BIODEVICES 2017 Abstracts


Full Papers
Paper Nr: 2
Title:

DWT based Low Power Image Compressor for Wireless Capsule Endoscopy

Authors:

Kushaagra Goyal, Abhishek Lal and Basabi Bhaumik

Abstract: In WCE literature so far, the stress is on having an image compressor with low power consumption and silicon area. However one needs to consider the image compressor along with the serialiser, the interface between image compressor and transmitter as a single unit. In this paper, we propose the design of a hardware efficient, low power image compression system along with the serialiser for wireless capsule endoscopy. It is based on integer version of discrete wavelet transform and uses low complexity encoders like adaptive Golomb-Rice encoder. An alternative architecture for serialiser is proposed specific to the algorithm which runs at only 8 times instead of 32 times the frequency required at the existing compressors in the literature. The proposed algorithm gives a compression of 91.88 percent at a PSNR of 38.17. The implementation of the compressor plus serialiser in 130nm HS (high speed) standard CMOS process technology consumes 16.9uW of power at 2 frames per second for 256256 image. Compared to the existing designs at similar power consumption, the proposed scheme reduces the serialiser’s frequency by a factor of four besides giving at least 1.5 % higher compression.

Paper Nr: 4
Title:

In-vitro Force Assessments of an Autoclavable Instrumented Sternal Retractor

Authors:

Giovanni Saggio, Giuseppe Tancredi, Laura Sbernini, Costantino Del Gaudio, Alessandra Bianco and Jacob Zeitani

Abstract: It is well known that median sternotomy might lead to rib and/or sternum micro/macro-fractures and/or brachial plexus injuries, eventually resulting in chronic pain with significant impact on patient’s quality life.Postoperative chronic pain is recognized as a multifactorial complex issue, it has been assessed that excessive sternum retraction forces can be considered one of these factors. On this basis, the Authors developed a reliable and sterilizable system potentially able to real-time monitor and control the retraction forces along the hemisternums. A Finochietto sternal retractor was instrumented by means of ultra-thin force sensors interfaced with ad hoc electronic circuitry. Two different sets of sensors were adopted, one of which able to support autoclave operating conditions. In vitro tests were performed by means of a made on purpose dummy. The instrumented retractor allows monitoring of the force exerted on both the arms during the opening procedure. Force versus time patterns were real-time acquired and stored, distribution of forces was determined along with the values of mean, maximum and plateau force. Results demonstrate the reliability of the instrumented retractor in measuring forces, up to 400N. Cost-effectiveness and feasibility can be considered further additional values of the proposed instrumented retractor.

Paper Nr: 15
Title:

Effects of Configuration and Dimension of Concentric Ring Electrodes in EEnG Recording Applications

Authors:

V. Zena-Giménez, J. Garcia-Casado, G. Prats-Boluda and Y. Ye-Lin

Abstract: Implementing Laplacian techniques through ring electrodes in bioelectrical records can improve the signal quality and spatial resolution in comparison to that obtained with conventional disk electrodes. Different dimensions of the rings and recording settings in one electrode can facilitate bioelectric mapping, and provide flexibility to studies in the field of bioelectrical signal recording. A concentric multi-ring electrode (multi-CRE), flexible, with gel, auto-adhesive, that can be configured for monopolar and bipolar records is presented in this paper. Simultaneous recording of intestinal myoelectric activity (electroenterogram, EEnG) by means of multi-CRE and conventional disk electrodes, respiration and electrocardiogram signals were performed in healthy subjects. The results revealed that the ability to detect intestinal slow waves was greatly influenced by the ability to reject its main interferences. Regarding the recording configuration, it can be concluded that the use of flexible concentric electrodes in bipolar configuration improves the quality of EEnG signals. Regarding to the effect of the electrode size, the middle ring (30 mm) reached a balance between better performance against respiratory interference of small rings and better response to low frequency interference of large rings.

Paper Nr: 17
Title:

μSmartScope: 3D-printed Smartphone Microscope with Motorized Automated Stage

Authors:

Luís Rosado, João Oliveira, Maria João M. Vasconcelos, José M. Correia da Costa, Dirk Elias and Jaime S. Cardoso

Abstract: Microscopic examination is currently the gold standard test for diagnosis of several neglected tropical diseases. However, reliable identification of parasitic infections requires in-depth train and access to proper equipment for subsequent microscopic analysis. These requirements are closely related with the increasing interest in the development of computer-aided diagnosis systems, and Mobile Health is starting to play an important role when it comes to health in Africa, allowing for distributed solutions that provide access to complex diagnosis even in rural areas. In this paper, we present a 3D-printed microscope that can easily be attached to a wide range of mobile devices models. To the best of our knowledge, this is the first proposed smartphone-based alternative to conventional microscopy that allows autonomous acquisition of a pre-defined number of images at 1000x magnification with suitable resolution, by using a motorized automated stage fully powered and controlled by a smartphone, without the need of manual focus of the smear slide. Reference smears slides with different parasites were used to test the device. The acquired images showed that was possible to visually detect those agents, which clearly illustrate the potential that this device can have, specially in developing countries with limited access to healthcare services.

