Digital photoelasticity in biomedical sensing.

This research investigates on the use of digital photoelasticityin biomedical sensing applications with a particular emphasis on assessment of diabetic foot ulceration. One of the main causes of foot ulceration in diabetic patients is excessive pressure at the sole of the foot, which involves vertical as well as shear forces. Precise role of these forces in predisposing the foot to ulceration is not very well understood, however, a general consensus is that the combined effect of vertical and shear forces is much more harmful than the vertical force alone. Whilst the vertical force can be measured relatively easily,it is difficult to decouple the shear force from the combined force,which is considered to be of more clinical relevance in assessment of diabetic foot ulceration. The major impediment in achieving this objective is lack of suitable shear force measuring devices and limitation of the existing systems that can simulate the actual conditions of foot loading. In this research a photoelastic material has been used to develop a prototype-sensing device, which develops coloured fringes due to foot loading. Intelligent image processing techniques have been employed to analyse and obtain relevant load information from these fringes. The research surveys the existing sensing devices that are commonly used in diabetic foot clinics. It highlights the need for a new sensor design that can be used for pressure-induced pathologies. To meet these requirements and develop a sensor based on the principle of photoelasticity, conventional techniques of RGB photoelasticity and Phase-shifting methods have been fully investigated. This led to identify suitable optical elements for the system design and applicability of these techniques for the intended application. This resulted in devising an experimental set up that can provide coloured image of foot per se actual conditions of foot loading. However, the conventional technique of stress analysis cannot be directly applied in the present case, since the photoelastic effect is induced due to the material deformation as opposed to the usual component loading in photoelastic experiments with coatings. Also, in the current application the applied load has to be estimated from the fringe patterns (i.e. inverse problem) under varying environmental conditions with different loading situations for each subject. As it is difficult to develop analytical models under these conditions and the related inverse might have infinite number of solutions, the use of neural networks has been proposed to overcome these complexities. The network has been trained with direct image data which provides input load information under controlled experimental conditions of vertical as well as shear forces. The prototype sensor also provides qualitative whole-field data of the actual foot loading, which can be used for quick differentiation of foot with or without callus. This may also find use in haptics, pattern recognition and other biomedical sensing applications such as pressure sore assessment for disabled subjects or patients with numbness. With further enhancement in image processing technique this can be developed into a clinically viable system capable of providing complete foot analysis from early stage detection to prevention of ulceration

Digital photoelasticity in biomedical sensing

This research investigates on the use of digital photoelasticityin biomedical sensing applications with a particular emphasis on assessment of diabetic foot ulceration. One of the main causes of foot ulceration in diabetic patients is excessive pressure at the sole of the foot, which involves vertical as well as shear forces. Precise role of these forces in predisposing the foot to ulceration is not very well understood, however, a general consensus is that the combined effect of vertical and shear forces is much more harmful than the vertical force alone. Whilst the vertical force can be measured relatively easily,it is difficult to decouple the shear force from the combined force,which is considered to be of more clinical relevance in assessment of diabetic foot ulceration. The major impediment in achieving this objective is lack of suitable shear force measuring devices and limitation of the existing systems that can simulate the actual conditions of foot loading. In this research a photoelastic material has been used to develop a prototype-sensing device, which develops coloured fringes due to foot loading. Intelligent image processing techniques have been employed to analyse and obtain relevant load information from these fringes. The research surveys the existing sensing devices that are commonly used in diabetic foot clinics. It highlights the need for a new sensor design that can be used for pressure-induced pathologies. To meet these requirements and develop a sensor based on the principle of photoelasticity, conventional techniques of RGB photoelasticity and Phase-shifting methods have been fully investigated. This led to identify suitable optical elements for the system design and applicability of these techniques for the intended application. This resulted in devising an experimental set up that can provide coloured image of foot per se actual conditions of foot loading. However, the conventional technique of stress analysis cannot be directly applied in the present case, since the photoelastic effect is induced due to the material deformation as opposed to the usual component loading in photoelastic experiments with coatings. Also, in the current application the applied load has to be estimated from the fringe patterns (i.e. inverse problem) under varying environmental conditions with different loading situations for each subject. As it is difficult to develop analytical models under these conditions and the related inverse might have infinite number of solutions, the use of neural networks has been proposed to overcome these complexities. The network has been trained with direct image data which provides input load information under controlled experimental conditions of vertical as well as shear forces. The prototype sensor also provides qualitative whole-field data of the actual foot loading, which can be used for quick differentiation of foot with or without callus. This may also find use in haptics, pattern recognition and other biomedical sensing applications such as pressure sore assessment for disabled subjects or patients with numbness. With further enhancement in image processing technique this can be developed into a clinically viable system capable of providing complete foot analysis from early stage detection to prevention of ulceration.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Soft pneumatic devices for blood circulation improvement

