A NOVEL DESIGN AND DEVELOPMENT OF A SINGLE CHANNEL INTEGRATED DIGITAL BODY SOUND DATA ACQUISITION DEVICE

Ali Alouani, Omar Elkeelany and Mohammed A. S. Abdallah

This paper discusses the design, development, and testing of an integrated compact digital stethoscope capable of performing body sound measurement and processing without the need of a personnel computer and hardware interface. The cost of the proposed device is a fraction of that of the data acquisition system used with current digital stethoscopes to collect body sound, such as lung sound, in a digital format. Preliminary testing of the device shows faithful reproduction of the body sound signals used. Not only the new design strategy saves hardware, space, and power consumption; it allows for the signal processing and data interpretation in the same device. This is due to the proposed integrated design of the subsystems involved in the data acquisition process. It also has the capability of sending collected data to remote location through the Internet.

METHODOLOGY AND SYSTEM OF EVALUATING THE DRIVER’S VIGILANCE LEVEL IN AN AUTOMOBILE TRANSPORTATION EXAMINING BOTH PHYSIOLOGICAL AND MECHANICAL DATA

A. Giusti, C. Zocchi and A.Rovetta

This paper deals with the methodology followed in order to design a new intelligent system to improve the driver’s safety in an automobile transportation and the actual realization of a first prototype. The results of the study are reported. A simulator system has been developed at the Robotics Laboratory of the “Politecnico di Milano”. A description of the necessary hardware and architecture is made in detail. Driver’s physiological data, acquired from sensors on the wheel, is correlated, using statistical multivariate analysis, with his/her vigilance level evaluated using polysomnography. This statistical model is applied on the data off-line in order to define a controller, to be applied on real time acquired data. The platform’s mechanical data is also acquired and studied. All the elaboration of the data results in one vigilance level index for the current driver and situation. Future steps and possibilities are also discussed.

DIFFERENTIAL ELECTRIC FIELD SENSITIVE FIELD EFFECT TRANSISTOR - Characteristics, Modeling and Applications

Yehya H. Ghallab and Wael Badawy

This paper presents the Differential Electric Field Sensitive Field Effect Transistor (DeFET) as a CMOS electric field sensor. The DeFET is based on a standard 0.18-µm Taiwan Semiconductor Manufacturing Company (TSMC) CMOS technology. This paper also presents the DeFET’s DC and AC models. The experimental and simulation results which validate the different models of the DeFET are presented. Moreover, some applications of the DeFET on the biomedical and lab-on-a-chip are presented.

EFFICIENT EVALUATION OF THE INFLUENCE OF ELECTRIC PULSE CHARACTERISTICS ON THE DYNAMICS OF CELL TRANS-MEMBRANE VOLTAGE

N. Citro, L. Egiziano, P. Lamberti and V. Tucci

This paper aims at presenting a systematic approach for evaluating the effects induced on the dynamics of the Trans-Membrane Voltage of a biological cell by the characteristics of the non-ideal applied electric pulses. The proposed methodology is based on a combined use of the Design of Experiments (DoE) and Response Surface Methodology that allows to put in evidence the self and mutual effects produced on the time evolution of the Trans-Membrane Voltage (TMV) by the characteristic parameters of the applied electrical pulse. The most influencing parameters of the pulse can be identified in an efficient way. A comparison is performed on the TMV characteristics by considering either a basic Hodgkin-Huxley (HH) lumped parameter circuit or a modified model taking also into account the electroporation phenomenon.

BIOMETRIC AUTHENTICATION DEVICES AND SEMANTIC WEB SERVICES - An Approach for Multi Modal Fusion Framework

L. Puente Rodríguez, M. J. Poza, J. M. Gómez and B. Ruiz

Biometric research is now information intensive; the volume and diversity of new data sources challenges current database technologies. Biometric identity heterogeneity arises when different data sources interoperate. New promising application fields such as the Semantic Web and Semantic Web Services can leverage the potential of biometric identity heterogeneity, providing a platform to integrate the lattice of biometric identity data widely distributed both across the Internet and within individual organizations. In this paper, we present a framework for solving biometric identity heterogeneity based on Semantic Web Services. We use a multimodal fusion recognition scenario as a test-bed for evaluation.

TREATMENT OF MITRAL VALVE INSUFFICIENCY BY SHAPE MEMORY POLYMER BASED ACTIVE ANNULOPLASTY

Pilar Lafont Morgado, Andrés Díaz Lantada, Héctor Lorenzo-Yustos, Julio Muñoz-García, Ignacio Rada Martínez, Antonio Jiménez Ramos and José Luis Hernández Riesco

Active materials are capable of responding in a controlled way to different external physical or chemical stimuli by changing some of their properties. These materials can be used to design and develop sensors, actuators and multifunctional systems with a large number of applications for developing medical devices. (for both surgery and implants). Shape memory polymers are active materials with thermo-mechanical coupling (changes in temperature induce shape changes) and a capacity to recover from high levels of distortion, (much greater than that shown by shape memory alloys), which combined with a lower density and cost has favoured the appearance of numerous applications. In many cases, these materials are of medical grade, which increases the chances of obtaining biocompatible devices. This paper presents the design, manufacture, “shape memory” programming process and in vitro trials of an active annuloplasty ring for the treatment of mitral valve insufficiency, developed by using shape memory polymers. This has been done with the collaboration betweeen researchers from “Universidad Politécnica de Madrid” and doctors from the “Madrid Gómez Ulla Hospital”.

A SIMPLE DEVICE TO MEASURE GAZE ANGLES IN VISUAL TASK ANALYSES

A. Page, B. Mateo, J. Garrido-Jaén, R. Marzo, J. C. Dürsteler, A. Giménez and C. Prieto

This paper presents a simple device to measure visual maps and head motion to analyze the visual strategy in optometric applications. Instead of using the common approach of conventional eye-trackers based on continuous pupil–corneal reflection detection, a simple method based on photogrammetry is proposed. This method only measures the head movements, the gaze direction and the visual map can be calculated on the hypothesis that subjects’ gaze follows a known visual stimulus accurately. In order to validate this hypothesis, an experiment has been carried out to calculate the subject’s accuracy when tracking the stimulus. The gaze direction was measured both with a conventional eye-tracking and with the proposed technique and the measured gaze angles were compared. The results show that the subjects effectively follow the stimulus during the task; the main hypothesis of the proposed system is confirmed. Therefore, the measurement of the head movement can supply an indirect measurement of the visual angles that is as accurate as the measurement obtained in devices that are more complex.

DEVELOPMENT OF A MULTI-CAMERA CORNEAL TOPOGRAPHER - Using an Embedded Computing Approach

A. Soumelidis, Z. Fazekas, F. Schipp, A. Edelmayer, J. Németh and B. Csákány

A multi-camera corneal topographer is presented in the paper. Using this topographer, the corneal surface under examination is reconstructed from corneal images taken synchronously by a number of calibrated cameras. The surface reconstruction is achieved by the joint solution of several partial differential equations (PDE's), one PDE for each camera. These PDE's describe the phenomenon of light-reflection for different overlapping regions of the corneal surface. Both algorithmic and implementation issues are covered in the paper.

MEASURING THE FORCES APPLIED TO A VIRTUAL REALITY LAPAROSCOPIC SURGICAL SIMULATOR WITH QUANTUM TUNNELLING COMPOSITE SENSORS

I. W. Mack, K. McMenemy, R. S. Ferguson, S. Potts and A. Dick

Abdominal surgery performed by laparoscopy requires a very high degree of skill in the surgeon. This skill level can only be acquired through practice and training. However, a virtual reality (VR) training simulator commands a high price. There is no reason for a VR simulator to be expensive, as a modern personal computer can produce high-quality graphics. If all that was required was good graphics, every surgeon could have a training tool within their laptop computer. What is missing is suitable low-cost human interface hardware – the equivalent of the computer game ‘joystick’. This paper presents a design for a low cost device to address this issue. In order to provide force feedback, the forces exerted on the surgical instruments have to be measured by sensors mounted at various points. The sensors are constructed from quantum tunnelling composite pills which measure the pressure applied to them by the surgeon. The force feedback is produced by small direct current motors. The low cost design has been tested by both specialist laparoscopic surgeons and non surgical personnel to assess its benefits in training at different levels of expertise. A preliminary qualitative report is given which documents the findings from these initial tests.

MACHINE BIOLOGICAL CLOCK - The time dimension in a organic-based operating system

Mauro Marcelo Mattos

A Knowledge-Based Operating System is an endogenous self-adaptive and self-reconfigurable approach to operating system design for organic computing. The system is based on (i) a hyper dimensional world model, (ii) on DEVS formalism as a runtime environment and, (iii) uses the concept of plans instead of programs and (iv) is based on the Biological Machine Clock concept in order to provide the system ability to perceive the time flow intuitively. This work presents the Biological Machine Clock concept

CAPILLARY ELECTROPHORESIS ELECTROCHEMICAL DETECTOR WITH NOBLE MICROCHANNEL STRUCTURE FOR MINIATURIZATION - Development of a Capillary Electrophoresis Microchip Format Electrochemical Detector for Endocrine Disruptors Sensing

Kon Ha, Gi-sung Joo, Grace Nisola, Wook-Jin Chung, C. J. Kang and Yong-Sang Kim

Numerous researches have been focused on capillary electrophoresis (CE) and amperometric detection (AD) using a double-T micro-channel configuration. The combination of these two techniques becomes a powerful analytical tool due to enhanced features in terms of sensitivity and selectivity. The developed CE-AD chip is low cost and requires less power consumption. Its high compatibility with micro-fabrication technology has made it popular for analysis of different compounds. However, due to the need to further miniaturize the CE-AD device, a twisted CE micro-channel configuration is fabricated and tested in this study. Furthermore, enhanced analyte separation due to delayed response time can be achieved using a serpentine CE separation micro-channel. Phenolic compounds were used as testing analytes to confirm the results using different types of running buffers. Also, the data gathered from the new micro-channel configuration is compared with the previously gathered results obtained from double-T separation micro-channels.

A NEWINSTRUMENTED BIOLOGICAL DEVICE DESIGNED TO APPLY MECHANICAL SHOCKS TO BONE CELLS

Laurent Navarro, Jean-Charles Pinoli, Henri Besset, René Guyonnet, Laurence Vico and Alain Guignandon

A new device called biomechanical stimulation device (BSD) has been recently developped. This BSD allows to apply shocks to a biomaterial disc, on which bone cells have been seeded. To observe the real behaviour of the biomaterial under shock loading, the BSD is instrumented with an impact hammer and an accelerometer. Force and acceleration signals are recorded, and signal analysis can be performed, in particular Fourier analysis. The results obtained lead to a better understanding of the stimulus that the cells can perceive at the top surface of the biomaterial disc. It appears that mechanical shocks applied at 1 Hps (Hit per second) or 10 Hps generate a frequency content up to 35 kHz. The main further objective will be to characterize the influence of mechanical shocks on bone cells proliferation.

NOVEL HAPTIC TOOL AND INPUT DEVICE FOR BILATERAL BIOMANIPULATION ADDRESSING ENDOSCOPIC SURGERY

K. Houston, O. Tonet, C. Eder, A. Menciassi, P. Dario and A. Sieber

In this paper a sensorised polymer microgripper is presented which can be used as a suitable end effector on an endoscopic microinstrument for robot-assisted and possibly teleoperated surgery to enable the operator to receive haptic feedback information on the forces generated during the procedure. A novel tweezer-like haptic input device is also described, which gives the operator the ability to remotely feel these forces generated by grasping operations with the microgripper. This feedback is used to control the amount of force applied in manipulation of tissues during the procedure. The mechanical and electronic design of the microgripper, microinstrument and haptic tweezers is also presented and preliminary results detailed.