Paper Nr: 21
Title:

Single Cell Array Impedance Analysis for Cell Detection and Classification in a Microfluidic Device

Authors:

Emre Altinagac, Selen Taskin and Hüseyin Kizil

Abstract: Impedance analysis of single cells is presented in this paper. Following the separation of a target cell type by dielectrophoresis in our previous work, this paper focuses on capturing the cells as a single array and performing impedance analysis to point out the signature difference between each cell type. Lab-on-a-chip devices having a titanium interdigitated electrode layer on a glass substrate and a PDMS microchannel are fabricated to capture each cell in a single form and perform impedance analysis. MDA-MB-231 and HeLa cells are used in our experiments.

Paper Nr: 23
Title:

A Portable Sensing System for Impedance based Detection of Biotoxin Substances

Authors:

V. I. Ogurtsov, K. Twomey and J. Pulka

Abstract: The study describes the development of a portable autonomous biosensing platform for impedance based detection of biotoxin substances. The platform implements a label-free approach, which is based on detection of the biosensor interfacial changes due to a bio recognition reaction. The interfacial changes are sensed by means of Electrochemical Impedance Spectroscopy in a frequency range from 10 Hz to 100 kHz. The platform comprises of an electrochemical biosensor, portable low-noise mix signal hardware and associated software incorporating signal processing algorithms for extraction biotarget concentration from the biosensor response. The biosensor is realized as an on-chip package-free three electrode micro electrochemical cell consisted of a counter electrode (CE), a reference electrode (RE) and a working electrode (WE) patterned on a single silicon chip. WE represents an array of 40 um diameter gold disks with 400 m center-to-center distance, which were undergone of corresponding surface modification for antibody immobilisation. The developed system was validated by an example of T-2 toxin detection. Performed calibration in the range of 0 –250 ppm of T2 toxin concentrations confirmed that the system can provide successful detection of the toxin at the levels below 25 ppm.

Paper Nr: 39
Title:

Microfluidic Prototype of a Lab-on-Chip Device for Lung Cancer Diagnostics

Authors:

Dalila Vieira, Filipa Mata, Ana Moita and António Moreira

Abstract: Cell sorting for disease diagnostics is often achieved by fluorescence based identification of specific markers. However, in lung cancer diagnostics, cytological analysis of pleural fluids is not always reliable and immunofluorescence essays demand for specific sample preparation. Hence, this paper addresses the development of a microfluidic device for lung cancer diagnostics which infers on the potential of a diagnosis based on analysing the cell deformability (stiffness) that alters the rheological properties and consequently the flow characteristics. Cell deformability will be induced by external actuation. Electrowetting is used to transport the samples in an open configuration system using microdroplets. Effects of the test chip configuration, sample physico-chemical properties and potential adsorption mechanisms are discussed. Wettability plays here a vital role in the sample transport and in the diagnostic method to be tested. Hence, an innovative approach is presented, the 3D Laser Scanning Fluorescence Confocal Microscopy (3D-LSCFM) to provide a detailed reconstruction of the surface topology at the liquid-solid interface region thus allowing contact angles measurement with high spatial resolution.

Paper Nr: 40
Title:

A Hardware-in-the-loop Simulation Study of a Mechatronic System for Anterior Cruciate Ligament Injuries Rehabilitation

Authors:

Juan C. Yepes, A. J. Saldarriaga, Jorge M. Vélez, Vera Z. Pérez and Manuel J. Betancur

Abstract: One of the main ligaments of the knee is the Anterior Cruciate Ligament (ACL), which is critical to maintain stability and regular gait patterns. Moreover, the knee is the most complex and largest joint in the human body. There are many traditional methods and devices to assist therapy. Nevertheless, there are several research studies in robotic platforms for lower limb rehabilitation. This paper presents a hardware-in-the-loop (HIL) simulation of a movement control algorithm for mechatronic-assisted rehabilitation based on exercises and movements associated with therapies for ACL injuries. The implementation of the algorithm was conducted using a computational model in order to test the mechatronic system Nukawa without having to use the actual robot. Several tests were performed in order to validate the mathematical model of Nukawa. In order to assess whether the implemented HIL simulator works properly for ACL rehabilitation exercises, a physiotherapist performed six exercises and the movements were recorded with a commercial acquisition device, these trajectories were conducted to the HIL simulator. The Integral-Square-Error (ISE) was computed for each test, and since it was small, it may be despised. Therefore, the motion control algorithm is able to manipulate the three joints at the same time, hence it is possible to follow specific trajectories. In addition, the mean execution time M = 11.5 ms and the standard deviation SD = 3.9 taken by the controller is smaller than the sampling period, therefore we proposed that this system can be tested in real-time, without notable delays related to the movement control algorithm.

