Reliable noninvasive measurement of blood gases

Claim 3

The method as set forth in claim 1, further including the step of determining whether said set of spectral intensities v. wavelengths from said blood containing tissue is an outlier by comparing said set of spectral intensities v. wavelengths from said blood containing tissue with a set of spectral intensities v. wavelengths obtained from irradiating calibration samples.

Claim 4

The method as set forth in claim 2, wherein said step of determining whether said set of spectral intensities v. wavelengths from said blood containing tissue represents an outlier is specific for each of said unknown blood gas parameters being measured.

Claim 5

The method as set forth in claim 2, wherein said determination of whether said set of spectral intensities v. wavelengths from said blood containing tissue represents an outlier includes the step of comparing said set of spectral intensities v. wavelengths from said blood containing tissue to said set of spectral intensities v. wavelengths from said calibration samples, to determine a measure of the magnitude of the difference between said set of spectral intensities v. wavelengths from said blood containing tissue and said set of spectral intensities v. wavelengths from said calibration samples.

Claim 6

The method as set forth in claim 4, wherein a statistical test is used to indicate the probability of said magnitude being caused by random chance, further including the step of classifying said set of spectral intensities v. wavelengths from said blood containing tissue as representing an outlier when said probability is determined to be too low.

Claim 7

The method as set forth in claim 1, further including the steps of providing calibration samples and determining whether any of said calibration samples represents an outlier.

Claim 8

The method as set forth in claim 1, further including the step of pretreatment of said set of spectral intensities v. wavelengths from said blood containing tissue.

Claim 9

The method as set forth in claim 7, wherein said pretreatment includes trimming, wavelength selection, centering, scaling, normalizing, taking first or higher order derivatives, smoothing, Fourier transforming, linearization and transformation.

Claim 10

The method as set forth in claim 1, wherein said step of determining said unknown values is performed by a multivariate algorithm using 2 or more variables and at least one calibration model, said calibration model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the range of 500-2500 nm.

Claim 11

The method as set forth in claim 9, wherein said algorithm is selected from the group including PLS, PLS2, PCR, CLS, Q-matrix, ridge regression, cross-correlation, Kalman filtering, MLR, neural networks, and continuum methods.

Claim 12

The method as set forth in claim 10, wherein said multivariate algorithm is capable of utilizing more discrete spectral intensities per sample than the number of calibration samples.

Claim 13

The method as set forth in claim 11, wherein said algorithm can construct models which approximate mathematical nonlinearities.

Claim 14

The method as set forth in claim 11, wherein said algorithm can explicitly model mathematical nonlinearities.

Claim 15

The method as set forth in claim 1, wherein said determination of said unknown values is accomplished by utilizing at least two algorithms and at least two calibration models, said calibration models being a function of conventionally measured blood gas parameters obtained from calibration samples and at least one set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the range of 500-2500 nm.

Claim 16

The method as set forth in claim 14, wherein both of said algorithms are multivariate algorithms and wherein each of said algorithms is capable of utilizing more discrete spectral intensities per sample than the number of said calibration samples.

Claim 17

The method as set forth in claim 1, further including the step of providing separate calibration models for each of said unknown values of each blood gas parameter being determined.

Claim 18

The method as set forth in claim 1, wherein said unknown values for all 5 blood gas parameters are determined.

Claim 19

The method as set forth in claim 1 wherein one of said unknown values of pH, HCO 3 - and PCO 2 , is determined with the use of the Henderson-Hasselbach equation.

Claim 20

The method as set forth in claim 1, further including the step of transmitting said wavelengths to said blood containing tissue via fiber optics.

Claim 21

The method as set forth in claim 19, further including the step of transmitting said wavelengths from said blood containing tissue via fiber optics.

Claim 24

The method as set forth in claim 21, further including the step of determining whether said set of spectral intensities v. wavelengths from said blood represents an outlier by comparing said set of spectral intensities v. wavelengths from said blood with a set of intensities v. wavelengths obtained from irradiating calibration samples.

Claim 25

The method as set forth in claim 21, further including the steps of providing calibration samples and determining whether any of said calibration samples represents an outlier.

Claim 26

The method as set forth in claim 21, wherein the step of determining said unknown values is performed by a multivariate algorithm using 2 or more variables and at least one calibration model, said calibration model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the visible and infrared.

