ELEC ENG 4BD4
Lecture 1
Biomedical Instrumentation
Instructor: Dr. H. de Bruin
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Cochlear Implant
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Advances in Vision (Retinal
Stimulation)
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Mini Gastric Imaging
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Calendar Description:
Principles of instrumentation; Noise and interference in electrical
measurements; Generation and nature of bioelectric potentials;
electrodes and other transducers; electrical safety; neuromuscular and
cardiovascular instrumentation; ultrasonics for bio-measurements
other than imaging; computer interfaces for data acquisition systems.
Course Objectives:
Students will be able to apply the principles of electronic circuits and
devices to the use and design of instrumentation in the biomedical
area. They will have gained a basic knowledge of the operating
principles of electrical and other transducers, analog and digital
instrumentation, applied signal acquisition and processing, electrical
safety in the medical environment, electrical properties of nerve and
muscle physiology; and instrumentation used in cardiopulmonary,
neurological, surgical, and rehabilitation areas of medicine.
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Outline of Topics
Lectures Topics
1. Measurement systems
2. Noise and coherent interference in measurements
3. Analog signal conditioning
4. Origin of Electrophysiological Signals
5. Measurement of Electrical potentials and Magnetic
Fields from the Body surface
6. Electrodes; Half-Cell Potential; Equivalent Circuits
7. Biopotential amplifiers; Medical isolation amplifiers;
1. Electrical Functioning of the heart
2. The ECG; Electrode placement;
3. The ECG; Vector cardiography; Driven-Leg ECG
amplifiers; Design Example: QRS complex
segmentation
4. Muscle
5. The EMG; Design Example:
6. Brain
7. The EEG; Design Example: Auditory event
related potentials
8. Other body surface potentials; EOG;
Electroretinogram Design Example: Human
Computer Interface using EOG signals
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1. Sensors commonly encountered in biomedical applications
1. Temperature sensors – Design Example: ICU system for
body temperature monitoring
2. Large displacement sensors
1. Motivation: Studying Muscle Activation and
Fatigue during the propulsion of a wheel chair
2. LVDT
3. Mechano-optical sensors
4. Design Example: Studying Muscle Activation and
Fatigue during the propulsion of a wheel chair
3. Small displacement sensors
1. Motivation: Respiratory gating for lung CT
2. Strain gauges
3. Piezoelectric transducers
4. Design example: Respiratory gating for lung CT
4. Pressure measurements –
1. Invasive blood pressure measurements
2. Automatic non – invasive blood pressure
measurements
3. Design Example: Design a non-invasive blood
pressure measurement system
5. Electro-chemical sensors – noninvasive blood gas
sensing with electrodes
6. Optical sensors – Pulse Oximetry
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1. Plethysmography; volume
displacement; impedance
2. Ultrasound - Doppler US for
blood and tissue velocity
measurements
3. Stimulation of excitable tissues;
Cardiac pacing and defibrillation
4. Digital Interfaces in
measurement systems; Sampling
Theorem; Quantization Noise;
Dithering;
5. Digital to Analog converters;
Analog to digital converters
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Laboratory Sessions:
Lab 1 : Differential amplifiers; DAQ / DSP /
Statistical Analysis
Key Concepts: Discrete Signals, Acquisition,
Amplifiers, Frequency Domain
Lab 2 : ECG / Heart Rate
Key Concepts: Biopotentials,
Electrocardiogram, Einthoven's Triangle, Noise
Artifact, Bio-instrumentation amplifier for ECG
Lab 3 : EEG
Key Concepts: Alpha & Beta Waves (Alpha
Blockers) – in phase or out of phase. Spectral and
time analysis, Irregularities, Bio-instrumentation
amplifier for EEG
Lab 4 : EMG & Motor Control
Key Concepts: Muscle twitches, rectification,
averaging, RMS, Force vs EMG, Filtering effects
on applications of EMG, Bio-instrumentation
amplifier for EMG
Lab 5 : EOG & Environmental Control
Key Concepts: DC Signals, DC Amplifiers,
Frequency component of blinking, Scaling of
signals and creation of algorithms to make raw
data into useful information, Bio-instrumentation
amplifier for EOG
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Textbooks (Optional):
1. Medical Instrumentation: Application and
Design. John G. Webster
2. Custom Courseware, Lecture Notes posted on
the class website
Additional resources:
1. Introduction to Instrumentation and
Measurements; Second Edition; Robert B
Northrop; Taylor and Francis; ISBN 0-84933773-9
2. Noninvasive Instrumentation and Measurement
in Medical Diagnosis; Robert N. Northrop;
CRC press; ISBN 0-8493-0961-1
3. Design and Development of Medical Electronic
Instrumentation, D. Prutchi and M. Norri,
Wiley-Interscience, 2005
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Course Assessment
Assessment:
Labs 10%
Midterm 30%
Homework 10%
Final Exam 50%
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Process of Measurement
• Understand the event (variable) you are
measuring
• Is variable directly related to event?
• Is variable indirectly related to event?
• Is variable statistically related to event?
• Is event itself random?
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Process of Measurement (cont’d)
• Is measurement biased (will final result
have an offset, e.g. does it always read
high)?
• What are unavoidable sources of noise?
• How much does this contaminate your
measurement?
• Maximize your signal-to-noise ration SNR
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Measurement Specifications
• What is amplitude range of selected
variable
• What is bandwidth of variable (does
variable change rapidly or slowly)?
• What is required resolution (smallest
change you need to measure)?
• What is required accuracy?
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EE 4BD4 Lab Instrumentation
• Modular McMaster Analog Instrumentation
System
• National Instruments DAQ system with
Laboratory Interface
• Desktop PC running National Instruments
Virtual Instrumentation language
“Labview”
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MacECE BiomedLab
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Course Objectives
• Be able to analyse a biomedical
measurement problem and plan a solution
• Be able to design analog “front ends” for a
variety of physiologically related signals
• Gain familiarity with a number of different
instrumentation sensors
• Design a simple computer data acquisition
program
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Course Objectives (cont’d)
• Gain experience with collecting and
analysing different electrophysiological
signals (ECG, EMG, EEG, etc.)
• Be exposed to concepts of electrical safety
and professional medical instrument codes
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