MULTIPARAMETER SINGLE LOCUS INTEGRATED MULTILAYER POLYMER MICROSENSOR SYSTEM

Yindar Chuo and Bozena Kaminska

Miniaturization and microintegration is well known for their potentials in providing microsystems and sensors with unmatched performance, reliability, and lower costs. Current technologies in implementation of microsensors, however, span a large variety of platforms. It is thus common for microsensors measuring differing parameters to exist on different combinations of substrates, not to even mention the associated signal conditioning, processing, and data communication electronics. It remains a challenge to integrate multiple sensors with complex electronics into a single high-density microsystem, particularly for certain applications in medical diagnostics and healthcare where flexibility of the substrate and biocompatibility also becomes crucial considerations. Traditional microintegration technologies such as system-in-package, system-on-chip, and advanced assembly and packaging, are often inadequate. A mutliparameter single locus integrated multilayer polymer microsensor system is proposed to address the fundamental issues of high-density integration, flexibility, biocompatibility, easy application, high sensitivity, and reliability for medical grade diagnostics and other physiological applications. The architecture of the multilayer system is discussed, as well, implementation and fabrication of the multisensor layer is demonstrated, and the results on performance discussed.

SENSORIZED MICROCATHETER - Smart Microinstrumentation Adressing Fetal Surgery – First Results

A. Sieber, K. Houston, A. Menciassi, G. Nauer and P. Dario

Pulmonary Atresia is a malfunction that is diagnosed in about 1 out of 20.000 fetus. The authors propose a novel surgical intervention where the fetal heart is accessed with an endoscopic intervention through the umbilical cord. The key for this innovative procedure is a novel micro-catheter that is equipped with sensor and actuators that allow active navigation inside the heart and also tissue characterisation. The present paper presents the first prototype.

FORCE MEASUREMENT DURING GAIT THERAPY - The Case of Lokomat®

M. Bocciolone, M. Lurati, M. Vanali and F. Molteni

The present paper deals with force measurement during gait therapy assisted by a special robotic treadmill with driven robotic orthoses that guide inferior limbs movements. The objectives, the measurement setup and the results are presented. This work has been carried out in order to get data necessary to begin the analysis and the design of a new ankle motion device. The presented data also show as these measurements can be useful in gait parameters assessment and patient’s muscle activity level.

A MECHATRONIC DEVICE FOR THE REHABILITATION OF ANKLE MOTION

Giuseppe Bucca, Alberto Bezzolato, Stefano Bruni and Franco Molteni

The paper presents the main results from a research aiming at the design of an electro-mechanical actuator to assist walking movements of the ankle articulation, for use in the rehabilitation of lower limb motion in patients suffering neurological disease. Motivations for the research project are discussed within the framework of the application of mechatronic concepts within rehabilitation practice. The entire design process is then described, from the definition of project target through the mechanical concept and control design steps until design validation by means of numerical simulations and tests on a prototype.

SCREEN-PRINTED SENSOR FOR CHLORIDE QUANTIFICATION IN SWEAT FOR EARLY DETERMINATION OF CYSTIC FIBROSIS

Javier Gonzalo-Ruiz, Roser Mas, F. Xavier Muñoz and Rafael Camero

One-use screen-printed sensor capable to generate sweat and measure the chloride concentration is presented. Sweat is induced by iontophoresis, pilocarpine is forced to get into de skin and stimulate the sweat glands. Chloride concentration is measured by potentiometry. The performance of the devices has been tested by means of reproducibility studies. Finally, the application of these sensors in several volunteers has been carried out. Errors less than 10% have been obtained in real samples

BRAIN COMPUTER INTERFACE - Comparison of Neural Networks Classifiers

José Luis Martínez Pérez and Antonio Barrientos Cruz

Brain Computer Interface is an emerging technology that allows new output paths to communicate the user’s intentions without use of normal output ways, such as muscles or nerves. In order to obtain its objective BCI devices shall make use of classifier which translate the inputs provided by user’s brain signal to commands for external devices. The primary uses of this technology will benefit persons with some kind blocking disease as for example: ALS, brainstem stroke, severe cerebral palsy. This report describes three different classifiers based on three different types of neural networks: Radial Basis Functions RBF, Probabilistic Neural Networks PNN, and Multi-Layer Perceptrons MLP. The report compares the results produced by them in order to obtain conclusions to apply to an on-line BCI device, it also describes the experimental procedure followed in the experiments. As result of the tests carried out on five healthy volunteers an estimation of the success rate for each type of classifier, the type and architecture of the classifier, and filtering windows are established.

NEW DEVELOPMENT ON SHAPE MEMORY ALLOYS ACTUATORS

Roberto Romano and Eduardo Aoun Tannuri

Shape Memory Alloys (SMA) consist of a group of metallic materials that demonstrate the ability to return to some previously defined shape when subjected to the appropriate thermal procedure. The shape memory effect occurs due to a temperature and stress dependent shift in the materials crystalline structure between two different phases. Martensite, the low temperature phase, is relatively soft whereas Austenite, the high temperature phase, is relatively hard. The change that occurs within SMAs crystalline structure is not a thermodynamically reversible process and results in temperature hysteresis. The key feature of these materials is the ability to undergo large strains and subsequently recover these strains when a load is removed or the material is heated. Such property can be used to build silent and light actuators, similar to a mechanical muscular fiber. SMA actuators have several advantages in several engineering fields, mainly in robotics, replacing the conventional actuators like motors or solenoids. However, the good performance of the SMA actuator depends on a complex control and cooling systems, reducing the time constant and minimizing the effects of hysteresis. In the present paper, a novel cooling system is proposed, based on thermo-electric effect (Seebeck-Peltier effect). Such method has the advantage of reduced weight and requires a simpler control strategy compared to other forced cooling systems. A complete mathematical model of the actuator is derived, and an experimental prototype was implemented. Several experiments were used to validate the model and to identify all parameters. A robust and nonlinear controller, based on sliding-mode theory, was derived and implemented. Experiments were used to evaluate the actuator closed-loop performance, stability and robustness properties. The results showed that the proposed actuator presents, indeed, a very good dynamic response, compared to other actuators described in the literature.

STUDY OF OXYGEN PLASMA FOR APPLICATION IN STERILIZATION PROCESSES

A. Moreira, T. Pinto, R. Mansano, N. Ordonez and L. Vilhegas

This paper proposes a medical device sterilization technique; with less exposure time than current plasma techniques and that can be applied to temperature sensitive materials. A Reactive Ion Etching (RIE) plasma system was used; as test microorganisms were used: Bacillus subtilis spores of the variation niger ATCC 9372 and Bacillus stearothermophilus. For the Bacillus subtilis indicators, two types of support were used: glass plates with 2,0 x 107 UFC/ml microbial load, and paper strips with 3,8 x 106 UFC/ml microbial charge. For Bacillus stearothermophilus indicators only paper strips were used, with 1,0 x 106 UFC/mL initial load. Process efficiency was evaluated based on survival curves and their respective decimal reduction values (D values). In each test Petri dishes were used with triple B. stearothermophilus and B. subtilis samples. Process parameters were the following: oxygen flows of 100, 200 and 500 sccm, 100 and 330 mTorr process pressure, 50, 100 and 150 W RF power and times between 2 to 60 minutes. These tests were followed by survivor counting tests to evaluate the plasma efficiency as a sterilizing agent, spectrophotometric analysis to verify oxygen consumption during the whole process and scanning electron microscope analysis to observe plasma effect on the microbial forms. With these results, it has been possible to adapt process parameters for each type of support, in order to avoid support degradation due to plasma action.

PROGRAMMABLE CYTOGENETIC SUBMICROLITRE LAB-ON-A-CHIPFOR MOLECULAR DIAGNOSTIC APPLICATIONS

Daniela Woide, Veronika Schlentner, Teresa Neumaier, Thorsten Wachtmeister, Herwig G. Paretzke, Zeno von Guttenberg, Achim Wixforth and Stefan Thalhammer

This project focuses on the development of an acoustic driven, freely programmable multifunctional biochemical lab-on-a-chip. By combining different platform elements, like microdissection-, nanofluidic- and detection-modules, the lab-on-a-chip can be adapted to question- and patient-specific cytogenetic and forensic applications. In contrast to many common lab-on-a-chip approaches presently available, the fluidic handling is done on a planar surface of the lab-on-a-chip. Minute amounts of biochemical fluids are confined in ‘virtual’ reaction chambers and ‘virtual’ test tubes in the form of free droplets. The droplets, fluidic tracks and reaction sites are defined at the chip surface by a monolayer chemical modification of the chip surface. Surface acoustic waves are employed to agitate and actuate these little ‘virtual’ test tubes along predetermined trajectories. Well-defined investigations, controlled in the submicrolitre regime, can be conducted quickly and gently on the lab-on-a-chip.

THE DESIGN OF BIAXIAL JOINT FOR MOBILE ELECTRONICS WITH THE ANALYSIS ON ARTHROSIS

Zhao Danpu, Yi Qiang, Nie Chenghui, Chen Ken, Liu Li, Xu Leon and Salo Antti

To bring forward the new form factors is one of the key drivers for future mobile electronic devices. On the other hand, some form factors in nature with evolution process have been the excellent and adaptive. In this paper, we pay attention to the characteristics of arthrosis, researched on the difference between the arthrosis and machine joint. Then the essentials and parameters of the biaxial joint design were introduced. After that a biaxial joint concept for portable electronics based on the bionic principle was proposed. Finally, we provided the statics analysis of the biaxial joint.

A VERSATILE ROBOTIC WHEELCHAIR COMMANDED BY BRAIN SIGNALS OR EYE BLINKS

Teodiano Bastos-Filho, Andre Ferreira, Rafael Silva, Mario Sarcinelli-Filho and Mario Sarcinelli-Filho

A system allowing a person with severe neuromotor disfunction to choose symbols in a Personal Digital Assistent (PDA) using electroencephalography (EEG) and electromyography (EMG) is implemented onboard an electrical wheelchair. Through this system the user is able to elicit personal needs or states, like sleep, thirst and hunger; to write texts using an alpha-numeric keyboard and to command a robotic wheelchair. The EEG patterns used are event-related syncronization and desyncronization (ERS and ERD, respectively) occurring in the alpha band of the spectrum of the the signal captured in the occipital region of the head, while the EMG patterns are eye-blinks. The results so far obtained with the system developed, in indoor and outdoor environments, are quite satisfactory. This paper describes the system so far implemented and shows some experimental results associated to it.

A 2.4 GHZ WIRELESS ELECTRONIC SHIRT FOR VITAL SIGNALS MONITORING

J. P. Carmo, P. M. Mendes, C. Couto and J. H. Correia

This paper presents a wireless sensor network for wireless electronic shirts. This allows the monitoring of individual biomedical data, such as the cardio-respiratory function. The solution chosen to transmit the body’s measured signals for further processing was the use of a wireless link, working at the 2.4 GHz ISM band. A radio-frequency (RF) CMOS transceiver chip was designed in the UMC RF 0.18 m CMOS process. The power supply of the RF CMOS transceiver is of only 1.5 V, thus it can be supplied by a single coin-sized battery. The receiver has a sensibility of -60 dBm and consumes 6.2 mW. The transmitter delivers an output power of 0 dBm with a power consumption of 15.6 mW. Innovative topics concerning efficient power management was taken into account during the design of the RF CMOS transceiver.

PROBABILISTIC WORKPSACE SCAN MODES OF A ROBOT MANIPULATOR COMMANDED BY EEG SIGNALS

Fernando Alfredo Auat Cheeín, Fernando di Sciascio, Ricardo Carelli and Teodiano Freire Bastos Filho

In this paper, probabilistic-based workspace scan modes of a robot manipulator are presented. The scan modes are governed by a Brain Computer Interface (BCI) based on Event Related Potentials (Synchronization and Desynchronization events). The user is capable to select a specific position at the robot’s workspace, which should be reached by the manipulator. The robot workspace is divided into cells. Each cell has a probability value associated to it. Once the robot reaches a cell, its probability value is updated. The mode the scans are made is determined by the probability of all cells at the workspace. The updating process is governed by a recursive Bayes algorithm. A performance comparison between a sequential scan mode and the ones proposed here is presented. Mathematical derivations and experimental results are also shown in this paper. Finally, the manipulator can be teleoperated via TCP/IP.

