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Nature Aug 2023Speech brain-computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech...
Speech brain-computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech into text or sound. Early demonstrations, although promising, have not yet achieved accuracies sufficiently high for communication of unconstrained sentences from a large vocabulary. Here we demonstrate a speech-to-text BCI that records spiking activity from intracortical microelectrode arrays. Enabled by these high-resolution recordings, our study participant-who can no longer speak intelligibly owing to amyotrophic lateral sclerosis-achieved a 9.1% word error rate on a 50-word vocabulary (2.7 times fewer errors than the previous state-of-the-art speech BCI) and a 23.8% word error rate on a 125,000-word vocabulary (the first successful demonstration, to our knowledge, of large-vocabulary decoding). Our participant's attempted speech was decoded at 62 words per minute, which is 3.4 times as fast as the previous record and begins to approach the speed of natural conversation (160 words per minute). Finally, we highlight two aspects of the neural code for speech that are encouraging for speech BCIs: spatially intermixed tuning to speech articulators that makes accurate decoding possible from only a small region of cortex, and a detailed articulatory representation of phonemes that persists years after paralysis. These results show a feasible path forward for restoring rapid communication to people with paralysis who can no longer speak.
Topics: Humans; Amyotrophic Lateral Sclerosis; Brain-Computer Interfaces; Cerebral Cortex; Microelectrodes; Paralysis; Speech; Vocabulary; Neural Prostheses
PubMed: 37612500
DOI: 10.1038/s41586-023-06377-x -
Science (New York, N.Y.) Apr 2021Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address...
Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address this need, we introduce the Neuropixels 2.0 probe together with newly designed analysis algorithms. The probe has more than 5000 sites and is miniaturized to facilitate chronic implants in small mammals and recording during unrestrained behavior. High-quality recordings over long time scales were reliably obtained in mice and rats in six laboratories. Improved site density and arrangement combined with newly created data processing methods enable automatic post hoc correction for brain movements, allowing recording from the same neurons for more than 2 months. These probes and algorithms enable stable recordings from thousands of sites during free behavior, even in small animals such as mice.
Topics: Action Potentials; Algorithms; Animals; Brain; Electrodes, Implanted; Electrophysiology; Male; Mice; Mice, Inbred C57BL; Microelectrodes; Miniaturization; Neurons; Rats
PubMed: 33859006
DOI: 10.1126/science.abf4588 -
JACC. Clinical Electrophysiology Jul 2019This study sought to evaluate the safety and short-term performance of a novel catheter for very high power-short duration (vHPSD) ablation in the treatment of...
OBJECTIVES
This study sought to evaluate the safety and short-term performance of a novel catheter for very high power-short duration (vHPSD) ablation in the treatment of paroxysmal atrial fibrillation.
BACKGROUND
The vHPSD catheter is a novel contact force-sensing catheter optimized for temperature-controlled radiofrequency ablation with microelectrodes and 6 thermocouples for real-time temperature monitoring; the associated vHPSD algorithm modulates power to maintain target temperature during 90 W, 4 s lesions.
METHODS
QDOT-FAST (Clinical Study for Safety and Acute Performance Evaluation of the THERMOCOOL SMARTTOUCH SF-5D System Used With Fast Ablation Mode in Treatment of Patients With Paroxysmal Atrial Fibrillation) is a prospective, multicenter, single-arm study enrolling patients with symptomatic paroxysmal atrial fibrillation indicated for catheter-based pulmonary vein isolation. Primary endpoints were short-term effectiveness (confirmation of entrance block in all targeted pulmonary veins after adenosine/isoproterenol challenge) and short-term safety (primary adverse events). Participants were screened for silent cerebral lesions by magnetic resonance imaging. Patients were followed for 3 months post-ablation.
