Dynamic Facial Prosthetics for Sufferers of Facial Paralysis

BackgroundThis paper discusses the various methods and the materialsfor the fabrication of active artificial facial muscles. Theprimary use for these will be the reanimation of paralysedor atrophied muscles in sufferers of non-recoverableunilateral facial paralysis.MethodThe prosthetic solution described in this paper is based onsensing muscle motion of the contralateral healthy musclesand replicating that motion across a patient’s paralysed sideof the face, via solid state and thin film actuators. Thedevelopment of this facial prosthetic device focused onrecreating a varying intensity smile, with emphasis ontiming, displacement and the appearance of the wrinklesand folds that commonly appear around the nose and eyesduring the expression.An animatronic face was constructed with actuations beingmade to a silicone representation musculature, usingmultiple shape-memory alloy cascades. Alongside theartificial muscle physical prototype, a facial expressionrecognition software system was constructed. This formsthe basis of an automated calibration and reconfigurationsystem for the artificial muscles following implantation, soas to suit the implantee’s unique physiognomy.ResultsAn animatronic model face with silicone musculature wasdesigned and built to evaluate the performance of ShapeMemory Alloy artificial muscles, their power controlcircuitry and software control systems. A dual facial motionsensing system was designed to allow real time control overmodel – a piezoresistive flex sensor to measure physicalmotion, and a computer vision system to evaluate real toartificial muscle performance.Analysis of various facial expressions in real subjects wasmade, which give useful data upon which to base thesystems parameter limits.ConclusionThe system performed well, and the various strengths andshortcomings of the materials and methods are reviewedand considered for the next research phase, when newpolymer based artificial muscles are constructed andevaluated.Key WordsArtificial Muscles, facial prosthetics, stroke rehabilitation,facial paralysis, computer vision, automated facialrecognition

Status dystonicus resembling the intrathecal baclofen withdrawal syndrome: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Status dystonicus is a rare but life-threatening disorder characterized by increasingly frequent and severe episodes of generalized dystonia that may occur in patients with primary or secondary dystonia. Painful and repetitive spasms interfere with respiration and may cause metabolic disturbances such as hyperpyrexia, dehydration, respiratory insufficiency, and acute renal failure secondary to rhabdomyolysis. Intrathecally administered baclofen, delivered by an implantable pump system, is widely used for the treatment of refractory spasticity. Abrupt cessation of intrathecal baclofen infusion has been associated with a severe withdrawal syndrome comprised of dystonia, autonomic dysfunction, hyperthermia, end-organ failure and sometimes death. The aetiology of this syndrome is not well understood. Status dystonicus describes the episodes of acute and life-threatening generalized dystonia, which occasionally manifest themselves in patients with dystonic syndromes.</p> <p>Case presentation</p> <p>We present the case of a nine-year-old Caucasian boy who experienced a severe episode of status dystonicus with no known cause and clinical features resembling those described in intrathecal baclofen withdrawal. Our patient subsequently underwent the placement of an intrathecal baclofen pump without incident.</p> <p>Conclusion</p> <p>The similarity between the clinical features of the case we present and those reported in connection to abrupt withdrawal of intrathecal baclofen is emphasized. Several drugs, although not intrathecal baclofen withdrawal, have previously been associated with status dystonicus. The similarity between the life-threatening dystonic episode experienced by our patient, and those reported in intrathecal baclofen withdrawal, highlights the possibility that, rather than representing a true physiological withdrawal syndrome, abrupt withdrawal of intrathecal baclofen may simply precipitate an episode of status dystonicus in susceptible individuals. The clinical similarities between the intrathecal baclofen withdrawal syndrome and status dystonicus have not previously been highlighted.</p

Shape Memory Alloys in Facial Nerve Paralysis

BackgroundThe Facial Nerve can be damaged at a peripheral level by a stroke or, for example by trauma or infection within the face or the ear. In these cases the facial muscles are paralysed with little or no chance of spontaneous recovery. This research focuses on the potential utilisation of a Shape Memory Alloy (SMA) to replace the function of the Facial Nerve, which will allow in conjunction with passive reconstructive methods, a patient to regain limited but active movement of the mouth corner. Paralysis of the mouth corner is a very disabling both functionally and cosmetically, speech and swallowing are hampered and the patient loses saliva, with presents a social problem.  MethodsThis work addresses the design activity by implementing a methodology utilising integrated methods for achieving successful product engineering. Research and development is related to the investigation of the utilisation of an SMA to supplement the “passive” technique. Operational design and development work has already been undertaken in relation to a SMA being controlled by a dedicated electronic control interface and power supply. The interface measures the active potential of the healthy Zygomatic muscle by means of electromyography (EMG) and produces a signal to control the actuation of the SMA. The research centres on the entire device ultimately being implantable, similar to a pacemaker or deep brain stimulator. Results To identify the key parameters of the EMG sensing device the system testing strategy needed to ascertain the output signal from the device for a range of facial movements. Data was collected relating to five different ‘levels’ of smile with a sampling period of 30 seconds for each ‘level’.  Experimental work confirmed that there is definite viability for the precise control of an SMA system based on EMG data. The next stage            of development will address the issue of a ‘tuneable’ dedicated controller for this specific SMA control application and will also examine the potential integration and control of Electroactive Polymers (EAP’s).  Conclusions The first stages in assessing both the strengths and limitations of SMA’s towards resolving biomechanical problems and relieving disability have been undertaken. Experimental work to date has confirmed there is definite viability for the precise control of an SMA system based on EMG data. A considerable amount of research and developmental work has still to be undertaken before the system can be considered effective for precise control. The research and experimental work undertaken to date provides a firm foundation for the further development of the EMG/SMA control system for an animatronic head and, in addition will potentially provide proof of principle for effective and real time EMG/SMA or EMG/EAP control

