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Über dieses Buch

This volume presents the contributions of the third International Conference on Advancements of Medicine and Health Care through Technology (Meditech 2011), held in in Cluj-Napoca, Romania.

The papers of this Proceedings volume present new developments in

- Health Care Technology,

- Medical Devices, Measurement and Instrumentation,

- Medical Imaging, Image and Signal Processing,

- Modeling and Simulation,

- Molecular Bioengineering,

- Biomechanics.

Inhaltsverzeichnis

Frontmatter

Health Care Technology

AWARD – An Innovative Training Tool for Accessible Built Environment

The goal of this paper is to present some of the results of the Leonardo da Vinci Project no. 07/0227-L/LLP-LdV-TOI-2007 – HU_001 “Accessible World for All Respecting Differences” – AWARD. The main objective of the project was to develop a teaching material in the field of barrier-free built environment by applying the concepts of universal design, in order to include the necessary knowledge in the curricula of vocational and higher technical institutions, thus contributing to changing mentality and attitude towards this important part of population. The teaching material is learner-oriented and may be used by a large range of vocations, also facilitating the Lifelong Learning Programme of practicing professionals and craftsmen.

C. Aciu, N. Cobirzan, M. Brumaru

The Development of the ALPHA Rollator

After a short presentation of the most important mobility aids, details about rollators are given and few representative examples are described. The original design of ALPHA rollator is presented and the constructive and technological aspects are emphasized. The paper presents the developed prototypes and their advantages as well as the results of the experimental tests.

A. Abrudean

Ethical Issues in Nanomedicine

Nanomedicine is a top developing domain. However, there are neither sound rules, nor a proper legislation that might regulate the ethics in this domain. Here we discuss the main topics pertaining to the ethics in nanomedicine at this time. From issues such as equity and discrimination, to profound modifications of the human body, far beyond the limit of human and non-human, there are many ethical aspects that can give rise to conflicting opinions.

F. Graur, R. Elisei, A. Szasz, H. C. Neagos, A. Muresan, L. Furcea, I. Neagoe, C. Braicu, G. Katona, M. Diudea

Innovative Technologies in Vitreo-Retinal Surgery for Rhegmatogenous Retinal Detachment

Vitreo-retinal surgery techniques have significantly improved over time and increased the success rates in the surgery of Rhegmatogenous Retinal Detachment (RRD). The purpose of this study is to evaluate the results of the primary vitrectomy for RRD. We have conducted a retrospective study on all the RRD cases that we have operated on by pars plana vitrectomy between October 2009 – October 2010 (70 cases). The description of the surgical techniques concerns the vitrectomy itself and the associated maneuvers: drainage of the subretinal fluid, retinopexy (endolaser/exocryo), internal tamponade. The peroperative complications are presented and the results are evaluated 3 months after surgery as: success, simple recurrence, Proliferative Vitreo-Retinopathy (PVR), Cystoid Macular Edema (CME). All the posterior vitrectomies have been performed with the Accurus machine (Alcon). We used the 20 gauge system and a high speed vitrectomy probe (2500 cuts/minute). The vitrectomy has been as complete as possible in all situations, up to the vitreous base. The subretinal fluid has been drained by PerFluoroCarbon Liquids (PFCL) injection in 65 cases (92.85%) or by fluid/air exchange in the remaining 5 cases (7.14%). The retinopexy has been performed with a cryoprobe in 46 cases (65.71%) and with the endolaser fiber in 24 cases (34.28%). The endolaser cerclage has been associated in 26 cases (37.14%) and we used the silicone oil for the internal tamponade in all the situations. We have accidentally injured the retina in 5 cases (7.14%) and touched the lens in 4 cases (5.71%). Success has been achieved in 58 cases (82.85%), simple recurrence has been identified in 8 cases (11.42%), PVR in 3 cases (4.28%), CME in one case (1.42%). The technical advances are emphasized (high-speed cutting rate, 3D system), with implications in the surgery of RRD. The modern vitrectomy techniques have proven their efficacy in the treatment of RRD.

S. D. Talu, S. Rus, I. Tamasoi, C. Dragos

PerFluoroCarbon Liquids in Vitreo-Retinal Surgery – Personal Experience

The combination of the physical and chemical properties of the PerFluoroCarbon Liquids (PFCL) has propeled their clinical use not only for the repair of the complex retinal detachments, but also for a range of intraocular surgical maneuvres. The purpose of this study is to outline the status of the use of PFCL in vitreo-retinal surgery, as it emerges from our personal clinical experience. We have used the PFCL in 82 vitrectomies over a one-year time period (October 2009 – October 2010). The PFCL were injected into the vitreous cavity in patients with the following conditions: rhegmatogenous retinal detachment (RRD), tractional retinal detachment (TRD), combined retinal detachment (rhegmatogenous and tractional) and severe proliferative diabetic retinopathy (PDR). In the RRD group (65 cases), success has been achieved in 55 cases (84.61%), simple recurrence has been identified in 6 cases (9.23%), Proliferative VitreoRetinopathy – in 3 cases (4.61%) and Cystoid Macular Edema – in 1 case (1.53%). The remaining 17 cases in which PFCL have been used (20.71%) were all caused by diabetes. In the severe PDR subgroup, the disease has been stabilized in all the 3 cases. In the TRD subgroup, success has been obtained in all the 4 cases (retinal reattachment), whereas in the combined retinal detachment subgroup (RRD+TRD) the retina has reattached in 8 cases (80%) and maintained detached in 2 cases (20%) after surgery. PFCL have proved their efficacy in vitreo-retinal surgery.

S. D. Talu, I. Tamasoi, C. Dragos, S. Rus

E-NOTES Transumbilical Cholecystectomy

Laparoscopic cholecystectomy has become the gold standard for the symptomatic gallbladder lithiasis. Usually, the procedure is performed using 4 trocars. Reducing the number of trocars is one of the ways of minimizing the invasiveness of this procedure. Single port laparoscopy through the umbilical scar, also known as “embryonic natural orifice transumbilical endoscopic surgery” (E-NOTES) was developed as an attempt to improve the aesthetic aspect after surgical procedures and to reduce the morbidity of minimally invasive surgery.

We report a case of transumbilical laparoscopic cholecystectomy without the use of clips, for symptomatic gallbladder lithiasis, the sealing of the cystic duct and cystic artery being obtained by using a LigaSure 5 mm. A 35 year old young male with history of pain in the upper abdomen and right upper quadrant, nausea and vomiting was diagnosed with gallbladder lithiasis after an ultrasound examination. The gallbladder was of normal size, with multiple gallstones. Under general anesthesia, a pneumoperitoneum was created. Three trocars were inserted into the peritoneal cavity for this intervention through the SILS port, through a single incision at the umbilical scar. The cholecystectomy was performed in a retrograde manner. One subhepatic drainage tube was inserted. The operative time was 50 min. There was no intra- or postoperative complications. The patient was discharged in the second postoperative day after a normal course. The 1 month follow-up was normal.

F. Graur, A. Szasz, R. Negru, H. C. Neagos, R. Elisei, A. Muresan, L. Furcea

Multiagent System for Monitoring Chronic Diseases

The aim of this paper is to present a society of intelligent agents linked into a multiagent system with the scope of monitoring a large group of human beings in order to detect possibilities of estimating catching chronic diseases. For this purpose a heterogeneous group of patients was taken into observation into approximately 15 years period. The group is provided by a family doctor and is formed by many social categories, many age increments and some different cities. The paper will prove that such monitoring will detect in the first stage or will detect the possibilities of being ill based only on historical dates of the patients. Obviously the names of the patients were not taken into multiagent system, but in real cases the family doctor could prevent a real patient about the danger of his life style or medical historical dates.

D. Floroian, L. Floroian, F. Moldoveanu

Real Time Biostatistics Software: Application in Acute Myeloid Leukemia Assessment

The aim of this paper is to present an useful software in medical research. The new concept proposed is “real time biostatistics” and its application in Acute Myeloid Leukemia. For this purpose open source software (wxWidgets, R and SQLLite3) are used. The cases were patients with AML from Hematological Department, County Emergency Clinical Hospital Tirgu Mures. We created a friendly interfaced software that allows appropriate data collection and real time update of statistical parameters as each case is introduced.

The medical importance derives from the possibility to have valid study and to see in each moment a change in the evolution of patients.

Collaboration between specialists (hematologist, PC programmer, biostatistician and methodologist) was really important for accomplishing our goal.

