1st International Conference
Computational Mechanics and Virtual Engineering 
COMEC 2005
20 – 22 October 2005, Brasov, Romania
STUDY UPON ADVANCED MODELS AND SYSTEMS FOR HUMAN
BODY PROTECTION AGAINST VIBRATIONS AND OCCUPATIONAL
DISEASES PREVENTION
Lache Simona
1
University Transilvania of Brasov, ROMANIA, slache@unitbv.ro
Abstract: Within labour medicine, occupational diseases due to vibrations represent a particular sector, being widely spread
into a large number of occupational categories. This paper is a study of the state of the art in the subject of mechanical
vibrations influence on the human body, within operation conditions. It also proposes solutions for developing modern
methods of dynamic analysis and of active control advanced systems for protecting the human body against vibrations..
Keywords: human body vibrations, occupational disease, active control
1. INTRODUCTION
Within labour medicine, occupational diseases due to vibrations represent a particular sector, being
widely spread into a large number of occupational cathegories. The research in this field revealed three
frequency intervals with negative influence on the human body: range 0-2 Hz, with the following exposed
occupations: aeronautic, maritime transport staff; range 2-20 Hz, with the following exposed occupations:
drivers of trucks, vehicles (for intra-factory transport), tractors (agricultural, forest), escavators, bulldozers,
concrete platforms, workers around fixed machines that transmit vibrations through the floor; range 20-200 Hz,
with the following exposed occupations: all occupations that use vibratory machines and tools, acting on the
hand-arm system: miners (pneumatic hammers for rock boring, hydro-electric power plants, railways, etc.,
workers form machine building (rivetting, casted parts cleaning, etc.), forestry workers (using mechanical sews),
roads construction workers, etc.
The occupational diseases due to long term vibration exposure are divided in four categories of affections:
1. Osteo-mulscular-articular syndrome; 2. Digestive syndrome; 3. Raynaud syndrome; 4. Nervous syndrome.
During the last time, the research team from University of Padova, Italy [1] revealed that long term vibration
exposure may cause chronic diseases with serious affections on individual cognitive and emotional system.
Today, the researchers succeeded to systematize and divide this problem in two distinct categories:
 Whole Body Vibration (known by the acronym WHB) – with effects on the entire body;
 Hand Arm Vibrations (known by the acronym HAV) – transmit significant accelerations and
displacements only to the hand-arm system.
There are mentioned only some of the identified effects of these diseases:
 Mechanical effects: tissue damage;
 Physiological effects: stress, heart activity enhancement;
 Psychological effects: uncomfortable state, lack of concentration, etc.
Therefore, due to the complex effects of vibrations on the human body, it is not at all hazardous the increased
attention given by the researchers all over the world from different research fields (mechanical engineering,
medicine) to a thematic area having as main objective the occupational sickening prevention.
A joint research team from Transilvania University of Brasov, consisting of engineers, physicians and
computer scientists is preoccupied to develop advanced models of the vibration phenomenon and its influence on
the human body, in order to further propose active control systems for protection against vibrations. The first
step in this demarche is to thoroughly study the state of the art in the field, which is given as a survey in the
present paper.
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2. STATE OF THE ART IN HUMAN BODY VIBRATIONS FIELD ON INTERNATIONAL
LEVEL
On international level, actual knowledge stage analysis revealed the enhanced interest upon the reduction
of different vibration sources level (systematically presented above). This interest is motivated by the present
legislation, the health expenses (it is a well known truth: it is less expensive to prevent then to cure) but also by
the more and more increased requirements regarding the products competitiveness. A detailed analysis of the
state of the art in this field led to the following conclusions, as well:
 The publications are structured on two research fields: the field of engineering sciences (with applications in
biomedical engineering) [2], [3], [4], [5] and the field of medical sciences [1], [6]. This aspect demonstrates
the knowledge boundary research feature, within which the engineers and physicians join their forces and
knowledge in order to improve the human working conditions, in a more and more technologized society
that expose humans to enhanced risks.
 Publications in the aimed research field are widely spread, there are interests in this subject in Europe [1],
[2], [6], [7], [8], etc., USA and Canada [4], 9], [10] but also in Middle East [11], [12] and Japan [13].
