Robust control of burst suppression for medical coma
Objective. Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world oper...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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IOP Publishing
2016
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| Online Access: | http://hdl.handle.net/1721.1/102355 https://orcid.org/0000-0003-2668-7819 https://orcid.org/0000-0002-4518-4208 |
| _version_ | 1811097689987743744 |
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| author | Kim, Seong-Eun Ching, ShiNung Brown, Emery N. Westover, M. Brandon Purdon, Patrick L. |
| author2 | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences Kim, Seong-Eun Ching, ShiNung Brown, Emery N. Westover, M. Brandon Purdon, Patrick L. |
| author_sort | Kim, Seong-Eun |
| collection | MIT |
| description | Objective. Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world operating conditions, subject to substantial pharmacokinetic and pharmacodynamic parameter uncertainty and unpredictable external disturbances. We sought to develop a robust closed-loop anesthesia delivery (CLAD) system to control medical coma. Approach. We developed a robust CLAD system to control the burst suppression probability (BSP). We developed a novel BSP tracking algorithm based on realistic models of propofol pharmacokinetics and pharmacodynamics. We also developed a practical method for estimating patient-specific pharmacodynamics parameters. Finally, we synthesized a robust proportional integral controller. Using a factorial design spanning patient age, mass, height, and gender, we tested whether the system performed within clinically acceptable limits. Throughout all experiments we subjected the system to disturbances, simulating treatment of refractory status epilepticus in a real-world intensive care unit environment. Main results. In 5400 simulations, CLAD behavior remained within specifications. Transient behavior after a step in target BSP from 0.2 to 0.8 exhibited a rise time (the median (min, max)) of 1.4 [1.1, 1.9] min; settling time, 7.8 [4.2, 9.0] min; and percent overshoot of 9.6 [2.3, 10.8]%. Under steady state conditions the CLAD system exhibited a median error of 0.1 [−0.5, 0.9]%; inaccuracy of 1.8 [0.9, 3.4]%; oscillation index of 1.8 [0.9, 3.4]%; and maximum instantaneous propofol dose of 4.3 [2.1, 10.5] mg kg[superscript −1]. The maximum hourly propofol dose was 4.3 [2.1, 10.3] mg kg[superscript −1] h[superscript −1]. Performance fell within clinically acceptable limits for all measures. Significance. A CLAD system designed using robust control theory achieves clinically acceptable performance in the presence of realistic unmodeled disturbances and in spite of realistic model uncertainty, while maintaining infusion rates within acceptable safety limits. |
| first_indexed | 2024-09-23T17:03:21Z |
| format | Article |
| id | mit-1721.1/102355 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T17:03:21Z |
| publishDate | 2016 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1023552022-10-03T10:06:30Z Robust control of burst suppression for medical coma Kim, Seong-Eun Ching, ShiNung Brown, Emery N. Westover, M. Brandon Purdon, Patrick L. Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences Picower Institute for Learning and Memory Kim, Seong-Eun Brown, Emery N. Objective. Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world operating conditions, subject to substantial pharmacokinetic and pharmacodynamic parameter uncertainty and unpredictable external disturbances. We sought to develop a robust closed-loop anesthesia delivery (CLAD) system to control medical coma. Approach. We developed a robust CLAD system to control the burst suppression probability (BSP). We developed a novel BSP tracking algorithm based on realistic models of propofol pharmacokinetics and pharmacodynamics. We also developed a practical method for estimating patient-specific pharmacodynamics parameters. Finally, we synthesized a robust proportional integral controller. Using a factorial design spanning patient age, mass, height, and gender, we tested whether the system performed within clinically acceptable limits. Throughout all experiments we subjected the system to disturbances, simulating treatment of refractory status epilepticus in a real-world intensive care unit environment. Main results. In 5400 simulations, CLAD behavior remained within specifications. Transient behavior after a step in target BSP from 0.2 to 0.8 exhibited a rise time (the median (min, max)) of 1.4 [1.1, 1.9] min; settling time, 7.8 [4.2, 9.0] min; and percent overshoot of 9.6 [2.3, 10.8]%. Under steady state conditions the CLAD system exhibited a median error of 0.1 [−0.5, 0.9]%; inaccuracy of 1.8 [0.9, 3.4]%; oscillation index of 1.8 [0.9, 3.4]%; and maximum instantaneous propofol dose of 4.3 [2.1, 10.5] mg kg[superscript −1]. The maximum hourly propofol dose was 4.3 [2.1, 10.3] mg kg[superscript −1] h[superscript −1]. Performance fell within clinically acceptable limits for all measures. Significance. A CLAD system designed using robust control theory achieves clinically acceptable performance in the presence of realistic unmodeled disturbances and in spite of realistic model uncertainty, while maintaining infusion rates within acceptable safety limits. 2016-05-02T17:08:39Z 2016-05-02T17:08:39Z 2015-05 2015-03 Article http://purl.org/eprint/type/JournalArticle 1741-2560 1741-2552 http://hdl.handle.net/1721.1/102355 Westover, M Brandon, Seong-Eun Kim, ShiNung Ching, Patrick L Purdon, and Emery N Brown. “Robust Control of Burst Suppression for Medical Coma.” Journal of Neural Engineering 12, no. 4 (May 28, 2015): 046004. https://orcid.org/0000-0003-2668-7819 https://orcid.org/0000-0002-4518-4208 en_US http://dx.doi.org/10.1088/1741-2560/12/4/046004 Journal of Neural Engineering Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf IOP Publishing PMC |
| spellingShingle | Kim, Seong-Eun Ching, ShiNung Brown, Emery N. Westover, M. Brandon Purdon, Patrick L. Robust control of burst suppression for medical coma |
| title | Robust control of burst suppression for medical coma |
| title_full | Robust control of burst suppression for medical coma |
| title_fullStr | Robust control of burst suppression for medical coma |
| title_full_unstemmed | Robust control of burst suppression for medical coma |
| title_short | Robust control of burst suppression for medical coma |
| title_sort | robust control of burst suppression for medical coma |
| url | http://hdl.handle.net/1721.1/102355 https://orcid.org/0000-0003-2668-7819 https://orcid.org/0000-0002-4518-4208 |
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