RESULTS
A total of 52 patients underwent ablation and completed follow-up. Pulmonary vein isolation was achieved in all patients using the study catheter alone, with total procedure and fluoroscopy times of 105.2 ± 24.7 min and 6.6 ± 8.2 min, respectively. Most patients (n = 49; 94.2%) were in sinus rhythm at 3 months. Two primary adverse events were reported: 1 pseudoaneurysm; and 1 asymptomatic thromboembolism. There were no deaths, stroke, atrioesophageal fistula, pulmonary vein stenosis, or unanticipated adverse device effects. Six patients had identified silent cerebral lesions-all classified as asymptomatic without clinical or neurologic deficits.
CONCLUSIONS
This first-in-human study of a novel catheter with optimized temperature control demonstrated the clinical feasibility and safety of vHPSD ablation. Procedure and fluoroscopy times were substantially lower than historical standard ablation with point-by-point catheters. (Clinical Study for Safety and Acute Performance Evaluation of the THERMOCOOL SMARTTOUCH SF-5D System Used With Fast Ablation Mode in Treatment of Patients With Paroxysmal Atrial Fibrillation [QDOT-FAST]; NCT03459196).
Topics: Aged; Atrial Fibrillation; Catheter Ablation; Catheters; Equipment Design; Female; Fluoroscopy; Humans; Male; Microelectrodes; Middle Aged; Prospective Studies; Pulmonary Veins; Therapeutic Irrigation; Treatment Outcome
PubMed: 31320006
DOI: 10.1016/j.jacep.2019.04.009 -
JAMA Neurology Oct 2021It is unknown if there is a difference in outcome in asleep vs awake deep brain stimulation (DBS) of the subthalamic nucleus for advanced Parkinson disease. (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
It is unknown if there is a difference in outcome in asleep vs awake deep brain stimulation (DBS) of the subthalamic nucleus for advanced Parkinson disease.
OBJECTIVE
To determine the difference in adverse effects concerning cognition, mood, and behavior between awake and asleep DBS favoring the asleep arm of the study.
DESIGN, SETTING, AND PARTICIPANTS
This study was a single-center prospective randomized open-label blinded end point clinical trial. A total of 187 persons with Parkinson disease were referred for DBS between May 2015 to March 2019. Analysis took place from January 2016 to January 2020. The primary outcome follow-up visit was conducted 6 months after DBS.
INTERVENTIONS
Bilateral subthalamic nucleus DBS was performed while the patient was asleep (under general anesthesia) in 1 study arm and awake in the other study arm. Both arms of the study used a frame-based intraoperative microelectrode recording technique to refine final target placement of the DBS lead.
MAIN OUTCOMES AND MEASURES
The primary outcome variable was the between-group difference in cognitive, mood, and behavioral adverse effects as measured by a composite score. The secondary outcomes included the Movement Disorders Society Unified Parkinson's Disease Rating Scale, the patient assessment of surgical burden and operative time.
RESULTS
A total of 110 patients were randomized to awake (local anesthesia; n = 56; mean [SD] age, 60.0 (7.4) years; 40 [71%] male) or to asleep (general anesthesia; n = 54; mean [SD] age, 61.3 [7.9] years; 38 [70%] male) DBS surgery. The 6-month follow-up visit was completed by 103 participants. The proportion of patients with adverse cognitive, mood, and behavioral effects on the composite score was 15 of 52 (29%) after awake and 11 of 51 (22%) after asleep DBS (odds ratio, 0.7 [95% CI, 0.3-1.7]). There was no difference in improvement in the off-medication Movement Disorders Society Unified Parkinson's Disease Rating Scale Motor Examination scores between groups (awake group: mean [SD], -27.3 [17.5] points; asleep group: mean [SD], -25.3 [14.3] points; mean difference, -2.0 [95% CI, -8.1 to 4.2]). Asleep surgery was experienced as less burdensome by patients and was 26 minutes shorter than awake surgery.
CONCLUSIONS AND RELEVANCE
There was no difference in the primary outcome of asleep vs awake DBS. Future large randomized clinical trials should examine some of the newer asleep based DBS technologies because this study was limited to frame-based microelectrode-guided procedures.
TRIAL REGISTRATION
trialregister.nl Identifier: NTR5809.