Robust contact force controller for slip prevention in a robotic gripper

Grasping a soft or fragile object requires the use of minimum contact force to prevent damage or deformation. Without precise knowledge of object parameters, real-time feedback control must be used with a suitable slip sensor to regulate the contact force and prevent slip. Furthermore, the controller must be designed to have good performance characteristics to rapidly modulate the fingertip contact force in response to a slip event. In this paper, a fuzzy sliding mode controller combined with a disturbance observer is proposed for contact force control and slip prevention. The controller is based on a system model that is suitable for a wide class of robotic gripper configurations. The robustness of the controller is evaluated through both simulation and experiment. The control scheme was found to be effective and robust to parameter uncertainty. When tested on a real system, however, chattering phenomena, well known to sliding mode research, was induced by the unmodelled suboptimal components of the system (filtering, backlash, and time delays), and the controller performance was reduced

A methodology for design and appraisal of surgical robotic systems

Surgical robotics is a growing discipline, continuously expanding with an influx of new ideas and research. However, it is important that the development of new devices take account of past mistakes and successes. A structured approach is necessary, as with proliferation of such research, there is a danger that these lessons will be obscured, resulting in the repetition of mistakes and wasted effort and energy. There are several research paths for surgical robotics, each with different risks and opportunities and different methodologies to reach a profitable outcome. The main emphasis of this paper is on a methodology for ‘applied research’ in surgical robotics. The methodology sets out a hierarchy of criteria consisting of three tiers, with the most important being the bottom tier and the least being the top tier. It is argued that a robotic system must adhere to these criteria in order to achieve acceptability. Recent commercial systems are reviewed against these criteria, and are found to conform up to at least the bottom and intermediate tiers, the most important first two tiers, and thus gain some acceptability. However, the lack of conformity to the criteria in the top tier, and the inability to conclusively prove increased clinical benefit, is shown to be hampering their potential in gaining wide establishment

Impairment of Adolescent Hippocampal Plasticity in a Mouse Model for Alzheimer's Disease Precedes Disease Phenotype

The amyloid precursor protein (APP) was assumed to be an important neuron-morphoregulatory protein and plays a central role in Alzheimer's disease (AD) pathology. In the study presented here, we analyzed the APP-transgenic mouse model APP23 using 2-dimensional gel electrophoresis technology in combination with DIGE and mass spectrometry. We investigated cortex and hippocampus of transgenic and wildtype mice at 1, 2, 7 and 15 months of age. Furthermore, cortices of 16 days old embryos were analyzed. When comparing the protein patterns of APP23 with wildtype mice, we detected a relatively large number of altered protein spots at all age stages and brain regions examined which largely preceded the occurrence of amyloid plaques. Interestingly, in hippocampus of adolescent, two-month old mice, a considerable peak in the number of protein changes was observed. Moreover, when protein patterns were compared longitudinally between age stages, we found that a large number of proteins were altered in wildtype mice. Those alterations were largely absent in hippocampus of APP23 mice at two months of age although not in other stages compared. Apparently, the large difference in the hippocampal protein patterns between two-month old APP23 and wildtype mice was caused by the absence of distinct developmental changes in the hippocampal proteome of APP23 mice. In summary, the absence of developmental proteome alterations as well as a down-regulation of proteins related to plasticity suggest the disturption of a normally occurring peak of hippocampal plasticity during adolescence in APP23 mice. Our findings are in line with the observation that AD is preceded by a clinically silent period of several years to decades. We also demonstrate that it is of utmost importance to analyze different brain regions and different age stages to obtain information about disease-causing mechanisms

Contribution à l'étude du cycle annuel de reproduction d'une population d'asterias rubens (Echinodermata, Asteroidea) du littoral belge

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Robust contact force controller for slip prevention in a robotic gripper

Grasping a soft or fragile object requires the use of minimum contact force to prevent damage or deformation. Without precise knowledge of object parameters, real-time feedback control must be used with a suitable slip sensor to regulate the contact force and prevent slip. Furthermore, the controller must be designed to have good performance characteristics to rapidly modulate the fingertip contact force in response to a slip event. In this paper, a fuzzy sliding mode controller combined with a disturbance observer is proposed for contact force control and slip prevention. The controller is based on a system model that is suitable for a wide class of robotic gripper configurations. The robustness of the controller is evaluated through both simulation and experiment. The control scheme was found to be effective and robust to parameter uncertainty. When tested on a real system, however, chattering phenomena, well known to sliding mode research, was induced by the unmodelled suboptimal components of the system (filtering, backlash, and time delays), and the controller performance was reduced

Ethno-Religious Conflict in Europe: Typologies of Radicalisation in Europe's Muslim Communities. CEPS Paperbacks. February 2009

This book addresses the greatest source of societal tensions and violent conflict in contemporary Europe, involving people from minority groups of Muslim culture. Six country case studies – on Belgium, France, the Netherlands, Spain, Russia and the United Kingdom – give a comprehensive account of Islam-related tensions and violence, from the jihadist terrorist acts seen in Europe in the aftermath of 9/11 in the US, through to the urban riots of the type seen in France in 2005. These events are analysed with a common typology together with detailed accounts of the social context in each country. Also included is an interpretation of the fundamental nature of the Islamist terrorism in Europe, with the outline of a strategy to repel it. The book is a unique source for those seeking to understand the nature of ethno-religious violence in contemporary Europe