Paper Nr: 46
Title:

Determination of the Selectivity of Printed Wearable Sweat Sensors

Authors:

Alicia Zörner, Susanne Oertel, Björn Schmitz, Nadine Lang, Michael P. M. Jank and Lothar Frey

Abstract: The characterization and system integration of a fully screen-printed electrolyte biosensor is described. The purpose of this sensor is to determine the state of fitness during sports activity by measuring the ammonium concentration in sweat. Focusing on the selectivity of the ammonium sensor against interfering sodium and potassium ions, the separate solution method (SSM) and the fixed interference method (FIM) are compared on the basis of a single sensing device. The latter is mainly supported by the excellent stability of the sensors. For both interfering ions, the FIM analysis shows a sufficient margin for the operation of the sensor in the desired application in wearable health and fitness monitoring from sweat. The selectivity coefficients are better than 0.01 for sodium and still better than 0.1 for potassium. SSM delivers higher selectivity in both cases, although the discrepancies in selectivity point towards further optimization potential in the sensor architecture or materials combination.

Short Papers
Paper Nr: 5
Title:

Ambulatory Devices Measuring Cardiorespiratory Activity with Motion

Authors:

Marcel Młyńczak, Marek Żyliński, Wiktor Niewiadomski and Gerard Cybulski

Abstract: Holter-type devices with sets of sensors, enabling long-term measurement of quantitative respiratory parameters, were designed and constructed. Pneumonitor 2 was intended for physiologic and athletic applications, and Pneumonitor 3 for sleep studies. Both allow simultaneous, comfortable, ambulatory monitoring of cardiorespiratory activity, such as ECG, impedance pneumography (IP), and motion; the second device also allows pulse oximetry and uses improved setting with combined receiving ECG and IP electrodes. Preliminary results showed that our prototypes provide signals reliable to monitor heart and breathing activity quantitatively. We tested the devices in different conditions, including walking, stair-climbing, cycle ergometer training, natural daily activity, and sleep. They can quantitatively measure respiratory flows, volumes, and minute ventilation using IP after calibration. They are also able to estimate tachogram from ECG. They allow the detection of subject activity and body position via accelerometer and gyroscope, which is helpful during IP calibration and interpretation. Pneumonitor 3 also enables measurement of blood saturation with a pulse wave (pulse oximetry).

Paper Nr: 9
Title:

Modeling of Blood Perfusion in Dependence of Scanning Angle from LDPI Data

Authors:

Jan Kubicek, Iveta Bryjova, Marek Penhaker, Vladimir Kasik, Zbynek Labza, Martin Cerny and Martin Augustynek

Abstract: The paper deals with issue of the modelling and analysis of a scanning angle influence on the blood perfusion, and consequent proposal for their elimination. The first essential step of analysis is angle stabilization. In this step, we utilize special artificial arm allowing for a measuring angle adjustment in the scale of two axes. The modelling allows for simulation of perfusion units (PU) in the form of the quadratic model, which is consequently recalculated in the form of the linear expression. The second part of the analysis deals with the PU modelling in the dependence of the distance. In our analysis, we particularly use a segment of middle finger and forearm. In the last part, we propose theoretical conception of the curvature correction influence. This theoretical proposal leads to the relationship between measured and real PU parameter.

Paper Nr: 11
Title:

Objective Measurement of Hypertrophic Scars using Skin Colorimeter

Authors:

Iveta Bryjova, Jan Kubicek, Vladimir Kasik, Daniel Kamensky, Hana Klosova, Marek Penhaker and Martin Cerny

Abstract: The paper deals with the methodology of the scars pigmentation objective assessment and their time evaluation on the base acquired data with the skin colorimeter prototype DSC1 (Detection of Scar Color). The analysis is primarily focused on the hypertrophic scars pigmentation assessment after heeling of deep burns which often exhibit the pigmentation. In the process of the scars evaluation in some patients it goes to the spontaneous pigmentation changes. If the pigmentation changes long-term persist and patient requires corrections, various treatment methods can influence these pigmentation changes (for instance the laser therapy and others). In the context of the complex development evaluation and in the process of the scars treatment, these changes are commonly observable well but their quantification is usually difficult, therefore using of the objective methods is desirable. The particular kind of such objective method is the skin colorimeter. The technical concept and testing of the skin colorimeter prototype DSC1 is presented in this paper.

