Publications by authors named "Richer F"

Article Synopsis
  • Recent advancements in mechatronics have led to the development of advanced arm prostheses, but challenges remain in designing effective control schemes, particularly for those with higher levels of impairment.
  • Current commercial options are limited in versatility and customization, pushing researchers to use specialized lab apparatus for testing new innovations.
  • The Smart Arm platform was created as a customizable, multi-articulated robotic arm prosthesis that supports research on control and sensory feedback, demonstrating notable success in practical applications like the Cybathlon event.
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Article Synopsis
  • Natural arm movements involve controlling multiple joints at the same time, and robotic prostheses should replicate this ability for users.
  • Current methods for controlling robotic prosthetics, especially myoelectric interfaces, typically only allow for sequential movements or limited multi-joint synchronization, making them difficult to set up.
  • The study explores a new control method called Compensations Cancellation Control (CCC), which enables simultaneous control of wrist and elbow joints, showing improved performance in tasks without increasing user effort or complexity compared to traditional methods.
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Background: For many co-manipulative applications, variable damping is a valuable feature provided by robots. One approach is implementing a high viscosity at low velocities and a low viscosity at high velocities. This, however, is proven to have the possibility to alter human natural motion performance.

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Birdsong learning has been consolidated as the model system of choice for exploring the biological substrates of vocal learning. In the zebra finch (Taeniopygia guttata), only males sing and they develop their song during a sensitive period in early life. Different experimental procedures have been used in the laboratory to train a young finch to learn a song.

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Transhumeral amputees face substantial difficulties in efficiently controlling their prosthetic limb, leading to a high rate of rejection of these devices. Actual myoelectric control approaches make their use slow, sequential and unnatural, especially for these patients with a high level of amputation who need a prosthesis with numerous active degrees of freedom (powered elbow, wrist, and hand). While surgical muscle-reinnervation is becoming a generic solution for amputees to increase their control capabilities over a prosthesis, research is still being conducted on the possibility of using the surface myoelectric patterns specifically associated to voluntary Phantom Limb Mobilization (PLM), appearing naturally in most upper-limb amputees without requiring specific surgery.

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Objective: We describe the adaptation of an early childcare and development program to the Indigenous context of the Cree territory in Québec. We also share lessons on the challenging implementation of home visits by Indigenous family support workers (FSWs), which is a critical component of the intervention.

Participants: Â Mashkûpímâtsît Awash (AMA) aims to enhance the health and well-being of pregnant mothers, young children, and their families by providing intensive interdisciplinary care and follow-up.

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Background: Treatment-resistant depression (TRD) is a serious chronic condition disabling patients functionally and cognitively. Chronic vagus nerve stimulation (VNS) is recognized for the management of TRD, but few studies have examined its long-term effects on cognitive dysfunction in unipolar and bipolar resistant depression.

Objective: The purpose of this study was to assess the course of cognitive functions and clinical symptoms in a cohort of patients treated with VNS for TRD.

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Chronic tic disorders (TD) are associated with a number of psychological problems such as attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive behavior (OCB), oppositional-defiant disorder (ODD) as well as anxious and depressive symptoms. ODD is often considered a risk factor for many psychological symptoms and recent work suggests that different ODD dimensions show independent predictions of later psychological problems. This study examined the longitudinal predictions between ODD dimensions of Irritability and Defiance and the most frequent comorbidities in TD from childhood to early adulthood.

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Objectives: Treatment-resistant depression (TRD) carries a major burden on those affected by this disease and significantly impacts their quality of life (QOL). Vagus nerve stimulation (VNS) has showed promising results on symptoms, but its impact on QOL remains underresearched. This study aims to evaluate the long-term effects of VNS on both QOL and clinical symptoms for TRD patients, through a naturalistic 6-year follow-up.

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An arm amputation is extremely invalidating since many of our daily tasks require bi-manual and precise control of hand movements. Perfect hand prostheses should therefore offer a natural, intuitive and cognitively simple control over their numerous biomimetic active degrees of freedom. While efficient polydigital prostheses are commercially available, their control remains complex to master and offers limited possibilities, especially for high amputation levels.