In universities, research institute and big companies, there are research teams specialized in vibrations
influence upon the human body – theory and practice. Moreover, by developing international research laboratory
networks (through international research projects like FP6), the same research problem is approached by twothree research teams, the results are compared and analysed in order to correct mainly the testing techniques. For
example, at EU level, the research team coordinated by professor Griffin, from Acoustics and Vibrations
Institute, University of Southampton, UK, develops joint projects with University Saitama - Urawa, Japan (prof.
Matsumoto). Thus, important contributions have been achieved regarding the effects of vertical vibrations upon
the human body behavior in sitting position and simple, lumped, reduced order mathematical models have been
developed, allowing structural dynamic analyses [8], [14].
Peter Jonsson’s doctoral thesis, from Acoustics and Vibrations Department – Lulea University of Technology,
Sweden [2], demonstrates the possibility of developing systems for reducing vibrations induced uncomforting.
The new design strategies, by seat and cabin dampers changes, together with a thorough understanding of the
operation condition for the aimed vehicles or machine tools, may lead to diminishing vibration effects on human
operators. The research approach used in this process is depicted in Figure 1.
Figure 1: The research strategy illustrated uses four approaches to acquire information. The
arrows connecting the approaches depict the information flows. The black thin arrows correspond
to validations of the prediction model of discomfort and the thick arrows correspond to the
modification procedure for vehicle designs when using the prediction model of discomfort [2].
Reducing vibration discomfort can be carried out using dynamic computer simulations (#1 in Figure 1) but it
requires a prediction model (the square in centre of Figure 1) of discomfort that includes variables associated
with vibration discomfort (#4 in Figure 1). Usual operating conditions are measured in field conditions (#2 in
Figure 1) for exciting the computer simulation vehicle model (i.e. vibration input) to identify the minimal
vibration discomfort condition (#4 in Figure 1) as related to engineering solutions (#1 in Figure 1). Computer
model optimisations lower development cost for potential users such as vehicle manufacturers. Platform
simulations (#3 in Figure 1) can be used to collect subjective response data from appropriate subjects without the
need to build a vehicle prototype. The platform simulations also make it possible to collect data on different
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kinds of vehicles/and to model possible improvements without there being a need to construct/modify prototype
or production vehicles.
In the USA, at University of Washington, prof. Jacob Rosen cooperated in research projects with the
homologous research team from University of Tel-Aviv, coordinated until 2000 by the late prof. Mircea Arcan.
Important results were achieved regarding modeling and optimization of body/seat system in a vibration
environment [4].
On the occasion of several specialization stages the author of this paper accomplished in EU universities,
she got direct contact with different research teams studies and results on this subject: thus, at Katholieke
Universiteit Leuven, Belgium, professor Van Audekercke, leader of the biomechanics research group,
coordinates a research project aiming to model the muscular system for identifying and eliminating the lumbar
pain, that may degenerate into occupational disease. At University of Poitiers, France, within the Solid
Mechanics Laboratory, prof. Lacouture’s research team carries on projects having as object the study of human
body dynamic behaviour for the sportsmen participating in automobile races. At Universite Libre de Bruxelles,
Active Structures Laboratory, professor Andre Preumont and his research team achieve significant results
regarding the vibrations active control [15], as one of the potential solutions of the problem proposed for solving
within this project proposal.
Another significant result in the field was the standards regarding the human body exposure to shocks and
vibrations, when operating vehicles, machines and equipment or in building area [16]. An overview of the
existing standards is given in Table 1:
Table 1: The standards regarding the human body exposure to shocks and vibrations
CR 1030-1:1995 Hand-arm vibration - Guidelines for vibration hazards reduction - Part1: Engineering methods
by design of machinery
CR 1030-2:1995 Hand-arm vibration - Guidelines for vibration hazards reduction - Part2: Management measures
at the workplace
EN 1032:1996 Mechanical vibration - Testing of mobile machinery in order to determine the whole-body
vibration emission value - General