Claim 27

The method as set forth in claim 21, wherein said determining of said unknown values is accomplished by utilizing at least two algorithms and at least two calibration models, said calibration models being a function of conventionally measured blood gas parameters obtained from calibration samples and at least one set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the visible and infrared.

Claim 28

The method as set forth in claim 25, wherein both of said algorithms are multivariate algorithms and wherein each of said algorithms is capable of utilizing more discrete spectral intensities per sample than the number of said calibration samples.

Claim 31

The method as set forth in claim 27 wherein said parameter is pH.

Claim 32

The method as set forth in claim 27 wherein said parameter is HCO 3 .

Claim 33

The method as set forth in claim 27 wherein said parameter is PCO 2 .

Claim 36

The method as set forth in claim 31, further including the step of determining whether said set of spectral intensities v. wavelengths from said blood containing tissue represents an outlier by comparing said set of spectral intensities v. wavelengths from said blood containing tissue with a set of spectral intensities v. wavelengths obtained from radiating calibration samples.

Claim 37

The method as set forth in claim 32, wherein said step of determining whether said set of spectral intensities v. wavelengths from said blood containing tissue represents an outlier is specific for each of said unknown blood gas parameters being measured.

Claim 38

The method as set forth in claim 32, wherein said determination of whether said set of spectral intensities v. wavelengths from said blood containing tissue represents an outlier includes the step of comparing said set of spectral intensities v. wavelengths from said blood containing tissue to said set of spectral intensities v. wavelengths from said calibration samples, to determine a measure of the magnitude of the difference between said set of spectral intensities v. wavelengths from said blood containing tissue and said set of intensities v. wavelengths from said calibration samples.

Claim 39

The method as set forth in claim 34, wherein a statistical test is used to indicate the probability of said magnitude being caused by random chance, further including the step of classifying said set of spectral intensities v. wavelengths from said blood containing tissue as representing an outlier when said probability is determined to be too low.

Claim 40

The method as set forth in claim 31, further including the step of providing calibration samples and determining whether any of said calibration samples represents an outlier.

Claim 41

The method as set forth in claim 31, further including the step of pretreatment of said set of spectral intensities v. wavelengths from said blood containing tissue.

Claim 42

The method as set forth in claim 37, wherein said pretreatment includes trimming, wavelength selection, centering, scaling, normalizing, taking first or higher order derivatives, smoothing, Fourier transforming, linearization and transformation.

Claim 43

The method as set forth in claim 31, wherein said step of determining said unknown values is performed by a multivariate algorithm using 2 or more variables and at least one calibration model, said calibration model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the range of 500-2500 nm.

Claim 44

The method as set forth in claim 39, wherein said algorithm is selected from the group including PLS, PLS2, PCR, CLS, Q-matrix, ridge regression, cross-correlation, Kalman filtering, MLR, neural networks, and continuum methods.

Claim 45

The method as set forth in claim 40, wherein said multivariate algorithm is capable of utilizing more discrete spectral intensities per sample than the number of calibration samples.

Claim 46

The method as set forth in claim 41, wherein said algorithm can construct models which approximate mathematical nonlinearities.

Claim 47

The method as set forth in claim 41, wherein said algorithm can explicitly model mathematical nonlinearities.

Claim 48

The method as set forth in claim 31, wherein said determining of said unknown values is accomplished by utilizing at least two algorithms and at least two calibration models, said calibration models being a function of conventionally measured blood gas parameters obtained from calibration samples and at least one set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with 3 or more wavelengths of light in the range of 500-2500 nm.

Claim 49

The method as set forth in claim 44, wherein both of said algorithms are multivariate algorithms and wherein each of said algorithms is capable of utilizing more discrete spectral intensities per sample than the number of said calibration samples.

Claim 50

The method as set forth in claim 31, further including the step of providing separate calibration models for each blood gas parameter being determined.

Claim 51

The method as set forth in claim 31, wherein said unknown values for all 5 blood gas parameters are determined.

Claim 52

The method as set forth in claim 31, wherein one of said unknown values of pH, and PCO 2 is determined with the use of the Henderson-Hasselbach equation.

Claim 53

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue in a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood containing tissue; and e. means for indicating said determined values of said blood gas parameters.

Claim 54

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue in a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood containing tissue; and e. means for indicating said determined values of said blood gas parameters.

Claim 55

The analysis instrument of claim 49, further including a first optical means for introducing said light on one side of said tissue and further including a second optical means on the other side of said tissue for directing said light emerging from said blood containing tissue to said detector.