BIOMATERIAL FOR SOFT TISSUE REPLACEMENTS

David N. Ku and Jin Wu Fan

Typical biomaterials are stiff, difficult to manufacture, and not initially developed for medical implants. A new biomaterial is proposed that is similar to human soft tissue. The biomaterial provides mechanical properties similar to soft tissue in its mechanical and physical properties. Characterization is performed for modulus of elasticity, ultimate strength and wear resistance. The material further exhibits excellent biocompatibility with little toxicity and low inflammation. The material can be molded into a variety of anatomic shapes for use as a cartilage replacement, heart valve, and reconstructive implant for trauma victims. The biomaterial may be suitable for several biodevices of the future aimed at soft-tissue replacements.

QUANTUM CASCADE LASERS FOR BIOSENSING APPLICATIONS

Pietro Regoliosi, Andrea Vacchi, Giuseppe Scarpa and Paolo Lugli

Quantum cascade lasers (QCL) represent nowadays a mature technology to obtain MIR and FIR laser sources. Several advantages with respect to other coherent sources make QCL particularly attractive: the emission frequency can be selected by properly designing the growth structure, the emission wavelength is tunable with a very good precision and a high optical power can be emitted in a spot of small size. These properties make them suitable for several applications, including gas spectroscopy in the IR range. In this work we introduced different types of QCL and we provide a description of their performances and properties, showing that they are suitable candidates for biosensing applications.

A SIMULATION STUDY OF THE NEW CONCEPT OF A STAIR-CLIMBING WHEELCHAIR - Concept of Construction

Grzegorz Dobrzynski, Wlodzimierz Choromanski and Jerzy Kowara

Authors present the idea of construction, modelling and simulation studies of the new generation, mechatronical wheelchair. The wheelchair is going to be adapted for the drive on the various surface. The important feature of it is going to be the possibility of obstacle overcoming, such as doorstep of the maximal height of 220 mm. The construction model and simulation studies were carried out in the environment of MBS ADAMS package. The algorithm of controlling of doorstep entry was proposed and the analysis of parametrical sensitivity of the construction was done

ELBOW FLEXION AND EXTENSION MOVEMENTS CHARACTERIZATION BY MEANS OF EMG

L. M. Bittar and M. C. F. Castro

Electromyographic (EMG) signal is the electrical manifestation of neuromuscular activation associated with muscle contraction. The present work intends to characterize the behavior of the muscles biceps and triceps during elbow flexion and extension movements, without load. These movements were performed at horizontal and vertical planes. Three types of test were performed, for each plane, relating EMG signal with joint position. Five men volunteers, ages ranged between 18 and 21 years old, were selected to participate to the tests. The first test consisted to move 10 degrees for each three seconds until the allowed maximum flexion and then, to return at the same way to the initial position. For the second test, the same movement was made but continuously, without stopping at intermediate positions. And for the third test, continuously flexion and extension movements were repeated sequentially but for different amplitudes, increasing by 10 degrees each. The tests were repeated, three times each. Initially, graphical analysis of the data was made for standard behavior detection and, for a quantitative analysis, after EMG preprocessing, averages and variation coefficients were calculated from specific intervals at the beginning, middle and at the end of movement. Although an EMG signals inherent variability, results showed inter and intra subject's repeatability, but only for movements performed at the horizontal plane.

APPLICATION OF MODAL ANALYSIS FOR EXTRACTION OF GEOMETRICAL FEATURES OF BIOLOGICAL OBJECTS SET

Michal Rychlik, Witold Stankiewicz and Marek Morzyński

This article presents application of modal analysis for the computation of data base of biological objects set and extraction of three dimensional geometrical features. Authors apply two types of modal analysis: physical (vibration modes) and empirical (PCA – Principal Component Analysis) for human bones. In this work as the biological objects the fifteen human femur bones were used. The geometry of each bone was obtained by using of 3D structural light scanner. In this paper the results of vibration modal analysis (modes and frequencies) and PCA (mean shape and features – modes) were presented and discussed. Further the possibilities of application of empirical modes for creation three dimensional anthropometric data base were presented.

AN RFID TRANSPONDER LOCATION SYSTEM

Mou Tang, Graeme Chester and Jeffrey Neasham

This paper describes a location system based on RFID technology. This system can be used to map the image of an endoscope. Compared with other endoscope location systems, this is a wireless system. The transponder mounted along the shaft of an endoscope does not increase the size of the endoscope or affect the flexibility of endoscope. We build the mathematical model of this location system and verify this model by experiments. Although experiments are for a transponder moving along one dimension, we can develop a three-dimensional system based on our results.

OMNIDIRECTIONAL VISION TACKING SYSTEM BASED ON KALMAN FILTERING AND OMNICAMSHIFT

B.Allart, B. Marhic, L. Delahoche, O. Rémy-Néris and A. M. Jolly-Desodt

This project deals with technical assistance for people of reduced mobility. We propose to study the technical, psychological and clinical impact of an original approach, which consists of mounting a prehensile arm onto a mobile base. The use of this mobile unit in relation to the patient’s wheelchair is carried out on a master-slave basis. This study therefore has a plural-disciplinary nature: Science for the Engineer, Human and Social Science and Clinical. To ensure the tracking of the wheelchair by the mobile platform, we will present a tracking approach based on Kalman filter’s algorithm that we have upgraded in combination with two Kalman filtering levels. The first level permits an estimation of the wheelchair configuration in its environment and the second is used to compute the mobile platform configuration in connection with its environment. The association of the two filtering processes allows a robust tracking between a mobile target (wheelchair) and a mobile observer (assistive platform).

DESIGN OF ANALOG SIGNAL PROCESSING INTEGRATED CIRCUIT FOR MULTI-CHANNEL BIOMEDICAL STRAIN MEASUREMENT INSTRUMENT

Wenchao Qu, Syed K. Islam, Gary To and Mohamed R. Mahfouz

An analog signal processing integrated circuit for micro-cantilever array is designed for strain measurement in biomedical applications. The chip includes an analog multiplexer, an instrumentation amplifier, a sample and hold circuit, an on-chip voltage and current reference, a successive approximation register analog-to-digital converter and a digital control unit. The 8-bit ADC attains 45.4 dB signal-to-noise-and-distortion ratio and 56.4 dB spurious-free-dynamic-range while operating at 772 KHz. The chip occupies an area of 1.54 mm2 and consumes 17.8 mW power with a single 3.3 V supply. The chip has been fabricated in a 0.35μm 2-poly 4-metal CMOS process technology.

A WIRELESS ACQUISITION SYSTEM FOR MONITORING THE INFLUENCE OF LOADS ON VERTEBRAL COLUMN BEHAVIOUR

João Eduardo Castro Ribeiro and João Paulo Pereira do Carmo

It is presented a wireless acquisition module (WAM). This allows the monitoring of heavy loads influence on vertebral column’s behaviour. Each module makes the electromyography (EMG), to measure the electric potentials on the iliocostalis and longissimus thoracis muscles, and use a dual-axis accelerometer to get the movements of the body, in order to obtain the complete behaviour of the vertebral column. The solution chosen to transmit the body’s measured signals for further processing, is a wireless link working in the 433 MHz ISM band. The acquired information is transmitted with a maximum rate of 40 kbps, a resolution of 9.8 uV, and accommodates two analog channels. An analog channel with differential input connected to the electrodes, is used to measure the EMG signal, while the remained channel is used in the patient’s movements measurements. The dimensions of the proposed acquisition system are about 7×5×2 cm, and will help to understand the influence of heavy loads as a risk factors in the vertebral column, such as the scoliosis and lordosis

NEUROLAB: A MULTIMODAL NETWORKED EXOSKELETON FOR NEUROMOTOR AND BIOMECHANICAL RESEARCH

A. F. Ruiz, E. Rocon, F. Brunetti, L. Bueno, J. C. Moreno and J. L. Pons

NeuroLab refers to an experimental platform designed to enhance studies in human movement and neuro-motor control. The platform comprises a robotic exoskeleton and some other stand-alone devices. All of these components have communication capabilities integrated in hardware and can work cooperatively taking advantage of a networked architecture. A set of experiment have been conducted with NeuroLab. The objective of the trials was to use mechanical perturbations to identify the viscous-elastic properties in human elbow joint and to correlate such mechanical impedance with the electromyographic information of muscles associated to the joint, during a postural task and in a rest position. In each condition, a pseudo-random torque perturbation was applied directly to the arm and to the forearm by mean of an upper limb powered exoskeleton. The angular kinematics (velocity and position) and the muscular activation patterns (EMG) in the two main muscles (biceps and triceps brachii) intervening in the elbow flexion-extension movement were recorded.

A RECONFIGURABLE SYSTEM FOR MOVEMENT REHABILITATION AND DIAGNOSTICS WITH FES

Piotr Kaczmarek, Andrzej Kasiński, Marek Kraft and Przemysław Mazurkiewicz

The architecture of a custom FES system is described. The system is built from off-the-shelf components to obtain a target functionality. List of potential applications is provided. Some tasks have been already tested in laboratory and clinical conditions. Hardware specification of some components is given and interfacing issues are addressed.

WIDE-BANDWIDTH, HIGH FRAME RATE ELECTRICAL IMPEDANCE TOMOGRAPHY / SPECTROSCOPY - A Code Division Multiplexing (CDM) Approach

A. L. McEwan, D. S. Holder, J. Tapson and A van Schaik

We present a proposal and proof-of-concept results for a new type of electrical impedance tomography / spectroscopy system that makes use of code division multiplexing to achieve two important technological advances. The use of CDM allows all the impedance measurements to be made simultaneously in time, thereby increasing the frame rate; and the use of pseudorandom input signals allows a very wide range of frequencies to be sampled simultaneously in each channel. The combination of these two advances will result in a system with substantially higher performance than those reported previously

DEVELOPMENT OF AN ALTERNATIVE SYSTEM FOR SUSPENDED GAIT ANALYSIS

Gustavo Freitas de Lima and Alberto Cliquet Jr.

Spinal Cord Injury (SCI) may impair an individual’s gait. For these cases, a rehabilitation technique that has become more popular is Functional Electrical Stimulation (FES). Gait analysis is an important technique to evaluate rehabilitation of patients undergoing FES-assisted therapy. This work proposes a system that monitors gait variables – knee joint angles, and ground reaction forces (heel and metatarsal) – and uses them as inputs for gait analysis of paraplegic patients. The methods for building the data acquisition hardware (transducers and interface) and software are described, along with the transducer calibration methods. The results show the final prototype for the gait analysis system, which allows comparison between different individuals’ gaits, as well as different rehabilitation stages for the same individual. The software has a recording feature, as well as digital control outputs, which may be used in the future for training an Artificial Neural Network (ANN) and controlling the individual’s FES stimulator. In the near future, the system may be of great applicability for suspended FES-assisted gait analysis and control.

INSTRUMENTATION AND LABVIEW BASED CONTINUOUS PROCESSING FOR CHEST PHYSIOTHERAPY

Luc Marechal, Christine Barthod, Gérard Gautier, Jacques Lottin and Jean Claude Jeulin

Infant chest physiotherapy (CPT) has never been the purpose of any assessed scientific study although it is widely used for newborn babies suffering from bronchiolitis. It is thus compulsory to quantify the limits of the gesture to obtain the expected effect. In this paper, we present original instrumented gloves designed to perform measurements during the CPT act on babies to characterize the gesture. Associated electronics and software were specially developed with LabVIEW for data acquisition, continuous processing and analysis of the characteristic parameters. The measuring system and its readout electronics were calibrated. A drive to do measurement with babies in real situation validates the principle of the system. The analysis of the results highlights relevant parameters for typical phases of the CPT act

A NOVEL APPROACH FOR SIMULATING A BIO-CONTAMINATION PROCESS

Gerard Chalhoub, Antonio Freitas and Michel Misson

The phenomenon of bio-contamination in a population of individuals being contaminated in a near by near physical, viral or bacterial contact could be compared by analogy with a near by near exchange of "atomic" data between mobile entities of an ad hoc network. Would the tools of wireless communication engineering then make it possible to contribute in the modeling of a bio-contamination process? Does the use of CSMA/CA in order to share the “contamination medium” make it possible to simulate this process of contagion? To establish the limits of the analogy, we consider the most unfavorable case, the systematic contamination of proximity. A susceptible mobile becomes contaminated if it passes near a contaminant mobile at a distance lower than the contamination distance. Simulations under NS2 highlight the effect of the overall radiation compared to the power used for emitting the atomic data representing the virus and reveal an optimal frequency of atomic data diffusion in the case of a population with strong geographical density moving in confined environment.

