Oxygen control system with blood oxygen saturation sensing means and method for closed system breathing

Claim 1

In apparatus for controlling the oxygen concentration in a breathing mixture for supplying a user, in combination, means to measure supersaturation of oxygen in the blood stream of the user by establishing the time required for an anoxic mixture to reduce oxygen content at said blood stream below saturation, means providing a control signal determined by said time, and means responsive to said control signal to adjust the oxygen concentration in said breathing mixture in relation to the measured degree of supersaturation.

Claim 6

A system for regulating the rate of oxygen supply for closed system breathing in such manner as to avoid either under or over saturation of the user''s blood with oxygen, comprising in combination, an optical oximeter arranged for continuously monitoring the user''s blood, said oximeter being capable of detecting under-saturation of oxygen in the blood of the user, means for periodically reducing the supply rate of oxygen to the user to a constant oxygen-deficient rate, means for counting a succession of time intervals of substantially equal duration, means to start a count in said counting means coincidently with the beginning of the oxygen-deficient supply to the user, means to generate a signal when the oximeter first detects an oxygen concentration less than 100 percent in the blood of the user, means to use said signal to increase the supply rate of oxygen to a non-deficient value and to stop the said count, and means to use the magnitude of said count to regulate the said non-deficient rate of oxygen supply to the user in response to the measured degree of supersaturation.

Claim 7

A system for regulating the rate of oxygen supply for closed system breathing in such manner as to avoid either under or over saturation of the user''s blood with oxygen, comprising in combination, an optical oximeter arranged for continuously monitoring the user''s blood, said oximeter being capable of detecting under-saturation of oxygen in the blood of the user, means for periodically reducing the supply rate of oxygen to the user to a constant oxygen-deficient rate, means for counting a succession of time intervals of substantially equal duration, means to start a count in said counting means coincidently with the beginning of the oxygen-deficient supply to the user, means to generate a signal when the oximeter first detects an oxygen concentration less than 100 percent in the blood of the user, means to use said signal to increase the supply rate of oxygen to a non-deficient value and to stop the said count, and means to use the magnitude of said count to regulate the said non-deficient rate of oxygen supply to the user in response to the measured degree of supersaturation.

Claim 10

A system for regulating the rate of oxygen supply for closed system breathing in such manner as to avoid either under or over saturation of the user''s blood with oxygen, comprising in combination, first regulatory means designed to determine a relatively low, constant rate of oxygen supply useful for gradually relieving a condition of supersaturation of oxygen in the user''s blood, second regulatory means arranged to determine a variable rate of oxygen supply in accordance with the user''s demand for oxygen from time to time, a third regulatory means designed to determine a constant rate of oxygen supply greater in magnitude than any rate determined by either said first or said second regulatory means for rapidly making up any oxygen deficiency in the user''s blood, an optical oximeter arranged to continuously monitor the user''s blood, time interval measuring means, sample interval timing means for initiating a measurement of degree of supersaturation of oxygen in the blood, means actuated by said sample interval timing means to energize said first regulatory means, and to start a time measurement in said time interval measuring means, means operable by said oximeter upon detection of less than 100 percent oxygen saturation in the user''s blood to terminate a time interval measurement by said time interval measuring means and to disable said first regulatory means, means controlled by said time interval measuring means for adjusting the said second regulatory means, to determine an oxygen supply rate inversely proportional to the time interval so measured and to energize said second regulatory means, and means operable by said oximeter upon detection of an oxygen deficiency in the user''s blood to enable said third regulatory means while at the same disabling both said first and second regulatory means, to relieve said oxygen deficiency at any time regardless of the operation of the remainder of the system.

Claim 11

A system for regulating the rate of oxygen supply for closed system breathing in such manner as to avoid either under or over saturation of the user''s blood with oxygen, comprising in combination, first regulatory means designed to determine a relatively low, constant rate of oxygen supply useful for gradually relieving a condition of supersaturation of oxygen in the user''s blood, second regulatory means arranged to determine a variable rate of oxygen supply in accordance with the user''s demand for oxygen from time to time, a third regulatory means designed to determine a constant rate of oxygen supply greater in magnitude than any rate determined by either said first or said second regulatory means for rapidly making up any oxygen deficiency in the user''s blood, an optical oximeter arranged to continuously monitor the user''s blood, time interval measuring means, sample interval timing means for initiating a measurement of degree of supersaturation of oxygen in the blood, means actuated by said sample interval timing means to energize said first regulatory means, and to start a time measurement in said time interval measuring means, means operable by said oximeter upon detection of less than 100 percent oxygen saturation in the user''s blood to terminate a time interval measurement by said time interval measuring means and to disable said first regulatory means, means controlled by said time interval measuring means for adjusting the said second regulatory means, to determine an oxygen supply rate inversely proportional to the time interval so measured and to energize said second regulatory means, and means operable by said oximeter upon detection of an oxygen deficiency in the user''s blood to enable said third regulatory means while at the same disabling both said first and second regulatory means, to relieve said oxygen deficiency at any time regardless of the operation of the remainder of the system.

Claim 12

The method of controlling the oxygen concentration in a breathing mixture for supplying a user, comprising the steps of measuring supersaturation of oxygen in the blood stream of the user by establishing the time required for an anoxic mixture to reduce oxygen content at said blood stream below saturation, generating a control signal determined by said time, and using the said control signal to adjust the oxygen concentration in the said breathing mixture in relation to the degree of supersaturation measured.

Claim 13

The method of controlling the oxygen concentration in a breathing mixture for supplying a user, comprising the steps of measuring supersaturation of oxygen in the blood stream of the user by establishing the time required for an anoxic mixture to reduce oxygen content at said blood stream below saturation, generating a control signal determined by said time, and using the said control signal to adjust the oxygen concentration in the said breathing mixture in relation to the degree of supersaturation measured.

Claim 14

The method of measuring the degree of oXygen supersaturation in the blood stream with the aid of an oximeter of a type that can detect oxygen concentration up to 100 percent of saturation, which method comprises the steps of temporarily supplying to the lungs a breathing mixture having a constant oxygen deficiency, using the oximeter to continuously monitor the state of the blood and to give a signal when the blood stream is reduced from whatever degree of supersaturation existed when the oxygen-deficient mixture was first supplied to a condition of substantially 100 percent saturation, and measuring the time elapsed from the time at which the oxygen-deficient mixture was first supplied until the 100 percent saturation signal is generated by the oximeter, whereby the elapsed time is a measure of the original degree of supersaturation of the blood stream.

Claim 15

The method of measuring the degree of oXygen supersaturation in the blood stream with the aid of an oximeter of a type that can detect oxygen concentration up to 100 percent of saturation, which method comprises the steps of temporarily supplying to the lungs a breathing mixture having a constant oxygen deficiency, using the oximeter to continuously monitor the state of the blood and to give a signal when the blood stream is reduced from whatever degree of supersaturation existed when the oxygen-deficient mixture was first supplied to a condition of substantially 100 percent saturation, and measuring the time elapsed from the time at which the oxygen-deficient mixture was first supplied until the 100 percent saturation signal is generated by the oximeter, whereby the elapsed time is a measure of the original degree of supersaturation of the blood stream.