China
Africa
Explore chapters and articles related to this topic
Neural engineering
Published in Alex Mihailidis, Roger Smith, Rehabilitation Engineering, 2023
Since the first successful reports of electrically restoring micturition function by intraspinal microstimulation (Nashold Jr. et al. 1971), advances in implantable microelectrode technology and their applications in neural engineering have supported this approach as a potential long-term therapy for restoring urinary function. Microstimulation in both spinal-intact and chronically injured animals has demonstrated selective activation of preganglionic sacral parasympathetic and somatic (i.e., Onuf's nucleus) motor neurons, resulting in contraction of the urinary bladder and EUS muscles, respectively (Grill, Bhadra, and Wang 1999; Pikov, Bullara, and McCreery 2007). Electrical microstimulation of spinal interneurons has even been shown to inhibit reflexively the urinary sphincter muscle. However, this approach is still in the preclinical stage of development due to various factors: limited long-term reliability of microelectrodes implanted within the spinal cord (e.g., electrode damage or movement), difficulties associated with the precise placement of electrodes within the spinal cord, and the highly invasive surgical implant procedure.
Advances in Neuroprosthetics
Published in Chang S. Nam, Anton Nijholt, Fabien Lotte, Brain–Computer Interfaces Handbook, 2018
After implanting microelectrode arrays into the somatosensory cortex of an individual paralyzed by spinal cord trauma (Flesher et al. 2016), the electrodes generated microstimulation that was shown to generate tactile sensations reported by subject as taking place on his hand. Moreover, the patient experienced varying levels of pressure in relation to stimulus amplitude, suggesting the possibility that the neurotechnology reported could allow those with paralysis, amputations, or stroke could interact with objects through a system comprising a robotic hand and intracortical microstimulation neuroprosthesis (see Chapter 14 [by Melissa M. Smith et al., “Utilizing Subdermal Electrodes as a Noninvasive Alternative for Motor-Based BCIs”] and Chapter 15 [by Philip R. Kennedy et al., “Validation of Neurotrophic Electrode Long-Term Recordings in Human Cortex”]).
A Functional BCI Model by the P2731 working group: Physiology
Published in Brain-Computer Interfaces, 2021
Ali Hossaini, Davide Valeriani, Chang S. Nam, Raffaele Ferrante, Mufti Mahmud
Electrical modulation of the brain is accomplished through intracortical microstimulation (ICMS), a process which involves sending a low-amplitude electrical pulse through an implanted microelectrode. Minimum thresholds range from 1 to 17 μA, but currents up to 500 μA are used in experimental situations. An ideal system would target single neurons, but the electrical fields generated by ICMS influence populations of neurons near the target as well as passing axons. Thus the ‘one neuron’ precision attainable by recording has not been matched by stimulation technologies, and this may account for the ‘partially natural’ quality users ascribe to artificial sensations [154].