A. Bacarea, B. A. Haifa, M. Marusteri, M. Muji, A. Schiopu, D. Ghiga, M. Petrisor, V. Bacarea

Database External Level Architecture for Use in Healthcare Information Systems

Healthcare Information Systems rely very often on complex database structures and require complex processing of the data in order to offer relevant information to the user. In an attempt to extend the benefits deriving from the structural approach present at the internal level of such a database to its external level, this paper proposes a database external level architecture based mostly on server side views, supported by client side views and a minimal number of server side stored procedures.

P. Olah, D. Dobru, R. V. Ciupa, M. Marusteri, V. Bacarea, M. Muji

Beat-by-Beat Variability of QT ECG-Interval Holds a Well-Founded Promise for Clinical Cardiology: A Review

The advent of reliable software access to beat-by-beat QT interval series opened a novel insight to sympathetic control of ventricular myocardium.

Experimental measurement of time constant in the RR-QT system (

τ

QT

) using pharmacological or electrophysiological manipulations of heart rate (HR) has documented that

τ

QT

size may introduce in borderline subjects in normal life settings episodes of functional long-QT syndrome.

In type I young diabetics in the earliest phase of autonomic dysfunction, spectral QT and RR analyses suggest preferential vagal down-regulation but preservation of sympathetic responsiveness of ventricles to life challenges.

Both findings signal an early risk worth to be dealt with by specific preventive steps.

R. Negoescu

Monitoring System for a Medical Facility Using the OPC Platform

Efficient parameter monitoring and real-time medical data acquisition and presentation can prove to be crucial, especially in a medical unit treating patients with severe affections and highly unstable conditions. This paper proposes a monitoring system for the vital parameters of patients hospitalized in a Intensive Care Unit based on the OPC architecture.

V. D. Zaharia, F. Dragan

The Use of Medical Devices in Self Monitoring of Chronic Diseases

The range and complexity of medical devices used in homecare are increasing. Home medical devices must be safer, easier to use and more accessible for all users. The safety and the efficiency of the medical device used depend on the device’s design, users’ ability to operate with devices and the used environments for devices. In order to investigate the proper operation of the medical device and to identify sources and the nature of difficulties in their use, there were investigated three self monitoring medical devices which are most frequently used by the patients of Diagnostic and Treatment Center Cluj-Napoca for their chronic disease management. The compliance problems, focused on difficulties which may occur during the use of medical device, suggested that the proper functioning of the medical device depend, first of all, on user’ competency.

S. Mirel, S. Pop, E. Onaca, S. Domnita, V. Mirel

A Wireless System for Monitoring the Progressive Loading of Lower Limb in Post-Traumatic Rehabilitation

The paper presents a low cost system for wireless monitoring of the progressive loading of lower limb. This system contains a smart device able to measure the plantar pressure, to compare it with predefined levels and to signal the patient in order to avoid excessive loading of the limb in case of patients following post-traumatic rehabilitation.

F. Neaga, D. Moga, D. Petreus, M. Munteanu, N. Stroia

Telemonitoring of Vital Signs – An Effective Tool for Ambient Assisted Living

Telemedicine and e-health solutions provide (chronic) patients and elderly people services that enhance their quality of life. Advances in wireless sensor network technology and the overall miniaturization of their associated hardware low-power integrated circuits have enabled the design of low-cost, miniature and precise physiological sensor modules. These modules are capable of measuring, processing, communicating one or more physiological parameters, and can be integrated into a wireless personal area network (WPAN). This paper is dedicated to the most complex Romanian telemedical pilot project, TELEMON, that implemented a system for automatic and complex telemonitoring, everywhere and every time, in real time, of the vital signs of persons with chronic illnesses, of elderly people, of those having high medical risk and of those living in isolated regions. The main objective of this pilot project is to enable personalized medical teleservices delivery, and to act as a basis for a public service for telemedical procedures in Romania and abroad.

H. Costin, C. Rotariu, F. Adochiei, R. Ciobotariu, G. Andruseac, F. Corciova

eHealth – Unified Healthcare Logical Space through Applied Interoperability

The current paper presents a patient-centric approach that implements a unified healthcare logical space model for medical information environment. We focused our work on interoperability features with extensive usage of standards in order to develop a distributed information framework: a pilot system called CardioNET. This eHealth system was designed to integrate medical services from various healthcare providers and improve the quality of services, through some of latest medical and IT&C technologies. Modern healthcare activities require a patient-centric vision, where patients must receive medical attention or treatment anytime, regardless of their physical location. CardioNET embodies this approach where hardware, software and medical activities become “services” of a “logical cardio-health care domain-space”. This distributed environment also offers tools for remote interactions between patients, doctors, medical entities (e.g. hospitals, labs) and authorities. Based on international domain standards (IDC10, LOINC, HL7), the system creates an infrastructure for interoperability and data exchange using widely accepted formats (HL7 messages, or XML records). High level protocols (UDDI, SOAP/HL7 and HTTP) provide the presented framework the means to exchange of HL7 or XML compliant messages between the systems’ main healthcare actors. CardioNet subsystems have specialized metadata registries and shared data repositories, which altogether create a distributed healthcare pilot environment for medical decisions support, research and educational activities.

M. Rusu, C. Lelutiu, N. Todor, G. Saplacan

Medical Services Optimization Using Differential Evolution

This paper proposes a method to compose and optimize medical services as business workflows. Such a workflow consists in a set of abstract services, and for each abstract service there are several concrete services. Since each medical service has different QoS (Quality of Service) parameters such as

response time

,

rating

,

distance

and

cost

, determining the optimal combination of concrete services that realize the abstract services of the business workflow is an NP hard problem. Recent proposals for solving NP optimization problems indicate the Genetic Algorithms (GA) as the best approach for complex workflows. But this problem usually needs to be solved at runtime, a task for which GA may be too slow. We propose a new approach, based on Differential Evolution (DE), that converges faster and it is more scalable and robust than the existing solutions based on Genetic Algorithms.

F. -C. Pop, M. Cremene, M. -F. Vaida, A. Serbanescu

Direct Response Advertising in Romanian Dental Field: A Qualitative Analysis

Romanian

dental

industry

is in its initial stage of development, while the market has a huge potential for future growth. Hence, the advertiser from this field should integrate direct response with image based advertising for reaching more efficiency and effectiveness. The paper aims at identifying the degree of direct response advertising vs. image advertising, as a marketing tool for dental services and products. The assessment will be distinctly processed by different types of products. Moreover, the study tries to draw some correlation between dental market development and the above mentioned rate, during the latest five years.

The performed research is a qualitative one, based on content analysis of 748 advertisements, published in professionals’ magazines, between 2006 and 2010.

The research outcomes reflect a balanced advertising for materials, equipments, services and reveal strong image advertising for the dental products end-users. The economic crisis has changed the pattern in dental advertising, mainly by emphasizing rather on emotion than on rational reason.

A. Constantinescu-Dobra

Software System for Medical Device Management and Maintenance

Concerning the inpatient care the present situation is characterized by intense charges of medical technology into the clinical daily routine and an ever stronger integration of special techniques into the clinical workflow. Medical technology is by now an integral part of health care according to consisting general accepted standards. Purchase and operation thereby represent an important economic position and both are subject of everyday optimization attempts. For this purpose by now exists a huge number of tools which conduce more likely to a complexness of the problem by a comprehensive implementation. In this paper the advantages of maintenance system architecture on the medical device management are shown and we are presenting original software that can be implemented in any hospital without being necessary the existence of a clinical engineering department.

C. Luca, R. Ciorap

Medical Devices, Measurement and Instrumentation

A Novel Concept of a Braille Device Based on Wax Paraffin Actuator

The aim of this paper is to investigate and develop a novel refreshable Braille device actuated by thermal actuators based of phase change transformation material. The paper starts with a short introduction about some representative tactile devices, the importance of those devices into society, and highlighting the author’s previous work in the field. Second paragraph presents the proposed design of a Braille cell, third paragraph discuss aspects regarding the thermal analysis of the proposed model along with numerical results. Forth paragraph deals with the presentation of the developed prototype along with results from the conducted test of its performances.

A. M. Alutei

Considerations on Electromagnetic Compatibility for Medical Devices

The paper deals with the electromagnetic compatible design of medical products, starting from the early stage of the design process (the prototype stage). This way of thinking is presented for the case of one kinetic therapy equipment. In the functional block diagram of the equipment are pointed out the main electromagnetic interference paths. The specific test setup and measurements in accordance with the European conducted immunity standards for electromagnetic compatibility are presented. Two kinds of measurement were performed: inter-system measurements (to the mains supply port) and intra-system measurements (to the printed circuit board and the internal cables). Several solutions for mitigating electromagnetic interference problems which greatly improved the electromagnetic immunity of the equipment are also depicted. The main conclusion which must be drawn from the present paper is that designing for electromagnetic compatibility is the most energy saving and cost effective policy.