EN 1032:1996/A1:1998 Mechanical vibration - Testing of mobile machinery in order to determine the wholebody vibration emission value - General -Amendment 1
EN 1032:2003 Mechanical vibration - Testing of mobile machinery in order to determine the vibration emission
value
EN 1033:1995 Hand-arm vibration - Laboratory measurement of vibration at the grip surface of hand-guided
machinery - General
EN 1299:1997 Mechanical vibration and shock - Vibration isolation of machines -Information for the application
of source isolation
CEN ISO/TS 8662-11:2004 Hand-held portable power tools - Measurement of vibrations at the handle - Part 11:
Fastener driving tools (ISO 8662-11:1999 + Amd.1:2001)
CEN ISO/TS 8662-11:2004 Hand-held portable power tools - Measurement of vibrations at the handle - Part 11:
Fastener driving tools (ISO 8662-11:1999 + Amd.1:2001)
EN 12096:1997 Mechanical vibration - Declaration and verification of vibration emission values
CR 12349:1996 Mechanical vibration - Guide to the health effects of vibration on the human body
EN 12786:1999 Safety of machinery - Guidance for the drafting of the vibration clauses of safety standards
EN 13490:2001 Mechanical vibration - Industrial trucks - Laboratory evaluation and specification of operator
seat vibration
EN 14253:2003 Mechanical vibration - Measurement and calculation of occupational exposure to whole-body
vibration with reference to health – Practical guidance
CEN ISO/TS 15694:2004 Mechanical vibration and shock - Measurement and evaluation of single shocks
transmitted from hand-held and hand-guided machines to the hand-arm system (ISO/TS 15694:2004)
ENV 25349:1992 Mechanical vibration - Guidelines for the measurement and the assessment of human exposure
to hand-transmitted vibration (ISO 5349:1986)
EN ISO 5349-1:2001 Mechanical vibration - Measurement and evaluation of human exposure to handtransmitted vibration - Part 1: General requirements (ISO 5349-1:2001)
EN ISO 5349-2:2001 Mechanical vibration - Measurement and evaluation of human exposure to handtransmitted vibration - Part 2: Practical guidance for measurement at the workplace (ISO 5349-2:2001)
ENV 28041:1993 Human response to vibration - Measuring instrumentation (ISO 8041:1990)
ENV 28041:1993/A1:2001 Human response to vibration - Measuring instrumentation (ISO 8041:1990/Amd.
1:1999)
EN ISO 8041:2005 Human response to vibration - Measuring instrumentation (ISO 8041:2005)
EN 28662-1:1992 Hand-held portable power tools - Measurement of vibrations at the handle - Part 1 to 14.
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EN 30326-1:1994 Mechanical vibration - Laboratory method for evaluating vehicle seat vibration - Part 1: Basic
requirements (ISO 10326-1:1992)
EN ISO 10819:1996 Mechanical vibration and shock - Hand-arm vibration - Method for the measurement and
evaluation of the vibration transmissibility of gloves at the palm of the hand (ISO 10819:1996)
EN ISO 13090-1:1998 Mechanical vibration and shock - Guidance on safety aspects of tests and experiments
with people - Part 1: Exposure to whole-body mechanical vibration and repeated shock (ISO 13090-1:1998)
EN ISO 13753:1998 Mechanical vibration and shock - Hand-arm vibration - Method for measuring the vibration
transmissibility of resilient materials when loaded by the hand-arm system (ISO 13753:1998)
EN ISO 20643:2005 Mechanical vibration - Hand-held and hand-guided machinery - Principles for evaluation of
vibration emission (ISO 20643:2005)
The actual knowledge stage presentation allow for a conclusion to be pointed out: by the large number of
publication, the study of vibrations influences upon the human body represents, nowadays, a research domain
perfectly contoured. Still, there are many unexplored issues the most of the present research being limited to
modelling and analysis of theoretical models. Moreover, the active control of vibrations applied in order to lower
their influence on the human body represents an open field, very challenging for scientists.
3. STATE OF THE ART IN HUMAN BODY VIBRATIONS FIELD ON NATIONAL LEVEL
On national level, at least for now, the cooperation within different research teams within the same
research subject are sporadic, even if there is, mainly in universities, human and material potential. The Ministry
of Education and Research initiative regarding the national grants type A consortium financing or the Excellence
Research Programmes financing creates the premises for setting-up and developing of such a kind of
cooperation. Presently, referable to research activity in biomechanics, the Romanian research units make
considerable effort for development, without having, yet, the human body vibrations as specific research subject.
In the paper Actual and Perspective Researches Regarding Biomechanical Studies, prof. Faur N. from University
Politehnica of Timisoara, describes a complex picture of the national state of the art in the domain. In this
respect, the contributions are mainly in the fields of orthopaedics, stomatology and very few in ergonomics and
psychiatry [17].
