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D'une manière générale, la biométrie a pour objectif d'identifier des individus, notamment à partir de leurs caractéristiques biologiques. Cette pratique tend à remplacer les méthodes traditionnelles de vérification d'identité des individus ; entre autres, les mots de passe et les codes de sécurité. Au quotidien, la biométrie trouve de vastes applications et la recherche de nouvelles méthodes biométriques est d'actualité. L'objectif de notre thèse consiste à développer et d'évaluer de nouvelles modalités biométriques basées sur des caractéristiques infalsifiables, ne pouvant être modifiées volontairement. Dans ce contexte, les signaux physiologiques sont pris en considération. Ainsi, nous avons proposé trois méthodes d'identification biométriques. La première méthode utilise l'électrocardiogramme (ECG) comme signature individuelle, alors que la deuxième est basée sur l'utilisation des signaux électromyographiques (EMG) de surface en réponse à une force d'intensité fixe. Enfin, la dernière technique explorée, utilise les réponses motrices obtenues suite à une stimulation électrique. Ces méthodes consistent d'abord à acquérir les signaux physiologiques chez des personnes saines. Ces signaux sont modélisés par des réseaux d'ondelettes afin d'en extraire des caractéristiques pertinentes. La phase d'identification automatique est effectuée par des réseaux de neurones. D'après les résultats obtenus suite à des expériences effectuées, les méthodes proposées conduisent à des performances d'identification intéressantes. La première méthode, utilisant le signal électro- cardiographique, permet d'obtenir un taux de reconnaissance de 92%, alors que l'identification par les signaux EMG, en réponse à une force d'une intensité fixe, permet une identification correcte à 80%. Enfin, une performance de 95% est obtenue par l'identification par réponse motrice. Pour ces trois techniques explorées, la robustesse par rapport au bruit à été étudiée / In general, biometrics aims to identify individuals from their biological characteristics. This practice tends to replace the traditional methods of identity verification of individuals, among others, passwords and security codes. Nowadays, biometrics found wide application and research of new biometric methods is topical. The objective of this thesis is to develop and evaluate new biometric methods based on tamper-proof characteristics that can not be changed voluntarily. In this context, the physiological signals are considered. Thus, we proposed three methods of biometric identification. The first method uses the electrocardiogram (ECG) as individual signature, while the second is based on the use of surface electromyography signals (EMG) in response to a force of fixed intensity. The final technique explored, uses the motor responses obtained after electrical stimulation. These methods consist first to acquire the physiological signals in healthy people. These signals are modeled by wavelets networks to extract relevant features. The identification phase is performed automatically by neural networks. According to the results obtained from experiments performed, the proposed methods lead to interesting performance identification. The first method, using the electro-cardiographic signal, achieves a recognition rate of 92%, while the identification by EMG signals, in response to a force of a fixed intensity, allows a correct identification of 80 %. Finally, a performance of 95% is obtained by identification by motor response. For these three techniques explored, the robustness to noise ratio was studied

A relação entre eletromiografia e força é objeto de numerosos estudos, porém tal relação ainda não está totalmente elucidada e necessita de uma melhor fundamentação. Uma possível razão para as divergências entre esses estudos reside na dificuldade em determinar a força de um músculo individualmente de forma direta. Dentro deste contexto, procurou-se utilizar a análise do sinal eletromiográfico, associada a um modelo biomecânico do segmento articular para a avaliação das forças internas do músculo. O objetivo do presente trabalho é avaliar o comportamento eletromiográfico do músculo quadríceps durante exercícios isométricos e isotônicos concêntricos e correlacioná-lo com a força muscular, calculada através de simulações, usando modelos biomecânicos. Busca-se também uma forma de reconstruir a sobrecarga a que o músculo é submetido durante o exercício isotônico, através do tratamento do sinal eletromiográfico. Para tanto, o exercício isotônico é realizado em baixa velocidade e com pequena sobrecarga, e além disso, utiliza-se o procedimento de normalizar o sinal eletromiográfico ponto-a-ponto. Tal procedimento não possibilitou que a força externa, aplicada pelo membro, fosse obtida a partir do tratamento do sinal