The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

Transcutaneous analyte sensor

Systems and methods for applying time-dependent algorithmic compensation functions to data output from a continuous analyte sensor. Some embodiments determine a time since sensor implantation and/or whether a newly initialized sensor has been used previously.

Systems and methods for processing analyte sensor data

Systems and methods for integrating a continuous glucose sensor, including a receiver, a medicament delivery device, and optionally a single point glucose monitor are provided. Manual integrations provide for a physical association between the devices wherein a user (for example, patient or doctor) manually selects the amount, type, and/or time of delivery. Semi-automated integration of the devices includes integrations wherein an operable connection between the integrated components aids the user (for example, patient or doctor) in selecting, inputting, calculating, or validating the amount, type, or time of medicament delivery of glucose values, for example, by transmitting data to another component and thereby reducing the amount of user input required. Automated integration between the devices includes integrations wherein an operable connection between the integrated components provides for full control of the system without required user interaction.

Integrated delivery device for continuous glucose sensor

Systems and methods for dynamically and intelligently estimating analyte data from a continuous analyte sensor, including receiving a data stream, selecting one of a plurality of algorithms, and employing the selected algorithm to estimate analyte values. Additional data processing includes evaluating the selected estimative algorithms, analyzing a variation of the estimated analyte values based on statistical, clinical, or physiological parameters, comparing the estimated analyte values with corresponding measure analyte values, and providing output to a user. Estimation can be used to compensate for time lag, match sensor data with corresponding reference data, warn of upcoming clinical risk, replace erroneous sensor data signals, and provide more timely analyte information encourage proactive behavior and preempt clinical risk.

Signal processing for continuous analyte sensor

Systems and methods for detecting noise episodes and processing analyte sensor data responsive thereto. In some embodiments, processing analyte sensor data includes filtering the sensor data to reduce or eliminate the effects of the noise episode on the signal.

Systems and methods for replacing signal data artifacts in a glucose sensor data stream

A technique for continuously determining and displaying the peak and mean velocities of spectral Doppler information is disclosed. Received spectral Doppler data is examined over a predetermined period to determine the signal to noise ratio of the Doppler signals. Individual instantaneous measurements, or lines, of Doppler spectral information are analyzed in the power versus frequency domain to compare the line information against a noise threshold determined by the signal to noise ratio. The maximum frequency signal component is thereby identified as the peak velocity of the spectral line. Mean velocity is calculated as an intensity weighted mean about the maximum power frequency of the line data. The identified peak and mean velocities are displayed in contrasting colors or shades on a continuously updated and displayed flow velocity versus time spectral display.

Continuous display of peak and mean blood flow velocities

An ultrasonic diagnostic and therapy system is described for stopping the bleeding of severely damaged blood vessels or vessels severed in a limb amputation. A cuff (30) is attached to the stump of the severed limb which contains a diagnostic transducer array and a HIFU transducer (42, 44). The diagnostic transducer surveys the tissue of the severed limb, searching for a Doppler flow signal. When a Doppler flow signal is detected, the range to and coordinates of the sample volume where the flow was detected are determined, as well as the flow velocity. This information is supplied to a HIFU therapy transducer controller, which controls the HIFU transducer to transmit focused ultrasound to the sample volume of the flow locus, the center of the lumen of a blood vessel. The focused ultrasound heats and coagulates blood in the severed vessel to stem the bleeding. Heat dissipation due to the blood flow is reduced by tracking and continuously heating the same bolus of blood as it flows, or by heating a significant length of the blood vessel instead of a fixed spot in the vessel.

Method and apparatus for guidance and application of high intensity focused ultrasound for control of bleeding due to severed limbs

A technique for continuously determining and displaying the peak velocities of spectral Doppler information is disclosed. A Doppler noise threshold level is determined from operating characteristics of the ultrasound system, probe, or both. Received spectral Doppler data for a spectral line is compared to this threshold to identify a valid peak velocity value. Spectral lines are examined in advance of their display to detect excursions due to artifacts such as valve clicks. Peak velocity values are interpolated and displayed in place of artifact peak values. Individual heart cycles over which quantified measures of cardiovascular performance are computed and displayed are selected by the R-wave intervals of an ECG trace. The interval of the concurrent spectral Doppler display corresponding to the heart cycle interval over which the quantified measures are computed or pertain is automatically highlighted for the user.

Continuous display of cardiac blood flow information

In an ultrasonic diagnostic imaging system, the parameters which govern the display of Doppler information are automatically optimized to make better use of the display range or area Spectral Doppler information may be used to optimize a spectral display or a colorflow display, and colorflow Doppler information may be used to optimize a spectral display or a colorflow display The optimization may be invoked by a manual user control which automatically optimizes one or a plurality of display parameters Automatic optimization may be invoked only when called for by the user, or periodically after a time interval, a given number of heart cycles, or when the user has made a change to the display or imaging mode Preferably the optimization processor runs continuously in the background so that optimized parameters are available immediately when called for The optimization processor may utilize 'hidden' Doppler data which has been acquired but is not used for display purposes

Automatic optimization of doppler display parameters

An ultrasound system produces an image including a blood vessel. A blood flow direction indicator is displayed over the blood vessel to indicate the direction of blood flow within the vessel. The direction of blood flow is used to correct the Doppler estimate for angle of insonation. The orientation of the blood flow direction indicator is set automatically by a vector processor. The automatically calculated angle is used to display the correct flow velocity without user intervention.

Helen F. Routh

Papers

Continuous display of peak and mean blood flow velocities

Method and apparatus for guidance and application of high intensity focused ultrasound for control of bleeding due to severed limbs

Continuous display of cardiac blood flow information

Automatic optimization of doppler display parameters

Automatic flow angle correction by ultrasonic vector