Claim 56

The analysis instrument of claim 49, further including at least one optical means positioned on one side of said blood containing tissue for introducing said light into said tissue and for directing said light emerging from said one side of said blood containing tissue to said detector.

Claim 57

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue in a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means including a multivariate algorithm and a calibration model for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood containing tissue, said algorithm using at least two variables, said model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and e. means for indicating said determined values of said blood gas parameters.

Claim 58

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue in a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means including a multivariate algorithm and a calibration model for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood containing tissue, said algorithm using at least two variables, said model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and e. means for indicating said determined values of said blood gas parameters.

Claim 59

The analysis instrument of claim 52, wherein said algorithm is selected from the group including PLS, PLS2, PCR, CLS, Q-matrix, ridge regression, cross-correlation, Kalman filtering, MLR, neural networks, and continuum methods.

Claim 60

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue of a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means including a multivariate algorithm and a calibration model for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values being within the physiological ranges observed in said blood containing tissue, said algorithm using at least two variables, said algorithm being capable of utilizing more discrete spectral intensities per sample than the number of calibration samples used to generate said model, said model being a function of conventionally measured blood gas parameters obtained from said calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and e. means for indicating said determined values of said blood gas parameters.

Claim 61

A quantitative analysis instrument for noninvasive measurement of blood gas parameters present in blood containing tissue of a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least a portion of said light emerging from said blood containing tissue at, at least, three wavelengths of said light; d. electronics, a microprocessor and memory means including a multivariate algorithm and a calibration model for processing said measured spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values being within the physiological ranges observed in said blood containing tissue, said algorithm using at least two variables, said algorithm being capable of utilizing more discrete spectral intensities per sample than the number of calibration samples used to generate said model, said model being a function of conventionally measured blood gas parameters obtained from said calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and e. means for indicating said determined values of said blood gas parameters.

Claim 62

A quantitative analysis instrument for noninvasive measurement of two or more blood gas parameters present in blood containing tissue of a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least three wavelengths of said light emerging from said blood containing tissue during the diastolic portion of the cardiac cycle of said human, to obtain a diastolic set of spectral intensities v. wavelengths, and for measuring the spectral intensities of at least three wavelengths of said light emerging from said blood containing tissue during the systolic portion of the cardiac cycle of said human, to obtain a systolic set of spectral intensities v. wavelengths; d. memory means for storing said diastolic set of spectral intensities v. wavelengths and said systolic set of spectral intensities v. wavelengths; e. electronics, a microprocessor and said memory means for processing said diastolic and systolic sets of spectral intensities to determine a measure of change between said diastolic and systolic sets, to obtain a blood specific set of spectral intensities v. wavelengths, said memory means including a multivariate algorithm and a multivariate calibration model, said electronics, said microprocessor and said memory means processing said blood specific set of spectral intensities v. wavelengths to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood, said algorithm using at least two variables, said model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and f. means for indicating said determined values of said blood gas parameters.

Claim 63

A quantitative analysis instrument for noninvasive measurement of two or more blood gas parameters present in blood containing tissue of a human, said instrument comprising: a. a device for positioning said blood containing tissue; b. a source of at least three different wavelengths of light positioned relative to said tissue positioning device, to direct light into said blood containing tissue, said wavelengths being in the range of 500 to 2500 nm; c. at least one detector positioned relative to said tissue positioning device for measuring the spectral intensities of at least three wavelengths of said light emerging from said blood containing tissue during the diastolic portion of the cardiac cycle of said human, to obtain a diastolic set of spectral intensities v. wavelengths, and for measuring the spectral intensities of at least three wavelengths of said light emerging from said blood containing tissue during the systolic portion of the cardiac cycle of said human, to obtain a systolic set of spectral intensities v. wavelengths; d. memory means for storing said diastolic set of spectral intensities v. wavelengths and said systolic set of spectral intensities v. wavelengths; e. electronics, a microprocessor and said memory means for processing said diastolic and systolic sets of spectral intensities to determine a measure of change between said diastolic and systolic sets, to obtain a blood specific set of spectral intensities v. wavelengths, said memory means including a multivariate algorithm and a multivariate calibration model, said electronics, said microprocessor and said memory means processing said blood specific set of spectral intensities v. wavelengths to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood, said algorithm using at least two variables, said model being a function of conventionally measured blood gas parameters obtained from calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the range of 500-2500 nm; and f. means for indicating said determined values of said blood gas parameters.

