Arrangement and process for controlling a numerical value for patient respiration
First Claim
1. A patient respiration numerical value control circuit arrangement comprising:
- a respiration circuit with a Y-piece for delivering a gaseous anesthetic mixture to the lungs of a patient;
a metering device for metering at least one anesthetic in the gaseous anesthetic mixture;
an electroencephalogram (EEG) control with an EEG sensor adapted to be connected to the brain of the patient via head electrodes for measuring an EEG actual value, a EEG set point transducer for sending an EEG set point, an EEG comparison point, which forms the difference between the EEG actual value and the EEG set point, and a EEG controller, which forms a manipulated variable from the difference for the metering device so that when the EEG set point is exceeded by the EEG actual value, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device and when the EEG actual value drops below the EEG set point, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the EEG actual value and the EEG set point agree.
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Accused Products
Abstract
An arrangement with a control circuit for controlling a numerical value for patient respiration as well as to a process for controlling the numerical value. The numerical value is controlled on the basis of an evaluation of the EEG (electroencephalogram) of the patient (1) by an EEG sensor (2), e.g., by determining the so-called BIS (bispectral index). A control of the inspiratory gaseous anesthetic concentrations is cascaded to the control of the EEG value in the manner of a cascade circuit. This has the advantage that a metering device (6) belonging to the arrangement meters a gaseous anesthetic mixture directly according to the patient'"'"'s needs. As an alternative, the control of the numerical value is performed on the basis of an evaluation of the expiratory gaseous anesthetic concentrations resolved for individual breaths at the Y-piece (19) of the respiration circuit (12) by a gaseous anesthetic sensor (8a), preferably an infrared optical gas sensor.
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Citations
20 Claims
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1. A patient respiration numerical value control circuit arrangement comprising:
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a respiration circuit with a Y-piece for delivering a gaseous anesthetic mixture to the lungs of a patient;
a metering device for metering at least one anesthetic in the gaseous anesthetic mixture;
an electroencephalogram (EEG) control with an EEG sensor adapted to be connected to the brain of the patient via head electrodes for measuring an EEG actual value, a EEG set point transducer for sending an EEG set point, an EEG comparison point, which forms the difference between the EEG actual value and the EEG set point, and a EEG controller, which forms a manipulated variable from the difference for the metering device so that when the EEG set point is exceeded by the EEG actual value, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device and when the EEG actual value drops below the EEG set point, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the EEG actual value and the EEG set point agree. - View Dependent Claims (2, 3, 4, 5)
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6. A control process, comprising the steps of:
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providing a metering device for metering at least one anesthetic in the gaseous anesthetic mixtures;
measuring an electroencephalogram (EEG) actual value with an EEG sensor;
sending an EEG set point from a EEG set point transducer;
forming a difference at an EEG comparison point from the EEG actual value and the EEG set point;
generating a manipulated variable with an EEG controller from the difference for controlling the metering device so that when the EEG set point is exceeded by the EEG actual value, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device and when the EEG actual value drops below the EEG set point, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the EEG actual value and the EEG set point agree. - View Dependent Claims (7, 8, 9)
using a numerical value control circuit arrangement with a respiration circuit with a piece for delivering a gaseous anesthetic mixture to the lungs of a patient connected thereto, the metering device and an EEG control with an EEG sensor connected to the brain of the patient via head electrodes for measuring an EEG actual value, a EEG set point transducer for sending an EEG set point, an EEG comparison point, which forms the difference between the EEG actual value and the EEG set point, and an EEG controller.
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8. A process in accordance with claim 7, further comprising:
using a control circuit for controlling the inspiratory gaseous anesthetic concentrations cascaded to the EEG control, wherein the EEG controller forms a set point for a gaseous anesthetic comparison point, to which the inspiratory gaseous anesthetic concentrations determined by a gaseous anesthetic sensor are sent as the actual value and which forms the difference between the actual value and the set point, from the difference between the EEG actual value and the EEG set point instead of forming the manipulated variable for the metering device, and a gaseous anesthetic controller, which generates a manipulated variable for the metering device from the difference.
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9. A process in accordance with claim 8, further comprising:
using a changeover switch for either switching on the unit for the EEG control with the cascaded control circuit for controlling the inspiratory gaseous anesthetic concentrations and switches off a unit for controlling the expiratory gaseous anesthetic concentrations or switching off the unit for the EEG control with the cascaded control circuit for controlling the inspiratory gaseous anesthetic concentrations and switches on the unit for controlling the expiratory gaseous anesthetic concentrations when no EEG actual value of the EEG sensor is available over a predetermined time period, wherein the unit for controlling the expiratory gaseous anesthetic concentrations comprises the gaseous anesthetic sensor for measuring an actual value of the expiratory gaseous anesthetic concentrations, a gaseous anesthetic set point transducer for sending a set point for the expiratory gaseous anesthetic concentrations, a gaseous anesthetic comparison point, which forms the difference between the actual value and the set point, and a gaseous anesthetic controller, which forms a manipulated variable from the difference for the metering device, so that when the actual value drops below the set point, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device and when the set point is exceeded by the actual value, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the actual value and the set point agree.
