Abstract: The invention relates to an automated calibration procedure for analyte sensors such as glucose sensors. The system can provide a calibration point at zero analyte concentration as well as a second calibration point at a known analyte concentration or other pre-determined points. Although not restricted to two point calibration procedure, the system as described enables the system to create one or more calibration points. The use of multiple calibration points can allow the system to correct for both slope and bias drifts. The system also provides the opportunity to provide one or more validation samples. The present invention enables a multitude of options in both calibration and validation to ensure effective operation of the system.

Abstract: The present invention provides methods and apparatuses that can provide measurement of analytes such as glucose with a variety of sensors in connection with hemodynamic monitoring. Some embodiments of the present invention enable the use of a single arterial access site for automated blood glucose measurement as well as hemodynamic monitoring. Some embodiments of the present invention can reduce or eliminate nuisance hemodynamic alarms. Some embodiments of the present invention can provide hemodynamic monitoring during an automated analyte measurement process. An example apparatus according to the present invention comprises a blood access system, adapted to remove blood from a body and infuse at least a portion of the blood back into the body. Such an apparatus also comprises an analyte sensor, mounted with or integrated into the blood access system such that the analyte sensor measures the analyte in the blood that has been removed from the body by the blood access system.

Abstract: Embodiments of the present invention provide robust systems for the removal and subsequent infusion of blood for measurement purposes, and embodiments of the present invention provide methods of operating such systems and providing capabilities such as predicting and avoiding occlusions and/or bubbles, managing occlusions and/or bubbles if they occur, automatic cleaning of the blood access system, and determining and managing the patency of the blood access site. Such operational challenges can occur during any of several phases of operation of a blood access system. Embodiments of the present invention can effectively incorporate a variety of inputs for the identification of trends consistent with present or pending occlusions. An embodiment of the present invention can be aware of the stage of operation, e.g., withdrawal, infusion, or cleaning, and the prior performance of the system.

Abstract: A medical luer connection improves liquid mixing thereby reducing areas of low or stagnant flow within the plenum chamber formed between the male and female luer connectors. Stagnation or low flow areas in the plenum can be reduced by imparting a non-axial flow component to the fluid flow as it passes through the plenum. Improvement of the cleaning effectiveness of the luer connection reduces the amount of flushing fluid needed to clean the connection, reduces the residual blood matter at a fixed volume of fluid relative to a standard luer connection, or combinations of the above.

Abstract: An indwelling fiber optic probe can be used to make in vivo blood glucose measurements through a central venous catheter. The fiber optic probe can operate in the near-infrared spectral region. The optical measurement can be backscattering, transmission, or a combination of both, depending on the optical configuration.

Abstract: The present invention is directed to methods and apparatuses of medication management based upon active authorization of medication infusion by a clinician that can provide for effective management of an analyte in a patient's blood, reducing the opportunities for human error common with current manual systems while still placing final control of the medication management with the human clinician. For example, a semi-automated glucose management system can measure the glucose level in a patient's blood, recommend infusion parameters to a clinician who can authorize an infusion of glucose or insulin, and infuse the glucose or insulin into the patient.

Abstract: The present invention provides methods and apparatuses that can provide measurement of glucose with variable intervals between measurements, allowing more efficient measurement with greater patient safety. A method according to the present invention can comprise measuring the value of an analyte such as glucose at a first time; determining a second time from a patient condition, an environmental condition, or a combination thereof; then measuring the value of the analyte at the second time (where the second time can be expressed as an interval after the first time, an absolute time, or a time indicated when certain patient or environmental conditions, or both, are reached or detected). The second time can be determined, as an example, from a comparison of the analyte value at the first time with a threshold. The interval between the first time and the second time can be related to the difference between the analyte value at the first time and the threshold; e.g.

