title: Data clustering methods for the determination of cerebral autoregulation functionality.
abstract: Cerebral blood flow is regulated over a range of systemic blood pressures through the cerebral autoregulation (CA) control mechanism. The COx measure based on near infrared spectroscopy (NIRS) has been proposed as a suitable technique for the analysis of CA as it is non-invasive and provides a simpler acquisition methodology than other methods. The COx method relies on data binning and thresholding to determine the change between intact and impaired autoregulation zones. In the work reported here we have developed a novel method of differentiating the intact and impaired CA blood pressure regimes using clustering methods on unbinned data. K-means and Gaussian mixture model algorithms were used to analyse a porcine data set. The determination of the lower limit of autoregulation (LLA) was compared to a traditional binned data approach. Good agreement was found between the methods. The work highlights the potential application of using data clustering tools in the monitoring of CA function.
authors.affiliation: Respiratory and Monitoring Solutions, Medtronic, Technopole Centre, Edinburgh, EH26 0PJ, UK. dean.montgomery@medtronic.com.
authors.forename: Dean
authors.identifier: http://orcid.org/0000-0001-5200-3439
authors.initials: D
authors.lastname: Montgomery
authors.affiliation: Respiratory and Monitoring Solutions, Medtronic, Technopole Centre, Edinburgh, EH26 0PJ, UK.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Addison
authors.affiliation: Respiratory and Monitoring Solutions, Medtronic, 6135 Gunbarrel Avenue, Boulder, CO, 80301, USA.
authors.forename: Ulf
authors.initials: U
authors.lastname: Borg
mesh_terms: D000465:Algorithms; D000777:Anesthetics; D000818:Animals; D062186:Arterial Pressure / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002404:Catheterization; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016000:Cluster Analysis; D003627:Data Interpretation, Statistical; D005260:Female; D006706:Homeostasis; D006801:Humans; D000860:Hypoxia; D008168:Lung / Q000502:physiology; D008297:Male; D008991:Monitoring, Physiologic; D016011:Normal Distribution; D012044:Regression Analysis; D015203:Reproducibility of Results; D012771:Shock, Hemorrhagic / Q000503:physiopathology; D019265:Spectroscopy, Near-Infrared; D013552:Swine
chemical_list: D000777:Anesthetics
keywords: COx; Cerebral autoregulation; Clustering; Gaussian mixture models; NIRS; k-means