Background:The cochlear implant has become the standard of care for severe or worse losses in hearing and indeed has produced the first substantial restoration of a lost or absent human sense using a medical intervent...Background:The cochlear implant has become the standard of care for severe or worse losses in hearing and indeed has produced the first substantial restoration of a lost or absent human sense using a medical intervention.However,the devices are not perfect and many efforts to narrow the remaining gaps between prosthetic and normal hearing are underway.Objective:To assess the present status of cochlear implants and to describe possibilities for improving them.Results:The present-day devices work well in quiet conditions for the great majority of users.However,not all users have high levels of speech reception in quiet and nearly all users struggle with speech reception in typically noisy acoustic environments.In addition,perception of sounds more complex than speech,such as most music,is generally poor unless residual hearing at low frequencies can be stimulated acoustically in conjunction with the electrical stimuli provided by the implant.Possibilities for improving the present devices include increasing the spatial specificity of neural excitation by reducing masking effects or with new stimulus modes;prudent pruning of interfering or otherwise detrimental electrodes from the stimulation map;a further relaxation in the criteria for implant candidacy,based on recent evidence from persons with high levels of residual hearing and to allow many more people to benefit from cochlear implants;and 'top down' or 'brain centric' approaches to implant designs and applications.Conclusions:Progress in the development of the cochlear implant and related treatments has been remarkable but room remains for improvements.The future looks bright as there are multiple promising possibilities for improvements and many talented teams are pursuing them.展开更多
Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode b...Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root re- mains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9_10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimu- lation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation.展开更多
The emerging field of neuroprosthetics is focused on design and implementation of neural prostheses to restore some of the lost neural functions. Remarkable progress has been reported at most bioelectronic levels—par...The emerging field of neuroprosthetics is focused on design and implementation of neural prostheses to restore some of the lost neural functions. Remarkable progress has been reported at most bioelectronic levels—particularly the various brain-machine interfaces (BMIs)—but the electrode-tissue contacts (ETCs) remain one of the major obstacles. The success of these BMIs relies on electrodes which are in contact with the neural tissue. Biological response to chronic implantation of Microelectrode arrays (MEAs) is an essential factor in determining a successful electrode design. By altering the material compositions and geometries of the arrays, fabrication techniques of MEAs insuring these ETCs try to obtain consistent recording signals from small groups of neurons without losing microstimulation capabilities, while maintaining low-impedance pathways for charge injection, high-charge transfer, and high-spatial resolution in recent years. So far, none of these attempts have led to a major breakthrough. Clearly, much work still needs to be done to accept a standard model of MEAs for clinical purposes. In this paper, we review different microfabrication techniques of MEAs with their advantages and drawbacks, and comment on various coating materials to enhance electrode performance. Then, we propose high-density, three-dimensional (3D), silicon-based MEAs using micromachining methods. The geometries that will be used include arrays of penetrating variable-height probes.展开更多
Most biological tissues are supple and elastic, while current electronic devices fabricated by semiconductors and metals are usually stiff and brittle. As a result, implanted electronic devices can irritate and damage...Most biological tissues are supple and elastic, while current electronic devices fabricated by semiconductors and metals are usually stiff and brittle. As a result, implanted electronic devices can irritate and damage surrounding tissues, causing immune reaction and scarring. In this work, we develop stretchable microelectrode arrays, with the development of a novel soft lithography technology, which are designed and fabricated with a polymer/stretchable metal/polymer sandwich structure. With the great deformability of stretch, compression, bend and twisting, while preserving electrical property, this technology overcomes the fundamental mismatch of mechanical properties between biological tissues and electronic devices, and provides highly-compliant, confonnal and stretchable bio-electronic interfaces. Here we also describe the following three applications of the stretchable electrode arrays： a. monitoring intracranial electroencephalography （EEG）; b. stimulating peripheral nerves to drive muscles; c. monitoring epicardial electrocardiography （ECG）. Stretchable microelectrode arrays create a promising field in biomedical applications for its better modulus match with biological tissues and robust mechanical and electrical properties. They allow for construction of electronic integrated circuits spread over on complex and dynamic curved surfaces, providing a much friendlier bio-electronic interface for diagnosis, treatment and in- telligent bio-control.展开更多
While brain computer interfaces(BCIs)ofer the potential of allowing those sufering from loss of muscle control to once again fully engage with their environment by bypassing the afected motor system and decoding user ...While brain computer interfaces(BCIs)ofer the potential of allowing those sufering from loss of muscle control to once again fully engage with their environment by bypassing the afected motor system and decoding user intentions directly from brain activity,they are prone to errors.One possible avenue for BCI performance improvement is to detect when the BCI user perceives the BCI to have made an unintended action and thus take corrective actions.Error-related potentials(ErrPs)are neural correlates of error awareness and as such can provide an indication of when a BCI system is not performing according to the user’s intentions.Here,we investigate the brain signals of an implanted BCI user sufering from locked-in syndrome(LIS)due to late-stage ALS that prevents her from being able to speak or move but not from using her BCI at home on a daily basis to communicate,for the presence of error-related signals.We frst establish the presence of an ErrP originating from the dorsolateral pre-frontal cortex(dLPFC)in response to errors made during a discrete feedback task that mimics the click-based spelling software she uses to communicate.Then,we show that this ErrP can also be elicited by cursor movement errors in a continuous BCI cursor control task.This work represents a frst step toward detecting ErrPs during the daily home use of a communications BCI.展开更多
As the most important and mysterious organ in our body,the brain has been explored by numerous scientists.In this context,this paper mainly aims at Hilary Putnam's hypothesis of"brain in a tank"in his bo...As the most important and mysterious organ in our body,the brain has been explored by numerous scientists.In this context,this paper mainly aims at Hilary Putnam's hypothesis of"brain in a tank"in his book"Reason,Truth and History",and considers the possibility of the realization of this hypothesis in combination with practical experiments such as brain machine connection and brain wave transmission from regenerated brain cells,hoping to play a certain guiding role.展开更多
文摘Background:The cochlear implant has become the standard of care for severe or worse losses in hearing and indeed has produced the first substantial restoration of a lost or absent human sense using a medical intervention.However,the devices are not perfect and many efforts to narrow the remaining gaps between prosthetic and normal hearing are underway.Objective:To assess the present status of cochlear implants and to describe possibilities for improving them.Results:The present-day devices work well in quiet conditions for the great majority of users.However,not all users have high levels of speech reception in quiet and nearly all users struggle with speech reception in typically noisy acoustic environments.In addition,perception of sounds more complex than speech,such as most music,is generally poor unless residual hearing at low frequencies can be stimulated acoustically in conjunction with the electrical stimuli provided by the implant.Possibilities for improving the present devices include increasing the spatial specificity of neural excitation by reducing masking effects or with new stimulus modes;prudent pruning of interfering or otherwise detrimental electrodes from the stimulation map;a further relaxation in the criteria for implant candidacy,based on recent evidence from persons with high levels of residual hearing and to allow many more people to benefit from cochlear implants;and 'top down' or 'brain centric' approaches to implant designs and applications.Conclusions:Progress in the development of the cochlear implant and related treatments has been remarkable but room remains for improvements.The future looks bright as there are multiple promising possibilities for improvements and many talented teams are pursuing them.