Abstract: The present invention comprises methods and apparatuses that can provide accurate measurement of glucose or other analytes from a multilumen catheter in the presence of infusion of substances, including glucose. Examples of “multilumen catheters” include central venous catheters having multiple lumens, midline catheters having multiple lumens, multiple catheters configured or emplaced such that their lumens are in proximity to each other, and, in the case of indwelling analyte sensors, a catheter with a lumen for infusion and an indwelling sensor spaced apart from the infusion lumen. For blood withdrawal, anti-cross contamination controls can prevent the entrainment of blood which might be contaminated with feeding fluids or medications that are administered through other lumens within the catheter and in proximity of the blood sampling port. Cross contamination can occur under various situations, and is known to occur when the patient is connected to a ventilator.

Abstract: The present invention comprises methods and apparatuses that can provide accurate measurement of glucose or other analytes from a multilumen catheter in the presence of infusion of substances, including glucose. Examples of “multilumen catheters” include central venous catheters having multiple lumens, midline catheters having multiple lumens, multiple catheters configured or emplaced such that their lumens are in proximity to each other, and, in the case of indwelling analyte sensors, a catheter with a lumen for infusion and an indwelling sensor spaced apart from the infusion lumen. For blood withdrawal, anti-cross contamination controls can prevent the entrainment of blood which might be contaminated with feeding fluids or medications that are administered through other lumens within the catheter and in proximity of the blood sampling port. Cross contamination can occur under various situations, and is known to occur when the patient is connected to a ventilator.

Abstract: A method and app for controlling blood withdrawal and infusion flow rate with the use of a pressure controller in connection with a blood measurement system. The pressure controller uses pressure targets based upon occlusion limits that are calculated as a function of flow. The controller has the ability to switch from controlling withdrawal pressure to controlling infusion pressure based upon the detection of an occlusion. The controller distinguishes between partial and total occlusions of the withdrawal vein providing blood access. Depending on the nature of occlusion, the controller limits or temporarily reverses blood flow and, thus, prevents withdrawal vessel collapse or reverses blood flow to quickly infuse blood into the vessel without participation from operator.

Abstract: The present invention comprises methods and apparatuses that can provide measurement of glucose and other analytes with a variety of sensors without many of the performance-degrading problems of conventional approaches. An apparatus according to the present invention comprises a blood access system, adapted to remove blood from a body and infuse at least a portion of the removed blood back into the body. Such an apparatus also comprises an analyte sensor, mounted with the blood access system such that the analyte sensor measures the analyte in the blood that has been removed from the body by the blood access system. A method according to the present invention comprises removing blood from a body, using an analyte sensor to measure an analyte in the removed blood, and infusing at least a portion of the removed blood back into the body. The use of a non-contact sensor with a closed system creates a system will minimal infection risk.

Abstract: The present invention comprises methods and apparatuses that can provide measurement of glucose and other analytes with a variety of sensors without many of the performance-degrading problems of conventional approaches. An apparatus according to the present invention comprises a blood access system, adapted to remove blood from a body and infuse at least a portion of the removed blood back into the body. Such an apparatus also comprises an analyte sensor, mounted with the blood access system such that the analyte sensor measures the analyte in the blood that has been removed from the body by the blood access system. A method according to the present invention comprises removing blood from a body, using an analyte sensor to measure an analyte in the removed blood, and infusing at least a portion of the removed blood back into the body. The use of a non-contact sensor with a closed system creates a system will minimal infection risk.

Abstract: The present invention comprises methods and apparatuses that can provide measurement of glucose and other analytes with a variety of sensors without many of the performance-degrading problems of conventional approaches. An apparatus according to the present invention comprises a blood access system, adapted to remove blood from a body and infuse at least a portion of the removed blood back into the body. Such an apparatus also comprises an analyte sensor, mounted with the blood access system such that the analyte sensor measures the analyte in the blood that has been removed from the body by the blood access system. A method according to the present invention comprises removing blood from a body, using an analyte sensor to measure an analyte in the removed blood, and infusing at least a portion of the removed blood back into the body. The use of a non-contact sensor with a closed system creates a system will minimal infection risk.

