BMEN Course 260
Introduction to Biomechanics
Guiren Wang
Tel: [phone]; Room: A221
email: [e-mail]
Department of Mechanical Engineering
& Biomedical Engineering Program
University of South Carolina, Columbia
Copyright
All the materials used in these power point
presentations have copyright. They are used only
for this class. Distribution to others or for other
purposes are forbidden.
Course BMEN 260
Introduction to Biomechanics
LECTURE # 1
Course Background and Selected Topics in Biomedical Studies
Introduction
Multidisciplinary
Official Pre-requisite: MATH 142, BMEN 211
Practical Pre-requisite : Differential equation, Vector, Physics I
Office hours are as follows;
Tuesday 6:00 PM 7:00 PM
Friday
6:00 PM 7:00 PM
Location: A221, 300 Main Str.
Walk-ins are welcome at other times.
If you require additional time, or if my office hours conflict with
your schedule, please see me to schedule an appropriate time.
Textbook and reference books
There is no a good textbook available for biomechanics so far for
sophomore level without physics and advanced mathematics
background
Textbook
An Introduction to Biomechanics: Solids and Fluids, Analysis
and Design
by Jay D. Humphrey (Author), Sherry DeLange (Author).
ISBN: 978-0-387-40249-9
Reference books
Fundamentals of Biomechanics: Equilibrium, Motion, and
Deformation
by Nihat zkaya (Author), Margareta Nordin (Author).
ISBN: 978-0-387-98283-0
Introductory Biomechanics: From Cells to Organisms
(Cambridge)
Biomechanics: Motion, Flow, Stress, and Growth by Y.C. Fung
(1998)
Biomechanics by Y.C. Fung (1996)
Grading
Homework, lab report, quiz 20%
Three Examinations
50% (1st: 15%; 2nd: 20%; 3rd: 15%)
Final Examination
30%
Total
100%
A:
B+:
B:
C +:
C:
D+:
D:
F:
> 90
85< B+<90
80<B<85
75<C+<80
70<C<75
65<D+ <70
60<D<65
<60
Contribution of Course to Meeting the
Professional Component
Engineering Topics:
Math and Science:
Biomechanics aims to explain the mechanics of life and living. From molecules to
organism, everything must obey the law of mechanics. (Fung 1990)
Those laws which are just mathematical definitions (say, fundamental law of
mechanics - second Newton's law ), - are absolutely correct (simply by
definition). They are extremely useful - because they can not be violated nor
falsified. (Wikipedia)
The method of biomechanics is the method of engineering, which consists of
observation
experimentation
theorization
validation
application
To understand any object, we must know its
geometry and materials of construction,
the mechanics property of the material involved
the governing natural laws
the mathematical formulation of specific problems and their solutions
and the results of validation (Fung 1990)
In many cases, the solution is not a number, but a formulation
70%
30%
Course description
BMEN 260 Biomechanics. (3) (Prereq: MATH 142, BMEN 111)
Introduction to
Continuum mechanics including statics, dynamics, and
deformable bodies using integrated laboratory experiences
on biological materials.
Laws of motion.
Free body diagrams.
Stress and strain.
Constitutive equations, focusing on models relevant to
biomaterials.
Mechanical properties of biological materials.
Basic modes of deformation including bending and inflation.
Injury.
Numerical solutions.
Objectives of the course
At the conclusion of this course, students will be able to:
Use free body diagrams to assess static and dynamic
equilibrium of biomechanical systems
Interpret experimental data in terms of fundamental material
properties including initial stiffness, yield strength, etc
Apply basic constitutive models for biomaterials to analyze
common modes of deformation including inflation, bending,
and extension
Assess stress and strain in Cartesian, cylindrical, and spherical
coordinate systems
Purpose of our class
Introduce fundamental concepts and results from solid
mechanics that can be applied to many different problems of
importance in biology and medicine
Illustrate some of the many possible applications by focusing
on the mechanics of
human health (skeletal joints and muscles)
disease (Coronary arteries atherosclerotic lesion, ischemia
stroke)
Contents
Bio-solid mechanics
Bio-fluid mechanics
Definition
Biology
Study of living things
Mechanics
Study of motions and the applied loads (forces) that cause them
Biomechanics:
Study of the response (motion and deformation) of living things
to applied loads
Or in more detail:
Development, extension and application of mechanics to
improve our understanding the of influence of mechanical
loads on the structure, properties and function of living
things
Domain of Biomechanics
There are many fields that biomechanics can be applied to.