University Politehnica of Timisoara distinguishes itself by the research groups coordinated by prof. dr.
ing. Toader M. si prof. dr. ing. D. Dragulescu [18]. There have been carried on researches regarding the
vibrations influence upon the hand-arm system [19]. By the numerous doctoral thesis in the field of
biomechanics and mechanical vibrations (over 15 were finalized in the past 5 years and there are other to be
finalized) important results have been achieved in modelling different parts of the locomotion apparatus and the
facial skeleton [20], [21], [22], [23]. Here is also acting the Research Centre with Multiple Users –Surgical and
Prosthetic Investigation Centre for Human Skeleton Modelling and within the parst years two CNCSIS grants
were carried out: Study About Mandible Dynamics And Implants Modelling To Correct Its Accidental Fractures
By Using Surgical Interventions (A235, 2003-2005, director prof. D. Dragulescu) and Design, Modeling and
Manufacturing of a Set of Medical Implants for the Oro-Maxilo-Facial and Orthopedic Surgery (A237, 20032004, director prof. M.F. Dreucean).
Important studies and contributions in biomechanics are present also at University Politehnica of
Bucharest, Department of Precision Mechanics and Mechatronics, within the Research & Development Centre in
Mechatronics, coordinated by Prof. dr. ing. Alexandrescu N. The centre has a strong research potential into:
biomedical devices, surgery block apparatus, invasive radiation apparatus, medical devices standardisation,
medical units management, stomatology devices service, biomedical equipment, biomechanics, prosthesis,
biomaterials [24], [25], [26].
Regarding University Transilvania of Brasov, the contributions in the research field are reflected on the
research activity of Faculty of Mechanical Engineering (Departments of Precision Mechanics and Mechatronics,
Strength of Materials and Mechanical Vibrations, Mechanics, Automotives and Engines). At the same time,
there are two strong research centres: the Research Centre in Mechanical Engineering, CESMA, and the
Research & Development Centre for Automotives, Thermal Machines and Equipment – Research Base with
Multiple Users (BCUM-CCDAMET). By very briefly referring to the most recent achievements, the CNCSIS
grant coordinated by Mrs. Prof. Rosca I.C. (finalized in 2004, A291) gives know-how in movement dynamics
analysis of elements within biomechanical systems, the CNCSIS grant coordinated by Mrs. Conf. Barbu D.
(finalized in 2004, AT22) gives a deeper insight into the biomechanical systems modelling and analysis, and the
undergoing CNCSIS grant AT133 (2005 being the first year of financing), also coordinated by Mrs. Conf. Barbu
D., opened the way toward the presently proposed subject, by analysing, modeling and simulation of human
body behaviour within a shock and vibration polluted medium, with implications in ocular prosthesis and
orthesis appliance. The research study in the field revealed also preoccupations of the research team from the
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Department of Mechanics, materialized in athletic motions simulations [27] and in solutions regarding reducing
the vibration influence for truck and tractor drivers [28].
5. CONCLUSION OF THE STUDY AND FUTURE WORK
At national level, considering the existing studies and achievements in the biomechanics domain, there
are present the premises for creating and developing of a research network in this domain, long term objectives
aiming to integrate this potential network into the European research networks. From the critical state-of-the-art
analysis it yields there are still many unexplored issues regarding the vibration effects study upon the human
body, the most of the present research being limited to modelling and analysis of theoretical models. It has been
also observed the studies are performed by totally different approaches, applied either by engineers or
physicians, in very few cases being recorded a cooperation between these two categories of researchers. It is,
thus, required a joint research team involving university staff from different fields – mechanical engineering,
mechatronics, and medicine. The main aim of unifying the human and material potential is to develop a complex
and integrated research program, able to give the expected results.
By synthesizing, it is considered that the proposed subject may bring a significant contribution to the field
knowledge development by the following issues:
 Development of dynamic analysis advanced techniques, within which the experimental results are used to
update the theoretical models performances, by sensitivity analysis approach.
 Development of advanced control systems for vibro-insulation of vehicles, machines and equipment
subassemblies – which are considered as potential vibration sources for the human body.
 Development and implementation of computer programs for modal analysis and active control of the
proposed systems.
 Setting–up the dynamic investigation framework methodologies for the different vehicles, machines and
equipment subassemblies, in order to set and diminish the vibration level the human body is subjected to.
 Development of databases with representative information about each occupational disease category.
 Comparative analysis of the admissible vibrations norms in Romania and EU, in the view of tuning the
Romanian legislation to the European one.
 Development of databases with testing methods, means and admissible norms, for each occupational disease
category.
 Setting-up the premises for creating of a national research network in this field, intended to be further
integrated into the European research networks.
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