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Decoding finger and hand movements from sEMG electrodes placed on the forearm of transradial amputees has been commonly studied by many research groups. A few recent studies have shown an interesting phenomenon: simple correlations between distal phantom finger, hand and wrist voluntary movements and muscle activity in the residual upper arm in transhumeral amputees, i.e.

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In chronic tic disorders such as Tourette syndrome (TS), tics often appear between 4 and 8 years but they can also appear in early childhood, a period in which symptom expression may be affected by early brain development. The present study examined whether symptom expression in early-onset TS was distinct from that observed in TS with a later onset. We compared the clinical characteristics in children with TS who developed tics before age 4 or after age 6.

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Background: Chronic vagus nerve stimulation (VNS) is a recognized treatment for refractory epilepsy and depression. The vagus nerve projects to several brainstem autonomic structures. As pupillary measures are an easy and non-invasive method to evaluate autonomic functioning, we used resting diameter and light reflex measures to investigate the influence of VNS on the human central autonomic nervous system.

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Gilles de la Tourette syndrome (TS) and chronic tic disorder (CT) are often associated with a variety of behavioral comorbidities including attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive behavior (OCB), oppositional-defiant disorder (ODD) and temper outbursts. ODD is often associated with ADHD but its links to other symptoms of TS/CT is not as clear. This study examined whether the various symptoms of ODD were differentially linked to the various comorbidities in TS.

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Objective: Tic disorders such as Gilles-de-la-Tourette syndrome (TS) are associated with difficulties in withholding movements and sometimes inappropriate actions. The present study examined whether these disorders lead to a specific difficulty in withholding preprogrammed voluntary movements irrespective of decisions on whether or not to move.

Method: Children with TS with or without attention-deficit hyperactivity disorder (ADHD) and controls performed a fast-paced simple reaction time task involving responses to a target in a rapid letter stream (9 letters/s, average foreperiod 332 ms) with feedback on response speed.

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In developmental lexical-gustatory synesthesia, specific words (inducers) can trigger taste perceptions (concurrents) and these synesthetic associations are generally stable. We describe a case of multilingual lexical-gustatory synesthesia for whom some synesthesias were bidirectional as some tastes also triggered auditory word associations. Evoked concurrents could be gustatory but also tactile sensations.

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Tourette syndrome (TS) is a neurodevelopmental disorder characterized by involuntary motor and vocal tics. Sub-clinical postural control anomalies have recently been reported in children with TS. The goal of the present study was to determine whether these anomalies interact with attention in postural control.

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Objective: To test the association between Tourette syndrome (TS) and genetic variants in genomic loci MEIS1, MAP2K5/LBXCOR1, and BTBD9, for which genome-wide association studies in restless legs syndrome and periodic limb movements during sleep revealed common risk variants.

Design: Case-control association study.

Setting: Movement disorder clinic in Montreal.

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This study examined discrete motor irregularities in ballistic aiming movements in patients with atypical parkinsonian syndromes (APS). Nine patients with APS were compared to 9 patients with idiopathic Parkinson's disease (PD) and 9 controls on ballistic arm extension movements performed on a digitizing tablet without visual feedback and without accuracy constraints. Patients with APS showed a higher number of irregularities in the acceleration and jerk time series compared to PD patients and controls.

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Introduction: Tics disorders and Tourette syndrome are commonly encountered in clinical practice. Currently, a vast number of behavioural, pharmacological and surgical treatments are available.

Methods: Relevant and recent articles about clinical features, neurobiology and treatment of tic disorders and Tourette syndrome were reviewed and summarized.

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Huntington's disease (HD) is a neurodegenerative disease affecting the striatum and associated with deficits in voluntary movement in early stages. The final portion of aiming movements is particularly affected in HD and one hypothesis is that this deficit is linked to attention or terminal control requirements. Sixteen patients with early HD and 16 age-matched controls were examined in aiming movements.

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