Claim 64

The analysis instrument of claim 55, wherein said algorithm is selected from the group including PLS, PLS2, PCR, CLS, Q-matrix, ridge regression, cross-correlation, Kalman filtering, MLR, neural networks, and continuum methods.

Claim 65

The analysis instrument of claim 56, wherein said algorithm is capable of utilizing more discrete spectral intensities per sample than the number of calibration samples used to generate said model.

Claim 66

The analysis instrument of claim 55, further including a first optical means for introducing said light on one side of said tissue and further including a second optical means on the other side of said tissue for directing said light emerging from said blood containing tissue to said detector.

Claim 67

The analysis instrument of claim 55, further including at least one optical means positioned on one side of said blood containing tissue for introducing said light into said tissue and for directing said light emerging from said one side of said blood containing tissue to said detector.

Claim 68

The analysis instrument as set forth in claim 55, wherein said electronics, said microprocessor and said memory means including said algorithm and said calibration model for processing said spectral intensities includes means to determine all four of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values being within the physiological ranges observed in said blood containing tissue.

Claim 69

A quantitative analysis instrument for invasive and in vivo measurement of blood gas parameters present in blood in human, said instrument comprising: a. a source of at least three different wavelengths of light optically coupled to said blood to direct light into said blood, said wavelengths being in the visible, near infrared, and infrared regions of the spectrum; b. at least one detector optically coupled to said blood for measuring the spectral intensities of at least a portion of said light emerging from said blood at, at least, three wavelengths of light; c. electronics, a microprocessor and memory means for processing said spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values being within the physiological ranges observed in said blood; and d. means for indicating said determined values of said blood gas parameters.

Claim 70

A quantitative analysis instrument for invasive and in vivo measurement of blood gas parameters present in blood in human, said instrument comprising: a. a source of at least three different wavelengths of light optically coupled to said blood to direct light into said blood, said wavelengths being in the visible, near infrared, and infrared regions of the spectrum; b. at least one detector optically coupled to said blood for measuring the spectral intensities of at least a portion of said light emerging from said blood at, at least, three wavelengths of light; c. electronics, a microprocessor and memory means for processing said spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values being within the physiological ranges observed in said blood; and d. means for indicating said determined values of said blood gas parameters.

Claim 71

A quantitative analysis instrument for invasive and in vivo measurement of blood gas parameters present in blood in a human, comprising: a. a source of at least three different wavelengths of light optically coupled to said blood to direct light into said blood, said wavelengths being in the visible, near infrared, and infrared regions of the spectrum; b. at least one detector optically coupled to said blood for measuring the spectral intensities of at least a portion of said light emerging from said blood at, at least, three wavelengths of light; c. electronics, a microprocessor and memory means, said memory means including a multivariate algorithm and a multivariate calibration model, for processing said spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood, said algorithm using at least two variables, said algorithm being capable of utilizing more discrete spectral intensities per sample than the number of calibration samples used to generate said model, said model being a function of conventionally measured blood gas parameters obtained from said calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the visible, near infrared, and infrared regions of the spectrum; and d. means for indicating said determined values of said blood gas parameters.

Claim 72

A quantitative analysis instrument for invasive and in vivo measurement of blood gas parameters present in blood in a human, comprising: a. a source of at least three different wavelengths of light optically coupled to said blood to direct light into said blood, said wavelengths being in the visible, near infrared, and infrared regions of the spectrum; b. at least one detector optically coupled to said blood for measuring the spectral intensities of at least a portion of said light emerging from said blood at, at least, three wavelengths of light; c. electronics, a microprocessor and memory means, said memory means including a multivariate algorithm and a multivariate calibration model, for processing said spectral intensities to determine at least two of pH, PCO 2 , HCO 3 - , and a measure of oxygen saturation at values within the physiological ranges observed in said blood, said algorithm using at least two variables, said algorithm being capable of utilizing more discrete spectral intensities per sample than the number of calibration samples used to generate said model, said model being a function of conventionally measured blood gas parameters obtained from said calibration samples and a set of spectral intensities v. wavelengths obtained from irradiating said calibration samples with at least three wavelengths of light in the visible, near infrared, and infrared regions of the spectrum; and d. means for indicating said determined values of said blood gas parameters.