M. I. Buzdugan, T. I. Buzdugan, H. Balan

Environmental Effects on the Center’s Offset of the Kistler Force Plate

Kistler Force Plate (FP) (model 9286AA) with the corresponding software Bioware (2812A1-3, Version: 3.2.6.104) were used for the research described in the present paper. The software contains a number of equations for the calculation of all the variables obtained in the form of amplified electrical signals from the piezoelectric sensors incorporated in the FP. After a few measurements taken on the plate with the purpose of analyzing the influence of environment on the equilibrium of the human body we’ve obtained the set of values and graphs that the software offers. Knowing the equations, that the software uses to determine the forces and moments, we made a calculation using both the equations and the values obtained to get a closer look at the errors that can appear. As a result we observed a variance of the constant parameters representing the distance from the center of the plate to the center of each sensor. This article exposes the graphs obtained, the variance of the parameters that should normally be constant. The study was taken at Transilvania University of Brasov.

I. Serban, I. C. Rosca, B. C. Braun, C. Druga

Transformation Design – A New Method for Developing Medical Products

“Transformation design” is the generic name of a new scientific method, appeared at the beginning of the 21st century [1], that is about to become a new independent scientific discipline [2]. The new method gains more importance in today’s conditions, when the effects of the world economic crisis are not completely eliminated.

Simplifying things, it can be said that transformation design is a process through which new, but obsolete, systems are brought to the requirements of the current quality standards [2].

Periodic mandatory consultations (chest X-ray) for certain occupational categories were made in Romania up till the EU pre-accession phase (2004 – 2006). For this were used the Micro- Radio-Photography systems (MRF), which were based on the Roentgen rays scanning principle. These systems weren’t compliant with new regulations in force and, due to the specific legal and economic situation of Romania, extremely strict conditions were imposed to be satisfied until the accession, respectively till January 2007. Thus, the Romanian government had to regulate and plan the decommissioning of all MRF systems. In this situation were 21 MRF systems, new versions, which were installed just a few years earlier and recently put into operation in various clinics in Romania. These 21 MRF systems were technically new, but their principle of operation, Roentgen ray chest scanning, was no longer compliant with valid legal regulations in July 2006. The article describes the finding of a technical solution to solve the situation of the 21 MRF systems removed from service. This is possible by means of transformation design, which offers the possibility to transform these systems, whose principle of operation is contrary to legal norms in force, into X-ray systems with a new operating principle, compliant to these rules.

H. Waedt, M. Popa, P. Manea

The Effects of Exposure of the Human Body to RADON. Integrated Measurements Performed in Alba County, Romania

In many countries, radon is the second most important cause of lung cancer after smoking. The proportion of lung cancers attributable to radon is estimated to range from 3 to 14% . The hygiene requirements, the people’s health and environment protection should be observed according to the regulations in force. In such a context, is included the protection against radioactive emissions that appear inside buildings, if one takes into account the consequences they can have for human health, as radon is the main radiation source for the population; it contributes with about 57% to the annual effective dose in general to radiation, though in some areas this percentage can increase to over 95%.

L. E. Muntean, D. L. Manea, C. Cosma

Education of Arms’ Users in Dealing with Technological Activities

The methodology is based upon the research conducted by help of two subjects’ samples, whose upper limbs skills will be tested and studied using the dedicated equipment in our laboratory. One sample consists of implant users and the other one of non-implant users, in order to be able to set the normal limits and compare them to the performances reached before and after the skills reeducation. Performance is usually expected from people involved in all kinds of activities without taking into consideration the possibility that some of them might be subjected to accidents or diseases, affecting their working capacity. Our goal is not only to improve the skills of healthy persons but also to offer a chance to a normal and productive life to those slightly disabled persons that posses the will and the motivation to pursue it.

M. Baritz, D. Cotoros

Strain Measurement in an Elastic Material under Large Deformation Using Optical Reconstruction Methods

The aim of this study was to explore photogrammetry- optical imaging method used to describe the local variation of strain in an elastic material undergoing large deformation. The material under investigation was marked with reference points (to identify the relative deformation) and imaged with two stereoscopically positioned cameras during a tensile test (strain rate 10 mm/ 60 s). The cameras were calibrated using the Bouguet calibration toolbox in Matlab to characterize their optics and establish their positions. Two dimensional (2D) images from both cameras were investigated to obtain the three dimensional (3D) position of the markers. The deformation of the elastic material was determined by 3D reconstruction of the deformed geometry. Strain results derived from Matlab were in good agreement (99 % ± 0.3 %) with a manual measurement using a caliper. Camera calibration and reconstruction accuracy results indicated an uncertainty of dot separation of the order 30

μ

m, with inter-point distance of approximately 3 mm.

The feasibility of application of photogrammetry for strain measurement through 3D reconstruction of an investigated object has been demonstrated in this study. The optical technique shows potential for development to investigate local strain variation in elastic biological materials.

I. Zwierzak, J. W. Fenner, A. J. Narracott

Hand Vein Biometric Authentication in Optical Multi-touch Systems

Multi-touch systems and their applications are entering a mainstream phase where fast access to visual data and collaborative environments are key factors for an informational age. However, most systems are envisioned as public workstations where resources are shared equally between the users with few or no restrictions on the content delivered by the applications. While real-time identification of the users of a multi-touch system is a difficult subject to tackle, authentication using biometric parameters could provide a hierarchy based content management system. Based on previous research in both hand vein biometric detection and multi-touch systems, this paper describes a hand vein authentication device usable in a touch/object sensing multi-user collaborative environment.

S. Crisan, I. G. Tarnovan, B. Tebrean, T. E. Crisan

Spatial Correlation in Mechanical Heart Valve Leakage Jets

Turbulent flow can be generated by prosthetic devices at the blood stream level, causing a mechanical stress on the blood particle. This mechanical stress can entail adverse impacts of prostheses’ recipients, such as hemolysis.

The experimental research is on the quantitative investigation of the flow field of mechanical bileaflet valve using Particle Image Velocimetry(PIV). Two major measurements focused on leakage jets study were taken. One is standard nozzle measurement and the other one is mechanical valve measurement. These quantitative data could be utilized as basis for a CFD simulation of relevant phenomena. The self-preservation of leakage jets was evaluated with a new method spatial correlation.

G. L. Wang, G. D’Avenio, C. Daniele, M. Grigioni

Peripheral Vascular Measurement Using Electrical Impedance Plethysmography

Impedance plethysmography (IPG) is a safe and noninvasive method for measuring peripheral hemodynamics. This paper’s aim is to develop a medical device system for a continuous monitoring of this parameter using the impedance technique. This system combines the advanced analog amplifier with the calculation power of digital signal processing to acquire real time monitoring. Our bioimpedance measuring system uses a generator which is under microprocessor control. Experimental investigations are conducted in order to determine the optimum interrelation between current injector output characteristics, power supply and electrode spacing.

C. Corciova, R. Ciorap, R. Matei, A. Salceanu

Portable Complex PCG Signal Analyzer

There are many

PCG

signal characterization methods and algorithms but their practical implementation are yet limited. This paper presents a device that is more than a classical electronic stethoscope. Therefore the main goal is to make a signal characterization of the

PCG

signal and on that basis to be able to classify the acquired pathology information in accordance with a stored set of reference signals.

S. Gergely, M. N. Roman, R. V. Ciupa

Monitoring Neuromuscular Fatigue – A Noninvasive Approach

Monitoring neuromuscular fatigue in fighter pilots is important and with serious effects. The limit conditions the pilots are submitted to during flight missions make monitoring neuromuscular fatigue (NMF) extremely important, as NMF significantly increases the risk of accident and affects the pilot’s efficiency. We developed a noninvasive approach of monitoring the NMF, based on the compression of the Power Spectral Density of the SEMG (surface electromyogram) toward lower frequencies with increasing NMF, quantified by the Instantaneous Median Scale (IMedS) computed from SEMG via the Wavelet Transform. The Raa parameter (Area/Amplitude Ratio) computed on the SEMG was concurrently used. The paper provides a functional, practically oriented overview.

M. Tarata, W. Wolf, D. Georgescu, D. Alexandru, M. Serbanescu

Applications of the Hybrid Shielding in Biomagnetometry

The work presents the experimental results concerning the electromagnetic characteristics of a shielded room destined to bio-electromagnetism researches and to the utilization of a high resolution SQUID magnetometer. The experimental results regarding the dependence of the shielding factor on the applied field frequency are presented. The phase of the residual magnetic field and its dependence on the frequency of the external field has also been determined. The experimental results confirm the theoretical studies on the utilization of the non-ferromagnetic material shields.

