IEEE Transactions on Rehabilitation Engineering (IEEE Trans Rehabil Eng)

Publications in this journal

• Article: High-side digitally current controlled biphasic bipolar microstimulator

  Hanson T, Omarsson B, O'Doherty J, Peikon I, Lebedev M, Nicolelis M
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  ABSTRACT: Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. With the realized device and standard recording hardware - without active artifact rejection - we are able to observe stimulus artifacts of less than 2 ms in duration.
  IEEE Transactions on Rehabilitation Engineering 02/2012;
• Article: Virtual active touch using randomly patterned intracortical microstimulation

  O'Doherty JE, Lebedev MA, Li Z, Nicolelis MA
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  ABSTRACT: Intracortical microstimulation (ICMS) has promise as a means for delivering somatosensory feedback in neuroprosthetic systems. Various tactile sensations could be encoded by temporal, spatial, or spatiotemporal patterns of ICMS. However, the applicability of temporal patterns of ICMS to artificial tactile sensation during active exploration is unknown, as is the minimum discriminable difference between temporally modulated ICMS patterns. We trained rhesus monkeys in an active exploration task in which they discriminated periodic pulse-trains of ICMS (200 Hz bursts at a 10 Hz secondary frequency) from pulse trains with the same average pulse rate, but distorted periodicity (200 Hz bursts at a variable instantaneous secondary frequency). The statistics of the aperiodic pulse trains were drawn from a gamma distribution with mean inter-burst intervals equal to those of the periodic pulse trains. The monkeys distinguished periodic pulse trains from aperiodic pulse trains with coefficients of variation 0.25 or greater. Reconstruction of movement kinematics, extracted from the activity of neuronal populations recorded in the sensorimotor cortex concurrent with the delivery of ICMS feedback, improved when the recording intervals affected by ICMS artifacts were removed from analysis. These results add to the growing evidence that temporally patterned ICMS can be used to simulate a tactile sense for neuroprosthetic devices.
  IEEE Transactions on Rehabilitation Engineering 01/2012; 20(1):85-93.
• Article: Determination of generic body-seat interface shapes by cluster analysis

  Yue Li, R. Aissaoui, D.N. Brienza, J. Dansereau
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  ABSTRACT: The purpose of this study was to determine typical or generic shape patterns of the buttock-seat interface for elderly wheelchair users. The group of subjects was composed of 30 elderly people (aged 65 or older) and the shapes of the body-seat interface were measured by the electronic shape sensor (ESS). By analyzing the dissimilarity in geometrical shape descriptors or parameters, four distinct generic shapes were identified by means of the cluster analysis method. The results suggest that the generic shapes were mainly characterized by the lateral symmetry of the shapes. The determination of elderly people's seat interface shapes into distinct clusters may lead to a more comprehensive understanding of the seat support interface and more effective seat cushion designs
  IEEE Transactions on Rehabilitation Engineering 01/2001;
• Article: A commentary: the impact of the IEEE TRANSACTIONS ON REHABILITATION ENGINEERING on the field of rehabilitation engineering and science.

  C J Robinson
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  ABSTRACT: The IEEE TRANSACTIONS ON REHABILITATION ENGINEERING, founded 8.5 years ago, has survived, thrived, been of high quality, attracted the best authors in its field and related fields, been the publication of choice for manuscript submission in the rehabilitation engineering and related science area, possessed a wide and international distribution and loyal readership, been oft-cited, been financially sound, and made a marked impact on the field of Rehabilitation Engineering.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):437-9.
• Source

  Available from: wisc.edu

  Article: Electrotactile adaptation on the abdomen: preliminary results.

