Apparatus and method for controlling fraction of inspired oxygen
First Claim
1. A method of operating a ventilator to control the fraction of pressure inspired oxygen (FiO2), the method comprising:
- providing a pulse oximeter to measure a patient'"'"'s pulse oximetry;
providing a FiO2 flow rate controller, wherein the flow rate controller controls the flow rate of FiO2 to the patient;
measuring the patient'"'"'s pulse oximetry and providing a measured pulse oximetry value;
averaging the patient'"'"'s measured pulse oximetry value over a period of time;
providing a ventilator controller responsive to the average of the patient'"'"'s measured pulse oximetry value, wherein the FiO2 flow rate controller is responsive to the ventilator controller and controls the flow rate of FiO2 to the patient;
selecting the time period for averaging the patient'"'"'s measured pulse oximetry value;
selecting a first, a second, and a third pulse oximetry level as set points for the ventilator controller;
selecting an FiO2 operating range having a low end, a high end and a mid-point, wherein the midpoint of the range is equal to one-half the sum of the low end and the high end;
selecting a first incremental amount for decreasing the flow rate of FiO2 and a second incremental amount for increasing the flow rate of FiO2;
selecting an update time interval, wherein the update time interval is the interval of time between comparisons by the ventilator controller of the set points and the averaged measured pulse oximetry value of the patient;
setting the FiO2 flow rate controller at a flow rate equal to the mid-point of the operating range;
decreasing the flow rate of FiO2 by the first incremental amount when the average pulse oximetry value is greater than the first level;
increasing the flow rate of FiO2 by the second incremental amount when the average pulse oximetry value is less than the second level; and
increasing the flow rate of FiO2 to a maximum rate when the average pulse oximetry value is less than the third level.
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Accused Products
Abstract
A method and apparatus for operating a ventilator to control the fraction of pressure inspired oxygen (FiO2) to a patient that includes: providing a ventilator controller that includes a software algorithm, a pulse oximeter and a FiO2 flow rate controller; measuring the pulse oximetry of the patient and computing an average pulse oximetry value over a time period; selecting a first, second and third pulse oximetry levels as set points for the ventilator controller; selecting an update time interval; decreasing the FiO2 flow rate by a first incremental amount when the average pulse oximetry value is greater than the first level; increasing the FiO2 flow rate by a second incremental amount when the average pulse oximetry value is less than the second level; increasing the FiO2 flow rate to the maximum and initiating an alarm condition when the average pulse oximetry value is less than the third level.
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Citations
24 Claims
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1. A method of operating a ventilator to control the fraction of pressure inspired oxygen (FiO2), the method comprising:
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providing a pulse oximeter to measure a patient'"'"'s pulse oximetry;
providing a FiO2 flow rate controller, wherein the flow rate controller controls the flow rate of FiO2 to the patient;
measuring the patient'"'"'s pulse oximetry and providing a measured pulse oximetry value;
averaging the patient'"'"'s measured pulse oximetry value over a period of time;
providing a ventilator controller responsive to the average of the patient'"'"'s measured pulse oximetry value, wherein the FiO2 flow rate controller is responsive to the ventilator controller and controls the flow rate of FiO2 to the patient;
selecting the time period for averaging the patient'"'"'s measured pulse oximetry value;
selecting a first, a second, and a third pulse oximetry level as set points for the ventilator controller;
selecting an FiO2 operating range having a low end, a high end and a mid-point, wherein the midpoint of the range is equal to one-half the sum of the low end and the high end;
selecting a first incremental amount for decreasing the flow rate of FiO2 and a second incremental amount for increasing the flow rate of FiO2;
selecting an update time interval, wherein the update time interval is the interval of time between comparisons by the ventilator controller of the set points and the averaged measured pulse oximetry value of the patient;
setting the FiO2 flow rate controller at a flow rate equal to the mid-point of the operating range;
decreasing the flow rate of FiO2 by the first incremental amount when the average pulse oximetry value is greater than the first level;
increasing the flow rate of FiO2 by the second incremental amount when the average pulse oximetry value is less than the second level; and
increasing the flow rate of FiO2 to a maximum rate when the average pulse oximetry value is less than the third level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of operating a ventilator to control the fraction of pressure inspired oxygen (FiO2), the method comprising:
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providing a pulse oximeter to measure a patient'"'"'s pulse oximetry;
providing a FiO2 flow rate controller, wherein the flow rate controller controls the flow rate of FiO2 to the patient;
measuring the patient'"'"'s pulse oximetry and providing a measured pulse oximetry value;
averaging the patient'"'"'s measured pulse oximetry value over a period of time;
providing a ventilator controller responsive to the average of the patient'"'"'s measured pulse oximetry value, wherein the FiO2 flow rate controller is responsive to the ventilator controller and controls the flow rate of FiO2 to the patient;