M. C. Rau, O. Baltag, I. Rau

Linear Active/Passive Upper Limb Exerciser

The objective of this paper is to describe an original linear type exerciser for the rehabilitation of the upper limb. The presentation of the most important characteristics of rehabilitation is followed by an analysis of different variants of exercisers. The core issues on design of exercisers are emphasized and the studied exerciser is described. It has one degree of freedom, is pneumatically actuated, being dedicated to both active and passive exercises.

B. Chetran, D. Mandru, S. Noveanu, O. Tatar

Model of the Current-Voltage Relation for a Skin Pore

Using a Nernst-Planck model, we show that the current density in a membrane’s pore as a function of voltage has three types of behavior: a quasi-ohmic behavior at low voltages, with a small slope, a non-ohmic linear dependence at large voltages, with a large slope, and a nonlinear transition region at intermediate voltages. The magnitude of the quasi-ohmic current from low voltages depends mainly on the height of energy barrier inside the pore,

w

, through an exponential term, e

w

. The low voltages domain is experimentally accessible and almost unexplored, despite the fact that it can offer direct information about the energy barrier inside a pore. The model has only two assumed parameters, the energy barrier height,

w

, and the relative size of the entrance region of the pore,

r

, with a clear physical meaning, an important advantage for fitting and interpreting experimental data. This simple model for the current-voltage nonlinearity is a good starting point for explaining the electrical behavior of the skin at low voltages.

N. M. Birlea, S. I. Birlea, E. Culea

The Skin’s Electrical Time Constants

We have studied the electrical time constants of human skin potential in response to a constant current impulse (0.4-16 mA/100

μ

s). Three relaxation times were found with values in the range 10-40

μ

s, 100-200

μ

s and 1-4 ms. By correlating the time constants with the electrical model of the skin we found that stratum corneum has a nonlinear resistance that diminishes and a nonlinear capacitance that increases with increasing values of current.

N. M. Birlea, S. I. Birlea, E. Culea

Experiments in Electrotherapy for Pain Relief Using a Novel Modality Concept

The paper presents a novel concept in the modality of electrotherapy use for pain relief. The classical electrotherapy physiological effects for pain relief are critically reviewed with the objective to complement it with a systemic whole human body pain perception management model. A novel chaotic oscillator based modality concept is introduced and objectives defined. For two clinical sample cases chaotic models are associated for clinical trials on the basis of estimated best synchronization. The double pendulum chaotic oscillator model use in electrotherapy for energy waveform delivery is detailed.

P. Cevei, M. Cevei, I. Jivet

Double Stimuli Paradigms Should Be Careful Interpreted When Applying Lumbar Magnetic Stimulation

We investigated the neural structures activated by transcutaneous magnetic stimulation of the spinal cord, by examining the evoked electromyographic responses in the lower limbs. Only in few cases posterior root-muscle reflexes could be elicited by activation of the posterior root afferent fibers. Generally, M-waves were elicited by direct stimulation of the alpha motoneuron axons within the anterior root or spinal nerve. However, the double stimulus paradigm in the interpretation of the muscle responses by their refractory behavior was inefficient. Stimulation evoked strong contraction of the paraspinal muscles by the first stimulus and increased the distance between magnetic coil and the back during the second pulse, i.e. changed the stimulation conditions. To avoid misinterpretation of the data, additional neurophysiological methods to condition the responses should be applied for their identification, such as tendon vibration.

L. Darabant, M. Krenn, K. Minassian, M. Cretu, W. Mayr, R. V. Ciupa

Virtual Instrument for Early Detecting Dental Decay Using Electrical Impedance Measurement Method

The paper presents a virtual instrument used to diagnose dental caries using NI data acquisition device and LabVIEW software. We also use two electrodes to measure dental impedance and the results respect the domain literature. Combining hardware and software resources we obtain a flexible and versatile interface very friendly with the user (dentist). Compared to known methods our method is very simple, fast and does not cause pain to patient.

S. G. Lacatusu, M. Branzila, M. Cretu, D. Lacatusu, S. Lacatusu

Analysis of a Dexterous Instrument for Minimally Invasive Procedures, Based on Bellows Actuators

The paper presents a review of actuators for bio-mechatronic applications, especially for regionally bending of smart instruments for minimally invasive procedures. More detailed analysis was done for bellows actuators. For a system of three parallel bellows an FEM study was performed. For different acting pressures FE results were compared with the analytical solution. The obtained results validate the methods and open future works in this field.

C. Dudescu, D. Mandru

The Contribution of Technology in Cholangiocarcinoma Treatment

This article is a review of the principals techniques used in the treatment of cholangiocarcinoma, aims at identifying the most frecquent and valuable methods of therapy. Moreover, its purpose is to emphasize the role of high technology in the cholangiocarcinoma treatment. The multimodal approach in cholangiocarcinoma treatment, involving hepatobiliary surgery, endoscopic biliary or percutaneous drainage as well as other controversial therapies (for example, the photodynamic therapy) represent a progress in biliary tract tumors but at the same time requires an highly developed technology being an essential circumstance for obtaining good results. Thus, it can be said that top technology associated with highly qualified human resources opens a new horizon in cholangiocarcinoma treatment.

H. C. Neagos, F. Graur, O. Neagos, R. Elisei, A. Szasz, A. Muresan, L. Furcea, C. Iancu, N. Al Hajjar, O. Bala, D. Munteanu, C. Puia, L. Vlad

Medical Imaging, Image and Signal Processing

Non-invasive Steatosis Assessment through the Computerized Processing of Ultrasound Images: Attenuation versus First Order Texture Parameters

Steatosis is a frequent histological finding in patients with chronic hepatitis C virus (VHC) infection. Usual ultrasonography (US) cannot accurately detect the steatosis grade, nor can it always discriminate between steatosis and fibrosis. An improvement of usual US examination is currently under research. A possible approach might be the computerized processing of the data comprised in the US image. In the present paper we set out to compare the performance of two computerized methods for the steatosis assessment on the US images: the attenuation coefficient and the first order textural parameters (FO): Mean, Standard Deviation and Skewness. The attenuation coefficient correlated significantly with steatosis (r=-0.444, p<0.0001), but not with fibrosis (r=-0.046, p=0.395) or necroinflammatory activity (r=-0056, p=0.211). Of the FO parameters, only the FO mean correlated significantly with steatosis (r=0.300, p<0.0001), but also with necroinflammatory activity (r=0.128, p=0004). The present study proves that, in patients having chronic hepatitis C, the attenuation coefficient, but also the FO mean, can discriminate between different steatosis grades; however, the attenuation coefficient has a better performance than the FO mean, being influenced only by steatosis, not by fibrosis or necroinflammatory activity. The area under the ROC curve is significantly better for the attenuation coefficient as compared to the FO mean for the prediction of steatosis regardless of the grade (0.741 vs 0.652, p=0.001), as well as for the prediction of moderate/severe steatosis (0.791 vs 0.719, p=0.043).

M. Lupsor, R. Badea, C. Vicas, S. Nedevschi, H. Stefanescu, M. Grigorescu, C. Radu, D. Crisan

ECG Signal Baseline Wander Removal Using Wavelet Analysis

One of the most common problems of ECG recordings is the baseline wandering in the ECG signals during data collection. Baseline wander elimination is considered as a classical problem in ECG signal filtering. This paper presents two wavelet analysis (WA) based ECG signal baseline wander removal methods, The Discrete Wavelet transform based method uses a high level decomposition and eliminates the lowest frequency component. The wavelet packet based searching algorithm uses the energy of the signal in different scales to identify the baseline wander. The algorithm calculates the corresponding energy of wavelet packet coefficients at each scale. After a comparison, the branch of the wavelet binary tree corresponding to higher energy wavelet spaces is chosen. These procedures are tested using specific data records.

Z. German-Sallo

Emotion Investigation Based on Biosignals

In this paper a physiological signal-based emotion recognition approach is presented. The input bio-signals are electromyogram, electrocardiogram, skin conductivity and respiration change. The feature vector is extracted from each signal type by using the same technique based on wavelets and TESPAR DZ method. A Support Vector Machine (SVM) classifier was employed to distinguish among four emotional states: joy, anger, sadness and pleasure. The database employed in our experiments is the AuBT corpus.

E. Lupu, S. Emerich, R. Arsinte

Multirate Sampling in PCG Signal Correlation

The complex structure of

PCG

signals make them difficult to characterize in an automated approach. This paper presents a method used in

DSP

signal cross-correlation by using a pattern recognizing algorithm based on multirate signal processing of the acquired

PCG

signals.