  K A Kaczmarek
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  ABSTRACT: Electrotactile (electrocutaneous) stimulation at currents greater than sensation threshold causes sensory adaptation, which temporarily raises the sensation threshold and reduces the perceived magnitude of stimulation. After 15 min of moderately intense exposure to a conditioning stimulus (10 s on, 10 s off), the sensation threshold elevation for seven observers was 60-270%, depending on the current, frequency, and number of pulses in the burst structure of the conditioning stimulus. Increases in any of these parameters increased the sensation threshold elevation. Adaptation and recovery were each complete in approximately 15 min.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):499-505.
• Article: Patient-driven control of FES-supported standing up and sitting down: experimental results

  R. Riener, M. Ferrarin, E.E. Pavan, C.A. Frigo
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  ABSTRACT: A patient driven control strategy for standing-up and sitting-down was experimentally tested on two paraplegic patients by applying functional electrical stimulation (FES) to the quadriceps muscle. The strategy-also known as “patient-driven motion reinforcement” (PDMR)-was developed by computer simulations reported in a former study. It is based on an inverse dynamic model (IDM) that predicts the stimulation pattern required to maintain the movement as it is initiated by the patient's voluntary effort. For reasons of safety and weight relief, the movement was supported by a seesaw construction. After some practice the patients were able to influence the stimulator output and to control the movement by their voluntary effort. Consequently, no pre-programmed reference trajectory was required. As a positive side effect, upper body effort could be minimized compared to trials without FES. To achieve a satisfactory performance of the PDMR controller a careful parameter identification of the inverse dynamic model was fundamental
  IEEE Transactions on Rehabilitation Engineering 01/2001;
• Article: EMG-based prediction of shoulder and elbow kinematics in able-bodied and spinal cord injured individuals

  A.T.C. Au, R.F. Kirsch
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  ABSTRACT: The authors have evaluated the ability of a time-delayed artificial neural network (TDANN) to predict shoulder and elbow motions using only electromyographic (EMG) signals recorded from six shoulder and elbow muscles as inputs, both in able-bodied subjects and in subjects with tetraplegia arising from C5 spinal cord injury. For able-bodied subjects, all four joint angles (elbow flexion-extension and shoulder-horizontal flexion-extension, elevation depression, and internal-external rotation) were predicted with average root-mean-square (rms) errors of less than 20° during movements of widely different complexities performed at different speeds and with different hand loads. The corresponding angular velocities and angular accelerations were predicted with even lower relative errors. For individuals with C5 tetraplegia, the absolute rms errors of the joint angles, velocities, and accelerations were actually smaller than for able-bodied subjects, but the relative errors were similar when the smaller movement ranges of the C5 subjects were taken into account. These results indicate that the EMG signals from shoulder and elbow muscles contain a significant amount of information about arm movement kinematics that could be exploited to develop advanced control systems for augmenting or restoring shoulder and elbow movements to individuals with tetraplegia using functional neuromuscular stimulation of paralyzed muscles
  IEEE Transactions on Rehabilitation Engineering 01/2001;
• Source

  Available from: uvic.ca

  Article: Implantable selective stimulator to improve bladder voiding: design and chronic experiments in dogs.

  S Boyer, M Sawan, M Abdel-Gawad, S Robin, M M Elhilali
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  ABSTRACT: Among the treatments to enhance the bladder voiding, the sacral roots neurostimulation is one of the most promising techniques. The electrostimulation of sacral nerves provokes a simultaneous contraction of the detrusor muscle as well as the external urethral sphincter (EUS). A new simplified-architecture implantable stimulator with its wireless controller have been designed to investigate high-frequency inhibition stimulation strategies. This innovative technique based on high-frequency inhibition reduces sphincter activity during stimulation. Low-frequency current pulses also applied to the sacral roots induces contraction of the detrusor muscle resulting in low pressure voiding. Chronic experiments were carried out on ten male mongrel paraplegic dogs. One cuff electrode was implanted along with each stimulator for eight months. The animals were stimulated twice a day using the prototypes of our implantable selective stimulator while voided and residual urine volume were measured during the procedure. These experiments revealed that the proposed stimulation strategy enhances bladder voiding by more than 50% in comparison with low-frequency only stimulation. The residual urine volume was reduced to an average of 9% and low pressure micturition was achieved as shown by weekly cystourethrogram.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):464-70.
• Article: The use of selective electrical stimulation of the quadriceps to improve standing function in paraplegia

