Development and test of algorithms for the use of peripheral neural interfaces to control robotic systems

In-vivo experiments with neural electrods have been done. Variety of feature extraction and classifcation algorithms have been used in order to choose the optimal one

Decoding Information From Neural Signals Recorded Using Intraneural Electrodes: Toward the Development of a Neurocontrolled Hand Prosthesis

The possibility of controlling dexterous hand prostheses by using a direct connection with the nervous system is particularly interesting for the significant improvement of the quality of life of patients, which can derive from this achievement. Among the various approaches, peripheral nerve based intrafascicular electrodes are excellent neural interface candidates, representing an excellent compromise between high selectivity and relatively low invasiveness. Moreover, this approach has undergone preliminary testing in human volunteers and has shown promise. In this paper, we investigate whether the use of intrafascicular electrodes can be used to decode multiple sensory and motor information channels with the aim to develop a finite state algorithm that may be employed to control neuroprostheses and neurocontrolled hand prostheses. The results achieved both in animal and human experiments show that the combination of multiple sites recordings and advanced signal processing techniques (such as wavelet denoising and spike sorting algorithms) can be used to identify both sensory stimuli (in animal models) and motor commands (in a human volunteer). These findings have interesting implications, which should be investigated in future experiments. © 2006 IEEE

A model for selection of eyespots on butterfly wings

The development of eyespots on the wing surface of butterflies of the family Nympalidae is one of the most studied examples of biological pattern formation.However, little is known about the mechanism that determines the number and precise locations of eyespots on the wing. Eyespots develop around signaling centers, called foci, that are located equidistant from wing veins along the midline of a wing cell (an area bounded by veins). A fundamental question that remains unsolved is, why a certain wing cell develops an eyespot, while other wing cells do not. We illustrate that the key to understanding focus point selection may be in the venation system of the wing disc. Our main hypothesis is that changes in morphogen concentration along the proximal boundary veins of wing cells govern focus point selection. Based on previous studies, we focus on a spatially two-dimensional reaction-diffusion system model posed in the interior of each wing cell that describes the formation of focus points. Using finite element based numerical simulations, we demonstrate that variation in the proximal boundary condition is sufficient to robustly select whether an eyespot focus point forms in otherwise identical wing cells. We also illustrate that this behavior is robust to small perturbations in the parameters and geometry and moderate levels of noise. Hence, we suggest that an anterior-posterior pattern of morphogen concentration along the proximal vein may be the main determinant of the distribution of focus points on the wing surface. In order to complete our model, we propose a two stage reaction-diffusion system model, in which an one-dimensional surface reaction-diffusion system, posed on the proximal vein, generates the morphogen concentrations that act as non-homogeneous Dirichlet (i.e., fixed) boundary conditions for the two-dimensional reaction-diffusion model posed in the wing cells. The two-stage model appears capable of generating focus point distributions observed in nature. We therefore conclude that changes in the proximal boundary conditions are sufficient to explain the empirically observed distribution of eyespot focus points on the entire wing surface. The model predicts, subject to experimental verification, that the source strength of the activator at the proximal boundary should be lower in wing cells in which focus points form than in those that lack focus points. The model suggests that the number and locations of eyespot foci on the wing disc could be largely controlled by two kinds of gradients along two different directions, that is, the first one is the gradient in spatially varying parameters such as the reaction rate along the anterior-posterior direction on the proximal boundary of the wing cells, and the second one is the gradient in source values of the activator along the veins in the proximal-distal direction of the wing cell

Intraneural stimulation elicits discrimination of textural features by artificial fingertip in intact and amputee humans.

Restoration of touch after hand amputation is a desirable feature of ideal prostheses. Here, we show that texture discrimination can be artificially provided in human subjects by implementing a neuromorphic real-time mechano-neuro-transduction (MNT), which emulates to some extent the firing dynamics of SA1 cutaneous afferents. The MNT process was used to modulate the temporal pattern of electrical spikes delivered to the human median nerve via percutaneous microstimulation in four intact subjects and via implanted intrafascicular stimulation in one transradial amputee. Both approaches allowed the subjects to reliably discriminate spatial coarseness of surfaces as confirmed also by a hybrid neural model of the median nerve. Moreover, MNT-evoked EEG activity showed physiologically plausible responses that were superimposable in time and topography to the ones elicited by a natural mechanical tactile stimulation. These findings can open up novel opportunities for sensory restoration in the next generation of neuro-prosthetic hands

Indebtedness and the road to monetary sovereignty following the international recognition of Montenegro in 1878

The paper is dedicated to furthering the research into different aspects of Montenegrin sovereign status gained the Congress of Berlin, with a focus on the country’s financial sovereignty. Becoming an independent state had great historical significance for Montenegro, marking the realisation of the centuries-old aspirations for liberation. Still, exercising sovereign power proved challenging for Montenegro as the country was still an underdeveloped, agrarian country with a high percentage of illiterate population, scarce human resources and modest economic opportunities. Aside from this, there were still many congressional restrictions to exercising the rights acquired by gaining access to the sea. The author seeks to determine the reasons for the high level of indebtedness, as well as the decisions made in trying to resolve the challenges in maintaining the country’s financial sovereignty. The author also touches upon the broader subject of the role of gold standard in international trade and argues to which extent Montenegro was able to adhere to this internationally accepted standard, having established its banking institutions and having introduced its own currency. Considering that this paper is a part of the scientific research work on the project ‘Montenegro on the political and cultural map of Europe’ (CLIO MAP), exhibiting the reasons for minting the first Montenegrin coin is but a way to examine a segment in exibiting the country’s sovereign status acquired at the Congress of Berlin.The paper is dedicated to furthering the research into different aspects of Montenegrin sovereign status gained the Congress of Berlin, with a focus on the country’s financial sovereignty. Becoming an independent state had great historical significance for Montenegro, marking the realisation of the centuries-old aspirations for liberation. Still, exercising sovereign power proved challenging for Montenegro as the country was still an underdeveloped, agrarian country with a high percentage of illiterate population, scarce human resources and modest economic opportunities. Aside from this, there were still many congressional restrictions to exercising the rights acquired by gaining access to the sea. The author seeks to determine the reasons for the high level of indebtedness, as well as the decisions made in trying to resolve the challenges in maintaining the country’s financial sovereignty. The author also touches upon the broader subject of the role of gold standard in international trade and argues to which extent Montenegro was able to adhere to this internationally accepted standard, having established its banking institutions and having introduced its own currency. Considering that this paper is a part of the scientific research work on the project ‘Montenegro on the political and cultural map of Europe’ (CLIO MAP), exhibiting the reasons for minting the first Montenegrin coin is but a way to examine a segment in exibiting the country’s sovereign status acquired at the Congress of Berlin