eletromiográfico, porém permitiu a correlação da eletromiografia com a força interna, gerada pelo músculo. Verificou-se também que a relação entre eletromiografia e força varia com a posição angular, com a força, com a velocidade de contração muscular e com a velocidade angular. No que se refere às análises da atividade isotônica, uma importante conclusão é que a relação entre eletromiografia e força não é linear; no entanto, quando normalizados pelos seus valores máximos podem ser considerados proporcionais. / The relationship between electromyography and force is largely investigated, however, such relation is not yet fully understood, still requiring better foundation. One of the reasons that might cause discrepancies between studies lies on directly calculating a single muscle force. Our approach handles the electromyographic signal coupled with a biomechanical model of the joint for assessment of internal muscle forces. This study aims at an evaluation of electromyographic behavior of the quadriceps muscle throughout isometric and concentric exercises, relating it to muscle force calculated by means of simulations, using biomechanical models. It is also handled in our study a means of assessing muscle overloading throughout dynamic exercises using eletromiographic signals. Accordingly, the dynamic exercise is undergone at slow speed and low resistance; and the electromyographic signal is normalized angle by angle. The approach did not allow the external force, produced by the limb, be assessed by means of electromyographic treatment, however, it allowed a relation between electromyography with internal force produced by the limb. It is worth mentioning that the electromyography-force relationship undergoes variations according to angular position, to degree of force, to muscle contraction velocity, to angular velocity. As to isotonic activity analysis, one important conclusion is the relation between electromyography and force is non-linear, with the proviso, that when normalized by peak values electromyography and force may be considered proportional.

O desempenho geral de um atleta está diretamente relacionado com o desenvolvimento da potência muscular, sendo esta a maior característica dos praticantes do Levantamento de peso olímpico (LPO), daí a sua utilização em diferentes planejamentos esportivos em procura do melhoramento do desempenho e potência muscular. Os movimentos do LPO recrutam os maiores grupos musculares e requerem intensos esforços físicos realizados com ênfase na velocidade e técnica. Velocidade, coordenação, níveis de coativação muscular são características dos movimentos próprios do Levantamento de Peso Olímpico e que são adquiridos e aperfeiçoados no tempo. O Power Snatch (PS) é um movimento derivado do Arranco, considerado como um dos movimentos mais difíceis de executar pela sua complexidade técnica. O PS é utilizado em diferentes modalidades esportivas em procura de elevar o desempenho atlético. Estudos prévios registraram dados cinemáticos e/ou medições eletromiográficas, mas sempre foram com atletas de alto rendimento. O presente estudo investigou os padrões cinemáticos e atividades musculares que representariam a execução técnica do PS e comportada por uma trajetória ótima observada desde o plano sagital do executante. Dezenove voluntários participaram do estudo, 11 sujeitos foram treinados (GT) durante 6 semanas e a cada duas semanas as variáveis cinemáticas e de atividade muscular foram registradas. 8 especialistas (GE) em levantamento participaram para registrar suas execuções técnicas. O PS foi dividido em 6 fases, representadas por 48 variáveis que comportam a análise cinemática por cada sujeito divididos em 3 sessões. 16 variáveis representaram dados da trajetória do GE. 8 músculos, correspondentes ao lado dominante de cada sujeitos foram registrados. Os dados cinemáticos e de atividade muscular foram analisados e comparados. Foram identificados parâmetros que comportam a trajetória óptima da barra e das atividades musculares nas diferentes fases da execução técnica do PS. O GT mostrou mudanças na sua execução, sendo que algumas delas se aproximaram aos do GE. Os coeficientes de ativação muscular foram maiores no GT que no GE. Os resultados do presente estudo levantam a questão da possibilidade de que a trajetória ótima no PS existe, mas varia entre os diferentes executantes / The performance of an athlete is directly related to the development of muscular power, this being the main characteristic of the Olympic Weightlifting (OW) practitioners. Hence their use in different training plans in order to improve performance and muscular power. The OW movements recruit the largest muscle groups and require intense physical effort performed with emphasis on speed and technique. Speed, coordination, levels of muscular coactivation are characteristic of the movements of