(SEM V) THEORY EXAMINATION 2024-25 BIO-MEDICAL SENSORS & INSTRUMENTATION

Subject Code: BEC052
Maximum Marks: 70
Time: 3 Hours
Paper ID: 310953

Question Paper Overview

SECTION A (2 × 7 = 14 Marks)

(Short conceptual and definition-based questions)

a. Define static characteristics of a measurement system.
b. What are the implications of inaccurate calibration in a measurement system?
c. Explain the concept of the man-instrument system.
d. What challenges are encountered when measuring bioelectric signals?
e. Describe the function of a pacemaker.
f. What is GSR (Galvanic Skin Response) and how is it measured?
g. Describe the function of a tonometer.

SECTION B (Attempt any three × 7 = 21 Marks)

a. List and describe the different types of transducers and their applications in measurement systems.
b. Explain the concept of the man-instrument system and describe its components.
c. How would you measure blood pressure using modern measurement systems? Explain the procedure and instruments used.
d. Explain the process of respiration and describe instruments used to monitor breathing mechanics.
e. Define non-invasive diagnostic instrumentation and provide examples used in clinical settings.

SECTION C (Attempt one part from each question × 7 = 35 Marks)

Q3

(a) Explain the input-output configuration of a measurement system and discuss its significance.
OR
(b) Analyze the role of standards and calibration in maintaining accuracy and reliability of measurement instruments.

Q4

(a) Define bioelectric potentials and list their sources in the human body.
OR
(b) Discuss the challenges in measuring a living system and the precautions to minimize errors.

Q5

(a) Explain how ECG (Electrocardiogram) works and its role in diagnosing heart conditions.
OR
(b) Analyze factors affecting cardiac output measurement and discuss how to control these factors.

Q6

(a) Define the physiological principles behind the respiratory system and describe the structure of the somatic nervous system.
OR
(b) Describe how EEG (Electroencephalogram) and EMG (Electromyography) are used to monitor brain and muscle activity.

Q7

(a) Explain the working principle of ultrasound and thermography in medical diagnostics.
OR
(b) Explain how an MRI (Magnetic Resonance Imaging) scanner is used to diagnose a brain tumor, including the procedure and required equipment.

Key Topics for Revision

1. Measurement System

Static Characteristics: Accuracy, precision, linearity, sensitivity, resolution, reproducibility.

Dynamic Characteristics: Speed of response, fidelity, damping.

Calibration: Compares instrument output to a standard for accurate results.

2. Man-Instrument System

Interaction between human, sensor, and display/control systems.

Components: Sensor → Signal processor → Display/Feedback → Operator.

Used in clinical diagnostics and biomedical feedback systems.

3. Transducers

4. Measurement of Bioelectric Signals

Challenges: Small amplitude, noise, motion artifacts, electrode-skin impedance.

Solutions: Shielded cables, proper grounding, amplification (using instrumentation amplifiers).

5. Pacemaker

Device that stimulates heart contractions using controlled electrical impulses.

Used in bradycardia or irregular heart rhythms.

Components: Pulse generator, power supply, lead wires, electrodes.

6. GSR (Galvanic Skin Response)

Measures skin conductance (sweat gland activity).   Reflects psychological or emotional arousal.

Sensors: Two electrodes on fingers or palms connected to conductance meter.

7. Tonometer

Measures intraocular pressure (IOP) of the eye.         Types: Applanation, Indentation, and Rebound tonometers.

Used in glaucoma detection.

8. Blood Pressure Measurement

Modern systems use oscillometric or electronic transducers.

Components: Cuff, pressure sensor, microcontroller, display.

Output: Systolic/diastolic readings displayed digitally.

9. Respiration and Monitoring

Instruments:

Spirometer: Measures lung volume and airflow.        Plethysmograph: Records volume changes.

Capnograph: Measures CO₂ levels in exhaled air.       Monitors respiratory rate, tidal volume, and vital capacity.

10. Bioelectric Potentials

11. Non-Invasive Diagnostic Instruments

Devices that do not penetrate the skin.

Examples:

ECG, EEG, EMG                            Pulse oximeter

Ultrasound imaging                    MRI, Thermography

12. ECG (Electrocardiogram)

Measures electrical activity of the heart.

Waves:

P-wave → Atrial depolarization                      QRS complex → Ventricular depolarization

T-wave → Ventricular repolarization              Diagnoses arrhythmia, ischemia, and infarction.

13. EEG and EMG

EEG: Detects brain wave patterns (alpha, beta, delta, theta).

Used in epilepsy, sleep disorders.                  EMG: Detects muscle potentials.

Used for neuromuscular diagnosis.

14. Imaging Techniques

15. Respiratory & Nervous Systems

Respiratory system: Gas exchange via lungs; monitored via spirometry.

Somatic nervous system: Controls voluntary muscle movement; sensory-motor coordination.

Exam Tips

Practice labelled diagrams (ECG waveform, spirometer, ultrasound).

Remember differences between invasive and non-invasive methods.

Revise signal acquisition and noise reduction techniques.

Prepare short notes on calibration and measurement accuracy.