Paper Nr: 14
Title:

Parkinson’s Disease Tremor Suppression - A Double Approach Study - Part 1

Authors:

Wellington C. Pinheiro, Bruno E. Bittencourt, Lucas B. Luiz, Lucas A. Marcello, Vinicius F. Antonio, Paulo Henrique A. de Lira, Ricardo G. Stolf and Maria Claudia F. Castro

Abstract: Parkinson’s Disease (PD) is a neurodegenerative disorder that affects mostly elderly people. Approximately 2% of world population, over 60 years old, lives with PD. This pathology is recognized not only by motor symptoms such as tremor, postural gait and rigidity, but also, nonmotor symptoms as depression and sleep abnormalities may be developed as well. In Brazil, according to the Ministry of Health, 200,000 people face the challenge to develop day-by-day activities due to PD. More than just a disease causing motor disturbances, PD brings to patients uncertainties about their ability to take care of themselves independently. In this context, assistive technologies assume an important position in order to bring back life quality and self-trust to PD patients. This work aims to study techniques, develop hardware and software for a better approach in tremor suppression in order to bring back life quality to PD patients. This study approaches the problem of flexion/extension carpi radialis tremor suppression using two different strategies. The first is a mechanical suppression based on a servomotor opposing to tremor movement. The second strategy is a functional electrical stimulator. Both systems are triggered by electromyogram (EMG).

Paper Nr: 19
Title:

Randles Model of Vitreous Humor

Authors:

Tjerignimin Silue, Saugandhika Minnikanti and Nathalia Peixoto

Abstract: The vitreous is a gel-like structure found in the eyes. It is located above the retina to prevent the passage of fluids. As aging occurs, the vitreous can liquefy and can cause retinal detachment. The literature has little characterization of the vitreous, as it is often a less interesting structure than the retinal tissue. We investigate the impedance properties of the stimulation electrodes such as the constant phase element (Q) and the resistance of the solution (Rsol). We show results on vitreous characterization through electrochemical methods as a first step toward understanding the role of electrical stimulation in retinal prosthetics applications as it pertains to vitreous liquefaction. Our objective is to characterize the vitreous for a wide frequency range and to determine how charge is distributed through its conductive structure. Our electrochemical experiments were performed using insulated stainless steel electrodes (1) in phosphate buffered saline (PBS) and (2) in thimerosal as controls, (3) in vitreous without thimerosal, as well as (4) in vitreous preserved with thimerosal. We also performed cyclic voltammetry to measure the cathodic charge storage capacity for the electrodes for all experimental groups. Our results showed that the resistivity of the vitreous increases as thimerosal is added and that the cathodic charge storage capacity of the vitreous does not show any significant difference in the means as thimerosal is added.

Paper Nr: 22
Title:

Implementation of Machine Learning for Breath Collection

Authors:

Paulo Santos, Valentina Vassilenko, Fábio Vasconcelos and Flávio Gil

Abstract: Economic and technologic progresses states the analysis of human’s exhaled air as a promising tool for medical diagnosis and therapy monitoring. Challenges of most pulmonary breath acquisition devices are related to the substances’ concentrations that are source (oral cavity, esophageal and alveolar) dependent and their low values (in ppbv - pptv range). We introduce a prototype that is capable of collecting samples of exhaled air according to the respiratory source and independent of the metabolic production of carbon dioxide. It also allows to access the breathing cycle in real-time, detects the optimized sampling instants and selects the collection pathway through the implementation of an algorithm containing a machine learning process. A graphical interface allows the interaction between the operator/user and the process of acquisition making it easy, quick and reliable. The imposition of breath rhythm led to improvements in accuracy of obtaining samples from specific parts of the respiratory tract and it should be adapted according to their age and physiological/health condition. The technology implemented in the proposed system should be taken into consideration for further studies, since the prototype is suitable for selectively sampling exhaled air from persons according to its age, genre and physiological condition.