Examples:
Physiology: tissue, cell and molecular level
Drug delivery
Oral, Inhaler, Transcutaneous, Intravenous (IV) infusion pump
Prosthetics
Sport, human athletic performance
Disease, injury and their treatment
External flow (swimming)
Internal flow (blood flow in vessel)
Artificial heart, stent
Robot (artificial muscle, bone)
Bionics
Bird flight
Drag reduction property of the skin of dolphin
Wind loads or gravity on the growth of plants
Like mechanics to engineering, Biomechanics is fundamental to
biomechanical engineering
History of Biomechanics
The need
Mankinds pursuit of a moon landing, 1960s
The Capability: new science and technology developed
Renaissance in continuum mechanics
Computer age begins
Numerical methods
Emergent modern biology
Biomechanics came into its own in the mid-1960s
Todays Motivation
Health care in Life science
Examples
Broken bones
Injury to synovial membrane
Drug delivery (e.g. infusion pump)
Stroke
Lab-on-a-Chip for point of care
To improve the quality of life
Less pain and suffering
Increased recreation time
Longer life
Improved health throughout life
In some situations, you may not care about the scientific aspect.
Here, you increase the safety factor and select material and
complete design.
For space exploration, you want to optimize the weight and
size to increase payload size
In this case, analysis and calculation, prediction, i.e. scientific
point of view, biomechanics, become important
Space exploration, including potential Mars landing
Length scale of study in biomechanics
Conventional (macroscale)
Human body
Tissues
Organ, Vascular, etc
Cell (microscale)
Multiple cells
Single cell
Interaction between cells
Interaction between cell and tissue
Molecular (micro to nanoscale)
Mechano-transduction in cell
Molecular scale interaction
Deformation of protein and DNA
Three examples
Conventional: Laser induced cavitation for thrombectomy
Cell: Dielectrophoresis: manipulating cells
Molecular: Mechanotransduction
Thrombectomy and tissue cutting:
Laser-induced cavitation and
dynamic micropumping
New catheter is being developed for blood
clot removal due to stroke by Endovasix Inc.
Induced
flow
Catheter
3 mm width
Artery in brain
Blood
clot
Chewing
fiber
Window
Bubble
Pumping
fiber
Sketch of laser catheter used to
break and remove blood clot in brain
Free fiber case: energetic micropumping
Duty Cycle parameter
(100, 200, 1, 0)
Phenomena:
An energetic and
steady vortex ring
Steady acoustic
streaming
Novel micropump
without moveing
part
Separation: biotic and abiotic particles
Particle: negative DEP
Yeast: no DEP
No AC power
10 MHz, 20Vp-p
With AC power
Biosolid mechanics
Development, extension and application of solid mechanics for
the purposes of understanding better the influence of
mechanical loads on the structure, properties and function of
living things
Use of the methodology of solid mechanics in living things
Biofluid Mechanics
Development, extension and application of fluid mechanics for
the purposes of understanding better the influence of
mechanical loads on the structure, properties and function of
living things
Use of the methodology of fluid mechanics in living things
Mechanics
Quantum
Statistics
Relativity
Continuum
Biomechanics
Continuum assumption will be used in most cases
However, caution is needed for biomechanics in
nanobiotechnology
Continuum assumption
Continuum assumption simply means that physical properties
are imagined to be distributed throughout space
Every point in space has finite values for physical properties
At a single point, no infinite changes in physical properties are
allowed
Macroscopic science
Mathematic description: (microscale)/(characteristic length scale)
of physical problem of interest) << 1
Examples:
Blood velocity distribution
Force felt by cells within the wall of a large artery due to the
distending blood pressure
Continuum mechanics
Solid and fluid mechanics are example of classic physical
science, in which the world is viewed as a continuum.
It is concerned with the behavior of matter on a natural scale
(modern physics concerns with extreme scale)
ENGR 707 is an graduate class focused on the development
of continuum mechanics formulations.
We will mostly use continuum assumption
Whether the assumption works has to be experimentally tested!
We will focus more on linear continua
Figure 1.4