PRECLINICAL TESTING OF A NEW VENOUS VALVE

Laura-Lee Farrell and David N. Ku

Venous valvular incompetency is a debilitating disease affecting millions of patients. Unfortunately, the current physiologic and surgical treatments are prone to the extreme risk of post-operative thrombosis. A new design for venous valves has been proposed using biomimicry. The medical device has the shape of a natural valve with sufficient elasticity to maintain patency and competency in the leg veins. The venous valve was tested for patency, competency, cyclic fatigue, compressibility, and thrombogenicity. Patency is maintained with a low opening pressure of less than 3 mmHg. Competency is maintained with backpressures exceeding 300 mmHg. The valve is fatigue resistant to over ¼ million cycles. The valve can maintain its integrity when compressed in a stent and deployed without tilting or mal-alignment. Little thrombus forms on the valve with perfusion of whole blood under pulsatile flow conditions. The pre-clinical tests demonstrate efficacy as a new venous valve for treatment of chronic venous insufficiency.

RESURE - Wireless Sensor Network for Health–Care Monitoring

Enrique A. Vargas Cabral, Vicente A. Gonzalez and Jean A. Guevara

This work presents a sensor system to monitoring a patient vital signs remotely. The proposed sensor network architecture is based on IEEE 802.15.4 PAN technology with start topology. An experimental set-up was implemented including the development of some biological sensors. In the implementation stage we use Xbee modules, the remote sensors was configured as RFD devices and the network coordinator as FFD device. As central device a smart phone was used. From the results, we conclude that the IEEE 802.15.4 technology is appropriate for medical WPAN sensor network implementation.

LAB-ON-A-CHIP WITH FLUID ACOUSTIC MICROAGITATION - Piezoelectric Polymer β-PVDF used as Ultrassonic Transducer

V. F. Cardoso, J. G. Rocha, F. O. Soares, G. Minas and S. Lanceros-Mendez

The main objective of this article is to describe the development of a fully-integrated disposable lab-on-a-chip for point of care testing and monitoring of biochemical parameters in biological fluids. The lab-on-a-chip is composed mainly by two dies: the fluid and the detection. The fluid die, fabricated in SU-8, comprises three microfluidic cuvettes, containing the fluids into analysis, and a β-PVDF microagitation system. The detection die is fabricated in a CMOS standard process and contains the photodetectors and the electronics for signal actuation and detection. The main innovation of this lab-on-a-chip is the application of an acoustic microagitation technique by the deposition of the β-PVDF piezoelectric polymer underneath the microfluidic structures, with automatic electronic control. This piezoelectric polymer produces mechanical vibrations, which allow the enhancement of the mixing and the reaction.

FPGA-BASED COMPUTATION OF THE INDUCTANCE OF COILS USED FOR THE MAGNETIC STIMULATION OF THE NERVOUS SYSTEM

Ionuţ Trestian, Octavian Creţ, Laura Creţ, Lucia Văcariu, Radu Tudoran and Florent de Dinechin

In the last years the interest for magnetic stimulation of the human nervous tissue has increased considerably, because this technique has proved its utility and applicability both as a diagnostic and as a treatment instrument. Research in this domain is aimed at removing some of the disadvantages of the technique: the lack of focalization of the stimulated region and the reduced efficiency of the energetic transfer from the stimulating coil to the tissue. Better stimulation coils can solve these problems. Designing coils is so far a trial-and error process, relying on very compute-intensive simulations. In software, such a simulation has a very high running time (several hours for complicated geometries of the coils). This paper proposes and demonstrates an FPGA-based hardware implementation of this simulation which reduces the computation time by 4 orders of magnitude. Thanks to this powerful tool, some significant improvements in the design of the coils have already been obtained.

VISION OF THE VIRTUAL PROGRAMMER - Steps Towards Change in Instrument Systems for Implantable Medical Devices

Touby Drew and Steve Goetz

Active implantable medical devices increasingly depend on and interact with external systems of instrument hardware and software. Based on our work in defining and refining the direction of next generation instruments, we submit that there are and will increasingly be a trend towards complex, mainstream instrument systems, which are distributed, decoupled and part of rich modular information ecologies. As this shift occurs, important challenges arise and must be met with domain-specific solutions including those in the areas of security, repartitioning, and changes to instrument architecture and development.

AUTOMATIC DEACTIVATION DESIGN FOR PHASED ARRAY SURFACE PROBE IN 1.5T MRI

Fotios N. Vlachos, Anastasios D. Garetsos and Nikolaos K. Uzunoglu

We have designed and developed an automatic switching mechanism that deactivates and activates a reception coil during the MR experiment according to the phase it is at. The mechanism uses a feedback loop in which a comparator defines whether the current reception signal derives from the RF excitation pulses or the MR signal and then triggers an analog switch at the back-end of the coil accordingly. We applied the mechanism on a custom-made four channel phased array probe and tested its functionality by transmitting RF pulses to the probe of similar length and power to those used in actual MRI systems. The results presented in this paper demonstrate the robustness of the design and its switching accuracy.

YEAST ON A CHIP - Single-cell Analyses of MAPK Signaling Pathways in Saccharomyces Cerevisiae using Cell Chips

Min Cheol Park, Moon Kyu Kwak, Hye Sung Cho, Kahp Y. Suh, Jae Young Hur and Sang-Hyun Park

The mitogen-activated protein kinase (MAPK) signaling pathways are essential for cell growth, cell differentiation and survival in eukaryotes. The MAPK signaling pathways transmit signals from the cell surface to nucleus. The mating and high osmolarity responses in the budding yeast, Saccharomyces cerevisiae, depend on the MAPK signaling pathways. Here we analyzed the mating and high osmolarity responses in the budding yeast, S. cerevisiae at single-cell level using cell chips. The cell chip analyses of the mating and high osmolarity responses were performed using fluorescent proteins fused to genes whose transcription is specifically upregulated by each signaling. Using the technique, we have determined the real-time gene expression patterns of the mating and high osmolarity responses at single-cell level. In this study, we observed that the mating and high osmolarity MAPK signaling showed a non-uniform, fluctuating flux in the population of yeast cells analyzed.

PERSONAL DIALYSIS USING A WEB-BASED, PORTABLE SYSTEM - C-PAK (Carry-on Pulse Artificial Kidney)

Byoung Goo Min, Jung Chan Lee, Wook Eun Kim, Ki Moo Lim and Jeong Chul Kim

While the number of patients suffering from acute and chronic renal failure has been steadily increasing every year, the mortality rate is not improving. For the purpose of improvement on the quality of life and mortality of renal disease patients, we employ the hemofiltration principle to treat the end-stage renal disease patients. Hemofiltration equipment can be installed without additional plumbing and electrical power construction; operated only with several pre-packaged fluid bags without a huge water treatment facility. This paper describes the development of portable renal treatment equipment based on hemofiltration treatment, Carry-on Pulse Artificial Kidney (C-PAK), and reports the results of animal test using the equipment. The web-based remote monitor/control system for C-PAK is introduced also. We expect that our portable hemofiltration device for chronic renal failure patient would be an alternative for conventional hemodialysis machine and a solution to home renal treatment.

SIMULTANEOUS WIRELESS MEASUREMENT OF BLOOD PRESSURE AND SYMPATHETIC NERVE ACTIVITY - A System for Investigating Neural Control Mechanisms in Long Term Blood Pressure Regulation

Daniel McCormick, Robert Kirton, Alan Easteal, Simon Malpas, Carolyn J. Barret, Sarah Jane Guild, Poul Nielson, Augio Patrick Hu, David Budgett, Matthew Lim and Bruce van Vliet

We report on the development of a combined sympathetic nerve activity and blood pressure telemeter for long term implantation in freely moving small animals. The devices simultaneously records and transmits blood pressure, temperature and sympathetic nerve data on the 2.4 GHz ISM band with a range of 5 m. Blood pressure is measured with a 400 Hz bandwidth, fluid filled catheter at a resolution of 0.1 mmHg. Sympathetic nerve activity is measured differentially using stainless steel electrodes attached to the renal nerve. The Telemeter measures 29x37x12mm and weighs 17g. Battery life is 12 h when used continuously, however the device’s lifespan is effectively indefinite due to the use of in vitro inductively coupled battery charging. Example data recorded in a conscious unconstrained rat is provided which verifies the telemeters operation.

STUDY OF A 4DOF UPPER-LIMB POWER-ASSIST EXOSKELETON WITH PERCEPTION-ASSIST - Second Stage of Power-Assist

Kazuo Kiguchi and Manoj Liyanage

This paper presents a new concept of an upper-limb power-assist exoskeleton as a second stage of the research on power-assist exoskeleton systems in order to help daily activities of physically weak persons. The proposed exoskeleton assists not only the motion of the user but also the perception of the user using sensors. In the proposed power-assist method, the assisted user’s motion can be modified based on the environment information obtained by the sensors if problems are found in the user’s motion. The effectiveness of the proposed concept was evaluated by experiment.

NOVEL CONTROLLER FOR REBREATHER DIVING SYSTEMS - True Sensor Signal Validation and Safe Oxygen Injection

GrA. Sieber, B. Koss, R. Bedini, K. Houston, A. L’Abbate and P. Dario

In electronically controlled closed rebreather diving systems the partial pressure of oxygen (p O2) inside the loop is controlled with 3 pO2 sensors, a microcontroller and a solenoid valve, critical components that are prone to fail. State of the art failure detection integrated in rebreather diving systems for recreational purposes does not offer the necessary reliability required for life sustaining systems. The present paper describes a novel controller that combines true sensor signal validation with safe oxygen injection.

MAGNETIC COUPLING ANALYSIS OF A TET POWER DELIVERY SYSTEM

Thushari Dissanayake, David Budgett and Aiguo Patrick Hu

This paper presents a comparative study of methods to determine the coupling coefficient between primary and secondary coils used in a transcutaneous energy transfer system designed for powering implantable biomedical devices. A coupling analysis covering typical misalignments between coils is presented using an analytical model, a simulated model and practical experimental measurements. The simulated model shows good agreement with the experimental measurements. The performance of the system is characterized by carrying out a loss analysis to compute the power efficiency of the system for different misalignment situations. It was established that variable coupling affects the maximum power transfer capacity but has a low impact on the power efficiency for coil separations of less than 30mm.

A NEW METABOLISM MODEL FOR HUMAN SKELETAL MUSCLE

Dayu Lv and Bill Goodwine

The human body metabolic regulatory system is very complex, containing thousands of metabolites involved in biochemical reactions. Glucose metabolism is one of the key procedures maintaining daily energy balance. Mobility of glucose is implemented by glucose transporters with different transporting characteristics locally, which are distributed in cells of brain, liver, pancreas, kidney and skeletal muscle, etc. This paper presents a component of a new model that is focused on skeletal muscle which consumes energy consistently due to either slight movement or high-energy demanded activities, such as running or swimming. This paper presents a mathematical model where glucose, insulin, glucose-6-phosphate (G6P), etc. are introduced and connected by ordinary differential equations.