Paper Nr: 25
Title:

Development of an Integrated Optofluidic Platform for Droplet and Micro Particle Sensing - Microflow Analyzer for Interrogating Self Aligned Droplets and Droplet Encapsulated Micro Objects

Authors:

P. K. Shivhare, A. Prabhakar and A. K. Sen

Abstract: Here we report the development of a micro flow analyser that integrates digital microfluidics technology with optoelectronics for the detection of micron size droplets and particles. Digital microfluidics is employed for the encapsulation of microparticles inside droplets that self-align at the centre of a microchannel thus eliminates the need of complicated 3D focusing. Optoelectronics comprise a laser source and detectors for the measurement of forward scatter (FSC), side scatter (SSC) and fluorescence (FL) signals from the microparticles. The optoelectronics was first used with a simple 2D flow focusing channel to detect microparticles which showed uncertainty in the data due to lack of 3D focusing. The integrated device with digital microfluidics technology and optoelectronics was then used for the enumeration and detection of Rhodamine droplets of different size. Rhodamine droplets of different size were characterized based on FSC, SSC and FL. Finally, the device was used for the detection of fluorescent microbeads encapsulated inside aqueous droplets.

Paper Nr: 26
Title:

Development of a Lab on a Chip Flow Cytometer - Portable and Affordable Flowcytometer for Point of Care Diagnostics in Rural Areas

Authors:

A. Mohan, N. Marshkole, A. P. Nair, A. Bharadwaj, A. Prabhakar and T. Saiyed

Abstract: We have developed a lab prototype of a microfluidic flow analyzer, which is capable of quick and efficient analysis of biological samples. Low cost and portability makes it suitable for point of care diagnostics in rural area of developing countries. A significant size reduction has been achieved by choosing a microfluidic flow and pumping system, micro-electronic components, integrated circuits boards, and fiber optics. A two dimensional microfluidic chip fabricated with nanolithography technique integrates the fluidics and optics into a single platform. Forward scatters (FSC), side scatter (SSC) and fluorescence (FL) are measured from polystyrene beads as well as from different live cells. Overall dimension achieved for the final prototype is 39 cm x 22 cm x 10 cm.

Paper Nr: 28
Title:

in-vitro Assessment of Expanded-Polytetrafluoroethylene Stentless Tri-leaflet Valve Prosthesis for Aortic Valve Replacement

Authors:

Guangyu Zhu, Masakazu Nakao, Qi Yuan and Joon Hock Yeo

Abstract: Truly stentless polymeric valve prosthesis can be a viable alternative for aortic valve replacement (AVR). In the present paper, the dynamic and hemodynamic performance of a novel designed expanded-polytetrafluoroethylene (ePTFE) stentless tri-leaflet valve was assessed experimentally. The in-vitro tests were performed under time-varying physiological pressure by using the Vivitro pulse duplicator. A high-speed camera, a flow meter, and pressure transducers were utilized to evaluate the dynamic leaflet behaviours and coaptation parameters. The maximum effective orifice area, mean pressure gradient, regurgitant volume, leakage volume and energy loss of the stentless ePTFE tri-leaflet valve are 2.86 cm2, 9.89 mmHg, 7.09 ml/beat, 2.81 ml/beat and 129.03 mJ, respectively. The results of the current study may provide a viable option for the future clinical application.

Paper Nr: 33
Title:

Modulation of Impedance and Muscle Activation of the Upper Limb Joints while Simultaneously Controlling Manual-grasping and Walking

Authors:

Joseph Mizrahi, Navit Roth and Rahamim Seliktar

Abstract: The design of spring-based artificial and robotic arm joints presents a challenge in problems of transportation of manually-held objects during walking. For maintaining stability of these objects, stiffness and damping of the arm joints have to be adjusted by continuously tuning muscle activation. This necessitates knowledge about the mechanisms by which stiffness and damping (mechanical impedance) are being modulated in walking movement. The paradigm employed in this study consisted of modeling the impedance adjustments from input data obtained in simultaneously controlled grasping and walking experiments. While walking on a treadmill, tested subjects held a cup filled with liquid and were asked to aim at minimizing liquid spillage. Monitoring liquid spillage served to quantify stability of the hand as the end-effector of the upper limb. Kinematic data were obtained for the shoulder, elbow and wrist joints. Accelerometer data were obtained for the wrist and for the knee. Electro-myography (EMG) data were collected for the wrist flexor and extensor muscles. Based on the measured data, regressive functions were used to express stiffness and damping as a function of angle and angular velocity. The joints of the upper limb were thereafter successively constrained to study the effect of joint immobilization on joint impedance and muscle activation. The obtained results indicate the nonlinearity of the joint impedances as required in tasks of manual grasping of objects during locomotion, with and without joint constraints.