The research activity I am presenting in this thesis lies within the framework of a cooperation between the University of Cagliari (Applied Mechanics and Robotics lab, headed by professor Andrea Manuello Bertetto, and the research group of physicians referencing to professor Alberto Concu at the Laboratory of Sports Physiology, Department of Medical Sciences), and the Polytechnic of Turin (professor Carlo Ferraresi and his equipe at the Group of Automation and Robotics, Department of Mechanical and Aerospace Engineering) This research was also funded by the Italian Ministry of Research (MIUR – PRIN 2009). My activity has been mainly carried on at the Department of Mechanics, Robotics lab under the supervision of prof. Manuello; I have also spent one year at the Control Lab of the School of Electrical Engineering at Aalto University (Helsinki, Finland). The tests on the patients were taken at the Laboratory of Sports Physiology, Cagliari. I will be describing the design, development and testing of some soft pneumatic flexible devices meant to apply an intermittent massage and to restore blood circulation in lower limbs in order to improve cardiac output and wellness in general. The choice of the actuators, as well as the pneumatic circuits and air distribution system and PLC control patterns will be outlined. The trial run of the devices have been field--‐tested as soon a prototype was ready, so as to tune its features step--‐by--‐ step. I am also giving a characterization of a commercial thin force sensor after briefly reviewing some other type of thin pressure transducer. It has been used to gauge the contact pressure between the actuator and the subject’s skin in order to correlate the level of discomfort to the supply pressure, and to feed this value back to regulate the supply air flow. In order for the massage to be still effective without causing pain or distress or any cutoff to the blood flow, some control objective have been set, consisting in the regulation of the contact force so that it comes to the constant set point smoothly and its value holds constant until unloading occurs. The targets of such mechatronic devices range from paraplegic patients lacking of muscle tone because of their spinal cord damage, to elite endurance athletes needing a circulation booster when resting from practicing after serious injuries leading to bed rest. Encouraging results have been attained for both these two categories, based on the monitored hemodynamic variables