基金supported by the International Cooperation Projects of Jilin Province Science and Technology Commission,No.20100735
文摘Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root re- mains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9_10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimu- lation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation.
文摘The emerging field of neuroprosthetics is focused on design and implementation of neural prostheses to restore some of the lost neural functions. Remarkable progress has been reported at most bioelectronic levels—particularly the various brain-machine interfaces (BMIs)—but the electrode-tissue contacts (ETCs) remain one of the major obstacles. The success of these BMIs relies on electrodes which are in contact with the neural tissue. Biological response to chronic implantation of Microelectrode arrays (MEAs) is an essential factor in determining a successful electrode design. By altering the material compositions and geometries of the arrays, fabrication techniques of MEAs insuring these ETCs try to obtain consistent recording signals from small groups of neurons without losing microstimulation capabilities, while maintaining low-impedance pathways for charge injection, high-charge transfer, and high-spatial resolution in recent years. So far, none of these attempts have led to a major breakthrough. Clearly, much work still needs to be done to accept a standard model of MEAs for clinical purposes. In this paper, we review different microfabrication techniques of MEAs with their advantages and drawbacks, and comment on various coating materials to enhance electrode performance. Then, we propose high-density, three-dimensional (3D), silicon-based MEAs using micromachining methods. The geometries that will be used include arrays of penetrating variable-height probes.
基金National Natural Science Foundation of China (No. 61102042)Youth Innovation Foundation of Chinese Academy of SciencesShenzhen"Peacock Plan"to Z.Y.
文摘Most biological tissues are supple and elastic, while current electronic devices fabricated by semiconductors and metals are usually stiff and brittle. As a result, implanted electronic devices can irritate and damage surrounding tissues, causing immune reaction and scarring. In this work, we develop stretchable microelectrode arrays, with the development of a novel soft lithography technology, which are designed and fabricated with a polymer/stretchable metal/polymer sandwich structure. With the great deformability of stretch, compression, bend and twisting, while preserving electrical property, this technology overcomes the fundamental mismatch of mechanical properties between biological tissues and electronic devices, and provides highly-compliant, confonnal and stretchable bio-electronic interfaces. Here we also describe the following three applications of the stretchable electrode arrays： a. monitoring intracranial electroencephalography （EEG）; b. stimulating peripheral nerves to drive muscles; c. monitoring epicardial electrocardiography （ECG）. Stretchable microelectrode arrays create a promising field in biomedical applications for its better modulus match with biological tissues and robust mechanical and electrical properties. They allow for construction of electronic integrated circuits spread over on complex and dynamic curved surfaces, providing a much friendlier bio-electronic interface for diagnosis, treatment and in- telligent bio-control.
文摘While brain computer interfaces(BCIs)ofer the potential of allowing those sufering from loss of muscle control to once again fully engage with their environment by bypassing the afected motor system and decoding user intentions directly from brain activity,they are prone to errors.One possible avenue for BCI performance improvement is to detect when the BCI user perceives the BCI to have made an unintended action and thus take corrective actions.Error-related potentials(ErrPs)are neural correlates of error awareness and as such can provide an indication of when a BCI system is not performing according to the user’s intentions.Here,we investigate the brain signals of an implanted BCI user sufering from locked-in syndrome(LIS)due to late-stage ALS that prevents her from being able to speak or move but not from using her BCI at home on a daily basis to communicate,for the presence of error-related signals.We frst establish the presence of an ErrP originating from the dorsolateral pre-frontal cortex(dLPFC)in response to errors made during a discrete feedback task that mimics the click-based spelling software she uses to communicate.Then,we show that this ErrP can also be elicited by cursor movement errors in a continuous BCI cursor control task.This work represents a frst step toward detecting ErrPs during the daily home use of a communications BCI.
文摘As the most important and mysterious organ in our body,the brain has been explored by numerous scientists.In this context,this paper mainly aims at Hilary Putnam's hypothesis of"brain in a tank"in his book"Reason,Truth and History",and considers the possibility of the realization of this hypothesis in combination with practical experiments such as brain machine connection and brain wave transmission from regenerated brain cells,hoping to play a certain guiding role.