Paper Nr: 34
Title:

Evaluation of the Imaging Properties of a CT Scanner with the Adaptive Statistical Iterative Reconstruction Algorithm - Noise, Contrast and Spatial Resolution Properties of CT Images Reconstructed at Different Blending Levels

Authors:

Patrizio Barca, Marco Giannelli, Maria Evelina Fantacci and Davide Caramella

Abstract: X-ray Computed Tomography (CT) is an essential imaging technique for different diagnostic and therapeutic tasks. However, ionizing radiation from CT scanners represents the largest source of medical exposure for the population of industrialized countries. In order to reduce CT dose during patient examination, iterative reconstruction algorithms have been developed to help existing dose reduction methods. In this paper, we studied the image quality performance of a 64-slice CT scanner (Optima CT660, GE Healthcare, Waukesha, WI, USA) that implements both the conventional filtered back-projection (FBP) and the Adaptive Statistical Iterative Reconstruction (ASIR, GE Healthcare, Waukesha, WI, USA) algorithm. In order to compare the performance of these two reconstruction technologies, CT images of the Catphan®504 phantom were reconstructed using both conventional FBP and ASIR with different percentages of reconstruction from 20% to 100%. Noise level, noise power spectrum (NPS), contrast-to-noise ratio (CNR) and modulation transfer function (MTF) were estimated for different values of the main radiation exposure parameters (i.e. mAs, kVp, pitch and slice thickness) and contrast objects. We found that, as compared to conventional FBP, noise/CNR decreases/increases non-linearly up to 50%/100% when increasing the ASIR blending level of reconstruction. Furthermore, ASIR modifies the NPS curve shape (i.e. the noise texture). The MTF for ASIR-reconstructed images depended on both tube load and contrast level, whereas MTF of FBP-reconstructed images did not. For lower tube load and contrast level, ASIR offered lower performance as compared to conventional FBP in terms of reduced spatial resolution and MTF decreased with increasing ASIR blending level of reconstruction.

Paper Nr: 36
Title:

A Low Cost Wireless System to Monitor Plantar Pressure using Insole Sensor: Feasibility Approach

Authors:

Renato Varoto, Gustavo Casagrande Oliveira, Adolfo Victor Freire de Lima, Matheus Missola Critter and Alberto Cliquet Jr.

Abstract: Plantar pressure analysis is an important strategy applied in clinical, orthopaedics, sports and rehabilitation studies. In this context, this work describes the development and application of wireless system to monitor plantar pressure. This system is composed by a data acquisition module based on low cost electronic instrumentation, high resolution insole flexible pressure sensor and Java application for data real-time visualization. To verify the feasibility and effectiveness of the system, workbench tests were realized and a healthy subject performed pilot trials based on static and dynamic activities on the biomechanics platform. According to the preliminary results, this system is effective to show the interaction between the foot and floor in static and dynamic conditions, presenting a measurement range of pressure of 0-300kPa and rapid response, among other features. Thus, this system is a feasible tool for quick and practical mapping of plantar pressure.

Paper Nr: 44
Title:

A CMOS Tracking System Approach for Cell Motility Assays

Authors:

Cristina Martínez-Gómez, Alberto Olmo, Gloria Huertas, Pablo Pérez, Andres Maldonado-Jacobi and Alberto Yúfera

Abstract: This work proposes a method for studying and monitoring in real-time a single cell on a 2D electrode matrix, of great interest in cell motility assays and in the characterization of cancer cell metastasis. A CMOS system proposal for cell location based on occupation maps data generated from Electrical Cell-substrate Impedance Spectroscopy (ECIS) has been developed. From this cell model, obtained from experimental assays data, an algorithm based on analysis of the 8 nearest neighbors has been implemented, allowing the evaluation of the cell center of mass. The path followed by a cell, proposing a Brownian route, has been simulated with the proposed algorithm. The presented results show the success of the approach, with accuracy over 95% in the determination of any coordinate (x, y) from the expected center of mass.

Posters
Paper Nr: 6
Title:

New Simple Phenomenological Model for Laser Doppler Measurements of Blood Flow in Tissue

Authors:

Denis Lapitan, Dmitry Rogatkin, Saydulla Persheyev and Andrey Rogatkin

Abstract: Laser Doppler flowmetry (LDF) for measurements of tissue blood flow is well-known today. The basic theory of forming the registered optical signal in LDF is the model developed by R.Bonner and R. Nossal. However, claiming to be a detailed and comprehensive analysis of the interaction of light with tissues, it does not describe many phenomena. Multiple simplifications and assumptions in the model diminish the efforts on the analysis of peculiarities of light scattering inside the tissue, resulting in a very approximate output. In this our study, a qualitatively similar result was obtained with the use of more simple and general approach. It was shown, that the power spectra of analyzed signals in the form of the exponential decay, similar to a fractal noise (1/f noise), is a consequence mainly of the Maxwell’s distribution of moving particles’ velocities. Moreover, in contrast to the classic model, our model shows that the first moment of the frequency is linearly proportional not only to the velocity of red blood cells, but also is inversely proportional to the wavelength of illuminating radiation, that is more physically grounded.