  J.P. Uhlir, R.J. Triolo, R. Kobetic
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  ABSTRACT: Persons with spinal cord injury (SCI) can benefit significantly from functional neuromuscular stimulation (FNS) systems for standing if manual tasks can be performed while upright. Using FNS to sufficiently activate the knee extensors to rise from a sitting position often results in inadvertent activation of the rectus femoris and/or sartorius, which flex the hip. In this study, intramuscular electrodes implanted in the vastus lateralis and medialis of four subjects with SCI were used to activate these muscles individually and simultaneously to measure knee extension moment. Support forces applied to the arms and feet were measured while upright to quantify the effects of recruiting rectus femoris and/or sartorius. In three of the four subjects, vastus lateralis, by itself, generated adequate knee extension moment for rising from a chair and to maintain static standing. Simultaneous activation of the vastus lateralis and medialis using a bifurcated electrode generated adequate knee extension moment in one subject, and was within 10% of the required moment in another. While upright, activation of the rectus femoris resulted in arm support force increases of 4-11% body weight, while deactivation resulted in arm support force decreases of 6-9% body weight. The results indicate that selective activation of the vastus lateralis, individually or in combination with vastus medialis, can improve current FNS standing systems by reducing the arm support forces required to remain upright
  IEEE Transactions on Rehabilitation Engineering 01/2001;
• Article: Determination of generic body-seat interface shapes by cluster analysis.

  Y Li, R Aissaoui, D M Brienza, J Dansereau
  [show abstract] [hide abstract]
  ABSTRACT: The purpose of this study was to determine typical or generic shape patterns of the buttock-seat interface for elderly wheelchair users. The group of subjects was composed of 30 elderly people (aged 65 or older) and the shapes of the body-seat interface were measured by the electronic shape sensor (ESS). By analyzing the dissimilarity in geometrical shape descriptors or parameters, four distinct generic shapes were identified by means of the cluster analysis method. The results suggest that the generic shapes were mainly characterized by the lateral symmetry of the shapes. The determination of elderly people's seat interface shapes into distinct clusters may lead to a more comprehensive understanding of the seat support interface and more effective seat cushion designs.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):481-9.
• Source

  Available from: hmc.edu

  Article: Using time-dependent neural networks for EEG classification.

  E Haselsteiner, G Pfurtscheller
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  ABSTRACT: This paper compares two different topologies of neural networks. They are used to classify single trial electroencephalograph (EEG) data from a brain-computer interface (BCI). A short introduction to time series classification is given, and the used classifiers are described. Standard multilayer perceptrons (MLPs) are used as a standard method for classification. They are compared to finite impulse response (FIR) MLPs, which use FIR filters instead of static weights to allow temporal processing inside the classifier. A theoretical comparison of the two architectures is presented. The results of a BCI experiment with three different subjects are given and discussed. These results demonstrate the higher performance of the FIR MLP compared with the standard MLP.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):457-63.
• Article: EMG-based prediction of shoulder and elbow kinematics in able-bodied and spinal cord injured individuals.

  A T Au, R F Kirsch
  [show abstract] [hide abstract]
  ABSTRACT: We have evaluated the ability of a time-delayed artificial neural network (TDANN) to predict shoulder and elbow motions using only electromyographic (EMG) signals recorded from six shoulder and elbow muscles as inputs, both in able-bodied subjects and in subjects with tetraplegia arising from C5 spinal cord injury. For able-bodied subjects, all four joint angles (elbow flexion-extension and shoulder horizontal flexion-extension, elevation-depression, and internal-external rotation) were predicted with average root-mean-square (rms) errors of less than 20 degrees during movements of widely different complexities performed at different speeds and with different hand loads. The corresponding angular velocities and angular accelerations were predicted with even lower relative errors. For individuals with C5 tetraplegia, the absolute rms errors of the joint angles, velocities, and accelerations were actually smaller than for able-bodied subjects, but the relative errors were similar when the smaller movement ranges of the C5 subjects were taken into account. These results indicate that the EMG signals from shoulder and elbow muscles contain a significant amount of information about arm moVement kinematics that could be exploited to develop advanced control systems for augmenting or restoring shoulder and elbow movements to individuals with tetraplegia using functional neuromuscular stimulation of paralyzed muscles.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):471-80.
• Article: WARD: a pneumatic system for body weight relief in gait rehabilitation.

