Background: Closed-loop control of the hypnotic component of anesthesia has been proposed in an attempt to optimize drug delivery. Here, we introduce a newly developed Bayesian-based, patient-individualized, model-based, adaptive control method for bispectral index (BIS) guided propofol infusion into clinical practice and compare its accuracy and clinical feasibility under direct observation of an anesthesiologist versus BIS guided, effect compartment controlled propofol administration titrated by the anesthesiologist during ambulatory gynecological procedures.
Methods: Forty ASA patients were randomly allocated to the closed-loop or manual control group. All patients received midazolam 1 mg IV and alfentanil 0.5 mg IV before induction. In the closed-loop control group, propofol was administered using the previously described closed-loop control system to reach and maintain a target BIS of 50. In the manual control group, the propofol effect-site concentration was adapted at the discretion of the anesthesiologist to reach and maintain a BIS as close as possible to 50. Induction characteristics, performance, and robustness during maintenance and recovery times were compared. Hemodynamic and respiratory stability were calculated as clinical feasibility parameters.
Results: The closed-loop control system titrated propofol administration accurately resulting in BIS values close to the set point. The closed-loop control system was able to induce the patients within clinically accepted time limits and with less overshoot than the manual control group. Automated control resulted in beneficial recovery times. Our closed-loop control group showed similar acceptable clinical performance specified by similar hemodynamic, respiratory stability, comparable movement rates, and quality scores than the manual control group.
Conclusions: The Bayesian-based closed-loop control system for propofol administration using the BIS as a controlled variable performed accurate during anesthesia for ambulatory gynecological procedures. This control system is clinical feasibility and can be further validated in clinical practice.
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http://dx.doi.org/10.1213/ane.0b013e31817bd1a6 | DOI Listing |
Sensors (Basel)
January 2025
School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China.
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January 2025
College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China.
High-precision, low-power MEMS accelerometers are extensively utilized across civilian applications. Closed-loop accelerometers employing switched-capacitor (SC) circuit topologies offer notable advantages, including low power consumption, high signal-to-noise ratio (SNR), and excellent linearity. Addressing the critical demand for high-precision, low-power MEMS accelerometers in modern geophones, this work focuses on the design and implementation of closed-loop interface ASICs (Application-Specific Integrated Circuits).
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Taiwan Instrument Research Institute, National Applied Research Laboratories, Hsinchu 300092, Taiwan.
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View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Lightweight Optics and Advanced Materials Technology Center, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China.
Direct energy deposition is an additive technology that can quickly manufacture irregularly shaped quartz-glass devices. Based on this technology and coaxial laser/wire feeding, open-loop tests were conducted under different process parameters. A closed-loop temperature control system was designed and built for the molten pool temperature in quartz-glass additive manufacturing.
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