S. Gergely, M. N. Roman, C. Fort

EMG Signals Case Study: A Time and Frequency Domain Analysis

The paper aims to analyze the time and frequency domains of EMG signals coming from healthy patients and from patients with muscular disorders (muscular myopathy and neuropathy). The study of these signals can reveal some features in time domain or in frequency domain, that can serve as a basis for diagnosis.

M. Munteanu, C. Rusu, D. Moga, R. Moga, G. Tont

Medical Image Diagnosis Based on Rough Sets Theory

This paper proposes the utilization of rough set theory for modeling the medical images to help physicians in diagnosing. The rough set theory is a powerful approach that permits the searching for patterns in medical images using the minimal length principles. Searching for models with small size is performed by means of many different kinds of reducts that generate the decision rules capable for identifying the medical diagnosis.

A. L. Ion, S. Udristoiu

On the Stability and Convergence Rate of Some Discretized Schemes for Parametric Deformable Models Used in Medical Image Analysis

In order to find the energy-minimizing surface and to reduce the computational requirements, we consider an associated simplified model, [1], and we derive an algorithm for solving numerically the corresponding Euler-Gauss-Ostrogradsky equation of Calculus of Variations. The stability and the convergence of the algorithm are discussed, together with some aspects regarding the statistical modeling, applied in medical imaging.

A. I. Mitrea, O. M. Gurzau, P. Mitrea

Texture-Based Methods and Dimensionality Reduction Techniques Involved in the Detection of the Inflammatory Bowel Diseases from Ultrasound Images

The inflammatory bowel diseases (IBD) are severe, chronic and recurring disorders, requiring continuous patient monitoring. The most reliable methods for the diagnosis of the inflammatory bowel diseases are invasive (endoscopy, colonoscopy, histopathology) or irradiating (CT). We aim to develop computerized methods for the noninvasive assessment of the bowel inflammation level based on information obtained from ultrasound images. In this work, we study the role of the textural parameters in characterizing different types of inflammatory bowel diseases and the colorectal tumors. The dimensionality reduction techniques are taken into consideration in order to obtain the relevant textural features and to improve the result of the automatic diagnosis. The Principal Component Analysis (PCA) method and the Correlation based Feature Selection (CFS) method, as well as their combinations, are assessed for this purpose. The methods of Support Vector Machines (SVM) and Multilayer Perceptron (MLP), which gave very good results in our former experiments, are implemented for the automatic diagnosis. B-mode ultrasound images belonging to biopsied patients, are used. The patients were suffering from the following types of diseases: Crohn’s disease, ulcerative recto-colitis, colo-rectal cancer.

D. Mitrea, P. Mitrea, R. Badea, M. Socaciu, L. Ciobanu, A. Golea, C. Hagiu, A. Seiceanu

Computer Assisted Optical Podoscope for Orthostatic Measurements

Extensive static and dynamic foot problems in modern society are a direct consequence of the lifestyle of the individual. Continuous use of transportation, prolonged periods of physical inactivity and obesity modify the normal structure of the foot in time leading to traumatic disorders. Correctly assessing the plantar pressure and identifying potential problems due to the unbalance of the foot structure are key factors in preventing and treating of conditions such as flat feet, high arches, bunions, hammertoes, plantar fasciitis etc. The research leading to this paper addresses these issues and a low cost computer aided optical podoscope is presented. With the use of modern computational systems, patient information can be analyzed, stored and compared and visual pressure points can be linked to accurate measurements when body mass and touch areas are known. By combining different illumination techniques the effects of the environment lighting are diminished and the images of the foot interaction with the sensitive surface increase in resolution. Moreover, the pressure information can be separated or connected to the rest of the foot allowing for better visual identification of the static and dynamic foot problems.

S. Crisan, V. D. Zaharia, C. Curta, E. D. Irimia

Digital Microscopy Used in Synthetic Structures Analysis of Dental Prosthesis

In this paper we present some aspects related to the analysis of surface quality for dental materials obtained by synthesis (photo-polymerization) process. In the first part, the biocompatibility properties of dental materials are analyzed, using Fuzzy logic. In the second part, the images obtained from the digital microscope with 500x of magnification, of some samples made of photo-polymerizable materials are analyzed using software dedicated to image processing. The results of these procedures are presented in a modular way in order to highlight both the 3D surface profile and the shape of roughness variation along the selected direction on the studied surface. In the final part of the paper we presented some conclusions both concerning the mechanical tests and images analysis.

M. Baritz, D. Cotoros

Modelling and Simulation

Robustness Tests of a Model Based Predictive Control Strategy for Depth of Anesthesia Regulation in a Propofol to Bispectral Index Framework

This paper verifies the robustness of a model based predictive control scheme for depth of anesthesia (DOA) regulation. The manipulated variable is Propofol, which is used in a Model based Predictive Control (MPC) algorithm for automatic induction and control of DOA. In turn, DOA is evaluated by means of the Bispectral index (BIS). The simulation tests are performed on a set of 17 virtually generated realistic patients with significantly varying sensitivity to Propofol infusion. The results show a high-efficiency, optimal dosage and robustness of the MPC algorithm to induce and maintain the desired BIS reference while rejecting typical disturbances from surgery.

C. M. Ionescu, I. Nascu, R. De Keyser

An Overview on Mathematical Models of Human Crystalline Lens

To describe the human crystalline lens, mathematical models are required. Advanced mathematical models are applied for human vision studies and biomechanical behavior of the crystalline lens. The accurate modeling of the crystalline lens is important in the development of intraocular lenses. This paper presents an overview of researches for human crystalline lens modeling using mathematical models.

S. Talu, S. Giovanzana, S. D. Talu, M. Talu

Mathematical Analysis of the Human Crystalline Lens in Giovanzana Parametric Model

The objective of this paper is to present a mathematical analysis of the human crystalline lens in Giovanzana parametric model. This model can serve to improve computational modeling, such as finite element modeling of the human crystalline lens.

S. Talu, S. Giovanzana, M. Talu, S. D. Talu

On Approximation of Human Corneal Surface with Superellipsoids

The objective of this paper is to present results of the theoretical and experimental researches for determination of an approximation of human corneal surface with superellipsoids using computational geometry. The mathematical formula permits a complex representation and the tool allowing exploring the physical and optical characteristics of the cornea. The spatial shape of the cornea can be described using different mathematical models with particular parameters for different subjects (women and men). These researches are applied in geometric constructions and computer aided design used in corneal refractive surgery, human vision studies, solid modelling and biomechanical behavior of the cornea.

M. Talu, S. Talu, S. D. Talu, R. Shah

Numerical Simulation of Thrombus Aspiration Catheter: Preliminary Results

Thrombus aspiration is one of the available therapies for the treatment of thrombosis diseases. It is an effective option especially in the case of early stage clot formation. Nowadays there is a major research effort to improve catheter design in term of ease of use, less drawback and higher efficiency. The main aim of this study is to consider the performance of a standard catheter and predict the behavior of clot during the aspiration phase using computational fluid dynamics (CFD) techniques. Three cases are modeled and compared one another to assess catheter performance and efficiency according to different rheological models for the clot. In the first case the clot is considered to be Newtonian with early stage coagulation and no surface tension, in the second case the clot exhibits higher viscosity due to the longer time passed after coagulation, but it has not surface tension, in the third case the clot is assumed to be Newtonian which is formed in early stages of coagulation but has surface tension. In all cases clot is assumed to behave like a viscous fluid.

S. Soleimani, G. Pennati, G. Dubini

Developing a Lumped Model for the Vestibular Receptors

Researching on the vestibular-sympathetic reflex mechanism requires as an intermediary step to establish a lumped model for the Vestibular Receptors. Knowing that Otolith Organs and Semicircular Canals are sensing changes in the head velocity on 6 degrees of freedom, the purpose of this paper is to set up models for both types of receptors, branching them into Regular and Irregular subcategories, and to consider a certain convergence of their outputs. The developed model for the Vestibular Receptors is tested in the sit to stand orthostatic stress scenario.

A. Codrean, A. Korodi, I. Jivet, T. -L. Dragomir

Integration of the Calcium Dynamics in the Excitation Contraction Coupling Process within a Multiscale Model of the Left Ventricle

The description of multiscale processes in a unified and coherent fashion is of paramount importance in cardiovascular computational physiology. In this paper, a model that links the process of cardiac excitation and contraction from a cellular to a tissue level will be presented. A model of the action potential will be linked to the kinetics (attachment and detachment) of the proteins responsible for cardiac contraction (via the so called “crossbridges mechanism”). As a final step, the coupling of the calcium-dependent kinetics model to a higher-scale model of the left ventricle will complete the multi-scale model of cardiac dynamics from the sub-cellular level to the organ.