Design Of A Piezoelectric Tactile Sensor

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2012Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012İnsanlardaki dokunma duyusu, dokunsal algılayıcıların ana ilham kaynağı olmuştur. Bu çalışmadaki amaç ise dokunma duyusuna yakınsayacak yeni nesil sentetik polimer fiber dizisinin tasarımı ve üretimidir. Bu fiber dizisinin üzerindeki basınç dağılımını algılaması amaçlanmaktadır. Tasarlanan fiber dizisinin hem yüzey pürüzlülüğüne adapte olabilen biyolojiden esinlenilmiş fiber yapısının bulunması, hem de oluşan temas ile ortaya çıkan basıncı elektriksek potansiyel farka çevirebilecek piezoelektrik ince tabakaya sahip olması gerekmektedir. Yapılan çalışmada basıncı algılama kabiliyetine sahip PVDF piezoelektrik tabakaya ilave edilmiş PDMS polimer düşey fiber dizisini sonlu eleman metodu kullanılarak analizi yapılmıştır. Piezoelektrik polimer uygulanan kuvvet sonucunda elektriksek potansiyel farkı yaratmaktadır. Bu potansiyel fark mikro/nano polimer fiberler sayesinde ayrıştırılabilir ve bu ayrıştırma polimer tabaka üzerindeki basıncın haritalandırılmasına yarar. Tasarlanan algılayıcıda PDMS polimerden üretilmiş fiberlerin çıkış voltajına ve insan elinin uzamsal çözünürlüğe yakınsamasındaki boyutsal değişkenlere etkisi araştırılmıştır. Tüm bu tasarım ölçütlerinin sağlanabilmesi statik ve dinamik çalışma koşullarının incelenmesi ve dokunma algısının altında yatan nörofizyolojinin özümsenmesini içermektedir. Piezoelektrik polimerin elektrotlanması sayesinde gecko ayaklarının yapışma ve yüzeyi tanıma özelliği taklit edilmeye çalışılmıştır. Fiberlerin geometrileri sayesinde basıncın belli bir alana yoğunlaştırılması sağlanmış bu sayede birim kuvvete elde edilecek potansiyel farkın artırılması ve algılayıcının hassasiyetinin artırımı sağlanmıştır. Fakat piezoelektrik PVDF polimerin yüzey enerjisinin diğer polimerlere oranla daha düşük kalmasından dolayı yapışma özelliği yetersiz kalmaktadır. Bu ise üzerine yerleştirilmiş PDMS ya da PMMA gidi sık kullanılan polimerler sayesinde telafi edilmiştir.The human sense of touch is the main inspiration to tactile sensing. The aim of this thesis is to design and manufacture a novel synthetic polymer fiber array with sensing capability of the pressure distribution. The polymer fiber array has both bio-inspired fibrillar structures that can adapt to the surface roughness and polymer piezoelectric film that can generate potential difference proportional to the pressure generated by the contact with the surrounding. In this work, the sensing capability of polyvinylidene fluoride (PVDF) piezoelectric film integrated with PDMS (Polydimethylsiloxane) polymer vertical fiber array has been analyzed using finite element method (FEM). Piezoelectric polymer generates electric potential difference with the applied force, which can be decoupled by the micro/nano polymer pillars, results in the mapping of the pressure distribution among the polymer film. The contribution of the pillars, made out of PDMS (Polydimethylsiloxane), to the output voltage and the dimensional parameters are examined for a satisfactory design that can meet the spatial resolution of the human hand. In order to meet all design requirements, the sensor design should include the static and dynamic analysis and understanding of neurophysiology of touch. By electroding the polymer film, it is aimed to mimic the adhesion and surface adaptation characteristics of the foot of gecko. The geometry of the fiber increases the pressure concentration and the sensitivity of the sensor. However, since the surface energy of PVDF polymer is low, polymers like PDMS or PMMA have been used to compensate the drawback.Yüksek LisansM.Sc

Development of a \u27Smart Glove\u27 Monitoring System for Personal Protective Equipment Applications

A proof of concept prototype of a smart glove system, which could monitor the physiological stresses related to repetitive strain and vibration-induced injuries, was developed at the University of Limerick Enterprise Research Centre in Ireland. The device logged grip force, vibration and goniometry data and could alert the user if dangerous vibration levels were reached. This prototype will provide a basis for future developments of devices that would enable safety by providing more information about injury risk in the workplace

Advances in Intelligent Robotics and Collaborative Automation

This book provides an overview of a series of advanced research lines in robotics as well as of design and development methodologies for intelligent robots and their intelligent components. It represents a selection of extended versions of the best papers presented at the Seventh IEEE International Workshop on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications IDAACS 2013 that were related to these topics. Its contents integrate state of the art computational intelligence based techniques for automatic robot control to novel distributed sensing and data integration methodologies that can be applied to intelligent robotics and automation systems. The objective of the text was to provide an overview of some of the problems in the field of robotic systems and intelligent automation and the approaches and techniques that relevant research groups within this area are employing to try to solve them.The contributions of the different authors have been grouped into four main sections:• Robots• Control and Intelligence• Sensing• Collaborative automationThe chapters have been structured to provide an easy to follow introduction to the topics that are addressed, including the most relevant references, so that anyone interested in this field can get started in the area

NASA Thesaurus. Volume 1: Hierarchical listing

There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

Advances in Intelligent Robotics and Collaborative Automation

This book provides an overview of a series of advanced research lines in robotics as well as of design and development methodologies for intelligent robots and their intelligent components. It represents a selection of extended versions of the best papers presented at the Seventh IEEE International Workshop on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications IDAACS 2013 that were related to these topics. Its contents integrate state of the art computational intelligence based techniques for automatic robot control to novel distributed sensing and data integration methodologies that can be applied to intelligent robotics and automation systems. The objective of the text was to provide an overview of some of the problems in the field of robotic systems and intelligent automation and the approaches and techniques that relevant research groups within this area are employing to try to solve them.The contributions of the different authors have been grouped into four main sections:• Robots• Control and Intelligence• Sensing• Collaborative automationThe chapters have been structured to provide an easy to follow introduction to the topics that are addressed, including the most relevant references, so that anyone interested in this field can get started in the area