Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury
Cervical spinal cord injury (SCI) paralyzes muscles of the hand and arm, making it difficult to perform activities of daily living. Restoring the ability to reach can dramatically improve quality of life for people with cervical SCI. Any reaching system requires a user interface to decode parameters...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2014-05-01
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| Series: | Frontiers in Neuroscience |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnins.2014.00123/full |
| _version_ | 1818049860068179968 |
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| author | Elaine Anna Corbett Elaine Anna Corbett Elaine Anna Corbett Nicholas A Sachs Konrad eKoerding Konrad eKoerding Konrad eKoerding Eric Jon Perreault Eric Jon Perreault Eric Jon Perreault |
| author_facet | Elaine Anna Corbett Elaine Anna Corbett Elaine Anna Corbett Nicholas A Sachs Konrad eKoerding Konrad eKoerding Konrad eKoerding Eric Jon Perreault Eric Jon Perreault Eric Jon Perreault |
| author_sort | Elaine Anna Corbett |
| collection | DOAJ |
| description | Cervical spinal cord injury (SCI) paralyzes muscles of the hand and arm, making it difficult to perform activities of daily living. Restoring the ability to reach can dramatically improve quality of life for people with cervical SCI. Any reaching system requires a user interface to decode parameters of an intended reach, such as trajectory and target. A challenge in developing such decoders is that often few physiological signals related to the intended reach remain under voluntary control, especially in patients with high cervical injuries. Furthermore, the decoding problem changes when the user is controlling the motion of their limb, as opposed to an external device. The purpose of this study was to investigate the benefits of combining disparate signal sources to control reach in people with a range of impairments, and to consider the effect of two feedback approaches. Subjects with cervical SCI performed robot-assisted reaching, controlling trajectories with either shoulder electromyograms (EMGs) or EMGs combined with gaze. We then evaluated how reaching performance was influenced by task-related sensory feedback, testing the EMG-only decoder in two conditions. The first involved moving the arm with the robot, providing congruent sensory feedback through their remaining sense of proprioception. In the second, the subjects moved the robot without the arm attached, as in applications that control external devices. We found that the multimodal decoding algorithm worked well for all subjects, enabling them to perform straight, accurate reaches. The inclusion of gaze information, used to estimate target location, was especially important for the most impaired subjects. In the absence of gaze information, congruent sensory feedback improved performance. These results highlight the importance of proprioceptive feedback, and suggest that multi-modal decoders are likely to be most beneficial for highly impaired subjects and in tasks where such feedback is unavailable. |
| first_indexed | 2024-12-10T10:44:17Z |
| format | Article |
| id | doaj.art-0e752110a7524d938b46750d034adece |
| institution | Directory Open Access Journal |
| issn | 1662-453X |
| language | English |
| last_indexed | 2024-12-10T10:44:17Z |
| publishDate | 2014-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Neuroscience |
| spelling | doaj.art-0e752110a7524d938b46750d034adece2022-12-22T01:52:12ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2014-05-01810.3389/fnins.2014.0012382873Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injuryElaine Anna Corbett0Elaine Anna Corbett1Elaine Anna Corbett2Nicholas A Sachs3Konrad eKoerding4Konrad eKoerding5Konrad eKoerding6Eric Jon Perreault7Eric Jon Perreault8Eric Jon Perreault9Northwestern UniversityRehabilitation Institute of ChicagoUniversity of MelbourneNorthwestern UniversityRehabilitation Institute of ChicagoNorthwestern UniversityNorthwestern UniversityRehabilitation Institute of ChicagoNorthwestern UniversityNorthwestern UniversityCervical spinal cord injury (SCI) paralyzes muscles of the hand and arm, making it difficult to perform activities of daily living. Restoring the ability to reach can dramatically improve quality of life for people with cervical SCI. Any reaching system requires a user interface to decode parameters of an intended reach, such as trajectory and target. A challenge in developing such decoders is that often few physiological signals related to the intended reach remain under voluntary control, especially in patients with high cervical injuries. Furthermore, the decoding problem changes when the user is controlling the motion of their limb, as opposed to an external device. The purpose of this study was to investigate the benefits of combining disparate signal sources to control reach in people with a range of impairments, and to consider the effect of two feedback approaches. Subjects with cervical SCI performed robot-assisted reaching, controlling trajectories with either shoulder electromyograms (EMGs) or EMGs combined with gaze. We then evaluated how reaching performance was influenced by task-related sensory feedback, testing the EMG-only decoder in two conditions. The first involved moving the arm with the robot, providing congruent sensory feedback through their remaining sense of proprioception. In the second, the subjects moved the robot without the arm attached, as in applications that control external devices. We found that the multimodal decoding algorithm worked well for all subjects, enabling them to perform straight, accurate reaches. The inclusion of gaze information, used to estimate target location, was especially important for the most impaired subjects. In the absence of gaze information, congruent sensory feedback improved performance. These results highlight the importance of proprioceptive feedback, and suggest that multi-modal decoders are likely to be most beneficial for highly impaired subjects and in tasks where such feedback is unavailable.http://journal.frontiersin.org/Journal/10.3389/fnins.2014.00123/fullElectromyographyspinal cord injuryEye-trackingKalman filterproprioceptive feedback. |
| spellingShingle | Elaine Anna Corbett Elaine Anna Corbett Elaine Anna Corbett Nicholas A Sachs Konrad eKoerding Konrad eKoerding Konrad eKoerding Eric Jon Perreault Eric Jon Perreault Eric Jon Perreault Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury Frontiers in Neuroscience Electromyography spinal cord injury Eye-tracking Kalman filter proprioceptive feedback. |
| title | Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| title_full | Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| title_fullStr | Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| title_full_unstemmed | Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| title_short | Multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| title_sort | multimodal decoding and congruent sensory information enhance reaching performance in subjects with cervical spinal cord injury |
| topic | Electromyography spinal cord injury Eye-tracking Kalman filter proprioceptive feedback. |
| url | http://journal.frontiersin.org/Journal/10.3389/fnins.2014.00123/full |
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