Abstract: The present invention comprises methods and apparatuses that can provide measurement of glucose and other analytes with a variety of sensors without many of the performance-degrading problems of conventional approaches. As apparatus according to the present invention comprises a blood access system, adapted to remove blood from a body and infuse at least a portion of the removed blood back into the body. Such an apparatus also comprises an analyte sensor, mounted with the blood access system such that the analyte sensor measures the analyte in the blood that has been removed from the body by the blood access system. A method according to the present invention comprises removing blood from a body, using an analyte sensor to measure an analyte in the removed blood, and infusing at least a portion of the removed blood back into the body. The use of a non-contact sensor with a closed system creates a system will minimal infection risk.

Abstract: Methods and apparatus for non-invasively verifying human identities using near-infrared spectroscopy. Near-infrared tissue spectra can be obtained by projecting near-infrared radiation into skin on the underside of human forearms and capturing the light reflected back and out through the tissue. The tissue spectrum collected preferably includes primarily diffuse reflected light reflected from the inner dermis. Multiple tissue spectra and identities can be collected from individuals for whom identity verification may later be desired. The tissue spectra for each individual can be analyzed on a computer, and the spectra for each individual clustered or classified together using tools such as linear discriminant analysis. A target individual seeking identity verification can submit both a purported identity and a near-infrared tissue spectrum for analysis through near-infrared spectroscopy of the forearm.

Abstract: A method is provided for building improved calibration models or for improving modifications to these models or validation of the models used in the non-invasive spectroscopic measurement of an analyte or attribute of tissue. The method uses a matched reference sample and measurement of that sample to ensure that the correct relationship between the spectra and analyte is made during the model building, modification or calibration process. A matched reference sample is one in which the analyte of interest or attribute of interest in the reference sample is representative of the analyte or attribute at the site being non-invasively sampled or the agreement between the reference concentration and the non-invasively sampled concentration is clinically significant.

Abstract: The present invention provides methods and devices for using feedback to improve non-invasive tissue measurements by making measurements faster, easier to perform, and less error prone. In some embodiments, a set of metrics is identified as measurable potential sources of measurement error that can be controlled by a user. In some embodiments, the set of metrics can be analyzed to determine which metrics are related to one another, and some possible error metrics can be discarded, and others used as surrogate metrics for measuring and monitoring measurement errors.

Abstract: Methods and apparatus for non-invasively verifying human identities using near-infrared spectroscopy. Near-infrared tissue spectra can be obtained by projecting near-infrared radiation into skin on the underside of human forearms and capturing the light reflected back and out through the tissue. The tissue spectrum collected preferably includes primarily diffuse reflected light reflected from the inner dermis. Multiple tissue spectra and identities can be collected from individuals for whom identity verification may later be desired. The tissue spectra for each individual can be analyzed on a computer, and the spectra for each individual clustered or classified together using tools such as linear discriminant analysis. A target individual seeking identity verification can submit both a purported identity and a near-infrared tissue spectrum for analysis through near-infrared spectroscopy of the forearm.

Abstract: Methods and apparatus for non-invasive tissue urea concentrations during or subsequent to hemodialysis using near-infrared spectroscopy are discussed. Near-infrared tissue spectra can be obtained by projecting near-infrared radiation into skin on the underside of human forearms and capturing the light reflected back and out through the tissue. An index matching medium is used to couple the tissue to the analyzer. The tissue spectrum collected preferably includes primarily diffuse reflected light reflected from the inner dermis. Multiple tissue spectra of known urea concentration are used to build a model from which the urea concentration of an unknown sample can be devised. The model is based on a partial least squares algorithm applied to multiple tissue scans and concomitant blood sample urea measurements. This model is then applied to an unknown tissue spectra.

Abstract: A method is provided for building improved calibration models or for improving modifications to these models or validation of the models used in the non-invasive spectroscopic measurement of an analyte or attribute of tissue. The method uses a matched reference sample and measurement of that sample to ensure that the correct relationship between the spectra and analyte is made during the model building, modification or calibration process. A matched reference sample is one in which the analyte of interest or attribute of interest in the reference sample is representative of the analyte or attribute at the site being non-invasively sampled or the agreement between the reference concentration and the non-invasively sampled concentration is clinically significant.