Brain Controlled Wheelchair using EEG Headset

In this paper, a brain controlled wheelchair has been designed which tends to reduce the complexity of movement for paralyzed people who are not capable of using various wheelchairs operating on technologies like joystick, finger movement or gesture controlled due to disability of moving body parts. The entire model is centrally based on Brain-computer Interface (BCI) combined with Raspberry Pi 3 and EEG sensor headset capture signals based on Neurosky mindwave technology which are further processed using MATLAB. Despite of the physical disabilities, this model will help quadriplegic patients to assist on their own and feel independent. Keywords: EEG, BCI, Matlab, Raspberry Pi, Neurosignal, NeuroSkyTechnology.

Extensors respond faster than flexors for the MCP joints even under the loss of the corticospinal system

Damage in the corticospinal system following stroke produces imbalance between flexors and extensors in the upper extremity including the fingers, eventually leading to flexion-favored postures. The substitution of the reticospinal tract for the damaged corticospinal tract is known to excessively activate flexors of the fingers while the fingers are voluntarily being extended. Here, we questioned whether the cortical source or/and neural pathways of the flexors and extensors of the fingers are coupled and what factor of impairment influences finger movement. In this study, a total of 7 male participants with hemiplegic stroke conducted isometric flexion and extension at the MCP joints in response to auditory tones. We measured activation and de-activation delays of the flexor and extensor of the MCP joints on the paretic side, as well as, force generation and co-contraction between the flexor and extensor. All participants generated greater torque in the direction of flexion (p=0.017). Regarding co-contraction, coupled activation of the extensor is also made during flexion in the similar way to coupled activation of the flexor made during extension. As opposite to our expectation, we observed that during extension, the extensor showed marginally significantly faster activation (p=0.66) while it showed faster de-activation (p=0.038), in comparison to activation and de-activation of the flexor during flexion. But movement smoothness was not affected by those factors. Our results imply that the cortical source and neural pathway for the extensors of the MCP joints are not coupled with those for the flexors of the MCP joints and extensor weakness mainly contributes to the asymmetry between flexors and extensors.

Extensors respond faster than flexors for the MCP joints even under the loss of the corticospinal system

Damage in the corticospinal system following stroke produces imbalance between flexors and extensors in the upper extremity including the fingers, eventually leading to flexion-favored postures. The substitution of the reticospinal tract for the damaged corticospinal tract is known to excessively activate flexors of the fingers while the fingers are voluntarily being extended. Here, we questioned whether the cortical source or/and neural pathways of the flexors and extensors of the fingers are coupled and what factor of impairment influences finger movement. In this study, a total of 7 male participants with hemiplegic stroke conducted isometric flexion and extension at the MCP joints in response to auditory tones. We measured activation and de-activation delays of the flexor and extensor of the MCP joints on the paretic side, as well as, force generation and co-contraction between the flexor and extensor. All participants generated greater torque in the direction of flexion (p=0.017). Regarding co-contraction, coupled activation of the extensor is also made during flexion in the similar way to coupled activation of the flexor made during extension. As opposite to our expectation, we observed that during extension, the extensor showed marginally significantly faster activation (p=0.66) while it showed faster de-activation (p=0.038), in comparison to activation and de-activation of the flexor during flexion. But movement smoothness was not affected by those factors. Our results imply that the cortical source and neural pathway for the extensors of the MCP joints are not coupled with those for the flexors of the MCP joints and extensor weakness mainly contributes to the asymmetry between flexors and extensors.

A Review- Brain Controlled Wheelchair using EEG headset

In this review paper, a brain controlled wheelchair models has been discussed which tends to reduce the complexity of movement for paralyzed people who are not capable of using various wheelchairs operating on technologies like joystick, finger movement or gesture controlled due to disability of moving body parts. The entire model is centrally based on Brain-computer Interface (BCI) combined with Raspberry Pi 3 and EEG sensor headset capture signals based on Neurosky mindwave technology which are further processed using MATLAB. Despite of the physical disabilities, this model will help quadriplegic patients to assist on their own and feel independent. Keywords: EEG, BCI, Matlab, Raspberry Pi, Neurosignal, NeuroSkyTechnology

Finger somatotopy is preserved after tetraplegia but deteriorates over time

Previous studies showed reorganised and/or altered activity in the primary sensorimotor cortex after a spinal cord injury (SCI), suggested to reflect abnormal processing. However, little is known about whether somatotopically-specific representations can be activated despite reduced or absent afferent hand inputs. In this observational study we used functional MRI and an (attempted) finger movement task in tetraplegic patients to characterise the somatotopic hand layout in primary somatosensory cortex. We further used structural MRI to assess spared spinal tissue bridges. We found that somatotopic hand representations can be activated through attempted finger movements in absence of sensory and motor hand functioning, and no spared spinal tissue bridges. Such preserved hand somatotopy could be exploited by rehabilitation approaches that aim to establish new hand-brain functional connections after SCI (e.g., neuroprosthetics). However, over years since SCI the hand representation somatotopy deteriorated, suggesting that somatotopic hand representations are more easily targeted within the first years after SCI.