the Olympic Weightlifting themselves and are acquired and improved over time. Power Snatch (PS) is a movement derived from the Snatch, considered as one of the most difficult movements to perform due to its technical complexity. The PS is used in different sports modalities in order to increase athletic performance. Previous studies have recorded kinematic data and/or electromyographic measurements, but these studies were limited to elite athletes. The present study investigated the kinematic patterns and muscular activities that represent the technical execution of the PS, referred by an optimal trajectory observed from the sagittal plane of the performer. Nineteen volunteers participated in the study, 11 subjects were trained (GT) for 6 weeks and every two weeks the kinematic and muscle activity variables were recorded. 8 specialists in ow training (GE) participated to register their technical executions. The PS was divided into 6 phases, represented by 48 variables that involve the kinematic analysis for each subject divided into 3 sessions. 16 variables represented GE trajectory data. 8 muscles, corresponding to the dominant side of each subject were recorded. Kinematic and muscle activity data were analyzed and compared. Parameters were identified that include the optimal trajectory of the bar and muscular activities in the different phases of the PS technical execution. The GT showed changes in its execution, with some of them approaching those of GE. The muscle activation coefficients were higher in the GT than in the EG. The results of the present study raise the question of the possibility that the optimal trajectory in PS exists, but varies among the different performers

La stimulation électrique fonctionnelle (FES) est présente depuis des décennies dans les centres de rééducation. Le principe de cette technique est de créer une dépolarisation de la membrane (potentiel d’action) des cellules excitables (axones ou myocytes) entrainant une contraction musculaire. Employée dans la plupart des cas pour le renforcement musculaire et la prévention des atrophies musculaires faisant suite à une lésion de la moelle épinière, la FES peut également être utilisée pour diminuer la spasticité et restaurer des mouvements des membres. Ainsi, certains dispositifs (neuroprothèses) utilisant la FES sont utilisés depuis plus de 25 ans, pour permettre à certains patients atteints de paralysies des membres supérieurs de pouvoir effectuer des préhensions. Les patients gagnent alors en autonomie dans les activités de la vie quotidienne ce qui limite leurs recours aux aides humaines. Cependant, bien que ce type de neuroprothèse se présente comme l’une des techniques les plus prometteuses pour le rétablissement de la fonction de préhension chez des sujets atteints d’une lésion de la moelle épinière, son utilisation reste limitée. En effet, les dispositifs de stimulation externe provoque des mouvements peu précis et les modes de pilote de cette stimulation, peu ergonomiques, ne sont pas accessibles à la plupart des patients lésés médullaires. Ces difficultés sont atténuées lorsque la stimulation est implantée et le mode de contrôle adapté à la pathologie. Parmi les dispositifs implantées, tous utilisent la stimulation des points moteurs pour rétablir des mouvements de main ce qui nécessite l’implantation de nombreuses électrodes et donc une opération chirurgicale lourde. Des complications liées aux matériels implantés peuvent apparaître au cours du temps. Ce travail de thèse propose une approche originale basée sur (i) la stimulation sélective nerveuse (à l’aide d’une électrode gouttière multi contact) pour rétablir des mouvements de préhension chez des patients tétraplégiques et (ii) l’utilisation de signaux émanant de muscles supra lésionnels pour le contrôle de cette stimulation. Des expérimentations humaines et animales réalisées en conditions aiguës ont démontré la faisabilité de notre approche. Ainsi, la stimulation du nerf sciatique par notre électrode gouttière a permis d’activer sélectivement plusieurs muscles antagonistes chez les 5 animaux de l’étude inclus dans l’étude. Une sélectivité intra fasciculaire est retrouvée chez 3 des 5 animaux. La stimulation du nerf médian chez un patient tétraplégique a permis d’activer sélectivement les muscles palmaris longuset flexor carpi radialis. Concernant le contrôle de la neuroprothèse, nous avons mis en évidence chez les 5 sujets tétraplégiques ayant participé aux expérimentations, une combinaison de muscles pouvant être utilisée pour piloter facilement un dispositif. Des contractions continues ou gradées de ces muscles peuvent être maintenues et ce, sans aucun apprentissage ou entrainement préalable. Les modalités de contrôle et les muscles préférentiels sont patient-dépendant. / Functional electrical stimulation (FES) is used for decades in rehabilitation