Referred Sensation Areas in Bilateral Upper Limb Amputee.

Phantom limb pain (PLP) following amputation considerably reduces the quality of life, given a difficult to treat pain of highly variate profile. The loss of sensory input induces a complex pattern of neuroplastic changes of the sensory neural pathways and their central projections. Referred sensation areas (RSAs) may occur on the stump as a consequence of amputation, providing a direct path towards the altered central sensory projections.

From pulse width modulated TENS to cortical modulation: based on EEG functional connectivity analysis.

Modulation in the temporal pattern of transcutaneous electrical nerve stimulation (TENS), such as Pulse width modulated (PWM), has been considered a new dimension in pain and neurorehabilitation therapy. Recently, the potentials of PWM TENS have been studied on sensory profiles and corticospinal activity. However, the underlying mechanism of PWM TENS on cortical network which might lead to pain alleviation is not yet investigated.

Gamma-band enhancement of functional brain connectivity following transcutaneous electrical nerve stimulation.

Transcutaneous electrical nerve stimulation (TENS) has been suggested as a possible non-invasive pain treatment. However, the underlying mechanism of the analgesic effect of TENS and how brain network functional connectivity (FC) is affected following the use of TENS is not yet fully understood. The purpose of this study was to investigate the effect of high-frequency TENS on the alteration of functional brain network connectivity and the corresponding topographical changes, besides perceived sensations.

Short-Term Suppression of Somatosensory Evoked Potentials and Perceived Sensations in Healthy Subjects Following TENS.

Transcutaneous electrical nerve stimulation (TENS) has been reported to alleviate pain in chronic pain patients. Currently, there is limited knowledge how TENS affects can cause cortical neuromodulation and lead to modulation of non-painful and painful sensations. Our aim was therefore to investigate the effect of conventional, high-frequency TENS on cortical activation and perceived sensations in healthy subjects.

Referred Sensation Areas in a Bilateral Toes Amputee.

Various mechanisms in generating phantom limb pain (PLP) have been hypothesized in the literature. However, there still is no clear understanding of how PLP develops and why it presents. Amputation leads to permanent anatomical and physiological changes of the neural path previously supplying the brain with sensory input, as well as to formation of referred sensation areas (RSAs) on the stump or its vicinity.

Referred Sensation Areas in Transpelvic Amputee.

Electrical stimulation (ES) of referred sensation areas (RSAs) may provide sensory input attempting to alleviate phantom limb pain (PLP). Characterization of referred sensation areas (RSAs) in a 34 year-old male with transpelvic amputation is presented in this paper. PLP was experienced as cramps of muscles of phantom leg and as piercing sensation of the phantom ankle alternating with unpleasant sensation as that given by crawling spiders in an atypical pattern lasting for e.

Dynamics of movement-related cortical potentials and sensorimotor oscillations during palmar grasp movements.

Movement-related cortical potentials (MRCP) and sensorimotor oscillatory electroencephalographic (EEG) activity (event-related desynchronization/synchronization-ERD/ERS) provide complementary information of the associated motor activity. The aim of this study was to provide comparative spatio-temporal analysis of both EEG phenomena associated with palmar grasping motions including hand opening and closing phases. Nine healthy participants were instructed to perform self-paced, right hand grasping movements.

Error-Free Text Typing Performance of an Inductive Intra-Oral Tongue Computer Interface for Severely Disabled Individuals.

For severely paralyzed individuals, alternative computer interfaces are becoming increasingly essential for everyday life as social and vocational activities are facilitated by information technology and as the environment becomes more automatic and remotely controllable. Tongue computer interfaces have proven to be desirable by the users partly due to their high degree of aesthetic acceptability, but so far the mature systems have shown a relatively low error-free text typing efficiency. This paper evaluated the intra-oral inductive tongue computer interface (ITCI) in its intended use: Error-free text typing in a generally available text editing system, Word.

Development and functional demonstration of a wireless intraoral inductive tongue computer interface for severely disabled persons.

Purpose: Individuals with tetraplegia depend on alternative interfaces in order to control computers and other electronic equipment. Current interfaces are often limited in the number of available control commands, and may compromise the social identity of an individual due to their undesirable appearance. The purpose of this study was to implement an alternative computer interface, which was fully embedded into the oral cavity and which provided multiple control commands.

Mapping sensor activation time for typing tasks performed with a tongue controlled oral interface.

Two tetraplegic subjects performed typing tasks on a computer in an experiment using a tongue controlled oral interface. This paper reports mapping of the sensor activation time for a full alphabet text input using 10 inductive sensors. A small cylindrical piece of soft ferromagnetic material activated the sensors when placed at or glided along the surface of the sensor.

Alternative design of inductive pointing device for oral interface for computers and wheelchairs.

An inductive pointing device was designed and implemented successfully in a tongue controlled oral interface. Sensors were manufactured as an assembly of multilayer coils in the printed circuit board technology on two pads. The sensor pads were encapsulated together with electronics and battery in a mouthpiece, placed in the upper palate of the oral cavity.

Features of cortical neuroplasticity associated with multidirectional novel motor skill training: a TMS mapping study.

Given the evidence that the primary motor cortex (MI) consists of subpopulations of upper motor neurons tuned to different directional parameters of a motor movement, this study hypothesized that novel motor skill training involving either a bidirectional or more complex multidirectional tongue-typing movement should produce distinct training-related features of tongue MI neuroplasticity in humans. Novel motor skill training consisted of tongue typing using custom-made intra-oral keypads for 30-min over two consecutive days. The bidirectional keypad consisted of three sensors positioned along the upper palatal midline as a 3 × 1 array, whereas the multidirectional keypad consisted of nine sensors arranged as a 3 × 3 array that was centred along the upper palatal midline.