B. Bhattacharya-Ghosh, S. Schievano, V. Díaz-Zuccarini

Biomechanics of Noncarious Cervical Lesions

Noncarious cervical lesions (NCCLs) restoration represents a unique clinical situation due to their multifactorial etiology. Though the mechanical theory of cervical lesions formation is widely accepted, its mechanism is not fully understood. The incidence of NCCL refers to the facial and oral aspects of the teeth. Finite Elements Method (FEM) were drawn up, applied with various occlusal forces and analyzed in order to observe the stress distribution. The standard biomechanical unit involves restorative material, tooth structure and interface between the restoration and tooth. The purpose of this study was to examine the NCCL formation caused by occlusal forces and the behavior of restored and unrestored lesions.

G. Beresescu, L. C. Brezeanu

Modelling the Development of In-Stent Restenosis: Preliminary Results of a Structural Model

Coronary artery diseases are at present commonly treated by minimally invasive treatment such as intravascular stents. However, such treatment is compromised by in-stent restenosis, a re-narrowing of the artery related to the injury of the vessel wall as a result of the local stress caused by the stent struts. The aim of this study is to develop a computational model to represent this tissue growth in a finite element model of a stented coronary artery.

A 1/6 symmetry section of a coronary artery was generated within ANSYS Mechanical APDL version 12.0 (ANSYS Inc.). A ‘ghost’ finite element mesh was used to represent the region of the vessel where neointimal growth is expected to occur. The model was used to assess the influence of the initial strain in the neointima on the stress state within the vessel under subsequent pulsatile pressure loading.

These results suggest that, if the proliferative response within the neointima is related to local stress, some initial strain must be present during the deposition of the tissue. A validated model has the potential to reduce the occurrence of restenosis through improved understanding of stent/artery interactions.

C. M. Amatruda, D. R. Hose, P. V. Lawford, A. J. Narracott

In Silico Evaluation of Some Dihydroxamic Derivatives of Diphenylether, as Hybrid Hydroxamic-Allosteric Inhibitors for MMP13

Synthetic inhibitors for MMPs may become effective if they include a functional group as hydroxamic acid, carboxylic acid, sulfhydryl, etc. capable of binding the catalytic Zn, while at least one functional group provides a hydrogen bond interaction with the enzyme backbone, and one or more side chains will undergo effective van der Waals interactions with the enzyme subsites.

Due to the fact that previous clinical trials that have used small inhibitor molecules and especially hydroxamic derivatives (batiamastat, marimastat) have shown poor clinical results and even malignancy rebound, the next generation of MMP inhibitors is directed toward exodomain-substrate interactions.

In the present study we have docked both known and experimentally tested inhibitors and also new proposed inhibitor models. Then we have compared binding affinities of the known compounds with those of three newly proposed ligands.

The purpose of this study was evaluate the affinity degree of these hypothetic hybrid inhibitors for the catalytic domain of MMP13.

The docking study performed with the open source software Autodock Vina, have generated promising results regarding the possibility to propose hypothetical but potent hybrid hydroxamic-allosteric inhibitors for the catalytic domain of MMP. Interactions between the newly proposed ligands and the catalytic site of MMP13 show new interesting alternative options for tunnel-like catalytic site enzymes. It appears that the direct Zn ion coordination is not solely responsible for enzyme inhibition but also allosteric inhibition may play an important role.

Our results show that the proposed inhibitors, nominated as ligands 3, 4 and 5, mainly dihydroxamic derivatives of diphenylether, has both hydroxamic potency but als the ability to perform allosteric inhibition at least for MMP13 catalytic site.

Further studies will consider evaluation of these theoretical inhibitors by docking on other MMPs with different S1’ pockets. Regarding the proposed extended docking studies, we suppose that the synthesis of ligand-5 and the experimental data should confirm our molecular docking results.

T. Petreus, C. E. Cotrutz, B. Stoica, M. Neamtu, P. D. Sirbu, A. Neamtu

The Effectiveness of Interactive Clinical Case Study Simulation in Palliative Medicine

The medical students’ interest in case studies used as an instructional strategy in modern medical education and in teaching tools like virtual patients and simulations is growing. Professional skills and knowledge about palliative care are widely accepted to be deficient and the medical care in palliative care settings remains inadequate. Reduced student-patient contact times in hospitals, mainly in palliative care settings with progressive chronic disease patients and increasing cost of technology means generated the need to create innovative methods that help students develop their clinical skills. Palliative medicine interactive clinical case study simulation (ICCSS) offers a cost-effective method to measure the impact of this virtual instructional tool on the students’ clinical skills. It helped us to measure and compare their choices made in diagnosis, treatment, and follow-up process prior and after an educational module in palliative medicine. By simulating the most common patient profiles for palliative medicine, the interactive clinical case study simulation (ICCSS) allowed us to record the students’ diagnostic and treatment decisions, to show the likely outcome of each decision, and to provide individualized feedback to identify and correct inappropriate decisions.

The interactive clinical case study simulation (ICCSS) can be successfully integrated with face-to-face teaching in palliative medicine like a supportive and innovative educational method.

M. Florea, M. Crisan, M. Gherman, R. Manasia

Stent Fracture Prediction in Percutaneous Pulmonary Valve Implantation: A Patient-Specific Finite Element Analysis

The major limitation of the current percutaneous pulmonary valve implantation (PPVI) device is stent fracture. In this study, patient-specific analyses were developed to reproduce the realistic loading conditions experienced by the device

in-situ

, in order to predict fractures.

Biplane fluoroscopy images of 5 patients who underwent PPVI and experienced fracture were used to reconstruct the 3D

in-situ

device geometry at 3 different times of the procedure and cardiac cycle (end of balloon inflation, early systole and diastole). From the superimposition of these 3 stent configurations, the displacements of the strut junctions of the stent were measured. Asymmetries were calculated in all 3 orthogonal directions for every instant reproduced.

A finite element (FE) model of the stent in the initial crimped configuration was created. The previously measured displacements were applied to 2 nodes of the FE stent model in the corresponding strut junction, and the stent deployment history was reproduced for each patient. A fatigue study was performed using the Goodman method and the Sines criterion. Both these methods were able to predict stent fracture in every analysed case. Furthermore, the zones with the highest risk of fracture predicted by the simulations included the areas where fractures were actually detected from X-rays images.

D. Cosentino, C. Capelli, G. Pennati, V. Díaz-Zuccarini, P. Bonhoeffer, A. M. Taylor, S. Schievano

The Study of Massive Trochanterion Fractures

This paper studies the massive trochanterion fractures using two methods of fixation, namely DHS (Dynamic Hip Screw) and Gamma rod. The analysis is carried out both experimentally (photoelasticimetry and tests on human femur) and numerically (finite element method).

A. I. Botean, I. A. Takacs, M. Hardau

Multi-physics and Multi-scale Computational Evaluation of the Thrombogenic and Cavitational Potential of a Bileaflet Mechanical Heart Valve

The paper presents a multi-physics and multi-scale modeling approach on the closure dynamics of a bileaflet prosthetic heart valve. The modeling methodology consists of coupling a multi-scale model of the left ventricle contraction to a 3D CFD-FSI model, in order to investigate the closure of a cavity pivot bileaflet valve. The rebound motion of the valve is also modeled. The potential of the valve to generate thrombogenic and cavitation effects are assessed on the basis of the duration for which the blood flow is exposed to elevated wall shear stress, large negative pressure transients and increased flow vorticity. A special attention is given to the flow field in the hinge region of the valve.

R. K. Nallamothu, Yan Li, D. R. Rafiroiu, V. Díaz-Zuccarini, A. J. Narracott, P. V. Lawford, D. R. Hose

CFD Analysis Study on the Impact of the Coronary Anatomy on the Efficiency of the Coronary Thrombectomy: The Effect of Bend Angles

Primary percutaneous coronary intervention is effective in opening the infarct-related artery in patients with myocardial infarction with ST-segment elevation. However, the embolization of athero-thrombotic debris induces micro vascular obstruction and diminishes myocardial reperfusion. The aspiration catheter’s design, the coronary anatomy and the physical properties of the thrombi are key factors in ensuring a successful interventional procedure.

The aim of our study is to use computational fluid dynamics (CFD) analysis for assessing the impact that the thrombus age and the coronary anatomy might have on the aspiration efficiency. A generic model of an Export AP (Medtronic) catheter tip was created and extended with distal shafts having different bend angles. Double bended catheter shafts were also considered. A two-phase CFD model with different values for the viscosity of the thrombus was implemented in ANSYS-CFX, allowing us to explore the impact of the viscosity on the efficiency of the aspiration.