centers. The principle of this technique is to create a membrane depolarization (action potential) of excitable cells (myocytes or axons) to cause a muscle contraction. Used in most cases for muscle strengthening and prevention of muscle atrophy following a spinal cord injury, FES can also be used to reduce spasticity and restore limb movement. For example, some devices (neuroprostheses) using FES are used for over 25 years, to allow some patients with paralysis of the upper limbs to perform hand movements. Patients then becoming more independent in activities of daily living which limits their use of human aid. However, although this type of neuroprosthesis stands as one of the most promising techniques for the recovery of the gripping function in subjects with spinal cord injury, its use is limited. Indeed, external stimulation devices cause imprecise movements and modes of control modes, not very ergonomic, are not accessible to most spinal cord injured patients. These difficulties are alleviated when the stimulation is implanted and control mode adapted to the pathology. Among the implanted devices all use the stimulation of motor pointsto restore hand movements which requires the implantation of many electrodes and therefore a major surgery. Complications related to the implanted materials can occur over time. This thesis proposes an original approach based on (i) selective nerve stimulation (using a multi contact cuff electrode) to restore gripping motion in tetraplegic patients and (ii) use of signals from supra lesional muscles to control this stimulation. Human and animal experimentations performed in acute conditions have demonstrated the feasibility of our approach. Thus, stimulation of the sciatic nerve by our cuff electrode allowed to selectively activate several antagonistic muscles in the 5 animals included in the study. Intra fascicular selectivity was found in 3 of 5 animals. The stimulation of the median nerve of a tetraplegic patient allowed to selectively activate the palmaris longus and flexor carpi radialis muscles. For the control of neuroprosthesis we demonstrated in the 5 tetraplegics subjects who participated in the experiments, a combination of muscles that can be used to easily control a device. Continuous or graded contractions of these muscles can be maintained, without any prior learning or training. The control modalities and preferential muscles are patient-dependent.

"This compendium-format dissertation (i.e., comprised mostly of published and in-process articles) primarily reports on system identification methods that relate the surface electromyogram (EMG)—the electrical activity of skeletal muscles—to mechanical kinetics. The methods focus on activities of the elbow and hand-wrist. The relationship between the surface EMG and joint impedance was initially studied. My work provided a complete second-order EMG-based impedance characterization of stiffness, viscosity and inertia over a complete range of nominal torques, from a single perturbation trial with slowly varied torque. A single perturbation trial provides a more convenient method for impedance evaluation. The RMS errors of the EMG-based method were 20.01% for stiffness and 7.05% for viscosity, compared with the traditional mechanical measurement. Three projects studied the relationship between EMG and force/torque, a topic that has been studied for a number of years. Optimal models use whitened EMG amplitude, combining multiple EMG channels and a polynomial equation to describe this relationship. First, we used three techniques to improve current models at the elbow joint. Three more features were extracted from the EMG (waveform length, slope sign change rate and zero crossing rate), in addition to EMG amplitude. Each EMG channel was used separately, compared to previous studies which combined multiple channels from biceps and, separately, from triceps muscles. Finally, an exponential power law model was used. Each of these improvement techniques showed better performance (P<0.05 and ~0.7 percent maximum voluntary contraction (%MVC) error reduction from a nominal error of 5.5%MVC) than the current “optimal” model. However, the combination of pairs of these techniques did not further improve results. Second, traditional prostheses only control 1 degree of freedom (DoF) at a time. My work provided evidence for the feasibility of controlling 2-DoF wrist movements simultaneously, with a minimum number of electrodes. Results suggested that as few as four conventional electrodes, optimally located about the forearm, could provide 2-DoF simultaneous, independent and proportional control with error ranging from 9.0–10.4 %MVC, which is similar to the 1-DoF approach (error from 8.8–9.8 %MVC) currently used for commercial prosthesis control. The third project was similar to the second, except that this project studied controlling a 1-DoF wrist with one hand DoF simultaneously. It also demonstrated good performance with the error ranging from 7.8-8.7 %MVC, compared with 1-DoF control. Additionally, I participated in two team projects—EMG decomposition and static wrist EMG to torque—which are described herein. "