Paper Nr: 7
Title:

Design of a Portable Low-Cost Impedance Analyzer

Authors:

Abdulwadood Al-Ali, Ahmed Elwakil, Abdelaziz Ahmad and Brent Maundy

Abstract: Impedance analyzers available in the market are mostly bulky and often very expensive. In this paper, a low-cost, portable impedance analyzer is designed and implemented. The design utilizes the well-known, impedance network analyzer chip AD5933 and is capable of measuring a spectrum of impedances in the range 5 Hz to 100 kHz from 10 to 100 kOhm. Its specifications allow it to be used in agriculture for monitoring the bio-impedance of fruits in different stages of their lives, especially during the growth period while maintaining low-cost.

Paper Nr: 10
Title:

Influence of Microstructural Evolution Processed by ECAP on Corrosion Behavior of Pure Magnesium in RPMI-1640 Medium

Authors:

Taito Hosaka, Iman Amanina, Naohiro Saruwatari, Shoichiro Yoshihara and Bryan J. MacDonald

Abstract: Influence of microstructure changes caused by Equal-channel angular pressing (ECAP) process on corrosion behavior of pure magnesium in RPMI-1640 medium was investigated. The grain size of ECAPed samples (30µm) were greatly reduced compared with the grain size of the annealed sample (200µm). Then, the immersion test has been carried out for a certain period of time. It was revealed that mass loss of the ECAPed sample is larger than the as-received sample and the annealed sample. Thus, it could be considered that many crystal defects yielded by ECAP process reduced the corrosion resistance. However, the corrosion resistance has been improved to a certain extent according to reduction of crystal defects through the heat treatment at the recrystallization temperature or lower. In addition, the amount of gas generation of the ECAP sample after immersion test is larger compared with the as-received sample. Therefore, correlation between the amount of gas generated and the mass loss was confirmed. Based on qualitative identification of the elements by Energy Dispersive X-ray Spectrometry (EDS), the corrosion products of the sample surface after the immersion test has been estimated to be a kind of calcium phosphate. These above results have indicated the potential for fabrication of magnesium as bioabsorbable materials.

Paper Nr: 12
Title:

Biopotential Conducting Polymer Electrodes Design and Realization for ECG Measurement

Authors:

Marek Penhaker, Jan Polomik, Jan Kubicek and Vladimir Kasik

Abstract: The paper deals with the design and consequent realization of the alternative non-metal bio-potential electrodes and leads made from conductive polymers: polyaniline and polypyrrole. These alternative nonmetal biopotential electrodes and leads are intended for measurement of the ECG signal from chest by sensory T-shirt. The electrodes and leads are fixed on the T-shirt for continuous measurement and monitoring ECG signal. The alternative electrodes and leads were tested and compared against Ag/AgCl electrodes and common (metal) electrodes.

Paper Nr: 13
Title:

Radio Frequency CMOS Chem-bio Viscosity Sensors based on Dielectric Spectroscopy

Authors:

Subhajit Guha and Christian Wenger

Abstract: This paper presents a CMOS Radio frequency dielectric sensor platform for the detection of relative viscosity changes in a fluid sample. The operating frequency of the sensor is 12.28 GHz. This frequency range has been chosen for high signal to noise ratio and also to avoid other low frequency dispersion mechanisms for future lab on chip applications. The sensor chip has been fabricated in 250 nm BiCMOS technology of IHP. The measurements conducted to show the relative viscosity variation detection capability of the sensor chip, were based on mixtures of glycerol and water as well as glycerol and organic alcohol. The detection limit of viscosity is dependent on the permittivity contrast of the sample constituent. Therefore, it is also shown the choice of frequency inherently aids in the permittivity contrast of the sample constituents.

Paper Nr: 30
Title:

A Test Bed Model of an Advanced Handheld Bone Drilling System

Authors:

Tomislav Staroveski, Zlatko Catlak, Miho Klaic and Toma Udiljak

Abstract: Modern medical drilling systems utilized in bone and joint surgery are characterized with relatively low level of automation, i.e., with no process monitoring and/or adaptive control characteristics, which could potentially prevent mechanical and thermal bone damages. The quality of the drilling process depends solely on the operator skills and tool characteristics. Therefore, a group of research activities have been focused to the development of an advanced next generation hand-held drilling machine. It should provide mechanical and thermal monitoring capabilities of the tool and bone, automated tool feed movement with potential implementation of high-speed drilling regimes, as well as the application of an advanced adaptive control algorithms for cutting forces and drilling temperature limitation. The system would reduce human influence in drill guidance by allowing operator to define drilling location and desired tool direction/angle, while all other activities would be performed autonomously by the machine monitoring and control system. The test bed platform of such system which will be used in the final prototype shaping is presented in this paper.