Effects of sensory feedback in intra-oral target selection tasks with the tongue.

Purpose: To investigate the effects of visual and tactile intra-oral sensor-position feedback for target selection tasks with the tip of the tongue.

Method: Target selection tasks were performed using an inductive tongue-computer interface (ITCI). Visual feedback was established by highlighting the area on a visual display corresponding to the activated intra-oral target.

Tip of the tongue selectivity and motor learning in the palatal area.

This study assessed the ability of the tongue tip to accurately select intraoral targets embedded in an upper palatal tongue-computer interface, using 18 able-bodied volunteers. Four performance measures, based on modifications to Fitts's Law, were determined for three different tongue-computer interface layouts. The layouts differed with respect to number and location of the targets in the palatal interface.

Clinical evaluation of wireless inductive tongue computer interface for control of computers and assistive devices.

Typing performance of a full alphabet keyboard and a joystick type of mouse (with on-screen keyboard) provided by a wireless integrated tongue control system (TCS) has been investigated. The speed and accuracy have been measured in a form of a throughput defining the true correct words per minute [cwpm]. Training character sequences were typed in a dedicated interface that provided visual feedback of activated sensors, a map of the alphabet associated, and the task character.

Inductive tongue control of powered wheelchairs.

Alternative and effective methods for controlling powered wheelchairs are important to individuals with tetraplegia and similar impairments whom are unable to use the standard joystick. This paper describes a system where tongue movements are used to control a powered wheelchair thus providing users, with high level spinal cord injuries, full control of their wheelchair. The system is based on an inductive tongue control system developed at Center for Sensory-Motor Interaction (SMI), Aalborg University.

Design of inductive sensors for tongue control system for computers and assistive devices.

Purpose: The paper introduces a novel design of air-core inductive sensors in printed circuit board (PCB) technology for a tongue control system. The tongue control system provides a quadriplegic person with a keyboard and a joystick type of mouse for interaction with a computer or for control of an assistive device.

Method: Activation of inductive sensors was performed with a cylindrical, soft ferromagnetic material (activation unit).

Inductive pointing device for tongue control system for computers and assistive devices.

Experimental results for pointing tasks using a tongue control system are reported in this paper. Ten untrained subjects participated in the experiment. Both typing and pointing tasks were performed, in three short-term training sessions, in consecutive days, by each subject.

A framework for mouse and keyboard emulation in a tongue control system.

Effective human input devices for computer control are very important to quadriplegics and others with severe disabilities. This paper describes a framework for computer control without need for special PC software or drivers. The framework is based on a tongue control system recently developed at Center for Sensory-Motor Interaction (SMI), Aalborg University.

Character activation time prediction model for tongue-typing: adaptation of Fitts's law.

This paper presents the development of a character activation time prediction model for tongue-typing. This model is based on a modification of Fitts's law that is more suitable for tip-of-tongue selectivity tasks around the palatal area. The model was trained and evaluated with data from tongue-selectivity experiments using an inductive tongue-computer interface.

Fully integrated wireless inductive tongue computer interface for disabled people.

This work describes a novel fully integrated inductive tongue computer interface for disabled people. The interface consists of an oral unit placed in the mouth, including inductive sensors, related electronics, a system for wireless transmission and a rechargeable battery. The system is activated using an activation unit placed on the tongue, and incorporates 18 inductive sensors, arranged in both a key area and a mouse-pad area.

In vitro magnetic stimulation of pig phrenic nerve with transverse and longitudinal induced electric fields: analysis of the stimulation site.

The induced electric field transverse to peripheral nerve trunks has been shown to lead to stimulation, contrary to predictions of the cable equation. Two possible mechanisms of activation have been documented in literature: the change in the transmembrane voltage due to an electric field transverse to the membrane of a cylindrical fiber and the transverse field projection on the undulating fiber path within the fascicle. To distinguish between these alternatives, an analysis of the stimulation site was performed in vitro along 15 phrenic nerves from pigs, with a 5-cm-diameter round coil.

Focality assessment in transcranial magnetic stimulation with double and cone coils.

To evaluate the performance with respect to selectivity of the effect of the wings bending in the cone coil relative to the double coil in transcranial magnetic stimulation. The focal area and the width vector of the central lobe of the induced electrical field distributed along an elliptic surface approximating the cortex were computed for four coil models. The models represented the real coils, the double B70 and the cone B80 Medtronic, and their corresponding simulated flat coils (B70flat and B80flat).

Novel method for measurement of medium size arterial lumen area with an impedance catheter: in vivo validation.

There is no doubt that the transformation of a cardiac catheter into a conductance catheter that allows reliable and accurate assessment of lumen cross-sectional area (CSA) will provide a powerful diagnostic and treatment tool for the invasive cardiologist. The objective of this study was to develop a method based on the impedance catheter that allows accurate and reproducible measurements of CSA for medium size vessels (e.g.

Measurement of coronary lumen area using an impedance catheter: finite element model and in vitro validation.

The measurement of coronary lumen cross-sectional area (CSA) is important for coronary physiology and cardiology. The general objective of this study is to develop an accurate and reproducible method to measure the lumen CSA of left anterior descending (LAD) artery using an impedance or conductance catheter. The conductance catheter technique is based on a cylindrical model of the chamber of interest.