Biomedical Application of Vibration Energy: effects on the human body

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1





Biomedical Application of Vibration Energy:

effects on the human body


P. Abundo
1
, C. Trombetta
2
, C. Foti
3
and N. Rosato
1


1

Medical Engineering Service, Fondazione Policlinico Tor Vergata, Rome

2
PhD student in Advanced Technology in Rehabilitation Medicine, Tor Vergata University, Rome

3

Tor Vergata University, Physical and Rehabilitation Medicine, Public Health Department, Rome


February 9th 2010


2





Analysis of vibration
peculiar parameters

Vibration
human body
effects

Index


Vibration producing
methods

Negative
effects

Safety of workers
subject to vibrations

Positive
effects

Therapeutic application in
rehabilitation medicine

Hormonal effect

Neuro
-
muscular system effect

Bone tissue effect


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

Biomedical vibration
applications

3





Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

Analysis of vibration peculiar parameters

Period = T [s]

Frequency =1/T [Hz]


Movement Amplitude [m]

Velocity [m/s]

Acceleration [m/s
2
]

4





Analysis of vibration peculiar parameters

t
V
on
Accelerati



Human body feels more the
variation of a stimulus than
its persistence


Vibration intensity



T
dt
t
a
T
an Square
on Root Me
Accelerati
0
2
)
(
1
Resonance frequency

Vibration is amplified and the
maximum vibration amplitude is
theoretically infinite


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

5





Vibration producing methods

Centripetal force
generated by a body

rotating around a

non barycentric axis


Rotating
mass

(m)

Uniform
circular

motion


Circumference radius equal to
eccentricity

(
e
)

Costant
angular velocity

in
amplitude (Ω)

e
m
t
F
2
)
(


Mass

Non barycentric
rotation axis


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

6





Vibration producing methods

Piezoelectric effect


Jacques and Pierre Curie (1880)

Crystals specific property

Mechanical stress
(contraction or expansion)

Alternating current

Crystal material
thickness

Alternating current
Frequency

Crystal wave vibration
frequency

Optimize
vibrating head
dimensions

and
weight

Policrystal ceramic

(
Barium titanate
-

BaTiO
3
)


Topaz

Quartz

~
MHz

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

7





Vibration producing methods

Magnetic
-
dynamic transducer


Membrane

Electric coils

Permanent magnet

Alternating current

I
L
N
H
B





N= Coils number

L= Coils lenght

I= Coils current

m
= Magnetic


Permeability

Alternating current
through coils

Varying intensity
magnet

Permanent
magnetic field

Coils
vibrations

Membrane
vibrations

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

8





Biomedical vibration applications

Biomedical vibration applications

Piezoelectric
surgical scaler
(dental)

Piezoelectric

Ultrasound probes

Piezoelectric or electro
-
magnetic Lithotripter
(urological)



Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

9





Ultrasound rehabilitation
therapy (piezoelectric)

Rehabilitation Vibration
Therapeutic Exercise
(oscillating masses)

Biomedical vibration applications

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

10





Vibrations human body effects

Vibrations

Frequency

Bands



0

-

2

Hz



low

frequency

oscillations
,

generated

by

means

of

transportation

(buses,

airplains,

ships)
;



2

-

40

Hz



middle

frequency

oscillations
,

generated

by

machine

tools

and

industrial

plant
;



>

40

-

50

Hz



high

frequency

oscillations

generated

by

a

lot

of

vibrating

tools

used

in

industrial

field


Acceleration


Time Exposure

Contact Area

Contact Force

Ergonomical and environmental factors

Tissues Resonance Frequency

Body Effects

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

11





Vibrations human body negative effects


Negative effects: vibration wave energy

transferred from the oscillation
source to the exposed body causes different effects on human tissues and
organs crossed

