Arterial pressure control with isoflurane using fuzzy logic

Abstract

Arterial pressure is still one of the most important measures in estimating the required dose of inhaled anaesthetics. It is measured easily and reacts rapidly which makes it suitable as a variable for feedback control of depth of anaesthesia. Fuzzy logic, a novel approach to feedback control, was used to control arterial pressure in 10 patients during intraabdominal surgery by automatic adjustment of the concentration of isoflurane in fresh gas. During anaesthesia, fuzzy control periods of 45-min duration were alternated randomly with human control periods of equal duration. During the skin incision period (-3 to + 12 min) 48.2% of all fuzzy control pressure values were within +/- 10% of the desired mean arterial pressure compared with 40.4% of the human control values (P < 0.05). The corresponding values for the remainder of the operation were 78.3% and 83.2%, respectively. Thus fuzzy out-performed human control at skin incision, but was slightly inferior during the rest of the operation. We conclude that fuzzy logic is a promising new technique for control of isoflurane delivery during routine anaesthesia.

Fuzzy semi-numbers and a distance on them with a case study in medicine

“…As a case study, in this paper, a fuzzy logic controller is deployed to measure the MAP [21,22]. This controller simulates the relationship between the inflow concentration of Isoflurane, and the blood pressure.…”

Automated Drug Delivery in Anesthesia

“…The use of plasma or effect-site targeted drug administration is well understood and will lower the order of complexity of the resulting system [30]. Nowadays, the use of modern powerful microprocessors may allow better control through the incorporation of more sophisticated models describing the dose-response relationship, or by reverting to other control algorithms like MPC or fuzzy logic [31,32].…”

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“…Early developed closed-loop system used hemodynamic alterations to guide hypnotic drug delivery, due to a lack of availability of reliable cerebral drug effect monitors, such as EEG [21,22,31]. The commercialisation of more accurate cerebral effect measures enabled the development of EEG based closed-loop delivery of hypnotic-anesthetic drugs.…”

Predictive Control With Robust Dead-Time Compensation: Application to Drug Dosing During Anesthesia

“…It soon became clear that control of anesthesia poses a manifold of challenges, with multivariable characteristics (Zbinden et al;1995), time delay between drug administration and the clinical effect which can lead to system oscillations , different dynamics depending on anesthetics substances (Absalom and Struys; and stability problems (Asbury;1997). Further investigations proved Propofol to be an anesthetic tackled well in control problems (Kenny and Mantzaridis;, while recent studies showed that the control performance may also depend on the controlled variable (Ting et al;.…”