  F Gazzani, A Fadda, M Torre, V Macellari
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  ABSTRACT: The paper presents Walking Assistance and Rehabilitation Device (WARD), a system for walking rehabilitation devised to relieve the patient of his/her body weight of a constant and prescribed amount by externally supporting the subject at the upper trunk and pelvis level by means of a harness. The system is based on a pneumatic actuator that has proved to be effective at maintaining a constant relief force. The constancy of this force that should be maintained even under high body weight support (BWS) conditions (70-80% of body weight) seems to be important for a correct motor pattern. A law has been identified that may be useful to adjust walking speed as a function of the prescribed BWS. WARD is simple to construct, practical to use, and has been characterized on healthy subjects.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):506-13.
• Article: Patient-driven control of FES-supported standing up and sitting down: experimental results.

  R Riener, M Ferrarin, E E Pavan, C A Frigo
  [show abstract] [hide abstract]
  ABSTRACT: A patient-driven control strategy for standing-up and sitting-down was experimentally tested on two paraplegic patients by applying functional electrical stimulation (FES) to the quadriceps muscle. The strategy--also known as "patient-driven motion reinforcement" (PDMR)--was developed by computer simulations reported in a former study. It is based on an inverse dynamic model (IDM) that predicts the stimulation pattern required to maintain the movement as it is initiated by the patient's voluntary effort. For reasons of safety and weight relief, the movement was supported by a seesaw construction. After some practice the patients were able to influence the stimulator output and to control the movement by their voluntary effort. Consequently, no pre-programmed reference trajectory was required. As a positive side effect, upper body effort could be minimized compared to trials without FES. To achieve a satisfactory performance of the PDMR controller a careful parameter identification of the inverse dynamic model was fundamental.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):523-9.
• Article: The use of selective electrical stimulation of the quadriceps to improve standing function in paraplegia.

  J P Uhlir, R J Triolo, R Kobetic
  [show abstract] [hide abstract]
  ABSTRACT: Persons with spinal cord injury (SCI) can benefit significantly from functional neuromuscular stimulation (FNS) systems for standing if manual tasks can be performed while upright. Using FNS to sufficiently activate the knee extensors to rise from a sitting position often results in inadvertent activation of the rectus femoris and/or sartorius, which flex the hip. In this study, intramuscular electrodes implanted in the vastus lateralis and medialis of four subjects with SCI were used to activate these muscles individually and simultaneously to measure knee extension moment. Support forces applied to the arms and feet were measured while upright to quantify the effects of recruiting rectus femoris and/or sartorius. In three of the four subjects, vastus lateralis, by itself, generated adequate knee extension moment for rising from a chair and to maintain static standing. Simultaneous activation of the vastus lateralis and medialis using a bifurcated electrode generated adequate knee extension moment in one subject, and was within 10% of the required moment in another. While upright, activation of the rectus femoris resulted in arm support force increases of 4-11% body weight, while deactivation resulted in arm support force decreases of 6-9% body weight. The results indicate that selective activation of the vastus lateralis, individually or in combination with vastus medialis, can improve current FNS standing systems by reducing the arm support forces required to remain upright.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):514-22.
• Source

  Available from: hmc.edu

  Article: Optimal spatial filtering of single trial EEG during imagined hand movement.