selecting the time period for averaging the patient'"'"'s measured pulse oximetry value;
selecting a first, a second, and a third pulse oximetry level as set points for the ventilator controller;
selecting an FiO2 operating range having a low end, a high end and a mid-point, wherein the midpoint of the range is equal to one-half the sum of the low end and the high end;
selecting a first incremental amount for decreasing the flow rate of FiO2 and a second incremental amount for increasing the flow rate of FiO2;
selecting an update time interval, wherein the update time interval is the interval of time between comparisons by the ventilator controller of the set points and the averaged measured pulse oximetry value of the patient;
setting the FiO2 flow rate controller at a flow rate equal to the mid-point of the operating range;
decreasing the flow rate of FiO2 by the first incremental amount when the average pulse oximetry value is greater than the first level;
increasing the flow rate of FiO2 by the second incremental amount when the average pulse oximetry value is less than the second level;
increasing the flow rate of FiO2 to a maximum rate and initiating an alarm condition when the average pulse oximetry value is less than the third level;
maintaining the flow rate of FiO2 at the maximum after an alarm condition is initiated; and
resetting the alarm condition when the average pulse oximetry value increases above the third level. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A method of operating a ventilator to control the fraction of pressure inspired oxygen (FiO2), the method comprising:
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providing a pulse oximeter to measure a patient'"'"'s pulse oximetry;
providing a FiO2 flow rate controller, wherein the flow rate controller controls the flow rate of FiO2 to the patient;
measuring the patient'"'"'s pulse oximetry and providing a measured pulse oximetry value;
averaging the patient'"'"'s measured pulse oximetry value over a period of time;
providing a ventilator controller responsive to the average of the patient'"'"'s measured pulse oximetry value, wherein the FiO2 flow rate controller is responsive to the ventilator controller and controls the flow rate of FiO2 to the patient;
selecting a first, a second, and a third pulse oximetry level as set points for the ventilator controller, wherein the flow rate of FiO2 does not change when the pulse oximetry is between the first level and the second level;
selecting an FiO2 operating range having a low end, a high end and a mid-point, wherein the midpoint of the range is equal to one-half the sum of the low end and high end;
selecting a first incremental amount for decreasing the flow rate of FiO2 and a second incremental amount for increasing the flow rate of FiO2;
selecting an update time interval, wherein the update time interval is the interval of time between comparisons by the ventilator controller of the set points and the measured pulse oximetry of the patient and wherein the update time is at least 30 seconds;
setting the FiO2 flow rate controller at a flow rate equal to the mid-point of the operating range;
decreasing the flow rate of FiO2 by the first incremental amount when the average pulse oximetry value is greater than the first level and the flow rate is greater than or equal to the low end of the FiO2 operating range;
increasing the flow rate of FiO2 by the second incremental amount when the average pulse oximetry value is less than the second level and the flow rate is less than or equal to the high end of the FiO2 operating range;
increasing the flow rate of FiO2 to a maximum rate and initiating an alarm condition when the average pulse oximetry value is less than the third level, wherein the update time is automatically set to less than 1 minute when the alarm condition is initiated;
maintaining the flow rate of FiO2 at the maximum after an alarm condition is initiated; and
resetting the alarm condition when the average pulse oximetry value increases above the third level.
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22. A ventilator system for controlling the fraction of pressure inspired oxygen (FiO2) in air delivered to a patient, the ventilator system comprising:
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a pulse oximeter which measures the pulse oximetry of a patient and generates an output signal in response thereto;
a ventilator controller comprising a keypad, a display and a software algorithm, wherein the keypad and display are adapted to enter an update time interval, a first, second, and third pulse oximetry level set points, a FiO2 flow rate range, a first incremental amount for decreasing the flow rate of FiO2 and a second incremental amount for increasing the flow rate of FiO2; and
a time period over which the patient'"'"'s measured pulse oximetry value is averaged;
a FiO2 flow rate controller responsive to the ventilator controller; and
a face mask, nasal mask or endotracheal tube for delivering the air to the patient, wherein the ventilator controller software algorithm computes an average pulse oximetry value and, at the end of the update time interval, compares the average pulse oximetry value to the first, second and third pulse oximeter level set points, the ventilator controller automatically controlling the flow rate of FiO2 to the patient such that the flow rate of FiO2 decreases by a first incremental amount when the average pulse oximetry value is greater than the first level, increases the flow rate of FiO2 by a second incremental amount when the average pulse oximetry value is less than the second level, and increases the flow rate of FiO2 to a maximum rate when the average pulse oximetry value is less than the third level. - View Dependent Claims (23, 24)
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Specification