Topics: Aged; Anesthesia, General; Anesthesia, Local; Deep Brain Stimulation; Female; Humans; Male; Microelectrodes; Middle Aged; Parkinson Disease; Subthalamic Nucleus; Treatment Outcome
PubMed: 34491267
DOI: 10.1001/jamaneurol.2021.2979 -
Journal of Neural Engineering Apr 2022The micro-electrode array (MEA) is a cell-culture surface with integrated electrodes used for assays of electrically excitable cells and tissues. MEAs have been a...
The micro-electrode array (MEA) is a cell-culture surface with integrated electrodes used for assays of electrically excitable cells and tissues. MEAs have been a workhorse in the study of neurons and myocytes, owing to the scalability and millisecond temporal resolution of the technology. However, traditional MEAs are opaque, precluding inverted microscope access to modern genetically encoded optical sensors and effectors.. To address this gap, transparent MEAs have been developed. However, for many labs, transparent MEAs remain out of reach due to the cost of commercially available products, and the complexity of custom fabrication. Here, we describe an open-source transparent MEA based on the OpenEphys platform (Siegle2017045003).We demonstrate the performance of this transparent MEA in a multiplexed electrical and optogenetic assay of primary rat hippocampal neurons.This open-source transparent MEA and recording platform is designed to be accessible, requiring minimal microelectrode fabrication or circuit design experience. We include low-noise connectors for seamless integration with the Intan Technologies headstage, and a mechanically stable adaptor conforming to the 24-well plate footprint for compatibility with most inverted microscopes.
Topics: Animals; Microelectrodes; Neurons; Optogenetics; Rats
PubMed: 35349992
DOI: 10.1088/1741-2552/ac620d -
Stereotactic and Functional Neurosurgery 2023Deep brain stimulation has become an established technology for the treatment of patients with a wide variety of conditions, including movement disorders, psychiatric... (Review)
Review
BACKGROUND
Deep brain stimulation has become an established technology for the treatment of patients with a wide variety of conditions, including movement disorders, psychiatric disorders, epilepsy, and pain. Surgery for implantation of DBS devices has enhanced our understanding of human physiology, which in turn has led to advances in DBS technology. Our group has previously published on these advances, proposed future developments, and examined evolving indications for DBS.
SUMMARY
The crucial roles of structural MR imaging pre-, intra-, and post-DBS procedure in target visualization and confirmation of targeting are described, with discussion of new MR sequences and higher field strength MRI enabling direct visualization of brain targets. The incorporation of functional and connectivity imaging in procedural workup and their contribution to anatomical modelling is reviewed. Various tools for targeting and implanting electrodes, including frame-based, frameless, and robot-assisted, are surveyed, and their pros and cons are described. Updates on brain atlases and various software used for planning target coordinates and trajectories are presented. The pros and cons of asleep versus awake surgery are discussed. The role and value of microelectrode recording and local field potentials are described, as well as the role of intraoperative stimulation. Technical aspects of novel electrode designs and implantable pulse generators are presented and compared.
Topics: Humans; Deep Brain Stimulation; Parkinson Disease; Brain Neoplasms; Wakefulness; Magnetic Resonance Imaging; Microelectrodes; Electrodes, Implanted
PubMed: 36809747
DOI: 10.1159/000529040 -
Turkish Journal of Ophthalmology Sep 2019In outer retinal degenerative diseases such as retinitis pigmentosa, choroideremia, and geographic atrophy, 30% of the ganglion cell layer in the macula remains intact.... (Review)
Review
In outer retinal degenerative diseases such as retinitis pigmentosa, choroideremia, and geographic atrophy, 30% of the ganglion cell layer in the macula remains intact. With subretinal and epiretinal prostheses, these inner retinal cells are stimulated with controlled electrical current by either a microphotodiode placed in the subretinal area or a microelectrode array tacked to the epiretinal region. As the patient learns to interpret the resulting phosphene patterns created in the brain through special rehabilitation exercises, their orientation, mobility, and quality of life increase. Implants that stimulate the lateral geniculate nucleus or visual cortex are currently being studied for diseases in which the ganglion cells and optic nerve are completely destroyed.