Human
Body

Tolerable
vibration energy
level

Long terms
damages

Human body
deterioration


Human body doesn’t vibrate like a single mass with
only one natural frequency,
every

body part has a
its own resonance frequency


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

12





Vibrations human body negative effects

Vibration
Direction

Whole Body Vibrations

Low
-
middle frequency
vibrations

Lower
efficiency degree

Decrease of
fatigue threshold

Vibration Touch
point

Hand Arm Vibrations

High frequency
vibrations

Local negative effects

Local Vibrations

Middle
-

High
frequency vibrations

Local negative effects
(not only on HA system)

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

13

Hand Arm System





Safety of workers subject to vibrations

In order to
limit
the
negative
effects

of vibration on workers


D.Lgs 81/08

Equivalent Acceleration Exposure Limit Value =
5 m/s
2

8
)
8
(
Te
A
A
sum

T
e

=

daily

exposure

time

to

vibrations

(hour)

8

=

reference

time

(hours)

a
x
,

a
y
,a
z

=

r
.
m
.
s
.

acceleration

values

(in

m/s
2
)

along


x,

y,

z

axis

(ISO

5349
-
1
:

2001
)

Whole Body

Equivalent Acceleration Exposure
Limit Value =
1 m/s
2

8
)
8
(
Te
A
A
Max

T
e
=

daily

exposure

time

to

vibrations

(hour)

8

=

reference

time

(hours)

A
Max

=

Maximum

value

among

a
x
,

a
y
,

a
z


a
x
,

a
y
,a
z

=

r
.
m
.
s


acceleration

values

(in

m/s
2
)

along

axis

x,

y,

z

(ISO

2631
-
1
:

1997
)

)
a

a


(a

2
z
2
y
2
x



sum
A
Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

14





Vibrations human body positive effects

Reduced Exposure Time

Specific Oscillation
Frequency

Positive Effects

Metabolic
Adaptations

Bosco

C
.
,

Colli

R
.
,

Introini

E
.
,

Cardinale

M
.
,

Tsarpela

O
.
,

Madella

A
.
,

Tihanyi

J
.
,

Viru

A
.

-

Adaptive

responses

of

human

skeletal

muscle

to

vibration

exposure
.

Clinical

Physiology
.

19
(
2
)
:

183
-
187
,

1999
.

Skeletal and neuro
-
muscular system

+

Mechanical

Hormonal effects

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

15





Therapeutic applications of vibration energy in rehabilitation medicine

Whole Body Vibrations

Propagating to the whole
human body

Vibrating Platforms

Hand Arm/Local
Vibrations

involving Hand
-
Arm System
or specific body part

Vibrating Tools

…By using….

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

16





Hormonal effects

Testosterone and growth
-
hormone concentration


Cortisol concentration


Significant statistical improvement of testosterone and GH serum concentration

after whole body vibration exercise (10 times for 60 s, with 60 s rest time
-

B before, A after)

Vibration frequency
20
-
50 Hz

Bosco

C
.
,

Iacovelli

M
.
,

Tsarpela

O
.
,

Cardinale

M
.
,

Bonifazi

M
.
,

Tihanyi

J
.
,

Viru

M
.
,

De

Lorenzo

A
.
,

Viru

A
.

-

Hormonal

responses

to

whole
-
body

vibration

in

man
.

Eur

J

Appl

Physiol
.

81
:

449
-
454
,

2000
;

Kvorning

T
.
,

Bagger

M
.
,

Caserotti

P
.

-

Effects

of

vibration

and

resistance

training

on

neuromuscular

and

hormonal

measures
.

Eur

J

Appl

Physiol
.

2006

Mar
;
96
(
5
)
:

615
-
25

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

17





Neuro
-
muscular system effect



Tonic

Vibration

Reflex


Locally applied vibrations to
the muscle and to tendon
structure (10
-
40 Hz)

Whole Body
Vibrations (1
-
50 Hz)

Muscle spindle
receptors activation

Strengthening

of the
stimulation input
, through the spindle


motor
-
neural connections (stretch reflex)


Hagbarth

e

Eklund,

1966
;

Johnston

e

coll,

1970
;

Arcangel

e

coll
.
,

1971
;

Armstrong

e

coll
.
,

1987
;

Matyas

e

coll
.
,

1986
;

Samuelson

e

coll
.
,

1989
;

Bosco

e

coll
.
,

2000
;

Y
.