Some authors have recently used

in

 − 

vitro

tests for exploring the impact of the bends angles and thrombus age on the efficiency of some commercial thrombus aspiration devices, including the Export catheter.

Based on a fundamental study we tried to look for some explanations for their findings.

Yan Li, R. K. Nallamothu, D. Rafiroiu, A. Iancu, V. Díaz-Zuccarini, A. J. Narracott, D. R. Hose, P. V. Lawford

Magnetically Targeted Drug Transport and Fixation

This paper presents a mathematical model and numerical simulation results on transport and targeting of a medical substance carried by magnetic nanoparticles through a high gradient magnetic field. In our study we use simpler yet consistent models for the hemodynamic flow, and more complex, realistic computational domains based on medical images for the iliac arterial branching. The biocompatible drug carrier is injected in the blood. An optimized array of permanent magnets generates the targeting magnetic field, in the process of medication delivery in the region of therapeutic concern.

A. A. Dobre, A. M. Morega, M. Morega

3D Simulation Analysis of Transcranial Magnetic Stimulation

This paper presents the results from a simulation of Transcranial Magnetic Stimulation using realistic brain model. The simulation found some interesting results regarding the distribution of the electric field induced in the cortex.

C. Curta, S. Crisan, R. V. Ciupa

The Romanian Public’s Perception of Electromagnetic Fields Risk

Potential health risks from exposure to electromagnetic fields (EMF) are a hot topic in recent environmental health research. The aim of this survey is to help understanding of the perception that the Romanian public has upon the links between electromagnetic fields and health. Nervousness/restlessness, headache and sleep disturbances were the most often reported symptoms and power lines, mobile phones, microwave ovens, computers and TV screens were perceived as the main EMF sources suspected to be associated to symptoms. The general results show that the level of knowledge about the event increases the concern about risks incurring from it. Population’s information level was strongly related to level of perceived risk, growing concern about EMF.

D. Curseu, M. Popa, D. Sirbu

Consequences of a Stenosed Artery in an Arteriovenous Fistula on the Efficiency of the Hemodialysis Access

An arteriovenous fistula (AVF) is a surgical vessel connection between an artery and a vein. It is created in end stage renal disease to provide adequate blood access for hemodialysis. In the present study, the local hemodynamics is investigated in a patient-specific AVF using a computational fluid structure interaction (FSI) simulation. The fluid and solid governing equations are solved using ANSYS (ANSYS, Inc.).

We focus on an end-to-side AVF between the end of the cephalic vein and the brachial artery. The geometry of the vessel lumen is obtained from CT-scan angiography. The vessel wall is modeled as a monolayer of shell elements of uniform thickness, since the actual wall thickness cannot be obtained from medical images. We investigate the effect of the presence of a severe stenosis upstream of the anastomosis by comparing two different geometries: model 1 consists of the complete patient-specific AVF, presenting a stenosis inside the proximal brachial artery and an enlargement at the cephalic vein; model 2 is obtained from model 1 by substituting the stenosed artery with a straight cylinder. For both models, a physiological time-dependent velocity inlet profile and flow-dependent resistive pressure outlets are imposed as boundary conditions. The hyperelastic, 3

rd

-order Yeoh model is used as constitutive law to model the vessel wall.

The presence of the stenosis increases the mass flow through the cephalic vein by 9.6%, which could have a positive effect on the hemodialysis access in terms of flow rate. However, the stenosis causes an enlarged area of the vein subjected to low wall shear stresses and high oscillatory shear indices, which are risk factors for atherosclerotic plaque and neointima formation.

I. Decorato, Z. Kharboutly, C. Legallais, A. V. Salsac

A Method to Increase the Pulsatility in Hemodynamic Variables in an LVAD Supported Human Circulation System

Left Ventricular Assist Devices (LVADs) generally operate at a constant speed in the human body. This causes a decrease in the pulsatility of hemodynamic variables. To increase the pulsatility a stepwise change was applied to the LVAD operating speed over a cardiac cycle. To do this, a numerical cardiovascular system model and a pump model were used. The model was developed by considering the static characteristics of the MicroMed DeBakey LVAD. First, the simulations were performed at constant operating speeds, 8500 rpm, 9500 rpm and 10500 rpm. Pulsatility indexes were calculated for left ventricular (LV) pressure, aortic pressure, LV volume and LVAD flow. Cardiac output (CO) was calculated at constant operating speed and these values used for comparing the pulsatility indexes with stepwise and constant operating speeds. The LVAD was operated at two different constant speeds in the stepwise operating speed simulations. Low and high operating speeds were adjusted so as to obtain the same cardiac output values with the constant operating speed simulations. The operating speeds in the simulations were 7800-11250 rpm, 9300-11250 rpm and 10300-11250 rpm. The same cardiac output values were obtained with an increase in the pulsatility of the hemodynamic variables without significant changes in their shapes except the LVAD flow. The obtained results show that it is possible to obtain more physiological results by applying a stepwise change to LVAD operating speed over a cardiac cycle.

S. Bozkurt, K. A. M. A. Pennings, S. Schampaert, F. N. van de Vosse, M. C. M. Rutten

Blood Flow Analysis in Portal Vein System – Unsteady-State Case Study

Anatomical features and a complex vascular system characterize the liver. The blood flow results as a complex interaction between fluid, vascular system complex geometry and liver functional and structural features. The disease presence produces pathological changes that may induce hemodynamic perturbations not only due to geometry modification but especially due to liver perfusion alteration. The analysis of the blood flow dependence on the geometry variability in physiological condition could emerge in its parameterization and quantification. This may eliminate the confusion between blood flow modification due to geometry variability in physiological conditions and flow alteration due to pathological conditions or congenital anomalies presence.

In this paper the analysis focuses on portal vein system and consists in blood flow analysis under unsteady-state conditions. The study involves the investigation of 12 patients by MRI techniques followed by 3-D portal vein system geometry acquisition, blood flow simulations based on mathematical models that include constitutive equations describing the hemodymanics and its relations with the deformable vessels wall. The computational technique applied to model the blood flow approaches both the velocity field and the pressure field. The vessels wall was considered elastic, coupling in this way the vessel/wall deformability problem.

The blood flow analysis in physiological conditions enables the improvement of understanding of the complex blood flow behavior in the portal vein system; enables to identify critical information and to parameterize the domain of normal portal vein circulation.

C. C. Botar, A. Bintintan, P. S. Agachi, S. Clichici, P. Mircea, S. Sfrangeu

A Review of Atherosclerosis and Mathematical Transport Models

The mechanisms and definitive predictive components involved within the clinical initiation and formation of atherosclerosis remain elusive as of yet. Over the years, established fluid and mass transport theories and experimentally agreed upon vasoactive agents have contributed towards a boom of predictive mathematical models concerning atherogenesis. This paper aims to elucidate currently utilized theories available regarding initiation of atherosclerotic proliferation and provide a brief review of available mathematical transport phenomenon models which utilize these theories.

B. Keller, F. Clubb, G. Dubini

Molecular Bioengineering

Low-Field Nuclear Magnetic Resonance Relaxometry – A Tool in Monitoring the Melting Transition of Polymeric Capsules with Applications in Drug Delivery

Polymeric micro and nanocapsules are often used as drug delivery systems. Their main advantage is that the active substances can be placed inside the capsule and released at the position of the diseased tissue or organ. The release can be performed gradually, owing to a continuous exchange process, eventually influenced by temperature, or suddenly as a consequence of melting the capsule wall. In the last case the determination of the melting transition temperature of the fabricated capsules is an important issue. In the present contribution we are showing that low field nuclear magnetic resonance (NMR) relaxometry can be used as a valuable tool in monitoring the melting transition of polymeric capsules prepared by an interfacial polymerization technique. The NMR relaxation experiments were performed at a proton resonance frequency of 20 MHz. The data were analyzed using a numerical Laplace inversion algorithm that allowed us the determination of the melting point for the fabricated capsules.

R. E. Nechifor, I. Ardelean

Study on Cellulose/Chondroitin Sulfate Hydrogel Used in Drug Release Systems

The aim of this study was to combine the properties of cellulose and chondroitin sulfate in mixed hydrogels in order to obtain new materials for medical and pharmaceutical applications as drug delivery systems. Different swelling profiles and active drug release rates were observed for the proposed formulation compared with pure cellulose hydrogels. Along with this aim, hemotoxicity and subcutaneous implantation experiments had been performed showing a good biocompatibility of the studied hydrogels.

