This document provides an overview of biomedical transducers and basic bioinstrumentation systems. It describes the typical components as including a subject, primary sensing device, transducer, signal processing unit, and terminating stage. The transducer receives a physical quantity from the primary sensing device and converts it into an electrical quantity. The signal processing unit then amplifies and modifies the electrical signal as needed before it reaches the terminating stage, which can include a display, recorder, controller and computer to output the essential information measured from the subject in a meaningful way.

1. Biomedical Transducer
Ms. Dixita Dhobi, Lecturer
Biomedical Engineering

2. Introduction to Biomedical Instrumentation
CHAPTER-1

3. Introduction
•Biomedical instrumentation is the application of biomedical
engineering which is mainly focus on the devices and
mechanics which is used to measure and evaluate some
physical quantity. The main purpose of the biomedical
instrumentation is used to measure the presence of some
physical quantity.
•It is the branch which deals with the use of instruments to
measure and control variables.

4. Basic Bio instrumentation system
The basic Bio instrumentation system consists of the following
components,
•Subject (human body as a input)
•Primary Sensing device
•Transducer
•Signal processing unit
•Terminating stage (Display, Recorder, Controller and Computer)

5. Block diagram of Bio-instrumentation system
PRIMARY
SENSING
DEVICE
TRANSDUCER
SIGNAL
PROCESSING
UNIT
DISPLA
Y
RECOR
DER
CONTRO
LLER
COMPU
TER
TERMINATING STAGE
I/P

6. DescriptionSubject (Input)
• The subject is the human being on whom the measurements
are made.
Primary sensing device
• Primary sensing device is attached to the human body, which
is used to sense some physical quantity like temperature,
pressure etc and then transmit in to transducer.

7. Continue…Transducer
• Transducer is a device, which is connect to the primary
sensing device. Transducer receive some physical quantity
from the primary sensing device.
• Then transducer converts non-electrical quantity/physical
quantity in to electrical quantity.

8. Signal conditioning equipment
• The part of the instrumentation system that amplifies, modifies
or in any other way change the electric output of the transducer is
called signal conditioning or signal processing device/equipment.
• Signal conditioning equipment usually consists of functions such
as filtering ( digital or analog ) , amplification, Demodulation,
A/D converter and D/A converter.
• They help in increasing the sensitivity of device by amplification
of the original signal. And filter is used to remove unwanted noise
and frequency form signal and provide accurate output.

9. Continue…Display system
• The electrical output of the signal conditioning equipment
must be converted in to a form that can be perceived by one
of the man’s senses that can convey the information obtained
by the measurement in a meaningful way.
• The display system provides a visible representation of the
quantity as a analog or digital form.

10. Continue…Recording, Controller and Computer
• It is necessary to record the measured information or to
transmit it from one location to another location.
• For this purpose this component is required.
• A control device is used to have to an automatic control of
the stimulus, transducers, signal processing unit or any
other part of the ‘Bio instrumentation system’.
• Whole system is connected to the computer. It is necessary
to record the output and to transmit it from one location to
another location.