Nishihira,

T
.

Iwasaki,

A
.

Hatta,

T
.

Wasaka,

T
.

Kaneda,

K
.

Kuroiwa,

S
.

Akiyama,

T
.

Kida,

K
.

Ryol

-

Effect

of

whole

Body

Vibration

Stimulus

and

Voluntary

Contraction

on

Motoneuron

Pool
,

Advances

in

Exercise

and

Sports

Physiology,

Vol
.

8
,

No
.

4

-

03
/
03
/
2004


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

18





Neuro
-
muscular system effect



Human explosive power
improvement

Better motor unit
synchronization

Improvement of synergistic
muscles coordination

Increase of contractile ability in muscular area subject to vibration exercise induces an
evident “right
-
shift” of force
-
velocity curve and of force
-
power one

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

19





Bone Tissue effect



Vibration
Therapeutic
Exercise

Muscular function
improvement

Effective stress on
insertion bone

Bone mass
development

Positively
interfere on bone
metabolism,

also in

osteoporotic degeneration
case


therapy of choice
concerning
the

geriatric medicine
and the

osteoporosis
prevention

Rubin

e

coll
.
,

Nature,

441
:

603
-
604
,

2001
;

Miyamoto

K
.
,

Mori

S
.
,

Tsuij

S
.
,

Tanaka

S
.
,

Mashiba

T
.
,

Komatsubara

S
.
,

Akijama

T
.
,

Kawanishi

J
.
,

Norimatsu

H
.

-

Whole

Body

Vibration

Exercise

in

the

Elderly

People
;

P
506
F

IBMS

Osaka

2003

Rubin C., Turner A.S.,
Bain S., Mallinckrodt C.,
McLeod K.
-

Low mechanical signals
strengthen long bones.
Nature, 412(6847), 603
-
604, 2001.

Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

20





Bone Tissue effect



Upper and lower limb

bone fractures
treatment


More quickly bone
reparation

Mechanical factor

Bone tissue adaptive
response


Bone Deformation

Signal proportional
to the applied load

Increase
of bone forming


osteocyte


osteoblast


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

21





Positive stimulus for
the whole body


Vibration
Energy


Qualified clinicians


Using appropriate
devices/procedures


Using specific frequency

Patient application

By

IF

Conclusions

THEN


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

22





Conclusions



Application fields




In

rehabilitation

plans

in

which,

an

optimization

of

methods

aimed

at


extensibility

of

muscle
-
tendon

complex

improvement,

is

required
;



In

geriatric

patologies,

to

improve

myo
-
osteo
-
articular

functionality

and

in


osteoporotic

patients
;




In

sport

field

as

alternative/complementary

training

method

oriented

to


an

explosive
-
force

improvement
;



In

workplans

oriented

to

painful

pathologies

such

as

in

chronic

low

back
-

pain

therapy


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

23





Conclusions



…Last, but not
least…

if

applied in non specific way,
WBV

treatments could have

non positive effects


The
optimum

is obtained
localizing
vibrations to a specific body part

Importance
of
application
mechanisms


When a
systemic
response is required

Whole body
vibrations

When a
local
response is required

Local vibrations


Biomedical Application of Vibration Energy: effects on the human body

Paolo Abundo

24





Biomedical Application of Vibration Energy:

effects on the human body


P. Abundo
1
, C. Trombetta
2
, C. Foti
3
and N. Rosato
1


1

Medical Engineering Service, Fondazione Policlinico Tor Vergata, Rome

2
PhD student in Advanced Technology in Rehabilitation Medicine, Tor Vergata University, Rome

3

Tor Vergata University, Physical and Rehabilitation Medicine, Public Health Department, Rome


February 9th 2010


Thanks for the attention