  H Ramoser, J Müller-Gerking, G Pfurtscheller
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  ABSTRACT: The development of an electroencephalograph (EEG)-based brain-computer interface (BCI) requires rapid and reliable discrimination of EEG patterns, e.g., associated with imaginary movement. One-sided hand movement imagination results in EEG changes located at contra- and ipsilateral central areas. We demonstrate that spatial filters for multichannel EEG effectively extract discriminatory information from two populations of single-trial EEG, recorded during left- and right-hand movement imagery. The best classification results for three subjects are 90.8%, 92.7%, and 99.7%. The spatial filters are estimated from a set of data by the method of common spatial patterns and reflect the specific activation of cortical areas. The method performs a weighting of the electrodes according to their importance for the classification task. The high recognition rates and computational simplicity make it a promising method for an EEG-based brain-computer interface.
  IEEE Transactions on Rehabilitation Engineering 01/2001; 8(4):441-6.
• Article: A navigation system for increasing the autonomy and the security of powered wheelchairs

  S. Fioretti, T. Leo, S. Longhi
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  ABSTRACT: Assistive technology is an emerging area where some robotic devices can be used to strengthen the residual abilities of individuals with motor disabilities or to substitute their missing function thus helping them to gain a level of independence at least in the activities of daily living. This paper presents the design of a navigation system and its integration with a commercial powered wheelchair. The navigation system provides the commercial wheelchair with a set of functions which increase the autonomy of elderly and people with motor disabilities. In general, a robot device must be adapted to assistive applications in such a way as to be easily managed by the user. Users, especially young ones, prefer to directly control the robotic device and this aspect of usability has to be managed without affecting the security and efficiency of the navigation module. These aspects have been considered as specifications for the navigation module of powered wheelchairs. Different autonomy levels of the navigation module and proper user interfaces have been developed. Two autonomy levels have been designed. Simple collision avoidance is also implemented in order to stop the mobile base when an obstacle is detected. The preliminary technical tests performed on the navigation system have shown satisfactory results in terms of security and response time. A modular solution for the navigation module was considered in order to simplify the adaptation of the module to different powered wheelchairs
  IEEE Transactions on Rehabilitation Engineering 01/2001;
• Article: Simulated feedforward neural network coordination of hand grasp and wrist angle in a neuroprosthesis.

  M M Adamczyk, P E Crago
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  ABSTRACT: This study presents a possible solution of the general problem of coordinating muscle stimulation in a neuroprosthesis when multiarticular muscles introduce mechanical coupling between joints. In a hand-grasp neuroprosthesis, extrinsic hand muscles cross the wrist joint and introduce large wrist flexion moments during grasp. In order to control hand grasp and wrist angle independently, a controller must take the mechanical coupling into account. In simulation, we investigated the use of artificial neural networks to coordinate hand and wrist muscle stimulation. The networks were trained with data that is easily obtained experimentally. Feedforward control showed excellent hand and wrist coordination when the properties of the system were fixed and there were known external loads. Predictable disturbances (e.g., gravity acting on the hand) can be compensated by sensing arm orientation. However, since wrist angle is sensitive to unpredictable disturbances (e.g., fatigue or object weight), voluntary intervention or feedback control may be required to reduce residual errors.
  IEEE Transactions on Rehabilitation Engineering 10/2000; 8(3):297-304.
• Article: The relationship between electrical stimulus and joint torque: a dynamic model

  M. Ferrarin, A. Pedotti
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  ABSTRACT: The knowledge of the behavior of electrically activated muscles is an important requisite for the development of functional electrical stimulation (FES) systems to restore mobility to persons with paralysis. The aim of this work was to develop a model capable of relating electrical parameters to dynamic joint torque for FES applications. The knee extensor muscles, stimulated using surface electrodes, were used for the experimental preparation. Both healthy subjects and people with paraplegia were tested. The dynamics of the lower limb were represented by a nonlinear second order model, which took account of the gravitational and inertial characteristics of the anatomical segments as well as the damping and stiffness properties of the knee joint. The viscous-elastic parameters of the system were identified experimentally through free pendular movements of the leg. Leg movements induced by quadriceps stimulation were acquired too, using a motion analysis system. Results showed that, for the considered experimental conditions, a simple one-pole transfer function is able to model the relationship between stimulus pulsewidth (PW) and active muscle torque. The time constant of the pole was found to depend on the stimulus pattern (ramp or step) while gain was directly dependent on stimulation frequency
  IEEE Transactions on Rehabilitation Engineering 10/2000;