C. G. Coman, M. Al. Macsim, A. M. Oprea, L. Hurjui, T. Petreus, A. Neamtu

Timelapse Monitoring of Cell Behavior as a Tool in Tissue Engineering

Tissue engineering is a research field in biomedicine which has evolved rapidly during the last two decades. It is based on the isolation of cells, their proliferation

in vitro

on a scaffold, followed by the implantation of the construct inside a living organism. Each of the main elements from a tissue engineered construct – cells, scaffold, signaling molecules – has a vital role in assuring the desired characteristics and proper functioning of the whole structure. In order to ensure a normal healing process and no adverse reactions, biocompatibility tests have to be performed in complex experiments needing sophisticated equipments. Two such equipments are presented in this paper: BioStation IM, a microscope that allows capturing images by timelapse videomicroscopy, and xCELLigence, an instrument which determines cell impedance as a measure of cell adhesion, spreading, migration and proliferation. The usefulness of these two equipments in tissue engineering research is discussed

C. Niculiţe, M. Leabu

Clinical Experience with a Macroporous Synthetic Bone Substitute (Eurocer®) in the Treatment of the Patients with Bone Defects

The treatment of bone defects was a major challenge and may still be a problem today. Due to the disadvantages with biologically bone grafts there is a high clinical demand for synthetic bone substitution materials. The aim of this prospective study is to reveal biocompatibility integration and extension of osseous healing for a biphasic synthetic ceramic bone substitute (Eurocer), when used in the treatment of 31patients with 33 bone defects (fractures, nonunions, osteoarthritis). Eurocer® (FH Orthopaedics France) is an osteoconductive ceramic material representing a mixture of 55% hydroxyapatite and 45% tricalcium-phosphate and is available in granular form and in various geometric shapes. The authors used GESTO (Greffes et Substitutes Tissulaires en Orthopedie) protocol for preoperative selection and postoperative follow-up. The mean defect volume for all defects treated with Eurocer was 12cc. According to the size and type of defects the authors used Eurocer® as a single component or mixed with autologous bone graft. Stabilization was achieved by internal fixation in all operation except one (a fracture of humeral head). We have used for osteosynthesis classic plates or plates with angular stability, especially in compression fractures associated with osteoporosis. All patients have been followed-up clinically and radiologic for 2, 3, 4, 6, 9, 12 and 18 months post-operative. The mean time to clinically healing was 3.2 months while the mean time to radiographic healing was 4.5 months. We observed no implant fragmentation and no local inflammation or sepsis. Due to minimally invasive surgery and fast rehabilitation, no joint stiffness or limited joint motion was recorded. This prospective study demonstrates that the biphasic synthetic ceramic material Eurocer® is an effective bone graft substitute for usage in patients with bone defects. To insure a consistent result it is mandatory to strictly follow the three requirements for osteoconduction: proximity, viability and stability.

P. D. Sirbu, T. Petreus, Fl. Munteanu, M. Pertea, S. Lunca, V. Poroch, P. Botez

A Customized Dot Plot Analysis for Alpha Satellite DNA Localization

Numerical representation of genomic signals is very important as many of the methods for detecting repeated sequences are part of the digital signal processing field. An original nucleotide sequence representation and a mapping algorithm are used to provide a single numerical sequence for DNA repeats detection which includes information about repeats length. A customized dot plot analysis was used to estimate position of repeats, using two methods of estimating similarity between numerical subsequences. These approaches were combined to isolate position and length of DNA repeats from human alpha satellite DNA.

G. P. Pop, A. Voina, E. Onaca

Biomechanics

Comparison of Treadmill-Based and Overground Gait Analysis

This preliminary study was designed to assess the feasibility of gait analysis on a treadmill allowing multiple steps recording at a constant velocity, based on a comparative analysis between treadmill and overground gait. The measurements were realized using Zebris measuring system CMS-HS and a commercially available Hammer Walkrunner Pro Treadmill. One young volunteer (male, 24 years old) with mild instability of left ankle was involved in the study. To evaluate the spatio-temporal and kinematical parameters, the investigated subject performed gait with self-selected velocity both on the treadmill and overground. The main spatio-temporal parameters which have been analyzed are stance and swing phase, stride time, cadence, and velocity. The studied kinematical parameters were the flexion-extension angles of the hip and knee joint, and dorsi- plantar flexion angles of the ankle joint. The comparison of the kinematic parameters was focused on the left limb joints. The walking disorder of the patient has influenced both the kinematic parameters and gait symmetry.

D. I. Stoia, M. Toth-Tascau

Influence of Treadmill Velocity on Gait Characteristics – Case Study of a Patient with Ankle Instability

The paper proposes a treadmill-based gait study in three particular cases of walking velocity. This study was designed to assess the feasibility of extended gait analysis on a treadmill in relation to the treadmill velocity. The measurements were realized using Zebris measuring system CMS-HS and a commercially available Hammer Walkrunner Pro Treadmill. One young volunteer (male, 24 years old) with mild instability of left ankle was involved in the study. To evaluate the spatiotemporal and kinematical parameters, the investigated subject performed treadmill-based gait with three velocities. The main spatiotemporal parameters which have been analyzed are stride time, cadence, double support time, and velocity. The gait symmetry was also analyzed based on the symmetry of the swing and stance phases between the lower limbs and pelvis obliquity. The studied kinematical parameters were the flexion-extension angles of the hip and knee joint, and dorsi- plantar flexion of the ankle joint. We concluded that higher velocity leads to a lower variability of the gait parameters, while accurate recordings and interpretations of the human gait are achieved when the subject is waking with lower velocity closer to his normal walking speed.

M. Toth-Tascau, D. I. Stoia

Assisted Scanning Techniques Optimization with Application in Biomechanics

The paper presents a software interface dedicated to indicate the proper method used for the scanning different complex models with application in Biomechanics, like orthopedic orthesis. There is described the way in which certain physical models with application in Biomechanics were scanned using two different methods. The results on the scanning precision were synthesized as statistics into a software application created by us for this reason. Finally a conclusion about the proper scanning method depending on Biomechanics application can be obtained and established for our further research.

B. C. Braun, I. C. Rosca, C. N. Druga, M. Ionescu

Statistical Analysis of Anthropometric and Physiologic Performance of the Hand

All the experiments are, and should be, based on a strong statistical analysis that give a generalization of the cases experimented. This article is about the statistical analysis of data obtained from a population formed by 200 subjects mean aged of 20 years composed from 116 masculine gender and 91 of feminine gender. These subjects have been analyzed anthropometrically and physiologically. The experiment is looking forward to build up a database consisting of enough data to establish the base for a study regarding the physiology and anthropometry of the upper limb, especially the hand. It would statically evaluate and determine the physiologic limits of the upper limb according to some parameters took into consideration. This study can be useful to guide the production of prosthesis and orthotics, adapted to the upper limb. The study was taken at Transilvania University of Brasov.

I. Serban, M. Baritz, I. C. Rosca, L. D. Cotoros

Determining the Center of Pressure Trajectories during Lumbar Spine Flexion

The paper presents a preliminary study on a healthy female, performing back flexions, while standing on a force platform. The goal of the paper is to quantify how lumbar spine flexions influence the plantar center of pressure (CoP) distribution. Using Zebris CMS-HS ultrasound-based motion analysis system and FDM measuring system for force distribution the range of motion of lumbar spine flexion and CoP displacements during fully forward flexion were assessed simultaneously. Results showed a close symmetrical distribution of ground reaction forces on each subject foot.

M. Toth-Tascau, C. Saftescu-Jescu, D. Bugariu, L. Bereteu

CAD Methods for Orthopedic Orthosis Prototyping

This paper presents an important stage of our research on finding an efficient and low cost method for the modeling and prototyping on orthotic elements with applications in biomechanics.

Specifically CAD modeling is presented on the stage of the elements that will compose a family of plantar orthosis for locomotion and posture correction of certain human subjects who exhibit different locomotory diseases.

As a result of our research until now, we could identify the optimal method to scan the subjects’ feet, regarding the costs, accuracy and scanning duration. From this it was possible to establish an efficient and proper procedure for the CAD modeling on the plantar orthotic items, the negative surface of the scanned human subject’s being considered as reference.

B. C. Braun, I. C. Rosca, I. Serban, C. Coblis

Early Functional Results after Volar Fixed-Angle Plating of Distal Radius Fractures

Aim of the study was to evaluate the short term results and rehabilitation period after distal radius fractures treated with a volar locking plate and screws. 10 patients with unstable fractures of the distal radius were included in the study. Radiological and functional results were evaluated at 2 and 6 weeks postoperatively which showed no redisplacement of the fracture and faster rehabilitation than with other methods of treatment.

A. Todor, A. Pojar, C. Arghius, D. Lucaciu

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