Topics: Electric Stimulation; Electrodes, Implanted; Humans; Microelectrodes; Quality of Life; Retinal Degeneration; Retinitis Pigmentosa; Vision Disorders; Visual Prosthesis
PubMed: 31486609
DOI: 10.4274/tjo.galenos.2019.44270 -
Advanced Healthcare Materials Jun 2021Electrical microstimulation has enabled partial restoration of vision, hearing, movement, somatosensation, as well as improving organ functions by electrically... (Review)
Review
Electrical microstimulation has enabled partial restoration of vision, hearing, movement, somatosensation, as well as improving organ functions by electrically modulating neural activities. However, chronic microstimulation is faced with numerous challenges. The implantation of an electrode array into the neural tissue triggers an inflammatory response, which can be exacerbated by the delivery of electrical currents. Meanwhile, prolonged stimulation may lead to electrode material degradation., which can be accelerated by the hostile inflammatory environment. Both material degradation and adverse tissue reactions can compromise stimulation performance over time. For stable chronic electrical stimulation, an ideal microelectrode must present 1) high charge injection limit, to efficiently deliver charge without exceeding safety limits for both tissue and electrodes, 2) small size, to gain high spatial selectivity, 3) excellent biocompatibility that ensures tissue health immediately next to the device, and 4) stable in vivo electrochemical properties over the application period. In this review, the challenges in chronic microstimulation are described in detail. To aid material scientists interested in neural stimulation research, the in vitro and in vivo testing methods are introduced for assessing stimulation functionality and longevity and a detailed overview of recent advances in electrode material research and device fabrication for improving chronic microstimulation performance is provided.
Topics: Electric Stimulation; Electrodes, Implanted; Microelectrodes
PubMed: 34029008
DOI: 10.1002/adhm.202100119 -
Sensors (Basel, Switzerland) Nov 2022In recent decades, microelectrodes have been widely used in neuroscience to understand the mechanisms behind brain functions, as well as the relationship between neural... (Review)
Review
In recent decades, microelectrodes have been widely used in neuroscience to understand the mechanisms behind brain functions, as well as the relationship between neural activity and behavior, perception and cognition. However, the recording of neuronal activity over a long period of time is limited for various reasons. In this review, we briefly consider the types of penetrating chronic microelectrodes, as well as the conductive and insulating materials for microelectrode manufacturing. Additionally, we consider the effects of penetrating microelectrode implantation on brain tissue. In conclusion, we review recent advances in the field of in vivo microelectrodes.
Topics: Microelectrodes; Electrophysiological Phenomena; Brain; Neurons; Electric Conductivity; Electrodes, Implanted
PubMed: 36501805
DOI: 10.3390/s22239085 -
Annual International Conference of the... Jul 2022High signal-to-noise ratio (SNR) electromyography (EMG) recordings are essential for identifying and analyzing single motor unit activity. While high-density electrodes...
High signal-to-noise ratio (SNR) electromyography (EMG) recordings are essential for identifying and analyzing single motor unit activity. While high-density electrodes allow for greater spatial resolution, the smaller electrode area translates to a higher impedance and lower SNR. In this study, we developed an implantable and flexible 3D microelectrode array (MEA) with low impedance that enables high-quality EMG recording. With polyimide micro-cones realized by standard photolithography process and PEDOT:PSS coating, this design can increase effective surface area by up to 250% and significantly improve electrical performance for electrode sites with various geometric surface areas, where the electrode impedance is at most improved by 99.3%. Acute EMG activity from mice was recorded by implanting the electrodes in vivo, and we were able to detect multiple individual motor units simultaneously and with high resolution ([Formula: see text]). The charge storage capacity was measured to be 34.2 mC/cm, indicating suitability of the electrodes for stimulation applications as well.
Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Electric Impedance; Mice; Microelectrodes; Polymers
PubMed: 36086620
DOI: 10.1109/EMBC48229.2022.9871052