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures

Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined

Anti-obesity public health vs. fat acceptance: impacts on 'fat' as a marginalized identity

I will argue that anti-obesity public health (AOPH), with a focus on Canadian AOPH, performs three functions with respect to the fat acceptance movements (FAMs). These are as follows. Firstly, AOPH distracts by derailing FAMs’ advocation for fat justice towards matters of health and the weight-science surrounding fatness. Secondly, AOPH covers up and creates new fat stigmatizing attitudes through the use of linguistic strategies such as medicalized language and devices called figleaves, which resonate with the public precisely because they enact deeply entrenched cultural themes of healthism. Lastly, AOPH attempts to eradicate fatness and thus fat-positive identities, which effectively aims to eliminate a valuable marginalized perspective, and epistemically disadvantages society as a result. Chapter 1 examines the content of the Canadian AOPH’s latest (2011) Obesity in Canada report, which contains a skew in favour of a dominant and problematic discourse on ‘fat’ as interchangeable with ‘unhealthy’ and therefore objectionable, representing a pervasive mode of shaping FAMs’ discourse that facilitates the derailment towards talk of health, weight science, and economic burden. Chapter 2 focuses on linguistic devices called anti-fat figleaves, which are statements or symbols that work to obscure fat stigmatizing speech acts, behaviours, or actions. These linguistic devices, in conjunction with a healthist cultural backdrop that elevates health to a supervalue and stigmatizes illness, work to reinforce anti-fat attitudes and fat discrimination, as disseminated by AOPH. Chapter 3 examines how the first two functions of AOPH, to distract fat justice and cover up fat stigma, shape and work to eradicate fat identity, using a model of marginalized identity formation to demonstrate this disruption and eradication of fat identity. I conclude that while there is a promising increase in focus on the harms of fat stigma and acknowledgement of fat autonomy in medicine, much more work needs to be done to do away with a weight-centred healthcare paradigm that reinforces fat discrimination through over-emphasis on obesity prevention and eradication

The neural basis of perceived intensity in natural and artificial touch

Electrical stimulation of sensory nerves is a powerful tool for studying neural coding because it can activate neural populations in ways that natural stimulation cannot. Electrical stimulation of the nerve has also been used to restore sensation to patients who have suffered the loss of a limb. We have used long-term implanted electrical interfaces to elucidate the neural basis of perceived intensity in the sense of touch. To this end, we assessed the sensory correlates of neural firing rate and neuronal population recruitment independently by varying two parameters of nerve stimulation: pulse frequency and pulse width. Specifically, two amputees, chronically implanted with peripheral nerve electrodes, performed each of three psychophysical tasks-intensity discrimination, magnitude scaling, and intensity matching-in response to electrical stimulation of their somatosensory nerves. We found that stimulation pulse width and pulse frequency had systematic, cooperative effects on perceived tactile intensity and that the artificial tactile sensations could be reliably matched to skin indentations on the intact limb. We identified a quantity we termed the activation charge rate (ACR), derived from stimulation parameters, that predicted the magnitude of artificial tactile percepts across all testing conditions. On the basis of principles of nerve fiber recruitment, the ACR represents the total population spike count in the activated neural population. Our findings support the hypothesis that population spike count drives the magnitude of tactile percepts and indicate that sensory magnitude can be manipulated systematically by varying a single stimulation quantity

On the identification of sensory information from mixed nerves by using single-channel cuff electrodes

Background: Several groups have shown that the performance of motor neuroprostheses can be significantly improved by detecting specific sensory events related to the ongoing motor task (e.g., the slippage of an object during grasping). Algorithms have been developed to achieve this goal by processing electroneurographic (ENG) afferent signals recorded by using single-channel cuff electrodes. However, no efforts have been made so far to understand the number and type of detectable sensory events that can be differentiated from whole nerve recordings using this approach. Methods: To this aim, ENG afferent signals, evoked by different sensory stimuli were recorded using single-channel cuff electrodes placed around the sciatic nerve of anesthetized rats. The ENG signals were digitally processed and several features were extracted and used as inputs for the classification. The work was performed on integral datasets, without eliminating any noisy parts, in order to be as close as possible to real application. Results: The results obtained showed that single-channel cuff electrodes are able to provide information on two to three different afferent (proprioceptive, mechanical and nociceptive) stimuli, with reasonably good discrimination ability. The classification performances are affected by the SNR of the signal, which in turn is related to the diameter of the fibers encoding a particular type of neurophysiological stimulus. Conclusions: Our findings indicate that signals of acceptable SNR and corresponding to different physiological modalities (e.g. mediated by different types of nerve fibers) may be distinguished