Example: Signals generated
in Doppler Ultrasound Scanner used for Fetal
Monitoring.
5. Data Storage and Data Transmission: Data
storage is used to store the data and can be used
for future purpose. Recent days Electronic Health
records are utilized in hospitals. Data transmission
, is used in Telemetric systems, where data can be
transmitted from one location to another
remotely.
Bio Electrode Potential
Electrode Potential
The human body generates electrical signals on
the body surface. Recording electrodes picks the
bioelectric events produced in the body. The
picked up signals are given to the amplifier and
then to display. Electrodes transfer ionic
conduction in the tissue to electronic conduction
to measure the values. Generally, there are two
types of electrodes namely surface electrodes and
needle electrodes . A surface electrode picks the
potential difference from the tissue surface
without damaging the live tissue. Deep electrode
indicates the electric potential value from inside
the cell.
Characteristics of Biopotential Electrodes
Electric potential generated in the body are
