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PubMed · 9112204

FIx controller: an instrument to automatically adjust inspired oxygen fraction using feedback control from a pulse oximeter.

D B Raemer·X B Ji·G P Topulos
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Abstract

OBJECTIVE: To develop an instrument to help prevent pulmonary O2 toxicity, a syndrome that manifests itself in adult intensive care patients. METHODS: We designed, built, and tested a device that controls FIO2 exposure using oxygen saturation measured with a pulse oximeter (SpO2) in a negative feedback control system. A target SpO2 is designated by the clinician and the system adjusts the FIO2 from a mechanical ventilator so as to minimize the difference between the measured SpO2 and the target. Important elements of the system include a conservative artifact rejection algorithm, a gainscheduled sampled-data proportional-integral-derivative (PID) controller, and a safety system to prevent inspired mixtures with undesirably low FIO2 due to device failure. RESULTS: The control system was tuned in a series of animal experiments. Acceptable clinical response of the system was obtained using a gain-scheduled controller algorithm whereby the gain of the proportional term of a PID controller was adjusted based on the error signal and measured minute ventilation. Also, the artifact rejection algorithm and safety systems were successfully tested using simulation. CONCLUSIONS: Testing the effectiveness of this instrument will require comparison with manual control of FIO2 in an appropriately designed trial.

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AlgorithmsAnimalsArtifactsDogsFeedbackOximetryOxygenRespiration, ArtificialJournal ArticleResearch Support, Non-U.S. Gov't

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BibTeXRIS

D B Raemer, X B Ji, G P Topulos. 1997. FIx controller: an instrument to automatically adjust inspired oxygen fraction using feedback control from a pulse oximeter.. https://doi.org/10.1023/a%3A1007384122804

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