MECHATRONIC SYSTEM FOR TRANSURETHRAL RESECTION TRAINING

Ángel Asensio, Alejandro Ibarz, Jose Ignacio Artigas, Álvaro Marco, Javier Casas and Roberto Casas

Training the residents who start with endoscopic operations remains a challenge. This paper describes an electromechanical system developed for learning the transurethral resection (TUR) technique. This system can be easily set and cleared up in a classroom, and consists of a supervisor’s workbench with a wireless sensing device, connected to several trainees’ workbenches with motorised devices. These devices have a resectoscope mounted on an electromechanical structure that is able to reproduce all the movements of an actual endoscopic operation of the prostate.

MICRO-SHAFT-POKING - A Novel Instrument for Mechanically Characterizing Soft Biomimetic Membrance

Kuo-Kang Liu, Mark Ahearne, Eleftherios Siamantouras and Ying Yang

Characterizing viscoelastic properties of soft biomimetic membranes becomes increasingly important due to their biomedical applications such as tissue engineering/regenerative medicine and biosensors. This paper presents a new micro-shaft-poking (MSP) technique which is free from the complication of substrate backing, normally occurred as an intractable problem in the conventional indentation testing for soft membranes. A tailored indention apparatus with a spherical indenter was constructed to achieve the force resolution and displacement of 1μN and 1μm. The biomimetic membranes which were used for mechanical testing were made of two types of hydrogel, alginate and agarose. The results showed that the elastic modulus increased with gel concentration. A creep test has also been conducted to examine the time-dependent behaviors of various hydrogel and a viscoelastic model has been correspondingly developed and applied to describe the experimental results. Other potential applications of this new instrument to other membranes, both artificial and biological, have been addressed in the paper.

BIOINTERFACES BASED ON IMMOBILIZED BORONIC ACID WITH SPECIFITY TO GLYCATED PROTEINS

Jan Přibyl and Petr Skládal

Development of bioanalytical assays for determination of glycated hemoglobin content in blood samples is reported. First, a combined biosensor setup for determination of total and glycated hemoglobin content was successfully developed and tested. The effect of various operating parameters, such as ionic strength, flow rate and instrumental set-up, was optimised. The total hemoglobin content was analysed by measuring absorbance of the hemoglobin-cyanide derivative at 540 nm. Only one standard (calibrator), diluted in various ratia, was necessary for the method calibration. The full range of HbA1c content (4 to 15 %) present in blood can be analysed. Only 1 μl of blood was required for analysis. The developed method was successfully evaluated for analysis of blood samples collected from diabetics. Next, the heterogeneous affinity assay performed in microtitre plate with an immobilized boronic acid is described. This assay is based on ELISA (Enzyme-linked Immunosorbent Assay) principle; however stable chemiselective ligand is used in this case. The content of glycated hemoglobin is determined according to its peroxidase activity after attachment to immobilized boronic acid derivative; the total hemoglobin concentration is measured during a previous step as an absorbance at 405 nm.

COMPUTER-CONTROLLED NEUROSTIMULATION FOR A VISUAL IMPLANT

S. Romero, C. Morillas, F. Pelayo and E. Fernández

Current research in therapies for restoring a functional form of sight to the blind includes interfacing electronic neurostimulators with some point of the visual pathway. This approach requires controlling a number of waveform parameters which might vary for every implanted patient and for every channel in an interface that may have hundred or thousands of electrodes. Therefore, the clinical, acute research stage of the implant should be controlled in a flexible and easy way, in order to obtain the information that will lead to a chronic implantable device. We describe such a system, based on a PC connected to an electronic neurostimulator, which delivers bi-phasic pulses to a set of implanted microelectrodes. This platform performs an automated patient-driven procedure to find stimulation thresholds. The system implements a set of physchophysical tests in order to determine the properties of the elicited visual perceptions, and applies an automatic re-mapping of the electrodes to obtain better recognizable patterns of percepts. Our platform can interface some other tools oriented to obtain, in a next research stage, a portable and chronic version of the visual implant.

PULSE-TYPE NEURO DEVICES WITH SPIKE TIMING DEPENDENT SYNAPTIC PLASTICITY

Katsutoshi Saeki, Yugo Hayashi and Yoshifumi Sekine

Even though the neurons in the human brain are sensitive to noises, human central nervous systems can operate correctly under a noisy environment. Since neural networks have superior information processing functions, many investigators have attemptted to model biological neurons and neural networks. A number of recent studies of neural networks have been conducted with the purpose of applying engineering to the brain. Especially, neuro devices have been created that focus on how to have a learning function. Here, we focus on spike timing dependent synaptic plasticity (STDP) and construct pulse-type neuro devices with STDP using analog VLSI technology. We show that it is possible to extract phase differences representing the reinforcement part of the synaptic weight by using pulse-type neuro devices with STDP. Moreover, we investigate noise tolerance for thermal noise and fluctuation of time.

INSTRUMENTED SPLINT FOR THE DIAGNOSIS OF BRUXISM

Pilar Lafont Morgado, Andrés Díaz Lantada, Alexander Martínez Álvarez, Antonio Barrientos Cruz, Héctor Lorenzo-Yustos, Pedro Luis Castedo Cepeda, Roberto González Herranz, Julio Muñoz García and Javier Echavarri Otero

Bruxism is a health problem consisting in grinding or tightly clenching the upper and lower teeth. Both the grinding and sliding lead to wear of the teeth and produce a noise during the night that is sufficiently loud to disturb the sleep of anyone sharing the bedroom. The tension produced causes problems in the muscles, tissues and other structures surrounding the jaw, ear pain, headaches, lesions to the teeth and disorders in the jaw joints. For an early, rapid, effective and economical diagnosis of bruxism, we propose the use of instrumented splints to detect and record the intensity and duration of interdental pressure episodes. This paper sets out the design, manufacture and testing of an instrumented splint for diagnosing the signs of bruxism. The system stands out for its use of piezoelectric polymeric sensors which, because of their reduced thickness, do not cause any alteration to the patient’s bite. It lets a quantitative assessment of intraoral pressure be made and bruxism behaviour be diagnosed at an early stage, so as to being able to programme corrective actions before irreversible dental wear appears. The first “in vitro” simulations and “in vivo” trials performed served to demonstrate the feasibility of the system in accordance with the initial objectives.

PERSONAL TELEMETRIC SYSTEM – GUARDIAN

Dalibor Janckulík, Ondřej Krejcar and Jan Martinovič

This project deals with the problems of utility of mobile equipment working in the biomedicine field, particularly telemedicine. This field is relatively new; it focuses on the observation of the life functions from a distance. Practically developing system works with the ECG sensor connected to mobile equipments, such as PDA /Embedded , based on operation system Microsoft Windows. The whole system is based on the architecture of .NET Compact Framework, and other products, such as SQL Server by Microsoft too. This work also deals with the comunication of mobile equipments with sensors and with the server via Bluetooth , WiFi , and GPRS/EDGE . The mobile equipment used serves primarily for measuring and the processing of data from the sensors and their visualization as a graph. The data are also given to the server for further processing and the analysis of the current health of the patients, due to small efficiency of the mobile equipments.[1] The main task we deal in the server part of application is receiving of the data via web services and further processing, management and analysis of this data. For the analysis of received data and further evaluation of the electrocardiogram, there is a self-organizing neural network [2].

SYNCHRONIZATION ISSUES IN SURGICAL TRAINING

Álvaro Marco, Héctor Gracia, Ángel Asensio, Carlos Guallar, José Ignacio Artigas and Roberto Casas

Surgical training systems allow novel surgeons to acquire the required skills to successfully carry out an operation without harming a real patient. These systems emulate the situation of a real operation, replicating the information gathered by sensors, movements of the surgeon, patient response, etc. All this information must be synchronized to provide an experience to the novel surgeon as closest to reality as possible. A special case of information synchronization is when using video images from the operation. In this paper, we analyze these synchronization issues –video, movements, sensors, etc.- and show a particular case that bring all together: an endoscopic video-surgery learning system.

HIGH RESOLUTION ECG AND DEPTH DATA LOGGER - A Novel Device to Study Breath Hold Diving Induced Variations of the PQ Interval

A. Sieber, R. Bedini, X. Yong, A. Navarri, M. Dalle Luche, A. L’Abbate and P. Dario

Breath hold diving induces several physiological effects. The authors speculate that next to bradycardia, vasoconstriction, splenic contraction and blood shift, the form of the ECG and especially the PQ interval are also affected. Investigations of this effect requires a high resolution ECG monitor which is also capable of recording depth. This paper describes our data logger prototype. It samples ECG data at 1200 Hz, is equipped with a pressure sensor that allows depth measurement up to 100 m and stores all the data in an ASCII text file on a SD flash card in FAT 16 or FAT32 file format. The prototype is then encapsulated in a Lexan tube with an outer diameter of 42 mm and an overall length of 18cm that should withstand 20 bar pressure equal to 200 m depth.

POLYMER MEMS SYSTEM FOR MEASURING THE MECHANICAL MODULUS OF A BIOLOGICAL CELL

Wenyue Zhang, Markus Gnerlich, Yaohua Sun, Gaoshan Jing, Jonathan J. Paly, Arkady Voloshin and Svetlana Tatic-Lucic

The measurements of the mechanical modulus of biological cells are critical to studies of pathophysiology and the research for an effective treatment. This research has developed a more rapid and cost effective technique to measure the Poisson’s ratio and mechanical modulus of living biological cells by utilizing microelectromechanical system (MEMS) techniques in a biological application. The design, fabrication, and characterization of a polymer-based MEMS system that integrates a V-shaped electrothermal actuator array and a cell-positioning system in a single microelectronics chip are presented here. This BioMEMS device compressed a NIH3T3 fibroblasts cell and caused up to 20% mechanical strain.

ANIMAL STUDIES USING AN OXYGEN-TENSION SENSOR FOR TISSUE VIABILITY MONITORING

Dafina Tanase, Arie Draaijer, Johan F. Lange, Gert-Jan Kleinrensink, Johannes Jeekel and Paddy J. French

Leakage at the site of an anastomosis is the main, yet unsolved reason for mortality in abdominal surgery. Every year, a large number of patients die due to anastomotic leakage after surgery. An objective aid to monitor the anastomotic site pre- and postoperatively and detect leakage at an early stage, is needed. Therefore, a miniature, wireless measurement system to detect tissue viability during and after colon surgery (continuously for 7 days) is being developed. The complete sensor chip should include an oxygen-saturation sensor (sO2), an oxygen-tension sensor (pO2), a carbon-dioxide tension sensor (pCO2) and a temperature sensor. The present work focuses on the use of the oxygen-tension and temperature sensors for animal studies. Initial in-vivo measurements were carried out on the small and large intestines of male wistar rats. The main goal was to measure the distribution of pO2 on the colon around the anastomosis and to determine the changes in pO2 during repetitive ischemia-and-reperfusion experiments on the small intestine. The paper presents the obtained measurement results

NEWBORN HEARING SCREENER BASED ON AUTOMATIC AUDITORY BRAINSTEM RESPONSE DETECTION

Julio Aldonate, Carlos Mercuri, José Biurrun, Juan Manuel Reta, Claudia Bonell, Gerardo G. Gentiletti, Sergio Escobar and Rubén Acevedo

Hearing loss is one of the pathologies with the highest prevalence in newborns. If it is not detected in time, it can affect the nervous system and cause problems in speech, language and cognitive development. The recommended methods for early detection are based on otoacoustic emissions (OAE) and/or auditory brainstem response (ABR). In this work, the design and implementation of an automated system based on ABR to detect hearing loss in newborns is presented. Preliminary evaluation in adults was satisfactory.

METROLOGICAL CHARACTETIZATION OF A CYCLE ERGOMETER

Bocciolone Marco, Comolli Lorenzo and Molteni Franco

A cycle ergometer was instrumented with suitable strain gauges to obtain metrological qualified measurements of the left and right leg torque. A wireless device was used to transmit in real time the gathered signals to the acquisition PC. Advantages are to give to the doctors and physiotherapists a diagnostic tool, to analyze the cycling pattern of the patients and to monitor the improvements during rehabilitation. The real time measures are also suitable input data for the Functional Electrical Stimulation (FES). All the analysis was conducted with a particular attention to spinal cord injured patients, which are characterized by highly asymmetric cycling: this measurement setup, by independent measurement of right and left torques, can be used successfully also in this particular situation. An explanation of the measuring principles and a set of first results are given, that show the potentiality of the setup.

