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Biomedical Application of Vibration Energy: Biomedical Application of Vibration Energy: effects on the human bodyeffects 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, Rome2 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 2010February 9th 2010
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Analysis of vibration Analysis of vibration peculiar parameterspeculiar parameters
Vibration Vibration human body human body
effectseffects
IndexIndex
Vibration producing Vibration producing methodsmethods
Negative Negative effectseffects
Safety of workers Safety of workers subject to subject to vibrationsvibrations
Positive Positive effectseffects
Therapeutic application in Therapeutic application in rehabilitation medicinerehabilitation medicine
Hormonal effectHormonal effectNeuro-muscular system Neuro-muscular system
effecteffectBone tissue effectBone tissue effect
Biomedical Application of Vibration Energy: effects on the human body Paolo Abundo
Biomedical vibration Biomedical vibration applicationsapplications
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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/s2]
4 Analysis of vibration peculiar parameters
tVonAccelerati
Human body feels more
the variation of a stimulus than its persistence
Vibration intensity
T
dttaT
an Squareon Root MeAccelerati0
2 )(1
Resonance frequencyVibration 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 bodyrotating around a non barycentric axis
Rotating mass (m)Uniform circular motion
Circumference radius equal to eccentricity (e)
Costant angular velocity in amplitude (Ω)
emtF 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 propertyMechanical stress
(contraction or expansion)
Alternating current
Crystal material thicknessAlternating current Frequency
Crystal wave vibration frequency
Optimize vibrating head dimensions and weight
Policrystal ceramic (Barium titanate -
BaTiO3)
Topaz Quartz
~MHz
Biomedical Application of Vibration Energy: effects on the human body Paolo Abundo
7 Vibration producing methods
Magnetic-dynamic transducer
MembraneElectric coils
Permanent magnetAlternating current
ILNHB
N= Coils numberL= Coils lenghtI= Coils currentm= Magnetic Permeability
Alternating current through
coils
Varying intensity magnet
Permanent magnetic field
Coils vibrations
Membrane
vibrationsBiomedical 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
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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 ExposureContact AreaContact Force
Ergonomical and environmental factorsTissues 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
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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 5 m/sm/s22
8)8( TeAA sum
Te = daily exposure time to vibrations (hour)8 = reference time (hours)ax, ay,az = r.m.s. acceleration values (in m/s2) along x, y, z axis (ISO 5349-1: 2001)
Whole BodyEquivalent Acceleration
Exposure Limit Value = 1 m/s1 m/s22
8)8( TeAA Max
Te= daily exposure time to vibrations (hour)8 = reference time (hours)AMax = Maximum value among ax, ay, az ax, ay,az = r.m.s acceleration values (in m/s2) along axis x, y, z (ISO 2631-1: 1997)
)a a (a 2z
2y
2x sumA
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
partVibrating 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 concentrationafter 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
ExerciseMuscular function
improvementEffective 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; P506F 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
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Positive stimulus for the whole body
Vibration Energy
Qualified clinicians Using appropriate
devices/procedures Using specific frequency
Patient application
ByIFIF
Conclusions
THENTHEN
Biomedical Application of Vibration Energy: effects on the human body Paolo Abundo
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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
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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
requiredWhole body vibrations
When a local response is
requiredLocal
vibrations
Biomedical Application of Vibration Energy: effects on the human body Paolo Abundo
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Biomedical Application of Vibration Energy: Biomedical Application of Vibration Energy: effects on the human bodyeffects 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, Rome2 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 2010February 9th 2010
Thanks for the
attention