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10. An arrangement with a control circuit for controlling a numerical value for patient respiration, the arrangement comprising:
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a respiration circuit for delivering a gaseous anesthetic mixture to the lungs of a patient via a Y-piece;
a metering device for metering at least one anesthetic in the gaseous anesthetic mixture;
a unit for controlling a physiological parameter of the patient, comprising a sensor for measuring an actual value of the physiological parameter of the patient;
a set point transducer for the physiological parameter of the patient for sending a set point for the physiological parameter of the patient;
a comparison element forming a difference between the actual value of the physiological parameter of the patient and the set point of the physiological parameter of the patient;
a controller for controlling the metering device so that when the set point of the physiological parameter of the patient is exceeded by the actual value of the physiological parameter of the patient, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device, and when the actual value of the physiological parameter of the patient drops below the set point of the physiological parameter of the patient, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the actual value of the physiological parameter of the patient and the set point of the physiological parameter of the patient agree. - View Dependent Claims (11, 12, 13, 14)
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15. A process for controlling a numerical value, the process comprising:
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measuring an actual value of a physiological parameter of the patient with a sensor for the physiological parameter of the patient;
sending a set point of the physiological parameter of the patient with a set point transducer for the physiological parameter of the patient;
forming the difference between the actual value of the physiological parameter of the patient and the set point of the physiological parameter of the patient at a comparison point for the physiological parameter of the patient; and
generating a manipulated variable from the difference by a controller of the physiological parameter of the patient for controlling the metering device including;
increasing a percentage of at least one anesthetic in the gaseous anesthetic mixture when the set point of the physiological parameter of the patient is exceeded by the actual value of the physiological parameter of the patient; and
reducing the percentage of at least one anesthetic in the gaseous anesthetic mixture when the actual value of the physiological parameter of the patient drops below the set point of the physiological parameter of the patient until the actual value of the physiological parameter of the patient and the set point of the physiological parameter of the patient agree. - View Dependent Claims (16, 17, 18)
using a numerical value control circuit arrangement with a respiration circuit with a Y-piece for delivering a gaseous anesthetic mixture to the lungs of a patient connected thereto, the metering device and an EEG control with an EEG sensor connected to the brain of the patient via head electrodes for measuring an EEG actual value, a EEG set point transducer for sending an EEG set point, an EEG comparison point, which forms the difference between the EEG actual value and the EEG set point, and an EEG controller.
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17. A process in accordance with claim 16, further comprising:
using a control circuit for controlling the inspiratory gaseous anesthetic concentrations cascaded to the EEG control, wherein the EEG controller forms a set point for a gaseous anesthetic comparison point, to which the inspiratory gaseous anesthetic concentrations determined by a gaseous anesthetic sensor are sent as the actual value and which forms the difference between the actual value and the set point, from the difference between the EEG actual value and the EEG set point instead of forming the manipulated variable for the metering device, and a gaseous anesthetic controller, which generates a manipulated variable for the metering device from the difference.
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18. A process in accordance with claim 17, further comprising:
using a changeover switch for either switching on the unit for the EEG control with the cascaded control circuit for controlling the inspiratory gaseous anesthetic concentrations and switches off a unit for controlling the expiratory gaseous anesthetic concentrations or switching off the unit for the EEG control with the cascaded control circuit for controlling the inspiratory gaseous anesthetic concentrations and switches on the unit for controlling the expiratory gaseous anesthetic concentrations when no EEG actual value of the EEG sensor is available over a predetermined time period, wherein the unit for controlling the expiratory gaseous anesthetic concentrations comprises the gaseous anesthetic sensor for measuring an actual value of the expiratory gaseous anesthetic concentrations, a gaseous anesthetic set point transducer for sending a set point for the expiratory gaseous anesthetic concentrations, a gaseous anesthetic comparison point, which forms the difference between the actual value and the set point, and a gaseous anesthetic controller, which forms a manipulated variable from the difference for the metering device, so that when the actual value drops below the set point, the percentage of at least one anesthetic in the gaseous anesthetic mixture is increased by the metering device and when the set point is exceeded by the actual value, the percentage of at least one anesthetic in the gaseous anesthetic mixture is reduced by the metering device until the actual value and the set point agree.
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19. A process for controlling anesthetic to a patient, the process comprising the steps of:
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providing a set physiological point for a physiological parameter of the patient;
measuring an actual physiological value of a physiological parameter of the patient;
calculating a physiological difference between said set physiological point and said actual physiological value;
creating an anesthetic set point based on said physiological difference;
delivering anesthetic to the patient;
measuring an anesthetic concentration to form an anesthetic actual value;
comparing said anesthetic actual value with said anesthetic set point;
controlling the anesthetic to the patient to cause said anesthetic actual value to be substantially equal to said anesthetic set point. - View Dependent Claims (20)
said anesthetic actual value, is an inspiratory anesthetic actual value;
said anesthetic set point is an inspiratory anesthetic set point;
said controlling is a physiological controlling;
an expiratory controlling is also provided, said expiratory controlling including;
measuring the anesthetic exhaled from the patient to form an expiratory anesthetic actual value;
providing an expiratory anesthetic set point;
comparing said expiratory anesthetic actual value with said expiratory anesthetic set point;
expiratory controlling the anesthetic to the patient to cause said expiratory anesthetic actual value to be substantially equal to said expiratory anesthetic set point;
the process of controlling the anesthetic gas selectively switches between said physiological controlling and said expiratory controlling.
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Specification