A MINIMALLY INVASIVE MICROWAVE HYPERTHERMIC APPLICATOR WITH AN INTEGRATED TEMPERATURE SENSOR

Guido Biffi Gentili and Mariano Linari

In the field of microwave hyperthermia and thermo-ablation, the use of minimally invasive applicators is recognized as a very promising means for the treatment of small, early stage, cancer lesions because a very thin applicator can be easily introduced inside the body and precisely directed towards a deep seated tumour using the most advanced 3D imaging techniques and surgical stereo-navigation. Minimally invasive applicators have been successfully employed for the treatment of bladder carcinoma and brain tumours but the accurate temperature monitoring of the heated tissue volume still remains an open problem. In this paper we propose a new minimally invasive applicator, integrating a low-cost metallic wired temperature sensor. The miniaturised endocavitary applicator consists of a asymmetric isolated dipole operating at 2.45 GHz. The very slim shape of the applicator allows to easily insert it into the lesion through a soft plastic tube (catheter) while a temperature sensor, properly embedded in the applicator body, measures the tissue temperature at the interface with the catheter surface. An electromagnetic analysis based on the Finite Integration Technique (FIT) and experimental verifications over a tissue sample proved that a coaxial choke, enclosing the temperature sensor wires, allows localize the heating pattern in a restrict volume while drastically reducing measuring artefacts due to the perturbing effects induced by the probe leads.

AUTOREGRESSIVE FEATURES FOR A THOUGHT-TO-SPEECH CONVERTER

N. Nicolaou, J. Georgiou and M. Polycarpou

This paper presents our investigations towards a non-invasive custom-built thought-to-speech converter that decodes mental tasks into morse code, text and then speech. The proposed system is aimed primarily at people who have lost their ability to communicate via conventional means. The investigations presented here are part of our greater search for an appropriate set of features, classifiers and mental tasks that would maximise classification accuracy in such a system. Here Autoregressive (AR) coefficients and Power Spectral Density (PSD) features have been classified using a Support Vector Machine (SVM). The classification accuracy was higher with AR features compared to PSD. In addition, the use of an SVM to classify the AR coefficients increased the classification rate by up to 16.3% compared to that reported in different work, where other classifiers were used. It was also observed that the combination of mental tasks for which highest classification was obtained varied from subject to subject; hence the mental tasks to be used should be carefully chosen to match each subject.

RAPID FINITE STATE MACHINE CONTROL OF INDIVIDUAL DNA MOLECULES IN A NANOPORE

William B. Dunbar, Noah A. Wilson, Robin Abu-Shumays, Elizabeth Koch and Seico Benner

The contribution of this paper is to demonstrate feedback voltage control of individual DNA molecules cap- tured in a nanopore. In the nanopore system, an electrical potential (voltage) is applied across a lipid bilayer, formed across a 20 ?m teflon aperture. A single protein channel is inserted in the bilayer, resulting in a mea- surable ionic current flow through the channel. A finite state machine is used to program voltage control logic, executed on a field-programmable gate array, for rapid detection and regulation of each DNA molecule. In particular, prompt voltage reduction is used to demonstrate extension of the dwell time of DNA hairpins in the nanopore. Next, voltage reversal after a preset dwell time is used to demonstrate automated expulsion of each molecule prior to hairpin unzipping. Such rapid control authority of single molecular complexes captured in the nanopore device, and the ability to control hundreds of such complexes in much less than one hour, demonstrates a novel high-throughput, high-resolution capability. This capability is an integral part of our ongoing research for rapid sequencing and dynamic force spectroscopy of enzyme-bound biopolymers.

THERMORESPONSIVE POLYMER-BASED MICRODEVICE FOR NANO-LIQUID CHROMATOGRAPHY

Guillaume Paumier, Sovann Siv, Aurélien Bancaud, Jan Sudor and Anne-Marie Gué

We report here on the development of an integrated device for sample desalting and pre-concentration for nanoLC / ESI-MS analysis combining poly(N-isopropyl acrylamide) (PNIPAM) grafted microbeads and the means to dynamically control their temperature. Thermoresponsive properties of PNIPAM induce switchable hydrophobic/hydrophilic surfaces on which peptides can reversibly adsorb and desorb. The device is fabricated on a glass or pyrex substrate with deposited Ti/Au electrodes serving as built-in resistive heating sources. Pre-molded microfluidic channels and reservoirs made in PDMS are eventually assembled. Electrical and thermal characterization together with multiphysics modeling have been performed. The SiO2 surfaces of the channels and silica beads used as carriers of the stationary phases have been end-grafted with PNIPAM and employed to study the reversible adsorption and release kinetics of albumin-fluorescein conjugates by fluorescence video microscopy. It is clearly shown albumin-fluorescein complexes adsorb on beads surfaces above the transition temperature of NIPAM (hydrophobic state), and are released when the temperature decreases (hydrophilic state), yet not fully reversibly.

WIRELESS CONTEXTUAL INFORMATION ELECTRONIC SYSTEM FOR PEOPLE WITH DISABILITIES

S. Borromeo, C. Rodriguez-Sánchez, J. A. Hernández-Tamames and N. Malpica

In this work we present a prototype of two electronic devices for providing relevant information to disabled people, such as the blind, deaf or elderly, in public environments (railway stations, airports, etc). Usually, this kind of collectivities is discriminated in terms of information access. Most of the public information is in text panels, monitors or traffic signals. The rights of these people are easily forgotten. With this work we try to make an effort in this direction facilitating the information access to these collectivities. In order to avoid them feeling different we try to adapt the transmission to standard portable devices. We based the work on bluetooth technology. Concerned by costs, in order to popularize this technology, our designs use off-the-shelf components. We also propose a new device to avoid the proximity marketing spam so that these people don’t suffer its consequences.

ULTRASONIC MOTION TRACKING OF INSTRUMENTS IN OPERATING THEATRE

Alejandro Ibarz, Roberto Casas, Álvaro Marco, Héctor Gracia, Rubén Blasco and Jorge Falcó

The purpose of this paper is to address the design of a system to track surgical instrument’s movement during an operation. Motion tracking of surgical instruments is one of the most interesting methods to survey the data needed for medical robotics, computer-aided surgery, skills assessment and training progress applications. Over the wide range of tracking technologies, low frequency ultrasound was selected to meet the system’s requirements. Factors that bring about measurement inaccuracies are analyzed and taken into account when developing the system. Furthermore, a localization algorithm that calculates three-dimensional position using one-dimensional distances and overriding signal blockings is presented. Moreover, experimental results of a resectoscope mock up motion tracking are shown.

AUTOMATED CELL CHARACTERIZATION PLATFORM: APPLICATION TO YEAST PROTOPLAST STUDY BY ELECTROROTATION

J. Laforêt, M. Frénéa-Robin, H. Cérémonie, F. Buret and L. Nicolas

This paper aims at studying yeast protoplasts and yeast cells electrorotation spectra, obtained using polynomial microelectrode structures powered by computer-controlled generators. Measurements were made over the frequency range 100 kHz to 80MHz, mostly in a suspending medium of conductivity 50 mS/m inside the rotation chamber. The rotation rate of yeast protoplasts was inferior to that of whole yeast cells. To understand such behavioral differences, yeast protoplasts were modelled as single-shell spheres in a first approach.

MICROCOMPUTERIZED SYSTEM TO ASSESS THE PERFORMANCE OF INFANT INCUBATORS

Mário Anderson de Oliveira, Maurício Campelo Tavares and Raimes Moraes

This work presents a system based on a microcomputer to assess the performance of infant incubators in a semi-automatic manner. It carries out the tests described by the section 8 of the NBR IEC 601- 2-19 (1999). The developed electronic circuit acquires data from the sensors using a microcontroller. A set of sensors are used: five for temperature, one for humidity and one for air flow. The sampled data is sent to the PC via Bluetooth. The software running on the PC manages the data sampling, as well as guides the user through the test procedure by means of messages and sound alerts at the end of each stage. The sampled data is shown on the screen and also stored in a database that can be remotely accessed. The results are presented on a graph where the measurements (temperature, humidity and air flow) performed during the whole test can be seen. The procedure to calibrate the sensors and an infant incubator assessment carried out with the developed system is presented.

COMANIPULATION WITH FORCE FEEDBACK IN ROBOTIC SURGERY

Barthélemy Cagneau, Delphine Bellot, Guillaume Morel, Nabil Zemiti and Gianluca D'Agostino

This paper presents a control scheme for augmented comanipulation with force feedback in robotic surgery. This approach aims at increasing the surgeon's dexterity. The surgeon manipulates a handle mounted on the robot which manipulates the instrument. The control law ensures that the instrument applies on the organ the same forces that the surgeon applies on the handle but decreased by a scale factor. As a consequence, the robotic device provides the surgeon with an augmented sensation of the interaction forces between the instrument and the organ. The proposed control law does not require any knowledge of the environment. This control scheme is proven stable thanks to a passivity study. Indeed, passivity analysis is a useful tool for the stability analysis of a robot interacting with an unknown environment. Experimental results are presented on a robot dedicated to minimally invasive surgery.

COMPACT PULSE OXIMETER USING PIC18F4550 MICROCONTROLLER

Leonardo Zane Vilhegas, Adir José Moreira and Ronaldo Domingues Mansano

In this paper is propose one compact pulse oximeter system using a PIC18F4550 micrcontroller, which makes use of USB (Universal Serial Bus) communication technology. The device has one LCD (Liquid Crystal Display) 20x4 to continuous check and has the possibility to get one parallel communication with a PC (Personal Computer) to analysis more detailed. The system is compound for oxygen saturation measures (SpO2) and heart rate. The equipment is compact and show easy to handle and simple use.

MPSOC ARCHITECTURAL DESIGN AND SYNTHESIS FOR REAL-TIME BIOMEDICAL SIGNAL PROCESSING IN GAMMA CAMERAS

Kai Sun, Hongxing Wei, Tianmiao Wang, Meng Wang, Zili Shao and Hui Liu

MPSoC (Multi-Processor System-on-Chip) architecture is becoming increasingly used because it can provide designers much more opportunities to meet specific performance and power goals. In this paper, we propose an MPSoC architecture for implementing real-time signal processing in gamma camera. Based on a fully analysis of the characteristics of the application, we design several algorithms to optimize the systems in terms of processing speed, power consumption, and area costs etc. Two types of DSP core have been designed for the integral algorithm and the coordinate algorithm, the key parts of signal processing in a gamma camera. An interconnection synthesis algorithm is proposed to reduce the area cost of the Network-on-Chip. We implement our MPSoC architecture on FPGA, and synthesize DSP cores and Network-on-Chip using Synopsys Design Compiler with a UMC 0.18um standard cell library. The results show that our technique can effectively accelerate the processing and satisfy the requirements of real-time signal processing for 256*256 image construction.

A PORTABLE ECG DEVICE IN A HOME CARE ENVIRONMENT USING BURST TRANSMISSION

Emilio M. Bumachar, Rodrigo V. Andreão and José G. Pereira-Filho

This article presents a wireless microcontrolled system for ECG home monitoring. The main particularity of the system is related to the data transmission strategy, which is intermittent to save battery power. In order to evaluate the strategy proposed, a comparison of the transmission time spent is made between a theoretical estimation and the experiments. Despite the fact that the success in the experiments is too dependent on the microcontroller used, the strategy proposed here clearly allows for improvements in power consumption.

