K. Mazurek, B. J. Holinski, D. Everaert, V. Mushahwar, R. Etienne-Cummings
{"title":"A Mixed-Signal VLSI System for Producing Temporally Adapting Intraspinal Microstimulation Patterns for Locomotion.","authors":"K. Mazurek, B. J. Holinski, D. Everaert, V. Mushahwar, R. Etienne-Cummings","doi":"10.1109/TBCAS.2015.2501419","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2501419","url":null,"abstract":"Neural pathways can be artificially activated through the use of electrical stimulation. For individuals with a spinal cord injury, intraspinal microstimulation, using electrical currents on the order of 125 μ A, can produce muscle contractions and joint torques in the lower extremities suitable for restoring walking. The work presented here demonstrates an integrated circuit implementing a state-based control strategy where sensory feedback and intrinsic feed forward control shape the stimulation waveforms produced on-chip. Fabricated in a 0.5 μ m process, the device was successfully used in vivo to produce walking movements in a model of spinal cord injury. This work represents progress towards an implantable solution to be used for restoring walking in individuals with spinal cord injuries.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 4 1","pages":"902-11"},"PeriodicalIF":5.1,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2501419","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Soltan, B. McGovern, E. Drakakis, M. Neil, P. Maaskant, M. Akhter, J. Lee, P. Degenaar
{"title":"High density, high radiance μLED matrix for optogenetic retinal prostheses and planar neural stimulation","authors":"A. Soltan, B. McGovern, E. Drakakis, M. Neil, P. Maaskant, M. Akhter, J. Lee, P. Degenaar","doi":"10.1109/TBCAS.2016.2623949","DOIUrl":"https://doi.org/10.1109/TBCAS.2016.2623949","url":null,"abstract":"Optical neuron stimulation arrays are important for both in-vitro biology and retinal prosthetic biomedical applications. Hence, in this work, we present an 8100 pixel high radiance photonic stimulator. The chip module vertically combines custom made gallium nitride μLEDs with a CMOS application specific integrated circuit. This is designed with active pixels to ensure random access and to allow continuous illumination of all required pixels. The μLEDs have been assembled on the chip using a solder ball flip-chip bonding technique which has allowed for reliable and repeatable manufacture. We have evaluated the performance of the matrix by measuring the different factors including the static, dynamic power consumption, the illumination, and the current consumption by each LED. We show that the power consumption is within a range suitable for portable use. Finally, the thermal behavior of the matrix is monitored and the matrix proved to be thermally stable.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"11 1","pages":"347-359"},"PeriodicalIF":5.1,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2016.2623949","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62966201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}