Paper Nr: 38
Title:

Consideration of the Human Factor in the Design and Development of a New Medical Device: Example of a Device to Assist Manual Ventilation

Authors:

L. Pazart, F. S. Sall, A. De Luca, A. Vivot-Pugin, S. Pili-Floury, G. Capellier and A. Khoury

Abstract: The human factor is often critical in the performance and safety of a large number of medical devices. To minimize risks to users and patients, health authorities have reinforced their requirements including human factors and usability testing during the development of new technologies. Human factors engineering (HFE) is an interdisciplinary approach to evaluating and improving use safety, efficiency, and robustness of work systems. The new device should be tested to show its safety and effectiveness for the intended users, uses and use environments. In order to fulfill these regulatory requirements, international standards suggest implementing the User Centered Design process during the technology design and development lifecycle. We would like to present here a case study of a HFE plan about an ongoing medical device development in order to illustrate how to practically process; then we will present some more general considerations on HFE development for medical devices. Manual ventilation is an essential step in the resuscitation of respiratory distressed patients. It must be carried out adequately so as not to worsen patient’s condition. This technique has its advantages but also risks such as excessive insufflated pressures resulting in pulmonary barotrauma and gastric insufflation. In fact, many studies have shown that manual ventilation practices are far above recommended guidelines. Several solutions have been proposed by some manufacturers to achieve better control over manual ventilation parameters, but none has really convinced the medical community to date. Thus we propose to develop a new technology guided by a well adapted HFE. We first carried out a study with the existing material to observe the practices of 140 professionals in several clinical situations on an artificial lung, allowing to reproduce situations of respiratory deficiency and to record the parameters. The preliminary results showed a fairly low rate of manual ventilation performance with high ventilation rates, confirming the fragmented data of the literature on the subject. Thus, with the help of a local company, Polycaptil, we developed a new medical device, with an algorithm for real-time analysis on the basis of the 54,000 ventilatory cycles recorded during our study. After the prototype reached the technical objectives and demonstrated good reliability, we organized a usability validation test with 40 end-users. After the ventilation tests, participants were asked to complete a survey on the ease of use of the prototype, including the ergonomics of the entire system, the human-machine interface and its main functions. Both usability surveys provided important guidance for the development of the final device. Finally, the human factors validation testing should be realized during a prospective clinical trial of the first use in humans of a device for monitoring manual ventilation. The human factor is one of the most differentiating characteristics of the development of a medical device compared to the development plan of a drug. Specific methodologies are being developed and adapted tools have been set up. Based on our example, methods and purposes of HFE evaluation will be described at every stage of the device development lifecycle in order to sensitizing designers of new technologies.

Paper Nr: 41
Title:

Analysis of Impedance Spectroscopy Measurements of Biological Tissue using the Distribution of Relaxation Times Method

Authors:

Roberto Giovanni Ramírez-Chavarría, Celia Sánchez-Pérez and Daniel Matatagui

Abstract: This work proposes a method for analysing electrical impedance spectroscopy (EIS) measurements of biological tissue in the range of 100 Hz to 1 MHz by means of the distribution of relaxation times (DRT) to evaluate and study the different relaxation time constant involved in electrical response. We numerically analyse different configurations of RC circuits and compare the electrical response in time domain by DRT with that of classical EIS representation in frequency domain as Bode plots. Experimental validation of the technique using RC circuits, gives an error of less than 1% for the EIS measurement system with respect to theoretical calculation. We present preliminary measurements for WISTAR rat tissue samples of spleen, lung and kidney fixed in formaldehyde solution at 3.8% founding a more detailed occurrence of relaxation mechanism that could provide useful information about the structure and composition of biological tissues in a more precise way.

Paper Nr: 45
Title:

Virtual Application for Preventing Repetitive Strain Injuries on Hands: First Insights

Authors:

Helder Freitas, Vitor Carvalho, Filomena Soares and Demetrio Matos

Abstract: This paper is focused on the problem of repetitive strain injuries in hands. These injuries are mostly related to professional activities, especially in people that work at high levels of industrialization, patchwork or in use of advanced technology in productive process, as they are subject to a high rate of work where the performed tasks often lead to repetitive actions. The objective of this paper is the development of an application for hands detection and their movements to develop a game for preventing strain injuries. The activity will be developed in the software Unity, where it will be associated a 3D sensor, Intel RealSense 3D Camera F200. During the activity, the user will execute several prevention/relaxation exercises. With the activity implementation in companies and establishments, the employees will be able to exercise their hands, thus reducing the risk of being affected by strain injuries, contributing to the decrease or even elimination of the subsequent related costs with these injuries.