Document Detail


Closed-loop control if the inspired fraction of oxygen in mechanical ventilation.
MedLine Citation:
PMID:  12885181     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: Supplemental oxygen treatment of patients on mechanical ventilation is crucial in maintaining the patients' oxygen levels in the normal range. The purpose of this study was to evaluate the effectiveness of a closed-loop controller for automatic adjustment of the fraction of inspired oxygen, FIO2. More specifically, the aim of the study was to assess the robustness of the controller in correcting hypoxemia as well as its effectiveness in prevention of hyperoxemia and oxygen toxicity. METHODS: The microprocessor-based feedback control system combines a rapid control algorithm with a proportional-integral-derivative (PID) control procedure to automatically adjust FIO2. The system is designed to prevent hypoxemia by applying a stepwise control procedure in response to rapid declines in arterial oxygen saturation while fine-tuning FIO2 and avoiding hyperoxemia by resuming to the PID control procedure when appropriate. The system includes a sophisticated safeguard unit which is designed to communicate any oxygenation problems or measurement artifacts to the medical personnel while keeping FIO2 at a safe and sufficiently high level. The control system has been tested by using computer simulations as well as animal studies. RESULTS: In response to different disturbances, the arterial oxygen saturation returned to the normal safe range within less than 20 seconds, thereby avoiding any untoward effects of hypoxemia. Under steady state conditions, the variations in arterial oxygen saturation were kept within +/- 3% of the mean value. The controller corrected hypoxemia within seconds while preventing hyperoxemia, rejecting artifacts, and minimizing exposure to high concentrations of oxygen. CONCLUSION: The results of the study attest to the reliability of the proposed closed-loop control scheme for automatic adjustment of FIO2. Further evaluation of the controller will require testing the effectiveness of the system on different patient groups.
Authors:
Fleur Tehrani; Mark Rogers; Takkin Lo; Thomas Malinowski; Samuel Afuwape; Michael Lum; Brett Grundl; Michael Terry
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of clinical monitoring and computing     Volume:  17     ISSN:  1387-1307     ISO Abbreviation:  J Clin Monit Comput     Publication Date:  2002 Aug 
Date Detail:
Created Date:  2003-07-29     Completed Date:  2003-10-28     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  9806357     Medline TA:  J Clin Monit Comput     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  367-76     Citation Subset:  IM    
Affiliation:
Department of Electrical Engineering, California State University, Fullerton, California 92834-6870, USA. ftehrani@fullerton.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Algorithms*
Anoxia
Automation
Computer Simulation
Humans
Numerical Analysis, Computer-Assisted
Oximetry
Oxygen / blood*
Oxygen Inhalation Therapy*
Reference Values
Respiration, Artificial*
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Unconsciousness indication using time-domain parameters extracted from mid-latency auditory evoked p...
Next Document:  Biasing effect of the electromyogram on BIS: a controlled study during high-dose fentanyl induction.