DEVELOPMENT OF AN AMPEROMETRIC SENSOR FOR POTASSIUM IONS

Marcos F. S. Teixeira, Alex S. Lima, Patricia Monteiro Seraphim and Nerilso Bocchi

Hollandite-type manganese oxides are nanofibrous crystals with sub-nanometer open tunnels that provide a unique property for sensing applications. Sensor based on hollandite-type manganese oxide was investigated for amperometric detection of potassium. With an operating potential of +0.63 V versus SCE, potassium ions produce oxidation currents at the sensor, which can be exploited for quantitative determinations. The amperometric signals are linearly proportional to potassium ions concentration in the range 2.7 × 10−4 to 9.1 ×10−4 mol l−1 with a correlation coefficient of 0.9990. The construction and renewal are simple and inexpensive.

WIDEBAND WIRELESS LINK FOR BCI CONTROL - 100 kHz – 8/16 Channel for High Resolution EEG

C. P. Figueiredo, N. Dias, J. H. Correia and P. M. Mendes

This work presents a solution to obtain a wireless biopotential acquisition system with high data rate. Wireless systems are currently emerging with the possibility of being used for monitorization of several physiological parameters. However, most of the solutions are based on standard wireless systems. Besides the wireless throughput limitation, those systems are also limited in their software solutions and data acquisition capabilities. A trade-off solution between commercial of-the-shelf and custom design was explored by interfacing a MICAz with external instrumentation, while maximizing the rate of communication. The wireless system is being used for BCI control, operates at 2.4 GHz (Zigbee compliant), with a data rate of 250 Kbps for wireless link, and up to 1 Mbps for serial communication. Signals down to about 23 µV can be detected, and 8/16 single-ended channels are provided with 100 kHz sampling rate.

OPTIMIZATION OF A FES CYCLING NEUROPROSTHESIS ON STROKE PATIENTS BY MEANS OF THE LEFT AND RIGHT CRANK MEASUREMENTS

Ferrante Simona, Comolli Lorenzo, Pedrocchi Alessandra, Bocciolone Marco, Ferrigno Giancarlo and Molteni Franco

The use of functional electrical stimulation (FES) is a well established method in the rehabilitation of stroke patients. In particular, a bilateral movement such as cycling induced by FES would be crucial for these patients who had an unilateral motor impairment and had to recover an equivalent use of the limbs. To improve the rehabilitative effects of the FES cycling, a metrologically qualified cycle ergometer was used, so that the left and right crank torque values are measured in real time. Three protocols were evaluated. First, healthy subjects performed voluntary pedaling. Second, healthy subjects were stimulated one muscle individually to study the contribution of each single muscle to the cycling. Third, stroke patients executed a complete FES cycling trials. Results demonstrated that the proposed sensors could be successfully used to monitor online the unbalance of the cycling. Single muscle tests showed that only the quadriceps and the hamstrings provided a significant contribution to the crank torque. Patient trials confirmed the difficulty for stroke subjects to carry out symmetrical cycling. The use of the proposed sensors, hence, could offer a good signal for biofeedback neuroprostheses and for closed loop controllers.

THRESHOLD LOGIC GENE REGULATORY MODEL - Prediction of dorsal-ventral patterning and hardware-based simulation of Drosophila

Tejaswi Gowda, Samuel Leshner, Sarma Vrudhula and Seungchan Kim

Motivation: Precise characterization of gene regulatory mechanisms is a fundamental problem in develop- mental biology. The vast amount of data generated by the sequencing of the genome of various organisms will not be of much value without a detailed understanding of the interaction between the different genes and gene products. In this paper we present a new gene regulatory network (GRN) model which is based on threshold logic (TL). Two different set of genes are responsible for the cell patterning of the Drosophila embryo. By using the proposed threshold logic gene regulatory model (TLGRM), we derive the different gene regulatory rules for the gene products involved. We use these rules to model and explain the interaction between the genes. This is done by discrete time step simulation until a steady state is obtained. The steady state represents a pattern that corresponds to the fixed gene expression in the Drosophila embryo. Results: The steady state gene expression predicted by the model clearly mimics the actual wild-type gene expression along the dorsal-ventral axis in the Drosophila embryo. We thus demonstrate that for a well char- acterized gene regulatory system, the nature and topology of interaction is enough to model gene regulation.

APPLICATION OF WEIGHTED LEAST SQUARES TO CALIBRATE A DIGITAL SYSTEM FOR MEASURING THE RESPIRATORY PRESSURES

José Leonardo Ferreira, Nadja Carvalho Pereira, Marconi de Oliveria Júnior, João Lucas da Silva Flávio Henrique Vasconcelos, Carlos Julio Tierra-Criollo, Raquel Britto and Verônica Franco Parreira

This article presents the results associated to calibration and evaluation of the measurement uncertainty of a digital respiratory pressures measuring system developed at the Biomedical Engineering Research & Development Laboratory (NEPEB) of the Department of Electrical Engineering – UFMG. The proposed method uses the least squares weighted regression to establish the measurement model and to evaluate the uncertainty. Results are presented for a measurement point, where the standard and combined uncertainties are determined.

PATIENT SIMULATOR APPLIED TO AUDITORY EVOKED POTENTIALS, ELECTROCARDIOGRAPHY AND ELECTRONYSTAGMOGRAPHY

M. Tavares, C. Richter, R. Moraes and T. Oliveira

This paper describes an electronic device, named SimPac I, developed to simulate auditory evoked potentials of short, middle and long latencies, ECG and electronystagmography signals. It uses sampled waveforms in order to better reproduce real physiologic AEPs. The simulator is based on the ADuC841 microconverter, a device with an 8052-like core, FLASH memory and two 12-bit DACs. The SimPac I is portable and easy to operate, and it is very useful for calibration of AEP, ECG, ENG and VENG systems during manufacture and maintenance. The simulator can also be used to support development and testing of DSP algorithms intended to filter and/or average the above mentioned signals. As a result, examples of several waveforms generated by the SimPac I are shown.

MEMS ANTENNA FOR WIRELESS BIOMEDICAL MICROSYSTEMS - Extremely Small Antenna for RF Receivers in Implantable Devices

P. M. Mendes and L. A. Rocha

This paper presents an extremely small antenna for wireless biomedical devices. Most of the implantable devices require very small dimensions. On way to achieve it is to use microtechnologies to obtain the required size reduction. One of the most challenging devices to integrate is the antenna, required if we want to communicate with the device trough a wireless link. The proposed antenna uses a MEMS structure to convert the incoming electromagnetic field in a voltage. This antenna allows the reception of signals using a carrier at 20 kHz and uses only a chip area of 2x2 mm2.

SOFTWARE FOR EMBEDDED CONTROLLER DESIGN - Application in Air and Water Caloric Electronystagmographic Stimulators

C. Richter, P. Mendes, M. Tavares and V. Alves

This paper describes the development and tests of software which was projected to support the work of designing and testing dedicated embedded controllers. The software was developed to accomplish two main features: helping to model the physical system to be controlled; and helping to easily implement and test a proposed controller to be applied to the physical system. Two practical applications of this software are presented. The first one is the design of a temperature controller for the next version of a water bi-thermal caloric stimulator named E96, which has as main requirement fast and accurate temperature response with no overshoot. The second one is also a caloric stimulator, but the transfer media is air instead of water. Those equipments help otorhinolaryngologists in electronystagmography exam. Details on the caloric stimulators hardware and software, the proposed controllers and the results obtained, are presented. The software was considered functional for the proposed applications.

MECHANOMYOGRAPHIC SENSOR - A Triaxial Accelerometry Approach

Guilherme Nunes Nogueira-Neto, Ronie Wesley Müller, Fábio Andrey Salles, Percy Nohama and Vera Lúcia da Silveira Nantes Button

Recently, accelerometers have been used to acquire mechanomyography signals. These signals are due to muscle lateral oscillations during contraction. In this study, a sensor acquired such vibrations in three directions. A triaxial accelerometer-based sensor was constructed and tested with a controlled mechanical vibrator and subwoofer speaker (both from 10Hz up to 40Hz) during isokinetic muscle contraction (3 volunteers, 50 extensions at 300 degrees/s). With triaxial accelerometry it was possible to compute the MMG modulus signal. For normalised and average values, MMG amplitude presented strong correlation coefficients (R=0,89) with RMS and peak torque. Below 80% of normalised data, MMG amplitude and torque values (RMS and peak) seem to converge.

SMART DIELECTRIC ELASTOMERS AND THEIR POTENTIAL FOR BIODEVICES

Todd A. Gisby, Iain A. Anderson, Emilio P. Calius and Shane Xie

Dielectric Elastomer (DE) actuators are compliant, ultra light-weight electromechanical devices that can be used as actuators, sensors, and power generators. While a relatively new technology, DE actuators can be produced using biocompatible materials and have already exhibited excellent performance in terms of strain, speed, pressure, specific energy density, and efficiency when compared to conventional actuation technologies and natural muscle. Further research is required in order for promising laboratory results to be translated into real-world applications, particularly in the areas of modelling and control, but the potential for multiple functions to be integrated into a single element is an exciting prospect for flexible smart structures and biodevices.

PUNCTURE DEPTH AND THE MECHANICAL STABILITY OF MICRONEEDLES

D. C. C. Lam, Y. H. Lee, K. T. Shek and G. Pang

Microneedles penetrating less than 1mm beneath the skin can deliver the drugs directly without piercing blood vessels or damaging nerves. The mechanical stability and the puncture behaviour of such needles were investigated experimentally by inserting steel needles into silicone rubber and pig skin. Puncture tests revealed that the length of needle actually buried in the flesh is less than 50% of the nominal insertion depth when the insertion depth is less 1mm. The mechanical stability of the buried needle-flesh assembly, as measured by the force needed to retract the needle, decreased with buried depth and needle diameter. Analysis of load data suggested that a 100-micron diameter microneedle buried 100 microns deep in pig skin would have a retraction force of 0.1mN, which is approximately 1% of the retraction force of a conventional needle inserted 5mm into the skin. The mechanical stability can be increased by using a microneedle array.

JUST PUSH PRINT - Biodevice Printing Using Bioinks, Electroinks and Quantum Dot Inks

Jan Lawrence Sumerel and Kai Sudau

Many advanced medical and environmental test devices require microscale patterning of cells, proteins, or other biological materials, and the need for these devices to contain active functional material components has increased dramatically. In addition, the biological material often times requires an interface with an electrical or optical output signal. Efficient production methods are paramount to meeting market demands, and ink jet printing offers an easy, low cost alternative to materials deposition used in current biodevice manufacturing. However, fluid development and proper printing parameters at the research level are required for manufacturing processing and will be critical to process adoption. In this paper, operating parameters and fluid characterization have been developed through processing biofluids, organic and inorganic conductive fluids and semiconductor nanoparticles. Because of the inherent versatility, uniformity and scalability of this system, established operating parameters coupled with proper fluid characterization will ultimately be translatable to production line systems. Our results demonstrate that piezoelectric ink jet deposition is a powerful non-contact, non-destructive additive process that will allow microscale patterning of biodevice components.

MEASUREMENT OF CELL FORCES USING A POLYMER MEMS SENSOR

Nicholas Ferrell, James Woodard and Derek Hansford

Cellular mechanics are responsible for execution and regulation of a number of cell functions. Mechanical forces generated within the cytoskeleton are transmitted via transmembrane linkages to the underlying substrate. Measurement of these forces could lead to a wealth of additional information about how cellular mechanics plays a role in cell function and signal transduction. Here we describe the design, fabrication, and testing of a polystyrene cantilever beam array for measuring forces generated by WS1 human skin fibroblasts. Finite element analysis was used to guide the design of a compound cantilever beam. Sensors were fabricated from polystyrene to provide a well-studied and biocompatible surface for cell attachment. Soft lithography based techniques were used for microfabrication of the sensors. Cells were placed on four and eight probe cantilever sensors and deflection of the probes was measured optically during attachment and spreading of the cells. The device was successfully used to measure time varying mechanical forces generated by fibroblast cells.