The electrical activity of skeletal muscle¡ªthe electromyogram (EMG)¡ªis of value to many different application areas, including ergonomics, clinical biomechanics and prosthesis control. For many applications the EMG is related to muscular tension, joint torque and/or applied forces. In these cases, a goal is for an EMG-torque model to emulate the natural relationship between the central nervous system and peripheral joints and muscles. This thesis mainly describes an experimental study which relates the simultaneous biceps/triceps surface EMG of 12 subjects to elbow torque at seven joint angles (ranging from 45¡ÃƒÂ£to 135¡ÃƒÂ£) during constant-posture, quasi-constant-torque contractions. The contractions ranged between 50% maximum voluntary contractions (MVC) extension and 50% MVC flexion. Advanced EMG amplitude (EMG¦Ãƒâ€™) estimation processors were investigated, and three nonlinear EMG¦Ãƒâ€™-torque models were evaluated. Results show that advanced (i.e., whitened, multiple-channel) EMG¦Ãƒâ€™ processors lead to improved joint torque estimation, compared to unwhitened, single-channel EMG¦Ãƒâ€™ processors. Depending on the joint angle, use of the multiple-channel whitened EMG¦Ãƒâ€™ processor with higher polynomial degrees produced a median error that was 50%-66% that found when using the single-channel, unwhitened EMG¦Ãƒâ€™ processor with a polynomial degree of 1. The best angle-specific model achieved a minimum error of 3.39% MVCF90 (i.e., error referenced to MVC at 90¢X flexion), yet it does not allow interpolation across angles. The best model which parameterizes the angle dependence achieved an error of 3.55% MVCF90. This thesis also summarizes other collaborative research contributions performed as part of this thesis. (1) Decomposition of needle EMG data was performed as part of a study to characterize motor unit behavior in patients with amyotrophic lateral sclerosis (ALS) [with Spaulding Rehabilitation Hospital, Boston, MA]. (2) EMG-force modeling of force produced at the finger tips was studied with the purpose of assessing the ability to determine two or more independent, continuous degrees of freedom of control from the muscles of the forearm [with WPI and Sherbrooke University]. (3) Identification of a nonlinear, dynamic EMG-torque relationship about the elbow was studied [WPI]. (4) Signal whitening preprocessing for improved classification accuracies in myoelectric control of a prosthesis was studied [with WPI and the University of New Brunswick].

Este trabalho apresenta um método de estimativa de torque do joelho baseado em sinais eletromiográficos (EMG) durante terapia de reabilitação robótica. Os EMGs, adquiridos de cinco músculos envolvidos no movimento de flexão e extensão do joelho, são processados para encontrar as ativações musculares. Em seguida, mediante um modelo simples de contração muscular, são calculadas as forças e, usando a geometria da articulação, o torque do joelho. As funções de ativação e contração musculares possuem parâmetros limitados que devem ser calibrados para cada usuário, sendo o ajuste feito mediante a minimização do erro entre o torque estimado e o torque medido na articulação usando a dinâmica inversa. São comparados dois métodos iterativos para funções não-lineares como técnicas de otimização restrita para a calibração dos parâmetros: Gradiente Descendente e Quasi-Newton. O processamento de sinais, calibração de parâmetros e cálculo de torque estimado foram desenvolvidos no software MATLAB®; o cálculo de torque medido foi feito no software OpenSim com sua ferramenta de dinâmica inversa. / This work presents a method for knee torque estimation based on electromyographic signals (EMG) during robotic rehabilitation therapy. EMG, taken from five muscles acting during flexion and extension movements of the knee joint, are processed to get the muscle activations. Then, through a simple model of muscle contraction, the forces are computed and knee torque estimated using the joint geometry. Muscle activation and muscle contraction functions have bounded parameters to be adjusted for each user. This adjustment is made by minimizing the error between the estimated torque and the measured torque in the joint computed via inverse dynamics. Two iterative methods for constrained nonlinear optimization are compared, escending Gradient and Quasi-Newton. Signal processing, parameters calibration and estimated torque calculation are developed in the MATLAB® software. Measured torque calculation is performed on OpenSim software using the dynamic inverse tool.

