Journal ArticleDOI
Closed-Loop Control of an Anesthesia Delivery System: Development and Animal Testing
TLDR
An anesthesia system which integrates closed-loop control of ventilation, oxygen, nitrous oxide, and anesthetic agent delivery into a closed breathing circuit makes available the advantages of closed-system anesthesia without encumbering the anesthesiologist with the control tasks associated with the technique.Abstract:
An anesthesia system which integrates closed-loop control of ventilation, oxygen, nitrous oxide, and anesthetic agent delivery into a closed breathing circuit is described. Breathing circuit volume is regulated by controlling the sum of oxygen and nitrous oxide flow, and oxygen concentration in the breathing circuit is regulated by controlling the ratio of oxygen flow to the sum of oxygen and nitrous oxide flow. End-tidal anesthetic agent concentration is regulated by controlling the agent delivery, and end-tidal carbon dioxide concentration is regulated by controlling the ventilation. After tuning the ventilation and anesthetic delivery controllers in preliminary trials in ten dogs, the system was tested and evaluated in five dogs. All control loops were stable and exhibited time responses to step changes in setpoint or external disturbances which were clinically acceptable. The system makes available the advantages of closed-system anesthesia without encumbering the anesthesiologist with the control tasks associated with the technique.read more
Citations
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Journal ArticleDOI
Drug dosing control in clinical pharmacology
James M. Bailey,Wassim M. Haddad +1 more
TL;DR: The use of closed-loop control for clinical pharmacology can significantly advance the understanding of the effects of pharmacological agents and anesthetics, as well as advance the state-of-the-art in drug delivery systems.
Patent
Method and apparatus for closed loop drug delivery
TL;DR: In this article, a closed-loop drug delivery system uses patient response and rule based decision-making methods to achieve operator specified responses for diagnostic purposes Cardiac diagnosis is performed by pharmacologically stressing the heart by administration of an exercise simulating drug A protocol is defined, which preferably includes a target for a physiologic variable, such as heart rate, and a plan to achieve that target value.
Journal ArticleDOI
Modeling and control.
TL;DR: This discussion first comments on four aspects of physiologic modeling and control; it next raises general questions calculated to highlight further the differing perspectives of the panelists; and it summarizes each panelist's formal presentation and seeks expansion of material that may puzzle nonexperts.
Patent
Method and apparatus for controlling a ventilator
TL;DR: In this article, a controller determines PEEP, or CPAP, and F IO2, on the basis of data indicative of the patient's oxygen level, and uses the respiratory elastance and airway resistance data to determine any necessary adjustments in the I:E ratio.
Journal ArticleDOI
Control strategies for arterial blood pressure regulation
S. Isaka,A.V. Sebald +1 more
TL;DR: The theoretical development of automatic control strategies for arterial blood pressure regulation is reviewed in this article, where the literature is classified by control strategy, and a brief description of each control scheme is given, followed by examples of each from the literature.
References
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Journal ArticleDOI
A microprocessor based feedback controller for mechanical ventilation
TL;DR: Closed loop control of ventilation based on end-tidal PCO2 measurements successfully compensated for increases in CO2 production keeping PaCO2 constant, but the controller did not, however, keep Pa CO2 at the desired level when significant changes occurred in the distribution of blood flow to ventilation.
Journal ArticleDOI
Computer control of respiration and anaesthesia.
TL;DR: It is shown that a computer-controlled system, by monitoring values of arterial blood pressure, end-tidal CO2 percentage and inspired O2 percentage, can maintain the respiration and anaesthesia of a ventialted animal within close tolerances.
Journal ArticleDOI
Uptake of enflurane: a study of the variability between patients
TL;DR: The system described in this paper demonstrates the feasibility of using feedback control of fresh gas delivery for the automatic control of an "overpressure" induction technique and indicated that a single model cannot be used to deliver anaesthesia to a varied patient population.
Journal ArticleDOI
SERVO-CONTROLLED CLOSED-CIRCUIT ANAESTHESIA: A method for the automatic control of anaesthesia produced by a volatile agent in oxygen
TL;DR: Accurate estimation of anaesthetic uptake was readily obtained and results for the uptake of halothane agreed closely with those of previous workers and the major sources of error in the method were the result of zero offset in the Engstrom EMMA and the intrinsic characteristic of the simple proportional controller used.
Journal ArticleDOI
Instrumentation for Measuring Continuous Oxygen Consumption of Surgical Patients
TL;DR: The record of a surgical patient's VO2 while under balanced anesthesia shows a practical application of the system and shows the major error resulting from oxygen sensor or electronics dnift, leaks in the system, or changes in residual volume.