AN OBJECTIVE METHOD TO EVALUATE FORCE AND KNEE JOINT MOMENTS DURING ISOMETRIC EXTENSION

F. Paez, C. Frigo, E. Pavan, E. Guanziroli and S. Frasca

A simple method to evaluate force and moments of knee joint during isometric extension has been developed and provide to the physician a fast and objective tool for the evaluation of patients before and after a surgery or rehabilitative program. Experiments where made on 15 normal subjects (Age 12-15) and on 15 patients with cerebral palsy that were entering the rehabilitative treatment plan or candidate for surgery. Graphs of angle-force and anglemoment were obtained. The patients started from 90° of knee flexion and extended step-bystep the knee joint until the maximum knee extension was achieved. Force, angle and moment were measured at each step. The results show that the force and moment of knee joint decrease as far as the knee joint extends but there is a range of constant behaviour (between 20° and 40°). Future develop of this device is to make it easy to use directly in clinical applications

DESIGN OF A PC-BASED PATIENT SIMULATOR FOR TESTING AND CALIBRATION OF ELECTROMEDICAL DEVICES USING LABVIEW

Pedro Pablo Escobar, Gerardo Acosta and Marcos Formica

Modern digital biomedical devices need a testing and calibrating equipment to asses its functional state with the appropiate technology, so patient simulators have become an essential tool for maintenance and biomedical engineers. An interactive virtual instrument was developed in Labview for simulation of healthy and pathological conditions to test biomedical devices which acquire, register and store temporal evolution of human physiological variables. In this article we present some details of the design and implementation of a simple pc-based patient simulator using Labview, in order to obtain a low cost solution for teaching and practical purposes.

STUDY OF DENTAL GYPSUM USING FIBRE SENSORS - Analysis of Different Water/Powder Ratios of High Strength Dental Stone

Nélia Alberto, Rogério Nogueira, Lídia Carvalho, Ilda Abe, Hypolito Kalinowski and João L. Pinto

Within this work, it was experimentally studied the influence of the water/powder (W/P) ratios of a kind of dental gypsum, namely high strength dental stone, in the setting time and expansion, using fibre Bragg grating (FBG) sensors. Two sensors were used: one FBG in close contact with gypsum, which is sensitive to temperature and strain variations; the other one is inside a double needle, in order to be only sensitive to temperature. The results show that, a change in the W/P ratio influences the maximum strain value, as well as the setting time. This type of information is quite important to the dental prosthesis technician’s, being the present technique a good tool to acquire quantitative data from the expansion and temperature variation of the material.

MICROWAVE DIELECTRIC SPECTROSCOPY OF LOW-VOLUME FRACTION HUMAN CANCER CELLS EMBEDDED IN COLLAGEN GELS - Experimental Feasibility Study with an Open-ended Coaxial Probe

Stéphane Egot-Lemaire, Pierre-Olivier Bagnaninchi, Jacek Pijanka,Josep Sulé-Suso and Serguei Semenov

This paper addresses and demonstrates the feasibility for microwave dielectric spectroscopy of detecting small volume fractions of SK-MES lung cancer cells embedded in collagen gels with an open-ended coaxial probe. Measurements were performed on the frequency range 200 MHz – 2 GHz. For all the cell volume fractions tested, a significant difference in complex permittivity was observed between composite gels (containing cells) compared to gels alone. Statistically significant changes were especially found in the real part of the permittivity, which decreased consistently when the volume fraction increased.

ELECTRONIC DEVICES FOR RECONSTRUCTION OF HEARING

Albrecht Eiber

The effect of specific hearing impairments can be alleviated or compensated using electrically driven hearing aids. There is a broad variety of devices for stimulating the hearing either acoustically, mechanically or electrically. Their applications depend on the type, the severity and the location of a particular impairment. In order to get an optimal reconstruction, additionally to the medical aspects the dynamical behavior of the implant has to be regarded together with the individual situation of the patient simultaneously. Because of the broad variation of individuals and situations, the belonging parameters are time dependent and vary in a wide range, too. Thus, the design of a hearing device must be robust or insensitive against parameter variation and a sensitivity analysis with respect to parameters of the device, variation of anatomy and variation of insertion is needed. By means of mechanical simulation models enhanced by the behavior of the actuator and its control, the dynamical behavior of implants can be calculated and optimized. Such simulations helps to shorten series of experiments in the lab and in clinical practice and guidelines for the designer and for the surgeon can be derived.

SIMULATION TOOLS FOR WIRELESS SENSOR NETWORKS IN MEDICINE - A Comparative Study

Paulo A. C. S. Neves, Joel F. P. Fonseca and Joel J. P. C. Rodrigues

This paper presents a study on three simulation tools for Wireless Sensor Networks: Network Simulator 2 (ns-2), Java Simulator (J-Sim) and Sensor Network Emulator and Simulator (SENSE). We present the concept of Wireless Sensor Networks, each simulator in terms of its features, a view on current applications of Wireless Sensor Networks on medicine and a comparative study on the simulators studied. It was shown that SENSE should be the better approach for Wireless Sensor Networks, in comparison with ns-2 and J-Sim, in spite of a large user community and more experience on the ns-2 and J-Sim. The introduction of a graphical interface for SENSE will greatly benefit the simulator use.

A MICRO ULTRA LOW POWER RF RADIO FOR NEURAL SIGNAL RECORDING

Rui Zhong, Richard Liu, Haleh Fotowat and Fabrizio Gabbiani

This paper reports the development of a small, light-weight and mini-battery operated low power radio transmitter for neural signal recording. This system allows recording of neural signal down to the level of 50 μV. A micromachined electrode is used to obtain these signals. The neural signal is then amplified 10,000 times and transmitted to the receiver at 433 MHz. The manufactured radio system is 7 mm by 6 mm in size and 0.5 gram in weight, with a power consumption of 750 μW. Radio functionality is tested and verified on locusts.

NONLINEAR MODELLING IN BIOMEDICAL APPLICATIONS USING ANNS

Vančo Litovski and Miona Andrejević Stošović

During the design of many biomedical prostheses based on electrical and electronic fundamental actions, simulation is indispensable. It comprises, however, necessity for adequate models to be used. Main difficulties related to the modelling of such devices is their nonlinearity and dynamic behavior. Here we report application of recurrent artificial neural network for modelling of a nonlinear two-terminal circuit equivalent to a specific implantable hearing device. The method is general in the sense that any nonlinear dynamic two-terminal device or circuit may be modelled in the same way. The model generated was successfully used for simulation and optimization of a driver (operational amplifier) - transducer ensemble. That confirms our claim that optimization in the electrical domain should take place in order to achieve best performance of the hearing aid. It is to be contrasted to the optical methods based on surgery frequently used.

NOVEL FIELD-EFFECT CONTROLLED SINGLE-WALLED CARBON NANOTUBE NETWORK DEVICES FOR BIOMEDICAL SENSOR APPLICATIONS

Udo Schwalke

In this position paper we propose a novel method for the realization of carbon nanotube field-effect sensors (CNTFESs) which will most likely have a strong impact on the next-generation of sensors. CNTFESs are ideally suitable for biomedical sensor applications due to their excellent inherent properties such as ultra small size, high specific surface area and extremely high sensitivity. CNTFESs are based on carbon nanotube field-effect transistors (CNTFETs) which are optimized for sensor applications. We have succeeded to develop a simple, reproducible fabrication process to grow individual CNTs and CNT-networks directly within the specified device area. No tedious manual manipulation and alignment of the CNTs is necessary. Electrical results of the fabricated fully functional CNTFETs are presented and the use of these devices as single-walled CNT-based field-effect controlled sensors for virus detection is discussed.

SOFT GELS WITH HIGH ELECTRIC, ULTRASOUND CONDUCTIVITY AND STABLE THREE-DIMENSIONAL CONFIGURATION AS ENERGY TRANSMISSIBLE MEDIA

Yasuo Shikinami, Kazuhiro Yasukawa and Kaoru Tsuta

We had synthesized single component permanent gels, segmented polyurethane gels (SPUGs), essentially consisting of gelatinizing component-only, of which almost of segments and dangling chains are liquid state at ambient temperatures. SPUGs transmit energy well such as electricity, light and ultrasound. In this article, SPUGs were improved by adding dispersive media into swollen SPUGs (S-SPUGs), which acquired higher electro conductivity (1.2x10-3 S/cm) at room temperature and lower ultrasound attenuation (0.13 dB/cm/MHz) than SPUGs and readily responded to very low mechanical stress (Young modulus 3.7 Pa) due to its high flexibility like soft tissues of living body. The S-SPUGs, which have three-dimensionally casting moldability and stable configuration, are potentially applicable to soft biomaterials with energy transmissible, transducing faculty.

METHOD FOR MEASURING PARYLENE THICKNESS USING QUARTZ CRYSTAL MICROBALANCE

Henna Heinilä, Maunu Mäntylä and Pekka Heino

Biomedical implants have many strict requirements as they are being implanted for a long time under the skin. The primary demands are that the implant must be biocompatible and biostable. These are the main issues that must be considered when selecting the medical coating material. Parylene polymer is widely used in medical implant devices as coating material. Parylene is applied with vacuum deposition equipment that controls the coating rate and final coating thickness. The thickness is a function of substrate surface area in vacuum chamber, program parameters, and amount of dimer charge. Therefore it is difficult to know the exact final thickness of parylene in the beginning of the coating process. This paper describes a method for measuring parylene thickness with a quartz crystal and its resonance frequency. In future these results can be used for specifying the parylene thickness real-time during the coating process.

PATIENT-ADAPTABLE BIOMEDICAL DEVICES - Benefits and Barriers for Granting Patients More Control

James Andrew Smith and André Seyfarth

End-users of biomedical devices, like many patients undergoing treatment in healthcare systems, often demonstrate an active interest in their therapy. Patient-specific customization of medical devices, such as orthoses, prostheses and implants, is an expensive, time-consuming process. Given how many of these patients are pro-active and self-motivated it seems appropriate to the authors that these characteristics be harnessed to make the adaptation of the device to the patient more cost effective. In short, it is proposed that the device end-user – the patient – play an active role in the tuning and adaptation of the device, especially in the out-patient context. However, the perceived risk associated with a more pro-active and independent role for the patient is a barrier to this possibility. These factors are examined and a proposal for a practical approach to a patient-controlled device optimization process is put forward.

CONSIDERATIONS ON IMPROVING THE DESIGN OF CUFF ELECTRODE FOR ENG RECORDING - Geometrical Approach, Dedicated IC, Sensitivity and Noise Rejection

Fabien Soulier, Lionel Gouyet, Guy Cathébras, Serge Bernard, David Guiraud and Yves Bertrand

Cuff electrodes have several advantages for in situ recording ENG signal. They are easy to implant and not very invasive for the patient. Nevertheless, they are subject to background parasitic noise, especially the EMG generated by the muscles. We show that the use of cuff electrodes with large numbers of poles can to increase their sensitivity and their selectivity with respect to a efficient noise rejection. We investigate several configurations and compare the performances of a tripolar cuff electrode versus a multipolar one in numerical simulation. One the other hand the use of cuff electrodes leads to the recording of the sum of the signals generated by all the axons within the nerve. This puts in evidence the need of signal separation techniques that require a great quantity of information. Again, we show that multipolar electrodes can solve this problem since poles can be switched one to another, provided that they are distributed along a regular tessellation. Finally, we present the structure of an ASIC preamplifier processing a spatial filtering to obtain the Laplacian of the potential rejecting low-frequency noise.

AUTOMATIC FALL DETECTION AND ALERT SYSTEM - A Compact GPS/GSM Enabled Unit Based on Accelerometry

Hugo Silva, Filipe Silva, Hugo Gamboa and Vítor Viegas

Accidental falls are among one of the main causes of death and incapability of elderly subjects. This stands both as a healthcare problem, in the sense that, upon falling, if subjects are not assisted in an early stage severe long term consequences may arise; and as a limitation for the subject’s daily life, in the sense that they generally deprive themselves of regular routines as a preventive measure. In this paper we describe a hardware unit conceived to automatically detect fall events and trigger a set of alert actions, which allow the remote detection of the occurrence and facilitate rapid assistance.