<p>After the acute spell of poliomyelitis, patients commonly suffers from sequelae of weakness. Some of these patients experience new weakness after a time period of stable symptoms.</p><p>The aim of this thesis was to evaluate the possible mechanisms for persistent weakness and development of new weakness in prior polio patients.</p><p>The usefulness of neurophysiologic methods to study prior polio was evaluated. Also two follow up investigations were performed in the attempt to investigate a possible relationship between development of weakness over time and possible failure in neuromuscular function and relation to muscular activity. In another investigation an evaluation of the exceptional finding of a history of paralytic poliomyelitis without neurophysiologic signs of anterior horn cell death was made. The last investigation dealt with reflex pattern in prior polio and it’s relation to weakness and anterior horn cell loss.</p><p>The weakness in prior polio is mainly due to loss of motor neurons with incomplete compensatory mechanisms of reinnervation. The new weakness is mainly due to exaggerated physiological age dependent loss of whole motor neurons, but also fragmentation of the motor unit is likely when these have reached an upper size. Defective neuromuscular transmission and failure in the central drive contribute to a lesser degree to weakness. </p><p>Neurophysiologic method of choice for the assessment of motor unit size and the micro-physiology of the motor unit is Macro EMG.</p><p>Muscular overuse may accelerate motor unit loss over time in prior polio. Extremely large motor units measured with Macro EMG predict new weakness and Macro EMG can be used for prognostication of development of new weakness in prior polio.</p>

Seit vier Jahrzehnten werden verschiedene Neurofeedbackmethoden bei der Behandlung unterschiedlicher Störungen, unter anderem bei AD/HS-Kindern, eingesetzt. Die Grundlage der Anwendung von Neurofeedback bei dieser Störung besteht darin, dass die Kinder Auffälligkeiten in ihrem EEG zeigen. Dort treten im Vergleich zu unauffälligen Kindern vermehrt Theta-Gehirnwellen und weniger Beta-Gehirnwellen auf. Mittels Neurofeedback wird versucht, die Gehirnfunktionen zu korrigieren. Zahlreiche Einzellfallstudien bestätigen die Wirksamkeit dieser Therapiemethode bei der AD/HS-Behandlung. Bisher wurde jedoch keine Studie veröffentlicht, in der die Wirksamkeit von Neurofeedback mit einer Placebogruppe verglichen wurde. Ziel der vorliegenden Studie war es, die Wirksamkeit eines Theta/Beta-Neurofeedbacks (NF) bei der Behandlung von AD/HS-Kindern zu überprüfen und mit einem EMG-Biofeedback (BF) als Placebobedingung zu vergleichen. Es wurden 35 ADHS-Kinder (6 -14 Jahre; 26 Jungen und 9 Mädchen) untersucht. Nach Standarddiagnostik und Vergabe der AD/HS-Diagnose durch einen unabhängigen Psychotherapeuten wurden die Kinder per Zufall zwei Gruppen (NF: n = 18 bzw. BF: n = 17) zugeteilt. Alle Kinder beider Gruppen erhielten ein 30 Sitzungen umfassendes Training mittels Theta/Beta-Neurofeedback bzw. EMG-Biofeedback. Unmittelbar vor und nach dem Training wurden Intelligenz- bzw. Aufmerksamkeitsleistungen untersucht und Einschätzungen des Verhaltens von Eltern und Lehrern erhoben. Im Anschluss an das Training erfolgte eine erneute diagnostische Einschätzung durch einen unabhängigen Psychotherapeuten. Die EEG-Daten in der NF-Gruppe zeigen eine Reduktion der Theta/Beta-Quotienten im Laufe der NF-Sitzungen. Die EMG-Daten zeigen für die EMG-Biofeedback-Bedingung gleichfalls eine Reduktion der EMG-Amplitude. Die Ergebnisse der zweifaktoriellen Varianzanalysen mit Messwiederholung auf einem Faktor zeigen für die angewendeten diagnostischen Verfahren die erwarteten signifikanten Interaktionen zwischen Messzeitpunkt und Gruppe. Die Ergebnisse des t-Tests zeigen signifikante Verbesserungen in der Aufmerksamkeitsleistung, dem Intelligenzniveau und im Verhalten der Kinder aus der NF-Gruppe im Vergleich zu den Resultaten des Prä-Tests. Die EMG-Biofeedbackgruppe zeigt mit Ausnahme einer Erhöhung des Arbeitstempos in den Paper-Pencil-Aufmerksamkeitstests (die im CPT nicht repliziert werden konnte) keine signifikanten Verbesserungen relativ zum Prä-Test. Nach dem Training erhielten 55,6 % (n = 10) der AD/HS-Kinder aus der Neurofeedbackgruppe und 23,5 % (n = 4) der Kinder aus der EMG-Biofeedbackgruppe keine AD/HS-Diagnose nach den Kriterien der ICD-10. Der Chi-Quadrat-Test zeigt jedoch lediglich einen tendenziell bedeutsamen Unterschied (p = .086). Insgesamt bestätigen die Ergebnisse die Wirksamkeit des Neurofeedbacks bei der Behandlung von ADHS-Kindern im Vergleich mit einer Placebogruppe. Weitere Studien in diesem Bereich sind notwendig, um die Wirksamkeit des Neurofeedbacktrainings im Vergleich zu einer Placebomethode bei der ADHS-Behandlung zu untersuchen. / Neurofeedback (NF) has been introduced four decades ago as an alternative treatment for different disorders, one of these being Attention Deficit/Hyperactivity Disorder (AD/HD). As compared to a control group (non ADHD children), children diagnosed with ADHD show an increased frequency of Theta waves and a decreased frequency of Beta waves in their EEGs. A treatment consisting of NF-training attempts to correct these anomalies. There are numerous single case studies in this area but only a few controlled studies. Furthermore, there are no studies comparing the effect of NF in the treatment of ADHD with a placebo group. This study sets out to evaluate the effects of 30 (Theta/Beta) NF training sessions on ADHD symptoms and compare those with the effects of the placebo EMG-biofeedback (BF) training group. The subjects, consisting of 35 children both male (n = 26) and female (n = 9) between the ages of 6 and 14 diagnosed with ADHD by independent psychotherapists, were randomly assigned to either the treatment group (NF; n = 18) or the placebo group (BF; n = 17). In addition to the Theta/Beta quotient (in NF group) and EMG-Amplitude (in BF group) as seen during the sessions, pre and post measures of the subjects´ intelligence (Raven Test), paper-pencil attention test scores (bp/d2), Continuous Performance Task (CPT) as well as symptom ratings (MEF and FBB-HKS) from both teachers and parents were obtained. Finally, subjects were re-evaluated after treatment by independent psychotherapists. The results showed a significant decrease in the Theta/Beta quotient after the NF training and a significant decrease in the EMG-Amplitude after the BF-training. The results of an ANOVA with repeated measures showed significant differences between the treatment group (NF training) and the placebo (BF training) group in attention tests and symptom rating scores after treatment. Compared to the pre-test scores, subjects in the NF group showed significant improvements in attention scores, intelligence scores, and behaviour after the NF training sessions. The BF placebo group showed no significant improvements in any of the outcome variables except on the speed scale of the paper-pencil attention tests (this was incompatible with the results of CPT). Finally, 55.6% (n = 10) of the children in the NF training group were not diagnosed with ADHD (using ICD-10 criteria) at the time of the second evaluation. In the BF group, 23.5% (n = 4) were not diagnosed with ADHD by independent psychotherapists at the end of the BF training. The results indicate that NF training in comparing with a placebo method is an effective treatment method in the treatment of ADHD children. Further studies are necessary in comparing the effectiveness of NF training with more neutral placebo interventions in the treatment of children with ADHD.